RESUMEN
MicroRNAs (miRs) contribute to biological robustness by buffering cellular processes from external perturbations. Here we report an unexpected link between DNA damage response and angiogenic signaling that is buffered by a miR. We demonstrate that genotoxic stress-induced miR-494 inhibits the DNA repair machinery by targeting the MRE11a-RAD50-NBN (MRN) complex. Gain- and loss-of-function experiments show that miR-494 exacerbates DNA damage and drives endothelial senescence. Increase of miR-494 affects telomerase activity, activates p21, decreases pRb pathways, and diminishes angiogenic sprouting. Genetic and pharmacological disruption of the MRN pathway decreases VEGF signaling, phenocopies miR-494-induced senescence, and disrupts angiogenic sprouting. Vascular-targeted delivery of miR-494 decreases both growth factor-induced and tumor angiogenesis in mouse models. Our work identifies a putative miR-facilitated mechanism by which endothelial cells can be insulated against VEGF signaling to facilitate the onset of senescence and highlight the potential of targeting DNA repair to disrupt pathological angiogenesis.
Asunto(s)
Senescencia Celular/genética , Daño del ADN/genética , Regulación de la Expresión Génica , MicroARNs/genética , Complejos Multiproteicos/metabolismo , Neovascularización Fisiológica/genética , Animales , Senescencia Celular/efectos de la radiación , Reparación del ADN/genética , Reparación del ADN/efectos de la radiación , Femenino , Regulación de la Expresión Génica/efectos de la radiación , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/efectos de la radiación , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Ratones Desnudos , MicroARNs/metabolismo , Neovascularización Fisiológica/efectos de la radiación , Radiación IonizanteRESUMEN
Rather than targeting tumour cells directly, elements of the tumour microenvironment can be modulated to sensitize tumours to the effects of therapy. Here we report a unique mechanism by which ectopic microRNA-103 can manipulate tumour-associated endothelial cells to enhance tumour cell death. Using gain-and-loss of function approaches, we show that miR-103 exacerbates DNA damage and inhibits angiogenesis in vitro and in vivo. Local, systemic or vascular-targeted delivery of miR-103 in tumour-bearing mice decreased angiogenesis and tumour growth. Mechanistically, miR-103 regulation of its target gene TREX1 in endothelial cells governs the secretion of pro-inflammatory cytokines into the tumour microenvironment. Our data suggest that this inflammatory milieu may potentiate tumour cell death by supporting immune activation and inducing tumour expression of Fas and TRAIL receptors. Our findings reveal miR-mediated crosstalk between vasculature and tumour cells that can be exploited to improve the efficacy of chemotherapy and radiation.