Associations between Diabetes Mellitus and Selected Cancers

Cancer is one of the major causes of mortality and is the second leading cause of death. Diabetes mellitus is a serious and growing problem worldwide, and its prevalence continues to grow; it is the 12th leading cause of death. An association between diabetes mellitus and cancer has been suggested for more than 100 years. Diabetes is a common disease diagnosed among patients with cancer, and evidence indicates that approximately 8-18% of patients with cancer have diabetes, with investigations suggesting an association between diabetes and some particular cancers, increasing the risk for developing cancers such as pancreatic, liver, colon, breast, stomach, and a few others. Breast and colorectal cancers have increased from 20% to 30% and there is a 97% increased risk of intrahepatic cholangiocarcinoma or endometrial cancer. On the other hand, a number of cancers and cancer therapies increase the risk of diabetes mellitus. Complications due to diabetes in patients with cancer may influence the choice of cancer therapy. Unfortunately, the mechanisms of the associations between diabetes mellitus and cancer are still unknown. The aim of this review is to summarize the association of diabetes mellitus with selected cancers and update the evidence on the underlying mechanisms of this association.

Incident Cancer Risk of Patients with Prevalent Type 2 Diabetes Mellitus in Hungary (Part 2)

(1) Background: Among the chronic complications of type 2 diabetes mellitus, cancer has become the leading cause of death in several countries. Our objective was to determine whether prevalent type 2 diabetes mellitus is associated with a higher incidence of cancer. (2) Methods: This study comprised a nationwide analysis conducted in Hungary. The study population was divided into two groups: a type 2 diabetes mellitus group vs. a non-diabetic group. The primary outcome was the risk related to overall cancer incidence; a key secondary outcome was the overall incidence of cancer in distinct study years; and a further outcome was the annual percent changes. (3) Results: The odds ratio related to the overall incidence of cancer was 2.50 (95% confidence interval: 2.46-2.55, p < 0.0001) in patients with diabetes as related to non-diabetic controls. The odds ratio was higher in males than in females [ORmales: 2.76 (2.70-2.82) vs. ORfemales: 2.27 (2.22-2.33), p < 0.05 for male-to-female comparison]. The annual cancer incidence rate declined in non-diabetic controls, but not in patients with diabetes [-1.79% (-2.07--1.52%), p < 0.0001] vs. -0.50% (-1.12-+0.10%), p = 0.0991]. Several types of cancer showed a decreasing tendency in non-diabetic controls, but not in patients with type 2 diabetes. (4) Conclusions: Type 2 diabetes is associated with a higher risk of cancer. While the cancer incidence decreased for non-diabetic individuals with time, it remained unchanged in patients with T2DM.

Prevalence of high-risk human papillomavirus infection among women with diabetes mellitus in Accra, Ghana

BACKGROUND

There is increasing evidence of a higher risk and poorer prognosis of cervical cancer among women with diabetes mellitus (DM) compared to the general population. These are mediated by higher susceptibility to persistent high-risk human papillomavirus (hr-HPV) infection due to dysfunctional clearance in an immunocompromised state. We aimed to determine the prevalence of hr-HPV infection and cervical lesions in a cohort of women with DM in Ghana. We further disaggregated the prevalence according to DM type and explored factors associated with hr-HPV infection.

METHODS

This retrospective descriptive cross-sectional study assessed 198 women with DM who underwent cervical screening via concurrent hr-HPV DNA testing and visual inspection with acetic acid in an outpatient department of the National Diabetes Management and Research Centre in Korle-Bu Teaching Hospital, Accra from March to May 2022. Univariate and multivariable binary logistic regression were used to explore factors associated with hr-HPV positivity.

RESULTS

Among 198 women with DM (mean age, 60.2 ± 12.1 years), the overall hr-HPV prevalence rate was 21.7% (95% CI, 16.1-28.1), disaggregated as 1.5% (95% CI, 0.3-4.4) each for HPV16 and HPV18 and 20.7% (95% CI, 15.3-27.0) for other HPV genotype(s). Respective hr-HPV prevalence rates were 37.5% (95% CI, 15.2-64.6) for type 1 DM, 19.8% (95% CI, 13.9-26.7) for type 2 DM, and 25.0% (95% CI, 8.7-49.1) for unspecified/other DM types. Past use of the combined contraceptive pill independently increased the risk of hr-HPV infection by approximately three times (adjusted odds ratio [aOR] = 2.98; 95% CI, 1.03 - 8.64; p-value = 0.045), whereas each unit increase in FBG level increased the odds of hr-HPV infection by about 15% (aOR = 1.15; 95% CI, 1.02 - 1.30; p-value = 0.021).

CONCLUSION

Our study points to a high prevalence of hr-HPV among women with DM and highlights a need for glycemic control among them as this could contribute to lowering their odds of hr-HPV infection. The low overall rates of HPV vaccination and prior screening also indicate a need to build capacity and expand the scope of education and services offered to women with DM as regards cervical precancer screening.

Insulin Resistance: The Increased Risk of Cancers

Insulin resistance, also known as impaired insulin sensitivity, is the result of a decreased reaction of insulin signaling to blood glucose levels. This state is observed when muscle cells, adipose tissue, and liver cells, improperly respond to a particular concentration of insulin. Insulin resistance and related increased plasma insulin levels (hyperinsulinemia) may cause metabolic impairments, which are pathological states observed in obesity and type 2 diabetes mellitus. Observations of cancer patients confirm that hyperinsulinemia is a major factor influencing obesity, type 2 diabetes, and cancer. Obesity and diabetes have been reported as risks of the initiation, progression, and metastasis of several cancers. However, both of the aforementioned pathologies may independently and additionally increase the cancer risk. The state of metabolic disorders observed in cancer patients is associated with poor outcomes of cancer treatment. For example, patients suffering from metabolic disorders have higher cancer recurrence rates and their overall survival is reduced. In these associations between insulin resistance and cancer risk, an overview of the various pathogenic mechanisms that play a role in the development of cancer is discussed.

