Research On Anti-tumor Molecular Mechanisms Of Panaxadiol And Mollugin From Medicinal Plants Of Changbai Mountain

Aim of the study:Tumor hypoxia associated HIF-1? signaling pathway and tumor inflammation related NF-?B,STAT3 signaling pathway faciliate tumorigenesis and development.These pathways regulate tumor proliferation,anti-apoptosis,angiogenesis,migration and invasion.In addition,the PD-L1 expressed by tumor cell,which can suppress the anti-tumor immunity and mediate tumor immune escape,is also regulated by HIF-la and STAT3 signaling.The active compound panaxadiol and mollugin,which are isolated from medicinal plants of Changbai Mountain,showed satisfactory antitumor activity through HIF-1?/STAT3 and NF-?B signaling pathway,respectively.In this study,the potential of anti-tumor activity of panaxadiol and mollugin were studied at the cellular and molecular level,which provided a reliable theoretical basis for the further development of novel anti-tumor therapeutics.Materials and methods:(1)MTT assay,Western blotting,RT-PCR,molecular docking,overexpression plasmid/siRNA transfection,immunofluorescence,tumor cell/T cell co-culture model,ELISA and immunoprecipitation experiment was performed to evaluate the anti-tumor effect of panaxadiol at celluar and molecular levels.Colony formation and EdU labeling assay was used to study the effect of panaxadiol on tumor proliferation.The xenograft model and immunohistochemical staining were used to detect the in vivo anti-tumor effect of panaxadiol;(2)MTT assay,luciferase reporter gene experiment,western blotting,apoptosis detection,immunofluorescence,and RT-PCR were used to study the effects of mollugin on tumor associate cytokines and signaling pathways.Colony formation and EdU labeling were used to detect the effect of mollugin on tumor proliferation.The in vivo antitumor activity of mollugin was measured using a xenograft modelResults:(1)Panaxadiol inhibits the activation and interaction of HIF-la and STAT3 signalings,consequently inhibits PD-L1 expression and restores T cell activity,and inhibits proliferation of HCT116 cells.Panaxadiol also suppresses tumor growth in a xenograft model;(2)Mollugin inhibited TNF-?-induced NF-?B activation and the expression of tumor-related target genes regulated by NF-?B dose-dependently,thereby inhibiting HeLa cell proliferation,promoting HeLa cell apoptosis,and inhibiting tumor growth in a xenograft modelConclusions:(1)Panaxadiol inhibits the PD-L1 expression and tumor proliferation in human colon cancer cells through HIF-1? and STAT3 signaling pathways;(2)Mollugin inhibits the TNF-? indeced of NF-?B activation to exert antitumor effect.