Tissues Of Gastric Cancer Patients Research Articles

Abstract 4929: UbcH10 may represent a potential marker of gastric carcinoma

Abstract Gastric cancer is a fatal disease with limited early diagnostic methods available. There is an urgent need to find more effective targets for early diagnosis and therapeutics. UbcH10 is an ubiquitin-conjugating enzyme with a high expression reported in some cancers. Several gastric tumor cell lines with high or low expression of UbcH10 were exploited to study the role of UbcH10 in gastric cancer. Knocking down of UbcH10 expression using siRNA in high expressing gastric cancer cell lines resulted in reduced proliferation, increased cisplatin-induced apoptosis and reduced serum-induced ERK, Akt and p38 phosphorylation signaling. In agreement, overexpression of UbcH10 expression in low-expression gastric cancer cell lines led to enhanced cell proliferation, resistance to cisplatin-induced apoptosis. Most importantly, IHC analyses showed that the UbcH10 protein expressed at a high level in patient gastric cancer tissues, but not in adjacent mesenchyme tissues. These data suggest that UbcH10 may promote gastric cancer growth and can serve as a biomarker for diagnosis or target for new therapeutics in gastric cancer. Citation Format: Mengxuan Yang, Yingying Qu, Gang Hu, Shiwei Tu, RL Shi, XB Wu, ZQ Hu, QM Zhang, SQ Liu, GF Pan, Ziping Zhang, He Zhou. UbcH10 may represent a potential marker of gastric carcinoma. [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 4929.

Ubiquitin-conjugating enzyme UbcH10 promotes gastric cancer growth and is a potential biomarker for gastric cancer.

Gastric cancer is a fatal disease and the availability of early diagnostic methods is limited. There is an urgent need to identify effective targets for early diagnosis and therapeutics. UbcH10 is a ubiquitin-conjugating enzyme with high expression in various types of cancers. In the present study, several gastric tumor cell lines with high or low expression of UbcH10 were exploited to study the role of UbcH10 in gastric cancer. Knockdown of UbcH10 expression using siRNA in gastric cancer cell lines with high expression of UbcH10 resulted in reduced proliferation, increased cisplatin-induced apoptosis and reduced serum-induced ERK, Akt and p38 phosphorylation signaling. In agreement, overexpression of UbcH10 in gastric cancer cell lines with low expression of UbcH10 led to enhanced cell proliferation and resistance to cisplatin-induced apoptosis. Most importantly, IHC analyses showed that the UbcH10 protein was expressed at a high level in most patient gastric cancer tissues, but was absent in adjacent mesenchyme tissues. These data suggest that UbcH10 may promote gastric cancer growth and can serve as a biomarker for diagnosis or as a target for novel therapeutics in gastric cancer.

MicroRNA-190 regulates FOXP2 genes in human gastric cancer

ObjectiveTo investigate how microRNA-190 (miR-190) regulates FOXP2 genes in gastric cancer (GC) cell line SGC7901.MethodsWe identified that miR-190 could target FOXP2 genes by using dual luciferase enzyme assay. Precursor fragment transfection of miR-190 was performed with GC cell line SGC7901 and human gastric mucosal cell line GES-1. miR-190 expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) and FOXP2 protein expression was measured by Western blotting.ResultsFOXP2-3′-untranslated region (UTR) in miR-190 transfection group was significantly decreased as compared with other groups. There were no significant differences in fluorescence signals of FOXP2mut-3′-UTR in each group. Therefore, it was assumed that miR-190 can target FOXP2 genes. Through RT-PCR verification, it was observed that the expression level of miR-190 was significantly higher in GC cell line SGC7901 than in human gastric mucosa cell line GES-1 after transfection with miR-190 mimics. The expression level of miR-190 was significantly higher in GES-1 cells than in SGC7901 cells after transfection with miR-190 inhibitors. Western blotting results showed the expression level of FOXP2 was significantly lower in GC cell line SGC7901 than in GES-1 cells. Compared with blank, mimics control, and inhibitors control groups, the miR-190 mimics group showed significantly enhanced proliferation, migration, and invasion abilities, while miR-190 inhibitors group showed decreased abilities toward proliferation, migration, and invasion (P<0.05). The transcription level of miR-190 and the expression level of FOXP2 in tumor tissues and adjacent normal tissues in GC patients were verified to be consistent with those of cell line experiments.ConclusionUpregulation of miR-190 can lead to downregulation of FOXP2 protein expression. miR-190 may serve as a potential target for GC diagnosis.

