The technique used for cancer monitoring is essential for effective cancer therapy. Currently, several methods such as diagnostic imaging and biochemical markers have been used for cancer monitoring, but these are invasive and show low sensitivity. A previous study reported that Caenorhabditis elegans sensitively discriminated patients with cancer from healthy subjects, based on the smell of a urine sample. However, whether C. elegans olfaction can detect the removal of cancerous tumours remains unknown. This study was conducted to examine C. elegans olfactory behaviour to urine samples collected from 78 patients before and after surgery. The diagnostic ability of the technique termed Nematode-NOSE (N-NOSE) was evaluated by receiver operating characteristic (ROC) analysis. The ROC curve of N-NOSE was higher than those of classic tumour markers. Furthermore, we examined the change in C. elegans olfactory behaviour following exposure to preoperative and postoperative samples. The results suggest that a reduction in attraction indicates the removal of the cancerous tumour. This study may lead to the development of a noninvasive and highly sensitive tool for evaluating postoperative cancer patients.
The technique used for cancer monitoring is essential for effective cancer therapy. Currently, several methods such as diagnostic imaging and biochemical markers have been used for cancer monitoring, but these are invasive and show low sensitivity. A previous study reported that Caenorhabditis elegans sensitively discriminated patients with cancer from healthy subjects, based on the smell of a urine sample. However, whether C. elegans olfaction can detect the removal of cancerous tumours remains unknown. This study was conducted to examine C. elegans olfactory behaviour to urine samples collected from 78 patients before and after surgery. The diagnostic ability of the technique termed Nematode-NOSE (N-NOSE) was evaluated by receiver operating characteristic (ROC) analysis. The ROC curve of N-NOSE was higher than those of classic tumour markers. Furthermore, we examined the change in C. elegans olfactory behaviour following exposure to preoperative and postoperative samples. The results suggest that a reduction in attraction indicates the removal of the cancerous tumour. This study may lead to the development of a noninvasive and highly sensitive tool for evaluating postoperative cancerpatients.
Cancer is the leading cause of death worldwide, and the number of people with cancer
is increasing. The major treatments for cancer include surgery, chemotherapy, and
radiotherapy.[1-3] Among these
methods, the prognosis of surgery depends on the complete removal of cancer tissue,
as any remaining cancer cells have the potential to spread to other tissues and
cause metastasis and recurrence.[4-6] Therefore, postoperative
observation is important for assessing surgical outcomes.Several methods have been developed for postoperative evaluation of cancer
conditions. Diagnostic imaging methods such as positron emission tomography–computed
tomography and endoscopy have been used for follow-up examination after
surgery;[7,8]
however, these methods can be invasive or costly, and their repeated application is limited.[9] Classic biochemical markers, such as carcinoembryonic antigen (CEA) and
carbohydrate antigen 19-9 (CA19-9), have been used for postoperative monitoring of
patients with cancer.[10,11] Although these methods are relatively noninvasive, their
sensitivity must be improved.[12,13] Therefore, noninvasive,
low-cost, and highly sensitive methods are needed for monitoring patients with
cancer after surgery.A recent study reported that the olfactory behaviour of the nematode
Caenorhabditis elegans to human urine can be utilized to
discriminate patients with cancer from healthy people.[14]
C. elegans showed an innate attractive behaviour towards urine from
patients with cancer, whereas they avoided urine from healthy subjects. Attractive
olfactory sensory neurons of C. elegans consistently responded to
urine from patients with cancer, and aversive sensory neurons have a role in
response to urine from healthy subjects.[14] Based on the olfactory response of C. elegans, a novel
cancer screening test was developed, named Nematode-NOSE (N-NOSE), which was
referred to as the nematode scent detection test (NSDT) in a previous study.[14] Both the sensitivity and specificity of N-NOSE, including those for
early-stage cancers, were more than 90%. Nematode-NOSE can detect broad types of
cancers including most gastrointestinal cancers.[14]However, whether N-NOSE can be used to monitor the progress of cancer in the same
patient remains unclear. The previous study indicated that C.
