Collagen synthesis in mouse embryonal carcinoma cells: effect of retinoic acid.

In five lines of mouse embryonal carcinoma cells, PCC3/A1, PCC4, PCC4/Aza-R1, and F9, collagen synthesis was examined by immunofluorescence reaction using specific antibodies directed against collagen. All the embryonal carcinoma cell lines showed type IV collagen, and PCC7-S/Aza-R1 revealed the additional presence of type III collagen. When the F9 and PCC3/A1 EC cells were treated with retinoic acid and dibutyryl-cAMP, they differentiated into morphologically different cellular types. These cellular types showed new types of collagen. Thus, in treated F9 cells, type I, type III, and type V collagen were detected and in treated PCC3/A1 cells, type III and type V collagen were detected. In two established cellular strains, PYS-2 corresponding to parietal endoderm and 3TDM-1 corresponding to trophoblastoma, collagen was identified by immunological reaction and electrophoretic mobility. The trophoblastoma cell line was characterized by the production of type I, type III, and type IV collagen, whereas endodermal PYS-2 revealed type IV collagen.