Musashi-2 promotes migration and invasion in bladder cancer via activation of the JAK2/STAT3 pathway

Musashi-2 (Msi2) is considered to have a crucial role in regulating various key cellular functions. However, the clinical significance and biological role of Msi2 in bladder cancer remains unknown. We examined the expression of Msi2 in bladder cancer cell lines in 167 clinical samples and the biological role of Msi2 in bladder cancer cells. Western blotting was used to investigate the possible mechanism of Msi2-induced migration and invasion in bladder cancer. Msi2 was significantly upregulated in bladder cancer cells and tissues compared with normal bladder urothelial cells and tissues. Immunohistochemical analysis revealed high expression of Msi2 in 57 of 167 (34.1%) bladder cancer specimens. Statistical analysis showed a significant correlation of Msi2 expression with advanced clinical stage, lymph node metastasis, and poor prognosis. Overexpression and ablation of Msi2 promoted and inhibited, respectively, the migration and invasion of bladder cancer cells. Furthermore, we found that Msi2 activated the JAK2/STAT3 pathway and promoted expression of genes downstream of JAK2/STAT3 in bladder cancer. This study demonstrates that Msi2 can induce bladder cancer cell migration and invasion by activating the JAK2/STAT3 pathway, and that Msi2 may be a valuable prognostic biomarker for bladder cancer patients.