RÉSUMÉ
Objective@#To study the effect of miR-28-5p on cisplatin ( DDP) -resistant A549 lung adenocarcinoma cell line (A549 / DDP) ，and to explore whether its mechanism is related to ferroptosis suppressor protein 1 (FSP1) mediated ferroptosis．@*Methods@#The A549 lung adenocarcinoma cell line and A549 / DDP cells were selected as the research objects. RT-qPCR method was used to detect the expression level of miR-28-5p in the cells．Cell proliferation was measured by CCK-8 method and colony formation assay．The target gene of miR-28-5p was identified and verified by luciferase reporter gene and Western blot analysis．A549 / DDP was transfected with miR-28-5p simulant or FSP1 overexpression plasmid to evaluate cell proliferation，mitochondrial morphology was evaluated by transmission electron microscope，and the levels of reactive oxygen species (ROS) ，glutathione ( GSH) and malondialdehyde (MDA) were measured by kit． A cell line-based xenograft model was established to evaluate the effect of miR-28-5p on tumor growth in vivo. @*Results@#Compared with A549 cells ，the expression level of miR-28-5p in A549 / DDP cells was significantly reduced ( P ＜0. 001 ) ． Compared with A549 cells ，the cell viability ( F = 49. 542，P＜0. 001) and colony forming ability (t = 4. 412，P＜0. 01) of A549 / DDP cells increased significantly. Compared with miR-NC group，the cell viability (t = 4. 612，P＜0. 01) and colony number (t = 4. 503，P＜0. 01) of A549 / DDP cells in miR-28-5p group significantly decreased．The luciferase activity decreased in the cells transfected with the miR-28-5p mimic，being significantly more so in the presence of the pGL3-FSP1 3 'UTR-WT vector. In addition，the expression of FSP1 in cells overexpressing miR-28-5p was significantly suppressed．Compared with the Vector + miR-28-5p group，the FSP1 + miR-28-5p group significantly increased cell viability and colony formation，cell mitochondrial length and GSH (P ＜0．01) ，and significantly increased cell apoptosis，ROS production and MDA formation decrease (P ＜0. 05 ) ． In vivo experiments showed that compared with the miR-NC + DDP group，the size and weight of tumors formed in the miR-28-5p + DDP group were significantly reduced (P＜0. 05) ， and the expression of Ki-67 and FSP1 protein was significantly reduced (P＜0. 05) ．@*Conclusion@#The mechanism of miR-28-5p reversing cisplatin resistance in lung adenocarcinoma cells may be related to the inhibition of FSP1 mediated ferroptosis.