A simple method to reveal possible ras mutations in DNA of urinary sediment cells.

Occupational and environmental exposure to carcinogens is reported to be responsible for 25% of all bladder tumors. Among many genetic alterations found in tumor bladder cells, chromosome aberrations and mutations of some oncogenes, such as ras genes, are common. Studies conducted to determine the rate and type of ras mutations involved reported rather contrasting results. Researchers agree that among the three members of the ras family, only H-ras is subject to mutations, mostly at codon 12. The rate of these mutations is still under investigation, although it has been evaluated as being between 6 and 76%. Using various techniques, some studies have shown that when a ras mutation occurs in a bladder tumor, it is also present in urinary sediment cells of the same patient. We suggest a simple method to directly detect ras mutations at codon 12 in urinary sediment.