Toxin of Staphylococcus aureus overcomes acquired cisplatin-resistance in malignant mesothelioma cells

Cancer Letters. 2008 Mar 22 [Epub ahead of print] [Link]

Johansson D, Johansson A, Behnam-Motlagh P.

Department of Medical Biosciences, Clinical Chemistry, Umeå University, Building 6M, 2nd Floor, S-901 85 Umeå, Sweden.


alpha-Toxin (alpha-hemolysin) of Staphylococcus aureus is a pore-forming bacterial toxin which after caveolin-1-dependent assembly induces apoptosis in eukaryotic cells. We investigated if a sub-toxic concentration of staphylococcal alpha-toxin could enhance cisplatin-induced apoptosis and overcome acquired cisplatin-resistance in cultured malignant pleural mesothelioma (MPM) cells. MPM cells (P31wt) and a cisplatin-resistant sub-line (P31res) was incubated with alpha-toxin and/or cisplatin followed by determination of cell viability, apoptosis, and signaling pathways. P31res cells were more sensitive to alpha-toxin than P31 wt cells due to induction of apoptosis. A low-toxic concentration of alpha-toxin re-sensitized cisplatin P31res cytotoxicity by apoptosis-induced through the mitochondrial pathway without detectable activation of common up-stream apoptosis signaling proteins. The toxin/drug combination should be tested for cisplatin-resistant mesothelioma treatment.

Keywords: Staphylococcal alpha-toxin; alpha-Hemolysin; Cisplatin; Acquired resistance; Apoptosis; alpha-Toxin