CYP1B1: A Promising Target in Cancer Drug Discovery.

CYP1B1 plays an essential role in cancer's pathogenesis since it activates procarcinogens. Significantly, this enzyme catalyzes the hydroxylation of 17ß-estradiol, leading to carcinogenic metabolites involved in carcinogenesis and cancer progression. Therefore, the inhibition of CYP1B1 activity is considered a therapeutic target for chemotherapy. In addition, CYP1B1 is overexpressed in hormone-dependent cancer cells and could be related to resistance to anticancer drugs. However, the activity of CYP1B1 in the tumor microenvironment can metabolize and activate prodrugs in cancer cells, providing more selectivity and being useful for chemoprevention or chemotherapy strategies. Furthermore, due to its importance in anticancer drug design, recent studies have reported using computational methods to understand the intermolecular interactions between possible ligands and CYP1B1. Therefore, in this perspective, we highlight recent findings in developing CYP1B1 inhibitors (flavonoids, trans-stilbenes, estradiol derivatives, and carbazoles) and CYP1B1-activated prodrugs (a chalcone DMU-135 and an oxime DMAKO-20). Finally, we have analyzed their possible molecular interactions with this enzymatic target by molecular docking, which can help to design new active substances.

Unraveling the Genetic Architecture of Hepatoblastoma Risk: Birth Defects and Increased Burden of Germline Damaging Variants in Gastrointestinal/Renal Cancer Predisposition and DNA Repair Genes.

The ultrarare hepatoblastoma (HB) is the most common pediatric liver cancer. HB risk is related to a few rare syndromes, and the molecular bases remain elusive for most cases. We investigated the burden of rare damaging germline variants in 30 Brazilian patients with HB and the presence of additional clinical signs. A high frequency of prematurity (20%) and birth defects (37%), especially craniofacial (17%, including craniosynostosis) and kidney (7%) anomalies, was observed. Putative pathogenic or likely pathogenic monoallelic germline variants mapped to 10 cancer predisposition genes (CPGs: APC, CHEK2, DROSHA, ERCC5, FAH, MSH2, MUTYH, RPS19, TGFBR2 and VHL) were detected in 33% of the patients, only 40% of them with a family history of cancer. These findings showed a predominance of CPGs with a known link to gastrointestinal/colorectal and renal cancer risk. A remarkable feature was an enrichment of rare damaging variants affecting different classes of DNA repair genes, particularly those known as Fanconi anemia genes. Moreover, several potentially deleterious variants mapped to genes impacting liver functions were disclosed. To our knowledge, this is the largest assessment of rare germline variants in HB patients to date, contributing to elucidate the genetic architecture of HB risk.

Influence of nicotine dependence, current smoking status and gender on CYP1A1, CYP1B1 and CYP2A6 expression in oral squamous cell carcinoma / Influência da dependência nicotínica, parâmetros de consumo de tabaco e gênero na expressão de CYP1A1, CYP1B1 e CYP2A6 em carcinoma de células escamosas oral

Objective: Tobacco smoke is composed of cancer-causing chemicals referred to as carcinogens. These carcinogens are metabolized by the enzymes of the cytochrome P450 (CYP) family. Our objective was to evaluate the correlation of tobacco consumption parameters with CYP1A1, CYP1B1 and CYP2A6 expression using qRT-PCR in samples of oral squamous cell carcinoma (OSCC). Material and Methods: The sample was divided into 2 groups: Cancer (36 subjects) and non-Cancer (12 subjects). The smokers' participants (36) were evaluated regarding their Nicotine dependence (ND) was assessed by the Fagerström test for cigarette dependence (FTCD). Questions regarding tobacco consumption like the number of cigarettes/day (CPD), duration of use, and pack-years were also evaluated. The Mann-Whitney and Spearman correlation tests were used at a significance level of 5%. Results: 48 participants were included, 32 men (66.7%), 36 smokers (75%) and 27 smokers with OSCC (56.3%). Samples of OSCC expressed more CYP1A1, CYP1B1, and CYP2A6. Especially, the CYP1B1 gene was significantly expressed in OSCC samples, regardless gender or tobacco use. No women expressed CYP2A6, as well as, non-smokers did not express the CYP1A1 and CYP2A6 genes. CYP1A1 gene was higher among men (P = 0.021). Conclusion: Lack of exposure to tobacco may justify the absence of CYP1A1 and CYP2A6 expression in non-smokers. The CYP1B1 gene was significantly expressed in the cancer presence despite gender or tobacco use. The assessment of ND and quantification of tobacco consumption are important instruments in monitoring smokers with benign oral lesions and, especially, in the presence of cancer.(AU)

