RESUMO
Acute myelogenous leukaemia (AML) originates and is maintained by leukaemic stem cells (LSCs) that are inherently resistant to antiproliferative therapies, indicating that a critical strategy for overcoming chemoresistance in AML therapy is to eradicate LSCs. In this work, we investigated the anti-AML activity of bortezomib (BTZ), emphasizing its anti-LSC potential, using KG-1a cells, an AML cell line with stem-like properties. BTZ presented potent cytotoxicity to both solid and haematological malignancy cells and reduced the stem-like features of KG-1a cells, as observed by the reduction in CD34- and CD123-positive cells. A reduction in NF-κB p65 nuclear staining was observed in BTZ-treated KG-1a cells, in addition to upregulation of the NF-κB inhibitor gene NFΚBIB. BTZ-induced DNA fragmentation, nuclear condensation, cell shrinkage and loss of transmembrane mitochondrial potential along with an increase in active caspase-3 and cleaved PARP-(Asp 214) level in KG-1a cells. Furthermore, BTZ-induced cell death was partially prevented by pretreatment with the pancaspase inhibitor Z-VAD-(OMe)-FMK, indicating that BTZ induces caspase-mediated apoptosis. BTZ also increased mitochondrial superoxide levels in KG-1a cells, and BTZ-induced apoptosis was partially prevented by pretreatment with the antioxidant N-acetylcysteine, indicating that BTZ induces oxidative stress-mediated apoptosis in KG-1a cells. At a dosage of 0.1 mg/kg every other day for 2 weeks, BTZ significantly reduced the percentage of hCD45-positive cells in the bone marrow and peripheral blood of NSG mice engrafted with KG-1a cells with tolerable toxicity. Taken together, these data indicate that the anti-LSC potential of BTZ appears to be an important strategy for AML treatment.
Assuntos
Bortezomib , Leucemia Mieloide Aguda , NF-kappa B , Células-Tronco Neoplásicas , Estresse Oxidativo , Bortezomib/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/metabolismo , Animais , NF-kappa B/metabolismo , Linhagem Celular Tumoral , Camundongos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Apoptose/efeitos dos fármacos , Antineoplásicos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos SCIDRESUMO
Multiple myeloma (MM) remains incurable due to disease relapse and drug resistance. Notch signals from the tumor microenvironment (TME) confer chemoresistance, but the cellular and molecular mechanisms are not entirely understood. Using clinical and transcriptomic datasets, we found that NOTCH3 is upregulated in CD138+ cells from newly diagnosed MM (NDMM) patients compared to healthy individuals and increased in progression/relapsed MM (PRMM) patients. Further, NDMM patients with high NOTCH3 expression exhibited worse responses to bortezomib (BOR)-based therapies. Cells of the TME, including osteocytes, upregulated NOTCH3 in MM cells and protected them from apoptosis induced by BOR. NOTCH3 activation (NOTCH3OE) in MM cells decreased BOR anti-MM efficacy and its ability to improve survival in in vivo myeloma models. Molecular analyses revealed that NDMM and PRMM patients with high NOTCH3 exhibit CXCL12 upregulation. TME cells upregulated CXCL12 and activated the CXCR4 pathway in MM cells in a NOTCH3-dependent manner. Moreover, genetic or pharmacologic inhibition of CXCL12 in NOTCH3OE MM cells restored sensitivity to BOR regimes in vitro and in human bones bearing NOTCH3OE MM tumors cultured ex vivo. Our clinical and preclinical data unravel a novel NOTCH3-CXCL12 pro-survival signaling axis in the TME and suggest that osteocytes transmit chemoresistance signals to MM cells.
