RESUMO
Malignant rhabdoid tumor (MRT) is a highly aggressive pediatric malignancy with no effective therapy. Therefore, it is necessary to identify a target for the development of novel molecule-targeting therapeutic agents. In this study, we report the importance of the runt-related transcription factor 1 (RUNX1) and RUNX1-Baculoviral IAP (inhibitor of apoptosis) Repeat-Containing 5 (BIRC5/survivin) axis in the proliferation of MRT cells, as it can be used as an ideal target for anti-tumor strategies. The mechanism of this reaction can be explained by the interaction of RUNX1 with the RUNX1-binding DNA sequence located in the survivin promoter and its positive regulation. Specific knockdown of RUNX1 led to decreased expression of survivin, which subsequently suppressed the proliferation of MRT cells in vitro and in vivo. We also found that our novel RUNX inhibitor, Chb-M, which switches off RUNX1 using alkylating agent-conjugated pyrrole-imidazole polyamides designed to specifically bind to consensus RUNX-binding sequences (5'-TGTGGT-3'), inhibited survivin expression in vivo. Taken together, we identified a novel interaction between RUNX1 and survivin in MRT. Therefore the negative regulation of RUNX1 activity may be a novel strategy for MRT treatment.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core , Tumor Rabdoide , Survivina , Humanos , Apoptose , Sequência de Bases , Linhagem Celular Tumoral , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Tumor Rabdoide/tratamento farmacológico , Tumor Rabdoide/genéticaRESUMO
Glioblastoma is the most common adult brain tumour, representing a high degree of malignancy. Transcription factors such as RUNX1 are believed to be involved in the malignancy of glioblastoma. RUNX1 functions as an oncogene or tumour suppressor gene with diverse target genes. Details of the effects of RUNX1 on the acquisition of malignancy in glioblastoma remain unclear. Here, we show that RUNX1 downregulates p21 by enhancing expressions of BIRC5 and PIF1, conferring anti-apoptotic properties on glioblastoma. A gene switch-off therapy using alkylating agent-conjugated pyrrole-imidazole polyamides, designed to fit the RUNX1 DNA groove, decreased expression levels of BIRC5 and PIF1 and induced apoptosis and cell cycle arrest via p21. The RUNX1-BIRC5/PIF1-p21 pathway appears to reflect refractory characteristics of glioblastoma and thus holds promise as a therapeutic target. RUNX gene switch-off therapy may represent a novel treatment for glioblastoma.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Animais , Apoptose/genética , Neoplasias Encefálicas/genética , Subunidade alfa 2 de Fator de Ligação ao Core , DNA Helicases , Glioblastoma/genética , Camundongos , OncogenesRESUMO
Malignancy of medulloblastoma depends on its molecular classification. Sonic Hedgehog (SHH)-type medulloblastoma with p53 mutation was recognized as one of the most aggressive types of tumors. We developed a novel drug, chlorambucil-conjugated PI-polyamides (Chb-M'), which was designed to compete with the RUNX consensus DNA-binding site. Chb-M' specifically recognizes this consensus sequence and alkylates it to inhibit the RUNX transcriptional activity. In-silico analysis showed all the RUNX families were upregulated in the SHH-type medulloblastoma. Thus, we tested the anti-tumor effects of Chb-M' in vitro and in vivo using Daoy cell lines, which belong to SHH with p53 mutation. Chb-M' inhibited tumor growth of Daoy cells by inducing apoptosis. The same inhibitory effect was also observed by knocking down of RUNX1 or RUNX2, but not RUNX3. Apoptosis array analysis showed that Chb-M' treatment induced phosphorylation of p53 serine 15 residues. In a subcutaneous tumor model, intratumoral injection of Chb-M' induced tumor growth retardation. Chb-M' mediated inhibition of RUNX1 and RUNX2 can be a novel therapeutic strategy for SHH-type medulloblastoma with p53 mutation.
