The Val158Met polymorphism in COMT gene and cancer risk: role of endogenous and exogenous catechols

Targeting Metabolic Syndrome in Hidradenitis Suppurativa by Phytochemicals as a Potential Complementary Therapeutic Strategy

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by the appearance of painful inflamed nodules, abscesses, and pus-draining sinus tracts in the intertriginous skin of the groins, buttocks, and perianal and axillary regions. Despite its high prevalence of ~0.4-1%, therapeutic options for HS are still limited. Over the past 10 years, it has become clear that HS is a systemic disease, associated with various comorbidities, including metabolic syndrome (MetS) and its sequelae. Accordingly, the life expectancy of HS patients is significantly reduced. MetS, in particular, obesity, can support sustained inflammation and thereby exacerbate skin manifestations and the chronification of HS. However, MetS actually lacks necessary attention in HS therapy, underlining the high medical need for novel therapeutic options. This review directs attention towards the relevance of MetS in HS and evaluates the potential of phytomedical drug candidates to alleviate its components. It starts by describing key facts about HS, the specifics of metabolic alterations in HS patients, and mechanisms by which obesity may exacerbate HS skin alterations. Then, the results from the preclinical studies with phytochemicals on MetS parameters are evaluated and the outcomes of respective randomized controlled clinical trials in healthy people and patients without HS are presented.

Prognostic and immunomodulatory roles of schizophrenia-associated genes HTR2A, COMT, and PRODH in pan-cancer analysis and glioma survival prediction model

Background

The shortened life expectancy in schizophrenia (SCZ) patients may be correlated with most cancers, yet there is heterogeneity in the studies examining these correlations. This study explored the expression of SCZ-related genes (HTR2A, COMT, and PRODH) in pan-cancer analysis. It helped to enhance the mechanistic understanding of the SCZ-cancer relationship and their immune mechanisms at the genetic level. Additionally, this study established a survival prediction model for glioblastoma and low-grade glioma (GBMLGG).

Methods and results

SCZ-associated genes (HTR2A, COMT, and PRODH) were subjected to pan-cancer analysis. COX regression analysis and survival analysis were carried out for differentially expressed genes in multiple cancers, and finally, GBMLGG was derived as the focus for further detailed analysis. The immune scores and immune cell infiltration analyses were performed. All three genes were considerably linked with immune infiltration in GBMLGG, consistent with survival analysis. Based on the immunocyte analysis, it was observed that CD8+ T cells might be critically involved in the survival of GBMLGG. Genomic heterogeneity studies identified correlations of three genes with GBMLGG in tumor mutational burden (TMB) and mutant-allele tumor heterogeneity (MATH). HTR2A and COMT were significantly negatively correlated in TMB. Furthermore, it was found that HTR2A had a significant positive correlation with MATH, whereas PRODH had a significant negative correlation with MATH. Accordingly, a survival prediction model was constructed for GBMLGG using these three genes and clinical data, with better results obtained when evaluated in two separate datasets. Finally, gene expression validation and further immunocyte analysis were carried out in the single-cell RNA sequencing (scRNA-seq) data of glioma.

Conclusion

SCZ-associated genes (HTR2A, COMT, and PRODH) were significantly differentially expressed in the carcinogenesis and survival of multiple cancers. The up or downregulation of gene expression varied across cancer types. In the GBMLGG analysis, upregulation of HTR2A and COMT was significantly positively correlated with carcinogenesis, while the opposite was noted for PRODH. Furthermore, a negative correlation was found between the upregulation of HTR2A and COMT and the survival of GBMLGG, and the opposite was also noted for PRODH. As reflected in the immunocyte analysis, abnormal expression of the three genes might be linked with CD8+ T cell infiltration, which might be critically involved in the survival of GBMLGG patients. The expression of HTR2A and COMT may inversely affect the efficacy of immunotherapy through the TMB pathway and further affect the prognosis of patient survival. The expression of HTR2A might positively indicate the degree of tumor heterogeneity through MATH and further affect the survival and prognosis of patients. The negative correlation of PRODH led to the opposite effect. Finally, the constructed survival prediction model demonstrated good predictive value, which was well validated in scRNA-seq analysis.

