All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. Thyroid Orthotopic Inoculation of Cells
- Cell preparation
- Engineer a Cal62 human thyroid cancer cell line to overexpress a transgenic construct that constitutively expresses GFP and luciferase. Select the transgenic cells by antibiotic resistance or by sorting the GFP-positive cells with flow cytometry.
- Grow these cells in DMEM supplemented with antibiotics (penicillin and streptomycin) and 10% FBS at 37 °C and 5% CO2.
- Suspend 1 x 105 cells in 5 μL of PBS.
- Cell inoculation into the thyroid gland of mice
- Inject 100 μL of analgesic (buprenorphine) and 100 μL of antibiotic (cephalosporin) subcutaneously into 7-week-old BALB/c nu/nu mice. Disinfect the injection site with alcohol.
- Inject 5 μL of the cell solution into the thyroid gland of the mice.
- Anesthetize the mouse using 3% isoflurane mixed with oxygen and place it under a stereomicroscope in a sterile flow cabinet. Assess the level of anesthesia by pedal reflex (firm toe pinch) and adjust anesthetic delivery as appropriate to maintain the surgical plane.
- Apply ophthalmic ointment to both eyes to prevent desiccation.
- For each mouse, disinfect the neck with iodopovidone and make an incision of approximately 2 cm in the skin with scissors. Once open, expose the neck by displacing the salivary glands.
- Dissect the strap muscles using dissection forceps and/or scissors to expose the trachea and the thyroid gland. Using a 10 μL syringe, inject 5 μL of the cell solution into the right thyroid lobule, located at the side of the cricoid cartilage.
- Reposition the salivary glands and suture the incision with silk using braided, coated, non-absorbable sutures.
- Add iodopovidone to the wound area and place the mouse on a thermic blanket while it recovers from the anesthesia.
- The following day post-surgery, inject subcutaneously analgesic (buprenorphine) and add 3 mL of liquid ibuprofen (40 mg/mL) into 250 mL of the drinking water for 1 week.