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Background. Despite recent advances in surgical techniques and treatment options, gastric cancer (GC) remains the third most common cause of cancer-related deaths worldwide. Besides DNA sequence mutations, epigenetic alterations have emerged as significantly major players in cancer development. A-to-I RNA editing is a post-transcriptional modification that converts adenosines to inosines in both coding and noncoding RNA transcripts, and has recently been recognized has a novel epigenetic mechanism in GC pathogenesis. More specifically, A-to-I editing of AZIN1 transcripts was shown to be regulated by an adenosine deaminase acting on RNA-1 (ADAR1), and edited AZIN1 resulted in an aggressive phenotype during disease progression in some human cancers. The aim of this study was to clarify the clinical consequences of RNA editing status of AZIN1 and the RNA editing enzymes (ADAR1 and 2) in GC patients. Methods. Two hundred eighty-eight gastric specimens from one hundred forty-four patients who underwent surgery for GC were evaluated. We analyzed the RNA editing status of AZIN1 by RNA editing site-specific quantitative PCR (RESSqPCR). RESSqPCR allows quantitation of RNA editing levels using wild-type or edited AZIN1-specific primers, and RNA editing levels are calculated by determining the ratios of Ct values between edited vs. wild-type transcript expression levels. Furthermore, expression levels of ADAR1 and ADAR2 were evaluated by qPCR in GC tissues. Results. We observed a higher frequency of the AZIN1 RNA editing in tumors compared with normal mucosa in GC. RNA editing status of AZIN1 was significantly increased in a stage-dependent manner, and high frequency of RNA editing in AZIN1 significantly correlated with advanced T stage and presence of lymph node metastasis in GC patients. Multivariate analysis revealed that high frequency of RNA editing in the AZIN1 gene was an independent prognostic factor for poor disease free survival and overall survival. Furthermore, significant upregulation of ADAR1 and downregulation of ADAR2 was also observed in GC tissues compared with matched normal mucosa, and these alterations also significantly correlated with disease progression factors and poor prognosis in GC patients. Interestingly, ADAR1 expression level was positively correlated with RNA editing status of AZIN1 in GC tissues. Conclusions. Our findings revealed that altered gene-specific A-to-I editing events mediated by ADAR1 promote disease progression in GC. We conclude that assessment of RNA editing status of the AZIN1 gene might offer a novel and superior biomarker for a more accurate diagnosis of disease staging and may help predict clinical outcomes in GC patients. Citation Format: Yoshinaga Okugawa, Yuji Toiyama, Kunitoshi Shigeyasu, Takashi Ichikawa, Satoshi Oki, Koichiro Mori, Yuka Nagano, Hiromi Yasuda, Shigeyuki Yoshiyama, Masaki Ohi, Koji Tanaka, Yasuhiro Inoue, Toshimitsu Araki, Yasuhiko Mohri, Motoyoshi Tanaka, Chikao Miki, Ajay Goel, Masato Kusunoki. Novel findings for the clinical significance of RNA editing status of AZIN1 and ADAR 1 and 2 expression levels in gastric cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4720. doi:10.1158/1538-7445.AM2017-4720

Background: Although present guidelines recommend periodic colonoscopy with multistep biopsies for surveillance of ulcerative colitis (UC)-associated colorectal cancer (CRC), it remains unclear about the effectively. To improve the surveillance, more effective markers are needed to identify patients at high risk for UC-CRC. MicroRNA (miRNA)-137 is often methylated in sporadic CRC. Methylation of this miRNA also occurs in an age-dependent manner, suggesting a potential “field defect”, and possibly an early event in colitis-associated carcinogenesis. The objective of this study was to determine whether a methylation-related “field defect” of miR-137 could be exploited clinically to identify individuals with UC who are at increased risk for developing neoplasia. Materials & Methods: We conducted four-step analysis using 387 samples from 238 UC patients of two independent cohorts, which included 152 patients without neoplasia (matched specimens obtained from cecum, transverse colon and rectum for each patient), 17 with dysplasia, and 69 with cancers (neoplasms and corresponding rectal mucosa). We performed bisulfite pyrosequencing to quantify miR-137 promoter methylation levels of these samples. Results: In non-neoplastic UC patients, methylation levels of miR-137 were significantly higher in rectal mucosa than in proximal cecum mucosa (7.0 ± 2.8% vs. 4.9 ± 2.0%, P Conclusions: Methylation of miR-137 occurs in an age- and cancer-dependent manner in UC patients. Analysis of miR-137 methylation levels in rectum may be a biomarker for identification of UC patients at greatest risk for UC-CRC. Citation Format: Yuji Toiyama, Yoshinaga Okugawa, Koji Tanaka, Toshimitsu Araki, Keiichi Uchida, Masato Kusunoki, C.Richard Boland, Ajay Goel. The clinical significance of epigenetic microRNA-137 silencing in patients with ulcerative colitis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3367. doi:10.1158/1538-7445.AM2017-3367

