RESUMO
Hyperactive Ras signalling is found in most cancers. Ras proteins are only active in membrane nanoclusters, which are therefore potential drug targets. We previously showed that the nanocluster scaffold galectin-1 (Gal1) enhances H-Ras nanoclustering via direct interaction with the Ras binding domain (RBD) of Raf. Here, we establish that the B-Raf preference of Gal1 emerges from the divergence of the Raf RBDs at their proposed Gal1-binding interface. We then identify the L5UR peptide, which disrupts this interaction by binding with low micromolar affinity to the B- and C-Raf-RBDs. Its 23-mer core fragment is sufficient to interfere with H-Ras nanoclustering, modulate Ras-signalling and moderately reduce cell viability. These latter two phenotypic effects may also emerge from the ability of L5UR to broadly engage with several RBD- and RA-domain containing Ras interactors. The L5UR-peptide core fragment is a starting point for the development of more specific reagents against Ras-nanoclustering and -interactors.
Assuntos
Peptídeos , Humanos , Peptídeos/metabolismo , Peptídeos/química , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/química , Galectina 1/metabolismo , Galectina 1/química , Galectina 1/genética , Ligação Proteica , Transdução de SinaisRESUMO
The trafficking chaperone PDE6D (or PDEδ) was proposed as a surrogate target for K-Ras, leading to the development of a series of inhibitors that block its prenyl binding pocket. These inhibitors suffered from low solubility and suspected off-target effects, preventing their clinical development. Here, we developed a highly soluble, low nanomolar PDE6D inhibitor (PDE6Di), Deltaflexin3, which has the lowest off-target activity as compared to three prominent reference compounds. Deltaflexin3 reduces Ras signaling and selectively decreases the growth of KRAS mutant and PDE6D-dependent cancer cells. We further show that PKG2-mediated phosphorylation of Ser181 lowers K-Ras binding to PDE6D. Thus, Deltaflexin3 combines with the approved PKG2 activator Sildenafil to more potently inhibit PDE6D/K-Ras binding, cancer cell proliferation, and microtumor growth. As observed previously, inhibition of Ras trafficking, signaling, and cancer cell proliferation remained overall modest. Our results suggest reevaluating PDE6D as a K-Ras surrogate target in cancer.
Assuntos
Proliferação de Células , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6 , Proteínas Proto-Oncogênicas p21(ras) , Citrato de Sildenafila , Humanos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/antagonistas & inibidores , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/metabolismo , Citrato de Sildenafila/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Mutação , Animais , Relação Estrutura-Atividade , Inibidores de Fosfodiesterase/farmacologia , Inibidores de Fosfodiesterase/química , Inibidores de Fosfodiesterase/síntese químicaRESUMO
BACKGROUND: Individuals carrying the risk variant p.I148M of patatin-like phospholipase domain-containing protein 3 (PNPLA3) have a higher susceptibility to fatty liver diseases and associated complications, including HCC, a cancer closely linked to chronic inflammation. Here, we assessed circulating cytokine profiles for patients with chronic liver diseases genotyped for PNPLA3. METHODS: Serum concentrations of 22 cytokines were measured by multiplex sandwich-ELISA. The cohort comprised 123 individuals: 67 patients with NAFLD without cirrhosis (57 steatosis, 10 NASH), 24 patients with NAFLD with cirrhosis, 21 patients with HCC (15 cirrhosis), and 11 healthy controls. Receiver operator characteristic analyses were performed to assess the suitability of the cytokine profiles for the prediction of steatosis, cirrhosis, and HCC. RESULTS: HGF, IL-6, and IL-8 levels were increased in patients, with â¼2-fold higher levels in patients with cirrhosis versus healthy, while platelet derived growth factor-BB (PDGF-BB) and regulated on activation, normal T cell expressed and secreted (RANTES) showed lower concentrations compared to controls. Migration inhibitory factor and monocyte chemoattractant protein-1 (MCP-1) were found at higher levels in NAFLD samples (maximum: NAFLD-cirrhosis) versus healthy controls and HCC samples. In receiver operator characteristic analyses, migration inhibitory factor, IL-8, IL-6, and monocyte chemoattractant protein-1 yielded high sensitivity scores