SOX11: friend or foe in tumor prevention and carcinogenesis?

Abstract

Sex-determining region Y-related high-mobility-group box transcription factor 11 (SOX11) is an essential member of the SOX transcription factors and has been highlighted as an important regulator in embryogenesis. SOX11 studies have only recently shifted focus from its role in embryogenesis and development to its function in disease. In particular, the role of SOX11 in carcinogenesis has become of major interest in the field. SOX11 expression is elevated in a wide variety of tumors. In many cancers, dysfunctional expression of SOX11 has been correlated with increased cancer cell survival, inhibited cell differentiation, and tumor progression through the induction of metastasis and angiogenesis. Nevertheless, in a limited number of malignancies, SOX11 has also been identified to function as a tumor suppressor. Herein, we review the correlation between the expression of SOX11 and tumor behaviors. We also summarize the mechanisms underlying the regulation of SOX11 expression and activity in pathological conditions. In particular, we focus on the pathological processes of cancer targeted by SOX11 and discuss whether SOX11 is protective or detrimental during tumor progression. Moreover, SOX11 is highlighted as a clinical biomarker for the diagnosis and prognosis of various human cancer. The information reviewed here should assist in future experimental designs and emphasize the potential of SOX11 as a therapeutic target for cancer.

Keywords: SOX11; biomarker; cancer; cell differentiation; cell proliferation; metastasis; prognosis.

Figure 1.

The molecular structure of SOX11. The SOX11 protein is composed of 441 amino acids. SOX11 contains two functional domains, the N-terminal HMG domain and the conserved TAD. SOX11, sex-determining region Y-related high-mobility-group box transcription factor 11; HMG, high mobility group; TAD, C-terminal transactivation domain.

Figure 2.

Overall carcinogenic actions of SOX11 on the hallmarks of tumor biology. SOX11 exerts tumor-stimulative effects through increasing cell proliferation, repressing cell differentiation, inducing angiogenesis, and promoting metastasis. BCL6, B-cell lymphoma 6; BNIP3, B-cell lymphoma 2 (BCL2)/adenovirus E1B 19 kDa protein-interacting protein 3; CIC, cancer-initiating cell; PAX5, Paired box protein 5; PDGFA, platelet-derived growth factor A; SETMAR, SET domain and mariner transposase fusion gene; SOX11, Sex-determining region Y-related high-mobility-group box transcription factor 11; TANK, TRAF family member-associated NF-κB activator.

Figure 3.

Schematic representation of tumor-suppressive roles of SOX11 in cancer development. SOX11 overexpression might be correlated with slower cancer progression. The tumor-suppressive effect of SOX11 has been attributed to its ability to decrease cell proliferation, repress CICs development, and reduce cancer invasion and metastasis. ATX, autotaxin; CIC, cancer-initiating cell; DCX, doublecortin; HIG-2, hypoxia-inducible protein 2; NGN2, neurogenin 2; NLK, Nemo-like kinase; SOX11, sex-determining region Y-related high-mobility-group box transcription factor 11; TGF-β, transforming growth factor-β.