Related Experiment Video

Updated: Aug 16, 2026

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
06:54

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells

Published on: October 27, 2020

Inhibition of epidermal growth factor-induced cell transformation by tannins

Masaaki Nomura1, Hirotaka Tsukada, Daisuke Ichimatsu

  • 1Department of Hospital Pharmacy, School of Medicine, Kanazawa University, 13-1 Takara-Machi, Kanazawa, Ishikawa 920-8641, Japan.

Phytochemistry
|September 13, 2005
PubMed

Insights

Certain tannins effectively inhibit tumor promotion in mouse JB6 cells by blocking key signaling pathways. These natural compounds, particularly ellagitannins, show promise as chemopreventive agents by interfering with epidermal growth factor-induced cell transformation.

Area of Science:

  • * Oncology
  • * Pharmacology
  • * Biochemistry

Background:

  • * The JB6 mouse epidermal cell system is a standard model for investigating tumor promotion.
  • * Epidermal growth factor (EGF) is known to induce neoplastic transformation in JB6 Cl 41 cells.
  • * Tannins and triterpenoids are natural compounds with potential anti-cancer properties.

Purpose of the Study:

  • * To evaluate the anti-tumor promoting effects of seven tannins and two triterpenoids.
  • * To investigate the molecular mechanisms by which these compounds inhibit EGF-induced cell transformation.
  • * To identify specific signaling pathways targeted by effective tannins.

Main Methods:

  • * Utilized the JB6 Cl 41 cell line to assess EGF-induced cell transformation.
  • * Tested the inhibitory effects of six tannins (ellagitannins and chromone gallates) and two triterpenoids.
  • * Analyzed the impact of tannins on activator protein 1 (AP-1) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways.
  • * Examined the phosphorylation of extracellular-signal regulated protein kinases and p38 kinases.

Main Results:

  • * Six tannins significantly inhibited EGF-induced cell transformation in a dose-dependent manner without affecting cell growth.
  • * Ellagitannins, but not chromone gallates, attenuated EGF-induced AP-1 activation.
  • * Tannins inhibited EGF-induced activation of the PI3K/Akt pathway, with compounds 3 and 4 suppressing PI3K activation.
  • * Compounds 1 and 3 inhibited EGF-induced phosphorylation of ERK and p38 kinases.

Conclusions:

  • * Tannins, particularly ellagitannins, demonstrate significant anti-tumor promoting activity in the JB6 cell model.
  • * The anti-neoplastic effects are linked to the inhibition of critical signaling pathways, including AP-1 and PI3K/Akt.
  • * These findings suggest that tannins could be valuable chemopreventive agents targeting signal transduction pathways involved in cancer development.

More Related Videos

Induction and Analysis of Epithelial to Mesenchymal Transition10:37

Induction and Analysis of Epithelial to Mesenchymal Transition

Published on: August 27, 2013

Network Pharmacology Prediction and Experimental Validation of Trichosanthes-Fritillaria thunbergii Action Mechanism Against Lung Adenocarcinoma13:18

Network Pharmacology Prediction and Experimental Validation of Trichosanthes-Fritillaria thunbergii Action Mechanism Against Lung Adenocarcinoma

Published on: March 3, 2023

Related Concept Videos

Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...