for predicting noncirrhotic NAFLD (vs. healthy). The top combination to predict cirrhosis was HGF plus PDGF-BB. Migration inhibitory factor performed best to discriminate HCC from NAFLD; the addition of monokine induced gamma (MIG), RANTES, IL-4, macrophage colony-stimulating factor (M-CSF), or IL-17A as second parameters further increased the AUC values (> 0.9). No significant impact of the PNPLA3I148M allele on cytokine levels was observed in this cohort. CONCLUSIONS: Cytokines have biomarker potential in patients with fatty liver, possibly suited for early HCC detection in patients with fatty liver. Patients carrying the PNPLA3 risk allele did not present significantly different levels of circulating cytokines.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/genética , Citocinas/genética , Quimiocina CCL2/genética , Becaplermina , Alelos , Carcinoma Hepatocelular/genética , Interleucina-6/genética , Interleucina-8/genética , Neoplasias Hepáticas/genética , Cirrose Hepática/diagnóstico , Cirrose Hepática/genéticaRESUMO
Therapy Induced Senescence (TIS) leads to sustained growth arrest of cancer cells. The associated cytostasis has been shown to be reversible and cells escaping senescence further enhance the aggressiveness of cancers. Chemicals specifically targeting senescent cells, so-called senolytics, constitute a promising avenue for improved cancer treatment in combination with targeted therapies. Understanding how cancer cells evade senescence is needed to optimise the clinical benefits of this therapeutic approach. Here we characterised the response of three different NRAS mutant melanoma cell lines to a combination of CDK4/6 and MEK inhibitors over 33 days. Transcriptomic data show that all cell lines trigger a senescence programme coupled with strong induction of interferons. Kinome profiling revealed the activation of Receptor Tyrosine Kinases (RTKs) and enriched downstream signaling of neurotrophin, ErbB and insulin pathways. Characterisation of the miRNA interactome associates miR-211-5p with resistant phenotypes. Finally, iCell-based integration of bulk and single-cell RNA-seq data identifies biological processes perturbed during senescence and predicts 90 new genes involved in its escape. Overall, our data associate insulin signaling with persistence of a senescent phenotype and suggest a new role for interferon gamma in senescence escape through the induction of EMT and the activation of ERK5 signaling.
Assuntos
Insulinas , Melanoma , Humanos , Multiômica , Linhagem Celular Tumoral , Melanoma/tratamento farmacológico , Melanoma/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Insulinas/uso terapêutico , Senescência Celular/genética , Proteínas de Membrana/genética , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/uso terapêuticoRESUMO
Background: Neutrophils are an important source of pro-inflammatory and immunomodulatory cytokines. This makes neutrophils efficient drivers of interactions with immune and non-immune cells to maintain homeostasis and modulate the inflammatory process by notably regulating the release of cytokines. Ca2+-dependent regulatory mechanism encompassing cytokine secretion by neutrophils are not still identified. In this context, we propose to define new insights on the role of Ca2+-binding proteins S100A8/A9 and on the regulatory role of miRNA-132-5p, which was identified as a regulator of S100A8/A9 expression, on IL-8 secretion. Methods: Differentiated HL-60 cells, a human promyelocytic leukemia cell line that can be induced to differentiate into neutrophil-like cells, were used as a model of human neutrophils and treated with N- formyl-methionyl-leucyl-phenylalanine (fMLF), a bacterial peptide that activates neutrophils. shRNA knockdown was used to define the role of selected targets (S100A8/A9 and miRNA-132-5p) on IL-8 secretion. Results and discussion: Different types of cytokines engage different signaling pathways in the secretion process. IL-8 release is tightly regulated by Ca2+ binding proteins S100A8/A9. miRNA-132-5p is up-regulated over time upon fMLF stimulation and decreases S100A8/A9 expression and IL-8 secretion. Conclusion: These findings reveal a novel regulatory loop involving S100A8/A9 and miRNA-132-5p that modulates IL-8 secretion by neutrophils in inflammatory conditions. This loop could be a potential target for therapeutic intervention in inflammatory diseases.
