Regulation Of Lipid Metabolism On Lung Cancer Gefitinib Sensitivity And Its Molecular Mechanism

[Objective] To investigate the effect of SREBP,a key lipid metabolic regulator,inhibition on EGFR TKIs sensitivity in lung adenocarcinoma cells;To study the synergistic effect between lipogenesis inhibition and EGFR targeting therapy and the potential mechanisms;To provide experimental evidence and theoretical basis for clinical combination therapy scheme with EGFR targeted drugs.[Methods] 1)Using small molecule inhibitors and small interference RNA as SREBP targeted intervention;Real time quantitative PCR and Western blot are used to detect knockout efficiency;CCK8 method is used to detect cell viability;Using nude mice subcutaneous transplantation tumor for experiments in vivo.2)Using co-ip and pulldown to identify the binding of SREBP and MARVELD1;Using si RNA to knockdown MARVELD1 and study the effect of MARVELD1 inhibition on gefitinib sensitivity;3)The incorporation of [U-14C] glucose into lipids was determined by isotope tracer technique;Cell membrane fluidity was determined by DPH incorporation assay;Oleic acid is used as membrane fluidizor;Using Western blot detection of EGFR kinase activity.[Results] 1)Targeted intervention of SREBP increase the sensitivity of the lung cancer cells to EGFR tyrosine kinase inhibitors;Targeting EGFR can increase the anti-tumor effect of SREBP small molecule inhibitors;Combined use of SREBP and EGFR inhibitors have a synergistic effect on tumor growth in vivo.2)MARVELD1 binds to SREBP transcription activation area directly,and positive regulate SREBP transcriptional activity;Targeted intervention of MARVELD1 increase the gefitinib sensitivity of lung cancer cells via SREBP pathway.3)Intervention of lipid synthesis metabolism can reduce the membrane fluidity;Cell membrane fluidity decrease led to the decrease of the EGFR kinase activity;Inhibition of lipid synthesis metabolism can reduce the treatment of EGFR kinase activity and increase sensitivity,and this effect attenuated by membrane fluidizor.[Conclusion] Targeting lipid synthesis metabolism can increase sensitivity to EGFR TKIs in lung cancer;Part of the mechanism is de novo lipogenesis increase cell membrane fluidity,and thus promote EGFR activity;Targeting lipid synthetic metabolism,especially the key factor SREBP,combined with EGFR tyrosine kinase inhibitors could potentially become a new method for the treatment of non-small cell lung cancer.