Development of a human breast-cancer derived cell line stably expressing a bioluminescence resonance energy transfer (BRET)-based phosphatidyl inositol-3 phosphate (PIP3) biosensor

• Published in: PloS one Vol. 9; no. 3; p. e92737
• Main Authors: Kuo, Mei-Shiue, Auriau, Johanna, Pierre-Eugène, Cécile, Issad, Tarik
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 19.03.2014; Public Library of Science (PLoS)
• Subjects: 1-Phosphatidylinositol 3-kinase; AKT protein; Biochemistry, Molecular Biology; Biology and life sciences; Bioluminescence; Bioluminescence Resonance Energy Transfer Techniques - methods; Biosensing Techniques - methods; Biosensors; Breast cancer; Breast Neoplasms - metabolism; Cancer; Catalysis; Catalytic activity; Cell growth; Cell Line, Tumor; Cell survival; Diabetes; Diabetes mellitus; Drug discovery; Energy transfer; Enzyme inhibitors; High-throughput screening; Homology; Humans; Insulin; Insulin-like growth factor I; Insulin-like growth factor II; Insulin-like growth factors; Kinases; Life Sciences; Ligands; Localization; Medicine and Health Sciences; Metabolism; Metabolites; Microscopy; Monoclonal antibodies; Phosphates; Phosphatidylinositol 3,4,5-triphosphate; Phosphatidylinositol 4,5-diphosphate; Phosphatidylinositol Phosphates - analysis; Phosphorylation; Pleckstrin; Protein-tyrosine kinase; Proteins; Receptors; Recruitment; Rodents; Screening; Signaling; Stimulation; Targeted cancer therapy; Tyrosine; France
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0092737

Stimulation of tyrosine kinase receptors initiates a signaling cascade that activates PI3K. Activated PI3K uses PIP2 to generate PIP3, which recruit Akt to the plasma membrane through its pleckstrin homology (PH) domain, permitting its activation by PDKs. Activated Akt controls important biological functions, including cell metabolism, proliferation and survival. The PI3K pathway is therefore an attractive target for drug discovery. However, current assays for measurement of PIP3 production are technically demanding and not amenable to high-throughput screening. We have established a MCF-7-derived breast cancer cell line, that stably co-expresses the PH domain of Akt fused to Renilla luciferase and YFP fused to a membrane localization signal. This BRET biosensor pair permits to monitor, in real time, in living cells, PIP3 production at the plasma membrane upon stimulation by different ligands, including insulin, the insulin analogue glargine, IGF1, IGF2 and EGF. Moreover, several known inhibitors that target different steps of the PI3K/Akt pathway caused inhibition of ligand-induced BRET. Cetuximab, a humanized anti-EGF receptor monoclonal antibody used for the treatment of cancer, completely inhibited EGF-induced BRET, and the tyrosine kinase inhibitor tyrphostine AG1024 inhibited insulin effect on PIP3 production. Moreover, the effects of insulin and IGF1 were inhibited by molecules that inhibit PI3K catalytic activity or the interaction between PIP3 and the PH domain of Akt. Finally, we showed that human serum induced a dose-dependent increase in BRET signal, suggesting that this stable clone may be used as a prognostic tool to evaluate the PI3K stimulatory activity present in serum of human patients. We have thus established a cell line, suitable for the screening and/or the study of molecules with stimulatory or inhibitory activities on the PI3K/Akt pathway that will constitute a new tool for translational research in diabetes and cancer.