Gene Summary

Gene:COMT; catechol-O-methyltransferase
Aliases: HEL-S-98n
Summary:Catechol-O-methyltransferase catalyzes the transfer of a methyl group from S-adenosylmethionine to catecholamines, including the neurotransmitters dopamine, epinephrine, and norepinephrine. This O-methylation results in one of the major degradative pathways of the catecholamine transmitters. In addition to its role in the metabolism of endogenous substances, COMT is important in the metabolism of catechol drugs used in the treatment of hypertension, asthma, and Parkinson disease. COMT is found in two forms in tissues, a soluble form (S-COMT) and a membrane-bound form (MB-COMT). The differences between S-COMT and MB-COMT reside within the N-termini. Several transcript variants are formed through the use of alternative translation initiation sites and promoters. [provided by RefSeq, Sep 2008]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:catechol O-methyltransferase
Source:NCBIAccessed: 13 March, 2017

Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 13 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Up-Regulation
  • Chromosome 22
  • Genetic Predisposition
  • Estrogens
  • Stomach Cancer
  • DNA Sequence Analysis
  • Restriction Fragment Length Polymorphism
  • Soy Foods
  • Registries
  • Case-Control Studies
  • Genotype
  • Urban Population
  • Premenopause
  • Bladder Cancer
  • Postmenopause
  • Single Nucleotide Polymorphism
  • Sensitivity and Specificity
  • Sleep Stages
  • Breast Cancer
  • Smoking
  • Risk Factors
  • beta-Arrestins
  • Valine
  • Taiwan
  • Survivors
  • Soybeans
  • Catechol O-Methyltransferase
  • Prostate Cancer
  • Risk Assessment
  • Syria
  • Regression Analysis
  • CYP17
  • Aryl Hydrocarbon Receptors
  • Tissue Array Analysis
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Retinoic Acid
  • Aryl Hydrocarbon Hydroxylases
  • Testosterone
  • Odds Ratio
  • CYP1B1
Tag cloud generated 13 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: COMT (cancer-related)

Kakino K, Kiyohara C, Horiuchi T, Nakanishi Y
CYP2E1 rs2031920, COMT rs4680 Polymorphisms, Cigarette Smoking, Alcohol Use and Lung Cancer Risk in a Japanese Population.
Asian Pac J Cancer Prev. 2016; 17(8):4063-70 [PubMed] Related Publications
BACKGROUND: Cytochrome P450 2E1 (CYP2E1) and catechol-O-methyltransferase (COMT) genes may contribute to susceptibility to lung cancer because of their critical involvement in mechanisms of carcinogenesis.
MATERIALS AND METHODS: We evaluated the role of CYP2E1 rs2031920 and COMT rs4680 in a case-control study involving 462 lung cancer cases and 379 controls in Japanese. Logistic regression was used to assess adjusted odds ratios (OR) and 95% confidence intervals (CI). Multiplicative and additive interactions with cigarette smoking or alcohol use were also examined.
RESULTS: Neither CYP2E1 rs2031920 nor COMT rs4680 was associated with lung cancer risk overall. However, smokers with the CC genotype of CYP2E1 rs2031920 (OR = 3.57, 95% CI = 2.26-5.63) presented a higher risk of lung cancer than those with at least one T allele (OR = 2.91, 95% CI = 1.70-4.98) as compared to never-smokers with at least one T allele (reference). Subjects with excessive drinking and the CC genotype of CYP2E1 rs2031920 had a significantly higher risk (OR=2.22, 95% CI =1.39-3.56) than appropriate drinkers with at least one T allele. A similar tendency was observed between COMT rs4680 and either smoking or drinking habits. There were no multiplicative or additive interactions between the polymorphisms and either smoking or alcohol use.
CONCLUSIONS: Our findings indicate that CYP2E1 rs2031920 and COMT rs4680 are not major contributors to lung cancer risk in our Japanese population. Future studies on the genetics of lung cancer in Japanese and their environment interactions are required.

Brureau L, Moningo D, Emeville E, et al.
Polymorphisms of Estrogen Metabolism-Related Genes and Prostate Cancer Risk in Two Populations of African Ancestry.
PLoS One. 2016; 11(4):e0153609 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Estrogens are thought to play a critical role in prostate carcinogenesis. It has been suggested that polymorphisms of genes encoding enzymes involved in estrogen metabolism are risk factors for prostate cancer. However, few studies have been performed on populations of African ancestry, which are known to have a high risk of prostate cancer.
OBJECTIVE: We investigated whether functional polymorphisms of CYP17, CYP19, CYP1B1, COMT and UGT1A1 affected the risk of prostate cancer in two different populations of African ancestry.
METHODS: In Guadeloupe (French West Indies), we compared 498 prostate cancer patients and 565 control subjects. In Kinshasa (Democratic Republic of Congo), 162 prostate cancer patients were compared with 144 controls. Gene polymorphisms were determined by the SNaPshot technique or short tandem repeat PCR analysis. Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI).
RESULTS: The AA genotype and the A allele of rs4680 (COMT) appeared to be inversely associated with the risk of prostate cancer in adjusted models for both Afro-Caribbean and native African men. For the A allele, a significant inverse association was observed among cases with low-grade Gleason scores and localized clinical stage, in both populations.
CONCLUSIONS: These preliminary results support the hypothesis that polymorphisms of genes encoding enzymes involved in estrogen metabolism may modulate the risk of prostate cancer in populations of African ancestry.

Naushad SM, Ramaiah MJ, Pavithrakumari M, et al.
Artificial neural network-based exploration of gene-nutrient interactions in folate and xenobiotic metabolic pathways that modulate susceptibility to breast cancer.
Gene. 2016; 580(2):159-68 [PubMed] Related Publications
In the current study, an artificial neural network (ANN)-based breast cancer prediction model was developed from the data of folate and xenobiotic pathway genetic polymorphisms along with the nutritional and demographic variables to investigate how micronutrients modulate susceptibility to breast cancer. The developed ANN model explained 94.2% variability in breast cancer prediction. Fixed effect models of folate (400 μg/day) and B12 (6 μg/day) showed 33.3% and 11.3% risk reduction, respectively. Multifactor dimensionality reduction analysis showed the following interactions in responders to folate: RFC1 G80A × MTHFR C677T (primary), COMT H108L × CYP1A1 m2 (secondary), MTR A2756G (tertiary). The interactions among responders to B12 were RFC1G80A × cSHMT C1420T and CYP1A1 m2 × CYP1A1 m4. ANN simulations revealed that increased folate might restore ER and PR expression and reduce the promoter CpG island methylation of extra cellular superoxide dismutase and BRCA1. Dietary intake of folate appears to confer protection against breast cancer through its modulating effects on ER and PR expression and methylation of EC-SOD and BRCA1.