Phytotherapeuthics Affecting the IL-1/IL-17/G-CSF Axis: A Complementary Treatment Option for Hidradenitis Suppurativa?

Hidradenitis suppurativa (HS; also designated as acne inversa) is a chronic inflammatory disease characterized by painful skin lesions that occur in the axillary, inguinal, gluteal and perianal areas of the body. These lesions contain recurring deep-seated, inflamed nodules and pus-discharging abscesses and fistulas. Affecting about 1% of the population, this common disease has gained appropriate clinical attention in the last years. Associated with numerous comorbidities including metabolic syndrome, HS is considered a systemic disease that severely impairs the quality of life and shortens life expectancy. Therapeutic options for HS are limited, comprising long-term antibiotic treatment, the surgical removal of affected skin areas, and neutralization of TNF-α, the only approved systemic treatment. Novel treatment options are needed to close the therapeutic gap. HS pathogenesis is increasingly better understood. In fact, neutrophilic granulocytes (neutrophils) seem to be decisive for the development of the purulent destructive skin inflammation in HS. Recent findings suggest a key role of the immune mediators IL-1β, IL-17A and G-CSF in the migration into and activation of neutrophils in the skin. Although phytomedical drugs display potent immunoregulatory properties and have been suggested as complementary therapy in several chronic disorders, their application in HS has not been considered so far. In this review, we describe the IL-1/IL-17/G-CSF axis and evaluate it as potential target for an integrated phytomedical treatment of HS.

Associations between Polymorphisms in Phase II Enzymes and Circulating Sex-Steroid Hormones in White Postmenopausal Women

Objectives

The purpose of this cross-sectional study was to examine whether single nucleotide polymorphisms (SNPs) in enzymes that metabolize sex steroid hormones were associated with the blood levels of these hormones in postmenopausal women and if the use of menopausal hormone therapy (MHT) could modify this association.

Methods

Baseline data were collected from 932 postmenopausal women enrolled in the Minnesota Green Tea Trial. Participants filled out a questionnaire about their demographics, lifestyle factors, and medical and reproductive history. Free, bioavailable, and total serum levels of reproductive hormones were measured through liquid chromatography/tandem mass spectrometry. For genotyping of UGT1A1 (rs10928303), UGT1A4 (rs10929301, rs11673726), UGT1A6 (rs1105879, rs2070959, rs6759892), UGT1A8 (rs10167119), UGT2B7 (rs7439366), and SULT1A1 (rs9282861, rs1968752), mass spectrometry based on multiplex methods and TaqMan assays were performed. Adjusted linear models were fit to assess the associations between SNPs and blood hormones using age, body mass index (BMI), and MHT as covariates.

Results

The mean age was 59.8 years, and the mean BMI was 25.1 kg/m². Past or recent use of MHT was reported by 41.2% of the participants. SNPs in SULT1A1 (rs1968752 and rs9282861) and UGT1A4 (rs11673726) genes were significantly associated with estrone levels, whereas SNPs in UGT1A6 (rs6759892) and UGT1A8 (rs10167119) genes were significantly associated with bioavailable estradiol levels.

Conclusions

There was no evidence that MHT use modified the association between SNPs and sex-steroid hormone levels; however, further studies are needed to establish the potential clinical significance of UGT1A4 (rs11673726), UGT1A6 (rs6759892), and UGT1A8 (rs10167119) SNPs and the modulation of hormone levels in postmenopausal women.

