Frequencies of promoter pentanucleotide (TTTTA)n of CYP11A gene in European and North African populations

Molecular basis for prostate cancer racial disparities

Prostate cancer (PCa) remains the most common cancer in American men. African-American (AA) men continue to have higher PCa prevalence and mortality rates compared to men in other populations. In addition to socioeconomic factors and lifestyle differences, molecular alterations contribute to this discrepancy. We summarize molecular genetics research results interrelated with the biology of PCa racial disparity. Androgen and androgen receptor (AR) pathways have long been associated with prostate growth. Racial differences have also been found among variants of genes of the enzymes involved in androgen biosynthesis and metabolism. Growth factors and their receptors are a potential cause of the disparity in PCa. Recent molecular and biotechnological approaches in the field of proteomics and genomics will greatly aid the advancement of translational research on racial disparity in PCa, which may help, in finding new prognostic markers and novel therapeutic approaches for the treatment of PCa in AA.

Repeat polymorphisms in estrogen metabolism genes and prostate cancer risk: results from the Prostate Cancer Prevention Trial

The etiology of prostate cancer remains elusive, although steroid hormones probably play a role. Considering the carcinogenic potential of estrogen metabolites as well as altered intraprostatic estrogen biosynthesis during the development of prostate cancer, we investigated associations between repeat polymorphisms of three key estrogen-related genes (CYP11A1, CYP19A1, UGT1A1) and risk of prostate cancer in the Prostate Cancer Prevention Trial (PCPT), designed to test finasteride versus placebo as a chemoprevention agent. Using data and specimens from 1154 cases and 1351 controls who were frequency matched on age, family history of prostate cancer and PCPT treatment arm, we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) separately in the placebo and finasteride arms. Among men in the placebo arm, CYP19A1 7/8 genotype carriers had a significantly higher risk of prostate cancer compared with those with the 7/7 genotype (OR = 1.70, 95% CI = 1.16-2.5), regardless of Gleason grade. This genotype was also associated with elevated serum estrogen levels. For the (TA)(n) repeat polymorphism in UGT1A1, the heterozygous short (<7 repeats)/long (≥7 repeats) genotype was significantly associated with the risk of low-grade prostate cancer (OR = 1.34, 95% CI = 1.05-1.70) compared with the short/short genotype. No significant association was found with CYP11A1. These associations were not observed among men in the finasteride arm. The results indicate that repeat polymorphisms in genes involved in estrogen biosynthesis and metabolism may influence risk of prostate cancer but that their effects may be modified by factors altering hormone metabolism, such as finasteride treatment.

The presence of the CYP11A1 (TTTTA)6 allele increases the risk of biochemical relapse in organ confined and low-grade prostate cancer

The involvement of the CYP11A1 gene in the synthesis of androgens makes it a compelling candidate for various hormone-dependent diseases, including prostate cancer. A microsatellite polymorphism (TTTTA)n in the promoter region of the CYP11A1 gene has been reported to be associated with an increased risk of metastatic and high-grade prostate cancer. In the present study of 110 prostate cancer patients and 96 population controls, we examined the association between the CYP11A1 (TTTTA)n polymorphism and prostate cancer risk, aggressiveness, and incidence of biochemical relapse after prostatectomy. We have also evaluated the potential of the (TTTTA)n polymorphism as a microsatellite marker for the detection of genomic instability in prostate cancer. A strong association of the genotype containing the (TTTTA)6 allele with the occurrence of biochemical relapse after prostatectomy in patients with organ confined prostate cancer (p<0.0001), as well as in patients with low-grade prostate cancer (p=0.002) or both (p<0.0003) was determined. The incidence of biochemical relapse in patients with organ confined and low-grade prostate cancer in our study group was 22%, but increased to 50% in carriers of the (TTTTA)6 allele. Our findings also suggest (TTTTA)n instability as a potential marker for the detection of early events in carcinogenesis.