Hypoxia-inducible Factor-1-dependent Repression of E-cadherin in Von Hippel-Lindau Tumor Suppressor-null Renal Cell Carcinoma Mediated by TCF3, ZFHX1A, and ZFHX1B

A critical event in the pathogenesis of invasive and metastatic cancer is E-cadherin loss of function. Renal clear cell carcinoma (RCC) is characterized by loss of function of the von Hippel-Lindau tumor suppressor (VHL), which negatively regulates hypoxia-inducible factor-1 (HIF-1). Loss of E-cadherin expression and decreased cell-cell adhesion in VHL-null RCC4 cells were corrected by enforced expression of VHL, a dominant-negative HIF-1alpha mutant, or a short hairpin RNA directed against HIF-1alpha. In human RCC biopsies, expression of E-cadherin and HIF-1alpha was mutually exclusive. The expression of mRNAs encoding TCF3, ZFHX1A, and ZFHX1B, which repress E-cadherin gene transcription, was increased in VHL-null RCC4 cells in a HIF-1-dependent manner. Thus, HIF-1 contributes to the epithelial-mesenchymal transition in VHL-null RCC by indirect repression of E-cadherin.