The contributions of resistin and adiponectin gene single nucleotide polymorphisms to the genetic risk for polycystic ovary syndrome in a Japanese population

Relationship Between Genetic Polymorphisms in Cell Cycle Regulatory Gene TP53 and Polycystic Ovarian Syndrome: A Case-Control Study and In Silico Analyses

Polycystic ovarian syndrome (PCOS) is a complex endocrine and metabolic condition with several potential causes. Insulin resistance is a hallmark of PCOS that often coexists with hirsutism, hyperandrogenism, being overweight, and hormonal imbalances. The functioning of multiple replication and transcription factors is regulated by tumor suppressor genes (TSGs), which play a crucial role in maintaining genomic integrity and controlling the cell cycle of granulosa cells. In the present study, we examined how three single nucleotide polymorphisms (SNPs) in TP53, a cell cycle regulatory gene, affect the risk of developing PCOS in a sample of an Iranian population. Genomic DNA was extracted from 200 PCOS patients and 200 healthy women to analyze TP53 rs17880604, rs1625895, and rs1042522 SNPs using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our findings revealed that the majority of PCOS cases were overweight [25 < body mass index (BMI) < 30]. A positive association was observed between the TP53 rs1042522 SNP and the risk of PCOS under codominant heterozygous and overdominant genetic patterns (odds ratio > 1). Meanwhile, a negative association was observed between TP53 SNPs (rs1625895, rs17880604) and susceptibility to PCOS under codominant heterozygous and dominant models of inheritance (odds ratio < 1). Moreover, different genotype and haplotype combinations of rs17880604/rs1625895/rs1042522 conferred a decreased risk of PCOS in our population. We found no statistical difference in the frequency of TP53 genotypes between PCOS cases and/or controls in terms of BMI, waist circumference, prolactin level, and markers of lipid and carbohydrate profile (P > 0.05). Molecular dynamic prediction showed that the missense substitution in the 17p13.1 position (rs1042522) could change the properties and secondary structure of the p53 protein. As inherited risk factors, TP53 variations may play a  pivotal role in the pathogenesis of PCOS among Iranian women. Replicated population-based studies on other ethnicities are required to find the genetic contribution of variants of TP53, or SNPs located in other TSGs, to the etiology of this endocrine disease.

Relation of resistin gene variants to resistin plasma levels and altered susceptibility to polycystic ovary syndrome: A case control study

BACKGROUND

A role for resistin in the pathogenesis of polycystic ovarian syndrome (PCOS) and related features were described for various ethnicities. As its expression is partly inherited, a role for RETN polymorphisms in regulating resistin levels and PCOS risk was shown, but with varied results.

AIM

To investigate the association of rs34124816 (-537A>C), rs1862513 (-420C>G), rs3219175 (-358G>A), rs3745367 (+299G>A), rs3745369 (+1263G>C), and rs1423096 (+4965C>T) RETN SNPs with PCOS.

METHODS

Study subjects included 583 women with PCOS, and 713 eumenorrheic women serving as controls. Genotyping was done by real-time PCR.

RESULTS

Higher minor allele frequency (MAF) of rs34124816, rs3219175, and rs3745369, and lower MAF of rs1862513 and rs1423096 were seen in PCOS cases. Reduced PCOS risk was found with rs3745367 minor-allele homozygotes and rs1423096 minor-allele homozygotes, while increased risk was linked with rs3745367 heterozygotes, and with rs3745369 heterozygotes and minor-allele homozygotes. While it did not reach statistical significance, serum resistin levels were elevated in PCOS cases than in control women and major-allele homozygotes of rs34124816 and rs1862513, and in rs1423096 minor-allele-containing carriers. Carriage of rs34124816 correlated positively with age and LH, whereas rs1862513 positively and rs3745367 negatively correlated with fasting glucose. Six-locus (rs34124816-rs1862513-rs3219175-rs3745367-rs3745369-rs1423096) haplotype analysis demonstrated a significant reduction in AGGGGG and a marked increase in AGGGCG haplotypes between cases and controls, thus assigning PCOS protective and susceptible nature to these haplotypes, respectively.

