Development of a tridimensional microvascularized human skin substitute to study melanoma biology.

Cutaneous malignant melanomas represent an important clinical problem because they are highly invasive, they can metastasize to distant sites and are typically resistant to available therapy. The precise molecular determinants responsible for melanoma progression and chemo-resistance are not yet known, in part due to lack of pertinent experimental models that mimic human melanoma progression. Accordingly, we developed a complex human microvascularized reconstructed skin substitute in which the organized three-dimensional (3D) architecture of the native skin is reproduced. Human melanoma cell lines derived from primary and metastatic sites were added to this 3D model. Our results demonstrate that histological features and behavior of melanoma cells applied in our skin substitute model are specific to their site of origin. In particular, the ability of melanoma cells to cross the dermal-epidermal junction correlates with their metastatic potential. In addition, a potent angiogenic effect was detected for an aggressive metastatic cell line that produces VEGF. The presence of a microvascular network within this model will allow studying a crucial step of the metastatic process. We conclude that such an in vitro human tumor microvascularized reconstructed skin substitute promises to be a versatile and efficient model to investigate skin cancer progression and to screen new anticancer drugs to improve currents clinical treatments.