STAT3-mediated activation of mitochondrial pathway contributes to antitumor effect of dihydrotanshinone I in esophageal squamous cell carcinoma cells

BACKGROUND Esophageal squamous cell carcinoma(ESCC)is one of the most common malignancies with a poor prognosis,and its treatment remains a great challenge.Dihydrotanshinone I(DHTS)has been reported to exert antitumor effect in many cancers.However,the role of DHTS in ESCC remains unclear.AIM To investigate the antitumor effect of DHTS in ESCC and the underlying mechanisms.METHODS CCK-8 assay and cell cycle analysis were used to detect proliferation and cell cycle in ESCC cells.Annexin V-PE/7-AAD double staining assay and Hoechst 33258 staining were used to detect apoptosis in ESCC cells.Western blot was used to detect the expression of proteins associated with the mitochondrial pathway.Immunofluorescence was used to detect the expression of phosphorylated STAT3(pSTAT3)in DHTS-treated ESCC cells.ESCC cells with STAT3 knockdown and overexpression were constructed to verify the role of STAT3 in DHTS induced apoptosis.A xenograft tumor model in nude mice was used to evaluate the antitumor effect of DHTS in vivo.RESULTS After treatment with DHTS,the proliferation of ESCC cells was inhibited in a dose-and time-dependent manner.Moreover,DHTS induced cell cycle arrest in the G0/1 phase.Annexin V-PE/7-AAD double staining assay and Hoechst 33258 staining revealed that DHTS induced obvious apoptosis in KYSE30 and Eca109 cells.At the molecular level,DHTS treatment reduced the expression of pSTAT3 and anti-apoptotic proteins,while increasing the expression of pro-apoptotic proteins in ESCC cells.STAT3 knockdown in ESCC cells markedly promoted the activation of the mitochondrial pathway while STAT3 overexpression blocked the activation of the mitochondrial pathway.Additionally,DHTS inhibited tumor cell proliferation and induced apoptosis in a xenograft tumor mouse model.CONCLUSION DHTS exerts antitumor effect in ESCC via STAT3-mediated activation of the mitochondrial pathway.DHTS may be a novel therapeutic agent for ESCC.

Mechanism of dihydrotanshinone I in the treatment of helicobacter pylori infection based on network pharmacology and molecular docking technology

Objective:Based on the network pharmacology approach and molecular docking technology,the core targets of dihydrotanshinone I(DHT)for the treatment of helicobacter pylori(Hp)infection were searched and the potential mechanisms of drug therapy were explored.Methods:The TCMSPdatabase and Swiss Target Prediction database were employed to identify drug targets.To mine disease targets based on GeneCards,OMIM,DrugBank,DisGeNET,and TTDdatabases.Then the two were intersected to obtain common targets.The proteinproteininteraction(PPI)networkmap of common targets was constructed on the basis of the String network platform and Cytoscape software,and the targets with degree values over 1/2 maximum degree value were selected as core targets.Molecular docking verification of DHTand core targets were performed using AutoDock and PyMOL software.Finally,gene ontology(GO)functional enrichment analysis andKyoto Encyclopediaof Genes and Genomes(KEGG)pathway enrichment analysis of the common targets were carried out using the Metascape database and R-4.0.2-win software.Results:A total of 13 targets of DHTwas extracted for the treatment of Hp,and five core targets,includingSignal transducerand activator of transcription 1(STAT1),Signal transducerand activator of transcription 3(STAT3),Prostaglandin G synthase 2(PTGS2),Signal transducerand activator of transcription 4(STAT4)and Indoleamine 2,3-dioxygenase 1(IDO1),were screened according to their degree values.Molecular docking indicated that DHThad an excellent binding to the core target.29 pathways were yielded by KEGG enrichment analysis,and a total of 48 biological processes,7 cellular components and 13 molecular functions were derived from GO enrichment analysis.Conclusion:DHTmay decrease pro-inflammatory factor expression and immune cell infiltration to treat Hpinfection via the janus kinase(JAK)-signal transducer and activator of transcription(STAT)signaling pathway regulated by STAT1,STAT3,STAT4,etc.

Dihydrotanshinone I preconditions myocardium against ischemic injury via PKM2 glutathionylation sensitive to ROS

Ischemic preconditioning(IPC)is a potential intervention known to protect the heart against ischemia/reperfusion injury,but its role in the no-reflow phenomenon that follows reperfusion is unclear.Dihydrotanshinone I(DT)is a natural compound and this study illustrates its role in cardiac ischemic injury from the aspect of IPC.Pretreatment with DT induced modest ROS production and protected cardiomyocytes against oxygen and glucose deprivation(OGD),but the protection was prevented by a ROS scavenger.In addition,DT administration protected the heart against isoprenaline challenge.Mechanistically,PKM2 reacted to transient ROS via oxidization at Cys423/Cys424,leading to glutathionylation and nuclear translocation in dimer form.In the nucleus,PKM2 served as a co-factor to promote HIF-1a-dependent gene induction,contributing to adaptive responses.In mice subjected to permanent coronary ligation,cardiac-specific knockdown of Pkm2 blocked DT-mediated preconditioning protection,which was rescued by overexpression of wild-type Pkm2,rather than Cys423/424-mutated Pkm2.In conclusion,PKM2 is sensitive to oxidation,and subsequent glutathionylation promotes its nuclear translocation.Although IPC has been viewed as a protective means against reperfusion injury,our study reveals its potential role in protection of the heart from no-reflow ischemia.

Activated PKB/GSK-3β synergizes with PKC-δ signaling in attenuating myocardial ischemia/reperfusion injury via potentiation of NRF2 activity: Therapeutic efficacy of dihydrotanshinone-Ⅰ

Disrupted redox status primarily contributes to myocardial ischemia/reperfusion injury(MIRI).NRF2,the endogenous antioxidant regulator,might provide therapeutic benefits.Dihydrotanshinone-Ⅰ(DT)is an active component in Salvia miltiorrhiza with NRF2 induction potency.This study seeks to validate functional links between NRF2 and cardioprotection of DT and to investigate the molecular mechanism particularly emphasizing on NRF2 cytoplasmic/nuclear translocation.DT potently induced NRF2 nuclear accumulation,ameliorating post-reperfusion injuries via redox alterations.Abrogated cardioprotection in NRF2-deficient mice and cardiomyocytes strongly supports NRF2-dependent cardioprotection of DT.Mechanistically,DT phosphorylated NRF2 at Ser40,rendering its nuclear-import by dissociating from KEAP1 and inhibiting degradation.Importantly,we identified PKC-δ-(Thr505)phosphorylation as primary upstream event triggering NRF2-(Ser40)phosphorylation.Knockdown of PKC-δdramatically retained NRF2 in cytoplasm,convincing its pivotal role in mediating NRF2 nuclear-import.NRF2 activity was further enhanced by activated PKB/GSK-3βsignaling via nuclear-export signal blockage independent of PKC-δactivation.By demonstrating independent modulation of PKC-δand PKB/GSK-3β/Fyn signaling,we highlight the ability of DT to exploit both nuclear import and export regulation of NRF2 in treating reperfusion injury harboring redox homeostasis alterations.Coactivation of PKC and PKB phenocopied cardioprotection of DT in vitro and in vivo,further supporting the potential applicability of this rationale.