CONCLUSIONS

This study is the first to document the contribution of rs34124816 and rs1423096 RETN variants to the risk of PCOS. The varied association of RETN gene variants with PCOS suggests an ethnic contribution of RETN association with PCOS.

Pathophysiologic Mechanisms of Insulin Secretion and Signaling-Related Genes in Etiology of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrinopathy in women. PCOS is characterized by anovulation, hyperandrogenism, polycystic ovaries, insulin resistance, and obesity. Despite the finding that the genetic origin of PCOS is well demonstrated in previous twin and familial clustering studies, genes and factors that can exactly explain the PCOS pathophysiology are not known. Objective(s). In this review, we attempted to identify genes related to secretion and signaling of insulin aspects of PCOS and their physiological functions in order to explain the pathways that are regulated by these genes which can be a prominent function in PCOS predisposition. Materials and Methods. For this purpose, published articles and reviews dealing with genetic evaluation of PCOS in women from peer-reviewed journals in PubMed and Google Scholar databases were included in this review. Results. The genomic investigations in women of different populations identified many candidate genes and loci that are associated with PCOS. The most important of them are INSR, IRS1-2, MTNR1A, MTNR1B, THADA, PPAR-γ2, ADIPOQ, and CAPN10. These are mainly associated with metabolic aspects of PCOS. Conclusions. In this review, we proposed that each of these genes may interrupt specific physiological pathways by affecting them and contribute to PCOS initiation. It is clear that the role of genes involved in insulin secretion and signaling is more critical than other pathways.

Adiponectin (ADIPOQ) gene variants and haplotypes in Saudi Arabian women with polycystic ovary syndrome (PCOS): a case-control study

The aim of this study is to assess the association of nine SNPs on ADIPOQ on the PCOS risk among Saudi Arabian Women. A case-control study, including 162 cases and 162 controls in Saudi Arabia, was enrolled. Genotyping was carried out by the allelic discrimination method. Estimated haplotype frequencies were assessed using the maximum likelihood method. Results showed that ADIPOQ SNPs were not associated with PCOS for allelic and genotypic frequencies (p > .05). In haplotype estimation analysis, a significant positive association was detected between 21211 haplotype (rs2241766/rs1501299/rs2241767/rs3774261/rs17366743) in additive model with increased risk of PCOS (p = .009, OR = 2.16 [1.22-3.82] CI 95%). None of the nine SNPs illustrated significant association with the quantitative traits after multiple test corrections. These results support a significant association of 21211 haplotype (rs2241766/rs1501299/rs2241767/rs3774261/rs17366743) of ADIPOQ gene in Saudi women with polycystic ovary syndrome.

Pathophysiologic mechanisms of obesity- and chronic inflammation-related genes in etiology of polycystic ovary syndrome

OBJECTIVES

One of the common heterogeneous reproductive disorders in women of childbearing age is polycystic ovary syndrome (PCOS). It is characterized by lack of fertility due to anovulatory cycles, hyperandrogenemia, polycystic ovaries, hyperinsulinemia, and obesity. Both reproductive anomalies and metabolic disorders are involved in PCOS pathology. Although the role of increased levels of androgens in initiation of PCOS is almost proven, mechanisms of PCOS pathophysiology are not clear. Here we discuss roles of altered metabolic conditions, obesity, and chronic inflammation in PCOS pathophysiology.

MATERIALS AND METHODS

In this review, we attempted to identify genes related to obesity and chronic inflammation aspects of PCOS and their physiological functions to explain the pathways that are regulated by these genes and can be a prominent function in PCOS predisposition. For this purpose, published articles and reviews dealing with genetic evaluation of PCOS in women in peer-reviewed journals in PubMed and Google Scholar databases were included in this review.