Objetivo: A fumaça do tabaco é composta de substâncias químicas cancerígenas conhecidas como carcinógenos. Esses carcinógenos são metabolizados pelas enzimas da família do citocromo P450 (CYP). Nosso objetivo foi avaliar a correlação dos parâmetros do consumo de tabaco com a expressão de CYP1A1, CYP1B1 e CYP2A6 por qRT-PCR em amostras de carcinoma de células escamosas bucal (CCEB). Material e Métodos: A amostra foi dividida em 2 grupos: Câncer (36 indivíduos) e sem Câncer (12 indivíduos). Os participantes fumantes (36) foram avaliados quanto à dependência nicotínica (DN) pelo teste de Fagerström para dependência de cigarro (TFDC). Questões relacionadas ao consumo de tabaco como número de cigarros / dia (CPD), tempo de uso e anos-maço também foram avaliadas. Os testes de correlação de Mann-Whitney e Spearman foram utilizados com nível de significância de 5%. Resultados: foram incluídos 48 participantes, 32 homens (66,7%), 36 fumantes (75%) e 27 fumantes com CCEB (56,3%). Amostras de CCEB expressaram mais CYP1A1, CYP1B1 e CYP2A6. Especialmente, o gene CYP1B1 foi significativamente expresso em amostras de CCEB, apesar do sexo ou uso de tabaco. Nenhuma mulher expressou CYP2A6, assim como, não fumantes não expressaram os genes CYP1A1 e CYP2A6. O gene CYP1A1 foi maior entre os homens (P = 0,021). Conclusão: A falta de exposição pode justificar a ausência da expressão dos genes CYP1A1 e CYP2A6 entre não fumantes. O gene CYP1B1 foi significativamente expresso na presença de câncer, independentemente do sexo ou do uso de tabaco. A avaliação da DN e a quantificação do consumo de tabaco são importantes instrumentos no acompanhamento de fumantes com lesões bucais benignas e, principalmente, na presença de câncer (AU)

Interaction of Thalassia testudinum Metabolites with Cytochrome P450 Enzymes and Its Effects on Benzo(a)pyrene-Induced Mutagenicity.

The aim of the present work was to evaluate the effects of Thalassia testudinum hydroethanolic extract, its polyphenolic fraction and thalassiolin B on the activity of phase I metabolizing enzymes as well as their antimutagenic effects. Spectrofluorometric techniques were used to evaluate the effect of tested products on rat and human CYP1A and CYP2B activity. The antimutagenic effect of tested products was evaluated in benzo[a]pyrene (BP)-induced mutagenicity assay by an Ames test. Finally, the antimutagenic effect of Thalassia testudinum (100 mg/kg) was assessed in BP-induced mutagenesis in mice. The tested products significantly (p < 0.05) inhibit rat CYP1A1 activity, acting as mixed-type inhibitors of rat CYP1A1 (Ki = 54.16 ± 9.09 µg/mL, 5.96 ± 1.55 µg/mL and 3.05 ± 0.89 µg/mL, respectively). Inhibition of human CYP1A1 was also observed (Ki = 197.1 ± 63.40 µg/mL and 203.10 ± 17.29 µg/mL for the polyphenolic fraction and for thalassiolin B, respectively). In addition, the evaluated products significantly inhibit (p < 0.05) BP-induced mutagenicity in vitro. Furthermore, oral doses of Thalassia testudinum (100 mg/kg) significantly reduced (p < 0.05) the BP-induced micronuclei and oxidative damage, together with an increase of reduced glutathione, in mice. In summary, Thalassia testudinum metabolites exhibit antigenotoxic activity mediated, at least, by the inhibition of CYP1A1-mediated BP biotransformation, arresting the oxidative and mutagenic damage. Thus, the metabolites of T. testudinum may represent a potential source of chemopreventive compounds for the adjuvant therapy of cancer.

Involvement of Ahr Pathway in Toxicity of Aflatoxins and Other Mycotoxins.

The purpose of this review is to present information about the role of activation of aflatoxins and other mycotoxins, of the aryl hydrocarbon receptor (AhR) pathway. Aflatoxins and other mycotoxins are a diverse group of secondary metabolites that can be contaminants in a broad range of agricultural products and feeds. Some species of Aspergillus, Alternaria, Penicilium, and Fusarium are major producers of mycotoxins, some of which are toxic and carcinogenic. Several aflatoxins are planar molecules that can activate the AhR. AhR participates in the detoxification of several xenobiotic substances and activates phase I and phase II detoxification pathways. But it is important to recognize that AhR activation also affects differentiation, cell adhesion, proliferation, and immune response among others. Any examination of the effects of aflatoxins and other toxins that act as activators to AhR must consider the potential of the disruption of several cellular functions in order to extend the perception thus far about the toxic and carcinogenic effects of these toxins. There have been no Reviews of existing data between the relation of AhR and aflatoxins and this one attempts to give information precisely about this dichotomy.

Chemoprotective effects of Ulva lactuca (green seaweed) aqueous-ethanolic extract against subchronic exposure to benzo(a)pyrene by CYP1A1 inhibition in mice.

