Polymorphism for transforming growth factor beta 1-509 (TGF-B1-509): association with endometriosis

Association between polymorphisms of cytokine genes and endometriosis: A comprehensive systematic review and meta-analysis

INTRODUCTION

There is abundant evidence to suggest that cytokines play a part in the mechanisms responsible for the formation of endometrium heterotopy. Cytokine synthesis is not only determined by the body's immunological reactivity but also by polymorphisms in the immune regulatory genes. The study of these polymorphisms in the immune regulatory genes offers up new possibilities in terms of prognosticating the risk of endometriosis and susceptibility to its treatment. The purpose of this comprehensive systematic review and meta-analysis was to investigate whether or not cytokine gene polymorphisms were linked to an increased chance of endometriosis.

METHODS

By searching MEDLINE, Scopus, and Web of Science databases, the relevant studies were identified. The odds ratio (OR) with 95% confidence interval (CI) was used to assess the association between TNF-α/IL-10/IL-6/TGF-β/IFN-γ/IL-1β gene polymorphisms and endometriosis risk.

RESULTS

A total of 5128 cases and 5334 controls in 32 eligible studies were included in the meta-analysis. Overall, results indicated the negative association between the cytokine gene polymorphisms and endometriosis in the dominant model of TNF-α (rs1799964): [OR] = 0.64, [CI]: 0.46-0.89) and a positive association in IFN-γ a13 allele: OR= 1.45, [CI]: 1.07-1.98; and IL-10 (rs1800872): [OR]= 1.60, [CI]: 1.21-2.12).

CONCLUSION

The present study suggests that IL-10 (rs1800872) and IFN-γ a13 allele may be a risk factors for endometriosis. Also, TNF-α (rs1799964) is associated with decreased susceptibility to endometriosis.

Oxidative stress-related effects on various aspects of endometriosis

Endometriosis is a chronic and relatively common disease in women of childbearing age. Complications of this disease include a wide range of disorders. The cause of this disease is not known for sure, but several hypotheses have been proposed for it. In this disease, the entry of endometrial tissues into the peritoneal cavity causes oxidative stress through the Fenton reaction and inflammation in this site. Oxidative stress can be associated with many complications of endometriosis. In this review, an attempt has been made to discuss the effects of oxidative stress on various complications of this disease. This article is protected by copyright. All rights reserved.

Genetic and Epidemiological Similarities, and Differences Between Postoperative Intraperitoneal Adhesion Development and Other Benign Fibro-proliferative Disorders

Intraperitoneal adhesions complicate over half of abdominal-pelvic surgeries with immediate, short, and long-term sequelae of major healthcare concern. The pathogenesis of adhesion development is similar to the pathogenesis of wound healing in all tissues, which if unchecked result in production of fibrotic conditions. Given the similarities, we explore the published literature to highlight the similarities in the pathogenesis of intra-abdominal adhesion development (IPAD) and other fibrotic diseases such as keloids, endometriosis, uterine fibroids, bronchopulmonary dysplasia, and pulmonary, intraperitoneal, and retroperitoneal fibrosis. Following a literature search using PubMed database for all relevant English language articles up to November 2020, we reviewed relevant articles addressing the genetic and epidemiological similarities and differences in the pathogenesis and pathobiology of fibrotic diseases. We found genetic and epidemiological similarities and differences between the pathobiology of postoperative IPAD and other diseases that involve altered fibroblast-derived cells. We also found several genes and single nucleotide polymorphisms that are up- or downregulated and whose products directly or indirectly increase the propensity for postoperative adhesion development and other fibrotic diseases. An understanding of the similarities in pathophysiology of adhesion development and other fibrotic diseases contributes to a greater understanding of IPAD and these disease processes. At a very fundamental level, blocking changes in the expression or function of genes necessary for the transformation of normal to altered fibroblasts may curtail adhesion formation and other fibrotic disease since this is a prerequisite for their development. Similarly, applying measures to induce apoptosis of altered fibroblast may do the same; however, apoptosis should be at a desired level to simultaneously ameliorate development of fibrotic diseases while allowing for normal healing. Scientists may use such information to develop pharmacologic interventions for those most at risk for developing these fibrotic conditions.

Investigation of TGF-β1 gene variant and expression in a group of Iranian women with endometriosis

PURPOSE

Endometriosis is defined as a common gynecologic and inflammatory disease. Transforming growth factor-beta 1 (TGF-β1) gene and its protein level might play a role in the pathogenesis of endometriosis. The present study aimed for the first time to assess the associations between endometriosis risk and - 509 C/T (rs1800469) variant of the TGF-β1 gene as well as TGF-β1 mRNA expression in eutopic endometrium tissue of patients with and without endometriosis among a group of Iranian women.

METHODS

Genotyping was carried out in 100 endometriosis patients (cases) with confirmed histological diagnosis of endometriosis and 197 non-endometriosis subjects (controls). The expression level of TGF-β1 mRNA was determined using Real-Time PCR assay in 15 eutopic endometrium tissue of women with endometriosis and 15 healthy controls.

