Chaetoglobosin G inhibits proliferation, autophagy and cell cycle of lung cancer cells through EGFR/MEK/ERK signaling pathway

Chaetoglobosin G (CG) is a fungal secondary metabolite and shows anti-tumor effects. However, the mechanisms behind the anti-tumor effect is still unclear. In this study, we evaluated the anti-proliferation effect of CG on human NSCLC A549 cells and explored the underlying mechanisms. The anti-proliferation effect of CG on A549 cells was evaluated by MTT. The targets of CG were screened through transcriptome sequencing. A flow cytometer was used to detect cell cycle and apoptosis. Western blotting was used to analyze apoptosis, cell cycle and autophagy related protein expression. Our results showed that CG had a dose-dependent inhibitory effect on proliferation of A549 cells. Transcriptome sequencing analysis found that CG obviously induced cell cycle arrest. Flow cytometry analysis and western blot showed that CG induced G2/M arrest with p21 protein upregulation and cyclinBl protein downregulation. Western blot analysis also indicated that p-EGFR, EGFR, p-MEk and p-ERK protein expressions decreased and autophagy protein LC3II expression increased, indicating that CG can promote autophagy through EGFR/MEK/ERK/LC3 pathway. Moreover, CG can induce apoptosis with bcl-2 protein decrease. In conclusion, this study indicated that CG obviously inhibited A549 cell proliferation, and its mechanism may induce autophagy of A549 cells through EGFR/MEIVERK/LC3 pathway to upregulate the expression of P21, thus lead to G2/M phase arrest to exert an anti-tumor role.