Differences in tetranectin immunoreactivity between benign and malignant breast tissue

Summary Tetranectin (TN) is a human, plasminogen kringle 4 binding plasma protein with ubiquitous cellular distribution and lectin-like characteristics. By means of the peroxidase-antiperoxidase staining technique a polyclonal and a monoclonal antibody were used to demonstrate TN within the intracellular as well as the extracellular compartment of invasive breast carcinoma. Whereas cell associated TN was universal showing only quantitative differences depending of the growth pattern of the tumor, 78 of 133 tumors displayed TN extracellularly as well. The occurrence of this stromal TN immunoreactivity was closely associated with desmoplasia, recognized morphologically by an increase in fibroblastic cells and immunohistochemically by an intense staining for the connective tissue glycoprotein fibronectin (FN). Benign breast tissue displayed a universal, intense cytoplasmic but no extracellular reaction for TN, with the exception of rare foci of granulation tissue and around dilated cysts. Functional studies have shown that human embryonal lung fibroblasts increase their release of TN to the growth medium upon stimulation. The presence of TN extracellularly within fibroblast-rich foci of desmoplasia (and granulation tissue) suggests that a similar increased release of the protein takes place in vivo during active states. Desmoplasia has been found to have a protective effect on tumor cell propagation and metastasis in a murine model. The molecular interactions, which are responsible for this effect, are undoubtedly complex. However, TN may, by its specific binding to kringle 4 of plasminogen and its high affinity for sulphated polysaccharides, add to the understanding of how plasminogen activation is modulated at the local extracellular level.     

Differences in tetranectin immunoreactivity between benign and malignant breast tissue.

Tetranectin (TN) is a human, plasminogen kringle 4 binding plasma protein with ubiquitous cellular distribution and lectin-like characteristics. By means of the peroxidase-antiperoxidase staining technique a polyclonal and a monoclonal antibody were used to demonstrate TN within the intracellular as well as the extracellular compartment of invasive breast carcinoma. Whereas cell associated TN was universal showing only quantitative differences depending of the growth pattern of the tumor, 78 of 133 tumors displayed TN extracellularly as well. The occurrence of this stromal TN immunoreactivity was closely associated with desmoplasia, recognized morphologically by an increase in fibroblastic cells and immunohistochemically by an intense staining for the connective tissue glycoprotein fibronectin (FN). Benign breast tissue displayed a universal, intense cytoplasmic but no extracellular reaction for TN, with the exception of rare foci of granulation tissue and around dilated cysts. Functional studies have shown that human embryonal lung fibroblasts increase their release of TN to the growth medium upon stimulation. The presence of TN extracellularly within fibroblast-rich foci of desmoplasia (and granulation tissue) suggests that a similar increased release of the protein takes place in vivo during active states. Desmoplasia has been found to have a protective effect on tumor cell propagation and metastasis in a murine model. The molecular interactions, which are responsible for this effect, are undoubtedly complex. However, TN may, by its specific binding to kringle 4 of plasminogen and its high affinity for sulphated polysaccharides, add to the understanding of how plasminogen activation is modulated at the local extracellular level.     

Association between estradiol, estrogen receptors, total lipids, triglycerides, and cholesterol in patients with benign and malignant breast tumors

This study addresses the correlation between the levels of estradiol (E₂), total lipids, triglycerides, and cholesterol in serum and tissue samples of age-matched patients with benign (40 cases; 16 were premenopausal and 24 were postmenopausal) and malignant (50 cases; 17 were premenopausal and 33 were postmenopausal) breast tumors. Estradiol levels were determined in serum and cytosol, estrogen receptors (ER) were assayed in cytosol, and total lipids, triglycerides and cholesterol were determined in serum and membrane fractions of all benign and malignant breast disease patients. Serum E₂ was significantly higher in malignant cases than benign ones (P<0.05) with a significant reduction (40%) in postmenopausal than premenopausal women. ER-positive tumors were significantly higher in postmenopausal women with malignant breast tumors than benign cases (P<0.05). Tissue levels of total lipids, triglycerides, and cholesterol were highly significantly increased in breast cancer women than women with benign breast diseases (P<0.05, P<0.005 and P<0.05 respectively) and they were also significantly correlated with estradiol levels. It could be concluded that the uptake of lipids from plasma by the tumor tissue is greatly correlated to estradiol and it may confirm the possible role of lipids as risk factor in breast cancer.     

