The inhibitory effects of NKX3.1 on IGF-1R expression and its signalling pathway in human prostatic carcinoma PC3 cells.
The inhibitory effects of NKX3.1 on IGF-1R expression and its signalling pathway in human prostatic carcinoma PC3 cells.
复制标题
DOI：
10.1038/aja.2011.158
复制
发表时间：
2012-05
影响因子：
2.9
通讯作者：
Peng-ju Zhang;Xiao-yan Hu;Chun-Yan Liu;Zhaobo Chen;N. Ni;Yang Yu;Li-na Yang;Zhao-Qin Huang;Qing-wei Liu;An-li Jiang
中科院分区：
文献类型：
--
作者：
Peng-ju Zhang;Xiao-yan Hu;Chun-Yan Liu;Zhaobo Chen;N. Ni;Yang Yu;Li-na Yang;Zhao-Qin Huang;Qing-wei Liu;An-li Jiang
NKX3.1是前列腺特异性同源异型盒基因，在前列腺癌中起重要作用，通常作为肿瘤抑制基因发挥作用。在这项研究中，我们研究了NKX3.1对PC 3细胞中胰岛素样生长因子（IGF）-1R表达及其下游信号通路的抑制作用。用NKX3.1表达质粒（pcDNA3.1-NKX3.1）或载体质粒（pcDNA3.1+）稳定转染PC 3细胞。RT-PCR和Western blotting检测PC3-NKX3. 1转染细胞IGF-IR mRNA和蛋白表达水平。通过Western blotting和荧光素酶报告基因分析检测IGF-1/IGF-1R下游信号靶点的表达和激活。随后用相关浓度的IGF-1处理细胞。采用MTT法和流式细胞仪检测IGF-1对细胞生长的影响。NKX3.1在PC 3细胞中强制表达后，观察到IGF-1R mRNA和蛋白表达的显著抑制。相应地，NKX3.1的强制表达降低了IGF-1诱导的细胞外信号调节激酶1/2（ERK 1/2）和蛋白激酶B（AKT）的磷酸化以及Elk-1转录因子的激活，并下调了下游靶基因c-fos和细胞周期蛋白D1的表达。此外，NKX3.1的强制表达抑制IGF-1诱导的细胞生长。总之，NKX3.1可下调IGF-1R的表达，并可抑制IGF-1R介导的丝裂原活化蛋白激酶（MAPK）/ERK和AKT信号通路，这可能部分导致IGF-1诱导的细胞生长抑制。这项研究为NKX3.1对抗前列腺癌的分子机制提供了新的见解，并最终扩大了晚期前列腺癌治疗替代方法的范围。
NKX3.1, which is a prostate-specific homeobox gene, plays an important role in prostate cancer and usually functions as a tumour suppressor gene. In this study, we investigated the inhibitory effect of NKX3.1 on insulin-like growth factor (IGF)-1R expression and its downstream signalling pathway in PC3 cells. PC3 cells were stably transfected with NKX3.1 expression plasmid (pcDNA3.1-NKX3.1) or vector plasmid (pcDNA3.1+). The IGF-IR mRNA and protein expression levels were assessed in PC3-NKX3.1 transfectants by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. The expression and activation of IGF-1/IGF-1R downstream signalling targets were examined by Western blotting and luciferase reporter assay. The cells were subsequently treated with relevant concentrations of IGF-1. The effect of IGF-1 on cell growth was examined by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide (MTT) assay and flow cytometry analysis. A significant suppression of IGF-1R mRNA and protein expression was observed after forced expression of NKX3.1 in PC3 cells. Correspondingly, the forced expression of NKX3.1 decreased IGF-1-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (AKT) and activation of the Elk-1 transcription factor and downregulated the expression of the downstream target genes c-fos and cyclin D1. Furthermore, the forced expression of NKX3.1 inhibited IGF-1-induced cell growth. In conclusion, NKX3.1 could downregulate IGF-1R expression and could inhibit IGF-1R-mediated mitogen-activated protein kinase (MAPK)/ERK and AKT signalling pathways, which might partially leads to the inhibition of IGF-1-induced cell growth. This study provides new insights into the molecular mechanisms that NKX3.1 exerts against prostate cancer and ultimately expands the scope of alternative approaches in advanced prostate cancer therapy.