Cholesterol promotes EGFR-TKIs resistance in NSCLC by inducing EGFR/Src/Erk/SP1 signaling-mediated ERRα re-expression

Abstract

Background The use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) brings remarkable benefits for the survival of patients with advanced NSCLC harboring EGFR mutations. Unfortunately, acquired resistance seems to be inevitable and limits the application of EGFR-TKIs in clinical practice. This study reported a common molecular mechanism sustaining resistance and potential treatment options to overcome EGFR-TKIs resistance. Methods EGFR-TKIs resistant NSCLC cells were established and confirmed by MTT assay. Cholesterol content was detected and the promotional function of cholesterol on NSCLC growth was determined in vivo. Then, we identified ERRα expression as the downstream factor of cholesterol-mediated drug resistance. To dissect the regulatory mechanism, we conducted experiments, including immunofluorescence, co-immunoprecipitation, luciferase reporter assay and chromatin immunoprecipitation assay. Results Long-term exposure to EGFR-TKIs generate drug resistance with the characteristic of cholesterol accumulation in lipid rafts, which promotes EGFR and Src to interact and lead EGFR/Src/Erk signaling reactivation-mediated SP1 nuclear translocation and ERRα re-expression. Further investigation identifies ERRα as a target gene of SP1. Functionally, re-expression of ERRα sustains cell proliferation by regulating ROS detoxification process. Lovastatin, a drug used to decrease cholesterol level, and XCT790, an inverse agonist of ERRα, overcome gefitinib and osimertinib resistance both in vitro and in vivo. Conclusions Our study indicates that cholesterol/EGFR/Src/Erk/SP1 axis-induced ERRα re-expression promotes survival of gefitinib and osimertinib-resistant cancer cells. Besides, we demonstrate the potential of lowing cholesterol and downregulation of ERRα as effective adjuvant treatment of NSCLC.

Statin shapes inflamed tumor microenvironment and enhances immune checkpoint blockade in non–small cell lung cancer

“…As an unavoidable issue, the correlation between the doses of statin used for antitumor therapy and the safe therapeutic doses applied in patients to treat cholesterolemia should not be ignored. The dose of lovastatin used for anti-tumor study varies from 20 to 100mg/kg/d in the mouse, which were approximately varies from 1.62 to 8.11mg/kg/d in the adult according to the dose conversion factor between human and mouse (50)(51)(52). In addition, the dose of lovastatin used for anti-tumor clinical trials varies from 0.33mg/kg/d to 20 mg/kg/d (adult weight was regarded as 60kg), even the maximum tolerated dose (Reference: NCT00853580, NCT04297033, NCT00585052, NCT01478828, NCT00584012, and etc.).…”

Proteomic analysis of plasma exosomes in patients with non-small cell lung cancer

“…The tumor growth was related to the availability of the cholesterol ( 35 ). The reprogramming of the cholesterol metabolism and accumulation of cholesterol is a feature of NSCLC ( 36 ). Cell membrane cholesterol is critical for cancer cell proliferation and survival ( 37 ).…”

Protein tyrosine kinase inhibitor resistance in malignant tumors: molecular mechanisms and future perspective

“…Cholesterol accumulation in lipid rafts promotes EGFR-Src interaction, activates ERK/SP1 signaling via Src and enhances estrogen-related receptor alpha (ERRα) expression, which regulates ROS levels and maintains cell proliferation, leading to drug resistance. 292 Phospholipid metabolism is also associated with drug resistance. An elevated level of lysophosphatidylcholine acyltransferase 1 (LPCAT1), an important enzyme of phospholipid metabolism, was observed in LUAD-resistant cell lines.…”