Assuntos
Neoplasias Cerebelares , Meduloblastoma , Neoplasias Cerebelares/tratamento farmacológico , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/metabolismo , Clorambucila/farmacologia , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Proteínas Hedgehog/metabolismo , Humanos , Meduloblastoma/tratamento farmacológico , Meduloblastoma/genética , Meduloblastoma/metabolismo , Mutação , Nylons/química , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Renal cell carcinoma with Xp11.2 translocation involving the TFE3 gene (TFE3-RCC) is a recently identified subset of RCC with unique morphology and clinical presentation. The chimeric PRCC-TFE3 protein produced by Xp11.2 translocation has been shown to transcriptionally activate its downstream target genes that play important roles in carcinogenesis and tumor development of TFE3-RCC. However, the underlying molecular mechanisms remain poorly understood. Here we show that in TFE3-RCC cells, PRCC-TFE3 controls heme oxygenase 1 (HMOX1) expression to confer chemoresistance. Inhibition of HMOX1 sensitized the PRCC-TFE3 expressing cells to genotoxic reagents. We screened for a novel chlorambucil-polyamide conjugate (Chb) to target PRCC-TFE3-dependent transcription, and identified Chb16 as a PRCC-TFE3-dependent transcriptional inhibitor of HMOX1 expression. Treatment of the patient-derived cancer cells with Chb16 exhibited senescence and growth arrest, and increased sensitivity of the TFE3-RCC cells to the genotoxic reagent etoposide. Thus, our data showed that the TFE3-RCC cells acquired chemoresistance through HMOX1 expression and that inhibition of HMOX1 by Chb16 may be an effective therapeutic strategy for TFE3-RCC.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Clorambucila/farmacologia , Cromossomos Humanos X , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Nylons , Translocação GenéticaRESUMO
The emergence of tyrosine kinase inhibitors as part of a front-line treatment has greatly improved the clinical outcome of the patients with Ph+ acute lymphoblastic leukemia (ALL). However, a portion of them still become refractory to the therapy mainly through acquiring mutations in the BCR-ABL1 gene, necessitating a novel strategy to treat tyrosine kinase inhibitor (TKI)-resistant Ph+ ALL cases. In this report, we show evidence that RUNX1 transcription factor stringently controls the expression of BCR-ABL1, which can strategically be targeted by our novel RUNX inhibitor, Chb-M'. Through a series of in vitro experiments, we identified that RUNX1 binds to the promoter of BCR and directly transactivates BCR-ABL1 expression in Ph+ ALL cell lines. These cells showed significantly reduced expression of BCR-ABL1 with suppressed proliferation upon RUNX1 knockdown. Moreover, treatment with Chb-M' consistently downregulated the expression of BCR-ABL1 in these cells and this drug was highly effective even in an imatinib-resistant Ph+ ALL cell line. In good agreement with these findings, forced expression of BCR-ABL1 in these cells conferred relative resistance to Chb-M'. In addition, in vivo experiments with the Ph+ ALL patient-derived xenograft cells showed similar results. In summary, targeting RUNX1 therapeutically in Ph+ ALL cells may lead to overcoming TKI resistance through the transcriptional regulation of BCR-ABL1. Chb-M' could be a novel drug for patients with TKI-resistant refractory Ph+ ALL.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Proteínas de Fusão bcr-abl/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Animais , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/genética , Subunidade alfa 2 de Fator de Ligação ao Core/antagonistas & inibidores , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Mesilato de Imatinib/farmacologia , Camundongos , Mutação , Cromossomo Filadélfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Neuroblastoma, the most common extracranial solid tumor of childhood, is thought to arise from neural crest-derived immature cells. The prognosis of patients with high-risk or recurrent/refractory neuroblastoma remains quite poor despite intensive multimodality therapy; therefore, novel therapeutic interventions are required. We examined the expression of a cell adhesion molecule CD146 (melanoma cell adhesion molecule [MCAM]) by neuroblastoma cell lines and in clinical samples and investigated the anti-tumor effects of CD146-targeting treatment for neuroblastoma cells both in vitro and in vivo. CD146 is expressed by 4 cell lines and by most of primary tumors at any stage. Short hairpin RNA-mediated knockdown of CD146, or treatment with an anti-CD146 polyclonal antibody, effectively inhibited growth of neuroblastoma cells both in vitro and in vivo, principally due to increased apoptosis via the focal adhesion kinase and/or nuclear factor-kappa B signaling pathway. Furthermore, the anti-CD146 polyclonal antibody markedly inhibited tumor growth in immunodeficient mice inoculated with primary neuroblastoma cells. In conclusion, CD146 represents a promising therapeutic target for neuroblastoma.
Assuntos
Anticorpos/uso terapêutico , Antígeno CD146/antagonistas & inibidores , Terapia de Alvo Molecular/métodos , Neuroblastoma/terapia , RNA Interferente Pequeno/uso terapêutico , Animais , Apoptose , Antígeno CD146/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Quinase 1 de Adesão Focal/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Camundongos , NF-kappa B/metabolismo , Recidiva Local de Neoplasia , Transplante de Neoplasias , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Prognóstico , Transdução de Sinais , Esferoides Celulares , Transdução Genética/métodosRESUMO
Differentiation therapy is a less toxic but still a very effective treatment for a subset of acute myeloid leukaemia (AML) cases. With the goal to identify novel compounds that can effectively and safely induce the terminal differentiation of non-acute promyelocytic leukaemia (APL) AML cells, we performed a chemical screening and identified albendazole (ABZ), a widely used anti-helminthic drug, as a promising lead compound that can differentiate non-APL AML cells by stimulating the Krüppel-like factor 4-dihydropyrimidinase-like 2A (KLF4-DPYSL2A) differentiation axis to the monocytes. Our in vitro and in vivo findings demonstrate that ABZ is an attractive candidate drug as a novel differentiation chemotherapy for patients with non-APL AML.
Assuntos
Albendazol/farmacologia , Anti-Helmínticos/farmacologia , Antineoplásicos/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Fator 4 Semelhante a Kruppel/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Proteínas do Tecido Nervoso/metabolismo , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/uso terapêutico , Antineoplásicos/uso terapêutico , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Camundongos , Monócitos/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: Multiple myeloma (MM) is an incurable disease. The acquisition of resistance to drugs, including immunomodulatory drugs (IMiDs), has a negative effect on its prognosis. Cereblon (CRBN) is a key mediator of the bioactivities of IMiDs such as lenalidomide. Moreover, genetic alteration of CRBN is frequently detected in IMiD-resistant patients and is considered to contribute to IMiD resistance. Thus, overcoming resistance to drugs, including IMiDs, is expected to improve clinical outcomes. Here, we examined potential mechanisms of a histone deacetylase (HDAC) inhibitor and Akt inhibitor in relapsed/refractory MM patients. METHODS: We established lenalidomide-resistant cells by knocking down CRBN with RNAi-mediated downregulation or knocking out CRBN using CRISPR-Cas9 in MM cells. Additionally, we derived multi-drug (bortezomib, doxorubicin, or dexamethasone)-resistant cell lines and primary cells from relapsed/refractory MM patients. The effects of HDAC and Akt inhibitors on these drug-resistant MM cells were then observed with a particular focus on whether HDAC inhibitors enhance immunotherapy efficacy. We also investigated the effect of lenalidomide on CRBN-deficient cells. RESULTS: The HDAC inhibitor suppressed the growth of drug-resistant MM cell lines and enhanced the antibody-dependent cellular cytotoxicity (ADCC) of therapeutic antibodies by upregulating natural killer group 2D (NKG2D) ligands in MM cells. CRBN-deficient cells showed lenalidomide-induced upregulation of phosphorylated glycogen synthase kinase-3 (p-GSK-3) and c-Myc phosphorylation. Moreover, HDAC and Akt inhibitors downregulated c-Myc by blocking GSK-3 phosphorylation. HDAC and Akt inhibitors also exhibited synergistic cytotoxic and c-Myc-suppressive effects. The dual HDAC and PI3K inhibitor, CUDC-907, exhibited cytotoxic and immunotherapy-enhancing effects in MM cells, including multi-drug-resistant lines and primary cells from lenalidomide-resistant patients. CONCLUSIONS: The combination of an HDAC and an Akt inhibitor represents a promising approach for the treatment of relapsed/refractory MM.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Imunoterapia/métodos , Mieloma Múltiplo/tratamento farmacológico , Inibidores da Angiogênese/farmacologia , Animais , Feminino , Inibidores de Histona Desacetilases/farmacologia , Humanos , Masculino , Camundongos , Mieloma Múltiplo/patologiaRESUMO