Kleine JP, Camargo-Kosugi CM, Carvalho CV, et al.
Analysis of CYP1A1 and COMT polymorphisms in women with cervical cancer.
Genet Mol Res. 2015; 14(4):18965-73 [PubMed] Related Publications
The aim of this case-control study was to obtain a comprehensive panel of genetic polymorphisms present only in genes (cytochrome P-450 1A1--CYP1A1 and catechol-O-methyl transferase--COMT) within the metabolic pathway of sex steroids and determine their possible associations with the presence or absence of cervical cancer. Genotypes of 222 women were analyzed: a) 81 with cancer of the cervix treated at the Cancer Hospital Alfredo Abram, between June 2012 and May 2013, with diagnosis confirmed surgically and/or through histomorphological examination; and b) 141 healthy women who assisted at the Endocrine Gynecology and Climacteric Ambulatory, Department of Gynecology, UNIFESP-EPM. These polymorphisms were detected by polymerase chain reaction amplification-restriction fragment length polymorphism analysis and visualized on 3% agarose gels stained with ethidium bromide. We found a significant association between the frequency of the CYP1A1 polymorphism and the development of cervical cancer. A statistical difference was observed between patient and control groups for CYP1A1 polymorphism genotype distributions (P < 0.05). However, no significant differences were found in the COMT gene polymorphism genotype distributions between the patient and control groups (P > 0.05) or between other risk variables analyzed. The CYP1A1 gene involved in the metabolic pathway of sex steroids might influence the emergence of pathological conditions such as cervical cancer in women who carry a mutated allele, and result in 1.80 and 13.46 times increased risk for women with heterozygous or homozygous mutated genotypes, respectively.

Pan W, Liao H
Correlations between the COMT gene rs4680 polymorphism and susceptibility to ovarian cancer.
Genet Mol Res. 2015; 14(4):16813-8 [PubMed] Related Publications
The objective of this study was to perform a systematic review of the correlations between the single nucleotide polymorphism rs4680 in the catechol-O-methyltransferase (COMT) gene and susceptibility to ovarian cancer. A computer search was carried out for relevant case-control studies published between January 2000 to January 2014 in databases such as Ovid, EBSCO, PubMed, CNKI, CBMDISC, VIP, and WanFang Data. The literature was screened based on inclusion and exclusion criteria. A meta-analysis was performed by calculating the combined odds ratios (OR) and 95% confidence intervals (CI) using the RevMan 5.0. A total of 7 case-control studies were selected, which included 1439 cases and 2927 control subjects. Meta-analysis showed that the rs4680 polymorphism was not associated with ovarian cancer [GG vs (GA+AA): OR = 1.02, 95%CI = 0.88-1.19; G vs A allele: OR = 1.0, 95%CI = 0.90-1.11]. We, therefore, conclude that the COMT rs4680 polymorphism is not associated with susceptibility to ovarian cancer.

Bell GC, Donovan KA, McLeod HL
Clinical Implications of Opioid Pharmacogenomics in Patients With Cancer.
Cancer Control. 2015; 22(4):426-32 [PubMed] Related Publications
BACKGROUND: Pain can be a significant burden for patients with cancer and may have negative effects on their quality of life. Opioids are potent analgesics and serve as a foundation for pain management. The variation in response to opioid analgesics is well characterized and is partly due to genetic variability.
METHODS: We reviewed the results of clinical studies to evaluate the relationships between genetic variants and select genes involved in the pharmacokinetics and pharmacodynamics of opioids, with an emphasis on patients with cancer.
RESULTS: In patients with cancer-related pain, genetic variation in OPRM1, COMT, and ABCB1 is associated with response to morphine, which is the most well-studied opioid. Although it has not been studied in patients with cancer-related pain, the effect of CYP2D6 variation is well characterized with codeine and tramadol. Evidence is limited for associating the genetic variation and pain response of oxycodone, hydrocodone, and fentanyl in patients with cancer.
CONCLUSION: The clinical availability of pharmacogenomic testing and research findings related to these polymorphic genes suggest that genotyping patients for these genetic variants may allow health care professionals to better predict patient response to pain and, thus, personalize pain treatment.

Bozzetti C, Quaini F, Squadrilli A, et al.
Isolation and Characterization of Circulating Tumor Cells in Squamous Cell Carcinoma of the Lung Using a Non-EpCAM-Based Capture Method.
PLoS One. 2015; 10(11):e0142891 [PubMed] Free Access to Full Article Related Publications
INTRODUCTION: The exclusion of circulating tumor cells (CTCs) that have lost epithelial antigens during the epithelial-to-mesenchymal transition (EMT) process by using Epithelial Cell Adhesion Molecule (EpCAM) based capture methods is still a matter of debate. In this study, cells obtained after depletion procedure from blood samples of squamous cell lung cancer (SQCLC) patients were identified based on morphology and characterized with the combination of FISH assessment and immunophenotypic profile.
MATERIALS AND METHODS: Five mL blood samples, collected from 55 advanced SQCLC patients, were analyzed by a non-EpCAM-based capture method. After depletion of leukocytes and erythroid cells, the negative fraction was characterized by both FISH using a fibroblast growth factor receptor 1 (FGFR1) probe and by immunocytochemistry. Thirty healthy donors were also tested.
RESULTS: Based on morphology (nuclear dimension ≥10 μm, shape and hypercromatic aspect) suspicious circulating cells clearly distinguishable from contaminant leukocytes were observed in 49/55 (89%) SQCLC patients. Thirty-four of the 44 (77%) samples evaluable for FGFR1 FISH showed ≥ 6 FGFR1 gene copy number on average per cell. Vimentin expression involved 43% (18/42) of pooled circulating SQCLC cells, whereas only 29% (14/48) were EpCAM positive. Confocal microscopy confirmed the localization of FGFR1 probe in suspicious circulating cells. Suspicious circulating elements were also observed in healthy donors and did not show any epithelial associated antigens. A significantly lower number of suspicious circulating cells in healthy donors compared to SQCLC patients was found.
CONCLUSIONS: Among the heterogeneous cell population isolated by depletion procedure, the coexistence of cells with epithelial and/or mesenchymal phenotype suggests that EMT may participate to transendothelial invasion and migration of tumor cells in advanced SQCLC. The finding of cells with neither EpCAM or EMT phenotype, retrieved after non-EpCAM-based systems, underlines the presence of suspicious elements in the blood of both SQCLC patients and healthy donors. Further phenotyping and molecular analyses are necessary to fully characterize these circulating elements.

