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Biomedical subjects

V Castronovo

Publications and source records attributed to V Castronovo.

At least 91 records · Page 5Linked to original sources
PubMed1996

Detection of bone sialoprotein in human breast cancer tissue and cell lines at both protein and messenger ribonucleic acid levels.

The recent demonstration that bone sialoprotein (BSP) can be detected in human breast cancer tissue by immunoperoxidase suggests that this phosphoprotein is ectopically expressed by malignant mammary epithelial cells. Its detection in human breast cancer cells raises questions about its potential role(s) during breast cancer progression. Because BSP is secreted and is present in the serum, the positivity of breast cancer cells for BSP could have been the result of an uptake of the circulating phosphoprotein by the cells rather than of an intrinsic expression. We examined the expression of BSP at both the protein and mRNA levels in nine human breast cancer samples as well as in three human breast cancer cell lines (MCF-7, T47-D, and MDA-MB-231) using immunohistochemistry, flow cytometric analysis, immunoblot, and reverse-transcriptase PCR. BSP was detected at both protein and mRNA levels in human breast cancer tissue and in the three human breast cancer cell lines. Using a specific polyclonal anti-BSP antibody, we showed by both fluorescence-activated cell sorter analysis and immunohistochemistry experiments that all of the human breast cancer cell lines studied express BSP. This was localized at the cell surface and in the cytosol of the estrogen receptor-positive MCF-7 and T47-D cell lines, whereas it was detected only in the cytosol of the estrogen receptor-negative MDA-MB-231 cells. Using the same polyclonal anti-BSP antibody, we were able to identify an approximately 97-kd band on total protein extracts from the three cell lines by immunoblotting. Reverse-transcriptase PCR reactions using specific oligonucleotides performed on total RNA of nine human breast cancer biopsy samples and the three cell lines demonstrated the presence of BSP mRNA in all of the samples examined. This study is the first demonstration that human malignant breast epithelial cell lines express BSP at the protein and mRNA levels. Our study identified MCF-7, T47-D, and MDA-MB-231 cells as useful models for the examination of the molecular mechanisms involved in the ectopic expression of BSP in breast malignant lesions.

Base Sequence↗
PubMed1996

A possible role for the alpha 1-->3 galactosyl epitope and the natural anti-gal antibody in oncogenesis.

Glycoconjugates and their antibodies are vital components of host-tumor interaction. This review concentrates on the oncological implications of research concerning the alpha gal triad; the alpha 1-->3 galactosyl epitope (alpha Gal), the enzyme responsible for its construction, alpha 1,3 galactosyl transferase (alpha 1-3GT), and its associated antibody: anti-gal. Alpha gal epitopes, previously assumed to be absent from human tissue, have been demonstrated on several human cancer cell lines, senescent red blood cells, and Graves' disease thyrocytes. Alpha-gal presence on neoplastic lines is correlated with increased metastatic formation in animal models. The mechanisms of human response to these neoantigens are complex, as natural anti-gal antibodies exist in high titers in normal sera, thus predicting immunological recognition of cells expressing alpha gal epitopes. Hypotheses vary regarding the pathogenic contributions of metastasis-associated phenomena such as de novo expression of alpha gal and its unmasking by desialylation. The means by which alpha gal is sporadically expressed in human tissue remain unknown, as the galactosyl transferase which produces this epitope in constitutively expressive animals has undergone significant mutation at the genomic level in humans. Pathological re-expression is presumed to require permissive changes at a cellular level. Detailing these alterations is a prerequisite to the comprehension of the metastatic phenotype. In this context, the possibility of therapeutic strategies affecting alpha gal expression are also discussed.

Animals↗
PubMed1996

Expression of the Mr 67,000 laminin receptor is an adverse prognostic indicator in human thyroid cancer: an immunohistochemical study.

