Laminin and fibronectin expression during in vivo growth of embryoid bodies derived from teratocarcinoma.

Embryoid bodies (EB) derived from teratocarcinoma OTT6050 are a useful model for the study of early embryogenesis and tumorigenesis and are found in two forms: cystic and simple. After injection of cystic EB intraperitoneally into isogenic 129/Sv mice, their growth and the expression of laminin (LAM) and fibronectin (FN) were studied at 5, 7 and 9 days post-injection. LAM was highly expressed on the internal face of endodermal and on some internal cells in cystic type EB and in both endodermal cell faces in simple EB. Only slight FN expression was observed in cystic and simple EB. Extracellular matrix proteins can be studied in this model.