Expression profile of embryonic stem cell-associated genes Oct4, Sox2 and Nanog in human gliomas.
OBJECTIVE
To investigate whether Oct4, Sox2 and Nanog, three core regulatory factors maintaining pluripotency and self-renewal of embryonic stem cells (ESCs), are coexpressed in human gliomas, and whether their expression might be linked to carcinogenesis and the formation of cancer stem cells (CSCs).


RESULTS
Forty cases of human glioma were examined. The expression of Oct4, Sox2 and Nanog was analysed by immunohistochemistry, reverse transcription polymerase chain reaction and western blot. We found a positive correlation between the expression levels of Oct4, Sox2 and Nanog and tumour malignancy. Immunohistochemistry showed that Oct4 and Nanog were expressed in both the nuclei and the cytoplasm of glioma cells, whereas Sox2 was expressed only in the nuclei. Double immunofluorescence staining revealed that a majority of Oct4-positive cells coexpressed Sox2 and Nanog. More than 50% of Oct4-positive cells coexpressed the putative CSC markers CD133 and Nestin. Moreover, some cells exhibited Oct4 and Nanog immunoexpression in the cytoplasm, but the frequency of positive cells did not correlate with tumour malignancy.


CONCLUSIONS
The present findings suggest that ESC-associated pathways are activated in human gliomas and that these may be involved in glioma progression, a role that is distinct from that in ESCs.
Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, China.
Yuji
Y
Guo
Shangming
S
Liu
Ping
P
Wang
Shidou
S
Zhao
Fuwu
F
Wang
Lujun
L
Bing
Yanmin
Y
Zhang
Eng-Ang
EA
Ling
Jiangang
J
Gao
Aijun
A
Hao
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015153:Blotting, Western; D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D053595:Embryonic Stem Cells / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D005910:Glioma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D000071317:Nanog Homeobox Protein; D060787:Neoplasm Grading; D014411:Neoplastic Stem Cells / Q000378:metabolism; D050814:Octamer Transcription Factor-3 / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055748:SOXB1 Transcription Factors / Q000096:biosynthesis / Q000235:genetics*
D018398:Homeodomain Proteins; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors