RESUMO
Background: KDM5 enzymes are H3K4 specific histone demethylases involved in transcriptional regulation and DNA repair. These proteins are overexpressed in different kinds of cancer, including breast, prostate and bladder carcinomas, with positive effects on cancer proliferation and chemoresistance. For these reasons, these enzymes are potential therapeutic targets. Methods: In the present study, we analyzed the effects of three different inhibitors of KDM5 enzymes in MCF-7 breast cancer cells over-expressing one of them, namely KDM5B/JARID1B. In particular we tested H3K4 demethylation (western blot); radio-sensitivity (cytoxicity and clonogenic assays) and damage accumulation (COMET assay and kinetics of H2AX phosphorylation). Results: we show that all three compounds with completely different chemical structures can selectively inhibit KDM5 enzymes and are capable of increasing sensitivity of breast cancer cells to ionizing radiation and radiation-induced damage. Conclusions: These findings confirm the involvement of H3K4 specific demethylases in the response to DNA damage, show a requirement of the catalytic function and suggest new strategies for the therapeutic use of their inhibitors.
Assuntos
Neoplasias da Mama/enzimologia , Histona Desmetilases/antagonistas & inibidores , Histona Desmetilases com o Domínio Jumonji/genética , Proteínas Nucleares/genética , Radiossensibilizantes/farmacologia , Proteínas Repressoras/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Células MCF-7 , Modelos Moleculares , Estrutura Molecular , Proteínas Nucleares/metabolismo , Tolerância a Radiação/efeitos dos fármacos , Radiossensibilizantes/química , Proteínas Repressoras/metabolismo , Bibliotecas de Moléculas Pequenas/química , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/efeitos da radiaçãoRESUMO
Targeted approaches aiming at modulating NHERF1 activity, rather than its overall expression, would be preferred to preserve the normal functions of this versatile protein. We focused our attention on the NHERF1/PDZ1 domain that governs its membrane recruitment/displacement through a transient phosphorylation switch. We herein report the design and synthesis of novel NHERF1 PDZ1 domain inhibitors. These compounds have potential therapeutic value when used in combination with antagonists of ß-catenin to augment apoptotic death of colorectal cancer cells refractory to currently available Wnt/ß-catenin-targeted agents.
RESUMO
Tubulin is the primary target of an ever growing number of natural, semisynthetic and synthetic products as potential anticancer agents. The mechanisms of interaction of these molecules with tubulin are varied. These drug classes have shown to inhibit effectively several cancer types with IC50 from midmicromolar to low nanomolar concentrations. However, some limiting obstacles still remain, such as the development of multidrug resistance and cytotoxicity. We have reviewed recent advances in different classes of tubulin binding agents, including colchicine site agents, Vinca alkaloids, tryprostatins, moroidin, hemiasterlin, diazonamide, taxanes, epothilones and laulimalide.
Assuntos
Antineoplásicos , Moduladores de Tubulina , Tubulina (Proteína)/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Humanos , Moduladores de Tubulina/farmacologia , Moduladores de Tubulina/uso terapêuticoRESUMO
We designed new 3-arylthio- and 3-aroyl-1H-indole derivatives 3-22 bearing a heterocyclic ring at position 5, 6 or 7 of the indole nucleus. The 6- and 7-heterocyclyl-1H-indoles showed potent inhibition of tubulin polymerization, binding of colchicine to tubulin and growth of MCF-7 cancer cells. Compounds 13 and 19 inhibited a panel of cancer cells and the NCI/ADR-RES multidrug resistant cell line at low nanomolar concentrations. Compound 13â¯at 50â¯nM induced 77% G2/M in HeLa cells, and at 20â¯nM caused 50% stable arrest of mitosis. As an inhibitor of HepG2 cells (IC50â¯=â¯20â¯nM), 13 was 4-fold superior to 19. Compound 13 was a potent inhibitor of the human U87MG glioblastoma cells at nanomolar concentrations, being nearly one order of magnitude superior to previously reported arylthioindoles. The present results highlight 13 as a robust scaffold for the design of new anticancer agents.
Assuntos
Antineoplásicos/farmacologia , Indóis/farmacologia , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Indóis/química , Estrutura Molecular , Polimerização/efeitos dos fármacos , Relação Estrutura-Atividade , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Células Tumorais CultivadasRESUMO
Nuclear activated ß-catenin plays a causative role in colorectal cancers (CRC) but remains an elusive therapeutic target. Using human CRC cells harboring different Wnt/ß-catenin pathway mutations in APC/KRAS or ß-catenin/KRAS genes, and both genetic and pharmacological knockdown approaches, we show that oncogenic ß-catenin signaling negatively regulates the expression of NHERF1 (Na+/H+ exchanger 3 regulating factor 1), a PDZ-adaptor protein that is usually lost or downregulated in early dysplastic adenomas to exacerbate nuclear ß-catenin activity. Chromatin immunoprecipitation (ChIP) assays demonstrated that ß-catenin represses NHERF1 via TCF4 directly, while the association between TCF1 and the Nherf1 promoter increased upon ß-catenin knockdown. To note, the occurrence of a cytostatic survival response in settings of single ß-catenin-depleted CRC cells was abrogated by combining NHERF1 inhibition via small hairpin RNA (shRNA) or RS5517, a novel PDZ1-domain ligand of NHERF1 that prevented its ectopic nuclear entry. Mechanistically, dual NHERF1/ß-catenin targeting promoted an autophagy-to-apoptosis switch consistent with the activation of Caspase-3, the cleavage of PARP and reduced levels of phospho-ERK1/2, Beclin-1, and Rab7 autophagic proteins compared with ß-catenin knockdown alone. Collectively, our data unveil novel ß-catenin/TCF-dependent mechanisms of CRC carcinogenesis, also offering preclinical proof of concept for combining ß-catenin and NHERF1 pharmacological inhibitors as a mechanism-based strategy to augment apoptotic death of CRC cells refractory to current Wnt/ß-catenin-targeted therapeutics.
Assuntos
Neoplasias Colorretais/genética , Fosfoproteínas/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , beta Catenina/genética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Mutação , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/química , Fosfoproteínas/genética , Transporte Proteico/efeitos dos fármacos , Trocadores de Sódio-Hidrogênio/antagonistas & inibidores , Trocadores de Sódio-Hidrogênio/química , Trocadores de Sódio-Hidrogênio/genética , Sulfonamidas/farmacologia , Fator de Transcrição 4/genética , Fator de Transcrição 4/metabolismo , beta Catenina/antagonistas & inibidoresRESUMO
We designed 3-aroyl-1,4-diarylpyrrole (ARDAP) derivatives as potential anticancer agents having different substituents at the 1- or 4-phenyl ring. ARDAP compounds exhibited potent inhibition of tubulin polymerization, binding of colchicine to tubulin, and cancer cell growth. ARDAP derivative 10 inhibited the proliferation of BCR/ABL-expressing KU812 and LAMA84 cells from chronic myeloid leukemia (CML) patients in blast crisis and of hematopoietic cells ectopically expressing the imatinib mesylate (IM)-sensitive KBM5-WT or its IM-resistant KBM5-T315I mutation. Compound 10 minimally affected the proliferation of normal blood cells, indicating that it may be a promising agent to overcome broad tyrosine kinase inhibitor resistance in relapsed/refractory CML patients. Compound 10 significantly decreased CML proliferation by inducing G2/M phase arrest and apoptosis via a mitochondria-dependent pathway. ARDAP 10 augmented the cytotoxic effects of IM in human CML cells. Compound 10 represents a robust lead compound to develop tubulin inhibitors with potential as novel treatments for CML.