Expression Of Osteopontin Protein In Urothelium Carcinomas Of The Bladder And Its Clinical Significance

Bladder carcinoma is one of commonly seen solid tumors, which badly endangers the people's health and life. In clinical practice, to predictor the prognosis of patients with bladder cancer is mainly depend on TNM and grading systems, although there are many markers of bladder cancer, such as BTA, NMP-22, FDP, Telomerase, Microsatellite and so on. The sensitivities and specialities of these markers are limit. So a need for tumor marker which can be incorporated into clinical practice to add prognostic information and to refine the conventional TNM and grading systems in terms of treatment response and prognosis is crucial.Osteopontin (OPN) was initially isolated from bovine bone cortex, as a complex syalilated phospo-glyco-protein of around 60 kDa in 1986. It has been long considered a structural bone protein linking bone cells to the bone extracellular matrix. Many studies shown OPN is expressed and secreted by numerous human cancers. OPN functions in cell adhesion, chemotaxis, macrophage-directed interleukin-10(IL-10) suppression, stress-dependent angiogenesis, prevention of apoptosis, and anchorage-independent growth of tumor cells by regulating cell-matrix interactions and cellular signaling through binding with integrin and CD44 receptors. while constitutive expression of OPN exists in several cell types, induced expression has been detected in T-lymphocytes, epidermal cells, bone cells, macrophages, and tumor cells in remodeling processes such as inflammation, ischemia-reperfusion, bone resorption, and tumor progression. Recently, substantial evidence has linked OPN with the regulation of metastatic spread by tumor cells. However, the molecular mechanisms that define the role of OPN in tumor metastasis are incompletely understood, growing evidence supports a role for OPN as a potential prognostic factor for various human cancers. In order to elucidate the relationship between expression of osteopontin and bladder cancer, we conducted researches as follows:[Objective ] To investigate the expression of Osteopontin(OPN) in bladder urothelium carcinomas and the clinical significance of OPN in tumorigenesis and prognosis.[Methods] Immunohistochemistry has been used to detect OPN in 50 bladder urothelium carcinomas and 10 non-bladder tumor tissues. The correlation of OPN between the tumor stage, grade, recurrence and the numer of tumor were analyzed.[Results] (1) In all the 50 cases of bladder urothelium carcinoma, 14 cases in which were low positive, 31 cases were high positive,that is 62% in total bladder urothelium carcinoma cases; Only 1 case in 10 non-bladder tumor tissue was low positive, the others were negative. The difference between the two groups had significant meaning(P<0.01); (2) There were significant correlation between the level of OPN expression and clinical stage, pathology grade, tumor recurrence (P<0.05), but it was not associated with the number of tumor (P>0.05).[Conclusion] The high expression of OPN in bladder urothelium carcinoma was correlated with the malignancy of tumor, suggests an important role for OPN in tumor progression. OPN may be a novel diagnosis and prognostic factor in bladder urothelium carcinoma.