Genetic polymorphisms in obesity-related genes and endometrial cancer risk

Role of adipocytokines in endometrial cancer progression

Endometrial cancer is considered a significant barrier to increasing life expectancy and remains one of the most common malignant cancers among women in many countries worldwide. The increasing mortality rates are potentially proportional to the increasing obesity incidence. Adipose tissue secretes numerous adipocytokines, which may play important roles in endometrial cancer progression. In this scenario, we describe the role of adipocytokines in cell proliferation, cell invasion, cell adhesion, inflammation, angiogenesis, and anti-apoptotic action. A better understanding of the mechanisms of these adipocytokines may open up new therapeutic avenues for women with endometrial cancer. In the future, larger prospective studies focusing on adipocytokines and specific inhibitors should be directed at preventing the rapidly increasing prevalence of gynecological malignancies.

Diagnostic accuracy of calculated tumor volumes and apparent diffusion coefficient values in predicting endometrial cancer grade

Background:

Magnetic resonance imaging (MRI) has been shown to be an accurate imaging technique for the preoperative assessment of local staging of endometrial cancer and for evaluating the depth of myometrial invasion.

Materials and Methods:

This was a single-center retrospective study performed on patients with histopathologically proven endometrial carcinoma who underwent an MRI examination of the pelvis between October 2017 and May 2020.

Results:

In the present analysis, mean apparent diffusion coefficient (ADC) values for each histologic grade were 0.72 ± 0.13 × 10⁻³ mm²/s (G1), 0.76 ± 0.17 × 10⁻³ mm²/s (G2), and 0.74 ± 0.12 × 10⁻³ mm²/s (G3), respectively, showing no significant correlation between ADC values and tumor grade (P = 0.73). Overall, ADC minimum was significant in differentiating grades of endometrial carcinoma (P = 0.02) with the ability to differentiate Grade I and II lesions (P = 0.01). A mean tumor volume of 25.2 cc could differentiate low-grade tumors (Grade I and Grade II) from high-grade tumors (Grade III) with a sensitivity and specificity of 88% and specificity of 89%. The tumor volume/uterine volume ratio (TV/UV) differentiates high-grade tumors from low-grade tumors (P < 0.001), however, no significant difference in the ratio was observed among Grade I and II lesions (P = 0.48). The area under the curve of tumor volume was 0.875 (95% confidence interval 0.0–1.00) (P = 0.001), indicating that tumor volume was an effective tool for distinguishing high-grade and low-grade endometrioid adenocarcinomas. The corresponding sensitivity and specificity were 88.0% and 89.0%, respectively.

Conclusion:

Preoperative noninvasive radiological assessment for tumor volume, TV/ UV or tumor volume/uterine volume is important surrogate markers for preoperative prognostication of endometrial carcinoma.

The Influence of Biologically Active Substances Secreted by the Adipose Tissue on Endometrial Cancer

Endometrial cancer is one of the most frequently diagnosed gynecological neoplasms in developed countries and its incidence is rising. Usually, it is diagnosed in the early stages of the disease and has a good prognosis; however, in later stages, the rate of recurrence reaches up to 60%. The discrepancy in relapse rates is due to the heterogeneity of the group related to the presence of prognostic factors affecting survival parameters. Increased body weight, diabetes, metabolic disturbances and estrogen imbalance are important factors for the pathogenesis of endometrial cancer. Even though prognostic factors such as histopathological grade, clinical stage, histological type and the presence of estrogen and progesterone receptors are well known in endometrial cancer, the search for novel prognostic biomarkers continues. Adipose tissue is an endocrine organ involved in metabolism, immune response and the production of biologically active substances participating in cell growth and differentiation, angiogenesis, apoptosis and carcinogenesis. In this manuscript, we review the impact of factors secreted by the adipose tissue involved in the regulation of glucose and lipid metabolism (leptin, adiponectin, omentin, vaspin, galectins) and factors responsible for homeostasis maintenance, inflammatory processes, angiogenesis and oxidative stress (IL-1β, 6, 8, TNFα, Vascular endothelial growth factor (VEGF), Fibroblast growth factors (FGFs)) in the diagnosis and prognosis of endometrial cancer.

