[Effects of beta1-integrin, fibronectin and laminin on invasive behavior of human gliomas].
OBJECTIVE
To investigate the effects of beta1-integrin, fibronectin (FN) and laminin (LN) on the invasive behavior of human gliomas.


METHODS
Functional impacts of beta1-integrin, fibronectin and laminin on cell adhesion, migration and metastasis of U251 malignant glioblastoma cells were investigated by in vitro adhesion, migration and invasion assays. The amount and distributions of cellular microfilaments and pseudopodia were studied by fluorescent cytochemistry, confocal laser scanning microscope and scanning electron microscope. Lastly, beta1-integrin, fibronectin and laminin were investigated for their roles in cellular microfilament skeleton.


RESULTS
(1) Fibronectin did not affect cell adhesion of U251MG cells, but anti-beta1 integrin antibodies inhibited cell adhesion (P < 0.01); Laminin stimulated cell adhesion of U251MG cells (P < 0.01) but anti-beta1 integrin antibodies had little effect on the laminin-mediated cell adhesion. (2) The migration of U251MG cells on dishes coated with FN was inhibited by anti-beta1 integrin antibodies (P < 0.05). (3) F-actins formed strong and dense stress fibers in U251MG cells on dishes coated with FN and LN. Anti-beta1 integrin antibodies disrupted the microfilament network and F-actin aggregation. (4) FN and LN increased the number of pseudopodia on cell surface, whereas anti-beta1 integrin antibodies reversed this function. (5) FN and anti-beta1 integrin antibodies had little effects on the invasive ability of U251MG cells in vitro. The invasion was increased by LN, but inhibited by anti-beta1 integrin antibodies.


CONCLUSIONS
(1) The interaction between beta1-integrin, FN may stimulate U251MG cell migration via changing the structures of microfilament skeleton and the number of pseudopodia. (2) beta1-integrin may play a role in the LN-mediated in vitro invasion of U251MG cells.
Huang
Jiang-mei
JM
Department of Pathology, Health Science Center, Peking University, Beijing 100083, China.
Tian
Xin-xia
XX
Zhong
Yan-feng
YF
Ma
De-lian
DL
Ma
Yue
Y
You
Jiang-feng
JF
Zhang
Yan
Y
D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D005353:Fibronectins / Q000494:pharmacology*; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D005910:Glioma / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D019012:Integrin beta1 / Q000494:pharmacology*; D007797:Laminin / Q000494:pharmacology*; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D009361:Neoplasm Invasiveness
D005353:Fibronectins; D005904:Glial Fibrillary Acidic Protein; D019012:Integrin beta1; D007797:Laminin