Tumor Suppressor Gene Smad4Methylation And Abnormal Expressing In Gastric Cancer In The Xinjiang Kazak

Objective:To study the relationship between the smad4protein expression and biologicalbehavior of gastric carcinoma in Kazak. Preliminary study the relationshipbetween the smad4gene and gastric carcinoma in Kazak and find the smad4methylation sites which played an important role in the Kazakh.Methods:1. Use westernblot to detecte smad4protein in120cases gastric tissues；2. Use MALDI-TOF MS mehthod to detect smad4promoter methylation in120casesgastric tissuesResults:1. The results of westernblot: compared with the kazak normal gastric mucosatissues, in the kazak gastric cancer tissue and Smad4protein expressionsignificantly lower than the kazakh normal gastric mucosa tissues (P <0.05);(2) the kazakh gastric cancer group compared with the han nationality, kazakin gastric cancer tissue，Smad4protein expression significantly lower thanhan Chinese gastric cancer tissue (P <0.05);(3) compared with normal gastricmucosa tissues with the han nationality and the han nationality in gastriccancer tissue and Smad4protein expression significantly lower than the hannormal gastric mucosa tissues (P <0.05).2. The results of MALDI-TOF MS mehthod for detection of methylation:(1) Thekazak gastric cancer group compare with the kazakh normal gastric mucosa ofcontrol group, the kazak gastric cancer group average unit of Smad4genepromoter CpG methylation rate was higher than the kazakh normal gastricmucosa, average unit of Smad4gene promoter CpG methylation levels were38.4%and23.9%respectively, there was no statistically significant difference,P>0.05);(2) the Han gastric cancer group compare with the han normal gastricmucosa of control group, the han nationality gastric cancer group averageunit of Smad4gene promoter CpG methylation rate is higher than the hannormal gastric mucosa, average unit of Smad4gene promoter CpG methylationlevels were26.5%and21.7%respectively (P>0.05, no statisticallysignificant differences)；(3) the kazak gastric cancer group compare withthe han gastric cancer group, the kazak gastric cancer group average unitof Smad4gene promoter CpG methylation rate is higher than han Chinese gastriccancer group, the average unit of Smad4gene promoter CpG methylation levelswere38.4%and26.5%respectively (P>0.05, no statistically significantdifferences)；(4) both in the kazak and han ethnic group, gastric cancer groupof smad4gene promoter region CpG unit3-4and CpG10-11methylation ratein the two loci were higher than in normal mucosa, smad4gene promoter region with CpG3-4and CpG10-11units of these two unit of CpG methylation stateaverage methylation level in kazak gastric cancer group and the kazakh normalcontrol group were34.84%,7.87%, the average methylation level issignificantly higher than that of normal control group, average unit of CpGmethylation rate difference was statistically significant (P <0.05);(5)respectively, smad4gene promoter CpG unit3-4and CpG10-11units of thesetwo CpG methylation state average methylation in the Han gastric cancer groupand the han normal control group were19.18%,20.33%and10.90%，19.18%, boththe average methylation level is significantly higher than that of normalcontrol group, average unit of CpG methylation rate difference wasstatistically significant (P <0.05);(6) respectively,smad4gene promoterwith CpG3-4and CpG10-11units of these two unit of CpG methylation stateaverage methylation level in the kazak gastric cancer group and han Chinesegastric cancer group were34.84%,19.18%and34.84%,20.33%,the averagemethylation levels of the gastric cancer group was obviously higher than thatof han Chinese gastric cancer group, the average unit of CpG methylation ratedifference was statistically significant (P <0.05).Conclusion:1. Smad4protein expression of change is likely to cause the occurrence ofgastric cancer, and is one of the important molecular mechanism in the xinjiangkazak high incidence of gastric cancer.2. Indicating that smad4gene promoter region methylation may is the smad4protein expression decreased the main mechanism.3. Smad4gene promoter region with CpG3-4and CpG10-11units of these two unitof CpG methylation Configuration changes may is the kazak gastric cance ofthe pathogenesis in xinjiang.4. Suggesting that smad4gene promoter region CpG with CpG3-4and CpG10-11unitsof these two unit of CpG methylation status change may lead to the occurrenceof gastric cancer.