Oct4 is expressed in human gliomas and promotes colony formation in glioma cells.
There is increasing evidence that self-renewal capacity of cancer cells is critical for carcinogenesis; hence, it is vital to examine the expression and involvement of self-renewal regulatory genes in these cells. Here, we reported that Oct4, a well-known regulator of self-renewal in embryonic stem cells, was highly expressed in human gliomas and glioma cell lines, and the expression levels were increased in parallel with increasing glioma grades. In in vitro cell cultures, Oct4 was only expressed in rat C6 glioma cells and rat neural stem cells but not in rat brain differentiated cells. Downregulation of Oct4 expression by RNA interference in C6 cells was associated with reduced cell proliferation and colony formation. Further analysis revealed that Oct4 could upregulate phosphorylation of Stat3 to promote tumor cell proliferation. Overexpression of Oct4 in C6 cells increased the expression of nestin but decreased the expression of GFAP suggesting that Oct4 might inhibit the differentiation of glioma cells. Our findings may provide further evidence for the stem cell theory of carcinogenesis. In contrast, the results might also imply that Oct4 contributes to the existence of undifferentiated cells in gliomas.
Du
Zhanhui
Z
Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University School of Medicine, Jinan, China.
Jia
Deyong
D
Liu
Shangming
S
Wang
Fuwu
F
Li
Gang
G
Zhang
Yanmin
Y
Cao
Xinmin
X
Ling
Eng-Ang
EA
Hao
Aijun
A
D000818:Animals; D001921:Brain / Q000378:metabolism; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D015870:Gene Expression; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005910:Glioma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007381:Intermediate Filament Proteins / Q000378:metabolism; D009367:Neoplasm Staging; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009474:Neurons / Q000166:cytology; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D050796:STAT3 Transcription Factor / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism
D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat