Combined oral contraceptive synergistically activates mineralocorticoid receptor through histone code modifications

Circulating nucleosomes as potential biomarkers for cancer diagnosis and treatment monitoring

Nucleosomes play a crucial role in regulating gene expression through their composition and post-translational modifications. When cells die, intracellular endonucleases are activated and cleave chromatin into oligo- and mono-nucleosomes, which are then released into the body fluids. Studies have shown that the levels of nucleosomes are increased in serum and plasma in various cancer types, suggesting that analysis of circulating nucleosomes can provide an initial assessment of carcinogenesis. However, it should be noted that elevated serum nucleosome levels may not accurately diagnose certain tumor types, as increased cell death may occur in different pathological conditions. Nevertheless, detection of circulating nucleosomes and their histone modifications, along with specific tumor markers, can help diagnose certain types of cancer. Furthermore, monitoring changes in circulating nucleosome levels during chemotherapy or radiotherapy in patients with malignancies can provide valuable insights into clinical outcomes and therapeutic efficacy. The utilization of circulating nucleosomes as biomarkers is an exciting and emerging area of research, with the potential for early detection of various diseases and monitoring of treatment response. Integrating nucleosome-based biomarkers with existing ones may improve the specificity and sensitivity of current assays, offering the possibility of personalized precision medical treatment for patients.

An epigenetic hypothesis for ovarian cancer prevention by oral contraceptive pill use

BACKGROUND

Ovarian cancer is the second most common gynecological cancer type after uterine cancers. In 2020, according to worldwide statistics, there were more than 313,000 new cases of ovarian cancer. Most concerning with ovarian cancer is the poor overall survival, with only 30% of patients surviving for longer than 5 years after diagnosis. The reason for this poor outcome includes late diagnosis due to non-specific symptoms and a lack of any highly effective biomarkers of the early stages of ovarian carcinogenesis. However, it is important to note that some modifiable lifestyle factors can be preventative [pregnancy, breastfeeding and combined oral contraceptives pill (COCP) use].

RESULTS

There is now increasing data reporting the role of epigenetic changes, which are detectable in ovarian cancer tumors, suggesting the possibility that epigenetics may also play a key role in the mechanism of long-term effective prevention of ovarian cancer. To our knowledge, there is a lack of high-quality data on the molecular mechanisms of ovarian cancer prevention, although several hypotheses have been proposed.

CONCLUSIONS

This review focusses on the evidence for a proposed novel hypothesis-that COCPs act as a chemoprevention through the impact on the epigenome of the cells of origin of ovarian cancer-fallopian tubes epithelium.

A rodent model of human dose-equivalent progestin-only implantable contraception

BACKGROUND

Long-acting, reversible contraceptives (LARC; progestin only) are an increasingly common hormonal contraceptive choice in reproductive aged women looking to suppress ovarian function and menstrual cyclicity. The overall objective was to develop and validate a rodent model of implanted etonogestrel (ENG) LARC, at body size equivalent doses to the average dose received by women during each of the first 3 years of ENG subdermal rod LARC use.

METHODS

Intact, virgin, female Sprague-Dawley rats (16-wk-old) were randomized to 1 of 4 groups (n = 8/group) of ENG LARC (high-0.30μg/d, medium-0.17μg/d, low-0.09μg/d, placebo-0.00μg/d) via a slow-release pellet implanted subcutaneously. Animals were monitored for 21 days before and 29 days following pellet implantation using vaginal smears, ultrasound biomicroscopy (UBM), saphenous blood draws, food consumption, and body weights. Data were analyzed by chi-square, non-parametric, univariate, and repeated measures 2-way ANOVA.

RESULTS

Prior to pellet implantation there was no difference in time spent in estrus cycle phases among the treatment groups (p > 0.30). Following pellet implantation there was a dose-dependent impact on the time spent in diestrus and estrus (p < 0.05), with the high dose group spending more days in diestrus and fewer days in estrus. Prior to pellet insertion there was not an association between treatment group and estrus cycle classification (p = 0.57) but following pellet implantation there was a dose-dependent association with cycle classification (p < 0.02). Measurements from the UBM (ovarian volume, follicle count, corpora lutea count) indicate an alteration of ovarian function following pellet implantation.

CONCLUSION

Assessment of estrus cyclicity indicated a dose-response relationship in the shift to a larger number of acyclic rats and longer in duration spent in the diestrus phase. Therefore, each dose in this model mimics some of the changes observed in the ovaries of women using ENG LARC and provides an opportunity for investigating the impacts on non-reproductive tissues in the future.

Blockade of mineralocorticoid receptor ameliorates oral contraceptive-induced insulin resistance by suppressing elevated uric acid and glycogen synthase kinase-3 instead of circulating mineralocorticoid

Context: Estrogen-progestin combined oral contraceptive (COC) has been connected to mineralocorticoid receptor (MR) activation and adverse cardiometabolic events. We consequently hypothesised that insulin resistance (IR), hyperuricemia, and elevated circulating GSK-3 induced by COC is through activation of MR via mineralocorticoid and glucocorticoid pathways.Methods: Female Wistar rats aged 12 weeks received (po) vehicle and COC (1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel) with or without MR blocker (0.25 mg/kg spironolactone; Spl), daily for eight weeks.Results: Data showed that COC treatment led to increased IR, 1-hour postload glucose level, insulinemia, triglyceride/HDL-cholesterol ratio, total cholesterol/HDL-cholesterol ratio, uric acid, GSK-3, aldosterone, corticosterone values, impaired glucose tolerance and pancreatic β-cell function. However, MR blockade by Spl ameliorated all these alterations except that of aldosterone.Conclusion: The results demonstrate that COC induces IR, hyperuricemia and high GSK-3 levels through activation of MR via glucocorticoid dependent pathway.