The protective effect of the supplementation with an aqueous-ethanolic extract obtained from Ulva lactuca (Delile) green seaweed on benzo[a] pyrene-induced damage in mice was evaluated. Animals were treated with oral doses of U. lactuca extract (100 and 400 mg/kg) for 9 weeks. They were exposed to 50 mg/kg of oral doses of benzo(a)pyrene starting from the second week and up to the fifth week. Groups treated with benzo(a)pyrene only (second to fifth weeks), sunflower oil (vehicle, 9 weeks), or U. lactuca extract (100 and 400 mg/kg, 9 weeks) were also included in the study. The treatment with 400 mg/kg of the extract ameliorated the oxidative damage, decreased IL-1ß and TNF-α levels, and favorably regulated the antioxidant defenses compared with benzo(a)pyrene-exposed group. The benzo(a)pyrene-induced DNA damage was also reduced, as it was evidenced by the lower micronucleus formation in U. lactuca extract-supplemented animals. The extract protected the hepatic tissue, and it reduced the liver activity/expression of CYP1A1. These results altogether suggested a chemoprotective effect of U. lactuca extract against benzo(a)pyrene-induced-toxicity in mice, probably associated with an inhibitory effect of carcinogen bioactivation.

Associations between sperm quality, DNA damage, and CYP1A1, GSTT1 and GSTM1 polymorphisms with 1-hydroxypyrene urinary levels in men occupationally exposed to polycyclic aromatic hydrocarbons.

PURPOSE: During recent decades, several reports have suggested a decrease in semen quality and DNA damage due in part to environmental toxicants and industrial chemicals. Among these xenobiotics, polycyclic aromatic hydrocarbons (PAHs) are of particular concern because of their remarkable mutagenic and carcinogenic properties and because several experimental and epidemiological studies have reported adverse effects of PAHs on male reproductive health and DNA structure. The aim of the study was to evaluate the association between 1-hydroxypyrene (1-OHP) urinary levels and sperm quality, DNA damage and the frequency of CYP1A1, GSTT1, and GSTM1 polymorphisms. METHODS: Semen, urine and blood samples were taken for sperm-quality assessment, 1-OHP urinary level measurement, DNA damage evaluation and polymorphism frequency analysis of three genes implicated in PAH metabolism in a total of 70 Mexican subjects exposed and nonexposed to PAHs. RESULTS: A significant decrease in sperm quality and increased DNA damage were registered in occupationally exposed volunteers. Polymorphisms modified the 1-OHP urinary levels; however, no associations were found between them. Inverse associations were registered between the sperm concentration/mL and 1-OHP levels and between tail lengths and the GSMT1 null genotype. CONCLUSIONS: Our data showed an inverse association between 1-OHP urinary levels and both sperm quality and the DNA integrity. Additionally, the heterozygote variants of CYP1A1-m1 and CYP1A1-m2 significantly increased the urinary excretion of 1-OHP, and the GSTM1 null variant was inversely associated with the comet parameters evaluated.

Involvement of astrocytic CYP1A1 isoform in the metabolism and toxicity of the alkaloid pyrrolizidine monocrotaline.

Monocrotaline (MCT) and its pyrrole derivative, dehydromonocrotaline (DHMC), interact with molecular targets in cells of the central nervous system. DHMC presents higher toxicity than MCT indicating that its metabolism of MCT is a critical step of this alkaloid toxicity. This study sought to elucidate the metabolism and the toxicity of MCT in C6 astrocyte cell line and primary cultures of rat astrocytes by investigating metabolic enzymatic mechanisms of the cytochrome P450 (CYP) system and conjugation with glutathione. Treatment with omeprazole (OMP) (20 µM), a non-specific inducer of CYP450 induced approximately 10-fold increase in CYP1A1 activity after 2 h of treatment. Similarly, the 7-Ethoxyresorufin-O-deethylase (EROD) activity was induced by treatment with MCT (100-500 µM), indicating that the P450 CYP1A1 isoform was active and involved in the metabolism of MCT. Analysis of conjugation with glutathione showed a significant depletion of GSH after MCT (500 µM) treatment, and this was partially reversed by pretreatment with a P450 inhibitor (cimetidine 100 µM). These results suggest that not only the alkaloid MCT but, also its metabolite may deplete GSH. Rosenfeld staining showed intense vacuolization after MCT treatment, which was partially inhibited in the presence of a P450 activator. MTT test showed that association of MCT with OMP induced a reduction in cell viability in C6 and primary astrocytic cells. These results demonstrate that MCT is metabolized by astrocytic CYP1A1 to generate metabolites that can deplete GSH. Moreover, changes in the activity of the P450 enzymes interfere with the cytotoxic effects induced by the alkaloid.

Comparison of the Effects of Monastrol and Oxomonastrol on Human Hepatoma Cell Line HepG2/C3A.

