Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/antagonistas & inibidores , Leucemia/tratamento farmacológico , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Proteína 1 Parceira de Translocação de RUNX1/antagonistas & inibidores , Linhagem Celular Tumoral , Humanos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologiaRESUMO
Leukemia stem cells (LSCs) are deemed to the mainspring for treatment failure in acute myeloid leukemia (AML). Conventional chemotherapeutic drugs fail to eradicate leukemia stem cells, which becomes the root of drug resistance and disease recurrence. Hence, new therapeutic strategies targeting LSCs are supposed to be critical for patients with AML. Here we report that combination of Bcl-2 inhibitor AT-101 and chemotherapeutic drug idarubicin (IDA) results in synergistic lethality in CD34+CD38- leukemia stem-like cells sorted from KG-1α and Kasumi-1 AML cell lines and primary CD34+ AML cells in vitro while sparing the normal counterparts. In addition, combinatorial treatment also significantly inhibits the growth of patient-derived xenograft (PDX) mouse models generated from FLT3-ITDmut AML patient in vivo. Mechanistically, the synergistic effects of AT-101 with IDA to induce cell death are closely associated with blockage of DNA damage repair and thus activates the intrinsic apoptotic pathway. In summary, these findings suggest that combinatorial therapy with AT-101 and IDA selectively eliminates leukemia stem-like cells both in vitro and in vivo, representing a potent and alternative salvage therapy for the treatment of relapsed and refractory patients with AML.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologia , Mutações Sintéticas Letais/efeitos dos fármacos , Adolescente , Adulto , Idoso , Animais , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Proliferação de Células/efeitos dos fármacos , Reparo do DNA/genética , Sinergismo Farmacológico , Feminino , Seguimentos , Gossipol/administração & dosagem , Gossipol/análogos & derivados , Humanos , Idarubicina/administração & dosagem , Leucemia Mieloide Aguda/genética , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Prognóstico , Proteína 1 Parceira de Translocação de RUNX1/antagonistas & inibidores , Proteína 1 Parceira de Translocação de RUNX1/genética , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto Jovem , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
CBFA2T3 is a master transcriptional coregulator in hematopoiesis. In this study, we report novel functions of CBFA2T3 in acute myeloid leukemia (AML) relapse. CBFA2T3 regulates cell-fate genes to establish gene expression signatures associated with leukemia stem cell (LSC) transformation and relapse. Gene set enrichment analysis showed that CBFA2T3 expression marks LSC signatures in primary AML samples. Analysis of paired primary and relapsed samples showed that acquisition of LSC gene signatures involves cell type-specific activation of CBFA2T3 transcription via the NM_005187 promoter by GCN5. Short hairpin RNA-mediated downregulation of CBFA2T3 arrests G1/S cell cycle progression, diminishes LSC gene signatures, and attenuates in vitro and in vivo proliferation of AML cells. We also found that the RUNX1-RUNX1T1 fusion protein transcriptionally represses NM_005187 to confer t(8;21) AML patients a natural resistance to relapse, whereas lacking a similar repression mechanism renders non-core-binding factor AML patients highly susceptible to relapse. These studies show that 2 related primary AML-associated factors, the expression level of CBFA2T3 and the ability of leukemia cells to repress cell type-specific CBFA2T3 gene transcription, play important roles in patient prognosis, providing a paradigm that differential abilities to repress hematopoietic coregulator gene transcription are correlated with patient-specific outcomes in AML.