Steroid metabolism gene polymorphisms and their implications on breast and ovarian cancer prognosis.

A role for estrogen in the etiology of breast and ovarian cancers has been suggested; therefore, genetic polymorphisms in steroid metabolism genes could be involved in the carcinogenesis of these tumors. We have aimed to investigate the role of GSTP1 and CYP17 polymorphisms and their correlation with MSI (microsatellite instability) and LOH (loss of heterozygosity) in AR, ERß and CYP19 genes in women from Espírito Santo State, Brazil. The study population consisted of 107 female breast and 24 ovarian tumors. GSTP1 and CYP17 polymorphisms were detected by polymerase chain reaction (PCR) amplification followed by restriction fragment length polymorphism (RFLP) analysis while MSI and LOH were analyzed by PCR. GSTP1 and CYP17 polymorphisms alone were not associated with an increased risk for breast or ovarian tumors. However, when combined with MSI/LOH in AR, ERß and CYP19 genes, we were able to detect significant associations with the GSTP1 wild-type genotype in PR (progesterone receptor) negative breast cancers or the CYP17 wild-type genotype in ER (estrogen receptor) and PR-negative breast tumors. No associations with ovarian tumors were detected. Our results suggest that wild-type GSTP1 or CYP17 genes when combined with LOH/MSI in steroid metabolism genes may play a role in ER and/or PR negative breast cancers. These data support the hypothesis that genes related to steroid metabolism are important in the characterization of breast cancer and that the analysis of single polymorphisms may not be sufficient.

Molecular epidemiology of HFE gene polymorphic variants (C282Y, H63D and S65C) in the population of Espírito Santo, Brazil.

Hereditary hemochromatosis (HH) is an autosomal recessive disorder that leads to progressive iron accumulation and may cause cirrhosis, hepatocellular carcinoma, diabetes, and heart failure. Most cases of HH have been linked to mutations in genes associated with iron homeostasis. There have been three major variants in the high Fe (HFE) gene associated with the disease: C282Y, H63D and S65C. In this context, we aimed to evaluate the prevalence of the polymorphic variants (C282Y, H63D and S65C) of the HFE gene in the population of the Espírito Santo State (ES), Brazil by analyzing three different groups: general population (N = 120), Pomeranian descendants (N = 59), and patients with HH (N = 20). Using genomic DNA extracted from peripheral blood, polymorphic variant identification was performed by polymerase chain reaction-restriction fragment length polymorphism. Statistically significant differences were observed for genotype distribution of C282Y (P < 0.001) and H63D (P = 0.013) between the general population and the patients diagnosed with HH. This is the first study to analyze HFE gene allele frequencies for the general population, Pomeranian subpopulation, and patients with HH of ES, Brazil.

ΔF508 mutation screening of healthy individuals from two populations in Espírito Santo State, Brazil.

The ΔF508 mutation is the most common cause of cystic fibrosis and its prevalence varies worldwide. For instance, up to 20-fold variations in its frequency have been recorded across different areas of Brazil. This study aimed to compare the distribution of ΔF508 among healthy individuals of admixed Portuguese descent from Espírito Santo (ES), a state in Southeastern Brazil, to that in a subpopulation of Pomeranian descent, considered to be an isolated group in which the European gene pool has been preserved, living in Santa Maria do Jetibá (also in ES). We found this mutation to be present at a frequency of 0.81% among the Pomeranian group, and 0% in the general ES population. No genetic differentiation was noted between the two populations examined (FST = 0.004), and these frequencies were found to be similar to those estimated in other states of Southeastern Brazil. Although the population of Santa Maria de Jetibá has retained Pomeranian traits, such as language, fair skin, and eye color, to date, there is no evidence of inbreeding in this group (FIS = -0.004). Screening healthy individuals for the ΔF508 mutation can facilitate genetic counseling for cystic fibrosis, as well as inform evolutionary and population studies.

Analysis of microsatellite instability and loss of heterozygosity in ovarian cancer: a study in the population of Espírito Santo, Brazil.

Ovarian cancer is currently the most lethal gynecological malignancy in women. It is a heterogeneous and cytogenetically complex disease previously associated with genomic instability. Our purpose was to analyze microsatellite markers to determine patterns and levels of instability as well as possible correlations with histopathological parameters. Polymerase chain reaction was used to characterize microsatellite instability (MSI) and loss of heterozygosity (LOH) in 24 ovarian tumors at 12 microsatellite loci. A total of 11 samples displayed MSI or LOH. Only low-level MSI was found. Markers D5S346 and CYP11 showed the highest MSI and LOH frequencies. D17S250 LOH was significantly associated with tumor histological type (P = 0.0003), and estrogen receptor α was also associated with tumor histological type (P = 0.048) when a combined analysis of LOH and MSI was performed. Furthermore, LOH was observed in a greater number of markers compared with those displaying MSI. Thus, our results support that MSI is less common than LOH in ovarian cancers.