Abstract
Inhibitor of DNA-binding 3 (ID3) is a helix-loop-helix transcription factor that is associated with cell proliferation, differentiation and drug resistance in human cancer, and with anticancer effects in certain types of cancer cells. The present study investigated whether and how ID3 was involved in multidrug resistance (MDR) in human cisplatin (DDP)-resistant A549/DDP lung adenocarcinoma cells. The underlying mechanism of action was investigated in vitro. Cell Counting Kit-8 (CCK-8) and flow cytometry assays demonstrated that overexpression of ID3 enhanced chemosensitivity and decreased drug efflux in A549/DDP cells. Reverse transcription-quantitative polymerase chain reaction revealed that the expression of anti-apoptotic gene B-cell lymphoma-2 was significantly downregulated in cells expressing exogenous ID3 (P<0.05). These results indicated that ID3 may synergize with DDP to increase apoptosis in A549/DDP cells. ID3 overexpression modulated the activity of phosphoinositide 3-kinase/RAC serine/threonine-protein kinase signaling and downregulated the expression of multi-drug resistance protein-1, indicating that ID3 expression can reverse multi-drug resistance in A549/DDP cells. Collectively, these results indicate that ID3 is a potential effective chemotherapeutic target for the treatment of human DDP-resistant A549 lung adenocarcinoma therapy.