Association between the COMT Val158Met polymorphism and breast cancer risk: a meta-analysis of 30,199 cases and 38,922 controls

Accurate and sensitive detection of Catechol-O-methyltransferase activity by liquid chromatography with fluorescence detection

Catechol-O-methyltransferase (COMT) is a major drug metabolizing enzyme in humans. COMT expression is directedly associated with various mental diseases and cancers due to its essential role in catalyzing metabolic inactivation of endogenous catecholamines and catechol estrogens. However, a practical method to precisely measure COMT activities in biological samples is lacking. In the current study, we established a liquid chromatography-fluorescence detection (LC-FD) method based on fluorometric detection of the methylated product of 3-BTD, a fluorescent probe for COMT, to sensitively quantify COMT activities in human erythrocytes and cell homogenates. Assay validation of the established LC-FD based method was conducted for selectivity and sensitivity, range of linearity, precision and accuracy, recovery, biological matrices effect and stability. The limit of quantification for 3-BTMD (the methylated product of 3-BTD by COMT) of this method was 0.0083 nM, which is nearly 10-fold lower than that for previously published methods. The method was precise with intra- and inter-day relative standard deviation (RSD) lower than 5%. In addition, this method showed an excellent anti-interference ability with no effects of the endogenous substances on the fluorometric detection of 3-BTMD. The practical use of this method was established by its successful application for the measurement of COMT activities in individual human erythrocytes (n = 13), and in cell homogenates generated from four different human cell lines. Our results suggest that this method will be of great value in accurately determining the native activity of COMT in biological samples, which is beneficial for a complete understand of the role of COMT both in physiological and pathological conditions.

Associations of endocrine stress-related gene polymorphisms with risk of autism spectrum disorders: Evidence from an integrated meta-analysis

Autism spectrum disorders (ASD) are related to serotonin transporter (5-HTT) and catechol-O-methyl transferase (COMT) as two most monoaminergic polymorphic variations. However, multiple studies assessing rs4680 and 5-HTTLPR variants in ASD have reported inconsistent results. Therefore, we conducted an integrated meta-analysis to combine case-control and transmission/disequilibrium test (TDT) studies to determine whether COMT and 5-HTT are associated with ASD. We searched multiple electronic databases (PubMed, EmBase and Web of Science) to identify studies assessing the rs4680 and 5-HTTLPR variants in ASD from Jan 1997 to Dec 2016. Then allelic data from case-control and TDT studies were analyzed by the Catmap package in the R software. A total of 5 studies were eligible for the meta-analysis of rs4680, including 3 case-control, 1 TDT and 1 TDT & case-control studies. Meanwhile, 22 studies of 5-HTTLPR were available, including 16 TDT, 4 case-control and 2 TDT & case-control studies. The current meta-analysis included 814 ASD cases, 741 controls and 311 families related to rs4680; 749 ASD cases, 1,118 controls and 1,861 families relevant to 5-HTTLPR were also evaluated. For rs4680, the pooled OR was 1.18 (95% CI = 0.87-1.59, P = 0.29, P_{heterogeneity}  < 0.00001). There was no significant association of rs4680 with risk of ASD between the two subgroups. For 5-HTTLPR, the pooled OR was 1.05 (95% CI = 0.92-1.20, P = 0.4652, P_{heterogeneity}  < 0.00001). Meanwhile, we found no significant risk in individual case-control or TDT studies. The above findings indicated that neither COMT rs4680 nor 5-HTT 5-HTTLPR polymorphism significantly affects ASD risk. Autism Res 2017, 10: 1722-1736. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

Our results showed no evidence of significant association of either COMT rs4680 or 5-HTT 5-HTTLPR variants with ASD, showing that these two genes may not be major susceptible genetic factors in ASD occurrence, and may have a reciprocal action with each other in combination with environmental factors. These findings further provide evidence that a single gene variant may not dictate autism occurrence, but possibly contributes to a specific phenotype or subtype of ASD.

