Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a group of heterogenous malignancies arising from bile duct epithelium with distinct pathological features. Adaptor proteins have implicated in cell proliferation, migration, and invasion of different cancer cells. The objective of this study was to assess whether the adaptor protein XB130 (AFAP1L2) is a critical biological determinant of CCA outcome. XB130 expression levels were investigated in four CCA cell lines compared to an immortalized cholangiocyte cell line by Western blotting. Small interfering (si) RNA-mediated XB130 gene silencing was conducted to evaluate the effects of reduced XB130 expression on cell proliferation, migration, and invasion by MTT, transwell migration and cell invasion assay. The immunohistochemical quantification of XB130 levels were performed in surgically resected formalin-fixed, paraffin-embedded specimens obtained from 151 CCA patients. The relationship between XB130 expression and the clinicopathological parameters of CCA patients were analyzed. Our results showed that XB130 was highly expressed in KKU-213A cell line. Knockdown of XB130 using siRNA significantly decreased the proliferation, migration, and invasion properties of KKU-213A cells through the inhibition of PI3K/Akt pathway, suggesting that XB130 plays an important role in CCA progression. Moreover, elevated XB130 expression levels were positive relationship with lymphovascular space invasion (LVSI), intrahepatic type of CCA, high TNM staging (stage III, IV), high T classification (T3, T4), and lymph node metastasis. We provide the first evidence that the overexpression of XB130 is associated with tumorigenic properties of CCA cells, leading to CCA progression with aggressive clinical outcomes.

Introduction

Cholangiocarcinoma (CCA) is a malignancy of biliary epithelial cells and its incidence has increased worldwide [1]. The risk factors of CCA are heterogeneous and differ globally [1]. Primary sclerosing cholangitis is the most typical risk factor for CCA in the Western countries, while in several Asian countries Opisthorchis viverrini is determined as the key risk factor for CCA [2]. CCA is classified into intrahepatic and extrahepatic types, based on its anatomical location along the biliary tree. Intrahepatic CCA develops within the small and second order large bile duct branches, which are situated in the liver parenchyma. Extrahepatic CCA involves the extrahepatic large bile duct location within biliary tree and the hepatoduodenal ligament [3]. CCA is histologically graded into well, moderately, and poorly differentiated adenocarcinomas [4]. CCA remains a major health problem which leads to high mortality in Thailand, notably in the Northeastern region [5]. Because of a high degree of malignancy, rapid progression, low surgical resection rates and high recurrence rates, CCA prognoses are poor.

Several independent prognostic factors for CCA have been identified, including serum carcinoembryonic antigen (CEA) levels, alkaline phosphatase levels, relapse of disease, intraoperative blood transfusion, lymph node metastasis, TNM staging [6, 7], histological differentiation of tumors, surgical margins, types of CCA, Caudal Type Homeobox 2 (CDX2), and human epidermal growth factor receptor 2 (HER2) gene amplification [8]. It has been shown that serum CEA levels of greater than 2.5 ng/mL are considered as an independent poor prognostic factor for resectable CCA patients [6, 7]. CCA patients with CDX2-positive tumors were reported to have significantly better survival than those with CDX2-negative tumors [9]. Moreover, the overexpression of HER-2 gene amplification using chromogenic in situ hybridization (CISH) is an independent prognostic factor for survival in the subgroup of extrahepatic CCA patients with lymph node metastases [7]. However, the estimated overall 5-year survival rate of CCA is less than 10% and only approximately one third of the CCA patients are possible for receiving curative treatment at the diagnostic time [10]. Therefore, the search for novel prognostic marker is still needed for improvement of CCA therapy.

In the development of the human embryo, the liver, extrahepatic biliary ducts, gallbladder, and pancreas duct arise from the same epithelial anlage [11]. Accumulating evidence suggests that CCA and pancreatic ductal adenocarcinoma have similar pathology, background, and development [12]. Zhang et al. demonstrated that the high expression of XB130 is an independent prognostic marker to predict poor outcome after surgical resection of pancreatic ductal adenocarcinoma [13]. However, the roles and expression levels of XB130 protein in CCA, which is a malignancy developing from the biliary epithelial cells, have never been investigated.

XB130, which is also known as actin filament-associated protein 1 like 2 (AFAP1L2), is an important member of the actin filament-associated protein (AFAP) family of adaptor proteins. XB130 gene is located on human chromosome 10q25.3 and encodes a protein of 818 amino acids [14]. XB130 is an adaptor protein involved in cell proliferation, survival, and migration [15-17]. This adaptor protein has been shown to cause the activation of kinases and related downstream proteins in many signaling pathways [18]. It can also promote interactions between protein binding partners, triggering signaling cascades. For instance, XB130 binds to the p85α subunit of phosphatidylinositol-3-kinase (PI3K) and activates protein kinase B (Akt). The excessive activation of PI3K/Akt signaling pathway promotes cell proliferation by regulating cell cycle during G1 to S phase progression and by inducing cell migration and tumor cell survival [19]. XB130 is mainly distributed in the cytosol, where the chemical reactions predominantly occur and is associated with physiological processes and oncogenesis of certain malignancies [18]. Functional roles of XB130 have been examined in various types of cancer both in vitro and in vivo. For example, the overexpression of XB130 in human esophageal squamous cell carcinoma (ESCC) has shown to be associated with cell cycle progression and poor prognosis [20]. The previous studies in lung and thyroid cancer cells demonstrated that XB130 is a potential regulator of tyrosine kinase-mediated signaling and substrate that control of cell proliferation and apoptosis [19, 21]. Knockdown of XB130 in human lung and thyroid cancer cells by small interfering RNA (siRNA) suppressed cell cycle progression and induced spontaneous apoptosis [19, 21]. However, little is known about the roles of XB130 in CCA.