RESULTS

Obesity and chronic inflammation are not prominent diagnostic features of PCOS, but they play an important role in exacerbating metabolic and hyperandrogenic states. ADIPOQ, FTO TGFβ, and DENND1A as the main obesity- and chronic inflammation-related genes have roles in PCOS pathophysiology.

CONCLUSION

It seems that genes related to obesity pathology in genomic research association, are related to metabolic aspects and body mass index in PCOS patients. Genomes have roles in chronic inflammation, followed by obesity, in the pathogenesis of PCOS.

Novel oncogenic and chemoresistance-inducing functions of resistin in ovarian cancer cells require miRNAs-mediated induction of epithelial-to-mesenchymal transition

Resistin plays a role in the growth, proliferation, angiogenesis, metastasis and therapeutic resistance in different cancers. However, such effects of resistin have never been evaluated in ovarian cancer, a deadly gynecological malignancy. We observed a significant induction of ovarian cancer cells' growth, invasion and cisplatin resistance, and established a mechanism of resistin action that included induction of EMT and stemness, as evidenced by down-regulated epithelial marker e-cadherin and up-regulated mesenchymal markers vimentin/ ZEB1 and stemness markers sox2, oct4 and nanog. The mechanism also included suppression of tumor suppressor miRNAs, let-7a, miR-200c and miR-186. Over-expression of these miRNAs significantly reversed the resistin-mediated effects on invasion and chemoresistance. We further validated our results in vivo where resistin administration significantly enhanced tumor growth in mice. Our results provide first evidence for such oncogenic effects of resistin in ovarian cancer models and a rationale for future studies to further understand the mechanistic role of resistin in ovarian cancer invasiveness, metastasis and therapy resistance.

Association of adiponectin and resistin gene polymorphisms in South Indian women with polycystic ovary syndrome

OBJECTIVES

To investigate whether genetic polymorphisms in the resistin and adiponectin genes cause a predisposition towards polycystic ovary syndrome (PCOS) in a South Indian women population.

STUDY DESIGN

This case controlled study included samples from 484 study subjects (282 diagnosed with PCOS and 200 normal controls). The clinical and biochemical parameters of the samples assayed included BMI, LH, FSH, testosterone, fasting glucose, adiponectin and resistin levels. Three single nucleotide polymorphisms of the resistin (RETN) gene 420(C→G) (rs1862513), 299(G→A) (rs3745367), and 62(G→A) (rs3745368), and two single nucleotide polymorphisms of the adiponectin (ADPIOQ) gene 45(T→G) (rs2241766), and 276(G→T) (rs1501299), were analyzed using a PCR-RFLP method. Statistical analysis was carried out to determine the association of the genotypic and allelic variations with the syndrome and also analyze the influence of genotypic variations on adipokine levels.

RESULTS

Serum levels of testosterone, LH, fasting glucose and resistin were found to be significantly increased in the PCOS patients when compared to controls, while adiponectin was found to be significantly lower (P<0.05). BMI was found to positively correlate with resistin levels and negatively correlate with adiponectin levels. A positive association was found between the RETN promoter 420 (C→G) SNP and the intron 2 299 (G→A) variant of the resistin gene, while no association was found between the ADPIOQ gene polymorphisms and PCOS. The 'GG' variant of the adiponectin 45 (T→G) variant showed a near-significant tendency towards a decreased concentration of adiponectin in PCOS patients.

CONCLUSIONS

Polymorphisms of the resistin gene could be assigned to play a role in increasing the risk of PCOS. However, the adiponectin gene does not seem to play a major role in PCOS susceptibility in a South Indian population. Serum adiponectin and resistin levels were more dependent on BMI rather than the presentation of PCOS. Obesity plays a major role in aggravating the hormonal disturbances found associated with PCOS.

