Study On The Expression And The Correlation With Clinicopathological Factors Of Runx3 In Gastric Carcinoma Tissues

Objective: Study on the expression of tumor suppressor gene Runx3 in gastric carcinoma tissues and the correlation with clinicopathological factors by the RT-PCR method. Methods: Fifty-six primary gastric carcinoma tissues and normal gastric mucosa tissues were obtained from 56 stomach cancer patients by surgical resection between June, 2004 and June, 2005 in the 1st hospital of Lanzhou University. RT-PCR were performed for analysis of the expression of tumor suppressor gene Runx3 in gastric carcinoma and normal gastric mucosa tissues. Results: Runx3 mRNA was not detected in 62.5% (35/56) of the gastric carcinoma, but it was detected in 96.4% (54/56) of normal gastric mucosa tissues. In addition, the inactivation of Runx3 has notable significant correlation with clinicopathological factors, such as: depth of tumor infiltration. Conclusion: Novel gene, Runx3, is a candidate tumor suppressor gene and plays an important role in gastric carcinoma. Testing for Runx3 expression should become useful in gastric carcinoma early detection and diagnosis and estimation of prognosis.Part II: Study on the status of promoter hypermethylation of tumor suppressor gene Runx3 in gastric carcinoma, by the MSP method Objective: Study on the status of aberrant promoter hypermethylation in gastric carcinoma tissues, which induces the epigenetic inactivation of tumor suppressor gene, Runx3. And analyse the correlation between aberrant DNA methylation and clinicopathological factors in gastric carcinoma. Methods: Methylation-specific PCR(MS-PCR) were used for analyzing the status of aberrant promoter methylation of tumor suppressor gene, Runx3 in fifty-six primary gastric carcinoma tissues and normal gastric mucosa tissues, obtained from 56 stomach cancer patients by surgicalresection between June, 2004 and June, 2005 in the 1st hospital of Lanzhou University. Results: MS-PCR analysis demonstrated that Runx3 promoter region hypermethylation was found in 67.9% (38/56) of gastric carcinoma tissues. Methylation was detected only in 5.4% (3/56) of normal gastric mucosa tissues. In 88.6% of Runx3-nonexpressing gastric carcinoma tissues were methylated at the CpG sites in the promoter. Aberrant promoter hypermethylation of Runx3 correlated with depth of tumor infiltration. Conclusion: Runx3 inactivation might be caused by epigenetic and genetic mechanisms in gastric carcinoma. Aberrant promoter methylation may play a critical role in gastric carcinoma and might be involved in the progression of the disease. Testing for Runx3 methylation should become useful in gastric carcinoma early detection and diagosis and could be utilized as a molecular marker to estimate the pronosis of gastric carcinoma, should provide a new idea for treatment.