Jiyou Li

Comprehensive analysis of the gene expression profiles in human gastric cancer cell lines.

Gastric adenocarcinoma is one of the major malignancies worldwide. Gastric cell lines have been widely used as the model to study the genetics, pharmacology and biochemistry of gastric cancers. Here we describe a comprehensive survey of the gene expression profiles of 12 gastric carcinoma cell lines, using cDNA microarray with 43u200a000 clones. For comparison, we also explored the gene expression patterns of 15 cell lines derived from lymphoid, endothelial, stromal and other epithelial cancers. Expression levels of specific genes were validated through comparison to protein expression by immunohistochemistry using cell block arrays. We found sets of genes whose expression corresponds to the molecular signature of each cell type. In the gastric cancer cell lines, apart from genes that are highly expressed corresponding to their common epithelial origin from the gastrointestinal tract, we found marked heterogeneity among the gene expression patterns of these cell lines. Some of the heterogeneity may reflect their underlying molecular characteristics or specific differentiation program. Two putative gastric carcinoma cell lines were found to be B-cell lymphoma, and another one had no epithelial specific gene expression and hence was of doubtful epithelial origin. These cell lines should no longer be used in gastric carcinoma research. In conclusion, our gene expression database can serve as a powerful resource for the study of gastric cancer using these cell lines.

Post-operative imatinib in patients with intermediate or high risk gastrointestinal stromal tumor.

AIMSnThis study aims to determine whether adjuvant treatment with imatinib improves recurrence-free survival (RFS) in Chinese patients undergoing complete resection of localized primary gastrointestinal stromal tumor (GIST) compared with those not receiving adjuvant therapy. We also sought a correlation between c-KIT mutations and RFS.nnnMETHODSnPatients who had undergone complete tumor resection with intermediate or high risk of recurrence were enrolled in a single-center, non-randomized, prospective study. Patients either received adjuvant imatinib therapy (400 mg once-daily) for 3 years or did not. Mutation analyses of c-KIT were performed on available archival tumor samples.nnnRESULTSn105 patients were enrolled: 56 in the treatment group and 49 in the control group. Median follow-up was 45(43.1-46.9) months. RFS at 1, 2 and 3 years were higher in the treatment group than in the control group (100% vs. 90% at 1 year; 96% vs. 57% at 2 years; 89% versus 48% at 3 years, P < 0.001, HR = 0.188). Subgroup analyses showed that adjuvant therapy significantly decreased the risk of recurrence in patients whether at high risk or at intermediate risk compared with control patients (3-year RFS: 95% vs. 72%, in intermediate risk; 85% versus 31% in high risk; P < 0.001). In addition, imatinib adjuvant treatment decreased the risk of death (P = 0.025, [corrected] HR = 0.254).nnnCONCLUSIONSnAdjuvant imatinib can improve 1-, 2- and 3-year RFS rates in patients at intermediate or high risk of recurrence after complete tumor resection.nnnCLINICAL TRIALS REGISTRATION NUMBERnChiCTR-TCC-00000582.

S100A6 overexpression is associated with poor prognosis and is epigenetically up-regulated in gastric cancer.

S100A6 has been implicated in a variety of biological functions as well as tumorigenesis. In this study, we investigated the expression status of S100A6 in relation to the clinicopathological features and prognosis of patients with gastric cancer and further explored a possible association of its expression with epigenetic regulation. S100A6 expression was remarkably increased in 67.5% of gastric cancer tissues as compared with matched noncancerous tissues. Statistical analysis demonstrated a clear correlation between high S100A6 expression and various clinicopathological features, such as depth of wall invasion, positive lymph node involvement, liver metastasis, vascular invasion, and tumor-node metastasis stage (P < 0.05 in all cases), as well as revealed that S100A6 is an independent prognostic predictor (P = 0.026) significantly related to poor prognosis (P = 0.0004). Further exploration found an inverse relationship between S100A6 expression and the methylation status of the seventh and eighth CpG sites in the promoter/first exon and the second to fifth sites in the second exon/second intron. In addition, the level of histone H3 acetylation was found to be significantly higher in S100A6-expressing cancer cells. After 5-azacytidine or trichostatin A treatment, S100A6 expression was clearly increased in S100A6 low-expressing cells. In conclusion, our results suggested that S100A6 plays an important role in the progression of gastric cancer, affecting patient prognosis, and is up-regulated by epigenetic regulation.

