A. Gangopadhyay et al., DIFFERENTIAL EXPRESSION OF ALPHA-2,6-SIALYLTRANSFERASE IN COLON TUMORS RECOGNIZED BY A MONOCLONAL-ANTIBODY, Hybridoma, 17(2), 1998, pp. 117-123
Citations number
32
Categorie Soggetti
Immunology,"Biothechnology & Applied Migrobiology","Biochemical Research Methods
It has been reported that alpha 2,6-sialyltransferase (alpha 2,6-ST; E
.C. 2.4.99.1) activity is associated with cellular differentiation. To
define its role in colon carcinoma differentiation, we have generated
murine monoclonal antibodies (MAb) against alpha 2,6-sialyltransferas
e. The MAb, designated 6B9 of IgM isotype, showed strong reactivity wi
th the purified and crude alpha 2,6-ST by ELISA and dot blot assays. W
estern blotting with MAb 6B9 identified purified alpha 2,6-ST of MW 47
kDa and the same MW protein from rat and human liver extracts. The MA
b also reacted with two other liver proteins of approximate MW 65 and
100 kDa, Immunoperoxidase studies with formalin-fixed paraffin-embedde
d tissues showed that MAb 6B9 reacts with liver tissues, the staining
of hepatocytes was granular and cytoplasmic, There was a distinct patt
ern of zonal distribution of this enzyme in hepatocytes located partic
ularly in the portal areas of the liver corresponding to zone 1, Norma
l colon (100%) and hyperplastic polyps (100%) showed very weak to no r
eactivity, Adenomas (100%) demonstrated moderate reactivity, while the
poor (33%), moderate (100%) and well-differentiated (80%) colon adeno
carcinomas showed strong reactivity, Results suggest that alpha 2,6-ST
is associated with the differentiation state of colon tumors.