American Association for Cancer Research
00085472can143067-sup-139627_1_supp_0_nl443w.pptx (968.61 kB)

Supplemental Figure S4 from Oncogenic HRAS Activates Epithelial-to-Mesenchymal Transition and Confers Stemness to p53-Deficient Urothelial Cells to Drive Muscle Invasion of Basal Subtype Carcinomas

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posted on 2023-03-30, 23:10 authored by Feng He, Jonathan Melamed, Moon-shong Tang, Chuanshu Huang, Xue-Ru Wu

Supplemental Figure S4. Activation of the AKT-β-catenin-ZEB2 signaling axis in muscle-invasive urothelial carcinoma of the bladder.



Muscle-invasive urothelial carcinomas of the bladder (MIUCB) exhibit frequent receptor tyrosine kinase alterations, but the precise nature of their contributions to tumor pathophysiology is unclear. Using mutant HRAS (HRAS*) as an oncogenic prototype, we obtained evidence in transgenic mice that RTK/RAS pathway activation in urothelial cells causes hyperplasia that neither progresses to frank carcinoma nor regresses to normal urothelium through a period of one year. This persistent hyperplastic state appeared to result from an equilibrium between promitogenic factors and compensatory tumor barriers in the p19–MDM2–p53–p21 axis and a prolonged G2 arrest. Conditional inactivation of p53 in urothelial cells of transgenic mice expressing HRAS* resulted in carcinoma in situ and basal-subtype MIUCB with focal squamous differentiation resembling the human counterpart. The transcriptome of microdissected MIUCB was enriched in genes that drive epithelial-to-mesenchymal transition, the upregulation of which is associated with urothelial cells expressing multiple progenitor/stem cell markers. Taken together, our results provide evidence for RTK/RAS pathway activation and p53 deficiency as a combinatorial theranostic biomarker that may inform the progression and treatment of urothelial carcinoma. Cancer Res; 75(10); 2017–28. ©2015 AACR.