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Gastric cancer is one of the most common cancers in our country. Although a declined incidence has been observed in recent years, the gastric cancer is still contributed to the highest mortality among the malignant tumors. Most of the patients with gastric cancer die from tumor invasion, metastasis and recurrence. The metastasis of tumor is a major factor influencing the tumor therapeutic efficacy, as well as an insidious process in vivo and not easily observed. The clinicians paid more attention on the consequence of the metastasis, and learned less about the biological process of tumor metastasis.The occurrence, development and metastasis of tumor are complex pathologic processes, involving multi-stages evolution and multi-genes modulation. To study the molecular mechanism of tumor, to learn about the related genes in different phases during development of tumor, and to detect the expressions of these genes on mRNA and/or protein levels, have become the hot spots, which are contribute to molecular pathological diagnosis, judgement of clinical prognosis and selection of treatment plans.There have been many genes observed participating the development of gastric cancer, for example, EGFR, bFGF, MMPS, E-CD and MDR1. The expression of each gene takes place under the background of other genes expressions. Traditionally, the study on gastric cancer metastasis was limited to a single gene, and couldn’t reflect the potential of gastric cancer metastasis.On the other hand, results were diversified by different lab standards, so the comparability on the same level was poor. In this study, we converted the investigation from a single gene expression to multi-genes expressions mode. Claudini, cx43, CYR61, NOV and snail were selected and the expression of these five genes on both mRNA and protein levels were detected. Claudini and cx43 are important junction proteins that make up the intercellular junction. CYR61 and NOV are secreted, cysteine-riched and heparin-binding proteins, included in CCN gene family. Snail is a zinc-finger transcription factor and a member of snail super-family. The expressions of these genes altered variably in different tumors. In gastric carcinoma, up to the present, the reports about the expressions of these five genes, claudini, cx43, CYR61, NOV and snail, have been seldom.In this study, tissue chip (TC), also named tissue microarray (TMA) was untilized. TC is a newly developed molecular biologic technique based on cell morphology. It provides a high-flux, multi-samples and quick analysis tool for molecular biology.100 cases of gastric cancer samples between 1995 and 2000 were collected from the first hospital of Shaoxing. 25 samples collected from normal gastric ulceration tissues served as controls. Tissue microarrays were made based on the HE slices diagnostically proven by pathological experts. mRNA expressions of claudini, cx43, CYR61, NOV, snail and protein expressions of claudini and cx43 were examined by In situ hybridization and immunohistochemistry, respectively.Experiment data, clinicalpathologic feature and follow-up material were analyzed statistically by SPSS 13.0. x2 test> Spearman rank correlation analysis, Kaplan-Meier survival curve analysis and log-rank test were used. The level of statistical significance was defined as P<0.05.In situ hybridization results indicated that the expression rate of claudini, cx43 and NOV mRNA in gastric carcinoma / non-cancer gastric mucosa were 42%(42/100) / 100% (25/25), 35% (35/100) / 88% (22/25) and 50% (50/100) /64% (16/25), respectively. There was a significant negative relationship between claudini mRNA expression and TNM stage (r= -0.303, P= 0.015), invasion depth(r = -0.259, P = 0.021), vessel invasionCr = -0.312, P = 0.002) and lymph node (r = -0.307, P =0.002) . There was a significant negative relationship between cx43 mRNA expression and tumor diameter(r = -0.377, P = 0.000) , TNM stage (r = -0.306, P = 0.021), invasion depth (r = -0.288, P = 0.016), vessel invasion (r = -0.206, P =0.039), lymph node (r = -0.258, P =0.010) and distant metastasis (r = -0.235, P =0.019), and there was also a negative relationship between NOV mRNA expression and invasion depth (r =-0.262, P = 0.009) and differentiation (r =-0.244, P = 0.015) . The mean survival time and 5 year survival rate in cases with positive claudini mRNA and cx43 mRNA expression were significantly longer than that of negative cases. However, there was no significant relationship between NOV mRNA expression and survival time, and NOV could not act as an indicator of gastric cancer prognosis. The expression of CYR61 mRNA and snail mRNA in gastric carcinoma / non-cancer gastric mucosa were 37% (37/100) / 4% (1/25) and 46% (46/100) /16% (4/25), respectively. There was a positive relationship between CYR61 mRNA expression and tumor diameter (r=0.318, P= 0.001 ), TNM stage (r= 0.331, P= 0.007), invasion depth (r = 0.253, P = 0.014) , lymph node (r = 0.285, P = 0.004) . There was also a significant positive relationship between snail mRNA expression and TNM stage (r= 0.176 ,P= 0.027 ), differentiation (r = 0.203, P = 0.042), vessel invasion (r = 0.208, P = 0.038) and lymph nodeCr = 0.299, P = 0.003). The mean survival time and 5 year survival rate in cases with positive CYR61 mRNA and snail mRNA expression were significantly shorter than that of negative cases. Cox analyze suggested that claudini might be used as independent prognosis parameter (OR=0.036) .Immunohistochemistry results revealed that the expression rate of claudini protein and cx43 protein in gastric carcinoma /non-cancer gastric mucosa were 43%/100% and 40%/92%, respectively. There was a significantnegative relationship between claudini protein expression and tumor diameter (r = -0.207, P = 0.039 ) , invasion depth (r = -0.292, P = 0.013) , TNM stage (r = -0.371, P = 0.002), vessel invasion (r = -0.333, P = 0.001), lymph node (r =-0.366, P = 0.002) and distant metastasis (r =-0.249, P = 0.013) . There was a significant negative relationship between cx43 protein expression and tumor diameter (r = -0.208, P = 0.037) , invasion depth (r = -0.279, P = 0.012) , TNM stage (r = -0.346, P = 0.002) , vessel invasion (r = -0.352, P = 0.000) , lymph node (r = -0.351, P = 0.000) , distant metastasis(r = -0.223, P = 0.026)and nerve invasionCr = -0.286, P = 0.004). The mean survival time and 5 year survival rate in cases with positive claudini and cx43 protein expression were significantly longer than that of negative cases.In conclusion, we found that claudini, cx43 and NOV inhabited the growth, invasion, metastasis and recurrence of gastric cancer, while CYR61 and snail promoted the processes. There were some relationships between expressions of these genes. These five genes can be used as indexes to direct the clinical treatment and estimate the prognosis of gastric cancer.
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