Abstract 2638: Developing 3d hydrogel model for patient-derived organoids of metastatic colorectal cancer

The advances in the development of preclinical models for various cancers have tremendously helped study of the biology and genetics of human cancers as well as for development of therapeutics. Recently, patient-derived organoids (PDOs) have emerged as a robust preclinical platform that can provide insight into the patient specific genetic mechanisms, cancer progression and drug susceptibility. We have developed a novel PDO platform by embedding patient-derived organoids in a 3D hydrogel suspension culture. Our previous studies have shown that, when cultured in hydrogel, spheroids derived from cancer cell lines demonstrated upregulated gene expression signatures in relation to migration and angiogenesis compared to cultures in media, suggesting a more hypoxic, nutrient deficient environment. Given that hypoxia and nutrient deficiency are important feathers of solid tumors, the hydrogel environment could provide a good platform for in vitro study of tumor development and resistance to treatment. In the current study, we embedded PDOs derived from liver metastasis of colorectal cancer into the 3D suspension hydrogel culture. The PDOs adapted well in the hydrogel gel environment. We assessed the response of PDOs in hydrogel to anticancer agents, and compared that to those cultured in media. The PDOs cultured in hydrogel showed significantly elevated resistance to the treatments. The IC50s of chemotherapeutic drugs 5-fluorouracil and oxaliplatin are increased by ~5-10 fold when cultured in hydrogel compared to those in media. Further studies through RNAseq analysis revealed differentially activated signaling pathways. In particular, the levels of the CXC ligand family chemokines are significantly up-regulated in the PDOs cultured in the hydrogel. The CXC ligand family chemokines are important immune stimulants that are known to play key role in the chemotaxis and tumor recruitment of immune cells including neutrophil, T-cell and B-cells. Interestingly, the elevated levels of CXC-ligands have been shown to relate to resistance of colorectal cancer against drug treatment such as 5-fluorouracil. Our hydrogel model could help elucidate the mechanisms behind such resistance. Future study will focus on evaluating how well the hydrogel PDO platform can recapitulate tumor microenvironment and its potential in screening for personalized medicine. Citation Format: He Wei, Eveliina Karelehto, Karen Dubbin, Aimy Sebastian, Robert Warren, Monica Moya, Gaby Loots, Elizabeth Wheeler, Matthew Coleman. Developing 3d hydrogel model for patient-derived organoids of metastatic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2638.