The heart: a novel gonadotrophin-releasing hormone target

The Role of METTL3-Mediated N6-Methyladenosine (m6A) of JPH2 mRNA in Cyclophosphamide-Induced Cardiotoxicity

Cyclophosphamide (CYP)-induced cardiotoxicity is a common side effect of cancer treatment. Although it has received significant attention, the related mechanisms of CYP-induced cardiotoxicity remain largely unknown. In this study, we used cell and animal models to investigate the effect of CYP on cardiomyocytes. Our data demonstrated that CYP-induced a prolonged cardiac QT interval and electromechanical coupling time courses accompanied by JPH2 downregulation. Moreover, N6-methyladenosine (m6A) methylation sequencing and RNA sequencing suggested that CYP induced cardiotoxicity by dysregulating calcium signaling. Importantly, our results demonstrated that CYP induced an increase in the m6A level of JPH2 mRNA by upregulating methyltransferases METTL3, leading to the reduction of JPH2 expression levels, as well as increased field potential duration and action potential duration in cardiomyocytes. Our results revealed a novel mechanism for m6A methylation-dependent regulation of JPH2, which provides new strategies for the treatment and prevention of CYP-induced cardiotoxicity.

Platelet proteome changes in dogs with congestive heart failure

BACKGROUND

Platelets play a central role in the development of cardiovascular diseases and changes in their proteins are involved in the pathophysiology of heart diseases in humans. There is lack of knowledge about the possible role of platelets in congestive heart failure (CHF) in dogs. Thus, this study aimed to investigate the changes in global platelet proteomes in dogs with CHF, to clarify the possible role of platelets in the physiopathology of this disease. Healthy-dogs (n = 10) and dogs with acute CHF due to myxomatous mitral valve disease (MMVD, n = 10) were used. Acute CHF was defined based on the clinical (increased respiratory rate or difficulty breathing) and radiographic findings of pulmonary edema. Dogs Blood samples were collected into tubes with acid-citrate-dextrose, and platelet-pellets were obtained by centrifuge and washing steps. Platelet-proteomes were identified using LC-MS based label-free differential proteome expression analysis method and matched according to protein database for Canis lupus familiaris.

RESULTS

Totally 104 different proteins were identified in the platelets of the dogs being 4 out of them were significantly up-regulated and 6 down-regulated in acute CHF dogs. Guanine-nucleotide-binding protein, apolipoproteins (A-II and C-III) and clusterin levels increased, but CXC-motif-chemokine-10, cytochrome-C-oxidase-subunit-2, cathepsin-D, serine/threonine-protein-phosphatase-PP1-gamma-catalytic-subunit, creatine-kinase-B-type and myotrophin levels decreased in acute CHF dogs. These proteins are associated with several molecular functions, biological processes, signaling systems and immune-inflammatory responses.

CONCLUSION

This study describes by first time the changes in the protein composition in platelets of dogs with acute CHF due to MMVD. Our findings provide a resource for increase the knowledge about the proteome of canine platelets and their roles in CHF caused by MMVD and could be a tool for further investigations about the prevention and treatment of this disease.

Cardiovascular risks and toxicity - The Achilles heel of androgen deprivation therapy in prostate cancer patients

Androgen deprivation therapy (ADT) is the primary systemic therapy for treating locally advanced or metastatic prostate cancer (PCa). Despite its positive effect on PCa patient survival, ADT causes various adverse effects, including increased cardiovascular risk factors and cardiotoxicity. Lifespans extension, early use of ADT, and second-line treatment with next-generation androgen receptor pathway inhibitors would further extend the duration of ADT and possibly increase the risk of ADT-induced cardiotoxicity. Meanwhile, information on the molecular mechanisms underlying ADT-induced cardiotoxicity and measures to prevent it is limited, mainly due to the lack of specifically designed preclinical studies and clinical trials. This review article compiles up-to-date evidence obtained from observational studies and clinical trials, in order to gain new insights for deciphering the association between ADT use and cardiotoxicity. In addition, potential cardioprotective strategies involving GnRH receptors and second messenger cGMP are discussed.

Cardiovascular Risk Profile in Prostate Cancer Patients Treated with GnRH Agonists versus Antagonists: An Italian Real-World Analysis

Purpose

To evaluate and compare the incidence of cardiovascular (CV) events in a large contemporary cohort of patients diagnosed with prostate cancer (PCa) and in treatment with GnRH agonists or GnRH antagonists.

Patients and Methods

An Italian observational retrospective cohort study based on administrative databases of three local health units and two Regions was performed. PCa patients treated with GnRH agonists or antagonist were included between January 01, 2013 and December 31, 2016. Index date (ID) was the date of first GnRH agonist/antagonist prescription during inclusion period. Follow-up was from ID to December 31, 2017. Patients were excluded if they were under abiraterone treatment or combination therapy with antiandrogens during follow-up. The incidence rate of CV events (acute myocardial infarction, ischemic heart diseases, cerebrovascular diseases, cardiac dysrhythmias, heart failure, atherosclerosis, aneurism, other CV-related conditions) was calculated among patients not switching to androgen deprivation therapy (ADT) in the overall cohort and in a sub-cohort of patients without previous CV events.

