Clinical-genetic findings in a group of subjects with macular dystrophies due to mutations in rare inherited retinopathy genes.

PURPOSE: To describe the results of clinical and molecular analyses in a group of patients suffering from inherited macular dystrophies, in which next-generation sequencing (NGS) efficiently detected rare causative mutations. METHODS: A total of eight unrelated Mexican subjects with a clinical and multimodal imaging diagnosis of macular dystrophy were included. Visual assessment methods included best corrected visual acuity, color fundus photography, Goldmann visual field tests, kinetic perimetry, dark/light adapted chromatic perimetry, full-field electroretinography, autofluorescence imaging, and spectral domain-optical coherence tomography imaging. Genetic screening was performed by means of whole exome sequencing with subsequent Sanger sequencing validation of causal variants. RESULTS: All patients exhibited a predominantly macular or cone-dominant disease. Patients' ages ranged from 12 to 60 years. Three cases had mutations in genes associated with autosomal dominant inheritance (UNC119 and PRPH2) while the remaining five cases had mutations in genes associated with autosomal recessive inheritance (CNGA3, POC1B, BEST1, CYP2U1, and PROM1). Of the total of 11 different pathogenic alleles identified, three were previously unreported disease-causing variants. CONCLUSIONS: Macular dystrophies can be caused by defects in genes that are not routinely analyzed or not included in NGS gene panels. In this group of patients, whole exome sequencing efficiently detected rare genetic causes of hereditary maculopathies, and our findings contribute to expanding the current knowledge of the clinical and mutational spectrum associated with these disorders.

Association of CYP2R1 and VDR Polymorphisms with Metabolic Syndrome Components in Non-Diabetic Brazilian Adolescents.

Associations between vitamin D deficiency and metabolic syndrome (MS) have been reported; however, the underlying biological mechanisms remain controversial. The aim of this study was to investigate the associations of CYP2R1 and VDR variants with MS and MS components in non-diabetic Brazilian adolescents. This cross-sectional study included 174 adolescents who were classified as overweight/obese. Three CYP2R1 variants and four VDR variants were identified by allelic discrimination. The CYP2R1 polymorphisms, rs12794714 (GG genotype) (odds ratio [OR] = 3.54, 95% confidence interval [CI] = 1.24-10.14, p = 0.023) and rs10741657 (recessive model-GG genotype) (OR = 3.90, 95%CI = 1.18-12.92, p = 0.026) were significantly associated with an increased risk of MS and hyperglycemia, respectively. The AG + GG genotype (dominant model) of the rs2060793 CYP2R1 polymorphism was associated with hyperglycemia protection (OR = 0.28, 95%CI = 0.08-0.92, p = 0.037). Furthermore, the CC genotype (recessive model) of the rs7975232 VDR polymorphism was significantly associated with a risk of hypertension (OR = 5.91, 95%CI = 1.91-18.32, p = 0.002). In conclusion, the CYP2R1 rs12794714 polymorphism could be considered a possible new molecular marker for predicting the risk of MS; CYP2R1 rs10741657 polymorphism and VDR rs7975232 polymorphism are associated with an increased risk of diabetes and hypertension in adolescents with overweight/obesity.

Polymorphisms CYP2R1 rs10766197 and CYP27B1 rs10877012 in Multiple Sclerosis: A Case-Control Study.

