Expression pattern and clinical significance of beta 2-adrenergic receptor in oral squamous cell carcinoma: an emerging prognostic indicator and future therapeutic target.

PURPOSE

Beta 2-Adrenergic Receptor (β2-AR) is significantly overexpressed in various types of malignancies, which is associated with the worst prognosis. However, the role of β2-AR in oral cancer is not well identified. The present study aimed at investigating the β2-AR gene expression and its significance in relation with the clinicopathological features and overall survival of oral squamous cell carcinoma (OSCC) patients.

METHODS

Immunohistochemistry, western blot and quantitative real-time PCR techniques were used to analyze β2-AR protein and mRNA levels in a total of 65 histopathologically confirmed OSCC tissues (case group) and 65 normal tissues (control group) from the oral cavity.

RESULTS

Out of the total of 65 OSCC tissues, 41 tissues (63.1%) exhibited  high expression  for β2-AR protein. Percent positivity and relative density (mean ± SD) of protein were higher in the case group as compared to the control group (positivity 40.31 ± 3.01 vs. 20.46 ± 1.93, p < 0.001; density 2.77 ± 1.17 vs. 1.28 ± 0.37, p < 0.001). In addition, β2-AR mRNA level was also upregulated in patients compared to the controls (2.36 ± 1.30 vs. 1.09 ± 0.42, p < 0.001) and showed a positive correlation with immunostaining of protein in OSCC (r = 0.48, p = 0.011). High β2-AR protein expression was significantly associated with multiple risk habits (p = 0.045), histological differentiation (p = 0.013), clinical TNM stages (p = 0.014), and poor survival (p = 0.006) of patients. In the Cox proportional hazards model, β2-AR was identified as a prognostic biomarker of OSCC (p = 0.047).

CONCLUSION

β2-AR protein level is identified as an independent significant prognostic factor in patients with oral carcinoma.