elegans detected cancer-specific odours in urine from cancerpatients,
even when the cancer was in stage 0 or I,[14] suggesting that C. elegans sensitively detect the potential
for cancer development. As postoperative patients have a history of carcinogenesis
and potential for recurrence, C. elegans may fail to show aversive
behaviour to the urine samples clearly. We therefore hypothesized that the degree of
attractive behaviour to postoperative urine is decreased compared to preoperative
urine.In this study, we investigated the ability of N-NOSE as a postoperative tool for
monitoring the removal of cancer. We first performed receiver operating
characteristic (ROC) analysis to compare the diagnostic performance of N-NOSE and
conventional tumour markers, CEA and CA19-9. We next tested our hypothesis and
examined alterations in C. elegans olfactory behaviour between
preoperative and postoperative samples from the same patient. Our results
demonstrated that the reduction in attractive olfactory behaviour for postoperative
samples indicates the removal of cancer. This study may lead to the development of
an effective tool for postoperative evaluation based on C. elegans
olfaction.
Results
To examine the diagnostic performance of N-NOSE for monitoring the removal of cancer,
we performed ROC analysis using preoperative and postoperative samples from the same
patient (N = 78 patients; Table
1). Conventionally, ROC analysis has been used to quantify how accurately
a medical diagnostic tool can discriminate between 2 groups (eg, cancerpatients and
healthy subjects). In this study, ROC analysis was used to quantify the
differentiation between preoperative and postoperative samples to investigate
whether chemotaxis index (see Methods) reflects the removal of cancer. Values
obtained for N-NOSE, CEA, and CA19-9 are listed in Supplementary Table S1. Chemotaxis indices of each patient were
listed in Supplementary Table S2. The area under the curve (AUC) indicates the
usefulness of N-NOSE, AUC = 0.742, P < .001, 95% confidence
interval (CI): 0.664-0.819, compared to that of classic tumour markers, CEA
(AUC = 0.638, P = .003, 95% CI: 0.551-0.724) and CA19-9
(AUC = 0.570, P = .133, 95% CI: 0.480-0.660), for diagnosing the
removal of cancer (Figure 1,
Table 2).
Furthermore, we examined the diagnostic ability of N-NOSE for different pathological
stages and cancer types. In stages 0 and I cancer, the AUC of N-NOSE was higher than
those of CEA and CA19-9 (Figure
2, Table 3).
In addition, in the 2 types of cancer, the AUC of N-NOSE was higher than those of
CEA and CA19-9 (Figure 3,
Table 4). Images
showing animals were attracted to the preoperative sample, but not to the
postoperative are described in Supplementary Figure S1. These results suggest that N-NOSE detected
the removal of cancer more sensitively than the classical tumour markers.
Table 1.
Patient characteristics.
Characteristics
Colorectal cancer patients (N = 46)
Gastric cancer patients (N = 32)
Total (N = 78)
Age (years)
Mean ± SD
67.4 ± 12.1
67.0 ± 10.8
67.3 ± 11.5
Range
35-86
43-89
35-89
Gender
Female
19
8
27
Male
27
24
51
Tumour stage
0-I
15
24
39
II
15
6
21
III-IV
16
2
18
Abbreviations: SD: standard deviation.
Figure 1.
ROC curves depicting the diagnostic capability of N-NOSE.
Area under the ROC curve for N-NOSE (red line), CEA (black dotted line), and
CA19-9 (grey line).
Abbreviations: AUC, area under the curve; CA19-9, carbohydrate antigen
19-9; CEA, carcinoembryonic antigen; N-NOSE, Nematode-NOSE; ROC,
receiver operating characteristic.
