Reactive oxygen species stabilize hypoxia-inducible factor-1 alpha protein and stimulate transcriptional activity via AMP-activated protein kinase in DU145 human prostate cancer cells.
Hypoxia-inducible factor (HIF-1) plays a central role in the cellular adaptive response to hypoxic conditions, which are closely related to pathophysiological conditions, such as cancer. Although reactive oxygen species (ROS) have been implicated in the regulation of hypoxic and non-hypoxic induction of HIF-1 under various conditions, the role of ROS is quite controversial, and the mechanism underlying the HIF-1 regulation by ROS is not completely understood yet. Here, we investigated the biochemical mechanism for the ROS-induced HIF-1 by revealing a novel role of adenosine monophosphate-activated protein kinase (AMPK) and the upstream signal components. AMPK plays an essential role as energy-sensor under adenosine triphosphate-deprived conditions. Here we report that ROS induced by a direct application of H(2)O(2) and menadione to DU145 human prostate carcinoma resulted in accumulation of HIF-1alpha protein by attenuation of its degradation and activation of its transcriptional activity in an AMPK-dependent manner. By way of contrast, AMPK was required only for the transcriptional activity of HIF-1 under hypoxic condition, revealing a differential role of AMPK in these two stimuli. Furthermore, our data show that inhibition of AMPK enhances HIF-1alpha ubiquitination under ROS condition. Finally, we show that the regulation of HIF-1 by AMPK in response to ROS is under the control of c-Jun N-terminal kinase and Janus kinase 2 pathways. Collectively, our findings identify AMPK as a key determinant of HIF-1 functions in response to ROS and its possible role in the sophisticated HIF-1 regulatory mechanisms.
Jung
Seung-Nam
SN
Department of Biochemistry and Molecular Biology, Kyung Hee University School of Medicine, Seoul 130-701, Korea.
Yang
Woo Kyeom
WK
Kim
Joungmok
J
Kim
Hak Su
HS
Kim
Eun Ju
EJ
Yun
Hee
H
Park
Hyunsung
H
Kim
Sung Soo
SS
Choe
Wonchae
W
Kang
Insug
I
Ha
Joohun
J
D000263:Adenylate Kinase / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms; D004789:Enzyme Activation; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D016259:Genes, myc; D006367:HeLa Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics*; D008113:Liver Neoplasms; D008175:Lung Neoplasms; D008297:Male; D011471:Prostatic Neoplasms / Q000235:genetics*; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D025801:Ubiquitin / Q000378:metabolism
C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012334:RNA, Neoplasm; D017382:Reactive Oxygen Species; D025801:Ubiquitin; D000263:Adenylate Kinase