The neuregulin-1 (NRG-1)/receptor tyrosine-protein kinase erbB (ErbB) system is an endothelium-controlled paracrine system modulating cardiac performance and adaptation. Recent studies have indicated that NRG-1 has antifibrotic effects in the left ventricle, which were explained by direct actions on cardiac fibroblasts. However, the NRG-1/ErbB system also regulates the function of macrophages. In this study, we hypothesized that the antifibrotic effect of NRG-1 in the heart is at least partially mediated through inhibitory effects on macrophages. We also hypothesized that the antifibrotic effect of NRG-1 may be active in other organs, such as the skin and lung. First, in a mouse model of angiotensin II (ANG II)-induced myocardial hypertrophy and fibrosis, NRG-1 treatment (20 µg·kg·day ip) significantly attenuated myocardial hypertrophy and fibrosis and improved passive ventricular stiffness (4 wk). Interestingly, 1 wk after exposure to ANG II, NRG-1 already attenuated myocardial macrophage infiltration and cytokine expression. Furthermore, mice with myeloid-specific deletion of the gene () showed an intensified myocardial fibrotic response to ANG II. Consistently, NRG-1 activated the ErbB4 receptor in isolated macrophages, inhibited phosphatidylinositide 3-kinase/Akt and STAT3 signaling pathways, and reduced the release of inflammatory cytokines. Further experiments showed that the antifibrotic and anti-inflammatory effects of NRG-1 were reproducible in mouse models of bleomycin-induced dermal and pulmonary fibrosis. Overall, this study demonstrates that the antifibrotic effect of NRG-1 in the heart is linked to anti-inflammatory activity NRG-1/ErbB4 signaling in macrophages. Second, this study shows that NRG-1 has antifibrotic and anti-inflammatory effects in organs other than the heart, such as the skin and lung. Our study contributes to the understanding of the antifibrotic effect of neuregulin-1 during myocardial remodeling. Here, we show that the antifibrotic effect of neuregulin-1 is at least partially mediated through anti-inflammatory activity, linked to receptor tyrosine-protein kinase erbB-4 activation in macrophages. Furthermore, we show that this effect is also present outside the heart.

The human BON-1 and QGP-1 cell lines are two frequently used models in pancreatic neuroendocrine tumor (PNET) research. Data on the whole-exome genetic constitution of these cell lines is largely lacking. This study presents, to our knowledge, the first wholeexome profile of the BON-1 and QGP-1 cell lines. Cell line identity was confirmed by short tandem repeat profiling. Using GTG-banding and a CytoSNP-12v2 Beadchip array, cell line ploidy and chromosomal alterations were determined in BON-1 and QGP-1. The exomes of both cell lines were sequenced on Ilumina's HiSeq next-generation sequencing (NGS) platform. Single-nucleotide variants (SNVs) and insertions and deletions (indels) were detected using the Genome Analysis ToolKit. SNVs were validated by Sanger sequencing. Ploidy of BON-1 and QGP-1 was 3 and 4 respectively, with long stretches of loss of heterozygosity across multiple chromosomes, which is associated with aggressive tumor behavior. In BON-1, 57 frameshift indels and 1725 possible protein-altering SNVs were identified in the NGS data. In the QGP-1 cell line, 56 frameshift indels and 1095 SNVs were identified. ATRX, a PNET-associated gene, was mutated in both cell lines, while mutation of TSC2 was detected in BON-1. A mutation in NRAS was detected in BON-1, while KRAS was mutated in QGP-1, implicating aberrations in the RAS pathway in both cell lines. Homozygous mutations in TP53 with possible loss of function were identified in both cell lines. Various MUC genes, implicated in cell signaling, lubrication and chemical barriers, which are frequently expressed in PNET tissue samples, showed homozygous proteinaltering SNVs in the BON-1 and QGP-1 cell lines.

BackgroundBreast cancer is the most frequent cancer among women worldwide. Biomarkers for early detection and prognosis of these patients are needed. We hypothesized that deafness, autosomal dominant 5 (DFNA5) may be a valuable biomarker, based upon strong indications for its role as tumor suppressor gene and its function in regulated cell death. In this study, we aimed to analyze DFNA5 methylation and expression in the largest breast cancer cohort to date using publicly available data from TCGA, in order to further unravel the role of DFNA5 as detection and/or prognostic marker in breast cancer. We analyzed Infinium HumanMethylation450k data, covering 22 different CpGs in the DFNA5 gene (668 breast adenocarcinomas and 85 normal breast samples) and DFNA5 expression (Agilent 244K Custom Gene Expression: 476 breast adenocarcinomas and 56 normal breast samples; RNA-sequencing: 666 breast adenocarcinomas and 71 normal breast samples).ResultsDFNA5 methylation and expression were significantly different between breast cancer and normal breast samples. Overall, breast cancer samples showed higher DFNA5 methylation in the putative gene promoter compared to normal breast samples, whereas in the gene body and upstream of the putative gene promoter, the opposite is true. Furthermore, DFNA5 methylation, in 10 out of 22 CpGs, and expression were significantly higher in lobular compared to ductal breast cancers. An important result of this study was the identification of a combination of one CpG in the gene promoter (CpG07504598) and one CpG in the gene body (CpG12922093) of DFNA5, which was able to discriminate between breast cancer and normal breast samples (AUC = 0.93). This model was externally validated in three independent datasets. Moreover, we showed that estrogen receptor state is associated with DFNA5 methylation and expression. Finally, we were able to find a significant effect of DFNA5 gene body methylation on a 5-year overall survival time.ConclusionsWe conclude that DFNA5 methylation shows strong potential as detection and prognostic biomarker for breast cancer.Electronic supplementary materialThe online version of this article (10.1186/s13148-018-0479-y) contains supplementary material, which is available to authorized users.

In addition to its implication in hereditary hearing loss, the Gasdermin E ( GSDME ) gene is also a tumor suppressor involved in cancer progression through programmed cell death. GSDME epigenetic silencing through methylation has been shown in some cancer types, but studies are yet to fully explore its diagnostic/prognostic potential in colorectal cancer on a large‐scale. We used public data from The Cancer Genome Atlas (TCGA) to investigate differences in GSDME methylation and expression between colorectal cancer and normal colorectal tissue, and between left‐ and right‐sided colorectal cancers in 432 samples. We also explored GSDME 's diagnostic capacity as a biomarker for colorectal cancer. We observed differential methylation in all 22 GSDME CpGs between tumor and normal tissues, and in 18 CpGs between the left‐ and right‐sided groups. In the cancer tissue, putative promoter probes were hypermethylated and gene body probes were hypomethylated, while this pattern was inversed in normal tissues. Both putative promoter and gene body CpGs correlated well together but formed distinct methylation patterns with the putative promoter exhibiting the most pronounced methylation differences between tumor and normal tissues. Clinicopathological parameters, excluding age, did not show any effect on CpG methylation. Although the methylation of 5 distinct probes was a good predictor of gene expression, we could not identify an association between GSDME methylation and expression in general. Survival analysis showed no association between GSDME methylation and expression on 5‐year patient survival. Through logistic regression, we identified a combination of 2 CpGs, that can discriminate between cancer and normal tissue with high accuracy (AUC = 0.95) irrespective of age and tumor stage. We also validated our model in 3 external methylation datasets, from the Gene Expression Omnibus database, and similar results were reached. Our results suggest that GSDME is a promising biomarker for the detection of colorectal cancer.

Background:The mTOR-inhibitor everolimus improves progression-free survival in advanced pancreatic neuroendocrine tumours (PNETs). However, adaptive resistance to mTOR inhibition is described.Methods:QGP-1 and BON-1, two human PNET cell lines, were cultured with increasing concentrations of everolimus up to 22 weeks to reach a dose of 1 μM everolimus, respectively, 1000-fold and 250-fold initial IC50. Using total DNA content as a measure of cell number, growth inhibitory dose–response curves of everolimus were determined at the end of resistance induction and over time after everolimus withdrawal. Response to ATP-competitive mTOR inhibitors OSI-027 and AZD2014, and PI3K-mTOR inhibitor NVP-BEZ235 was studied. Gene expression of 10 PI3K-Akt-mTOR pathway-related genes was evaluated using quantitative real-time PCR (RT–qPCR).Results:Long-term everolimus-treated BON-1/R and QGP-1/R showed a significant reduction in everolimus sensitivity. During a drug holiday, gradual return of everolimus sensitivity in BON-1/R and QGP-1/R led to complete reversal of resistance after 10–12 weeks. Treatment with AZD2014, OSI-027 and NVP-BEZ235 had an inhibitory effect on cell proliferation in both sensitive and resistant cell lines. Gene expression in BON-1/R revealed downregulation of MTOR, RICTOR, RAPTOR, AKT and HIF1A, whereas 4EBP1 was upregulated. In QGP-1/R, a downregulation of HIF1A and an upregulation of ERK2 were observed.Conclusions:Long-term everolimus resistance was induced in two human PNET cell lines. Novel PI3K-AKT-mTOR pathway-targeting drugs can overcome everolimus resistance. Differential gene expression profiles suggest different mechanisms of everolimus resistance in BON-1 and QGP-1.

This prospective study showed that tumor-specific mutation and NPY methylation ddPCR assays performed on circulating DNA can be used for the follow-up of mCRC patients during treatment and could complement current follow-up methods. The analysis of NPY methylation is promising, as it has the additional advantage that no prior knowledge of tumor mutations is needed.

The mammalian target of rapamycin (mTOR) is part of the phosphoinositide-3-kinase

Background: Detection of tumor-specific alterations in cell-free DNA (cfDNA) has proven valuable as a liquid biopsy for several types of cancer. So far, use of cfDNA remains unexplored for pancreatic neuroendocrine tumor (PNET) patients.Methods: From 10 PNET patients, fresh frozen tumor tissue, buffy coat and plasma samples were collected. Whole-exome sequencing of primary tumor and germline DNA was performed to identify tumor-specific variants and copy number variations (CNVs). Subsequently, tumor-specific variants were quantified in plasma cfDNA with droplet digital PCR. In addition, CNV analysis of cfDNA was performed using shallow whole-genome sequencing.Results: Tumor-specific variants were detected in perioperative plasma samples of two PNET patients, at variant allele fractions (VAFs) of respectively 19 and 21%. Both patients had metastatic disease at time of surgery, while the other patients presented with localized disease. In the metastatic patients, CNV profiles of tumor tissue and cfDNA were significantly correlated. A follow-up plasma sample of a metastatic patient demonstrated an increased VAF (57%) and an increased chromosomal instability, in parallel with an increase in tumor burden.Conclusions: We are the first to report the presence of tumor-specific genetic alterations in cfDNA of metastatic PNET patients and their evolution during disease progression. Additionally, CNV analysis in cfDNA shows potential as a liquid biopsy.