1. ¹Department of Microbiology & Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA
2. ²Shands Cancer Center, University of Florida, Gainesville, FL, USA
3. ³Leo Jenkins Cancer Center, Brody School of Medicine at East Carolina University, Greenville, NC, USA

Correspondence: JA McCubrey, Department of Microbiology & Immunology, Brody School of Medicine at East Carolina University, Greenville, NC 27858, USA. Fax: 1 252 816 3104

⁴The first two authors contributed equally to this work.

Received 3 September 2002; Accepted 23 January 2002.

Abstract

The PI3K/Akt signal transduction cascade has been investigated extensively for its roles in oncogenic transformation. Initial studies implicated both PI3K and Akt in prevention of apoptosis. However, more recent evidence has also associated this pathway with regulation of cell cycle progression. Uncovering the signaling network spanning from extracellular environment to the nucleus should illuminate biochemical events contributing to malignant transformation. Here, we discuss PI3K/Akt-mediated signal transduction including its mechanisms of activation, signal transducing molecules, and effects on gene expression that contribute to tumorigenesis. Effects of PI3K/Akt signaling on important proteins controlling cellular proliferation are emphasized. These targets include cyclins, cyclin-dependent kinases, and cyclin-dependent kinase inhibitors. Furthermore, strategies used to inhibit the PI3K/Akt pathway are presented. The potential for cancer treatment with agents inhibiting this pathway is also addressed.