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GSTM1, GSTT1, and GSTP1 polymorphisms, breast cancer risk factors and mammographic density in women submitted to breast cancer screening
Aguiar, Ernestina Silva de;Giacomazzi, Juliana;Schmidt, Aishameriane Venes;Bock, Hugo;Saraiva-Pereira, Maria Luiza;Schuler-Faccini, Lavínia;Duarte Filho, Dakir;Santos, Pollyanna Almeida Costa dos;Giugliani, Roberto;Caleffi, Maira;Camey, Suzi Alves;Ashton-Prolla, Patrícia;
Revista Brasileira de Epidemiologia , 2012, DOI: 10.1590/S1415-790X2012000200002
Abstract: genetic polymorphisms in genes related to the metabolism of xenobiotics, such as genes of the glutathione s-transferases (gstm1, gstt1, and gstp1) superfamily have been associated with an increased risk for breast cancer (bc). considering the high incidence of bc in the city of porto alegre in southern brazil, the purpose of this study was to characterize genotypic and allelic frequencies of polymorphisms in gstm1, gstt1, and gstp1, and correlate these molecular findings with established risk factors for breast cancer including mammographic density, in a sample of 750 asymptomatic women undergoing mammographic screening. molecular tests were performed using the multiplex polymerase chain reaction (pcr) for gstm1 and gstt1, and quantitative pcr for gstp1 polymorphisms. overall, the frequencies of gstm1 and gstt1 null genotypes were 45% and 21%, respectively. for gstp1 polymorphism, genotypic frequencies were 44% for the ile/ile genotype, 44% for the ile/val genotype, and 12% for val/val genotype, with an allelic frequency of 66% for the wild type allele in this population, similar to results of previous international publications. there was a statistically significant association between the combined gstm1 and gstt1 null genotypes (m-/t-) and mammographic density in post menopausal women (p = 0.031). when the gstt1 null (t-) genotype was analyzed isolated, the association with mammographic density in post menopausal women and in the overall sample was also statistically significant (p = 0.023 and p = 0.027, respectively). these findings suggest an association of gstm1 and gstt1 null genotypes with mammographic density.
CYP17 gene polymorphism in relation to breast cancer risk: a case-control study
Kristjana Einarsdóttir, Tove Rylander-Rudqvist, Keith Humphreys, Susanne Ahlberg, Gudrun Jonasdottir, Elisabete Weiderpass, Kee Chia, Magnus Ingelman-Sundberg, Ingemar Persson, Jianjun Liu, Per Hall, Sara Wedrén
Breast Cancer Research , 2005, DOI: 10.1186/bcr1319
Abstract: We genotyped 1,544 incident cases of primary breast cancer and 1,502 population controls, all postmenopausal Swedish women, for the CYP17 c.1-34T>C polymorphism and calculated odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression models.No overall association was found between CYP17 c.1-34T>C and breast cancer risk, OR 1.0 (95% CI 0.8–1.3) for the A2/A2 (CC) carriers compared to the A1/A1 (TT) carriers, regardless of histopathology. We detected an interaction between CYP17 c.1-34T>C and age at menarche (P = 0.026) but regarded that as a chance finding as no dose-response pattern was evident. Other breast cancer risk factors, including menopausal hormone use and diabetes mellitus, did not modify the overall results.It is unlikely that CYP17 c.1-34T>C has a role in breast cancer etiology, overall or in combination with established non-genetic breast cancer risk factors.Estrogen is a central factor in the etiology of breast cancer [1]. One of the key enzymes in the synthesis of sex hormones, such as estrogens and androgens, is cytochrome P450c17 (CYP17). CYP17 catalyses the 17α-hydroxylation of pregnenolone and progesterone, and these intermediates are then converted to dehydroepiandosterone and androstenedione by the 17,20-lyase activity of the enzyme [2,3].A single T (A1 allele) to C (A2 allele) base change in the 5' promoter region of CYP17 (c.1-34T>C) has been suggested to create an additional binding site for the transcription factor Sp1 [4]. This could theoretically lead to increased levels of the enzyme, but use of the extra binding site has not been confirmed experimentally [5]. Three groups have reported an association of the A2 allele with increased breast cancer risk [6-8] but others have failed to replicate those findings [5,9-21]. A recent meta-analysis of 15 case-control studies did not find any overall association [22] but this analysis was criticized by Feigelson and colleagues [23], who found a borderline significant association
Cytochrome P450c17alpha (CYP17) gene polymorphism is not associated with leiomyoma susceptibility
Yao-Yuan, Hsieh;Fuu-Jen, Tsai;Chi-Chen, Chang;Chang-Hai, Tsai;Cheng-Chieh, Lin;Lian-Shun, Yeh;
Genetics and Molecular Biology , 2002, DOI: 10.1590/S1415-47572002000400002
Abstract: estrogen plays a role in the pathogenesis of leiomyoma. the cyp17 gene codes for the cytochrome p450c17a enzyme, which is involved in the biosynthesis of estrogen. our aim was to investigate if cyp17 polymorphism could be a useful marker to predict the susceptibility to leiomyoma. our sample of female subjects was divided into two groups: (1) with leiomyoma (n = 159); (2) without leiomyoma (n = 128). a 169-bp fragment encompassing the a1/a2 polymorphic site of the cyp17 gene was amplified by polymerase chain reaction (pcr), restricted by enzyme mspa1i and electrophored on agarose gel. genotypes and allelic frequencies for this polymorphism in both groups were compared. there was no significant difference between the two groups regarding the distribution of the cyp17 gene polymorphism frequencies. the a1 homozygote/heterozygote/a2 homozygote proportions for cyp17 in both groups were: (1) 17.0/46.5/36.5%, and (2) 17.2/45.3/37.5%. the proportions for alleles a1 and a2 were also comparable in the two groups. a1 and a2 allele frequencies were: 7% (40.3/59) in group 1, and 2% (39.8/60) in group 2. no significant association was observed between the risk of leiomyoma and polymorphisms of the cyp 17 gene. so, cyp17 gene polymorphism does not appear to be a useful marker for the prediction of leiomyoma susceptibility.
