The use of organoids, which are 3D miniaturized, simplified versions of organs produced in the lab in vitro that shows realistic micro-anatomy and function, has been increasingly utilized to test hypotheses in the absence of live tissue or prior to in vivo studies.
In this study, the authors used bladder cancer cell lines (RT4 and 5637, representing luminal and basal phenotypes) to generate organoids. They also utilized actual patient bladder specimens to generate organoids independent of these cell lines.
The Wnt/beta-catenin pathway was activated by using a small molecule CHIR99021 (GSK3 inhibitor, Wnt activator) and inhibited by siRNA against beta-catenin. Utilization of CHIR99021 promoted proliferation of cancer cell lines cultured as organoids with activation of Wnt/beta-catenin pathway. Enhanced proliferation of cancer cells with activation of Wnt/beta-catenin pathway by CHIR99021 was also confirmed in ex-vivo organoids from patient samples.
However, when beta-catenin was knocked down using siRNA, growth of organoids was significantly suppressed. Cytokeratin 20, a terminal differentiation marker, was less expressed over CHIR99021-enhanced cell proliferation.
Between the two of these, the authors were able to better demonstrate the importance of the Wnt/Beta-catenin pathway in bladder cancer proliferation. While further work is needed, this is an important step forwards to new drug therapy.
Presented by: Takahiro Yoshida, MD, PhD
Co-Authors: Max Kates MD¹, Nikolai Sopko MD, PhD¹, Gregory Joice MD¹, Xiaopu Liu BS¹, David McConkey PhD² and Trinity Bivalacqua MD, PhD¹
Affiliation: ¹The James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD; ²Greenburg Bladder Cancer Institute, The Johns Hopkins University School of Medicine, Baltimore, MD
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, twitter: @tchandra_uromd at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC