Long Noncoding RNA FGD5-AS1 Knockdown Decrease Viability, Migration, and Invasion of Non-Small Cell Lung Cancer (NSCLC) Cells by Regulating the MicroRNA-944/MACC1 Axis

OBJECTIVE: Long noncoding RNA FGD5 antisense RNA 1 (FGD5-AS1) participates in the regulation of non-small cell lung cancer (NSCLC) progression, but the underlying mechanisms are not fully revealed. This study aimed to determine the regulatory mechanism of FGD5-AS1 on the viability, migration, and invasion of NSCLC cells. METHODS: QRT-PCR was performed to measure the expression of FGD5-AS1, microRNA-944 (miR-944), and MACC1 in NSCLC. The correlation between FGD5-AS1 and clinicopathological features of NSCLC patients was analyzed. The viability of NSCLC cells were detected using MTT assay, and the migration and invasion were measured by transwell assay. Additionally, dual-luciferase reporter assay was used to demonstrate the interactions among FGD5-AS1, miR-944, and MACC1. Furthermore, exosomes were isolated from NSCLC cells and identified by transmission electron microscopy (TEM) and western blot. Then, the macrophages treated with exosomes were co-cultured with NSCLC cells to assess the effect of exosomes containing lower FGD5-AS1 level on NSCLC. RESULTS: The expression of FGD5-AS1 and MACC1 was increased in NSCLC, but miR-944 expression was decreased. FGD5-AS1 expression had significantly correlation with TNM stage and metastasis in NSCLC patients. FGD5-AS1 knockdown decreased the viability, migration, and invasion of NSCLC cells. Additionally, FGD5-AS1 and MACC1 were both targeted by miR-944 with the complementary binding sites at 3’ UTR. In the feedback experiments, miR-944 inhibition or MACC1 overexpression reversed the reduction effect of FGD5-AS1 knockdown on the tumorigenesis of NSCLC. Moreover, silencing of FGD5-AS1 suppressed macrophages M2 polarization, and eliminated the promoting effects of exosomes mediated macrophages on NSCLC cell migration and invasion. CONCLUSIONS: FGD5-AS1 knockdown attenuated viability, migration, and invasion of NSCLC cells by regulating the miR-944/MACC1 axis, providing a new therapeutic target for NSCLC.