Assuntos
Quimiocina CXCL12 , Resistencia a Medicamentos Antineoplásicos , Mieloma Múltiplo , Receptor Notch3 , Transdução de Sinais , Microambiente Tumoral , Animais , Humanos , Camundongos , Bortezomib/farmacologia , Bortezomib/uso terapêutico , Linhagem Celular Tumoral , Quimiocina CXCL12/metabolismo , Quimiocina CXCL12/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Mieloma Múltiplo/genética , Receptor Notch3/metabolismo , Receptor Notch3/genética , Transdução de Sinais/efeitos dos fármacosRESUMO
The proteasome inhibitor bortezomib (BTZ) is proposed to deplete activated B cells and plasma cells. However, a complete picture of the mechanisms underlying BTZ-induced apoptosis in B lineage cells remains to be established. In this study, using a direct in vitro approach, we show that deletion of the tumor suppressor and cell cycle regulator p53 rescues recently activated mouse B cells from BTZ-induced apoptosis. Furthermore, BTZ treatment elevated intracellular p53 levels, and p53 deletion constrained apoptosis, as recently stimulated cells first transitioned from the G1 to S phase of the cell cycle. Moreover, combined inhibition of the p53-associated cell cycle regulators and E3 ligases MDM2 and anaphase-promoting complex/cyclosome induced cell death in postdivision B cells. Our results reveal that efficient cell cycle progression of activated B cells requires proteasome-driven inhibition of p53. Consequently, BTZ-mediated interference of proteostasis unleashes a p53-dependent cell cycle-associated death mechanism in recently activated B cells.
Assuntos
Antineoplásicos , Inibidores de Proteassoma , Animais , Camundongos , Bortezomib/farmacologia , Bortezomib/metabolismo , Inibidores de Proteassoma/farmacologia , Antineoplásicos/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Linhagem Celular Tumoral , Complexo de Endopeptidases do Proteassoma/metabolismo , ApoptoseRESUMO
Several studies have shown that diverse components of the bone marrow (BM) microenvironment play a central role in the progression, pathophysiology, and drug resistance in multiple myeloma (MM). In particular, the dynamic interaction between BM mesenchymal stem cells (BM-MSC) and MM cells has shown great relevance. Here we showed that inhibiting both PKC and NF-κB signalling pathways in BM-MSC reduced cell survival in the MM cell line H929 and increased its susceptibility to the proteasome inhibitor bortezomib. PKC-mediated cell survival inhibition and bortezomib susceptibility induction were better performed by the chimeric peptide HKPS than by the classical enzastaurin inhibitor, probably due to its greatest ability to inhibit cell adhesion and its increased capability to counteract the NF-κB-related signalling molecules increased by the co-cultivation of BM-MSC with H929 cells. Thus, inhibiting two coupled signalling molecules in BM-MSC was more effective in blocking the supportive cues emerging from the mesenchymal stroma. Considering that H929 cells were also directly susceptible to PKC and NF-κB inhibition, we showed that treatment of co-cultures with the HKPS peptide and BAY11-7082, followed by bortezomib, increased H929 cell death. Therefore, targeting simultaneously connected signalling elements of BM-MSC responsible for MM cells support with compounds that also have anti-MM activity can be an improved treatment strategy.