In this study, we aimed to investigate: i) the expression levels of XB130 in four different CCA cell lines (KKU-100, KKU-213A, KKU-213C, and KKU-023) compared to an immortalized cholangiocyte cell line (MMNK1); ii) the effects of decreased XB130 expression on cell proliferation, cell migration and invasion in XB130-expressing KKU-213A cells; iii) the expression levels of XB130 in CCA tissues using immunohistochemistry; and iv) the relationship between the XB130 expression levels with the clinicopathological features and survival rates of CCA patients.

Materials and methods

Cell culture

For different CCA cell lines (KKU-100, KKU-213A, KKU-213C, and KKU-023) and an immortal cholangiocyte cell line (MMNK1) were obtained from the Cholangiocarcinoma Research Institute, Khon Kaen University, Thailand. KKU-213A and KKU-213C CCA cell lines were established and characterized by Sripa B [22]. All cell lines were cultured in Ham′s F-12 (Life technologies, Grand Island, NY, USA) containing 10% heat-inactivated fetal bovine serum, 100 U/mL penicillin and 100 ug/mL streptomycin (Life technologies, Grand Island, NY, USA). Cells were incubated at 37°C in a humidified incubator with an atmosphere of 5% CO2.

Screening of the XB130 expression in cell lines using Western blot analysis

Cells were lysed on ice in RIPA buffer (150 mM NaCl, 50 mM Tris-HCl, 1% (v/v) Triton X-100, 1% (w/v) sodium deoxycholate, 0.1% (w/v) sodium dodecyl sulfate (SDS) supplemented with protease inhibitor cocktail (Thermo Fisher Scientific, MA, USA; S1 Appendix) The protein concentration was measured using Pierce BCA Protein assay kit (Pierce Biotechnology, Rockford, USA). Proteins in the total cell lysate were separated onto SDS-PAGE (4% stacking gel and 8% separating gel) and transferred onto a polyvinylidene difluoride (PVDF) membrane (Bio-Rad, CA, USA). After blocking the blot in a solution of 5% skimmed milk in Tris-buffered saline (TBS) pH 8.0 at room temperature for 1 h, membrane-bound proteins were probed with mouse anti-XB130 monoclonal antibody (1:1000; Santa Cruz, USA), rabbit anti-E-cadherin antibody (1:1000, Cell Signaling Technology, Danvers, MA, USA), mouse anti-vimentin antibody (1:1000, Agilent Dako, Santa Clara, CA, US), rabbit anti-Akt antibody (1:1000, Cell Signaling Technology, Danvers, MA, USA), rabbit anti-Ser473 phosphorylated Akt (pAkt) antibody (1:1000, Cell Signaling Technology, Danvers, MA, USA) and mouse anti-β-actin antibody (1:60000, Sigma, Louis, MO, USA) overnight at 4°C. The membrane was washed and incubated with peroxidase-labelled anti-rabbit or anti-mouse secondary antibodies (1:2000) for 1 h at room temperature. Finally, immunoreactive bands were visible to Amersham™ ECL™ Prime Western Blotting Detection Reagent (GE Healthcare, Buckinghamshire, UK) for chemiluminescence detection which was performed using an Amersham Imager™ 600 (GE Healthcare Bio-Sciences AB, Uppsala, Sweden). Original images of Western blot results are shown in S1–S7 Figs.

Knockdown of XB130 in an CCA cell line using siRNA

Specific siRNA against XB130 (siXB130), ON-TARGET plus Human XB130 siRNAs; cat. no. L-014917-02-0005, and a negative control or scramble, ON-TARGET plus Non-targeting Pool siRNAs; cat no. D-001810-10-05, were purchased from GE Healthcare Dharmacon Inc. (Lafayette, CO, USA). KKU-213A cells (12 x 104 cells/well) were transfected with 50 nM of siXB130 or scramble using lipofectamine® RNAiMax (Invitrogen, Carlsbad, CA, USA) according to the manufacturer’s protocol. After 48 h transfection, cells were used for detection of XB130 expression by western blot analysis as well as cell proliferation, invasion and migration assays.

Cell proliferation assay

At 48 h after XB130 knockdown, treatment with scramble and siXB130, the cells were trypsinized and seeded onto 96-well plates (3.0 × 104 cells) in quintuplicate. Cell proliferation was measured using the methyl thiazolyl tetrazolium (MTT) assay as previously described [23].

Cell invasion assay

Cell invasion assay was performed using a 24-well Matrigel Invasion Chamber (Discovery Labware, Inc, Bedford, MA, USA) as previously described [24]. The cell invasion was determined at 24 h after incubation.

Cell migration assay

The migration ability of CCA cells across the membrane filter of 8 μm pore-size was measured using a Boyden chamber in a 24-well plate (Corning, NY, USA) as previously described [23]. The number of cells migrated across the membrane was determined at 24 h.

