ABSTRACT
BACKGROUND:
The objective of this study is to determine the expression pattern of G1-S inhibitor molecules in normal
trophoblasts and
gestational trophoblastic diseases, including
hydatidiform moles and
choriocarcinoma.
METHODS:
A total of 157 cases comprising 47 normal
placentas and 110
gestational trophoblastic diseases such as
choriocarcinoma (19 cases) and
hydatidiform moles (91 cases of which 58 were complete, 12 were partial and 21 were
invasive mole) were immunohistochemically analyzed on
paraffin blocks using anti-p21, antip27, anti-p16, anti-p53, anti-pRb
antibodies.
RESULTS:
The results revealed that in the normal
placenta, all the G1-S
cell cycle inhibitors were maximally expressed by the first-trimester
trophoblasts and these levels decreased with
gestational age. The expression of p21 and p53 was greatly enhanced in the
gestational trophoblastic diseases, particularly in
invasive mole and
choriocarcinoma, whereas the p27 expression was significantly downregulated in
choriocarcinoma. Especially, Rb expression was typically enhanced in the
invasive mole, but not in
choriocarcinoma. The expression level of p16 was low in all the cases, and particularly in
choriocarcinoma.
CONCLUSIONS:
In conclusion, we demonstrated that the expression of G1/S
cell cycle inhibitors correlates well with normal
trophoblast differentiation, and these expressions are considerably altered in the
gestational trophoblastic diseases, including complete/partial/
invasive hydatidiform mole and
choriocarcinoma.