Increased expression of the Mr 67,000 laminin receptor (LR) is a consistent event which appears as cancer cells acquire an invasive and metastatic phenotype. The Mr 67,000 LR is one of the many laminin-binding proteins able to interact with the major glycoprotein of basement membranes, laminin. The recent development of a specific monoclonal antibody directed against the Mr 67,000 LR MLuC5 has allowed us to study large retrospective groups of human cancers with the aim of correlating the Mr 67,000 LR expression to the clinical, pathological, and survival data of the patients. A significant correlation has already been established between the increased expression of Mr 67,000 LR and survival of patients with breast, colon, ovary, lung, and endometrial cancers. In this study, we investigated the possibility that the detection of Mr 67,000 LR in thyroid human cancers could also be of prognostic value. We analyzed the expression of Mr 67,000 LR with immunohistochemistry using MLuC5 antibodies in paraffin sections of 40 benign and 170 malignant thyroid human tumors. We found that Mr 67,000 LR was not usually detectable in normal thyroid tissues adjacent to the lesion. Only 3 of the 40 thyroid adenomas examined (7.5%) presented cells positive for Mr 67,000 LR. For the malignant thyroid tumors examined, we found that 22.3% of papillary thyroid carcinomas, 38% of follicular thyroid carcinomas, 40% of poorly differentiated carcinomas, 25% of medullary carcinomas, and 58.3% of anaplastic carcinomas expressed a high level of Mr 67,000 LR. Although no correlation between the Mr 67,000 LR expression and survival was found in patients with follicular thyroid carcinomas, papillary thyroid carcinomas, anaplastic carcinomas, and medullary carcinomas, there was a significant correlation in primary thyroid cancers. Our data represent the first extensive study of the Mr 67,000 LR expression in human thyroid cancers and strongly suggest that its detection could be of prognostic value in the investigation of primary thyroid cancers.

Adult↗
PubMed1995

Highly-expressed p100/p52 (NFKB2) sequesters other NF-kappa B-related proteins in the cytoplasm of human breast cancer cells.

Several observations have suggested that NF-kappa B transcription factors could be involved in carcinogenesis. To investigate the possibility that members of the NF-kappa B family participate in the molecular control of the transformed phenotype, we examined the expression of these proteins in human breast cancer cell lines as well as in primary tumors. Western Immunoblots demonstrated high expression of the p52 precursor p100 (NFKB2) in several breast cancer cell lines while human mammary epithelial cells express this protein only faintly. Eighteen primary breast tumors out of 24 displayed significant expression of the p100/p52 protein. In MDA-MB-435 cells, overexpressed p100 and p52 are predominantly cytoplasmic and coimmunoprecipitation experiments demonstrated that p100 sequesters the heterodimer p50/p65 in the cytoplasm. We demonstrate that most p65 protein is complexed with p100 in these cells while it is complexed predominantly with I kappa B-alpha in cell lines expressing less p100. Our data strengthen the hypothesis that NF-kappa B could be involved in carcinogenesis and suggest that the p100/p52 NF-kappa B subunit could play a role in the development of human breast cancers, possibly by sequestering other NF-kappa B-related proteins in the cytoplasm.

Adenocarcinoma↗
PubMed1995

Retinoic acid induces three newly cloned HOXA1 transcripts in MCF7 breast cancer cells.

Coordinated expression of genes involved in development, differentiation and malignant transformation is regulated by transcription factors including homeodomain-containing proteins. However, most of their cDNA sequences are still unknown. We report here the molecular characterization of three newly cloned HOXA1 transcripts from human breast cancer cells. In addition, we provide evidence that these alternatively spliced transcripts encode one homeodomain-containing protein and two products lacking the conserved DNA-binding domain. Moreover, we demonstrate that all three HOXA1 transcripts are induced by retinoic acid in MCF7 cells. Taken together, our results suggest that HOXA1 gene may be a key element in the establishment of the breast cancer cell phenotype.

Actins↗
PubMed1995

Galectin-1 modulates human melanoma cell adhesion to laminin.

