Abstract

Point mutations of c-K-ras in ovarian cancer were detected by replacement of GGT of codon 12 by GAT, AGT, TGT and GTT, polymerase chain reaction, agarose gel electrophoresis and Southern blot hybridization with a digoxigenin detection system. The incidence of four-typed point mutations of c-K-ras oncogene in 37 ovarian cancers was 35.1% (13/37) and the distributions were 32.4% (12/37), 2.7% (1/37), 0% and 0% of GGT to GAT, GGT to AGT, GGT to TGT, and GGT to GTT, respectively. The incidence of c-K-ras point mutations on codon 12 among 37 patients with ovarian cancer was 35.5% (8/22) in those with serous cystadenocarcinomas and 28.6% (2/7) in those with mucinous cystadenocarcinomas. c-K-ras point mutations on codon 12 were detected in 14.3% (1/7) of patients with stage I disease, 28.6% (2/7) with stage II disease, and in 43.5% (10/23) with stage III/IV disease, and there was a statistically significant increase in point mutations of c-K-ras oncogene with advancing clinical stage. The incidence of c-K-ras point mutations on codon 12 among 33 patients who had a pelvic lymph node dissection was 52.4% (11/21) in those with pelvic lymph node metastases and 16.7% (2/12) in those without pelvic lymph node metastases, a statistically significant difference. Furthermore, point mutation of c-K-ras gene was found most frequently in patients with advanced stage disease, and in those with pelvic lymph node metastases. Activation of c-K-ras oncogene seems to be a major factor in ovarian carcinogenesis and tumor progression.