Background
β-elemene is known to play a critical role in tumorigenesis as well as tyrosine kinase inhibitor (TKI) resistance in lung cancer. However, the biological function and molecular mechanism remain largely unknown.
Conclusion
Our research indicated that β-elemene suppressed proliferation and enhanced sensitivity to gefitinib by inducing apoptosis through the FBP1/STAT3 axis in gefitinib-resistant lung cancer cells.
Methods
In this study, the common genes involved in gefitinib resistance and β-elemene were identified using bioinformatic analysis. The expression of FBP1 was examined by qRT-PCR and Western blot analysis. Cell proliferation, flow cytometry, clone formation and IC50 assays were performed to assess the effects of β-elemene and FBP1. Western blot analysis was used to evaluate apoptosis-related gene expression. Finally, in vivo experiments were conducted to assess the crucial role of FBP1 in gefitinib-resistant HCC827/GR cells in nude mice.
Results
Screening analysis demonstrated that fructose-1,6-bisphosphatase (FBP1) was induced by β-elemene and downregulated in gefitinib-resistant lung cells. Functionally, overexpression of FBP1 inhibited proliferation and gefitinib resistance and promoted apoptosis of PC9/GR and HCC827/GR cells in vitro. Mechanistically, FBP1 impeded the nuclear translocation of p-STAT3. The FBP1/STAT3 axis was required for FBP1-mediated apoptosis-related gene expression. In vivo experiments further confirmed the enhanced effects of FBP1 on lung cancer cell sensitivity to gefitinib.