Wang XS, Song HB, Chen S, et al.
Association of single nucleotide polymorphisms of ABCB1, OPRM1 and COMT with pain perception in cancer patients.
J Huazhong Univ Sci Technolog Med Sci. 2015; 35(5):752-8 [PubMed] Related Publications
Pain perception is influenced by multiple factors. The single nucleotide polymorphisms (SNPs) of some genes were found associated with pain perception. This study aimed to examine the association of the genotypes of ABCB1 C3435T, OPRM1 A118G and COMT V108/158M (valine 108/158 methionine) with pain perception in cancer patients. We genotyped 146 cancer pain patients and 139 cancer patients without pain for ABCB1 C3435T (rs1045642), OPRM1 A118G (rs1799971) and COMT V108/158M (rs4680) by the fluorescent dye-terminator cycle sequencing method, and compared the genotype distribution between groups with different pain intensities by chi-square test and pain scores between groups with different genotypes by non-parametric test. The results showed that in these cancer patients, the frequency of variant T allele of ABCB1 C3435T was 40.5%; that of G allele of OPRM1 A118G was 38.5% and that of A allele of COMT V108/158M was 23.3%. No significant difference in the genotype distribution of ABCB1 C3435T (rs1045642) and OPRM1 A118G (rs1799971) was observed between cancer pain group and control group (P=0.364 and 0.578); however, significant difference occurred in the genotype distribution of COMT V108/158M (rs4680) between the two groups (P=0.001). And the difference could not be explained by any other confounding factors. Moreover, we found that the genotypes of COMT V108/158M and ABCB1 C3435T were associated with the intensities of pain in cancer patients. In conclusion, our results indicate that the SNPs of COMT V108/158M and ABCB1 C3435T significantly influence the pain perception in Chinese cancer patients.

Barratt DT, Klepstad P, Dale O, et al.
Innate Immune Signalling Genetics of Pain, Cognitive Dysfunction and Sickness Symptoms in Cancer Pain Patients Treated with Transdermal Fentanyl.
PLoS One. 2015; 10(9):e0137179 [PubMed] Free Access to Full Article Related Publications
Common adverse symptoms of cancer and chemotherapy are a major health burden; chief among these is pain, with opioids including transdermal fentanyl the mainstay of treatment. Innate immune activation has been implicated generally in pain, opioid analgesia, cognitive dysfunction, and sickness type symptoms reported by cancer patients. We aimed to determine if genetic polymorphisms in neuroimmune activation pathways alter the serum fentanyl concentration-response relationships for pain control, cognitive dysfunction, and other adverse symptoms, in cancer pain patients. Cancer pain patients (468) receiving transdermal fentanyl were genotyped for 31 single nucleotide polymorphisms in 19 genes: CASP1, BDNF, CRP, LY96, IL6, IL1B, TGFB1, TNF, IL10, IL2, TLR2, TLR4, MYD88, IL6R, OPRM1, ARRB2, COMT, STAT6 and ABCB1. Lasso and backward stepwise generalised linear regression were used to identify non-genetic and genetic predictors, respectively, of pain control (average Brief Pain Inventory < 4), cognitive dysfunction (Mini-Mental State Examination ≤ 23), sickness response and opioid adverse event complaint. Serum fentanyl concentrations did not predict between-patient variability in these outcomes, nor did genetic factors predict pain control, sickness response or opioid adverse event complaint. Carriers of the MYD88 rs6853 variant were half as likely to have cognitive dysfunction (11/111) than wild-type patients (69/325), with a relative risk of 0.45 (95% CI: 0.27 to 0.76) when accounting for major non-genetic predictors (age, Karnofsky functional score). This supports the involvement of innate immune signalling in cognitive dysfunction, and identifies MyD88 signalling pathways as a potential focus for predicting and reducing the burden of cognitive dysfunction in cancer pain patients.

Meloto CB, Segall SK, Smith S, et al.
COMT gene locus: new functional variants.
Pain. 2015; 156(10):2072-83 [PubMed] Free Access to Full Article Related Publications
Catechol-O-methyltransferase (COMT) metabolizes catecholaminergic neurotransmitters. Numerous studies have linked COMT to pivotal brain functions such as mood, cognition, response to stress, and pain. Both nociception and risk of clinical pain have been associated with COMT genetic variants, and this association was shown to be mediated through adrenergic pathways. Here, we show that association studies between COMT polymorphic markers and pain phenotypes in 2 independent cohorts identified a functional marker, rs165774, situated in the 3' untranslated region of a newfound splice variant, (a)-COMT. Sequence comparisons showed that the (a)-COMT transcript is highly conserved in primates, and deep sequencing data demonstrated that (a)-COMT is expressed across several human tissues, including the brain. In silico analyses showed that the (a)-COMT enzyme features a distinct C-terminus structure, capable of stabilizing substrates in its active site. In vitro experiments demonstrated not only that (a)-COMT is catalytically active but also that it displays unique substrate specificity, exhibiting enzymatic activity with dopamine but not epinephrine. They also established that the pain-protective A allele of rs165774 coincides with lower COMT activity, suggesting contribution to decreased pain sensitivity through increased dopaminergic rather than decreased adrenergic tone, characteristic of reference isoforms. Our results provide evidence for an essential role of the (a)-COMT isoform in nociceptive signaling and suggest that genetic variations in (a)-COMT isoforms may contribute to individual variability in pain phenotypes.

