Expression of the retinoblastoma-related p107 and Rb2/p130 genes in human placenta: an immunohistochemical study

It has been proposed that tumor suppressor genes may have a role in the mec hanisms of proliferation and differentiation during human placental develop ment. The Retinoblastoma gene family is a well known family of tumor suppre ssor genes. Many studies have pointed out a role of this family not only in cell cycle progression, but also during development and differentiation. O n the light of these observations we have investigated the immunohistochemi cal expression pattern of the Retinoblastoma family members, p107 and Rb2/p 130 in human placenta samples in first trimester and full-term placental se ctions. p107 and pRb2/p130 showed the most abundant expression levels durin g the first trimester of gestation and progressively declined to being bare ly detectable in the placenta by late gestation. These results indicate tha t the expression of the above genes is modulated during placental developme nt and suggest a mechanism for controlling trophoblast proliferation.