Over-Expression of Lipocalin 2 Promotes Cell Migration and Invasion Through Activating ERK Signaling to Increase SLUG Expression in Prostate Cancer
Over-Expression of Lipocalin 2 Promotes Cell Migration and Invasion Through Activating ERK Signaling to Increase SLUG Expression in Prostate Cancer
复制标题
前列腺癌中脂质运载蛋白 2 的过度表达通过激活 ERK 信号传导增加 SLUG 表达来促进细胞迁移和侵袭
DOI：
10.1002/pros.22978
复制
发表时间：
2015-06-15
期刊：
影响因子：
2.8
通讯作者：
Liu, Jun
中科院分区：
文献类型：
--
作者：
Ding, Guanxiong;Fang, Jie;Liu, Jun
背景
转移是前列腺癌（PCa）致死的主要原因，并构成了巨大的临床障碍。脂质运载蛋白2（LCN2）是脂质运载蛋白家族的成员，在一些人类癌症中异常表达，并与某些肿瘤的进展有关。然而，LCN2在前列腺癌转移能力中的作用知之甚少。
方法
通过实时定量聚合酶链反应（RT - qPCR）和/或免疫印迹法检测人前列腺组织标本以及前列腺癌细胞系LNCaP、C4 - 2、22RV1、PC3、DU - 145和PC3MM2中LCN2的表达。通过酶联免疫吸附测定（ELISA）确定人血清样本中LCN2蛋白水平。利用慢病毒介导LCN2的过表达和敲低来评估LCN2在前列腺癌细胞迁移和侵袭能力中的作用。通过Transwell小室实验检测细胞迁移和侵袭。利用慢病毒敲低slug来研究其在LCN2促进的体外细胞迁移和侵袭（22RV1细胞系）以及体内转移（裸鼠尾静脉转移实验）中的作用。通过使用细胞外调节蛋白激酶（ERK）抑制剂U0126检测ERK信号在LCN2介导的slug上调中的作用。
结果
我们证实LCN2水平在人体组织和血清样本中与侵袭性前列腺癌呈正相关，并且也始终与前列腺癌细胞系的侵袭能力相关。在22RV1细胞（非高侵袭性）中LCN2的过表达促进了上皮 - 间质转化（EMT），增加了细胞运动性和侵袭性，而在PC3细胞（高侵袭性）中敲低LCN2抑制了EMT，降低了细胞运动性和侵袭性。在多种EMT转录因子中，LCN2特异性诱导slug的表达，在此表明slug是LCN2在体外和体内诱导前列腺癌细胞侵袭能力增加所必需的。从机制上讲，LCN2通过激活ERK信号通路促进slug表达。
结论
LCN2通过ERK/slug轴诱导EMT，在促进前列腺癌细胞迁移和侵袭中起重要作用。因此，靶向抑制LCN2可能是一种预防前列腺癌转移的治疗策略。《前列腺》2015年第75卷第957 - 968页。（c）2015威利期刊公司
BACKGROUNDMetastasis is the primary cause of prostate cancer (PCa) lethality and poses a huge clinical obstacle. Lipocalin 2 (LCN2), a member of the lipocalin family, is aberrantly expressed in some human cancers and has been implicated in the progression of some tumors. However, the role of LCN2 in the metastatic capacity of prostate cancer (PCa) is poorly understood.METHODSLCN2 expression was examined by RT-qPCR and/or immunoblotting in human prostate tissue specimens and prostate cancer cell lines LNCaP, C4-2, 22RV1, PC3, DU-145, and PC3MM2. LCN2 protein level in human serum samples was determined by ELISA. Lentiviruses-mediated over-expression of LCN2 and knockdown of LCN2 was conducted to evaluate the role of LCN2 in cell migratory and invasive capacities of prostate cancer cells. Cell migration and invasion was examined by transwell chamber assay. Knockdown of SLUG by lentivirus was performed to investigate its role in LCN2-promoted cell migration and invasion in vitro (22RV1 cell line) and metastasis in vivo (tail vein metastasis assay in nude mice). Role of ERK signaling in LCN2-mediated up-regulation of SLUG was assayed by using ERK inhibitor U0126.RESULTSWe confirmed that LCN2 levels were correlated positively with invasive prostate cancer in human tissue and serum samples, and were also consistently associated with the invasive capacity of prostate cancer cell lines. The over-expression of LCN2 in 22RV1 cells (not highly invasive) promoted the epithelial-mesenchymal transition (EMT), increasing cell motility and invasiveness, while the knockdown of LCN2 in PC3 cells (highly invasive) inhibited EMT, decreasing cell motility and invasiveness. Among the multiple EMT transcription factors, LCN2 specifically induces the expression of SLUG, which was shown here to be required for the LCN2-induced increase in the invasive capacity of prostate cancer cells both in vitro and in vivo. Mechanistically, LCN2 promoted SLUG expression via activating ERK signaling pathway.CONCLUSIONLCN2 plays an important role in promoting cell migration and invasion of prostate cancer by inducing EMT through the ERK/SLUG axis. Therefore, targeted inhibition of LCN2 may represent a therapeutic strategy to prevent the metastasis of prostate cancer. Prostate 75:957-968, 2015. (c) 2015 Wiley Periodicals, Inc.