Impact of Catechol-O-Methyltransferase Val 158Met (rs4680) Polymorphism on Breast Cancer Susceptibility in Asian Population

Background:

Catechol-O-methyltransferase (COMT) is an important estrogen-metabolizing enzyme. Numerous case-control studies have evaluated the role COMT Val 158Met (rs4680;472G->A) polymorphism in the risk of breast cancer and provided inconclusive results, hence present meta-analysis was designed to get a more reliable assessment in Asian population.

Methods:

A total of 26 articles were identified through a search of four electronic databases-PubMed, Google Scholar, Science Direct and Springer link, up to March, 2016. Pooled odds ratios (ORs) with 95% con¬fidence intervals (CIs) were used as association measure to find out relationship between COMT Val158Metpolymorphism and the risk of breast cancer. We also assessed between study heterogeneity and publication bias. All statistical analyses were done by Open Meta-Analyst.

Results:

Twenty six case-control studies involving 5,971 breast cancer patients and 7,253 controls were included in the present meta-analysis. The results showed that the COMT Val158Met polymorphism was significantly associated with breast cancer risk except heterozygote model(allele contrast odds ratio (ORAvsG)= 1.13, 95%CI=1.02-1.24,p=0.01; heterozygote/co-dominant ORGAvsGG= 1.03, 95%CI=0.96-1.11,p=0.34; homozygote ORAAvsGG= 1.38, 95%CI= 1.08-1.76,p=0.009; dominant model ORAA+GAvsGG= 1.08, 95%CI=1.01-1.16,p=0.02; and recessive model ORAAvsGA+GG= 1.35, 95%CI=1.07-1.71,p=0.01). In addition, we also performed subgroup analysis based on source of controls and menopausal state of patients.

Conclusions:

In conclusion, the COMT Val158Met polymorphism was related to increased breast cancer susceptibility in the Asian population.

Investigation of polymorphisms in genes involved in estrogen metabolism in menstrual migraine

Migraine is a common, disabling headache disorder, which is influenced by multiple genes and environmental triggers. After puberty, the prevalence of migraine in women is three times higher than in men and >50% of females suffering from migraine report a menstrual association, suggesting hormonal fluctuations can influence the risk of migraine attacks. It has been hypothesized that the drop in estrogen during menses is an important trigger for menstrual migraine. Catechol-O-methyltransferase (COMT) and Cytochrome P450 (CYP) enzymes are involved in estrogen synthesis and metabolism. Functional polymorphisms in these genes can influence estrogen levels and therefore may be associated with risk of menstrual migraine. In this study we investigated four single nucleotide polymorphisms in three genes involved in estrogen metabolism that have been reported to impact enzyme levels or function, in a specific menstrual migraine cohort. 268 menstrual migraine cases and 142 controls were genotyped for rs4680 in COMT (Val158Met), rs4646903 and rs1048943 in CYP1A1 (T3801C and Ile462Val) and rs700519 in CYP19A1 (Cys264Arg). Neither genotype nor allele frequencies for the COMT and CYP SNPs genotyped were found to be significantly different between menstrual migraineurs and controls by chi-square analysis (P>0.05). Therefore we did not find association of functional polymorphisms in the estrogen metabolism genes COMT, CYP1A1 or CYP19A1 with menstrual migraine. Further studies are required to assess whether menstrual migraine is genetically distinct from the common migraine subtypes and identify genes that influence risk.