RESULTS

There was a significant association for allele and genotype frequencies of rs1800469 variant and endometriosis. No significant difference for TGF-β1 expression was observed between eutopic endometrium of patients and healthy group. Also, evaluation of TGF-β1expression across the menstrual cycle showed the same level of TGF-β1 among case and control subjects.

CONCLUSION

Our investigations indicated enough evidence for the effect of TGF-β1 genetic variant on endometriosis risk in an Iranian population. Furthermore, we could not find any relations between TGF-β1 mRNA expression and susceptibility to endometriosis.

Functional nucleotide polymorphisms up-regulating transforming growth factor β1 expression are associated with increased tuberculosis susceptibility

Previous studies demonstrated that transforming growth factor (TGT) β1 plays an immunosuppressive role in clinical tuberculosis. However, the contribution of TGF-β1 gene polymorphisms to human tuberculosis susceptibility remains undetermined. In this study, we showed that single-nucleotide polymorphisms (SNPs) in TGF-β1 gene were associated with increased susceptibility to tuberculosis in the discovery cohort (1533 case patients and 1445 controls) and the validation cohort (832 case patients and 1084 controls), and 2 SNPs located in the promoter region (rs2317130 and rs4803457) are in strong linkage disequilibrium. The SNP rs2317130 was associated with the severity of tuberculosis. Further investigation demonstrated that rs2317130 CC genotype is associated with higher TGF-β1 and interleukin 17A production. The mechanistic study showed that rs2317130 C allele affected TGF-β1 promoter activity by regulating binding activity to nuclear extracts. These findings provide insights into the pathogenic role of TGF-β1 in human tuberculosis and reveal a function for the TGF-β1 promoter SNPs in regulating immune responses during Mycobacterium tuberculosis infection.

Polymorphisms and endometriosis: a systematic review and meta-analyses

BACKGROUND

Endometriosis is an estrogen-dependent gynecological disorder that affects at least 10% of women of reproductive age. It may lead to infertility and non-specific symptoms such as chronic pelvic pain. Endometriosis screening and diagnosis are difficult and time-consuming. Late diagnosis (with a delay ranging from 3.3 to 10.7 years) is a major problem and may contribute to disease progression and a worse response to treatment once initiated. Efficient screening tests might reduce this diagnostic delay. As endometriosis is presumed to be a complex disease with several genetic and non-genetic pathogenic factors, many researchers have sought to identify polymorphisms that predispose to this condition.

OBJECTIVE AND RATIONALE

We performed a systematic review and meta-analysis of the most regularly reported polymorphisms in order to identify those that might predispose to endometriosis and might thus be of value in screening.

SEARCH METHODS

The MEDLINE database was searched for English-language publications on DNA polymorphisms in endometriosis, with no date restriction. The PubTator text mining tool was used to extract gene names from the selected publications' abstracts. We only selected polymorphisms reported by at least three studies, having applied strict inclusion and exclusion criteria to their control populations. No stratification based on ethnicity was performed. All steps were carried out according to PRISMA guidelines.

OUTCOMES

The initial selection of 395 publications cited 242 different genes. Sixty-two genes (corresponding to 265 different polymorphisms) were cited at least in three publications. After the application of our other selection criteria (an original case-control study of endometriosis, a reported association between endometriosis and at least one polymorphism, data on women of reproductive age and a diagnosis of endometriosis in the cases established by surgery and/or MRI and confirmed by histology), 28 polymorphisms were eligible for meta-analysis. Only five of the 28 polymorphisms were found to be significantly associated with endometriosis: interferon gamma (IFNG) (CA) repeat, glutathione S-transferase mu 1 (GSTM1) null genotype, glutathione S-transferase pi 1 (GSTP1) rs1695 and wingless-type MMTV integration site family member 4 (WNT4) rs16826658 and rs2235529. Six others showed a significant trend towards an association: progesterone receptor (PGR) PROGINS, interCellular adhesion molecule 1 (ICAM1) rs1799969, aryl-hydrocarbon receptor repressor (AHRR) rs2292596, cytochrome family 17 subfamily A polypeptide 1 (CYP17A1) rs743572, CYP2C19 rs4244285 and peroxisome proliferator-activated receptor gamma (PPARG) rs1801282), and 12 showed a significant trend towards the lack of an association: tumor necrosis factor (TNF) rs1799964, interleukin 6 (IL6) rs1800796, transforming growth factor beta 1 (TGFB1) rs1800469, estrogen receptor 1 (ESR1) rs2234693, PGR rs10895068, FSH receptor (FSHR) rs6166, ICAM1 rs5498, CYP1A1 rs4646903, CYP19A1 rs10046, tumor protein 53 (TP53) rs1042522, X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1) rs25487 and serpin peptidase inhibitor clade E member 1 (SERPINE1) rs1799889; however, for the 18 polymorphisms identified in the latter two groups, further studies of the potential association with the endometriosis risk are needed. The remaining five of the 28 polymorphisms were not associated with endometriosis: glutathione S-transferase theta 1 (GSTT1) null genotype, vascular endothelial growth factor alpha (VEGFA) rs699947, rs833061, rs2010963 and rs3025039.

