Patient-derived xenograft (PDX) model involves the transfer of fresh tumor tissue into immunodeficient mice after surgical resection or other medical procedures. Since PDX can be passaged without in vitro culture steps, the PDX model allows the propagation and expansion of patient tumors without significant genetic transformation like tumor cells over multiple generations. Within PDX models, tumor cells grow in physiologically-relevant tumor microenvironments that mimic the levels of oxygen, hormone, and nutrient that are found in the patient's primary tumor site. Moreover, the implanted tumor tissue retains the genetic and epigenetic abnormalities found in the patient, and the xenograft tissue can be excised from the patient to include the surrounding stroma. Numerous studies have found that PDX models exhibit similar responses to anticancer agents as seen in the actual patient who provided the tumor sample. Therefore, PDX models are becoming the preclinical tool of choice in drug development. The translational cancer research is also facilitated by several collections of widely characterized PDX model and it is considered as a useful tool for the application of personalized medicine.
To establish a PDX model, fresh patient tumors are obtained from surgery and processed into fragments by chemical digestion or mechanical sectioning. They are then injected into immunodeficient mice. The first generation receiving the patient's tumor fragments is termed F0, with subsequent generations numbered consecutively F1, F2, F3 and so on. For drug development studies, expansion of mice after the F3 generation is commonly used.
Figure 1. The process of establishing PDX.
Creative Bioarray has established many PDX models, covering a variety of solid tumors such as ovarian, lung, and colorectal cancers, as well as hematopoietic tumors such as leukemia. All of these PDX models were evaluated by histopathological examination and comprehensive gene expression analysis. You can select the most appropriate cohort to gain the data and knowledge necessary to develop disease-specific or target-specific therapeutics.