Liping Li1, Lihong Li2, Wu Lin3*
1Department of Laboratory Medicine Center, the First People's Hospital of Chenzhou City, Chenzhou 423000, PR China - 2Department of Ophthalmology, Otolaryngology, Head and Neck Surgery, Jiahe County People's Hospital, Chenzhou 4245000, PR China - 3Department of Laboratory, Shenzhen Hospital, Peking University, Shenzhen 518040, PR China
Objective: To investigate the expression and correlation of programmed death receptor (PD-1) and T-cell immunoglobulin-3 (TIM-3) in patients with oral squamous cell carcinoma (OSCC).
Methods: The selected oral squamous cell carcinoma tissue and normal oral mucosal tissue in this study were all from patients admitted to our hospital from May 2013 to June 2014, including 44 cases of oral squamous cell carcinoma tissue and 24 cases of normal oral mucosal tissue. The mRNA and protein expression of PD-1 and TIM-3 in oral squamous cell carcinoma and normal mucosa were detected by real-time fluorescence-based quantitative PCR and immunohistochemistry, respectively, and the relationship between PD-1 and TIM-3 was analysed.
Results: The expression of PD-1 and TIM-3 mRNA in OSCC was significantly higher than that found in normal oral mucosa (P<0.05). The high expression rate of PD-1 in oral squamous cell carcinoma was 61.36% (27 / 44), which was significantly higher than that in normal mucosa (20.83%; 5/24). The high expression rate of TIM-3 in oral squamous cell carcinoma was 63.64% (28/44), which was also significantly higher than that in normal mucosa (16.67%; 4/24). Although the expression level of PD-1 was correlated with tumour size (P<0.05), TIM-3 was not correlated with clinicopathological parameters (P>0.05). The 5-year survival rate of patients with high expression of PD-1 was 51.85% (14/27), which was significantly lower than that of patients with low expression of PD-1 (82.35%; 14/17; P < 0.05). The 5-year survival rate of patients with high expression of TIM-3 was 57.14% (16/28). In comparison, the 5-year survival rate of patients with low expression of TIM-3 was 75.00% (12/16), a difference that was not statistically significant (P>0.05). A positive correlation was noted between PD-1 and TIM-3 in OSCC (r = 0.437, P = 0.032).
Conclusion: The expression of PD-1 and TIM-3 increases in OSCC. The expression level of PD-1 correlates with the tumour size of OSCC, and PD-1 positively correlates with TIM-3. Both are expected to be new targets in immunotherapy for oral squamous cell carcinoma.
Oral squamous cell carcinoma, PD-1, TIM-3, correlation.