Micronuclei level in exfoliated buccal mucosa cells of patients with benign and malignant tumors of female reproductive organs and breast

Micronucleus (MN) levels in exfoliated buccal mucosa cells of primary breast, cervix and corpus uteri cancer patients, and patients with benign tumors of uterus (myoma) and breast (fibroadenoma) were studied. Significantly increased number of MN in cells of cancer patients was observed compared to both healthy persons and patients with benign tumors. In patients with benign tumors no increase in MN quantity was observed. The evaluation of MN number in buccal mucosa cells shows genomic instability caused by malignant tumor in somatic cells of humans.     

Oxidant/antioxidant status in blood of patients with malignant breast tumour and benign breast disease

The aim of this study was to investigate the alterations in lipid peroxidation and antioxidant enzyme defences in the blood of patients with malignant breast tumour and benign breast disease. Forty patients with malignant breast tumour, 20 patients with benign breast disease and also 20 healthy control subjects were recruited for the study. Malondialdehyde levels in plasma and erythrocytes, and the activities of erythrocyte CuZn-superoxide dismutase, catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase were measured. Malondialdehyde levels were higher in patients with both benign breast disease and malignant breast tumour compared with control subjects. The activities of all antioxidant enzymes were higher in patients with malignant breast tumour, while only glutathione peroxidase and CuZn-superoxide dismutase activities were higher in patients with benign breast disease. Except for glucose-6-phosphate dehydrogenase, the antioxidant enzymes studied correlated positively with the malondialdehyde levels in patients with malignant breast tumour. On the other hand, only glucose-6-phosphate dehydrogenase activity was increased by the level of malignancy. The activity increases in erythrocyte antioxidant enzymes may be a compensatory upregulation in response to increased oxidative stress especially in patients with malignant breast tumour.     

Assessment of VEGF and VEGF receptor concentrations in patients with benign and malignant thyroid tumors

Neoangiogenesis is a significant event in a cascade of growth and progression of solid tumors. Assessment of the tissue expression and measurement of the concentrations of angiogenic and antiangiogenic factors, contributing to this process, in body fluids, can be used not only for an early diagnosis of tumors and their staging but also as an important parameter of treatment efficiency evaluation. The aim of this study is to evaluate the concentrations of crucial angiogenic cytokine VEGF and its soluble receptors in peripheral blood of patients with benign and malignant thyroid tumors. The study comprised 35 patients with thyroid cancer and 10 patients with follicular neoplasm, both diagnosed by means of ultrasound-guided fine-needle aspiration biopsy. For these patients surgical treatment was instituted. The examined angiogenic factors were determined preoperatively and 4 weeks after the surgical procedures. The results were compared with the control group which comprised 10 healthy individuals. Analysing obtained results, we demonstrated high VEGF concentrations and low soluble VEGF receptor concentrations in patients with benign and malignant thyroid tumors. This fact confirms a vital role of VEGF in angiogenesis of thyroid tumors and a hypothetical antiangiogenic activity of its soluble receptors. Disequilibrium of the above-mentioned angiogenic factor concentrations is probably essential for the growth and progression of benign and malignant thyroid tumors.     

Expression of the apoptosis-inducing ligands FasL and TRAIL in malignant and benign human breast tumors

