RESUMO
Alveolar rhabdomyosarcoma (ARMS) is an aggressive pediatric cancer with poor prognosis. Cancer stem cells (CSCs) are seeds for tumor relapse and metastasis. However, pathways that maintain stemness genes are not fully understood. Here, we report that the enzyme euchromatic histone lysine methyltransferase 1 (EHMT1) is expressed in primary and relapse ARMS tumors. EHMT1 suppression impaired motility and induced differentiation in ARMS cell lines and reduced tumor progression in a mouse xenograft model in vivo. RNA sequencing of EHMT1-depleted cells revealed downregulation of ALDH1A1 that is associated with CSCs. Consistent with this, inhibition of ALDH1A1 expression and activity mimicked EHMT1 depletion phenotypes and reduced tumorsphere formation. Mechanistically, we demonstrate that EHMT1 does not bind to the ALDH1A1 promoter but activates it by stabilizing C/EBPß, a known regulator of ALDH1A1 expression. Our findings identify a role for EHMT1 in maintenance of stemness by regulating ALDH1A1 expression and suggest that targeting ALDH+ cells is a promising strategy in ARMS. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Assuntos
Família Aldeído Desidrogenase 1/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Células-Tronco Neoplásicas/enzimologia , Retinal Desidrogenase/metabolismo , Rabdomiossarcoma Alveolar/enzimologia , Família Aldeído Desidrogenase 1/genética , Animais , Proteína beta Intensificadora de Ligação a CCAAT/genética , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Progressão da Doença , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Histona-Lisina N-Metiltransferase/genética , Humanos , Camundongos Nus , Invasividade Neoplásica , Células-Tronco Neoplásicas/patologia , Fenótipo , Retinal Desidrogenase/genética , Rabdomiossarcoma Alveolar/genética , Rabdomiossarcoma Alveolar/patologia , Transdução de Sinais , Carga TumoralRESUMO
Hepatocellular carcinoma (HCC) is one of the most lethal malignancies, and is also the fourth most common cancer worldwide with around 700,000 new cases each year. Currently, first line chemotherapeutic drugs used for HCC include fluorouracil, cisplatin, doxorubicin, paclitaxel and mitomycin, but most of these are non-selective cytotoxic molecules with significant side effects. Sorafenib is the only approved targeted therapy by the U.S. Food and Drug Administration for HCC treatment, but patients suffer from various kinds of adverse effects, including hypertension. The signal-transducer-and-activator-of-transcription 3 (STAT3) protein, one of the members of STATs transcription factor family, has been implicated in signal transduction by different cytokines, growth factors and oncogenes. In normal cells, STAT3 activation is tightly controlled to prevent dysregulated gene transcription, whereas constitutively activated STAT3 plays an important role in tumorigenesis through the upregulation of genes involved in anti-apoptosis, proliferation and angiogenesis. Thus, pharmacologically safe and effective agents that can block STAT3 activation have the potential both for the prevention and treatment of HCC. In the present review, we discuss the possible role of STAT3 signaling cascade and its interacting partners in the initiation of HCC and also analyze the role of various STAT3 regulated genes in HCC progression, inflammation, survival, invasion and angiogenesis.
Assuntos
Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Inflamação/metabolismo , Inflamação/patologia , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/patologia , Invasividade Neoplásica , Fator de Transcrição STAT3/efeitos dos fármacosRESUMO
Metastasis, therapy failure and tumour recurrence are major clinical challenges in cancer. The interplay between tumour-initiating cells (TICs) and epithelial-mesenchymal transition (EMT) drives tumour progression and spread. Recent advances have highlighted the involvement of epigenetic deregulation in these processes. The euchromatin histone lysine methyltransferase 1 (EHMT1) and euchromatin histone lysine methyltransferase 2 (EHMT2) that primarily mediate histone 3 lysine 9 di-methylation (H3K9me2), as well as methylation of non-histone proteins, are now recognised to be aberrantly expressed in many cancers. Their deregulated expression is associated with EMT, cellular plasticity and therapy resistance. In this review, we summarise evidence of their myriad roles in cancer metastasis, stemness and drug resistance. We discuss cancer-type specific molecular targets, context-dependent mechanisms and future directions of research in targeting EHMT1/EHMT2 for the treatment of cancer.
Assuntos
Transição Epitelial-Mesenquimal/genética , Antígenos de Histocompatibilidade/genética , Histona-Lisina N-Metiltransferase/genética , Proteínas de Neoplasias/genética , Recidiva Local de Neoplasia/genética , Neoplasias/genética , Antineoplásicos/uso terapêutico , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Terapia de Alvo Molecular/métodos , Metástase Neoplásica , Proteínas de Neoplasias/metabolismo , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Falha de TratamentoRESUMO
Phytochemicals and their synthetic derivatives are making a significant contribution in modern drug discovery programs by targeting several human diseases, including cancer. Most of these natural compounds are often multitargeted in nature, which is generally a very desirable property for cancer therapy, as carcinomas typically involve dysregulation of multiple genes and associated cell-signaling pathways at various stages of initiation, progression and metastasis. Additionally, these natural agents generally have lower side-effects, are readily available and hence are cost effective. One such natural compound is zerumbone, a cyclic eleven-membered sesquiterpene, isolated from the tropical plant Zingiber zerumbet Smith that has attracted great attention recently for its potent anticancer activities in several tumor models. This review summarizes the data based on various in vitro and in vivo studies related to the effects of zerumbone on numerous pivotal molecular targets in cancer and its reported chemopreventive/therapeutic effects in different models of cancer.