Centre for Cell Chromosome Biology, Biosciences, School of Health Sciences and Social Care, Brunel University, Uxbridge UB8 3PH, UK.
Int J Mol Med. 2010 Jan;25(1):65-9.
Emerging data suggest that nutritional status and body weight are related to reproductive function, and nutrient imbalances during pregnancy lead to changes in the expression of fetal genes. Recent studies show that the mTOR acts as a placental growth signalling sensor and its expression is down-regulated in intrauterine growth restriction. To date, very little is known about the expression of this signalling pathway in choriocarcinoma, one of the most lethal germ cell cancers. In this study, cultures of fusigenic (BeWo) and non-fusigenic (JEG-3) human choriocarcinoma cell lines were used to investigate the expression of mTOR and its downstream signalling components. The effects of an inducer of syncytialisation (forskolin) on mTOR, eIF4E binding proteins (4EBPs) and ribosomal protein S6 kinases (S6Ks) in BeWo cells were also assessed. RT-PCR studies revealed that mTOR, 4EBP and S6Ks are expressed at mRNA level in both JEG-3 and BeWo cells. Semi-quantitative RT-PCR analysis revealed that in early stages of syncytialisation (50 microM forskolin for 48 h), the expression of mTOR and 4EBP was down-regulated when compared to unstimulated cells. In fully syncytialised cells (50 microM forskolin for 72 h) the expression of both genes was similar to basal levels. Interestingly, the phosphorylation (Ser371, Thr389) status of p70S6K remained unaltered upon forskolin treatment. These data validate BeWo cells as an experimental model to study the effects of forskolin-induced syncytialisation on mTOR signalling.
新兴数据表明，营养状况和体重与生殖功能有关，而怀孕期间的营养失衡会导致胎儿基因表达的变化。最近的研究表明，mTOR 作为胎盘生长信号传感器发挥作用，其在宫内生长受限中的表达下调。迄今为止，人们对绒毛膜癌（最致命的生殖细胞癌之一）中这种信号通路的表达知之甚少。在这项研究中，使用融合（BeWo）和非融合（JEG-3）人绒毛膜癌细胞系培养物来研究 mTOR 及其下游信号成分的表达。还评估了诱导合胞体形成的诱导剂（forskolin）对 BeWo 细胞中 mTOR、eIF4E 结合蛋白（4EBPs）和核糖体蛋白 S6 激酶（S6Ks）的影响。RT-PCR 研究表明，mTOR、4EBP 和 S6Ks 在 JEG-3 和 BeWo 细胞中均以 mRNA 水平表达。半定量 RT-PCR 分析显示，在合胞体形成的早期（50μM forskolin 刺激 48 小时），与未刺激的细胞相比，mTOR 和 4EBP 的表达下调。在完全合胞体形成的细胞（50μM forskolin 刺激 72 小时）中，这两个基因的表达与基础水平相似。有趣的是，p70S6K 的磷酸化（Ser371、Thr389）状态在 forskolin 处理后保持不变。这些数据验证了 BeWo 细胞作为研究 forskolin 诱导的合胞体形成对 mTOR 信号的影响的实验模型。
