Abstract: Objective The Objective of this study was to explore the expression of Sushi repeat containing protein X-linked 2(SRPX2)and Ras-related protein 31(Rab31)in oral squamous cell carcinoma(OSCC)and in-depth analysis of the relationship between the two proteins and the occurrence or development of the disease as well as clinical significance,to provide a new direction for the future development of new targeted drugs and the search for prognostic indicators for OSCC. Methods The expression of SRPX2 and Rab31 in OSCC and normal oral mucosal(NOM)tissues was analyzed by Oncomine database.A total of 68 cases of OSCC and 30 cases of NOM tissues of non-cancer patients were collected.Immunohistochemical staining was used to detect the expression of SRPX2 and Rab31 in the OSCC and NOM tissues.The correlation between the expression of SRPX2 and Rab31 as well as the relationship between their positive expression and the clinicopathological characteristics of OSCC patients were further analyzed. Results Based on the analysis of the Oncomine database, the expression of SRPX2 and RAB31 in OSCC tissues was higher than that in the NOM tissues.The expression of SRPX2 in OSCC tissues was higher than that in NOM tissues(0.6 % vs. 33.3 %,P＜0.05).The expression of Rab31 in OSCC tissues was also higher than that in NOM tissues(66.2% vs. 40.0%,P＜0.05).The expression of SRPX2 and Rab31 was significantly positively correlated in OSCC tissues(P＜0.05).The expression of SRPX2 and Rab31 was also related to the degree of tumor differentiation and lymph node metastasis.Kaplan-Meier survival analysis showed that SRPX2 and RAB31 were related to the poor prognosis of patients with OSCC. Conclusion The significant overexpression and correlation of SRPX2 and RAB31 suggest that SRPX2 and RAB31 can be combined as an important indicator and a new drug target for the prognosis evaluation of OSCC,bringing hope to the treatment of OSCC.

Key words: Oral squamous cell carcinoma, SRPX2, Rab31, Immunohistochemistry, uPA