Overexpression of Endothelial Cell Specific Molecule-1 (ESM-1) in Gastric Cancer

BackgroundThe endothelial cell-specific molecule-1 (ESM-1) gene is involved in various biological events. This study was designed to clarify its clinical significance and explore its biological behavior in gastric cancer (GC).MethodsESM-1 mRNA expression was evaluated by real-time PCR in GC (nxa0=xa034) and matched adjacent normal tissues (nxa0=xa014). The expression of ESM-1 protein was investigated by immunohistochemistry in GC (nxa0=xa0159) and matched normal tissues (nxa0=xa040), and its correlation with the clinicopathological features and overall survival of patients was analyzed. Microvessel density (MVD) in GC was assessed by anti-CD34 and the pattern of ESM-1 expression in tumor-related vascular was evaluated. The effect of ESM-1 promotion of proliferation in the GC MKN28 cell line and human microvascular endothelial cell line HMEC-1 were tested using the MTT assay.ResultsESM-1 mRNA was significantly overexpressed in GC compared with adjacent noncarcinoma controls (Pxa0<xa00.01). ESM-1 protein was predominantly expressed in GC. ESM-1 expression was associated with distant metastasis and Borrmann type IV (Pxa0<xa00.05) and was strongly associated with vascular invasion (Pxa0=xa00.0057). Patients with ESM-1 expression showed lower 5-year survival rate (Pxa0=xa00.0339). Multivariate analysis revealed that ESM-1 was an independent prognostic factor. In GC, CD34-MVD of GC vessels positively expressing ESM-1 was higher than that of GC with negative vessels expression of ESM-1 (Pxa0<xa00.05). Besides, ESM-1 antibody dose-dependently impaired MKN28 and HMEC-1 growth.ConclusionsESM-1 is overexpressed in GC and can serve as a tumor biomarker to predict survival of GC patients, and it might promote tumor angiogenesis and growth in GC and, hence, may represent a potential therapeutic target.

Phospholipase A2 group IIA expression correlates with prolonged survival in gastric cancer

Xing X‐F, Li H, Zhong X‐Y, Zhang L‐H, Wang X‐H, Liu Y‐Q, Jia S‐Q, Shi T, Niu Z‐J, Peng Y, Du H, Zhang G‐G, Hu Y, Lu A‐P, Li J‐Y, Chen S & Ji J‐F u2028(2011) Histopathology59, 198–206

Presence of S100A9-positive inflammatory cells in cancer tissues correlates with an early stage cancer and a better prognosis in patients with gastric cancer

BackgroundS100A9 was originally discovered as a factor secreted by inflammatory cells. Recently, S100A9 was found to be associated with several human malignancies. The purpose of this study is to investigate S100A9 expression in gastric cancer and explore its role in cancer progression.MethodsS100A9 expression in gastric tissue samples from 177 gastric cancer patients was assessed by immunohistochemistry. The expression of its dimerization partner S100A8 and the S100A8/A9 heterodimer were also assessed by the same method. The effect of exogenous S100A9 on motility of gastric cancer cells AGS and BGC-823 was then investigated.ResultsS100A9 was specifically expressed by inflammatory cells such as macrophages and neutrophils in human gastric cancer and gastritis tissues. Statistical analysis showed that a high S100A9 cell count (>u2009=u2009200) per 200x magnification microscopic field in cancer tissues was predictive of early stage gastric cancer. High S100A9-positive cell count was negatively correlated with lymph node metastasis (Pu2009=u20090.009) and tumor invasion (Pu2009=u20090.011). S100A9 was identified as an independent prognostic predictor of overall survival of patients with gastric cancer (Pu2009=u20090.04). Patients with high S100A9 cell count were with favorable prognosis (Pu2009=u20090.021). Further investigation found that S100A8 distribution in human gastric cancer tissues was similar to S100A9. However, the number of S100A8-positive cells did not positively correlate with patient survival. The inflammatory cells infiltrating cancer were S100A8/A9 negative, while those in gastritis were positive. Furthermore, exogenous S100A9 protein inhibited migration and invasion of gastric cancer cells.ConclusionsOur results suggested S100A9-positive inflammatory cells in gastric cancer tissues are associated with early stage of gastric cancer and good prognosis.