BACKGROUND: Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease. Low vitamin D levels have been reported to be a risk factor for MS, and genetic variances could be implicated. The aim of this study was to evaluate the association of MS with rs10766197 polymorphism of CYP2R1 gene and rs10877012 polymorphism of CYP27B1 gene. The second aim was to analyse whether these polymorphisms are associated with the severity of the progression of MS. Material and Methods. In a case-control study, we included 116 MS patients and 226 controls, all of whom were Mexican Mestizo. MS was diagnosed by McDonald criteria (2017). A complete neurological evaluation was performed to evaluate the severity of disease progression. Serum 25-hydroxyvitamin D [25(OH) vitamin D] levels were measured by ELISA. Single nucleotide polymorphisms rs10766197 of CYP2R1 gene and rs10877012 SNP of CYP27B1 gene were genotyped by real-time PCR. RESULTS: Serum 25(OH) vitamin D levels were lower in MS patients than in controls (p = 0.009). No differences were observed between serum 25(OH) vitamin D levels of MS patients with severe progression compared to low progression (p = 0.88). A higher frequency of the A allele of CYP2R1 rs10766197 was observed between MS patients and controls (p = 0.05). No differences were observed in the frequency of T allele of CYP27B1 rs10877012 (p = 0.65). In subanalysis, patients with GA + AA genotypes of CYP2R1 rs10766197 had an increased risk of MS compared to controls (p = 0.03). No increased risk was observed in GT + TT genotypes of CYP27B1 rs10877012 (p = 0.63). No differences were observed in allele frequencies of either polymorphism between patients with severe vs. low disease progression. CONCLUSION: Lower serum 25(OH) vitamin D levels were observed in MS patients than in controls, although these levels were not associated with disease progression. Carriers of GA + AA genotypes of CYP2R1 rs10766197 had an increased risk of MS. None of these polymorphisms was associated with severe progression of MS.

Protective Effects of Dietary Capsaicin on the Initiation Step of a Two-Stage Hepatocarcinogenesis Rat Model.

Capsaicin (CPS), an ingredient of Capsicum plants, has anti-inflammatory, antioxidant and antitumoral properties. The mechanisms of CPS on hepatocarcinogenesis preclinical bioassays are not described. Thus, the protective effects CPS were evaluated in the early stages of chemically-induced hepatocarcinogenesis. Male Wistar rats received diet containing 0.01% or 0.02% CPS for 3 weeks. Afterwards, animals received a dose of hepatocarcinogen diethylnitrosamine (DEN, 100 mg/kg body weight). From weeks 4-12, groups had their diet replaced by a 0.05% phenobarbital supplemented one to promote DEN-induced preneoplastic lesions. Animals were euthanized 24 h after DEN administration (n = 5/group) or at week 12 (n = 9/group). The estimated CPS intake in rats resembled human consumption. At the end of week 3, dietary 0.02% CPS attenuated DEN-induced oxidative damage and, consequently, hepatocyte necrosis by reducing serum alanine aminotransferase levels, liver CD68-positive macrophages, lipid peroxidation, while increasing antioxidant glutathione system. Additionally, 0.02% CPS upregulated vanilloid Trpv1 receptor and anti-inflammatory epoxygenase Cyp2j4 genes in the liver. Ultimately, previous 0.02% CPS intake decreased the number of GST-P-positive preneoplastic lesions at week 12. Thus, CPS attenuated preneoplastic lesion development, primarily by diminishing DEN-induced oxidative liver injury. Findings indicate that CPS is a promising chemopreventive agent when administered after and during the early stages of hepatocarcinogenesis.

Association of Vitamin D Metabolism Gene Polymorphisms with Autoimmunity: Evidence in Population Genetic Studies.

A high prevalence of vitamin D (calcidiol) serum deficiency has been described in several autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (AR), and systemic lupus erythematosus (SLE). Vitamin D is a potent immunonutrient that through its main metabolite calcitriol, regulates the immunomodulation of macrophages, dendritic cells, T and B lymphocytes, which express the vitamin D receptor (VDR), and they produce and respond to calcitriol. Genetic association studies have shown that up to 65% of vitamin D serum variance may be explained due to genetic background. The 90% of genetic variability takes place in the form of single nucleotide polymorphisms (SNPs), and SNPs in genes related to vitamin D metabolism have been linked to influence the calcidiol serum levels, such as in the vitamin D binding protein (VDBP; rs2282679 GC), 25-hydroxylase (rs10751657 CYP2R1), 1α-hydroxylase (rs10877012, CYP27B1) and the vitamin D receptor (FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) VDR). Therefore, the aim of this comprehensive literature review was to discuss the current findings of functional SNPs in GC, CYP2R1, CYP27B1, and VDR associated to genetic risk, and the most common clinical features of MS, RA, and SLE.

Epigenetic modifications in the GH-dependent Prlr, Hnf6, Cyp7b1, Adh1 and Cyp2a4 genes.

