MicroRNA-101 inhibits invasion and angiogenesis through targeting ITGA3 and its systemic delivery inhibits lung metastasis in nasopharyngeal carcinoma

Clinically, distant metastasis after primary treatment remains a key problem in nasopharyngeal carcinoma (NPC), and the treatment outcome of metastatic NPC remains disappointing, so there is a pressing need to identify novel therapeutic strategies. In accordance with our previous microarray data, we found that miR-101 was downregulated in NPC clinical specimens and cell lines. Ectopic expression of miR-101 significantly suppressed NPC cell migration, invasion and angiogenesis in vitro and inhibited angiogenesis and metastasis in vivo using the chicken chorioallantoic membrane model. Furthermore, ITGA3 was identified and validated as a novel target of miR-101, and the restoration of ITGA3 expression potently rescued the suppressive effects of miR-101. In addition, NPC patients with high ITGA3 expression had poorer overall survival and distant metastasis-free survival than patients with low ITGA3 expression, and ITGA3 overexpression was an independent poor prognostic factor in NPC. More importantly, we demonstrated that the systemic delivery of lentivirus-mediated miR-101 abrogated the lung metastatic colonization formation of NPC cells without obvious toxicity. Our study elucidates the molecular mechanisms of miR-101/ITGA3 pathway in regulating NPC metastasis and angiogenesis, and the systemic delivery of miR-101 provides a potent evidence for the development of a novel microRNA-targeting anticancer strategy for NPC patients.