ABSTRACT
TNF-related apoptosis-inducing ligand (TRAIL) is a type II transmembrane protein capable of selectively inducing apoptosis in cancer cells by binding to its cognate receptors. Here, we examined the anticancer efficacy of a recently developed chimeric AD-O51.4 protein, a TRAIL fused to the VEGFA-originating peptide. We tested AD-O51.4 protein activity against human colorectal cancer (CRC) models and investigated the resistance mechanism in the non-responsive CRC models. The quantitative comparison of apoptotic activity between AD-O51.4 and the native TRAIL in nine human colorectal cancer cell lines revealed dose-dependent toxicity in seven of them; the immunofluorescence-captured receptor abundance correlated with the extent of apoptosis. AD-O51.4 reduced the growth of CRC patient-derived xenografts (PDXs) with good efficacy. Cell lines that acquired AD-O51.4 resistance showed a significant decrease in surface TRAIL receptor expression and apoptosis-related proteins, including Caspase-8, HSP60, and p53. These results demonstrate the effectiveness of AD-O51.4 protein in CRC preclinical models and identify the potential mechanism underlying acquired resistance. Progression of AD-O51.4 to clinical trials is expected.
Subject(s)
Antineoplastic Agents/pharmacology , Drug Resistance, Neoplasm/drug effects , Recombinant Fusion Proteins/pharmacology , TNF-Related Apoptosis-Inducing Ligand/metabolism , Vascular Endothelial Growth Factor A/metabolism , Animals , Apoptosis/drug effects , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Cell Line, Tumor , Cell Membrane/metabolism , Disease Models, Animal , Dose-Response Relationship, Drug , Humans , Mice , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , TNF-Related Apoptosis-Inducing Ligand/chemistry , TNF-Related Apoptosis-Inducing Ligand/genetics , Vascular Endothelial Growth Factor A/chemistry , Vascular Endothelial Growth Factor A/genetics , Xenograft Model Antitumor AssaysABSTRACT
Several studies employed the genome-wide association (GWA) analysis of single-nucleotide polymorphisms (SNPs) to identify susceptibility regions in colorectal cancer (CRC). However, the functional studies exploring the role of associating SNPs with cancer biology are limited. Herein, using chromatin immunoprecipitation assay (ChIP), reporter assay and chromosome conformation capture sequencing (3C-Seq) augmented with publically available genomic and epigenomic databases we aimed to define the function of rs6702619/1p21.2 region associated with CRC in the Polish population. Using ChIP we confirmed that rs6702619 region is occupied by a CTCF, a master regulator of long-range genomic interactions, and is decorated with enhancer-like histone modifications. The enhancer blocking assay revealed that rs6702619 region acts as an insulator with activity dependent on the SNP genotype. Finally, a 3C-Seq survey indicated more than a hundred loci in the rs6702619 locus interactome, including GNAS gene that is frequently amplified in CRC. Taken together, we showed that the CRC-associated rs6702619 region has in vitro and in vivo properties of an insulator that demonstrates long-range physical interactions with CRC-relevant loci.
Subject(s)
Colorectal Neoplasms/genetics , Penetrance , Polymorphism, Single Nucleotide/genetics , Population/genetics , Binding Sites , CCCTC-Binding Factor/chemistry , CCCTC-Binding Factor/genetics , Carcinogenesis/genetics , Chromogranins/genetics , Chromosomes, Human, Pair 1/genetics , Colorectal Neoplasms/pathology , Epigenesis, Genetic , GTP-Binding Protein alpha Subunits, Gs/genetics , Genetic Loci , Genetic Predisposition to Disease , Genome-Wide Association Study , HCT116 Cells , HeLa Cells , Humans , Poland , Promoter Regions, Genetic , RiskABSTRACT
Inhibition of oncogenic transcriptional programs is a promising therapeutic strategy. A substituted tricyclic benzimidazole, SEL120-34A, is a novel inhibitor of Cyclin-dependent kinase 8 (CDK8), which regulates transcription by associating with the Mediator complex. X-ray crystallography has shown SEL120-34A to be a type I inhibitor forming halogen bonds with the protein's hinge region and hydrophobic complementarities within its front pocket. SEL120-34A inhibits phosphorylation of STAT1 S727 and STAT5 S726 in cancer cells in vitro. Consistently, regulation of STATs- and NUP98-HOXA9- dependent transcription has been observed as a dominant mechanism of action in vivo. Treatment with the compound resulted in a differential efficacy on AML cells with elevated STAT5 S726 levels and stem cell characteristics. In contrast, resistant cells were negative for activated STAT5 and revealed lineage commitment. In vivo efficacy in xenotransplanted AML models correlated with significant repression of STAT5 S726. Favorable pharmacokinetics, confirmed safety and in vivo efficacy provide a rationale for the further clinical development of SEL120-34A as a personalized therapeutic approach in AML.
Subject(s)
Antineoplastic Agents/pharmacology , Cyclin-Dependent Kinase 8/antagonists & inhibitors , Leukemia, Myeloid, Acute/metabolism , Protein Interaction Domains and Motifs/drug effects , Protein Kinase Inhibitors/pharmacology , STAT1 Transcription Factor/metabolism , STAT5 Transcription Factor/metabolism , Animals , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cyclin-Dependent Kinase 8/chemistry , Disease Models, Animal , Gene Expression Profiling , Gene Expression Regulation, Leukemic/drug effects , Humans , Leukemia, Myeloid, Acute/genetics , Mice , Models, Molecular , Molecular Conformation , Phosphorylation/drug effects , Protein Binding , Protein Kinase Inhibitors/chemistry , STAT1 Transcription Factor/chemistry , STAT5 Transcription Factor/chemistry , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: Transplanting a fecal sample from lean, healthy donors to obese recipients has been shown to improve metabolic syndrome symptoms. We therefore examined the gut microbiota in mice after administering a long-term, high-fat diet (HFD) supplemented with feces from lean mice through the fecal-oral route. METHODS: C57BL6/W mice were allowed to adapt to a non-specific pathogen free (SFP) environment for 2 weeks before being divided into three groups of 16 animals. Animals were fed for 28 weeks with a normal diet (ND), HFD or HFD supplemented with feces from ND-fed mice (HFDS). The composition of colonizing bacteria was evaluated in droppings collected under SPF conditions at the beginning of the study and at 12 and 28 weeks using an 16S Metagenomics Kit on Ion PGM sequencer. RESULTS: HFD and HFDS-fed mice attained (p < 0.05) greater body weights by weeks 6 and 5, respectively. HFDS-fed mice gained more weight than HFD-fed mice by week 25. Both species diversity and richness indices increased with time in HFDS mice only. CONCLUSIONS: Prolonged HFD-fed mice supplementation with feces from lean mice altered bacteria species diversity and richness, accelerated the onset of obesity, and caused increased weight gain in the later weeks of the HFD regimen.