Many sex differences in liver gene expression originate in the brain, depend on GH secretion and may underlie sex disparities in hepatic disease. Because epigenetic mechanisms may contribute, we studied promoter methylation and microRNA abundance in the liver, associated with expression of sexual dimorphic genes in mice with selective disruption of the dopamine D2 receptor in neurons (neuroDrd2KO), which decreases hypothalamic Ghrh, pituitary GH, and serum IGFI and in neonatally androgenized female mice which have increased pituitary GH content and serum IGFI. We evaluated mRNA levels of the female predominant genes prolactin receptor (Prlr), alcohol dehydrogenase 1 (Adh1), Cyp2a4, and hepatocyte nuclear transcription factor 6 (Hnf6) and the male predominant gene, Cyp7b1. Female predominant genes had higher mRNA levels compared to males, but lower methylation was only detected in the Prlr and Cyp2a4 female promoters. In neuroDrd2KO mice, sexual dimorphism was lost for all genes; the upregulation (feminization) of Prlr and Cyp2a4 in males correlated with decreased methylation of their promoters, and the downregulation (masculinization) of Hnf-6 mRNA in females correlated inversely with its promoter methylation. Neonatal androgenization of females evoked a loss of sexual dimorphism only for the female predominant Hnf6 and Adh1 genes, but no differences in promoter methylation were found. Finally, mmu-miR-155-5p, predicted to target Cyp7b1 expression, was lower in males in association with higher Cyp7b1 mRNA levels compared to females and was not modified in neuroDrd2KO or TP mice. Our results suggest specific regulation of gene sexually dimorphic expression in the liver by methylation or miRNAs.

Relationship of anti-tuberculosis drug-induced liver injury and genetic polymorphisms in CYP2E1 and GST

ABSTRACT Setting: Treatment of tuberculosis (TB) can result in Drug-Induced Liver Injury (DILI) since hepatotoxic metabolites are formed during the biotransformation of isoniazid (INH).DILI can be related to the genetic profile of the patient. Single nucleotide polymorphisms in the CYP2E1 gene and GSTM1 and GSTT1 deletion polymorphisms have been associated with adverse events caused by INH. Objective: To characterize the genetic polymorphisms of CYP2E1, GSTT1 and GSTM1 in TB carriers. Design: This is an observational prospective cohort study of 45 patients undergoing treatment of TB. PCR-RFLP and multiplex-PCR were used. Results: The distribution of genotypic frequency in the promoter region (CYP2E1 gene) was: 98% wild genotype and 2% heterozygous. Intronic region: 78% wild genotype; 20% heterozygous and 2% homozygous variant. GST enzyme genes: 24% Null GSTM1 and 22% Null GSTT1. Patients with any variant allele of the CYP2E1 gene were grouped in the statistical analyses. Conclusion: Patients with the CYP2E1 variant genotype or Null GSTT1 showed higher risk of presenting DILI (p = 0.09; OR: 4.57; 95% CI: 0.75-27.6). Individuals with both genotypes had no increased risk compared to individuals with one genotype.

Relationship of anti-tuberculosis drug-induced liver injury and genetic polymorphisms in CYP2E1 and GST.

SETTING: Treatment of tuberculosis (TB) can result in Drug-Induced Liver Injury (DILI) since hepatotoxic metabolites are formed during the biotransformation of isoniazid (INH). DILI can be related to the genetic profile of the patient. Single nucleotide polymorphisms in the CYP2E1 gene and GSTM1 and GSTT1 deletion polymorphisms have been associated with adverse events caused by INH. OBJECTIVE: To characterize the genetic polymorphisms of CYP2E1, GSTT1 and GSTM1 in TB carriers. DESIGN: This is an observational prospective cohort study of 45 patients undergoing treatment of TB. PCR-RFLP and multiplex-PCR were used. RESULTS: The distribution of genotypic frequency in the promoter region (CYP2E1 gene) was: 98% wild genotype and 2% heterozygous. Intronic region: 78% wild genotype; 20% heterozygous and 2% homozygous variant. GST enzyme genes: 24% Null GSTM1 and 22% Null GSTT1. Patients with any variant allele of the CYP2E1 gene were grouped in the statistical analyses. CONCLUSION: Patients with the CYP2E1 variant genotype or Null GSTT1 showed higher risk of presenting DILI (p=0.09; OR: 4.57; 95% CI: 0.75-27.6). Individuals with both genotypes had no increased risk compared to individuals with one genotype.