Sleeping Beauty Mouse Models of Cancer: Microenvironmental Influences on Cancer Genetics

The Sleeping Beauty (SB) transposon insertional mutagenesis system offers a streamlined approach to identify genetic drivers of cancer. With a relatively random insertion profile, SB is uniquely positioned for conducting unbiased forward genetic screens. Indeed, SB mouse models of cancer have revealed insights into the genetics of tumorigenesis. In this review, we highlight experiments that have exploited the SB system to interrogate the genetics of cancer in distinct biological contexts. We also propose experimental designs that could further our understanding of the relationship between tumor microenvironment and tumor progression.

Endometrial carcinoma-related genetic factors: application to research and clinical practice in China

Genetic factors affect the initiation and progression of endometrial carcinoma (EC). The routine detection of genetic factors involved in EC has not been extensively performed in Chinese clinical practice, however. In this review we summarise EC-related genetic factors, including Lynch syndrome-associated mutations and non-Lynch syndrome-associated genetic predispositions found in Chinese women, and their potential clinical applications. In addition, we propose a clinical testing strategy for patients with EC and their family members. The objective of this review is to advance basic research regarding the genetic factors involved in EC and to improve its clinical implementation in China.

TWEETABLE ABSTRACT

Review summarises Chinese research progression of EC-related genetic factors and proposes innovative screening strategy.

Association of polymorphisms in LEPR with type 2 diabetes and related metabolic traits in a Chinese population

Background

Leptin acts as a mediator of inflammation and energy homeostasis by activating leptin receptor (LEPR). We conducted this study to explore the association of polymorphisms in LEPR with type 2 diabetes mellitus (T2DM) and its related metabolic traits.

Methods

We performed a case–control study to investigate the association of polymorphisms in LEPR with T2DM and related metabolic traits in a Chinese population, with a total of 922 T2DM patients and 1031 nondiabetic subjects. Polymorphisms were genotyped using MassARRAY assay.

Results

The G allele of rs1327118 was associated with a decreased risk of T2DM in men (P = 0.044, odds ratio = 0.707, 95% confidence interval = 0.504–0.991) and the G allele of rs3806318 was associated with increased systolic blood pressure (SBP) in men with T2DM. Besides, the women patients carrying the G allele of rs1327118 showed increased SBP and diastolic blood pressure (DBP) levels, but decreased high density lipoprotein cholesterol (HDL-C) level.

Conclusion

Our results suggest that rs1327118 may be associated with SBP, DBP and HDL-C levels in women with T2DM, and rs3806318 may be associated with T2DM and SBP level in men with T2DM. Further studies with larger sample size or functional experiments focused on exact mechanism are required to verify our observations.

Hormones and endometrial carcinogenesis

Endometrial cancer (EC) is the commonest gynaecological cancer in the Western World with an alarmingly increasing incidence related to longevity and obesity. Ovarian hormones regulate normal human endometrial cell proliferation, regeneration and function therefore are implicated in endometrial carcinogenesis directly or via influencing other hormones and metabolic pathways. Although the role of unopposed oestrogen in the pathogenesis of EC has received considerable attention, the emerging role of other hormones in this process, such as androgens and gonadotropin-releasing hormones (GnRH) is less well recognised. This review aims to consolidate the current knowledge of the involvement of the three main endogenous ovarian hormones (oestrogens, progesterone and androgens) as well as the other hormones in endometrial carcinogenesis, to identify important avenues for future research.

