Placenta previa may acquire invasive nature by factors associated with epithelial-mesenchymal transition and matrix metalloproteinases.

AIM: To investigate the differences in epithelial-mesenchymal transition (EMT)- and matrix metalloproteinases (MMP)-related factors among placenta previa with and without placenta accreta spectrum (PAS) (n = 69), and normal placenta (n = 51).

METHODS: The women diagnosed with placenta previa with or without PAS, and normal placentas, who delivered at our institution between 2006 and 2016, were enrolled. The difference of EMT-related factors' expression by immunochemical analysis in chorionic villi and decidual cells between the normal placenta and placenta previa with or without PAS were evaluated.

RESULTS: In chorionic villi of placenta previa with and without PAS, E-cadherin expression decreased, while that of ZEB1, SNAIL2 and MMP-9 increased than that in normal placenta. In decidual cells of placenta previa with and without PAS, expression of vimentin, ZEB1 and MMP-9 increased than that in normal placenta. In placenta previa with and without PAS, there was strong co-expression of ZEB1 and vimentin in chorionic villi, of ZEB1 and MMP-2 or MMP-9 in decidual cells, and of SNAIL2 and vimentin or MMP-9 in both chorionic villi and decidual cell. Vimentin expression in both chorionic villi and decidual cells was higher in placenta previa with PAS (n = 18) than in placenta previa without PAS (n = 51). MMP-2 expression in decidual cells was higher in placenta previa with PAS than in placenta previa without PAS.

CONCLUSION: This study revealed that EMT- and MMP-associated factors may be related to placenta previa with and without PAS. Furthermore, placenta previa without PAS may acquire invasive nature.