Steroids and miRNAs in assessment of ovarian tissue damage following cryopreservation

Abstract

Ovarian cortical tissue cryopreservation is a relatively novel approach to preserving fertility in women diagnosed with cancer. However, the effects of freezing-thawing are not fully understood, mainly due to the lack of suitable methods to assess tissue’s survival after thawing. Disparities in steroid production have been associated with ovarian failure by disrupting folliculogenesis, ovulation and oocyte apoptosis. Moreover, specific miRNAs, identified in human ovarian follicles, are thought to play a fundamental role in folliculogenesis. In this study, we investigated the possible interplay between the ovarian steroidal production and miRNA expression patterns in spent culture media, as potential non-invasive markers for ovarian tissue damage after cryopreservation. Cryopreservation of ovarian cortical tissue decreased (P < 0.05) both steroid production (oestradiol and progesterone) and expression of miRNA-193b and 320A in spent culture media over 5 days; however, expression of miRNA-24 increased (P < 0.05). The number of primordial follicles was also reduced (P < 0.05) in fresh-cultured and cryopreserved-cultured cortical tissues when compared with fresh tissues. Downregulation of miRNA-193b and miRNA-320A together with upregulation of miRNA-24 could have a synergistic role in cell apoptosis, and consequently leading to reduced oestradiol and progesterone production. Thus, there appears to be an interplay between these miRNAs, ovarian steroid production and cell damage, which can be further explored as novel non-invasive markers of cell damage following cryopreservation.

Slow-Freezing Cryopreservation Ensures High Ovarian Tissue Quality Followed by In Vivo and In Vitro Methods and Is Safe for Fertility Preservation

“…Many studies have been conducted to search for cancer biomarkers using mRNA from cryopreserved ovarian tissue or section staining of the tissue with antibodies [ 16 , 18 , 34 , 35 ]. Different research groups have started conducting studies to search for circulating miRNAs [ 36 , 37 ] or miRNAs in the tissue [ 20 , 38 , 39 , 40 ] as specific cancer biomarkers, but a study of miRNA expression after cryopreservation has just been recently published [ 19 ]. This study showed that upregulated miRNA–24 and downregulated expression of miRNA–193b, miRNA–320A, and steroid production could be non-invasive (expression patterns in culture media) markers for cell damage.…”

“…These practices include histological and immunohistochemical evaluations for: (1) structural, functional, and DNA integrity; (2) malignant cell contamination; and polymerase chain reaction (PCR) for the detection of molecular tumor markers [ 16 , 17 , 18 ]. Moreover, currently, disparities in steroid production and altered expression of specific microRNAs (miRNAs), e.g., miRNA–193b, miRNA–320A, and miRNA–24, after cryopreservation have been associated with failure of ovarian tissue functioning and folliculogenesis [ 19 ]. MicroRNAs are a class of small non–coding RNA molecules that have been shown to be potential biomarkers for different cancers and prognostics [ 20 ] and are involved in gametogenesis, embryo development, and fertility [ 21 , 22 ].…”

Female Oncofertility: Current Understandings, Therapeutic Approaches, Controversies, and Future Perspectives

“…Several genetic defects in BRCA1/2 [ 224 , 225 ], minichromosome maintenance complex component 8/9 [ 226 ], helicase for meiosis 1 [ 227 ], nucleoporin 107 [ 228 ], and synaptonemal complex central element protein 1 [ 229 ] are suggested to be implicated in ovarian insufficiency. Disparities in steroid production and altered expression of specific microRNAs (miRNAs), e.g., miRNA–193b, miRNA–320A, and miRNA–24, after cryopreservation are also related to impaired ovarian functioning and folliculogenesis [ 230 ]. For OTC, recent advances allow examination of tissue vitality; structural, functional, and DNA integrity; malignant cell contamination; and detection of molecular tumor markers [ 231 ].…”