Extravasation monolayers

Variations on the filter-based assay have been designed to approximate more physiological contexts. Such assays include tumor cell invasion across a confluent cell monolayer (e.g., endothelial cells (EC) as a surrogate for intravasation or extravasation during hematogenous metastasis (24)) and ovarian carcinoma invasion of mesothelial cell monolayers (25). Additionally, 1 mm thick slices of human brain tissue have been used as a tissue barrier on Transwell filters with invasion of GFP-labeled glioma cells measured by confocal microscopy (26). 

M. B. Furie, B. L. Nnprstek, and S. C Silverstein. Migration of neutrophils across monolayers of cultured endothelial cells an in vitro model for leucocyte extravasation. 3. Cell ScL 8 161-175 f19871. 

The RPE of the eye is a monolayer membrane located between the photoreceptors and the chorioid (Fig. 14.2), and it is thought to function as a support tissue for the photoreceptors. hRPE cells are involved in retinoid transport, esterification and isomerization processes, and the phagocytosis and degradation of shed outer segments. It participates in the regulation of ion channels and the extravasation of metabohtes, and - depending on the developmental state of the individual - synthesis of melanin. 

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