Cyp1B1 mRNA expression in correlation to cotinine levels with respect to the Cyp1B1 L432V gene polymorphism

A web-based scoping review assessing the influence of smoking and smoking cessation on antidiabetic drug meabolism: implications for medication efficacy

Currently 1.3 billion individuals globally engage in smoking, leading to significant morbidity and mortality, particularly among diabetic patients. There is urgent need for a better understanding of how smoking influences antidiabetic treatment efficacy. The review underscores the role of cigarette smoke, particularly polycyclic aromatic hydrocarbons (PAHs), in modulating the metabolic pathways of antidiabetic drugs, primarily through the induction of cytochrome P450 (CYP450) enzymes and uridine diphosphate (UDP)-glucuronosyltransferases (UGTs), thus impacting drug pharmacokinetics and therapeutic outcomes. Furthermore, the review addresses the relatively uncharted territory of how smoking cessation influences diabetes treatment, noting that cessation can lead to significant changes in drug metabolism, necessitating dosage adjustments. Special attention is given to the interaction between smoking cessation aids and antidiabetic medications, a critical area for patient safety and effective diabetes management. This scoping review aims to provide healthcare professionals with the knowledge to better support diabetic patients who smoke or are attempting to quit, ensuring tailored and effective treatment strategies. It also identifies gaps in current research, advocating for more studies to fill these voids, thereby enhancing patient care and treatment outcomes for this at-risk population.

Association of Leu432Val (rs1056836) polymorphism of the CYP1B1 gene with lipid profile in hypertensive Slovak women

Leu432Val (rs1056836) polymorphism of the CYP1B1 gene was examined in relationship with lipid profile in hypertensive Slovak women according to their menopausal status. The entire study sample comprised 255 women suffering from hypertension aged from 39 to 65 years who were recruited from different localities in the western, southern, and middle parts of Slovakia. The participants provided a saliva or blood sample for DNA genotyping and a blood sample for biochemical analysis. The Leu432Val genotypes demonstrated statistically significant associations with all monitored atherogenic indices – total cholesterol-to-HDL-Cholesterol (AI1), Non-HDL-Cholesterol (AI2), LDL-Cholesterol-to-HDL-Cholesterol (AI3), and the logarithm of the ratio of plasma concentration of triglycerides to HDL-cholesterol (AIP log) in hypertensive pre/perimenopausal women. The mean values were significantly lower in women carrying the Val/Val genotype. In early postmenopausal hypertensive women the Leu432Val genotypes were statistically significant and associated with LDL-cholesterol (LDL-C) and AI2. The mean values of LDL-C and AI2 were significantly lower in women carrying the Leu/Leu genotype. In conclusion, the Leu432Val polymorphism may be associated with the atherogenic indices and LDL-C in hypertensive women.

Association of cytochrome P450 1B1 gene polymorphisms and environmental biomarkers with hypertension in Slovak midlife women

OBJECTIVE

This study investigated the association of the Leu432Val and Asn453Ser CYP1B1 polymorphisms and selected environmental biomarkers with hypertension (HT) in Slovak midlife women.

METHODS

We studied 575 women. Divided according to their blood pressure status: 255 with HT and 320 without HT. All data was obtained by using standard anthropometric, genetic methods and analyzed by regression models to adjust for HT risk factors such as age, obesity, smoking, and level of education.

RESULTS

Our findings revealed that CYP1B1 Leu432Val polymorphism was associated with HT, whereas no association was found between Asn453Ser polymorphism and HT. Women with at least one Val allele had significantly higher odds of HT compared to women with the Leu/Leu genotype in the total sample (Exp(B) = 1.82, CI 1.16-2.84, P = 0.009). After dividing women by menopausal status and the presence of HT environmental risk factor, the association between CYP1B1 polymorphism and HT was observed in pre/perimenopausal women (Exp(B), 2.36; 95% CI 1.13-4.92; P = 0.02), smokers (Exp(B), 3.40; 95% CI 1.48-7.82; P = 0.004), abdominal obesity (Exp(B), 2.41; 95% CI 1.23-4.75; P = 0.01) and in women with only basic education (Exp(B), 4.20, 95% CI 1.12-15.71; P = 0.03). However, general linear models did not reveal a statistically significant interactions between CYP1B1, menopausal status, and HT risk factors and their common association with HT (P > 0.05).