Contribution of Biotransformations Carried Out by the Microbiota, Drug-Metabolizing Enzymes, and Transport Proteins to the Biological Activities of Phytochemicals Found in the Diet

The consumption of dietary phytochemicals has been associated with several health benefits and relevant biological activities. It is postulated that biotransformations of these compounds regulated by the microbiota, Phase I/II reactions, transport proteins, and deconjugating enzymes contribute not only to their metabolic clearance but also, in some cases, to their bioactivation. A number of factors (age, genetics, sex, physiopathological conditions, and the interplay with other dietary phytochemicals) modulating metabolic activities are important sources and contributors to the interindividual variability observed in clinical studies evaluating the biological activities of phytochemicals. In this review, we discuss all the processes that can affect the bioaccessibility and beneficial effects of these bioactive compounds. Herein, we argue that the role of these factors must be further studied to correctly understand and predict the effects observed following the intake of phytochemicals. This is, in particular, with regard to in vitro investigations, which have shown great inconsistency with preclinical and clinical studies. The complexity of in vivo metabolic activity and biotransformation should therefore be considered in the interpretation of results in vitro and their translation to human physiopathology.

Genetic regressive trajectories in colorectal cancer: A new hallmark of oligo-metastatic disease?

Colorectal cancer (CRC) originates as consequence of multiple genetic alterations. Some of the involved genes have been extensively studied (APC, TP53, KRAS, SMAD4, PIK3CA, MMR genes) in highly heterogeneous and poly-metastatic cohorts. However, about 10% of metastatic CRC patients presents with an indolent oligo-metastatic disease differently from other patients with poly-metastatic and aggressive clinical course. Which are the genetic dynamics underlying the differences between oligo- and poly-metastatic CRC? The understanding of the genetic trajectories (primary→metastatic) of CRC, in patients selected to represent homogenous clinical models, is crucial to make genotype/phenotype correlations and to identify the molecular events pushing the disease towards an increasing malignant phenotype. This information is crucial to plan innovative therapeutic strategies aimed to reverse or inhibit these phenomena. In the present study, we review the genetic evolution of CRC with the intent to give a developmental perspective on the border line between oligo- and poly-metastatic diseases.

Computational analysis of deleterious single nucleotide polymorphisms in catechol O-Methyltransferase conferring risk to post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is one of the prevalent neurological disorder which is drawing increased attention over the past few decades. Major risk factors for PTSD can be categorized into environmental and genetic factors. Among the genetic risk factors, polymorphisms in the catechol-O-methyltransferase (COMT) gene is known to be associated with the risk for PTSD. In the present study, we analysed the impact of deleterious single nucleotide polymorphisms (SNPs) in the COMT gene conferring risk to PTSD using computational based approaches followed by molecular dynamic simulations. The data on COMT gene associated with PTSD were collected from several databases including Online Mendelian Inheritance in Man (OMIM) search. Datasets related to SNP were downloaded from the dbSNP database. To study the structural and dynamic effects of COMT wild type and mutant forms, we performed molecular dynamics simulations (MD simulations) at a time scale of 300 ns. Results from screening the SNPs using the computational tools SIFT and Polyphen-2 demonstrated that the SNP rs4680 (V158M) in COMT has a deleterious effect with phenotype in PTSD. Results from the MD simulations showed that there is some major fluctuations in the structural features including root mean square deviation (RMSD), radius of gyration (Rg), root mean square fluctuation (RMSF) and secondary structural elements including α-helices, sheets and turns between wild-type (WT) and mutant forms of COMT protein. In conclusion, our study provides novel insights into the deleterious effects and impact of V158M mutation on COMT protein structure which plays a key role in PTSD.

Nordihydroguaiaretic Acid as a Novel Substrate and Inhibitor of Catechol O-Methyltransferase Modulates 4-Hydroxyestradiol-Induced Cyto- and Genotoxicity in MCF-7 Cells

