Characterization of Native COMPASS Complex in Urothelial Carcinoma Cells by Size Exclusion Chromatography.

The human COMPASS complexes regulate gene expression during development and cell differentiation. Three distinct subunits, KMT2C, KMT2D, and KDM6A (also known as UTX), are frequently mutated in urothelial carcinoma, possibly disrupting the formation of functional COMPASS complexes. Here, we describe methods to evaluate the formation of these large native protein complexes in urothelial carcinoma (UC) cell lines harboring different mutations in KMT2C/D.

Proteomic and transcriptomic profiles of human urothelial cancer cells with histone deacetylase 5 overexpression.

Urothelial carcinoma (UC) of the urinary bladder is a prevalent cancer worldwide. Because histone deacetylases (HDACs) are important factors in cancer, targeting these epigenetic regulators is considered an attractive strategy to develop novel anticancer drugs. Whereas HDAC1 and HDAC2 promote UC, HDAC5 is often downregulated and only weakly expressed in UC cell lines, suggesting a tumor-suppressive function.

Epigenetics in the Diagnosis and Therapy of Malignant Melanoma.

Epigenetic mechanisms are fundamentally important for cancer initiation and development. However, a survey of the literature reveals that, to date, they appear less comprehensively investigated in melanoma than in many other cancers, e.g.

Alterations of Chromatin Regulators in the Pathogenesis of Urinary Bladder Urothelial Carcinoma.

Urothelial carcinoma (UC) is the most frequent histological type of cancer in the urinary bladder. Genomic changes in UC activate MAPK and PI3K/AKT signal transduction pathways, which increase cell proliferation and survival, interfere with cell cycle and checkpoint control, and prevent senescence. A more recently discovered additional category of genetic changes in UC affects chromatin regulators, including histone-modifying enzymes (KMT2C, KMT2D, KDM6A, EZH2), transcription cofactors (CREBBP, EP300), and components of the chromatin remodeling complex SWI/SNF (ARID1A, SMARCA4).

The Dual Histone Deacetylase-Proteasome Inhibitor RTS-V5 Acts Synergistically With Ritonavir to Induce Endoplasmic Reticulum Stress in Bladder Cancer Cells.

Background/aim: Simultaneous inhibition of histone deacetylase and proteasomes induces endoplasmic reticulum (ER) stress efficiently. RTS-V5 is the first dual histone deacetylase-proteasome inhibitor, and we anticipated that combining it with the cytochrome P450 family 3 subfamily A member 4 inhibitor ritonavir would enhance its activity in bladder cancer cells.

Materials And Methods: Using bladder cancer cells (human T-24, J-82, murine MBT-2), we evaluated the ability and mechanism by which the combination of RTS-V5 and ritonavir induced ER stress and killed cancer cells.

Ubiquitin-proteasome System Is a Promising Target for Killing Cisplatin-resistant Bladder Cancer Cells.

Background/aim: Activation of the ubiquitin-proteasome system (UPS) has been shown to be associated with drug resistance in cancer. Using bladder cancer cells, we investigated the association between UPS activation and cisplatin resistance and also the efficacy of UPS-targeting drugs.

Materials And Methods: We established cisplatin-resistant bladder cancer cells (J82-cisR, T24-cisR) and examined the activation status of the UPS and the efficacy of MLN7243, oprozomib, ixazomib, and RTS-V5.

Epigenetic Treatment of Urothelial Carcinoma Cells Sensitizes to Cisplatin Chemotherapy and PARP Inhibitor Treatment.

Muscle-invasive urothelial carcinoma (UC) is treated with cisplatin-based chemotherapy, which is only moderately efficient, mostly due to development of resistance. New therapy approaches are therefore urgently needed. Epigenetic alterations due to frequent mutations in epigenetic regulators contribute to development of the disease and to treatment resistance, and provide targets for novel drug combination therapies.

Downregulation of Cell Cycle and Checkpoint Genes by Class I HDAC Inhibitors Limits Synergism with G2/M Checkpoint Inhibitor MK-1775 in Bladder Cancer Cells.