Role of NF-κB in cytochrome P450 epoxygenases down-regulation during an inflammatory process in astrocytes.

Cytochrome P450 (CYP) epoxygenases and their metabolic products, epoxyeicosatrienoic acids (EETs), have been proposed as important therapeutic targets in the brain. However, CYP expression can be modified by the presence of diverse pro-inflammatory cytokines and the subsequent activation of the NF-κB pathway. It has been indicated that CYP epoxygenases are down-regulated by inflammation in the heart, kidney and liver. However, up to this point, there has been no evidence regarding regulation of CYP epoxygenases during inflammation in the brain. Therefore, in order to explore the effects of inflammation and NF-κB activation in CYP2J3 and CYP2C11 regulation, rat primary astrocytes cultures were treated with LPS with and without IMD-0354 (selective NF-κB inhibitor). Cyp2j3 and Cyp2c11 mRNA expression was determined by qRT-PCR; protein expression was determined by immunofluorescence and by Western Blot and total epoxygenase activity was determined by the quantification of EETs by ELISA. NF-κB binding sites in Cyp2j3 and Cyp2c11 promoter regions were bioinformatically predicted and Electrophoretic Mobility Shift Assays (EMSA) were performed to determine if each hypothetic response element was able to bind NF-κB complexes. Results shown that LPS treatment is able to down-regulate astrocyte CYP2J3 and CYP2C11 mRNA, protein and activity. Additionally, we have identified NK-κB as the transcription factor involved in this regulation.

Common and Rare Variants Genetic Association Analysis of Cigarettes per Day Among Ever-Smokers in Chronic Obstructive Pulmonary Disease Cases and Controls.

INTRODUCTION: Cigarette smoking is a major environmental risk factor for many diseases, including chronic obstructive pulmonary disease (COPD). There are shared genetic influences on cigarette smoking and COPD. Genetic risk factors for cigarette smoking in cohorts enriched for COPD are largely unknown. METHODS: We performed genome-wide association analyses for average cigarettes per day (CPD) across the Genetic Epidemiology of COPD (COPDGene) non-Hispanic white (NHW) (n = 6659) and African American (AA) (n = 3260), GenKOLS (the Genetics of Chronic Obstructive Lung Disease) (n = 1671), and ECLIPSE (the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) (n = 1942) cohorts. In addition, we performed exome array association analyses across the COPDGene NHW and AA cohorts. We considered analyses across the entire cohort and stratified by COPD case-control status. RESULTS: We identified genome-wide significant associations for CPD on chromosome 15q25 across all cohorts (lowest p = 1.78 × 10-15), except in the COPDGene AA cohort alone. Previously reported associations on chromosome 19 had suggestive and directionally consistent associations (RAB4, p = 1.95 × 10-6; CYP2A7, p = 7.50 × 10-5; CYP2B6, p = 4.04 × 10-4). When we stratified by COPD case-control status, single nucleotide polymorphisms on chromosome 15q25 were nominally associated with both NHW COPD cases (ß = 0.11, p = 5.58 × 10-4) and controls (ß = 0.12, p = 3.86 × 10-5) For the gene-based exome array association analysis of rare variants, there were no exome-wide significant associations. For these previously replicated associations, the most significant results were among COPDGene NHW subjects for CYP2A7 (p = 5.2 × 10-4). CONCLUSIONS: In a large genome-wide association study of both common variants and a gene-based association of rare coding variants in ever-smokers, we found genome-wide significant associations on chromosome 15q25 with CPD for common variants, but not for rare coding variants. These results were directionally consistent among COPD cases and controls. IMPLICATIONS: We examined both common and rare coding variants associated with CPD in a large population of heavy smokers with and without COPD of NHW and AA descent. We replicated genome-wide significant associations on chromosome 15q25 with CPD for common variants among NHW subjects, but not for rare variants. We demonstrated for the first time that common variants on chromosome 15q25 associated with CPD are similar among COPD cases and controls. Previously reported associations on chromosome 19 showed suggestive and directionally consistent associations among common variants (RAB4, CYP2A7, and CYP2B6) and for rare variants (CYP2A7) among COPDGene NHW subjects. Although the genetic effect sizes for these single nucleotide polymorphisms on chromosome 15q25 are modest, we show that this creates a substantial smoking burden over the lifetime of a smoker.

