High expression of Notch ligand Jagged2 is associated with the metastasis and recurrence in urothelial carcinoma of bladder

Background: The Notch signaling pathway is closely related with human organ development and tumorgenisis. Jagged2 is among the most popular topic in Notch studies currently. Recent studies found its vital role in tumor metastasis in breast cancer; however, its expression profile and its prognostic value in urothelial carcinoma of bladder have not been investigated. Methods: Immunohistochemistry was used to detect the expression of Jagged2 in 120 bladder urothelial carcinoma. Moreover, the expression of Jagged2 was analyzed by Western blot in 60 bladder urothelial carcinoma and 20 normal epithelial tissues. MTT assay and flow cytometry and transwell assay were used to examine the proliferative and invasive ability of bladder cancer cells with the treatment of GSIXX (the inhibitor of Jagged2). Prognostic value of Jagged2 expression and its correlation with tumor metastasis and recurrence were evaluated, and the proliferative and invasive ability and cell cycle process of the bladder cancer cells were detected as well. Results: There was a significantly higher Jagged2 expressions in bladder urothelial carcinoma and highly invasive bladder T24 cells than those in bladder normal tissues and the superficial bladder BIU-87 cells. Jagged2 expression was positively correlated with histological grade, p T stage, recurrence, and metastasis. With the increasing concentration of GSIXX, we found that not only the cell proliferation and invasion activity decreased significantly, but also the cell cycle was blocked at G₂/M stage. Conclusions: Jagged2 expression status was closely correlated with important histopathologic characteristics (grades and stages) and the recurrence and metastasis of bladder urothelial carcinomas. Furthermore, Jagged2 played an important function on the bladder cancer cells’ proliferation by regulating the cancer cell cycle from G₁/S to G₂/M and probably promoted the invasion and metastasis of bladder cancer.