title: Combination of lentivirus-mediated silencing of PPM1D and temozolomide chemotherapy eradicates malignant glioma through cell apoptosis and cell cycle arrest.
abstract: Temozolomide (TMZ) is approved for use as first-line treatment for glioblastoma multiforme (GBM). However, GBM shows chemoresistance shortly after the initiation of treatment. In order to detect whether silencing of human protein phosphatase 1D magnesium dependent (PPM1D) gene could increase the effects of TMZ in glioma cells, glioma cells U87-MG were infected with lentiviral shRNA vector targeting PPM1D silencing. After PPM1D silencing was established, cells were treated with TMZ. The multiple functions of human glioma cells after PPM1D silencing and TMZ chemotherapy were detected by flow cytometry and MTT assay. Significantly differentially expressed genes were distinguished by microarray-based gene expression profiling and analyzed by gene pathway enrichment analysis and ontology assessment. Western blotting was used to establish the protein expression of the core genes. PPM1D gene silencing improves TMZ induced cell proliferation and induces cell apoptosis and cell cycle arrest. When PPM1D gene silencing combined with TMZ was performed in glioma cells, 367 genes were upregulated and 444 genes were downregulated compared with negative control. The most significant differential expression pathway was pathway in cancer and IGFR1R, PIK3R1, MAPK8 and EP300 are core genes in the network. Western blotting showed that MAPK8 and PIK3R1 protein expression levels were upregulated and RB1 protein expression was decreased. It was consistent with that detected in gene expression profiling. In conclusion, PPM1D gene silencing combined with TMZ eradicates glioma cells through cell apoptosis and cell cycle arrest. PIK3R1/AKT pathway plays a role in the multiple functions of glioma cells after PPM1D silencing and TMZ chemotherapy.
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Jing-An
authors.initials: JA
authors.lastname: Ye
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Chong-Xian
authors.initials: CX
authors.lastname: Hou
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Sheng-Quan
authors.initials: SQ
authors.lastname: Zhan
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D058543:Class Ia Phosphatidylinositol 3-Kinase; D003131:Combined Modality Therapy; D003606:Dacarbazine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D015316:Genetic Therapy; D005910:Glioma / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D051058:Oncogene Protein v-akt / Q000096:biosynthesis / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis / Q000235:genetics; D000071636:Protein Phosphatase 2C / Q000037:antagonists & inhibitors / Q000235:genetics*; D000077204:Temozolomide
chemical_list: D058543:Class Ia Phosphatidylinositol 3-Kinase; D003606:Dacarbazine; D009363:Neoplasm Proteins; D051058:Oncogene Protein v-akt; D019869:Phosphatidylinositol 3-Kinases; D000071636:Protein Phosphatase 2C; D000077204:Temozolomide; C588001:PIK3R1 protein, human; C000607458:PPM1D protein, human