BAALC is identified as a leukemia-associated gene and is highly expressed in CD34-positive hematopoietic stem cells. High BAALC expression is associated with poor prognosis in several types of acute myeloid leukemia. We explored binding partner proteins of BAALC by means of mass spectrometry and analyzed biological properties of BAALC-expressing leukemic cells. We found that BAALC physically interacts with DBN1, which is an actin-binding protein and promotes cell adhesion and mobility by forming cell membrane spines during cell-cell interactions. Drebrin1 downregulation impeded cell adhesion to bone marrow stromal cells, resulting in improvement of sensitivity to cytarabine. Taken together, our findings suggest that BAALC-DBN1 interaction contributes to the anchoring of BAALC-expressing cells in the bone marrow, which in turn leads to resistance to cytotoxic drugs. Therefore, the BAALC-DBN1 interaction provides us with an opportunity to overcome the chemotherapy resistance in BAALC-activated leukemia via functional blockage of these genes.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Citarabina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Leucemia/tratamento farmacológico , Proteínas de Neoplasias/metabolismo , Neuropeptídeos/metabolismo , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Células Jurkat , Leucemia/genética , Leucemia/metabolismo , Proteínas de Neoplasias/genética , Neuropeptídeos/genética , Mapas de Interação de Proteínas/efeitos dos fármacosAssuntos
Síndrome de Down/patologia , Lectinas Tipo C/análise , Leucemia Megacarioblástica Aguda/patologia , Receptores Mitogênicos/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/patologia , Criança , Síndrome de Down/complicações , Feminino , Humanos , Leucemia Megacarioblástica Aguda/complicações , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/patologia , Estudos Prospectivos , Adulto JovemRESUMO
Malignant rhabdoid tumor (MRT) is a rare and highly aggressive pediatric malignancy primarily affecting infants and young children. Intensive multimodal therapies currently given to MRT patients are not sufficiently potent to control this highly malignant tumor. Therefore, additive or alternative therapy for these patients with a poor prognosis is necessary. We herein demonstrated that the inhibition of runt-related transcription factor 1 (RUNX1) by novel alkylating conjugated pyrrole-imidazole (PI) polyamides, which specifically recognize and bind to RUNX-binding DNA sequences, was highly effective in the treatment of rhabdoid tumor cell lines in vitro as well as in an in vivo mouse model. Therefore, suppression of RUNX1 activity may be a novel strategy for MRT therapy.
Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Clorambucila/uso terapêutico , Subunidade alfa 2 de Fator de Ligação ao Core/antagonistas & inibidores , Tumor Rabdoide/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Clorambucila/análogos & derivados , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Modelos Animais de Doenças , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Interferência de RNA , RNA Interferente Pequeno/genética , Proteína SMARCB1/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The t(8;21) translocation is the most common cytogenetic abnormality in acute myeloid leukemia (AML). Although t(8;21) AML patients have a relatively favorable prognosis, relapse is a frequent occurrence, underscoring the need to develop novel therapeutic approaches. Here, we showed that t(8;21) AML is characterized by frequent mutation and overexpression of CCND2. Analysis of 19 AML cell lines showed that t(8;21) AML cells had lower IC50 values for the selective CDK4/6 inhibitors palbociclib and abemaciclib than non-t(8;21) AML cells. CDK4/6 inhibitors caused cell cycle arrest at G1 phase and impaired cell proliferation in t(8;21) AML cells. CDK4/6 inhibition decreased MAP-ERK and PI3K-AKT-mTOR signaling pathway activity, induced LC3B-I to LC3B-II conversion, and enhanced autophagosome formation, suggesting autophagy induction. Treatment of t(8;21) AML cells with the autophagy inhibitors chloroquine (CQ) or LY294002 in combination with the CDK4/6 inhibitor abemaciclib significantly increased the percentage of apoptotic (Annexin V positive) cells, whereas CQ or LY294002 single treatment had no significant effects. The effectiveness of co-inhibiting CDK4/6 and autophagy was confirmed in primary t(8;21) AML cells. The results suggest that the combination of CDK4/6 and autophagy inhibitors had a synergistic effect on inducing apoptosis, suggesting a novel therapeutic approach for the treatment of t(8;21) AML.
