动物造模,直结肠癌 z-bo 2022-02-03 450

　　Since Rygaard and Povlsen first successfully transplanted excised human cancer tissue specimens into nude mice in 1969, the transplanted tumor model has been widely used in tumor growth and metastasis research. .. Common methods for establishing CRC xenotransplantation animal models include cell transplantation and tissue transplantation. According to different inoculation sites, they can be divided into heterotopic subcutaneous transplantation and orthotopic transplantation. When establishing transplanted tumor models, athymic nude mice or severe combined immunodeficiency SCID mice are usually used to reduce rejection. [Modeling mechanism] Use standard cell lines or tissue blocks of human or animal origin to directly inoculate or transplant into immunodeficient nude mice or SCID mice. Tumor-bearing mice will not reject allogeneic or xenogeneic tissues and organs, because the transplanted tumor retains its original tissue structure or function. Tumor etiology, etiology, immunology, pharmacology and therapeutics are widely used in research.

　　[Modeling method]

　　1. In the subcutaneous transplantation tumor model, a large amount of human tumor tissue is taken out under aseptic conditions, and after treatment, it is cut into small pieces of 1-2 mm in RPMI1640 solution, or directly used to generate standard colon cancer cell lines . Make and make a single cell suspension (5 x 100000000? 2.5 x 100000000000/L) subcutaneously implanted into nude mice. The implantation sites are neck, armpit, back, groin, chest wall, neck, etc. The fastest growth. Observe every day until the tumor reaches 1.0 Ω. The nude mouse is sacrificed 1.5 cm, and the tumor tissue or cells are removed and passaged according to the above method.

　　2. Orthotopic xenograft tumor models usually use subcutaneous xenograft tumor models to pass stable tumor tissues and cut them into 1 mm diameter slices for later use. The experimental animals were anesthetized through the abdominal cavity. After the skin is disinfected, make an abdominal incision in the abdomen, pull out the cecum, scrape off the small serous tissue, suture 1 cubic millimeter of tumor tissue to the injured serous membrane, or insert the tumor mass directly into the lesion. A groove is formed in the serosa, and a drop of OB adhesive is dropped on the surface of the tumor to fix the tumor. Return the cecum to the abdomen and close the abdomen layer by layer. Alternatively, direct injection of tumor cells through the rectal mucosa can reduce anesthesia and surgical trauma, as well as the impact on the immune system and tumor cell growth in mice.

　　3. The colostomy model is to transplant experimental mice through colostomy, and then inoculate tumor cells or colon submucosa to observe tumor growth and metastasis. Routine procedure: After anesthetizing the mouse, make a small incision in the left abdominal skin and peritoneum, raise the cecum to about 0.5 cm above the abdominal wall, and then suture the cecum to fix it on the surrounding skin. After 23 days you may have knots. CRC cells or tissues can be seeded into the submucosa of the stoma colon. [Model characteristics] Because the tumor formation rate, tumor growth and metastasis rate of cell lines in different transplant models are inconsistent, in the study of CRC tumor models, cell lines with high metastasis rates should be used as much as possible in humans. Need better simulation. The natural process of CRC development. Table 7-4 shows the model characteristics caused by different inoculation methods and locations. In addition, there are other human colon cancer cell lines, such as HT29, SW480, SW620 and mouse colon cancer cell lines TCM37, CT26, MCA38. Inoculation of the same strain of mice can establish transplanted tumor models.

　　[Model Evaluation and Application]

　　1. The subcutaneous xenograft model is the simplest operation to establish a subcutaneous xenograft model, and has a high tumor formation rate. Although it is convenient to monitor tumor growth in real time and evaluate the treatment effect, it is difficult to truly simulate the in situ growth of human CRC, and it is also difficult to show the malignancy of tumor invasion and metastasis. Characteristics; However, there are also reports of lung metastases in subcutaneous tumors of SCID mice, and orthotopic cell and tissue transplantation can better compensate for this.

　　2. Orthotopic transplantation tumor model Orthotopic cell and tissue transplantation can completely simulate the occurrence, development and metastasis of CRC, making it an ideal animal model for studying the pathogenesis, metastasis and new therapies of human CRC. Offers. The orthotopic tissue transplantation model was compared with the orthotopic cell transplantation model. The resulting malignant tumor tissue has a perfect cell surface structure, good inter-cell synergy, high tumorigenicity of orthotopic transplantation, and can better reflect in-situ growth and metastasis. Ability is currently the most clinically similar animal model of tumors, making it one of the most commonly used methods for establishing CRC animal models. However, the operation process of this method is complicated, demanding and time-consuming. Anesthesia and surgery can cause great harm to nude mice. Intestinal obstruction may occur after surgery, leading to model failure. Observing tumor growth is not easy. Observe the tumor growth and intervention effect.

　　3. The advantage of the colostomy model is that the tumor is located on the surface of the body and is easy to observe. Repeat sampling and planting for evaluation. If unsuccessful, replanting can be repeated to reduce animal use. The disadvantage is also the difficulty of the operation and the huge harm to mice.