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Inducible Expression of p57KIP2
Inhibits Glioma Cell Motility and Invasion
K Sakai, A Peraud, T
Mainprize, J Nakayama, A Tsugu, K Hongo, S Kobayashi, James T.
Rutka
Department of Neurosurgery, Shinshu University School
of Medicine, Canada (K.S., K.H., S.K.); The Arthur and Sonia Labatt Brain Tumour
Research Centre, The Hospital for Sick Children, and the Division of
Neurosurgery, University of Toronto, Canada (A.P., T.M., J.T.R.); Department of
Organ Regeneration, Institutes of Organ Transplants, Reconstructive Medicine and
Tissue Engineering, Shinshu University Graduate School of Medicine, Canada (J.N.);
Department of Neurosurgery, Tokai University School of
Medicine, Canada (A.T.)
To examine the role of p57KIP2 in human malignant
glioma cells, we studied its expression in a panel of human malignant glioma
specimens by western blot and immunohistochemical analysis.
To determine the effects of p57KIP2 expression on the
phenotype of glioma cells, we analyzed two inducible stably transfected p57KIP2expressing
glioma cell lines.
Expression of p57KIP2 was induced in U373 and U87 malignant
glioma cells with doxycycline using the tetracycline repressor system.
A phagokinetic track assay on gold particles was used to investigate differences
in cell migration between p57KIP2 expressing and
non-expressing control cells.
The effects of the extracellular matrix (ECM) on U373 motility was determined in
p57+ and p57- cells on surfaces coated with 5 μg/cm2
of fibronectin, laminin, type I and type IV collagens.
The
invasion of p57+ and p57- glioma cells across BD Biocoat
Matrigel invasion chambers was then determined.
p57KIP2
was weakly expressed in 4/6 glioblastoma (GBM) specimens by western blot.
By
immunohistochemistry, p57KIP2 immunoreactivity was positive
in 8/40 GBMs, and was primarily nuclear in location.
The
motility of U373 glioma cells was significantly reduced after p57KIP2
induction.
The
presence of ECM proteins did not further alter the motility of p57+
and p57- glioma cells.
The
results of the invasion chamber assay showed that p57+ cells
exhibited a 35% reduction in their invasive capacity as compared to p57-
cells.
These
data suggest that p57KIP2 is expressed in at least some
malignant gliomas.
Inducible
expression of 57KIP2 in cell lines deficient in this
cyclin-dependent kinase inhibitor reduces their motility and invasiveness.
Keywords: invasion assay, motility assay, p57KIP2
Copyright
©
2004 Kluwer Academic Publishers. All rights reserved
Source: http://ipsapp009.kluweronline.com/IPS/content/ext/x/J/5042/I/119/A/5/abstract.htm
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