Oral Contraceptive Use and Risks of Cancer in the NIH-AARP Diet and Health Study

Although use of oral contraceptives (OCs) is common, their influence on carcinogenesis is not fully understood. We used Cox proportional hazards models to examine OC use (never/<1 year (referent), 1-4, 5-9, ≥10 years) and development of incident cancers across body sites within the same base population: women in the prospective National Institutes of Health-AARP Diet and Health Study (enrolled 1995-1996 and followed until 2011). Adjustment for confounding varied by outcome; all models accounted for age, race, body mass index, and smoking status, and included at least 100,000 women. Any OC use conferred a 3% reduction in the risk for any cancer (hazard ratio = 0.97, 95% confidence interval: 0.95, 0.99). Expected risk reductions that strengthened with duration of use were identified for ovarian and endometrial cancers and were suggested for kidney cancer (all P for trend < 0.05). Non-Hodgkin lymphoma risk (hazard ratio = 0.79, 95% confidence interval: 0.64, 0.97) was reduced with 10 or more years of OC use. There was a 37% reduced risk for bladder cancer and 46% increased risk for pancreatic cancer among long-term OC users who were 60 years of age or younger at baseline. OC use did not influence risks for most other cancers evaluated. Given the high prevalence of use and changing formulations, additional studies are warranted to fully understand the chemopreventive effects of these medications.

Activation of cardiac renin-angiotensin system and plasminogen activator inhibitor-1 gene expressions in oral contraceptive-induced cardiometabolic disorder

CONTEXT

Clinical studies have shown that combined oral contraceptive (COC) use is associated with cardiometabolic disturbances. Elevated renin-angiotensin system (RAS) and plasminogen activator inhibitor-1 (PAI-1) have also been implicated in the development of cardiometabolic events.

OBJECTIVE

To determine the effect of COC treatment on cardiac RAS and PAI-1 gene expressions, and whether the effect is circulating aldosterone or corticosterone dependent.

METHODS

Female rats were treated (p.o.) with olive oil (vehicle) or COC (1.0 µg ethinylestradiol and 10.0 µg norgestrel) daily for six weeks.

RESULTS

COC treatment led to increases in blood pressure, HOMA-IR, Ace1 mRNA, Atr1 mRNA, Pai1 mRNA, cardiac PAI-1, plasma PAI-1, C-reactive protein, uric acid, insulin and corticosterone. COC treatment also led to dyslipidemia, decreased glucose tolerance and plasma 17β-estradiol.

CONCLUSION

These results demonstrates that hypertension and insulin resistance induced by COC is associated with increased cardiac RAS and PAI-1 gene expression, which is likely to be through corticosterone-dependent but not aldosterone-dependent mechanism.

Combined oral contraceptive-induced hypertension is accompanied by endothelial dysfunction and upregulated intrarenal angiotensin II type 1 receptor gene expression

Combined oral contraceptive (COC) use is associated with increased risk of developing hypertension. Activation of the intrarenal renin-angiotensin system (RAS) and endothelial dysfunction play an important role in the development of hypertension. We tested the hypothesis that COC causes hypertension that is associated with endothelial dysfunction and upregulation of intrarenal angiotensin-converting enzyme 1 (Ace1) and angiotensin II type 1 receptor (At1r). Female Sprague-Dawley rats aged 12 weeks received (p.o.) olive oil (control) and a combination of 0.1 μg ethinylestradiol and 1.0 μg norgestrel (low COC) or 1.0 μg ethinylestradiol and 10.0 μg norgestrel (high COC) daily for 6 weeks. Blood pressure was recorded by tail cuff plethysmography. Expression of genes in kidney cortex was determined by quantitative real-time polymerase chain reaction. COC treatment led to increased blood pressure, circulating uric acid, C-reactive protein and plasminogen activator inhibitor-1, renal uric acid, and expression of renal Ace1 and At1r. COC treatment resulted in increased contractile responses to phenylephrine in endothelium-denuded aortic rings. Endothelium-dependent relaxation responses to acetylcholine, but not endothelium-independent relaxation responses to nitric oxide (NO) donation by sodium nitroprusside, were attenuated in COC-exposed rings. Impaired relaxation responses to acetylcholine were masked by the presence of NO synthase inhibitor (L-NAME) in the COC-exposed rings, whereas the responses to acetylcholine in the presence of selective cyclooxygenase-2 inhibitor (NS-398) were enhanced. These findings indicate that COC induces hypertension that is accompanied by endothelial dysfunction, upregulated intrarenal Ace1 and At1r expression, and elevated proinflammatory biomarkers.