Interstrain differences in the expression and activity of Cyp2a5 in the mouse liver.

BACKGROUND: Cytochrome P450 2A5 (Cyp2a5), a mouse enzyme orthologous of human CYP2A6, catalyzes a number of toxicologically important reactions, including the metabolism of nicotine, aflatoxin B1, and several other xeno- and endobiotics. Cyp2a5 expression is complex and not yet fully understood. We investigated inter-strain differences in the activity and mRNA expression of hepatic Cyp2a5. Cyp1a1/2 and Cyp2b9/10 activities were evaluated for comparative purposes. Data on the interstrain differences in the expression and activity of Cyp2a5 are important to select a suitable mouse model for studying CYP2A6-mediated metabolism. RESULTS: Activity of Cyp2a5 (coumarin 7-hydroxylase) was highest in DBA-2 and DBA-1, intermediate in B6D2F1 (hybrid) and low in the remaining strains (C57BL/6, C57BL/10, CBA, BALB/cAn, SW). Contrasting with the activity, background levels of Cyp2a4/5 mRNA did not differ between high- and low-activity murine strains. Phenobarbital (PB, 80 mg/kg body weight/day × 3 days, i.p.) increased Cyp2a5, Cyp1a1/2 (ethoxyresorufin-O-deethylase) and Cyp2b9/10 (bezyloxyresorufin-O-debenzylase) activities while only Cyp2a5 was enhanced by pyrazole (PYR, 100 mg/kg body weight/day × 3 days, i.p.). Inductions of Cyp2a5 activity by PYR and PB were accompanied by increases of Cyp2a4/5 mRNA. PYR and PB did not upregulate heme oxygenase-1 (hmox-1) mRNA expression in any strain, a finding that is apparently at odds with the notion that Cyp2a5 and hmox-1 inductions are coordinated events. CONCLUSIONS: Since background levels of Cyp2a4/5 gene transcripts of high-activity strains did not differ from those of low-activity mice, distinct constitutive activities did not result from different transcription rates and/or mRNA half-lives. Results therefore suggested that interstrain differences in constitutive activity of Cyp2a5 possibly arise from distinct translation efficiencies, protein half-lives and/or enzyme kinetics toward the substrate. Data from this study indicated that all tested strains are suitable models for studying toxicants that are substrates for human CYP2A6; DBA-2, DBA-1 and the hybrid B62DF1, however, have the advantage of presenting high constitutive activities of Cyp2a5.

Effect of weaning age on cortisol release in piglets.

The effect of weaning age on the adrenal cortex, which plays a vital role in the stress response, is currently unknown. Therefore, plasma adrenocorticotropic hormone (ACTH) and cortisol levels, weights and relative weights of adrenal glands, and steroidogenesis-related protein and enzyme expression levels in piglets weaned on different days were determined. Piglets weaned at 35 days had significantly lower ACTH levels than those weaned at 14 or 21 days, and cortisol levels of piglets weaned at 21, 28, and 35 days were significantly lower than those of piglets weaned on day 14. Adrenal gland weights of piglets weaned at 28 and 35 days and relative adrenal gland weights of piglets weaned at 35 days were significantly lower than those of piglets weaned at 14 days. However, no significant difference was detected in the expression of melanocortin-type 2 receptor mRNA, which is associated with weaning age. Steroidogenic acute-regulatory (StAR) mRNA and cholesterol side-chain cleavage cytochrome P450 mRNA expression levels in piglets weaned at 28 and 35 days were significantly lower than in those weaned at 14 or 21 days, and P450 11ß mRNA expression levels in piglets weaned at 28 and 35 days were significantly lower than in those weaned at 14 days. Therefore, early-weaned piglets exhibited increased adrenal gland weights and StAR and steroidogenic enzyme expression, all of which contributed to high cortisol levels. The high plasma ACTH and cortisol levels in early-weaned piglets indicate that these animals would be greatly affected by stress.

