Expression of G Protein-Coupled Receptor 19 in Human Lung Cancer Cells Is Triggered by Entry into S-Phase and Supports G2-M Cell-Cycle Progression
Expression of G Protein-Coupled Receptor 19 in Human Lung Cancer Cells Is Triggered by Entry into S-Phase and Supports G2-M Cell-Cycle Progression
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DOI：
10.1158/1541-7786.mcr-12-0139
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发表时间：
2012-10-01
影响因子：
5.2
通讯作者：
Sommergruber, Wolfgang
中科院分区：
文献类型：
--
作者：
Kastner, Stefan;Voss, Tilman;Sommergruber, Wolfgang
G蛋白偶联受体（GPCR）在肿瘤细胞中的表达是不正常的。据推测，劫持GPCR的正常生理功能有助于肿瘤发生期间获得的所有生物学能力。在这里，我们搜索了在肺癌中表达的GPCR：发现编码孤儿G蛋白偶联受体19（GPR 19）的mRNA在小细胞肺癌患者的组织样本中经常过表达。一些观察结果表明，Gpr 19的过表达通过加速细胞周期的转变而赋予肺癌细胞特定的优势。(i)通过RNA干扰敲低Gpr 19 mRNA降低人肺癌细胞系的细胞生长。(ii)在用针对Gpr 19的siRNA转染的细胞中，通过G（2）-M期的细胞周期进程受损，这与细胞周期蛋白B1和磷酸化组蛋白H3的蛋白水平增加有关。(iii)Gpr 19 mRNA的表达水平沿着细胞周期的变化而变化，在S期出现一个高峰。(iv)通过染色质免疫沉淀验证了E2 F转录因子对Gpr 19表达的推定控制：针对E2 F-1至-4的抗体允许Gpr 19启动子的恢复。(v)去除Gpr 19启动子中的E2 F结合位点减少了荧光素酶报告基因的表达。(vi)肺癌患者样本中E2 f和Gpr 19表达相关。据了解，这是GPCR显示细胞周期特异性mRNA表达的第一个例子。我们的数据还验证了GPR 19在肺癌中过表达时作为候选靶标。Mol Cancer Res; 10（10）; 1343-58. (C)2012年AACR。
It has long been known that G protein-coupled receptors (GPCR) are subject to illegitimate expression in tumor cells. Presumably, hijacking the normal physiologic functions of GPCRs contributes to all biologic capabilities acquired during tumorigenesis. Here, we searched for GPCRs that were expressed in lung cancer: the mRNA encoding orphan G protein-coupled receptor 19 (GPR19) was found frequently overexpressed in tissue samples obtained from patients with small cell lung cancer. Several observations indicate that overexpression of Gpr19 confers a specific advantage to lung cancer cells by accelerating transition through the cell-cycle. (i) Knockdown of Gpr19 mRNA by RNA interference reduced cell growth of human lung cancer cell lines. (ii) Cell-cycle progression through G(2)-M-phase was impaired in cells transfected with siRNAs directed against Gpr19 and this was associated with increased protein levels of cyclin B1 and phosphorylated histone H3. (iii) The expression levels of Gpr19 mRNA varied along the cell-cycle with a peak observed in S-phase. (iv) The putative control of Gpr19 expression by E2F transcription factors was verified by chromatin immunoprecipitation: antibodies directed against E2F-1 to -4 allowed for the recovery of the Gpr19 promoter. (v) Removal of E2F binding sites in the Gpr19 promoter diminished the expression of a luciferase reporter. (vi) E2f and Gpr19 expression correlated in lung cancer patient samples. To the best of knowledge, this is the first example of a GPCR showing cell-cycle-specific mRNA expression. Our data also validate GPR19 as a candidate target when overexpressed in lung cancer. Mol Cancer Res; 10(10); 1343-58. (C) 2012 AACR.