Expression of transforming growth factor-beta and insulin-like growth factor in molar and placental tissues

The semiquantitative reverse transcription polymerase chain reaction was employed to detect the expression of transforming growth factor beta (TGF-beta) and insulin-like growth factor (IGF) in complete hydatidiform mole, normal first-trimester villi, the normal term placenta (after vaginal/abdominal deliver) and the preeclamptic placenta at term. The expression of IGF-I mRNA was seen in all five tissues, but its level was much lower in the term placental tissues with preeclampsia than in other tissues. The content of IGF-I mRNA in villous tissues from molar pregnancy was slightly higher than in normal first-trimester villi. IGF-II mRNA was detected at similar levels in all three sorts of term placental tissues. However, the expression level of IGF-II mRNA in tissues of complete molar pregnancy was significantly lower than in normal first-trimester villi. TGF-beta(3) was found expressed in all five tissues, while TGF-beta(1) and TGF-beta(2) mRNA were not detected. Compared to the normal first-trimester villi, the expression of TGF-beta(3) in complete hydatidiform molar tissues was comparatively higher. Furthermore, the expression levels of TGF-beta(3) in the preeclamptic placenta and the normal placenta after cesarean birth were higher than in the placenta after vaginal delivery. We concluded that, the change of TGF-beta and IGF expression in placental tissues might be involved in the development of trophoblastic diseases of pregnancy.