The results correspond to those shown in Figure 1. AUC indicates area
under the curve. The P-values indicate whether the
value of AUC is significantly different from the value of 0.5 AUC. The n
is the number of the chemotaxis indices or values of tumour markers (eg,
the 78 preoperative chemotaxis indices versus 78 postoperative
indices).
Figure 2.
ROC curves of N-NOSE by pathological stage.
Area under the ROC curve for N-NOSE (red line), CEA (black dotted line), and
CA19-9 (grey line) in stages 0 and I (a), stage II (b), and stages III and
IV (c).
Abbreviations: AUC, area under the curve; CA19-9, carbohydrate antigen
19-9; CEA, carcinoembryonic antigen; N-NOSE, Nematode-NOSE; ROC,
receiver operating characteristic.
The results correspond to those shown in Figure 2. The
P-values indicate whether the value of AUC is
significantly different from the value of .5 AUC. The n is the number of
the chemotaxis indices or values of tumour markers.
Figure 3.
ROC curves of N-NOSE by cancer type.
Area under the ROC curve for N-NOSE (red line), CEA (black dotted line), and
CA19-9 (grey line) in colorectal cancer (a) and gastric cancer (b).
Abbreviations: AUC, area under the curve; CA19-9, carbohydrate antigen
19-9; CEA, carcinoembryonic antigen; N-NOSE, Nematode-NOSE; ROC,
receiver operating characteristic.
The results correspond to those shown in Figure 3. The
P-values indicate whether the value of AUC is
significantly different from the value of 0.5 AUC. The n is the number
of the chemotaxis indices or values of tumour markers.
Patient characteristics.Abbreviations: SD: standard deviation.ROC curves depicting the diagnostic capability of N-NOSE.Area under the ROC curve for N-NOSE (red line), CEA (black dotted line), and
CA19-9 (grey line).CA19-9 indicates carbohydrate antigen 19-9; CEA, carcinoembryonic antigen;
N-NOSE, Nematode-NOSE; ROC, receiver operating characteristic.ROC analysis results.Abbreviations: AUC, area under the curve; CA19-9, carbohydrate antigen
19-9; CEA, carcinoembryonic antigen; N-NOSE, Nematode-NOSE; ROC,
receiver operating characteristic.The results correspond to those shown in Figure 1. AUC indicates area
under the curve. The P-values indicate whether the
value of AUC is significantly different from the value of 0.5 AUC. The n
is the number of the chemotaxis indices or values of tumour markers (eg,
the 78 preoperative chemotaxis indices versus 78 postoperative
indices).ROC curves of N-NOSE by pathological stage.Area under the ROC curve for N-NOSE (red line), CEA (black dotted line), and
CA19-9 (grey line) in stages 0 and I (a), stage II (b), and stages III and
IV (c).CA19-9 indicates carbohydrate antigen 19-9; CEA, carcinoembryonic antigen;
N-NOSE, Nematode-NOSE; ROC, receiver operating characteristic.Results of ROC analysis by pathological stage.Abbreviations: AUC, area under the curve; CA19-9, carbohydrate antigen
19-9; CEA, carcinoembryonic antigen; N-NOSE, Nematode-NOSE; ROC,
receiver operating characteristic.The results correspond to those shown in Figure 2. The
P-values indicate whether the value of AUC is
significantly different from the value of .5 AUC. The n is the number of
the chemotaxis indices or values of tumour markers.ROC curves of N-NOSE by cancer type.Area under the ROC curve for N-NOSE (red line), CEA (black dotted line), and
CA19-9 (grey line) in colorectal cancer (a) and gastric cancer (b).CA19-9 indicates carbohydrate antigen 19-9; CEA, carcinoembryonic antigen;
N-NOSE, Nematode-NOSE; ROC, receiver operating characteristic.Results of ROC analysis by cancer type.Abbreviations: AUC, area under the curve; CA19-9, carbohydrate antigen
19-9; CEA, carcinoembryonic antigen; N-NOSE, Nematode-NOSE; ROC,
receiver operating characteristic.The results correspond to those shown in Figure 3. The
P-values indicate whether the value of AUC is
significantly different from the value of 0.5 AUC. The n is the number
of the chemotaxis indices or values of tumour markers.We next investigated whether N-NOSE can indicate the removal of cancer. To evaluate
whether the removal of cancer induced a reduction in attractive behaviour, we
analysed changes in the chemotaxis index using preoperative to postoperative samples
from the same patient. Among the 78 samples, 59 samples showed a reduced chemotaxis
index from preoperative to postoperative samples (Figure 4). One-sample t-test
revealed that the differences of the preoperative and postoperative chemotaxis index
were significantly different from 0 (mean ± standard error of the
M: −0.066 ± 0.013, t = −5.053,
P < .0001). These results suggest that decreased attractive
olfactory behaviour of C. elegans can indicate the removal of
cancerous tumours.
