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Biomedical subjects

V Castronovo

Publications and source records attributed to V Castronovo.

At least 19 recordsLinked to original sources
PubMed1992

Genes involved in tumor invasion and metastasis are differentially modulated by estradiol and progestin in human breast-cancer cells.

Invasion of basement membranes by cancer cells is a critical step in metastasis, which requires the coordinated expression of specific genes such as laminin receptors and metalloproteinases. Estradiol and progesterone modulate the clinical progression of steroid-sensitive breast cancers; however, little is known about the molecular regulation of the invasive phenotype by these hormones. We therefore examined the effects of 10 nM estradiol and/or 10 nM progestin R5020 on the expression of 2 non-integrin laminin binding proteins, the 67-kDa laminin receptor (67LR) and HLBP31 as well as the 72-kDa type-IV collagenase (MMP-2) and its inhibitor, TIMP-2, in steroid-receptor-positive (T47D and MCF-7) and -negative (MDA-MB 231) human breast-cancer cells. The relative steady-state level of 67LR mRNA was increased 2- to 3-fold by estradiol in both MCF-7 (p < 0.001) and T47D (p < 0.001) cells, also by R5020, alone or in combination with estradiol, in T47D cells (p < 0.001) and to a much less extent in MCF-7 cells. HLBP31 mRNA and protein levels were increased 2- to 3-fold (p < 0.001) by R5020 alone or in combination with estradiol, but not by estradiol alone. None of the steroid treatments affected the expression or activity of MMP-2. Interestingly, however, TIMP-2 mRNA levels and protein expression in MCF-7 and T47D cells were 50% down-regulated (p < 0.001) by treatment with R5020 or R5020 plus estradiol, but not by treatment with estradiol alone. None of these genes were modulated in steroid-independent MDA-MB231 cells. The data suggest that estradiol and progesterone might act as coordinators regulating specific genes in the steroid-sensitive breast-cancer cell, leading to the acquisition of the metastatic phenotype.

Breast Neoplasms↗
PubMed1992

Identification of a 14-kDa laminin binding protein (HLBP14) in human melanoma cells that is identical to the 14-kDa galactoside binding lectin.

The carbohydrate moieties present on laminin play a crucial role in the multiple biological activities of this basement membrane glycoprotein. We report the identification of a human laminin binding protein with an apparent molecular mass of 14 kDa on sodium dodecyl sulfate-polyacrylamide gels that was found, after purification and amino acid microsequencing, to be identical to the previously described 14-kDa galactoside binding soluble L-14 lectin. We have designated this human laminin binding protein as HLBP14. HLBP14 was purified from human melanoma cells in culture by laminin affinity chromatography and gel electroelution. We demonstrate that HLBP14 binds specifically to the poly-N-acetyllactosamine residues of murine laminin and does not bind to other glycoproteins that do not contain such structures, such as fibronectin. HLBP14 was eluted from a murine laminin column by lactose, N-acetyllactosamine, and galactose but not by other control saccharides, including glucose, fucose, mannose, and melibiose. It did not bind to laminin treated with endo-beta-galactosidase. Lactose also eluted HLBP14 off a human laminin affinity column, implying that human laminin also contains poly-N-acetyllactosamine residues. On immunoblots, polyclonal antibodies raised against HLBP14 recognized HLBP14 as well as 31- and 67-kDa molecules that are also laminin binding proteins, indicating that these proteins share common epitopes. L-14, a dimeric lactose binding lectin, is expressed in a wide variety of tissues. Although the expression of this molecule has been linked to a variety of biological events, the elucidation of its specific functions has been elusive. The observation that HLBP14, a human cancer cell laminin binding protein, is identical to L-14 strongly suggests that the functions attributed to this lectin could be mediated, at least in part, through its ability to interact with the poly-N-acetyllactosamine residues of laminin. HLBP14 could potentially play a role during tumor invasion and metastasis by modulating the interactions between cancer cells and laminin.

Amino Acid Sequence↗
PubMed1992

Inverse modulation of steady-state messenger RNA levels of two non-integrin laminin-binding proteins in human colon carcinoma.