Assuntos
MicroRNAs , Neutrófilos , Humanos , Calgranulina B/genética , Calgranulina B/metabolismo , Interleucina-8/metabolismo , Regulação para Baixo , Retroalimentação , Células HL-60 , Calgranulina A/genética , Calgranulina A/metabolismo , Citocinas/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismoRESUMO
The gut microbiome is a key player in the immunomodulatory and protumorigenic microenvironment during colorectal cancer (CRC), as different gut-derived bacteria can induce tumour growth. However, the crosstalk between the gut microbiome and the host in relation to tumour cell metabolism remains largely unexplored. Here we show that formate, a metabolite produced by the CRC-associated bacterium Fusobacterium nucleatum, promotes CRC development. We describe molecular signatures linking CRC phenotypes with Fusobacterium abundance. Cocultures of F. nucleatum with patient-derived CRC cells display protumorigenic effects, along with a metabolic shift towards increased formate secretion and cancer glutamine metabolism. We further show that microbiome-derived formate drives CRC tumour invasion by triggering AhR signalling, while increasing cancer stemness. Finally, F. nucleatum or formate treatment in mice leads to increased tumour incidence or size, and Th17 cell expansion, which can favour proinflammatory profiles. Moving beyond observational studies, we identify formate as a gut-derived oncometabolite that is relevant for CRC progression.
Assuntos
Neoplasias Colorretais , Microbioma Gastrointestinal , Animais , Bactérias , Neoplasias Colorretais/metabolismo , Formiatos , Fusobacterium nucleatum , Humanos , Camundongos , Microambiente TumoralRESUMO
Colorectal cancer (CRC) accounts for about 10% of cancer deaths worldwide. Colon carcinogenesis is critically influenced by the tumor microenvironment. Cancer associated fibroblasts (CAFs) and tumor associated macrophages (TAMs) represent the major components of the tumor microenvironment. TAMs promote tumor progression, angiogenesis and tissue remodeling. However, the impact of the molecular crosstalk of tumor cells (TCs) with CAFs and macrophages on monocyte recruitment and their phenotypic conversion is not known in detail so far. In a 3D human organotypic CRC model, we show that CAFs and normal colonic fibroblasts are critically involved in monocyte recruitment and for the establishment of a macrophage phenotype, characterized by high CD163 expression. This is in line with the steady recruitment and differentiation of monocytes to immunosuppressive macrophages in the normal colon. Cytokine profiling revealed that CAFs produce M-CSF, and IL6, IL8, HGF and CCL2 secretion was specifically induced by CAFs in co-cultures with macrophages. Moreover, macrophage/CAF/TCs co-cultures increased TC invasion. We demonstrate that CAFs and macrophages are the major producers of CCL2 and, upon co-culture, increase their CCL2 production twofold and 40-fold, respectively. CAFs and macrophages expressing high CCL2 were also found in vivo in CRC, strongly supporting our findings. CCL2, CCR2, CSF1R and CD163 expression in macrophages was dependent on active MCSFR signaling as shown by M-CSFR inhibition. These results indicate that colon fibroblasts and not TCs are the major cellular component, recruiting and dictating the fate of infiltrated monocytes towards a specific macrophage population, characterized by high CD163 expression and CCL2 production.
Assuntos
Antígenos CD/genética , Antígenos de Diferenciação Mielomonocítica/genética , Quimiocina CCL2/genética , Colo/metabolismo , Neoplasias Colorretais/genética , Receptores de Superfície Celular/genética , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Diferenciação Celular/genética , Movimento Celular/genética , Proliferação de Células/genética , Colo/patologia , Neoplasias Colorretais/sangue , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Células HCT116 , Humanos , Fator Estimulador de Colônias de Macrófagos/genética , Masculino , Células Mieloides/metabolismo , Células Mieloides/patologia , Transdução de Sinais/genética , Microambiente Tumoral/genéticaRESUMO
Reduced levels of intratumoural oxygen are associated with hypoxia-induced pro-oncogenic events such as invasion, metabolic reprogramming, epithelial-mesenchymal transition, metastasis and resistance to therapy, all favouring cancer progression. Small extracellular vesicles (EV) shuttle various cargos (proteins, miRNAs, DNA and others). Tumour-derived EVs can be taken up by neighbouring or distant cells in the tumour microenvironment, thus facilitating intercellular communication. The quantity of extracellular vesicle secretion and their composition can vary with changing microenvironmental conditions and disease states. Here, we investigated in melanoma cells the influence of hypoxia on the content and number of secreted EVs. Whole miRNome and proteome profiling revealed distinct expression patterns in normoxic or hypoxic growth conditions. Apart from the well-known miR-210, we identified miR-1290 as a novel hypoxia-associated microRNA, which was highly abundant in hypoxic EVs. On the other hand, miR-23a-5p and -23b-5p were consistently downregulated in hypoxic conditions, while the protein levels of the miR-23a/b-5p-predicted target IPO11 were concomitantly upregulated. Furthermore, hypoxic melanoma EVs exhibit a signature consisting of six proteins (AKR7A2, DDX39B, EIF3C, FARSA, PRMT5, VARS), which were significantly associated with a poor prognosis for melanoma patients, indicating that proteins and/or miRNAs secreted by cancer cells may be exploited as biomarkers.