WIDER IMPLICATIONS

By carefully taking account of how the control populations were defined, we identified polymorphisms that might be candidates for use in endometriosis screening and polymorphisms not associated with endometriosis. This might constitute the first step towards identifying polymorphism combinations that predispose to endometriosis (IFNG (CA) repeat, GSTM1 null genotype, GSTP1 rs1695, WNT4 rs16826658 and WNT4 rs2235529) in a large cohort of patients with well-defined inclusion criteria. In turn, these results might improve the diagnosis of endometriosis in primary care. Lastly, our present findings may enable a better understanding of endometriosis and improve the management of patients with this disease.

The role of TGF-β in the pathophysiology of peritoneal endometriosis

BACKGROUND

Endometriosis is estimated to affect 6-10% of women of reproductive age and it is associated with chronic pelvic pain, dysmenorrhoea and subfertility. It is currently managed surgically or medically but symptoms recur in up to 75% of cases and available medical treatments have undesirable side effects. Endometriosis is defined as the presence of endometrial tissue outside the uterus with lesions typically found on the peritoneum. The aetiology of endometriosis is uncertain but there is increasing evidence that transforming growth factor (TGF)-β plays a major role.

OBJECTIVE AND RATIONALE

A descriptive review was undertaken of the published literature on the expression pattern of TGF-β ligands and signalling molecules in women with and without endometriosis, and on the potential roles of TGF-β signalling in the development and progression of peritoneal endometriosis. The current understanding of the TGF-β signalling pathway is summarized.

SEARCH METHODS

We searched the Pubmed database using the terms 'transforming growth factor beta' and 'endometriosis' for studies published between 1995 and 2016. The initial search identified 99 studies and these were used as the basic material for this review. We also extended our remit for important older publications. In addition, we searched the reference lists of studies used in this review for additional studies we judged as relevant. Studies which were included in the review focused on peritoneal endometriosis only as increasing evidence suggests that ovarian and deep endometriosis may have a differing pathophysiology. Thus, a final 95 studies were included in the review.

OUTCOMES

TGF-β1 is reported to be increased in the peritoneal fluid, serum, ectopic endometrium and peritoneum of women with endometriosis compared to women without endometriosis, and TGF-β1-null mice have reduced endometriosis lesion growth when compared to their wild-type controls. Studies in mice and women have indicated that increasing levels of TGF-β ligands are associated with decreased immune cell activity within the peritoneum, together with an increase in ectopic endometrial cell survival, attachment, invasion and proliferation, during endometriosis lesion development. TGF-β1 has been associated with changes in ectopic endometrial and peritoneal cell metabolism and the initiation of neoangiogenesis, further fuelling endometriosis lesion development.

WIDER IMPLICATIONS

Together these studies suggest that TGF-β1 plays a major role in the development of peritoneal endometriosis lesions and that targeting this pathway may be of therapeutic potential.

Recent Advances in Molecular Genetics of Endometriosis

Endometriosis (MIM 131200) is a prevalent and complex gynecological disease polygenically inherited with multifactorial pathogenesis. It is increasingly recognized as a major women's health issue. Endometriosis is characterized by the presence of endometrial-like tissue in sites outside the uterus, mainly the pelvic peritoneum, ovaries and rectovaginal septum causing severe dysmenorrhoea, dyspareunia, chronic pelvic pain and subfertility. Recent advances in molecular technologies have provided many evidences about the underlying biological events that are likely to be involved in the development of endometriosis. Different chromosomal regions, genes and other molecules, such as microRNAs, have been identified as potentially involved in endometriosis pathogenesis. Moreover, genome-wide analyses of endometriosis have showed novel molecular signatures or individual genes that had not been previously associated with the disease. The goal of these studies is to provide information that might, in turn, lead to new therapies. In this review, some previous studies were updated supporting the polygenic/multifactorial inheritance and the association with malignant neoplasias. We have also emphasized the importance of identifying the causative genes and determining novel diagnostic and predictive biomarkers.

Expression and Role of Peptides, Proteins and Growth Factors in the Pathogenesis of Endometriosis

Growing evidence is demonstrating that several peptides (corticotrophin-releasing factor, urocortins, ghrelin), proteins (leptin, adiponectin) and growth factors (vascular endothelial growth factor; epidermal growth factor family of growth factors and receptors, fibroblast growth factor, insulin like growth factor and insulin like growth factor-binding proteins, transforming growth factor-β and, activin A and related proteins) are expressed in endometriotic implants, and locally play a relevant role in affecting the biological mechanisms leading to endometriosis. They establish a complex network of interactions by which they are therefore able to stimulate angiogenesis, inflammatory cell recruitment and reaction, the growth of endometriotic tissue and its survival through the modulation of the narrow immune system. This review will evaluate the role played by several regulatory peptides, proteins and growth factors in affecting endometrial physiology and the putative mechanisms advocated to explain endometriosis (angiogenesis, cellular and humoral immunity, inflammatory response, endometrial cell proliferation, activation, motility, adhesion and invasion).

