Generating PDOX Mouse Model of Colorectal Cancer: Studying Progression of Colorectal Cancer in a Murine Model

- Lymph nodes, or LNs, provide a microenvironment for tumor growth due to the stromal cells present in LNs. Follicular dendritic cells, or FDCs, are the most abundant types of stromal cells that release chemokines, cytokines, and growth factors, which interact with colorectal cancer stem cells and increase tumor growth.

FDCs also promote extranodal metastasis of colorectal cancer to organs such as the lungs and liver. To study the colorectal cancer progression, we implant patient tumor-derived cancer cells into the organ, which matches the tumor histotype in an immunocompromised mouse model known as patient-derived orthotopic xenograft, or PDOX.

Begin by securing an anesthetized mouse in a supine position on a dissection board using lab tape. Now, mix a required amount of luciferase-tagged colorectal cancer cells and FDCs in a tube. Take the resulting suspension in a syringe. Next, locate the anal opening of the mouse and inject the prepared colorectal cancer mix into the submucosal layer of the rectum.

To observe metastatic burden, inject luciferin intraperitoneally every week and image the mouse using bioluminescent imaging. In the presence of luciferase enzyme and ATP, luciferin