Figure 4.
Change in chemotaxis index in individual samples.
Differences in chemotaxis indices were obtained by subtracting the
preoperative chemotaxis index from the postoperative chemotaxis index in
each sample. Among the 78 samples, 59 samples showed a decreased chemotaxis
index. Red asterisk indicates the mean and error bar indicates standard
error of the mean.
Change in chemotaxis index in individual samples.Differences in chemotaxis indices were obtained by subtracting the
preoperative chemotaxis index from the postoperative chemotaxis index in
each sample. Among the 78 samples, 59 samples showed a decreased chemotaxis
index. Red asterisk indicates the mean and error bar indicates standard
error of the mean.
Discussion
We investigated the use of N-NOSE as a postoperative tool for monitoring the presence
of cancer. We found that N-NOSE showed a higher area under the ROC curves than CEA
and CA19-9. In the comparison of the area under ROC curve by pathological stage and
cancer type, N-NOSE showed a higher area under the ROC than CEA and CA19-9. We then
focused on changes in the chemotaxis index in individual samples. Among the 78
samples, 59 samples showed a decreased chemotaxis index in postoperative samples,
supporting our hypothesis. These results indicate that N-NOSE is a useful surrogate
marker for detecting the postoperative cancer status.We investigated the diagnostic ability of N-NOSE to detect the removal of cancerous
tumours. The ROC analysis revealed that N-NOSE was more accurate than CEA or CA19-9
(Figure 1). The
detection ability of C. elegans olfaction was validated in 2 types
of cancer (ie, colorectal and gastric cancer) and pathological stages (Figures 2 and 3, Tables 3 and 4). The results revealed that C.
elegans can detect cancer regardless of the types and stages.[14] In stages 0 and I cancers, CEA and CA19-9 showed nearly negative results, in
which the classic tumour markers showed less than 0.6 AUC values (Figure 2A and Table 3) and then we could
not use these markers as indicators of cancer removal. In contrast, N-NOSE could
discriminate the preoperative and postoperative status even in stages 0 and I
cancers. These results suggest that N-NOSE can detect cancer removal regardless of
the number of cancer cells present. In gastric cancers, compared to colorectal
cancers, N-NOSE showed a higher AUC than the classical tumour markers. This may be
because more early-stage patients were included in the gastric cancer group (ie, 24
of 32 samples were from stages 0 and I cancerpatients). Analysis of the changes in
C. elegans olfaction also revealed the ability to detect cancer
removal in the same individuals (Figure 4). Furthermore, the follow-up test using 3 samples showing
recurrence supported the clinical usefulness of N-NOSE. In these 3 samples, the
chemotaxis index was decreased following cancer removal and increased following
recurrence (patient A; preoperative index = 0.027, postoperative index = −0.016, and
recurrence index = 0.002, patient B; preoperative index = 0.095, postoperative
index = −0.148, and recurrence index = 0.034, patient C; preoperative index = 0.027,
postoperative index = 0.023, and recurrence index = 0.067, Supplementary Figure S2). For example, patient B was a female with
stage II rectal cancer. Her CEA and CA19-9 levels were sustained within the normal
limit during follow-up regardless of surgery or recurrence. In contrast, the
chemotaxis index changed as described above, reflecting removal and recurrence. We
also found that in several stage IV patients who underwent palliative surgery, the
chemotaxis index changed according to their tumour volumes (Supplementary Figure S3), in which the tumour volume was measured
according to revised RECIST guideline (version 1.1).[15] The chemotaxis index decreased when the primary sites were removed and then
increased when metastatic sites increased. These results suggest that N-NOSE has the
potential to be a postoperative tool for monitoring cancer.Our results suggest that the olfactory behaviour of C. elegans
reflected the change in urinary cancer-specific odour caused by surgical removal.
