EVALUATION OF DNA-POLYMERASE BETA-GENE MUTATION AS A GENETIC-MARKER FOR COLORECTAL-CARCINOMA

DNA polymerase beta is known to be involved in repair of DNA damage. F requent mutation of its gene in the segment encoding amino acids 149-2 97 has been reported in colorectal cancer. To investigate whether muta tion in this region is available as a genetic marker for colorectal ca ncer, 11 primary tumors and 4 liver metastases from 11 patients were e xamined by fragment length analysis and single-strand conformation pol ymorphism (SSCP) analysis of reverse-transcription polymerase chain re action (RT-PCR) products. Although allelic imbalance in the p53 and DC C genes were observed in ten out of eleven primary tumors and all live r metastases using a dinucleotide repeat polymorphism, mutation was no t detected in the DNA polymerase beta mRNA. Neither was it detected in seven colon cancer cell lines. Present results suggest that mutation in this region is uncommon in colorectal cancers and is not a useful g enetic marker for colorectal cancer.