W. Debinski et al., Receptor for interleukin 13 is abundantly and specifically over-expressed in patients with glioblastoma multiforme, INT J ONCOL, 15(3), 1999, pp. 481-486
We have recently documented that the vast majority of patients with gliobla
stoma multiforme (GBM) over-express a receptor (R) for interleukin 13 (IL13
) in situ. We have now evaluated further the degree of relative specificity
of the binding of IL13 to GEM when compared with other growth factor recep
tors. Tumor samples of 11 patients with CEM, 7 various normal brain samples
, and several cell lines in culture were examined. Same patient tissue sect
ions were incubated with I-125-labeled: IL13, monoclonal antibody HB21 agai
nst human transferrin (Tf) receptor, epidermal growth factor (EGF), and an
IL4 antagonist, IL4.Y124D. All 11 GBMs stained specifically, densely, and r
elatively homogeneously for both IL13R and TW. Seven GEM specimens showed s
pecific binding for I-125-EGF, but it was less homogeneous when compared wi
th IL13R or TfR. Two of the GBMs studied demonstrated extremely high densit
y of the EGFR. Furthermore, we did not detect significant presence of the I
L4R in the studied GEM specimens in situ. All sections of nonmalignant brai
n tissues examined showed avid binding by the TfR with lack of consistent a
nd specific binding of I-125-IL13 or -EGF. Thus, it appears that the GEM-as
sociated IL13R is considerably more specific to GEM that the one for Tf and
more frequently and homogeneously expressed than the EGFR. These results r
ender further support for the hIL13R being a new unique candidate for deliv
ery of variety of anti-GBM therapies.