Ophiopogonin B-inducing Pyroptosis Through Caspase-1/gsdmd Pathway Contributes to Alleviation of Paclitaxel Resistance in Lung Cancer Cells 

Abstract Background: Drug resistance has become the main reason for the failure of tumor chemotherapy. In our previous study, ophiopogonin B (OP-B) has been verified to inhibit cell proliferation in numerous non-small cell lung cancer (NSCLC) cells. However, it is still unknown whether it can improve the drug resistance of lung cancer cells. Herein, we compared the inhibition effects of OP-B on NCI-H460, A549, A549/DDP and A549/PTX cells, and tried to find out the most sensible cell line to OP-B and the underlying reasons. Methods: The sensitivity of NCI-H460, A549, A549/DDP, and A549/PTX cells to OP-B was determined by CCK-8 assay, and the results were further verified in orthotopic tumor nude mice model and zebrafish tumor model. To identify pyroptosis in the cells, electron microscopy was used to observe cell morphology, flow cytometry was used to detect the mitochondrial membrane potential, and the LDH release rate was analyzed by microplate reader. Otherwise, immunofluorescence and immunohistochemical staining assay, western blot and qRT-PCR were used for detection of pyroptosis-correlated pathway.Results: In vitro, A549/DDP cell was verified to be most sensitive to OP-B than NCI-H460, A549, or A549/PTX cells. In vivo, OP-B inhibited the growth of A549/DDP orthotopic tumor more significantly than that of A549 both in nude mice and zebrafish models. Cell morphological feature, mitochondrial membrane potential, LDH release rate, production of IL-1β and expression of Caspase-1/GSDMD all showed that pyroptosis happened more significantly in A549/DDP cells than that in A549 cells after OP-B treatment.Conclusion: Though inducing more significantly pyroptosis by activating Caspase-1/GSDMD pathway, OP-B relieved DDP resistance of A549 cells.