The carcinogenesis and development is a progress of multi-gene alterations in the humangastric cancer (HGC). In order to determine the relation between the aberraion of these genes and gastriccancer, we chose c-met (7q3l), hMLHl (3p2l)、 E-cadherin (16q22.l) and HLA Ioci DQA1、 DR2、DR3、 DR4、 DR7、DR9 and detected their changes in 32 tumor specimens of inteStinal tyPe HGC and 4cell lines of gastric cancer by performing analysis of SSP/PCR PCR/SSCP and MSI technigUes. Our datashow that none point mutation was detected in c-met gene. We examined two microatllitos loci D3S 1298and D3S1561 in hMLH 1 gene and detected that 6 cases retan MSI (Microsatellitc Instability) and 2 casesof LOH (Loss of Heterozygosity) at D3S 1298 and 2 cases of MSI at D3S1561. We also examined E-cadherin gene at two microsatellites loci D 16S3083 and D 16S3095 close to the gche and for that 5 casesretain MSI and 1 case of LOH at D16S3O83 and no change at D16S3095. The Point mndon incidence ofHLA-DR4 loci is 9/20 (45%), higher than the 0ther 10ci in HLA- I. High frequen deletion, expressionderegulation and methylation of mtsl/pl6 gene were detected in cell lines and solid tomors from humangastric cancer patients.Our data showed that the point mutation of c-met gene is not-the main pattern of aiteration in intestinaltype HGC that is consistent with the previous results. E-cadherin and hMLHl are related to intestinaltype HGC but whether they are susceptibility gene still need further study. The point mutation of theHLA-Ⅱ loci DR4 is closely related to intestinal type HGC. Methylation pf mtsl/Pl6 gene 5 CpG islandmight be plays an important role in the carcinogenesis in HGC.
