The Sensitivity of Triple Negative Breast Cancer Cells to Doxorubicin Treatment is Decreased when Cultured within an Engineered Biomimetic Tumor Microenvironment
Yoshiko Toyoda, BA, Karel-Bart Celie, BA, Daniel Lara, BS, Sofya Oshchepkova, BA, Kristy Brown, PhD, Jason A. Spector, MD.
Weill Cornell Medical College, New York, NY, USA.
Purpose: Breast cancer (BC) research has suffered from a lack of model systems that can recapitulate the complex 3D microenvironment that exists within the tumor. This has limited the translation of many promising pre-clinical therapies into clinical application. The tumor microenvironment significantly influences BC cell phenotype and similarly the microenvironment is modulated by the tumor cells themselves. This is particularly relevant to patients with breast reconstruction who undergo dynamic changes in their breast microenvironments. We have engineered a patient specific miniature three-dimensional model of breast tissue containing patient-derived adipocytes, adipose stromal cells (ASCs), and BC cells for high-throughput and rapid analysis of potential therapeutic drug/tissue interactions. Herein, we studied the effect of doxorubicin on BC cells in our organotypic model. Methods: Breast adipose tissue was acquired from patients according to an IRB approved protocol. The tissue was enzymatically digested to retrieve mature adipocytes and ASCs. Clear-bottom 96 well plates were filled with a biomimetic mixture of type I collagen containing mature adipocytes, ASCs, and either MDA-MB-231 or MDA-MB-468 triple negative BC cells which were tagged with red fluorescent protein (RFP). Cultures of collagen with only BC cells as well as the biomimetic mixture without BC cells served as controls. All groups were treated with serially diluted doses of doxorubicin (0, 0.001, 0.01, 0.1, 1, 10uM) for 3 days and stained with the blue nuclear stain DAPI. BC cell survival, defined as co-localization of RFP and DAPI, was analyzed using widefield microscopy. Results: After 3 days of doxorubicin treatment, the MDA-MB-231 cells in the collagen only control demonstrated a decline in cell survival with a 50% inhibition concentration (IC50) between 0.01 and 0.1uM (Figure 1A). In contrast, the MDA-MB-468 cells in the collagen control were less sensitive to increased doxorubicin concentration (Figure 1B). Importantly, when cultured within the biomimetic platform, MDA-MB-231 BC cells experienced less toxicity with increasing doxorubicin doses compared with the same cells cultured within collagen only matrices (Figure 1A). Conclusion: These results demonstrate that the local microenvironment highly influences the response of different BC cell lines to treatment with therapeutic drugs, a result of the presence of other native cells types found within the breast tumor microenvironment. This versatile ex vivo engineered patient-specific biomimetic platform will allow us to further untangle the complex interplay within the dynamic BC tumor microenvironment in breast reconstruction patients and ultimately utilize patient-specific and tumor-specific variability in determining therapeutic options for BC patients.
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