1. Nuclear Phospho-Akt Increase Predicts Synergy of PI3K Inhibition and Doxorubicin in Breast and Ovarian Cancer
- Author
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Jane Guan, Lori Friedman, Marcia Belvin, Wei Wei Prior, Kyle A. Edgar, Deepak Sampath, Robert Kassees, and Jeffrey Wallin
- Subjects
Indazoles ,Breast Neoplasms ,Pharmacology ,Biology ,Article ,Mice ,chemistry.chemical_compound ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Doxorubicin ,Phosphatidylinositol ,PI3K/AKT/mTOR pathway ,Phosphoinositide-3 Kinase Inhibitors ,Ovarian Neoplasms ,Sulfonamides ,Antibiotics, Antineoplastic ,Cancer ,Drug Synergism ,General Medicine ,medicine.disease ,chemistry ,Apoptosis ,Mutation ,Cancer cell ,Female ,Signal transduction ,Ovarian cancer ,Proto-Oncogene Proteins c-akt ,Neoplasm Transplantation ,Signal Transduction ,medicine.drug - Abstract
The phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway is frequently disrupted in cancer and implicated in multiple aspects of tumor growth and survival. In addition, increased activity of this pathway in cancer is associated with resistance to chemotherapeutic agents. Therefore, it has been hypothesized that PI3K inhibitors could help to overcome resistance to chemotherapies. We used preclinical cancer models to determine the effects of combining the DNA-damaging drug doxorubicin with GDC-0941, a class I PI3K inhibitor that is currently being tested in early-stage clinical trials. We found that PI3K inhibition significantly increased apoptosis and enhanced the antitumor effects of doxorubicin in a defined set of breast and ovarian cancer models. Doxorubicin treatment caused an increase in the amount of nuclear phospho-Akt(Ser473) in cancer cells that rely on the PI3K pathway for survival. This increased phospho-Akt(Ser473) response to doxorubicin correlates with the strength of GDC-0941's effect to augment doxorubicin action. These studies predict that clinical use of combination therapies with GDC-0941 in addition to DNA-damaging agents will be effective in tumors that rely on the PI3K pathway for survival.
- Published
- 2010
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