Effects of cisplatin and letrozole on surgically induced endometriosis and comparison of the two medications in a rat model

This study was to investigate the effects of cisplatin (CDDP) and letrozole on surgically induced endometriosis and comparison of the two drugs in a rat model. Endometriosis was surgically induced by autologous transplantation of endometrial pieces. Thirty model rats were divided into three groups, randomly. Group 1 (n=10) served as control and received no medication. Group 2 (n=10) received 0.2mg/kg/day of oral letrozole. Group 3 (n=10) received 35mg/m(2) CDDP via peritoneal perfusion every four days. All the rats were treated for 24days. The growth and histologic score of the implants were evaluated. The proliferation- and angiogenesis-associated proteins were assessed using immunohistochemistry and western blotting. The serum sex hormones were assayed using ELISA. After the medication, the growth and histologic score of the implants were significantly lower in the 2 and 3 groups than in the control group. The protein expressions of vascular endothelial growth factor (VEGF), aromatase P450 (P450arom), transforming growth factor-beta (TGF-β), and matrix metalloproteinase (MMP)-2, were significantly lower in groups 2 and 3 than in the control group. Further, the P450arom level was lower in the letrozole group than in the CDDP group. The TGF-β and MMP-2 levels were lower in the CDDP group than in the letrozole group. Serum T level was significantly higher in the letrozole group, and serum E2 level was lower in the letrozole group. In conclusion, cisplatin and letrozole caused similar regression of the implants in the endometriosis model rats. But their effects on the proliferation- and angiogenesis-associated protein expressions and the serum sex hormone levels were different. Cisplatin and letrozole might cause the effects in the endometriotic foci through different mechanism.

Association of the intercellular adhesion molecule-1 (ICAM-1) gene polymorphisms with endometriosis: a systematic review and meta-analysis

BACKGROUND

Reported associations of the G241R and K469E polymorphisms of the intercellular adhesion molecule-1 gene (ICAM-1) gene with endometriosis have differed in magnitude.

MATERIALS AND METHODS

In a meta-analysis of six published case-control studies (from five articles), we estimated risk [odds ratio (OR) 95 % confidence intervals (CI)] of associations with these polymorphisms using the Review Manager 5.3 software.

RESULTS

Based on 1213 cases and 1103 controls, overall analysis showed significant increased risk in the homozygous (OR 2.83, 95 % CI 0.99-8.10, p = 0.05), dominant (OR 1.86, 95 % CI 1.00-3.46, p = 0.05) and codominant (OR 2.15, 95 % CI 1.06-4.35, p = 0.03) models. Confined to the studies in Hardy-Weinberg Equilibrium erased the significance (OR 1.59-2.59, 95 % CI 0.81-8.22, p = 0.10-0.15). Asian effects were variable (OR 0.93-1.09, p = 0.50-0.57), but Caucasian effects were not (OR 4.09-13.60, p < 0.0001). Independent data for the late stages of endometriosis suggest protection of the ICAM-1 K469E polymorphism among the Asians (OR 0.91-0.95, p = 0.35-0.71). These effects were weak but non-heterogeneous (P heterogeneity = 0.17-0.57, I (2) = 0-40 %).

CONCLUSION

In summary, strengths of the overall effects were consistency, significance and robustness but limited by their high heterogeneity. These strengths and limitations were also observed in the Caucasian subgroup which when tested for interaction against the contrasting Asian effects, highlighted Caucasian susceptibility (p = 0.004-0.01). The findings are an interplay of strengths and limitations, which warrant awareness of their interpretation as susceptibility markers for this disorder.

Association of cytokine gene polymorphisms and serum concentrations with the outcome of chronic hepatitis B

OBJECTIVE

The present paper investigated possible correlations between the clinical presentation of hepatitis B and the TNF-α -308G/A, IFN-γ +874A/T, TGF-beta1 -509C/T, and IL-10 -1081A/G polymorphisms and associated serum levels of these cytokines.

METHODS

Fifty-three hepatitis patients were selected and divided into two groups: A - inactive (n=30) and B - chronic hepatitis/cirrhosis (n=23). The control group consisted of 100 subjects who were positive for anti-HBc and anti-HBs. The serum concentrations of the cytokines were determined by immunoenzymatic assays. The polymorphisms of the cytokines genes were assessed by PCR and PCR-SSP.

RESULTS

The mean serum levels of IFN-γ of the control group were significantly higher than those of groups A and B, whereas the mean levels TGF-beta1 were significantly higher in groups A and B in comparison with the control. In the case of IL-10, the mean serum level recorded in the control group was significantly higher than that of group B. The TNF-α -308AG genotype was considerably more frequent in group B (43.3%) than the control (14.4%).

CONCLUSION

Higher serum levels of IFN-γ and TGF-beta1 were associated with chronic hepatitis B, and lower serum levels of IL-10 were found in patients with the active disease. Furthermore the presence of allele A of the TNF-α -308 polymorphism suggest a risk of the progressive disease.

