INFREQUENT SOMATIC ALTERATION OF P16 MTS1 IN HUMAN PRIMARY SUPERFICIAL BLADDER CANCERS/

Although superficial bladder cancer, usually presenting as low grade t ransitional cell carcinomas, are easily resected by transurethral inte rvention, their frequent recurrence and progression of satage or grade of the recurrent tumors in some cases is a major problem in urology. Deletion of chromosome 9, bands 9p21-22 in bladder cancers including t he lowest grade and stage, suggest potential location of candidate tum or suppressor genes. Recently, p16/MTS1 was isolated from 9p21-22 as a multiple tumor suppressor gene, which regulates the cyclin dependent kinase 4 in the G1/S phase of the cell cycle. In the present study, so matic alterations of p16/MTS1 were examined concentrating on histologi cally defined superficial bladder carcinomas by polymerase chain react ion (PCR)-single strand conformation polymorphism (SSCP) technique usi ng paraffin embedded materials. Infrequent alterations of p16/MTS1 in superficial bladder cancers, one deletion and one silent mutation in 1 5 cases, were detected. The results suggest that p16/MTS1 mutation is not involved in the development of superficial urinary bladder carcino mas.