A 3D model of tumour angiogenic microenvironment to monitor hypoxia effects on cell interactions and cancer stem cell selection

Abstract

Tumour microenvironment determines the fate of treatments. Reconstitution of tumour conditions is mandatory for alternative in vitro methods devoted to cancer development and the selection of therapeutic strategies. This work describes a 3D model of melanoma growth in its environment. Introducing means to mimic tumour angiogenesis, which turns on tumour progression, the model shows that melanoma tumour spheroids allow reconstitution of solid tumours with stromal cells. Angiogenesis evidenced the differential recruitment of endothelial cells (EC) from early progenitors (EEPCs) to mature ECs. Hypoxia was the key parameter that selected and stabilized melanoma cancer stem like cells (CSCs) phenotype based on aldehyde dehydrogenase expression as the best criterion. The 3D-tumour-model demonstrated the distinct reactivity of ECs toward tumour cells in terms of cellular cross-talk and humoral response. Intra-spheroid cell-to-cell membrane dye exchanges, mediated by intercellular interactions, uncovered the melanoma-to-EEPC cooperation. The resulting changes in tumour milieu were evidenced by the chemokinic composition and hypoxia-related variations in microRNA expression assessed in each cellular component of the spheroids. This method brings new tools to decipher the molecular mechanism of tumour-mediated cell recruitment and for in vitro assessment of therapeutic approaches.

Progress in melanoma modelling in vitro

“…Malignant melanoma (MM) is a highly aggressive cancer of the skin originating from melanocytes. MM is the most life‐threatening tumor of the skin (70%), although it represents only 4% of all skin cancers . MM is regarded as a major health problem due to the high mortality associated with tumor and to its growing incidence.…”

“Turn‐On” Activatable AIE Dots for Tumor Hypoxia Imaging

“…The multicellular tumor spheroid (MCTS) model, a well‐established 3D cell culture method, has proved superiority over monolayer cell culture models to recapitulate in vivo tumor growth . In particular, MCTS mimics in vivo tumor models by developing hypoxic and apoptotic/necrotic areas as a consequence of the formation of oxygen and nutrient gradients . To investigate whether PEG‐Azo‐TPE can be used to image the hypoxia area in the MCTS, we incubated PEG‐Azo‐TPE with preformed MCTS of HeLa cells for different time.…”

“…[42,43] In particular, MCTS mimics in vivo tumor models by developing hypoxica nd apoptotic/necrotic areas as ac onsequence of the formation of oxygen and nutrient gradients. [44,45] To investigate whether PEG-Azo-TPE can be used to image the hypoxiaa rea in the MCTS, we incubatedP EG-Azo-TPE with preformed MCTS of HeLa cells for differentt ime. Figure 4s hows the fluorescencem icroscopyi mages of HeLa MCTS with or withoutt he treatment of PEG-Azo-TPE.I nc omparisont ot he HeLa MCTS treated withP BS, HeLa MCTS treated with PEG-Azo-TPE shows as ignificantly higherf luorescence emission.…”

Cancer research with a human touch

“…Kieda's lab combines melanoma and endothelial cells in a matrix composed of collagen, growth factors and a 3D scaffold called Matrigel. This mixture allows the cells to form a structure that resembles a tumour and its surroundings, especially in terms of oxygenation 7 . "Everyone is working in conditions that are like an incubator, where the partial pressure of oxygen is much higher than in the body, " Kieda says.…”