POU class 5 homeobox 1B (POU5F1B)

POU class 5 homeobox 1B (POU5F1B) is a protein-coding gene once considered a pseudogene, now shown to encode a protein highly homologous to the pluripotency factor OCT4. The protein is a weak transcriptional activator and is found predominantly in the cytoplasm and membranes, rather than the nucleus[2]. POU5F1B expression is low in normal tissues but highly upregulated in several cancers due to retroviral promoter or superenhancer activation. Its protein product fosters tumor growth, colony formation, angiogenesis, and metastatic potential, and serves as a strong negative prognostic biomarker in colorectal and other cancers[1][2][3]. Mechanistically, it activates intracellular signaling (e.g., AKT pathway) and may interact with membrane kinases and cytoskeletal elements[2][5]. Targeting POU5F1B is under investigation but not yet clinically established.

Other names

OCT4PG1OTF3COTF3P1POU5F1P1POU5F1P4POU5FLC20POU5FLC8Oct4-pg1Octamer-binding transcription factor 3-likeOCT4-PG1POU class 5 homeobox 1 pseudogene 1POU domain transcription factor OCT4-pg1POU domain transcription factor Oct-4Octamer binding protein 3-like sequencePOU 5 domain protein

Gene/protein knockdown or inhibition leads to increased radiosensitivity and reduced proliferation (suggests potential utility for RNAi, CRISPR, or small molecule inhibition in cancer therapy). No approved drugs targeting POU5F1B yet.