Involvement of Akt-1 and mTOR in Sensitivity of Breast Cancer to Targeted Therapy

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)
Stephen L. Abrams (Creator)
William H. Chappell (Creator)
Lyudmyla B. Drobot (Creator)
Richard A. Franklin (Creator)
Massimo Libra (Creator)
Alberto M. Martelli (Creator)
James A. McCubrey (Creator)
Ferdinando Nicoletti (Creator)
Melissa L. Sokolosky (Creator)
Kristin M. Stadelman (Creator)
Linda S. Steelman (Creator)
Franca Stivala (Creator)
Institution
East Carolina University (ECU )
Web Site: http://www.ecu.edu/lib/

Abstract: Elucidating the response of breast cancer cells to chemotherapeutic and hormonal based drugs is clearly important as these are frequently used therapeutic approaches. A signaling pathway often involved in chemo- and hormonal-resistance is the Ras/PI3K/PTEN/Akt/mTOR cascade. In the studies presented in this report, we have examined the effects of constitutive activation of Akt on the sensitivity of MCF-7 breast cancer cells to chemotherapeutic- and hormonal-based drugs as well as mTOR inhibitors. MCF-7 cells which expressed a constitutively-activated Akt-1 gene [?Akt-1(CA)] were more resistant to doxorubicin, etoposide and 4-OH-tamoxifen (4HT) than cells lacking ?Akt-1(CA). Cells which expressed ?Akt-1(CA) were hypersensitive to the mTOR inhibitor rapamycin. Furthermore, rapamycin lowered the IC50s for doxorubicin, etoposide and 4HT in the cells which expressed ?Akt-1(CA), demonstrating a potential improved method for treating certain breast cancers which have deregulated PI3K/PTEN/Akt/mTOR signaling. Understanding how breast cancers respond to chemo- and hormonal-based therapies and the mechanisms by which they can become drug resistant may enhance our ability to treat breast cancer. These results also document the potential importance of knowledge of the mutations present in certain cancers which may permit more effective therapies.

Additional Information

Publication
Other
Oncotarget; 2:7 p. 538-550
Language: English
Date: 2011
Keywords
Targeted Therapy, mTOR, Drug Resistance, Akt

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Involvement of Akt-1 and mTOR in Sensitivity of Breast Cancer to Targeted Therapyhttp://hdl.handle.net/10342/5703The described resource references, cites, or otherwise points to the related resource.