Effect of metformin use on the risk and prognosis of ovarian cancer: an updated systematic review and meta-analysis

INTRODUCTION

Emerging evidence suggests that metformin has a potential antitumor effect both in vitro and in vivo. Increasing epidemiological studies indicate that diabetic patients receiving metformin therapy have lower incidences of cancer and have better survival rates. However, there are limited and inconsistent studies available about the effect of metformin therapy on ovarian cancer (OC). Thus, we conducted this meta-analysis to study the effect of metformin therapy on OC. Meanwhile, we systematically reviewed relevant studies to provide a framework for future research.

EVIDENCE ACQUISITION

We conducted a systematic literature search on PubMed, Web of Science, Springerlink, CNKI, VIP, SinoMed, and Wanfang up to the period of October 2018. A random-effects meta-analysis model was used to derive pooled effect estimates.

EVIDENCE SYNTHESIS

A total of 13 studies were retrieved of which 5 studies explained the prevention and 8 studies explained the treatment for OC. Our pooled results showed that metformin has a potential preventive effect on OC in diabetic women (pooled odds ratio [OR] 0.62, 95% confidence interval [95% CI] 0.34, 1.11; P<0.001). In addition, metformin can also significantly prolong progression-free survival (PFS) (pooled hazard ratio [HR] 0.49, 95% CI 0.34, 0.70; P=0.002), and overall survival (OS) (HR 0.71, 95%CI 0.61, 0.82; P<0.001) in patients with OC, regardless of whether they had diabetes.

CONCLUSIONS

The use of metformin can potentially reduce the risk of OC among diabetics, and it also can significantly improve PFS and OS in patients with OC. A further large clinical investigation would be needed to adopt our finding in practice, however, our systematic review provides an insight for future study designs.

[Diabetes mellitus and the female reproductive system tumors]

The article discusses various pathophysiological conditions and processes that lead to the development of tumors in diabetes mellitus. These include obesity, hyperglycemia, hyperinsulinemia, inflammation, and oxidative stress. The data of epidemiological studies are given, in which it was found that diabetes mellitus (both type 1 and type 2) increases the risk of developing the female reproductive system tumors, such as ovarian cancer, endometrial cancer, while for cervical cancer, vaginal cancer and vulvar cancer, such a relationship has not been clearly identified.

Does the Intersectionality of Race/Ethnicity and Type 2 Diabetes Increase the Odds of a Cervical Cancer Diagnosis? A Nested Case-Control Study of a Florida Statewide Multisite EHR Database

Cervical cancer and Type 2 Diabetes (T2D) share common demographic risk factors. Despite this, scarce research has examined the relationship between race/ethnicity, having T2D, and cervical cancer incidence. We analyzed statewide electronic health records data between 2012 and 2019 from the OneFlorida+ Data Trust. We created a 1:4 nested case-control dataset. Each case (patient with cervical cancer) was matched with four controls (patients without cervical cancer) without replacement by year of encounter, diagnosis, and age. We used conditional logistic regression to estimate the unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to examine the association between race/ethnicity, T2D, and cervical cancer incidence. A total of 100,739 cases and 402,956 matched controls were identified. After adjusting for sociodemographic characteristics, non-Hispanic Black women with T2D had higher odds of cervical cancer compared with non-Hispanic White women with T2D (OR: 1.58, 95% CI 1.41-1.77). Living in a rural area, having Medicaid/Medicare insurance, and having high social vulnerability were associated with higher odds of having a cervical cancer diagnosis. Our findings imply the need to address the higher burden of cervical cancer diagnosis among non-Hispanic Black women with T2D and in underserved populations.

Clinical and metabolic characteristics of endometrial lesions in polycystic ovary syndrome at reproductive age

BACKGROUND

We aimed to explore the clinical and metabolic characteristics in polycystic ovary syndrome (PCOS) patients with different endometrial lesions.

METHODS

234 PCOS patients who underwent hysteroscopy and endometrial biopsy were categorized into four groups: (1) normal endometrium (control group, n = 98), (2) endometrial polyp (EP group, n = 92), (3) endometrial hyperplasia (EH group, n = 33), (4) endometrial cancer (EC group, n = 11). Serum sex hormone levels, 75 g oral glucose tolerance test, insulin release test, fasting plasma lipid, complete blood count and coagulation parameters were measured and analyzed.

RESULTS

Body mass index and triglyceride level of the EH group were higher while average menstrual cycle length was longer in comparison with the control and EP group. Sex hormone-binding globulin (SHBG) and high density lipoprotein were lower in the EH group than that in the control group. 36% of the patients in the EH group suggested obesity, higher than the other three groups. Using multivariant regression analysis, patients with free androgen index > 5 had higher risk of EH (OR 5.70; 95% CI 1.05-31.01), while metformin appeared to be a protective factor for EH (OR 0.12; 95% CI 0.02-0.80). Metformin and hormones (oral contraceptives or progestogen) were shown to be protective factors for EP (OR 0.09; 95% CI 0.02-0.42; OR 0.10; 95% CI 0.02-0.56). Hormones therapy appeared to be a protective factor for EC (OR 0.05; 95% CI 0.01-0.39).

