Zygote 25 (October ), pp. 583–591. c  Cambridge University Press 2017 doi:10.1017/S0967199417000429 First Published Online 08 August 2017 Relationship between apoptosis and survival molecules in human cumulus cells as markers of oocyte competence Liana Bosco 1 , Roberto Chiarelli 2 , Maria Carmela Roccheri 2 , Domenica Matranga 3 and Giovanni Ruvolo 4 Università degli Studi di Palermo, STEBICEF; Università degli Studi di Palermo, Scienze per la Promozione della Salute e Materno Infantile ‘G.D’ Alessandro’; and Centro di Biologia della Riproduzione, Palermo, Italy Date submitted: 06.04.2017. Date revised: 06.04.2017. Date accepted: 28.06.2017 Summary To select from a single patient the best oocytes able to reach the blastocyst stage, we searched for valuable markers for oocytes competence. We evaluated the DNA fragmentation index (DFI) and the level of some survival molecules, such as AKT, pAKT and pERK1/2, in individual cumulus cell–oocyte complexes (COC). The study included normo-responder women. The average age of the patients was 34.3. DFI in cumulus cells was evaluated using the terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labelling (TUNEL) assay in situ. AKT, pAKT and pERK1/2 were measured by immunological assay and densitometric analysis of fluorescent signals using NIS-Elements BR 3.10 image software. Statistical analysis was performed using STATA SE/14.1. The study focused on 53 patients involved after informed consent. Out of 255 MII oocytes, 197 were fertilized and the derived embryos had the following evolution: 117 completed the development to blastocyst and were transferred to uterus; 57 were vitrified at the blastocyst stage; and 23 were arrested during in vitro culture at different stages of cleavage. We found a significant statistical difference between the DFI of cumulus cells of the arrested embryos and the transferred blastocysts (P = 0.004), confirming that DFI could be considered as a valuable marker of oocyte competence. In addition, the pAKT/DFI ratio was higher in cumulus cells of oocytes able to produce blastocysts, indicating that DFI is significantly lower when pAKT is higher (P = 0.043). This study demonstrates for the first time that the relationship between apoptosis and survival molecules can be used as a marker to select the best oocytes. Keywords: Apoptosis, Human cumulus cells, Molecular markers, Oocyte competence, Survival molecules Introduction About 15% of couples have fertility issues during their reproductive years (World Health Organization, 1 All correspondence to: Liana Bosco. Università degli Studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Viale delle Scienze, Ed.16, 90128 Palermo, Italy. Tel: +39 09123897411. Fax: +39 0916577210. E-mail: liana.bosco@unipa.it 2 Università degli Studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Viale delle Scienze, Ed.16, 90128 Palermo, Italy. 3 Università degli Studi di Palermo, Scienze per la Pro- mozione della Salute e Materno Infantile ‘G.D’Alessandro’, Via del Vespro, 133, 90127 Palermo, Italy. 4 Centro di Biologia della Riproduzione, via V. Villareale, 54, 90141 Palermo, Italy. 1983). In vitro fertilization (IVF) has the highest success rates of pregnancy and live-birth outcomes among treatments available for infertile couples, even if the more conventional methods of embryo selection are still associated with a relatively low success rate, with a clinical pregnancy rate (PR) of 30% per transfer (Andersen et al., 2008). The assessment of oocyte and embryo competence in IVF treatment is critical to determine which one embryo to be transferred is the most viable. To date, the evaluation of embryo competence uses morpho-kinetics information (Herrero & Meseguer, 2013). The transfer of two or three embryos is a common practice that aims to increase pregnancy probability but can increase the risk of multiple gestations, resulting in preterm birth and its complications, such as cerebral palsy and infant death (Strömberg et al., 2002). In the field of assisted Downloaded from https://www.cambridge.org/core. 27 Oct 2021 at 16:55:03, subject to the Cambridge Core terms of use.