Aims The aim of this study was to evaluate the mismatch repair gene expression and their correlation with NF-kB in patients with oral squamous cell carcinoma (SCC).

Methods Total RNA was isolated from 28 biopsy samples. A control group was composed of 20 volunteers. Differential expression of hMSH2, hMSH6 and NF-kB genes was accessed by quantitative PCR.

Results There is increased expression of all the analysed genes when the patients were smokers and alcoholics. In addition, there is increased expression of hMSH2 when SCC was removed from the base of the tongue. There was a correlation between NF-kB and hMSH2 and hMSH6 as well as between repair genes hMSH2 and hMSH6 expression levels. There is increased expression of the hMSH2 gene in patients with SCC, especially in the alcoholics.

Conclusions There is a strong indication that NF-kB gene was expressed along with the studied repair genes, evidencing the possibility that this system can be activated by the inflammatory pathway.