BACKGROUND: Interactions between cells and the basement membrane glycoprotein laminin are altered during colon cancer progression. Colon carcinoma and normal mucosa cells express a variety of laminin-binding proteins, including the 67-kd laminin receptor (67 LR) and a 31-kd human laminin-binding protein (HLBP31) homologous to the 31-kd human IgE-binding protein/galactoside-binding lectin. PURPOSE: To investigate whether various laminin-binding proteins are differentially expressed in human colon carcinoma, we studied messenger RNA (mRNA) levels of the 67 LR and HLBP31 in matched tumor and adjacent normal mucosa samples from a series of 21 patients. METHODS: Total cellular RNA from tumor and normal mucosa was isolated and analyzed by Northern and slot blot hybridization. In addition, HLBP31 protein levels were assessed by the immunoblot technique. Quantitative laminin affinity chromatography was also used to measure the synthesis of HLBP31 protein in five human cancer cell lines. RESULTS: The steady-state mRNA level of HLBP31 was downregulated (i.e., decreased) in 18 of 21 human colon carcinomas compared with the level in their corresponding normal colonic mucosa. On average, the level of HLBP31 mRNA was decreased 50% +/- 30% (+/- SD) in the colon cancers. The mean ratio of colon cancer HLBP31 mRNA to adjacent normal mucosa HLBP31 mRNA was twofold lower in primary tumors of patients with metastases (0.3 +/- 0.2 SD) than in primary tumors of patients free of metastatic lesions (0.6 +/- 0.2 SD). The differences between the two groups of patients were statistically significant (P less than .05, Wilcoxon-Mann-Whitney test). We have previously shown that the ratio of colon cancer 67 LR mRNA to corresponding normal mucosa 67 LR mRNA was increased in the same patient population. When the two ratios (ratio of cancer to normal HLBP31 mRNA and ratio of cancer to normal 67 LR mRNA) were compared, HLBP31 mRNA/67 LR mRNA was significantly lower (P less than .05) in primary tumors with metastases (mean +/- SD, 0.3 +/- 0.2) than in primary cancers without metastases (mean +/- SD, 0.7 +/- 0.5). The steady-state level of HLBP31 mRNA was directly correlated with the amount of HLBP31 protein in both colon tissue samples and human cancer cell lines. CONCLUSION: HLBP31 mRNA expression in colon cancer tissues is modulated inversely to that of 67 LR mRNA expression. The down-regulation of HLBP31 appears to be associated with the metastatic capabilities of colon cancer cells. IMPLICATIONS: Prospective studies on a large cohort should determine if the systematic detection of HLBP31 and 67 LR protein and/or mRNA can be a valuable adjunct in the prognostic evaluation of primary colon cancers.

Amino Acid Sequence↗
PubMed1992

Extracellular matrix receptors and mouse skin carcinogenesis: altered expression linked to appearance of early markers of tumor progression.

Interaction of cells with the basement membrane is important for cell proliferation and differentiation. Disruption of the basement membrane is an early event during progression of benign tumors to cancer. Using the techniques of immunohistochemistry and immunofluorescence, we show that cell-matrix interactions via the cell surface integrin receptors alpha 3 beta 1, alpha 5 beta 1, alpha 6 beta 4, the Mr 67,000 laminin receptor (67LR) laminin-binding protein, and the secreted matrix protein laminin are strictly regulated during differentiation of mouse epidermis. While alpha 6 beta 4 and alpha 5 beta 1 are polarized to the basal surface of basal cells in contact with the basement membrane, alpha 3 beta 1 and the non-integrin 67LR are primarily detected in the cell periphery of suprabasal cells, where cell to cell contacts are found. Sequential changes in expression of matrix receptors occur following multistage carcinogenesis of mouse skin. In an analysis of benign and malignant skin tumors induced by chemical carcinogens or oncogene transduction, we found that alpha 3 beta 1 and alpha 5 beta 1 as well as the non-integrin 67LR are sequentially down-regulated in the progression from benign to malignant, while alpha 6 beta 4 is the predominant receptor expressed in the carcinomas. Tumor expression of alpha 6 beta 4 is not polarized and is dissociated from its colocalized normal partner bullous pemphigoid antigen, which remains restricted to the basement membrane. The changes in matrix receptors are linked to appearance of keratin 13 in suprabasal regions, but always in alpha 6 beta 4 negative cells. The predominance of alpha 6 beta 4 in the proliferating cells during progression is associated with decreased expression of keratin 13 in carcinomas. These results suggest that matrix interactions with its receptors are important determinants of ordered differentiation in normal skin and show characteristic alterations during carcinogenesis that parallel changes in differentiation of the tumors.

