Preliminary Study On Promoter Hypermethylation Of BLU Gene In Gastric Cancer

Objective The hypermethylation of tumor suppressor genes (TSG) is believed tobe the main mechanism for inactivating the TSG and lead to the development of tumor.In this study, by detecting gastric cancer and paracancerous tissues of gastric cancer, therate difference between peripheral blood and normal peripheral blood hypermethylationso as to explore the BLU gene promoter hypermethylation in gastric carcinoma patients.Methods Collecting92cases of gastric carcinoma,92cases of paracanceroustissues,79cases of gastric carcinoma in peripheral blood,79cases of normal humanperipheral blood and applying methylation-specific PCR，MSP to measure their BLUgenes methylation levels and methylation status. Combining with clinical data, apreliminary study of the correlation between hypermethylation of BLU gene in patientsand their gender, age, tumor size, degree of differentiation, lymph node metastasis, TNMstaging, degree of invasion. Secondly, using reverse transcription PCR, RT-PCR) todetect BLU gene expression of mRNA, and analyzing of the relationship between theexpression of mRNA state and BLU gene hypermethylation.Results Ⅰ.92cases of gastric carcinoma BLU gene hypermethylation rate is higherthan92cases of carcinoma adjacent tissue hypermethylation rate （67.39%vs.52.17%）.The different rate of BLU hypermethylation was significantly between gastriccancer tissue specimens and para-carcinoma tissue ones（P<0.05）. Ⅱ. BLU promoterhypermethylation was not correlated with sex, age, tumor size, tumor differentiationdegree, TNM stage and depth of infiltration. However, BLU hypermethylation wasrelated with node metastasis (P>0.05), Ⅲ.92cases of human gastric carcinoma BLUmRNA negative expression rate was higher than that of92cases of carcinoma adjacenttissue of mRNA negative expression rate of BLU(33.7%vs.10.9%) and the different expression rate of BLU mRNA was significantly between gastric cancer tissue specimensand para-carcinoma tissue ones（P<0.05）. Ⅳ.In the92tumor tissues, hypermethylationrate of BLU gene mRNA negative ones is higher than that of positive ones(80.6%vs60.7%).The different rate of BLU hypermethylation was not significantly(P>0.05).Ⅴ. Ithas no Statistical significance that79cases of BLU gene promoter in peripheral blood in patients withstomach cancer rate is higher than that of79cases of normal peripheral blood hypermethylation rate（P>0.05）.Conclusion Ⅰ.BLU gene promoter hypermethylation in gastric cancer are highlymethylated in tissue, suggesting that BLU gene might be associated with tumorsuppressor gene inactivationⅡ.. Hypermethylation of BLU may be involved inlymphatic metastasis of gastric cancer.Ⅲ. In the BLU mRNA loss of individualexpression, the hypermethylation frequency of BLU gene was significantly increased, butstatistically significant correlation between gastric cancer BLU gene in tumor tissuemRNA expression and its hypermethylation status was not obvious(P>0.05)Ⅳ.. BLUpromoter CpG island hypermethylation in the peripheral blood of gastric cancer shows nosigificance.Further study is needed.