mPRα mediates P4/Org OD02-0 to improve the sensitivity of lung adenocarcinoma to EGFR-TKIs via the EGFR-SRC-ERK1/2 pathway.

The discovery of epidermal growth factor receptor (EGFR) mutations has made EGFR tyrosine kinase inhibitors (EGFR-TKIs) a milestone in the treatment for advanced non-small cell lung cancer (NSCLC). However, patients lacking EGFR mutations are not sensitive to EGFR-TKI treatment and the emergence of secondary resistance poses new challenges for the targeted therapy of lung cancer. In this study, we identified that the expression of membrane progesterone receptor α (mPRα) was associated with EGFR mutations in lung adenocarcinoma patients and subsequently affected the efficacy of EGFR-TKIs. Progesterone (P4) or its derivative Org OD02-0 (Org), which is mediated by mPRα, increases the function of EGFR-TKIs to suppress the proliferation, migration, and invasion of lung adenocarcinoma cells in vitro and in vivo. In addition, the mPRα pathway triggers delayed resistance to EGFR-TKIs. Mechanistic investigations demonstrated that the mPRα pathway can crosstalk with the EGFR pathway by activating nongenomic effects to inhibit the EGFR-SRC-ERK1/2 pathway, thereby promoting antitumorigenic effects. In conclusion, our data describe an essential role for mPRα in improving sensitivity to EGFR-TKIs, thus rationalizing its potential as a therapeutic target for lung adenocarcinomas.