Epigenetic changes of CDX2 in gastric adenocarcinoma.

Gastric cancer is one of the most commonplace and lethal cancers in the world. Molecular investigation of this disease, in order to obtain diagnostic and treatments achievements is important and vital. Relatively, in this research study, one of the most important epigenetic factors, the methylation of CDX2 gene was investigated in tumoral and non-tumoral tissues of gastric cancer patients by bisulfite treatment followed by sequencing of the 5'UTR region of CDX2 in both tissues. The results indicated a hypomethylation in tumoral tissues of adenocarcinoma. Consequently, the methylation amount of CDX2 in tumoral tissues was significantly reduced compared with non-tumoral tissues.

Prognostic Significance of Carcinoembryonic Antigen Staining in Cancer Tissues of Gastric Cancer Patients.

The aim of this study was to assess the significance of the correlation among tissue carcinoembryonic antigen (CEA) expression with serum CEA (sCEA) levels and long-term survival to highlight the clinical prognostic significance of tissue CEA expression in gastric cancer patients. Immunohistological method and radioimmunoassay were used to assess tissue and sCEA expression, respectively. Univariate and multivariate analyses were performed to determine correlations, and the Kaplan-Meier method was used to investigate the prognostic significance. Our results demonstrate that tissue CEA in gastric cancer is significantly correlated with preoperative sCEA levels (p=0.031), depth of invasion (p=0.001), lymph node metastasis (p<0.001), distant metastasis (p=0.001), and TNM staging (p<0.001). The 5-year survival rates were 67.6, 53.9, and 40.1% for negatively, moderately, and intensely positively stained tissues (p<0.001), and 57.0 and 37.9% for serum with normal and elevated CEA expression (p=0.031). Multivariate analysis revealed that tissue CEA can be considered an independent prognostic factor. Further analysis illustrated that patients with negative expression in both tissue and serum had better prognosis compared with those positively expressing CEA in both tissue and serum and/or those positively expressing CEA in either tissue or serum (p<0.001). Our results also demonstrated that patients with negative tissue CEA staining and elevated sCEA expression had a better 5-year survival. Tissue CEA expression in gastric cancer is directly correlated with sCEA levels and long-term prognosis. Thus, tissue CEA expression can be considered as a useful biomarker to improve the interpretation of sCEA levels in predicting long-term survival.

Integrated Proteomic and Genomic Analysis of Gastric Cancer Patient Tissues.

V-erb-b2 erythroblastic leukemia viral oncogene homologue 2, known as ERBB2, is an important oncogene in the development of certain cancers. It can form a heterodimer with other epidermal growth factor receptor family members and activate kinase-mediated downstream signaling pathways. ERBB2 gene is located on chromosome 17 and is amplified in a subset of cancers, such as breast, gastric, and colon cancer. Of particular interest to the Chromosome-Centric Human Proteome Project (C-HPP) initiative is the amplification mechanism that typically results in overexpression of a set of genes adjacent to ERBB2, which provides evidence of a linkage between gene location and expression. In this report we studied patient samples from ERBB2-positive together with adjacent control nontumor tissues. In addition, non-ERBB2-expressing patient samples were selected as comparison to study the effect of expression of this oncogene. We detected 196 proteins in ERBB2-positive patient tumor samples that had minimal overlap (29 proteins) with the non-ERBB2 tumor samples. Interaction and pathway analysis identified extracellular signal regulated kinase (ERK) cascade and actin polymerization and actinmyosin assembly contraction as pathways of importance in ERBB2+ and ERBB2- gastric cancer samples, respectively. The raw data files are deposited at ProteomeXchange (identifier: PXD002674) as well as GPMDB.

Effect of expression of immunohistochemical marker Ki-67 on the life expectancy of patients with gastric cancer 0-III stages

In Ukraine 60,9% of patients with gastric cancer die within 1 year after ascertainment of diagnosis. Aim: In order to investigate the effect of Ki-67 overexpression on life expectancy, study was conducted among 129 patients with gastric cancer of 0 - III stages, who received treatment in Zaporizhzhia Regional Clinical Oncology Center from June 2006 till October 2013. Methods and results. All patients included in the study underwent radical surgical treatment. 62 patients with gastric cancer (48%) received adjuvant chemotherapy. Immunohistochemical study was performed using monoclonal antibodies Mo a-Hu Ki-67 Antigen, Clone MIB-1. It has been found that the Ki-67 overexpression is observed in 65,9% of the tumor tissue of gastric cancer patients and indicates aggressive process. Conclusion. Using adjuvant chemotherapy among patients with gastric cancer II stage significantly improves the life expectancy (p <0.05) in cases when patients have the presence of high Ki-67 proliferative activity.