Assuntos
Células-Tronco Mesenquimais , Mieloma Múltiplo , Humanos , Bortezomib/farmacologia , Bortezomib/uso terapêutico , Mieloma Múltiplo/metabolismo , NF-kappa B/metabolismo , Linhagem Celular Tumoral , Células-Tronco Mesenquimais/metabolismo , Microambiente TumoralRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Virola oleifera (Schott) A.C. Smith, Myristicaceae, has been widely used in traditional medicine in Brazil to treat rheumatic pain, joint tumours, skin diseases, halitosis, bronchial asthma, haemorrhoids, and intestinal worms. Recently, research data showed the antioxidant properties in several oxidative stress-related models. However, there is no experimental evidence supporting its potential use in managing rheumatic diseases and bone malignancies. AIMS OF THE STUDY: To evaluate the therapeutic potential of the resin from Virola oleifera in joint and bone diseases, namely arthritis, osteosarcoma, chondrosarcoma, and multiple myeloma. MATERIALS AND METHODS: To determine Virola oleifera resin (VO) effects on arthritis-associated inflammation and cartilage degradation, the LPS-induced NO production, and mRNA and protein expression of ADAMTS5, MMP13, COL2, and ACAN, were evaluated in chondrocytes (ATDC5 and TC28 cell lines). The cytotoxic effects of VO (0.05-50 µg/ml) on multiple myeloma (ARH-77), osteosarcoma (SAOS-2), and chondrosarcoma (SW-1353) cell lines were analysed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The VO effects, combined with dexamethasone or bortezomib, were evaluated in a multiple myeloma cell line. The mechanisms of VO, alone or in combination with bortezomib, were determined by cell cycle analysis through flow cytometry, while expression levels of p-Akt/Akt, p-ERK/ERK, p-p38/p38 MAPK, Bax, Bcl-2, and cleaved-caspase-3/caspase-3 proteins by Western blot. RESULTS: VO had no significant effect on LPS-induced NO production in chondrocytes at non-cytotoxic concentrations. VO treatment diminished the mRNA levels of metalloproteinases and ECM components; however, any significant effect was observed on the protein expression levels. The cell viability of a multiple myeloma cell line was strongly reduced by VO treatment in a dose- and time-dependent manner, while osteosarcoma and chondrosarcoma cell lines viability was significantly affected only by the highest dose assessed. In multiple myeloma cells, VO leads to G2/M cell cycle arrest. Furthermore, it synergizes with dexamethasone by increasing cell toxicity. Finally, VO reverts bortezomib activity by counteracting ERK1/2, Bax, and caspase-3 activation. CONCLUSIONS: The current work supports the ethnopharmacological use of Virola oleifera (Schott) A.C. Smith in bone and joint diseases, but there is no evidence for the amelioration of arthritis-associated inflammatory or catabolic processes. Our data also supports the potential use of Virola oleifera as adjuvant therapy to optimize the pharmacologic effects of current chemotherapeutic drugs. However, possible herb-drug interactions should be considered before clinical application.
Assuntos
Proliferação de Células/efeitos dos fármacos , Mieloma Múltiplo/tratamento farmacológico , Doenças Musculoesqueléticas/tratamento farmacológico , Myristicaceae/química , Resinas Vegetais/farmacologia , Animais , Antineoplásicos/farmacologia , Antineoplásicos Hormonais/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Bortezomib/farmacologia , Brasil , Cartilagem/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dexametasona/farmacologia , Quimioterapia Combinada , Interações Ervas-Drogas , Humanos , Inflamação/metabolismo , CamundongosRESUMO
Autophagy is a mechanism responsible for intracellular degradation and recycling of macromolecules and organelles, essential for cell survival in adverse conditions. More than 40 autophagy-related (ATG) genes have been identified and characterized in fungi, among them ATG4 and ATG8. ATG4 encodes a cysteine protease (Atg4) that plays an important role in autophagy by initially processing Atg8 at its C-terminus region. Atg8 is a ubiquitin-like protein essential for the synthesis of the double-layer membrane that constitutes the autophagosome vesicle, responsible for delivering the cargo from the cytoplasm to the vacuole lumen. The contributions of Atg-related proteins in the pathogenic yeast in the genus Cryptococcus remain to be explored, to elucidate the molecular basis of the autophagy pathway. In this context, we aimed to investigate the role of autophagy-related proteins 4 and 8 (Atg4 and Atg8) during autophagy induction and their contribution with non-autophagic events in C. neoformans. We found that Atg4 and Atg8 are conserved proteins and that they interact physically with each other. ATG gene deletions resulted in cells sensitive to nitrogen starvation. ATG4 gene disruption affects Atg8 degradation and its translocation to the vacuole lumen, after autophagy induction. Both atg4 and atg8 mutants are more resistant to oxidative stress, have an impaired growth in the presence of the cell wall-perturbing agent Congo Red, and are sensitive to the proteasome inhibitor bortezomib (BTZ). By that, we conclude that in C. neoformans the autophagy-related proteins Atg4 and Atg8 play an important role in the autophagy pathway; which are required for autophagy regulation, maintenance of amino acid levels and cell adaptation to stressful conditions.
