Field
The present application relates to a method for measuring a ratio of a patient-derived stromal tumor and a mouse stromal tumor in a patient derived xenograft (PDX) model and analyzing an origin of cancer tissue or cell development because while generation of the xenograft model progresses, cancer tissues or cells of the human disappear and the stroma ratio of the human and the mouse varies according to conversion into the mouse stroma. More particularly, it relates to a analysis kit including primers and probes capable of detecting cross contamination of mouse and human genes and a method for analyzing cross contamination of the mouse gene for human cells using the same.
Description of the Related Art
Recently, researches for overcoming cancers through patient-specific anticancer therapy have been competitively conducted. A preclinical test that determines whether to enter clinical trials of novel therapeutic agents in a process of developing drugs for anticancer therapy is an important process for selecting therapeutic agents having high possibility of success. In this case, an ideal model to be used needs to satisfy various conditions, such as prediction for accurate therapeutic response, understanding of preceding target molecular pathway, preservation of histological, molecular, and cancer-ambient microenvironments that can represent actual clinical patients, and ease of pharmacokinetic or pharmacodynamic analysis. Currently, three main models of the preclinical test for the novel anticancer therapeutic agents include genetically engineered models, xenograft models derived from human tumor cell lines, and tumorgraft models derived from patients implanted directly into immunodeficient mice.
Over the past several decades, a xenograft model derived from a cell line panel representing various tumor species has been pointed out as a main limitation due to low predictability of success in actual clinical. In an alternative for overcoming the problem, patient-derived tumorgrafts (PDX) in which a patient-derived tumor tissue surgically removed is directly implanted into the immunodeficient mice are proposed. The patient derived xenograft (PDX) and cell derived xenograft (CDX) tumor models may provide clinical models required for new drug development, and the PDX model has been widely used in approaching new anticancer agents in the previous clinical studies because a clinical real situation of the patient may be summarized well in the mouse model. The PDX model is installed by implanting a surgically resected patient's tissue into immunodeficient mice and the xenografted tissue may be sequentially sub-cultured, kept in a freezer, and revived. In addition, it has been reported that while the patient-derived stroma which was initially maintained in the successive subculture is gradually replaced with the mouse stromal cells, the absolute amount thereof is decreased, but a relative cancer-to-stroma ratio is maintained. Through a comparison of gene expression profiles performed for the heterogeneous tissues in the early and late subcultures, a change in stroma characteristics may be inferred. Further, the change in stroma characteristics may be analyzed by separating cancer and cancer-ambient microenvironments through a selective gene expression array analysis in only the human and the mouse. Accordingly, by measuring the ratio of the patient-derived stromal tumors and the mouse stromal tumors in the patient-derived xenograft and cell-derived xenograft tumor models, while the patient-derived stroma that has been initially maintained in the successive subculture process is gradually replaced with the mouse stromal cells, a method for easily analyzing contamination of a mouse-derived tissue is required.