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Leucemia Mieloide Aguda/patologia , Proteínas de Fusão Oncogênica/genética , Proteína 1 Parceira de Translocação de RUNX1/genética , Proteínas Repressoras/genética , Animais , Subunidade alfa 2 de Fator de Ligação ao Core/antagonistas & inibidores , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Intervalo Livre de Doença , Pontos de Checagem da Fase G1 do Ciclo Celular , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Camundongos , Camundongos Knockout , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Proteínas de Fusão Oncogênica/metabolismo , Prognóstico , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteína 1 Parceira de Translocação de RUNX1/antagonistas & inibidores , Proteína 1 Parceira de Translocação de RUNX1/metabolismo , Recidiva , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Translocação Genética , Células Tumorais Cultivadas , Fatores de Transcrição de p300-CBP/genética , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
AML1-ETO, the most common fusion oncoprotein by t (8;21) in acute myeloid leukaemia (AML), enhances hematopoietic self-renewal and leukemogenesis. However, currently no specific therapies have been reported for t (8;21) AML patients as AML1-ETO is still intractable as a pharmacological target. For this purpose, leukaemia cells and AML1-ETO-induced murine leukaemia model were used to investigate the degradation of AML1-ETO by melatonin (MLT), synthesized and secreted by the pineal gland. MLT remarkedly decreased AML1-ETO protein in leukemic cells. Meanwhile, MLT induced apoptosis, decreased proliferation and reduced colony formation. Furthermore, MLT reduced the expansion of human leukemic cells and extended the overall survival in U937T-AML1-ETO-xenografted NSG mice. Most importantly, MLT reduced the infiltration of leukaemia blasts, decreased the frequency of leukaemia stem cells (LSCs) and prolonged the overall survival in AML1-ETO-induced murine leukaemia. Mechanistically, MLT increased the expression of miR-193a, which inhibited AML1-ETO expression via targeting its putative binding sites. Furthermore, MLT decreased the expression of ß-catenin, which is required for the self-renewal of LSC and is the downstream of AML1-ETO. Thus, MLT presents anti-self-renewal of LSC through miR-193a-AML1-ETO-ß-catenin axis. In conclusion, MLT might be a potential treatment for t (8;21) leukaemia by targeting AML1-ETO oncoprotein.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Leucemia/tratamento farmacológico , Melatonina/farmacologia , MicroRNAs/genética , Proteína 1 Parceira de Translocação de RUNX1/genética , Animais , Apoptose/efeitos dos fármacos , Sítios de Ligação/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Autorrenovação Celular/efeitos dos fármacos , Cromossomos Humanos Par 21/genética , Cromossomos Humanos Par 8/genética , Subunidade alfa 2 de Fator de Ligação ao Core/antagonistas & inibidores , Modelos Animais de Doenças , Humanos , Leucemia/genética , Leucemia/patologia , Camundongos , MicroRNAs/antagonistas & inibidores , Proteínas de Fusão Oncogênica/genética , Proteína 1 Parceira de Translocação de RUNX1/antagonistas & inibidores , Translocação Genética/efeitos dos fármacos , beta Catenina/genéticaRESUMO
Polyphyllin I (PPI), a bioactive constituent extracted from traditional medicinal herbs, is cytotoxic to several cancer types. However, whether PPI can be used to treat t(8;21) acute myeloid leukemia (AML) cells requires further investigation. Here, we determined the inhibitory effects of PPI on t(8;21) AML cells by Cell Counting Kit-8 (CCK-8) and the trypan blue dye exclusion assay. DAPI staining and Wright-Giemsa staining were performed to check for apoptosis. Detection of apoptotic protein and AML1-ETO signaling protein expression were conducted by Western blot analysis. Our results suggested that PPI decreased growth and induced apoptosis in a dosage-dependent manner in the t(8;21) AML cell line Kasumi-1. PPI significantly downregulated AML1-ETO expression in a dosage- and time-dependent manner. PPI also upregulated P21 and downregulated survivin expression by reducing AML1-ETO. Mechanistically, PPI significantly reduced the expression of C-KIT, another therapeutic target for AML with t(8;21), followed by inhibition of Akt signaling. These results suggest that PPI can suppress growth and induce apoptosis of t(8;21) AML by suppressing the AML1-ETO and C-KIT/Akt signaling pathways. Therefore, PPI may be an anticancer therapeutic to treat t(8;21) AML.
