Blocking β2-AR and Inhibiting COX-2: A Promising Approach to Suppress OSCC Development.

Objectives: β2-adrenergic receptor (β2-AR) and cyclooxygenase-2 (COX-2) are overexpressed in various malignant tumours including oral squamous cell carcinoma (OSCC), suggesting that they may contribute to the development of OSCC. This study aims to investigate the potential synergistic effect of β2-AR blockade and COX-2 inhibition on suppressing the development of OSCC.

Methods: Effects of blocking β2-AR and inhibiting COX-2 on migration and invasion of OSCC cells were detected by wound-healing assay and transwell invasion assay. Western blot and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression of genes related to the progression of OSCC. In vivo, OSCC xenograft models were established to evaluate the effect of combined treatment on survival time, tumour size, and submandibular lymph node metastasis. Immunohistochemistry, Western blot, and ELISA were used to detect the expression of invasion and metastasis relative genes.

Results: In vitro, blocking β2-AR or inhibiting COX-2 alone could suppress invasion and metastasis of OSCC cells, and suppression with combined treatment was more significant. Expression of genes related to invasion and metastasis, including EGFR, TGF-β1, IL-1β, MMP2, and VEGFA, were downregulated significantly, especially in the combined treatment group. In vivo, the combined treatment could significantly prolong survival time in tumour-bearing mice and inhibit the growth of tumours. Furthermore, submandibular lymph node metastasis was less in the combined treatment group, and expression of the abovementioned genes was also downregulated.

Conclusions: The combination of β2-AR blockade and COX-2 inhibition can significantly suppress the development of OSCC via downregulating EGFR, TGF-β1, IL-1β, MMP2, and VEGFA. Findings suggest that the combined use of a β2-AR blocker and a COX-2 inhibitor could be a promising adjuvant therapy in OSCC. Both drugs are commonly prescribed, and their safety and efficacy are well established. Their use in adjuvants in OSCC should therefore be promoted in clinical practice.