Breast cancer cells form primary tumors on ex vivo four-dimensional lung model

Breast cancer mortality is most common in cancer in women, and there are no ex vivo models that can capture the primary growth of tumor with fidelity to the in vivo tumor growth. In this study, we grew human breast cancer cell lines in an acellular lung matrix of the ex vivo four-dimensional lung model to determine if they form primary tumor and the extent to which they mimic the histology and characteristics of the human tumors.

Rat lungs were harvested, decellularized, and placed in a bioreactor. To study the primary tumor growth, we seeded the lung via the trachea with human breast cancer cells SUM159, MCF7, or MDMB231 and perfused the pulmonary artery with oxygenated media. Lobectomies were performed and processed for hematoxylin and eosin, Ki-67, caspase-3, estrogen receptor, and progesterone receptor antibodies.

All three cell lines grew in the ex vivo four-dimensional model and formed perfusable tumor nodules with similar histology and morphology as the primary tumors. SUM159 and MDAMB231 showed higher proliferation and apoptotic indices than MCF7. In addition, MCF7 retained its estrogen receptor and progesterone receptor positivity, whereas SUM159 and MDAMB 231 did not have any staining.

Overall, our study showed that human breast cancer cells can be grown on the ex vivo four-dimensional lung model, which then form primary tumor nodules that mimic the morphology and histology of the original tumor.