Human Lung Cancer-associated Fibroblasts Enhance Motility.pdfVIP

Abstract. The metastatic potential of non-small cell lung cancer (NSCLC) cells has been shown to be associated with the tumor microenvironment. Cancer-associated fibroblasts (CAFs) are a major component of the tumor microenvironment, regulating tumor cell function by secreting growth factors, chemokines, and extracellular matrix (ECM). In this study, we examined the role of CAFs in the tumor progression of NSCLC. Firstly, we established primary cultures of CAFs and matched normal fibroblasts (NFs) from patients with resected NSCLC. CAFs exhibited greater expression of the pan-mesenchymal marker α-smooth muscle actin (α-SMA) than did NFs, although they displayed similar morphology. Furthermore, we employed a direct co-culture assay with human NSCLC A549 and H358 cells, and found that CAFs were more potent in inducing the epithelial-to-mesenchymal transition (EMT) phenotype than NFs, as indicated by an elongated and disseminated appearance. CAF-induced EMT led to an increase in motility and a decrease in proliferation of NSCLC cells through SMAD family number-3 (SMAD3)-dependent up- regulation of the growth inhibitory gene p21CIP1 [cyclin- dependent kinase inhibitor-1A (CDKN1A)] and α-SMA. Taken together, these findings provide evidence that lung CAFs have tumor-promoting capacity distinct from NFs and might play a significant role in the metastatic potential of NSCLC. Lung cancer is the leading cause of cancer-related death worldwide (1, 2), and 85% of all lung cancer cases are of non- small cell lung cancer (NSCLC). Most NSCLCs are characterized by the appearance of desmoplasia at the time of diagnosis (3, 4), stromal alterations characterized by trans- differentiation of stromal fibroblasts into carcinoma-associated fibroblasts (CAFs), enhanced deposition of extracellular matrix (ECM) in tumors, and angiogenesis (5, 6). These changes have been reported to promote tumor progression, resistance to treatment, and immune reactions (7). It has been observed decades ag