CMTM3 inhibits cell migration and invasion and correlates with favorable prognosis in gastric cancer

The CKLF‐like MARVEL transmembrane domain containing 3 (CMTM3) gene is a novel tumor suppressor with frequent epigenetic inactivation. In this study, we showed the role played by CMTM3 in gastric cancer cells as a tumor suppressor gene, and examined the correlation between CMTM3 expression and clinicopathological parameters using immunohistochemistry in gastric cancer patients with different pathological stages (n = 350). We found that CMTM3 expression was reduced or silenced by epigenetic regulation in gastric cell lines, and dramatically downregulated in primary gastric cancer tissues. Restoration of CMTM3 significantly affected migration and invasion of AGS and SGC‐7901 cells (P < 0.001). In vivo experiments showed that peritoneal disseminated metastases were significantly suppressed by CMTM3 (P < 0.001). We further showed that the expression of MMP2 and the phosphorylation of Erk1/2 were decreased when CMTM3 was restored. In addition, by immunohistochemical staining, we found that the expression of CMTM3 was remarkably weaker in gastric cancer tissues than in normal mucosae (P = 0.008), and was significantly correlated with gender (P = 0.033), tumor depth (P = 0.049), stage (P = 0.021), and histological grade (P = 0.022). More importantly, CMTM3 expression was associated with prognosis in gastric cancer patients (P = 0.041), and was a significant independent prognostic indicator (hazard ratio = 0.704, 95% confidence interval, 0.498–0.994; P = 0.046). Our findings indicate that CMTM3 regulates migration and invasion of gastric cancer cells. Moreover, CMTM3 is a candidate marker for prognosis of gastric cancer in the clinic.

Neoadjuvant chemotherapy with FOLFOX: improved outcomes in Chinese patients with locally advanced gastric cancer.

Although the role of peri‐operative chemotherapy is established in the treatment of locally advanced gastric cancer, the optimal regime remains to be determined. FOLFOX has been used in palliative setting with good response rates but its role in a neoadjuvant setting is not well established.

PTK7 as a novel marker for favorable gastric cancer patient survival.

Protein tyrosine kinase 7 (PTK7) plays important functions in several cancer types but its expression in gastric cancer remains unknown. This study was designed to investigate PTK7 expression in gastric cancer.

Coexistence of gastrointestinal stromal tumors and gastric adenocarcinomas.

The purpose of this study is to detect the clinicopathology of gastrointestinal stromal tumors (GISTs) occurring synchronously with gastric adenocarcinomas and to unveil the potential underlying relationship between the synchronous GIST and gastric adenocarcinoma. This study included 15 patients with incidental GISTs found during operations for gastric adenocarcinoma and 30 patients who underwent gastrectomy for gastric cancer without discovering GIST between January 2005 and December 2010 at the Beijing Cancer Institute. We collected the clinicopathological data and analyzed the KIT/PDGFRA mutational status of GISTs, corresponding gastric adenocarcinoma specimens, and the normal tissue around the cancer lesions. Additionally, as a control group, the mutational status of the patients with gastric adenocarcinoma and no other tumors was assayed. Overall, 18 GISTs were found in 15 gastric adenocarcinoma patients. Multiple GIST lesions were found in three cases (20xa0%). The patients’ age ranged from 46 to 85xa0years, with an average of 67.6xa0years. The average size of the GISTs was 0.85xa0cm. All mesenchymal lesions showed low proliferative activity, were of low or very low risk, and were identified as CD117-positive by immunostaining. In GIST lesions, mutations in KIT were detected in 7 out of 13 cases, and of these mutations, 6 were found in exon 11 (46.2xa0%), and 1 was found in exon 9 (7.7xa0%). A total of five deletions and one point mutation were in exon 11, and one insertion was in exon 9. Mutations were not detected in exon 17 or 13 of KIT. There was no remarkable mutation analyzed in the gastric adenocarcinoma lesions or normal tissues from either the test or control groups. Clinicopathological profiles and molecular analysis of KIT/PDGFRA showed no obvious relationship between gastric cancer and GISTs in tumor genesis, such as similar oncogene mutations.