Impact of c-erbB-2 protein on 5-year survival rate of gastric cancer patients after surgery: a cohort study and meta-analysis.

To explore the association of c-erbB-2 protein expression with clinicopathological characteristics and prognosis of gastric cancer (GC) after surgery. A total of 133 patients undergoing surgical resection for GC between March 2006 and January 2009 in the Second Affiliated Hospital of Wenzhou Medical University were included in this study. c-erbB-2 protein expression was determined by immunohistochemistry. Afterwards, a meta-analysis was performed to further confirm the association between c-erbB-2 protein expression and GC by employing stringent inclusion and exclusion criteria. All data analyses were conducted with STATA 12.0 and SPSS 19.0. There was no significant difference in c-erbB-2 expression among patients with various parameters including age, gender and histological types (all p>0.05). Among 133 GC patients, 32 patients presented c-erbB-2-positive expression and 101 presented c-erbB-2-negative expression (24.1% vs. 75.9%). The c-erbB-2-positive expression rate was significantly higher in GC tissues of patients with lymph node metastasis than those without. Similarly, a significant increase in c-erbB-2 expression was observed in well/moderately differentiated GC tissues compared with poorly differentiated GC. Patients with negative c-erbB-2 expression had a higher 5-year survival rate than those with positive c-erbB-2 expression, which was consistent with the results of the meta-analysis (OR = 0.54, 95% CI 0.37-0.80, p = 0.002). Our study demonstrated that high expression of c-erbB-2 protein was strongly associated with lymph node metastasis, histological differentiation and 5-year survival rate in GC patients after surgery.

Expression of 17β-hydroxysteroid dehydrogenase type 2 is associated with some clinicopathological features in gastric cancer

In most populations, gastric cancer (GC) incidence is higher in men than in women, which may suggest the role of sex steroid hormones in gastric cancerogenesis. Both, androgens and estrogens can be synthetised in peripherial tissues. This process is controlled by expression of steroidogenic enzymes. Therefore, we evaluate the 17β-hydroxysteroid dehydrogenase type 2 (HSD17B2) transcript and protein levels in gastric tumoral and nontumoral tissue. We also determined the association between HSD17B2 transcript and protein levels and some clinicopathological features in GC. We found significantly decreased levels of HSD17B2 transcript (P=0.00072) and protein (P=0.00017) in primary tumoral tissues of GC patients, as compared to nontumoral tissues. In patients above 60years of age the amounts of HSD17B2 transcript (P=0.00044) and protein (P=0.00027) were significantly lower in tumoral than nontumoral tissues. Similarly, lower HSD17B2 levels, both in terms of the transcript and protein, were observed in tumoral tissues of male (P=0.013, P=0.0014), patients stomach (P=0.0062, P=0.045) and cardia (P=0.02, P=0.02) site of tumor, T3 (P=0.018, P=0.014) depth of invasion, N0 (P=0.017, P=0.045) lymph node metastasis, G3 (P=0.0027, P=0.014) malignancy grade. We also observed significantly reduced level of HSD17B2 transcript in tumoral tissue specimens of females (P=0.014), T4 depth of invasion (P=0.02), N3 lymph node metastasis (P=0.037) and G2 malignancy grade (P=0.045). Furthermore, diffuse GC histological types were associated with lower HSD17B2 protein level (P=0.024) than nontumoral tissues. We demonstrated that HSD17B2 transcript and protein levels are linked to some clinicopathological features in GC.

