Slow freezing versus vitrification technique for human ovarian tissue cryopreservation: An evaluation of histological changes, WNT signaling pathway and apoptotic genes expression

Abstract This study compared slow freezing and vitrification of ovarian tissue by evaluation of histological changes, WNT signaling pathway and apoptotic genes expression. Ovarian tissue was obtained from women aging 27–38 years old. Ovarian cortex from each patient was divided into three pieces and randomly grouped as slow freezing, vitrification and control groups for investigation of WNT signaling gene expression and β-CATENIN presence as well as histological studies. The stromal structure of all ovaries were preserved. The number of secondary follicles decreased in vitrified group (P  WNT-3 , β-CATENIN , FZD-2 and GSK-3β expressions were significantly higher in slow frozen and vitrified groups, compared to control group (P  AXIN1 expression in slow frozen samples were significantly lower than that of the vitrified and control group. The expression of apoptotic genes, excluding CASP3 , was significantly decreased in slow-frozen samples (P  BAX : BCL-2 percentage significantly increased in vitrification versus slow freezing and control(P