Animals↗
PubMed1992

Detection of laminin receptor mRNA in human cancer cell lines and colorectal tissues by in situ hybridization.

The 67-kd high-affinity laminin receptor (67 LR) is a gene product whose expression appears to be associated with the invasive and metastatic phenotype of a variety of human cancer cells. Northern blot hybridization has been routinely used to quantify the level of 67 LR mRNA from total cellular RNA extracts of homogenized tissue specimens or in vitro grown cell populations. This technique is useful to assess the average expression of the 67 LR mRNA of a particular sample but does not provide information about expression in specific cell types nor about heterogeneity of expression from cell to cell. In this study, we analyzed the expression of 67 LR mRNA in four human cancer cell lines with varying degrees of expression of 67 LR protein (renal cancer A-704, breast carcinoma MCF-7/4 and MCF-7/7, and pancreatic cancer Panc-1) using in situ hybridization performed with 67 LR riboprobes. Total cellular RNA was simultaneously extracted from the cell lines and hybridized on Northern blots with a 67 LR cDNA probe to assess the validity of the mRNA detection by in situ hybridization. Sixty-seven LR mRNA expression was higher in Panc-1 and MCF-7/4 cells than in MCF-7/7 and renal carcinoma A-704. There was a direct correlation (R2 = 0.88) between the in situ hybridization analysis and the mRNA levels detected by Northern blot analysis. The in situ hybridization method showed a heterogeneous expression of the 67 LR mRNA in the four cell lines with different subpopulations of cells showing a range from negative to high levels of the message. Sixteen freshly frozen human colorectal tissues (seven adenocarcinomas, five matched normal mucosae, and four adenomas) were also analyzed by in situ hybridization. The 67 LR mRNA was localized in normal and neoplastic epithelial cells. Adenocarcinoma cells showed a 1.6- to 5-fold higher expression (P < 0.02 according to the Wilcoxon-Mann-Whitney test) than did epithelial colonic cells from normal mucosae or adenomas. The signal tended to be stronger in poorly differentiated carcinomas and carcinomas with metastases than in moderately differentiated and nonmetastatic tumors. We conclude that the high expression of 67 LR mRNA in colorectal tumors is due to an increased production by tumor cells. Furthermore, in situ hybridization is an effective method to detect the expression of LR mRNA in cultured cell lines as well as in frozen tissue sections.

Adenoma↗
PubMed1991

Functional domains of the 67-kDa laminin receptor precursor.

We report the characterization of two functional domains of the metastasis-associated 67-kDa laminin receptor (67-LR). Using synthetic peptides deduced from the cDNA sequence of the 37-kDa precursor of the laminin receptor (37-LRP) as well as their corresponding affinity-purified polyclonal antibodies, we identified a unique laminin binding site as well as a membrane-associated domain of the receptor. In laminin dot blot and solid phase radioligand assays, a 20 amino acid synthetic peptide (IPCNNKGAHSVGLMWWMLAR, amino acid residues 161-180, designated peptide G) specifically bound to laminin with high affinity (Kd = 5 x 10(-8) M). Peptide G also specifically eluted the 67-LR from a laminin affinity column. Peptide G and laminin reacted with a 1:1 stoichiometry, suggesting that there is one recognition site on laminin for the peptide G domain. Immunofluorescence studies, performed on permeabilized and nonpermeabilized human A2058 melanoma cells using 10 different affinity-purified antibodies to distinct regions of the 37-LRP, identified an unusually short membrane-associated domain that was consistent with a computer predicted transmembrane domain (residues 86-101). Our data demonstrate for the first time that the 37-LRP has two functional domains consistent with the characteristics of the mature 67-LR. Furthermore, we propose peptide G as a potential inhibitor of tumor cell interactions with laminin.

Amino Acid Sequence↗
PubMed1991

Laminin receptor complementary DNA-deduced synthetic peptide inhibits cancer cell attachment to endothelium.

Stable attachment of cancer cells to the endothelium is a key step in the formation of metastasis. In this study, we have investigated the possibility that interaction between laminin and its Mr 67,000 high-affinity receptor (67 LR) could play a major role in this process. Scatchard analysis of laminin-binding studies showed that bovine aortic endothelial cells exhibit 46,000 high-affinity receptors that mediate, at least in part, the attachment of highly invasive melanoma cells. This endothelial cell-melanoma cell interaction was significantly inhibited by soluble laminin and by anti-laminin antibodies. Peptide G, an eicosapeptide derived from the complementary DNA sequence of the 67 LR precursor (IPCNNKGAHSVGLMWWMLAR) that specifically binds to laminin and presumably contains the active ligand-binding site of the receptor, specifically prevented attachment of the melanoma cells to both the bovine aortic endothelial cell monolayer and human umbilical vein endothelium. Thus, peptide G may selectively interfere with the metastatic cascade by inhibiting tumor cell attachment to endothelium via the laminin-67 LR pathway and is a potential new antimetastatic agent.