Results

In total, 9785 (mean age 76.8 ± 8.5) patients were included: 9158 (93.6%) were treated with a GnRH agonist and 627 (6.4%) with a GnRH antagonist. Of them, 9627 did not switch to ADT and were considered in the analyses. The incidence of CV events was significantly higher in patients treated with GnRH agonists rather than antagonists (8.8 vs 6.2, p=0.002). Mean time to CV event was beyond 1 year of treatment in both groups. In the multivariable regression analysis, the risk of experiencing CV events was significantly lower in patients treated with GnRH antagonist rather than those treated with GnRH agonists [HR (95% CI): 0.76 (0.60-0.95), p=0.018]. These findings were confirmed in the sub-cohort of patients without previous CV events.

Conclusion

This Italian observational study shows that most patients received a GnRH agonist rather than a GnRH antagonist prescription. GnRH antagonist seems to have a better CV risk profile than GnRH agonist, both in patients with and without a history of CV events.

Cardiovascular Effects of Androgen Deprivation Therapy in Prostate Cancer: Contemporary Meta-Analyses

Androgen deprivation therapy is a cornerstone of prostate cancer treatment. Pharmacological androgen deprivation includes gonadotropin-releasing hormone agonism and antagonism, androgen receptor inhibition, and CYP17 (cytochrome P450 17A1) inhibition. Studies in the past decade have raised concerns about the potential for androgen deprivation therapy to increase the risk of adverse cardiovascular events such as myocardial infarction, stroke, and cardiovascular mortality, possibly by exacerbating cardiovascular risk factors. In this review, we summarize existing data on the cardiovascular effects of androgen deprivation therapy. Among the therapies, abiraterone stands out for increasing risk of cardiac events in meta-analyses of both randomized controlled trials and observational studies. We find a divergence between observational studies, which show consistent positive associations between androgen deprivation therapy use and cardiovascular disease, and randomized controlled trials, which do not show these associations reproducibly.

Is androgen deprivation therapy for prostate cancer associated with cardiovascular disease? A meta-analysis and systematic review

BACKGROUND

Androgen deprivation therapy (ADT) is widely being applied in men who suffered from prostate cancer. Whether androgen deprivation therapy (ADT) is associated with an increased risk of developing cardiovascular-related disease is poorly defined.

OBJECTIVES

The aim of the present meta-analysis is to explore the relationship between ADT and the risk of cardiac events. MATERIALS AND METHODS: For this systematic review and meta-analysis, we searched databases from inception to April 2019 for randomized controlled trials (RCT) or observational studies that reported data on ADT administration and cardiac event incidence. The connection was evaluated through estimating relative risk ratio (RR) and 95% confidence intervals (CIs).

RESULTS

A significantly increased acute myocardial infarction (AMI) was detected in the ADT group compared with the control group (RR = 1.19, 95% confidence interval (CI), 1.02-1.39, P < .05). A significant difference between cardiovascular disease (CVD) and ADT was also observed, with summary RR = 1.25, 95% CI, 1.11-1.40, P < .05. Furthermore, our study also suggested ADT was not related to increased incidence of sudden cardiac death (SCD) (RR = 1.13, 95% CI, 0.92-1.38, P = .24); AMI and CVD were not connected with the duration of ADT (AMI: RR = 1.31; 95% CI, 0.66-2.63, P = .44, for > 5 year group; CVD: RR = 1.12, 95% CI, 0.97-1.30, P = .12, for > 5 year group). In addition, the RR for risk of CVD was 1.28 (95% CI, 1.01-1.62, P < .05) for men with PCa on new hormonal agents.

DISCUSSION

Various ADT modalities have different impact on cardiovascular disease risk in different level. Long-term application of ADT is not associated with increased risk of AMI and CVD. Both abiraterone and enzalutamide could significantly increase the incidence of cardiac events in patients who suffered from prostate cancer. Cautions and periodic cardiovascular elevation are necessary for patients before the ADT starting.

CONCLUSIONS

Androgen deprivation therapy is associated with increased risk of AMI, CHD, in contrast, this association is not detected in SCD.

Neuropeptide and steroid hormone mediators of neuroendocrine regulation

To maintain the health and well-being of all mammals, numerous aspects of physiology are controlled by neuroendocrine mechanisms. These mechanisms ultimately enable communication between neurones and glands throughout the body and are centrally mediated by neuropeptides and/or steroid hormones. A recent session at the International Workshop in Neuroendocrinology highlighted the essential roles of some of these neuropeptide and steroid hormone mediators in the neuroendocrine regulation of stress-, reproduction- and behaviour-related processes. Accordingly, the present review highlights topics presented in this session, including the role of the neuropeptides corticotrophin-releasing factor and gonadotrophin-releasing hormone in stress and reproductive physiology, respectively. Additionally, it details an important role for gonadal sex steroids in the development of behavioural sex preference.

Androgen Deprivation Therapy Is Associated With Prolongation of QTc Interval in Men With Prostate Cancer

CONTEXT

Androgen deprivation therapy (ADT) for prostate cancer (PCa) is associated with increased cardiovascular mortality and sudden cardiac death, with some events occurring early after initiation of ADT. Testosterone levels are inversely associated with corrected QT (QTc) interval duration; therefore, prolongation of QTc duration could be responsible for some of these events during ADT.

OBJECTIVE

To evaluate changes in QTc duration during ADT.

DESIGN AND INTERVENTIONS

A 6-month prospective cohort study that enrolled men with PCa about to undergo ADT (ADT group) and a control group of men who previously underwent prostatectomy for PCa and never received ADT (non-ADT group).