Cytochrome P450c17a (CYP17) gene polymorphism is not associated with leiomyoma susceptibility
Yao-Yuan Hsieh,Fuu-Jen Tsai,Chi-Chen Chang,Chang-Hai Tsai
Genetics and Molecular Biology , 2002,
Abstract: Estrogen plays a role in the pathogenesis of leiomyoma. The CYP17 gene codes for the cytochrome P450c17alpha enzyme, which is involved in the biosynthesis of estrogen. Our aim was to investigate if CYP17 polymorphism could be a useful marker to predict the susceptibility to leiomyoma. Our sample of female subjects was divided into two groups: (1) with leiomyoma (n = 159); (2) without leiomyoma (n = 128). A 169-bp fragment encompassing the A1/A2 polymorphic site of the CYP17 gene was amplified by polymerase chain reaction (PCR), restricted by enzyme MspA1I and electrophored on agarose gel. Genotypes and allelic frequencies for this polymorphism in both groups were compared. There was no significant difference between the two groups regarding the distribution of the CYP17 gene polymorphism frequencies. The A1 homozygote/heterozygote/A2 homozygote proportions for CYP17 in both groups were: (1) 17.0/46.5/36.5%, and (2) 17.2/45.3/37.5%. The proportions for alleles A1 and A2 were also comparable in the two groups. A1 and A2 allele frequencies were: 7% (40.3/59) in group 1, and 2% (39.8/60) in group 2. No significant association was observed between the risk of leiomyoma and polymorphisms of the CYP 17 gene. So, CYP17 gene polymorphism does not appear to be a useful marker for the prediction of leiomyoma susceptibility.
GSTM1 null polymorphism – a possible key for oral carcinogenesis
Tanwar Renu,Asha R. Iyengar,Kekkeri Sitaram Nagesh
RSBO , 2013,
Abstract: Introduction: Carcinogenesis is a multistep process and individual risk to development of cancer depends not only on environmental factors or extrinsic exposure to carcinogens but also on genetic susceptibility of an individual. In head and neck cancer, tobacco exposure and alcohol consumption are predominantly the most significant external factors for tumor formation. Individual’s susceptibility to cancer may be partly explained by variability in enzymatic activities of metabolic genes. Mutations in genes concerned with production of enzymes for metabolism of tobacco products may lead to increased risk of carcinogenesis with respect to oral mucosa. Therefore variations in the expression of these genes due to heritable genetic polymorphisms might modulate the process of carcinogenesis by altering the exposure levels of tobacco derived carcinogens. Objective: This non systematic review summarizes current data available on the role of environment gene interaction in form of GSTM1 null polymorphism and oral carcinogenesis. Literature review: Relevant data was selected in order to summarize the studies conducted on GSTM1 null polymorphism and oral cancer. Conclusion: Relationship between GSTM1 null polymorphism in oral cancer needs to be established to confirm the role of environment gene interaction in oral carcinogenesis.