CONCLUSION

Obesity, prolonged menstrual cycle, decreased SHBG, and dyslipidemia are risk factors for EH in patients with PCOS. Oral contraceptives, progestogen and metformin are recommended for prevention and treatment of endometrial lesions in PCOS patients.

Gynecological malignancies and obesity

The global pandemic of obesity has had a significant impact on gynecological malignancies, most notably endometrial cancer. It has resulted in worldwide increases in the incidence of endometrial cancer and a change in patient demographics, resulting in more diagnoses than ever before being made in pre-menopausal women, who are often keen to pursue fertility-sparing treatments. Obesity increases the risk of gynecological cancers by creating a pro-carcinogenic environment of unopposed estrogen, hyperinsulinemia, and chronic inflammation. It can present both a diagnostic challenge and strongly influence management decisions, including the practicalities of performing surgery, increase anesthetic risks, and alter response rates to adjuvant and medical therapies. Obesity may also influence endometrial cancer mortality and certainly contributes to poorer overall survival due to an excess of deaths related to cardiovascular disease. Weight loss may well, therefore, be the key to the prevention of gynecological cancers and their recurrence.

Metformin Exhibits an Attractive Antineoplastic Effect on Human Endometrial Cancer by Regulating the Hippo Signaling Pathway

Metformin, the first-line oral antidiabetic medicine, has shown great antineoplastic potential in various cancer types, despite an unclear mechanism. This study aimed to elucidate the possible mechanism of metformin as a chemotherapy agent with less reproductive and genetic toxicity in human endometrial cancer. The type I endometrial carcinoma cell lines Ishikawa and RL95-2 were treated with metformin. Cell functions, such as proliferation, migration, and invasion, were analyzed. Flow cytometry was performed for cell cycle and apoptosis analyses. Simultaneously, RT-qPCR and western blotting were performed to explore the possible mechanism. Moreover, YAP1 knockout Ishikawa cells were established via lentivirus to demonstrate the underlying mechanism. The results showed that metformin mediated Ishikawa and RL95-2 cell growth inhibition in a dose- and time-dependent manner. The IC50 values of metformin in Ishikawa and RL95-2 cells were 10 mM and 8 mM, respectively. The migration and invasion abilities were also inhibited in the metformin-treated group using wound healing assays and transwell migration and invasion assays, and Ishikawa and RL95-2 cells were arrested in the G1 or G2 phase, respectively. Moreover, the cell proportions of cells in both early and late apoptosis stages were dramatically elevated when treated with metformin, as was the ratio of Bax/Bcl-2 expression. Additionally, the expression levels of YAP1 mRNA and protein in the treatment group were much lower than those in the control group. The cellular behaviors of YAP1 knockout Ishikawa cells were similar to those in the metformin-treated group. Our results demonstrated that it is an attractive alternative to cytotoxic chemotherapy in human endometrial cancer, and YAP of the Hippo pathway may be a potential molecular target. This study provides novel ideas for the adjuvant therapy of endometrial cancer patients, especially for women with strong fertility desires and demands.

Cervical cancer screening and predictors of screening by diabetes status

PURPOSE

Women with diabetes have lower survival rates after a cervical cancer diagnosis compared to women without diabetes. Pap smears and human papilloma virus (HPV) testing are highly effective screening tests for cervical cancer, therefore, it is important to know the prevalence of guideline-concordant screening among women with diabetes and understand if their predictors of screening differ. The purpose of this analysis was to assess guideline-concordant cervical cancer screening and predictors by diabetes status.

METHODS

We used the 2019 National Health Interview Survey data, limited to women aged 21-65 years without a previous diagnosis of cancer, a hysterectomy, or diagnosed with diabetes in the year prior to the survey. We considered the Pap and HPV tests together and concordance as being tested within the past 3 years as part of a routine exam. We calculated weighted, adjusted prevalence, and prevalence ratios (PRs) of screening concordance comparing women with diabetes to those without.

RESULTS

The unadjusted prevalence of concordant screening was 66.5% for women with diabetes compared to 73.3% for women without diabetes (PR = 0.91 95% CI 0.84-0.98). In the fully adjusted model adjusting for factors known to be associated with diabetes and access to healthcare, the association was attenuated and no longer statistically significant (PR = 0.96 95% CI 0.89-1.04).

CONCLUSION

Cervical cancer screening concordance was lower in women with diabetes compared to those without overall but the deficit appears to be due primarily to underlying differences in sociodemographic characteristics and access to healthcare and not diabetes independently.

Differential Expression of RAD51AP1 in Ovarian Cancer: Effects of siRNA In Vitro

Background: DNA double strand breaks can affect genome integrity potentially leading to cancer. RAD51-associated protein 1 (RAD51AP1), an accessory protein to RAD51, is critical for homologous recombination, a key DNA damage response pathway. Emerging studies indicate a novel role for RAD51AP1 in carcinogenesis. Here we provide additional insight into the role of RAD51AP1 in ovarian cancer (OvCa). Methods: Gene expression and patient phenotype data were obtained from TCGA and GTEX project consortia for bioinformatics analysis. Immunohistochemistry of OvCa tissue microarray was undertaken. Functional analyses were performed in a SKOV3 OvCa cell line with down-regulation of RAD51AP1 using siRNA. Results: RAD51AP1 is overexpressed at gene level in primary and recurrent OvCa compared to controls. At protein level, RAD51AP1 was up-regulated in low grade serous tumors compared to high grade OvCa. There was higher expression of RAD51AP1 in OvCa metastatic to lymph nodes compared to primary cancer samples. Gene enrichment analyses identified 12 differentially expressed genes (DEGs) related to OvCa, eight of which are also common in tissue from patients with type 2 diabetes mellitus (T2DM). Conclusions: RAD51AP1 is overexpressed in OvCa, Given the link between OvCa and T2DM, the eight-gene signature shows potential for predictive value.

