The Inhibitory Role Of Protein Kinase B (Akt) Inhibito Perifosine Against Human Glioblastoma Cells:a Mechanisms Study

Background & AimsGlioblastoma multiforme (GBM) is the most common and malignant primary brain tumor in adults, after decades of research, although the current best standard of care includes extensive surgery followed by radiotherapy concurrently plus temozolomide, the life expectancy of patients diagnosed with GBM is only 14 months. Hence, the search for more effective anti-GBM agents is urgent. The goal of this study was to investigate the effects and mechanisms of The protein kinase B (Akt) inhibitor perifosine on proliferation, AMPK, Akt/mTOR signaling and growth factor receptors expression in human GBM cell lines.Methods(1) Cells were treated with indicated perifosine, and cultured for indicated time, MTT assay, colony formation assay, trypan blue, and flow cytometry were used to evaluate the effects of perifosine on proliferation in GBM cell lines. (2) Activation of Akt/mTORC1 was reflected by inhibited expressions of phosphorylated Akt, S6 and 4EBP1. AMPK activation and growth factor receptors were determined by the expression of phosphorylated ACC, AMPK, LKB1, EGFR, PDGFRa and PDGFRβ via immunoblotting. (3) The mRNA expression of PDGFRa and PDGFRβ in Perifosine-treated U87MG and U251 cells were tested by RT-PCR.Result(1) Perifosine significantly inhibited proliferation on human GBM cell lines U87MG and U251. The effect of Perifosine against GBM cells was dose-and time-dependently, and has little cytotoxicity on astrocytes. (2) Examined by FACS assay Perifosine suppressed U87MG and U251 cell cycle progression through inducing G2/M arrest, At high dosage, Perifosine induced U87MG and U251 cells apoptisis, and the effect was dose-dependently,. (3)Perifosine induced significant Akt/mTOR inhibition in U87MG and U251 cells, and expressions of p-Akt (S473) p-S6 (S235/236) and p-4 EBP1 (Ser65) reduced significantly in Perifosine-treated GBM cells.Whiletime induced AMPK activation and growth factor receptors (EGFR/PDGFR) degradation. But the PCR assay results failed to detect a significant in the mRNA expression of PDGFR in Perifosine-treated U87MG and U251 cells.ConclusionTaken together, Perifosine inhibitd the proliferation of U87MG and U251 cells and induced cell cycle arrest at G2/M phase while induced cell apoptosis at high dosage; furthermore, Perifosine is a potential anti-GBM agent, and it may exert its anti-neoplasm activity by modulation of Akt/mTOR and AMPK signaling, and EGFR/PDGFR degradation,which is pivotal for GBM. and has little or no cytotoxicity at any of the dosages tested. These results warrant further investigation of Perifosine as a candidated anti-GBM and anti-cancer drug.