Nordihydroguaiaretic acid (NDGA) is a major lignan metabolite found in Larrea spp., which are widely used in South America to treat various diseases. In breast tissue, estradiol is metabolized to the catechol estrogens such as 4-hydroxyestradiol (4-OHE₂), which have been proposed to be cancer initiators potentially involved in mammary carcinogenesis. Catechol-O-methyltransferase (COMT) catalyzes the O-methylation of catechol estrogens to their less toxic methoxy derivatives, such as 4-O-methylestradiol (4-MeOE₂). The present study investigated the novel biological activities of NDGA in relation to COMT and the effects of COMT inhibition by NDGA on 4-OHE₂-induced cyto- and genotoxicity in MCF-7 human breast cancer cells. Two methoxylated metabolites of NDGA, 3-O-methylNDGA (3-MNDGA) and 4-O-methyl NDGA (4-MNDGA), were identified in the reaction mixture containing human recombinant COMT, NDGA, and cofactors. K_m values for the COMT-catalyzed metabolism of NDGA were 2.6 µM and 2.2 µM for 3-MNDGA and 4-MNDGA, respectively. The COMT-catalyzed methylation of 4-OHE₂ was inhibited by NDGA at an IC₅₀ of 22.4 µM in a mixed-type mode of inhibition by double reciprocal plot analysis. Molecular docking studies predicted that NDGA would adopt a stable conformation at the COMT active site, mainly owing to the hydrogen bond network. NDGA is likely both a substrate for and an inhibitor of COMT. Comet and apurinic/apyrimidinic site quantitation assays, cell death, and apoptosis in MCF-7 cells showed that NDGA decreased COMT-mediated formation of 4-MeOE₂ and increased 4-OHE₂-induced DNA damage and cytotoxicity. Thus, NDGA has the potential to reduce COMT activity in mammary tissues and prevent the inactivation of mutagenic estradiol metabolites, thereby increasing catechol estrogen-induced genotoxicities.

The presence of polymorphisms in genes controlling neurotransmitter metabolism and disease prognosis in patients with prostate cancer: a possible link with schizophrenia

Polymorphisms of neurotransmitter metabolism genes were studied in patients with prostate cancer (PC) characterized by either reduced or extended serum prostate-specific antigen doubling time (PSADT) corresponding to unfavorable and favorable disease prognosis respectively. The ‘unfavorable prognosis’ group (40 cases) was defined by PSADT ≤ 2 months, whereas patients in the ‘favorable prognosis’ group (67 cases) had PSADT ≥ 30 months. The following gene polymorphisms known to be associated with neuropsychiatric disorders were investigated: a) the STin2 VNTR in the serotonin transporter SLC6A4 gene; b) the 30-bp VNTR in the monoamine oxidase A MAOA gene; c) the Val158Met polymorphism in the catechol-ortho-methyltransferase COMT gene; d) the promoter region C-521T polymorphism and the 48 VNTR in the third exon of the dopamine receptor DRD4 gene.

The STin2 12R/10R variant of the SLC6A4 gene (OR = 2.278; 95% CI = 0.953–5.444) and the -521T/T homozygosity of the DRD4 gene (OR = 1.579; 95% CI = 0.663–3.761) tended to be overrepresented in PC patients with unfavorable disease prognosis. These gene variants are regarded as protective against schizophrenia, and the observed trend may be directly related to a reduced PC risk described for schizophrenia patients. These results warrant further investigation of the potential role of neurotransmitter metabolism gene polymorphisms in PC pathogenesis.

Analytical methodologies for sensing catechol-O-methyltransferase activity and their applications

Mammalian catechol-O-methyltransferases (COMT) are an important class of conjugative enzymes, which play a key role in the metabolism and inactivation of catechol neurotransmitters, catechol estrogens and a wide range of endobiotics and xenobiotics that bear the catechol group. Currently, COMT inhibitors are used in combination with levodopa for the treatment of Parkinson's disease in clinical practice. The crucial role of COMT in human health has raised great interest in the development of more practical assays for highly selective and sensitive detection of COMT activity in real samples, as well as for rapid screening and characterization of COMT inhibitors as drug candidates. This review summarizes recent advances in analytical methodologies for sensing COMT activity and their applications. Several lists of biochemical assays for measuring COMT activity, including the probe substrates, along with their analytical conditions and kinetic parameters, are presented. Finally, the challenges and future perspectives in the field, such as visualization of COMT activity in vivo and in situ, are highlighted. Collectively, this review article overviews the practical assays for measuring COMT activities in complex biological samples, which will strongly facilitate the investigations on the relevance of COMT to human diseases and promote the discovery of COMT inhibitors via high-throughput screening.