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

Catechol-O-methyltransferase, COMT, is an important phase II enzyme catalyzing the transfer of a methyl-group from S-adenosylmethionine to a catechol-containing substrate molecule. A genetic variant Val158Met in the COMT gene leads to a several-fold decrease in the enzymatic activity giving rise to the accumulation of potentially carcinogenic endogenous catechol estrogens and their reactive intermediates and increasing thus the risk of tumorigenesis. However, numerous association studies between the COMT genotype and susceptibility to various malignancies have shown inconsistent and controversial findings indicating that additional gene-gene and gene-environment interactions might be crucial in modulating the physiological role of the COMT. In this review article, the important contribution of dietary catechol-containing flavonoids to modification of the relationships between the COMT genotype and cancer risk is discussed. Whereas, the diverse anticancer activities of common phytochemicals, such as green tea polyphenols, quercetin, fisetin or luteolin, can be markedly changed (both decreased or increased) by the COMT-mediated O-methylation of these exogenous substrates, flavonoids can also behave as potent inhibitors of the COMT enzyme slowing detoxification of endogenous catechol estrogens. Such a many-featured functioning of the COMT and its complex regulation by several different genetic and environmental factors, including plant-based food ingredients, emphasizes the necessity to further stratify the association studies between the COMT genotype and tumor risk by consumption of catechol-containing dietary flavonoids. Currently, it can be only speculated that some of the possible associations might be masked by the regular intake of specific food polyphenols, taking effect in certain communities or populations.

Association between the COMT Val158Met polymorphism and risk of cancer: evidence from 99 case-control studies

Catechol-O-methyltransferase (COMT) plays a central role in DNA repair and estrogen-induced carcinogenesis. Many recent epidemiologic studies have investigated the association between the COMT Val158Met polymorphism and cancer risk, but the results are inconclusive. In this study, we performed a meta-analysis to investigate the association between cancer susceptibility and COMT Val158Met in different genetic models. Overall, no significant associations were found between COMT Val158Met polymorphism and cancer risk (homozygote model: odds ratio [OR] =1.05, 95% confidence interval [CI] = [0.98, 1.13]; heterozygote model: OR =1.01, 95% CI = [0.98, 1.04]; dominant model: OR =1.02, 95% CI [0.97, 1.06], and recessive model: OR =1.03, 95% CI [0.97, 1.09]). In the subgroup analysis of cancer type, COMT Val158Met was significantly associated with increased risks of bladder cancer in recessive model, and esophageal cancer in homozygote model, heterozygote model, and dominant model. Subgroup analyses based on ethnicities, COMT Val158Met was significantly associated with increased risk of cancer in homozygote and recessive model among Asians. In addition, homozygote, recessive, and dominant models were significantly associated with increased cancer risk in the subgroup of allele-specific polymerase chain reaction genotyping. Significant associations were not observed when data were stratified by the source of the controls. In summary, this meta-analysis suggested that COMT Val158Met polymorphism might not be a risk factor for overall cancer risk, but it might be involved in cancer development at least in some ethnic groups (Asian) or some specific cancer types (bladder and esophageal cell cancer). Further evaluations of more preclinical and epidemiological studies are required.

Lack of association between the COMT rs4680 polymorphism and ovarian cancer risk: evidence from a meta-analysis of 3,940 individuals

Catechol-O-methyltransferase (COMT) is involved in estrogen metabolism and is vital to estrogen-induced carcinogenesis, including that of ovarian cancer. Although many recent epidemiologic studies have investigated associations between the COMT rs4680 polymorphism and ovarian cancer risk, the results remain inconclusive. We therefore performed a meta-analysis to derive a more precise estimate of associations. Systematic searches of the PubMed, Embase, Web of Science, Cochrane Library, Wanfang, China National Knowledge Infrastructure, and Chinese Biomedicine databases were undertaken to retrieve eligible studies. Odds ratios (ORs) with their corresponding 95% confidence intervals (CIs) were pooled to assess the strength of the association. In total, 8 case-control studies involving 1,293 cases and 2,647 controls were included in the meta-analysis. Overall, the results showed no evidence of significant association between the COMT rs4680 polymorphism and ovarian cancer risk in any of the assessed genetic models. Subgroup analyses by ethnicity also did not reveal any significant association in any genetic model (p>0.05). In conclusion, our findings suggest that the COMT rs4680 polymorphism may not contribute to the risk of ovarian cancer.