Background Abnormal DNA methylation is an important epigenetic mechanism that has been strongly implicated in the pathogenesis and progression of colorectal neoplasia. In contrast to other potential biomarker species such as mRNA and protein levels, measurement of DNA methylation has been shown to be stable, reproducible and consistent between individuals. Based on these standpoints, detecting aberrant methylation of cancer-related genes helps for the development of diagnostic and prognostic biomarkers in colorectal cancer (CRC). In this study, we comprehensively evaluated whole-genome methylation analysis using colorectal cancer tissues and normal colonic mucosa to discover candidate CRC-specific DNA methylation as potential diagnostic and predictive biomarkers for risk stratification in CRC patients. Patients and Method The study design included an initial discovery phases, and followed by a subsequent clinical validation phase. In discovery phase, we performed whole-genome methylation analysis using CRC tissues and normal colonic mucosae from total fourteen patients to identify CRC-specific methylated CpG cites. Furthermore, we evaluated methylation levels of candidate methylated CpG cites by quantitative bisulfite pyrosequencing using one hundred six colorectal specimens from fifty-three CRC patients to validate the findings from discovery phase. Result In discovery phase, we successfully identified several candidates of CRC-specific hypermethylated- and hypomethylated-CpG cites in CRC tissues compared with normal colonic mucosa. Promoter lesion of PDX1 is one of candidate methylated CpG cites in discovery phase, and we focus a specific CpG cite of PDX1 promoter lesion as a target cite to progress in validation phase. We quantified methylation status of PDX1 using 106 colonic tissues, and demonstrated that PDX1 were significantly hyper-methylated in CRC tissues compared with normal mucosa (p Conclusion Assessment of the PDX1 methylation status could be used as potential of diagnostic and predictive biomarker for risk stratification in CRC patients. Citation Format: Takashi Ichikawa, Yuji Toiyama, Yoshinaga Okugawa, Hiromi Yasuda, Hiroyuki Fujikawa, Yoshiki Okita, Shigeyuki Yoshiyama, Junichiro Hiro, Minako Kobayashi, Toshimitsu Araki, Masaki Ohi, Yasuhiro Inoue, Keiichi Uchida, Yasuhiko Mohri, Masato Kusunoki. Hypermethylation status of PDX1 has potential of diagnostic and predictive biomarker for risk stratification in colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1795. doi:10.1158/1538-7445.AM2017-1795

Background: MicroRNA (miRNA)-1290 is known to activate Wnt signaling pathway and increase the reprogramming-related transcript factors c-Myc and Nanog. Additionally, miR-1290 promotes the epithelial-mesenchymal transition and interferes with cellular differentiation. Previous report demonstrated that overexpressing miR-1290 shows extensive atrophy and intestinal metaplasia of the gastric mucosa, indicating that miR-1290 is involved in the precancerous lesions of the gastric epithelial cells. However, to the best of our knowledge, miR-1290 expression pattern, its clinical significance and molecular mechanism in colorectal cancer (CRC) have not been investigated. Materials and Methods: We screened miR-1290 expression in a subset of 36 tissue samples from normal colonic mucosa (n = 12), adenoma (n = 12) and CRC (n = 12). Next, we further validated miR-1290 expression in a larger, independent cohort, which included normal colonic mucosa (n = 21), adenoma (n = 26) and CRC (n = 179), and investigated the clinical significance of miR-1290 in CRC. In addition, CRC cell lines were transfected with anti-miR against miR-1290 for the assessment of its function. Results: In screening step, miR-1290 expression stepwise increased according to adenoma-carcinoma sequence, and its expression in adenoma and CRC was significantly higher than that in normal colonic mucosa, respectively (adenoma: p40mm), high grade of T stage (T3/4), lymphatic and venous invasion positive, lymph node metastasis and liver metastasis. In addition, Kaplan-Meier survival curves revealed that the CRC patients with high miR-1290 expression were significantly poorer overall survival than that with low expression, respectively (p = 0.0082). Our in vitro study demonstrated that attenuated miR-1290 expression resulted in inhibition of proliferation, invasion and migration capacity of CRC cell lines. Conclusions: We, for the first time, demonstrated that miR-1290 in CRC acts as onco-miRNAs that is supported by several evidences from our in vitro analysis and clinical data. MiR-1290 is significantly associated with malignant potential of CRC and can be the biomarker for predicting poor prognosis in patients with CRC. Citation Format: Yuka Nagano, Yuji Toiyama, Hiroki Imaoka, Hiroyuki Fujikawa, Junichiro Hiro, Susumu Saigusa, Minako Kobayashi, Toshimitsu Araki, Masaki Ohi, Koji Tanaka, Yasuhiro Inoue, Yasuhiko Mohri, Kenichiro Ishii, Masato Kusunoki. MicroRNA-1290 promotes tumor progression and acts as a novel biomarker for poor prognosis in human colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1967.

