Objective: We aimed to investigate the association between gastric cancer and microsatellite instability (MSI) in the present study.
Method: Phenol-chloroform method was employed for DNA extraction from the cancer tissues of 65gastric cancer patients and the dysplasia tissues and normal control tissues of 32 non-gastric cancer patients. The microsatellite loci Bat25, Bat26, D2S123, D5S346 and D17S250 were detected by using PCR-SSCP silver staining technique, and the MSI of the gastric cancer tissues and the precancerous tissues was analyzed.
Results: Of 65 gastric cancer cases, MSI was detected in 43 cases, with the detection rate of 66.2%. There were 13 cases showing MSI-H and 30 cases showing MSI-L, accounting for 30.2% and 69.8%, respectively. Among 32 cases of dysplasia tissues, MSI was detected in 10 cases, with the detection rate of 31.3%. Two cases of dysplasia tissues showed MSI-H and 8 cases showed MSI-L, accounting for 20.0% and 80.0%, respectively.
Conclusion: Gastric cancer patients had a high detection rate of MSI. It is speculated that MSI is another molecular mechanism of carcinogenesis and may serve as a sensitive diagnostic indicator of gastric cancer.
Keywords: Gastric cancer; PCR-SSCP analysis; microsatellite instability.