LACK OF SYNERGISTIC ASSOCIATION BETWEEN HUMAN PAPILLOMAVIRUS AND RAS GENE POINT MUTATION IN LARYNGEAL CARCINOMAS

The spectrum of human papillomavirus (HPV) subtypes in laryngeal carci nomas was investigated by combined polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. HPV DNA was detect ed in 11 (24%) of 45 cases, including HPV 16 in 9 cases and HPV 18 in 2 cases. Other HPV subtypes commonly found in the female genital organ s were not detected. In addition, the point mutation of codons 12 and 13 in c-Ki-ras-2, c-Ha-ras-1, and N-ras genes was studied by the PCR-s ingle-strand conformational polymorphism (SSCP) method. Of 45 cases te sted, only 1 had a point mutation of c-Ki-ras-2 gene at codon 12. Thes e results indicate that the incidence of ras gene point mutation is un common and that the synergistic effect of HPV infection and ras gene a ctivation in laryngeal carcinogenesis is probably rare.