Galectins constitute a gene family of beta-galactoside-specific lectins that show high homology in their carbohydrate-binding site. They have been postulated to be involved in many biological events, but their specific functions are not yet well defined. Galectin-1 is a laminin binding protein that recognizes poly-N-acetyllactosamine chains on this major basement membrane glycoprotein. In this study, we analyzed the possibility that galectin-1 could modulate interactions between human melanoma cells and laminin. We demonstrated that A375 and A2058 cell lines express galectin-1 both intracellularly and on the cell surface. In an in vitro assay, recombinant galectin-1 increased melanoma cell attachment to laminin in a dose-dependent manner. This effect was abolished by lactose. Anti-galectin-1 inhibited adhesion of melanoma cells to laminin in a dose-dependent fashion. However, neither galectin-1 nor anti-galectin-1 antibody affected melanoma cell spreading on laminin in vitro. These data indicate that galectin-1 might participate in melanoma cell adhesion to laminin and therefore could be a modulator of invasion and metastasis.

Cell Adhesion↗
PubMed1995

Tamoxifen and its active metabolite inhibit growth of estrogen receptor-negative MDA-MB-435 cells.

Tamoxifen (TAM), the non-steroidal anti-estrogen most widely administered to breast cancer patients, acts, at least in part, by competing with estrogen receptors (ER). However, the existence of an alternative mechanism of action for this drug is supported by the clinical observations that: (a) 30% of patients with ER-negative cancer cells respond to TAM, and (b) 30% of patients with ER-positive cancer cells are not sensitive to this anti-estrogen. In this study, we observed that growth of the human ER-negative breast cancer cell line MDA-MB-435 was inhibited by TAM and 4-hydroxytamoxifen (4OH-TAM) in a concentration-dependent fashion. Both monoclonal enzymoimmunoassay and Dextran Charcoal Coated Scatchard radioimmunoassay analysis demonstrated that this MDA-MB-435 cell line does not express ER. The absence of ER in MDA-MB-435 cells was also demonstrated at the mRNA level by both northern blot hybridization and reverse transcription-polymerase chain reaction techniques. MDA-MB-435 cell proliferation was not affected by 17 beta-estradiol or by the pure anti-estrogen ICI 164384, further demonstrating that the observed effects of TAM and its active metabolite on the proliferation of MDA-MB-435 cells were due to an ER-independent mechanism, yet to be identified. MDA-MB-435 thus appears to be a promising original model for the study of the alternative ER-independent mechanisms of action of TAM.

Breast Neoplasms↗
PubMed1995

Expression of the monomeric 67-kd laminin-binding protein in human lymphomas as defined by MLuC5 monoclonal antibody and paraffin section immunohistochemistry.

Interactions between cancer cells and laminin, a major component of basement membranes, are mediated through a large variety of cell surface proteins designated as laminin receptors. Among the above proteins, a 67-kd monomeric high affinity laminin receptor (67 LR) has long been suspected to be involved in tumor progression. In this study we wished to establish whether the 67 LR molecule is detectable on tumor cells of Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHLs), to define its pattern of expression, and to assess the potential utility of 67 LR in differentiating these pathological entities. Morphological and immunohistological studies were performed on 85 specimens of HD and a series of 334 NHL specimens, including anaplastic large cell (ALC) (CD30-positive) lymphomas (73 specimens). For immunohistochemical assessment of the 67 LR we used the monoclonal antibody (MoAb) MLuC5 directed against the 67-kd laminin receptor on paraffin-embedded sections. Reed-Sternberg cells reacted with MLuC5 MoAb in four of 85 (4.7%) HD specimens. Among the NHL specimens, a MLuC5-positive reaction was expressed in 3.3% of B-cell lymphomas. They all belonged to the high grade subtypes. On the other hand, a MLuC5-positive reaction was detected in none of the T-cell lymphomas tested. In contrast to the results obtained with the other NHLs, in 30.2% of ALC (CD30-positive) lymphoma specimens, tumor cells reacted with MLuC5 MoAb. MLuC5-expressing ALC (CD30-positive) lymphoma cells were of either T-cell (six of 17 specimens), B-cell (three of 25 specimens), or undetermined phenotype (10 of 31 specimens). Our investigation has shown that 67 LR as shown by MLuC5 MoAb is detectable only in neoplastic cells of a fraction of ALC (CD30-positive) lymphomas and small subsets of B-cell high grade NHLs and HD. The restricted expression of the 67 LR molecule to ALC (CD30-positive) lymphomas provides a potential tool for the phenotypic separation of this pathological entity from HD and other lymphomas. Whether the detection of the 67 LR expression in these lymphoma subsets may be related to the aggressiveness of the disease remains to be ascertained.