PATIENTS

At study entry, all participants were eugonadal and had no history of cardiac arrhythmias or complete bundle branch block.

OUTCOMES

Difference in change in QTc duration from baseline on a 12-lead electrocardiogram at 6, 12, and 24 weeks after initiation of ADT compared with electrocardiograms performed at the same intervals in the non-ADT group. PR, QRS, and QT interval durations were also evaluated.

RESULTS

Seventy-one participants formed the analytical sample (33 ADT and 38 non-ADT). ADT was associated with prolongation of the QTc by 7.4 ms compared with the non-ADT group [95% confidence interval (CI) 0.08 to 14.7 ms; P = 0.048]. ADT was also associated with shortening of the QRS interval by 2.4 ms (95% CI -4.64 to -0.23; P = 0.031). Electrolytes did not change.

CONCLUSIONS

Men undergoing ADT for PCa experienced prolongation of the QTc. These findings might explain the increased risk of sudden cardiac death seen in these patients.

Metabolic changes in patients with prostate cancer during androgen deprivation therapy

Androgen deprivation therapy continues to be widely used for the treatment of prostate cancer despite the appearance of new-generation androgen-receptor targeting drugs after 2000. Androgen deprivation therapy can alleviate symptoms in patients with metastatic prostate cancer and might have a survival benefit in some patients, but it causes undesirable changes in lipid, glucose, muscle or bone metabolism. These metabolic changes could lead to new onset or worsening of diseases, such as obesity, metabolic syndrome, diabetes mellitus, cardiovascular disease, sarcopenia or fracture. Several studies examining the influence of androgen deprivation therapy in Japanese patients with prostate cancer also showed that metabolic changes, such as weight gain, dyslipidemia or fat accumulation, can occur as in patients in Western countries. Efforts to decrease these unfavorable changes and events are important. First, overuse of androgen deprivation therapy for localized or elderly prostate cancer patients should be reconsidered. Second, intermittent androgen deprivation therapy might be beneficial for selected patients who suffer from impaired quality of life as a result of continuous androgen deprivation therapy. Third, education and instruction, such as diet or exercise, to decrease metabolic changes before initiating androgen deprivation therapy is important, because metabolic changes are likely to occur in the early androgen deprivation therapy period. Fourth, routine monitoring of weight, laboratory data or bone mineral density during androgen deprivation therapy are required to avoid unfavorable events.

[Cardiovascular risk patients under androgen deprivation therapy: Lower risk with GnRH antagonists compared to LHRH agonists?]

BACKGROUND

Androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) agonists or GnRH antagonists is the mainstay of treatment for metastatic prostate cancer (mCaP). However, ADT is associated with serious cardiovascular events. Only a few studies that directly compare the cardiovascular risk of LHRH agonists versus GnRH antagonists have been published.

OBJECTIVES

This review aims to compare the cardiovascular risk of LHRH agonists versus GnRH antagonists based on the literature.

METHODS

A literature search that considered full publications and abstracts published before December 10, 2014 was performed. Due to their high evidence quality, only meta-analyses and pooled studies were included in this review.

RESULTS

Four studies were included. These investigated the cardiovascular risk of patients receiving an ADT with LHRH agonists and/or GnRH antagonists. However, only one of these directly compared the cardiovascular risk of ADT with LHRH agonists versus GnRH antagonists. This meta-analysis showed a significant reduction in cardiovascular risk for patients receiving a GnRH antagonist compared to those patients receiving a LHRH agonist (HR: 0.597; 95 % CI: 0.380-0.938; P = 0.0253). Subgroup analyses showed that, in particular, patients with pre-existing cardiovascular diseases who were treated with a GnRH antagonist have a significantly lower risk of experiencing a cardiovascular event when compared with patients receiving a GnRH agonist (HR: 0.44; 95 % CI: 0.26-0.74; P = 0.002).

CONCLUSION

In conclusion, GnRH antagonists are associated with a lower risk of cardiovascular events, compared with LHRH agonists, when administered as ADT in CaP patients, and particularly in patients with a history of cardiovascular disease. Thus, patients with a history of cardiovascular disease may benefit from ADT with a GnRH antagonist.

Cognitive, Emotional, and Psychosocial Functioning of Girls Treated with Pharmacological Puberty Blockage for Idiopathic Central Precocious Puberty

Central precocious puberty (CPP) develops due to premature activation of the hypothalamic-pituitary-gonadal (HPG) axis, resulting in early pubertal changes and rapid bone maturation. CPP is associated with lower adult height and increased risk for development of psychological problems. Standard treatment of CPP is based on postponement of pubertal development by blockade of the HPG axis with gonadotropin releasing hormone analogs (GnRHa) leading to abolition of gonadal sex hormones synthesis. Whereas the hormonal and auxological effects of GnRHa are well-researched, there is a lack of knowledge whether GnRHa treatment influences psychological functioning of treated children, despite the fact that prevention of psychological problems is used as one of the main reasons for treatment initiation. In the present study we seek to address this issue by exploring differences in cognitive function, behavior, emotional reactivity, and psychosocial problems between GnRHa treated CPP girls and age-matched controls. Fifteen girls with idiopathic CPP; median age 10.4 years, treated with slow-release GnRHa (triptorelin acetate-Decapeptyl SR® 11.25) and 15 age-matched controls, were assessed with a comprehensive test battery consisting of paper and pencil tests, computerized tasks, behavioral paradigms, heart rate variability, and questionnaires filled in by the children's parents. Both groups showed very similar scores with regard to cognitive performance, behavioral and psychosocial problems. Compared to controls, treated girls displayed significantly higher emotional reactivity (p = 0.016; Cohen's d = 1.04) on one of the two emotional reactivity task conditions. Unexpectedly, the CPP group showed significantly lower resting heart rates than the controls (p = 0.004; Cohen's d = 1.03); lower heart rate was associated with longer treatment duration (r = -0.582, p = 0.037). The results suggest that GnRHa treated CPP girls do not differ in their cognitive or psychosocial functioning from age matched controls. However, they might process emotional stimuli differently. The unexpected finding of lower heart rate that was associated with longer duration of the treatment should be further explored by methods appropriate for assessment of cardiac health.

