CoCl2-induced HIF-1alpha expression correlates with proliferation and apoptosis in MKN-1 cells: a possible role for the PI3K/Akt pathway.
The exact mechanism behind the effect of hypoxia-inducible factor-1alpha (HIF-1alpha) on the proliferation and/or apoptosis of carcinoma cells is still a matter of debate. We treated a human gastric carcinoma cell line, MKN-1 (mutant P53), with 500 microM CoCl(2). A dual-phase pattern of HIF-1alpha expression with an increase until 4 h followed by a decrease until 36 h was observed. Immunocytochemistry showed that nuclear translocation was maximal at 4 h of treatment, while trypan blue staining showed a dual-phase pattern. Instead of G1/S arrest, FACS showed an increase in the pre-G1 fraction and G(2)/M arrest that correlated with Cyclin-B1, SKP-2 and P27 expression. Starting at 6 h, the apoptotic index increased in a time-dependent manner, in correlation with the expression of HIF-1alpha, Bcl-2, Bcl-xL, Bax and cleaved-Caspase-9. Phosphorylation of Akt was inhibited by CoCl(2) treatment and LY294002 treatment inhibited HIF-1alpha expression in a dose-dependent manner. These results suggested that the alteration of CoCl(2)-induced HIF-1alpha expression correlated with proliferation and apoptosis in MKN-1 cells. A possible role for the PI3K/Akt pathway was indicated in this model of hypoxia.
Ardyanto
Tonang Dwi
TD
Department of Microbiology and Pathology, Division of Organ Pathology, Faculty of Medicine, Tottori University, Tottori, Japan.
Osaki
Mitsuhiko
M
Tokuyasu
Naruo
N
Nagahama
Yumi
Y
Ito
Hisao
H
D016587:Antimutagenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D015687:Cell Hypoxia; D049109:Cell Proliferation / Q000187:drug effects*; D058534:Class I Phosphatidylinositol 3-Kinases; D003035:Cobalt / Q000494:pharmacology*; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D006801:Humans; D051793:Hypoxia-Inducible Factor 1 / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D044786:S-Phase Kinase-Associated Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000378:metabolism; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
D016587:Antimutagenic Agents; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D051793:Hypoxia-Inducible Factor 1; D019253:Proto-Oncogene Proteins c-bcl-2; D044786:S-Phase Kinase-Associated Proteins; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D050760:Cyclin-Dependent Kinase Inhibitor p27; D003035:Cobalt; D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; D051057:Proto-Oncogene Proteins c-akt; C506433:CASP9 protein, human; D053453:Caspase 9; D020169:Caspases; C018021:cobaltous chloride