Renal Capsule Tumor Xenografting: A Technique to Generate an Experimental Animal Model to Evaluate Prostate Carcinogenesis

In renal capsule tumor xenografting, small pieces of cancerous tissue from a donor organism are implanted into the kidney of an immunodeficient recipient animal belonging to a different species.

To begin, prep an immunocompromised anesthetized mouse in the prone position. Make a small dorsal midline incision and gently separate the skin from the underlying muscle wall.

Shift the mouse to the lateral position. Pull the separated skin to locate the kidney by viewing the renal profile through the muscle wall. Make a minor incision in the muscle wall to expose the body cavity. Widen the incision to exteriorize the kidney.

Now, make a small incision in the kidney capsule or the thin membranous outer covering of the kidney. Using a round-edged glass pipette, open a small pocket through the cut edge of the kidney capsule. Insert the prostate tissue graft into the pocket.

Gently push the kidney back into the body cavity. Suture the wound and allow the mouse to recover. Monitor the animal regularly to observe the xenograft.

The highly vascularized microenvironment of the renal tissue ensures a constant supply of oxygen and nutrients, favoring the successful engraftment and growth of the tumor mass eventually.

Before beginning the surgical procedure, sterilize all necessary instruments and prepare the work area. Once the animal is properly anesthetized, disinfect the surgical site with repeated applications of betadine and alcohol.

After sterile drapes are applied to the area, a 2 to 3 centimeter dorsal midline incision is performed. Next, separate the underlying dermis from the body wall. Separate both sides of the incision for bilateral grafting or just one for unilateral grafting. Once separated, place the mouse into a lateral position and locate the kidney by viewing the renal profile through the muscle wall. Applying gentle pressure with the thumb and index finger may assist with visualizing the internal organs.

Using fine iris scissors and taking care to avoid major vessels and spinal nerves, make a 1 centimeter incision in the body wall parallel to the spine. Widen this incision to 1.5 to 2 centimeters by gently opening the scissors wider after placing them in the initial incision.

Exteriorize the kidney by applying gentle pressure outside the muscle wall on either side of the kidney. Next, tuck the skin edges below the exteriorized kidney, which will rest on the body wall. If other structures are also present, they can be gently tucked in. While the kidney is exteriorized, maintain hydration of the renal capsule by applying sterile saline.

Gently lift the kidney capsule and make a 2 to 4 millimeter incision. The size of the incision is determined by the size of the graft but should be minimized in order to maintain the integrity of the capsule. Insert the rounded closed end of the pipette prepared earlier under the capsule tangential to the surface of the kidney. Once inserted, gently open a small pocket for the grafts using great care not to damage the kidney parenchyma. Tissue grafts are prepared from fresh prostate tissue obtained during surgical resection.

Lift the cut edge of the kidney capsule and insert the graft into the pocket using the pipette tip. Several grafts can be placed under the kidney capsule and evenly spaced on the kidney surface. When grafting is complete, gently lift the sides of the muscle wall incision to replace the kidney back into the body cavity. Make sure that the grafts do not slip out from under the capsule.

• Renal Capsule - Protective layer enveloping kidney, ensuring organ integrity.
• Adipose Capsule - Fatty layer around the kidney providing cushion against damage.
• Sterilization - Process for eliminating/preventing any microorganisms on medical instruments.
• Grafting - Surgical procedure to transplant tissue or organ in body.
• Incision - A cut made during a surgery, size and location vary based on procedure.

• Introduction to Renal Capsule - The renal capsule is a transparent, fibrous membrane covering the exterior surface of the kidney (e.g., renal capsule).
• Dprescription of Key Concepts - Delve into key concepts related to grafting, focusing on the placement and spacing on the kidney surface (e.g., grafting).
• Explain Surgical Process - Overview on how incisions are made and the kidney is exteriorized for the procedure (e.g., incision).
• Connect to Experiment - Describe the repositioning of the kidney and the completion of grafting in this procedure (e.g., surgery).

• How is the renal capsule related to grafting procedures?
• What role does sterilization play in these surgical procedures?
• How are incisions made and managed during kidney surgeries?

• Practical Application - These techniques are used in kidney surgeries and transplantation procedures (e.g., surgery).
• Industry Impact - Direct implications for healthcare, specifically in the field of organ transplantation (e.g., healthcare).
• Societal Importance - Improves patient survival rate and quality of life after kidney surgery (e.g., patient care).
• Scientific Advancements - Ongoing development of better surgical techniques and tools for safer procedures (e.g., medical research).