Expression pattern alterations of syndecans and glypican-1 in normal and pathological trophoblast

Syndecans (syn-1, -2, -3, -4) and glypican-1 are proteoglycans expressed du ring development in association with changes in tissue organization and dif ferentiation. They participate in the modulation of growth factor actions a nd in cell-cell and cell-matrix adhesion, The expression of syn-1, -2, -3, -4, and glypican-1 has been studied in normal human placenta and in gestati onal trophoblastic disease such as hydatidiform mole, invasive molt, and ch oriocarcinoma, using immunohistochemistry and western blots. Syndecan-3 was not expressed in normal or pathological tissues, During normal gestation, the other proteoglycans showed a specific staining pattern, which for some was modified during pregnancy. For instance, syn-1 mas only expressed in sy ncytiotrophoblast; syn-4 was mainly localized in the villous and extravillo us cytotrophoblast in the first trimester, whereas at term it was expressed in the syncytiotrophoblast, The most striking results are the altered expr ession patterns of syndecans and glypican-1 in pathological tissues. These proteoglycans showed a progressive decrease of immunostaining related to th e increase of severity of trophoblastic disease, in particular in invasive mole and choriocarcinoma. In addition, dysregulation in the localization of the expression patterns was observed for syn-2 and -4, Because changes in syndecan expression enable cells to become more or less responsive to their micro-environment, the down-regulation and/or dysregulation of syndecans i n relation to the degree of severity of trophoblastic diseases provides new insights into the progression of these pathologies, Copyright (C) 1999 Joh n Wiley & Sons, Ltd.