Knockdown of miR-1293 attenuates lung adenocarcinoma angiogenesis via Spry4 upregulation-mediated ERK1/2 signaling inhibition.

Lung adenocarcinoma (LUAD) is the most common histologic subtype of lung cancer. Angiogenesis plays a pivotal role in LUAD progression via supplying oxygen and nutrients for cancer cells. Non-coding miR-1293, a significantly up-regulated miRNA in LUAD tissues, can be potentially used as a novel biomarker for predicting the prognosis of LUAD patients. However, little information is available about the function of miR-1293 in LUAD progression especially cancer-induced angiogenesis. Herein, we found that miR-1293 knockdown could obviously attenuate LUAD-induced angiogenesis in vitro and down-regulate two most important pro-angiogenic cytokines VEGF-A and bFGF expression and secretion. Indeed, miR-1293 abrogation inactivated the angiogenesis-promoting ERK1/2 signaling characterized by decreased ERK1/2 phosphorylation and translocation from nucleus to cytoplasm. Next we found that miR-1293 knockdown reactivated the endogenous ERK1/2 pathway inhibitor Spry4 expression and Spry4 perturbance with specific siRNA transfection abolished the inhibition of ERK1/2 pathway and LUAD-induced angiogenesis by miR-1293 knockdown. Finally, with in vivo assay, we found obvious Spry4 up-regulation and VEGF-A, bFGF, ERK1/2 phosphorylation, micro-vessel density marker CD31 expression down-regulation in vivo, respectively. Collectively, these results indicated that miR-1293 knockdown could significantly attenuate LUAD angiogenesis via Spry4-mediated ERK1/2 signaling inhibition, which might be helpful for uncovering more functions of miR-1293 in LUAD and providing experimental basis for possible LUAD therapeutic strategy targeting miR-1293.