ABSTRACT
Although the multi-tyrosine kinase inhibitor sorafenib is useful in the treatment of several cancers, cholangiocarcinoma (CCA) is refractory to this drug. Among other mechanisms of chemoresistance, impaired uptake through human organic cation transporter type 1 (hOCT1) (gene SLC22A1) has been suggested. Here we have investigated the events accounting for this phenotypic characteristic and have evaluated the interest of selective gene therapy strategies to overcome this limitation. Gene expression and DNA methylation of SLC22A1 were analyzed using intrahepatic (iCCA) and extrahepatic (eCCA) biopsies (Copenhagen and Salamanca cohorts; n = 132) and The Cancer Genome Atlas (TCGA)-CHOL (n = 36). Decreased hOCT1 mRNA correlated with hypermethylation status of the SLC22A1 promoter. Treatment of CCA cells with decitabine (demethylating agent) or butyrate (histone deacetylase inhibitor) restored hOCT1 expression and increased sorafenib uptake. MicroRNAs able to induce hOCT1 mRNA decay were analyzed in paired samples of TCGA-CHOL (n = 9) and Copenhagen (n = 57) cohorts. Consistent up-regulation in tumor tissue was found for miR-141 and miR-330. High proportion of aberrant hOCT1 mRNA splicing in CCA was also seen. Lentiviral-mediated transduction of eCCA (EGI-1 and TFK-1) and iCCA (HuCCT1) cells with hOCT1 enhanced sorafenib uptake and cytotoxic effects. In chemically induced CCA in rats, reduced rOct1 expression was accompanied by impaired sorafenib uptake. In xenograft models of eCCA cells implanted in mouse liver, poor response to sorafenib was observed. However, tumor growth was markedly reduced by cotreatment with sorafenib and adenoviral vectors encoding hOCT1 under the control of the BIRC5 promoter, a gene highly up-regulated in CCA. Conclusion: The reason for impaired hOCT1-mediated sorafenib uptake by CCA is multifactorial. Gene therapy capable of selectively inducing hOCT1 in tumor cells can be considered a potentially useful chemosensitization strategy to improve the response of CCA to sorafenib.
Subject(s)
Bile Duct Neoplasms/drug therapy , Cholangiocarcinoma/drug therapy , Down-Regulation/genetics , Octamer Transcription Factor-1/genetics , Protein Kinase Inhibitors/pharmacology , Sorafenib/pharmacology , Animals , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/pathology , Cell Line, Tumor/drug effects , Cholangiocarcinoma/genetics , Cholangiocarcinoma/pathology , DNA Methylation/genetics , Disease Models, Animal , Drug Resistance/genetics , Genetic Therapy/methods , Humans , Immunoblotting , Male , RNA, Messenger/genetics , Random Allocation , Rats , Rats, Wistar , Real-Time Polymerase Chain Reaction/methods , Statistics, NonparametricABSTRACT
The indisputable role of epigenetics in cancer and the fact that epigenetic alterations can be reversed have favoured development of epigenetic drugs. In this study, we design and synthesize potent novel, selective and reversible chemical probes that simultaneously inhibit the G9a and DNMTs methyltransferase activity. In vitro treatment of haematological neoplasia (acute myeloid leukaemia-AML, acute lymphoblastic leukaemia-ALL and diffuse large B-cell lymphoma-DLBCL) with the lead compound CM-272, inhibits cell proliferation and promotes apoptosis, inducing interferon-stimulated genes and immunogenic cell death. CM-272 significantly prolongs survival of AML, ALL and DLBCL xenogeneic models. Our results represent the discovery of first-in-class dual inhibitors of G9a/DNMTs and establish this chemical series as a promising therapeutic tool for unmet needs in haematological tumours.
Subject(s)
Antineoplastic Agents/pharmacology , DNA Modification Methylases/antagonists & inhibitors , Drug Design , Enzyme Inhibitors/pharmacology , Hematologic Neoplasms/drug therapy , Histone-Lysine N-Methyltransferase/antagonists & inhibitors , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Apoptosis/genetics , Apoptosis/immunology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/genetics , Crystallography, X-Ray , DNA Modification Methylases/chemistry , DNA Modification Methylases/genetics , DNA Modification Methylases/metabolism , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/therapeutic use , Epigenesis, Genetic/drug effects , Female , Hematologic Neoplasms/genetics , Hematologic Neoplasms/immunology , Hematologic Neoplasms/mortality , Histocompatibility Antigens/chemistry , Histocompatibility Antigens/genetics , Histocompatibility Antigens/metabolism , Histone-Lysine N-Methyltransferase/chemistry , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/metabolism , Humans , Interferons/immunology , Interferons/metabolism , Mice , Mice, Inbred BALB C , Microsomes, Liver , Molecular Docking Simulation , Survival Analysis , Treatment Outcome , Xenograft Model Antitumor AssaysABSTRACT
Genome sequence analysis reveals that all organisms synthesize S-adenosylmethionine (AdoMet) and that a large fraction of all genes is AdoMet-dependent methyltransferases. AdoMet-dependent methylation has been shown to be central to many biological processes. Up to 85% of all methylation reactions and as much as 48% of methionine metabolism occur in the liver, which indicates the crucial importance of this organ in the regulation of blood methionine. Of the two mammalian genes (MAT1A, MAT2A) that encode methionine adenosyltransferase (MAT, the enzyme that makes AdoMet), MAT1A is specifically expressed in adult liver. It now appears that growth factors, cytokines, and hormones regulate liver MAT mRNA levels and enzyme activity and that AdoMet should not be viewed only as an intermediate metabolite in methionine catabolism, but also as an intracellular control switch that regulates essential hepatic functions such as regeneration, differentiation, and the sensitivity of this organ to injury. The aim of this review is to integrate these recent findings linking AdoMet with liver growth, differentiation, and injury into a comprehensive model. With the availability of AdoMet as a nutritional supplement and evidence of its beneficial role in various liver diseases, this review offers insight into its mechanism of action.