| Dai S |
------>authors3_c=None ------>paper_class1=1 ------>Impact_Factor=None ------>paper_class3=2 ------>paper_class2=1 ------>vol=55 ------>confirm_bywho=shiemin ------>insert_bywho=hsuc ------>Jurnal_Rank=None ------>authors4_c=None ------>comm_author= ------>patent_EDate=None ------>authors5_c=None ------>publish_day=None ------>paper_class2Letter=None ------>page2=1036 ------>medlineContent= ------>unit=E0123 ------>insert_date=20041202 ------>iam=3 ------>update_date=None ------>author=??? ------>change_event=4 ------>ISSN=None ------>authors_c=None ------>score=427 ------>journal_name=Int J Radiation Oncology (Biol Phys) ------>paper_name=Inhibition of hypoxia inducible factor 1-alpha causes oxygenindependent cytotoxicity and induces p53 independent apoptosis in glioblastoma cells. ------>confirm_date=20050628 ------>tch_id=091141 ------>pmid=12605983 ------>page1=1027 ------>fullAbstract=PURPOSE: Hypoxia, which activates the hypoxia inducible factor-1 alpha (HIF-1alpha) pathway, is a common feature in malignant gliomas and has been linked with tumor cell survival and therapy resistance. In this study, we examined the effect of antisense inhibition of HIF-1alpha on the survival, apoptosis and responses to chemotherapy in U-87 malignant glioma cells. MATERIALS AND METHODS: Hypoxia (1% oxygen) was achieved in a tri-gas incubator with intermittent N(2) gas flushing or in a gas tight-module sealed with 94% N(2), 1% O(2) and balance CO(2). HIF-1alpha inhibition was achieved with antisense phosphorothioate oligodeoxynucleotide (AS-HIF ODN), delivered using cytofectin GSV3815. HIF-1alpha expression level was monitored by a hypoxia-responsive luciferase reporter assay and verified by northern blot and immunoblot analyses. Cell viability was quantified by a colorimetric microtiter plate MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl) -2H-tetrazolium, inner salt] assay. Apoptotic cell death was detected with a colorimetric caspase-3 assay, as well as using terminal transferase-catalyzed in situ end labeling (TUNEL) staining. RESULTS: Antisense HIF-1alpha phosphorothioate oligodeoxynucleotide (AS-HIF ODN) treatment suppressed HIF-1alpha expression by up to 80% under both normoxic and hypoxic conditions as measured by a hypoxia-responsive reporter assay and confirmed by northern and western blot analyses. Antisense knockdown of HIF-1alpha resulted in significant reduction in U-87 cells survival and an acceleration of apoptosis, which did not involve p53 transactivation. Pretreatment of cells with Z-Val-Ala-Asp (-OCH(3))-fluoromethylketone (Z-VAD), a broad-spectrum caspase inhibitor largely eliminated this effect of AS-HIF. Caspase-3 specific activity was markedly induced 3 days after AS-HIF treatment when increased cell death was also noted. Transient overexpression of HIF-1alpha in U-87 cells neutralized apoptosis-inducing effect of AS-HIF. AS-HIF treatment did not affect viability of primary astrocytes and was selectively more toxic to U-87 glioma cells than normal human fibroblasts. The HIF-1alpha antisense treatment exerted an oxygen-independent, and additive but not synergistic effect to the cytotoxicity of cisplatin, etoposide, and vincristine. CONCLUSIONS: These results together indicate that suppression of HIF-1alpha-expression may be a promising strategy that is selective for reducing the survival and facilitating chemotherapeutic efficacy of malignant glioma. ------>tmu_sno=None ------>sno=10414 ------>authors2=Huang ML ------>authors3=HSU CY ------>authors4=Chao KSC ------>authors5= ------>authors6= ------>authors6_c=None ------>authors=Dai S ------>delete_flag=0 ------>SCI_JNo=None ------>authors2_c=None ------>publish_area=None ------>updateTitle=Inhibition of hypoxia inducible factor 1alpha causes oxygen-independent cytotoxicity and induces p53 independent apoptosis in glioblastoma cells. ------>language=2 ------>check_flag=None ------>submit_date=None ------>country=None ------>no= ------>patent_SDate=None ------>update_bywho=None ------>publish_year=2003 ------>submit_flag=None ------>publish_month=None |