MicroRNA-18a inhibits hypoxia-inducible factor 1α activity and lung metastasis in basal breast cancers.
MicroRNA-18a inhibits hypoxia-inducible factor 1α activity and lung metastasis in basal breast cancers.
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DOI：
10.1186/bcr3693
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发表时间：
2014-07-28
期刊：
影响因子：
--
通讯作者：
Fan M
中科院分区：
文献类型：
--
作者：
Krutilina R;Sun W;Sethuraman A;Brown M;Seagroves TN;Pfeffer LM;Ignatova T;Fan M
在乳腺癌中，microRNAs （miRNAs）的不同表达谱与分子亚群和临床病理特征相关，这意味着miRNAs在诊断和预后方面的作用。然而，不受调控的mirna在肿瘤进展中的生物学功能尚未完全确定。在本研究中，我们研究了miR-18a通过缺氧诱导因子1α (HIF1A)依赖的缺氧反应调节乳腺癌转移的功能。原位转移性乳腺癌异种移植模型（MDA-MB-231细胞）用于鉴定与自发性肺转移相关的mirna。然后通过评估miR-18a异位表达或miR-18a抑制，在体外和体内研究miR-18a调节HIF1A表达的功能，以及细胞对缺氧和转移的反应。在常氧或缺氧条件下评估miRNA-mRNA相互作用（AGO2免疫沉淀和3 '非翻译区荧光素酶报告检测）、基因表达（定量PCR和微阵列）、细胞迁移和侵袭以及细胞生长，并将肿瘤细胞原位移植到乳腺脂肪垫，以研究调节miR-18a表达对原发肿瘤生长和肺转移的影响。最后，使用已发表的表达阵列乳腺肿瘤数据集评估miR-18a、HIF1A、缺氧反应性基因表达与远端无转移生存（DMFS）之间的临床相关性。与原发肿瘤相比，肺转移瘤中MIR17HG基因编码的miRNAs表达下调。miR-18a是MIR17HG家族成员，在MDA-MB-231细胞的转移变体中异位表达可降低原发肿瘤生长和肺转移，而亲代细胞中miR-18a的抑制可促进肿瘤生长和肺转移。我们发现HIF1A是miR-18a的直接靶点。在体外，调节miR-18a表达以依赖hif1a的方式显著影响缺氧基因表达、细胞侵袭性和对缺氧和缺氧的敏感性。对先前发表的数据的分析显示，在基底样乳腺肿瘤患者中，HIF1A和一组缺氧基因的高表达与较短的DMFS间隔相关，并且在该亚型中，miR-18a表达与缺氧基因表达呈负相关。总之，这些数据支持miR-18a通过hif1a依赖途径抑制远处转移的作用。本研究结果揭示了miR-18a在靶向HIF1A和抑制基底样乳腺肿瘤转移中的新作用。本文的在线版本（doi:10.1186/bcr3693）包含补充材料，可供授权用户使用。
In breast cancer, distinct expression profiles of microRNAs (miRNAs) have been associated with molecular subgroups and clinicopathological characteristics, implicating a diagnostic and prognostic role of miRNAs. However, the biological functions of deregulated miRNAs in tumor progression are not yet completely defined. In this study, we investigated the function of miR-18a in regulating breast cancer metastasis through the hypoxia-inducible factor 1α (HIF1A)–dependent hypoxic response. An orthotopic metastatic breast cancer xenograft model (MDA-MB-231 cells) was used to identify miRNAs associated with spontaneous lung metastasis. The function of miR-18a in regulating HIF1A expression, as well as cellular responses to hypoxia and metastasis, were then studied in vitro and in vivo by assessing ectopic miR-18a expression or miR-18a inhibition. miRNA–mRNA interactions (AGO2 immunoprecipitation and 3′ untranslated region Luciferase reporter assays), gene expression (quantitative PCR and microarray), cell migration and invasion, and cell growth were assessed under normoxic or hypoxic conditions, complemented by orthotopic xenograft of tumor cells to the mammary fat pad to investigate the effect of modulating miR-18a expression on primary tumor growth and lung metastasis. Last, clinically relevant correlations between miR-18a, HIF1A, hypoxia-responsive gene expression and distant metastasis–free survival (DMFS) were assessed using published expression array breast tumors data sets. miRNAs encoded by the MIR17HG gene were downregulated in lung metastases compared to primary tumors. Ectopic expression of miR-18a, a MIR17HG family member, in a metastatic variant of MDA-MB-231 cells reduced primary tumor growth and lung metastasis, whereas miR-18a inhibition in the parental cells promoted tumor growth and lung metastasis. We identified HIF1A as a direct target of miR-18a. Modulating miR-18a expression significantly affected hypoxic gene expression, cell invasiveness and sensitivity to anoikis and hypoxia in vitro in a HIF1A-dependent manner. Analysis of previously published data revealed that higher expression of HIF1A and a panel of hypoxic genes is associated with shorter DMFS interval in patients with basal-like breast tumors, and that, within this subtype, miR-18a expression is inversely correlated with hypoxic gene expression. Together, these data support a role of miR-18a in repressing distant metastasis through a HIF1A-dependent pathway. The results of this study reveal a novel role for miR-18a in targeting HIF1A and repressing metastasis of basal-like breast tumors. The online version of this article (doi:10.1186/bcr3693) contains supplementary material, which is available to authorized users.
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影响因子：
29.4
作者：
Liu, Wan-Hsin;Yeh, Shiou-Hwei;Chen, Pei-Jer
通讯作者：
Chen, Pei-Jer
影响因子：
8
作者：
Kim, K.;Chadalapaka, G.;Lee, S-O;Yamada, D.;Sastre-Garau, X.;Defossez, P-A;Park, Y-Y;Lee, J-S;Safe, S.
通讯作者：
Safe, S.
影响因子：
7.3
作者：
Hubbi ME;Kshitiz;Gilkes DM;Rey S;Wong CC;Luo W;Kim DH;Dang CV;Levchenko A;Semenza GL
通讯作者：
Semenza GL
影响因子：
3.7
作者：
Enerly E;Steinfeld I;Kleivi K;Leivonen SK;Aure MR;Russnes HG;Rønneberg JA;Johnsen H;Navon R;Rødland E;Mäkelä R;Naume B;Perälä M;Kallioniemi O;Kristensen VN;Yakhini Z;Børresen-Dale AL
通讯作者：
Børresen-Dale AL
影响因子：
5.3
作者：
Hossain, Anwar;Kuo, Macus T.;Saunders, Grady F.
通讯作者：
Saunders, Grady F.