Troglitazone suppresses telomerase activity independently of PPARγ in estrogen-receptor negative breast cancer cells

<p>Abstract</p> <p>Background</p> <p>Breast cancer is one the highest causes of female cancer death worldwide. Many standard chemotherapeutic agents currently used to treat breast cancer are relatively non-specific and act on all rapidly dividing cells. In recent years, more specific targeted therapies have been introduced. It is known that telomerase is active in over 90% of breast cancer tumors but inactive in adjacent normal tissues. The prevalence of active telomerase in breast cancer patients makes telomerase an attractive therapeutic target. Recent evidence suggests that telomerase activity can be suppressed by peroxisome proliferator activated receptor gamma (PPARγ). However, its effect on telomerase regulation in breast cancer has not been investigated.</p> <p>Methods</p> <p>In this study, we investigated the effect of the PPARγ ligand, troglitazone, on telomerase activity in the MDA-MB-231 breast cancer cell line. Real time RT-PCR and telomerase activity assays were used to evaluate the effect of troglitazone. MDA-MB-231 cells had PPARγ expression silenced using shRNA interference.</p> <p>Results</p> <p>We demonstrated that troglitazone reduced the mRNA expression of hTERT and telomerase activity in the MDA-MB-231 breast cancer cell line. Troglitazone reduced telomerase activity even in the absence of PPARγ. In agreement with this result, we found no correlation between PPARγ and hTERT mRNA transcript levels in breast cancer patients. Statistical significance was determined using Pearson correlation and the paired Student's <it>t </it>test.</p> <p>Conclusions</p> <p>To our knowledge, this is the first time that the effect of troglitazone on telomerase activity in breast cancer cells has been investigated. Our data suggest that troglitazone may be used as an anti-telomerase agent; however, the mechanism underlying this inhibitory effect remains to be determined.</p

The structural and convergent validity of three commonly used measures of self-management in persons with neurological conditions

Purpose Self-management ability is commonly assessed in chronic disease research and clinical practice. The purpose of this study was to assess the structural and convergent validity of three commonly used self-management outcome measures in a sample of persons with neurological conditions. Methods We used data from a Canadian survey of persons with neurological conditions, which included three commonly used self-management measures: the Partners in Health Scale (PIH), the Patient Activation Measure (PAM), and the Self-Efficacy for Managing a Chronic Disease Scale (SEMCD). Confirmatory factor analysis was used to assess the structural and convergent validity of the three measures. Results When treated as single-factor constructs, none of the measurement models provided a good fit to the data. A four-domain version of the PIH was the best fitting model. Confirmatory factor analysis suggests that the three tools measure different, but correlated constructs. Conclusions While the PAM, PIH and SEMCD scales are all used as measures of patient self-management, our study indicates that they measure different, but correlated latent variables. None, when treated as single, uni-dimensional construct, provides an acceptable fit to our data. This is probably because self-management is multi-dimensional, as is consistently shown by qualitative evidence. While these measures may provide reliable summative measures, multi-dimensional scales are needed for clinical use and more detailed research on self-management

Epoxyeicosatrienoic acids and cardioprotection: The road to translation

AbstractCardiovascular disease, including acute myocardial infarction (AMI), is the leading cause of morbidity and mortality globally, despite well-established treatments. The discovery and development of novel therapeutics that prevent the progression of devastating consequences following AMI are thus important in reducing the global burden of this devastating disease. Scientific evidence for the protective effects of epoxyeicosatrienoic acids (EETs) in the cardiovascular system is rapidly emerging and suggests that promoting the effects of these cytochrome P450-derived epoxyeicosanoids is a potentially viable clinical therapeutic strategy. Through a translational lens, this review will provide insight into the potential clinical utility of this therapeutic strategy for AMI by 1) outlining the known cardioprotective effects of EETs and underlying mechanisms demonstrated in preclinical models of AMI with a particular focus on myocardial ischemia–reperfusion injury, 2) describing studies in human cohorts that demonstrate a relationship between EETs and associated pathways with coronary artery disease risk, and 3) discussing preclinical and clinical areas that require further investigation in order to increase the probability of successfully translating this rapidly emerging body of evidence into a clinically applicable therapeutic strategy for AMI