Detection of microsatellite instability in gastric cancer and dysplasia tissues.

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.