MTHFR c.677C>T is a risk factor for non-syndromic cleft lip with or without cleft palate in Chile.

OBJECTIVE: The functional variant within the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene c.677C>T, producing alterations in folate metabolism, has been associated with the risk of non-syndromic cleft lip with or without cleft palate (NSCL/P). We assessed this association in a Chilean population using a combined analysis of case-control and case-parent trio samples. SUBJECTS AND METHODS: Samples of 165 cases and 291 controls and 121 case-parent trios (sharing the cases) were genotyped. Odds ratio (OR) was estimated for case-control (allele and genotype frequency differences), and this result was confirmed by allele transmission distortion in trios. Due to that these samples are not independent, a combined OR was also computed. Maternal genotype effect was additionally evaluated based on a log-linear method. RESULTS: Borderline but not significant OR (1.28; CI 0.97-1.69) was observed for risk allele (T) in the case-control sample. However, triad sample showed a significant association (OR 1.56: CI 1.09-2.25) which was confirmed by the combined OR (1.37; CI 1.11-1.71). Maternal genotype has been also associated with the phenotype (P = 0.002). CONCLUSIONS: In contrast to previous reports considering Chilean subjects, our results demonstrated that the offspring and maternal genotypes for MTHFR c.677C>T variant are strongly associated with NSCL/P in this Chilean population.

Metastatic suppressor CD44 is related with oxidative stress in breast cancer cell lines.

Evidence has accumulated on the role of reactive oxygen species (ROS) in metastasis since surgical removal of tumors generates oxidative stress promoting metastasis and cell growth. Metastasis consists of a cascade of events which allow the cell to survive in target tissues and influence several processes such as dissemination from tumor tissue, transport in blood/lymphatic vessels, invasion and homing of malignant cells. A cDNA oligoarray was used to determine whether alterations of metastatic genes are associated with oxidative stress in breast cancer cell lines. The cell lines used for the experiments were derived from a pre-existent in vitro breast cancer progression model originated in our laboratory. The cDNA array showed alterations in functional gene groups related with cell-cell and cell-matrix interaction molecules, such as caveolin-1; metastasis suppressor genes, such as CD44; metastasis-associated proteases, such as cathepsin D and the protease inhibitor, plasminogen activator inhibitor type 1. The changes of the selected genes were validated by differential display-RT-PCR as well as by protein expression assessed by Western blot analysis. It was found that the cell line, called Tumor2 with down-regulation of basal ROS and manganese superoxide dismutase (MnSOD) expression as a constitutive pattern of this cell line, presented alterations in genes that confer metastatic potential in comparison to the Alpha5 cell line, showing overexpression of basal MnSOD and high levels of ROS. Interesting, it was to found that CD44, considered a metastatic suppressor gene, was influenced by ROS, measured by hydrogen peroxide treatments, as seen by decreased CD44 protein expression in the Alpha5 cell line in a compensatory response to increased MnSOD protein expression. In conclusion, alterations of metastatic genes in malignant breast cancer cell lines were observed in relation to ROS and basal levels of antioxidant enzymes.

Rat lung cancer induced by malathion and estrogen.

Lung cancer can originate from exposure to exogenous and endogenous environmental carcinogens. The use of organophosphorus insecticides has significantly increased in agricultural environments and in urban settings. There is evidence that estrogen can increase lung cancer risk in women. The aim of the present study was to analyze morphological and molecular alterations induced by malathion (M) and 17beta-estradiol (E2) in rat lung tissues. There were four groups: saline solution (control) (100 microg/100 g body weight; BW), M (22 mg/100 g BW), E2 (30 microg/100 gr BW) and combination of both. The animals were injected over a 5-day period and sacrificed 240 days after treatments and lung tissues were excised and analyzed for morphological alterations. Morphometric analysis indicated that M plus E2-treated animals showed a significantly (P<0.05) higher incidence of parenchyma with alveolar proliferative lesions (PAPL), preneoplastic lesions in bronchiolar epithelium (hyperplasia, metaplasia, carcinoma in situ and invasive carcinoma) and atypical lymphatic morphology (lymphatic cell aggregates; LCA) than M or E2 alone-treated and control animals after 240 days. Molecular biology studies indicated that c-ErbB2 and Rho-A had higher protein expression in M plus E2-treated animals in comparison to control and either M- or E-treated animals. In summary, the combination of M and E2 sharply induced pathological lesions in lung alveolar parenchyma, bronchiolar epithelia and lymphatic tissues, in comparison to control animals or in animals treated with either substance alone. These results indicated an increase in risk of rodent lung tumor formation by environmental and endogenous substances.