Since genes encoding epigenetic regulators are often mutated or deregulated in urothelial carcinoma (UC), they represent promising therapeutic targets. Specifically, inhibition of Class-I histone deacetylase (HDAC) isoenzymes induces cell death in UC cell lines (UCC) and, in contrast to other cancer types, cell cycle arrest in G2/M. Here, we investigated whether mutations in cell cycle genes contribute to G2/M rather than G1 arrest, identified the precise point of arrest and clarified the function of individual HDAC Class-I isoenzymes.

Aging-associated distinctive DNA methylation changes of LINE-1 retrotransposons in pure cell-free DNA from human blood.

LINE-1 hypomethylation of cell-free DNA has been described as an epigenetic biomarker of human aging. However, in the past, insufficient differentiation between cellular and cell-free DNA may have confounded analyses of genome-wide methylation levels in aging cells. Here we present a new methodological strategy to properly and unambiguously extract DNA methylation patterns of repetitive, as well as single genetic loci from pure cell-free DNA from peripheral blood.

Many Different LINE-1 Retroelements Are Activated in Bladder Cancer.

Human genomes contain about 100,000 LINE-1 (L1) retroelements, of which more than 100 are intact. L1s are normally tightly controlled by epigenetic mechanisms, which often fail in cancer. In bladder urothelial carcinoma (UC), particularly, L1s become DNA-hypomethylated, expressed and contribute to genomic instability and tumor growth.

In Vitro Assessment of the Genotoxic Hazard of Novel Hydroxamic Acid- and Benzamide-Type Histone Deacetylase Inhibitors (HDACi).

Histone deacetylase inhibitors (HDACi) are already approved for the therapy of leukemias. Since they are also emerging candidate compounds for the treatment of non-malignant diseases, HDACi with a wide therapeutic window and low hazard potential are desirable. Here, we investigated a panel of 12 novel hydroxamic acid- and benzamide-type HDACi employing non-malignant V79 hamster cells as toxicology guideline-conform in vitro model.

Knockdown of UTX/KDM6A Enriches Precursor Cell Populations in Urothelial Cell Cultures and Cell Lines.

The histone demethylase UTX (gene: ) directs cell and tissue differentiation during development. Deleterious mutations in occur in many human cancers, most frequently in urothelial carcinoma. The consequences of these mutations are poorly understood; plausibly, they may disturb urothelial differentiation.

Evaluation of HER2 expression in urothelial carcinoma cells as a biomarker for circulating tumor cells.

Background: Detection of circulating tumor cells (CTC) by techniques based on epithelial cell adhesion molecule (EpCAM) is suboptimal in urothelial carcinoma (UC). As HER2 is thought to be broadly expressed in UC, we explored its utility for CTC detection.

Methods: HER2 and EpCAM expression was analyzed in 18 UC cell lines (UCCs) by qRT-PCR, western blot and fluorescence-activated cell scanning (FACS) and compared to the strongly HER2-expressing breast cancer cell line SKBR3 and other controls.

Basic Hallmarks of Urothelial Cancer Unleashed in Primary Uroepithelium by Interference with the Epigenetic Master Regulator ODC1.

Urothelial carcinoma (UC) is a common disease causing significant morbidity and mortality as well as considerable costs for health systems. Extensive aberrant methylation of DNA is broadly documented in early UC, contributing to genetic instability, altered gene expression and tumor progression. However the triggers initiating aberrant methylation are unknown.

Combination of Decitabine and Entinostat Synergistically Inhibits Urothelial Bladder Cancer Cells via Activation of FoxO1.

Occurrence of cisplatin-resistance in bladder cancer is frequent and results in disease progression. Thus, novel therapeutic approaches are a high medical need for patients suffering from chemotherapy failure. The purpose of this study was to test the combination of the DNA methyltransferase inhibitor decitabine (DAC) with the histone deacetylase inhibitor entinostat (ENT) in bladder cancer cells with different platinum sensitivities: J82, cisplatin-resistant J82CisR, and RT-112.

Distinctive mutational spectrum and karyotype disruption in long-term cisplatin-treated urothelial carcinoma cell lines.