Cardiovascular risk after androgen deprivation therapy for prostate cancer: an Asian perspective

Androgen deprivation therapy (ADT) plays an important role in managing prostate cancer. However, ADT may result in major cardiovascular events and potentially lead to fatal consequences. Cardiovascular disease is the leading cause of mortality and it is a very important health condition to look into. Asians and Caucasians differ both physiologically and genetically, and they may have display different cardiovascular profiles. In this article, we reviewed the literature focusing on the cardiovascular risk after ADT for prostate cancer in the Asian population. We would discuss about the pathogenesis of ADT leading to cardiovascular events, summarize the findings concerning cardiac and stroke risks after ADT, compare between the different modalities of ADT and also provide genetic basics which are unique to Asians. We hope this article would provide more insights into the cardiovascular risk after ADT for prostate cancer in an Asian perspective.

Mortality, cardiovascular risk, and androgen deprivation therapy for prostate cancer: A systematic review with direct and network meta-analyses of randomized controlled trials and observational studies

Androgen deprivation therapy (ADT) is a cornerstone therapy for advanced prostate cancer (PCa). We hypothesized that cardiovascular (CV) risk is different across the various ADT modalities to compare their effects on CV morbidity and mortality, and all-cause mortality in patients with PCa. To investigate more in depth potential CV risk heterogeneity focusing on coronary (main outcome) and cerebrovascular risk, CV, and overall mortality. We performed a Medline and Embase query, without language restriction, since 1950 up to July 2014. We included randomized controlled trials (RCTs) and observational studies providing that they compared at least 1 ADT modality to another one or to placebo and they gave data on CV event or all-cause mortality. Sixty-eight studies out of 3419 met our eligibility criteria. Eleven observational studies were analyzed. Direct meta-analyses showed that antiandrogen was associated with a 30% decrease risk for myocardial infarction (MI) compared to GnRH agonists (RR, 0.70 [0.54-0.91]); combined androgen blockade (CAB) was associated with a 10% increase risk for stroke when compared to antiandrogen (RR, 1.10 [1.02-1.19]). With regard to RCTs, 57 were included: direct meta-analyses suggested that CAB was associated with a 10% decrease of all-cause mortality when compared to GnRH agonist (RR, 0.90 [0.82-1.00]). Network analysis could only be performed for all-cause mortality and it remains difficult to disentangle benefit (positive impact on cancer survival) and risk (including CV risk). The impact of the ADT modalities on CV morbidity remains difficult to quantify and more detailed prospective collection is required.

REGISTRATION

PROSPERO, CRD42014010598.

[Cardiovascular risk of androgen deprivation therapy for treatment of hormone-dependent prostate cancer : Differences between GnRH antagonists and GnRH agonists]

BACKGROUND

Several studies have indicated that reduction of testosterone levels in patients with prostate cancer undergoing androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) agonists can be associated with an increased risk of cardiovascular events. The GnRH antagonists have a different mode of action compared with GnRH agonists and may be preferred in ADT for patients with cardiovascular disease.

OBJECTIVE

This review article discusses potential mechanisms underlying the development of cardiovascular events associated with ADT when using GnRH agonists and explains the differences in mode of action between GnRH agonists and GnRH antagonists. Additionally, relevant studies are presented and practical recommendations for the clinical practice are provided.

MATERIAL AND METHODS

A literature search was performed. Full publications and abstracts published in the last 10 years up to September 2015 were considered to be eligible.

RESULTS

The GnRH antagonists were associated with a decreased risk of cardiovascular events compared with GnRH agonists in prostate cancer patients undergoing ADT and particularly in patients with cardiovascular risk factors or a history of cardiovascular disease. This decrease may be due to the different mode of action of GnRH antagonists compared with GnRH agonists.

CONCLUSION

Prostate cancer patients with either cardiovascular disease or an increased risk of experiencing a cardiovascular event undergoing ADT should be preferentially treated with GnRH antagonists.

Cardiovascular mortality in patients with prostate cancer exposed to androgen deprivation therapy

INTRODUCTION

A relationship between the administration of GnRH agonists and the risk of acute myocardial infarction (AMC) in patients with prostate cancer has been showed in the third observational study published in April 2014. The association AMC-orchiectomy was not found in any of these studies.

OBJECTIVE

Define risk factors for cardiovascular disease in patients treated with GnRH agonist. Their probable underlying pathogenic mechanism in the myocardium and peripheral vascular tree was also analyzed.

