Immunogenetics of prostate cancer and benign hyperplasia--the potential use of an HLA-G variant as a tag SNP for prostate cancer risk

Human leukocyte antigen G (HLA-G) is an immunomodulatory molecule with important roles both physiologically as well as an escape mechanism of cancer cells. In this study, we evaluated the impact of eight polymorphisms at the 3' untranslated region (3'UTR) of the HLA-G gene in the development of prostate cancer (PCa) and benign prostatic hyperplasia (BPH). A total of 468 DNA samples of Brazilian men predominantly Euro-descendant with PCa (N = 187), BPH (N = 152) and healthy control individuals (N = 129) were evaluated. The HLA-G 3'UTR region was amplified by polymerase chain reaction (PCR), sequenced and genotyped to identify the 14 bp insertion/deletion (rs371194629), +3003T/C (rs1707), +3010C/G (rs1710), +3027A/C (rs17179101), +3035C/T (rs17179108), +3142G/C (rs1063320), +3187A/G (rs9380142) and +3196C/G (rs1610696) polymorphisms. Regression logistic and chi-square tests were performed to verify the influence of single nucleotide polymorphisms (SNPs) in PCa and/or BPH susceptibility, as well as in PCa progression (clinicopathological status). Our data showed the UTR-4 haplotype as a risk factor to PCa in comparison with control [odds ratio (OR) 2.35, 95% confidence interval (CI) 1.39-3.96, P adjusted = 0.003) and BPH groups (OR 1.82, 95% CI 1.15-2.86, P adjusted = 0.030). Further, the 'non-14bp Ins_ + 3142G_+3187A' haplotype (OR 1.56, 95% CI 1.10-2.20, P adjusted = 0.036), the +3003CT genotype (OR 4.44, 95% CI 1.33-4.50, P adjusted = 0.032) and the +3003C allele (OR 2.33, 95% CI 1.38-3.92, P adjusted = 0.016) also conferred susceptibility to PCa. Our data suggest an important influence of HLA-G 3'UTR polymorphisms in PCa susceptibility and support the use of the +3003 variant as a tag SNP for PCa risk.

Predicting Homo pigmentation phenotype through genomic data: from Neanderthal to James Watson

BACKGROUND

Human pigmentation is regulated by several genes acting at different stages of melanin formation. Functional and association studies have elucidated the role of several of these genes in pigmentation phenotypes. Forensic and evolutionary studies can benefit from this knowledge.

OBJECTIVES

To evaluate the reliability of the prediction of pigmentation phenotypes using a large database of genetic markers in individuals with known phenotypes; and from this try to predict the pigmentation phenotype of prehistoric Homo specimens and of contemporary individuals whose visible phenotypes are not known.

METHODS

We compared predicted and observed phenotypic data through an analysis of 124 single nucleotide polymorphisms in 33 genic and seven intergenic regions of 30 subjects, five of them prehistoric, whose complete nuclear genomes are available in UCSC and PSU UCSC public databases.

RESULTS

For the molecular predicted versus observed phenotypes, the percentage of agreement was as follows: freckles: 91; skin: 64; hair: 44; eyes: 36; total: 59; while the molecular predicted versus probable (no visible observation available; inferences based on ethnic population characteristics) it was, respectively, 83, 60, 42, 67, and 63. The difference between two sets is statistically nonsignificant (P = 0.75).

CONCLUSION

To our knowledge, this is the first article to examine the effect of a large number of genetics markers for phenotype prediction. The approach could be useful for forensic applications, as well as for the determination of possible phenotypes of extinct prehistoric individuals.