PROJECT SUMMARY
50% of colorectal cancer (CRC) patients develop liver metastasis (CRLM). Despite adjuvant
chemotherapy and surgery, 75% of CRLM recurs due to microscopic residual disease (~1-3mm) that
escapes radiographic detection. The objective of this proposal is to engineer and utilize an adjuvant
chemotherapy screening platform specific to microscopic CRLM, to identify therapeutics that can
eradicate microscopic residual disease. Preclinical models like spheroids and patient-derived xenograft
models lack the architecture and extracellular matrix (ECM) composition of the liver metastatic
microenvironment. We hypothesize that by engineering the liver metastatic microenvironment, we
can produce reproducible instances of microscopic CRLM that can be used for therapeutic screening.
Engineered microscopic CRLM models will include: i) decellularized porcine liver biomatrix scaffolds
that contain both liver ECM composition and 3D architecture; ii) microscopic spheroids from cells
established from patient-derived xenografts of stage IV CRLM. Our methods offer advantages over
other decellularized models by: i) using patient-derived cells; and ii) using optical imaging to
quantitatively benchmark the establishment of microscopic CRLM; iii) using orthogonal validation
including clinical patient-response benchmarking of engineered models to therapeutics; iv) being
medium- and high-throughput amenable. The project will build on the PI's (Raghavan) expertise in
cancer tissue engineering, but represent significant changes in research directions: The PI's expertise
is in studying ovarian cancer initiation and chemoresistance, and this proposal focuses on CRC
metastasis and CRLM. To support these research pivots, the PI has assembled an investigative team
with expertise in clinical treatment and management of CRC (Kopetz), high-throughput drug
screening (Stephan) and microscopy (Walsh). Specific Aims proposed include: (1) : Establish and
characterize a bioengineered model of microscopic CRLM from human stage IV CRC; (2) Therapeutic
screening of microscopic CRLM using an NCI-approved library; (3) Validation of therapeutic targeting
of microscopic CRLM in orthotopic metastasis models. This will be the first instance of a
bioengineered in vitro model of microscopic CRLM. Immediate outcomes using the engineered
microscopic CRLM model include: i) screening a library of NCI-approved compounds; ii) identifying
efficacious strategies to treat microscopic CRLM. Long-term outcomes envisioned include: i) predict
the aggressiveness of microscopic residual disease, stratifying patients who are at high-risk of
recurrence; ii) testing compounds that can translate into phase I clinical trials in patients with
microscopic CRLM identified with circulating tumor DNA biomarkers.