The Catechol-O-Methyltransferase Val158Met Polymorphism Contributes to the Risk of Breast Cancer in the Chinese Population: An Updated Meta-Analysis

PURPOSE

Catechol-O-methyltransferase (COMT) enzyme plays a central role in estrogen-induced carcinogenesis. Emerging evidence from association studies has revealed that the functional Val158Met polymorphism (rs4680 G>A) of the Catechol-O-methyltransferase gene (COMT) has been implicated in susceptibility to breast cancer in the Chinese population, while results of individual published studies remain inconclusive and inconsistent. To assess this association in the Chinese population, a meta-analysis was performed.

METHODS

Eligible studies were searched on MEDLINE, Embase, Cochrane Library, China National Knowledge Infrastructure, and the Chinese Biomedicine Database. Odds ratios (ORs) with their corresponding 95% confidence intervals (CIs) were pooled to assess the association between COMT polymorphisms and the risk of breast cancer using RevMan 5.2 and Stata 12.0 software.

RESULTS

The meta-analysis included 14 eligible studies, with a total of 4,626 breast cancer cases and 5,637 controls. Overall, the COMT Val158Met polymorphism (rs4680 G>A) was significantly associated with an increased risk of breast cancer in several genetic models (A/A vs. G/G: OR, 1.59, 95% CI, 1.12-2.27; A/A vs. G/A+G/G: OR, 1.62, 95% CI, 1.14-2.29; A vs. G: OR, 1.15, 95% CI, 1.00-1.32), and a subgroup analysis according to menopausal status showed that this association was especially evident among premenopausal Chinese women (A/A vs. G/G: OR, 1.87, 95% CI, 0.99-3.54; A/A vs. G/A+G/G: OR, 1.94, 95% CI, 1.03-3.63).

CONCLUSION

The results of this meta-analysis indicated that COMT Val158Met variants contribute to breast cancer susceptibility in the Chinese population, particularly among premenopausal women.

Comprehensive interrogation of CpG island methylation in the gene encoding COMT, a key estrogen and catecholamine regulator

BACKGROUND

The catechol-O-methyltransferase (COMT) enzyme has been widely studied due to its multiple roles in neurological functioning, estrogen biology, and methylation metabolic pathways. Numerous studies have investigated variation in the large COMT gene, with the majority focusing on single nucleotide polymorphisms (SNPs). This body of work has linked COMT genetic variation with a vast array of conditions, including several neurobehavioral disorders, pain sensitivity, and multiple human cancers. Based on COMT's numerous biological roles and recent studies suggesting that methylation of the COMT gene impacts COMT gene expression, we comprehensively interrogated methylation in over 200 CpG dinucleotide sequences spanning the length of the COMT gene.

METHODS

Using saliva-derived DNA from a non-clinical sample of human subjects, we tested for associations between COMT CpG methylation and factors reported to interact with COMT genetic effects, including demographic factors and alcohol use. Finally, we tested associations between COMT CpG methylation state and COMT gene expression in breast cancer cell lines. We interrogated >200 CpGs in 13 amplicons spanning the 5' UTR to the last exon of the CpG dinucleotide-rich COMT gene in n = 48 subjects, n = 11 cell lines and 1 endogenous 18S rRNA control.

RESULTS

With the exception of the CpG island in the 5'UTR and 1st exon, all other CpG islands were strongly methylated with typical dynamic ranges between 50-90%. In the saliva samples, methylation of multiple COMT loci was associated with socioeconomic status or ethnicity. We found associations between methylation at numerous loci and genotype at the functional Val158Met SNP (rs4680), and most of the correlations between methylation and demographic and alcohol use factors were Val158Met allele-specific. Methylation at several of these loci also associated with COMT gene expression in breast cancer cell lines.

CONCLUSIONS

We report the first comprehensive interrogation of COMT methylation. We corroborate previous findings of variation in COMT methylation with gene expression and the Val158Met genotype, and also report novel associations with socioeconomic status (SES) and ethnicity at several methylated loci. These results point to novel mechanisms for COMT regulation, which may have broad therapeutic implications.