Andres SA, Bickett KE, Alatoum MA, et al.
Interaction between smoking history and gene expression levels impacts survival of breast cancer patients.
Breast Cancer Res Treat. 2015; 152(3):545-56 [PubMed] Related Publications
In contrast to studies focused on cigarette smoking and risk of breast cancer occurrence, this study explored the influence of smoking on breast cancer recurrence and progression. The goal was to evaluate the interaction between smoking history and gene expression levels on recurrence and overall survival of breast cancer patients. Multivariable Cox proportional hazards models were fitted for 48 cigarette smokers, 50 non-smokers, and the total population separately to determine which gene expressions and gene expression/cigarette usage interaction terms were significant in predicting overall and disease-free survival in breast cancer patients. Using methods similar to Andres et al. (BMC Cancer 13:326, 2013a; Horm Cancer 4:208-221, 2013b), multivariable analyses revealed CENPN, CETN1, CYP1A1, IRF2, LECT2, and NCOA1 to be important predictors for both breast carcinoma recurrence and mortality among smokers. Additionally, COMT was important for recurrence, and NAT1 and RIPK1 were important for mortality. In contrast, only IRF2, CETN1, and CYP1A1 were significant for disease recurrence and mortality among non-smokers, with NAT2 additionally significant for survival. Analysis of interaction between smoking status and gene expression values using the combined samples revealed significant interactions between smoking status and CYP1A1, LECT2, and CETN1. Signatures consisting of 7-8 genes were highly predictive for breast cancer recurrence and overall survival among smokers, with median C-index values of 0.8 and 0.73 for overall survival and recurrence, respectively. In contrast, median C-index values for non-smokers was only 0.59. Hence, significant interactions between gene expression and smoking status can play a key role in predicting breast cancer patient outcomes.

Cole PD, Finkelstein Y, Stevenson KE, et al.
Polymorphisms in Genes Related to Oxidative Stress Are Associated With Inferior Cognitive Function After Therapy for Childhood Acute Lymphoblastic Leukemia.
J Clin Oncol. 2015; 33(19):2205-11 [PubMed] Free Access to Full Article Related Publications
PURPOSE: Survivors of childhood acute lymphoblastic leukemia (ALL) exhibit increased rates of neurocognitive deficits. This study was conducted to test whether interpatient variability in neurocognitive outcomes can be explained by polymorphisms in candidate genes conferring susceptibility to neurocognitive decline.
METHODS: Neurocognitive testing was conducted in 350 pediatric leukemia survivors, treated on Dana-Farber Cancer Institute ALL Consortium Protocols 95-01 or 00-01. Genomic DNA was isolated from bone marrow collected at remission. Candidate polymorphisms were selected on the basis of prior literature, targeting genes related to drug metabolism, oxidative damage, altered neurotransmission, neuroinflammation, and folate physiology. Single nucleotide polymorphisms were detected using either a customized multiplexed Sequenom MassARRAY assay or polymerase chain reaction-based allelic discrimination assays. Multivariable logistic regression models were used to estimate the effects of genotype on neurocognitive outcomes, adjusted for the effects of demographic and treatment variables. False-discovery rate correction was made for multiple hypothesis testing, indicated as a Q value.
RESULTS: Inferior cognitive or behavioral outcomes were associated with polymorphisms in three genes related to oxidative stress and/or neuroinflammation: NOS3 (IQ, Q = 0.008; Vocabulary Q = 0.011; Matrix Reasoning Q = 0.008), SLCO2A1 (IQ Q = 0.043; Digit Span Q = 0.006; Block Design Q = 0.076), and COMT (Behavioral Assessment System for Children-2 Attention Q = 0.080; and Hyperactivity Q = 0.084). Survivors homozygous for NOS3 894T, with at least one SLCO2A1 variant G allele or with at least one GSTP1 variant allele, had lower mean estimated IQ scores than those without these genotypes.
CONCLUSION: These data are consistent with the hypothesis that oxidative damage contributes to chemotherapy-associated neurocognitive decline among children with leukemia.

Farnedi A, Rossi S, Bertani N, et al.
Proteoglycan-based diversification of disease outcome in head and neck cancer patients identifies NG2/CSPG4 and syndecan-2 as unique relapse and overall survival predicting factors.
BMC Cancer. 2015; 15:352 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Tumour relapse is recognized to be the prime fatal burden in patients affected by head and neck squamous cell carcinoma (HNSCC), but no discrete molecular trait has yet been identified to make reliable early predictions of tumour recurrence. Expression of cell surface proteoglycans (PGs) is frequently altered in carcinomas and several of them are gradually emerging as key prognostic factors.
METHODS: A PG expression analysis at both mRNA and protein level, was pursued on primary lesions derived from 173 HNSCC patients from whom full clinical history and 2 years post-surgical follow-up was accessible. Gene and protein expression data were correlated with clinical traits and previously proposed tumour relapse markers to stratify high-risk patient subgroups.
RESULTS: HNSCC lesions were indeed found to exhibit a widely aberrant PG expression pattern characterized by a variable expression of all PGs and a characteristic de novo transcription/translation of GPC2, GPC5 and NG2/CSPG4 respectively in 36%, 72% and 71% on 119 cases. Importantly, expression of NG2/CSPG4, on neoplastic cells and in the intralesional stroma (Hazard Ratio [HR], 6.76, p = 0.017) was strongly associated with loco-regional relapse, whereas stromal enrichment of SDC2 (HR, 7.652, p = 0.007) was independently tied to lymphnodal infiltration and disease-related death. Conversely, down-regulated SDC1 transcript (HR, 0.232, p = 0.013) uniquely correlated with formation of distant metastases. Altered expression of PGs significantly correlated with the above disease outcomes when either considered alone or in association with well-established predictors of poor prognosis (i.e. T classification, previous occurrence of precancerous lesions and lymphnodal metastasis). Combined alteration of all three PGs was found to be a reliable predictor of shorter survival.
CONCLUSIONS: An unprecedented PG-based prognostic portrait is unveiled that incisively diversifies disease course in HNSCC patients beyond the currently known clinical and molecular biomarkers.

Naponelli V, Modernelli A, Bettuzzi S, Rizzi F
Roles of autophagy induced by natural compounds in prostate cancer.
Biomed Res Int. 2015; 2015:121826 [PubMed] Free Access to Full Article Related Publications
Autophagy is a homeostatic mechanism through which intracellular organelles and proteins are degraded and recycled in response to increased metabolic demand or stress. Autophagy dysfunction is often associated with many diseases, including cancer. Because of its role in tumorigenesis, autophagy can represent a new therapeutic target for cancer treatment. Prostate cancer (PCa) is one of the most common cancers in aged men. The evidence on alterations of autophagy related genes and/or protein levels in PCa cells suggests a potential implication of autophagy in PCa onset and progression. The use of natural compounds, characterized by low toxicity to normal tissue associated with specific anticancer effects at physiological levels in vivo, is receiving increasing attention for prevention and/or treatment of PCa. Understanding the mechanism of action of these compounds could be crucial for the development of new therapeutic or chemopreventive options. In this review we focus on the current evidence showing the capacity of natural compounds to exert their action through autophagy modulation in PCa cells.

