Restriction fragment length polymorphism and activation of c-Ha-ras gene in urothelial cancer.

The human c-Ha-ras gene shows restriction length polymorphism (RFLP) due to the variable tandem repetition (VTR) of DNA sequences in the 3'-flanking region. It was suggested that RFLP of the c-Ha-ras gene may be useful in detecting individuals at risk of cancer. In vitro studies showed transcriptional enhancer and promoter activities in the VTR region. In some human tumors, the loss of one c-Ha-ras allele is observed. We discuss here the possible role of VTR and allelic deletion of the c-Ha-ras allele in primary human cancers in relation to c-Ha-ras expression, and the usefulness of c-Ha-ras RFLP in the risk assessment of urothelial cancer.