Role of Genetic Variations in the Hepatic Handling of Drugs

The liver plays a pivotal role in drug handling due to its contribution to the processes of detoxification (phases 0 to 3). In addition, the liver is also an essential organ for the mechanism of action of many families of drugs, such as cholesterol-lowering, antidiabetic, antiviral, anticoagulant, and anticancer agents. Accordingly, the presence of genetic variants affecting a high number of genes expressed in hepatocytes has a critical clinical impact. The present review is not an exhaustive list but a general overview of the most relevant variants of genes involved in detoxification phases. The available information highlights the importance of defining the genomic profile responsible for the hepatic handling of drugs in many ways, such as (i) impaired uptake, (ii) enhanced export, (iii) altered metabolism due to decreased activation of prodrugs or enhanced inactivation of active compounds, and (iv) altered molecular targets located in the liver due to genetic changes or activation/downregulation of alternative/compensatory pathways. In conclusion, the advance in this field of modern pharmacology, which allows one to predict the outcome of the treatments and to develop more effective and selective agents able to overcome the lack of effect associated with the existence of some genetic variants, is required to step forward toward a more personalized medicine.

In Silico Prediction of the Effects of Nonsynonymous Single Nucleotide Polymorphisms in the Human Catechol-O-Methyltransferase (COMT) Gene

Catechol-O-methyltransferase (COMT) enzyme performs transfer of methyl group to endogenous and exogenous catechol substrates. The COMT enzyme draws interest because of its association with psychiatric, neurological and cardiovascular diseases, and several cancers. Moreover, many prescribed drugs, supplements, and their metabolites are used as substrates of COMT enzyme. The human COMT gene has 226 nonsynonymous single nucleotide polymorphisms (nsSNPs) according to public databases. Uncovering of the molecular impacts of nsSNPs on COMT enzyme function and structure may provide standpoint on how COMT nsSNPs affect enzyme activity and contribute to disease development. Therefore, we aimed in this study to predict possible structural and functional damaging effects of all knowns nsSNPs in COMT gene by applying various bioinformatics tools. Two hundred and twenty-six nsSNPs were obtained from Ensembl, HGMD, ClinVar, and dbSNP databases. Twenty-eight nsSNPs were found to be high-risk changes for protein structure. Some of them were detected in extremely conserved sequences have functional and structural properties. Besides, high-risk nsSNPs were also uncovered to change properties of native COMT protein. Our findings demonstrated the significance of COMT high-risk nsSNPs on protein structure and function. We expect that our results will be helpful in future studies concerning experimental evaluation of the COMT gene polymorphisms and/or the association between COMT polymorphisms and disease development.

Natural product-based nanoformulations for cancer therapy: Opportunities and challenges

Application of natural product-based nanoformulations for the treatment of different human diseases, such as cancer, is an emerging field. The conventional cancer therapeutic modalities, including surgery, chemotherapy, immunotherapy, radiotherapy has limited achievements. A larger number of drawbacks are associated with these therapies, including damage to proliferating healthy tissues, structural deformities, systemic toxicity, long-term side effects, resistance to the drug by tumor cells, and psychological problems. The advent of nanotechnology in cancer therapeutics is recent; however, it has progressed and transformed the field of cancer treatment at a rapid rate. Nanotherapeutics have promisingly overcome the limitations of conventional drug delivery system, i.e., low aqueous solubility, low bioavailability, multidrug resistance, and non-specificity. Specifically, natural product-based nanoformulations are being intentionally studied in different model systems. Where it is found that these nanoformulations has more proximity and reduced side effects. The nanoparticles can specifically target tumor cells, enhancing the specificity and efficacy of cancer therapeutic modalities which in turn improves patient response and survival. The integration of phytotherapy and nanotechnology in the clinical setting may improve pharmacological response and better clinical outcome of patients.

