Hepatocyte Growth Factor Overexpression Slows the Progression of 4NQO-Induced Oral Tumorigenesis

Xiaoxi He; Si Chen; Yinghua Tang; Xiaomin Zhao; Liting Yan; Lihong Wu; Zhicong Wu; Weijia Liu; Xinming Chen; Xinhong Wang

doi:10.3389/fonc.2021.756479

Hepatocyte Growth Factor Overexpression Slows the Progression of 4NQO-Induced Oral Tumorigenesis

Front Oncol. 2021 Dec 14:11:756479. doi: 10.3389/fonc.2021.756479. eCollection 2021.

Authors

Xiaoxi He¹, Si Chen², Yinghua Tang³, Xiaomin Zhao¹, Liting Yan⁴, Lihong Wu⁵, Zhicong Wu¹, Weijia Liu¹, Xinming Chen⁶, Xinhong Wang¹

Affiliations

¹ Department of Oral Mucosal Diseases, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Guangzhou, China.
² Key Laboratory for Oral Biomedical Engineering of the Ministry of Education, Department of Oral Implantology, School and Hospital of Stomatology of Wuhan University, Wuhan, China.
³ Department of Periodontics, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Guangzhou, China.
⁴ Department of Periodontics, Wuxi Stomatology Hospital, Wuxi, China.
⁵ Department of Basic Oral Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangdong Engineering Research Center of Oral Restoration and Reconstruction, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Guangzhou, China.
⁶ Department of Pathology, School and Hospital of Stomatology of Wuhan University, Wuhan, China.

Abstract

Objectives: To investigate the role of hepatocyte growth factor (HGF)/c-Met signaling in oral malignant transformation.

Methods: We used immunohistochemistry to investigate HGF and c-Met expression in 53 oral squamous cell carcinoma (OSCC) specimens and 21 adjacent nontumor specimens and evaluated the associations between HGF and c-Met expression and clinicopathological parameters. Additionally, HGF-overexpression transgenic (HGF-Tg) and wild-type (Wt) mice were treated with 4-nitroquinoline-1-oxide (4NQO) to induce oral carcinogenesis for 16 weeks. At 16, 20, and 24 weeks, tongue lesions were collected for clinical observation; estimation of HGF, c-Met, and PCNA expression; apoptosis (TUNEL) assays; and RNA sequencing (RNA-seq).

Results: HGF and c-Met were positively expressed in 92.5% and 64% of OSCC samples, respectively. High HGF expression was significantly associated with smaller tumor size (p = 0.006) and inferior TNM stage (p = 0.032). No correlation between HGF and c-Met levels and other clinical parameters or prognosis was noted. In addition, HGF and c-Met expression was elevated in 4NQO-induced lesions of Wt mice. Compared with Wt mice, HGF-Tg mice have lower tumor incidence, number, volume, and lesion grade. In addition, the percentage of PCNA-positive cells in Wt mice was significantly higher than that in HGF-Tg mice at different time points. At 16 weeks, HGF-Tg mice exhibited less apoptotic cells compared with Wt mice (p < 0.000), and these levels gradually increased until the levels were greater than that of Wt mice at 24 weeks (p < 0.000). RNA-seq data revealed that 140 genes were upregulated and 137 genes were downregulated in HGF-Tg mice. KEGG enrichment analysis showed that upregulated differentially expressed genes (DEGs) are highly correlated with oxidative and metabolic signaling and that downregulated DEGs are related to MAPK and PI3K-AKT signaling.

Conclusions: HGF and c-Met expression is upregulated in OSCC tissues and is associated with the occurrence and development of OSCC. HGF overexpression in normal oral epithelial tissue can inhibit 4NQO-induced tumorigenesis potentially through inhibiting proliferation and accelerating apoptosis via MAPK and PI3K-AKT signaling.

Keywords: 4NQO; HGF; OSCC; c-Met; transgenic mouse; tumorigenesis.