O-21: Differential Expression and Epigenetic Pattern of HOX Family Genes in Cumulus Cells of Mature MII Oocytes from Patients with Polycystic Ovary Syndrome

Background Ovarian tissue cryopreservation represents a promising strategy to preserve the ovarian function in cancer patients. It is usually performed by slow freezing/rapid thawing (SF/RT). Recent studies emphasize an ultrarapid cryopreservation procedure, vitrification/warming (V/W), since it might prevent damages due to ice crystal formation. Comparative studies between the cryopreservation procedures are primarily based on morphological evaluation of ovarian tissue. This study aims to investigate the bioenergy/oxidative status using Confocal Laser Scanning Microscopy (CLSM) of ovarian tissue cryopreserved by SF/RT and V/W, in association with a morpho-ultrastructural analysis by Light (LM) and Transmission Electron Microscopy (TEM). MaterialsAndMethods Six ovarian biopsies of consent cancer patients were cryopreserved by SF/RT and V/W. Fresh and cryopreserved tissues were processed for CLSM using MitoTracker Orange CMTM Ros (mitochondria activity) and DCHFDA (intracellular reactive oxygen species levels-ROS) fluorescent probes and for ematossilin/eosin staining (LM) and TEM. Mitochondria activity and ROS levels of fresh, SF/ RT and V/W samples were compared by ANOVA. Results Bioenergy/oxidative status resulted significantly different in fresh and cryopreserved ovarian tissues. Fresh samples presented higher mitochondria activity and ROS levels than SF/RT (P=0.002 and P