Background: Tropomyosin-related receptor kinase B (TrkB) signaling, stimulated by brain-derived neurotrophic factor (BDNF) ligand, promotes tumor progression, and is related to the poor prognosis of various malignancies. Studies in our laboratory revealed: an association between TrkB levels and tumor progression and patient prognosis in gastric cancer; the association of TrkB with chemotherapy resistance in esophageal cancer; and TrkB's involvement in the epithelial-mesenchymal transition in colorectal cancer. We have also demonstrated the involvement of the BDNF/TrkB pathway in tumor progression in gastric cancer. Aim: We sought to examine the clinical relevance of BDNF/TrkB expression in colorectal cancer (CRC) tissues, its prognostic value for CRC patients, and its therapeutic potential in vitro and in vivo. Methods: Two hundred and twenty-three CRC patient specimens were used to determine both BDNF and TrkB mRNA levels. The expression of these proteins in their primary and metastatic tumors was investigated by immunohistochemistry. CRC cell lines and recombinant BDNF and K252a (a Trk inhibitor) were used for in vitro proliferation, migration, invasion, anoikis resistance and in vivo peritoneal metastasis assays. Results: Tissue BDNF mRNA levels were significantly associated with an undifferentiated histology as well as lymph node and liver metastasis. The co-expression of BDNF and TrkB mRNA was significantly associated with lymph node, and liver metastasis and peritoneal carcinomatosis. Patients with high BDNF mRNA had a significantly poor prognosis, and those that co-expressed both BDNF and TrkB mRNA showed a trend toward poor prognosis. BDNF promoted tumor cell proliferation and migration, facilitated invasion and inhibited anoikis in the TrkB-expressing CRC cell lines. These effects were suppressed by K252a. In mice injected with DLD1 co-expressing BDNF and TrkB, and subsequently treated with K252a, peritoneal tumor metastasis was found to be significantly reduced, as compared with control mice. Conclusion: Blockade of BDNF-induced Trk B signaling inhibits peritoneal carcinomatosis arising arising from colorectal cancer. BDNF/TrkB signaling may thus be a potential target for treating the peritoneal carcinomatosis arising from colorectal cancer. Citation Format: Hiroki Imaoka, Koji Tanaka, Yoshinaga Okugawa, Tadanobu Shimura, Takahito Kitajima, Satoru Kondo, Shozo Ide, Susumu Saigusa, Yuji Toiyama, Yasuhiro Inoue, Toshimitsu Araki, Keiichi Uchida, Yasuhiko Mohri, Kenichiro Ishii, Masato Kusunoki. Blockade of BDNF-induced Trk B signaling inhibits peritoneal carcinomatosis arising arising from colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3451. doi:10.1158/1538-7445.AM2014-3451

Background: c-MET (hepatocyte growth factor receptor) gene is overexpressed in approximately 20% of gastric cancer. Onartuzumab, a MET-selective humanized one-armed monoclonal antibody, has been studied in metastatic Met-positive non-small cell lung cancer and expected to be introduced to MET-positive gastric cancer. Two-photon laser scanning microscopy (TPLSM) has revolutionized in vivo real-time imaging because of the benefits of higher resolution, increased tissue penetration, and reduced photodamage. We established a method of intravital imaging for intra-abdominal organs using TPLSM with an organ stabilizing system (Japanese Patent No.5268282). Aim: To visualize the binding of fluorescence labeled-antibody to its receptor of cancer cells in peritoneal metastatic xenografts of living mice using a TPLSM. Method: Human gastric cancer cell lines (NUGC4) were inoculated into the peritoneal cavity of green fluorescent protein (GFP) expressing nude mice to make macroscopic peritoneal metastases. In vitro study, the binding of Zenon Alexa Fluor 594 labeled anti-c-MET antibody to viable NUGC4 cells was imaged using fluorescence microscopy. In vivo study, the binding of fluorescence labeled-antibody to viable NUGC4 cells of peritoneal metastatic xenografts was imaged using a TPLSM. Result: Zenon Alexa Fluor 594 labeled anti-c-MET antibody (red) was bound to the surface of viable NUGC4 cells, and clearly visualized under a fluorescence microscopy. Peritoneal metastases with label-free NUGC4 cells (black) and