Assuntos
Família da Proteína 8 Relacionada à Autofagia/fisiologia , Proteínas Relacionadas à Autofagia/fisiologia , Cryptococcus neoformans/fisiologia , Proteínas Fúngicas/fisiologia , Aminoácidos/metabolismo , Autofagia/genética , Autofagia/fisiologia , Família da Proteína 8 Relacionada à Autofagia/genética , Proteínas Relacionadas à Autofagia/genética , Bortezomib/farmacologia , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/genética , Farmacorresistência Fúngica , Proteínas Fúngicas/genética , Genes Fúngicos , Teste de Complementação Genética , Humanos , Técnicas In Vitro , Mutação , Nitrogênio/metabolismo , Estresse Oxidativo/genética , Inibidores de Proteassoma/farmacologia , Processamento de Proteína Pós-Traducional , Vacúolos/metabolismoRESUMO
INTRODUCTION: Multiple myeloma (MM) remains incurable due to high rates of relapse after various treatment regimens. WEE1 is a cell cycle related gene that regulates the G2/M checkpoint and promotes cell cycle suspension for consequent DNA repair. To date, there are clinical studies for the evaluation of WEE1 inhibitors in the treatment of solid tumors and studies on cell lines of non-MM hematological tumors. OBJECTIVES: To perform in vitro functional studies to verify the effect of the inhibition of WEE1 on MM cell lines viability and its potential as therapeutic target. MATERIAL AND METHODS: WEE1 expression was evaluated in 22 newly diagnosed MM patients and in four MM cell lines, RPMI-8226, U266 and SKO-007 and SK-MM2, by quantitative real-time PCR (qPCR). After treatment with the WEE1 inhibitor (MK-1775), with or without proteasome inhibitor (bortezomib) pretreatment, we assessed cell viability through Prestoblue functional test, microspheres formation in soft agar, and induction of apoptosis and cell cycle alterations by flow cytometry. RESULTS: All MM cell lines showed WEE1 expression by qPCR. RPMI-8226 and U266 showed a 50% reduction in cell viability after 24â¯h of incubation with MK-1775, at concentrations of 5⯵M and 20⯵M, respectively. SKO-007 showed dose and time dependence to this drug. Combination therapy with bortezomib and MK-1775 abolished the formation of soft agar microspheres in the RPMI-8226â¯cell line (also responsive to the use of both drugs) and U266, but SKO-007 was resistant to all drugs, isolated and combined. However, treatment of bortezomib followed by MK-1775 (sequential treatment) versus bortezomib alone showed statistically significant impact on cell lines total apoptosis: 88.8% vs 74.1% in RPMI-8222 (confirmed by cell cycle experiments); 92.5% vs 86.6% in U266; and 60.2% 30.9% on SKO-007 (pâ¯<â¯0.05). CONCLUSION: The sequential combination of bortezomib and WEE1 inhibitor, MK-1775, induced apoptosis in RPMI-8226, U266, and especially SKO-007â¯cell lines, more efficiently than the use of the same isolated drugs, highlighting its effect in inhibition of proliferation of tumor cells in MM cell lines. Our data suggest that WEE1 can figure as a MM target and that the sequential combination of bortezomib and MK-1775 may be explored in future clinical trials.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Bortezomib/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirazóis/farmacologia , Pirimidinonas/farmacologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
INTRODUCTION: Glioblastoma multiforme (GBM) is the most lethal form of gliomas. New therapies are currently in development to tackle treatment limitations such as chemotherapy resistance. One mechanism of resistance may be the stress granules (SG) assembly, a stress-related cellular response that allows cells to recruit and protect mRNAs during stress. SG are composed of various proteins, being G3BP1 a core element that enucleates and results in SG assembly. Here, we aimed to evaluate the effects of inhibiting the G3PB1 expression in the chemotherapeutical-induced cell death of the U87 glioblastoma cell line. MATERIALS AND METHODS: G3BP1 mRNA and protein expression were modulated with short-interference RNA (siRNA). The viability of U87 cells after Bortezomib (BZM), a proteasome inhibitor, and Temozolomide (TMZ), an alkylating agent, was assessed by MTT assay. Apoptosis was evaluated