Zhu Youlong, Kong Feifei, Zhang Caihua, Ma Cheng, Xia Hong, Quan Bin, Cui Huaixin
Department of Second Gastrointestinal Surgery, Xuzhou Central Hospital, School of Medicine, Southeast University, Xuzhou, Jiangsu 221000, P.R. China.
Department of Oncology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221000, P.R. China.
Oncol Lett. 2017 Dec;14(6):7211-7216. doi: 10.3892/ol.2017.7163. Epub 2017 Oct 10.
Cluster of differentiation (CD)133 has been reported to be involved in the activation of the extracellular signal-regulated kinase (ERK) signaling pathway in different types of cancer cells. CD133 has been reported to be involved in the activation of the ERK signaling pathway in various cancer cells. Transforming growth factor (TGF)-β1 has also been reported to mediate the activation of the ERK signaling pathway. In addition, TGF-β1 has been previously shown to mediate the activation of the ERK signaling pathway. Hence, the present study investigated the function of CD133 in the TGF-β1-induced activation of the ERK/P70S6K signaling pathway in human gastric cancer (GC) cells. To this end, GC cell lines SGC7901 and MKN45 were treated with TGF-β1. The expression of CD133, phospho-ERK (p-ERK) and phospho-P70S6 kinase (p-P70S6K) was upregulated in the cells treated with TGF-β1, while the expression of ERK and P70S6K was not altered. To investigate whether CD133 is involved in the TGF-β1-induced activation of the ERK/P70S6K signaling pathway in GC cells, immunomagnetic cell sorting was employed to isolate CD133 GC cells, and a CD133-expression construct or CD133-targeting small interfering ribonucleic acids were transfected into cells to modulate the expression of CD133. Subsequently, the expression of CD133, ERK, p-ERK, P70S6K, and p-P70S6K was analyzed by western blotting. The CD133 cells displayed a high expression of p-ERK and p-P70S6K. Furthermore, SGC7901 GC cells were treated with U0126, an inhibitor of the ERK signaling pathway, to assess whether CD133 is upstream of ERK/P70S6K. The results showed that the expression of p-ERK and p-P70S6K was downregulated in the cells treated with U0126, while the expression of CD133 remained unaltered. The above preliminary results showed that CD133 likely mediates the TGF-β1-induced activation of the ERK/P70S6K signaling pathway in human GC cells. To further understand the mechanism of regulation of the ERK/P70S6K signaling pathway by CD133, the expression of CD133 was modulated by transfecting cells with CD133-expression constructs or CD133-targeting small interfering ribonucleic acids. Results indicated that overexpression and silencing of CD133 directly increased and decreased the expression of p-ERK and p-P70S6K, respectively. Therefore, we hypothesized that CD133 mediates the TGF-β1-induced activation of the PI3K/ERK/P70S6K signaling pathway in human GC cells.
据报道，分化簇（CD）133参与了不同类型癌细胞中细胞外信号调节激酶（ERK）信号通路的激活。据报道，CD133参与了各种癌细胞中ERK信号通路的激活。转化生长因子（TGF）-β1也被报道介导ERK信号通路的激活。此外，先前已表明TGF-β1介导ERK信号通路的激活。因此，本研究调查了CD133在TGF-β1诱导的人胃癌（GC）细胞中ERK/P70S6K信号通路激活中的作用。为此，用TGF-β1处理GC细胞系SGC7901和MKN45。在用TGF-β1处理的细胞中，CD133、磷酸化ERK（p-ERK）和磷酸化P70S6激酶（p-P70S6K）的表达上调，而ERK和P70S6K的表达未改变。为了研究CD133是否参与GC细胞中TGF-β1诱导的ERK/P70S6K信号通路的激活，采用免疫磁珠细胞分选法分离CD133阳性的GC细胞，并将CD133表达构建体或靶向CD133的小干扰核糖核酸转染到细胞中以调节CD133的表达。随后，通过蛋白质印迹法分析CD133、ERK、p-ERK、P70S6K和p-P70S6K的表达。CD133阳性细胞显示出高表达的p-ERK和p-P70S6K。此外，用ERK信号通路抑制剂U0126处理SGC7901 GC细胞，以评估CD133是否位于ERK/P70S6K的上游。结果表明，在用U0126处理的细胞中，p-ERK和p-P70S6K的表达下调，而CD133的表达保持不变。上述初步结果表明，CD133可能介导了TGF-β1诱导的人GC细胞中ERK/P70S6K信号通路的激活。为了进一步了解CD133对ERK/P70S6K信号通路的调节机制，通过用CD133表达构建体或靶向CD133的小干扰核糖核酸转染细胞来调节CD133的表达。结果表明，CD133的过表达和沉默分别直接增加和降低了p-ERK和p-P70S6K的表达。因此，我们假设CD133介导了TGF-β1诱导的人GC细胞中PI3K/ERK/P70S6K信号通路的激活。