The DNA-damaging compound cisplatin is broadly employed for cancer chemotherapy. The mutagenic effects of cisplatin on cancer cell genomes are poorly studied and might even contribute to drug resistance. We have therefore analyzed mutations and chromosomal alterations in four cisplatin-resistant bladder cancer cell lines (LTTs) by whole-exome-sequencing and array-CGH.

Epigenetics of Urological Cancers.

The major urological cancers comprise prostate adenocarcinoma, urinary bladder (or upper urinary tract) carcinoma, renal cell carcinoma, testicular cancer and penile carcinoma, in this order of incidence, each with various histological and molecular subtypes [...

ISG15 Deficiency Enhances HIV-1 Infection by Accumulating Misfolded p53.

Macrophages and dendritic cells dominate early immune responses to lentiviruses. HIV-1 sensing by pathogen recognition receptors induces signaling cascades that culminate in type I alpha/beta interferon (IFN-α/β) induction. IFN-α/β signals back via the IFN-α/β receptors, inducing a plethora of IFN-stimulated gene (ISGs), including ISG15, p53, and p21 p21 inhibits HIV-1 replication by inactivating the deoxynucleoside triphosphate (dNTP) biosynthesis pathway and activating the restriction factor SAMHD1.

Upregulation of the long non-coding RNA CASC9 as a biomarker for squamous cell carcinoma.

Background: Few diagnostic and prognostic biomarkers are available for head-and-neck squamous cell carcinoma (HNSCC). Long non-coding RNAs (lncRNAs) have shown promise as biomarkers in other cancer types and in some cases functionally contribute to tumor development and progression. Here, we searched for lncRNAs useful as biomarkers in HNSCC.

HDAC5 Expression in Urothelial Carcinoma Cell Lines Inhibits Long-Term Proliferation but Can Promote Epithelial-to-Mesenchymal Transition.

Class I histone deacetylases (HDACs) generally promote cell proliferation and tumorigenesis, whereas class IIA HDACs like HDAC4 and HDAC5 may promote or impede cancer development in a tissue-dependent manner. In urothelial carcinoma (UC), HDAC5 is often downregulated. Accordingly, HDAC5 was weakly expressed in UC cell lines suggesting a possible tumor-suppressive function.

Contingencies of UTX/KDM6A Action in Urothelial Carcinoma.

The histone demethylase Ubiquitously Transcribed Tetratricopeptide Repeat Protein X-Linked (UTX/KDM6A) demethylates H3K27me2/3 at genes and enhancers and is often inactivated by mutations in urothelial carcinoma (UC). The consequences of its inactivation are however poorly understood. We have investigated the consequences of moderate UTX overexpression across a range of UC cell lines with or without mutations in or its interaction partners and in a normal control cell line.

Detailed methylation map of LINE-1 5'-promoter region reveals hypomethylated CpG hotspots associated with tumor tissue specificity.

Background: Long interspersed nuclear elements (LINE-1) sequences constitute a substantial portion of the human genome, and their methylation often correlating with global genomic methylation. Previous studies have highlighted the feasibility of using LINE-1 methylation to discriminate tumors from healthy tissues. However, most studies are based on only a few specific LINE-1 CpG sites.

Oxidative stress and LINE-1 reactivation in bladder cancer are epigenetically linked through active chromatin formation.

Oxidative stress and reactivation of long interspersed element-1 (LINE-1) are coincidently observed in bladder cancer (BlCa), but the mechanistic connection between these two oncogenic phenomena is unknown. Previously, we reported increases in oxidative stress and LINE-1 protein (ORF1p) expression in human BlCa tissues. In this study, we measured 5-methylcytosine (5mC), 8-hydroxydeoxyguanosine (8-OHdG), 8-oxoguanosine DNA glycosylase-1 (OGG1), H3K9me3 and HP1α in bladder tissues obtained from BlCa patients.

The histone demethylase UTX/KDM6A in cancer: Progress and puzzles.

The lysine-specific demethylase 6A/UTX (gene name KDM6A) acts as a component of the COMPASS complex to control gene activation. UTX demethylates H3K27me2/3 at genes and enhancers. Deleterious mutations in KDM6A are found in many cancer types, prominently urothelial carcinoma and certain T-cell leukemias.