Ivanova TI, Krikunova LI, Ryabchenko NI, et al.
Association of the apolipoprotein E 2 allele with concurrent occurrence of endometrial hyperplasia and endometrial carcinoma.
Oxid Med Cell Longev. 2015; 2015:593658 [PubMed] Free Access to Full Article Related Publications
Genes encoding proteins with antioxidant properties may influence susceptibility to endometrial hyperplasia (EH) and endometrial carcinoma (ECa). Patients with EH (n = 89), EH concurrent with ECa (n = 76), ECa (n = 186), and healthy controls (n = 1110) were genotyped for five polymorphic variants in the genes involved in metabolism of lipoproteins (APOE Cys112Arg and Arg158Cys), iron (HFE Cys282Tyr and His63Asp), and catecholamines (COMT Val158Met). Patients and controls were matched by ethnicity (all Caucasians), age, body mass index (BMI), and incidence of hypertension and diabetes. The frequency of the APOE E 2 allele (158Cys) was higher in patients with EH + ECa than in controls (P = 0.0012, P(Bonferroni) = 0.018, OR = 2.58, 95% CI 1.49-4.45). The APOE E 4 allele (112Arg) was more frequently found in patients with EH than in controls and HFE minor allele G (63Asp) had a protective effect in the ECa group, though these results appeared to be nonsignificant after correction for multiple comparisons. The results of the study indicate that E 2 allele might be associated with concurrent occurrence of EH and ECa.

Wu W, Wu Q, Hong X, et al.
Catechol-O-methyltransferase, a new target for pancreatic cancer therapy.
Cancer Sci. 2015; 106(5):576-83 [PubMed] Free Access to Full Article Related Publications
Catechol-O-methyltransferase (COMT) is an important molecule in different types of cancers. Its biological effect and therapeutic significance, however, rarely been investigated fully in pancreatic cancer. Immunohistologically, high COMT expression was significantly correlated with the longer overall survival of patients (P < 0.05), indicating its protective nature. The effects of COMT on cell growth, apoptosis, and invasion were evaluated using overexpression and silencing methods. In detail, we carried out experiments using one stably transduced and two transiently transfected pancreatic cancer cell lines in vitro, and one stably transduced cell line in vivo mice xenograft models. In vitro experiments showed that COMT inhibited cell proliferation, enhanced gemcitabine-induced apoptosis, and inhibited cell invasion in stably transduced and transiently transfected cell lines by regulating the PI3K/Akt pathway, p53, and E-cadherin. The COMT overexpressed and silenced cell lines showed significantly inhibited and enhanced growth capacities in in vivo xenograft models, respectively. In conclusion, COMT suppressed pancreatic cancer and its high expression predicted longer survival time. The interaction of COMT with the PI3K/Akt pathway makes it a potential target for therapy.

Naushad SM, Vijayalakshmi SV, Rupasree Y, et al.
Multifactor dimensionality reduction analysis to elucidate the cross-talk between one-carbon and xenobiotic metabolic pathways in multi-disease models.
Mol Biol Rep. 2015; 42(7):1211-24 [PubMed] Related Publications
Putatively functional polymorphisms of one-carbon and xenobiotic metabolic pathways influence susceptibility for wide spectrum of diseases. The current study was aimed to explore gene-gene interactions among these two metabolic pathways in four diseases i.e. breast cancer, systemic lupus erythematosus (SLE), coronary artery disease (CAD) and Parkinson's disease (PD). Multifactor dimensionality reduction analysis was carried out on four case-control datasets. Cross-talk was observed between one-carbon and xenobiotic pathways in breast cancer (RFC 80 G>A, COMT H108L and TYMS 5'-UTR 28 bp tandem repeat) and SLE (CYP1A1 m1, MTRR 66 A>G and GSTT1). Gene-gene interactions within one-carbon metabolic pathway were observed in CAD (GCPII 1561 C>T, SHMT 1420 C>T and MTHFR 677 C>T) and PD (cSHMT 1420 C>T, MTRR 66 A>G and RFC1 80 G>A). These interaction models showed good predictability of risk for PD (The area under the receiver operating characteristic curve (C) = 0.83) and SLE (C = 0.73); and moderate predictability of risk for breast cancer (C = 0.64) and CAD (C = 0.63). Cross-talk between one-carbon and xenobiotic pathways was observed in diseases with female preponderance. Gene-gene interactions within one-carbon metabolic pathway were observed in diseases with male preponderance.

Hagleitner MM, Coenen MJ, Patino-Garcia A, et al.
Influence of genetic variants in TPMT and COMT associated with cisplatin induced hearing loss in patients with cancer: two new cohorts and a meta-analysis reveal significant heterogeneity between cohorts.
PLoS One. 2014; 9(12):e115869 [PubMed] Free Access to Full Article Related Publications
Treatment with cisplatin-containing chemotherapy regimens causes hearing loss in 40-60% of cancer patients. It has been suggested that genetic variants in the genes encoding thiopurine S-methyltransferase (TPMT) and catechol O-methyltransferase (COMT) can predict the development of cisplatin-induced ototoxicity and may explain interindividual variability in sensitivity to cisplatin-induced hearing loss. Two recently published studies however, sought to validate these findings and showed inconsistent results. The aim of this study was to evaluate the role of polymorphisms in the TPMT and COMT genes in cisplatin-induced ototoxicity. Therefore we investigated two independent cohorts of 110 Dutch and 38 Spanish patients with osteosarcoma and performed a meta-analysis including all previously published studies resulting in a total population of 664 patients with cancer. With this largest meta-analysis performed to date, we show that the influence of TPMT and COMT on the development of cisplatin-induced hearing loss may be less important than previously suggested.

