Blood contains cfDNA fragments derived from dying cells 1 . cfDNA has a half-life of ~15 min 2 and, therefore, represents events that occurred close to sampling time. cfDNA analysis is used for assessment of fetus chromosomal aberrations, graft rejection, monitoring tumor dynamics and targeted treatment [3][4][5][6][7] . These applications rely on genetic differences between the host and the tissue of interest. Analysis of CpG methylation in cfDNA is emerging as an alternative independent of genetic alteration 5,[8][9][10][11] . CpG methylation profiles are determined during differentiation and are stable afterwards and, thus, are highly informative about cell identity (for example, liver or lung). However, genetic and methylation-based approaches do not report on recent transcriptional events, as mutations and methylation changes occur over developmental time scales.The basic repeating unit of chromatin is the nucleosome, which is a histone-DNA complex encompassing ~150 base pairs (bp) of DNA 12 . Histone proteins are subject to multiple covalent modifications, which are involved in nearly all aspects of messenger RNA (mRNA) biogenesis [13][14][15][16] . Histone modification patterns reflect recent events related to chromatin regulation and activity of RNA polymerase 13,15 , and different combinations of such modifications mark the location and activity of non-coding regions, enhancers, promoters and gene bodies [17][18][19][20][21][22] . Chromatin immunoprecipitation and sequencing (ChIP-seq) enables genome-wide mapping of histone modifications and provides detailed understanding of the regulatory activity within cells [17][18][19][23][24][25][26][27] .Upon cell death, the genome is fragmented, and chromatin, mostly in the form of nucleosomes, is released into the circulation as cell-free nucleosomes (cf-nucleosomes) 28-30 that retain some histone modifications [31][32][33] . We reasoned that capturing and DNA sequencing of modified nucleosomes from plasma might inform on DNA-related activities, including transcription, within the cells of origin (Fig. 1a). This currently inaccessible epigenetic information extends beyond cfDNA modalities examined to date [4][5][6][7][8][9][10][11][34][35][36][37][38][39][40][41][42][43] .In this study, we performed chromatin immunoprecipitation and sequencing of cell-free nucleosomes directly from human plasma (cfChIP-seq). We show that cfChIP-seq recapitulates the original genomic distribution of modifications associated with transcriptionally active promoters, enhancers and gene bodies, demonstrating that plasma nucleosomes retain the epigenetic information of their
Bevacizumab treatment is associated with an increased risk of hypertension (HTN), a potential marker for effectiveness. We aimed to assess whether grades 2-3 HTN during bevacizumab treatment was associated with increased overall survival (OS) or progression-free survival (PFS). One hundred and eighty-one patients with metastatic colorectal cancer (CRC), who were treated in our Department from January 2009-February 2011 were included. Bevacizumab was administered jointly with standard first- or second-line chemotherapy protocols. Blood pressure was measured before each treatment. HTN was graded using common toxicity criteria. There were 181 CRC patients. Grades 2-3 HTN developed in 81 patients (44.75 %) but not in 100 patients (55.25 %); no patient developed grades 4-5 HTN. Median follow-up was 15.2 months. HTN was associated with better OS in HTN-positive versus HTN-negative patients (median not reached vs. 36.8 months, p = 0.029) and better PFS (29.9 vs. 17.2 months, p = 0.024, respectively). Bevacizumab-related HTN may represent a biomarker for clinical benefit in metastatic colorectal cancer patients.
Unreamed humeral nailing of the pathological humeral shaft fractures provides immediate stability and pain relief, minimum morbidity and early return of function to the extremity.
The analysis of cell-free DNA (cfDNA) in plasma represents a rapidly advancing field in medicine, providing information on pathological processes in the body. Blood cfDNA is in the form of nucleosomes, which maintain their tissue-and cancer-specific epigenetic state. We developed EPINUC, a single-molecule multi-parametric assay to comprehensively profile the Epigenetics of Plasma Isolated Nucleosomes, DNA methylation and cancer-specific protein biomarkers. Our system allows high-resolution detection of six active and repressive histone modifications, their ratios and combinatorial patterns, on millions of individual nucleosomes by single-molecule imaging. In addition, it provides sensitive and quantitative data on plasma proteins, including detection of nonsecreted tumor-specific proteins such as mutant p53. Applying this analysis to a cohort of plasma samples detected colorectal cancer at high accuracy and sensitivity, even at early stages. Finally, combining EPINUC with direct single-molecule DNA sequencing revealed the tissue-of-origin of colorectal, pancreatic, lung and breast tumors. EPINUC provides multi-layered clinical-relevant information from limited liquid biopsy material, establishing a novel approach for cancer diagnostics.
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