Antibodies, Monoclonal↗
PubMed1995

Snoring in twins.

Snoring is a prerequisite for obstructive sleep apnoea (OSA) and is known to run in families. Recent studies have provided sufficient evidence for a familial predisposition to OSA. In our study, 492 monozygotic and 284 dizygotic twins were contacted by telephone and asked to attend an interview which included questions of life habits, medical history, sleep habits and disorders, with particular emphasis on snoring. Our study showed that the probandwise concordance rate for habitual snoring was higher in monozygotic twins than in dizygotic ones, but the difference was not significant. The comparison of concordant pairs for habitual snoring vs. concordant pairs for non-snoring confirmed that habitual snoring is significantly associated with older age, male gender, higher body mass index (BMI), smoking and respiratory diseases. The multivariate analysis in the discordant groups confirmed that BMI is more strongly associated to habitual snoring in dizygotic twins than in the monozygotic ones. Our logistic analysis showed that other variables, such as smoking and respiratory diseases, are associated with habitual snoring in dizygotic pairs, but not in monozygotic ones. These findings suggest a genetic predisposition to habitual snoring.

Age Factors↗
PubMed1995

[Epithelial cancers of the ovary. Recent trends].

Ovarian carcinomas constitute the major cause of the mortality and morbidity in gynaecology. Most ovary carcinomas are epithelial tumours. Our understanding of ovarian cancerogenesis has been hampered by the lack of a well defined precursor lesion, the lack of knowledge about tumour progression, and by the relative inaccessibility of the ovaries in the abdominal cavity. Recent studies using experimental models allow us to better define the fundamental mechanisms of carcinogenesis from the serous ovarian cells and of invasion of the abdominopelvic cavity by proximity. This review article tries to update on epidemiology, genetic syndromes, biology, screening, and therapy of these epithelial tumours, and about the new directions taken by basic and clinical research. We will present data concerning oncogenes and tumour suppressor genes involved in epithelial ovarian tumours, regulation of tumour cells by growth factors, genes involved in tumour invasion, and mechanisms used by the cancer cell to resist to therapies. Non-epithelial ovarian tumours will not be examined in this manuscript.

Biomarkers, Tumor↗
PubMed1995

Increased expression of osteonectin and osteopontin, two bone matrix proteins, in human breast cancer.

