Mesci Aruz, Huang Xiaoyong, Taeb Samira, Jahangiri Sahar, Kim Yohan, Fokas Emmanouil, Bruce Jeff, Leong Hon S, Liu Stanley K
Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.
Br J Cancer. 2017 May 9;116(10):1350-1357. doi: 10.1038/bjc.2017.105. Epub 2017 Apr 18.
MicroRNAs (miRs) are involved in the regulation of many processes that contribute to malignancy, including cell proliferation, radiation resistance, invasion and metastasis. The role of miR-330-3p, an miR upregulated in breast cancer, remains unclear.
We examine the association of miR-330-3p with distant relapse-free survival in the Oxford cohort of breast cancer patients. We also study miR-330-3p function using in vitro invasion and ex ovo metastasis assays. Using in vitro luciferase assays, we validate a novel target gene for miR-330-3p, Collagen And Calcium Binding EGF Domains 1 (CCBE1). We assess functional consequences of CCBE1 loss by using siRNA-mediated knockdown followed by in vitro invasion assays. Lastly, we examine the expression profile of CCBE1 in breast carcinomas in the Curtis and TCGA Breast Cancer data sets using Oncomine Platform as well as distant relapse-free and overall survival of patients in the Helsinki University breast cancer data set according to CCBE1 expression status.
miR-330-3p is enriched in breast cancer, and higher levels of miR-330-3p expression are associated with lower distant relapse-free survival in a cohort of breast cancer patients. Consistent with these observations, overexpression of miR-330-3p in breast cancer cell lines results in greater invasiveness in vitro, and miR-330-3p-overexpressing cells also metastasise more aggressively ex ovo. We identify CCBE1 as a direct target of miR-330-3p, and show that knockdown of CCBE1 results in a greater invasive capacity. Accordingly, in breast cancer patients CCBE1 is frequently downregulated, and its loss is associated with reduced distant relapse-free and overall survival.
We show for the first time that miR-330-3p targets CCBE1 to promote invasion and metastasis. miR-330-3p and CCBE1 may represent promising biomarkers in breast cancer.
微小RNA（miR）参与调控许多促成恶性肿瘤的过程，包括细胞增殖、辐射抗性、侵袭和转移。miR-330-3p是一种在乳腺癌中上调的miR，其作用仍不清楚。
我们在牛津乳腺癌患者队列中研究了miR-330-3p与远处无复发生存率的关联。我们还使用体外侵袭和卵外转移试验研究了miR-330-3p的功能。通过体外荧光素酶试验，我们验证了miR-330-3p的一个新靶基因，胶原蛋白和钙结合表皮生长因子结构域1（CCBE1）。我们通过使用小干扰RNA介导的敲低，然后进行体外侵袭试验，评估CCBE1缺失的功能后果。最后，我们使用Oncomine平台检查了Curtis和TCGA乳腺癌数据集中乳腺癌组织中CCBE1的表达谱，以及根据CCBE1表达状态分析了赫尔辛基大学乳腺癌数据集中患者的远处无复发生存率和总生存率。
miR-330-3p在乳腺癌中富集，在一组乳腺癌患者中，较高水平的miR-330-3p表达与较低的远处无复发生存率相关。与这些观察结果一致，在乳腺癌细胞系中过表达miR-330-3p会导致体外侵袭性增强，并且过表达miR-330-3p的细胞在卵外转移也更具侵袭性。我们确定CCBE1是miR-330-3p的直接靶标，并表明敲低CCBE1会导致侵袭能力增强。因此，在乳腺癌患者中，CCBE1经常下调，其缺失与远处无复发生存率和总生存率降低相关。
我们首次表明miR-330-3p靶向CCBE1以促进侵袭和转移。miR-330-3p和CCBE1可能是乳腺癌中有前景的生物标志物。
