Abstract
BACKGROUND AND OBJECTIVE: The results of published data on the effect of CD40 signal related to cancer cell sensitivity to chemotherapy are inconclusive. The aim of this study is to investigate the effect of soluble CD40 ligand (sCD40L) combined with vinorelbine on lung adenocarcinoma cell line A549. METHODS: Lung adenocarcinoma A549 cells were chosen as target cells and CD40 signal was stimulated by sCD40L. MTT assay and flow cytometry were used to determine the changes of cell proliferation, cell cycle and apoptosis of A549 cells treated by vinorelbine after CD40 was stimulated. The activity of Caspase-3 was measured using Caspase-3 cellular activity assay kit plus. RESULTS: After CD40 stimulation, an increase of inhibition on CD40 positive cell line A549 proliferation was confirmed when vinorelbine was added (P < 0.05). However, no significant changes were shown in apoptosis and cell cycle (P > 0.05). On the other hand, the activity of Caspase-3 was substantially decreased (P < 0.05). CONCLUSIONS: Stimulation of CD40 can increase lung adenocarcinoma cell line A549 sensitivity to vinorelbine, which may be through a non-apoptosis, Caspase independent mechanism, and not associated with the inhibition of cell cycle.