Previous studies showed that urinary chemical components, including volatile
components, in patients with cancer different from those in control
subjects,[16-18] and the
pattern of urinary components were changed by surgical therapy.[19] Such changes were detected by C. elegans in this study.
C. elegans showed dose-dependent olfactory behaviour, with
attractive behaviour to attractants corresponding to the concentration of spotted
odour samples.[20-24] These results support those of
the current study.Our results showed that N-NOSE had a higher AUC than CEA and CA19-9 except for in the
diagnosis of stages III and IV disease (Figure 2C, Table 3), although the classic tumour
markers also showed decreased values in postoperative samples (Supplementary Table S1). The superiority of N-NOSE in the AUC may be
explained by the distribution of values. The values for CEA and CA19-9 are individual-specific,[25] and such dispersion may lead to relatively low diagnostic performance.
Indeed, the ranges of values for CEA and CA19-9 in this study were 0.5 to 476.9 and
0.1 to 82 171.4, respectively. The values of CEA and CA19-9 indicate their
concentrations in serum, and individual difference is directly reflected by the
values. In contrast, in N-NOSE, the chemotaxis index is a normalized value that
indicates the ratio of animals showing attractive behaviour to the spotted sample.
Thus, the value showed a relatively low distribution compared to the classic tumour
markers. Such characteristics may also contribute to diagnostic performance in our
results. However, the normalization in chemotaxis index might account for the
difference of AUC in our results, which might be noted as limitation. To compare the
diagnostic abilities more impartially, other response of C. elegans
to urine, such as olfactory neural response, could be utilized instead of
behavioural response.There were some limitations to this study. Our results suggest that the absolute
value of the chemotaxis index might be unsuitable for indicating cancer removal. The
animals did not show aversive behaviour to postoperative urine, with only 32 urine
samples showing a negative chemotaxis index in postoperative samples compared to 63
samples showing a positive chemotaxis index preoperatively. This may be because
postoperative patients have some differences from healthy subjects, such as a
history of carcinogenesis and the potential for recurrence. In addition, patients
with cancer utilize unique metabolic pathways that have residual effects on
postoperative urine samples. Indeed, several reports showed that urine from patients
with cancer have a specific pattern of bioactive molecules, such as DNA, miRNA, and
extracellular vesicle proteins.[1,26,27] Thus, C.
elegans would fail to show aversive behaviour in postoperative samples.
