Analysis of microsatellite instability in stool DNA of patients with colorectal cancer using denatur

AIM: To evaluate the usefulness of denaturing high performance liquid chromatography (DHPLC) for analyzing microsatellite instability (MSI) status in stool DNA of patients with colorectal cancer.METHODS: A total of 80 cancer tissues from patients with primary sporadic colorectal tumor (proximal cancer:27, distal cancer: 53) and matched stool (which were employed for comparison with the tissues) were analyzed for MSI status in BAT 26. DNA samples extracted from stool were evaluated by nested polymerase chain reaction (PCR) and DHPLC for MSI analysis.RESULTS: Six cases (7.5%) of MSI were identified in BAT 26 from 80 cancer tissues. All the stool DNA samples from patients whose cancer tissue showed MSI also displayed MSI in BAT 26.CONCLUSION: As MSI is one of the established fecal DNA markers to screen colorectal cancer, we propose to use DHPLC for the MSI analysis in fecal DNA.