Xenograft Tumor Models

        In tumor-related basic research and applied research, there are various models used to simulate the occurrence, development, metastasis of tumors, and the efficacy evaluation of new molecules, etc. Among them, the most widely used in drug development is the xenograft model of human tumors (Human cancer xenografts). The basic process of the xenograft model is to inoculate human-derived tumor cells into immunodeficient mice. When the tumor grows to a certain volume, mice with suitable tumor volumes are selected for group administration. The human-derived tumor cells can be isolated and cultured tumor cell lines (Cell-Derived Xenografts, CDX), or tumor tissue blocks (Patient-Derived Xenografts, PDX). The choice of immunodeficient mouse strains has a crucial impact on the success rate and experimental quality of modeling. Commonly used immunodeficient mouse strains include BALB/c Nude, NU/NU, NOD SCID, NSG, etc. In addition, there are multiple choices for the inoculation site, the most common being subcutaneous inoculation, and other inoculation methods include orthotopic inoculation, intraperitoneal inoculation, and intravenous inoculation, etc. 

        Although the CDX model cannot well simulate the process of tumor occurrence, development, and evolution in the human body, it has several advantages, which makes it widely used in the preclinical pharmacodynamic evaluation of drugs. Its advantages include, 1. It can quickly model, has good repeatability and stable data quality; 2. Usually, the pharmacodynamic activity of the same tumor cell in vitro and in vivo is relatively good; 3. Tumor cell lines usually have a lot of historical research data and bioinformatics data, which helps to understand the mechanism of action of drugs.