Oncogenic Sox2 regulates and cooperates with VRK1 in cell cycle progression and differentiation

• Published in: Scientific reports 2016-06, Vol.6 (1), p.28532-28532, Article 28532
• Main Authors: Moura, David S., Fernández, Isabel F., Marín-Royo, Gema, López-Sánchez, Inmaculada, Martín-Doncel, Elena, Vega, Francisco M., Lazo, Pedro A.
• Format: Article
• Language: English
• Subjects: 13/51; 13/95; 38; 42/109; 42/89; 631/337/572/2102; 631/337/641/83; 631/45/275; 631/67/395; 631/80/86/388; 96/1; Biomarkers - metabolism; Cadherins - genetics; Carcinogenesis - genetics; Cell cycle; Cell Cycle - genetics; Cell differentiation; Cell Differentiation - genetics; Cell division; Cell growth; Cell Line; Cell Line, Tumor; Cell Proliferation - genetics; Cyclin D1 - genetics; Down-Regulation - genetics; Epithelium - metabolism; Genotype & phenotype; HEK293 Cells; HeLa Cells; Humanities and Social Sciences; Humans; Intracellular Signaling Peptides and Proteins - genetics; Kinases; Localization; MCF-7 Cells; multidisciplinary; Oncogenes - genetics; PAX6 Transcription Factor - genetics; Phosphorylation; Promoter Regions, Genetic - genetics; Protein-Serine-Threonine Kinases - genetics; Proteins; Roles; Science; SOXB1 Transcription Factors - genetics; Stem cells; Transcription factors; Up-Regulation - genetics
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep28532

Sox2 is a pluripotency transcription factor that as an oncogene can also regulate cell proliferation. Therefore, genes implicated in several different aspects of cell proliferation, such as the VRK1 chromatin-kinase, are candidates to be targets of Sox2. Sox 2 and VRK1 colocalize in nuclei of proliferating cells forming a stable complex. Sox2 knockdown abrogates VRK1 gene expression. Depletion of either Sox2 or VRK1 caused a reduction of cell proliferation. Sox2 up-regulates VRK1 expression and both proteins cooperate in the activation of CCND1 . The accumulation of VRK1 protein downregulates SOX2 expression and both proteins are lost in terminally differentiated cells. Induction of neural differentiation with retinoic acid resulted in downregulation of Sox2 and VRK1 that inversely correlated with the expression of differentiation markers such as N-cadherin, Pax6, mH2A1.2 and mH2A2. Differentiation-associated macro histones mH2A1.2and mH2A2 inhibit CCND1 and VRK1 expression and also block the activation of the VRK1 promoter by Sox2. VRK1 is a downstream target of Sox2 and both form an autoregulatory loop in epithelial cell differentiation.