DNA-POLYMERASE BETA-GENE MUTATIONS IN HUMAN BLADDER-CANCER

We examined 24 human bladder cancer tissues for possible mutations in the entire coding region of the human DNA polymerase beta gene using p olymerase chain reaction analysis, single-strand conformational polymo rphism analysis of RNA, and sequence analysis. DNA polymerase beta gen e mutations were observed in four of the 24 cases (16.7%) and included three missense point mutations and a single base insertion. The singl e base insertion was also observed in our previous study of human pros tate cancer, suggesting that this region may be a hot spot for mutatio n of the DNA polymerase beta gene. No clinical or pathological associa tion was found among the four cases that contained the mutation. Three of the four cases with DNA polymerase beta gene mutation had mutation s of the p16 or RE genes or loss of heterozygosity of the p53 and APC gene loci. The results of the study presented here suggest that DNA po lymerase beta gene mutations, in combination with mutations of tumor s uppressor genes, may be involved in certain cases of human bladder can cer. (C) 1996 Wiley-Liss, Inc.