Fas-FasL system in molar pregnancy

Hydatidiform mole (molar pregnancy) is the commonest form of Gestational Trophoblastic Disease, with the risk of undergoing malignant transformation. The molecular pathway leading to pathogenesis and progression of molar pregnancy is barely understood. The study focuses on Fas/FasL system which represents one of the main apoptotic pathways controlling placental morphogenesis.

Placental tissues from 52 patients with complete hydatidiform moles (CHMs) and 55 age-matched controls were examined for Fas and FasL expression using immunohistochemistry, immunofluorescence and Western blotting. The protein expression was also correlated with trophoblast apoptosis (assessed by M30 Cyto DEATH), clinico-pathological parameters and disease progression.

Immunohistochemistry and immunofluorescence revealed both cytoplasmic and membranous expression of Fas in villous syncytiotrophoblast as well as cytotrophoblast but FasL was confined merely to the cytoplasm of syncytiotrophoblast. Both Fas (cytoplasm and membrane) and FasL were significantly upregulated in syncytiotrophoblast of CHMs (P = 0.004, P < 0.0001 and P < 0.0002 respectively) and showed a positive association between them (P = 0.019). However, none of the proteins reveal any correlation with M30 index. The results were revalidated using Western blotting.

This study demonstrated differential expression of Fas and FasL in CHMs and its implications in the pathogenesis of molar pregnancy has been discussed.