Deletional Mapping of 2q21-37 Region in Oral Cancer

Tumor suppressor genes are defined as genetic elements whose loss or mutational inactivation allows cells to display one or more phenotypes of neoplastic growth. Frequent deletion in a chromosomal region suggests existence of a candidate tumor suppressor gene. We analyzed Ch2q21-37.3 region by using 17 polymorphic microsatellite markers in 39 matched oral normal and cancer tissues. Loss of heterozygosity (LOH) was detected at least one location in 36 of 39 (92%) tumor tissues. High deletions were detected at microsatellite marker locations, D2S2304 (35%), D2S111 (40%), D2S155 (35%), D2S164 (29%), D2S125 (71%) and D2S140 (39%). Three frequently deleted regions at 2q22, 2q35-36 and 2q37.3 were observed. Chromosomal 2q22-37.3 region is highly populated with genes. Several candidate tumor suppressor genes in this region including such as ING5, CASP8, CASP10, PPP1R7 and BOK are located. We are currently analyzing inactivation mutations and mRNA expressions in oral squaomus cell carcinomas.