Comparison of Placental PTEN and beta 1 Integrin Expression in Early Spontaneous Abortion, Early and Late Normal Pregnancy

Background: PTEN seems to play an important role in cell cycle, growth, migration, and death. Integrins are cell surface receptors that play a role in the regulation of cell proliferation, differentiation, implantation, and embryogenesis. PTEN inhibits beta 1 integrin signaling. The objective of this study is to investigate the expression of PTEN and beta 1 integrin in placental tissues of early spontaneous abortion and first and third trimesters of normal pregnancy. Method: A total of 43 placental tissue samples were evaluated using immunohistochemistry for PTEN and beta 1 integrin. Group 1 included placental tissues of volunteer termination of normal pregnancy during the first trimester (5-10 wk gestation). Group 2 included placental tissues of normal vaginal delivery at the third trimester of pregnancy (36-40 wk gestation). Group 3 included placental tissues of pregnancy termination because of spontaneous abortion during the first trimester (5-10 wk gestation). Results: PTEN expression of villous trophoblast was decreasing as the pregnancy advanced. PTEN staining of decidual cells was significantly stronger in tissue samples from early spontaneous abortion than in tissue samples from early and late normal pregnancy (p=0.003, p=0.001, respectively). There was no significant difference between beta 1 integrin expression of villous trophoblast and decidual cells in three groups. Conclusion: Our findings suggest that altered patterns of PTEN expression may be associated with abortion, but it seems that beta 1 integrin does not contribute to this process as a signaling protein. Further evaluation is needed to highlight this subject.