Association of a tgf-b1-509c/t polymorphism with gastric cancer risk: a meta-analysis

Published data on the association between the transforming growth factor B1 (TGF-B1) gene 509C/T polymorphism and gastric cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis of the TGFB1-509C/T polymorphism (with 2130 cases and 2374 controls) from seven published case-control studies was performed. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the codominant model, the dominant model, and the recessive model. In the overall analysis, the T allele was significantly associated with susceptibility to gastric cancer in the recessive model (TT vs. CC+CT) (TT vs. CC+CT: OR = 1.35, 95% CI: 1.10-1.66, P = 0.10 for heterogeneity) when all the included studies were pooled into the meta-analysis. In the stratified analysis by country, the T allele was also found to be significantly associated with increased gastric cancer risk in the recessive model (TT vs. CC+CT) in Chinese studies and in T versus C in the Indian study. In conclusion, this meta-analysis supports the TGFB1-509T polymorphism as a susceptibility factor for gastric cancer.

Association between TGF-β1-509C/T polymorphism and endometriosis: a systematic review and meta-analysis

OBJECTIVE

To evaluate the association between the transforming growth factor β1 gene-509C/T (TGF-β1-509C/T) polymorphism and the risk of endometriosis.

STUDY DESIGN

Relevant studies published before October 2011 were identified by searching PubMed and Embase. Studies were selected using prior defined criteria. The strength of the relationship between the TGF-β1-509C/T polymorphism and endometriosis risk was assessed by Odds Ratios (ORs). Fixed- or random-effects model was calculated according to study heterogeneity. Stratification analysis and sensitivity analysis were also conducted. Possible publication bias was tested by funnel plots and Egger's test.

RESULTS

Of 49 potentially relevant studies, six case-control studies were identified in this meta-analysis. The integrated result showed that the TGF-β1-509C/T polymorphism was not associated with the endometriosis risk for the allele contrast (T vs. C: OR=1.57, 95%CI=0.88-2.79), the additive genetic model (T/T vs. C/C: OR=2.96, 95%CI=0.97-9.10), the dominant genetic model (T/T+T/C vs. C/C: OR=1.80, 95%CI=0.80-4.07) and the recessive genetic model (T/T vs. C/C+T/C: OR=1.91, 95%CI=0.89-4.12). In the stratified analysis by ethnicity, genotyping method and source of control, no significantly association was found. Publication bias was not detected in the included studies.

CONCLUSIONS

Meta-analyses of the available data showed that the association between TGF-β1-509C/T polymorphism and susceptibility of endometriosis was not significant. More studies are needed to elucidate its role in endometriosis.

Intercellular adhesion molecule-1 (ICAM-1) gene polymorphism and endometriosis in northern Iran

PURPOSE

Endometriosis is a chronic pleomorphic disorder with pelvic or systemic manifestations, and is characterized by the presence of endometrial glands and stroma. It is generally considered to involve genetic, environmental, immunological, angiogenic and endocrine processes. The aim of this study was to evaluate the frequency of intercellular adhesion molecule-1 (ICAM-1) polymorphism at position 241 in exon 4 of the ICAM-1 gene in patients with endometriosis and in healthy control subjects in northern Iran.

METHODS

A total of 84 unrelated patients and 120 consecutive unrelated healthy controls from the northern Iran were recruited for the study. ICAM-1 codon 241 polymorphism analysis was performed by two independent PCR reactions, based on the two set of oligoprimers specific for Arg (AGG) or Gly (GGG) coding sequence, respectively.

RESULTS

Genotype distributions of ICAM-1 gene show significant difference between patients and controls. The R241 allele was detected in 23% of endometriosis patients and in 6% of controls (P = 0.001; odds ratio 4.67; 95% confidence interval 1.81-12.07). Comparing patients with different stage of endometriosis, we found a trend to higher frequency of R241 in patients with stage IV (65 vs 6%; P < 0.0001).

CONCLUSION

Our results suggest that ICAM-1 polymorphism in codon 241 is associated with the development of endometriosis susceptibility in the population of northern Iran.

DNA repair genes in endometriosis

Several polymorphisms in the DNA repair gene are thought to have significant effects on cancer risk. We investigated the association of polymorphisms in the DNA repair genes XRCC1 Arg399Gln, XRCC3 Thr241Met, XPD Lys751Gln, XPG Asp1104His, APE1 Asp148Glu, and HOGG1 Ser326Cys with endometriosis risk. Genotypes were determined by PCR-RFLP assays in 52 patients with endometriosis and 101 age-matched healthy controls. Although there were no significant (P > 0.05) differences in the frequencies of genotypes or alleles of APE1, XRCC1, XPD, XPG, and HOGG1 genes between patients and controls, the frequency of the XRCC3 Thr/Thr genotype was significantly greater in endometriosis patients compared with controls (P = 0.005). XRCC3 Thr/Met genotypes (P = 0.022), and the Met allele (P = 0.005) seem to have a protective role against endometriosis. The distributions of genotypes and alleles of the genes APE1, XRCC1, XRCC3, XPD, XPG, and HOGG1 were not significantly associated with the different stages of endometriosis (P > 0.05). We conclude that the XRCC3 Thr/Thr genotype is associated with endometriosis in Turkish women.

