Reactivity of a monoclonal antibody recognizing an estrogen receptor regulated glycoprotein in relation to lectin histochemistry in breast cancer

The lectin-binding sites for peanut agglutinin in invasive breast ductal carcinomas and their metastasis

Peanut agglutinin (PNA) lectin-binding site patterns in primary invasive breast ductal not otherwise specified (NOS) carcinomas are related to aggressiveness of the tumor. The present study was designed to compare the expression of PNA-binding sites in the primary tumor and in local lymph node metastases. The expression of lectin-binding sites was studied using the avidin-biotin complex/immunoperoxidase technique and analyzed in relation to age of the patient and size of the breast cancer. Breast cancers and their metastases showed negativity or positivity, the latter being divided into "apical" and "non-apical" (i.e. membrane and/or cytoplasmic) depending on the main localization of staining in tumor cells. No correlation was found between primary tumors and metastases as regards PNA-binding patterns, which confirms the opinion that advanced primary tumors are polyclonal and that selected subclones of malignant cells give rise to metastases. Furthermore, the fact that primary tumors with PNA non-apical expression, a feature related to aggressiveness and poor differentiation, may have lymph node metastases with apical expression, suggests that this pattern, although no longer evident in the primary tumor, is involved in the process of cell metastasis.

The lectin-binding sites for peanut agglutinin in invasive breast ductal carcinomas and their role as a prognostic factor

The present study was designed to analyze the expression of lectin-binding sites for peanut agglutinin (PNA) in paraffin sections of primary invasive ductal carcinoma not otherwise specified and to consider PNA lectin histochemistry as a further aid in the prognostic evaluation of breast cancer. The expression of lectin-binding sites was studied using the avidin-biotin complex/ immunoperoxidase technique, and analyzed in relation to the different clinical, pathological, and biological parameters of the primary disease, i.e. the presence or absence of nodal metastases, pre- or post-menopausal age, size of the tumor, mitotic activity index, morphometric prognostic index, DNA content, S-phase fraction, and steroid receptor status. The results show significant differences in PNA binding patterns among malignant epithelial breast cells. There was no expression of PNA-binding sites in 14 out of 157 tumors, while 64 showed mostly apical (membrane) staining and 124 non-apical (membrane and/or cytoplasmic) staining. Apical staining was mostly observed in patients without lymph node metastasis, with positive steroid receptor status, and those who were postmenopausal diagnosis; non-apical staining was mostly observed in lymph-node-positive premenopausal patients negative for steroid receptors and with aneuploid tumor cells. Our results indicate that, in malignant breast cells, there is an alteration of cell-surface glycoconjugates, shown by heterogeneity within a histopathologically defined group, which is related to different properties of tumor cells. The apical PNA binding pattern indicates a better differentiation of tumor cells while non-apical PNA binding suggests a higher metastatic potential. Specific PNA lectin binding patterns should be considered as a further reliable prognostic factor in breast cancer.

Peanut agglutinin binding to human prolactin-producing pituitary adenomas

Peanut agglutinin (PNA)-binding sites in human prolactin (PRL)-producing pituitary adenomas were examined by light and electron microscopy together with immunoblot analysis. At the light microscopic level, the majority of the PRL-producing adenoma cells stained positively for PNA in 15 of 20 cases. PNA binding observed in the cytoplasm had a granular appearance. PRL-producing cells adjacent to the adenoma tissue showed negative PNA staining. In normal pituitary glands, the PRL-positive glandular cells were negative for PNA staining. By electron microscopy, reaction products showing PNA-binding sites were detected in some of the secretory granules. Immunoblotting analysis revealed that the PRL bands corresponded to PNA-stained ones with the exception of the main 23-kDa band. PNA-binding sites have some relation to the secretory granules containing glycosylated forms of PRL. These observations suggest that PNA staining can be used as a valuable method to analyze human PRL-producing pituitary adenomas.

Peanut lectin: a histochemical marker for phaeochromocytomas

Fifty-five neuroendocrine tumours and 6 adrenocortical tumours were examined immunohistochemically for the expression of neuron-specific enolase (NSE), chromogranin and synaptophysin. The results were compared with the staining patterns obtained with peanut lectin (PNA) using a streptavidin-biotin staining technique. In separate experiments, sections were preincubated with neuraminidase for the demonstration of masked PNA binding sites. Two of the 24 phaeochromocytomas, 1 of the 6 medullary carcinomas of the thyroid gland, 5 out of the 7 islet cell tumours of the pancreas and all 4 extra-adrenal paragangliomas were negative with PNA. When the sections were first incubated with neuraminidase all these tumours were positive with PNA. Six adrenocortical tumours and 7 neuroblastomas were examined and found to be negative with PNA with or without neuraminidase pre-treatment. Seven carcinoid tumours were examined and found to be positive with PNA only in tubular areas and negative in solid areas; pre-treatment with neuraminidase did not alter the staining pattern. Immunoreactivity for NSE was absent in only 1 of the neuroendocrine tumours. A higher proportion of neuroendocrine tumours was positive with anti-chromogranin than with anti-synaptophysin.

A comparative study of histopathology, hormone receptors, peanut lectin binding, Ki-67 immunostaining, and nucleolar organizer region-associated proteins in human breast cancer

The current study was performed on 71 cases of human female breast cancer and compares the results of five morphologic methods developed for the detection of estrogen receptors (ER), progesterone receptors (PgR), lectin Peanut agglutinin (PNA) binding sites, monoclonal antibody Ki-67 immunoreactivity, and the mean number of argyrophilic nucleolar organizer regions (Ag-NOR). All the parameters were evaluated on serial cryostat sections representative of a closely related, if not identical, neoplastic population. A significant positive correlation was found between the occurrence of estrogen, progesterone, and peanut receptors and between Ki-67 immunoreactivity, mean number of NOR, and mitotic index. Furthermore, ER, PgR, and PNA receptors showed a significant, inverse correlation with Ki-67 immunoreactivity, mitotic index, and mean number of Ag-NOR. These results provide further data that support the hypothesis that (1) progesterone and PNA receptors are estrogen-induced and indicate a metabolic response of the target cells to functioning estrogen receptors; (2) the mean number of NOR reflects the cell kinetics of the tumor; and (3) metabolic differentiation of neoplastic cells is inversely correlated to the proliferation index.

Human milk fat globule antigen III D 5, steroid receptors and histopathologic parameters in breast cancer

Immunohistochemical reactivity of mammary carcinomas with the monoclonal human milk fat globule (HMFG) antibody III D 5, and the estrogen receptor (ER) and progesterone receptor (PR) status were compared with the histopathology of primary breast cancer. The reactivity with III D 5 has earlier been shown to be associated with the estrogen receptor status of tumours and with a favourable prognosis. The reactivity of tumours with III D 5, as well as the presence of ER and PR correlated significantly with the histological features of differentiation; histological grade, nuclear grade, tumour necrosis and lymphoid infiltration. Reactivity with III D 5 correlated with all these parameters, while the presence of ER did not correlate with the nuclear grade and that of PR correlated only with the nuclear grade and the lymphoid infiltration of tumours. Reactivity of III D 5 may thus have prognostic and therapeutic implications in the management of breast cancer.