Extracellular Vesicles Derived from Lung Cancer Cells Induce Transformation of Normal Fibroblasts into Lung Cancer-Associated Fibroblasts and Promote Metastasis of Lung Cancer by Delivering lncRNA HOTAIR
Xiaoxuan Zhang, Yan Zhang, Xin Qiu, Jing Cai, Zhenzhou Yang, Fangzhou Song
Abstract
Human lung cancer (LC) cells A549/H358, normal lung epithelial cells BEAS-2B, and lung normal fibroblasts (NFs) were cultured, followed by transfection of H358 cells with HOTAIR shRNA. Extracellular vesicles (EVs) extracted from H358 cells were identified. The internalization of Dil-labeled-EVs by NFs was tested, and protein levels of cancer-associated fibroblast (CAF) surface markers, inflammatory cytokines, cell proliferation, invasion, and migration, and lncRNA HOTAIR levels were determined. A549 cells were cultured in an H358-EVs-treated conditioned medium of NFs (NFCM), followed by intravenous injection of A549 cells into nude mice. The lesions and Ki-67-positive cells in lung tissues were measured. The results showed that tumor cell-derived EVs (T-EVs) motivated the transformation of NFs into CAFs. Specifically, EVs can be internalized by NFs, and the protein levels of CAF surface markers and inflammation levels were elevated in H358-EVs-treated NFs. The proliferation, invasion, and migration of A549 cells cultured in T-EVs-treated NFCM were increased. H358-EVs carried HOTAIR into NFs and promoted the transformation of NFs into CAFs. Inhibition of HOTAIR partially reversed the promoting effect of H358-EVs on the transformation of NFs into CAFs and invasion and migration of LC cells. T-EVs promoted metastasis of LC in vivo by transforming NFs into CAFs.