Infrequent mutations of the WT1 gene in primary cancers of the adult urinary tract.

Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis of all of the ten exons of the WT1 gene and restriction fragment length polymorphism (RFLP) analysis of the WT1 locus were performed on primary urinary tract cancers: seven renal pelvic cancers, one ureteral cancer, 11 bladder cancers, and 22 renal cell cancers. Four human bladder cancer cell lines (T24, JTC30, JTC32, and HUB41) and three human prostate cancer cell lines (PC-3, DU145, and LNCaP) were also examined. None of the primary cancers showed any apparent mutations of the gene, whereas one base substitution of exon 5 was found in DU 145 and gross alteration of the gene was recognized in HUB41. Heterozygosity of polymorphic exon 7 was retained in all of the 12 informative cases, and none of 10 informative cases showed loss of heterozygosity at the WT1 locus in RFLP analysis. It is concluded that mutations of the WT1 gene may not be involved in the formation of malignant tumors of the adult urinary tract.