下调 FGL2/凝血酶原酶可延缓 HCCLM6 异种移植瘤的生长并减少肿瘤血管生成。

Downregulation of FGL2/prothrombinase delays HCCLM6 xenograft tumour growth and decreases tumour angiogenesis.

机构信息

Department and Institute of Infectious Disease, Tongji hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

出版信息

Liver Int. 2012 Nov;32(10):1585-95. doi: 10.1111/j.1478-3231.2012.02865.x. Epub 2012 Aug 24.

DOI:10.1111/j.1478-3231.2012.02865.x

PMID:22925132

Abstract

BACKGROUND

Fibrinogen-like protein 2 (FGL2), which directly generates thrombin from prothrombin without activation of the conventional coagulation cascade, was shown to be overexpressed in various human malignant tumours.

AIMS

Herein, we aimed to investigate its expression pattern, biological function and mechanism of action in hepatocellular carcinoma (HCC).

METHODS

FGL2 expression and colocalization with fibrin was examined in 15 HCC tissues. FGL2 downregulation was performed by targeting microRNA in a HCCLM6 cell line in which FGL2 was highly expressed in xenografts of nude mice. The effects of FGL2 knockdown on tumour growth and angiogenesis were evaluated in vitro and in vivo. Cytometric bead arrays were employed to identify FGL2-regulated signalling pathways.

RESULTS

FGL2 was overexpressed in HCC tissues and colocalized with fibrin deposition. Knockdown of FGL2 expression in HCCLM6 cells (hFGL2(low) HCCLM6) resulted in delayed xenografts tumour growth within an observation period of 42 days and decreased vascularization, which was accompanied by decreased phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). In vitro hFGL2(low) HCCLM6 cells exhibited decreased proliferation without significant induction of apoptosis. Overexpression of FGL2 in HCCLM6 cells or addition of recombinant hFGL2 protein induced phosphorylation of p38-MAPK and ERK1/2 involving protease-activated receptors (PARs).activation.

CONCLUSIONS

FGL2 contributes to HCC tumour growth and angiogenesis in a thrombin-dependent manner, and downregulation of its expression might be of therapeutic significance in HCC.

摘要

背景

纤维蛋白原样蛋白 2（FGL2）可直接将凝血酶原转化为凝血酶，而无需传统凝血级联的激活，其在各种人类恶性肿瘤中过度表达。

目的

本研究旨在探讨其在肝细胞癌（HCC）中的表达模式、生物学功能和作用机制。

方法

在 15 例 HCC 组织中检测 FGL2 的表达及其与纤维蛋白的共定位。在 HCCLM6 细胞系中，通过靶向 microRNA 下调 FGL2 的表达，该细胞系在裸鼠异种移植中 FGL2 表达较高。在体外和体内评估 FGL2 敲低对肿瘤生长和血管生成的影响。采用流式细胞术检测 FGL2 调控的信号通路。

结果

FGL2 在 HCC 组织中过度表达，并与纤维蛋白沉积共定位。在 HCCLM6 细胞中下调 FGL2 表达（hFGL2(low) HCCLM6），在 42 天的观察期内导致异种移植肿瘤生长延迟，血管生成减少，同时细胞外信号调节激酶（ERK）和 c-Jun N-末端激酶（JNK）磷酸化减少。体外 hFGL2(low) HCCLM6 细胞增殖减少，而凋亡无明显诱导。在 HCCLM6 细胞中过表达 FGL2 或添加重组 hFGL2 蛋白可诱导丝裂原活化蛋白激酶（MAPK）p38 和 ERK1/2 的磷酸化，涉及蛋白酶激活受体（PARs）的激活。