CYP17 genetic polymorphism, breast cancer, and breast cancer risk factors: Australian Breast Cancer Family Study
Jiun-Horng Chang, Dorota M Gertig, Xiaoqing Chen, Gillian S Dite, Mark A Jenkins, Roger L Milne, Melissa C Southey, Margaret RE McCredie, Graham G Giles, Georgia Chenevix-Trench, John L Hopper, Amanda B Spurdle
Breast Cancer Research , 2005, DOI: 10.1186/bcr1040
Abstract: Risk factor and CYP17 genotyping data were derived from a large Australian population-based case-control-family study of 1,284 breast cancer cases and 679 controls. Crude and adjusted odds ratio (OR) estimates and 95% confidence intervals (CIs) were calculated by unconditional logistic regression analyses.We found no associations between the CYP17 genotype and breast cancer overall. Premenopausal controls with A2/A2 genotype had a later age at menarche (P < 0.01). The only associations near statistical significance were that postmenopausal women with A1/A1 (wild-type) genotype had an increased risk of breast cancer if they had ever used hormone replacement therapy (OR 2.40, 95% CI 1.0 to 5.7; P = 0.05) and if they had menopause after age 47 years (OR 2.59, 95% CI 1.0 to 7.0; P = 0.06). We found no associations in common with any other studies, and no evidence for interactions.We observed no evidence of effect modification of reproductive risk factors by CYP17 genotype, although the experiment did not have sufficient statistical power to detect small main effects and modest effects in subgroups. Associations found only in subgroup analyses based on relatively small numbers require cautious interpretation without confirmation by other studies. This emphasizes the need for replication in multiple and large population-based studies to provide convincing evidence for gene–environment interactions.The association between exposure to endogenous and exogenous steroid hormones and breast cancer risk is well established [1]. Consequently, genetic polymorphisms in genes involved with hormone-metabolizing pathways have been widely studied for evidence of their contribution to breast cancer risk [2,3]. One such candidate gene is CYP17 on chromosome 10q24.3, which encodes the enzyme cytochrome P450c17α (17α-hydroxylase; 17/20 lyase). P450c17α functions at two different points in the steroid biosynthesis pathway; the 17α hydroxylase activity can convert progesterone to 17α-hydroxy
CYP17 genetic polymorphism, breast cancer, and breast cancer risk factors
Christine B Ambrosone, Kirsten B Moysich, Helena Furberg, Jo L Freudenheim, Elise D Bowman, Sabrina Ahmed, Saxon Graham, John E Vena, Peter G Shields
Breast Cancer Research , 2002, DOI: 10.1186/bcr570
Abstract: Questionnaire and genotyping data were obtained from a population-based, case–control study of premenopausal (n = 182) and postmenopausal (n = 214) European-American Caucasian women in western New York. Cases and controls were frequency matched by age and by county of residence. Odds ratios and 95% confidence intervals were used to estimate relative risks.The CYP17 genotype was not associated with breast cancer risk; however, controls with the A2/A2 genotype (associated with higher estrogens) had earlier menarche and earlier first full-term pregnancy. Premenopausal women with A1/A1 genotypes, but not with A2 alleles, were at significantly decreased risk with late age at menarche (odds ratio = 0.37, 95% confidence interval = 0.14–0.99), and at increased risk with late age at first full-term pregnancy (odds ratio = 4.30, 95% confidence interval = 1.46–12.67) and with use of oral contraceptives (odds ratio = 3.24, 95% confidence interval = 1.08–9.73). Associations were weaker among postmenopausal women.These results suggest that the effects of factors that may alter breast cancer risk through a hormonal mechanism may be less important among premenopausal women with putative higher lifetime exposures to circulating estrogens related to the CYP17 A2 allele.A number of studies have evaluated possible associations between a polymorphism in the cytochrome P450c17α (CYP17) gene and breast cancer risk [1-16]. Cytochrome P450c17α functions at key branch points in human steroidogenesis, catalyzing the ovarian and adrenal biosynthesis pathways for androstenedione, the immediate precursor of testosterone [17]. Three polymorphisms have been described in this gene: a C → T transition at nucleotide 5471 in intron 6 [18], a G → A transition at nucleotide 47 in the 5'-untranslated region promoter [19], and a thymidine substitution for cytosine at nucleotide 27 in the 5'-untranslated region promoter that creates a MspAI recognition site [20].The MspAI polymorphism gives rise to three g
The relationship between genetic polymorphism of GSTM1 and the outcome of chemotherapy in Chinese patients with primary lung cancer  [cached]
Weiying LI,Yanfei GU,Baitang LAI,Hui WANG
Chinese Journal of Lung Cancer , 2008,
