On the basis of their known fine specificities
we evaluated the immunohistochemical marker qualities
of two monoclonal antibodies (mabs) defining the
tumor-associated TF disaccharide GalBl-3GalNAc. This
antigen is expressed in certain tumors in correlation with
prognosis and metastasis. The reactivity of one of these
mabs (A78-G/A7) depends on clustered TF disaccharides
(glycosylation at vicinal Ser~Thr positions)
while the other - rnab BW835 - has been characterized to
bind specifically to TF disaccharide linked to a motif
within the MUCl repeat. Therefore, rnab BW835
represents an interesting tool for the identification of
tumor-associated glycoforms of MUC1, which are
involved in tumor progression and metastasis, but also in
the recognition of tumor cells by cytotoxic T cells.
As references the TF-binding lectins from peanut
(PNA) and Arrocarpus integrifolia (jacalin) were
applied. The binding patterns of these immunoreagents
were strikingly distinct. Mab BW835 showed a
significantly stronger reactivity than rnab A78-G/A7,
especially in gastric, mammary, pancreatic, thyreoideal,
renal and bladder carcinomas. PNA and jacalin receptors
exhibited an expression in the majority of all cancer
types, with the exception of seminoma and glioblastoma/
sarcoma. These results can be explained by the
broader fine specificities of the lectins. Furthermore, a
strong expression of MUC1-bound TF antigen is
indicated by the staining pattern of rnab BW835. The
marker qualities of both antigens, TF and MUC1, are
combined in the binding specificity of BW835, and
hence this antibody may have a high impact for the
immunodetection of these tumor-associated antigens
