Intra-prostatic Injection of Cancer Cells: A Technique to Deliver Cancer Cells for Establishing Orthotopic Prostate Cancer Mouse Model

After confirming a lack of response to toe pinch, apply ointment to the mouse's eyes and shave all of the fur from the animal's abdomen. Sterilize the exposed skin with three rounds of surgical scrub using sterile non-adhering pads followed by sterile alcohol wipes. When the skin is dry, place the mouse in the supine position on a clean surface over a heating pad directly under the objective of a clean surgical microscope, and cover the animal with a sterile drape with a small hole cut out over the abdomen.

Make a 1-centimeter incision in the outer skin and the inner abdominal musculature along the midline of the abdomen superior to the penis and the preputial glands. Locate one of the bilateral seminal vesicles and attached anterior prostate lobes that are typically posterior, lateral, and slightly superior to the bladder. Ask an assistant to mix the Myc-CaP matrigel cancer cell solution with gentle pipetting and to slowly aspirate 30 microliters of cells into a 28 gauge needle attached to a 50-microliter syringe.

Then, using Graefe tissue forceps, gently raise the tip of one seminal vesicle to create tension on the tissue without puncturing the vesicle, and carefully insert the bevel of the needle parallel to the long axis of the anterior prostate lobe. Slowly inject the entire volume of cells into the lobe, followed by slow retraction of the needle to prevent leakage.

A successful injection will be apparent by an engorgement of the interior prostate lobe. Carefully and steadily, maintain the seminal vesicle and injected prostate lobe outside of the mouse for approximately 30 seconds to allow the matrigel to partially solidify within the lobe. Use a sterile polyester-tipped applicator to collect any cell solution leakage into the abdomen to prevent non-orthotopic tumor development.

An accurate intra-prostatic injection is critical for orthotopic tumor development. Taking extra care to avoid puncturing the seminal vesicle, to slowly inject the cancer cell suspension, and to collect any cell leakage will increase the success of this procedure.

Now, gently return the seminal vesicle and injected lobe to the abdomen without putting pressure on the lobe and replace any externalized tissues. Using 5-0 vicryl absorbable reverse cutting needle sutures, close the inner abdominal musculature with continuous stitches, followed by closure of the outer abdominal skin with interrupted stitches using 4-0 nylon monofilament non-absorbable reverse cutting needle sutures.

Then, administer post-operative analgesia and place the mouse in a cage with no bedding halfway on a heating pad with monitoring until full recovery.