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Updated: Jun 13, 2026

An Orthotopic Bladder Cancer Model for Gene Delivery Studies
07:48

An Orthotopic Bladder Cancer Model for Gene Delivery Studies

Published on: December 1, 2013

Drugs that target specificity proteins downregulate epidermal growth factor receptor in bladder cancer cells

Gayathri Chadalapaka1, Indira Jutooru, Robert Burghardt

  • 1Department of Veterinary Physiology and Pharmacology, Texas A&M University, 4466 TAMU, Veterinary Research Building 410, College Station, TX 77843-4466, USA.

Molecular Cancer Research : MCR
|April 22, 2010
PubMed

Insights

Betulinic acid and curcumin inhibit bladder cancer growth by downregulating epidermal growth factor receptor (EGFR) expression through specificity protein (Sp) transcription factors. This novel approach targets EGFR in bladder cancer, offering a new therapeutic strategy.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • Epidermal growth factor receptor (EGFR) is a key target in bladder cancer therapy, with existing treatments including tyrosine kinase inhibitors and antibodies.
  • Specificity protein (Sp) transcription factors play a role in cancer cell proliferation and gene regulation.
  • Betulinic acid (BA) and curcumin are natural compounds with known anticancer properties.

Purpose of the Study:

  • To investigate the role of Sp transcription factors in regulating EGFR expression in bladder cancer.
  • To determine if betulinic acid and curcumin can inhibit bladder cancer cell growth by targeting EGFR via Sp proteins.
  • To explore the potential of BA and curcumin as novel therapeutic agents for bladder cancer targeting EGFR.

Main Methods:

  • Bladder cancer cells were treated with betulinic acid (BA), curcumin, or a small inhibitory RNA cocktail (iSp) targeting Sp1, Sp3, and Sp4.
  • EGFR mRNA and protein levels were measured using quantitative PCR and Western blotting.
  • Phosphorylation of Akt and autophagy markers (LC3) were assessed to understand downstream effects.

Main Results:

  • BA and curcumin treatment led to decreased bladder cancer cell growth, reduced Sp transcription factor levels, and downregulated EGFR expression.
  • EGFR expression was shown to be primarily regulated by Sp1 and Sp3 in bladder cancer cells.
  • Inhibition of EGFR by BA, curcumin, and iSp was associated with decreased Akt phosphorylation and induced autophagy.

Conclusions:

  • EGFR is an Sp-regulated gene in bladder cancer, and its expression can be effectively downregulated by compounds like BA and curcumin that inhibit Sp transcription factors.
  • Betulinic acid and curcumin represent a novel class of anticancer drugs that target EGFR in bladder cancer by repressing Sp proteins and inhibiting receptor expression.
  • This study highlights a new therapeutic strategy for bladder cancer by targeting the Sp-EGFR axis and inducing autophagic cell death.

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