EVIDENCE ACQUISITION

English articles cited in PubMed were reviewed. No time period is specified. The last search date was 11/30/14.

EVIDENCE SYNTHESIS

In patients with coronary history of AMC or congestive heart failure, hormonal neoadjuvant therapy increased cardiovascular mortality rates (HR: 1.96, IC 95%: 1.04-3.71; P=.04) as well as cardiovascular-specific mortality rates (AHR: 3.28; IC 95%: 1.01-10.64; P=.048). Two possible mechanisms can be involved: a) direct mechanism through myocardial receptor for GnRH/PKA along with atherogenic plaques; and b) indirect mechanism related with metabolic disturbances.

CONCLUSIONS

Patients with AMC or congestive heart failure history could present a higher risk of death related to the use of GnRH agonists. In these cases, should carefully consider appropriateness of such treatment. These effects can explained by a direct mechanism on myocardium and peripheral vascular tree and indirect ones related with modified metabolic syndrome.

Cardiovascular risk with androgen deprivation therapy for prostate cancer: potential mechanisms

Androgen deprivation therapy (ADT) is frequently used for the treatment of advanced prostate cancer. ADT is associated with numerous side effects related to its mode of action, namely the suppression of testosterone to castrate levels. Recently, several large retrospective studies have also reported an increased risk of diabetes and cardiovascular disease in men receiving ADT, although these risks have not been confirmed by prospective randomized trials. We review the literature to consider the risk of cardiovascular disease with different forms of ADT and examine in detail potential mechanisms by which any such risk could be mediated. Mechanisms discussed include the metabolic syndrome resulting from low testosterone level and the potential roles of testosterone flare, gonadotropin-releasing hormone receptors outside the pituitary gland, and altered levels of follicle-stimulating hormone. Finally, the clinical implications for men prescribed ADT for the treatment of advanced prostate cancer are considered.

Risk of acute myocardial infarction after androgen-deprivation therapy for prostate cancer in a Chinese population

OBJECTIVE

To investigate the risk of acute myocardial infarction (AMI) after androgen-deprivation therapy (ADT) for prostate cancer in a Chinese population.

PATIENTS AND METHODS

All Chinese patients with prostate cancer who were treated primarily with radical prostatectomy or radiotherapy, with or without further ADT at our hospital from the year 2000 to 2009 were retrospectively reviewed. We compared the risk of AMI in the patients who were given further ADT (ADT group) with those who were not given any ADT (non-ADT group). Potential risk factors of AMI including age, diabetes mellitus, hypertension, hyperlipidaemia, history of stroke, ischaemic heart disease, Eastern Cooperative Oncology Group Performance Status (ECOG PS) and duration of ADT were reviewed. The risk of AMI after ADT was first analysed using the Kaplan-Meier method, followed by Cox regression analyses including the potential risk factors mentioned.

RESULTS

In all, 452 patients were included, with 200 patients in the non-ADT group and 252 patients in the ADT group. The mean (sd) age was 68.2 (5.9) years in the non-ADT group and 69.5 (6.5) years in the ADT group, and the difference was statistically significant (P = 0.031). There were no significant differences in their pre-existing medical conditions or ECOG PS. The ADT group was associated with an increased risk of AMI when compared with the non-ADT group (P = 0.004) upon Kaplan-Meier analysis. Upon multivariate Cox regression analysis, hyperlipidaemia, poor ECOG PS and the use of ADT were the only three significant factors that were associated with increased risk of developing new AMI.

CONCLUSIONS

There was increased risk of AMI after ADT for prostate cancer in a Chinese population. Hyperlipidaemia and poor ECOG PS were also significant risk factors for developing AMI. The risk of AMI should be considered when deciding on ADT, especially in patients with history of hyperlipidaemia and relatively poor ECOG PS.

Identification of microRNA-mRNA dysregulations in paroxysmal atrial fibrillation

BACKGROUND

The molecular mechanisms underlying the early development of atrial fibrillation (AF) remain poorly understood. Emerging evidence suggests that abnormal epigenetic modulation via microRNAs (miRNAs) might be involved in the pathogenesis of paroxysmal AF (pAF).

OBJECTIVE

To identify key molecular changes associated with pAF, we conducted state-of-the-art transcriptomic studies to identify the abnormal miRNA-mRNA interactions potentially driving AF development.

METHODS

High-quality total RNA including miRNA was isolated from atrial biopsies of age-matched and sex-matched pAF patients and control patients in sinus rhythm (SR; n=4 per group) and used for RNA-sequencing and miRNA microarray. Results were analyzed bioinformatically and validated using quantitative real-time (qRT)-PCR and 3'UTR luciferase reporter assays.

RESULTS

113 genes and 49 miRNAs were differentially expressed (DE) in pAF versus SR patients. Gene ontology analysis revealed that most of the DE genes were involved in the "gonadotropin releasing hormone receptor pathway" and "p53 pathway". Of these DE genes, bioinformatic analyses identified 23 pairs of putative miRNA-mRNA interactions that were altered in pAF (involving 15 miRNAs and 17 mRNAs). Using qRT-PCR and 3'UTR luciferase reporter assays, the interaction between upregulation of miR-199a-5p and downregulation of FKBP5 was confirmed in samples from pAF patients.

