RESUMEN
The characteristics of mesenchymal stromal cells (MSCs) which derived from multiple myeloma (MM) patients are typically impaired in osteogenic differentiation. However, the underlying molecular mechanisms need to be further investigated. lncRNAs are emerging as critical regulation molecules in oncogenic pathways. In this study, we identified that bioactive lncRNA HOXC-AS3, which is transcribed in opposite to HOXC10, was presented in MSCs derived from bone marrow (BM) of MM patients (MM-MSCs). HOXC-AS3 was able to interact with HOXC10 at the overlapping parts and this interaction increased HOXC10 stability, then promoted its expression, conferring osteogenesis repression to MM-MSCs. In mouse models, intravenously administered siHOXC-AS3 was proven to be effective in prevention of bone loss, sustained by both anticatabolic activities and bone-forming. These data showed that lncHOXC-AS3 was required for osteogenesis in BM-MSCs by enhancing HOXC10 expression. Our finding thus unveils a novel insight for the potential clinical significance of lncRNA HOXC-AS3 as a therapeutic target for bone disease in MM. Stem Cells 2019;37:247-256.
Asunto(s)
Proteínas de Homeodominio/metabolismo , Células Madre Mesenquimatosas/metabolismo , Mieloma Múltiple/metabolismo , Oligonucleótidos Antisentido/metabolismo , Osteoblastos/metabolismo , ARN Largo no Codificante/metabolismo , Animales , Estudios de Casos y Controles , Diferenciación Celular/fisiología , Línea Celular Tumoral , Células Cultivadas , Femenino , Xenoinjertos , Proteínas de Homeodominio/genética , Humanos , Células Madre Mesenquimatosas/citología , Ratones , Mieloma Múltiple/genética , Mieloma Múltiple/patología , Oligonucleótidos Antisentido/genética , Osteogénesis , ARN Largo no Codificante/genética , Transfección , Regulación hacia ArribaRESUMEN
Treatment failure remains a main challenge in the management of high-risk multiple myeloma (MM) even with the expanding repertoire of new drugs. Combinatorial therapy is considered an encouraging strategy that can overcome the compensatory mechanisms and undesirable off-target effects that limit the benefits of many prospective agents. Preliminary results of a current phase I trial have indicated that the new BET bromodomain inhibitor OTX015 has favorable activity and tolerability. However, OTX015 is not efficacious enough as a monotherapy. Here, we provide evidence that synergistic drug combinations with OTX015 were generally more specific to particular cellular contexts than single agent activities. In addition, pairing OTX015 with three classes of drugs dramatically enhanced the antitumor activity in mouse models of disseminated human myeloma. Our studies further underscored that the BET inhibitor OTX015 sensitized MM cells by interrupting several pathways and genes critical for MM cell proliferation and drug response, which provided the rationale for multiple myeloma therapy with OTX015 combined with conventional chemotherapeutic drugs. Thus, the context specificity of synergistic combinations not only provide profound insights into therapeutically relevant selectivity but also improve control of complex biological systems.
Asunto(s)
Acetanilidas/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Compuestos Heterocíclicos con 3 Anillos/farmacocinética , Mieloma Múltiple/tratamiento farmacológico , Acetanilidas/uso terapéutico , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Línea Celular Tumoral , Sinergismo Farmacológico , Compuestos Heterocíclicos con 3 Anillos/uso terapéutico , Humanos , Ratones , Mieloma Múltiple/patología , Estudios Prospectivos , Proteínas/antagonistas & inhibidores , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
PURPOSE: How exosomal RNAs released within the bone marrow microenvironment affect proteasome inhibitors' (PI) sensitivity of multiple myeloma is currently unknown. This study aims to evaluate which exosomal RNAs are involved and by which molecular mechanisms they exert this function.Experimental Design: Exosomes were characterized by dynamic light scattering, transmission electron microscopy, and Western blot analysis. Coculture experiments were performed to assess exosomal RNAs transferring from mesenchymal stem cells (MSC) to multiple myeloma cells. The role of PSMA3-AS1 in PI sensitivity was further evaluated in vivo. To determine the prognostic significance of circulating exosomal PSMA3 and PSMA3-AS1, a cohort of patients with newly diagnosed multiple myeloma was enrolled to study. Cox regression models and Kaplan-Meier curves were used to analyze progression-free survival (PFS) and overall survival (OS). RESULTS: We identified that PSMA3 and PSMA3-AS1 in MSCs could be packaged into exosomes and transferred to myeloma cells, thus promoting PI resistance. PSMA3-AS1 could form an RNA duplex with pre-PSMA3, which transcriptionally promoted PSMA3 expression by increasing its stability. In xenograft models, intravenously administered siPSMA3-AS1 was found to be effective in increasing carfilzomib sensitivity. Moreover, plasma circulating exosomal PSMA3 and PSMA3-AS1 derived from patients with multiple myeloma were significantly associated with PFS and OS. CONCLUSIONS: This study suggested a unique role of exosomal PSMA3 and PSMA3-AS1 in transmitting PI resistance from MSCs to multiple myeloma cells, through a novel exosomal PSMA3-AS1/PSMA3 signaling pathway. Exosomal PSMA3 and PSMA3-AS1 might act as promising therapeutic targets for PI resistance and prognostic predictors for clinical response.
Asunto(s)
Resistencia a Antineoplásicos/genética , Mieloma Múltiple/tratamiento farmacológico , Inhibidores de Proteasoma/farmacología , ARN sin Sentido/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Línea Celular Tumoral , Proliferación Celular , Exosomas/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Células Madre Mesenquimatosas/metabolismo , Ratones , Persona de Mediana Edad , Mieloma Múltiple/genética , Mieloma Múltiple/mortalidad , Pronóstico , Supervivencia sin Progresión , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma/uso terapéutico , Estabilidad Proteica , Transducción de Señal/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Multiple myeloma (MM) is characterized by the decreased osteogenic potential of mesenchymal stem cells (MSCs). Communication between cancer cells and cancer stromal cells is a driving factor in tumor progression. Understanding the myeloma-stroma interactions is critical to the development of effective strategies that can reverse bone diseases. Here we identified that bioactive lncRNA RUNX2-AS1 in myeloma cells could be packed into exosomes and transmitted to MSCs, thus repressing the osteogenesis of MSCs. RUNX2-AS1, which arises from the antisense strand of RUNX2, was enriched in MSCs derived from MM patients (MM-MSCs). RUNX2-AS1 was capable of forming an RNA duplex with RUNX2 pre-mRNA at overlapping regions and this duplex transcriptionally repressed RUNX2 expression by reducing the splicing efficiency, resulting in decreased osteogenic potential of MSCs. In vivo mouse models, administered an inhibitor of exosome secretion, GW4869, was found to be effective in preventing bone loss, sustained by both bone formation and anticatabolic activities. Therefore, exosomal lncRNA RUNX2-AS1 may serve as a potential therapeutic target for bone lesions in MM. In summary, our results indicated a key role of exosomal lncRUNX2-AS1 in transferring from MM cells to MSCs in osteogenic differentiation, through a unique exosomal lncRUNX2-AS1/RUNX2 pathway.