Human cholangiocarcinoma tissues

The formalin-fixed and paraffin-embedded CCA tissues used in this study were the leftover tissues after pathological diagnosis of CCA (n = 151 cases) in the Srinagarind Hospital, Khon Kaen University, from January 2007 to August 2017 and performed tissue microarray (4 cores, 2 mm). The protocol of this study was approved by the Ethics Committee for Human Research, Khon Kaen University (HE621409).

Immunohistochemical staining

The immunohistochemistry (IHC) method for XB130 protein was performed on tissue microarray slide sections, using a VENTANA BenchMark XT Slide Staining System (Roche Diagnostics, NJ, USA). The tissue microarray slides were cut at 4 μm thickness and dried in a hot-air oven overnight at 50°C. Immunohistochemical staining was carried out following the manufacturer’s recommended protocol. Mouse anti-AFAP1L2/XB130 monoclonal antibody (1:100; Santa Cruz, TX, USA) was used as a primary antibody and its presence was visualized using an OptiView DAB IHC detection kit (Ventana, AZ, USA). For XB130 assessment, the stained tissue microarray slides were entirely scanned to assign the scores using a ScanScope® XT digital slide scanner (Leica Biosystems, Singapore).

Evaluation of immunohistochemical staining

The semi-quantitative analysis of IHC scores using an ImageJ software, Java-based image processing program developed at the National Institutes of Health and the Laboratory for Optical and Computational Instrumentation, University of Wisconsin [25, 26]. The quantification methods were performed following the previous report [27]. XB130 expression levels (IHC scores) of 151 CCA tissues examined ranged from 28.00 to 220.45.

Clinicopathological parameters of CCA tissues

The clinicopathologic variables included age, gender, type of CCA, histological type, histologic differentiation, LVSI, T classification, N classification (lymph node metastasis), M classification, TNM staging, and surgical margins were used for data analysis. By anatomical location of the tumor, CCA was classified into intrahepatic CCA and extrahepatic CCA. Histologic differentiation of CCA was classified by histology into well, moderately, and poorly differentiated adenocarcinomas [4]. Histologic type was defined as papillary or tubular base on architectural growth pattern. The LVSI is the histologic visible invasion of a cancer cells into lymphatic and/or blood vessels which is the cause of lymphatic and vascular spreading. Lymph node metastasis is cancer that has spread to lymph nodes and a surgical margin is the margin of apparently non-tumorous tissue around a tumor that has been surgically removed [28]. The TNM classification of Malignant Tumors seventh edition is an anatomically based system that records the primary size, regional nodal extent of the tumor, and distance metastasis. TNM is a notation system that describes the stage of a cancer, T category describes the primary tumor site, N category describes the regional lymph node involvement and M category describes the presence or otherwise of distant metastatic spread [29].

Statistical analyses

The relationship between XB130 expression levels with clinicopathological features were performed by linear regression. Survival analysis was performed using the Kaplan-Meier method and the difference between survival curves was calculated using the log-rank test. Cox’s proportional hazards models of univariate and multivariate analyses were performed to define risks and identify independent prognostic factors of XB130 protein expression. Univariate and multivariate logistic regression analyses were performed to identify factors affecting lymph node metastasis (N1) in CCA. All statistical analyses were performed using STATA 10.1 software (StataCorp LLC, TX, USA). Statistical significance is defined as a P-value < 0.05.

Results

Evaluation of XB130 expression levels in CCA cell lines and an immortal cholangiocyte cell line

XB130 expression levels in the immortal cholangiocyte (MMNK1) and four CCA cell lines (KKU-100, KKU-213C, KKU-213A, and KKU-023) were measured semi-quantitatively using Western blot analysis. The results showed that XB130 was not expressed in MMNK1 cells (Fig 1). Among four studied CCA cell lines, XB130 was highly expressed in the KKU-213A cell line, but it was not expressed in other cells lines (i.e., KKU-100, KKU-213C and KKU-023 cell lines).

Fig 1

Western blot analysis of XB130 in MMNK1, KKU-100, KKU-213C, KKU-213A and KKU-023 cell lines, with β-actin as a loading control.

Roles of XB130 in proliferation, migration and invasion in CCA

The effects of down-regulation of XB130 by siRNA on cell proliferation, migration and invasion were examined in KKU-213A cell line. XB130 gene silencing using siRNA technology successfully suppressed the expression levels of XB130 compared with the scrambled control at 48 h after treatment (Fig 2A). The cell proliferation rates and cell invasion and migration activities of siXB130-treated KKU-213A cell line were significantly reduced compared to control cells (Fig 2B–2F).

Fig 2

Effects of siXB130 on proliferation, motility and invasiveness of KKU-213A cell line.

A): The expressions of XB130 (130 kDa), E-cadherin (~135 kDa), vimentin (~54 kDa), Akt (~60 kDa), pAkt (~60 kDa) in siXB130 and scramble groups measured by western blotting, with β-actin as a loading control. B): MTT assays of the scramble and siXB130 treated cells. C): Hematoxylin-staining invasive cells from cell invasion assays of the scramble and siXB130 treated cells. D): Graphical represents numbers of invasive cells from cell invasion assays. E): Hematoxylin staining migrated cells from cell migration assays. F): Graphical represents numbers of migrating cells from cell migration assays. The asterisk (*) indicates statistical significance at P<0.05 and asterisks (***) indicates statistical significance at P < 0.001.

