Bladder cancer is one of the most prevailing cancers worldwide. Although treatments for urothelial carcinoma have improved, the rate of recurrence observed in the clinic is still high. The aim of this study was to evaluate whether cholesterol biosynthesis is involved in the effect of Farnesoid X Receptor (FXR) on bladder cancers. FXR overexpression contributed to activation of 5' AMP-activated protein kinase (AMPK) and decreased cholesterol levels. FXR overexpression reduced cholesterol biosynthesis and secretion by downregulating Sterol Regulatory Element Binding Protein 2 (SREBP2) and 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGCR) expression. In addition, an AMPK inhibitor, dorsomorphin, reversed the inhibition of migration, invasion and angiogenesis by FXR overexpression. In a metastatic xenograft animal study, FXR overexpression suppressed bladder cancer lung metastasis by decreasing matrix metalloproteinase-2 (MMP2), SREBP2 and HMGCR expression. Moreover, FXR overexpression combined with atorvastatin treatment further enhanced the downregulation of the migratory, adhesive, invasive and angiogenic properties in human urothelial carcinoma. In clinical observations, statin administration was associated with better survival rates of early-stage bladder cancer patients. Our results may provide guidance for improving therapeutic strategies for the treatment of urothelial carcinoma.
Keywords: AMPK; FXR; angiogenesis; atorvastatin; bladder cancer; cholesterol; invasion; migration.