Going out and grabbing that information, I think should be done by the submitter not by the database, and it would be great if the collections made it easy to do so by involvement such as yours. I went to the site you gave and followed the links for animal and cell lines. If this what you are referring to, then I don't think it will work for two reasons. One is that cell lines are at the root of the hierarchy which makes sense for collections but not for microarray experiments which use samples which are not cell lines. The other problem is your hierarchy is too flat.
Cell line has a brief description, tissue is a brief description, tissue is one of a list.