Histone Methylation Marks on Circulating Nucleosomes as Novel Blood-Based Biomarker in Colorectal Cancer.

Circulating nucleic acids (CNAs) are under investigation as a liquid biopsy in cancer as potential non-invasive biomarkers, as stable structure in circulation nucleosomes could be valuable sources for detection of cancer-specific alterations in histone modifications. Our interest is in histone methylation marks with a focus on colorectal cancer, one of the leading cancers respective the incidence and mortality. Our previous work included the analysis of trimethylations of lysine 9 on histone 3 (H3K9me3) and of lysine 20 on histone 4 (H4K20me3) by chromatin immuno- precipitation-related PCR in circulating nucleosomes. Here we asked whether global immunologic measurement of histone marks in circulation could be a suitable approach to show their potential as biomarkers. In addition to H3K9me3 and H4K20me3 we also measured H3K27me3 in plasma samples from CRC patients (n = 63) and cancer free individuals (n = 40) by ELISA-based methylation assays. Our results show that of three marks, the amounts of H3K27me3 (p = 0.04) and H4K20me3 (p < 0.001) were significantly lower in CRC patients than in healthy controls. For H3K9me3 similar amounts were measured in both groups. Areas under the curve (AUC) in receiver operating characteristic (ROC) curves indicating the power of CRC detection were 0.620 for H3K27me3, 0.715 for H4K20me3 and 0.769 for the combination of both markers. In conclusion, findings of this preliminary study reveal the potential of blood-based detection of CRC by quantification of histone methylation marks and the additive effect of the marker combination.

Long-term discontinuation of warfarin in a patient with HeartMate 3 left ventricular assist device without thromboembolic events.

The gold standard therapy for end-stage heart failure is cardiac transplantation. However, in the face of a donor shortage, a mechanical assist device such as the left ventricular assist device HeartMate 3 (Abbott Laboratories, Abbott Park, IL, USA) serves as bridging therapy to transplantation and/or destination therapy. Current guidelines recommend anticoagulation with a vitamin K antagonist in combination with low-dose aspirin. We herein report a challenging anticoagulation regimen in a patient with a HeartMate 3 in whom systemic anticoagulation with warfarin was not feasible for 4 years because of low compatibility and a rare X-factor deficiency. This is a rare hematological disorder, estimated to affect approximately 1 in every 500,000 to 1,000,000 people in the general population. The patient finally received a modified anticoagulation regimen involving the combination of rivaroxaban and clopidogrel without warfarin. Under this regimen, the patient remained free of thromboembolic complications for 4 years with in situ placement of the left ventricular assist device. This case illustrates that under specific circumstances, long-term absence of warfarin therapy is feasible in patients with a HeartMate 3.

Novel serum nucleosomics biomarkers for the detection of colorectal cancer.

BACKGROUND: To improve prognosis of patients with colorectal cancer, powerful blood-based biomarkers enabling for early detection are needed. As genome-wide DNA hypomethylation is associated with carcinogenesis, and cell-free DNA, thought to be of tumor origin, is found in the circulation of patients with cancer, we investigated the relevance of 5-methylcytosine-modified DNA present in cell-free circulating nucleosomes as a serum biomarker using a convenient enzyme-linked immunosorbent assay (ELISA) technique. MATERIALS AND METHODS: Serum samples from 90 individuals [24 with colorectal cancer (CRC), 10 with benign colorectal diseases (BCD) and 56 healthy controls (HC)] were tested for the differential diagnostic performance of a novel ELISA for nucleosome-bound methylated DNA. Methodical features, including intra- and interassay imprecision, were tested using serum pools. To minimize interassay variability, values were transformed to adjusted optical densities and robust statistics were applied for clinical evaluation. Findings were later re-evaluated on a set of 113 patients (49 CRC, 26 BCD and 38 HC). RESULTS: Intra- and interassay reproducibility were 3.4% and 15.3%, respectively. Levels of circulating methylated DNA were significantly decreased in CRC and BCD when compared to HC (p<0.05), although there was no difference between BCD and CRC. For discrimination of CRC from HC, the area under the curve in receiver operating characteristic curve was 0.78 and sensitivities were 33% at 95% specificity and 75% at 70% specificity, respectively. The findings were generally confirmed when validated in the second set of patients. CONCLUSION: Reduced methylation of DNA on circulating nucleosomes detected by ELISA can potentially serve as a diagnostic tool in patients with CRC.