No association between the microsatellite polymorphism (TTTTA)n in the promoter of the CYP11A gene and ovarian hyperstimulation syndrome

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.

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

The present work attempts to determine the distribution of CYP11A (TTTTA)n genotype and allele frequencies in 10 European and North African populations. This polymorphism has been associated with hyperandrogenism by several association studies. To our knowledge, this is the first study investigating the ethnic variation of this polymorphism. DNA was extracted from 868 whole-blood samples with the standard phenol-chloroform technique, and PCR reactions were carried out using fluorescent primers as described previously. PCR products were analyzed by an ABI 3,730 DNA Analyzer. A total of six alleles were identified, ranging from 220 bp (4 repeats [4R]) to 250 bp (10R). The most frequent allelic fragment size in all populations was 4R, with frequencies ranging from 47.9% (Sicily) to 62.8% (Tuscany and Germany). Allelic frequencies showed high heterogeneity between analyzed populations. We detected a significant gradient for alleles 4R and 8R. In this study, we report the allele frequency distribution of CYP11A (TTTTA)n showing a north-south geographic gradient. This result could be useful for epidemiological studies about hyperandrogenism.