Selective cell death of oncogenic Akt-transduced brain cancer cells by etoposide through reactive oxygen species–mediated damage

SY Oh, YW Sohn, JW Park, HJ Park, HM Jeon… - Molecular cancer …, 2007 - AACR
SY Oh, YW Sohn, JW Park, HJ Park, HM Jeon, TK Kim, JS Lee, JE Jung, X Jin, YG Chung…
Molecular cancer therapeutics, 2007AACR
We have established several glioma-relevant oncogene-engineered cancer cells to
reevaluate the oncogene-selective cytotoxicity of previously well-characterized anticancer
drugs, such as etoposide, doxorubicin, staurosporine, and carmustine. Among several
glioma-relevant oncogenes (activated epidermal growth factor receptor, Ras, and Akt, as
well as Bcl-2 and p53DD used in the present study), the activated epidermal growth factor
receptor, Ras, and Akt exerted oncogenic transformation of Ink4a/Arf−/− murine astrocyte …
Abstract
We have established several glioma-relevant oncogene-engineered cancer cells to reevaluate the oncogene-selective cytotoxicity of previously well-characterized anticancer drugs, such as etoposide, doxorubicin, staurosporine, and carmustine. Among several glioma-relevant oncogenes (activated epidermal growth factor receptor, Ras, and Akt, as well as Bcl-2 and p53DD used in the present study), the activated epidermal growth factor receptor, Ras, and Akt exerted oncogenic transformation of Ink4a/Arf−/− murine astrocyte cells. We identified that etoposide, a topoisomerase II inhibitor, caused selective killing of myristylated Akt (Akt-myr)–transduced Ink4a/Arf−/− astrocytes and U87MG cells in a dose- and time-dependent manner. Etoposide-selective cytotoxicity in the Akt-myr–transduced cells was shown to be caused by nonapoptotic cell death and occurred in a p53-independent manner. Etoposide caused severe reactive oxygen species (ROS) accumulation preferentially in the Akt-myr–transduced cells, and elevated ROS rendered these cells highly sensitive to cell death. The etoposide-selective cell death of Akt-myr–transduced cells was attenuated by pepstatin A, a lysosomal protease inhibitor. In the present study, we show that etoposide might possess a novel therapeutic activity for oncogenic Akt-transduced cancer cells to kill preferentially through ROS-mediated damage. [Mol Cancer Ther 2007;6(8):2178–87]
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