Two putative tumor suppressor genes on chromosome arm 8p may play different roles in prostate cancer

Although loss of heterozygosity (LOH) on the short arm of chromosome s has been frequently observed in human prostate cancer, the relationship between LOH and clinical background is poorly understood. Fluorescence in situ hyb ridization (FISH) was employed to evaluate the chromosomal deletion on 8p i n 42 prostate cancers using a centromeric probe for chromosome 8, in combin ation with 4 cosmid probes spanning 8p12 to 8p22 Deletions for at least one locus on the 8p were observed in 29 (69.0%) tumors. The most frequently de leted regions were 8p22 (55.&%) and 8p21.3 (52.4%). in almost the same freq uency. The second most frequently deleted region was 8p21.1-p21.2 (38.1%). Deletions of 8p22 and Sp21.3 significantly correlated with tumor grade (P=0 .0034), Fishers exact probability test. A significantly higher frequency of the deletion on 8p21.1-p21.2 was observed in advanced prostate cancer (bey ond capsular penetration or positive nodal metastases) than in localized pr ostate cancer (P=0.0033). Ln particular, deletion of 8p21.1-p21.2 was more frequently observed in the cases with lymph node metastases than without th em (P=0.0029). No clinicopathological parameters had significant relation t o deletions on 8p12, These results suggest that deletions on 8p22-p21.3 pla y an important role in tumor differentiation, while an 8p21.1-p21.2 deletio n plays a role in the progression of prostate cancer. (C) 2001 Elsevier Sci ence Inc. All rights reserved.