Monastrol and its analog oxomonastrol differ by replacement of the sulfur atom present in monastrol to an oxygen atom in oxomonastrol. Monastrol inhibits the mitotic kinesin family member 11 (EG5), which has been studied for its potential use in cancer therapy. The aim of this study was to investigate the effect of monastrol and oxomonastrol on HepG2/C3A cells. Our results showed that monastrol induced DNA damage, reduced cell proliferation, and up-regulated the cytochrome P450 family 1 subfamily A member 1 (CYP1A1) mRNA levels. However, oxomonastrol was cytotoxic only at the highest concentrations used, without reducing cell proliferation and viability. Moreover, no genotoxic damage or alteration of levels of mRNA were found. Our results suggest that monastrol has greater antiproliferative activity compared to oxomonastrol, and this effect is probably related to the DNA damage induced by monastrol and its possible bioactivation demonstrated by the increase in CYP1A1 mRNA expression. Moreover, these effects appear to be related to the presence of the sulfur atom in its structure.

Association of CYP1A1 and CYP1B1 polymorphisms with bone mineral density variations in postmenopausal Mexican-Mestizo women.

Herein, we investigated potential associations between polymorphisms of genes related to estrogen metabolism and bone mineral density (BMD) in postmenopausal women. This was a cross-sectional study, in which two hundred and ninety postmenopausal Mexican-Mestizo women were studied. The BMD of the lumbar spine (LS), total hip (TH), and femoral neck (FN) was measured. The distribution of the genetic polymorphisms, including rs1799814 and rs1048943 at CYP1A1 as well as rs1056836 at CYP1B1, were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), single-stranded conformational polymorphism (SSCP), and DNA sequencing. Deviations from Hardy-Weinberg equilibrium (HWE) were tested, and linkage disequilibrium (LD) was calculated by direct correlation (r2). Moreover, haplotype analysis was performed. All polymorphisms were in HWE. The genotype and allele distributions of the three single nucleotide polymorphisms (SNPs) studied showed no significant differences. However, statistical significance was reached when constructing haplotypes. The CG haplotype in CYP1A1 was associated with variations in LS and FN BMD after adjustment for covariates (p = 0.021 and 0.045, respectively), but the association with TH BMD was not significant. These results suggested that the CG haplotype in CYP1A1 may play an important role in the mechanism of osteoporosis and may be useful as a genetic marker.

CYP1A1, CYP2E1 and EPHX1 polymorphisms in sporadic colorectal neoplasms.

AIM: To investigate the contribution of polymorphisms in the CYP1A1, CYP2E1 and EPHX1 genes on sporadic colorectal cancer (SCRC) risk. METHODS: Six hundred forty-one individuals (227 patients with SCRC and 400 controls) were enrolled in the study. The variables analyzed were age, gender, tobacco and alcohol consumption, and clinical and histopathological tumor parameters. The CYP1A1*2A, CYP1A1*2C CYP2E1*5B and CYP2E1*6 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The EPHX1 Tyr113His, EPHX1 His139Arg and CYP1A1*2C polymorphisms were detected by real-time PCR. Chi-squared test and binary logistic regression were used in the statistical analysis. Haplotype analysis was conducted using the Haploview program, version 2.05. RESULTS: Age over 62 years was a risk factor for SCRC development (OR = 7.54, 95%CI: 4.94-11.50, P < 0.01). Male individuals were less susceptible to SCRC (OR = 0.55, 95%CI: 0.35-0.85, P < 0.01). The CYP2E1*5B polymorphism was associated with SCRC in the codominant (heterozygous genotype: OR = 2.66, 95%CI: 1.64-4.32, P < 0.01), dominant (OR = 2.82, 95%CI: 1.74-4.55, P < 0.01), overdominant (OR = 2.58, 95%CI: 1.59-4.19, P < 0.01), and log-additive models (OR = 2.84, 95%CI: 1.78-4.52, P < 0.01). The CYP2E1*6 polymorphism was associated with an increased SCRC risk in codominant (heterozygous genotype: OR = 2.81, 95%CI: 1.84-4.28, P < 0.01; homozygous polymorphic: OR = 7.32, 95%CI: 1.85-28.96, P < 0.01), dominant (OR = 2.97, 95%CI: 1.97-4.50, P < 0.01), recessive (OR = 5.26, 95%CI: 1.35-20.50, P = 0.016), overdominant (OR = 2.64, 95%CI: 1.74-4.01, P < 0.01), and log-additive models (OR = 2.78, 95%CI: 1.91-4.06, P < 0.01). The haplotype formed by the minor alleles of the CYP2E1*5B (C) and CYP2E1*6 (A) polymorphisms was associated with SCRC (P = 0.002). However, the CYP1A1*2A, CYP1A1*2C, EPHX1 Tyr113His and EPHX1 His139Arg polymorphisms were not associated with SCRC. CONCLUSION: In conclusion, the results demonstrated that CYP2E1*5B and CYP2E1*6 minor alleles play a role in the development of SCRC.

