Orthotopic Inoculation of Thyroid Cancer Cells into Murine Thyroid: A Procedure to Establish Orthotopic Thyroid Cancer Mouse Model

Orthotopic inoculation facilitates the delivery of cancer cells to a recipient animal at an organ or site that matches the tissue histotype. To begin, prep an anesthetized immunocompromised nude mouse in the supine position.

Next, make a surgical incision in the neck region to reveal the salivary glands. Displace the salivary glands and dissect the strap muscles to expose the underlying trachea and thyroid gland.

The thyroid gland, an endocrine gland, consists of two lobes that lie on either side of the trachea and surround the cricoid cartilage. These two lobes are connected by a thin strip of thyroid tissue called the isthmus.

Now, prepare a suspension of thyroid cancer cells with a suitable buffer in a syringe. Carefully inject the cell suspension into the mouse’s thyroid lobe.

Subsequently, reposition the salivary glands and suture the incision. Allow the mouse to recover. Monitor the mouse weekly to observe the growth of orthotopic tumors within the thyroid lobe.

For orthotopic thyroid tumor cell inoculation, suspend an aliquot of Cal62 cells in 5 microliters of PBS, and subcutaneously inject 100 microliters of analgesic and 100 microliters of antibiotic into a 7-week-old BALB/c nude mouse. After confirming a lack of response to toe pinch, place the animal under a dissecting microscope and disinfect the neck of the animal with iodopovidone.

Next, make an approximately 2-centimeter incision in the skin and displace the salivary glands to expose the neck. Use dissection forceps and/or scissors to dissect the strap muscles to expose the trachea and thyroid gland, and use a 10-microliter syringe to inject the 5-microliter volume of tumor cells into the right thyroid lobule, located at the side of the cricoid cartilage.

When all of the cells have been delivered, reposition the salivary glands and use silk-braided, coated, non-absorbable sutures to close the incision. Then, apply iodopovidone to the wound area and place the mouse on a thermic blanket with monitoring until full recovery.