Adipose tissue PCB levels and CYP1B1 and COMT genotypes in relation to breast cancer risk in postmenopausal Danish women

Exposure to PCBs may be an etiologic factor for breast cancer. The cytochrome P450 1B1 (CYP1B1) and catechol-O-methyltransferase (COMT) enzymes are involved in estrogen metabolism and PCB metabolism, both of which may relate to breast cancer susceptibility. Polymorphisms in genes regulating these enzymes control efficiency. Our objective was to assess whether CYP1B1 and COMT gene polymorphisms modulate the effect of PCBs in breast cancer risk, among postmenopausal Danish women. Neither CYP1B1 Leu432Val polymorphisms nor adipose tissue PCBs were independently associated with breast cancer risk. When assessing the independent effect of the COMT Val158Met polymorphism, we observed reduced risk for breast cancer amongst hormone replacement therapy using women who were homozygous carriers of the variant allele compared with those carrying the wild-type variant (RR = 0.41; 95% CI: 0.29-0.89). We found no statistically significant interactions between any of the PCB groups and CYP1B1 or COMT polymorphisms on the risk of breast cancer.

MMP-2 -1306C>T polymorphism in breast cancer: a case-control study in a South European population

This case control study aims to investigate the role of MMP-2 -1306C>T polymorphism as a potential risk factor and possible prognostic marker for breast cancer in a South European population. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy controls were recruited. MMP-2 -1306C>T polymorphism was genotyped; multivariate logistic regression as well as Cox regression analysis were performed. MMP-2 -1306C>T status was not associated with breast cancer risk either at the total sample or at the subanalyses on premenopausal and postmenopausal women. At the survival analysis, a trend towards a favorable association between MMP-2 -1306C>T allele and disease-free survival as well as overall survival was observed. Regarding subanalyses on ER-negative and ER-positive cases, the favorable association implicating MMP-2 -1306C>T allele was particularly evident among ER-positive cases; no significant associations emerged among ER-negative cases. MMP-2 -1306C>T polymorphism does not seem to be a risk factor for breast cancer in South European population; however, a trend towards a favorable association with survival has been observed.

Catechol-O-methyltransferase Val158Met polymorphism and risk of autism spectrum disorders

Objective

Autism spectrum disorders (ASD) are a family of childhood-onset neurodevelopmental disorders with complex genetic mechanisms underlying their aetiology. The aim of this case–control study was to evaluate the effect of the catechol-O-methyltransferase ( COMT) gene Val158Met polymorphism on ASD risk in a Chinese Han population.

Methods

The COMT gene Val158Met polymorphism was detected by polymerase chain reaction–restriction fragment length polymorphism in children (≤18 years old) with ASD and healthy control subjects.

Results

The frequency of the Val158/Val158 genotype in children with ASD (22/186; 11.8%) was significantly lower than in controls (38/186; 20.4%). When stratifying by select-item scores on the Autism Diagnostic Interview-Revised protocol, it was found that children with ‘current overactivity’ and ‘ever overactivity’ had a significantly lower frequency of the Val158/Val158 genotype than those without. There were no significant associations between the COMT gene Val158Met polymorphism and ASD subtypes.

Conclusions

The COMT gene Val158Met polymorphism may be a biomarker for phenotypic variation in ASD, but these preliminary findings remain tentative, pending replication in larger, independent samples.

Epistasis analysis for estrogen metabolic and signaling pathway genes on young ischemic stroke patients

Background

Endogenous estrogens play an important role in the overall cardiocirculatory system. However, there are no studies exploring the hormone metabolism and signaling pathway genes together on ischemic stroke, including sulfotransferase family 1E (SULT1E1), catechol-O-methyl-transferase (COMT), and estrogen receptor α (ESR1).

Methods

A case-control study was conducted on 305 young ischemic stroke subjects aged ≦ 50 years and 309 age-matched healthy controls. SULT1E1 -64G/A, COMT Val158Met, ESR1 c.454−397 T/C and c.454−351 A/G genes were genotyped and compared between cases and controls to identify single nucleotide polymorphisms associated with ischemic stroke susceptibility. Gene-gene interaction effects were analyzed using entropy-based multifactor dimensionality reduction (MDR), classification and regression tree (CART), and traditional multiple regression models.