CONCLUSIONS

In this pilot study, we have provided novel data that supports the significant association of CYP1B1 Leu432Val gene polymorphism with HT in Slovak midlife women.

Biomarkers of Exposure and Effect in the Lungs of Smokers, Nonsmokers, and Electronic Cigarette Users

BACKGROUND

Nicotine-containing electronic cigarette (e-cig) use has become widespread. However, understanding the biological impact of e-cigs compared with smoking on the lung is needed. There are major gaps in knowledge for chronic effects and for an etiology to recent acute lung toxicity leading to death among vapers.

METHODS

We conducted bronchoscopies in a cross-sectional study of 73 subjects (42 never-smokers, 15 e-cig users, and 16 smokers). Using bronchoalveolar lavage and brushings, we examined lung inflammation by cell counts, cytokines, genome-wide gene expression, and DNA methylation.

RESULTS

There were statistically significant differences among never-smokers, e-cig users, and smokers for inflammatory cell counts and cytokines (FDR q < 0.1). The e-cig users had values intermediate between smokers and never-smokers, with levels for most of the biomarkers more similar to never-smokers. For differential gene expression and DNA methylation, e-cig users also more like never-smokers; many of these genes corresponded to smoking-related pathways, including those for xenobiotic metabolism, aryl hydrocarbon receptor signaling, and oxidative stress. Differentially methylated genes were correlated with changes in gene expression, providing evidence for biological effects of the methylation associations.

CONCLUSIONS

These data indicate that e-cigs are associated with less toxicity than cigarettes for smoking-related pathways. What is unknown may be unique effects for e-cigs not measured herein, and a comparison of smokers completely switching to e-cigs compared with former smokers. Clinical trials for smokers switching to e-cigs who undergo serial bronchoscopy and larger cross-sectional studies of former smokers with and without e-cig use, and for e-cigs who relapse back to smoking, are needed.

IMPACT

These data can be used for product regulation and for informing tobacco users considering or using e-cigs. What is unknown may be unique effects for e-cigs not measured herein, and clinical trials with serial bronchoscopy underway can demonstrate a direct relationship for changes in lung biomarkers.

Modification of adverse health effects of maternal active and passive smoking by genetic susceptibility: Dose-dependent association of plasma cotinine with infant birth size among Japanese women-The Hokkaido Study

OBJECTIVES

We aimed to assess the individual dose-response effects of eight maternal polymorphisms encoding polycyclic aromatic hydrocarbon-metabolizing and DNA-repair genes on prenatal cotinine levels according to infant birth size.

METHODS

In total, 3263 Japanese pregnant women were assigned to five groups based on plasma cotinine levels during the 8th month of pregnancy, as measured using ELISA (cut-offs: 0.21, 0.55, 11.48, and 101.67ng/mL). Analyses were performed using multiple linear regression.

RESULTS

Birth weight reduction showed a dose-dependent relationship with prenatal cotinine levels (P for trend<0.001). When considering the specific aromatic hydrocarbon receptor (AHR) (G>A, Arg554Lys; db SNP ID: rs2066853) and X-ray cross-complementing gene 1 (XRCC1) (C>T, Arg194Trp, rs1799782) genotypes, a larger birth weight reduction was noted among infants born to mothers with the highest cotinine level.

CONCLUSION

Infants born to women with specific AHR and XRCC1 genotypes may have higher genetic risks for birth weight reduction.