Assuntos
Apoptose/genética , Autofagia/genética , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Leucemia Mieloide Aguda/genética , Translocação Genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromossomos Humanos Par 21 , Cromossomos Humanos Par 8 , Ciclina D2/genética , Quinase 4 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/genética , Expressão Gênica , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Mutação , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Interferência de RNA , Transdução de Sinais/efeitos dos fármacosRESUMO
Although the biological importance of Krüppel-like factor 4 (KLF4) transcription factor in the terminal differentiation of hematopoietic cells to the monocytes has been well established, the underlying mechanisms remain elusive. To clarify the molecular basis of KLF4-mediated monocytic differentiation, we performed detailed genetic studies in acute myeloid leukemia (AML) cells. Here, we report that dihydropyrimidinase like 2 (DPYSL2), also known as CRMP2, is a novel key differentiation mediator downstream of KLF4 in AML cells. Interestingly, we discovered that KLF4-mediated monocytic differentiation is selectively dependent on one specific isoform, DPYSL2A, but not on other DPYSL family genes. Terminal differentiation to the monocytes and proliferation arrest in AML cells induced by genetic or pharmacological upregulation of KLF4 were significantly reversed by short hairpin RNA (shRNA)-mediated selective depletion of DPYSL2A. Chromatin immunoprecipitation assay revealed that KLF4 associates with the proximal gene promoter of DPYSL2A and directly transactivates its expression. Together with the unique expression patterns of KLF4 and DPYSL2 limited to the differentiated monocytes in the hematopoietic system both in human and mouse, the identified KLF4-DPYSL2 axis in leukemia cells may serve as a potential therapeutic target for the development of novel differentiation therapies for patients with AML.
Assuntos
Diferenciação Celular/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Fatores de Transcrição Kruppel-Like/fisiologia , Leucemia Mieloide Aguda/patologia , Monócitos/citologia , Proteínas do Tecido Nervoso/fisiologia , Linhagem Celular Tumoral , Regulação Leucêmica da Expressão Gênica , Humanos , Fator 4 Semelhante a Kruppel , Leucemia Mieloide Aguda/genética , Regiões Promotoras GenéticasRESUMO
Mixed-lineage leukemia (MLL) gene rearrangements are among the most frequent chromosomal abnormalities in acute myeloid leukemia (AML). MLL fusion patterns are associated with the patient's prognosis; however, their relationship with driver mutations is unclear. We conducted sequence analyses of 338 genes in pediatric patients with MLL-rearranged (MLL-r) AML (n = 56; JPLSG AML-05 study) alongside data from the TARGET study's pediatric cohorts with MLL-r AML (n = 104), non-MLL-r AML (n = 581), and adult MLL-r AML (n = 81). KRAS mutations were most frequent in pediatric patients with high-risk MLL fusions (MLL-MLLLT10, MLL-MLLT4, and MLL-MLLT1). Pediatric patients with MLL-r AML (n = 160) and a KRAS mutation (KRAS-MT) had a significantly worse prognosis than those without a KRAS mutation (KRAS-WT) (5-year event-free survival [EFS]: 51.8% vs 18.3%, P < .0001; 5-year overall survival [OS]: 67.3% vs 44.3%, P = .003). The adverse prognostic impact of KRAS mutations was confirmed in adult MLL-r AML. KRAS mutations were associated with adverse prognoses in pediatric patients with both high-risk (MLLT10+MLLT4+MLLT1; n = 60) and intermediate-to-low-risk (MLLT3+ELL+others; n = 100) MLL fusions. The prognosis did not differ significantly between patients with non-MLL-r AML with KRAS-WT or KRAS-MT. Multivariate analysis showed the presence of a KRAS mutation to be an independent prognostic factor for EFS (hazard ratio [HR], 2.21; 95% confidence interval [CI], 1.35-3.59; P = .002) and OS (HR, 1.85; 95% CI, 1.01-3.31; P = .045) in MLL-r AML. The mutation is a distinct adverse prognostic factor in MLL-r AML, regardless of risk subgroup, and is potentially useful for accurate treatment stratification. This trial was registered at the UMIN (University Hospital Medical Information Network) Clinical Trials Registry (UMIN-CTR; http://www.umin.ac.jp/ctr/index.htm) as #UMIN000000511.
