Specific inhibition of AKT2 by RNA interference results in reduction of ovarian cancer cell proliferation: Increased expression of AKT in advanced ovarian cancer

Noske, Aurelia; Kaszubiak, Alexander; Weichert, Wilko; Sers, Christine; Niesporek, Silvia; Koch, Ines; Schaefer, Birgit; Sehouli, Jalid; Dietel, Manfred; Lage, Herman; Denkert, Carsten

doi:10.1016/j.canlet.2006.02.018

« Previous Next »Cancer Letters
Volume 246, Issue 1 , Pages 190-200, 8 February 2007

Specific inhibition of AKT2 by RNA interference results in reduction of ovarian cancer cell proliferation: Increased expression of AKT in advanced ovarian cancer

Aurelia Noske
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
- Corresponding author. Tel.: +49 30 450536033; fax: +49 30 450536900.
Alexander Kaszubiak
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Wilko Weichert
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Christine Sers
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Silvia Niesporek
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Ines Koch
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Birgit Schaefer
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Jalid Sehouli
- Department of Gynecology and Obstetrics, Charité University Hospital Berlin, Berlin, Germany
Manfred Dietel
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Herman Lage
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany
Carsten Denkert
- Institute of Pathology, Charité University Hospital Berlin, Campus Mitte, Schumannstr. 20/21, D-10117 Berlin, Germany

Received 13 February 2006; received in revised form 13 February 2006; accepted 20 February 2006.

Abstract

The protein kinase AKT is involved in several signaling pathways that are important for tumor development and progression, suggesting that AKT might be an interesting target for a molecular tumor therapy.

In this study, we investigated the AKT expression in ovarian carcinomas and the role of the AKT isoforms to ovarian cancer cell proliferation. We observed an increased AKT expression in 58% of the primary ovarian carcinomas as compared to normal ovaries by immunohistochemistry. AKT expression was significantly associated with positive lymph node status (P=0.002) and advanced FIGO stage (P=0.009). In western blot analysis, total AKT was expressed in all ovarian cancer cell lines and HOSE cells, while phosphorylated AKT was only observed in OVCAR-3 and SKOV-3 cells. The isoforms AKT1 and AKT2 were expressed at the mRNA level in all cell lines, while no relevant AKT3 mRNA levels were detected by conventional and quantitative RT-PCR. To determine the effects on cell proliferation, we used the unselective PI3K-inhibitor LY294002 as well as RNA interference to selectively inhibit the AKT isoforms. Treatment with LY294002 and the AKT2 siRNA reduced proliferation of OVCAR-3 cells. Our results show that AKT is expressed in a subpopulation of advanced ovarian carcinomas suggesting a role for this protein in the progression of this entity. Deactivation of AKT, especially AKT2 can result in reduction of cell growth. Accordingly, AKT is an interesting target for therapeutic intervention in ovarian cancer.

Keywords: AKT, Ovarian cancer, RNA interference