Differential effect of DDT, DDE, and DDD on COX-2 expression in the human trophoblast derived HTR-8/SVneo cells.

The purpose of this study was to investigate the effect of 1,1,1-trichloro-2,2-bis-(chlorophenyl)ethane (DDT), 1,1-bis-(chlorophenyl)-2,2-dichloroethene (DDE), and 1,1-dichloro-2,2-bis(chlorophenyl)ethane (DDD) isomers on COX-2 expression in a human trophoblast-derived cell line. Cultured HTR-8/SVneo trophoblast cells were exposed to DDT isomers and its metabolites for 24 h, and COX-2 mRNA and protein expression were assessed by RT-PCR, Western blotting, and ELISA. Prostaglandin E2 production was also measured by ELISA. Both COX-2 mRNA and protein were detected under control (unexposed) conditions in the HTR-8/SVneo cell line. COX-2 protein expression and prostaglandin E2 production but not COX-2 mRNA levels increased only after DDE and DDD isomers exposure. It is concluded that DDE and DDD exposure induce the expression of COX-2 protein, leading to increased prostaglandin E2 production. Interestingly, the regulation of COX-2 by these organochlorines pesticides appears to be at the translational level.

Prenatal exposure to the major DDT metabolite 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and growth in boys from Mexico.

Recent data suggest that prenatal exposure to p,p'-DDE may reduce height and increase body mass index (BMI) in childhood, thus potentially raising the risk of adult health problems. The association between prenatal DDE exposure and growth was evaluated in 788 boys from Chiapas, an area of Mexico where DDT was recently used. The median DDE levels in maternal serum at birth (2002-2003) were 2.7 microg/g lipid. 2633 measurements of height (cm) and weight (kg) were obtained in 2004-2005. The median age of the children during follow-up was 18 months (quartiles 14 and 22 months). Height and body mass index (kg/m(2)) were age-standardized and expressed as standard deviation scores (SDS). Multivariate random-effect models for longitudinal data were fitted and predicted height and BMI SDS were estimated from the adjusted models. Overall, associations between prenatal DDE level and height or BMI SDS at any given age were not observed. For example, the predicted values showed that children with the highest exposure (DDE: >9.00 microg/g) compared to those least exposed (DDE: <3.01 microg/g) grew similarly and they had a BMI SDS similar to the referent group. The results do not support the prior findings of an association of DDE exposure with childhood height or BMI.

Organochlorines and breast cancer: a case-control study in Brazil.

Breast cancer is an important cause of morbidity and mortality in Brazil. Some studies have analyzed the potential role of organochlorine compounds in breast cancer etiology. These chemical compounds have been widely used in agriculture and in vector-control programs in Brazil. A case-control study was carried out in the main cancer hospital of the Instituto Nacional de Câncer in Rio de Janeiro to investigate exposure to organochlorinated pesticides as a risk factor for breast cancer. We investigated 177 cases of invasive breast cancer at the hospital, between May 1995 and July 1996, and 350 controls selected among female visitors at the same hospital. In addition to information obtained from interviews, blood samples were taken, to analyze residual amounts of organochlorine by gas chromatography using an electron capture detector. [1,1-Dichloro-2, 2-bis(p-chlorophenyl)ethylene] (DDE) was determined in sera of 457 women from a total of 493 participants who had serum samples available. Residues of hexachlorobenzene were found in 11 women only. No statistically significant association was found between breast cancer risk and serum level of DDE or history of exposure to pesticides. Serum levels of DDE (ng/ml) were similar in patients (median = 3.1, mean = 5.1) and controls (median = 3.1, mean = 4.8) (p = 0.93). The age-adjusted odds ratio of breast cancer for women in the upper quintile compared with those in the lowest quintile was 0.90 (95% confidence interval 0.47-1.73). When adjusted for other variables, the risk remained not statistically significant (upper quintile odds ratio = 0.79, 95% confidence interval 0.39-1.60). In our hands, exposure to organochlorinated pesticides measured by history or serum analysis was thus not a risk factor for breast cancer.