Anlotinib suppresses lung adenocarcinoma growth via inhibiting FASN-mediated lipid metabolism

BACKGROUND: Anlotinib, a vascular endothelial growth factor receptor (VEGFR) inhibitor, has been widely used in advanced lung cancer patients, but the intrinsic mechanism of cancer cell elimination is not fully disclosed. In this study, we reported that anlotinib suppressed lung adenocarcinoma (LUAD) growth through inhibiting fatty acid synthase (FASN)-mediated lipid metabolism. METHODS: To investigate the underlying mechanisms of anlotinib, an A549 cell line-derived xenograft model was constructed and a proteomics technique was employed to screen potential markers. Gas chromatography-mass spectrometry (GC-MS) profiling of medium-long chain fatty acid and neutral lipid droplet fluorescence staining were employed to detect lipid metabolism in cancer cells. Subsequently, the effects of anlotinib on FASN expression were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. Short hairpin RNA (shRNA) knockdown of FASN was used to assess the role of FASN in the antitumor effect of anlotinib. A patient-derived xenograft (PDX) model was established to validate the efficacy of anlotinib in the patient and IHC staining of FASN was examined. RESULTS: Our data revealed that anlotinib significantly decreased the expression of proteins related to lipid metabolism. GC-MS profiling of medium-long chain fatty acid and neutral lipid droplet fluorescence staining validated that anlotinib could disturb the fatty acid metabolism in cancer cells, especially de novo lipogenesis. Mechanically, the messenger RNA (mRNA) and protein of FASN were down-regulated by anlotinib in A549 cells and FASN knockdown could diminish the antitumor effect of anlotinib in vitro. Remarkable tumor shrinkage by anlotinib was further shown in a patient with multiple-line treatment failure, and FASN reduction was evidenced in the corresponding patient-derived xenograft (PDX) model. CONCLUSIONS: Anlotinib could inhibit the growth of LUAD through FASN-mediated lipid metabolism. Our findings provide new insights into the antitumor mechanism of anlotinib in lung adenocarcinoma.