Bonacini M, Coletta M, Ramazzina I, et al.
Distinct promoters, subjected to epigenetic regulation, drive the expression of two clusterin mRNAs in prostate cancer cells.
Biochim Biophys Acta. 2015; 1849(1):44-54 [PubMed] Related Publications
The human clusterin (CLU) gene codes for several mRNAs characterized by different sequences at their 5' end. We investigated the expression of two CLU mRNAs, called CLU 1 and CLU 2, in immortalized (PNT1a) and tumorigenic (PC3 and DU145) prostate epithelial cells, as well as in normal fetal fibroblasts (WI38) following the administration of the epigenetic drugs 5-aza-2'-deoxycytidine (AZDC) and trichostatin A (TSA) given either as single or combined treatment (AZDC-TSA). Our experimental evidences show that: a) CLU 1 is the most abundant transcript variant. b) CLU 2 is expressed at a low level in normal fibroblasts and virtually absent in prostate cancer cells. c) CLU 1, and to a greater extent CLU 2 expression, increased by AZDC-TSA treatment in prostate cancer cells. d) Both CLU 1 and CLU 2 encode for secreted CLU. e) P2, a novel promoter that overlaps the CLU 2 Transcription Start Site (TSS), drives CLU 2 expression. f) A CpG island, methylated in prostate cancer cells and not in normal fibroblasts, is responsible for long-term heritable regulation of CLU 1 expression. g) ChIP assay of histone tail modifications at CLU promoters (P1 and P2) shows that treatment of prostate cancer cells with AZDC-TSA causes enrichment of Histone3(Lys9)acetylated (H3K9ac) and reduction of Histone3(Lys27)trimethylated (H3K27me3), inducing active transcription of both CLU variants. In conclusion, we show for the first time that the expression of CLU 2 mRNA is driven by a novel promoter, P2, whose activity responds to epigenetic drugs treatment through changes in histone modifications.

Ng T, Chan M, Khor CC, et al.
The genetic variants underlying breast cancer treatment-induced chronic and late toxicities: a systematic review.
Cancer Treat Rev. 2014; 40(10):1199-214 [PubMed] Related Publications
A systematic review was performed to describe the findings from 19 genetic association studies that have examined the genetic variants underlying four common treatment-induced chronic and late toxicities in breast cancer patients, and to evaluate the quality of reporting. Three out of 5 studies found an association between HER2 lle655Val polymorphisms and trastuzumab-induced cardiotoxicity. Two studies found a positive association between cognitive impairment and the Val allele of the COMT gene and the ε4 allele of the apolipoprotein E gene. Genetic associations were established between fatigue and the G/G genotype of IL6-174 and TNF-308, and the Met allele of the COMT gene in 4 studies. Among studies (N=8) that evaluated the genetic associations underlying peripheral neuropathy, CYP2C8∗3 variant is commonly reported as the associated gene. Most studies failed to conform to the major criteria listed in the STREGA guidelines, with a lack of transparent reporting of methods and results.

Hevir-Kene N, Rižner TL
The endometrial cancer cell lines Ishikawa and HEC-1A, and the control cell line HIEEC, differ in expression of estrogen biosynthetic and metabolic genes, and in androstenedione and estrone-sulfate metabolism.
Chem Biol Interact. 2015; 234:309-19 [PubMed] Related Publications
Estrogens have important roles in the pathogenesis of endometrial cancer. They can have carcinogenic effects through stimulation of cell proliferation or formation of DNA-damaging species. To characterize model cell lines of endometrial cancer, we determined the expression profiles of the estrogen receptors (ERs) ESR1, ESR2 and GPER, and 23 estrogen biosynthetic and metabolic genes, and investigated estrogen biosynthesis in the control HIEEC cell line and the Ishikawa and HEC-1A EC cell lines. HIEEC and Ishikawa expressed all ERs to different extents, while HEC-1A cells lacked expression of ESR1. Considering the estrogen biosynthetic and metabolic enzymes, these cells showed statistically significant different gene expression profiles for SULT2B1, HSD3B2, CYP19A1, AKR1C3, HSD17B1, HSD17B7, HSD17B12, CYP1B1, CYP3A5, COMT, SULT1A1, GSTP1 and NQO2. In these cells, E2 was formed from E1S and E1, while androstenedione was not converted to estrogens. HIEEC and Ishikawa had similar profiles of androstenedione and E1 metabolism, but hydrolysis of E1S to E1 was weaker in Ishikawa cells. HEC-1A cells were less efficient for activation of E1 into the potent E2, but metabolized androstenedione to other androgenic metabolites better than HIEEC and Ishikawa cells. This study reveals that HIEEC, Ishikawa, and HEC-1A cells can all form estrogens only via the sulfatase pathway. HIEEC, Ishikawa, and HEC-1A cells expressed all the major genes in the production of hydroxyestrogens and estrogen quinones, and in their conjugation. Significantly higher CYP1B1 mRNA levels in Ishikawa cells compared to HEC-1A cells, together with lack of UGT2B7 expression, indicate that Ishikawa cells can accumulate more toxic estrogen-3,4-quinones than HEC-1A cells, as also for HIEEC cells. This study provides further characterization of HIEEC, Ishikawa, and HEC-1A cells, and shows that they differ greatly in expression of the genes investigated and in their capacity for E2 formation, and thus they represent different in vitro models.

Habib CN, Al-Abd AM, Tolba MF, et al.
Leptin influences estrogen metabolism and accelerates prostate cell proliferation.
Life Sci. 2015; 121:10-5 [PubMed] Related Publications
AIM: The present study was designed to investigate the effect of leptin on estrogen metabolism in prostatic cells.
MAIN METHODS: Malignant (PC-3) and benign (BPH-1) human prostate cells were treated with 17-β-hydroxyestradiol (1 μM) alone or in combination with leptin (0.4, 4, 40 ng/ml) for 72 h. Cell proliferation assay, immunocytochemical staining of estrogen receptor (ER), liquid chromatography-tandem mass spectrometry method (LC-MS) and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) were used.
KEY FINDINGS: Cell proliferation assay demonstrated that leptin caused significant growth potentiation in both cells. Immunocytochemical staining showed that leptin significantly increased the expression of ER-α and decreased that of ER-β in PC-3 cells. LC-MS method revealed that leptin increased the concentration 4-hydroxyestrone and/or decreased that of 2-methoxyestradiol, 4-methoxyestradiol and 2-methoxyestrone. Interestingly, RT-PCR showed that leptin significantly up-regulated the expression of aromatase and cytochrome P450 1B1 (CYP1B1) enzymes; however down-regulated the expression of catechol-o-methyltransferase (COMT) enzyme.
SIGNIFICANCE: These data indicate that leptin-induced proliferative effect in prostate cells might be partly attributed to estrogen metabolism. Thus, leptin might be a novel target for therapeutic intervention in prostatic disorders.

