Reverse-ChIP Techniques for Identifying Locus-Specific Proteomes: A Key Tool in Unlocking the Cancer Regulome.

A phenotypic hallmark of cancer is aberrant transcriptional regulation. Transcriptional regulation is controlled by a complicated array of molecular factors, including the presence of transcription factors, the deposition of histone post-translational modifications, and long-range DNA interactions. Determining the molecular identity and function of these various factors is necessary to understand specific aspects of cancer biology and reveal potential therapeutic targets. Regulation of the genome by specific factors is typically studied using chromatin immunoprecipitation followed by sequencing (ChIP-Seq) that identifies genome-wide binding interactions through the use of factor-specific antibodies. A long-standing goal in many laboratories has been the development of a 'reverse-ChIP' approach to identify unknown binding partners at loci of interest. A variety of strategies have been employed to enable the selective biochemical purification of sequence-defined chromatin regions, including single-copy loci, and the subsequent analytical detection of associated proteins. This review covers mass spectrometry techniques that enable quantitative proteomics before providing a survey of approaches toward the development of strategies for the purification of sequence-specific chromatin as a 'reverse-ChIP' technique. A fully realized reverse-ChIP technique holds great potential for identifying cancer-specific targets and the development of personalized therapeutic regimens.

Effects of Cardiac Rehabilitation on Sleep Quality in Heart Disease Patients with and without Heart Failure.

Insomnia is a modifiable cardiovascular risk factor. Previous studies suggested that attending a cardiac rehabilitation program may improve sleep quality in cardiac patients and pointed out the association between heart failure and poor sleep quality. The primary aim of this study was to evaluate sleep quality in patients attending a Multidisciplinary Cardiac Rehabilitation Program (MRCP), and to compare sleep quality between patients with and without heart failure. A prospective observational study was carried out on a consecutive sample of 240 patients attending an 8-week MRCP; 50 patients (20.8%) were included due to heart failure (NYHA stages I-III) and the rest of them after having undergone any revascularization procedure or valvular surgery. Before and after the completion of the MRCP, the quality of sleep was assessed by the Pittsburgh Sleep Quality Index (PSQI) score. Post-intervention global PSQI scores were statistically significantly lower than those of pre-intervention (p = 0.008), but only 60 patients (25%) registered a clinically significant improvement. When comparing patients with heart failure with those without, no differences in sleep quality were found. This suggests that only a small percentage of patients can achieve clinically significant improvements in sleep quality attending conventional MCRP. Suggestions for future research are given.