Epigallocatechin-3-gallate prevents tumor cell implantation/growth in an experimental rat bladder tumor model
Jerzy Jankun1, Rick W Keck, Steven H Selman
1Urology Research Center, Department of Urology, College of Medicine, University of Toledo, Toledo, OH 43614, USA.
Abstract:
The aim of this study was to determine the efficacy of epigallocatechin-3-gallate (EGCG) (Polyphenon E®) in comparison with mitomycin C (MMC) to prevent tumor cell implantation/growth in an animal model of superficial bladder cancer and search for possible mechanism(s) of action. Female Fisher 344 rats were used to study the effects of EGCG and mitomycin C for the prevention of transitional cell tumor implantation (AY-27). Twenty rats served as a control, tumor implantation and saline wash only. Sixty rats were treated with EGCG (100, 200 and 400 µM) intravesically for 60 or 120 min after tumor implantation. Thirty other rats were divided equally and pretreated with 400 µM EGCG or saline for 120 min before tumor initiation. In a separate series of experiments, 30 rats were treated 2 weeks after tumor initiation with saline or EGCG (400 µM). In a different experiment 39 rats were treated with: saline (n=10) EGCG (n=9) 400 µM, MMC (n=10) 0.5 µM, MMC (n=10) 400 µM. Rats were sacrificed 3 weeks following treatment. Gross and histological analyses were performed on the bladders. EGCG and mitomycin C prevented intravesical tumor growth in a concentration- and time-dependent manner. EGCG pretreatment or treatment 2 weeks post tumor implantation did not have therapeutic effects. Molecular modeling suggests that EGCG inhibits urokinase and matrix metalloproteinase-9. EGCG prevents intravesical tumor implantation/growth with a slightly better efficacy than mitomycin C in this experimental model. The data suggest that EGCG lowers proteolytic activity and lowers probability of cancer cell implantation rather than direct cancer cell killing.
Insights
Epigallocatechin-3-gallate (EGCG) effectively prevents superficial bladder cancer cell implantation and growth, outperforming mitomycin C (MMC) in an animal model. EGCG works by reducing proteolytic activity, not direct cancer cell killing.
Area of Science:
- Urology
- Oncology
- Pharmacology
Background:
- Superficial bladder cancer poses a significant clinical challenge.
- Current treatments like mitomycin C (MMC) have limitations.
- Epigallocatechin-3-gallate (EGCG), a natural polyphenol, shows potential anticancer properties.
Purpose of the Study:
- To compare the efficacy of EGCG versus MMC in preventing tumor implantation and growth in a superficial bladder cancer model.
- To investigate the potential mechanisms of action for EGCG in this context.
Main Methods:
- An animal model of superficial bladder cancer (AY-27) in Fisher 344 rats was utilized.
- Intravesical administration of EGCG (100-400 µM) or MMC (0.5-400 µM) at various time points (post-implantation, pre-treatment, 2 weeks post-implantation).
- Gross and histological analyses were performed 3 weeks after treatment; molecular modeling was used to predict mechanisms.
Main Results:
- Both EGCG and MMC demonstrated concentration- and time-dependent prevention of intravesical tumor growth.
- EGCG exhibited slightly superior efficacy compared to MMC in preventing tumor implantation/growth.
- EGCG pretreatment or delayed treatment (2 weeks post-implantation) did not yield therapeutic effects.
Conclusions:
- EGCG is a promising agent for preventing superficial bladder cancer implantation and growth.
- EGCG's mechanism appears to involve reducing urokinase and matrix metalloproteinase-9 activity, thereby lowering proteolytic activity and cancer cell implantation probability.
- EGCG demonstrates potential as a chemopreventive agent with a mechanism distinct from direct cytotoxicity.
