动物造模,药效评价,原位移植肿瘤转移 z-bio 2024-07-24 440

　　Clinical observations have shown that tumor metastasis often has organ specificity rather than random distribution. Certain tumor cells have a special tendency to metastasize to specific organs, such as gastric or colorectal cancer usually metastasize to the liver, and liver cancer usually metastasizes to the lungs. Therefore, the "seed and soil theory" has been proposed. Although subcutaneous transplant tumors can maintain the tissue structure and growth characteristics of the original tumor, they are separated from the microenvironment of their originating tissue and organ, and are wrapped in a fibrous membrane (pseudocapsule), often exhibiting localized growth. Their biological characteristics, especially their metastatic properties, are difficult to express. In situ transplantation is the process of implanting human tumors into host organ tissues corresponding to the primary site of the tumor, creating a microenvironment similar to that of human tumors, which is more suitable for tumor growth and metastasis. The in situ transplantation model effectively simulates the growth and metastasis process of clinical tumors, making it an ideal model for tumor prevention, treatment, and anti metastasis research. So far, most tumors have established corresponding in situ transplantation models in nude mice. The metastasis rate of different tumors and the same tumor from different sources also varies, generally not exceeding 50%. Metastasis is mainly through the blood route, and may also be accompanied by lymphatic metastasis. The in situ transplantation model has the following characteristics: ① The number of tumor cells required for tumor formation in situ transplantation is less than that in subcutaneous transplantation, and the tumor formation rate is also higher. ② The tissue and cell morphology of in situ transplanted tumors are consistent with the source tumor, and the growth environment of the tumor is more similar to that of clinical patients After subcutaneous transplantation, tumors often show localized growth, wrapped in fibrous capsules, and rarely infiltrate or metastasize, while in situ transplanted tumors show extensive invasive growth and metastasis Tissue blocks are more ideal transplant materials than cell suspensions. Cell suspensions, treated with digestive enzymes, destroy the original tissue structure of tumors, while tissue block rules preserve the intercellular connections that are necessary for tumor cells to fully express their biological characteristics. The in situ tumorigenicity and metastasis rates of tissue block transplantation models are significantly improved Choosing deeper immunodeficient animals (such as SCID mice, BNX mice, etc.) can significantly improve tumor formation and metastasis rates.