Abstract 3858: Peristalsis-like mechanical stimuli in the intestinal milieu promotes colorectal cancer invasion through GABAergic signaling changes in an organ-on-chip platform

Abstract Mechanical forces in the tumor microenvironmental milieu are often understudied due to a lack of relevant preclinical model systems. Here we describe a microfluidic organ-on-chip platform that incorporates tissue-tissue interfaces and physical forces to aid in the examination of colorectal cancer (CRC) progression. A major advantage of this model is the ability to mimic peristalsis, a physiological process occurring in the gut. Live-cell imaging with a 3D printed organ-on-chip cradle was used to quantify the number of CRC cells that have invaded from the epithelial channel into the vascular channel over time. We determined that peristalsis-like motions in our organ-on-chip model enhanced the invasion capacity of CRC cells, mimicking intravasation. We subsequently examined the effluent media in stretched compared to non-stretched conditions using mass spectrometry based metabolomics and discovered an increase in the secretion of gamma-aminobutyric acid (GABA) by CRC cells, implicating peristalsis-mediated tumor cell invasion with neurotransmitter release. Inhibitors targeting the GABA-A receptor reversed the observed tumor cell invasion phenotype when cells were subjected to peristalsis-like motions. Interestingly, even in the absence of peristalsis, tumor cell invasion was promoted when GABA agonists were introduced into the organ-on-chip system. This work reveals important interactions between CRC cells and their microenvironment, and that disrupting GABAergic signaling might be an approach to prevent or delay cancer progression. Citation Format: Carly Strelez, Sujatha Chilakala, Kimya Ghaffarian, Ah Young Yoon, Jonathan Katz, Shannon M. Mumenthaler. Peristalsis-like mechanical stimuli in the intestinal milieu promotes colorectal cancer invasion through GABAergic signaling changes in an organ-on-chip platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3858.