Assuntos
Leucemia Mieloide Aguda , Proteínas Proto-Oncogênicas p21(ras) , Adulto , Criança , Histona-Lisina N-Metiltransferase/genética , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Mutação , Proteína de Leucina Linfoide-Mieloide/genética , Prognóstico , Proteínas Proto-Oncogênicas p21(ras)/genéticaRESUMO
Shwachman-Diamond syndrome (SDS), an autosomal recessive disorder characterized by bone marrow failure, exocrine pancreatic insufficiency, and skeletal abnormalities, is caused by mutations in the Shwachman-Bodian-Diamond syndrome (SBDS) gene, which plays a role in ribosome biogenesis. Although the causative genes of congenital disorders frequently involve regulation of embryogenesis, the role of the SBDS gene in early hematopoiesis remains unclear, primarily due to the lack of a suitable experimental model for this syndrome. In this study, we established induced pluripotent stem cells (iPSCs) from patients with SDS (SDS-iPSCs) and analyzed their in vitro hematopoietic and endothelial differentiation potentials. SDS-iPSCs generated hematopoietic and endothelial cells less efficiently than iPSCs derived from healthy donors, principally due to the apoptotic predisposition of KDR+CD34+ common hemoangiogenic progenitors. By contrast, forced expression of SBDS gene in SDS-iPSCs or treatment with a caspase inhibitor reversed the deficiency in hematopoietic and endothelial development, and decreased apoptosis of their progenitors, mainly via p53-independent mechanisms. Patient-derived iPSCs exhibited the hematological abnormalities associated with SDS even at the earliest hematopoietic stages. These findings will enable us to dissect the pathogenesis of multiple disorders associated with ribosomal dysfunction.
Assuntos
Diferenciação Celular , Células Endoteliais , Hematopoese , Células-Tronco Hematopoéticas , Células-Tronco Pluripotentes Induzidas , Síndrome de Shwachman-Diamond , Apoptose/genética , Células Cultivadas , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Japão , Masculino , Mutação , Proteínas/genética , Síndrome de Shwachman-Diamond/metabolismo , Síndrome de Shwachman-Diamond/patologiaRESUMO
Comprehensive inhibition of RUNX1, RUNX2, and RUNX3 led to marked cell suppression compared with inhibition of RUNX1 alone, clarifying that the RUNX family members are important for proliferation and maintenance of diverse cancers, and "cluster regulation of RUNX (CROX)" is a very effective strategy to suppress cancer cells. Recent studies reported by us and other groups suggested that wild-type RUNX1 is needed for survival and proliferation of certain types of leukemia, lung cancer, gastric cancer, etc. and for their one of metastatic target sites such as born marrow endothelial niche, suggesting that RUNX1 often functions oncogenic manners in cancer cells. In this review, we describe the significance and paradoxical requirement of RUNX1 tumor suppressor in leukemia and even solid cancers based on recent our findings such as "genetic compensation of RUNX family transcription factors (the compensation mechanism for the total level of RUNX family protein expression)", "RUNX1 inhibition-induced inhibitory effects on leukemia cells and on solid cancers through p53 activation", and "autonomous feedback loop of RUNX1-p53-CBFB in acute myeloid leukemia cells". Taken together, these findings identify a crucial role for the RUNX cluster in the maintenance and progression of cancers and suggest that modulation of the RUNX cluster using the pyrrole-imidazole polyamide gene-switch technology is a potential novel therapeutic approach to control cancers.
