Table 2 Advantages and disadvantages of using patient-derived xenografts as preclinical models

Preservation of Tumor Heterogeneity: PDX models preserve tumor heterogeneity by directly transplanting the patient's breast cancer tissue into immunodeficient mice, maintaining the complexity of the original tumor microenvironment

Reliance on Immunodeficient Mice: PDX models depend on immunodeficient mice, restricting the study of interactions with the immune system and potentially impacting the assessment of immune-related responses to PI3K inhibitors

Clinical Relevance: PDX models provide a clinically relevant representation of human breast tumors, preserving molecular and genetic features, including PI3K signaling pathway alterations, more effectively than traditional cell line models

Time-Consuming Establishment: Establishing and disseminating PDX models is time-consuming, impacting the speed of preclinical studies and potentially causing delays in obtaining results

Translatability of Results: Using the patient's own tissue enhances result translatability, enabling researchers to assess the effects of PI3K inhibitors on tumors closely resembling the patient's original tumors

Variability in Transplant Success Rates: Transplant success rates for PDX models vary with tumor type and individual patient characteristics, introducing variability in the effectiveness of model establishment

Recapitulation of Tumor Microenvironment: PDX models recapitulate the tumor microenvironment's complexity, allowing the study of tumor-stromal interactions and the effects of PI3K inhibitors on the microenvironment, including stromal cells, immune cells, and blood vessels

Insights into Tumor Response and Resistance: Longitudinal studies with PDX models provide insights into tumor response and resistance to PI3K inhibitors, aiding in identifying potential predictive biomarkers for personalized therapeutic strategies