Engineered Colorectal Cancer Tissues Employing Patient-derived Cells for Recapitulating the Tumor Microenvironment

Abstract

Colorectal cancer (CRC) remains the third most prevalent cancer and the third-highest cause of cancer-related deaths among both men and women in the United States. The development of pre-clinical CRC models is vital for understanding tumor biology to identify new, effective anti-cancer therapeutics. However, the current CRC models are unable to accurately represent disease pathophysiology and the complex tumor microenvironment. Patient-derived xenografts (PDXs), an in vivo model, demonstrate high potential in clinical translatability due to the recapitulation of key characteristics of the patient tumor; however, the use of PDXs is costly and low-throughput. This research focuses on the establishment of an in vitro 3D engineered CRC model using cells isolated from CRC PDX (CRC-PDX) tumor lines to recapitulate the key attributes of the originating tumors. This study demonstrates the use of poly(ethylene glycol)-fibrinogen (PEG-Fb) hydrogels for CRC tissue engineering. Chapter 1 introduces the current preclinical CRC models and the need for better models to recapitulate the CRC tumor microenvironment. Chapter 2, as a proof of concept, demonstrates the ability of a PEG-Fb-based tissue-engineered cancer model to support the investigation of CRC cell line phenotypes. Chapter 3 describes the establishment of engineered CRC tissue that recapitulates the key attributes of a stage II CRC-PDX tumor line. In Chapter 4, two other PDX lines originated from stages III-B and IV of CRC patients were incorporated into the tissue-engineered CRC model to recapitulate patient-to-patient and/or cancer stage-to-stage variabilities. Chapter 5 describes the rapid generation of CRC tissue-engineered microspheres for high-throughput study. Overall, the robust in vitro tissue-engineered CRC models reported in this research demonstrate significant potential for future implementation in the study of disease progression, tumorigenic mechanisms, and drug-testing applications.