Effect of fibulin-5 on adhesion, migration and invasion of hepatocellular carcinoma cells via an integrin-dependent mechanism.
OBJECTIVE
To elucidate the role of fibulin-5 (FBLN-5) as a suppressor of hepatocellular carcinoma (HCC) cell metastasis via integrin.


METHODS
The expression of FBLN-5 was determined by immunohistochemistry in 140 HCC samples and matched normal tissues, and was further confirmed by RT-PCR and Western blot analyses in various cell lines. Recombinant FBLN-5 was expressed in Escherichia coli BL21(DE3), purified and used in cell attachment assays. Expression of a specific plasmid or a specific siRNA in HCC cells resulted in the overexpression or knockdown of FBLN-5, respectively. Further, the migration and invasion of HCC cells were investigated using the Boyden chamber and transwell assays. The concentration of secreted matrix metalloproteinase 7 (MMP-7) was determined using ELISA.


RESULTS
FBLN-5 expression was found to be downregulated in HCC. Its expression was significantly correlated with advanced tumor metastasis; this was indicative of poor 5-year overall survival. Recombinant full-length human FBLN-5 promoted the attachment of HCC cells via integrins: it inhibited HCC cell adhesion and migration to fibronectin in a concentration-dependent manner. It also inhibited HCC cell migration and invasion through an integrin-binding arginine-glycine-aspartic acid (RGD) motif by downregulating MMP-7.


CONCLUSIONS
These results suggest that lower FBLN-5 expression is an important indicator of poor survival and that FBLN-5 inhibits HCC motility via an integrin-dependent mechanism. RGD-dependent suppression of MMP-7 by FBLN-5 might contribute to the development of new therapeutic strategies for HCC.
Jia-Cheng Tang, Jing-Hua Liu, Xiao-Long Liu, Xiao Liang, Xiu-Jun Cai, Key Lab of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, Zhejiang Province, China.
Jia-Cheng
JC
Tang
Jia-Cheng Tang, Jing-Hua Liu, Xiao-Long Liu, Xiao Liang, Xiu-Jun Cai, Key Lab of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, Zhejiang Province, China.
Jing-Hua
JH
Liu
Jia-Cheng Tang, Jing-Hua Liu, Xiao-Long Liu, Xiao Liang, Xiu-Jun Cai, Key Lab of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, Zhejiang Province, China.
Xiao-Long
XL
Liu
Jia-Cheng Tang, Jing-Hua Liu, Xiao-Long Liu, Xiao Liang, Xiu-Jun Cai, Key Lab of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, Zhejiang Province, China.
Xiao
X
Liang
Jia-Cheng Tang, Jing-Hua Liu, Xiao-Long Liu, Xiao Liang, Xiu-Jun Cai, Key Lab of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, Zhejiang Province, China.
Xiu-Jun
XJ
Cai
D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002465:Cell Movement; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D008297:Male; D020783:Matrix Metalloproteinase 7 / Q000378:metabolism; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009842:Oligopeptides / Q000378:metabolism; D034622:RNA Interference; D012189:Retrospective Studies; D015398:Signal Transduction; D016019:Survival Analysis; D013997:Time Factors; D014162:Transfection
D016326:Extracellular Matrix Proteins; C492373:FBLN5 protein, human; D005353:Fibronectins; D016023:Integrins; D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7
Adhesion; Fibulin-5; Hepatocellular carcinoma; Integrin; Invasion; Migration