title: PMA and ionomycin induce glioblastoma cell death: activation-induced cell-death-like phenomena occur in glioma cells.
abstract: Phorbol myristate acetate (PMA) and ionomycin (Io) can induce T cell activation and proliferation. Furthermore, they stimulate activation-induced cell death (AICD) in mature lymphocytes via Fas/Fas ligand (FasL) up-regulation. In this study, we explored the influence of PMA/Io treatment on glioblastoma cells, and found that AICD-like phenomena may also occur in glioma. Using the MTT assay and cell counting, we demonstrated that treatment of PMA/Io significantly inhibited the proliferation of glioma cell lines, U87 and U251. TUNEL assays and transmission electron microscopy revealed that PMA/Io markedly induced U87 and U251 cell apoptosis. Propidium iodide staining and flow cytometry showed that treatment with PMA/Io resulted in an arrestment of cell cycle and an increase in cell death. Using real-time PCR and western blot, we found that PMA/Io up-regulated the expression of Fas and FasL at both mRNA and protein level, which confirmed that PMA/Io induced glioma cell death. Specific knockdown of NFAT1 expression by small hairpin RNA greatly reduced the PMA/Io induced cell death and apoptosis by inhibition of FasL expression. Microarray analysis showed that the expression of NFAT1 significantly correlated with the expression of Fas. The coexistence of Fas with NFAT1 in vivo provides the background for AICD-like phenomena to occur in glioma. These findings demonstrate that PMA/Io can induce glioblastoma cell death through the NFAT1-Fas/FasL pathway. Glioma-related AICD-like phenomena may provide a novel avenue for glioma treatment.
authors.affiliation: Department of Neurosurgery, The First Hospital of China Medical University, Shenyang, Liaoning, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Han
authors.forename: Xinxin
authors.initials: X
authors.lastname: Tie
authors.forename: Lingxuan
authors.initials: L
authors.lastname: Meng
authors.forename: Yunjie
authors.initials: Y
authors.lastname: Wang
authors.forename: Anhua
authors.initials: A
authors.lastname: Wu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D053222:Fas Ligand Protein / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D015759:Ionomycin / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D050778:NFATC Transcription Factors / Q000235:genetics; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D019014:fas Receptor / Q000235:genetics
chemical_list: C491901:FAS protein, human; D053222:Fas Ligand Protein; D050778:NFATC Transcription Factors; D019014:fas Receptor; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate