Ml. Turner et al., COMPARATIVE ADHESION OF HUMAN HEMATOPOIETIC-CELL LINES TO EXTRACELLULAR-MATRIX COMPONENTS, BONE-MARROW STROMAL AND ENDOTHELIAL CULTURES, British Journal of Haematology, 100(1), 1998, pp. 112-122
We used flow cytometry to characterize cell adhesion molecule expressi
on of the human haemopoietic cell lines KG1a, K562, HL-60, NALM-6 and
CEM. A (51)chromium labelling assay was used to study the adhesion of
these cell lines to extracellular matrix components and to bone marrow
stromal and endothelial cultures. Both adhesion molecule expression a
nd functional binding behaviour varied between cell lines, All five ce
ll lines expressed the integrins alpha(4) beta(1) and alpha(5) beta(1)
and all adhered to fibronectin, However, differences in intensity of
expression of these integrins failed to correlate with extent of fibro
nectin adhesion, inhibition experiments demonstrated that adhesion of
KG1a to fibronectin was completely inhibited by divalent cation chelat
ion and partially inhibited by RGDS peptides and chondroitinase ABC, s
uggesting that both alpha(4) beta(1) and alpha(5) beta(1) as well as C
D44 were responsible for this interaction. Adhesion to bone marrow str
omal and endothelial layers was superior to that to purified extracell
ular matrix components and tvas partially inhibited by divalent cation
chelation. RGD peptides and anti-alpha(4) monoclonal antibody also pa
rtially inhibited KG1a adhesion to bone marrow endothelium. Discordanc
e between cell adhesion molecule expression and adhesive behaviour sug
gest that current phenotypic descriptions remain incomplete and reinfo
rce the need for complementary functional binding studies.