title: Hypoxia inducible factor 1-alpha regulates of platelet derived growth factor-B in human glioblastoma cells.
abstract: Hypoxia inducible factors (HIF) are transcription factors regulating expression of several genes related to oxygen homeostasis in response to hypoxic stress. Although HIF1-alpha and platelet derived growth factor-B (PDGF-B) are expressed in glioma tissue and closely related to tumor angiogenesis mediating vascular endothelial growth factor (VEGF) activity, their direct relationship has not yet been clarified. The aim of this study is to investigate whether HIF1-alpha regulates PDGF-B expression. The human glioblastoma cell lines, U87MG, U251MG, and A172, were exposed to 1-21% oxygen for 24 h. PDGF-B mRNA expression were quantitatively analyzed by real time RT-PCR, their intracellular protein levels were determined by computerized image analysis supported by flow cytometry to detect intracellular PDGF-B, and the concentration of secreted PDGF-B protein was assayed by ELIA. We also assayed following transfection of the cells with short interference RNA (siRNA) targeting HIF1-alpha mRNA. Relative PDGF-B mRNA and secretion of PDGF-B protein were significantly elevated at 1% oxygen. Following transfection of HIF1-alpha siRNA at 1% oxygen, PDGF-B expression was significantly suppressed at mRNA level. Our findings indicated that HIF1-alpha up-regulated expression of PDGF-B in human glioblastoma cells and showed the feasibility of siRNA technology in glioblastoma cell lines.
authors.affiliation: Department of Neurosurgery, Nippon Medical School, 1-1-5, Sendagi, 113-8603, Tokyo, Japan. dyoshida@nms.ac.jp
authors.forename: Daizo
authors.initials: D
authors.lastname: Yoshida
authors.forename: Kyongson
authors.initials: K
authors.lastname: Kim
authors.forename: Masahiro
authors.initials: M
authors.lastname: Noha
authors.forename: Akira
authors.initials: A
authors.lastname: Teramoto
mesh_terms: D001932:Brain Neoplasms / Q000473:pathology*; D015687:Cell Hypoxia; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D034741:RNA, Small Interfering