SNP genetic polymorphisms of MDR-1, CYP1A2 and CYPB11 genes in four canine breeds upon toxicological evaluation.

The fields of pharmacogenetics and pharmacogenomics have become increasingly promising regarding the clinical application of genetic data to aid in prevention of adverse reactions. Specific screening tests can predict which animals express modified proteins or genetic sequences responsible for adverse effects associated with a drug. Among the genetic variations that have been investigated in dogs, the multidrug resistance gene (MDR) is the best studied. However, other genes such as CYP1A2 and CYP2B11 control the protein syntheses involved in the metabolism of many drugs. In the present study, the MDR-1, CYP1A2 and CYP2B11 genes were examined to identify SNP polymorphisms associated with these genes in the following four canine breeds: Uruguayan Cimarron, Border Collie, Labrador Retriever and German Shepherd. The results revealed that several SNPs of the CYP1A2 and CYP2B11 genes are potential targets for drug sensitivity investigations.

Modulation of cytochrome P450 2A5 activity by lipopolysaccharide: low-dose effects and non-monotonic dose-response relationship.

Mouse cytochrome P450 (CYP) 2A5 is induced by inflammatory conditions and infectious diseases that down-regulate the expression and activity of most other CYP isoforms. Enhanced oxidative stress and nuclear factor (erythroid 2-related factor) 2 (Nrf2) transcription factor activation have been hypothesised to mediate up-regulation of CYP2A5 expression in the murine liver. The unique and complex regulation of CYP2A5, however, is far from being thoroughly elucidated. Sepsis and high doses of bacterial lipopolysaccharide (LPS) elicit oxidative stress in the liver, but depression, not induction, of CYP2A5 has been observed in studies of mice treated with LPS. The foregoing facts prompted us to evaluate the response of CYP2A5 liver activity in female DBA-2 mice over a broad range of LPS doses (0, 0.025, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, and 20 mg/kg). Cytokine levels (interleukin [IL]-2, IL-4, IL-6, IL-10, IL-17A, interferon gamma, tumour necrosis factor alpha) and nitric oxide (NO) were measured in the blood serum. Activities of CYP1A (EROD) and CYP2B (BROD) in the liver were also determined for comparative purposes. LPS depressed CYP2A5 at low doses (0.025-2.0 mg/kg) but not at doses (>2 mg/kg) that increased pro-inflammatory cytokines and NO serum levels, and depressed CYP1A and CYP2B activities. Blockade of pro-inflammatory cytokines and the overproduction of NO induced by co-treatment with pentoxifylline and LPS and iNOS inhibition with aminoguanidine both extended down-regulation of CYP2A5 to the high dose range while not affecting LPS-induced depression of CYP1A and CYP2B. Overall, the results suggested that NO plays a role in the reversal of the low-dose LPS-induced depression of CYP2A5 observed when mice were challenged with higher doses of LPS.

Differential expression of cytochrome P450 enzymes in normal and tumor tissues from childhood rhabdomyosarcoma.

Intratumoral expression of genes encoding Cytochrome P450 enzymes (CYP) might play a critical role not only in cancer development but also in the metabolism of anticancer drugs. The purpose of this study was to compare the mRNA expression patterns of seven representative CYPs in paired tumor and normal tissue of child patients with rabdomyosarcoma (RMS). Using real time quantitative RT-PCR, the gene expression pattern of CYP1A1, CYP1A2, CYP1B1, CYP2E1, CYP2W1, CYP3A4, and CYP3A5 were analyzed in tumor and adjacent non-tumor tissues from 13 child RMS patients. Protein concentration of CYPs was determined using Western blot. The expression levels were tested for correlation with the clinical and pathological data of the patients. Our data showed that the expression levels of CYP1A1 and CYP1A2 were negligible. Elevated expression of CYP1B1 mRNA and protein was detected in most RMS tumors and adjacent normal tissues. Most cancerous samples exhibit higher levels of both CYP3A4 and CYP3A5 compared with normal tissue samples. Expression of CYP2E1 mRNA was found to be significantly higher in tumor tissue, however no relation was found with protein levels. CYP2W1 mRNA and/or protein are mainly expressed in tumors. In conclusion, we defined the CYP gene expression profile in tumor and paired normal tissue of child patients with RMS. The overexpression of CYP2W1, CYP3A4 and CYP3A5 in tumor tissues suggests that they may be involved in RMS chemoresistance; furthermore, they may be exploited for the localized activation of anticancer prodrugs.