Evolving role of adiponectin in cancer-controversies and update

Adiponectin (APN), an adipokine produced by adipocytes, has been shown to have a critical role in the pathogenesis of obesity-associated malignancies. Through its receptor interactions, APN may exert its anti-carcinogenic effects including regulating cell survival, apoptosis and metastasis via a plethora of signalling pathways. Despite the strong evidence supporting this notion, some work may indicate otherwise. Our review addresses all controversies critically. On the whole, hypoadiponectinaemia is associated with increased risk of several malignancies and poor prognosis. In addition, various genetic polymorphisms may predispose individuals to increased risk of obesity-associated malignancies. We also provide an updated summary on therapeutic interventions to increase APN levels that are of key interest in this field. To date efforts to manipulate APN levels have been promising, but much work remains to be done.

Association Between Single Nucleotide Polymorphism +276G > T (rs1501299) in ADIPOQ and Endometrial Cancer

Current literature gives evidence of an indisputable role adiponectin plays in adipose tissue metabolism and obesity-related diseases. Moreover, latest research efforts focus on linking genetic markers of this adipocytokine's gene (ADIPOQ) with cancer. Aim of this study was to determine the genotype distribution of single nucleotide polymorphism +276G > T (rs1501299) in ADIPOQ and an attempt to identify the impact this polymorphism exerts on endometrial cancer risk in obese females. The test group comprised 90 women treated surgically for endometrial cancer between 2000 and 2012 in the Department of Surgical & Endoscopic Gynecology and Gynecologic Oncology, Polish Mothers' Memorial Hospital - Research Institute, Lodz, Poland. 90 individuals treated in the parallel period for uterine fibroids constituted the control group. Patients within both groups were stratified according to BMI into: lean, overweight and obese subjects. Statistical analysis was performed between two major groups and, furthermore, within the abovementioned subgroups. The analysis revealed that allele G of the investigated polymorphism in obese women with endometrial cancer is significantly more frequent, and allele T is significantly less frequent than in lean controls. However, no significant correlation was observed between the polymorphism and endometrial cancer in lean and overweight females. Single nucleotide polymorphism +276G > T (rs1501299) in ADIPOQ may be considered to be a risk factor of endometrial cancer. Further research on SNP in EC is warranted to obtain more conclusive outcomes.

Genetic variations of the ADIPOQgene and risk of prostate cancer in Chinese Han men

Adiponectin secreted by adipose tissue has been implicated in prostate carcinogenesis. Genetic variations in ADIPOQ are thought to influence the activity of adiponectin, thus relating to cancer occurrence. In this hospital-based case-control study of 917 prostate cancer (PCa) cases and 1036 cancer-free controls, we evaluated the association of single nucleotide polymorphisms in ADIPOQ with risk of PCa and adiponectin levels in Chinese Han men. Variants of ADIPOQ were genotyped by Taqman polymerase chain reaction method. The plasma adiponectin concentrations were measured by enzyme-linked immunosorbent assay (ELISA) in a subset of cases and controls. We found that the ADIPOQ rs3774262 variant AA genotype was associated with both decreased PCa risk [adjusted odds ratio (OR): 0.66, 95% confidence interval (CI) =0.48–0.92] and increased plasma adiponectin levels (P = 0.036 and 0.043), with significant difference by tumor grade, clinical stage, and aggressiveness. A significant interaction between ADIPOQ rs3774262 and body mass index was observed in modifying the risk of PCa (P = 6.7 × 10⁻³). ADIPOQ rs266729 and rs182052 were not related to PCa risk or plasma adiponectin levels. Our data support that ADIPOQ rs3774262 may affect PCa risk in combination with plasma adiponectin levels in Chinese Han men. It may contribute to the molecular basis for the association between obesity and PCa.

