Low frequency of allelic imbalance at the prostate cancer susceptibility loci HPC1 and 1p36 in Swedish men with hereditary prostate cancer

The aim of this study was to investigate allelic imbalance at the major hum an prostate cancer susceptibility locus HPCI at Iq24-25 and the recently re ported, putative, susceptibility locus at Ip36 in prostate tumors from Swed ish families with hereditary prostate cancer. We analyzed 31 prostate tumor s and two lymph node metastases from 33 Swedish men in 22 families with her editary prostate cancer for the presence of allelic imbalance using microsa tellite markers DISI58, DIS422, and DIS238 for the HPCI locus and DISI597, DIS407, and DIS489 for the Ip36 locus. Frequencies of allelic imbalance at the two investigated loci were quite low, 3 of 27 informative tumors at the Ip36 locus and 3 of 27 informative tumors at the HPCI locus. interestingly , two tumors showed allelic imbalance at both loci investigated, suggesting that they may have lost a great part of chromosome I. Taking this possibil ity into consideration, the specific loss of the two investigated loci may be even tower (I of 27 informative rumors for either locus). The very low l evel of allelic imbalance found at HPCI and Ip36 makes it unlikely that the se loci encode genes that are acting as classic tumor suppressor genes in t he initiation or progression of hereditary prostate cancer. Of the eight tu mors from HPCI-linked families, only two showed Al at the HPCI locus, one o f which had lost the wild-type allele. (C) 2000 Wiley-Liss, Inc.