Vascular endothelium function among male carriers of BRCA 1&2 germline mutation.

Background: Breast cancer susceptibility genes 1&2 (BRCA1&2) mutations hinder DNA-repair. Germline mutations in these genes are known to cause cancer; however, they may have other consequences. In this study we evaluated for the first time, the effect of the BRCA mutations on the vascular endothelium of young healthy males. Results: The study included 82 participants (53 BRCA mutation positive-carriers and 29 negative-carriers). Subjects mean age was 40. There were no significant differences in the baseline characteristics of the two groups. BRCA-carriers had significantly higher levels of EPCs (fraction of CD34+/VEGF or CD133+/VEGF positive-cells) compared to non-carriers of the mutation (median 6.78[1.96,14.48]% vs. 1.46[0.65,6.18]%, p < 0.001, and median 7.17[1.70,16.69]% vs. 1.54[0.85,5.10]%, p < 0.001, respectively). This difference remained consistent after multivariate adjustment. We did not identify differences in endothelial function, endothelial damage markers and EPCs activity between the two groups. Methods: This was a prospective cohort study to test the association between BRCA status and possible endothelial alterations. The Study population included males, 18-50 years, with no cardiovascular morbidity, who were referred for BRCA screening. We tested the endothelial system by: Endothelial progenitor cells (EPC) production, endothelial function (EndoPAT2000), endothelial damage and related hormonal levels. We stratified the cohort by germline BRCA status and compared measurements between BRCA mutation positive- and negative-carriers. Conclusions: Male BRCA1&2 mutation positive-carriers had increased level of EPCs which may reflect a subclinical accumulative endothelial damage. These novel findings suggest that the effect of mutations in BRCA is not limited to increased cancer risk, but may affect the cardiovascular system.

Cardiovascular Morbidity in a Randomized Trial Comparing GnRH Agonist and GnRH Antagonist among Patients with Advanced Prostate Cancer and Preexisting Cardiovascular Disease.

PURPOSE: Androgen deprivation therapy may increase the risk of cardiovascular disease. Limited data suggest that GnRH (gonadotropin-releasing hormone) antagonist may be associated with a lower risk of cardiovascular disease than GnRH agonist. MATERIALS AND METHODS: We performed a phase II, randomized, open label study in men with prostate cancer and preexisting cardiovascular disease who were randomized to receive GnRH agonists or antagonists for 1 year. The primary outcome was endothelial function measured by the EndoPAT 2000 device (Itamar Medical, Caesarea, Israel). The predefined secondary outcome was a new cardiovascular event. Patients were followed for the development of cardiovascular disease, defined as death, myocardial infarction, a cerebrovascular event, percutaneous angioplasty with coronary stent insertion or hospitalizations due to cardiac events. RESULTS: A total of 80 patients were enrolled in study, including 41 and 39 who received GnRH antagonist and agonist, respectively. Patients in each arm had similar baseline characteristics. We did not detect a difference in the primary end point (endothelial function) between the groups (mean ± SD reactive hyperemia index 2.07 ± 0.15 vs 1.92 ± 0.11, p=0.42). However, during the trial period a new cardiovascular event (the secondary end point) developed in 15 patients. Of cases new major cardiovascular and cerebrovascular events developed in 9, including death in 2, myocardial infarction in 1, a cerebrovascular event in 2 and percutaneous angioplasty with coronary stent insertion in 4. Of the patients 20% randomized to GnRH agonist experienced a major cardiovascular and cerebrovascular event compared to 3% of those on GnRH antagonist (p=0.013). The absolute risk reduction in major cardiovascular and cerebrovascular events at 12 months using GnRH antagonist was 18.1% (95% CI 4.6-31.2, p=0.032). CONCLUSIONS: To our knowledge this is the first prospective study to test cardiovascular outcomes among patients with prostate cancer who received androgen deprivation therapy. No differences in the primary end point were noted between the study arms. However, the secondary end point revealed that patients treated with GnRH agonist experienced significantly more major cardiovascular and cerebrovascular events than those treated with GnRH antagonist. These phase II results suggest that in patients with prostate cancer who have preexisting cardiovascular disease selecting the androgen deprivation therapy modality may differentially affect cardiac outcomes.

Single-molecule quantification of 5-hydroxymethylcytosine for diagnosis of blood and colon cancers.

BACKGROUND: The DNA modification 5-hydroxymethylcytosine (5hmC) is now referred to as the sixth base of DNA with evidence of tissue-specific patterns and correlation with gene regulation and expression. This epigenetic mark was recently reported as a potential biomarker for multiple types of cancer, but its application in the clinic is limited by the utility of recent 5hmC quantification assays. We use a recently developed, ultra-sensitive, fluorescence-based single-molecule method for global quantification of 5hmC in genomic DNA. The high sensitivity of the method gives access to precise quantification of extremely low 5hmC levels common in many cancers. METHODS: We assessed 5hmC levels in DNA extracted from a set of colon and blood cancer samples and compared 5hmC levels with healthy controls, in a single-molecule approach. RESULTS: Using our method, we observed a significantly reduced level of 5hmC in blood and colon cancers and could distinguish between colon tumor and colon tissue adjacent to the tumor based on the global levels of this molecular biomarker. CONCLUSIONS: Single-molecule detection of 5hmC allows distinguishing between malignant and healthy tissue in clinically relevant and accessible tissue such as blood and colon. The presented method outperforms current commercially available quantification kits and may potentially be developed into a widely used, 5hmC quantification assay for research and clinical diagnostics. Furthermore, using this method, we confirm that 5hmC is a good molecular biomarker for diagnosing colon and various types of blood cancer.

Overweight and CpG methylation of the Pomc promoter in offspring of high-fat-diet-fed dams are not "reprogrammed" by regular chow diet in rats.

This study aimed to determine whether epigenetic malprogramming induced by high-fat diet (HFD) has an obesogenic effect on nonmated and mated female rats and their offspring. Further, it aimed to reprogram offspring's epigenetic malprogramming and phenotype by providing normal diet after weaning. Body weight (BW) was measured, and plasma and hypothalamic arcuate nuclei were collected for analysis of hormones, mRNA, and DNA CpG methylation of the promoter of Pomc, a key factor in control of food intake. In nonmated females, HFD decreased Pomc/leptin ratio by ∼38%. This finding was associated with Pomc promoter hypermethylation. While heavier during pregnancy, during lactation HFD dams showed sharper BW decrease (2.5-fold) and loss of Pomc promoter hypermethylation. Moreover, their weight loss was correlated with demethylation (r=-0.707) and with gadd45b mRNA expression levels (r=0.905). Even though offspring of HFD dams ate standard chow from weaning, they displayed increased BW, Pomc promoter hypermethylation, and vulnerability to HFD challenge (3-fold kilocalorie intake increase). These findings demonstrate a long-term effect of maternal HFD on CpG methylation of the Pomc promoter in the offspring, which was not reprogrammed by standard chow from weaning. Further, the results suggest a possible mechanism of demethylation of the Pomc promoter following pregnancy and lactation.