CONCLUSION

Our combined transcriptomic analysis and miRNA microarray study of atrial samples from pAF patients revealed novel pathways and miRNA-mRNA regulations that may be relevant in the development of pAF. Future studies are required to investigate the potential involvement of the gonadotropin releasing hormone receptor and p53 pathways in AF pathogenesis.

Radiosynthesis of high affinity fluorine-18 labeled GnRH peptide analogues: in vitro studies and in vivo assessment of brain uptake in rats

A series of high affinity ¹⁸F-GnRH peptides have been synthesized and show utility as imaging agents for GnRH receptor expression in vivo.

Quantifying observational evidence for risk of fatal and nonfatal cardiovascular disease following androgen deprivation therapy for prostate cancer: a meta-analysis

CONTEXT

Whether androgen deprivation therapy (ADT) for men with prostate cancer (PCa) increases the risk of cardiovascular disease (CVD) remains controversial. Pooled analyses using data from randomised controlled trials suggest no increased risk of fatal CVD following ADT, but no pooled analyses exist for observational studies.

OBJECTIVE

To perform a meta-analysis using observational data on ADT and risk of CVD events in men with PCa.

EVIDENCE ACQUISITION

PubMed and Embase were searched using predefined inclusion criteria to perform meta-analyses on associations between types of ADT and nonfatal and fatal CVD outcomes using information from observational studies. Random effects meta-analyses were conducted to estimate relative risks (RRs) and 95% confidence intervals (CIs).

EVIDENCE SYNTHESIS

A total of eight observational studies were identified studying at least one type of ADT and a nonfatal or fatal CVD outcome. The RR for risk of any type of nonfatal CVD was 1.38 (95% CI, 1.29-1.48) for men with PCa on gonadotropin-releasing hormone (GnRH) agonists, compared with men not treated with ADT. When analysing nonfatal ischemic heart disease only, the RR was 1.39 (95% CI, 1.26-1.54). The associations between GnRH agonists and nonfatal or fatal myocardial infarction or stroke were even stronger: RR: 1.57 (95% CI, 1.26-1.94) and RR: 1.51 (95% CI, 1.24-1.84), respectively. The results for other types of ADT in relation to the risk of any nonfatal CVD were RR: 1.44 (95% CI, 1.28-1.62) for orchiectomy and RR: 1.21 (95% CI, 1.07-1.367) for antiandrogens.

CONCLUSIONS

Observational data show a consistent positive association between ADT and the risk of CVD. This finding supports the need for future randomised trials of PCa patients that include older patients and men with multiple comorbidities to better reflect the general population.

PATIENT SUMMARY

We investigated all the available data from observational studies on hormonal treatment for prostate cancer and its possible cardiovascular adverse effects. We found consistent evidence that this treatment may increase the risk of cardiovascular disease.

The effects of androgen deprivation therapy on cardiac function and heart failure: implications for management of prostate cancer

Conflicting clinical evidence regarding the possible association between androgen deprivation therapy (ADT) with heart failure in men with prostate cancer is reviewed, including 2 population-based registries showing such an association, and 1 showing no association. Studies of the effects of androgens on cardiomyocyte contractility at the molecular level, the effects of testosterone on the cardiovascular system, particularly cardiac function, and the beneficial effects of testosterone therapy for patients with heart failure might help illuminate this controversy. Future studies are needed to evaluate the effect of ADT on end points of heart failure. The authors weigh the possible adverse effects of ADT on cardiac function and heart failure against its known benefits to cancer outcomes, defined according to published, randomized trials, in a discussion of the implications of the preclinical and clinical literature on the management of prostate cancer in men at risk for heart failure. In the absence of conclusive evidence that ADT causes heart failure, the authors discuss clinical situations in which ADT may be delayed, given on a short-term or intermittent basis, or withheld from treatment with the goal of reducing the risks of heart failure without compromising prostate cancer outcomes.

Effects of inhibition of gonadotropin releasing hormone secretion on the response to novel objects in young male and female sheep

This study investigated the actions of blocking the GnRH receptor using a specific agonist on the response of male and female sheep to a novel object placed in their pen. The study is part of a series performed on 46 same sex twin animals. One of the pair received a subcutaneous implant of the GnRH agonist Goserelin acetate every four weeks while the other remained untreated. Implantation began immediately prior to puberty; at 8 weeks in the males and 28 weeks in the females (as timing of puberty is sex specific). To determine the effects of agonist treatment on the reproductive axis blood samples were collected for measurement of testosterone in the males and progesterone in the females. In addition the volume of the scrotum was determined. The present study aimed to determine whether there are sexually differentiated behavioural responses to a novel object at different stages of brain development (8, 28 and 48 weeks of age) and whether these responses are altered by GnRHa treatment. Approach behaviour towards and interactions with the novel object were monitored as was the number of vocalisations per unit time during the test period. GnRHa treatment suppressed testosterone concentrations and testicular growth in the males and progesterone release in the females. Sheep vocalised significantly more prior to weaning (8 weeks of age) than post weaning (28 and 48 weeks of age) suggesting stress on separation from their dams. Our current study shows that males are more likely to leave their conspecifics to approach a novel object than females. As this behaviour was not altered by suppression of the reproductive axis we suggest that, although sex differences are more obviously expressed in the phenotype after puberty, these may be developed during adolescence but not primarily altered during puberty by sex hormones.

