Genomic instabilities in squamous cell carcinoma of head and neck from the Indian population

Intrinsic genomic instability of an incipient tumor cell drives the development of cancer. In colorectal cancer, an inverse relationship between microsatellite instability (MIN) and chromosomal instability (CIN) has been reported. The relationship between MIN and CIN in head and neck squamous cell carcinoma (HNSCC) is uncertain. In the present study, we examined these two types of instabilities in HNSCC using microsatellite markers and arbitrary primed PCR (APPCR) technique. HNSCC tumors showed high frequency of MIN and loss of heterozygosity (LOH). We observed that, in contrast to colorectal tumors, the frequency of LOH increased with the increase in MIN. There was no significant difference between MIN- and MIN+ groups of HNSCC tumors in the extent of overall genomic alterations; rather higher MIN+ tumors exhibited higher incidence of deletion. Thus, in sporadic HNSCC, both MIN and CIN pathways operate simultaneously to drive tumor formation.