Furthermore, several postoperative samples showed an increased chemotaxis index
(Figure 4). Studies are
needed to identify the factors that increase the chemotaxis index in postoperative
samples. The premise of ROC analysis might not be congruent with this study. The ROC
curve relies on a measure of ‘true positives’ and ‘true negative’. Although we
confirmed that the tumour was removed from the patient by intraoperative macroscopic
findings, histopathological examination, and postoperative imaging inspection, the
recurrence was found (Supplementary Figure S2). An alternative analysis, which is
congruent with this study and enables to examine the resolution from preoperative to
postoperative samples, might be needed. There may be a limitation that the method of
N-NOSE can be optimized to make larger different chemotaxis indices between
preoperative and postoperative samples. For example, in Supplementary Figure S2, patients A and C showed no significance,
though the alteration of chemotaxis index could trace the condition of cancer (ie,
decreased by removal of cancer and increased by recurrence). For the optimization of
N-NOSE with more accuracy, other chemotaxis assay formats and devices could be
utilized. In past C. elegans studies, several methods were used to
investigate and examine the olfactory behaviour of C. elegans in
detail, such as single animal assay,[24] animal tracking system,[24] and monitoring neural response in moving animals.[21] Otherwise, identification of cancer-specific odourants and the olfactory
receptor could also lead to optimization of N-NOSE. Based on the previous studies
suggesting the cancer-specific odourants,[16-18] method of N-NOSE assay could
be enhanced more accurately. Furthermore, no individual-specific normalization of
urine samples was performed due to following the previous study.[14] The normalization of urine concentration might lead to the optimization.
Those methods of optimization would help to brush up N-NOSE as a more accurate
technique to monitor preoperative patients. The analysis of other types of cancer
might be needed. In this study, only 2 types of cancer (ie, colorectal and gastric
cancer) were tested. Although the previous study showed that N-NOSE can detect
several types of cancer,[14] more number of types of cancer should be analysed to investigate the
capability of N-NOSE for prognosis.In conclusion, we demonstrated that N-NOSE can reflect the removal of cancerous
tumours using preoperative and postoperative urine samples collected from patients.
Nematode-NOSE shows potential as a tool for monitoring cancer in patients as well as
for detecting cancer.
Methods
Study populations
Urine samples were collected from 78 patients (age of mean ± SD = 67.3 ± 11.5,
female:male = 27:51) who were diagnosed as cancer at the Nanpuh Hospital
(Kagoshima, Japan) between June 2016 and February 2018. The characteristics of
the patients are listed in Table 1. Measurement was performed within 60 days before and after
surgery. Multiple cancers were excluded. Preoperative urine was collected before
26 ± 11 (mean ± SD) days, while postoperative urine was collected after 29 ± 9
(mean ± SD) days. In all patients, the pathologic stages were determined by
histological diagnosis of the primary tumour. The classical tumour markers CEA
and CA19-9 were also measured in the patients. Blood samples were collected
before 26 ± 11 and after 28 ± 9 days of surgery. Collected urine samples were
stored frozen until analysis by N-NOSE. The volume of tumour was measured
according to revised RECIST guideline (version 1.1).[15] Briefly, the targeted tumour was picked out up to 10 pieces, then the sum
of the maximum lengths of the tumour pieces was calculated in the preoperative,
postoperative, and recurred samples.The study was approved by the Ethics Committee of Nanpuh Hospital, Kagoshima
Kyosaikai, Public Interest, Inc. Association, Japan. Clinical examinations were
performed according to the principles of the Declaration of Helsinki. Research
consent was obtained in writing from each patient. Informed consent was obtained
from all participants. The first author guarantees the accuracy and completeness
of the data and analysis and of the study’s fidelity regarding technical and
biostatistics protocols.
Measurement by N-NOSE
Nematode-NOSE detects cancer by sensing a distinguishable cancer odour in urine
using the C. elegans olfactory system.[14] The olfactory behaviour of C. elegans was evaluated by
population assays, which was in accordance with the classical method by Bargmann
et al.[20] This method uses the chemotactic attraction or avoidance of C.
elegans to odourants in urine. C. elegans
(wild-type N2) were cultured at 20°C under well-fed and uncrowded conditions
with the Escherichia coli strain NA22 as a food source.