Abstract: Background and objective GSTM1 takes part in the metabolism of environmental pollutants such as benzopyrene other polycyclic aromatic hydrocarbons and anticancer drugs and so on. The study aims to investigate the relationship between the gene polymorphism of GSTM1 and chemotherapy as well as to study the effect to survival of Chinese patients with lung cancer. Methods The genotypes of GSTM1 were examined with polymerase chain reaction in 137 primary lung cancer patients accepted chemotherapy. Results GSTM1 -null genotype frequency was 58.4%(80?137). The frequency of non-null GSTM1 genotype was 41.6%(57?137). The frequency of GSTM1-null genotype was 69.05%(58?84) in the response group of chemotherapy and 41.51%(22?53) in the non-response group of chemotherapy. They were significantly different (P=0.001). In the patients with platinum chemotherapy, the frequency of GSTM1-null genotype was 65.43%(53?81) in the response group of chemotherapy and 42%(21?50) in the non-response group. There werestastically differences in them (P=0.0025). For the advanced cases, GSTM1 -null genotype frequency was 70.13% (54 ? 77) in the response group of chemotherapy, 41.51% (22?53) in the non-response group of chemotherapy respectively and they were significantly different(P=0.001). When the chemotherapy was effective, the survival time of patients in squamous carcinoma and small cell carcinoma with non-null GSTM1 genotype (the median survival times were 42 months and 14 months respectively) were longer than those with null GSTM1 genotype (the median survival times were 6 months and 7 months respectively)(P0.05. When chemotherapy was not effective, the median survival time were not significantly different (P>0.05). Conclusions The effect of chemotherapy of GSTM1-null genotype patients was better than that of GSTM1-postive genotype patients. The chemotherapy effect of the cases with null GSTM1 type was better than those with non-null GSTM1 type when the patients accepted platinum chemotherapy. When the chemotherapy was effective, the survival time may be related to the histological types and GSTM1 genotypes.
Evaluation of Mammographic Density Changes during Estrogen and Estrogen-Progesterone Therapy in Postmenopausal Women
N. Ahmadi Nejad,M. Guity,M. Farahani,S. Farzane
Iranian Journal of Radiology , 2005,
Abstract: Background/Objectives: To determine the effects of estrogen and estrogen plus progesterone on mammographic density in postmenopausal women. Patients and Methods: In a descriptive cohort study, ba seline and 12-month mammograms were obtained from 97 healthy postmenopausal women, aged 45-55 years. Estrogen or combined estrogen and progesterone replacement ther apies were used for them. After one year, we classified breast density in the first and second mammograms according to Breast Imaging Reporting and Data System (BIRADS) as patterns 1 (mostly fatty) through 4 (mostly dense tissue). Results: None of our cases had a decrease in density, while 35.1% showed an increased density.The results showed that an increase in mammographic density had no significant association with the type of prescribed hormone (P=0.77). In cases with no change in density, the parity was 3.51.86; while in the group with one-level rise, it was 4.241.84; and 5.21. 92 in the two-level rise group. Statistical analysis showed that changes in density had significant association with parity in our cases (P=0.015). Conclusion: HRT was associated with increases in mammographic density, suggesting that increasing mammographic density may be a marker of elevated breast cancer risk in postmenopausal women who use postmenopausal hormone replacement therapies. However, the link between changes in breast density resulting from hormone use and the change in breast cancer risk remains uncertain.
Association between GSTM1 Genetic Polymorphism and Lung Cancer Risk by SYBR Green I Real-time PCR Assay  [PDF]
Dejie ZHENG,Feng HUA,Chaorong MEI,Haisu WAN
Chinese Journal of Lung Cancer , 2010,
Abstract: Background and objective Glutathione S-transferase M1 (GSTM1) is an important phase II metabolic enzyme gene which involves metabolism of various carcinogens in human body. Many studies showed that GSTM1 genetic polymorphism was associated with lung cancer risk. The aim of this study is to investigate the relationship between GSTM1 genetic polymorphism and lung cancer risk among Han nationality population in Tianjin district. Methods GSTM1 genetic polymorphism was detected by melting curve analysis of SYBR green I real-time PCR assay. Two hundred and sixty-five histological confirmed lung cancer patients and 307 health controls were recruited in this case-control study and the relationship between GSTM1 genetic polymorphism and lung cancer risk was investigated. Results (1) The frequency of the GSTM1(-) in lung cancer and control groups was 56.6% and 57.0% respectively, and no significant difference was found between the distribution of the GSTM1(-) genotype in the two groups (χ2=0.831, P=0.362). (2) When considered the GSTM1(+) genotype as reference, there was no overall statistically increased lung cancer risk for carriers with the GSTM1(-) genotype adjusted by age, gender and smoking status (OR=0.840, 95%CI: 0.578-1.221, P=0.362). (3) The frequency of the GSTM1(-) genotype for squamous cell carcinoma, adenocarcinoma, SCLC and other histological types was 65.8%, 48.5%, 47.8% and 52.2% respectively, compared with the control group, no statistically increased lung cancer risk was observed (P>0.05). Conclusion No evidence is found between GSTM1 genetic polymorphism and lung cancer risk among Han nationality population in Tianjin district.
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