[Identification of differentially expressed genes of acute hypoxia-treated HepG2 cells and hypoxia-acclimatized HepG2 cells].
To provide necessary information for further understanding of molecular mechanism of hypoxia acclimatization, the differentially expressed genes of HepG2 cells exposed to normoxia, acute hypoxia-treated cells which were exposed to 1% oxygen for 48 h, and hypoxia-acclimatized HepG2 cells which were cultured for 6 circles of alternate low oxygen (1% oxygen for 24 h) and normal oxygen (21% oxygen for 24 h), were identified respectively by combining the suppression subtractive hybridization (SSH) and cDNA microarray. Thirty-seven genes were expressed differentially in cells exposed to 1% oxygen for 48 h compared with those in cells exposed to normoxia. The expression of all these 37 genes was down-regulated, including the genes participating in cell cycle, cell response to stimulus, and cell signal transduction, and cell cytoskeleton formation, the genes associated with transcription and cell metabolism, 4 expressed sequence tags (ESTs), and 12 genes of which the functions are not known. There is a novel gene sequence, which has not been found in existing databases. There were only 6 genes differentially expressed in the hypoxia-acclimatized cells compared with cells exposed to normoxia, including two mitochondrion genes, metalloprotease-1 gene, ferritin gene, thymosin beta-4 and TPT1 genes. The expressions of mitochondrion ND4, ferritin, thymosin beta-4 and TPT1 were up-regulated, while the expressions of mitochondrion ND1 gene and metalloproease-1 gene were down-regulated. Cell tolerance to hypoxia increased after the cells were hypoxia-acclimatized. The different gene expression patterns of the acute hypoxia-treated cells and the hypoxia-acclimatized cells may be related to the increased tolerance of the cells to hypoxia.
Wang
Jin-Hui
JH
Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850. wangjinhui20@yahoo.com.cn
Shan
Ya-Jun
YJ
Cong
Yu-Wen
YW
Wu
Lan-Jun
LJ
Yuan
Xiao-Ling
XL
Zhao
Zhen-Hu
ZH
Wang
Sheng-Qi
SQ
Chen
Jia-Pei
JP
D000222:Adaptation, Physiological / Q000235:genetics* / Q000502:physiology; D015687:Cell Hypoxia / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006801:Humans; D009693:Nucleic Acid Hybridization / Q000379:methods; D010100:Oxygen / Q000378:metabolism*; D059467:Transcriptome; D000090324:Tumor Protein, Translationally-Controlled 1
C000715647:TPT1 protein, human; D000090324:Tumor Protein, Translationally-Controlled 1; D010100:Oxygen