Cigarette smoking, dietary habits and genetic polymorphisms in GSTT1, GSTM1 and CYP1A1 metabolic genes: A case-control study in oncohematological diseases.

AIM: To analyze the association between oncohematological diseases and GSTT1/GSTM1/CYP1A1 polymorphisms, dietary habits and smoking, in an argentine hospital-based case-control study. METHODS: This hospital-based case-control study involved 125 patients with oncohematological diseases and 310 control subjects. A questionnaire was used to obtain sociodemographic data and information about habits. Blood samples were collected, and DNA was extracted using salting out methods. Deletions in GSTT1 and GSTM1 (null genotypes) were addressed by PCR. CYP1A1 MspI polymorphism was detected by PCR-RFLP. Odds ratio (OR) and 95%CI were calculated to estimate the association between each variable studied and oncohematological disease. RESULTS: Women showed lower risk of disease compared to men (OR 0.52, 95%CI: 0.34-0.82, P = 0.003). Higher levels of education (> 12 years) were significantly associated with an increased risk, compared to complete primary school or less (OR 3.68, 95%CI: 1.82-7.40, P < 0.001 adjusted for age and sex). With respect to tobacco, none of the smoking categories showed association with oncohematological diseases. Regarding dietary habits, consumption of grilled/barbecued meat 3 or more times per month showed significant association with an increased risk of disease (OR 1.72, 95%CI: 1.08-2.75, P = 0.02). Daily consumption of coffee also was associated with an increased risk (OR 1.77, 95%CI: 1.03-3.03, P = 0.03). Results for GSTT1, GSTM1 and CYP1A1 polymorphisms showed no significant association with oncohematological diseases. When analyzing the interaction between polymorphisms and tobacco smoking or dietary habits, no statistically significant associations that modify disease risk were found. CONCLUSION: We reported an increased risk of oncohematological diseases associated with meat and coffee intake. We did not find significant associations between genetic polymorphisms and blood cancer.

Effect of [Cu(4,7-dimethyl-1,10-phenanthroline)(acetylacetonato)]NO3, Casiopeína III-Ea, on the activity of cytochrome P450.

Casiopeína III-Ea (Cas III-Ea(1)) is a copper complex with antiproliferative and antitumor activities, designed to act via alternative mechanisms of action different from Cisplatin. This compound has also been well characterized in preclinical test and pharmacokinetic analysis, being a good candidate for clinical phases. Since very little is known about the processes of biotransformation of therapeutic metal based drugs, this paper report the first approach to the study of the interaction between metal complex Cas III-Ea and cytochromes P450 with the aim to find out possible biotransformation pathways for this complexes and feasible drug-drug interactions. Results showed that Cas III-Ea is a strong irreversible competitive inhibitor of CYP1A1 (IC50 = 7.5 ± 1.0 µM; Ki = 240 nM). The magnitude of values indicate that it is necessary to be taken into account such effect when analyzing possible drug interactions with these new drugs in order to prevent adverse reactions derived from this inhibition.

Comparative Expression Analysis of Cytochrome P450 1A1, Cytochrome P450 1B1 and Nuclear Receptors in the Female Genital and Colorectal Tissues of Human and Pigtailed Macaque.

This manuscript summarizes our recent progress in examine the CYP1A1 and CYP1B1 as well as a number of nuclear receptors in the female genital and colorectal tissues of human and pigtailed macaque. Understanding the nuclear receptor mediated regulation of CYP1A1 and 1B1 expression in these tissues is necessary for identifying cancer risk factors and developing CYP1A1/1B1-targeted anti-cancer therapeutics. However, there is a lack of systematic and comparative analysis of the expression profile of CYP1A1, 1B1 and NRs in the female genital and colorectal tissues of human and clinically relevant animal models. The current study aims to fill this gap. We found CYP1A1, CYP1B1 and a number of nuclear receptors were expressed in the female genital and colorectal tissues of human and macaque. However, the mRNA level and protein localization of these CYP enzymes and NRs depended on the type of tissue examined. Cytochrome P450 (CYP) 1A1 and CYP1B1 activate hormonal and environmental procarcinogens, and are associated with carcinogenesis in female genital and colorectal tissues. Understanding the nuclear receptor (NR) mediated regulation of CYP expression in these tissues is necessary for identifying cancer risk factors and developing CYP1A1/1B1-targeted anti-cancer therapeutics. The study aims to analyze the expression profile of CYP1A1, 1B1 and NRs in the female genital and colorectal tissues of human and pigtailed macaques. We found that compared to the liver, human CYP1A1 mRNA level in the genital and colorectal tissues was significantly lower, while the CYP1B1 level was significantly higher. CYP1A1 protein was mainly localized in the plasma membrane of the uterine and endocervical epithelial cells. The CYP1B1 protein was concentrated in the nucleus of genital and colorectal tissues. Fourteen NRs in the genital tract and 12 NRs in colorectal tissue were expressed at levels similar to or higher than the liver. The expression and localization of CYP1A1, CYP1B1, and NRs in macaque tissues were usually comparable to those of human tissues. In addition, menopause did not significantly alter the ectocervical mRNA levels of CYP1A1, CYP1B1, or NRs.