Amino Acid Sequence↗
PubMed1991

Biosynthesis of the 67 kDa high affinity laminin receptor.

High affinity interactions between cells and laminin are mediated, at least in part, by the 67 kDa laminin receptor (67 LR). A 37 kDa nascent polypeptide (37 LRP), predicted by a full length cDNA clone and obtained by in vitro translation of hybrid-selected laminin receptor mRNA, has been immunologically identified in cancer cell extracts as the putative precursor of the 67 LR. In this study, we used affinity purified antibodies developed against cDNA-deduced 37 LRP synthetic peptides in pulse chase experiments and demonstrated a precursor-product relationship between the 37 LRP and the 67 LR. Immunoblot, pulse chase and immunofluorescence experiments showed that transient transfection of the full length 37 LRP cDNA clone induced a dramatic increase in the synthesis of the 37 LRP but not of the mature 67 LR. We propose that the 67 LR results from the association of two gene products: the 37 LRP and a polypeptide yet to be identified.

Animals↗
PubMed1991

Malignant cell attachment to endothelium of ex vivo perfused human umbilical vein. Modulation by platelets, plasma and fibronectin.

The success of blood-born metastatic spread depends upon a key event: the tumor cell arrest and attachment to the host organ vasculature. In the present study, we have investigated interactions between several normal and cancer cell lines and vascular endothelium in a model of ex vivo perfusion of human umbilical vein. In this system, hydrodynamic parameters are monitored and endothelial cells are kept in their original environment known to modulate their phenotype. Metastatic tumor cell adhesion to the perfused endothelium was found to be significantly higher than that of normal cells tested. Platelets and soluble plasma factors including fibronectin promoted tumor cell arrest and adhesion to endothelium. Altogether our results indicate that the ex vivo perfusion of human umbilical vein allows the study of the interactions between malignant tumor cells, circulating plasma or blood cells and the endothelium during blood-born metastatic spread.

Blood Platelets↗
PubMed1991

The high affinity murine laminin receptor is a member of a multicopy gene family.

The high affinity laminin receptor is differentially expressed in metastasis. We now report that there are multiple copies (6 +/- 1) of the laminin receptor gene in the murine genome of normal diploid cells as well as in cell lines derived from cancer cells. We have analyzed three distinct cDNA clones isolated from an Okayama-Berg cDNA library of transformed mouse fibroblasts that may represent transcripts of three different laminin receptor genes. Polymorphic changes include insertion of bases at the 5' terminus, a base substitution within the coding region resulting in an amino acid change from phenylalanine to leucine, a base substitution obliterating a polyadenylation signal, as well as changes in the length of the 3' untranslated domains. The discovery of multiple transcripts of laminin receptor genes suggests that there is a strong selective pressure to maintain laminin receptor expression in murine cells.

Animals↗
PubMed1991

Increased expression of the laminin receptor in human colon cancer.

It has been proposed that among the various cell-surface proteins capable of interacting with laminin, the 67-kd high-affinity laminin receptor plays a crucial role during tumor invasion and metastasis. In this study, the expression of laminin-receptor-precursor messenger RNA (mRNA) and 67-kd protein was analyzed in human colon adenocarcinoma. In 22 of 23 patients with colon cancer, we found a 2- to 23-fold increase in levels of laminin-receptor-precursor mRNA in the cancer tissues compared with those in matched normal adjacent colonic mucosa. In 10 of 11 cases studied, the level of 67-kd laminin receptor, detected by affinity-purified anti-laminin-receptor synthetic peptide antibodies on immunoblots of matched tumor and normal tissue extracts, was higher in the colon carcinoma tissue. Immunodetection of laminin receptor in tissue sections using anti-laminin-receptor-peptide antibodies confirmed that the increased expression of laminin receptor was specifically associated with the cancer cells. In a series of 72 paraffin sections of colon lesions, we observed a correlation between the expression of the laminin receptor and the Dukes' classification. Our observations indicate that increased expression of laminin-receptor-precursor mRNA is associated with enhanced levels of the 67-kd laminin receptor as well as with the invasive phenotype of colon carcinoma. Detection of this metastasis-associated gene product may be a valuable adjunct in the evaluation of human colon cancer.

