Abstract: Objective: To study the differences of 4-1BBL expression between in oral squamous cell carcinomas and inflammation. Methods: The expression of 4-1BBL in oral squamous cell carcinomas, inflammation tissues and normal tissues were detected by PCR , Real-time PCR and immunohistochemistry. Results: The results of PCR showed that 4-1BBL in oral squamous cell carcinomas, inflammation tissues and normal tissues all had expressed. In addition, compared with normal tissues, the 4-1BBL mRNA expression in oral squamous cell carcinomas increased to 2.2106 fold (P<0.05); the expression in inflammation tissues imcreased to 1.1151 fold (P<0.05); In different differentiation stages of oral squamous cell carcinomas, it was 1.516 times of high differentiation group than moderately differentiation group (P<0.05), but also significantly higher than in poorly differentiated group (P<0.05). Immunohistochemical Results: compared with normal group, the expression of 4-1BBL was significantly more higher in squamous carcinoma tissues; the expression of 4-1BBL in inflammation tissue was between normal group and squamous cell carcinomas. At the same time the different differentiated squamous carcinoma tissues enhanced by the increasing of the degree of differentiation. Conclusion: The expression of 4-1BBL mRNA and protein in the oral squamous carcinoma tissues is significantly higher than normal and inflammation tissues; And its expression increases with the degree of differentiation.

Key words: 4-1BBL , Oral squamous cell carcinomas(OSCC) , Inflammation tissues