Results

COMT Val158Met polymorphism showed a significant association with susceptibility of young ischemic stroke among females. There was a two-way interaction between SULT1E1 -64G/A and COMT Val158Met in both MDR and CART analysis. The logistic regression model also showed there was a significant interaction effect between SULT1E1 -64G/A and COMT Val158Met on ischemic stroke of the young (P for interaction = 0.0171). We further found that lower estradiol level could increase the risk of young ischemic stroke for those who carry either SULT1E1 or COMT risk genotypes, showing a significant interaction effect (P for interaction = 0.0174).

Conclusions

Our findings support that a significant epistasis effect exists among estrogen metabolic and signaling pathway genes and gene-environment interactions on young ischemic stroke subjects.

HTERT MNS16A polymorphism in breast cancer: a case-control study

This case-control study aims to investigate the role of HTERT MNS16A polymorphism as a potential risk factors and/or a prognostic marker for breast cancer. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy controls were recruited. HTERT MNS16A polymorphism was genotyped (L: long allele, S: short allele); multivariate logistic regression was performed. No significant association was noted either at the overall analysis (OR = 1.57, 95 % CI 0.84-2.93 for heterozygous LS carriers; OR = 1.02, 95 % CI 0.54-1.95 for homozygous SS carriers) or at the subanalyses in premenopausal and postmenopausal women. With respect to survival analysis, HTERT MNS16A polymorphism was not associated with either disease-free survival or overall survival. HTERT MNS16A polymorphism does not seem to be a risk factor for breast cancer in the Caucasian Greek population. Further, larger studies from other countries and subjects seem to be needed as this novel polymorphism is being examined in depth.

HSP90, HSPA8, HIF-1 alpha and HSP70-2 polymorphisms in breast cancer: a case-control study

This case control study aims to investigate the role of HSP90 Gln488His (C > G), HSP70-2 P1/P2, HIF-1 alpha C1772T and HSPA8 intronic 1541-1542delGT polymorphisms as potential risk factors and/or prognostic markers for breast cancer. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy cases were recruited. The above mentioned polymorphisms were genotyped; multivariate logistic regression was performed. HSP90 GG (His/His) genotype was associated with elevated breast cancer risk. Similarly, the allele dose-response model pointed to increase in breast cancer risk per G allele. HSP70-2 P1/P2, HSPA8 intronic 1541-1542delGT and HIF-1 alpha polymorphisms were not associated with breast cancer risk, as evidenced by the dose-response allele models. The positive association between HSP90 G allele and breast cancer risk seemed to pertain to both premenopausal and postmenopausal women. With respect to survival analysis, none of the aforementioned polymorphisms was associated with either disease-free survival or overall survival. HSP90α Gln488His polymorphism seems to be a risk factor for breast cancer. On the other hand, our study did not point to excess risk conferred by HSPA8 1541-1542delGT, Hsp70-2 P1/P2 and HIF-1α C1772T.

Catechol-O-methyltransferase: characteristics, polymorphisms and role in breast cancer

Catechol estrogens are carcinogenic, probably because of their estrogenicity and potential for further oxidative metabolism to reactive quinones. Estrogenic quinones cause oxidative DNA damage as well as form mutagenic depurinating adenine and guanine adducts. O-Methylation by catechol-O-methyltransferase (COMT) blocks their estrogenicity and prevents their oxidation to quinones. A single gene encodes both membrane bound (MB) and soluble (S) forms of COMT. The COMT gene contains 34 single nucleotide polymorphisms (SNPs). The valine108 (S-COMT)/158 (MB-COMT) SNP encodes a low activity form of COMT and has been widely studied as a putative risk factor for breast cancer, with inconsistent results. Investigations of two other SNPs in the promoter of MB-COMT that may affect its expression have also provided mixed results. Future studies on the role of COMT in breast cancer should incorporate measurement of biomarkers that reflect COMT activity and its protective effects.