Abstract:

Objective   To investigate the mechanism of inhibiting glioma cells proliferation with Erlotinib and Rapamycin, and provide new methods for glioma targeted therapy. Methods   C6 cells were cultured by the serum free medium, and the tumor stem cells (GSCs) were obtained. Cell immunofluorescence staining was used for detection of CD133 and nestin to identify the tumor stem cells; CCK -8, RT -PCR and Western blot were used to observe the relationship of tumor cell proliferation, cell cycle and EGFR, mTOR signal pathways related genes, and the expressions of proteins (EGFR, Akt, p-Akt, mTOR, p-mTOR, rps6k, p-rps6k) after intervention of Erlotinib and Rapamycin. Results   The expressions of CD133 and nestin were detected in the glioma stem cells; Erlotinib and Rapamycin had the dose- time dependence antiproliferative effect in C6 and C6 GSCs (P<0.05). Erlotinib and Rapamycin can increase the ratio of cells in G1 phase and reduce the ratio of cells in S phase.The sensitivity to Erlotinib and Rapamycin in GSCs was lower than that in C6 cells (P<0.05); protein expressions of EGFR and mTOR pathways in the treatment group were lower than those in the control group (P<0.05), the efficacy is significant  in the combined treatment group.  Conclusion   Tumor stem cells exist in C6 glioma cell lines. Erlotinib and Rapamycin can inhibit the proliferation and cell cycle of C6 and C6 GSCs by means of blocking the EGFR and mTOR signaling pathways.

Key words:  Erlotinib； Rapamycin； Tumor stem cells；  EGFR； mTOR