COMT and Alpha-Tocopherol Effects in Cancer Prevention: Gene-Supplement Interactions in Two Randomized Clinical Trials

BACKGROUND

Vitamins are among the most frequently used supplements (48% of US adults). However, little is known about contributions of genetic variation to their efficacy and safety. Multiple pathways link catechol-O-methyltransferase (COMT) to the vitamin E supplement, alpha-tocopherol, and cancer.

METHODS

Here we determined if COMT exerted pharmacogenetic effects on cancer prevention in two randomized trials of alpha-tocopherol supplementation. Pharmacogenetic effects of common COMT rs4680 (val158met), which encodes a nonsynonymous valine-to-methionine substitution, were examined in the trial plus a 10-year post-trial follow-up (overall) period of The Women's Genome Health Study (WGHS, N = 23 294), a 10-year alpha-tocopherol and aspirin trial with 10 years post-trial follow-up. Results were validated in a case/control (N = 2396/2235) subset of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC, N = 29 133). The primary outcome was total cancers. Rates of cancer types prevalent in women (colorectal, breast, lung, uterine, and lymphoma/leukemia) were also examined. All statistical tests were two-sided.

RESULTS

Random-effects meta-analysis of rs4680 genotype strata, in WGHS and ATBC overall periods, revealed differential alpha-tocopherol effects compared with placebo: met/met (hazard ratio [HR] = 0.88; 95% confidence interval [CI] = 0.80 to 0.97; P = .01), val/met (HR = 0.99; 95% CI = 0.92 to 1.06; P = .74), and val/val (HR = 1.18; 95% CI = 1.06 to 1.31; P = .002) with a statistically significant COMT by alpha-tocopherol interaction (Pinteraction <.001). Timing of effects differed, with stronger effects in WGHS trial and ATBC post-trial.

CONCLUSION

Pharmacogenetic analysis of COMT and cancer prevention in two large randomized trials revealed statistically significant COMT by alpha-tocopherol interaction, such that alpha-tocopherol was beneficial among rs4680 met-allele (28.0%), but not val-allele (22.8%) homozygotes. These effects indicate the need for additional studies of genetic variation as a determinant of the benefits and possible harms of over-the-counter supplements, like alpha-tocopherol, used for health promotion.

Systems pharmacogenomics - gene, disease, drug and placebo interactions: a case study in COMT

Disease, drugs and the placebos used as comparators are inextricably linked in the methodology of the double-blind, randomized controlled trial. Nonetheless, pharmacogenomics, the study of how individuals respond to drugs based on genetic substrate, focuses primarily on the link between genes and drugs, while the link between genes and disease is often overlooked and the link between genes and placebos is largely ignored. Herein, we use the example of the enzyme catechol-O-methyltransferase to examine the hypothesis that genes can function as pharmacogenomic hubs across system-wide regulatory processes that, if perturbed in andomized controlled trials, can have primary and combinatorial effects on drug and placebo responses.

Green Tea Catechin Extract Supplementation Does Not Influence Circulating Sex Hormones and Insulin-Like Growth Factor Axis Proteins in a Randomized Controlled Trial of Postmenopausal Women at High Risk of Breast Cancer

BACKGROUND

Consumption of green tea has been associated with reduced risk of breast cancer. Hormonal modulation has been suggested as one of the potential underlying mechanisms; however, it has yet to be fully elucidated in large, long-term human clinical trials.

OBJECTIVE

We investigated the effects of decaffeinated green tea extract (GTE) on circulating sex hormones and insulin-like growth factor (IGF) proteins.