Diabetes associated with cervical carcinoma among high-risk HPV-infected patients with cytologically diagnosed high grade squamous intraepithelial lesion

BACKGROUND

Diabetes causes metabolic disorders and immune changes that may be potential triggers of cervical cancer. Therefore, diabetes is not a "bystander" to cervical cancer. However, the conclusion that diabetes promotes cervical cancer lacks clinical epidemiological evidence, and the reported potential association between diabetes and cervical cancer is controversial.

METHODS

We conducted an explorative cross-sectional study of 791 women with cytological HGSIL and HR-HPV, who attended the cervical clinic of the largest academic women's hospital in China from May 2019 to March 2022. After cervical screening, patients who were requiring colposcopy were tested for HbA1c. HbA1c level of 6.5% or higher defines diabetes and HbA1c level of 5.7%-6.4% was defined as prediabetes. The relationship between diabetes and cervical cancer was observed by a dose-response graph. Subgroup analysis and multivariate logistic regression analysis were conducted to estimate the associations between diabetes and cervical cancer.

RESULTS

Among HGSIL patients with high-risk HPV infection, compared with women with HbA1c &lt;5.7%, the odds ratio for women with prediabetes was 1.72 (95% CI: 0.87-3.41) and the odds ratio for women with diabetes was 3.29 (95% CI: 1.10-9.80) for cervical cancer. Sensitivity analysis showed that diabetes was significantly associated with cervical cancer in different age groups and different HPV variant. E-value analysis showed robustness to unmeasured confounding.

CONCLUSIONS

In patients with HR-HPV combined with HGSIL, diabetes and prediabetes are associated with cervical cancer.

Disparities in Cervical Cancer Screening with HPV Test among Females with Diabetes in the Deep South

Simple Summary

Diabetes is linked with poorer cervical cancer prognosis, and people residing in the Southern region of the U.S. are disproportionately diagnosed with diabetes and cancer. The HPV test was recently recognized as the preferred method of cervical cancer screening by the American Cancer Society. Through our observational study, we sought to investigate the HPV testing behaviors among females with and without diabetes across the U.S. Our nationally representative estimates reveal that less than half of females reported HPV testing, and females with diabetes in the Deep South have the lowest rates of HPV testing. Various risk factors were identified to significantly lower the odds of HPV testing, including a diabetes diagnosis, older age, living in the Southern region of the U.S., and absence of certain comorbidities. The lower rates of HPV testing among females with diabetes, especially those living in the Deep South, leave these populations vulnerable to cervical cancer.

Abstract

Background: Due to diabetes being linked with poorer cervical cancer prognosis, this study aimed to evaluate HPV testing behaviors among females with and without diabetes across the U.S. by geographic area in 2016, 2018, and 2020. Methods: This cross-sectional study used the Behavioral Risk Factor Surveillance System (BRFSS) from 2016, 2018, and 2020. The study population included females aged 25–69 years old, stratified by self-reported diabetes status. The primary outcome measure was cervical cancer screening behavior, which was evaluated by self-reported HPV test uptake/receipt (yes/no). Results: A total of 361,546 females from across the U.S. were sampled. Within the study population combined from all study years, the overall likelihood of receiving an HPV test was significantly lower among females with diabetes [37.95% (95% CI: 36.87–39.04)] compared to those without diabetes [46.21% (95% CI: 45.84–46.58)] (p < 0.001). Screening rates with HPV tests were lowest among females with diabetes in the South in 2016 (29.32% (95% CI: 26.82–31.83)), 2018 (39.63% (95% CI: 36.30–42.96)), and 2020 (41.02% (95% CI: 37.60–44.45)). Conclusions: Females with diabetes are screening with HPV tests less frequently than females without diabetes, and females living in the South, particularly states in the Deep South, report the lowest rates of HPV testing.

Progesterone Receptor Membrane Component (PGRMC)1 and PGRMC2 and Their Roles in Ovarian and Endometrial Cancer

Cancers of the female reproductive tract are both lethal and highly prevalent. For example, the five-year survival rate of women diagnosed with ovarian cancer is still less than 50%, and endometrial cancer is the fourth most common cancer in women with > 65,000 new cases in the United States in 2020. Among the many genes already established as key participants in ovarian and endometrial oncogenesis, progesterone receptor membrane component (PGRMC)1 and PGRMC2 have gained recent attention given that there is now solid correlative information supporting a role for at least PGRMC1 in enhancing tumor growth and chemoresistance. The expression of PGRMC1 is significantly increased in both ovarian and endometrial cancers, similar to that reported in other cancer types. Xenograft studies using human ovarian and endometrial cancer cell lines in immunocompromised mice demonstrate that reduced expression of PGRMC1 results in tumors that grow substantially slower. While the molecular underpinnings of PGRMCs' mechanisms of action are not clearly established, it is known that PGRMCs regulate survival pathways that attenuate stress-induced cell death. The objective of this review is to provide an overview of what is known about the roles that PGRMC1 and PGRMC2 play in ovarian and endometrial cancers, particularly as related to the mechanisms through which they regulate mitosis, apoptosis, chemoresistance, and cell migration.