Apoptosis-inducing ligands such as Fas ligand (FasL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) have been found to play an important role in cell regulation. Different malignant tumors show an altered expression of these ligands and their respective receptors compared to normal tissues. The purpose of this study was therefore to investigate expression of TRAIL, FasL, and its receptor Fas on protein and mRNA levels in breast carcinomas (n=40), fibroadenomas (n=7), and normal breast tissues (n=5). Immunohistochemical reaction demonstrated that FasL was strongly expressed in breast cancer tissues (34/40) while only one fibroadenoma and one normal breast tissue reacted weakly positive for FasL. All fibroadenomas and normal breast tissues as well as the majority of breast cancer tissues expressed Fas on protein level. Quantitative RT-PCR analysis detected high expression of FasL mRNA in breast cancer tissues and fibroadenomas, whereas fibroadenomas showed the highest Fas mRNA copy numbers, followed by breast cancer tissues and normal breast tissues (P<0.05). Compared to FasL expression, TRAIL could be detected in less breast cancer tissues on protein level (21/40) and was found in only one fibroadenoma and none of the normal breast tissues. Thus, it can be concluded that malignant breast tumors show an altered expression of the two apoptosis-inducing ligands FasL and TRAIL. Accepted: 4 January 2000     

Induction of malignant and benign tumors with embryonic tissues.

The inoculation of viruses into the placenta of fetectomized rats induces the development of malignant tumors from extraembryonic fetal membranes. The same membrane--visceral yolk sac--gives rise to benign teratomas if displaced outside the uterus after fetectomy. Moreover, the transplantation of 3 to 7 day old embroys under the kidney capsule of adult mice gives rise of malignant teratocarcinoma. The methods to induction of these tumors are described.     

Chromosome analysis in 31 cases of benign and malignant breast tumors: a study in Brazil

Cultures of 31 breast tumors, being 20 carcinomas and 11 benign lesions, were cytogenetically analysed. Clonal chromosome aberrations were detected in 16 carcinomas and in 4 benign lesions. Nine carcinomas and 2 benign lesions had multiple cytogenetically unrelated and related clones, whereas a single abnormal clone was observed in 7 carcinomas and in 2 benign lesions. Polyploid clones were found in 7 carcinomas and in 2 benign lesions. The presence of clonal chromosome aberrations and polyploid cells was not associated with the clinicopathologic parameters tested. Carcinomas had more clonal changes than benign lesions (p = 0.031), showing that cytogenetic features are of diagnostic value and that different chromosome anomalies might have different pathogenetic and prognostic significance.     

Localization of decorin gene expression in normal human breast tissue and in benign and malignant tumors of the human breast

The small extracellular matrix proteoglycan decorin which possesses a potent antitumor activity has been shown to be present in various amounts in the stroma of several tumors including those of the breast. Regarding decorin in breast malignancies the published data are conflicting, i.e., whether breast cancer cells express it or not. Here, we first compared decorin gene expression levels between healthy human breast tissue and selected types of human breast cancer using GeneSapiens databank. Next, we localized decorin mRNA in tissue specimen of normal human breast, intraductal breast papillomas and various histologic types of human breast cancer using in situ hybridization (ISH) with digoxigenin-labeled RNA probes for decorin. We also examined the effect of decorin transduction on the behavior of cultured human breast cancer MCF7 cells. Analysis of GeneSapiens databank revealed that in various human breast cancers decorin expression is significant. However, ISH results clearly demonstrated that human breast cancer cells independently of the type of the cancer do not express decorin mRNA. This was also true for papilloma-forming cells of the human breast. Indeed, decorin gene expression in healthy human breast tissue as well as in benign and malignant tumors of human breast was shown to take place solely in cells of the original stroma. Decorin transduction using decorin adenoviral vector in decorin-negative MCF7 cells resulted in a significant decrease in the proliferation of these cells and changed cell cohesion. Decorin-transduced MCF7 cells also exhibited increased apoptosis. In conclusion, our study shows that in human breast tissue only cells of the original stroma are capable of decorin gene expression. Our study also shows that transduction of decorin in decorin-negative human breast cancer cells markedly modulates the growth pattern of these cells.     

Studies on the changes in plasma lipids and lipoproteins in patients with benign and malignant breast cancer

Experimental studies and epidemiological data suggest that, high fat diet increases the risk of developing breast cancer, both in animal and in human population. Cases of postmenopausal, untreated women with malignant and benign breast tumors, were compared for their age, body weight, plasma lipid fractions and lipoproteins. There was a significant increase in body weight, total plasma lipids, total cholesterol, LDL--cholesterol, VLDL--cholesterol, phospholipids, triacylglycerols, free fatty acids in malignant breast cancer patients. HDL--cholesterol had been significantly decreased in benign and malignant patients when compared with the control subjects.     