Transforming growth factorβ1 L10P variant plays an active role on the breast cancer susceptibility in Caucasian: evidence from 10,392 cases and 11,697 controls

In view of the essential role of transforming growth factorβ1 (TGFB1) on both inhibiting the development of early benign breast tumors as well as promoting tumor invasion, the association of TGFB1 L10P polymorphism and breast cancer risk has been widely reported, but results of previous studies were somewhat contradictory and underpowered. To overcome the limitations of individual study and to understand the real situation, we conducted a systematic review and meta-analysis towards the association between TGFB1 L10P polymorphism and breast cancer. Through retrieving MEDLINE, PubMed, Embase, and Web of Science, a total of 16 studies with 10,392 cases and 11,697 controls were identified. The results showed that significant association was found in the recessive genetic model for Caucasian (OR = 1.152, 95% CI = 1.020-1.301). However, we did not find any associations in additive genetic model (PP vs. LL for total: OR = 1.026, 95% CI = 0.940-1.121), allele contrast (L vs. P for total: OR = 1.004, 95% CI = 0.966-1.044), and dominant genetic model (PP + LP vs. LL for total: OR = 1.001, 95% CI = 0.946-1.061). Conclusively, this meta-analysis strongly suggests that TGFB1 L10P polymorphism may play a low penetrance role in breast cancer susceptibility in Caucasian. Large well-designed epidemiological studies will be necessary to validate the risk identified in the current meta-analysis.

Association of interleukin 1beta gene (+3953) polymorphism and severity of endometriosis in Turkish women

Endometriosis is regarded as a complex trait, in which genetic and environmental factors contribute to the disease phenotype. We investigated whether the interleukin (IL) 1beta (+3953) polymorphism is associated with the severity of endometriosis. Diagnosis of endometriosis was made on the basis of laparoscopic findings. Stage of endometriosis was determined according to the Revised American Fertility Society classification. 118 women were enrolled in the study. 78 women did not have endometriosis, 6 women had stage I, 3 had stage II, 13 had stage III and 18 had stage IV endometriosis. Polymerase Chain Reaction (PCR), Restriction Fragment Length Polymorphism (RFLP), and agarose gel electrophoresis techniques were used to determine the IL 1beta (+3953) genotype. Frequencies of the IL-1beta (+3953) genotypes in the control group were: CC, 0.397; TT, 0.115; CT, 0.487. Frequencies of the IL-1beta (+3953) genotypes in cases were: CC, 0.375; TT, 0.225; CT, 0.400. We found a 2.22 fold increase in TT genotype in the endometriosis group. However, the difference was not statistically significant (P > 0.05). We also observed an increase in the frequency of IL-1beta (+3953) T allele in the endometriosis group. However, the difference was not statistically significant. We also investigated the association between IL-1beta (+3953) polymorphism and the severity of endometriosis. The frequencies of CC+CT genotypes in stage I, III and IV endometriosis patients were 83.3, 84/6 and 72.2%, respectively; and TT genotypes were 16.7, 15.4 and 27.8%, respectively. We observed a statistically insignificant increase in TT genotype in stage IV endometriosis (P > 0.05). We suggest that IL-1beta (+3953) polymorphism is not associated with endometriosis in Turkish women.

TGFB1 509 C/T polymorphism and colorectal cancer risk: a meta-analysis

Transforming growth factor β (TGF-β) is a cytokine. The TGF-β signaling pathway plays an important role in controlling cell proliferation and differentiation involved in colorectal carcinogenesis. In mammalian cells, TGFB1 is the most abundant subtype of TGF-β. The 509 C/T polymorphism in TGFB1 has been implicated in colorectal cancer risk. However, published data remain conflicting. To derive a more precise estimation of the relationship, a meta-analysis of 994 cases and 2,335 controls from five published case-control studies was performed. Overall, significantly increased colorectal cancer risks were found for CC versus TT (OR=1.62; 95% CI: 1.30-2.02; Pheterogeneity=0.118), TC+CC versus TT (OR=1.30; 95% CI: 1.08-1.58; Pheterogeneity=0.259) and CC versus TC+TT (OR=1.48; 95% CI: 1.26-1.75; Pheterogeneity=0.244). In the subgroup analysis by ethnicity, significantly increased risks were also found among Asians for CC versus TT (OR=1.77; 95% CI: 1.40-2.24; Pheterogeneity=0.519), TC+CC versus TT (OR=1.38; 95% CI: 1.13-1.68; Pheterogeneity=0.679) and CC versus TC+TT (OR=1.58; 95% CI: 1.31-1.89; Pheterogeneity=0.340). However, no significant associations were found among Europeans for all genetic models. This meta-analysis showed that TGFB1 509 C allele is a risk factor for developing colorectal cancer in Asians.

Analysis of the transforming growth factor beta1 gene -509 C/T polymorphism in patients with advanced-stage endometriosis

OBJECTIVE

To investigate whether the transforming growth factor beta (TGF-beta) gene -509 C/T polymorphism is associated with susceptibility to advanced-stage endometriosis.

DESIGN

Case-control study.

SETTING

University department of obstetrics and gynecology.

PATIENT(S)

Women with advanced-stage endometriosis (n = 485) and without endometriosis (n = 352).

INTERVENTION(S)

Genotyping by real-time polymerase chain reaction using a Taqman assay.

MAIN OUTCOME MEASURE(S)

Genotype distribution and allele frequency of the -509 C/T polymorphism in the TGF-beta1 gene.