Microcalcifications are a common phenomenon associated with breast cancer and are often the only mammographic sign of a malignant breast disease. Although microcalcifications are not restricted to breast cancer and can be also associated with benign lesions, it is noteworthy that they are composed exclusively of hydroxyapatite in breast carcinoma. Hydroxyapatite is the bone-associated phosphocalcic crystal the deposition of which in bone tissue requires the coordinated expression of several molecules such as osteonectin (OSN) and osteopontin (OPN), synthesized by cells of the osteoblastic lineage. In this study, we evaluated the expression of these two bone matrix proteins, using an immunoperoxidase technique and specific antibodies, in 79 breast lesions including 28 benign and 51 cancerous specimens. We found that normal mammary tissue associated with the lesions examined expressed generally undetectable or lightly detectable (0 or 1+) amounts of OSN and OPN (92 and 81%, respectively). Benign breast lesions, including fibroadenoma and fibrocystic dysplasia, were generally weakly stained (0 or 1+) with both anti-OSN and anti-OPN antibodies (96.4 and 60.7%, respectively). Interestingly, the majority of both in situ and invasive breast carcinoma lesions showed a strong expression (2+ or 3+) for OSN or OPN (74.5 and 84.3%, respectively). High expression of these two bone matrix proteins was associated with frequent microcalcification deposition in the lesion. This study is the first extensive study of OSN and OPN expression in mammary cancers. Our data suggest that OSN and OPN could play a role in the formation of ectopic microcalcifications often associated with breast cancer. It is also tempting to speculate that the expression of these two glycoproteins by breast cancer cells play a role in the preferred bone homing of breast metastases.

Amino Acid Sequence↗
PubMed1995

Galectin-3, a laminin binding protein, fails to modulate adhesion of human melanoma cells to laminin.

Galectin-3 is a laminin binding protein which expression is altered in a variety of human carcinomas including colon, breast and endometrium. In these tumors, we consistently observed a down regulation of galectin-3 expression related to increased aggressiveness. Galectin-3 belongs to a family of galactose-binding lectins and binds laminin through its numerous poly-N-acetyllactosamine chains. To date, the exact role of galectin-3 in the complex interactions between cancer cells and laminin has not been clearly defined. Adhesion of melanoma cells to laminin is a critical event during tumor invasion and metastasis. In this study, we explore the possibility that galectin-3 could modulate attachment of two human melanoma cell lines to laminin. A2058 and A375 melanoma cell expressed galectin-3 on their surface as demonstrated by immunofluorescence, and attached to laminin in an in vitro assay. We demonstrate that neither recombinant galectin-3 nor an affinity purified antigalectin-3 antiserum altered adhesion of A2058 or A375 melanoma cells to laminin. Our data strongly suggest that galectin-3 is not a key element in adhesion of the melanoma cells to laminin. These results are not surprising in light of the observation that galectin-3 expression is down regulated in cancer and that increased adhesion to laminin is a constant feature of invasive cancer cells.

Antigens, Differentiation↗
PubMed1994

Tamoxifen restores the E-cadherin function in human breast cancer MCF-7/6 cells and suppresses their invasive phenotype.

Tamoxifen is an antiestrogen used in adjuvant therapy of breast carcinoma and could potentially prevent the development of mammary cancer. While it is widely clinically used, its exact mechanisms of action are not yet fully elucidated. MCF-7/6 cells are estrogen receptor-positive invasive human breast cancer cells with a functionally inactive cell surface E-cadherin. In this study, we report that tamoxifen, and to a lesser extent its metabolites 4-OH-tamoxifen and N-desmethyltamoxifen, restore the function of E-cadherin in MCF-7/6 cells. In an aggregation assay, 10(-6) M tamoxifen significantly increases the aggregation of MCF-7/6 cells. This effect is abrogated by a monoclonal antibody against E-cadherin (HECD-1), is fast (within 30 min), and does not require de novo protein synthesis. Tamoxifen was also found to inhibit the invasion of MCF-7/6 cells in organ culture. Our data is the first demonstration that tamoxifen can activate the function of an invasion suppressor molecule and suggest that the restoration of E-cadherin function may contribute to the therapeutic benefit of tamoxifen in breast cancer patients.

Breast Neoplasms↗
PubMed1994

Expression of bone sialoprotein, a bone matrix protein, in human breast cancer.