Association of CYP1A1 A4889G and T6235C polymorphisms with the risk of sporadic breast cancer in Brazilian women

OBJECTIVES:We examined the influence of CYP1A1 A4889G and T6235C polymorphisms on the risk of sporadic breast cancer.METHODS:DNA from 742 sporadic breast cancer patients and 742 controls was analyzed using the polymerase chain reaction, followed by the restriction fragment length polymorphism technique.RESULTS:More patients had the CYP1A1 4889AG+GG genotype compared to controls (29.0% versus 23.2%, p=0.004). The G allele carriers had a 1.50-fold increased risk (95% CI: 1.14-1.97) of sporadic breast cancer compared to the other study participants. The frequency of the 4889AG+GG genotype among the Caucasian patients was higher than in the non-Caucasian patients (30.4% versus 20.2%, p=0.03) and controls (30.4% versus 23.2%, p=0.002). Caucasians and G allele carriers had a 1.61-fold increased risk (95% CI: 1.20-2.15) of sporadic breast cancer compared to other subjects. The CYP1A1 4889AG+GG genotype was more common among patients with a younger median age at first full-term pregnancy than among controls (33.8% versus 23.2%, p=0.001) and subjects whose first full-term pregnancies occurred at an older age (33.8% versus 26.1%, p=0.03). Women with the CYP1A1 4889AG+GG genotype and earlier first full-term pregnancies had a 1.87-fold (95% CI: 1.32-2.67) increased risk of sporadic breast cancer compared to the other study participants. Excess CYP1A1 4889AG+GG (39.8% versus27.1%, p=0.01) and 6235TC+CC (48.4% versus 35.9%, p=0.02) genotypes were also observed in patients with grade I and II tumors compared to patients with grade III tumors and controls (39.8% versus 23.2%, p=0.04; 48.4% versus 38.6%, p=0.04). The G and C allele carriers had a 2.44-fold (95% CI: 1.48-4.02) and 1.67-fold (95% CI: 1.03-2.69) increased risk, respectively, of developing grade I and II tumors compared to other subjects.CONCLUSIONS:The CYP1A1 A4889G and T6235C polymorphisms may alter the risk of sporadic breast cancer in Brazilian women.

Polimorfismo CYP1A1*2A e infertilidad en hombres de la región Caribe colombiana / CYP1A1*2A polymorphism and infertility in Colombian Caribbean male subjects

Objetivo: El objetivo de este estudio fue investigar la asociación del polimorfismo CYP1A1*2A (T-C) y la infertilidad en una muestra de hombres del Caribe colombiano. Materiales y Métodos: Se analizaron características macroscópicas y microscópicas de la muestra seminal de 31 hombres infértiles y 20 fértiles. La genotipificación del polimorfismo se realizó a partir de la técnica PCR-RFLP. Resultados: Se encontraron diferencias significativas (p<0.05) en las características seminales microscópicas en ambos grupos. Además, se identificaron alteraciones en movilidad, concentración y/o morfología. Fueron identificados tres genotipos: TT, TC y CC. En los inértiles se presentaron 25 individuos con genotipo TT (80.6 %), 5 TC (16.1 %) y 1 CC (3.2 %), y en el grupo fértil 16 individuos presentaron genotipo TT (80.0 %), 4 TC (20.0 %) y 0 CC (0.0 %). La distribución genotípica se encontró en equilibrio Hardy - Weinberg en ambos grupos. El análisis de regresión logística mostró que no hubo asociación significativa entre el polimorfismo CYP1A1*2A y la infertilidad en hombres del Caribe colombiano (p>0.05). Conclusión: Estos resultados preliminares sugieren que el polimorfismo CYP1A1*2A no contribuye a la infertilidad masculina en hombres del Caribe colombiano. Sin embargo, son de gran importancia debido a que existe escasa información que asocie polimorfismos del gen CYP1A1 con la infertilidad masculina.

Objective: The aim of this study was to investigate the association of CYP1A1*2A polymorphism (T-C substitution) with male infertility in Colombian Caribbean subjects. Materials and Methods: Macroscopic and microscopic characteristics were analyzed in the semen sample of 31 infertile and 20 fertile men. The polymorphism was genotyped through PCR-RFLP. Results: Both groups evidenced significant differences in microscopic characteristics (p< 0.05), as well as alterations in sperm motility, count and morphology. Three genotypes were identified: wild type homozygous (TT), heterozygous (TC) and variant homozygous (CC). 25 TT genotype (80.6%), 5 TC genotype (16.1%) and 1 CC genotype (3.2%) in infertile men, and 16 TT genotype (80.0%), 4 TC genotype (20.0%) and 0 CC genotype (0.0%) in fertile men were identified. In both infertile and fertile men, distributions of the genotypes were in Hardy-Weinberg equilibrium. Logistic regression analysis showed no significant association between CYP1A1*2A polymorphism and male infertility in Colombian Caribbean men (p>0.05). Conclusion: These preliminary results suggest that CYP1A1*2A polymorphism do not contribute to male infertility of Colombian Caribbean men. However, they are very important because there is limited information about CYP1A1 gene polymorphisms associated with male infertility.

