DELETION ANALYSIS AT THE DEL-27, APC AND MTS1 LOCI IN BLADDER-CANCER - LOH AT THE DEL-27 LOCUS ON 5P13-12 IS A PROGNOSTIC MARKER OF TUMOR PROGRESSION

Inactivation of relevant tumor-suppressor genes by allelic or homozygo us deletion is a characteristic event in tumor cells, Here, the progno stic value of allelic deletions on 5p13-12 at the putative del-27 tumo r-suppressor locus and in the APC tumor-suppressor gene on 5q21, as we ll as homozygous deletions of the MTSI (p/6(INK4), CDKN 2) tumor-suppr essor gene on 9p21 was assessed in 87 bladder cancers using microdisse ction and PCR-based assays, Tumor-specific LOH was detected in 10 of 3 8 (26%, del-27), and 15 of 30 (50%, APC) informative specimens. Homozy gous deletion of the MTSI gene was detected in 33% of 84 tumors invest igated. These deletion frequencies implicate the 3 tumor-suppressor re gions in the genesis of transitional-cell carcinoma. In contrast to de letions of the APC or MTSI genes, LOH at the del-27 locus correlated w ith tumor progression. This suggests that loss of the putative tumor-s uppressor gene DEL-27 is involved in an aggressive behavior of the tum or cells and appears to be a prognostic marker for the clinical outcom e of patients with transitional-cell carcinoma. (C) 1997 Wiley-Liss, I nc.