Renal carcinoma/kidney progenitor cell chimera organoid as a novel tumourigenesis gene discovery model

Three-dimensional organoids provide a new way to model various diseases, including cancer. We made use of recently developed kidney organ primordia tissue engineering technologies to create novel renal organoids for cancer gene discovery. We then tested whether our novel assays can be used to examine kidney cancer development. First we identified the transcriptome profiles of quiescent embryonic metanephric mesenchymes (MM) and of MM in which the nephrogenesis program had been induced ex vivo. The transcriptome profiles were then compared to the profiles of RCC patients and controls. Certain signature genes were identified that correlated in the developmentally induced MM and RCC, including components of the caveolar-mediated endocytosis signalling pathway. An efficient siRNA mediated knock down (KD) of Bnip3, Gsn, Lgals3, Pax8, Cav1, Egfr and Itgb2 gene expression was achieved in renal carcinoma (Renca) cells. The live cell imaging analysis revealed inhibition of cell migration and cell viability in the gene KD RCC cells in comparison to the controls. Upon siRNA treatment, the transwell invasion capacity of the RCC cells was also inhibited. Finally, we mixed the nephron progenitors with the Yellow Fluorescent Protein (YFP) RCC model cells to establish chimera organoids. Strikingly, we found that the siBnip3, siCav1 and siGSN KD RCC-YFP+ cells as a chimera with the MM in 3D organoid rescued, in part, the RCC-mediated inhibition of the nephrogenesis program during epithelial tubules formation. Altogether our research indicates that comparing renal ontogenesis control genes to the genes involved in kidney cancer may provide new growth associated gene screens and that 3D RCC-MM chimera organoids can serve as a novel model with which to investigate the behavioural roles of cancer cells within the context of emergent complex tissue structures.