Altered gene expression in HepG2 cells exposed to a methanolic coal dust extract.

Exposure to coal dust has been associated with different chronic diseases and mortality risk. This airborne pollutant is produced during coal mining and transport activities, generating environmental and human toxicity. The aim of this study was to determine the effects of a coal dust methanolic extract on HepG2, a human liver hepatocellular carcinoma cell line. Cells were exposed to 5-100ppm methanolic coal extract for 12h, using DMSO as control. MTT and comet assays were used for the evaluation of cytotoxicity and genotoxicity, respectively. Real time PCR was utilized to quantify relative expression of genes related to oxidative stress, xenobiotic metabolism and DNA damage. Coal extract concentrations did not induce significant changes in HepG2 cell viability after 12h exposure; however, 50 and 100ppm of the coal extract produced a significant increase in genetic damage index with respect to negative control. Compared to vehicle control, mRNA CYP1A1 (up to 163-fold), NQO1 (up to 4.7-fold), and GADD45B (up to 4.7-fold) were up regulated, whereas PRDX1, SOD, CAT, GPX1, XPA, ERCC1 and APEX1 remained unaltered. This expression profile suggests that cells exposed to coal dust extract shows aryl hydrocarbon receptor-mediated alterations, changes in cellular oxidative status, and genotoxic effects. These findings share some similarities with those observed in liver of mice captured near coal mining areas, and add evidence that living around these industrial operations may be negatively impacting the biota and human health.

Influence of CYP1A1*2C on high triglyceride levels in female Mexican indigenous Tarahumaras.

BACKGROUND AND AIMS: High triglyceride levels are closely related to cardiovascular disease. Its development lays on age, diet, physical activity, ethnicity and genetic factors. Among the last, the CYP1A1*2C allele has an influence on the metabolism of cholesterol and other fatty acids. We undertook this study to determine the frequency of CYP1A1*2C and its association with triglyceride levels in Mexican indigenous Tarahumaras and Tepehuanos. METHODS: Anthropometric and biochemical data were recorded. Genotyping of CYP1A1*2C by RT-PCR was done in 110 Tepehuano, 69 Tarahumara and 64 Mestizo. RESULTS: Significant differences in age, waist diameter, BMI, creatinine, glucose, cholesterol, triglycerides, HDL and VLDL measurements were found between Tarahumaras and Tepehuanos (p <0.05). Additionally, Tarahumara women showed the highest values of waist diameter, BMI and triglycerides (p <0.05). It was found that Tarahumaras showed a significant association between high triglyceride levels and CYP1A1*2C allele (OR = 2.57; 95% CI 1.12-5.88, p = 0.024) under a recessive inheritance model. However, the Tepehuano group showed a significant protective association between normal triglyceride levels and CYP1A1*2C polymorphism (OR = 0.28; 95% CI 0.10-0.80, p = 0.015) following a dominant inheritance model. The same pattern was observed after analysis with females of both ethnicities. CONCLUSION: A significant association between CYP1A1*2C and high triglyceride levels in Amerindian Tarahumaras from Chihuahua has been found; this allele was significantly associated with normal triglyceride levels in Tepehuanos from Durango, Mexico. Further studies are needed to elucidate the genetic role of CYP1A1 in cardiovascular disease susceptibility.

Biomarkers of sensitivity to potent and selective antitumor 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F203) in ovarian cancer.

2-(4-Amino-3-methylphenyl)-5-fluorobenzothiazole (5F203, NSC 703786) lysylamide belongs to a novel mechanistic class of antitumor agents. It elicits activity against ovarian, breast, kidney and colorectal cancer models. In sensitive breast cancer cells, 5F203 activates aryl hydrocarbon receptor (AhR) signaling. Herein, we evaluate the role of AhR in 5F203 activity in two ovarian cancer cell lines: IGROV-1 (sensitive to 5F203), SKOV-3 (resistant to this agent). In addition, cancer cells have been isolated from ascites fluid of ovarian cancer patients; sensitivity to 5F203 and concurrent AhR signal transduction has been examined in ascites-isolated ovarian cancer patients' cells. 5F203 induced enhanced CYP1A1 expression, AhR translocation and ROS formation in IGROV-1 cells and ascites-isolated ovarian cancer cells that were sensitive to 5F203. In IGROV-1 cells 5F203-induced ROS formation was accompanied by JNK, ERK and P38MAPK phosphorylation, DNA damage and cell cycle arrest prior to apoptosis. In contrast, 5F203 failed to induce CYP1A1 expression, AhR translocation or oxidative stress in 5F203-resistant SKOV-3 cells, or in ovarian cancer ascites cells inherently resistant to this agent. We propose that AhR may represent a new molecular target in the treatment of ovarian tumors and 5F203 may exemplify a potential novel treatment. Furthermore, putative biomarkers of sensitivity to this agent have been identified.