Microcalcifications are often associated with human mammary lesions, particularly with breast carcinomas. To date, the molecular mechanism that leads to the deposition of hydroxyapatite in the mammary tissue has not been elucidated. Bone sialoprotein (BSP) is a glycoprotein the expression of which coincides with the appearance of the first hydroxyapatite crystals during bone development. In this study, we report the observation that BSP, a bone matrix protein, is expressed in human mammary cancer cells. Using an immunoperoxidase technique, we studied the expression of BSP in 79 breast lesions, including 28 benign and 51 malignant specimens. Two polyclonal antibodies, one directed against intact human BSP and the other against a synthetic peptide of BSP (residues 277-294), were used and gave identical results. Normal mammary glands expressed undetectable or barely detectable amounts of BSP, and the majority of the benign lesions examined were generally unstained (0) or weakly stained (1+). Most of the breast carcinoma specimens (around 87%) showed a significant increase (P = 0.0001) in BSP expression. Breast carcinomas with microcalcifications had the highest immunoreactivity (2+ or 3+) to BSP antibodies. This is the first demonstration that BSP expression is significantly increased in breast cancer. Expression of BSP by breast cancer cells could play a major role in the deposition of microcalcifications and in the preferred bone homing of breast cancer cells.

Breast↗
PubMed1994

Inverse expression of two laminin binding proteins, 67LR and galectin-3, correlates with the invasive phenotype of trophoblastic tissue.

Tumor invasion of host tissues and trophoblastic penetration of the endometrium share common biological features. Both processes involve the invasion of basement membranes, an event that is initiated by adhesion of cancer or trophoblast cells to basement membrane components and particularly to laminin. Adhesion to this latter glycoprotein is mediated through a variety of cell surface receptors. We have previously shown that the 67 kD Laminin Receptor (67LR) and a 31 kD Human Laminin Binding Protein, recently renamed galectin-3, are inversely modulated as the invasive phenotype of cancer cells progresses, with up regulation of the former, and down regulation of the latter, respectively. In this study, we examined the expression of these two proteins in 27 human trophoblastic specimens at different gestational ages using Northern and Western blot techniques. Expression of the 67LR increased from 7 weeks to a maximum at 12 weeks, when invasion is maximal, and then decreased. Expression of galectin-3 was inversely modulated by the gestational age, with a minimum expression at 12 weeks. Our data demonstrate that invasive trophoblast displays the same pattern of laminin binding proteins expression than invasive cancer cells, and further demonstrates that invasion of the extracellular matrix by trophoblast and cancer cells share common molecular mechanisms.

Antigens, Differentiation↗
PubMed1994

AGM-1470, a potent angiogenesis inhibitor, prevents the entry of normal but not transformed endothelial cells into the G1 phase of the cell cycle.

AGM-1470 is a potent angiogenesis inhibitor that is very effective in inhibiting endothelial cell proliferation in both in vitro and in vivo models and that prevents tumor growth in vivo. Although this molecule appears to be a most promising anticancer drug, its mechanism of action has not yet been elucidated. In this study, we examined the effects of AGM-1470 on the cell cycle of normal and transformed endothelial cells. We showed that AGM-1470, at picomolar concentrations, specifically inhibits the proliferation of both bovine aortic endothelial cells and human umbilical vein endothelial cells. AGM-1470 was ineffective in significantly inhibiting the proliferation of Ea.hy926 cells, a hybrid cell line obtained by the fusion of human umbilical vein endothelial cells with a human carcinoma cell line, or cEnd.1 cells, a polyoma middle T oncogene-transformed endothelioma cell line derived from mouse embryo. Using a double labeling technique with anti-Ki67 antibodies and propidium iodide, we demonstrated, with flow cytometry analysis, that AGM-1470 specifically prevents the entry of endothelial cells into the G1 phase of the cell cycle. We also showed that AGM-1470 was ineffective in inhibiting endothelial cell migration toward laminin or capillary-like tube formation inside a type I collagen matrix induced by phorbol esters. Our data strongly suggest that AGM-1470 is a molecule that specifically inhibits a cell cycle control pathway active in normal cells but which could be bypassed or altered in transformed cells.

Animals↗