Research article

Antimicrobial peptides of the Cecropin-family show potent antitumor activity against bladder cancer cells

Henrik Suttmann¹ , Margitta Retz² , Friedrich Paulsen³ , Jürgen Harder⁴ , Ulrike Zwergel¹ , Jörn Kamradt¹ , Bernd Wullich¹ , Gerhard Unteregger¹ , Michael Stöckle¹ and Jan Lehmann¹

¹Department of Urology and Pediatric Urology, Saarland University Hospital, Homburg/Saar, Germany

²Department of Urology, TU rechts der Isar, München, Germany

³Department of Anatomy and Cell Biology, Martin-Luther-Universität Halle-Wittenberg, Germany

⁴Department of Dermatology, University Hospital Schleswig-Holstein, Campus Kiel, Germany

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BMC Urology 2008, 8:5doi:10.1186/1471-2490-8-5

Published:	3 March 2008

Abstract

Background

This study evaluated the cytotoxic and antiproliferative efficacy of two well-characterized members of the Cecropin-family of antimicrobial peptides against bladder tumor cells and benign fibroblasts.

Methods

The antiproliferative and cytotoxic potential of the Cecropins A and B was quantified by colorimetric WST-1-, BrdU- and LDH-assays in four bladder cancer cell lines as well as in murine and human fibroblast cell lines. IC₅₀ values were assessed by logarithmic extrapolation, representing the concentration at which cell viability was reduced by 50%. Scanning electron microscopy (SEM) was performed to visualize the morphological changes induced by Cecropin A and B in bladder tumor cells and fibroblasts.

Results

Cecropin A and B inhibit bladder cancer cell proliferation and viability in a dose-dependent fashion. The average IC₅₀ values of Cecropin A and B against all bladder cancer cell lines ranged between 73.29 μg/ml and 220.05 μg/ml. In contrast, benign fibroblasts were significantly less or not at all susceptible to Cecropin A and B. Both Cecropins induced an increase in LDH release from bladder tumor cells whereas benign fibroblasts were not affected. SEM demonstrated lethal membrane disruption in bladder cancer cells as opposed to fibroblasts.

Conclusion

Cecropin A and B exert selective cytotoxic and antiproliferative efficacy in bladder cancer cells while sparing targets of benign murine or human fibroblast origin. Both peptides may offer novel therapeutic strategies for the treatment of bladder cancer with limited cytotoxic effects on benign cells.