Weight reduction and pioglitazone ameliorate polycystic ovary syndrome after removal of a Sertoli-stromal cell tumor

This report presents an unusual case of Sertoli-stromal cell tumor and polycystic ovary syndrome successfully treated with weight reduction and an insulin-sensitizing agent. A 22-year-old woman, gravida 0, para 0, visited our hospital for the first time with a 12-year history of secondary amenorrhea and hypertrichosis. Transvaginal ultrasonography revealed a solid tumor in the right ovary. Right salpingo-oophorectomy was performed and pathological examination confirmed a Sertoli-stromal cell tumor. The patient's serum androgen levels declined postoperatively, but remained above normal. Pioglitazone treatment for 6 months also significantly reduced serum androgen levels, but they still remained above normal. However, after losing 12 kg of body weight, the patient's serum androgen levels declined to normal, and spontaneous menstruation became regular. Weight reduction with pioglitazone is an effective means of treating hyperandrogenism.

Association of the T45G and G276T polymorphisms in the adiponectin gene with PCOS: A meta-analysis

Adiponectin is the most abundant adipocytokine in human body and may play a role in the pathogenesis of polycystic ovary syndrome (PCOS). To clarify the conflicting data in the literature concerning the association between PCOS and two polymorphisms of the adiponectin gene, T45G and G276T, a meta-analysis was performed in this study. Literature search was conducted through PubMed, EMBASE and other relevant studies. Pooled odds ratios (OR) were estimated using fixed-effects (FE) models in codominant, recessive and dominant models. Sensitive analysis was performed by excluding invalid studies. Eight articles investigated the T45G polymorphism in PCOS, and five publications are associated with the G276T polymorphism in PCOS. Significant associations of adiponectin T45G polymorphism with PCOS were found in codominant (FEM: OR = 1.36, 95% CI: 1.12-1.65), recessive (FEM: OR = 2.02, 95% CI: 1.17-3.47) or dominant models (FEM: OR = 1.33, 95% CI: 1.06-1.67). For adiponectin G276T polymorphism, the OR and 95% CI are 0.81(0.68, 0.98), 0.74(0.51, 1.09) and 0.78 (0.61, 0.99) in codominant, dominant and recessive models, respectively. This study provides positive evidence for a causal relationship between the adiponectin gene and PCOS which needs to be further confirmed by further studies.

Lipodystrophy and insulin resistance in combination antiretroviral treated HIV-1-infected patients: implication of resistin

BACKGROUND

Little information is available with respect to the involvement of resistin in lipodystrophy and metabolic disturbances in HIV-1-infected patients treated with combination antiretroviral therapy (cART). We determined whether the resistin (rest) -420C>G single-nucleotide polymorphism and plasma resistin are associated with the development of lipodystrophy and metabolic disturbances in HIV-1-infected patients treated with cART.

METHODS

The study group comprised 299 HIV-1-infected patients treated with a stable cART for at least 1 year (143 with lipodystrophy and 156 without) and 175 uninfected controls. Anthropometric, clinical, and metabolic variables were determined. Homeostasis model assessment for insulin resistance was used to evaluate insulin resistance. Plasma resistin levels were determined by enzyme-linked immunosorbent assay. The rest -420C>G was assessed using restriction fragment length polymorphism. Student t test, 1-way and 2-way analysis of variance, χ2 test, and Pearson and Spearman correlations were performed for statistical analysis.

RESULTS

Genotypes containing the rest -420G variant allele were significantly more common in HIV-1-infected patients without lipodystrophy compared with those with lipodystrophy (P = 0.037). Infected patients had significantly greater plasma resistin levels than uninfected controls (P < 0.001). Among infected patients, plasma resistin levels were significantly lower in patients with lipodystrophy with respect to those without (P = 0.034). In infected patients, plasma resistin levels had a significant positive correlation with insulin and homeostasis model assessment for insulin resistance: P < 0.001 and P = 0.002 in the lipodystrophy subset and P = 0.002 and P = 0.03 in the nonlipodystrophy subset, respectively.

CONCLUSIONS

In our cohort of white Spaniards, the rest -420C>G single-nucleotide polymorphism may be associated with cART-related lipodystrophy. Plasma resistin correlates with insulin resistance in infected patients with and without lipodystrophy.