RESUMO
Although tyrosine kinase inhibitors (TKIs) revolutionized the management of chronic myeloid leukemia (CML), resistance against TKIs and leukemia stem cell (LSC) persistence remain a clinical concern. Therefore, new therapeutic strategies combining conventional and novel therapies are urgently needed. Since telomerase is involved in oncogenesis and tumor progression but is silent in most human normal somatic cells, it may be an interesting target for CML therapy by selectively targeting cancer cells while minimizing effects on normal cells. Here, we report that hTERT expression is associated with CML disease progression. We also provide evidence that hTERT-deficient K-562 cells do not display telomere shortening and that telomere length is maintained through the ALT pathway. Furthermore, we show that hTERT depletion exerts a growth-inhibitory effect in K-562 cells and potentiates imatinib through alteration of cell cycle progression leading to a senescence-like phenotype. Finally, we demonstrate that hTERT depletion potentiates the imatinib-induced reduction of the ALDH+-LSC population. Altogether, our results suggest that the combination of telomerase and TKI should be considered as an attractive strategy to treat CML patients to eradicate cancer cells and prevent relapse by targeting LSCs.
Assuntos
Mesilato de Imatinib/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Telomerase/genética , Família Aldeído Desidrogenase 1/genética , Apoptose/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Linhagem da Célula/genética , Proliferação de Células/efeitos dos fármacos , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Proteínas de Fusão bcr-abl/genética , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Células-Tronco Neoplásicas/patologia , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Elevated levels of the pro-inflammatory cytokine tumor necrosis factor-α (TNFα) inhibit erythropoiesis and cause anemia in patients with cancer and chronic inflammatory diseases. TNFα is also a potent activator of the sphingomyelinase (SMase)/ceramide pathway leading to ceramide synthesis and regulating cell differentiation, proliferation, apoptosis, senescence, and autophagy. Here we evaluated the implication of the TNFα/SMase/ceramide pathway on inhibition of erythropoiesis in human CD34+ hematopoietic stem/progenitor cells (CD34/HSPCs) from healthy donors. Exogenous synthetic C2- and C6-ceramide as well as bacterial SMase inhibited erythroid differentiation in erythropoietin-induced (Epo)CD34/HSPCs shown by the analysis of various erythroid markers. The neutral SMase inhibitor GW4869 as well as the genetic inhibition of nSMase with small interfering RNA (siRNA) against sphingomyelin phosphodiesterase 3 (SMPD3) prevented the inhibition by TNFα, but not the acid SMase inhibitor desipramine. Moreover, sphingosine-1-phosphate (S1P), a ceramide metabolite, restored erythroid differentiation, whereas TNFα inhibited sphingosine kinase-1, required for S1P synthesis. Analysis of cell morphology and colony formation demonstrated that erythropoiesis impairment was concomitant with a granulomonocytic differentiation in TNFα- and ceramide-treated EpoCD34/HSPCs. Inhibition of erythropoiesis and induction of granulomonocytic differentiation were correlated to modulation of hematopoietic transcription factors (TFs) GATA-1, GATA-2, and PU.1. Moreover, the expression of microRNAs (miR)-144/451, miR-146a, miR-155, and miR-223 was also modulated by TNFα and ceramide treatments, in line with cellular observations. Autophagy plays an essential role during erythropoiesis and our results demonstrate that the TNFα/neutral SMase/ceramide pathway inhibits autophagy in EpoCD34/HSPCs. TNFα- and ceramide-induced phosphorylation of mTORS2448 and ULK1S758, inhibited Atg13S355 phosphorylation, and blocked autophagosome formation as shown by transmission electron microscopy and GFP-LC3 punctae formation. Moreover, rapamycin prevented the inhibitory effect of TNFα and ceramides on erythropoiesis while inhibiting induction of myelopoiesis. In contrast, bafilomycin A1, but not siRNA against Atg5, induced myeloid differentiation, while both impaired erythropoiesis. We demonstrate here that the TNFα/neutral SMase/ceramide pathway inhibits erythropoiesis to induce myelopoiesis via modulation of a hematopoietic TF/miR network and inhibition of late steps of autophagy. Altogether, our results reveal an essential role of autophagy in erythroid vs. myeloid differentiation.