Polymorphisms in CYP1B1, CYP3A5, GSTT1, and SULT1A1 Are Associated with Early Age Acute Leukemia

Based on observational studies, early age leukemia (EAL) was associated with maternal hormone exposure during pregnancy. We studied the association between genetic polymorphisms of estrogen metabolism and EAL. Using data from the Brazilian Collaborative Study Group of Infant Acute Leukemia (2000–2012), 350 cases and 404 age-matched controls and 134 mothers of cases and controls were genotyped to explore polymorphisms in genes of the estrogen metabolism pathway: CYP1B1 (c.1294C>G, rs1056836), CYP3A4 (c.-392A>G, rs2740574), CYP3A5 (c.219-237G>A, rs776746), GSTM1/GSTT1 deletions, and SULT1A1 (c.638G>A, rs9282861; and c.667A>G, rs1801030). Logistic regression was used to calculate the odds ratios (OR) with 95% confidence intervals (CIs), and unconditional logistic regression was used to estimate adjusted odds ratios (aORs) by ethnicity. Because of multiple testing, p values < 0.01 were significant after Bonferroni correction. SULT1A1 (c.638G>A) was associated to infant acute lymphoblastic leukemia and acute myeloid leukemia (AML) risk in males (additive model: aOR = 0.52; 95% CI: 0.29–0.95, p = 0.03; dominant model: aOR = 2.18; 95% CI: 1.17–4.05, p = 0.01, respectively). CYP1B1 polymorphism was associated with a decreased risk of AML either for non-white or female children (additive model: OR = 0.24; 95% CI: 0.08–0.76, p < 0.01; additive model: aOR = 0.27; 95% CI: 0.08–0.89, p = 0.03, respectively). Since polymorphisms of Cytochrome P450 genes presented gender-specific risk associations, we also investigated their expression. CYP1B1 was not expressed in 57.1% of EAL cases, and its expression varied by genotype, gender, and leukemia subtype. Maternal-fetal GSTT1 null genotype was associated with risk of EAL. This study shows that polymorphisms in genes of estrogen metabolism confer genetic susceptibility to EAL, mainly in males, and maternal susceptibility genes modify the risk for developing EAL in newborns.

Effects of SNPs (CYP1B1*2 G355T, CYP1B1*3 C4326G, and CYP2E1*5 G-1293C), smoking, and drinking on susceptibility to laryngeal cancer among Han Chinese

Purpose

This study was conducted to explore the effects of genetic polymorphisms (CYP1B1*2 G355T, CYP1B1*3 C4326G, and CYP2E1*5 G-1293C) and environmental factors (smoking and drinking) on susceptibility to laryngeal cancer in a Han Chinese study group.

Methods

This case-control study included 552 Han Chinese patients diagnosed with laryngeal cancer and 666 healthy control subjects of the same ethnicity, similar age, and gender. Genetic polymorphisms were examined using multi-PCR and Matrix Assisted Laser Desorption Ionization - Time of Flight (MALDI-TOF MS) methodology. The association of these genetic and environmental factors with susceptibility to laryngeal cancer was evaluated using a statistical approach.

Results

The frequencies of all three polymorphisms in the patient cohort were significantly different from those in the control cohort. Compared to the control cohort, carriers of variant alleles of CYP1B1*2 355T and CYP2E1*5 -1293C showed a higher risk for developing laryngeal cancer (for CYP1B1*2 355T, adjusted OR = 2.657, P <0.001; for CYP2E1*5 -1293C, adjusted OR = 1.938, P <0.001), while carriers of mutation allele CYP1B1*3 4326G showed a lower risk (adjusted OR = 0.562, P <0.001). Joint effects of these polymorphisms were observed. When compared to haplotype G₃₅₅C₄₃₂₆G₋₁₂₉₃, haplotypes T₃₅₅C₄₃₂₆G₋₁₂₉₃ (adjusted OR = 1.809, P <0.001), G₃₅₅C₄₃₂₆C₋₁₂₉₃ (adjusted OR = 1.644, P = 0.044), and T₃₅₅C₄₃₂₆C₋₁₂₉₃ (adjusted OR = 3.104, P <0.001) were associated with a significantly higher laryngeal cancer risk. The adjusted ORs for non-smokers, non-drinkers, smokers, and drinkers with the GT/TT genotype at CYP1B1*2 G355T were 2.190 (P = 0.006), 2.008 (P = 0.001), 5.875 (P <0.001), and 4.518 (P <0.001), respectively.

