RESUMEN
Prostate cancer (PCa) is the most frequent malignancy in older men with a high propensity for bone metastases. Characteristically, PCa causes osteosclerotic lesions as a result of disrupted bone remodeling. Extracellular vesicles (EVs) participate in PCa progression by conditioning the pre-metastatic niche. However, how EVs mediate the cross-talk between PCa cells and osteoprogenitors in the bone microenvironment remains poorly understood. We found that EVs derived from murine PCa cell line RM1-BM increased metabolic activity, vitality, and cell proliferation of osteoblast precursors by >60%, while significantly impairing mineral deposition (-37%). The latter was further confirmed in two complementary in vivo models of ossification. Accordingly, gene and protein set enrichments of osteoprogenitors exposed to EVs displayed significant downregulation of osteogenic markers and upregulation of proinflammatory factors. Additionally, transcriptomic profiling of PCa-EVs revealed the abundance of three microRNAs, miR-26a-5p, miR-27a-3p, and miR-30e-5p involved in the suppression of BMP-2-induced osteogenesis in vivo, suggesting the critical role of these EV-derived miRNAs in PCa-mediated suppression of osteoblast activity. Taken together, our results indicate the importance of EV cargo in cancer-bone cross-talk in vitro and in vivo and suggest that exosomal miRNAs may contribute to the onset of osteosclerotic bone lesions in PCa.
Asunto(s)
Complejo Multienzimático de Ribonucleasas del Exosoma/genética , Osteoblastos/fisiología , Neoplasias de la Próstata/genética , Animales , Huesos/metabolismo , Huesos/fisiología , Comunicación Celular , Línea Celular Tumoral , Proliferación Celular , Complejo Multienzimático de Ribonucleasas del Exosoma/metabolismo , Exosomas/genética , Vesículas Extracelulares/metabolismo , Expresión Génica/genética , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica/genética , Masculino , Células Madre Mesenquimatosas , Ratones , Ratones Endogámicos C57BL , MicroARNs/genética , Osteogénesis , Transcriptoma/genética , Microambiente TumoralRESUMEN
For cementless total joint replacement implants, the biological response to physicochemical surface characteristics is crucial for their success that depends on fixation by newly formed bone. In this study, the surface of TiAl6V4 (Tilastan®) implants was modified by (a) corundum blasting, (b) corundum blasting followed by electrochemical calcium phosphate (CaP) deposition, and (c) titanium plasma spraying followed by electrochemical CaP deposition. All modifications resulted in a surface roughness suitable to enhance primary implant stabilization and to favor osteoblast adhesion and function; the thin, biomimetic CaP coating is characterized by fast resorbability and served as chemical cue to stimulate osteogenesis. After implantation in a full weight-bearing rabbit intramedullary distal femur model, osseointegration was investigated after 3, 6, and 12 weeks. For all modifications, new bone formation, occurring from the endosteum of the femoral cortical bone, was observed in direct contact to the implant surface after 3 weeks. At the later time points, maturation of the woven bone into lamellar bone with clearly defined osteons was visible; the remodeling process was accelerated by the CaP coating. The ingrowth of newly formed bone into the pores of the titanium plasma sprayed surfaces indicates a strong interlock and finally implant fixation. Our findings indicate a positive impact of the tested surface modifications on osseointegration.