SCREENING OF HUMAN BLADDER-TUMORS AND URINE SEDIMENTS FOR THE PRESENCE OF H-RAS MUTATIONS

A series of 111 human bladder tumors were screened using oligonucleoti de mutant specific probes, restriction enzyme analysis and single-stra nded confirmation polymorphism (SSCP) for the presence of H-ras activa tion events. Thirty-three tumors were found to harbor H-ras mutations where a glycine to valine (G --> T) change in codon 12 was the most co mmon point mutation recorded (26 tumors). Additional mutations involve d glycine to cysteine at codon 13 (2 tumors) and glutamine to arginine /lysine/leucine at codon 61 (3/1/1 tumors, respectively). Ambiguous si gnals recorded with oligonucleotide probes were further analyzed using SSCP analysis revealing the presence of H-ras mutations in restricted regions of some tumors. The apparent sensitivity of SSCP enabled us t o extend this study to DNA isolated from urine sediments where 4 of th e 9 patients studied showed representation of mutant H-ras. Our study demonstrates a sensitive, non-invasive assay for the screening of urin e-borne cells, with no requirement for prior knowledge of the mutation al change at the H-ras locus. (C) 1993 Wiley-Liss, Inc.