miR-145 和 miR-133a 作为肿瘤抑制因子发挥作用，直接调控膀胱癌中 FSCN1 的表达。

miR-145 and miR-133a function as tumour suppressors and directly regulate FSCN1 expression in bladder cancer.

机构信息

Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, Japan.

出版信息

Br J Cancer. 2010 Mar 2;102(5):883-91. doi: 10.1038/sj.bjc.6605570. Epub 2010 Feb 16.

BACKGROUND

We have recently identified down-regulated microRNAs including miR-145 and miR-133a in bladder cancer (BC). The aim of this study is to determine the genes targeted by miR-145, which is the most down-regulated microRNA in BC.

METHODS

We focused on fascin homologue 1 (FSCN1) from the gene expression profile in miR-145 transfectant. The luciferase assay was used to confirm the actual binding sites of FSCN1 mRNA. Cell viability was evaluated by cell growth, wound-healing, and matrigel invasion assays. BC specimens were subjected to immunohistochemistry of FSCN1 and in situ hybridisation of miR-145.

RESULTS

The miR-133a as well as miR-145 had the target sequence of FSCN1 mRNA by the database search, and both microRNAs repressed the mRNA and protein expression of FSCN1. The luciferase assay revealed that miR-145 and miR-133a were directly bound to FSCN1 mRNA. Cell viability was significantly inhibited in miR-145, miR-133a, and si-FSCN1 transfectants. In situ hybridisation revealed that miR-145 expression was markedly repressed in the tumour lesion in which FSCN1 was strongly stained. The immunohistochemical score of FSCN1 in invasive BC (n=46) was significantly higher than in non-invasive BC (n=20) (P=0.0055).

CONCLUSION

Tumour suppressive miR-145 and miR-133a directly control oncogenic FSCN1 in BC.

背景

我们最近在膀胱癌（BC）中发现下调的 microRNA 包括 miR-145 和 miR-133a。本研究的目的是确定 miR-145 的靶基因，miR-145 是 BC 中下调最明显的 microRNA。

方法

我们专注于 miR-145 转染体中的基因表达谱中的 fascin 同源物 1（FSCN1）。荧光素酶测定用于确认 FSCN1 mRNA 的实际结合位点。通过细胞生长、划痕愈合和基质胶侵袭测定评估细胞活力。对 FSCN1 的 BC 标本进行免疫组织化学和 miR-145 的原位杂交。

结果

数据库搜索显示 miR-133a 和 miR-145 都有 FSCN1 mRNA 的靶序列，这两种 microRNA 均抑制 FSCN1 mRNA 和蛋白的表达。荧光素酶测定显示 miR-145 和 miR-133a 直接结合到 FSCN1 mRNA 上。miR-145、miR-133a 和 si-FSCN1 转染的细胞活力显著受到抑制。原位杂交显示 FSCN1 在 miR-145 表达明显受抑制的肿瘤病变中强烈染色。在 46 例浸润性 BC（n=46）中 FSCN1 的免疫组化评分明显高于 20 例非浸润性 BC（n=20）（P=0.0055）。