Atorvastatin suppressed proliferation and facilitated apoptosis of A549 cells through mediating recruitment of Fas and CD59 in lipid raft

Purpose: Lipid raft facilitated progression of NSCLC and atorvastatin could break cholesterol. The purpose of this study was to determine the potential mechanism of atorvastatin through lipid raft mediation in NSCLC. Methods: A549 cells were first grouped as NC, methyl-beta-cyclodextrin (M6CD, lipid raft inhibitor, 5mM and 10mM), atorvastatin (0, 5mM, 10mM and 15mM) and M beta CD (10mM) with atorvastatin (15mM). Later 10mM M6CD treated A549 cells were divided into three groups: NC, 3BDO (mTOR agonist) (60 mu M) and 3BDO (60 mu M) with atorvastatin (15mM) group. Thereafter, FLOT-2, SLP-2 expressions were assessed with RT-qPCR, mTOR proteins were measured by western blot and cell viability by CCK-8 method. Meanwhile, apoptosis was analyzed by flow cytometry. Moreover, lipid raft isolation was performed for acquiring Fas and CD59 and concentrations were detected by ELISA. Results: M beta CD treatment significantly inhibited FLOT-2 and SLP-2 RNA expressions and cell viability of A549 cells but up-regulated apoptosis. Besides that, Fas protein level was promoted and CD59 was suppressed. Atorvastatin also repressed FLOT-2 and SLP-2 RNA levels. Meanwhile, atorvastatin downregulated cell viability and accelerated apoptosis. Moreover, Fas was increased and CD59 was inhibited by atorvastatin and M beta CD enhanced functions of atorvastatin. M beta CD inhibited mTOR RNA expression in A549 cells was increased by 3BDO but atorvastatin restored 3BDO caused up-regulation of mTOR. Furthermore, up regulated cell viability of A549 by 3BDO was declined with atorvastatin and decreased apoptosis by 3BDO was reversed through atorvastatin. Fas suppressed by 3BDO and promotion of CD59 were also resumed by atorvastatin. Conclusion: Atorvastatin suppressed FLOT-2 and SLP-2 and mediated recruitments of Fas and CD59 with suppressing cell viability and facilitating apoptosis of A549 cells via mTOR signaling pathway.