HMSH2 gene alterations associated with recurrence of oral squamous cell carcinoma.

Oral cancer, one of the ten most widespread cancers in Thailand, is a major public health problem. The aim of the study was to assess hMSH2 and hMLH1 gene mutations, microsatellite DNA alterations, and investigate the association between these alterations and clinicopathological features of oral squamous cell carcinomas (SCC) in a sample of Thai patients. Microsatellite alterations at D2S391, D3S647, D17S513, and D17S520 were detected at a frequency of 40.6%. Among these alterations, 12.5% exhibited loss of heterozygosity (LOH) at D3S647 and D17S513, while 34.4% exhibited microsatellite instability (MI) at D2S391, D17S513, and D17S520. Polymorphic change in the intronic region of hMSH2 at IVS 1 nt 211+9, c-->g was observed in 50% of cases. Significant correlation was observed between IVS 1 nt 211+9 polymorphism and the recurrence status of the patients (p = 0.030, OR = 10.67). This study demonstrated that the polymorphism of hMSH2 at IVS 1 nt 211+9 (c-->g) was associated with oral cancer recurrence status and could be used as a biomarker for prognosis and follow-up treatment of oral cancer.