RESULT(S)

The genotype distribution of the TGF-beta1 gene -509 C/T polymorphism in the endometriosis group was not different from that of the control group (CC/CT/TT rates were 29.3%/48.2%/22.5% and 27.3%/50.3%/22.4% for the endometriosis and control groups, respectively). Further subgroup analyses according to the stage of endometriosis or bilaterality of ovarian endometrioma also revealed no significant differences in the genotype distribution between each of the subgroups and the control group.

CONCLUSION(S)

These results suggest that the TGF-beta1 -509 C/T polymorphism may not be associated with an increased risk for advanced-stage endometriosis.

The role of iron in the pathogenesis of endometriosis

BACKGROUND

Endometriosis may cause symptoms including chronic pelvic pain and infertility, and increases susceptibility to the development of ovarian cancer. Genomic studies have started to delineate the wide array of mediators involved in the development of endometriosis. Understanding the mechanisms of endometriosis development and elucidating its pathogenesis and pathophysiology are intrinsic to prevention and the search for effective therapies.

METHOD OF STUDY

The present article reviews the English language literature for biological, pathogenetic and pathophysiological studies on endometriosis. Several recent genomic studies are discussed in the context of endometriosis biology.

RESULTS

Severe hemolysis occurring during the development of endometriosis results in high levels of free heme and iron. These compounds oxidatively modify lipids and proteins, leading to cell and DNA damage, and subsequently fibrosis development. Recent studies based on genome-wide expression analysis technology have noted specific expression of heme/iron-dependent mediators in endometriosis. The heme/iron-dependent signaling pathway of endometriosis, which is providing new insights into the regulation of inflammation, detoxification and survival, is discussed.

CONCLUSION

Several important endometriosis-specific genes overlap with those known to be regulated by iron. Other genes are involved in oxidative stress. Iron has a significant impact on endometriotic-cell gene expression. This review summarizes recent advances in the heme/iron-mediated signaling and its target genes, outlines the potential challenges to understanding of the pathogenesis and pathophysiology of endometriosis, and proposes a possible novel model.

Functional genetic polymorphisms and female reproductive disorders: part II--endometriosis

BACKGROUND

Endometriosis has a strong genetic component, and numerous genetic studies have been reported.

METHODS

We have systematically reviewed these studies and included 114 in our final selection.

RESULTS

We found no consistent evidence linking endometriosis with specific polymorphisms in genes encoding inflammatory mediators, proteins involved in sex steroid metabolism, vascular function and tissue remodelling. Although a number of polymorphisms have been associated with endometriosis in selected populations, the associations have not been independently confirmed, either because only single studies were carried out on these markers/genes or because other studies reported no association. The most solid evidence linking specific polymorphisms to endometriosis came from studies investigating glutathione-S-transferase, a phase II detoxification enzyme. Carriage of the GSTT1 null deletion variant showed consistent association with endometriosis with a 29% increased risk; however, it cannot be excluded that this result was due to publication bias, and this association should be independently confirmed in large-scale, well-designed case–control studies.

CONCLUSIONS

The evidence of an association between genetic polymorphisms and endometriosis is weak. Carriage of the GSTT1 null deletion may moderately increase the risk of this disease. We suggest that the methodology of association studies should be improved in order to identify and validate associations in endometriosis.

Association of estrogen receptor alpha and interleukin-10 gene polymorphisms with endometriosis in a Chinese population

OBJECTIVE

To determine whether polymorphisms of the estrogen receptor alpha (ERalpha) and interleukin-10 (IL-10) genes are associated with endometriosis in a Chinese population.

DESIGN

Association study.

SETTING

University hospital.

PATIENT(S)

Chinese women diagnosed with endometriosis by laparotomy or laparoscopy.

INTERVENTION(S)

Determination of polymorphisms of the ERalpha and IL-10 genes was performed by polymerase chain reaction and restriction fragment length polymorphism analysis in 214 affected women and 160 controls.

MAIN OUTCOME MEASURE(S)

Frequency and distribution of PvuII and XbaI polymorphisms of ERalpha and of BslI, SspI, and RsaI polymorphisms of IL-10.

RESULT(S)

There was no significant difference between the endometriosis patients and the control groups in the genotype frequency of ERalpha-PvuII and promoter of IL-10 gene polymorphisms in the position of -1082. However, the frequency of ERalpha-XbaI and -592 or -819C alleles of IL-10 in the endometriosis group was significantly higher than that of controls, and further analysis showed that the X allele of ERalpha-XbaI was associated with endometriosis.

CONCLUSION(S)

The X allele of ERalpha-XbaI and the -592 or -819 C allele of IL-10 are associated with endometriosis.

Evaluation of transforming growth factor and vascular endothelial growth factor polymorphisms in Taiwan Chinese patients with pterygium

PURPOSE

Pterygium is an invasive and highly vascularized growth, thought to arise from activated and proliferating limbal epithelial stem cells. Epidemiologic studies have found the increase of active angiogenic and epithelial growth factors in pterygia, and implicated that these molecules could be involved directly or indirectly in the pathogenesis of pterygia as causative factors. The aim of this study was to investigate the association of polymorphisms of transforming growth factor (TGF) and vascular endothelial growth factor (VEGF) with pterygium.

