Many polymorphisms in genes, such as ELAC2 (locus HPC2), RNase L (locus hereditary prostate cancer 1 gene [HPC1]), and MSR1 have been recognized as important genetic factors that confer an increased risk of developing prostate cancer in many populations.
Early linkage results have provided targeted candidate regions for prostate cancer susceptibility loci, including HPC1 on chromosome 1q23-25, PCAP on chromosome 1q42-43, CAPB on chromosome 1p36, linkage to chromosome 8p22-23, HPC2 on chromosome 17p, HPC20 on chromosome 20q13, and HPCX on chromosome Xq27-28.
The present study suggested that the common variants in the HPC2/ELAC2 gene play a limited role in the risk of prostate cancer in the Japanese population.
The ELAC2 gene has been proposed to be a prostate cancer susceptibility gene and is being referred to as HPC2, in part because three case-control studies suggested that two common polymorphisms (Ser217Leu and Ala541Thr) are associated with risk.
We tested for possible associations between the two HPC2 gene variants and prostate cancer risk in incident prostate cancer cases (199) and healthy male controls (525) from the Calgary region.
To determine the contribution of two HPC2/ELAC2 missense variants (Ser217Leu and Ala541Thr) to the risk of developing prostate cancer, we conducted a population-based case-control study of middle-aged men (40-64 years).
Prostate cancer susceptibility loci that have been reported so far include HPC1 (1q24-q25), PCAP (1q42-q43), HPCX (Xq27-q28), CAPB (1p36), HPC20 (20q13), HPC2/ELAC2 (17p11) and 16q23.
We conclude that HPC2 genotyping is unlikely to be a useful adjunct to PSA in the prediction of the presence of biopsy-detected prostate cancer in asymptomatic men.
Three prostate cancer susceptibility genes have been reported to be linked to different regions on chromosome 1: HPC1 at 1q24-25, PCAP at 1q42-43, and CAPB at 1p36.
There is, however, little evidence for excess clustering of the T allele within the multiplex families known to be segregating this allele, and there is no evidence for linkage of prostate cancer to the HPC2/ELAC2 region of chromosome 17p11.2 in these families.
The results of this study lead us to reject the three alternative hypotheses of (1) a highly penetrant, major prostate cancer-susceptibility gene at 17p11, (2) the allelic variants Leu217 or Thr541 of HPC2/ELAC2 as high-penetrance mutations, and (3) the variants Leu217 or Thr541 as low-penetrance, risk-modifying alleles.
These results suggest that common variants at HPC2/ELAC2 are associated with CaP risk in a sample unselected for family history or other factors associated with CaP risk.