Upregulation of HIF-1α protects neuroblastoma cells from hypoxia-induced apoptosis in a RhoA-dependent manner.
Hypoxic conditions regulate several metabolic enzymes and transcription factors that are involved in cancer, ischemia and pulmonary diseases. The Ras homolog (Rho) family, including Rho member A (RhoA), is involved in reorganization of the actin cytoskeleton, cell migration and in the regulation of apoptosis and gene transcription. The aim of the present study was to investigate the expression of hypoxia‑inducible factor (HIF)‑α and the activity of RhoA in PC12 neuroblastoma cells under hypoxic conditions. The upregulation of HIF‑α and RhoA by hypoxia was determined using reverse transcription‑quantitative polymerase chain reaction and western blot assays, cell apoptosis was analyzed using flow cytometry, and the activity of caspase 3 was examined using a western blot assay and caspase 3 activity assay kit. The PC12 cells were induced to apoptosis following exposure to hypoxia, and exhibited increased expression of HIF‑α and increased mRNA and protein expression levels of RhoA. The overexpression of HIF‑α attenuated the hypoxia‑induced apoptosis of the PC12 cells. In addition, RhoA knockdown using small interfering RNA abrogated the antagonism of HIF‑1α towards hypoxia‑induced apoptosis. The results of the present study confirmed the protective role of HIF‑1α and RhoA in hypoxia‑induced PC12 cell apoptosis, and that the upregulation of HIF‑1α by hypoxia is RhoA‑dependent.
Department of Physical Medicine and Rehabilitation, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China.
Cui-Ping
CP
Yin
Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China.
Shang-Hui
SH
Guan
Department of Physical Medicine and Rehabilitation, Dongying People's Hospital, Dongying, Shandong 257091, P.R. China.
Bo
B
Zhang
Department of Physical Medicine and Rehabilitation, Yuhuangding Hospital, Yantai, Shandong 264000, P.R. China.
Xue-Xin
XX
Wang
Department of Physical Medicine and Rehabilitation, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China.
Shou-Wei
SW
Yue
D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D015854:Up-Regulation; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011065:Poly(ADP-ribose) Polymerases; D053148:Caspase 3; D020742:rhoA GTP-Binding Protein