Chemotaxis assays with human urine were performed on 9-cm plates containing
10-mL 2% agar, 5 mM KPO4, 1 mM CaCl2, and 1 mM
MgSO4 as previously described.[14,20,24] Chemotaxis assays were
conducted as described previously.[14] Briefly, 1 μL of urine was added at 2 spots on one end of the assay
plates, and 0.5 μL of 1 M sodium azide was added at 2 spots on both ends of the
plates. As the diluent of urine samples, we used water, and we confirmed that
animals showed no chemotaxis behaviour to 1 µL of water. Thus, no diluent was
put on the opposite side of the plate. Animals were collected, washed 3 times
with chemotaxis buffer (0.05% gelatine, 5 mM KPO4, 1 mM
CaCl2, and 1 mM MgSO4), and transferred to the centre
of the plate to move freely for 30 min. Approximately 50 to 100 synchronized
young adults were used per plate. The chemotaxis index was calculated as the
number of animals in the region near the urine samples minus the animals in the
region without the samples divided by the total number of animals.[14,24] The format
of an agar plate to count animals is described in Supplementary Figure S4. The average chemotaxis indices of more
than 10 assay plates were determined. Hirotsu et al[14] reported that the chemotaxis index is positive in urine samples from
patients with diluted by 10- to 1000-fold and is not observed in urine samples
from healthy volunteers. Therefore, running behaviour against 10- to 1000-fold
diluted urine was investigated; positive peaks were considered as positive
results, and a lack of chemotaxis was considered as a negative result. In this
study, the result of N-NOSE was obtained using 10-fold diluted urine samples. We
performed 2 sets of chemotaxis assay, in which the one was for preoperative
urine samples, and the other was for postoperative samples.
Statistical analyses
Receiver operating characteristic analysis was performed based on logistic
regression using SPSS, version 25 (IBM Co, Armonk, NY, USA). A value of
P < .05 was considered significant. In ROC analysis,
chemotaxis indices listed in Supplementary Table S2 were used, in which the preoperative
chemotaxis indices were considered as cancer samples, and postoperative indices
were considered as healthy samples. In ROC analysis, the asymptotic significance
(null hypothesis: AUC = 0.5, α level = 0.05) was obtained, which indicates the
reliability of the AUC (ie, whether the value of AUC is significantly different
from the value of 0.5 AUC).Click here for additional data file.Supplemental material, Revised_SupplementaryInformation_4_xyz2778816687648 for
Behavioural Response Alteration in Caenorhabditis elegans to
Urine After Surgical Removal of Cancer: Nematode-NOSE (N-NOSE) for Postoperative
Evaluation by Hirotake Kusumoto, Kotaro Tashiro, Syunji Shimaoka, Koichiro
Tsukasa, Yukiko Baba, Saori Furukawa, Junichiro Furukawa, Toyokuni Suenaga,
Masaki Kitazono, Sadao Tanaka, Toru Niihara, Takaaki Hirotsu and Takayuki Uozumi
in Biomarkers in Cancer
Authors: Roberta Pang; Wai Lun Law; Andrew C Y Chu; Jensen T Poon; Colin S C Lam; Ariel K M Chow; Lui Ng; Leonard W H Cheung; Xiao R Lan; Hui Y Lan; Victoria P Y Tan; Thomas C Yau; Ronnie T Poon; Benjamin C Y Wong Journal: Cell Stem Cell Date: 2010-06-04 Impact factor: 24.633
Authors: Marta Lukaszewicz-Zając; Barbara Mroczko; Mariusz Gryko; Bogusław Kędra; Maciej Szmitkowski Journal: Clin Exp Med Date: 2010-10-12 Impact factor: 3.984
Authors: Emanuele Ferrari; Andrea Wittig; Fabrizio Basilico; Rossana Rossi; Antonella De Palma; Dario Di Silvestre; Wolfgang A G Sauerwein; Pier Luigi Mauri Journal: Molecules Date: 2019-02-22 Impact factor: 4.411
Authors: Brian D Nicholson; Bethany Shinkins; Indika Pathiraja; Nia W Roberts; Tim J James; Susan Mallett; Rafael Perera; John N Primrose; David Mant Journal: Cochrane Database Syst Rev Date: 2015-12-10
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