摘要

microRNAs have been implicated in hepatocellular carcinoma (HCC) metastasis, which is predominant cause of high mortality in these patients. Although an increasing body of evidence indicates that miR-149 plays an important role in the growth and metastasis of multiple types of cancers, its role in the progression of HCC remains unknown. Here, we demonstrated that miR-149 was significantly down-regulated in HCC, which was correlated with distant metastasis and TNM stage with statistical significance. A survival analysis showed that decreased miR-149 expression was correlated with a poor prognosis of HCC as well. We found that over-expression of miR-149 suppressed migration and invasion of HCC cells in vitro. In addition, we identified PPM1F (protein phosphatase, Mg2+/Mn2+-dependent, 1F) as a direct target of miR-149 whose expression was negatively correlated with the expression of miR-149 in HCC tissues. The re-expression of PPM1F rescued the miR-149-mediated inhibition of cell migration and invasion. miR-149 regulated formation of stress fibers to inhibit migration, and re-expression of PPM1F reverted the miR-149-mediated loss of stress fibers. Moreover, we demonstrated that over-expression of miR-149 reduced pMLC2, a downstream effector of PPM1F, in MHCC-97H cells. In vivo studies confirm inhibition of HCC metastasis by miR-149. Taken together, our findings indicates that miR-149 is a potential prognostic biomarker of HCC and that the miR-149/PPM1F regulatory axis represents a novel therapeutic target for HCC treatment.

Keywords: hepatocellular carcinoma, miR-149, metastasis, PPM1F, microRNA

研究背景

越来越多研究表明miR-149对多种癌症的扩大和转移发挥重要作用,而在肝癌发展的角色仍未知。本研究发现miR-149的过表达抑制肝癌细胞的迁移和侵袭。且在肝癌组织中，miR-149与靶基因PPM1F表达呈负相关。本研究证明miR-149通过靶向肌动调控蛋白PPM1F抑制肝癌细胞的转移，为肝癌治疗提供一个新的方向。

技术路线

部分研究结果

1.miR-149在人肝癌组织中表达显著下调，其表达量与术后生存率相关；

2.miR-149的过表达抑制HepG2和MHCC-97H细胞的迁移和侵袭；

3.通过数据库预测，western blot，双荧光素酶报告基因筛选验证肌动调控蛋白PPM1F是miR-149的靶基因；

4.分别在肝癌组织和癌旁组织通过荧光原位杂交和免疫组化检测miR-149和PPM1F的表达情况，PPM1F与miR-149呈负相关；

5.miR-149通过抑制PPM1F行使功能；

miR-149抑制肝癌细胞的迁移和侵袭，回补PPM1F后，肝癌细胞的迁移和侵袭能力恢复。

6.小鼠模型中，miR-149过表达抑制肝癌转移。

HE染色显示miR-149过表达组肺转移肿瘤明显减少，免疫组化结果显示miR-149过表达组PPM1F表达下调。

伯信合作技术：荧光原位杂交（FISH）

参考文章

Gang L, Ya-Ling C, Bo T, et al. miR-149 represses metastasis of hepatocellular carcinoma by targeting actin-regulatory proteins PPM1F[J]. 

Oncotarget, 2015, 6(35):37808-23.

原文链接

http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC4741967&blobtype=pdf