J Cancer 2021; 12(20):5999-6011. doi:10.7150/jca.59331 This issue

Research Paper

EPHB4 Regulates the Proliferation and Metastasis of Oral Squamous Cell Carcinoma through the HMGB1/NF-κB Signalling Pathway

Chen Yi1,2*, Xiliu Zhang1,2*, Hongyu Li1,2*, Guanhui Chen3, Binghui Zeng1,2, Yiming Li1,2, Chao Wang1,2, Yi He1,2, Xun Chen1,2, Zixian Huang4, Dongsheng Yu1,2✉

1. Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangzhou, Guangdong, China, 510055.
2. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, China, 510055.
3. Department of Stomatology, the Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen. Guangdong, China, 518107.
4. Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China, 510120.
*Authors contributed equally to this work.

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Citation:
Yi C, Zhang X, Li H, Chen G, Zeng B, Li Y, Wang C, He Y, Chen X, Huang Z, Yu D. EPHB4 Regulates the Proliferation and Metastasis of Oral Squamous Cell Carcinoma through the HMGB1/NF-κB Signalling Pathway. J Cancer 2021; 12(20):5999-6011. doi:10.7150/jca.59331. Available from https://www.jcancer.org/v12p5999.htm

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Abstract

Graphic abstract

Background: Malignant proliferation and cervical lymphatic metastasis restrict the prognosis of oral squamous cell carcinoma (OSCC). Erythropoietin-producing human hepatocellular B4 (EPHB4) regulates a series of tumour functions involving tumourigenesis, cancer cell attachment and metastasis. However, the mechanism of EphB4 regulating the malignant progression of OSCC has not been fully elucidated.

Methods: EPHB4 expression was analysed in 65 OSCC samples and adjacent noncancerous tissues through immunohistochemistry (IHC). siRNA and overexpression plasmids were transfected into OSCC cells to modify EPHB4 expression, and then, regulatory functions were explored in vitro and in vivo. Co-immunoprecipitation (Co-IP) and mass spectrometry were applied to detect proteins interacting with EPHB4. Subsequently, protein stability assays and NF-κB pathway inhibition assays were used to verify the regulation of EPHB4, high-mobility group box 1 (HMGB1) and nuclear factor-κB (NF-κB) activation.

Results: EPHB4 was found to be highly expressed in OSCC tissues, which was related to tumour stage and lymphatic metastasis and resulted in a poor prognosis. Cellular experiments and mouse tongue xenograft models further confirmed that high EPHB4 expression promoted the proliferation and metastasis of OSCC tumours. Mechanistically, co-IP and mass spectrometry studies indicated that EPHB4 could bind to HMGB1 and maintain HMGB1 stability. Downregulation of HMGB1 inhibited the proliferation and metastasis of OSCC cells and inhibited NF-κB phosphorylation activation but did not affect EPHB4 expression.

Conclusion: This study revealed the mechanism by which EPHB4 promotes the proliferation and metastasis of OSCC by activating the HMGB1-mediated NF-κB signalling pathway, which can be exploited as a novel marker or therapeutic target to control metastasis and improve the survival rate of OSCC.

Keywords: Oral squamous cell carcinoma, proliferation, cervical lymphatic metastasis, EPHB4, HMGB1, NF-κB