Abstract 1396: Response of primary culture of breast cancer to hypoxia and drug treatment.
Authors: Yin Hong , Adegboyega Patrick , Smith Mylinh Smith , Glass Jonathan 
Published: August 2014

Breast cancer is a heterogeneous disease. Several subtypes of breast cancer have been characterized and corresponding treatment strategies have been devised. However, outcomes are not always satisfactory for a variety of reasons including individual variation in age, race, disease stages, and genetic variations. In order to improve the outcomes of breast cancer treatment, personalized treatment has been developed based on molecular profiling and genetic testing of each individual patient. To compliment the development of personalized treatment based on molecular data from genetic profiling, we hypothesized that culture of primary breast cancer tissue could provide a cell-based model that could be utilized in the evaluation of the response of individual breast cancer to therapeutic agents. In this model, breast cancer samples were cultured in matrigel. To identify the cell types that grew in the matrigel, the cells were subjected to the staining with antibodies against cytokeratin5, cytokeratin14, cytokeratin18, ER, vimentin, E-cadherin, N-cadherin, α-SMA, and β-catenin. The results demonstrated that the cells which grew from breast cancer tissue were heterogeneous, including epithelial and stromal cells. Further analysis of the effect of oxygen indicated that the growth of breast cancer cells increased by 1.4-1.5 fold with 5% O2 compared to growth with 21% O2. Interestingly, hypoxia did not stimulate growth of normal breast tissue. Very intriguingly, growth under hypoxic conditions demonstrated differential responses to several chemotherapeutic agents. In these studies cell proliferation was assayed at 5% and 21% O2 of primary cultures of normal and cancerous breast cells treated with doxorubicin, LY294002, and PHA665752 (c-Met inhibitor). With doxorubicin treatment normal breast cells under hypoxia showed significant drug resistance at 0.1 μM and 1 μM compared to normoxia (P&lt;0.05) while breast cancer cells were similarly responsive to doxorubicin under normoxic and hypoxic conditions. With LY294002 treatment hypoxic breast cancer cells showed an increased drug resistance at 10 and 40μM (P&lt;0.05) while hypoxic normal breast cells showed a significant increase in drug resistance at only 40 μM compared to normoxic cells. The effects of PHA665752 on cell proliferation were not affected by hypoxia for either normal or breast cancer cells. In conclusion, cells grown from breast cancer tissue are heterogeneous in cell type. These primary cells show some differential responses to hypoxia condition and drug treatment. An advantage of this primary cell culture model is that it contains cancer cells in the context of their respective native supportive stromal cells, thus creating a microenvironment that is similar to what obtains in vivo. Therefore, this in vitro primary culture model may have potential applications for the testing of drugs predicted to be effective for personalized treatment of breast cancer.

Citation Format: Hong Yin, Patrick Adegboyega, Mylinh Smith Smith, Jonathan Glass. Response of primary culture of breast cancer to hypoxia and drug treatment. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1396. doi:10.1158/1538-7445.AM2013-1396