Advancing Cancer Therapy Predictions with Patient-Derived Organoid Models of Metastatic Breast Cancer

Abstract

The poor outcome of metastasized breast cancer (BC) stresses the need for reliable personalized oncology and the significance of models recapitulating the heterogeneous nature of BC. Here, we cultured metastatic tumor cells derived from advanced BC patients with malignant ascites (MA) or malignant pleural effusion (MPE) using organoid technology. We identified the characteristics of tumor organoids by applying immunohistochemistry and mutation analysis. Tumor organoids preserved their expression patterns and hotspot mutations when compared to their original metastatic counterpart and are consequently a well-suited in vitro model for metastasized BC. We treated the tumor organoids to implement a reliable application for drug screenings of metastasized cells. Drug assays revealed that responses are not always in accord with expression patterns, pathway activation, and hotspot mutations. The discrepancy between characterization and functional testing underlines the relevance of linking IHC stainings and mutational analysis of metastasized BC with in vitro drug assays. Our metastatic BC organoids recapitulate the characteristics of their original sample derived from MA and MPE and serve as an invaluable tool that can be utilized in a preclinical setting for guiding therapy decisions.

Precision Immunotherapy Utilizing Adapter CAR-T Cells (AdCAR-T) in Metastatic Breast Cancer Leads to Target Specific Lysis

“…In order to test the efficacy of AdCAR-T cell lysis on BC patient-derived cells, we used our previously established in vitro models for metastasized BC derived from pleural effusions [ 14 ]. Figure 2 A shows a schematic overview of the isolation of MBC cells from pleural effusions and the establishment of MBC-PDO cultures.…”

“…All MBC-PDOs were previously established and characterized [ 14 ]. The study was approved by the Ethics Committee of the Eberhard Karl University of Tübingen (ethical approval 288/2022BO2) and is compliant with all relevant ethical regulations regarding research involving human participants.…”

“…Cryopreserved MBC-PDOs from our previous study were used for the study [ 14 ]. For the setup of organoid cultures, the required amount of cell suspension was mixed with basement membrane extract (BME; Cultrex Reduced Growth Factor Basement Membrane Extract, Type 2 Select, Bio-techne, Minneapolis, MN, USA, 3533-005-02) at a ratio of 30% cell suspension to 70% BME; 20 µL droplets were seeded on 48-well plates and placed upside down in an incubator (37 °C, 5% CO 2 ) to solidify for 30 min.…”

“…Recently, patient-derived BC organoids have been shown to be valuable three-dimensional models for research and personalized oncology, as they represent the characteristics of their respective origin and can be used for long-term culturing [ 13 , 14 ]. Cultured in an extracellular matrix, organoids of different sources have already been used in various methods, such as high-throughput drug assays [ 13 , 15 ].…”

“…In a previous study, we cultured tumor cells derived from MPE of advanced BC patients employing organoid technology and generated metastatic BC patient-derived organoids (MBC-PDOs). MBC-PDOs were then used as a platform to perform drug screenings applying various inhibitors [ 14 ].…”