Prostate cancer susceptibility genes influenced by ethnicity
MedWire News: US research findings confirm the involvement of ELAC2, MSR1, and RNASEL genes in the risk for development of prostate cancer, and show that the risk varies according to ethnicity.
The effect of these previously recognized susceptibility genes on prostate cancer risk also appears to be cumulative, report the Texas-based researchers in the journal Cancer Epidemiology Biomarkers and Prevention.
“This is the first association study to cover the three susceptibility genes for prostate cancer with haplotype-tagged single nucleotide polymorphisms (SNPs),” write Robin Leach and colleagues from the University of Texas at San Antonio.
“Our findings suggest that interactions among these genes likely confer prostate cancer risk consistent with a polygenic model for cancer susceptibility,” they add.
The team genotyped 41 SNPs covering the three genes in a case–control cohort of 1436 Caucasian men, 596 of whom had prostate cancer, 648 Hispanics, 194 of whom had prostate cancer, and 270 African Americans, 82 with prostate cancer.
The researchers determined the allele frequency for each SNP by ethnic group and compared the results with men who did not have prostate cancer.
In all, five SNPs (three in MSR1 and two in ELAC2) were significantly associated with prostate cancer risk among Caucasians, with the strongest associations seen for rs12718376 in MSR1 and rs11545302 in ELAC2 with odds ratios of 0.32 and 2.19, respectively.
In addition, a major haplotype G-A-C-G-C-G combining five SNPs within MSR1 gave Caucasian men a significant 1.58-fold increased risk for prostate cancer.
Among Hispanic men, three SNPs within RNASEL and one within MSR1 were significantly associated with prostate cancer risk, and two SNPs within MSR1 were significant among African–American men.
The researchers also noticed a cumulative effect of SNPs on prostate cancer risk in the cohort, with possession of both rs351572 and rs11545302 in Caucasians conferring a 2.31-fold risk increase for prostate cancer, and the combination of three SNPs conferring a 3.31-fold increased risk in Hispanic men. No cumulative effect was observed among African–American men, however.
Leach et al conclude: “The function of these genes in cellular defense against inflammation and oxidative stress is supportive of a possible interaction between these genes, which also corroborates previous suggestions that infection and prostate cancer could be linked.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
By Sarah Guy