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Activation status and function of the VLA‐4 (α4β1) integrin expressed on human melanoma cell lines
Author(s) -
Saini Asha,
Seller Zerrin,
Davies Dawn,
Marshall John F.,
Hart Ian R.
Publication year - 1997
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19971009)73:2<264::aid-ijc17>3.0.co;2-f
Subject(s) - integrin , cell adhesion , neural cell adhesion molecule , calphostin c , adhesion , cell culture , microbiology and biotechnology , cell adhesion molecule , peptide , chemistry , biology , cancer research , receptor , cell , protein kinase c , signal transduction , biochemistry , genetics , organic chemistry
We have examined the functional status of the VLA‐4/α4β1 integrin in a panel of human melanoma cell lines, focusing on the ability of cells expressing α4β1 to mediate adhesion to the α4‐specific ligands CS‐1 peptide and VCAM‐1. All melanoma cells expressing α4β1 (8 of 10 lines examined) were capable of adhering to these specific ligands in adhesion assays, whereas 2 cell lines (HMB2 and VUP) which lacked surface α4 were unable to do so. Adherence of different melanoma cell lines to VCAM‐1 was relatively uniform and not susceptible to up‐regulation with known integrin‐activating factors, such as manganese ions, phorbol ester and activating monoclonal antibody (mAb) TS2/16. Cell adhesion to CS‐1 peptide, however, varied according to cell surface receptor density and, in some cases, could be up‐regulated by integrin‐activating factors. Adhesion of SK23 cells to CS‐1 peptide was increased by all 3 activating stimuli, whereas for all other melanoma cells an increase was obtained only by the use of TS2/16 mAb. Our data indicate not only an unusually low activation state of α4β1 in SK23 cells but also heterogeneity in the activating capacity of the various stimuli. Moreover, a protein kinase C–dependent role in α4β1 activity was suggested by adhesion assays carried out in the presence of the protein kinase C inhibitor calphostin C, which considerably reduced adhesion to CS‐1 peptide. Int. J. Cancer 73:264–270, 1997. © 1997 Wiley‐Liss, Inc.