Assuntos
Eritropoese/genética , Inflamação/genética , Mielopoese/genética , Fator de Necrose Tumoral alfa/genética , Anemia/genética , Anemia/patologia , Autofagia/genética , Proteína 5 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Diferenciação Celular/efeitos dos fármacos , Ceramidas/genética , Ceramidas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Inflamação/patologia , Neoplasias/genética , Neoplasias/patologia , Fosforilação/efeitos dos fármacos , Transdução de Sinais/genética , Esfingolipídeos/genética , Esfingolipídeos/metabolismo , Esfingomielina Fosfodiesterase/genética , Serina-Treonina Quinases TOR/genéticaRESUMO
We synthetized and investigated the anti-leukemic potential of the novel cytostatic bis(4-hydroxycoumarin) derivative OT-55 which complied with the Lipinski's rule of 5 and induced differential toxicity in various chronic myeloid leukemia (CML) cell models. OT-55 triggered ER stress leading to canonical, caspase-dependent apoptosis and release of danger associated molecular patterns. Consequently, OT-55 promoted phagocytosis of OT-55-treated CML cells by both murine and human monocyte-derived macrophages. Moreover, OT-55 inhibited tumor necrosis factor α-induced activation of nuclear factor-кB and produced synergistic effects when used in combination with imatinib to inhibit colony formation in vitro and Bcr-Abl+ patient blast xenograft growth in zebrafish. Furthermore, OT-55 synergized with omacetaxine in imatinib-resistant KBM-5 R cells to inhibit the expression of Mcl-1, triggering apoptosis. In imatinib-resistant K562 R cells, OT-55 triggered necrosis and blocked tumor formation in zebrafish in combination with omacetaxine.
Assuntos
Alarminas/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Mepesuccinato de Omacetaxina/administração & dosagem , Humanos , Mesilato de Imatinib/administração & dosagem , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Macrófagos/imunologia , Camundongos , Fagocitose/efeitos dos fármacos , Fagocitose/imunologia , Peixe-ZebraRESUMO
Coumarins are natural compounds with antioxidant, anti-inflammatory and anti-cancer potential known to modulate inflammatory pathways. Here, non-toxic biscoumarin OT52 strongly inhibited proliferation of non-small cell lung cancer cells with KRAS mutations, inhibited stem-like characteristics by reducing aldehyde dehydrogenase expression and abrogated spheroid formation capacity. This cytostatic effect was characterized by cell cycle arrest and onset of senescence concomitant with endoplasmic reticulum and Golgi stress, leading to metabolic alterations. Mechanistically, this cellular response was associated with the novel capacity of biscoumarin OT52 to inhibit STAT3 transactivation and expression of its target genes linked to proliferation. These results were validated by computational docking of OT52 to the STAT3 DNA-binding domain. Combination treatments of OT52 with subtoxic concentrations of Bcl-xL and Mcl-1-targeting BH3 protein inhibitors triggered synergistic immunogenic cell death validated in colony formation assays as well as in vivo by zebrafish xenografts.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Fator de Transcrição STAT3/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto , 4-Hidroxicumarinas/administração & dosagem , 4-Hidroxicumarinas/química , Células A549 , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citostáticos/administração & dosagem , Citostáticos/química , Sinergismo Farmacológico , Complexo de Golgi/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Estrutura Molecular , Fragmentos de Peptídeos/química , Peptidomiméticos/administração & dosagem , Peptidomiméticos/química , Proteínas Proto-Oncogênicas/química , Fator de Transcrição STAT3/metabolismo , Peixe-ZebraRESUMO
Polysulfanes show chemopreventive effects against gastrointestinal tumors. We identified diallyl tetrasulfide and its derivative, dibenzyl tetrasulfide (DBTTS), to be mitotic inhibitors and apoptosis inducers. Here, we translate their application in colorectal cancer (CRC). MALDI-TOF-MS analysis identified both compounds as reversible tubulin binders, validated by in cellulo α-tubulin degradation. BRAF(V600E)-mutated HT-29 cells were resistant to DBTTS, as evidenced by mitotic arrest for 48 h prior to apoptosis induction compared to KRAS(G12V)-mutated SW480/620 cells, which committed to death earlier. The prolonged mitotic block correlated with autophagy impairment and p62 protein accumulation in HT-29 but not in SW480/620 cells, whereas siRNA-mediated p62 inhibition sensitized HT-29 cells to death. In silico analysis with 484 colorectal cancer patients associated higher p62 expression and reduced autophagic flux with greater overall survival. Accordingly, we hypothesized that DBTTS targets CRC survival/death through autophagy interference in cell types with differential autophagic capacities. We confirmed the therapeutic potential of DBTTS by the inhibition of spheroid and colony formation capacities in CRC cells, as well as in HT-29 zebrafish xenografts in vivo.
