Production of bioengineered cancer tissue constructs in vitro: Epithelium-mesenchyme heterotypic interactions

A few models have been established to study cancer cells in vitro. However. the cellular interactions have rarely been studied specifically using bioe ngineered cancer constructs combining human carcinoma cells and tumor-assoc iated fibroblasts. We developed an in vitro model of tridimensional bioengi neered cancer tissue constructs (bCTC) by seeding mammary epithelial cancer cells or normal keratinocytes over a mesenchymal layer containing tumor-de rived fibroblastic cells or normal skin fibroblasts. After the introduction of epithelial cells, each construct was cultured for another 10 d. Histolo gic analyses showed that carcinoma cell lines could invade the subjacent me senchymal layer and that the capacity to migrate was related to the invasiv e potential of cancer cells and the type of fibroblasts used, while noninva sive populations did not. Of the tested epithelial cells, MDA-MB-231 and, t o a lesser degrees HDQ-P1 cell lines were invasive, and the invasion was de eper into the mesenchymal component containing tumor-derived fibroblasts. H owever, with normal skin fibroblast.,, the mesenchymal layer was degraded t wice faster than with tumor-derived fibroblastic cells. MDA-MB-231 cells an d normal keratinocytes induced the highest level of gelatinase B. and the l evel was lowest with the MCF-7 cell line. The activated form of gelatinase B was, however, induced to the highest levels in the keratinocyte-seeded bC TC containing tumor-derived but not normal fibroblasts. MDA-MB-231 was the only epithelial cancer cell line whose activity of gelatinase A was reduced when cocultured with tumor-derived fibroblasts but not under normal fibrob last stimulation. Finally, a 50/48-kDa gelatinase band has been observed in bCTCs with noninvasive epithelial cells only. Our study demonstrates the s elective secretion of gelatinases according to the phenotype of the cells s eeded in the various bCTCs.