Embryo, mouse endothelial cells

Ex vivo models, such as mouse bladder (Poste et al., 1980) or human amnion (Russo et al., 1986) either denuded of epithelium and/or reseeded with endothelial cells (Foltz et al., 1982) may be considered too simplified systems. According to Kim et al. (1998), these recapitulate poorly the structure of the blood vessels and, in particular, small vessels. .. where most of the cancer cell invasion is believed to take place . These authors describe an interesting alternative where cells are inoculated on the chick chorioallantoic membrane (CAM) of an artificially created air sac in chick embryo. To detect and quantitate tumor cells actively penetrated in the ventral lower CAM , genomic DNA is extracted and used as a template for human Alu sequence identification by PCR. These sequences, unique to human and higher primate DNA, are repetitive... 

There are several in vivo assay models for angiogenesis, including the shell-less chicken chorioallantoic membrane (CAM) assay, the cornea assay, and the endothelial cell assay. The CAM assay is most frequently used assay method because it is easy to use and less costly. In this assay, an inhibitor s effect on the shell-less chicken embryo culture can be observed directly, although quantitating the result is subjective. The mouse cornea assay is widely favored because the cornea is an avascular tissue, any blood vessel development unequivocally demonstrates the lack of antiangiogensis activity [77-79]. However, all of these in vivo assay... 

Recently, a carbohydrate-binding protein, L-selectin, has been proposed as an adhesion molecule for human embryo implantation (19). L-Selectin is expressed on the surface of lymphocytes and interacts with sulfated and fucosylated carbohydrates expressed on lymph node endothelial cells (20-26). Carbohydrate ligand for L-selectin in the lymph node is closely related to MECA-79 antigen (Fig. 1). In human endometrium, the expression of MECA-79 antigen is hormonal cycle dependent but the presence of an embryo is not required (27). In the mouse, L-selectin nulls reproduce normally (28). Mutant mice lacking sulfotransferases (22,23,29-32) and glycosyltransferases (21,31,32) required for synthesis of L-selectin ligand exhibited no defects in reproduction. Therefore, it is clear that L-selectin is not required for the mouse embryo implantation. It thus appears that L-selectin is uniquely involved in human embryo implantation. 

Hatzopoulos AK, Folkman J, Vasile E, Eiselen GK, Rosenberg RD. Isolation and characterization of endothelial progenitor cells from mouse embryos. Development 1998 125 1457-1468. 

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