Transcription Factor FOSL1 Promotes Cisplatin Resistance in Non-Small Cell Lung Cancer Cells by Modulating the Wnt3a/β-Catenin Signaling through Upregulation of PLIN3 Expression.

Background: Lung adenocarcinoma (LUAD) is the most prevalent histological subtype of lung cancer, accounting for 45.3% of all cases and serving as a major cause of cancer-related mortality. Although cisplatin (DDP) is a cornerstone in LUAD therapy, its efficacy is often compromised by resistance, leading to therapeutic failure and poor patient outcomes. Lipid metabolism and associated proteins, such as perilipin 3 (PLIN3), have been increasingly implicated in cancer progression and chemoresistance. However, the precise mechanisms through which PLIN3 contributes to cisplatin (DDP) resistance in LUAD remain poorly understood.

Methods: To investigate the role of PLIN3 in DDP resistance, its expression in LUAD tissues and its correlation with patient prognosis were analyzed using bioinformatics databases and validated through clinical sample analysis. The effects of PLIN3 knockdown and overexpression on DDP resistance and Wnt3a/β-catenin signaling were assessed using quantitative real-time PCR (qPCR), western blotting, cytotoxicity assays, and colony formation assays. Bioinformatics screening identified FOS-like antigen 1 (FOSL1) as a transcription factor positively correlated with PLIN3, and its involvement in DDP resistance was further examined both in vitro and in vivo.

Results: PLIN3 expression is significantly elevated in LUAD tissues and correlates with poor overall survival. In LUAD cells, PLIN3 overexpression enhanced DDP resistance by upregulating Wnt3a expression and promoting β-catenin nuclear translocation. Bioinformatics analysis identified FOSL1 as a key transcription factor regulating PLIN3 expression. Experimental validation confirmed that FOSL1 directly binds to the PLIN3 promoter, activating the Wnt3a/β-catenin pathway and promoting DDP resistance. Knockdown of PLIN3 or inhibition of Wnt3a signaling reversed the effects of FOSL1 overexpression on DDP resistance.

Conclusion: This study demonstrates that PLIN3 contributes to DDP resistance in LUAD by activating the Wnt3a/β-catenin signaling pathway, with FOSL1 acting as a critical upstream regulator. Targeting the FOSL1/PLIN3/Wnt/β-catenin axis may provide a promising therapeutic strategy for overcoming chemoresistance in LUAD.