动物模型 z-bo 2020-08-04 603

　　[Modeling mechanism] Allogeneic transplantation refers to the process of transplanting into animals of the same species or the same family. The organisms between the donor and the recipient have a high degree of commonality, which can stay in the body, grow and proliferate, and reproduce the process of tumor . This is easy to do. Sprague Dawley rats under 6 weeks of age are usually selected (the immune function at this stage is not yet fully mature), and the rat osteosarcoma cell line UMR106 is used for orthotopic bone implantation of allogeneic bone. The cell line is a Sprague Dawley rat in the 1970s. Radiophosphate-induced osteosarcoma cell lines have recently been used to construct orthotopic transplantation models of osteosarcoma. It has high tumorigenicity and high lung metastasis potential, making it an ideal cell line for lung metastasis research. Tumor cells can escape and grow without effective immune surveillance, resulting in a higher success rate. There are many cell lines or cell lines to choose from today. Many cell lines are widely distributed around the world, and the biological characteristics of these cells are relatively well defined. The background information is usually clear, so animals can be vaccinated at the same time. Tumor cells have the same growth rate, small individual differences, high survival rate, easy to control and observe, all of which are favorable factors for comparison and exchange of scientific research results.

　　[Modeling method]

　　1. The rat osteosarcoma cell line UMR-106 is cultured in vitro to obtain exponentially growing cells for use. Choose 30-40 days old male and female Wistar rats anesthetized by intramuscular injection of ketamine hydrochloride (0.1 g/kg), disinfect the lower limbs with iodine, and choose the medial or lower femur of the physi end of the upper tibial shaft. An external incision is made to expose the bone surface of the subcutaneous tissue to be separated, and then a Kirschner wire with a diameter of 1 mm is used to drill the bone marrow cavity that has clearly disappeared. Then use a 12 gauge blood transfusion needle to pierce the bone marrow cavity diagonally along the gap to drill out the bone marrow and cancellous bone. Use serum-free RPMI1640 medium to dilute the primary osteosarcoma cells to 5x1000000/ml in the inclined channel, inject 0.2 ml of cells into each bone marrow cavity, seal with bone wax, and suture the muscle membrane and skin in turn. Sterilize the incision and bandage and nourish to ensure that the model can be constructed normally within 4 weeks.

　　2. The rabbit chose the VX2 cell line for research. Tumor-bearing rabbits were prepared by injecting the cell suspension into the muscles of the rabbit's hind legs. Once the tumor develops into a tumor with a diameter of about 5 cm within 3 weeks, mince and place fresh fish-like tumor tissue. Squeeze a 200-400 mesh cell sieve, filter and wash with Hanks solution. The cell suspension was collected, centrifuged at 1500 r/min for 3 minutes, and the formed pellet was resuspended in Hank's solution to obtain 1×1000000/ml tumor cell suspension, and the experimental animals were kept sterile. I am under anesthesia. A longitudinal incision is made under the bone of the right knee joint. The skin is about 1 cm long and touches the plateau of the tibia. The 18G bone puncture needle penetrates the proximal joint surface of the tibia. The puncture needle is parallel to the tibial shaft. The needle enters the bone marrow cavity, the puncture needle is delivered to 2.0-2.5 cm, the needle tip is placed in the upper center of the tibia bone marrow cavity, 0.3 ml tumor cell suspension is injected, the needle is pulled out and the skin is removed. Will be sewn. [Characteristics of the model] When tumor cells were inoculated into rats, the bone phy swelled 3 weeks after being transplanted into the bone, and many tortuous small blood vessels were found under the skin of the tumor area. The excised surface showed the destruction and destruction of the inner layer of the skin. The tumor invaded the soft tissues and cavities, and the tumor tissue was like a fish. After implantation, the bone phy swelled and the tumor diameter reached 2-3 cm. The mass is medium or slightly hard, and the bone cortex is more obviously damaged. There are some metastases on the edge, which are different in size from the hilar. Six weeks after transplantation, the tumor was a huge sphere, slightly stiff, the cortex of the bone on the cut surface disappeared, and only the spine stump was visible. A large number of metastases of different sizes were found in both lungs, and some tumors merged and turned gray. Seven weeks after transplantation, the diameter of the tumor in the right lower limb reached 3-5 cm, and it spread widely to two lungs, fused with the tumor foci, and basically lost the normal lung histological characteristics. The natural survival time of model mice is about 7 weeks.

　　[Model Evaluation and Application] The success rate of the rat model is slightly lower than that of the nude mouse tumor-bearing model, but homogenizing the tumor tissue that has grown or metastasized after inoculation can increase the success rate. Although the rejection between allogeneic animals is relatively weak, the physiological conditions of individuals in different environments are very different. Therefore, it is also possible to increase the formation of tumors by appropriately reducing immunity or changing vaccination methods. possible. The model has a short test cycle, low animal cost, and convenient feeding and management, so it is widely used. In the rabbit model, a hole was drilled in the proximal articular surface of the tibia to implant the tumor on the tibia, in the marrow cavity of the middle tibia. This will minimize mechanical damage to the periosteum. In addition, because the puncture hole is relatively far from the tumor implantation site, the tumor is not easy to pass through. The hole extends outward.