Abstract

High Throughput Screening Utilizing 3D Multicellular Tumor Spheroids Models

Geoffrey Bartholomeusz, Assistant Professor/Associate Professor and Director, University of Texas M D Anderson Cancer Center

Most anticancer drugs and molecular targeted therapies that have shown promise in pre-clinical studies yield little success in the clinic. A major reason for this failure is that two-dimensional (2D) monolayer cancer cell models used for these studies are somewhat artificial and poorly replicate the complexity of the three-dimensional tumor environment. Three dimensional spheroid cell cultures exhibit a higher degree of structural complexity and are of intermediate complexity between in vivo tumors and monolayer cultures. Their growth emulates the heterogeneity of solid tumors with necrosis and radiation-resistant hypoxic regions that often occur at the center of solid tumors, due to poor vasculature and subsequent lack of oxygen supply. Using a non-matrix, transparent, cycloolefin resinous sheets comprising nanoscale-indented patterns we generated a 3D spheroid model with the pancreatic cancer cell line PANC1. Using this model we successfully performeda high throughput RNAi screen and identified and validated targets that were novel regulators of spheroid architecture.  Loss of the protein product of these targeted gene resulting in loss of integrity of the spheroid architecture, reduction in hypoxia and sensitization of the spheroids to radiation. We hypothesize that targeting non-neoplastic components such as tumor architecture has the potential to improve our ability to treat solid tumors.