Imperatorin Suppresses Aberrant Hedgehog Pathway and Overcomes Smoothened Antagonist Resistance via STAT3 Inhibition

Drug Des Devel Ther. 2024 Nov 20:18:5307-5322. doi: 10.2147/DDDT.S482894. eCollection 2024.

Abstract

Background: Hyperactive Hedgehog (Hh) signaling initiates and drives the progression of various tumors. Despite the clinical success of Hh inhibitors targeting Smoothened (SMO), drug resistance, often stemming from SMO mutations, remains a formidable obstacle in cancer therapy. Here, we investigated the potential of imperatorin (IMP), a Chinese herbal medicine, to overcome drug resistance and revealed the potential mechanisms.

Methods: The effect of IMP on Hh signaling pathway was evaluated via Quantitative reverse transcription-polymerase chain reaction, Dual-luciferase reporter assay and Western blot. Meanwhile, we tested its ani-proliferative potential on Hh-driven tumor cells. Loss/gain-of-function, network pharmacology analysis, RNA-sequence analysis and molecular docking were performed to investigate the potential mechanisms of IMP-mediated functions. Furthermore, we established a subcutaneous Hh-driven medulloblastoma xenograft model using the DAOY cell line and examined the in vivo therapeutic efficacy of IMP.

Results: We identified IMP as a novel Hh inhibitor capable of overcoming drug-resistance caused by SMO mutants by inhibiting downstream transcription factor GLI1. IMP suppressed the proliferation of Hh-dependent cancer cells along with Hh activity inhibition. Mechanistically, IMP attenuated the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and its interaction with GLI1 promoter, consequently blocking GLI1 transcription and the target gene expressions. Molecular docking analysis revealed the favorable binding affinity between IMP and STAT3. Importantly, IMP application effectively inhibited the growth of medulloblastoma in vivo, accompanied by the downregulation of GLI1 and phosphorylated STAT3.

Conclusion: Our findings revealed IMP as an innovative approach to combat the drug resistance of SMO inhibitors in Hh-driven tumors, highlighting the crucial role of STAT3 as a transcriptional regulator in Hh signaling.

Keywords: GLI1; Hedgehog; STAT3; imperatorin; medulloblastoma; resistance.

MeSH terms

  • Animals
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Cell Proliferation* / drug effects
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Screening Assays, Antitumor
  • Furocoumarins
  • Hedgehog Proteins* / antagonists & inhibitors
  • Hedgehog Proteins* / metabolism
  • Humans
  • Medulloblastoma / drug therapy
  • Medulloblastoma / metabolism
  • Medulloblastoma / pathology
  • Mice
  • Mice, Nude
  • Molecular Docking Simulation
  • Molecular Structure
  • Neoplasms, Experimental / drug therapy
  • Neoplasms, Experimental / metabolism
  • Neoplasms, Experimental / pathology
  • STAT3 Transcription Factor* / antagonists & inhibitors
  • STAT3 Transcription Factor* / metabolism
  • Signal Transduction* / drug effects
  • Smoothened Receptor* / antagonists & inhibitors
  • Smoothened Receptor* / metabolism
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • STAT3 Transcription Factor
  • Hedgehog Proteins
  • Smoothened Receptor
  • STAT3 protein, human
  • imperatorin
  • SMO protein, human
  • Antineoplastic Agents
  • Furocoumarins

Grants and funding

This work was funded by the National Natural Science Foundation of China (grant number 82204450 and 82272278), Science and Technology Commission of Shanghai Municipality (grant number 23ZR1409100), Shanghai Municipal Health Commission (grant number 202140069), Young Clinical Scientist Training Program at Shanghai Medical College of Fudan University.