Expression And Significance Of Chromosomal Passenger Proteins In Oral Squamous Cell Carcinoma

The chromosomal passenger complex(CPC),which is composed of Borealin,Survivin,Aurora-B and inner centromere protein(INCENP),is mainly involved in chromosome segregation and cell division and is closely associated with tumor development.Objective : The objective of this study was to investigate the expression of Borealin in oral squamous cell carcinoma(OSCC)and to evaluate its functional relationship with other CPC proteins,thereby clarifying the function and significance of their abnormal expression in OSCC.Methods:Immunohistochemistry was used to detect the expression of Borealin,Survivin,Aurora-B and Ki-67 in 20 cases of normal oral mucosa and 111 cases of OSCC obtained by surgical resection;Moreover,the relationship between the expression levels of these proteins and the clinicopathological characteristics of OSCC was analyzed;si RNA application,Western blot and immunofluorescence were used to detect the impact of the down-regulation of Borealin expression in OSCC cell lines to further clarify the role of Borealin in the development of OSCC.Results:1.Borealin was highly expressed in OSCC(52/111cases)but was minimally expressed in normal oral mucosa(0/20 cases),the difference was statistically significant(P<0.01);2.The expression of Borealin,Survivin and Aurora-B in OSCC was closely related to the degree of tumor differentiation and lymph node metastasis(P<0.01);3.The expression of Borealin was highly correlated with the expression of Survivin and Aurora-B as well as to the expression of the cell proliferation marker Ki-67(P<0.01);4.The downregulation of Borealin expression in OSCC cells also led to reductions in the expression levels of other CPC proteins and to the suppression of cell proliferation and cell division.Conclusions:1.Borealin is highly expressed in OSCC and closely related to the degree of differentiation and lymph node metastasis of OSCC;2.Survivin and Aurora-B are highly expressed in OSCC and closely related to the degree of differentiation and lymph node metastasis of OSCC;3.The expression of Borealin and Survivin,Aurora-B in OSCC were synergistic with each other.Together,these proteins can promote the development of tumors and serve as important indicators to judge the degree of tumor malignancy;4.Down-regulation of Borealin expression in OSCC can inhibit the proliferation of tumor cells and interfere with the division of tumor cells;5.The combined detection of the expression of Borealin,Survivin and Aurora-B in OSCC may be of great significance in the determination of the proliferation,metastasis and degree of malignancy in OSCC,and therefore,these proteins are expected to become new diagnostic markers and therapeutic targets.