by staining cells with Annexin-V/7-AAD and analyzing by flow cytometry. Caspase-3 activation was evaluated by immunoblotting. The chorioallantoic membrane in vivo assay was used to evaluate angiogenesis. RESULTS: When G3BP1 was knocked-down, the SG assembly was reduced and the BZM-treated cells, but not TMZ-treated cells, had a significant increase in the apoptotic response. Corroborating this data, we observed increased Caspase-3 activation in the BZM-treated and G3BP1-knocked-down cells when compared to vehicle-treated and scramble-transfected cells. Worth mentioning, the conditioned culture medium of G3BP1-knocked-down BZM-treated cells inhibited angiogenesis when compared to controls. CONCLUSION: Our data suggest G3BP1 knockdown diminishes SG formation and stimulates BZM-induced apoptosis of U87 cells in vitro, in addition to inhibiting glioblastoma-induced angiogenesis in vivo.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Bortezomib/farmacologia , Grânulos Citoplasmáticos/efeitos dos fármacos , DNA Helicases/antagonistas & inibidores , Glioblastoma/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Proteínas de Ligação a Poli-ADP-Ribose/antagonistas & inibidores , RNA Helicases/antagonistas & inibidores , Proteínas com Motivo de Reconhecimento de RNA/antagonistas & inibidores , Antineoplásicos Alquilantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Grânulos Citoplasmáticos/patologia , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Temozolomida/farmacologia , Células Tumorais CultivadasRESUMO
Multiple myeloma (MM) is an incurable disease; a better understanding of the molecular aspects of this hematological malignancy could contribute to the development of new treatment strategies and help to improve the survival rates of patients with MM. Previously, the methylation status of the deleted in colorectal cancer (DCC) gene was correlated with the survival rate of patients with MM, thus the main goal of this study was to understand DCC contribution to MM tumorigenesis, and to assess the impact of DCC inhibition in the MM response to treatment with bortezomib. Our results demonstrated that hypermethylation of the DCC promoter inhibits gene expression, and DCC silencing is significantly correlated with a reduction in cell viability and an increase in cell death induced by bortezomib. In conclusion, our results suggested that hypermethylation is an important mechanism of DCC expression regulation in MM and that the absence of DCC contributes to the enhanced sensitivity to treatment with bortezomib.
Assuntos
Bortezomib/farmacologia , Receptor DCC/metabolismo , Regulação para Baixo/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Receptor DCC/antagonistas & inibidores , Receptor DCC/genética , Metilação de DNA/efeitos dos fármacos , Humanos , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Regiões Promotoras Genéticas , Interferência de RNA , RNA Interferente Pequeno/metabolismoRESUMO
INTRODUCTION: Multiple myeloma (MM) cells accumulate in the bone marrow and produce enormous quantities of immunoglobulins, causing endoplasmatic reticulum stress and activation of protein handling machinery, such as heat shock protein response, autophagy and unfolded protein response (UPR). METHODS: We evaluated cell lines viability after treatment with bortezomib (B) in combination with HSP70 (VER-15508) and autophagy (SBI-0206965) or UPR (STF- 083010) inhibitors. RESULTS: For RPMI-8226, after 72 hours of treatment with B+VER+STF or B+VER+SBI, we observed 15% of viable cells, but treatment with B alone was better (90% of cell death). For U266, treatment with B+VER+STF or with B+VER+SBI for 72 hours resulted in 20% of cell viability and both treatments were better than treatment with B alone (40% of cell death). After both triplet combinations, RPMI-8226 and U266 presented the overexpression of XBP-1 UPR protein, suggesting that it is acting as a compensatory mechanism, in an attempt of the cell to handle the otherwise lethal large amount of immunoglobulin overload. CONCLUSION: Our in vitro results provide additional evidence that combinations of protein homeostasis inhibitors might be explored as treatment options for MM.