Laminin deposition to type IV collagen enhances haptotaxis, chemokinesis, and adhesion of hepatoma cells through beta1-integrins.
OBJECTIVE
In hepatocellular carcinoma, laminin deposition to type IV collagen along the sinusoids is observed with the development of arterial network, coinciding with intrahepatic metastasis. We investigated the influence of laminin deposition to type IV collagen on hepatoma cell adhesion, motility and secretion of matrix metalloproteinases (MMPs), which are indispensable behaviors for tumor metastasis.


METHODS
Hepatoma cell lines (KYN-1, -2 and -3) were used. The expression of integrin subunit mRNAs in hepatoma cells was confirmed by RT-PCR. The influence of laminin addition to type IV collagen on the adhesion, chemokinesis, and migration of KYN-1, -2 and -3 was evaluated by the haptotactic migration, phagokinetic track motility, and cell adhesion assays. The effects of integrin subunits on these activities were evaluated using the function-blocking antibodies for integrins. Phosphorylation of MEK1/2 and secretion of MMPs were investigated by Western blotting and gelatin zymography.


RESULTS
Integrin alpha1, alpha2, alpha3, alpha6 and beta1 subunit mRNAs were detected. The combination of type IV collagen and laminin enhanced the migration, chemokinesis, and adhesion of hepatoma cells compared to that of type IV collagen when used alone. The enhanced activity was significantly suppressed by function-blocking antibodies for integrin alpha1, alpha2, alpha3, alpha6 and beta1 subunits. Hepatoma cells cultured on the combination of type IV collagen and laminin showed phosphorylation of MEK1/2 and increased secretion of MMPs.


CONCLUSIONS
The addition of laminin to type IV collagen enhances hepatoma cell adhesion and motility through beta1-integrins.
Torimura
T
T
The Second Department of Medicine, Kurume University School of Medicine, Japan. tori@med.kurume-u.ac.jp
Ueno
T
T
Kin
M
M
Harad
R
R
Nakamura
T
T
Sakamoto
M
M
Kumashiro
R
R
Yano
H
H
Kojiro
M
M
Sata
M
M
D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D002448:Cell Adhesion; D002465:Cell Movement; D024141:Collagen Type IV / Q000378:metabolism*; D006801:Humans; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism*; D016023:Integrins / Q000235:genetics / Q000378:metabolism; D007797:Laminin / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D020782:Matrix Metalloproteinases / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured
D024141:Collagen Type IV; D019012:Integrin beta1; D016023:Integrins; D007797:Laminin; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C482128:MAP2K2 protein, human; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D020782:Matrix Metalloproteinases