Binding of fluorescein isothiocyanate conjugated lectins to MXT mouse mammary neoplasm and their relation to steroid receptor status.

As previous studies have suggested a hormone dependence of binding sites for peanut agglutinin in mammary neoplasm, this feature has been thought to be correlated to steroid receptor status. The present investigation was undertaken on a well-established ovarian-dependent cancer model in order to check this hypothesis. Sections of primitive tumor transplants as well as of tumors induced in vivo by injection of cell clones were analyzed with the use of three fluorescent lectins. The lectin binding sites were evaluated semi-quantitatively and compared with estrogen and progesterone receptor levels. Using non-parametric statistical tests, the results revealed a strong correlation between the expression of peanut agglutinin (PNA) binding sites and steroid receptor status, but only in primitive tumor transplants. No such correlation was observed in tumors induced in vivo, by injection of cell clones. No correlation between the steroid receptor status and the two other lectins (Concanavalin A and Dolichos biflorus) was observed. These data suggest that PNA can be used as a valuable histochemical tool in steroid hormone dependence study.