| Literature DB >> 33976741 |
Yuanyuan Ban1,2,3,4, Yixin Tan5, Xiaoling Li1,2,3,4, Xiayu Li4, Zhaoyang Zeng1,2,3,4, Wei Xiong1,2,3,4, Guiyuan Li1,2,3,4, Bo Xiang1,2,3,4, Mei Yi3,6.
Abstract
Background: RNA-binding proteins (RBPs) play essential roles in post-transcriptional control of gene expression. Dysregulation of RBPs is intensively implicated in development and progression of human diseases, including cancers. However, the roles of RBPs in nasopharyngeal carcinoma (NPC), which is a distinct subtype of head and neck cancer, remain elusive.Entities:
Keywords: AURKA; RNA binding protein; YBX1; posttranscriptional regulation; translation.
Year: 2021 PMID: 33976741 PMCID: PMC8100805 DOI: 10.7150/jca.56262
Source DB: PubMed Journal: J Cancer ISSN: 1837-9664 Impact factor: 4.207
Figure 1Identification of YBX1 as an overexpressed RBP in NPC. (A) Venn diagram depicting RBPs encoding genes detected in normal nasopharynx tissues or NPC samples. (B) Differentially expressed RBPs encoding genes between normal nasopharynx tissue and NPC were showed in heatmap. (C) The mRNA level of YBX1 was increased in NPC. (D) YBX1 was up-regulated in a variety of human cancers. *P < 0.05, **p < 0.01.
Figure 2Expressions of YBX1 protein in NPC samples. (A) IHC staining demonstrated that YBX1 protein is overexpressed in NPC samples. a, negative staining of YBX1 in normal nasopharyngeal mucosa. b, negative staining of YBX1 in NPC. c, moderate staining of YBX1 in NPC. d, strong immunostaining of YBX1 protein in NPC. (B) High level of YBX1 mRNA predicts unfavorable overall survival in head and neck cancer patients. Data was analyzed by Kaplan-Meier Plotter Software according to TCGA dataset.
Figure 3Expression and localization of YBX1 in NPC cell lines. (A) Expression of YBX1 mRNA and protein in HK1, FaDu and C666-1cells were analyzed by RT-PCR or western blot, respectively. (B) Immunofluorescence assay showed that YBX1 protein was primarily distributed in cytoplasm in HK1 cell. Arrow showed YBX1-expressing cells. (C) Expression levels of YBX1 mRNA and protein in mock or siRNAs transfected HK1 cells were analyzed by RT-PCR or western blot, respectively. ***p < 0.001
Figure 4Loss of YBX1 suppressed NPC cell proliferation, migration and invasiveness (A), (B) HK1 and FaDu cells were transfected with siRNAs mixture, then mRNA and protein levels of YBX1 were determined by qPCR or western blot assays. (C) CCK-8 assays demonstrated that loss of YBX1 suppressed cell growth of HK1 and FaDu cells. (D) Loss of YBX1 inhibited cell migration and invasion in vitro. (E), (F) The mRNA and protein levels of YBX1 in control or shRNAs expressing lentivirus infected HK1 cells were determined by qPCR or western blot assays. (G) CCK-8 assays demonstrated that stable silencing of YBX1 delayed cell growth of HK1 cell. (H) Stable silencing of YBX1 repressed cell migration and invasiveness of HK1 cell in vitro. **p < 0.01, ***p < 0.001
Figure 5Knockdown of YBX1 suppressed tumor formation (A) Growth curve of xenograft tumor derived from control or YBX1 silenced HK1 cells in nude mice. (B) Macroscopic view of xenograft tumors isolated from nude mice at the end point of experiment. (C) Weight of xenograft tumors derived from control or YBX1 silenced HK1 cells. *P < 0.05, **p < 0.01.
Figure 6Correlations between YBX1 and AURKA/BUB1B mRNA levels in NPC. (A) Representative differentially expressed genes between YBX1high and YBX1low NPC samples were showed as heatmap. Original data were collected from NPC mRNA expression profile GSE12452. (B) GSEA analysis showed that high expression of YBX1 was positively correlated with overexpression of cell cycle G2/M checkpoint modulators. (C) The mRNA levels of AURKA and BUB1B were overexpressed in NPC. (D) The mRNA level of YBX1 was positively correlated with the mRNA levels of AURKA and BUB1B in NPC. ***P < 0.001.
Figure 7YBX1 bond AURKA mRNA and enhanced its protein level in NPC cells. (A) AURKA and BUB1B mRNA levels were determined by qPCR assays. (B) AURKA and BUB1B proteins were measured by western blot assays. (C) AURKA and BUB1B mRNA levels in YBX1-depleted cells were determined by qPCR assays. (D) AURKA and BUB1B protein levels in YBX1-depleted cells were measured by western blot assays. (E) RIP-qPCR assays showed that YBX1 bond to the mRNAs of AURKA and BUB1B. The mRNA of YBX1 itself was used as a positive control for binding assay. (F) Co-transfection of YBX1 plasmids with luciferase reporters inserted with the wild type or mutant untranslated regions which lack of the YBX1 binding site suggested that YBX1 bind to 3'-UTR of AURKA mRNA and enhanced the translation efficiency of AURKA mRNA. (G) AURKA mRNA levels were measured by qPCR assay. (G) Cell proliferation in AURKA plasmids transfected cells were measured by CCK-8 assays. (I) Cell migration and invasiveness in AURKA plasmids transfected cells were measured by transwell assays without or with Matrigel, respectively. **P<0.01. ***P<0.001.