K-ras exon 2 point mutations in human endometrial cancer

In the present study, we screened for the K-ras exon 2 point mutations in a group of 87 gynecological neoplasms (82 endometrial carcinomas, four carci nomas of the uterine cervix and one uterine carcinosarcoma) using the non-i sotopic PCR-SSCP-direct sequencing techniques. Direct sequencing analysis r evealed CAA --> CAC (Gln --> His) K-ras codon 61 point mutations in two (2. 4%) of the 82 endometrial carcinomas mentioned above. These two cases were endometrial endometrioid carcinomas at an early clinical stage of disease ( stage IB and IC due to FIGO). Those endometrial carcinomas that showed K-ra s exon 2 point mutations revealed a strong positivity for heterogeneous nuc lear retinoblastoma protein staining; none of these, however, have had the K-ras codon 12 point mutation. In addition, there were no K-ras gene point mutations in three endometrial carcinomas lacking the Rb protein immunohist ochemically. None of the cervical carcinomas tested had K-ras gene point mu tations, whereas one carcinosarcoma harbored K-ras codon 61 point mutation (CAA --> CAC). In conclusion, our data support the view that K-ras exon 2 p oint mutations are rare events in human endometrial cancer. Rb and K-ras ge ne abnormalities may occur independently of each Ether during endometrial c arcinogenesis in humans. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.