Conclusions

CYP1B1*2 355T and CYP2E1*5 -1293C are associated with an increased laryngeal cancer risk, while CYP1B1*3 4326G is associated with a decreased risk. These polymorphisms showed joint effects on laryngeal cancer risk. Smoking and drinking showed collaborative effects with two high risk alleles (CYP1B1*2 355T and CYP1B1*3 4326G) for promoting laryngeal cancer risk.

CYP1B1 mRNA inducibility due to benzo(a)pyrene is modified by the CYP1B1 L432V gene polymorphism

Benzo(a)pyrene (BaP), a primary component of tobacco smoke, is activated by cytochrome P450 1B1 (CYP1B1). Smokers homozygous for the C-allele (*1/*1) at the CYP1B1 Leu432Val polymorphism have shown increased CYP1B1 expression, compared to smokers homozygous for the G-allele *3/*3. Since no difference has been shown in CYP1B1 expression between both genotypes in non-smokers, we assumed that the genetic impact is produced in combination with an exogenous induction (e.g. BaP). To confirm this theory and to quantify the effect, we induced human leucocytes with increasing BaP concentrations and determined CYP1B1 mRNA expression with real-time polymerase chain reaction (PCR). We incubated human leucocytes from 27 healthy donors with BaP concentrations ranging from 2.5 to 250 µM. We identified the CYP1B1 genotypes by melting curve analysis and assessed relative CYP1B1 mRNA expression using real-time PCR. Expression was related to β-2-microglobulin with the 2(-ΔΔCT) method. Inducibility of CYP1B1 mRNA by BaP was higher in leucocytes carrying the CYP1B1*1/*1 genotype than in leucocytes carrying the CYP1B1*3/*3 genotype (P = 0.012). We revealed significant differences, with BaP concentrations of 2.5 µM (P = 0.0094), 5 µM (P = 0.027), 10 µM (P = 0.0006), 25 µM (P = 0.0007) and 50 µM (P = 0.017). Homozygous carriers of the C-allele (*1/*1) at the CYP1B1 Leu432Val polymorphism show a higher response to environmental factors, such as carcinogenic BaP, than homozygous carriers of the G-allele *3/*3.

Effects of tobacco smoking and nicotine on cancer treatment

A substantial number of the world's population continues to smoke tobacco, even in the setting of a cancer diagnosis. Studies have shown that patients with cancer who have a history of smoking have a worse prognosis than nonsmokers. Modulation of several physiologic processes involved in drug disposition has been associated with long-term exposure to tobacco smoke. The most common of these processes can be categorized into the effects of smoking on cytochrome P450-mediated metabolism, glucuronidation, and protein binding. Perturbation in the pharmacokinetics of anticancer drugs could result in clinically significant consequences, as these drugs are among the most toxic, but potentially beneficial, pharmaceuticals prescribed. Unfortunately, the effect of tobacco smoking on drug disposition has been explored for only a few marketed anticancer drugs; thus, little prescribing information is available to guide clinicians on the vast majority of these agents. The carcinogenic properties of several compounds found in tobacco smoke have been well studied; however, relatively little attention has been given to the effects of nicotine itself on cancer growth. Data that identify nicotine's effect on cancer cell apoptosis, tumor angiogenesis, invasion, and metastasis are emerging. The implications of these data are still unclear but may lead to important questions regarding approaches to smoking cessation in patients with cancer.

Common genetic variation in CYP1B1 is associated with concentrations of T₄, FT₃ and FT₄ in the sera of polycystic ovary syndrome patients

CYP1B1 encodes an estrogen enzyme that oxidizes 17β-estradiol to 4-hydroxyestradiol. The evidence demonstrates there may be a relationship between CYP1B1 and thyroid function. To date, no study has evaluated if genetic polymorphisms that regulate concentrations of serum FT3 and FT4 contribute to Polycyctic Ovary Syndrome (PCOS). To identify polymorphisms in the CYP1B1 locus associated with PCOS, we genotyped three common polymorphisms across the CYP1B1 locus in 226 patients. A test for association of common variants with susceptibility to PCOS was conducted in a large cohort of 609 subjects. The functional polymorphism CYP1B1 L432V (rs1056836) is associated with serum T4 (P = 0.003), serum FT3 (P < 0.001) and serum FT4 concentrations (P < 0.001). Our study provides the first evidence that genetic variants in CYP1B1 can be associated with serum T4, FT4 and FT3 levels in PCOS. These findings imply novel pathophysiological links between the CYP1B1 locus and thyroid function in PCOS.

Single nucleotide polymorphisms as susceptibility, prognostic, and therapeutic markers of nonsmall cell lung cancer

Lung cancer is a major public health problem throughout the world. Among the most frequent cancer types (prostate, breast, colorectal, stomach, lung), lung cancer is the leading cause of cancer-related deaths worldwide. Among the two major subtypes of small cell lung cancer and nonsmall cell lung cancer (NSCLC), 85% of tumors belong to the NSCLC histological types. Small cell lung cancer is associated with the shortest survival time. Although tobacco smoking has been recognized as the major risk factor for lung cancer, there is a great interindividual and interethnic difference in risk of developing lung cancer given exposure to similar environmental and lifestyle factors. This may indicate that in addition to chemical and environmental factors, genetic variations in the genome may contribute to risk modification. A common type of genetic variation in the genome, known as single nucleotide polymorphism, has been found to be associated with susceptibility to lung cancer. Interestingly, many of these polymorphisms are found in the genes that regulate major pathways of carcinogen metabolism (cytochrome P450 genes), detoxification (glutathione S-transferases), adduct removal (DNA repair genes), cell growth/apoptosis (TP53/MDM2), the immune system (cytokines/chemokines), and membrane receptors (nicotinic acetylcholine and dopaminergic receptors). Some of these polymorphisms have been shown to alter the level of mRNA, and protein structure and function. In addition to being susceptibility markers, several of these polymorphisms are emerging to be important for response to chemotherapy/radiotherapy and survival of patients. Therefore, it is hypothesized that single nucleotide polymorphisms will be valuable genetic markers in individual-based prognosis and therapy in future. Here we will review some of the most important single nucleotide polymorphisms in the metabolic pathways that may modulate susceptibility, prognosis, and therapy in NSCLC.

RNA expressions of AHR, ARNT and CYP1B1 are influenced by AHR Arg554Lys polymorphism

AIM

The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that together with Aryl Hydrocarbon Receptor Nuclear Translocator (ARNT) controls the expression of Xenobiotic metabolising enzymes (XME) such as CYP1B1. In the absence of exogenous ligands, AHR is supposed to be involved in promotion of cell cycle progression. Polymorphisms of the AHR gene are suggested to be associated with susceptibility to cancer. Because of its critical role in xenobiotic induced toxicity and carcinogenesis as well as its ligand independent relevance we investigated the effects of AHR Arg554Lys Polymorphism on gene expression level of the AHR, ARNT and CYP1B1.

METHODS

Detection of the AHR Arg554Lys polymorphism of the AHR gene was performed by rapid capillary PCR with melting curve analysis. The quantitative Real-Time PCR (qRT-PCR) of AHR, ARNT and CYP1B1 mRNAs was carried out in white blood cells from 287 Caucasians. Calculations of expression were made with the 2(-ΔΔCT) method.

RESULTS

The relative AHR mRNA expression revealed significant differences between the two homozygote AHR genotypes Arg554Arg (11.0±1.0; n=228) and Lys554Lys (0.6±0.4; n=3; p<0.001). Also significant differences were seen between the heterozygote genotype Arg554Lys (13.0±3.0; n=40) and the homozygote Lys554Lys genotype (0.6±0.4; n=3; p<0.001). These differences above were replicated significantly in the relative mRNA expression of ARNT and CYP1B1. Comparing the determined CT-values, a correlation coefficient of R=0.748 for AHR and ARNT, R=0.626 for ARNT and CYP1B1 as well as R=0.533 for AHR and CYP1B1 was calculated.

CONCLUSION

Our findings suggest that the homozygote variant genotype of AHR Lys554Lys is associated with a significantly lower AHR, ARNT and CYP1B1 mRNA expression.