Prevalence of Helicobacter pylori in Formaldehyde Fixed Paraffin Embedded Gastric Tissues of Gastric Cancer Patients by Scorpion Real-Time PCR Assay

Background: Gastric cancer is the second leading cause of cancer-related deaths worldwide and it seems that environmental and lifestyle factors and infection with Helicobacter pylori (H. pylori) have a major role in the etiology of gastric cancer. Objectives: The aim of this study was to investigate the presence of H. pylori DNA in archival gastric tissues of patients with gastric cancer disease by rapid, sensitive and specific technique of Scorpion real-time PCR. Patients and Methods: This retrospective cross-sectional study was performed during the year 2009, on 285 paraffin embedded gastric specimens of patients, who were pathologically proved to have gastric cancer and were admitted to Bou-Ali, Shahid Rajaie and Dehkhoda Hospitals and Bahar and Farzam Private Laboratory of Qazvin city, Iran. Results: The results of the Scorpion real-time PCR showed that H. pylori DNA was present in 8.42% of the total specimens. Modified McMullen’s staining of paraffin embedded sections were positive in ten patients. There was no significant relationship between the presence of H. pylori, sex, age and place of residence. Conclusions: Although the existence of H. pylori in gastric tissue samples of patients with gastric cancer is controversial however, our results showed that in our studied specimens a significant number of patients with gastric cancer had H. pylori colonization.

Overexpression of NRG1 promotes progression of gastric cancer by regulating the self-renewal of cancer stem cells

Gastric cancer stem cells (GCSCs) have been successfully isolated from patients. However, the molecular mechanisms underlying the self-renewal of GCSCs and their relationship with the microenvironment are poorly characterized. GCSCs and cancer-associated fibroblasts (CAFs) were cultured directly from gastric cancer patients. The self-renewal of GCSCs was assayed by sphere formation assay and in vivo tumorigenicity. Expression of neuregulin1 (NRG1) was examined by immunohistochemistry, real-time PCR and western blotting. CAFs increased the self-renewal of GCSCs by secreting NRG1. NRG1 activated NF-κB signaling and this activation regulated GCSC self-renewal. Moreover, NF-κB-active GCSCs were tumorigenic, however NF-κB-inactive GCSCs were not. The overexpression of NRG1 in stromal cells and cancer cells was observed in the tumor tissues of gastric cancer patients and was associated with clinical stage lymph node metastasis and survival in gastric cancer patients. In addition, we also found that NRG1 can regulate the proliferation and invasion of gastric cancer cells. These results indicate that NRG1, which can be secreted by CAFs or cancer cells, promotes progression of gastric cancer by regulating the self-renewal of GCSCs and its overexpression is associated with a prognosis of gastric cancer.

MicroRNA-25 promotes gastric cancer migration, invasion and proliferation by directly targeting transducer of ERBB2, 1 and correlates with poor survival.

Gastric cancer (GC) is one of the most common tumors and the molecular mechanism underlying its metastasis is still largely unclear. Here, we show that miR-25 was overexpressed in plasma and primary tumor tissues of GC patients with tumor node metastasis stage (III or IV) or lymph node metastasis. MiR-25 inhibition significantly decreased the metastasis, invasion and proliferation of GC cells in vitro, and reduced their capacity to develop distal pulmonary metastases and peritoneal dissemination in vivo. Furthermore, miR-25 repressed transducer of ERBB2, 1 (TOB1) expression by directly binding to TOB1-3'-UTR, and the inverse correlation was observed between the expressions of miR-25 and TOB1 mRNA in primary GC tissues. Moreover, the loss of TOB1 increased the metastasis, invasion and proliferation of GC cells, and the restoration of TOB1 led to suppressed metastasis, invasion and proliferation. The receiver operating characteristics analysis yielded an area under the curve value of 0.7325 in distinguishing the GC patients with death from those with survival. The analysis of optimal cutoff value revealed poor survival in GC patients with high plasma concentrations of miR-25 (>0.2333 amol/μl). Taken together, miR-25 promotes GC progression by directly downregulating TOB1 expression, and may be a noninvasive biomarker for the prognosis of GC patients.

Yin Yang 1 is a target of microRNA-34 family and contributes to gastric carcinogenesis.

Gastric cancer is the second leading cause of cancer-related death worldwide. Herein, we investigated the role of transcription factor Yin Yang 1 (YY1), a multi-functional protein, in tumorigenesis of gastric cancer cells. Results showed that YY1 contributed to gastric carcinogenesis of SC-M1 cells including growth, viability, and abilities of colony formation, migration, invasion, and tumorsphere formation. Levels of pluripotency genes CD44, Oct4, SOX-2, and Nanog were also up-regulated by YY1 in SC-M1 cells. Additionally, the 3'-untranslated region (3'-UTR) of YY1 mRNA was the target of microRNA-34 (miR-34) family consisting of miR-34a, miR-34b, and miR-34c. Overexpression of miR-34 family suppressed carcinogenesis through down-regulation of YY1 in NUGC-3 gastric cancer cells scarcely expressing miR-34 family. Alternatively, knockdown of miR-34 family promoted tumorigenesis via up-regulation of YY1 in SC-M1 and AZ521 gastric cancer cells with higher levels of miR-34 family. The miR-34 family also affected tumorsphere ultra-structure and inhibited the xenografted tumor growth as well as lung metastasis of SC-M1 cells through YY1. Expressions of miR-34a and miR-34c in gastric cancer tissues of patients were lower than those in normal tissues. Taken together, these results suggest that miR-34 family-YY1 axis plays an important role in the control of gastric carcinogenesis.

