title: Association between DNA methylation and multidrug resistance in human glioma SHG-44 cells.
abstract: The aim of the present study was to evaluate the association between DNA methylation and multidrug resistance (MDR) in glioma and identify novel effectors responsible for MDR in human gliomas. An MDR glioma cell line, SGH-44/ADM, was developed using adriamycin (ADM) impulse treatment. Cryopreservation, recovery and withdrawal were performed to evaluate the stability of SGH-44/ADM cells. The adherence rate and cellular morphology were observed by microscopy, and the cell growth curve and doubling time were determined. DNA methylation was analyzed using a methylated DNA immunoprecipitation microarray chip (MeDIP-Chip). The cell cycle, Rh123 ingestion and exudation, and SGH-44/ADM apoptosis were analyzed by flow cytometry. SGH-44/ADM cells showed little difference as compared with parental cells, except that SGH-44/ADM cells were bigger in size with a wizened nucleus. Compared to SGH-44 cells, a larger proportion of SGH-44/ADM cells remained in G1 and S phase, as measured by flow cytometry. The MDR of SGH-44/ADM was associated with the upregulation of multi-drug resistance 1, prostaglandin-endoperoxide synthase 2 (COX-2); protein kinase C α (PKCα); however, the expression of these genes was not associated with DNA methylation. In the MeDIP-Chip analysis, 74 functions were markedly enhanced, and seven significant pathways were observed. Genes including SNAP47, ARRB2, PARD6B, TGFB1, VPS4B and CBLB were identified by gene ontology analysis. The predominant molecular mechanism of MDR in SGH-44/ADM cells was identified as exocytosis and efflux. The expression of COX-2, PKCα and P-glycoprotein (Pgp) was not found to be associated with DNA methylation. Genes including SNAP47, VAMP4 and VAMP3 may serve as the downstream effectors of Pgp, COX-2 or PKCα; however, further experiments are required to verify these observations.
authors.affiliation: Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China.
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China.
authors.forename: Zhong-Ye
authors.initials: ZY
authors.lastname: Xu
authors.affiliation: Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002448:Cell Adhesion / Q000187:drug effects / Q000235:genetics; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019295:Computational Biology; D019175:DNA Methylation; D004305:Dose-Response Relationship, Drug; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D020869:Gene Expression Profiling; D005910:Glioma / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D058977:Molecular Sequence Annotation; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014410:Tumor Stem Cell Assay
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger; C421109:multidrug resistance-associated protein 1