Three-Dimensional Breast Cancer Model to Investigate CCL5/CCR1 Expression Mediated by Direct Contact between Breast Cancer Cells and Adipose-Derived Stromal Cells or Adipocytes

The tumor microenvironment (TME) in breast cancer is determined by the complex crosstalk of cancer cells with adipose tissue-inherent cells such as adipose-derived stromal cells (ASCs) and adipocytes resulting from the local invasion of tumor cells in the mammary fat pad. This leads to heterotypic cellular contacts between these cell types. To adequately mimic the specific cell-to-cell interaction in an in vivo-like 3D environment, we developed a direct co-culture spheroid model using ASCs or differentiated adipocytes in combination with MDA-MB-231 or MCF-7 breast carcinoma cells. Co-spheroids were generated in a well-defined and reproducible manner in a high-throughput process. We compared the expression of the tumor-promoting chemokine CCL5 and its cognate receptors in these co-spheroids to indirect and direct standard 2D co-cultures. A marked up-regulation of CCL5 and in particular the receptor CCR1 with strict dependence on cell-cell contacts and culture dimensionality was evident. Furthermore, the impact of direct contacts between ASCs and tumor cells and the involvement of CCR1 in promoting tumor cell migration were demonstrated. Overall, these results show the importance of direct 3D co-culture models to better represent the complex tumor-stroma interaction in a tissue-like context. The unveiling of tumor-specific markers that are up-regulated upon direct cell-cell contact with neighboring stromal cells, as demonstrated in the 3D co-culture spheroids, may represent a promising strategy to find new targets for the diagnosis and treatment of invasive breast cancer.

3D breast cancer microtissue reveals the role of tumor microenvironment on the transport and efficacy of free-doxorubicin in vitro

The use of 3D cancer models will have both ethical and economic impact in drug screening and development, to promote the reduction of the animals employed in preclinical studies. Nevertheless, to be effective, such cancer surrogates must preserve the physiological relevance of the in vivo models in order to provide realistic information on drugs' efficacy. To figure out the role of the architecture and composition of 3D cancer models on their tumor-mimicking capability, here we studied the efficacy of doxorubicin (DOX), a well-known anticancer molecule in two different 3D cancer models: our 3D breast cancer microtissue (3D-μTP) versus the golden standard represented by spheroid model (sph). Both models were obtained by using cancer associated fibroblast (CAF) and breast cancer cells (MCF-7) as cellular component. Unlike spheroid model, 3D-μTP was engineered in order to induce the production of endogenous extracellular matrix by CAF. 3D-μTP have been compared to spheroid in mono- (MCF-7 alone) and co-culture (MCF-7/CAF), after the treatment with DOX in order to study cytotoxicity effect, diffusional transport and expression of proteins related to cancer progression. Compared to the spheroid model, 3D-μTP showed higher diffusion coefficient of DOX and lower cell viability. Also, the expression of some tumoral biomarkers related to cell junctions were different in the two models.

STATEMENTS OF SIGNIFICANCE

Cancer biology has made progress in unraveling the mechanism of cancer progression, anyway the most of the results are still obtained by 2D cell cultures or animal models, that do not faithfully copycat the tumor microenvironment. The lack of correlation between preclinical models and in vivo organisms negatively influences the clinical efficacy of chemotherapeutic drugs. Consequently, even if a huge amount of new drugs has been developed in the last decades, still people are dying because of cancer. Pharmaceutical companies are interested in 3D tumor model as valid alternative in drug screening in preclinical studies. However, a 3D tumor model that completely mimics tumor heterogeneity is still far to achieve. In our work we compare 3D human breast cancer microtissues and spheroids in terms of response to doxorubicin and drug diffusion. We believe that our results are interesting because they highlight the potential role of the proposed tumor model in the attempts to improve efficacy tests.

Flow-perfusion bioreactor system for engineered breast cancer surrogates to be used in preclinical testing

There is a need for preclinical testing systems that predict the efficacy, safety and pharmacokinetics of cancer therapies better than existing in vitro and in vivo animal models. An approach to the development of predictive in vitro systems is to more closely recapitulate the cellular and spatial complexity of human cancers. One limitation of using current in vitro systems to model cancers is the lack of an appropriately large volume to accommodate the development of this complexity over time. To address this limitation, we have designed and constructed a novel flow-perfusion bioreactor system that can support large-volume, engineered tissue comprised of multicellular cancer surrogates by modifying current microfluidic devices. Key features of this technology are a three-dimensional (3D) volume (1.2 cm³ ) that has greater tissue thickness than is utilized in existing microfluidic systems and the ability to perfuse the volume, enabling the development of realistic tumour geometry. The constructs were fabricated by infiltrating porous carbon foams with an extracellular matrix (ECM) hydrogel and engineering through-microchannels. The carbon foam structurally supported the hydrogel and microchannel patency for up to 161 h. The ECM hydrogel was shown to adhere to the carbon foam and polydimethylsiloxane flow chamber, which housed the hydrogel-foam construct, when surfaces were coated with glutaraldehyde (carbon foam) and nitric acid (polydimethylsiloxane). Additionally, the viability of breast cancer cells and fibroblasts was higher in the presence of perfused microchannels in comparison to similar preparations without microchannels or perfusion. Therefore, the flow-perfusion bioreactor system supports cell viability in volume and stromal contexts that are physiologically-relevant. Copyright © 2015 John Wiley & Sons, Ltd.