RNA expression of cytochrome P450 in Mexican women with breast cancer.

Involvement of cytochrome P450 genes (CYPs) in breast cancer (BCa) may differ between populations, with expression patterns affected by tumorigenesis. This may have an important role in the metabolism of anticancer drugs and in the progression of cancer. The aim of this study was to determine the mRNA expression patterns of four cytochrome P450 genes (CYP2W1, 3A5, 4F11 and 8A1) in Mexican women with breast cancer. Real- time PCR analyses were conducted on 32 sets of human breast tumors and adjacent non-tumor tissues, as well as 20 normal breast tissues. Expression levels were tested for association with clinical and pathological data of patients. We found higher gene expression of CYP2W1, CYP3A5, CYP4F11 in BCa than in adjacent tissues and only low in normal mammary glands in our Mexican population while CYP8A1 was only expressed in BCa and adjacent tissues. We found that Ki67 protein expression was associated with clinicopathological features as well as with CYP2W1, CYP4F11 and CYP8A1 but not with CYP3A5. The results indicated that breast cancer tissues may be better able to metabolize carcinogens and other xenobiotics to active species than normal or adjacent non-tumor tissues.

Neonatal xenoestrogen exposure alters growth hormone-dependent liver proteins and genes in adult female rats.

The hypothalamic-growth hormone (GH)-liver axis represents a new concept in endocrine regulation of drug toxicity. Preponderant sex differences are found in liver gene expression, mostly dependent on the sexually dimorphic pattern of GH secretion which is set during the neonatal period by gonadal steroids. We tested if GH-dependent sexually dimorphic liver enzymes and proteins was perturbed by neonatal Bisphenol A (BPA) treatment in female rats. Female rats were sc injected with BPA (50 or 500 µg/50 µl) or castor oil vehicle from postnatal day 1 to 10. At five months serum prolactin, pituitary GH, and serum and liver insulin growth factor-I (IGF-I) were measured by RIA. Major urinary proteins (MUPs) were determined by electrophoresis. Liver Cyp2c11, Cyp2c12, Adh1, Hnf6, and Prlr mRNA levels were determined by real time PCR. Pituitary GH content and liver IGF-I concentration were increased by neonatal BPA treatment, indicating partial masculinization of the GH axis in treated females. GH-dependent female predominant liver enzyme genes (Cyp2c12 and Adh1) and a transcription factor (Hnf6) were downregulated or defeminized, while there were no changes in a male predominant gene (Cyp2c11) or protein (MUP). Our findings indicate that perinatal exposure to BPA may compromise the sexually dimorphic capacity of the liver to metabolize drugs and steroids.

CYP2W1, CYP4F11 and CYP8A1 polymorphisms and interaction of CYP2W1 genotypes with risk factors in Mexican women with breast cancer.

Breast cancer (BCa) is the leading type of cancer in Mexican women. Genetic factors, such as single nucleotide polymorphisms (SNP) of P450 system, have been reported in BCa. In this report, and for the first time in the literature, we analyzed the rs3735684 (7021 G>A), rs11553651 (15016 G>T) and rs56195291 (60020 C>G) polymorphisms in the CYP2W1, 4F11 and 8A1 genes in patients with BCa and in healthy Mexican women to identify a potential association between these polymorphisms and BCa risk. Patients and controls were used for polymorphism analysis using an allelic discrimination assay with TaqMan probes and confirmed by DNA sequencing. Links with clinic-pathological characteristics were also analyzed. Statistical analysis was performed using the standard χ2 or Fisher exact test statistic. No significant differences were observed in the distributions of CYP2W1 (OR 8.6, 95%CI 0.43-172.5 P>0.05; OR 2.0, 95%CI 0.76-5.4, P>0.05) and CYP4F11 (OR 0.3, 95%CI 0.01-8.4 P>0.05) genotypes between the patients and controls. Only the CYP8A1 CC genotype was detected in patients with BCa and the controls. All polymorphism frequencies were in Hardy-Weinberg Equilibrium (HWE) in the controls (P>0.05). We found a significant association between BCa risk and smoking, use of oral contraceptives or hormonal replacement therapy (HRT), obesity, hyperglycemia, chronic diseases, family history of cancer and menopausal status in the population studied (P<0.05). Tobacco, oral contraceptive or HRT, chronic diseases and obesity or overweight were strongly associated with almost eight, thirty-five, nine and five-fold increased risk for BCa. Tobaco, obesity and hyperglycemia significantly increased the risk of BCa in the patients carrying variant genotypes of CYP2W1 (P<0.05). These results indicate that the CYP2W1 rs3735684, CYP4F11 rs11553651 and CYP8A1 rs56195291 SNPs are not a key risk factor for BCa in Mexican women. This study did not detect an association between the CYP2W1, 4F11 and 8A1 genes polymorphisms and BCa risk in a Mexican population. However, some clinico-pathological risk factors interact with CYP2W1 genotypes and modifies susceptibility to BCa.

