HISTOCHEMICAL-DEMONSTRATION OF DIFFERENT TYPES OF POLY-N-ACETYLLACTOSAMINE STRUCTURES IN HUMAN THYROID NEOPLASMS USING LECTINS AND ENDO-BETA-GALACTOSIDASE DIGESTION
N. Ito et al., HISTOCHEMICAL-DEMONSTRATION OF DIFFERENT TYPES OF POLY-N-ACETYLLACTOSAMINE STRUCTURES IN HUMAN THYROID NEOPLASMS USING LECTINS AND ENDO-BETA-GALACTOSIDASE DIGESTION, Histochemical Journal, 27(8), 1995, pp. 620-629
Blood-group-related antigens expressed in papillary carcinomas and oth
er types of neoplasm of the human thyroid glands have been shown to be
carried by poly-N-acetyllactosamines containing a linear domain susce
ptible to endo-beta-galactosidase digestion. To make clear more precis
ely the backbone poly-N-acetyllactosamine structures, labelled lectins
specific to different types of these structures and specific to core
structures with beta 1-6GlcNAc branching of N- and O-linked glycoprote
ins were employed in conjunction with prior endo-beta-galactosidase di
gestion on formalin-fixed, paraffin-embedded neoplasms of the human th
yroid glands. Ln papillary carcinomas, Datura stramonium agglutinin (D
SA) and succinyl wheat germ agglutinin (Suc-WGA) reacted most consiste
ntly and frequently with papillary carcinomas from all the individuals
examined. Pokeweed mitogen (PWM) likewise stained the cells of papill
ary carcinomas from all the individuals examined, but in some individu
als the number of lectin-reactive cells were very small. Lycoperscion
esculentum aggultinin (LEA), Solanum tuberosum agglutinin (STA), Phase
olus vulgaris agglutinin L (PHA-L) and Artocarpus integrifolia aggluti
nin (jacalin) similarly bound to the cancer cells from most of the ind
ividuals, and in these cases the number of reactive cells was usually
much more restricted than was the case with DSA or PWM. Ln adenoma and
other types of carcinoma, such as follicular carcinomas, these lectin
s specific to poly-N-acetyllactosamine exhibited slight or no reactivi
ty with the cells, whereas PHA-L and jacalin similarly bound to the ce
lls of adenomas and carcinomas from most of the individuals examined.
Prior digestion with endo-beta-galactosidase completely eliminated or
markedly reduced the reactivity with PWM and LEA in papillary carcinom
as. Reactivity with DSA, Suc-WGA, STA, PHA-L and jacalin was slightly
reduced or not at all affected by Enzyme digestion. These results conf
irmed that poly-N-acetyllactosamine species found in papillary carcino
mas are quite different from those in other types of thyroid neoplasm,
suggesting that at least three different types of poly-N-acetyllactos
amine, that is, linear unbranched short and long sequences and highly
branched ones are produced in these cells.