OCT4, also known as POU5F1 (POU domain class 5 transcription factor 1), is a transcription factor that acts as a master regulator of pluripotency in embryonic stem cells and is one of the reprogramming factors required for generating induced pluripotent stem cells. The human OCT4 encodes three isoforms, OCT4A, OCT4B, and OCT4B1, which are generated by alternative splicing. Currently, the functions and expression patterns of OCT4B remain largely unknown in malignancies, especially in human glioblastomas. Here, we demonstrated the function of OCT4B in human glioblastomas. Among the isoform of OCT4B, OCT4B-190 (OCT4B19kDa) was highly expressed in human glioblastoma stem cells and glioblastoma cells and was mainly detected in the cytoplasm rather than the nucleus. Overexpression of OCT4B19kDa promoted colony formation of glioblastoma cells when grown in soft agar culture conditions. Clinical data analysis revealed that patients with gliomas that expressed OCT4B at high levels had a poorer prognosis than patients with gliomas that expressed OCT4B at low levels. Thus, OCT4B19kDa may play a crucial role in regulating cancer cell survival and adaption in a rigid environment.
Bibliographical noteFunding Information:
We thank all members of the Cancer Growth Regulation Lab for their helpful discussion and technical assistance. We thank Dr. Jong-Hoon Kim (Korea University, Korea) for providing ESCs and iPSCs. This work was supported by grants from the National Research Foundation (NRF) (2015R1A5A1009024, 2017M3A9A8031425 and 2017R1E 1A1A01074205), Korea University (K1800851), and Brain Korea 21 Plus.
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- Anchorage-independent growth
- Cytoplasmic localization
- Mechanical stress response
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology