DEVELOPMENT OF PAPILLARY RENAL-CELL TUMORS IS ASSOCIATED WITH LOSS OFY-CHROMOSOME-SPECIFIC DNA-SEQUENCES

Twenty-two papillary renal cell tumours were analysed by Southern hybr idization using eight DNA probes from homologous regions of the X and Y chromosomes and two Y-chromosome-specific DNA probes. Sixteen of the 19 papillary renal cell tumours of male patients showed the loss of Y -chromosome-specific sequences. No loss of heterozygosity was detected in three tumours that developed in females. The frequency of loss of the Y chromosome was established in 50 non-papillary renal cell carcin omas as well. Only seven of the 31 non-papillary renal cell carcinomas obtained from male patients had lost the Y-chromosome-specific sequen ces, whereas no allelic loss was found in 19 non-papillary tumours obt ained from female patients. Papillary renal cell tumours show a strong male preponderance (6:1) and loss of Y chromosome in 84 per cent of t he cases, whereas non-papillary renal cell carcinomas show only a slig ht male preponderance (1.5:1) and the Y chromosome is lost in only 22 per cent of the cases. These data suggest that a tumour suppressor gen e is localized at one of the homologous regions of the X and Y chromos omes, the homozygous inactivation of which is associated with the deve lopment of papillary renal cell tumours.