Document Type : Full paper (Original article)
Stem Cells Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Background: Docetaxel is beneficial in oocyte cryopreservation. Aims: The effect of docetaxel, on the survival, fertilization rate and mRNA expression of apoptosis-related genes of vitrified mature oocytes was investigated. Methods: Mature oocytes were divided into eight experimental groups, including I) Control; II) docetaxel; III) docetaxel+CPA1 (Cryoprotectant); IV) docetaxel+CPA2; V) docetaxel+Vit1 (Vitrification); VI) docetaxel+Vit2; VII) Vit1; and VIII) Vit2. The survival and fertilization rates and the mRNA expression level of Bcl-xl, Bax and caspase-3 as apoptosis-related genes were evaluated. Results: The survival rate in Vit1 and Vit2 groups was significantly lower than in the control group (P<0.05). The fertilization rate in docetaxel+Vit1, docetaxel+Vit2, Vit1 and Vit2 was significantly lower than control, docetaxel and related groups using docetaxel and CPAs. Bax expression was significantly increased in groups which oocytes vitrified. Also, its expression in the Vit2 group increased significantly in comparison to the docetaxel+Vit2 group. The expression of the Bcl-xl gene was downregulated in docetaxel+CPA2, docetaxel+Vit2 and Vit2 compared to docetaxel group. The Bax/Bcl-xl ratio significantly increased in docetaxel+CPA2, docetaxel+Vit1, docetaxel+Vit2, Vit1 and Vit2 groups compared to control, docetaxel and the docetaxel+CPA1 group. Caspase-3 expression significantly increased in all six groups in comparison to the control and docetaxel groups. Its expression significantly increased in the Vit1 and Vit2 groups when compared with docetaxel+Vit1 and docetaxel+Vit2, respectively. Conclusions: Docetaxel ameliorates the damages to oocytes during vitrification by altering the expression of apoptosis-related genes and its effects are dependent on the vitrification solution used in cryopreservation of oocytes.