Adenocarcinoma↗
PubMed1991

Absence of laminin deposition in breast cancer and metastases except to the brain.

Laminin, a major glycoprotein of basement membrane has been found to play significant roles during invasion and metastases. In this study, we have examined the distribution of laminin in several human brain carcinoma metastases, human breast cancers, skin and lymph node metastases of breast cancer as well as in an in vitro and an in vivo model of invasion. A laminin accumulation was demonstrated a) at the border between human metastatic carcinoma cells and surrounding neural tissue; b) at the invasive edge between MO4 cells (a highly malignant cell line which synthesizes large amounts of laminin) and host tissues of syngenic mice; c) at the front of invasion between MO4 cells and precultured heart fragments in an in vitro model of invasion. Laminin, but not type IV collagen, promoted attachment of MO4 cells. This attachment was inhibited by preincubation of laminin matrix support with (+)-catechin, a flavonoid which also prevented invasion of the precultured heart fragment in vitro. Our data demonstrate that laminin accumulates between malignant cells and host tissue in human brain metastases and in an in vitro and an in vivo model of invasion. In these later models, accumulation of laminin is the consequence, at least in part, of its biosynthesis by MO4 cells. Since laminin promotes attachment of malignant cells in vitro, increases invasiveness and metastatic activities of murine malignant cells, it is tempting to speculate that laminin synthesized by invasive cells and accumulated at the front of invasion plays a significant role in the first step of invasion.

Adenocarcinoma↗
PubMed1991

Augmentation of type IV collagenase, laminin receptor, and Ki67 proliferation antigen associated with human colon, gastric, and breast carcinoma progression.

The proportion of neoplastic cells immunocytochemically positive for type IV collagenase (IVase), laminin receptor (LR), and Ki67 proliferation-associated antigen increased during the progression of human colon, gastric, and breast carcinomas. Thirty cases of colonic adenoma were compared with 30 cases of Dukes' A or B stage carcinoma and ten cases of Dukes' C stage carcinoma. The percentage of positive cells increased significantly (P less than 0.001) for all three antigens comparing carcinomas with adenomas and Dukes' C stage compared with Dukes' A/B stage. The same pattern of antigen correlation with progression was found with 40 human gastric carcinomas. Gastric carcinomas classified as well-differentiated advanced stage contained a significantly higher proportion of tumor cells positive for IVase (P less than 0.001), LR (P less than 0.001), and Ki67 (P less than 0.001) compared with well-differentiated superficial tumors. Gastric carcinomas classified as poorly differentiated superficial had a significantly higher proportion of cells positive for Ki67 (P less than 0.016), but not IVase (P less than 0.069) or LR (P less than 0.075), compared with poorly differentiated advanced tumors. Metastasis of colon and gastric carcinoma retained the immunostaining pattern of the primary tumors. Thirty cases of breast neoplasia were compared with 30 adjacent samples of normal duct epithelium. A positive correlation (P less than 0.001) was found for the immunoreactivity of all three antigens in the invasive carcinomas compared with the normal epithelium. Invasive ductal carcinoma and invasive lobular carcinoma had a significantly higher percentage of immunoreactivity for the three antigens compared with corresponding in situ lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1991

Molecular inhibition of cancer cell invasion and metastasis.

A group of coordinated cellular processes, not just one gene product, is responsible for invasion and metastasis, the most life-threatening aspect of cancer. It is now recognized that negative factors may be just as important as positive elements. Genetic changes causing an imbalance of growth regulation lead to uncontrolled proliferation necessary for both primary tumor and metastasis expansion. However, unrestrained growth does not, by itself, cause invasion and metastasis. This phenotype may require additional genetic changes. Thus, tumorigenicity and metastatic potential have both overlapping and separate features. Invasion and metastasis can be facilitated by proteins which stimulate tumor cell attachment to host cellular or extracellular matrix determinants, tumor cell proteolysis of host barriers, such as the basement membrane, tumor cell locomotion, and tumor cell colony formation in the target organ for metastasis. Facilitory proteins may act at many levels both intracellularly and extracellularly, but are counterbalanced by factors which can block their production, regulation or action. A common theme has emerged: in addition to loss of growth control, an imbalanced regulation of adhesion, proteolysis, and motility appears to be required for invasion and metastasis. Re-equilibrating the expression of the genes involved in these tumor invasion related events could potentially constitute the basis for new anti-cancer therapeutic strategies.