Frecuencia de los polimorfismos CYP1A1*2A y deleción del gen GSTM1 en pacientes con carcinoma de células escamosas de laringe en relación al hábito tabáquico: estudio piloto en Chile / Frequency of CYP1A1*2A and GSTM1 gene polymorphisms in Chilean patients with squamous cell carcinoma of the larynx in relation to smoking habit: a pilot study

Introducción: Entre los factores de riesgo para cáncer laríngeo (CL) son relevantes el consumo de tabaco y alcohol. Estos xenobióticos son metabolizados por un grupo de enzimas, entre las cuales están CYP1A1 y GSTM1, cuyas variantes polimórficas se postulan como factores de riesgo para esta enfermedad. Objetivos: Describir la frecuencia de las variantes de los polimorfismos de CYP1A1 y GSTM1 en un grupo de pacientes diagnosticados con CL. Analizar la posible correlación entre las variantes genéticas de ambas enzimas y la presencia de CL. Evaluar la influencia del hábito tabáquico en el riesgo de aparición de cáncer escamoso de laringe en pacientes con genotipos de riesgo. Material y método: Se seleccionaron 35 pacientes con CL entre los años 2000 y 2010 en Servicio de Otorrinolaringología del HBLT y 124 controles reclutados en el Centro de Investigaciones Farmacológicas y Toxicológicas (IFT). A todos los individuos se les registraron datos demográficos y extrajo una muestra de sangre para analizar las variantes polimórficas de CYP1A1 y GSTM1, mediante PCR-RFLP. Resultados: De un total de 35pacientes 54,3% presentan el genotipo GSTM1 (-/-) y 17,1% el genotipo CYP1A1*2A C/C. En el grupo control (n =140) estas frecuencias fueron de 19,35°% y 10,48%o, respectivamente. Se observó una correlación entre GSTM1 y el CL, estratificado por el hábito tabáquico y alcohólico. No se encontraron relaciones estadísticamente significativas con el hábito alcohólico y/o tabáquico. No se observaron asociaciones entre la patología y la combinación de genotipos o entre genotipos y el hábito tabáquico o alcohólico. Conclusiones: Los resultados muestran una asociación estadísticamente significativa entre la deleción de GSTM1 (-/-) y el riesgo de presentar CL, lo que refleja el importante papel que juega esta enzima en la desintoxicación de compuestos cancerígenos. Sin embargo, se requiere incrementar el número de pacientes para establecer apropiadamente la relación genético-ambiental que permite adjudicar un papel relevante a estos biomarcadores.

Introduction: Tobacco and alcohol consumption are recognized risk factors for squamous cell carcinoma of the larynx. These xenobiotics are metabolized by numerous enzymes, among which, CYP1A1 and GSTM1 gene polymorphisms have been identified as risk factors for developing tobacco related cancers as lung and laryngeal carcinomas. Nevertheless, these polymorphisms have not been studied in Chilean patients with squamous cell carcinoma of the larynx. Aim: To describe, for the first time, the frequency of CYP1A1 and GSTM1 gene polymorphisms in Chilean patients with squamous cell carcinoma of the larynx. Material and method: We conducted a case-control study. The case group consisted of 35 Chilean patients with squamous cell carcinoma of the larynx; the control group was formed by 124 Chilean subjects without cancer diagnosis. Demographic data as age, sex and quantification of tobacco smoking and alcohol consumption were recorded in all individuals. CYP1A1 and GSTM1 gene polymorphisms were evaluated by polymerase chain reaction and restriction enzymes (PCR-RFLP). Results: The frequency of CYP1A1*2A C/C genotype was 54, 3°% among laryngeal cancerpatients and 17,1%% among control subjects. The frequency ofGSTM1 (-/-) genotype was 19,35 %% among laryngeal cancer patients and 10,48%% among control subjects. There were no statistically significant relationships between this gene polymorphisms and tobacco smoking or alcohol consumption. There were no associations between the presence of both gene polymorphisms in the same individual and the presence of laryngeal cancer. Interestingly we found an OR of 8.69 (CI 2.90 to 26.01) for GSTM1 (-/-) polymorphism and laryngeal cancer, stratified by tobacco smoking and alcohol consumption. Conclusions: Our work shows that the deletion of GSTM1 could be an important risk factor for squamous cell carcinoma of the larynx in Chilean patients. This finding reflects the important role that detoxification of carcinogenic compounds plays in Chilean population. However, it is necessary to increase the number of studied patients to properly establish the genetic-environmental relationship ascribed to these biomarkers.