Chen Xiu-Ying, Xia He-Xia, Guan Hai-Yun, Li Bin, Zhang Wei
Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, China.
Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, Shanghai 200011, China.
Int J Mol Sci. 2016 May 30;17(6):836. doi: 10.3390/ijms17060836.
With increasing numbers of young female cancer survivors following chemotherapy, chemotherapy-induced fertility loss must be considered. Menstrual disorder and infertility are of particular concern in female cancer patients. We showed that treatment with the alkylating agent cyclophosphamide (CTX) could cause severe primordial follicle loss and growing follicle apoptosis, resulting in loss of ovarian reserve. SPF C57BL/6 female mice were treated with a single dose of 120 mg/kg of CTX or saline as a control, and both sides of ovaries were collected three or seven days after injection. Following CTX treatment, the ovaries were mostly composed of collapsed oocytes and presented marked cortical fibrosis and a reduced number of follicles, especially primordial follicles. The loss of primordial follicles was confirmed by primordial follicle counting, immunohistochemistry and Western blot detection of DDx4/MVH. Follicle apoptosis was tested by a TUNEL assay and the number of TUNEL-positive follicle cells increased, as expected, in CTX-treated mice. Furthermore, expression of APAF-1 and cleaved caspase-3 was also increased after CTX treatment. Analysis of the PI3K/Akt/mTOR signaling pathway showed that CTX increased phosphorylation of Akt, mTOR and downstream proteins without affecting total levels. These results demonstrated that the CTX treatment led to the hyperactivation of the PI3K/Akt/mTOR signaling pathway in ovaries which may be related to primordial follicle loss and growing follicle apoptosis.
随着接受化疗的年轻女性癌症幸存者数量不断增加，必须考虑化疗引起的生育能力丧失。月经紊乱和不孕在女性癌症患者中尤为令人担忧。我们发现，用烷化剂环磷酰胺（CTX）治疗可导致严重的原始卵泡丢失和生长卵泡凋亡，从而导致卵巢储备功能丧失。将SPF C57BL/6雌性小鼠用120mg/kg的CTX单剂量治疗或用生理盐水作为对照，在注射后三天或七天收集双侧卵巢。CTX治疗后，卵巢大多由塌陷的卵母细胞组成，呈现明显的皮质纤维化且卵泡数量减少，尤其是原始卵泡。通过原始卵泡计数、免疫组织化学以及DDx4/MVH的蛋白质印迹检测证实了原始卵泡的丢失。通过TUNEL检测法检测卵泡凋亡，正如预期的那样，在CTX处理的小鼠中TUNEL阳性卵泡细胞数量增加。此外，CTX处理后APAF-1和裂解的caspase-3的表达也增加。对PI3K/Akt/mTOR信号通路的分析表明，CTX增加了Akt、mTOR及下游蛋白的磷酸化，而不影响其总水平。这些结果表明，CTX治疗导致卵巢中PI3K/Akt/mTOR信号通路的过度激活，这可能与原始卵泡丢失和生长卵泡凋亡有关。
