Background: Gefitinib-resistance is a primary obstacle for the treatment of non-small-cell lung cancer (NSCLC). It has been shown that tanshinone IIA (Tan IIA) could induce apoptosis of NSCLC cells. However, the role of combination of gefitinib with Tan IIA on gefitinib-resistance NSCLC cells remains unclear. Thus, this study aimed to investigate the role of combination on the proliferation, apoptosis and invasion of gefitinib-resistance NSCLC cells.
Methods: CCK-8, flow cytometric and transwell assays were applied to detect proliferation, apoptosis and invasion in gefitinib-resistance NSCLC cells, respectively. In addition, Western blotting assay was used to detect the expressions of p-EGFR, p-VEGFR2, and p-Akt in HCC827/gefitinib cells.
Results: In this study, Tan IIA enhanced the cytotoxic effect of gefitinib in gefitinib-resistance NSCLC cells. In addition, the inhibitory effects of gefitinib on the proliferation, migration and invasion of gefitinib-resistance NSCLC cells were enhanced in the presence of Tan IIA. Moreover, Tan IIA enhanced the pro-apoptotic effect of gefitinib in gefitinib-resistance NSCLC cells via increasing the level of cleaved caspase 3. Meanwhile, Tan IIA enhanced the sensitivity of HCC827/gefitinib cells to gefitinib via downregulation of the VEGFR2/Akt pathway. In vivo experiments further confirmed that combination of gefitinib with Tan IIA inhibited tumor growth in mouse xenograft model of HCC827/gefitinib.
Conclusion: We found that Tan IIA could enhance gefitinib sensitivity in gefitinib-resistance NSCLC cells. Therefore, combination of gefitinib with Tan IIA might be considered as a therapeutic approach for the treatment of gefitinib-resistant NSCLC.
Keywords: non-small-cell lung cancer, tanshinone IIA, gefitinib-resistance, VEGFR