Ubiquitin ligase Cbl-b represses IGF-I-induced epithelial mesenchymal transition via ZEB2 and microRNA-200c regulation in gastric cancer cells.

BackgroundInsulin-like growth factor I (IGF-I) can induce epithelial mesenchymal transition (EMT) in many epithelial tumors; however, the molecular mechanism by which this occurs is not clearly understood. Additionally, little is known about the involvement of IGF-I in gastric cancer.MethodsTwo gastric cancer cell lines were treated with IGF-I to induce EMT and levels of transcription factor ZEB2 and microRNA-200c (miR-200c) were measured. Cells were treated with Akt/ERK inhibitors to investigate the role of these pathways in IGF-I-mediated EMT. Transfection of shRNA plasmids was used to silence the ubiquitin ligase Cbl-b to assess its involvement in this process. The relationship between IGF-IR and Cbl-b expression, and the effect of IGF-IR and Cbl-b on metastasis were analyzed in primary gastric adenocarcinoma patients.ResultsIGF-I-induced gastric cancer cell EMT was accompanied by ZEB2 up-regulation. Furthermore, both Akt/ERK inhibitors and knockdown of Akt/ERK gene reversed IGF-I-induced ZEB2 up-regulation and EMT through up-regulation of miR-200c, suggesting the involvement of an Akt/ERK-miR-200c-ZEB2 axis in IGF-I-induced EMT. The ubiquitin ligase Cbl-b also ubiquitinated and degraded IGF-IR and inhibited the Akt/ERK-miR-200c-ZEB2 axis, leading to the repression of IGF-I-induced EMT. There was a significant negative correlation between the expression of IGF-IR and Cbl-b in gastric cancer patient tissues (r = -0.265, p < 0.05). More of patients with IGF-IR-positive expression and Cbl-b-negative expression were with lymph node metastasis (p < 0.001).ConclusionsTogether, these findings demonstrate that the ubiquitin ligase Cbl-b represses IGF-I-induced EMT, likely through targeting IGF-IR for degradation and further inhibiting the Akt/ERK-miR-200c-ZEB2 axis in gastric cancer cells.

Up-regulation of neogenin-1 increases cell proliferation and motility in gastric cancer.

Although elevated expression of neogenin-1 has been detected in human gastric cancer tissue, its role in gastric tumorigenesis remains unclear due to the lack of neogenin-1 studies in cancer. Therefore, we demonstrated here the function and regulatory mechanism of neogenin-1 in gastric cancer. Neogenin-1 ablation decreased proliferation and migration of gastric cancer cells, whereas its over-expression reversed these effects. Xenografted analyses using gastric cancer cells displayed statistically significant inhibition of tumor growth by neogenin-1 depletion. Interestingly, galectin-3 interacted with HSF-1 directly, which facilitated nuclear-localization and binding on neogenin-1 promoter to drive its transcription and gastric cancer cell motility. The galectin-3-increased gastric cancer cell motility was down-regulated by HSF-1 depletion. Moreover, the parallel expression patterns of galectin-3 and neogenin-1, as well as those of HSF-1 and neogenin-1, were detected in the malignant tissues of gastric cancer patients. Taken together, high-expression of neogenin-1 promotes gastric cancer proliferation and motility and its expression is regulated by HSF-1 and galectin-3 interaction. In addition, we propose further studies for neogenin-1 and its associated pathways to provide them as a proper target for gastric cancer therapy.