Network Medicine-Based Analysis of Association Between Gynecological Cancers and Metabolic and Hormonal Disorders

Different metabolic and hormonal disorders like type 2 diabetes mellitus (T2DM), obesity, and polycystic ovary syndrome (PCOS) have tangible socio-economic impact. Prevalence of these metabolic and hormonal disorders is steadily increasing among women. There are clinical evidences that these physiological conditions are related to the manifestation of different gynecological cancers and their poor prognosis. The relationship between metabolic and hormonal disorders with gynecological cancers is quite complex. The need for gene level association study is extremely important to find markers and predicting risk factors. In the current work, we have selected metabolic disorders like T2DM and obesity, hormonal disorder PCOS, and 4 different gynecological cancers like endometrial, uterine, cervical, and triple negative breast cancer (TNBC). The gene list was downloaded from DisGeNET database (v 6.0). The protein interaction network was constructed using HIPPIE (v 2.2) and shared proteins were identified. Molecular comorbidity index and Jaccard coefficient (degree of similarity) between the diseases were determined. Pathway enrichment analysis was done using ReactomePA and significant modules (clusters in a network) of the constructed network was analyzed by MCODE plugin of Cytoscape. The comorbid conditions like PCOS-obesity found to increase the risk factor of ovarian and triple negative breast cancers whereas PCOS alone has highest contribution to the endometrial cancer. Different gynecological cancers were found to be differentially related to the metabolic/hormonal disorders and comorbid condition.

Perspectives of metformin use in endometrial cancer and other gynaecological malignancies

Insulin resistance and hyperinsulinemia play a key role in type 1 endometrial cancer pathogenesis. Most of these cancers develop on a background of overweight or type 2 diabetes mellitus (T2DM). One of the medications widely used in the treatment of T2DM is biguanide derivative, metformin, which exerts promising anticancer properties principally through activation of adenosine monophosphate kinase (AMPK) and inhibition of mammalian target of rapamycin (mTOR) pathways. Many epidemiological studies on diabetic patients show potential preventative role of metformin in endometrial cancer patients, but data regarding its therapeutic role is still limited. So far, most of attention has been paid to the concept of metformin use in fertility sparing treatment of early-stage cancer. Another investigated alternative is its application in patients with primary advanced or recurrent disease. In this review we present the latest data on clinical use of metformin in endometrial cancer patients and potential underlying mechanisms of its activity. Finally, we present some most important clinical information regarding metformin efficacy in other gynaecological malignancies, mainly breast and ovarian cancer.

Review of Mendelian Randomization Studies on Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest gynecological cancers worldwide. Previous observational epidemiological studies have revealed associations between modifiable environmental risk factors and OC risk. However, these studies are prone to confounding, measurement error, and reverse causation, undermining robust causal inference. Mendelian randomization (MR) analysis has been established as a reliable method to investigate the causal relationship between risk factors and diseases using genetic variants to proxy modifiable exposures. Over recent years, MR analysis in OC research has received extensive attention, providing valuable insights into the etiology of OC as well as holding promise for identifying potential therapeutic interventions. This review provides a comprehensive overview of the key principles and assumptions of MR analysis. Published MR studies focusing on the causality between different risk factors and OC risk are summarized, along with comprehensive analysis of the method and its future applications. The results of MR studies on OC showed that higher BMI and height, earlier age at menarche, endometriosis, schizophrenia, and higher circulating β-carotene and circulating zinc levels are associated with an increased risk of OC. In contrast, polycystic ovary syndrome; vitiligo; higher circulating vitamin D, magnesium, and testosterone levels; and HMG-CoA reductase inhibition are associated with a reduced risk of OC. MR analysis presents a2 valuable approach to understanding the causality between different risk factors and OC after full consideration of its inherent assumptions and limitations.

Tissue and circulating microRNAs as biomarkers of response to obesity treatment strategies

BACKGROUND

Obesity, characterized by an increased amount of adipose tissue, is a metabolic chronic alteration which has reached pandemic proportion. Lifestyle changes are the first line therapy for obesity and a large variety of dietary approaches have demonstrated efficacy in promoting weight loss and improving obesity-related metabolic alterations. Besides diet and physical activity, bariatric surgery might be an effective therapeutic strategy for morbid obese patients. Response to weight-loss interventions is characterised by high inter-individual variability, which might involve epigenetic factors. microRNAs have critical roles in metabolic processes and their dysregulated expression has been reported in obesity.

AIM

The aim of this review is to provide a comprehensive overview of current studies evaluating changes in microRNA expression in obese patients undergoing lifestyle interventions or bariatric surgery.

RESULTS

A considerable number of studies have reported a differential expression of circulating microRNAs before and after various dietary and bariatric surgery approaches, identifying several candidate biomarkers of response to weight loss. Significant changes in microRNA expression have been observed at a tissue level as well, with entirely different patterns between visceral and subcutaneous adipose tissue. Interestingly, relevant differences in microRNA expression have emerged between responders and non-responders to dietary or surgical interventions. A wide variety of dysregulated microRNA target pathways have also been identified, helping to understand the pathophysiological mechanisms underlying obesity and obesity-related metabolic diseases.

CONCLUSIONS

Although further research is needed to draw firm conclusions, there is increasing evidence about microRNAs as potential biomarkers for weight loss and response to intervention strategies in obesity.