murine stromal cells (green) were imaged under TPLSM in vivo real-time. Fluorescence labeled-antibody could be visualized within tumor vessels of peritoneal metastases after its intravenous administration. Thereafter, label-free NUGC4 cells were identified by the binding of fluorescence labeled- anti-c-MET antibody to c-MET of NUGC4 cells. Conclusion: We could visualize fluorescence labeled-antibody in peritoneal metastases of gastric cancer in living mice using a TPLSM. The binding of fluorescence labeled- anti-c-MET antibody to c-MET of viable NUGC4 cells was clearly imaged at high magnification and high resolution in vivo real-time. It is valuable to develop a method of in vivo optical pathology for therapeutic monoclonal antibodies using MPM on metastatic tumor xenografts. Citation Format: Shozo Ide, Koji Tanaka, Tadanobu Shimura, Masato Okigami, Satoru Kondo, Takahito Kitajima, Hiroki Imaoka, Yoshinaga Okugawa, Susumu Saigusa, Yuji Toiyama, Hiromi Yasuda, Masaki Ohi, Yasuhiro Inoue, Toshimitsu Araki, Keiichi Uchida, Yasuhiko Mohri, Masato Kusunoki. In vivo visualization using two-photon laser scanning microscopy of anti-c-MET antibody in peritoneal metastatic gastric cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4938. doi:10.1158/1538-7445.AM2014-4938

Background. Vasohibin 1 (VASH1) is an angiogenesis inhibitor which is expressed in the endothelial cells (ECs) of blood vessels of the tumor stroma. VASH1 expression of tumor stromal ECs has been reported to be associated with poor prognosis of human breast cancer and urothelial carcinoma. High VASH1 expression of tumor cells themselves was also reported to be associated with poor prognosis in hepatocellular carcinoma, whereas low VASH1 in tumor cells correlated with unfavorable clinicopathological features in renal cell carcinoma. Aim. This study aims to investigate the expression of VASH1 in tumor cells using immunohistochemistry and to evaluate its clinical and prognostic significance in patients with colorectal cancer (CRC). Materials and methods. Three hundred and nine (n=309) samples of CRC patients who underwent surgery between 2006 and 2011 were investigated for the expression of VASH1 using standard immunohistochemistry (IHC). The IHC score of VASH1 in tumor cells was determined on the basis of both staining intensity and the percentage of positive cells. The IHC score was dichotomized at the cutoff value predictive of overall survival using a non-parametric receiver operating characteristic analysis. The association between the expression of VASH1 in tumor cells and clinicopathological characteristics was analyzed. Impact of VASH1 expression in tumor cells on overall survival (OS) was also analyzed using univariate and multivariate analyses. Results. The number of CRC patients with stage I, II, III, and IV were 65, 91, 82, and 71, respectively. The median follow-up of all patients was 19.0 months (range: 2-77 months). Forty one patients had recurrent disease, and 44 patients had died. In CRC tissues, VASH1 protein was localized mainly in the cytoplasm of tumor cells, and partly in vascular endothelial cells. Imunoreactive VASH1 was detected in tumor cells of 272 CRC patients(88%). High VASH1 expression showed a trend towards an association with degree of differentiation. No significant association between VASH1 expression in tumor cells and the other clinicopathological variables was observed. In univariate analysis, high VASH1 expression was significantly associated with poor prognosis of CRC patients [p=0.02, hazard ratio (HR)=2.21, 95 % CI, 1.13-4.74]. In multivariate analysis, high VASH1 expression retained an independent prognostic factor for CRC patients [p Citation Format: Takahito Kitajima, Koji Tanaka, Susumu Saigusa, Tadanobu Shimura, Satoru Kondo, Yuji Toiyama, Yoshinaga Okugawa, Yasuhiro Inoue, Masaki Ohi, Toshimitsu Araki, Keiichi Uchida, Yasuhiko Mohri, Hiroki Hori, Masato Kusunoki. Prognostic impact of Vasohibin 1 (VASH1) expression in tumor cells of colorectal cancer patients. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1149. doi:10.1158/1538-7445.AM2013-1149