Relationship between promoter methylation of Syk and Runx3 genes and postoperative recurrence and metastasis in gastric carcinoma

To investigate the relationship between aberrant methylation of Syk and Runx3 genes and recurrence and metastasis after resection of gastric cancer. Applying methylation-specific polymerase chain reaction technique, promoter methylation of Syk and Runx3 genes in the tumor tissues and adjacent normal tissues of gastric cancer patients were detected to investigate the relationship between methylation status of the promoter region of Syk and Runx3 genes and postoperative recurrence and metastasis. In the 70 cases of gastric cancer, the frequencies of promoter methylation of Syk and Runx3 genes were 45.7% (32/70) and 55.7% (39/70) in gastric cancer, and 0 (0/70) and 7.1% (5/70), respectively, in the adjacent normal tissues. The rates of promoter methylation of Syk and Runx3 genes in the gastric cancers were significantly higher than that in the adjacent normal tissues (P < 0.001 for all). The promoter methylation of Syk and Runx3 genes was significantly correlated with the degree of tumor differentiation, depth of invasion, lymph node metastasis and pathological staging (P < 0.05 for all). The frequency of postoperative recurrence and metastasis in 32 patients with Syk promoter methylation was 65.6% (21/32) and that in 38 cases with Syk promoter unmethylation was 18.4% (7/38), showing a significant difference between the two subgroups (χ(2) = 16.13, P < 0.001). The rate of postoperative recurrence and metastasis in 39 patients with Runx3 promoter methylation was 61.5% (24/39) and that in 31 patients with Runx3 promoter unmethylation was 12.9% (4/31, P < 0.001). The methylation of Syk and Runx3 promoters plays an important role in postoperative recurrence and metastasis of gastric cancer. Combined detection of promoter methylation of Syk and Runx3 genes is helpful for early diagnosis and evaluation of prognosis of gastric cancer.

Distribution of endothelial progenitor cells in tissues from patients with gastric cancer.

It is accepted that endothelial progenitor cells (EPCs) are recruited into tumor sites and take part in the neovascularization of tumors. However, few articles have discussed the specific distribution of EPCs in vivo in tissues of gastric cancer patients. For this reason, the present study sought to elucidate EPC distribution in vivo in tissues of patients with gastric cancer. Fresh tumor tissues were collected from 26 newly diagnosed patients with histologically confirmed gastric cancer (mean age, 51 years; range, 21–81 years; 7 females, 19 males). All patients were treated surgically with curative intent. One portion of the fresh tissues was prepared for flow cytometric analysis and another was immediately snap frozen in liquid nitrogen and stored at −80°C for later use in quantitative polymerase chain reaction. The analysis was based on two groups of tissues, namely the cancer group and cancer-adjacent group. The presence of CD34/CD133 double-positive cells was determined in cancer-adjacent and cancer tissues by flow cytometry. The analysis revealed that the total number of EPCs in cancer tissue was slightly greater than the number in the cancer-adjacent tissue, but not to the point of statistical significance. The number of EPCs in cancer-adjacent and cancer tissues of patients with early-stage gastric cancer was higher than the EPC count in late-stage gastric cancer patients, and significant differences were identified in the number of EPCs in cancer tissue between patients of different tumor stages. Levels of cluster of differentiation (CD)34, CD133 and vascular endothelial growth factor receptor 2 were not significantly different in cancer-adjacent tissue compared with cancer tissue. These results suggest that cancer-adjacent and cancer tissue of gastric cancer patients may be used as a reference index in the clinical and pathological staging of tumors.

A systematic review and meta-analysis of runt-related transcription factor 3 gene promoter hypermethylation and risk of gastric cancer.

To evaluate the association between runt-related transcription factor 3 (RUNX3) gene promoter hypermethylation and gastric cancer risk by meta-analysis. By searching Medline, EMBASE, Ovid, China National Knowledge Infrastructure and Wanfang databases, the open published articles reporting the relationship between RUNX3 gene promoter hypermethylation, and gastric carcinoma risk, were screened. The aggregated odds ratio of RUNX3 gene promoter hypermethylation in cancerous sample of gastric cancer patients compared to normal gastric tissue of gastric cancer patients was pooled by statistic software STATA-11.0. Sixteen studies include 2631 samples were finally included in this meta-analysis. The aggregated results indicated that the hypermethylation rate in cancerous tissue was much higher than that in normal tissue (55.1% vs. 26.5%, P < 0.05). And the pooled results showed that the RUNX3 gene promoter methylation odds in tumor tissue in gastric cancer patients compared to normal gastric tissue was 5.47 (95% confidence interval: 3.34-8.96). RUNX3 gene promoter hypermethylation rate was much higher in tumor tissue than that in normal gastric tissue in the patient with gastric cancer.