XB130 activates the PI3K/Akt pathway and alters metastasis-associated proteins in CCA

To explore the mechanisms underlying XB130 expression, the possible downstream targets of XB130 including PI3K downstream (Akt), Ser473 phosphorylated Akt (pAkt) and epithelial-mesenchymal transition (EMT) markers (E-cadherin and vimentin) were measured in the XB130 knockdown-CCA cell lines using western blot analysis. The results indicated that XB130 siRNA effectively reduced XB130 protein levels; a phenomenon associated with decreased the expression and phosphorylation of Akt as well as the expression of EMT inducing protein (vimentin) as shown in Fig 2A. Our findings suggest that XB130 has an oncogenic property that can induce cell proliferation, migration and invasion in CCA via the activation of PI3K/Akt pathway leading to increasing of EMT processes.

Expression levels of XB130 in CCA tissues

The expression levels of XB130 protein in CCA tissues (n = 151) were determined using immunohistochemistry. The protein was highly localized in cytoplasm of CCA cells, whereas it was weakly stained in normal bile duct and hepatocyte cells. The representative results of normal bile duct, hepatocyte and CCA tissues with XB130 expression levels were shown in Fig 3.

Fig 3

XB130 expression patterns in: A) normal bile duct; intensity = 48, B) hepatocyte; intensity = 72 and C) CCA intensity = 220 analyzed by IHC.

The scale bar equals 50 μm.

Relationship between the XB130 expression levels and clinicopathological data of CCA patients

The relationship between XB130 protein expression levels and the clinicopathological features of CCA patients were summarized in Table 1. No relationship was observed between XB130 expression and the following variables: age (β = -0.0023, P = 0.976), gender (β = 0.0042, P = 0.958), histological type (β = 0.0262, P = 0.749), margin status (β = -0.1305, P = 0.110), moderate differentiation (β = 0.1238, P = 0.128), poor differentiation (β = 0.1477, P = 0.070) or M classification (β = 0.074, P = 0.365). The XB130 expression was significantly positive relationship with LVSI (β = 0.2274, P = 0.005), intrahepatic type of CCA (β = 0.1623, P = 0.046), stage III of TNM staging (β = 0.4048, P < 0.001), stage IV of TNM staging (β = 0.2363, P = 0.012), T3 classification (β = 0.4314, P < 0.001), T4 classification (β = 0.3327, P < 0.001) and lymph node metastasis (β = 0.2060, P = 0.011).

Table 1

Relationship between XB130 expression and clinicopathologic features of CCA patients.

Variable	XB130 expression
	Coef.	95% CI	β	P-value
Gender
Female/male	-0.12	-8.9111–8.6517	0.0042	0.976
Age
Years	0.41	-15.4027–16.2285	-0.0023	0.958
LVSI
Yes/No	22.08	6.7806–37.3836	0.2274	0.005
Histological type
Tubular/Papillary type	2.48	-12.8509–17.8225	0.0262	0.749
Margin status
Yes/No	-12.75	-28.4395–2.9211	-0.1305	0.110
Type of CCA
Intrahepatic/Extrahepatic	17.03	0.2762–33.8017	0.1623	0.046
Histologic Differentiation
Well		1
Moderated	15.78	-4.5935–36.1560	0.1238	0.128
Poor	50.16	-4.1080–104.4313	0.1477	0.070
TNM staging
I		1
II	10.58	-10.0906–31.2698	0.0970	0.313
III	41.17	21.5696–60.7782	0.4048	< 0.001
IV	28.41	6.2269–50.6001	0.2363	0.012
T classification
T1		1
T2	3.93	-11.8204–19.6827	0.0412	0.623
T3	56.87	35.8058–77.9391	0.4314	< 0.001
T4	54.32	29.1228–79.5356	0.3327	< 0.001
N classification
N1/N0	19.71	4.5583–34.8619	0.2060	0.011
M classification
M1/M0	8.91	-10.494–28.3251	0.074	0.365

*Definition of TNM staging system described in the S1 Data.

*Coef, coefficients; 95% CI, 95%confidence interval; β, correlation coefficient.

Univariate and multivariate analyses of clinicopathological variables influencing survival and lymph node metastasis in CCA