Molecular and Cellular Mechanisms of Metformin in Cervical Cancer

Simple Summary

The potential effects of metformin in terms of cancer prevention and therapy have been widely studied, and a number of studies have indicated its potential role in cancer treatment. Metformin exerts anticancer effects, alone or in combination with other agents, on cervical cancer in vitro and in vivo. Metformin might thus serve as an adjunct therapeutic agent for cervical cancer.

Abstract

Cervical cancer is one of the major gynecologic malignancies worldwide. Treatment options include chemotherapy, surgical resection, radiotherapy, or a combination of these treatments; however, relapse and recurrence may occur, and the outcome may not be favorable. Metformin is an established, safe, well-tolerated drug used in the treatment of type 2 diabetes; it can be safely combined with other antidiabetic agents. Diabetes, possibly associated with an increased site-specific cancer risk, may relate to the progression or initiation of specific types of cancer. The potential effects of metformin in terms of cancer prevention and therapy have been widely studied, and a number of studies have indicated its potential role in cancer treatment. The most frequently proposed mechanism underlying the diabetes–cancer association is insulin resistance, which leads to secondary hyperinsulinemia; furthermore, insulin may exert mitogenic effects through the insulin-like growth factor 1 (IGF-1) receptor, and hyperglycemia may worsen carcinogenesis through the induction of oxidative stress. Evidence has suggested clinical benefits of metformin in the treatment of gynecologic cancers. Combining current anticancer drugs with metformin may increase their efficacy and diminish adverse drug reactions. Accumulating evidence is indicating that metformin exerts anticancer effects alone or in combination with other agents in cervical cancer in vitro and in vivo. Metformin might thus serve as an adjunct therapeutic agent for cervical cancer. Here, we reviewed the potential anticancer effects of metformin against cervical cancer and discussed possible underlying mechanisms.

Gut Microbiota and Gynecological Cancers: A Summary of Pathogenetic Mechanisms and Future Directions

Over the past 20 years, important relationships between the microbiota and human health have emerged. A link between alterations of microbiota composition (dysbiosis) and cancer development has been recently demonstrated. In particular, the composition and the oncogenic role of intestinal bacterial flora has been extensively investigated in preclinical and clinical studies focusing on gastrointestinal tumors. Overall, the development of gastrointestinal tumors is favored by dysbiosis as it leads to depletion of antitumor substances (e.g., short-chain fatty acids) produced by healthy microbiota. Moreover, dysbiosis leads to alterations of the gut barrier, promotes a chronic inflammatory status through activation of toll-like receptors, and causes metabolic and hormonal dysregulations. However, the effects of these imbalances are not limited to the gastrointestinal tract and they can influence gynecological tumor carcinogenesis as well. The purpose of this Review is to provide a synthetic update about the mechanisms of interaction between gut microbiota and the female reproductive tract favoring the development of neoplasms. Furthermore, novel therapeutic approaches based on the modulation of microbiota and their role in gynecological oncology are discussed.

Gestational diabetes mellitus and risks of gynecologic cancers: Results from a nationwide Swedish twin study

BACKGROUND

Type 2 diabetes has been associated with increased risk of gynecologic cancers, yet the effect of gestational diabetes mellitus (GDM) on gynecologic cancers is unclear.

OBJECTIVES

To examine associations between GDM history and subsequent gynecologic cancers in parous women, and to explore whether gestational hypertension (GH) plays a role in the associations.

STUDY DESIGN

The population-based cohort study included 15,941 individuals from the Swedish Twin Registry. The history of GDM and GH was ascertained based on self-reports. Incident cases of gynecologic cancers (including cancers of the cervix, uterus, ovaries and other female genitalia) were obtained from the National Patients Registry and the Swedish Cancer Registry. Generalized estimating equation models were applied to analyze associations between GDM and gynecologic cancers. Stratified analysis was used to explore whether associations between GDM and gynecologic cancers differed by GH. Additive and multiplicative interactions were calculated between GDM and GH.

RESULTS

Of all participants, 350 (2.2%) had GDM, and 1762 (11.1%) had incident gynecologic cancers. No statistically significant associations were found between GDM and risks of any gynecologic cancers. However, GDM was associated with an increased risk of ovarian cancer (OR = 5.29, 95% CI: 1.63-17.19) in women with GH. Interactions between GDM and GH were observed on the additive scale (Attributable proportion due to interaction: 0.86, 95% CI 0.42-1.30, P < 0.001).

CONCLUSIONS

The associations between GDM and risks of gynecologic cancers were not evident, but the effect of GDM on the risk of ovarian cancer was modified by GH. Further validation in larger cohorts is warranted.

MicroRNA Modulation by Dietary Supplements in Obesity

The prevalence of obesity has dramatically increased over the last decades. Weight loss obtained through diet and exercise leads to a significant decrease in morbidity and mortality. Recently, there has been growing interest in the possible beneficial effects of dietary supplements (DSs), including polyphenols, fatty acids, and other plant-derived substances, as adjuvants in the management of obesity and metabolic diseases. Specifically, polyphenols, widely spread in vegetables and fruits, significantly modulate adipose tissue activities, contrasting inflammation and improving insulin sensitivity in preclinical and clinical studies. Remarkably, polyphenols are involved in complex microRNA networks, which play crucial roles in metabolic processes. The administration of different polyphenols and other plant-derived compounds led to significant changes in the microRNA expression profile in peripheral tissues in a growing number of preclinical studies. In particular, these compounds were able to revert obesity-induced microRNA dysregulation, leading to the inhibition of adipogenesis and the induction of weight loss. Furthermore, through microRNA modulation, they attenuated key metabolic alterations, including insulin resistance and lipid anomalies, in animal models of obesity. Some of them were also able to reduce proinflammatory cytokines in adipose tissue. The aim of this review is to summarize current evidence about the effect of plant-derived DSs on microRNA expression in obesity.