Differential neonatal testosterone imprinting of GH-dependent liver proteins and genes in female mice.

Abnormal exposure to steroid hormones within a critical developmental period elicits permanent alterations in female reproductive physiology in rodents, but the impact on the female GH axis and the underlying sexual differences in hepatic enzymes have not been described in detail. We have investigated the effect of neonatal androgenization of female mice (achieved by s.c. injection of 100 µg testosterone propionate (TP) on the day of birth: TP females) on the GHRH-somatostatin-GH axis and downstream GH targets, which included female and male predominant liver enzymes and secreted proteins. At 4 months of age, an organizational effect of neonatal testosterone was evidenced on hypothalamic Ghrh mRNA level but not on somatostatin (stt) mRNA level. Ghrh mRNA levels were higher in males than in females, but not in TP females. Increased expression in TP females correlated with increased pituitary GH content and somatotrope population, increased serum and liver IGF-I concentration, and ultimately higher body weight. Murine urinary proteins (MUPs) that were excreted at higher levels in male urine, and whose expression requires pulsatile occupancy of liver GH receptors, were not modified in TP females and neither was liver Mup 1/2/6/8 mRNA expression. Furthermore, a male predominant liver gene (Cyp2d9) was not masculinized in TP females either, whereas two female predominant genes (Cyp2b9 and Cyp2a4) were defeminized. These data support the hypothesis that neonatal steroid exposure contributes to the remodeling of the GH axis and defeminization of hepatic steroid-metabolizing enzymes, which may compromise liver physiology.

Celecoxib activates Stat5 and restores or increases the expression of growth hormone-regulated genes in hepatocarcinogenesis.

We have previously evaluated the chemopreventive effect of celecoxib on preneoplastic lesions in rat liver. However, though the effects of celecoxib have been tested in a variety of carcinomas, there has not been a study on the modulation of gene expression in response to this drug. Here, we evaluated the effect of celecoxib on the gene expression profile associated with hepatocarcinogenesis. Male Sprague-Dawley rats underwent the modified resistant hepatocyte model and were fed a diet containing 1500 ppm of celecoxib. Gene expression profiles were evaluated using DNA microarrays and further validations were performed using quantitative PCR, western blotting and immunohistochemical staining. Celecoxib modulated the expression of 46 genes, and those regulated by growth hormone were selected for further analysis. Celecoxib significantly upregulated the expression of the Cyp2b1/2, Cyp3a1, and alpha2-urinary globulin (alpha2uG) genes and restored the expression of Cyp2b3 to normal. The protein expression of Cyp2b1/2 was increased, but the expressions of Cyp3a1 and alpha2uG were only restored to normal levels. The increased Cyp2b1/2 expression in response to celecoxib was mainly confined to preneoplastic lesions. A search for the upstream mediator of these genetic alterations found that carcinogenesis inactivated by 87% the signal transducer and activator of transcription 5 (Stat5), a transcription factor that is activated by growth hormone signaling, but celecoxib treatment restored its activation. In conclusion, these results suggest that celecoxib exerts anticancer effects on altered hepatic cells by restoring mRNA and the protein expression levels of specific genes, in part through the reactivation of Stat5.