[Germline polymorphisms of Bat26 and its significance in gastric cancer microsatellite instability].

Objective: To detect the germline polymorphic variations of Bat26 in Chinese and its significance in microsatellite instability (MSI) study of gastric cancers.

Methods: Bat26 was analyzed by PCR-based denatured polyacrymide gel electrophoresis-silver stain method in peripheral blood from 389 healthy people and 34 gastric cancers with matched normal mucosa. Eleven other microsatellite loci were also detected for gastric cancers.

Result: (1) No Bat26 variations were identified in 423 genomic DNA from peripheral blood or normal mucosa by polyacrymide gel electrophoresis. (2) Two MSI-H cancers, oth Bat26+, were detected in 34 cases of gastric cancer. The alterations of Bat26 and MSI-H status were identical (P<0.05). (3) Compared with those of RER-cancers, MSI-H (RER+)cancers showed more obvious infiltration of intraepithelial lymphocytes and peri-tumoral lymphocytes, and more pushing borders (P<0.05).

Conclusion: (1) The germline polymorphisms of Bat26 in Chinese people are quasimonomorphic. Thus, no matched genomic DNA is needed while Bat26 was selected for tumor MSI analysis. (2) Bat26 is an independent indicator of MSI-H gastric cancers with distinct clinicopathological features.