Assuntos
Compostos Alílicos/farmacologia , Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Compostos de Benzil/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Mitose/efeitos dos fármacos , Sulfetos/farmacologia , Tubulina (Proteína)/metabolismo , Compostos Alílicos/metabolismo , Animais , Compostos de Benzil/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Células HT29 , Xenoenxertos , Humanos , Mutação , Ligação Proteica , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Interferência de RNA , Proteína Sequestossoma-1/genética , Proteína Sequestossoma-1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sulfetos/metabolismo , Fatores de Tempo , Transfecção , Peixe-ZebraRESUMO
Cells reprogram their metabolism very early during carcinogenesis; this event is critical for the establishment of other cancer hallmarks. Many oncogenes and tumor suppressor genes control metabolism by interplaying with the existing nutrient-sensing intracellular pathways. Mammalian target of rapamycin, mTOR, is emerging as a collector and sorter of a metabolic network controlling upstream and downstream modulation of these same genes. Natural compounds represent a source of anti-cancer molecules with chemopreventive and therapeutic properties. This review describes selected pathways and genes orchestrating the metabolic reprogramming and discusses the potential of natural compounds to target oncogenic metabolic aberrations.
Assuntos
Antineoplásicos/farmacologia , Transformação Celular Neoplásica/metabolismo , Neoplasias/tratamento farmacológico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Reprogramação Celular/genética , Curcumina/farmacologia , Humanos , Neoplasias/genética , Neoplasias/patologia , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Quercetina/farmacologia , Resveratrol , Transdução de Sinais/genética , Estilbenos/farmacologia , Serina-Treonina Quinases TOR/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Valproic acid (VPA) exhibits important pharmacological properties but has been reported to trigger side effects, notably on the hematological system. We previously reported that VPA affects hematopoietic homeostasis by inhibiting erythroid differentiation and promoting myeloid and megakaryocyte differentiation. Here, we analyzed the effect of VPA on regulatory factors involved in erythro-megakaryocytic differentiation pathways, including transcription factors and microRNAs (miRs). We demonstrate that VPA inhibited erythroid differentiation in erythropoietin (Epo)-stimulated TF1 leukemia cells and CD34(+)/hematopoietic stem cells (HSCs) and in aclacinomycin-(Acla)-treated K562 cells. Mir-144/451 gene expression was decreased in all erythroid and megakaryocyte models in correlation with GATA-1 inhibition. In Epo-stimulated CD34(+)/HSCs, VPA induced the expression of the ETS family transcription factors PU.1, ETS-1, GABP-α, Fli-1 and GATA-2, which are all known to be negative regulators of erythropoiesis, while it promoted the megakaryocytic pathway. PU.1 and ETS-1 expression were induced in correlation with miR-155 inhibition; however, the GATA-1/PU.1 interaction was promoted. Using megakaryoblastic Meg-01 cells, we demonstrated that VPA induced megakaryocyte morphological features and CD61 expression. GATA-2 and miR-27a expression were increased in correlation with a decrease in RUNX1 mRNA expression, suggesting megakaryocyte differentiation. Finally, by using valpromide and the Class I HDACi MS-275, we validated that the well-described HDACi activity of VPA is not required in the inhibitory effect on erythropoiesis. Overall, this report shows that VPA modulates the erythro-megakaryocytic differentiation program through regulatory micro-networks involving GATA and ETS transcription factors and miRNAs, notably the GATA-1/miR-144/451 axis.