METHODS

We conducted a placebo-controlled double-blind randomized clinical trial recruiting from 8 clinical centers in Minnesota. Participants were 538 healthy postmenopausal women randomly assigned to the GTE group (463 completed the study; mean age = 60.0 y) and 537 to the placebo group (474 completed; mean age = 59.7 y). Women in the GTE group orally took 4 decaffeinated capsules containing 1315 mg total catechins including 843 mg epigallocatechin-3-gallate daily for 1 y, whereas women in the placebo group took similar capsules containing no tea catechins. Blood sex hormones (estrone, estradiol, androstenedione, testosterone, and sex hormone-binding globulin) and IGF proteins (IGF-1 and IGF binding protein-3) were quantified at baseline and months 6 (for IGF proteins only) and 12, and were assessed as secondary outcomes of the study using a mixed-effect repeated-measures ANOVA model.

RESULTS

Women in the GTE group had significantly higher blood total estradiol (16%; P = 0.02) and bioavailable estradiol (21%; P = 0.03) than in the placebo group at month 12. There was a statistically significant interaction between GTE supplementation and duration of treatment on estradiol and bioavailable estradiol (both Ps for interaction = 0.001). The catechol-O-methyltransferase genotype did not influence blood sex hormones before or after GTE supplementation. The circulating concentrations of IGF proteins were comparable between GTE and placebo groups at all 3 time points.

CONCLUSION

These results suggest that a 12-mo GTE supplementation significantly increases circulating estradiol concentrations in healthy postmenopausal women. This trial was registered at clinicaltrials.gov as NCT00917735.

The extra virgin olive oil phenolic oleacein is a dual substrate-inhibitor of catechol-O-methyltransferase

Catechol-containing polyphenols present in coffee and tea, while serving as excellent substrates for catechol-O-methyltransferase (COMT)-catalyzed O-methylation, can also operate as COMT inhibitors. However, little is known about the relationship between COMT and the characteristic phenolics present in extra virgin olive oil (EVOO). We here selected the EVOO dihydroxy-phenol oleacein for a computational study of COMT-driven methylation using classic molecular docking/molecular dynamics simulations and hybrid quantum mechanical/molecular mechanics, which were supported by in vitro activity studies using human COMT. Oleacein could be superimposed onto the catechol-binding site of COMT, maintaining the interactions with the atomic positions involved in methyl transfer from the S-adenosyl-L-methionine cofactor. The transition state structure for the meta-methylation in the O5 position of the oleacein benzenediol moiety was predicted to occur preferentially. Enzyme analysis of the conversion ratio of catechol to O-alkylated guaiacol confirmed the inhibitory effect of oleacein on human COMT, which remained unaltered when tested against the protein version encoded by the functional Val¹⁵⁸Met polymorphism of the COMT gene. Our study provides a theoretical determination of how EVOO dihydroxy-phenols can be metabolized via COMT. The ability of oleacein to inhibit COMT adds a new dimension to the physiological and therapeutic utility of EVOO secoiridoids.

Analysis of the relationship between COMT polymorphisms and endometriosis susceptibility

This study was aimed to explore the correlation between catechol-O-methyltransferase (COMT) gene polymorphisms and endometriosis susceptibility in Chinese Han population.This case-control study recruited 134 endometriosis patients and 139 healthy individuals. COMT gene rs4680, rs2020917, and rs4646312 polymorphisms in the subjects were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. Association between COMT polymorphisms and endometriosis susceptibility was evaluated by χ test and adjusted by Logistic regression. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to present the relative risk of endometriosis.A allele of rs4680 was distinctly correlated with increased susceptibility of endometriosis (OR = 1.450, 95% CI = 1.012-2.076). However, when adjusted by the confounding factors, these associations become not significant. We failed to find any significant association between rs2020917 and endometriosis risk in the crude results. The adjusted results suggested that rs2020917 TT genotype and T allele were distinctly correlated with enhanced endometriosis risk (TT vs CC: P = .038, OR = 2.894, 95% CI = 1.060-7.903; T vs C: P = .039, OR = 1.481, 95% CI = 1.021-2.149). Besides, rs4646312 C allele was significantly correlated with endometriosis risk both in the crude (P = .027, OR = 1.502, 95% CI = 1.047-2.154) and adjusted (P = .019, OR = 1.564, 95% CI = 1.078-2.269) results.COMT polymorphisms might predict the occurrence of endometriosis.