Type 2 diabetes mellitus facilitates endometrial hyperplasia progression by activating the proliferative function of mucin O-glycosylating enzyme GALNT2

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is thought to be a risk factor for endometrial hyperplasia, but potential links between the two diseases are unknown. This study aims to evaluate the role of T2DM in the progression of endometrial hyperplasia.

METHODS

Female Sprague-Dawley rats were randomly divided into normal (N) group, endometrial hyperplasia (NH) group, T2DM (T) group, and endometrial hyperplasia with T2DM (TH) group. Proteomics analysis was performed to determine the protein profile of endometrial tissues. Proliferation, migration, and invasion of cells with/without GLANT2-knockdown were assessed. Immunohistochemical staining and ELISA were used to examine the expression of GALNT2 in endometrial tissues and serum of clinical samples.

RESULTS

The highest uterus index and endometrial thickness were observed in TH group, with the expression of proliferation marker PCNA increased significantly, indicating that T2DM facilitates the progress of endometrial hyperplasia. Proteomics analysis showed that there were significant differences in protein profiles among groups and differential proteins were mainly enriched in metabolic pathways. Further verification by molecular biology analysis indicated that GALNT2 is the key target for T2DM facilitating endometrial hyperplasia. The expression of GALNT2 was significantly decreased in high glucose environment. T2DM could synergize the proliferative function of GALNT2 aberration by activating EGFR/AKT/ERK pathway. The decreased expressions of GALNT2 in clinical samples were associated with worse subtypes of endometrial hyperplasia.

CONCLUSION

T2DM promoted the progression of endometrial hyperplasia by regulating the GALNT2-mediated phosphorylation of EGFR and enhancing cell proliferation. GALNT2 has the potential to be a novel biomarker in the treatment of endometrial hyperplasia.

Therapeutic effect of metformin in the treatment of endometrial cancer

The present review aims at reviewing the role of metformin in the treatment of endometrial cancer (EC). According to the literature, excessive estrogen levels and insulin resistance are established risk factors of EC. As a traditional insulin sensitizer and newly discovered anticancer agent, metformin directly and indirectly inhibits the development of EC. The direct mechanisms of metformin include inhibition of the LKB1-AMP-activated protein kinase-mTOR, PI3K-Akt and insulin-like growth factor 1-related signaling pathways, which reduces the proliferation and promotes the apoptosis of EC cells. In the indirect mechanism, metformin increases the insulin sensitivity of body tissues and decreases circulating insulin levels. Decreased levels of insulin increase the blood levels of sex hormone binding globulin, which leads to reductions in circulating estrogen and androgens. The aforementioned findings suggest that metformin serves an important role in the treatment of EC. Increased understanding of the mechanism of metformin in EC may provide novel insights into the treatment of this malignancy.

Transcriptional Profiling and Biological Pathway(s) Analysis of Type 2 Diabetes Mellitus in a Pakistani Population

The epidemic of type 2 diabetes mellitus (T2DM) is an important global health concern. Our earlier epidemiological investigation in Pakistan prompted us to conduct a molecular investigation to decipher the differential genetic pathways of this health condition in relation to non-diabetic controls. Our microarray studies of global gene expression were conducted on the Affymetrix platform using Human Genome U133 Plus 2.0 Array along with Ingenuity Pathway Analysis (IPA) to associate the affected genes with their canonical pathways. High-throughput qRT-PCR TaqMan Low Density Array (TLDA) was performed to validate the selected differentially expressed genes of our interest, viz., ARNT, LEPR, MYC, RRAD, CYP2D6, TP53, APOC1, APOC2, CYP1B1, SLC2A13, and SLC33A1 using a small population validation sample (n = 15 cases and their corresponding matched controls). Overall, our small pilot study revealed a discrete gene expression profile in cases compared to controls. The disease pathways included: Insulin Receptor Signaling, Type II Diabetes Mellitus Signaling, Apoptosis Signaling, Aryl Hydrocarbon Receptor Signaling, p53 Signaling, Mitochondrial Dysfunction, Chronic Myeloid Leukemia Signaling, Parkinson's Signaling, Molecular Mechanism of Cancer, and Cell Cycle G1/S Checkpoint Regulation, GABA Receptor Signaling, Neuroinflammation Signaling Pathway, Dopamine Receptor Signaling, Sirtuin Signaling Pathway, Oxidative Phosphorylation, LXR/RXR Activation, and Mitochondrial Dysfunction, strongly consistent with the evidence from epidemiological studies. These gene fingerprints could lead to the development of biomarkers for the identification of subgroups at high risk for future disease well ahead of time, before the actual disease becomes visible.

The impact of adjunctive metformin to progesterone for the treatment of non-atypical endometrial hyperplasia in a randomized fashion, a placebo-controlled, double blind clinical trial

OBJECTIVE

Endometrial hyperplasia (EH) is a premalignant neoplasm. Most recently, metformin has been suggested as an adjuvant medication for treating of EH with better outcome. Recent evidence has suggested that metformin has anticancer activity by inhibiting cell proliferation and tumor growth. The aim of this study was to evaluate the effect of metformin plus megestrol acetate versus megestrol acetate alone on patient with EH without atypia.

