Localization of H-ras mRNA in oral squamous cell carcinomas

Expression of the H-ras oncogene was examined in 5 SCC of the oral cavity. The presence of oncogene mRNA was detected and localized in the tumor tissue by in situ hybridization. Tumor tissues were also examined for the presence of the oncogene product, p21, by immunohistochemical techniques. H-ras mRNA and p21 were detected in all 5 tumors in cells that were also positive for both keratin mRNA and keratin protein. The distribution of the mRNA was not uniform throughout the tumor tissue. Distinct spatial localizations of the H-ras mRNA were present in regions of the tumors with both higher proliferative and invasive potential. The results suggest that the distribution of the oncogene mRNA may be related to the pattern of development and progression of oral SCC.