Association of the Promoter Methylation and the rs12917 Polymorphism of MGMT with Formation of DNA Bulky Adducts and the Risk of Lung Cancer in Mexican Mestizo Population.

O-Methylguanine-DNA methyltransferase (MGMT) is an enzyme that repairs the DNA damage caused by the tobacco habit, and low activity of this enzyme has been associated with a risk of lung cancer (LC). Our objective was to determine the association of the promoter methylation and the rs12917 polymorphism of MGMT with formation of DNA bulky adducts and the risk of LC in the Mexican Mestizo population. In this study are included 431 subjects.

CHRNA3 rs1051730 and CHRNA5 rs16969968 polymorphisms are associated with heavy smoking, lung cancer, and chronic obstructive pulmonary disease in a mexican population.

Background And Purpose: Smoking is a major public health problem worldwide. Polymorphisms in CHRNA3, CHRNA5, and CHRNB4 receptors play a critical role in nicotine dependence, lung cancer (LC) risk, and chronic obstructive pulmonary disease (COPD). This study characterized the CHRNA3 rs1051730 and CHRNA5 rs16969968 polymorphisms in a Mexican population and its association with nicotine dependence, LC, and COPD.

The GSTM1null (deletion) and MGMT84 rs12917 (Phe/Phe) haplotype are associated with bulky DNA adduct levels in human leukocytes.

Tobacco smoke and air pollutants contain carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and tobacco specific nitrosamines (TSNA), that are substrates of metabolizing enzymes generating reactive metabolites that can bind to DNA. Variation in the activity of these enzymes may modify the extent to which these metabolites can interact with DNA. We compared the levels of bulky DNA adducts in blood leukocytes from 93 volunteers living in Mexico City with the presence of 13 single nucleotide polymorphisms (SNPs) in genes related to PAH and TSNA metabolism (AhR rs2044853, CYP1A1 rs1048943, CYP1A1 rs1048943, CYP1A1 rs1799814, EPHX1 rs1051740, EPHX1 rs2234922, GSTM1 null, GSTT1 null and GSTP1 rs947894), DNA repair (XRCC1 rs25487, ERCC2 rs13181 and MGMT rs12917) and cell cycle (TP53 rs1042522).

Polymorphisms associated with the risk of lung cancer in a healthy Mexican Mestizo population: Application of the additive model for cancer.

Lung cancer is the leading cause of cancer mortality in Mexico and worldwide. In the past decade, there has been an increase in the number of lung cancer cases in young people, which suggests an important role for genetic background in the etiology of this disease. In this study, we genetically characterized 16 polymorphisms in 12 low penetrance genes (AhR, CYP1A1, CYP2E1, EPHX1, GSTM1, GSTT1, GSTPI, XRCC1, ERCC2, MGMT, CCND1 and TP53) in 382 healthy Mexican Mestizos as the first step in elucidating the genetic structure of this population and identifying high risk individuals.

Sp1 polymorphism in collagen I α1 gene is associated with osteoporosis in lumbar spine of Mexican women.

The Sp1 binding site polymorphism in collagen type I alpha 1 gene (COLIA1) has been associated with osteoporosis (OP) and bone mineral density (BMD). The aim of this study was to explore the association of this polymorphism with OP and BMD in the Mexican population by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) procedure. Allelic and genotypic frequencies from the Sp1 polymorphism were determined in 100 women with OP, 100 women without OP and 500 subjects from general Mexican population (GMP).

RecBCD and RecFOR dependent induction of chromosomal deletions by sodium selenite in Salmonella.

RecBCD and RecFOR homologous recombination pathways induced bacterial chromosomal duplication-segregation by sodium selenite (SSe) at sub-inhibitory concentrations. This evidence suggests that SSe induces both, double and single DNA strand damage with a concomitant DNA repair response, however the strong dependence for recombinogenic activity of RecB product suggests that the main DNA repair pathway copes with dsDNA breaks. A role for SSe recombinogenic induction is proposed to explain its effect on DNA instability.

Polymorphism of CYP1A1*2C, GSTM1*0, and GSTT1*0 in a Mexican Mestizo population: a similitude analysis.

Cytochrome 1A1 (CYP1A1), glutathione transferase M1 (GSTM1), and glutathione transferase T1 (GSTT1) catalyze the bioactivation and detoxification of a wide variety of xenobiotic compounds that are mutagenic and/or carcinogenic (e.g., polycyclic aromatic hydrocarbons).

Trypanocidal activity of oleoresin and terpenoids isolated from Pinus oocarpa.

Fractionation with n-hexane/ethyl acetate (1:1 v/v) by open column chromatography of the oleoresin from Pinus oocarpa Schiede yielded two diterpenes, pimaric acid (1) and dehydroabietic acid (5), the sesquiterpene longifolene (3) and a diterpenic mixture containing pimaric acid (1), isopimaric acid (4) and dehydroabietic acid (5). Subsequently, the isolated compounds, the mixture of 1, 4 and 5, the oleoresin and the dehydroabietic acid methyl ester (2), were tested in vitro against epimastigotes of Trypanosoma cruzi, the causative agent of Chagas disease. The most active compounds were 1, 3 and the oleoresin, being as active as nifurtimox, a drug effective in the treatment of acute infection by American trypanosomiasis and used in this work as positive control.

Synthesis and in vitro antitrypanosomal activity of novel Nifurtimox analogues.

Eight novel analogues of Nifurtimox, 4-[(5-nitrofurfurylidene)amino]-3-methylthiomorpholine-1,1-dioxide, containing alpha-beta unsaturated amides, were synthesized and evaluated for their in vitro activity against Trypanosoma cruzi epimastigotes. Four derivatives bearing a nitro group at the 5-position of the furan ring were the most active in inhibiting culture growth and provoking cell death, showing trypanocidal activity more than threefold the potency of Nifurtimox, our positive control. Two derivatives lacking a nitro group were less potent than the positive control.

Upregulation and intrarenal redistribution of heat shock proteins 90alpha and 90beta by low-sodium diet in the rat.

Two genes encoding isoforms heat shock protein (Hsp) 90alpha and Hsp90beta constitute the Hsp90 subfamily. In addition to their role in regulating mineralocorticoid and glucocorticoid receptors, these proteins have been associated with nitric oxide production. However, little is known regarding Hsp90 isoform expression and regulation in kidney.