Promoters of genes MTHFR from patients with hyperhomocysteinemia and PTEN from patients with malignant and benign endometrial and ovarian tumors

Mutational changes in the promoter regions of MTHFR genes from patients with hyperhomocysteinemia and PTEN genes from patients with endometrial and ovarian tumors were studied. An increased level of homocysteine was found in a part of the patients with a heterozygous C677T mutation in the MTHFR gene, although a moderate hyperhomocysteinemia is usually associated with homozygous mutation. We hypothesized that, in this case, the allele lacking the C677T mutation may be inactivated by the promoter mutation. The sequencing of both DNA strands of the minimal promoter region of the MTHFR gene in ten patients did not reveal any mutation, which implied another mechanism of the development of hyperhomocysteinemia in these patients. A PCR analysis of the minimal promoter region of the tumor suppressor PTEN in the presence of 2-pyrrolidone in 101 patients from Moscow clinics revealed changes in it in patients with endometrial (56%) or ovarian (29%) cancer, as well as in patients with endometrial hyperplasia and benign ovarian tumors (34 and 29%, respectively). It was presumed that the found modification of PTEN gene promoters may arise from epigenetic alterations (erroneous methylation) or may (more rarely) be induced by mutations. As a result of the studies, new molecular markers associated with endometrial and ovarian tumors were revealed and a simple and effective method of detection of these markers was developed.     

Promoters of genes MTHFR from patients with hyperhomocysteinemia and PTEN from patients with malignant and benign endometrial and ovarian tumors

Mutational changes in the promoter regions of MTHFR genes from patients with hyperhomocysteinemia and PTEN genes from patients with endometrial and ovarian tumors were studied. An increased level of homocysteine was found in a part of the patients with a heterozygous C677T mutation in the MTHFR gene, although a moderate hyperhomocysteinemia is usually associated with homozygous mutation. We hypothesized that, in this case, the allele lacking the C677T mutation may be inactivated by the promoter mutation. The sequencing of both DNA strands of the minimal promoter region of the MTHFR gene in ten patients did not reveal any mutation, which implied another mechanism of the development of hyperhomocysteinemia in these patients. A PCR analysis of the minimal promoter region of the tumor suppressor PTEN in the presence of 2-pyrrolidone in 101 patients from Moscow clinics revealed changes in it in patients with endometrial (56%) or ovarian (29%) cancer, as well as in patients with endometrial hyperplasia and benign ovarian tumors (34.6 and 29%, respectively). It was presumed that the found PTEN gene promoters may arise from epigenetic alterations (erroneous methylation) or may (more rarely) be induced by mutations. As a result of the studies, new molecular markers associated with endometrial and ovarian tumors were revealed and a simple and effective method of detection of these markers was developed.     

Keratin polypeptide distribution in benign and malignant breast tumors: subdivision of ductal carcinomas using monoclonal antibodies

Monoclonal antibodies which recognize one or only a few keratin polypeptides have been used to study the distribution of different keratins in benign and malignant breast lesions by immunocytochemical methods. Seven monoclonal antibodies which recognized either different keratin polypeptides by immunoblotting techniques, or identified different epithelial cell types in complex tissues were used. In two mastopathies and three fibroadenomas the antibody lu5 stained luminal cells as well as myoepithelial cells. In contrast the antibodies CK7, Troma 1, CK2 and KA4 labeled only luminal cells, whereas antibody CKB1 decorated only myoepithelial cells. All 15 ductal carcinomas showed a uniform staining of tumor cells with the antibodies Troma 1, CK2, KA4 and lu5. The antibody CK7 also stained all ductal carcinomas, but in two specimens the staining was heterogeneous. The antibody CKB1 decorated only the pre-existing myoepithelial cells in 11 of 12 ductal carcinomas but in the remaining specimen the tumor cells were also strongly positive. Tumor cells in lobular carcinomas were labeled by antibodies CK7, Troma 1, CK2, KA4, bu not by CKB1. The antibody CKS1 showed no staining of any of the benign and malignant breast lesions.