Peri-pubertal gonadotropin-releasing hormone agonist treatment affects sex biased gene expression of amygdala in sheep

The nature of hormonal involvement in pubertal brain development has attracted wide interest. Structural changes within the brain that occur during pubertal development appear mainly in regions closely linked with emotion, motivation and cognitive functions. Using a sheep model, we have previously shown that peri-pubertal pharmacological blockade of gonadotropin releasing hormone (GnRH) receptors, results in exaggerated sex-differences in cognitive executive function and emotional control, as well as sex and hemisphere specific patterns of expression of hippocampal genes associated with synaptic plasticity and endocrine signaling. In this study, we explored effects of this treatment regime on the gene expression profile of the ovine amygdala. The study was conducted with 30 same-sex twin lambs (14 female and 16 male), half of which were treated with the GnRH agonist (GnRHa) goserelin acetate every 4th week, beginning before puberty, until approximately 50 weeks of age. Gene expression profiles of the left and right amygdala were measured using 8×15 K Agilent ovine microarrays. Differential expression of selected genes was confirmed by qRT-PCR (Quantitative real time PCR). Networking analyses and Gene Ontology (GO) Term analyses were performed with Ingenuity Pathway Analysis (IPA), version 7.5 and DAVID (Database for Annotation, Visualization and integrated Discovery) version 6.7 software packages, respectively. GnRHa treatment was associated with significant sex- and hemisphere-specific differential patterns of gene expression. GnRHa treatment was associated with differential expression of 432 (|logFC|>0.3, adj. p value <0.05) and 46 (p value <0.0.5) genes in the left and right amygdala, respectively, of female animals, relative to the reference sample which consisted of all a pooled sample from control and treated animals of both sexes. No genes were found to be differentially expressed as a result of GnRHa treatment in the male animals. The results indicated that GnRH may, directly and/or indirectly, be involved in the regulation of sex- and hemisphere-specific differential expression of genes in the amygdala. This finding should be considered when long-term peri-pubertal GnRHa treatment is used in children.

Characterization of the gonadotropin releasing hormone receptor (GnRHR) expression and activity in the female mouse ovary

GnRH agonists (GnRHa) are increasingly used for fertility preservation in women undergoing gonadotoxic chemotherapy. However, the protective mechanisms of action for these compounds have not yet been elucidated. In this study, we aimed to determine whether GnRHa have a direct effect on ovarian granulosa cells. GnRH receptor (GnRHR) expression was determined in mouse somatic and gonadal tissues including granulosa/cumulus cells and oocytes using quantitative RT-PCR and immunohistochemistry. Granulosa cells were isolated from mouse ovaries primed with pregnant mare serum gonadotropin. Response to GnRHa in cultured granulosa cells was assessed by determining the increase of intracellular cAMP and by assessing phosphorylation of downstream mediators of GnRH signaling: ERK and p38. To measure intracellular cAMP in our system, the cells were transfected with a cAMP-responsive luciferase reporter plasmid and stimulated with GnRHa. For all experiments, pituitary tissue and/or the αT3-1 mouse pituitary cell line were used as controls. GnRHR mRNA and protein were detected in mouse ovaries, granulosa/cumulus cells, and oocytes. After GnRHa stimulation at various time intervals, we were unable to detect a cAMP increase or activation of the ERK or p38 signaling pathway in cultured primary mouse granulosa cells, whereas activation was detected in the control αT3-1 mouse pituitary cells. In this study, we have not detected activation of the canonical GnRH signaling pathways in mouse ovarian somatic cells. Our findings suggest that the mechanism of action of GnRHa in the ovary is either below the detection level of our experimental design or is different from that in the pituitary.

Androgens and prostate cancer; pathogenesis and deprivation therapy

Although androgen receptor signaling is critical for prostate cancer growth and survival, evidence supporting a favorable risk-benefit ratio of androgen deprivation therapy (ADT) is currently limited to men with high-risk or metastatic disease. This is in part because ADT has been associated with a number of constitutional and somatic side effects, consistent with the widespread tissue expression of sex steroid receptors. ADT is the most common contemporary cause of severe hypogonadism, and men receiving this therapy represent a unique model of severe sex steroid deficiency with a defined time of onset. This review will present an update on the role of ADT in the treatment of prostate cancer, will summarize recent evidence regarding ADT-associated adverse effects with particular emphasis on cardiometabolic and musculoskeletal health, and will provide recommendations for further research.

Androgen-deprivation therapy in treatment of prostate cancer and risk of myocardial infarction and stroke: a nationwide Danish population-based cohort study

BACKGROUND

Androgen-deprivation therapy (ADT) has been suggested to increase the risk for cardiovascular diseases, including myocardial infarction (MI) and stroke, but data are inconsistent.

OBJECTIVES

To investigate the association between ADT and risk for MI and stroke in Danish men with prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

A national cohort study of all patients with incident prostate cancer registered in the Danish Cancer Registry from January 1, 2002, through 2010 was conducted.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used Cox regression analysis to estimate hazard ratios (HR) of MI and stroke for ADT users versus nonusers, adjusting for age, prostate cancer stage, comorbidity, and calendar period. Additionally, we stratified the analysis on preexisting MI/stroke status.