Clinicopathological parameters of 151 CCA patients (95 males and 56 females) with an age range of 34–79 years were analyzed. The impact of 12 variables, including age, gender, type of CCA, histological type, histologic differentiation, LVSI, T classification, N classification (lymph node metastasis), M classification, TNM staging, surgical margins and XB130 expression, on survival was investigated using univariate and multivariate analyses. On univariate analysis using the Cox’s proportional hazards model, the poor survival was associated with the following parameters: LVSI (HR = 1.6150, P = 0.007), tubular histological type (HR = 1.6348, P = 0.005), positive margin status (HR = 1.6777, P = 0.003), TNM staging (stage IV, HR = 4.2664, P ≤ 0.001), T classification (T4, HR = 2.0254, P = 0.028), N1 classification (HR = 2.3754, P ≤ 0.001) and M1 classification (HR = 3.4339, P ≤ 0.001), but not with gender (HR = 1.0722, P = 0.659), age (HR = 1.0139, P = 0.163), intrahepatic type of CCA (HR = 1.1532, P = 0.451), moderate differentiation, (HR = 1.5331, P = 0.055), poor differentiation, (HR = 0.4662, P = 0.287), T classification (T2, HR = 1.3788, P = 0.111), T classification (T3, HR = 1.1805, P = 0.543), TNM staging (stage II, HR = 1.2338, P = 0.400), TNM staging (stage III, HR = 1.4768, P = 0.101), XB130 expression (HR = 1.000, P = 0.356) (Table 2). The Kaplan-Meier survival curves showed the comparison of the survival rate in 151 cases of CCA patients between gender, histological type, type of CCA, M classification, LVSI, margin status, histologic differentiation, TNM staging, T classification and N classification. Tubular histological type (P = 0.0052), M1 classification (P < 0.0001), LVSI (P = 0.0062), positive margin status (P = 0.0041), stage IV of TNM staging (P < 0.001) and N1 classification (P < 0.001) were significant related to prognosis as shown in S8 Fig.

Table 2

Univariate analysis (Cox’s proportional hazards model) for overall survival of CCA patients.

Characteristics	Univariate
	HR	95% CI	P-value
Gender
Female/male	1.0722	0.7569–1.5187	0.659
Age
Years	1.0139	0.9943–1.0339	0.163
LVSI
Yes/No	1.6150	1.1404–2.2870	0.007
Histological type
Tubular /Papillary type	1.6348	1.1583–2.3073	0.005
XB130 expression
Intensity	1.0000	0.9980–1.0053	0.356
Margin status
Yes/No	1.6777	1.1873–2.3708	0.003
Type of CCA
Intrahepatic/Extrahepatic	1.1534	0.7924–1.6788	0.451
Histologic Differentiation
Well		1
Moderated	1.5331	0.9907–2.3722	0.055
Poor	0.4662	0.1144–1.8988	0.287
TNM staging
I		1
II	1.2338	0.7559–2.0137	0.400
III	1.4768	0.9266–2.3538	0.101
IV	4.2664	2.4784–7.3443	< 0.001
T classification
T1		1
T2	1.3788	0.9291–2.0461	0.111
T3	1.1805	0.6919–2.0140	0.543
T4	2.0254	1.0781–3.8048	0.028
N classification
N1/N0	2.3754	1.6709–3.3769	< 0.001
M classification
M1/M0	3.43396	2.1942–5.3741	< 0.001

In addition, multivariate analysis using Cox’s proportional hazards model showed that only N1 classification (HR = 1.8707, P = 0.002) and M1 classification (HR = 2.3925, P < 0.001) were significantly correlated with poor survival. The two clinicopathologic variables, i.e., N and M classifications, can be used as independent prognostic factors (Table 3). Moreover, the results obtained from multivariate analysis using logistic regression demonstrated that M1 and LVSI were independent factors for lymph node metastasis (Table 4).

Table 3

Multivariate analysis (Cox’s proportional hazards model) for overall survival of CCA patients.

Characteristics	Multivariate
	HR	95% CI	P-value
N classification
N1/N0	1.8707	1.2589–2.7797	0.002
M classification
M1/M0	2.3925	1.4589–3.9237	0.001

Table 4

Univariate and multivariate analyses (logistic regression model) of factor correlated with lymph node metastasis (N1).

Clinicopathologic characteristics	Univariate			Multivariate
	Odds ratio	95% CI	P-value	Odds ratio	95% CI	P-value
M category (+)	29.84	6.7488–131.9561	< 0.001	22.17	4.9082–100.1789	< 0.001
LVSI (+)	5.32	2.4970–11.3455	< 0.001	3.69	1.6187–8.4202	0.002

Discussion

The main finding of this study was that XB130 overexpression in CCA was related to cell proliferation, migration, and invasion, leading to CCA progression with aggressive clinical outcomes. These results suggest that the expression levels of XB130 in CCA cell lines, XB130 was highly expressed in the KKU-213A cell line, but it was not expressed in other cells lines (i.e., KKU-100, KKU-213C and KKU-023 cell lines). The expression levels of XB130 in CCA cell lines may not be involved in the transformation from cholangiocytes to CCA cells. According to the cell line’s properties, KKU-213A has the highest proliferation, invasion and migration rates among the other tested cell lines [22, 30]. Thus, in CCA, XB130 may play a critical role in tumor cell progression, but not in tumorigenesis. The KKU-213A cell line was selected for further functional analysis of XB130 using specific siRNA technique. Significant inhibition of cell proliferation, migration, and invasion caused by XB130 silencing in KKU-213A cells suggests that XB130 plays an important role in the progression of CCA by promoting cell growth, migration, and invasion.