Background. Trefoil factor 3 (TFF3) is predominantly expressed by goblet cells of the small intestine and colon and its expression is maintained throughout the colon adenoma-carcinoma sequence. Aberrant TFF3 expression in tumor cells has been reported to be involved in tumor progression and unfavorable prognosis of certain human malignancies. In colorectal cancer (CRC), the association between TFF3 expression and tumor progression remains uncertain. Aim. We aimed to investigate the expression of TFF3 in tumor cells using immunohistochemistry and to evaluate its clinical and prognostic values in patients with colorectal cancer (CRC). Materials and methods. Three hundred (n=300) samples of CRC patients were investigated for the expression of TFF3 in tumor cells using standard immunohistochemistry (IHC). The IHC score of TFF3 in tumor cells was determined on the basis of both staining intensity and the percentage of positive cells. The IHC score was dichotomized at the cutoff value predictive of overall survival using a non-parametric receiver operating characteristic analysis. The association between the expression of TFF3 in tumor cells and clinicopathological features was analyzed. Impact of TFF3 expression in tumor cells on overall survival (OS) was also analyzed using univariate and multivariate analyses Results. TFF3 was expressed in all goblet cells of adjacent normal tissue. In adjacent normal colonic crypt, immunoreactive TFF3 protein was localized mainly in the cytoplasm or supranuclear cytoplasm of epithelial cells. Colorectal cancer cells showed an aberrant cytoplasmic TFF3 staining. By use of our dichotomous scoring system, 110 tumors (66%) were low and 190 (34%) were high for TFF3 immunostaining. Decreased expression of TFF3 was significantly associated with larger tumor size ( Conclusions. Decreased TFF3 expression was associated with colorectal tumor progression. Decreased or lack of TFF3 expression in tumor cells may have a potential prognostic value in CRC patients. Citation Format: Satoru Kondo, Koji Tanaka, Susumu Saigusa, Takahito Kitajima, Tadanobu Shimura, Yuji Toiyama, Yoshinaga Okugawa, Yasuhiro Inoue, Toshimitsu Araki, Keiichi Uchida, Yasuhiko Mohri, Kenichiro Ishii, Masato Kusunoki. Aberrant expression of trefoil factor 3 (TFF3) is associated with tumor progression and an unfavorable prognosis in patients with colorectal cancer . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1167. doi:10.1158/1538-7445.AM2013-1167

Background. Previously, we have reported the association between the expression of tropomyosin-related kinase B (TrkB) in tumor cells and gastric tumor progression, chemoresistance of esophageal cancer, and epithelial-mesenchymal transition in colorectal cancer. In gastric cancer, high tumoral TrkB mRNA level demonstrated to be an independent prognostic factor. Aim. In this study, we investigated the TrkB protein expression in tumor cells using immunohistochemistry, and evaluated its clinical and prognostic significance in patients with human gastric cancer (GC). Materials and methods. Three hundred and twenty (n=320) samples of GC patients were investigated for the TrkB protein expression in tumor cells using a standard immunohistochemistry (IHC). The IHC score of TrkB in tumor cells was determined on the basis of both staining intensity and the percentage of positive cells. The IHC score was dichotomized at the median value as a cutoff value. The association between the TrkB protein expression in tumor cells and clinicopathological features was analyzed. Impact of TrkB protein expression in tumor cells on overall survival (OS) was also analyzed using univariate and multivariate analyses. Results. Immunoreactive TrkB protein was localized in both cytoplasm and nucleus of gastric cancer cells. High cytoplasmic TrkB expression was significantly associated with larger tumor size (p Conclusions. Tumoral TrkB expression was associated with tumor progression in human gastric cancer. Increased TrkB at the tumor invasive front was an independent prognostic factor in patients with gastric cancer. Citation Format: Koji Tanaka, Tadanobu Shimura, Susumu Saigusa, Satoru Kondo, Takahito Kitajima, Yuji Toiyama, Yoshinaga Okugawa, Yasuhiro Inoue, Masaki Ohi, Toshimitsu Araki, Keiichi Uchida, Yasuhiko Mohri, Masato Kusunoki. Expression of tropomyosin-related kinase B (TrkB) at the tumor invasive front as an independent prognostic factor in gastric cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1144. doi:10.1158/1538-7445.AM2013-1144

