Three-Dimensional Microtumors for Probing Heterogeneity of Invasive Bladder Cancer.

Bladder cancer is an increasingly common malignancy, and muscle invasive bladder cancer is associated with particularly high rates of morbidity and mortality. The morphologic and molecular diversity of bladder cancer poses significant challenges in elucidating the invasion mechanisms responsible for disease progression. Furthermore, conventional invasion assays do not provide a physiological context for studying bladder cancer invasion within 3D microenvironments and have limited ability to capture the contribution of cellular phenotypic heterogeneity to disease progression. Here, we describe the development of a 3D microtumor invasion model suitable for the analysis of cellular phenotypic heterogeneity in cell lines and primary tumor cells from bladder cancer patients. This model incorporates a self-assembly approach for recapitulating features of bladder cancer invasion in 3D microenvironments and probing the invasive cell subpopulations. The gene expression profiles of invading microtumors were analyzed by incorporating a gold nanorod-locked nucleic acid biosensor. The incorporation of the single cell biosensor and transient gene knockdown into the system revealed the formation of invasive leader cells with upregulated Delta-like ligand 4 (DLL4) expression as well as the role of NOTCH1-DLL4 signaling in collective bladder cancer invasion. The involvement of DLL4 expressing cells in bladder cancer invasion was also observed in patient samples obtained from transurethral resection. Collectively, our study demonstrates a 3D microtumor invasion model for investigating intracellular heterogeneity of bladder cancer invasion and analyzing patient derived samples toward personalized medicine applications.

Analytical chemistry. 2020 Jun 24 [Epub ahead of print]

Peter Torab, Yue Yan, Hironobu Yamashita, Joshua I Warrick, Jay D Raman, David J DeGraff, Pak Kin Wong

Department of Mechanical Engineering, The Pennsylvania State University, 137 Reber Building, University Park, Pennsylvania 16802, United States., Department of Biomedical Engineering, The Pennsylvania State University, 122 Chemical and Biomedical Engineering Building, University Park, Pennsylvania 16802, United States., Department of Pathology and Laboratory Medicine, Penn State Health Milton S. Hershey Medical Center, 500 University Drive, Hershey, Pennsylvania 17033, United States., Department of Surgery, Division of Urology, Penn State Health Milton S. Hershey Medical Center, 200 Campus Drive, Hershey, Pennsylvania 17033, United States.