Genetics of endometrial cancer

Women who report a history of endometrial cancer in a first-degree relative are at increased risk of endometrial cancer, with a hazard ratio of 1.5 to 2.0. Only a minority of patients with familial endometrial cancer have a recognized cancer syndrome. Lynch syndrome is the most common genetic syndrome associated with endometrial cancer and a marked increased risk of colon cancer. Cowden syndrome is a rare condition resulting from a mutation in the tumor suppressor gene phosphatase and tensin homolog. The risk for endometrial cancer is about five times higher in women with Cowden syndrome than in the general population. Recently, a novel germline mutation in the POLD1 gene that encodes the catalytic subunit of DNA polymerase δ was described in several families with multiple cases of endometrial cancer. This mutation is also associated with colorectal cancer. The association between BRCA1 mutations and endometrial cancer has been investigated in several studies; it appears that the risk of endometrial cancer is restricted to women with a history of tamoxifen exposure. In recent years, research has focused on genetic polymorphisms that are associated with endometrial cancer risk. Although many polymorphisms have been identified, their clinical significance is unclear and they have not been adapted for clinical practice.

ADIPOQ polymorphism rs182052 is associated with clear cell renal cell carcinoma

Recent studies have indicated that low circulating adiponectin concentrations are associated with a higher risk of several cancers, including renal cell carcinoma. In this case–control study, we examined the frequency of single nucleotide polymorphisms (rs182052G>A, rs266729C>G, and rs3774262G>A) in the adiponectin gene (ADIPOQ) in 1004 patients with clear cell renal cell carcinoma (ccRCC) compared with a group of healthy subjects (n = 1108). Fasting serum adiponectin concentrations were also examined. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). The association of serum adiponectin concentration with genetic variants was calculated using a multivariate linear regression model. A significantly higher ccRCC risk was associated with the rs182052 variant A allele (adjusted OR, 1.36 and 95% CI, 1.07–1.74 for AA vs GG, P = 0.013; adjusted OR, 1.27 and 95% CI, 1.04–1.56 for AA vs GG+AG, P = 0.019), and this positive association was more evident in overweight subjects. Fasting serum adiponectin was lower in subjects carrying A alleles of rs182052 in both ccRCC patients (β = −0.399, P = 0.018) and healthy controls (β = −0.371, P = 0.024). These results suggest that ADIPOQ rs182052 is significantly associated with ccRCC risk.

In this case–control study, we examined the frequency of single nucleotide polymorphisms (rs182052G>A, rs266729C>G, and rs3774262G>A) in the adiponectin gene (ADIPOQ) in 1004 patients with clear cell RCC (ccRCC) compared with a group of healthy subjects (n = 1108). Fasting serum adiponectin concentrations were also examined. Fasting serum adiponectin was lower in subjects carrying minor alleles of rs182052 in both ccRCC patients (β = −0.399, P = 0.018) and healthy controls (β = −0.371, P = 0.024). These results suggest that ADIPOQ rs182052 is significantly associated with ccRCC risk.

Epistatic interaction between adiponectin and survivin gene polymorphisms in endometrial carcinoma

Adiponectin appears to play an important role in the development and progression of several obesity-related malignancies. Also, overexpression of survivin, an inhibitor of apoptosis protein, is associated with increased risk of cancers. The aim of this study was to investigate the association between two polymorphisms in the adiponectin gene and endometrial cancer (EC) risk. We also investigated whether epistasis between surviving and adiponectin gene polymorphisms are associated with EC risk in an Iranian population. The samples comprised formalin-fixed, paraffin-embedded tissue sections obtained from the archive of the pathology department, Imam-Khomeini Hospital and Firouzgar hospital. After DNA extraction the genotyping was performed using PCR-RFLP technique. Single nucleotide polymorphisms (SNPs) in adiponectin (rs1063539, rs2241766) and survivin (rs9904341) gene were evaluated in the study. The increased frequency of ADIPOQ rs1063539C allele (CC+CG genotype) was associated with decreased EC risk [OR: 0.39(0.17-0.90)]. Survivin rs9904341C allele (CC+CG genotype) was associated with increased EC risk [crude OR: 2.75(1.27-5.95), adjusted OR: 2.93(1.27-6.76)]. We observed an epistatic interaction between survivin rs9904341 CC+CG genotype and ADIPOQ rs1063539 GG genotype increasing the risk of EC compared to those with other genotypes [OR: 4.86(1.88-12.54), P=0.001]. Our findings indicate that adiponectin might have a modulatory effect on survivin role and function in EC, which requires further investigation.

Association between germline single nucleotide polymorphisms in the PI3K-AKT-mTOR pathway, obesity, and breast cancer disease-free survival

Obesity-related hormones and cytokines alter PI3 K-AKT-mTOR pathway activation in breast tumors contributing to poorer disease-free survival (DFS) and decreased responsiveness to tamoxifen and trastuzumab. We hypothesized that single nucleotide polymorphisms (SNPs) in candidate genes in the PI3 K-AKT-mTOR signaling pathway may act as genetic modifiers of breast cancer DFS. We analyzed the association of 106 tagging SNPs in 13 genes (ADIPOQ, IGF1, INS, IRS1, LEP, LEPR, LEPROT, PIK3CA, PIK3R5, PTEN, TSC1, TSC2, and AKT1) in the P13K-AKT-mTOR pathway with DFS in a sample of 1,019 women with stage I-II breast cancer. SNPs significantly associated with DFS in any genetic model (additive, dominant, or recessive) after correcting for false discovery rate (FDR = 0.10) were included in Cox proportional hazards multivariable analyses. After adjusting for race/ethnicity, age at diagnosis, tumor stage, and treatment, rs1063539 in ADIPOQ, rs11585329 in LEPR, and rs2519757 in TSC1 were associated with improved DFS, and rs1520220 in IGF1 and rs2677760 in PIK3CA were associated with worse DFS. The associations were not significantly modified by the type of systemic treatment received or body mass index. The SNPs were not associated with tumor characteristics such as tumor size, lymph node status, nuclear grade, or hormone receptor status. In this study, germline SNPs in the PI3 K-AKT-mTOR pathway were associated with breast cancer DFS and may be potential prognostic markers. Future studies are needed to replicate our results and to evaluate the relationship between these polymorphisms and activation of the PI3 K-AKT-mTOR pathway in breast tumors.

Endometrial cancer

Despite the questions and barriers, the incorporation of molecular therapy into treatment regimens in endometrial cancer is an exciting area of investigation with the potential to improve outcomes. Outside of the development of a reliable screening test for endometrial cancer, converting the disease to a chronic state and improving progression-free survival is our best hope to reverse the concerning trend of decreasing 5-year survival for this disease.

The role of adiponectin in cancer: a review of current evidence

Excess body weight is associated not only with an increased risk of type 2 diabetes and cardiovascular disease (CVD) but also with various types of malignancies. Adiponectin, the most abundant protein secreted by adipose tissue, exhibits insulin-sensitizing, antiinflammatory, antiatherogenic, proapoptotic, and antiproliferative properties. Circulating adiponectin levels, which are determined predominantly by genetic factors, diet, physical activity, and abdominal adiposity, are decreased in patients with diabetes, CVD, and several obesity-associated cancers. Also, adiponectin levels are inversely associated with the risk of developing diabetes, CVD, and several malignancies later in life. Many cancer cell lines express adiponectin receptors, and adiponectin in vitro limits cell proliferation and induces apoptosis. Recent in vitro studies demonstrate the antiangiogenic and tumor growth-limiting properties of adiponectin. Studies in both animals and humans have investigated adiponectin and adiponectin receptor regulation and expression in several cancers. Current evidence supports a role of adiponectin as a novel risk factor and potential diagnostic and prognostic biomarker in cancer. In addition, either adiponectin per se or medications that increase adiponectin levels or up-regulate signaling pathways downstream of adiponectin may prove to be useful anticancer agents. This review presents the role of adiponectin in carcinogenesis and cancer progression and examines the pathophysiological mechanisms that underlie the association between adiponectin and malignancy in the context of a dysfunctional adipose tissue in obesity. Understanding of these mechanisms may be important for the development of preventive and therapeutic strategies against obesity-associated malignancies.