These findings are consistent with previous studies on XB130 in a variety of cancers, e.g., thyroid tumor [19, 31], prostate cancer [15], lung cancer [17], gastric cancer [32], breast cancer [33], colorectal cancer [34], hepatocellular carcinoma [35], and skin tumor [24]. XB130 has been suggested to play significant roles in cancer progression through PI3K/Akt signaling pathway, leading to an increase in tumorigenic properties, including cell growth, migration, invasion and epithelial–mesenchymal transition (EMT) process [17, 31, 35–37]. It is worth noting that in CCA, the PI3K/Akt signaling pathway was constitutively activated and was involved in cell proliferation, migration and invasion [38, 39]. Suppression of the PI3K/Akt signaling pathway by various anti-cancer drugs could also inhibit CCA cell progression [35, 40–43]. From the above mentioned, we hypothesized that XB130 activates PI3K/Akt pathway resulting in the phosphorylation of Akt (pAkt) and induction of EMT process in CCA cells. To prove the hypothesis, the detections of PI3K/Akt pathway-downstream marker (pAkt) and EMT markers (E-cadherin and vimentin) expression levels in siXB130 and the vertical control cells were measured using western blot analysis. The results showed that pAkt and vimentin expression levels were decrease in the XB130 knockdown-CCA cell line. Therefore, we concluded that the overexpression of XB130 in CCA accelerates the cancer progression via PI3K/Akt signaling pathway.

The XB130 expression levels in clinical tissues were further analyzed to assess its potential for being used as an accurate prediction of survival of patients with CCA and as a valid biological indicator for the aggressiveness of CCA. The XB130 expression level was not an independent prognosis factor for survival in CCA. It should be noted that distant metastasis (M1-classification) has more potential clinical use to predict for the risk of lymph node metastasis in CCA than the LVSI. The XB130-mediated aggressiveness of CCA was confirmed by the biological function assays, i.e., cell proliferation, invasion, and migration in cell lines. In CCA tissues, the elevated XB130 expression levels had positive relationship with lymphovascular space invasion (LVSI), intrahepatic type of CCA, high TNM staging (stage III, IV), high T classification (T3, T4), and N1 classification (lymph node metastasis). The high T classification, LVSI, lymph node metastasis, and high TNM staging all indicate tumor extension and invasion, which supported the in vitro investigation of cell proliferation and invasion in KKU-213A cells. The Kaplan-Meier survival curves showing LVSI, margin status, TNM staging, and N classification were significantly related to prognosis. Although, XB130 level was not directly associated with survival outcome in CCA patients, but it was associated with other factors correlated with survival, including LVSI, high TNM staging and lymph node metastasis. Therefore, our findings demonstrated that the adapter protein XB130 is a significant player in CCA progression and metastasis.

Conclusion

In this work, the expression of XB130 was assessed along with its impact on CCA proliferation, migration, and invasion in vitro. Furthermore, high expression levels of XB130 in tissues reflect a role in predicting the aggressive behavior of CCA, as evidenced by significant risk factors, i.e., LVSI, lymph node metastasis, and high TNM staging in the patients. Targeting XB130 may assist in slowing tumor growth and decreasing cell migration and invasion. Therefore, high XB130 expression might be considered as an indicator of aggressive CCA and a potential target for CCA therapy.

Original image of western blot result of XB130 expression in cell lines.

(PDF)

Click here for additional data file.

Original image of western blot result of β-actin expression in cell lines.

(PDF)

Click here for additional data file.

Original image of western blot result of phosphorylation of Akt expression in media, scramble and siXB130 cells.

(PDF)

Click here for additional data file.

Original image of western blot result of Akt expression in media, scramble and siXB130 cells.

(PDF)

Click here for additional data file.

Original image of western blot result of E-cadherin expression in media, scramble and siXB130 cells.

(PDF)

Click here for additional data file.

Original image of western blot result of vimentin expression in media, scramble and siXB130 cells.

(PDF)

Click here for additional data file.

Original image of western blot result of β-actin in media, scramble and siXB130 cells.

(PDF)

Click here for additional data file.

The Kaplan-Meier analysis of clinical data.

(PDF)

Click here for additional data file.

Definition of TNM staging system.

(PDF)

Click here for additional data file.

Evaluation of immunohistochemical staining by ImageJ.

(PDF)

Click here for additional data file.

(PDF)

Click here for additional data file.

2 Feb 2021

PONE-D-20-37191

Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma

PLOS ONE

Dear Dr. Ungareevittaya,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

At the end of this letter you will find the reports and comments. Please read also carefully the suggested literature.and remind that you are free to choose , which references you will cite or not, if at all.

Please submit your revised manuscript by Mar 13 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

Konradin Metze

Academic Editor

PLOS ONE

Additional Editor Comments :

The investigation is original and quite interesting but there are important points to be considerably improved before the paper can be considered for publication:

The authors categorized a lot of variables initially expressed as cardinal numbers (which causes an important loss of information and may induce considerable bias).In particular,  the immunohistochemical quantification should also be expressed in cardinal numbers and not dichotomized. .

We are very aware, that this kind of “data treatment” is still popular among pathologists, but it is a great source of error and publications with low credibility. Therefore, all calculations must be repeated with cardinal numbers. The results might be different.

In a final step, the authors may suggest a score after categorizing of one or another variable, but this must be clearly justified both from a mathematical and a biological point of view and a comparison of the calculi done with and without categorizing must be given. (please see the last paper  for how to do this).

Please consult the following literature:

Dichotomizing continuous predictors in multiple regression: a bad idea. Stat Med 25: 127-141, 2006

Pitfalls in the assessment of prognostic factors. Lancet Oncol. 2011 Nov;12(12):1095-6.

