Allele-specific chromosome 9p deletion in oral cancer

Abstract

OBJECTIVE: The aim of this study was to investigate the relationship between loss of heterozygosity (LOH) on chromosome 9p and the pathogenesis of oral squamous cell carcinoma (OSCC). METHODS: A total of 24 human OSCC specimens were analyzed for LOH on chromosome 9p using 8 microsatellite markers by means of polymerase chain reaction. RESULTS: In 24 cases of OSCC, LOH on chromosome 9p was identified in 10 of 24 cases (41.67%) with at least one marker. The main LOH were found on 9p21 at locus D9S171 (21.05%) and D9S304 (10.00%). There were also a deletion on 9p22-23 at locus D9S168 (22.22%) and D9S162 (15.38%). However, there was no statistically significant correlation between LOH at these loci with such clinical parameters as pathological types, tumor size and lymph-node metastasis. Microsatellite instability (MSI) is rare for any of the 8 markers in 24 OSCC. No MSI could observed using the common criteria for defining MSI-its detection in two or more markers. CONCLUSION: We found that high frequency of LOH occurred at 9p21-23 band. Their results indicate that more than one tumor suppressor genes at chromosome 9p21-23 region related to a subset of OSCC, while MSI might not be a crucial event.