Patient-derived Leukemia xenograft models are crucial tools in drug development, particularly for evaluating the efficacy of new cancer therapies. Differently from immortalized cell lines, these models involve transplanting primary human leukemia cells into immunocompromised mice, allowing the human cancer cells to grow and proliferate in a living organism. Researchers use these models to study the behavior of leukemia under various treatment conditions, assess the effectiveness of novel drugs, and understand the mechanisms of drug resistance. By closely mimicking the human disease, patient-derived leukemia xenograft models provide valuable insights that help in the development and optimization of new therapeutic agents.

A variety of analyses can be performed on leukemia xenografts to evaluate treatment outcomes. These include:

• Tumor Engraftment Measurement: Monitoring the engraftment of the leukemia xenograft to assess the impact of treatments.
• Flow Cytometry: Analyzing cell populations within the xenograft to assess the effect of treatments on leukemia engraftment and disease composition
• Molecular Analysis: Conducting techniques such as PCR, Western blotting, or RNA sequencing to analyze gene expression, protein levels, and genetic mutations within the xenograft.

Leukemia xenograft models are created by implanting human leukemia cells into immunocompromised mice, which lack a fully functioning immune system and therefore do not reject the human cells. The process typically involves injecting the leukemia cells intravenously. Once the cells are implanted, they proliferate and home in the bone marrow, in accordance with what happens in the patients. These models are then used to study disease progression and evaluate potential therapeutic interventions.

A leukemia xenograft tumor model is an in vivo experimental system in which human leukemia cells are transplanted into immunocompromised mice to create a tumor that mimics the behavior of leukemia in humans. This model is used to study the growth and spread of leukemia, as well as to test the efficacy of new drugs and treatment strategies. The xenograft tumor model is particularly valuable because it provides a biologically relevant environment that closely resembles human disease, allowing researchers to obtain more predictive data on how therapy might perform in clinical settings. There are different types of leukemia xenograft models, including cell lines derived models, and patient-derived models. Since leukemia is a highly heterogeneous disease, the best models are those that fully mirror the diverse cellular composition of the disease. Cell-line-derived leukemia and serially passaged patient-derived leukemia xenograft models lose the heterogeneity typical of the disease, due to clonal selection as a result of immortalization and serial passaging respectively. On the other hand, primary, never-passaged, patient-derived leukemia xenograft models are the most reliable system to test novel therapeutic agents.