Assuntos
Subunidades alfa de Fatores de Ligação ao Core/genética , Transcrição Gênica/genética , HumanosRESUMO
In spite of distinct clinical importance, the molecular mechanisms how Additional sex combs-like 1 (ASXL1) mutation contributes to the pathogenesis of premalignant conditions are largely unknown. Here, with newly generated knock-in mice, we investigated the biological effects of the mutant. Asxl1G643fs heterozygous (Asxl1G643fs/+) mice developed phenotypes recapitulating human low-risk myelodysplastic syndromes (MDS), and some of them developed MDS/myeloproliferative neoplasm-like disease after long latency. H2AK119ub1 level around the promoter region of p16Ink4a was significantly decreased in Asxl1G643fs/+ hematopoietic stem cells (HSC), suggesting perturbation of Bmi1-driven H2AK119ub1 histone modification by mutated Asxl1. The mutant form of ASXL1 had no ability to interact with BMI1 as opposed to wild-type ASXL1 protein. Restoration of HSC pool and amelioration of increased apoptosis in hematopoietic stem and progenitor cells were obtained from Asxl1G643fs/+ mice heterozygous for p16Ink4a. These results indicated that loss of protein interaction between Asxl1 mutant and Bmi1 affected the activity of PRC1, and subsequent derepression of p16Ink4a by aberrant histone ubiquitination could induce cellular senescence, resulting in low-risk MDS-like phenotypes in Asxl1G643fs/+ mice. This model provides a useful platform to unveil the molecular basis for hematological disorders induced by ASXL1 mutation and to develop therapeutic strategies for these patients.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/antagonistas & inibidores , Hematopoese , Histonas/química , Mutação , Síndromes Mielodisplásicas/etiologia , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/fisiologia , Animais , Apoptose , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Masculino , Camundongos Endogâmicos C57BL , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologia , Complexo Repressor Polycomb 1/genética , Proteínas Proto-Oncogênicas/genéticaRESUMO
In acute myeloid leukemia (AML), MLL (KMT2A) rearrangements are among the most frequent chromosomal abnormalities; however, knowledge of the genetic landscape of MLL-rearranged AML is limited. In this study, we performed whole-exome sequencing (n = 9) and targeted sequencing (n = 56) of samples from pediatric MLL-rearranged AML patients enrolled in the Japanese Pediatric Leukemia/Lymphoma Study Group AML-05 study. Additionally, we analyzed 105 pediatric t(8;21) AML samples and 30 adult MLL-rearranged AML samples. RNA-sequencing data from 31 patients published in a previous study were also reanalyzed. As a result, we identified 115 mutations in pediatric MLL-rearranged AML patients (2.1 mutations/patient), with mutations in signaling pathway genes being the most frequently detected (60.7%). Mutations in genes associated with epigenetic regulation (21.4%), transcription factors (16.1%), and the cohesin complex (8.9%) were also commonly detected. Novel CCND3 mutations were identified in 5 pediatric MLL-rearranged AML patients (8.9%) and 2 adult MLL-rearranged AML patients (3.3%). Recurrent mutations of CCND1 (n = 3, 2.9%) and CCND2 (n = 8, 7.6%) were found in pediatric t(8;21) AML patients, whereas no CCND3 mutations were found, suggesting that D-type cyclins exhibit a subtype-specific mutation pattern in AML. Treatment of MLL-rearranged AML cell lines with CDK4/6 inhibitors (abemaciclib and palbociclib) blocked G1 to S phase cell-cycle progression and impaired proliferation. Pediatric MLL-MLLT3-rearranged AML patients with coexisting mutations (n = 16) had significantly reduced relapse-free survival and overall survival compared with those without coexisting mutations (n = 9) (P = .048 and .046, respectively). These data provide insights into the genetics of MLL-rearranged AML and suggest therapeutic strategies.