Assuntos
Células Eritroides , Células-Tronco Hematopoéticas/fisiologia , Megacariócitos/fisiologia , MicroRNAs/fisiologia , Fatores de Transcrição/fisiologia , Ácido Valproico/farmacologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Eritroides/efeitos dos fármacos , Sangue Fetal/citologia , Sangue Fetal/efeitos dos fármacos , Sangue Fetal/fisiologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Células K562 , Megacariócitos/efeitos dos fármacosRESUMO
Increased proliferation rates as well as resistance to apoptosis are considered major obstacles for the treatment of patients with chronic myelogenous leukemia (CML), thus highlighting the need for novel therapeutic approaches. Since senescence has been recognized as a physiological barrier against tumorigenesis, senescence-based therapy could represent a new strategy against CML. DNA demethylating agent 5-aza-2'-deoxycytidine (DAC) was reported to induce cellular senescence but underlying mechanisms remain to be elucidated. Here, we report that exposure to DAC triggers senescence in chronic leukemia cell lines as evidenced by increased senescence-associated ß-galactosidase activity and lysosomal mass, accompanied by an up-regulation of cell cycle-related genes. We provide evidence that DAC is able to decrease telomere length, to reduce telomerase activity and to decrease human telomerase reverse transcriptase (hTERT) expression through decreased binding of c-myc to the hTERT promoter. Altogether, our results reveal the role of c-myc in telomere-dependent DAC-induced senescence and therefore provide new clues for improving chronic human leukemia treatments.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Senescência Celular/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Proteínas Proto-Oncogênicas c-myc/genética , Telomerase/genética , Azacitidina/farmacologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Decitabina , Regulação para Baixo , Epigênese Genética , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Proto-Oncogênicas c-myc/metabolismo , Encurtamento do Telômero , Transcrição GênicaRESUMO
A chemical investigation of the endophytic fungus Epicoccum nigrum isolated from leaves of Mentha suaveolens collected in Morocco resulted in the isolation of five new polyketides, epicocconigrones A and B (1 and 2), 3-methoxyepicoccone B (3), 3-methoxyepicoccone (4), and 2,3,4-trihydroxy-6-(methoxymethyl)-5-methylbenzaldehyde (5), together with five known compounds (6-10). The structures of the new compounds were unambiguously determined by extensive analysis of the 1D and 2D NMR and mass spectroscopic data. Compounds 1 and 10 showed potent inhibition of at least 15 protein kinases with IC50 values ranging from 0.07 to 9.00 µM. Moreover, compounds 1 and 10 inhibited histone deacetylase (HDAC) activities with IC50 values of 9.8 and 14.2 µM, respectively. A preliminary structure-activity relationship is discussed. Interestingly, compounds 1 and 10 exert mainly cytostatic effects in human lymphoma RAJI and U-937 cell lines.
Assuntos
Ascomicetos/química , Inibidores de Histona Desacetilases/isolamento & purificação , Inibidores de Histona Desacetilases/farmacologia , Mentha/microbiologia , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Inibidores de Proteínas Quinases/isolamento & purificação , Inibidores de Proteínas Quinases/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/química , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Marrocos , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/microbiologia , Policetídeos/química , Inibidores de Proteínas Quinases/química , Proteínas Quinases , Relação Estrutura-AtividadeRESUMO
Glucocorticoids (GCs) block inflammation via interference of the liganded glucocorticoid receptor (GR) with the activity of pro-inflammatory transcription factors NF-κB and AP-1, a mechanism known as transrepression. This mechanism is believed to involve the activity of GR monomers. Here, we explored how the GR monomer-favoring Compound A (CpdA) affects AP-1 activation and activity. Our results demonstrate that non-steroidal CpdA, unlike classic steroidal GCs, blocks NF-κB- but not AP-1-driven gene expression. CpdA rather sustains AP-1-driven gene expression, a result which could mechanistically be explained by the failure of CpdA to block upstream JNK kinase activation and concomitantly also phosphorylation of c-Jun. In concordance and in contrast to DEX, CpdA maintained the expression of the activated AP-1 target gene c-jun, as well as the production of the c-Jun protein. As for the underlying mechanism, GR is a necessary intermediate in the CpdA-mediated gene expression of AP-1-regulated genes, but seems to be superfluous to CpdA-mediated JNK phosphorylation prolongation. The latter phenomenon concurs with the inability of CpdA to stimulate DUSP1 gene expression. ChIP analysis demonstrates that DEX-activated GR, but not CpdA-activated GR, is recruited to AP-1-driven promoters. Furthermore, in mice we observed that CpdA instigates a strong enhancement of TNF-induced AP-1-driven gene expression. Finally, we demonstrate that this phenomenon coincides with an increased sensitivity towards TNF lethality, and implicate again a role for JNK2. In conclusion, our data support the hypothesis that a ligand-induced differential conformation of GR yields a different transcription factor cross-talk profile.