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

Intra-prostatic orthotopic tumor injection delivers tumor cells matching the prostate tissue histotype directly into the prostate gland of the recipient animal.

To begin, prep an anesthetized male mouse in the supine position. Make a midline abdominal incision and dissect the inner musculature to expose the abdominal cavity. Locate one of the anterior prostate lobes. These prostate lobes are attached to the lesser curvature of the seminal vesicles and lie close to the urinary bladder.

Now, inject a chilled suspension of prostate cancer cells mixed with the desired basement membrane matrix into the long axis of the anterior prostate lobe. Ensure complete delivery of the cell suspension and gently retract the needle. Allow the matrix to solidify and embed the cells within.

Subsequently, place the prostate lobe along with the seminal vesicle back into the abdominal cavity. Suture the surgical incision. Allow the mouse to recover. Check the mouse weekly to observe the growth of orthotopic tumors within the anterior prostate lobe.

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.

• Prostate Cancer Model - A lab representation to study the progression & treatment of prostate cancer.
• Intraprostatic Injection - Technique of injecting medication or solution directly into the prostate.
• Matrigel - A gelatinous protein matrix used in tumor cell research.
• Orthotopic Tumor Model - Study model wherein tumor cells are implanted in their original organ.
• Seminal Vesicles - Male reproductive glands located near the prostate, integral to the injection procedure.

• Introduce Prostate Cancer Model – Biological method to examine prostate cancer (e.g., intraprostatic injection).
• Key Concepts – Involve steps like shaving, sterilizing, incising and suturing (e.g., prostate biopsy procedure video).
• Underlying Mechanisms – Seminal vesicles and anterior prostate lobes are involved (e.g., prostate cancer real images).
• Connect to Experiment – Demonstrate how injections ensure successful tumor implantation within prostate.

• What is intraprostatic injection used for in a prostate cancer model?
• How is the matrigel cancer cell solution involved in the procedure?
• Why is careful handling of seminal vesicles and prostate lobes crucial in this experiment?

• Practical Applications – Used in surgical training and cancer treatment research (e.g., prostate cancer injection).
• Industry Impact – Benefits medical industries, particularly oncology and urology (e.g., injection for prostate cancer).
• Societal Importance – Advancement in prostate cancer treatment techniques (e.g., injection prostate).
• Link to Scientific Advancements – Continuous improvement of prostate cancer models for research.