METHODS

A total of 133 pterygium patients and 105 volunteers without pterygium were enrolled in this study. Polymerase chain reaction based restriction fragment length polymorphism analysis was used to resolve the TGF-Beta1-509 and VEGF-460 genotypes.

RESULTS

There was no significant difference in the allele frequency or genotype of TGF-Beta1-509 or VEGF-460 between total pterygium and the control group. No interaction between TGF-Beta1-509 and VEGF-460 was found either.

CONCLUSIONS

These results indicate that TGF-Beta1-509 and VEGF-460 polymorphisms were not highly associated with the pathology of pterygium. However, it may still be worthwhile to continue to search for angiogenic gene polymorphisms in order to predict the development of pterygium.

Transforming growth factor beta1 gene polymorphism 509C/T in deep infiltrating endometriosis

Deep infiltrating endometriosis is characterized by the presence of nodular lesions largely composed of fibromuscular tissue. Transforming growth factor beta 1 (TGF-beta1) is the cytokine most causatively associated with disorders characterized by fibrosis throughout the body. Therefore, the hypothesis was tested that mechanisms increasing the fraction of biologically active TGF-beta1, such as TGF-beta 1 gene polymorphisms, lead to an increased risk of developing deep infiltrating endometriosis. The frequency of the -509C/T polymorphism of the TGF-beta 1 gene was tested in women with deep infiltrating endometriosis (n = 72), gynecological patients without symptoms of endometriosis (n = 95) and healthy females (n = 93). Detection of the -509C/T polymorphisms was performed using PCR-restriction fragment length polymorphism analysis. We did not observe statistically significant differences in the frequency of the -509C/T polymorphism between the groups. Our study does not support an association between the -509C/T polymorphism of the TGF-beta 1 gene and an increased risk of deep infiltrating endometriosis.

Molecular profiling of experimental endometriosis identified gene expression patterns in common with human disease

OBJECTIVE

To validate a rat model of endometriosis using complimentary DNA (cDNA) microarrays by identifying common gene expression patterns between experimental and natural disease.

DESIGN

Autotransplantation rat model.

SETTING

Medical school department.

ANIMALS

Female Sprague-Dawley rats.

INTERVENTION(S)

Endometriosis was surgically induced by suturing uterine horn implants next to the small intestine's mesentery. Control rats received sutures with no implants. After 60 days, endometriotic implants and uterine horn were obtained.

MAIN OUTCOME MEASURE(S)

Gene expression levels determined by cDNA microarrays and real-time quantitative polymerase chain reaction (qPCR). The Cy5-labeled cDNA was synthesized from total RNA obtained from endometriotic implants. The Cy3-labeled cDNA was synthesized using uterine RNA from a control rat. Gene expression levels were analyzed after hybridizing experimental and control labeled cDNA to PIQOR (Parallel Identification and Quantification of RNAs) Toxicology Rat Microarrays (Miltenyi Biotec, Cologne, Germany) containing 1,252 known genes. The Cy5/Cy3 ratios were determined, and genes with >2-fold higher or <0.5-fold lower expression levels were selected. Microarray results were validated by QRT-PCR.

RESULT(S)

We observed differential expression of genes previously shown to be up-regulated in patients, including growth factors, inflammatory cytokines/receptors, tumor invasion/metastasis factors, adhesion molecules, and antiapoptotic factors.

CONCLUSION(S)

This study presents evidence in support of using this rat model to study the natural history of endometriosis and to test novel therapeutics for this incurable disease.

Interleukin-10 gene promoter polymorphisms and their protein production in peritoneal fluid in patients with endometriosis

Although associations of interleukin-10 (IL-10) gene promoter polymorphisms and their protein production with endometriosis risk have been reported, the correlations remain controversial. The objective of this study was to determine IL-10 gene promoter polymorphisms at -1082, -819 and -592 sites and their protein production in peritoneal fluid (PF) in patients with and without endometriosis. IL-10 gene promoter polymorphisms at -1082 site were detected by amplification refractory mutation system (ARMS)-PCR and that at -819 and -592 sites was genotyped by restriction fragment length polymorphism (RFLP)-PCR. Protein levels of IL-10 in PF were measured by enzyme-linked immunosorbent assay (ELISA). There were no significant differences in the genotype and allele frequencies of IL-10 gene promoter polymorphisms at position -1082 between the endometriosis and the control groups. However, the frequency of -819 or -592 C alleles was significantly increased in patients with endometriosis compared with controls. The protein levels of IL-10 in PF were statistically higher in the endometriosis group than in the control group. Moreover, the polymorphisms at -1082, -819 and -592 sites were associated with protein levels of IL-10 in PF in the endometriosis group while in the control group only the polymorphisms at position -1082 correlated with protein levels. Increased frequency of -819 or -592 C allele and increased protein production of IL-10 in PF in patients with endometriosis compared with controls and correlations of polymorphisms at -819 and -592 sites with protein levels of IL-10 in PF in patients with endometriosis may suggest that polymorphisms at -819 and -592 sites and their protein production are associated with endometriosis risk.