Abstract B196: FGFR3 as a potential target for gastric cancer.

Abstract While trastuzumab against HER-2 over-expression is the only approved targeted therapy against gastric cancer, it is important to find the biologically significant genetic aberrations in most of gastric cancer without HER-2 overexpression. We performed phospho-RTK (receptor tyrosine kinase) array in 25 gastric cancer cell lines, and confirmed fibroblast growth factor receptor 2 and 3 (FGFR2, 3) as one of the highly phosphorylated RTKs. Knockdown of FGFR3 with transfecting small interfering RNA (siRNA) induced the decrement of phospho-FGFR (653/654) in a time-dependent manner in cell lines with highly activated FGFR3, Hs746T and SNU-5. While cell cycle analysis and apoptosis assay showed no significant changes, invasiveness and anchorage-independent growth was inhibited after FGFR3 siRNA transfection. Modulation of downstream signaling molecules was observed by western blot after transfecting FGFR3 siRNA in Hs746T and SNU-5 cell lines in comparing with FGFR2 activated cell lines (KATO III, SNU-16) transfected with FGFR2 siRNA, since previous reports showed that FGFR2 amplification is important in gastric cancer in influencing cell proliferation and survival. Phospho-AKT was down-regulated in both FGFR2 and FGFR3 activated cell lines after specific siRNA transfection, implying that gastric cancer cells with FGFR2 or FGFR3 activation might be both dependent on PI3K-AKT-mTOR pathway. When we treated mice bearing subcutaneous SNU-5 tumor xenografts with oral FGFR inhibitor TKI-258 (70mg/kg daily), TKI-258 treated group showed anti-tumor growth and anti-angiogenic effect compared with control group. Immunohistochemistry (IHC) against FGFR3 among 116 N3 gastric cancer patient tissues showed 3+ in 62.9%, while FGFR2 positivity was only 11.2%. In summary, we identified FGFR3 harbors significant biological role in subset of gastric cancer patients as FGFR2. Further studies for validating the efficacy of FGFR inhibition in preselected subset of patients would support the proper development of FGFR inhibitor in gastric cancer. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B196. Citation Format: Choong-kun Lee, Won Suk Lee, Jeong Min Kim, Myung Eun Lee, Kyu Hyun Park, Tae Soo Kim, Hyo Song Kim, Hei-Cheul Jeung, Hyun Cheol Chung, Sun Young Rha. FGFR3 as a potential target for gastric cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B196.

MiR-17-5p/20a are important markers for gastric cancer and murine double minute 2 participates in their functional regulation

AimTo investigate the potential roles and mechanisms of miR-17-5p/20a in human gastric cancer development and progression. MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was employed to determine miR-17-5p/20a expression profiles in 110 gastric cancer tissues. microRNAs’ (miRNAs) mimics and inhibitors were used to reveal their function in gastric cancer. Antagomirs were applied to treating gastric cancer cell derived xenograft in vivo. Western blot and luciferase assays were performed to uncover the targets and mechanisms of miR-17-5p/20a. ResultsmiR-17-5p/20a levels were upregulated in human gastric cancer tissues. Overexpression of miR-17-5p/20a promoted gastric cancer cell cycle progression and inhibited cell apoptosis, whereas knockdown of miR-17-5p/20a resulted in cell cycle arrest and increased apoptosis. p21 and tumour protein p53-induced nuclear protein 1 (TP53INP1) were validated as the targets of miR-17-5p/20a. Antagomirs against miR-17-5p/20a significantly inhibited gastric cancer growth via upregulation of p21 and TP53INP1 in a mouse xenograft model. The negative relationship between miR-17-5p/20a and TP53INP1 was observed in patient gastric cancer tissues. Murine double minute 2 (MDM2) was found to be involved in miRNA regulation and function. Targeted inhibition of MDM2 in a miRNA mimic-transfected gastric cancer cell line abolished miR-17-5p/20a function and inhibition of p21 expression. MDM2 restoration by pCMV-MDM2 rescued the functionality. ConclusionsOur findings indicate that miR-17-5p/20a promote gastric cancer cell proliferation and inhibit cell apoptosis via post-transcriptional modulation of p21 and TP53INP1. They may be promising therapeutic markers for gastric cancer. MDM2 contributes to miR-17-5p/20a function and inhibition of p21 in gastric cancer, and may be a novel mechanism underlying the oncogenic roles of miR-17-5p/20a.