Background. Angiopoietin-like protein 2 (ANGPTL2) is a secreted protein belonging to the angiopoietin family.It has been reported to act as a causative mediator of chronic inflammation andmetabolic abnormalities. In ovarian and lung cancer, ANGPTL2 expression in tumor cells was reported to be associated with unfavorable prognosis. So far,clinical and prognostic significance of ANGPTL2 in human gastric cancer remains unknown. Aim. This study investigated the expression of ANGPTL2 in tumor cells using immunohistochemistry and to evaluate its clinical and prognostic significance in patients with human gastric cancer (GC). Materials and methods. Two hundred and eighty two (n=282) samples of GC patients were investigated for the expression of ANGPTL2 in tumor cells using standard immunohistochemistry (IHC). The IHC score of ANGPTL2 in tumor cells was determined on the basis of both staining intensity and the percentage of positive cells. The IHC score was dichotomized at the cutoff value predictive of overall survival using a non-parametric receiver operating characteristic analysis. The association between the expression of ANGPTL2 intumor cells and clinicopathological features was analyzed. Impact of ANGPTL2 expression in tumor cells on overall survival (OS) was also analyzed usingunivariate and multivariate analyses. Results. ANGPTL2 protein was localized mainly in the cytoplasm of tumor cells, and partly in the nucleus. High cytoplasmic ANGPTL2 was significantly associated with higher age (p=0.04), larger tumor size (p In univariate analysis, high cytoplasmic ANGPTL2 and higher cytoplasmic ANGPTL2 at the invasive margin were significantly associated with poor prognosis (p Conclusions. Tumoral ANGPTL2 expression was associated with gastric tumor progression. Increased ANGPTL2 at both tumor center and invasive margin were independent prognostic indicators in patients with gastric cancer. Citation Format: Tadanobu Shimura, Koji Tanaka, Susumu Saigusa, Satoru Kondo, Takahito Kitajima, Yuji Toiyama, Yoshinaga Okugawa, Yasuhiro Inoue, Toshimitsu Araki, Keiichi Uchida, Yasuhiko Mohri, Tsutomu Nobori, Masato Kusunoki. Prognostic value of angiopoietin-like protein 2 (ANGPTL2) at the tumor margins in patients with gastric cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1139. doi:10.1158/1538-7445.AM2013-1139

Background: The pathogenesis of colorectal cancer in familial adenomatous polyposis (FAP) has been studied genetically. Recently, intestinal stem cell (ISC) or cancer stem cell (CSC) is being focused on colorectal carcinogenesis. The aim of this study is to investigate the immunohistochemical features of stem cell transcription factors on colorectal adenocarcinomas, adenomataous polyps, and normal crypts in patients with FAP. Methods: Lgr5 as an ISC marker, CD133 and CD44 as CSC markers, and NANOG, OCT4, and SOX2 as embryonic stem cell transcription factors were evaluated immunohistochemically. Matched specimens of colorectal adenocarcinoma, adenomatous polyps, and adjacent normal crypts were obtained from individual FAP patients (n=4), to clarify the association between stepwise progression from normal crypt to adenomatous polyp to adenocarcinoma and expression of stem cell transcription factors. Results: Lgr5, NANOG, OCT4, and SOX2 were mainly located in cytoplasm of cancerous and adenomatous cells. CD133 showed cytoplasmic or intraluminal membranous staining in cancerous and adenomatous cells. Immunoreactive CD44 protein was present in cell membrane or cytoplasm of cancerous and adenomatous cells. Immunoreactive positivity and intensity was greater in colorectal adenocarcinomas than in adenomatous polyps, except for NANOG. Adjacent normal crypts showed negative or weak staining of all markers. CD133, CD44, Lgr5, OCT4, and SOX2 were strongly expressed on cancerous cells at the advancing front of colorectal adenocarcinoma. Conclusions: ISC or CSC may be associated with colorectal carcinogenesis of FAP. Stem cell transcription factors may be involved in tumor invasion of colorectal adenocarcinoma in FAP patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3358.