Precision Cut Cancer Tissue Slices in Anti-Cancer Drug Testing

Abstract

Florian T Unger, Susanne Bentz, Jana Krüger, Cordula Rosenbrock, Janina Schaller, Katja Pursche, Annika Sprüssel, Hartmut Juhl, Kerstin A David

Background: To meet the urgent need to predict individual drug responses of patients and thus support drug development, better preclinical models of solid tumors are inevitable. Here, a newly developed precision cut cancer tissue slice culture is presented and its use in drug testing was evaluated. Methods: Efficacy of therapeutic compounds from different classes, i.e. Staurosporine, IRESSATM, and Herceptin® was tested within the drug testing platform using fresh precision cut cancer slices from human colon, lung, or breast tumor tissues. The stability and significance of the model were evaluated on the level of gene expression, by antibody diffusion assays, and drug responses were detected by immunohistochemical staining, Meso Scale Discovery (Akt, pAkt) analysis, Western blotting (pAkt, pMAPK), viability (ATP) and apoptosis assays (Caspase-3/7). Results: We obtained sufficient numbers of tissue slices from cancer specimens to be able to perform a wide range of experiments for each individual tumor. In our culture system, cells remained viable and proliferated for at least 4 days within their tissue environment. Viability of tissue slices decreased significantly due to therapeutic treatment in a dose-dependent manner. Gene expression varied remarkably in primary cultivated cells and HT-29 cells in comparison to cultivated tumor slices, which closely represent freshly isolated tumor tissue. An Alexa Fluor 488-labelled antibody showed diffusion in deeper cell layers and the ability of the system to evaluate effects of antibody therapy. Sustained viability of the precision cut cancer tissue slices over 72h enabled to test different drugs. Staurosporine, IressaTM, and Herceptin® showed a dose-dependent reduction of viability and downstream signaling pathways like Akt and MAPK kinase phosphorylation in EGFR- or Her-2-positive Caco-2 or BT-474 cells or tissue slices, respectively. No effect was seen in EGFR- or Her-2-negative cells and tissues. Conclusions: We showed that this preclinical model is applicable to examine the effects of various anti-cancer compounds like cytotoxic chemotherapeutic drugs as well as targeted th