Dichotomizing continuous prognostic factors can cause paradoxical results in survival models. J Am Coll Surg. 2011 Jan;212(1):132-4.

Dichotomization of continuous data--a pitfall in prognostic factor studies. Pathol Res Pract. 2008;204(3):213-4

Breaking up is hard to do: the heartbreak of dichotomizing continuous data. Can J Psychiatry 2002;47:262– 66.

A simple score derived from bone marrow immunophenotyping is important for prognostic evaluation in myelodysplastic syndromes  Sci Rep. 2020 Nov 20;10(1):20281.

Konradin Metze, Academic Editor

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. As part of your revisions, please indicate in your Methods statement whether you obtained any other type of authorization, consent or approval for the use of the leftover tissues following pathological diagnosis of CCA. This may include patient consent, consent from next of kin, and so forth. Thank you for your cooperation in this matter.

3. PLOS ONE now requires that authors provide the original uncropped and unadjusted images underlying all blot or gel results reported in a submission’s figures or Supporting Information files. This policy and the journal’s other requirements for blot/gel reporting and figure preparation are described in detail at https://journals.plos.org/plosone/s/figures#loc-blot-and-gel-reporting-requirements and https://journals.plos.org/plosone/s/figures#loc-preparing-figures-from-image-files. When you submit your revised manuscript, please ensure that your figures adhere fully to these guidelines and provide the original underlying images for all blot or gel data reported in your submission. See the following link for instructions on providing the original image data: https://journals.plos.org/plosone/s/figures#loc-original-images-for-blots-and-gels.

In your cover letter, please note whether your blot/gel image data are in Supporting Information or posted at a public data repository, provide the repository URL if relevant, and provide specific details as to which raw blot/gel images, if any, are not available. Email us at plosone@plos.org if you have any questions.

4. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

Reviewer #3: Partly

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The artical is clearly written with minimal spelling and grammatical error.

Very little data regarding mechanism of action is presented. The authors show that a CCA cell line with high XB130 expression has faster proliferation, more motility and more extensive invasiveness than a normal or two CCA cell lines with low XB130 expression using in vitro assays. The authors also show that these properties can be suppressed in the high expresser by siRNA knockdown of XB130 as compared to a scrambled control. What is not presented is why XB130 expression promotes these activities. Several pathways downstream of XB130 are mentioned in the introduction. The authors should inhibit individual downstream pathways (e.g., PI3K/Akt) to test whether such inhibition recapitulates the effect of siRNA knockdown of XB130. The authors should also over-express XB130 in MMNK1 cells and XB130-low CCA cells to test whether this expression is sufficient to confer the proliferative, motility and invasiveness characteristics of XB130-high CCA cells. There is published data indicating that XB130 can promote tumorigenesis via activation of the PI3K/Akt pathway, but it would improve the manuscript to show that in this system. As it is now, too much of the manuscript's mechanistic conclusions rest on a single CCA cell line. More controls and more mechanistic studies are needed for this aspect.

For use as a biomarker, the authors need to report specificity and sensitivity. Discussion should also be provided that compares the sensitivity and specificity of XB130 against existing CCA biomarkers of which there are now a great number.

Table 1 should include definitions of staging features:

N0 (No regional lymph node metastasis)

N1 (Regional lymph node metastasis)

M0 (No distant metastasis)

M1 (Distant metastasis)

T1 (Solitary tumor; no vascular invasion)

T2a (Solitary tumor with vascular invasion)

T2b (Multiple tumors)

T3 (Tumor that has perforated the visceral peritoneum or otherwise demonstrating invasivity)

T4 (Tumor with periductal invasion).

Stage I: T1+N0+M0

Stage II: T2+N0+M0

Stage III: T3+N0+M0

Stage IVA: T4+N0+M0

Stage IVB: T(1-4)+N1 or T(1-4)+M1

Reviewer #2: The authors analyze the expression of the adaptor protein XP130 in 151 cases with gall bladder carcinoma. They note poor survival rates in cases with high XP 130 expression, which they confirm by studies of 4 cell lines. This is a good article and should be published provided that

1. the discrepancies in table 1 (M0, M1<> TNM); (N0, N1<> Lymph node metastases) etc. should be explained 7 corrected

2. What about pTNM?, Tumor size, organ of metastasis (liver, others?)

3. The collection time (2007 - 2017) is quite long; what about changes of the TNM classification during that time?

4. The aspect of tumor cell heterogeity should be briefly adressed (for example see and cite: VULETIĆ, Filip et al. Intratumoral heterogeneity. Diagnostic Pathology, [S.l.], v. 4, n. 1, feb. 2018. ISSN 2364-4893. Available at: 5. The IHC color classification threshold / method should be explained more in detail (which color space, which color adjustment / image quality analysis has been performed (for details see and cite: KAYSER, Klaus et al. Texture and object related image analysis in microscopic images. Diagnostic Pathology, [S.l.], may 2015. ISSN 2364-4893. Available at: .

Reviewer #3: To the editor/authors:

The study by Poosekeaw et al, deals with the role of the adaptor protein XB130 in cholangiocarcinoma. The authors present data using 5 different cell lines, and one of them expressing XB130. For further experiments, they have used XB130-expressing cell line and via siRNA they knocked down XB130. They could show that XB130 plays a role in proliferation, migration and invasion, at least in this cell line. Additional, they have analysed XB130 expression in 151 CCA tissue samples and could find a correlation of XB130 expression, M classification and LVSI.

Although of interest, following improvements have to be done before it can be considered for publication in Plos One.

Critical points:

1) Figure 1: First, the authors should mention in the fig-legend that tubulin serves as a loading control. Second, please indicate kDa of target protein in brackets. Furthermore, it would also be interesting to know why the other cell do not express XB130 at all. Have the authors checked mRNA expression? Is there a post-transcriptional modification? Are there any mutations or epigenetically silencing in/of XB130 known?

2) Figure 2: General for Fig2A-F. It would be a nice control to see all parameters in untreated KKU-213A (meaning without any transfection). Next point: the authors show a complete down regulation after 48h but, if I understood the data right, the results of proliferation, migration and invasion were analysed after additional 24h? In order to check the efficiency of the XB130 knock down a time course would be helpful – Fig2A: Western Blot after 24, 48 and 72h post-transfection. An additional control experiment would be to use a XB130 non-expressing cell line (e.g. KKU213C).

3) Figure 3: Please give the scale bar! Furthermore, it would be helpful to mark the CCA cells (e.g. with a *), normal bile duct (e.g. with an arrow) and hepatocytes (e.g. with an arrowhead) for non-histologists.

4) Fig 4, legend: please indicate the number of patients (n)

5) Have the authors checked for downstream targets, like PI3K or Akt? These experiments could be easely done by Western Blotting and would underline the specific role of XB130 in tested cell lines and in FFPE material (in this case testing by IHC).

6) A further suggestion/question: are data available for Ki67 level in the FFPE samples?

7) Have the authors checked, both cell lines (WB) and FFPE (IHC), EMT-related targets (N-, E-cadherin, vimentin, or EMT-TFs, e.g. TWIST, SNAI, ZEB)? I think these experiments would improve the paper and underline the conclusions the authors have done!

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

29 Mar 2021

Please look at the response to reviewers letter in attached file

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

19 Apr 2021

PONE-D-20-37191R1

Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma

PLOS ONE

Dear Dr. Ungareevittaya,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please read carefully my ccomments below !

Please submit your revised manuscript by Jun 03 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Konradin Metze

Academic Editor

PLOS ONE

Academic Editor´s comments :

I am not satisfied with the changes. There are still variables, measured originally in cardinal numbera, but tater categorized , such as age. Why  is there a cut point at 50 years, instead of 45, 47 , 55 etc. ?

This decision is completely arbitraly and therefor unscientific.

Before applying  quartiles, the authors should calculate with the cardinal numbers of raw data  This applies to the correlations, as well as to Cox and logistic regressions !

The  graphic  in the reply to the editor should be i n t e g r a  t e d  into the manuscript.  Regarding this graphhic  please try non-linear curve-fittings , perhaps a logarithmic  or , perhaps still better, a hyperbolic  function  and give the Rsquares as estimates of goodness-of –fit !.  Please discuss this result !

In summary : You should calculate all models first with continus cardinal numbers whenever possible.  In a

s e c o n d  step you can establish models  using the quertiles, but always with a l l  other variables measured

in cardinal numbers  n o f categorized.

Please sen a copy m where you highlight your  changes.

Konradin Metze, Academic Editor

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: (No Response)

Reviewer #3: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #2: The authors have responded to all recommendations of the reviewers, and the article should be published in its revised form.

Reviewer #3: The authors have answered all my questions and comments. Furthermore, the could nicely show the downstream effects of XB130 in the cell line. To my hand the manuscript can be accepted for publishing in PlosOne.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

30 May 2021

Please see the cover letter and the response to Editor letter.

Submitted filename: Response to Editor.docx

Click here for additional data file.

5 Jul 2021

PONE-D-20-37191R2

Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma

PLOS ONE

Dear Dr. Ungareevittaya,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please corect according to the suggestions you find below !

Please submit your revised manuscript by Aug 19 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Konradin Metze

Academic Editor

PLOS ONE

Additional Editor Comments

The paper has been improved. Problems are still found in  table 1 . Are these data really all correlations ?Which kind of correlation ? Spearman ? Kendall ? Pearson ? The correlation coefficients are all missing  ! Please add the coefficients together with their confiidence intervals in all cases with p<0.05

Konradin Metze, Academic Editor

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: All of my past concerns were addressed in the prior review.

The current submission addresses questions regarding statistical methodology made by a different reviewer. I am satisfied with the revisions to the statistics provided in the current submission.

All data was and is provided. The new submission additionally has the blots used to generate the figures of the manuscript.

The English is intelligible and written in standard English

Reviewer #2: no comments can be made, a system's error is very likely. Unfortunately, I cannot be of any additional assistance.

Reviewer #3: (No Response)

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

23 Aug 2021

Please see the response to editor file

Submitted filename: Response to Editor.docx

Click here for additional data file.

13 Oct 2021

Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma

PONE-D-20-37191R3

Dear Dr. Ungareevittaya,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Konradin Metze

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

2 Nov 2021

PONE-D-20-37191R3

Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma

Dear Dr. Ungarreevittaya:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Prof. Konradin Metze

Academic Editor

PLOS ONE