PROJECT SUMMARY Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States. Despite the introduction of novel therapies, the five-year survival rate for metastatic disease remains around 10%. To improve our understanding of tumor progression and drug efficacy, it is vital to develop preclinical tumor models that accurately reflect the native pathophysiology of CRC “ex vivo”. The complexities of the tumor microenvironment (TME), including stromal cell types and mechanical forces, are not fully reproduced in existing preclinical models. Microfluidic-based “organ-on-chip” technologies, which are designed to simulate the 3-D human organ environment both mechanically (e.g., fluid flow and cyclic deformation) and biochemically (e.g., nutrient digestion, secretion, transport), have recently provided researchers with greater insights into and expanded control over the TME. In this proposal, we are adapting the organ-on-chip technology to create human colon organ chips colonized with patient-derived CRC cells and stromal elements (endothelial and cancer- associated fibroblast (CAF) cells) in relevant tissue:tissue compartments with integrated microfluidics and stretching to mimic in vivo peristalsis-like motions. The goal is to create a physiologically relevant, organ- dependent tumor model that will allow for long-term culture and characterization of CRC cellular dynamics, and serve as a platform for testing specific therapeutic modalities to prevent or delay tumor progression. Using novel imaging assays and “omics” based approaches, we will evaluate the role of the physical (i.e., peristalsis) and cellular (CAFs) microenvironment in colon tumor progression. In Aim 1, we will develop patient- derived CRC-on-Chips incorporating primary normal and tumor epithelium to assess CRC tumor growth and early metastatic spread (i.e., invasion into the vascular channel) in the presence of cyclic stretch, mimicking peristalsis. In Aim 2, we will analyze the impact of the stromal CAF microenvironment on tumor cell behavior and examine the extent and role of inter-patient CAF functional heterogeneity. In Aim 3, we will assess the drug screening capabilities of the CRC-on-Chip platform via monitoring of drug-induced cellular responses, and determine whether drug responses on chips can predict patient clinical responses. The longer-term vision for developing a microengineered CRC model that more closely resembles human disease is to expedite the identification and screening of novel drug targets and innovative treatment strategies with a focus on disrupting tumor-stromal interactions. Our multi-disciplinary team with complementary expertise, the groundbreaking technologies, and availability of clinical materials put us in a prime position to successfully address important aspects of CRC tumorigenesis and advance our understanding of the tumor niche.

PROJECT NARRATIVE The 5-year survival rate for metastatic colorectal cancer (CRC) remains at 11% despite the introduction of novel therapies. Preclinical models that more closely recapitulate the human pathophysiology of CRC are needed to better understand tumor progression and chemoresistance. Our objective is to develop and characterize a microengineered CRC-on-Chip model using patient biopsy material to identify key factors in the tumor microenvironment that influence cell behavior and treatment response, with an ultimate goal of developing innovative treatment strategies effective in CRC that focus on disrupting tumor-stromal interactions.