Impact of Occupational Exposures and Genetic Polymorphisms on Recurrence and Progression of Non-Muscle-Invasive Bladder Cancer

Introduction: Additional or better markers are needed to guide the clinical monitoring of patients with non-muscle-invasive bladder cancer (NMIBC). Aim: To investigate the influence of occupational exposures and genetic polymorphisms on recurrence and progression of NMIBC. Methods: The study includes 160 NMIBC patients. We collected on questionnaire information on demographic variables, lifetime smoking history, lifetime history of occupational exposure to aromatic amines and polycyclic aromatic hydrocarbons. Genetic polymorphism (glutathione S-transferase M1; T1; P1 (GSTM1; GSTT1; GSTP1); N-acetyltransferase 1; 2 (NAT1; NAT2); cytochrome P450 1B1 (CYP1B1); sulfotransferase 1A1 (SULT1A1); myeloperoxidase (MPO); catechol-O-methyltransferase (COMT); manganese superoxide dismutase (MnSOD); NAD(P)H:quinone oxidoreductase (NQO1); X-ray repair cross-complementing group 1; 3 (XRCC1; XRCC3) and xeroderma pigmentosum complementation group (XPD)) was assessed in peripheral blood lymphocytes. DNA adducts were evaluated by 32P-postlabeling. Predictors of recurrence (histological confirmation of a newly found bladder tumor) and progression (transition of tumor from low-grade to high-grade and/or increase in TNM stage) were identified by multivariate Cox proportional hazard regression with stepwise backward selection of independent variables. Hazard ratios (HR) with 95% confidence interval (95%CI) and two-tail probability of error (p-value) were estimated. Results: The risk of BC progression decreased with the homozygous genotype “ValVal” of both COMT and MnSOD (HR = 0.195; 95%CI = 0.060 to 0.623; p = 0.006). The results on BC recurrence were of borderline significance. No occupational exposure influenced recurrence or progression. Conclusion: Our results are supported by experimental evidence of a plausible mechanism between cause (ValVal genotype of both MnSOD and COMT) and effect (decreased progression of tumor in NMIBC patients). The genetic polymorphisms associated with better prognosis may be used in clinic to guide selection of treatment for patients initially diagnosed with NMIBC. However, external validation studies are required.

Cytotoxic action of methylquercetins in human lung adenocarcinoma cells

Lung cancer is the malignant disorder associated with a high number of fatalities in women and men worldwide. Despite continuous improvements in diagnostic strategies and therapeutic modalities over the past decades, the prognosis and survival rate of patients suffering from lung cancer are still unsatisfactory and suggest the requirement for further molecular studies with different lung cancer models. In the present study, the anticancer action of two methylated metabolites of quercetin, isorhamnetin and tamarixetin, was assessed by studying their antiproliferative and apoptosis-inducing potential in human lung adenocarcinoma cell lines, A549 and HCC-44. Both methylquercetins decreased the viability of lung cancer cells at doses significantly lower than those effective for parent quercetin. The IC50 values measured for isorhamnetin were 26.6 and 15.9 µM in A549 and HCC-44 cells, respectively. For tamarixetin, the IC50 values were 19.6 and 20.3 µM in A549 and HCC-44 cells, respectively. These results were many-fold lower than the respective values for quercetin (72.2 and 107.6 µM for A549 and HCC-44 cells, respectively). Based on the activation of caspase family members, both metabolites induced apoptotic cell death in the tested cell lines, predominantly via the extrinsic pathway in A549 cells and in both intrinsic and extrinsic pathways in HCC-44 cells. As A549 and HCC-44 lines were originally established from a male and female patient, current data may suggst some gender differences in the action of quercetin derivatives. Addition of a methyl group in the 3'- or 4'-position of the B-ring of quercetin significantly increased the anticancer activity of this flavonol towards lung adenocarcinoma cells, which demonstrated that these compounds may be considered as potential novel candidates for the development of future chemotherapeutics in the fight against lung cancer.