Amino Acid Sequence↗
PubMed1990

Laminin and fibronectin increase the steady state level of the 67 kD high affinity metastasis-associated laminin receptor mRNA in human cancer cells.

Among the various known laminin binding proteins, the 67 kD high affinity laminin receptor (LR) is intimately involved during tumor invasion and metastasis. In this study, we report that laminin and fibronectin, two attachment glycoproteins, significantly increased the total cellular level of 67 kD LR mRNA in two human cancer cell lines, T47D breast carcinoma cells and A2058 melanoma cells. Neither GRGDS nor YIGSR synthetic peptides induced such a stimulatory effect. Since the steady state level of LR mRNA has been shown to control the number of receptors expressed at the cell surface, these results suggest that contact of the cancer cells with laminin and fibronectin in the host matrix may be an important regulatory mechanism by which cancer cells maintain a high number of LR at their cell surface as they progress through the several steps of tumoral invasion and metastasis.

Amino Acid Sequence↗
PubMed1990

Spatiotemporal segregation of endothelial cell integrin and nonintegrin extracellular matrix-binding proteins during adhesion events.

Bovine aortic endothelial cell (BAEC) attachments to laminin, fibronectin, and fibrinogen are inhibited by soluble arginine-glycine-aspartate (RGD)-containing peptides, and YGRGDSP activity is responsive to titration of either soluble peptide or matrix protein. To assess the presence of RGD-dependent receptors, immunoprecipitation and immunoblotting studies were conducted and demonstrated integrin beta 1, beta 3, and associated alpha subunits as well as a beta 1 precursor. Immunofluorescence of BAECs plated on laminin, fibronectin, and fibrinogen reveals different matrix-binding specificities of each of these integrin subclasses. By 1 h after plating, organization of beta 1 integrin into fibrillar streaks is influenced by laminin and fibronectin, whereas beta 3 integrin punctate organization is influenced by fibrinogen and the integrin spatial distribution changes with time in culture. In contrast, the nonintegrin laminin-binding protein LB69 only organizes after cell-substrate contact is well established several hours after plating. Migration of BAECs is also mediated by both integrin and nonintegrin matrix-binding proteins. Specifically, BAEC migration on laminin is remarkably sensitive to RGD peptide inhibition, and, in its presence, beta 1 integrin organization dissipates and reorganizes into perinuclear vesicles. However, RGD peptides do not alter LB69 linear organization during migration. Similarly, agents that block LB69--e.g., antibodies to LB69 as well as YIGSR-NH2 peptide--do not inhibit attachment of nonmotile BAECs to laminin. However, both anti-LB69 and YIGSR-NH2 inhibit late adhesive events such as spreading. Accordingly, we propose that integrin and nonintegrin extracellular matrix-binding protein organizations in BAECs are both temporally and spatially segregated during attachment processes. High affinity nonintegrin interaction with matrix may create necessary stable contacts for longterm attachment, while lower affinity integrins may be important for initial cell adhesion as well as for transient contacts of motile BAECs.

Acid Phosphatase↗
PubMed1990

Immunodetection of the metastasis-associated laminin receptor in human breast cancer cells obtained by fine-needle aspiration biopsy.

Fine-needle aspiration biopsy of the breast is a very useful technique for the evaluation of a suspect lesion before surgical removal. Increased expression of the 67-kd laminin receptor has been associated with the metastatic phenotype of cancer cells, particularly in colon and breast cancers. In this study, the expression of laminin receptor was evaluated using the immunoperoxidase technique in 81 breast aspirates (26 benign and 55 neoplastic lesions). Cells obtained from benign samples exhibited a low level of laminin receptor antigen detected by affinity-purified antibody raised against a cDNA-derived laminin receptor peptide. In contrast, 71% of smears obtained from malignant breast lesions contained cells that were strongly stained by the antibody. Heterogeneous expression of the laminin receptor was noted in both breast aspirates and fixed tissue specimens. These data suggest that the immunodetection of laminin receptor in cells obtained by fine-needle aspiration of breast lesions could be a valuable adjunct in the prognostic evaluation of breast lesions.

Antibodies↗