Intracecal Tumor Cell Injection: A Technique to Deliver Cancer Cells for Establishing Orthotopic Colorectal Cancer Mouse Model

- Intracecal orthotopic tumor injection delivers tumor cells matching the cecal tissue histotype directly into the cecum of the recipient animal. To begin, prepare an anesthetized mouse for surgery. Incise its abdominal wall to exteriorize the cecum. Scrape the cecal wall to diminish any intestinal peristaltic movement. Align a syringe containing colorectal cancer cell or CRC suspension parallelly over the cecum.

Next, stretch the cecum to remove any folds. Gently pull the cecum over the cannula such that the tip perforates just the thin, translucent, outer intestinal membrane, or serosa. Next, inject the cancer cell suspension into the space between the serosa and inner muscular layer. Ensure complete delivery of the cell suspension and retract the cannula. Return the cecum to the abdominal cavity and suture the surgical incision. Allow the mouse to recover.

Within days of injection, an orthotopic tumor develops at the site of injection or metastasizes to distant tissues or organs. In the following protocol, we will demonstrate an intracecal colorectal cancer cell injection technique to develop an orthotopic CRC mouse model.

- Begin by using atraumatic forceps to carefully exterio