STUDY DESIGN

This double blind placebo-controlled clinical trial was conducted among 60 women with EH without atypia. Participants were allocated to two equal groups. Treatment group (M + M) received 40 mg megestrol acetate for 14 days of one month and 1000 mg metformin daily for three months. In placebo group (M + P) each patient received the same dose of megestrol acetate plus two tablets of placebo. Endometrial biopsy was performed in all patients three weeks after the last day of medication RESULTS: Data were evaluated based on 29 and 27 women in the M + M group and M + P group, respectively. After 3 months of therapy 27 (93.1 %) women in M + M group had not EH and responded to treatment, which was statistically higher than the rate of response (19 women, 70.4 %) in M + P group.

CONCLUSIONS

This study showed that megestrol plus metformin was significantly better than megestrol alone for the treatment of endometrial hyperplasia without atypia.

MorbiNet: multimorbidity networks in adult general population. Analysis of type 2 diabetes mellitus comorbidity

Multimorbidity has great impact on health care. We constructed multimorbidity networks in the general population, extracted subnets focused on common chronic conditions and analysed type 2 diabetes mellitus (T2DM) comorbidity network. We used electronic records from 3,135,948 adult people in Catalonia, Spain (539,909 with T2DM), with at least 2 coexistent chronic conditions within the study period (2006-2017). We constructed networks from odds-ratio estimates adjusted by age and sex and considered connections with OR > 1.2 and p-value < 1e-5. Directed networks and trajectories were derived from temporal associations. Interactive networks are freely available in a website with the option to customize characteristics and subnets. The more connected conditions in T2DM undirected network were: complicated hypertension and atherosclerosis/peripheral vascular disease (degree: 32), cholecystitis/cholelithiasis, retinopathy and peripheral neuritis/neuropathy (degree: 31). T2DM has moderate number of connections and centrality but is associated with conditions with high scores in the multimorbidity network (neuropathy, anaemia and digestive diseases), and severe conditions with poor prognosis. The strongest associations from T2DM directed networks were to retinopathy (OR: 23.8), glomerulonephritis/nephrosis (OR: 3.4), peripheral neuritis/neuropathy (OR: 2.7) and pancreas cancer (OR: 2.4). Temporal associations showed the relevance of retinopathy in the progression to complicated hypertension, cerebrovascular disease, ischemic heart disease and organ failure.

Metformin suppresses cancer cell growth in endometrial carcinoma by inhibiting PD-L1

Endometrial cancer is the most common cancer of the female reproductive system in the developed countries. Metformin is a widely used medication that has been prescribed to treat type 2 diabetes. In recent years, metformin has been found to improve the survival prognosis of cancer patients clinically. We aimed to investigate inhibition of metformin on the proliferation of endometrial carcinoma. Metformin was used to treat endometrial cancer cell lines Ishikawa and RL95-2. The expression of programmed death-ligand 1 (PD-L1) in the treated cells was assessed by western blot. The tumor cell proliferation was evaluated by colony formation assay. The binding between PD-L1 and AMP-activated protein kinase (AMPK) was identified by co-immunoprecipitation. Ishikawa and RL95-2 cells were co-cultured with activated T cells to detect the survival of Ishikawa and RL95-2 cells in the presence or absence of metformin. Our results showed that metformin treatment on endometrial cancer cells Ishikawa and RL95-2 decreased the expression level of PD-L1 protein. Metformin treatment significantly activated T cells against Ishikawa and RL95-2 cells. We demonstrated that the inhibition of PD-L1 by metformin is dependent on the AMPK signaling protein, and that metformin promotes direct binding of the AMPK protein to the PD-L1 protein. We confirmed that metformin, a conventional medication used in diabetes therapy, holds anti-tumor activity in endometrial cancer. The suppression of metformin is relevant to the inhibition of PD-L1 expression and the activation of AMPK signaling protein, providing a novel mechanism in the anti-tumor property of metformin.

Hyperglycemia-Associated Dysregulation of O-GlcNAcylation and HIF1A Reduces Anticancer Action of Metformin in Ovarian Cancer Cells (SKOV-3)

Although cancer cells need more glucose than normal cells to maintain energy demand, chronic hyperglycemia induces metabolic alteration that may dysregulate signaling pathways, including the O-GlcNAcylation and HIF1A (Hypoxia-inducible factor 1-alpha) pathways. Metformin was demonstrated to evoke metabolic stress and induce cancer cell death. The aim of this study was to determine the cytotoxic efficiency of metformin on SKOV-3 cells cultured in hyperglycemia and normoglycemia. To identify the potential mechanism, we assessed the expression of O-linked β-N-acetlyglucosamine transferase (OGT) and glycoside hydrolase O-GlcNAcase (OGA), as well as hypoxia-inducible factor 1-alpha (HIF1A) and glucose transporters (GLUT1, GLUT3). SKOV-3 cells were cultured in normoglycaemia (NG, 5 mM) and hyperglycemia (HG, 25 mM) with and without 10 mM metformin for 24, 48, and 72 h. The proliferation rate, apoptotic and necrotic SKOV-3 cell death were evaluated. Real-Time qPCR was employed to determine mRNA expression of OGT, OGA, GLUT1, GLUT3, and HIF1A. Metformin significantly reduced the proliferation of SKOV-3 cells under normal glucose conditions. Whereas, the efficacy of metformin to induce SKOV-3 cell death was reduced in hyperglycemia. Both hyperglycemia and metformin induced changes in the expression of genes involved in the O-GlcNAcylation status and HIF1A pathway. The obtained results suggest that dysregulation of O-GlcNAcylation, and the related HIF1A pathway, via hyperglycemia, is responsible for the decreased cytotoxic efficiency of metformin in human ovarian cancer cells.