RESULTS AND LIMITATIONS

Of 31,571 prostate cancer patients, 9204 (29%) received medical endocrine therapy and 2060 (7%) were orchidectomized. Patients treated with medical endocrine therapy had an increased risk for MI and stroke with adjusted HRs of 1.31 (95% confidence interval [CI], 1.16-1.49) and 1.19 (95% CI, 1.06-1.35), respectively, compared with nonusers of ADT. We found no increased risk for MI (HR: 0.90; 95% CI, 0.83-1.29) or stroke (HR: 1.11; 95% CI, 0.90-1.36) after orchiectomy. One limitation of the study is that information on prognostic lifestyle factors was not included and might have further informed our estimates.

CONCLUSIONS

In this nationwide cohort study of >30 000 prostate cancer patients, we found that endocrine hormonal therapy was associated with increased risk for MI and stroke. In contrast, we did not find this association after orchiectomy.

Morphological and enzymatic changes caused by a long-term treatment of female rats with a low dose of gonadoliberin agonist and antagonist

Background

Long-term treatment with gonadoliberin analogs is used to block the hypothalamic-pituitary-gonadal axis. The use of these agents is generally considered to be safe; however, some observations suggest the possibility of adverse effects.

Material/Methods

We investigated whether a 3-months administration of a low dose (6 μg/kg b.w.) of dalarelin – a new agonist, and cetrorelix – a known antagonist of GnRH to female rats causes morphological changes in pituitary gland, ovaries, uterus and liver (HE and VG staining); effects on pituitary, hepatic and blood enzyme activities (histochemical and kinetic methods, respectively), and on the blood lipid profile (colorimetric methods); and to what extent these changes are reversible.

Results

Applying analogs effectively inhibited ovulation, affected the uterine endometrium and changed histological appearance of the liver (e.g., steatosis). They altered activities of marker enzymes of cellular respiration, gluconeogenesis and intracellular digestion in the liver and, partially in the pituitary gland, caused undesirable changes in the activities of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and creatine kinase, and a concentration of cholesterol HDL fraction and triglycerides in the blood. Both morphological and enzymatic effects were more evident after antagonist administration; changes in the blood lipid profile were more evident after agonist administration. In both analogs histological and enzymatic changes persisted a relatively long time after the discontinuation of the treatment.

Conclusions

The low dose of dalarelin and cetrorelix is sufficient to cause limited damage of hepatic cells and may modify the function of pituitary, ovaries, uterus and liver as well as other organs, even after discontinuation of the treatment.

The cardiovascular risk of gonadotropin releasing hormone agonists in men with prostate cancer: an unresolved controversy

Gonadotropin-releasing hormone agonists (GnRH) play an important role in the treatment of prostate cancer, improving significantly overall survival. GnRH agonists belong to androgen deprivation therapy (ADT) together with surgical castration and, recently, GnRH antagonists. ADT has several side effects, such as sexual dysfunction and osteoporosis. Recently, changes in body composition, obesity, insulin resistance, hyperglycemia, dyslipidemia, and hypertension have emerged as complications of ADT, perhaps responsible for cardiovascular events, but discussion is still open. Since the majority of men with prostate cancer die of conditions other than their malignancy, recognition of these adverse effects is important. This review serves to focus attention on the pathogenetic mechanisms of ADT-related cardiovascular toxicity with also reference to the possible direct role of GnRH agonist on the cardiac receptors. Furthermore, this paper would generate recommendations for the management of patients treated with GnRH agonists balancing the potential benefits against the possible risks in prostate cancer men.

The extrapituitary effects of GnRH antagonists and their potential clinical implications: a narrated review

Potential roles of gonadotropin-releasing hormone (GnRH) antagonists on GnRH/GnRH receptor systems and their effects on the extrapituitary tissues are largely elusive. In this narrated review, we summarized the systemic effects of GnRH antagonists on ovary, endometrium, embryo implantation, placental development, fetal teratogenicity, reproductive tissue cancer cells, and heart while briefly reviewing the GnRH and GnRH receptor system. GnRH antagonists may have direct effects on ovarian granulosa cells. Data are conflicting regarding their effects on endometrial receptivity. The GnRH antagonists may potentially have detrimental effect on early placentation by decreasing the invasive ability of cytotrophoblasts if the exposure to them occurs during early pregnancy. The GnRH antagonists were not found to increase the rates of congenital malformations. Comparative clinical data are required to explore their systemic effects on various extrapituitary tissues such as on cardiac function in the long term as well as their potential use in other human cancers that express GnRH receptors.

Binding site of activators of the cystic fibrosis transmembrane conductance regulator in the nucleotide binding domains

The use of substances that could activate the defective chloride channels of the mutant cystic fibrosis transmembrane conductance regulator (CFTR) has been suggested as possible therapy for cystic fibrosis. Using epithelia formed by cells stably transfected with wildtype or mutant (G551D, G1349D) CFTR, we estimated the apparent dissociation constant, K(D), of a series of CFTR activators by measuring the increase in the apical membrane current. Modification of apparent K(D) of CFTR activators by mutations of the nucleotide-binding domains (NBDs) suggests that the binding site might be in these regions. The human NBD structure was predicted by homology with murine NBD1. An NBD1-NBD2 complex was constructed by overlying monomers to a bacterial ABC transporter NBD dimer in the "head-to-tail" conformation. Binding sites for CFTR activators were predicted by molecular docking. Comparison of theoretical binding free energy estimated in the model to free energy estimated from the apparent dissociation constants, K(D), resulted in a remarkably good correlation coefficient for one of the putative binding sites, located in the interface between NBD1 and NBD2.