Abstract B43: High-throughput drug screening model using 3D cultured human pancreatic ductal adenocarcinoma cells
Authors: Heuchel Rainer L. , Nania Salvatore , Liu Jianping , Löhr J. Matthias 
Published: December 2016

Abstract
Background: Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive disease and the fourth most common cause of cancer related death. It is lethal in nearly all patients, due to an almost complete chemo-resistance. Most if not all drugs which successfully pass preclinical tests, fail miserably in the clinic. PDAC is characterized by exceptionally fibrotic stroma, which is believed to be important for pancreatic cancer progression and general therapy resistance.
Compared to traditional 2D cell culture, cells in a three-dimensional (3D) context demonstrate different behavior and functions as reflected by building up a microenvironment that more closely mimics the one observed in native tissue. This feature is critical for testing drug efficiency, as the cellular response to drugs is profoundly affected by environmental cues. Our lab has previously set up a drug screening system using 3D cell culture containing human PDAC cells. We demonstrated that 3D cultures express more extracellular matrix compared to 2D cell culture and are much more resistant to chemotherapy compared to their 2D counterpart, offering a more predictive approach for drug screening before proceeding to more expensive in vivo models and clinical trials.
Methods: To be able to more efficiently screen for compounds, we adjusted our previously developed 3D PDAC 96-well cell culture model to a fully automated high-throughput screening (HTS) system on 384-well format. With this set up we screened a library of over 3000 natural compounds (TimTec_NL3000) on a PDAC cell line (Panc1), at a fixed concentration of 10 µM. As a read out we used a luminescence based cell viability assay (CellTiter Glo, Promega). The compounds found to decrease the cell viability were then validated by performing a dose-response curve in different cell lines.
Results: In the initial screen we identified 13 hits which significantly decreased the cell viability of the tested 3D PDAC cell cultures compared to the untreated vehicle control. In the validation phase, 5 out of these 13 compounds, were confirmed to significantly decrease cell viability in in a dose-dependent manner in Panc1 cells.
When those 5 compounds have been tested in a different cell line (HPAFII) at least 2 of them showed the ability to dramatically decrease the cell viability.
In the future, we are planning to add a level of complexity to the system by inserting a stromal compartment into the 3D cultures to be able to even better resemble the in vivo PDAC situation.
Conclusion: We have demonstrated that robotized high-throughput drug screening for pancreatic cancer is feasible even in organotypic 3D culture.
Citation Format: Rainer L. Heuchel, Salvatore Nania, Jianping Liu, J. Matthias Löhr.{Authors}. High-throughput drug screening model using 3D cultured human pancreatic ductal adenocarcinoma cells. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B43.