Son BH, Kim MK, Yun YM, et al.
Genetic polymorphism of ESR1 rs2881766 increases breast cancer risk in Korean women.
J Cancer Res Clin Oncol. 2015; 141(4):633-45 [PubMed] Related Publications
PURPOSE: We performed a case-control study to evaluate the association of genetic polymorphisms of estrogen-metabolizing enzyme genes and estrogen receptor genes with breast cancer risk according to age group and subtypes in Korean women.
METHODS: Breast cancer patients (n = 830) and the hospital healthy controls (n = 390) with both clinical information and SNP data were included in the study. Age was divided into three groups: premenopausal under 35 years (n = 64), premenopausal over 35 years (n = 456), and postmenopausal women (n = 310), respectively. Tumor subtype was classified into four subtypes: luminal A, luminal B, HER2-overexpressing, and triple-negative, respectively. Genotyping of the selected SNPs in ESR1, ESR2, CYP1A1, CYP1B1, and COMT was conducted using the VeraCode Golden Gate Genotyping Assay Technology. Multiple logistic regression models (dominant, recessive, and additive) were applied to determine the odds ratio, 95% confidence interval, and p value.
RESULTS: ESR1, rs2881766, rs2077647, rs926778, and rs2273206 polymorphisms increased breast cancer risk, and rs3798377 decreased the risk in overall patients. The association between SNP genotype and breast cancer risk was varied according to age groups and tumor subtypes. For age subgroups, rs2881766 increased breast cancer risk in the all three age groups, and rs926778 increased the risk in premenopausal over 35 years women and in postmenopausal women. For the tumor subtypes, rs2881766 increased breast cancer risk manly in luminal A, HER2-overexpressing, and triple-negative subtypes except for luminal B subtype, and rs926778 increased the risk in luminal A and triple-negative subtypes. Rs3798577 decreased the risk in luminal B and triple-negative subtypes.
CONCLUSION: The results showed that ESR1 rs2881766 polymorphism increased breast cancer risk and rs3798377 decreased the risk in Korean women. Because of wide variation of the association between SNP genotype and breast cancer risk according to age group and tumor subtypes, further studies such as a large-scale cohort study need for validation and test of biologic significance.

Tan X, Chen M
Association between Catechol-O-methyltransferase rs4680 (G>A) polymorphism and lung cancer risk.
Diagn Pathol. 2014; 9:192 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The association between the Val158Met polymorphism in the catechol-O-methyltransferase (COMT) gene and lung cancer risk remains controversial and inconclusive. Therefore, the meta-analysis was performed to provide a quality reevaluation of the association between the COMT Val158Met polymorphism and the risk of lung cancer.
METHODS: Two major public databases (Pubmed and Embase) and several Chinese databases were searched for eligible studies. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated to estimate the strength of the association.
RESULTS: Five publications, including six individual studies with a total of 4,043 subjects (1,796 cases and 2,247 controls) regarding the association of COMT Val158Met polymorphism with lung cancer susceptibility were included in this meta-analysis. Overall, pooled analysis indicated that there was no significant association between COMT Val158Met polymorphism and lung cancer susceptibility under all genetic models. Likewise, no association was observed in the stratified analysis by ethnicity and control source, either. However, Val158Met polymorphism was shown to increase lung cancer risk among women (AG vs. GG, OR=1.190, 95% CI=1.001-1.422, p=0.049).
CONCLUSION: These findings suggested that the COMT l58Val/Met polymorphism confer genetic susceptibility to lung cancer among women. However, no evidence was found for the association with lung cancer risk in ethnicity and smoking status.
VIRTUAL SLIDES: The virtual slide(s) for this article can be found here:

Chiu M, Tardito S, Pillozzi S, et al.
Glutamine depletion by crisantaspase hinders the growth of human hepatocellular carcinoma xenografts.
Br J Cancer. 2014; 111(6):1159-67 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: A subset of human hepatocellular carcinomas (HCC) exhibit mutations of β-catenin gene CTNNB1 and overexpress Glutamine synthetase (GS). The CTNNB1-mutated HCC cell line HepG2 is sensitive to glutamine starvation induced in vitro with the antileukemic drug Crisantaspase and the GS inhibitor methionine-L-sulfoximine (MSO).
METHODS: Immunodeficient mice with subcutaneous xenografts of the CTNNB1-mutated HCC cell lines HepG2 and HC-AFW1 were treated with Crisantaspase and/or MSO, and tumour growth was monitored. At the end of treatment, tumour weight and histology were assessed. Serum and tissue amino acids were determined by HPLC. Gene and protein expression were estimated with RT-PCR and western blot and GS activity with a colorimetric method. mTOR activity was evaluated from the phosphorylation of p70S6K1.
RESULTS: Crisantaspase and MSO depleted serum glutamine, lowered glutamine in liver and tumour tissue, and inhibited liver GS activity. HepG2 tumour growth was significantly reduced by either Crisantaspase or MSO, and completely suppressed by the combined treatment. The combined treatment was also effective against xenografts of the HC-AFW1 cell line, which is Crisantaspase resistant in vitro.
CONCLUSIONS: The combination of Crisantaspase and MSO reduces glutamine supply to CTNNB1-mutated HCC xenografts and hinders their growth.

Zhang D, Rajaratnam V, Al-Hendy O, et al.
Green tea extract inhibition of human leiomyoma cell proliferation is mediated via catechol-O-methyltransferase.
Gynecol Obstet Invest. 2014; 78(2):109-18 [PubMed] Related Publications
BACKGROUND/AIMS: To investigate the inhibitory effect of green tea extract, epigallocatechin gallate (EGCG), on wild-type human leiomyoma (WT-HuLM) cells and its potential action via catechol-o-methyltransferase (COMT) activity.
METHODS: Cell proliferation of WT-HuLM and COMT gene-silenced HuLM (COMT-shRNA-HuLM) cells treated with 0 or 100 µM EGCG for 7 days was measured using the MTT method. Total RNA and protein were extracted from cells treated with 0 or 100 µM of EGCG for 48 h. Gene expression profiling was performed using Human Signal Transduction PathwayFinder. Proliferation cell nuclear antigen (PCNA), cyclin-dependent kinase 4 (Cdk4) and COMT protein levels were detected by Western blot analyses. COMT enzyme activity was evaluated by HPLC.
RESULTS: EGCG-treated WT-HuLM cells showed significantly decreased COMT expression (p < 0.001) and enzyme activity (p < 0.05) compared to untreated WT-HuLM cells, while COMT-shRNA-HuLM cells showed no significant change. At 100 μM of EGCG, survival of WT-HuLM cells was significantly lower (p < 0.05) compared to COMT-shRNA-HuLM cells. EGCG treatment modulated multiple signaling pathways in WT-HuLM compared to untreated control, while changes were minimal or reversed in COMT-shRNA-HuLM cells. EGCG significantly decreased PCNA, Cdk4 and soluble COMT protein levels (p < 0.001) in WT-HuLM, but not in COMT-shRNA-HuLM cells.
CONCLUSIONS: The antiproliferative and gene-modulating effects of EGCG on HuLM cells are mediated, at least partially, via its effect on COMT expression and enzyme activity.

Shen Y, Ren ML, Xu J, et al.
A multicenter case-control study on screening of single nucleotide polymorphisms in estrogen-metabolizing enzymes and susceptibility to uterine leiomyoma in han chinese.
Gynecol Obstet Invest. 2014; 77(4):224-30 [PubMed] Related Publications
Uterine leiomyoma (UL) is an estrogen-responsive benign tumor in the female reproductive system and the main risk of hysterectomy for women. However, gene polymorphism of estrogen-metabolizing enzymes may lead to the different susceptibility to UL. We detected 10 single mucleotide polymorphisms in three key estrogen metabolite enzymes (COMT, CYP1A1, CYP1B1) in a Chinese Han population consisting of 800 patients and 800 healthy women from five different medical centers. The genetic polymorphism of rs3087869 (IVS1+2329C>T) (OR 3.200, 95% CI 1.614-6.345) and rs4680 (Val158Met) (OR 5.675, 95% CI 2.696-11.942) loci on COMT, rs1048943 (Ile462Val) (OR 4.629, 95% CI 2.216-9.672) and rs4646422 (Gly45Asp) (OR 3.240, 95% CI 1.624-6.461) loci on CYP1A1 and rs1065827 (Ala119Ser) (OR 5.635, 95% CI 2.990-10.619) locus on CYP1B1 were the risk factors to UL development and rs1056836 (Leu432Val) (OR 0.188, 95% CI 0.061-0.575) locus on CYB1B1 may be the protective factor to UL. The results provide a theoretical basis for genetic screening and early intervention to UL-susceptible populations.

Ghisari M, Eiberg H, Long M, Bonefeld-Jørgensen EC
Polymorphisms in phase I and phase II genes and breast cancer risk and relations to persistent organic pollutant exposure: a case-control study in Inuit women.
Environ Health. 2014; 13(1):19 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: We have previously reported that chemicals belonging to the persistent organic pollutants (POPs) such as perfluorinated compounds (PFAS) and polychlorinated biphenyls (PCBs) are risk factors in Breast Cancer (BC) development in Greenlandic Inuit women. The present case-control study aimed to investigate the main effect of polymorphisms in genes involved in xenobiotic metabolism and estrogen biosynthesis, CYP1A1, CYP1B1, COMT and CYP17, CYP19 and the BRCA1 founder mutation in relation to BC risk and to explore possible interactions between the gene polymorphisms and serum POP levels on BC risk in Greenlandic Inuit women.
METHODS: The study population consisted of 31 BC cases and 115 matched controls, with information on serum levels of POPs. Genotyping was conducted for CYP1A1 (Ile462Val; rs1048943), CYP1B1 (Leu432Val; rs1056836), COMT (Val158Met; rs4680), CYP17A1 (A1> A2; rs743572); CYP19A1 (C> T; rs10046) and CYP19A1 ((TTTA)n repeats) polymorphisms and BRCA1 founder mutation using TaqMan allelic discrimination method and polymerase chain reaction based restriction fragment length polymorphism. The χ2 -test was used to compare categorical variables between cases and controls and the odds ratios were estimated by unconditional logistic regression models.
RESULTS: We found an independent association of CYP1A1 (Val) and CYP17 (A1) with BC risk.Furthermore, an increased BC risk was observed for women with high serum levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) and carriers of at least: one CYP1A1 variant Val allele; one variant COMT Met allele; or the common CYP17 A1 allele. No combined effects were seen between PFAS exposure and CYP1B1 and CYP19 polymorphisms. The risk of BC was not found significantly associated with exposure to PCBs and OCPs, regardless of genotype for all investigated SNPs. The frequency of the Greenlandic founder mutation in BRCA1 was as expected higher in cases than in controls.
CONCLUSIONS: The BRCA1 founder mutation and polymorphisms in CYP1A1 (Val) and CYP17 (A1) can increase the BC risk among Inuit women and the risk increases with higher serum levels of PFOS and PFOA. Serum PFAS levels were a consistent risk factor of BC, but inter-individual polymorphic differences might cause variations in sensitivity to the PFAS/POP exposure.

Pud D, Har-Zahav G, Laitman Y, et al.
Association between variants of 5-hydroxytryptamine receptor 3C (HTR3C) and chemotherapy-induced symptoms in women receiving adjuvant treatment for breast cancer.
Breast Cancer Res Treat. 2014; 144(1):123-31 [PubMed] Related Publications
Administration of chemotherapy is associated with a wide array of symptoms affecting quality of life. Genetic risk factors for severity of chemotherapy-induced symptoms have not been determined. The present study aimed to explore the associations between polymorphisms in candidate genes and chemotherapy-induced symptoms. Women treated with at least two cycles of adjuvant doxorubicin and cyclophosphamide, with or without paclitaxel for early breast cancer (n = 105) completed the memorial symptom assessment scale and provided blood for genotyping. DNA was extracted from peripheral blood leukocytes and assayed for single nucleotide polymorphisms (SNPs) in GTP cyclohydrolase 1 (GCH1, rs10483639, rs3783641, and rs8007267), catecholamine-o-methyltransferase (COMT, rs4818), and 5-hydroxytryptamine (serotonin) receptor 3C (HTR3C, rs6766410, and rs6807362). Genotyping of HTR3C revealed a significant association between the presence of rs6766410 and rs6807362 SNPs (K163 and G405 variants) and increased severity of symptoms (p = 0.0001 and p = 0.007, respectively). Multiple regressions revealed that rs6766410 and rs6807362, but not age or stage at diagnosis, predicted severity of symptoms (p = 0.001 and p = 0.006, respectively) and explained 12 % of the variance in each regression model. No association was found between the genetic variants of CGH1 or COMT and symptom score. Our study indicates, for the first time, an association between variants of HTR3C and severity of chemotherapy-induced symptoms. Analyzing these genetic variants may identify patients at increased risk for the development of chemotherapy-induced symptoms and targeting the serotonin pathway may serve as a novel treatment strategy for these patients.

Swift-Scanlan T, Smith CT, Bardowell SA, Boettiger CA
Comprehensive interrogation of CpG island methylation in the gene encoding COMT, a key estrogen and catecholamine regulator.
BMC Med Genomics. 2014; 7:5 [PubMed] Free Access to Full Article Related Publications
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.

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