Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have used a double-labelling flow cytometry analysis of keratin (CK) and DNA in breast cancer. Five monoclonal anti-keratin antibodies were tested: KL1 recognizing Mr 55,000-57,000 keratins, and "anti-glandular epithelia," LE41, RGE-53, and LP2K specific for CK n. 7, 8, 18, and 19 of Moll's classification, respectively. Flow cytometric (DNA-CK) analysis was performed on 10 benign and 19 malignant human breast tumors. All the benign tumors were diploid and 63% of the malignant tumors were aneuploid. This technique permits the analysis of DNA in the epithelial fraction alone. In aneuploid tumors, gating the DNA-keratin-positive population allowed accurate DNA analysis without interference due to debris background and non-epithelial cells. Moreover, double-labelling using the CK19 antibody gave a better identification of near-diploid tumors. An enhancement of keratin expression in malignant tumors was observed with CK 19 (P less than 0.001), KL1 (P less than 0.01), CK 8 (P less than 0.05), and CK18 (n.s.) compared to benign tumors. The comparison of keratin expression in aneuploid and diploid malignant tumors revealed reduced CK8, CK18, and CK19 in the former.
 ...
PMID:Flow cytometric analysis of DNA content and keratins by using CK7, CK8, CK18, CK19, and KL1 monoclonal antibodies in benign and malignant human breast tumors. 169 38

The immunohistochemical reactivities of 69 cases of breast carcinoma were examined on methacarn-fixed, paraffin-embedded sections using eight different monoclonal antibodies which recognize one or a few keratin polypeptides. In the normal breast, the monoclonal antibodies RPN1162, RPN1165 and AE1 stained almost all the luminal cells but not the basal (myoepithelial) cells. The monoclonal antibodies 35BH11, M20, CK5 and CK8.12 stained only a subset of the luminal cells. In contrast, 312C8-1 stained basal cells but not luminal cells. All the tumour specimens reacted with AE1, while over 80% of them also reacted with 35BH11 (57/69), CK5 (57/69) and RPN1165 (55/69); 30% reacted with CK8.12 (21/69) and 16% with RPN1162 (11/69). Basal cell-specific keratin, as defined by 312C8-1, was detected in only 1% of cases (1/69). Monoclonal antibodies to different keratin polypeptides may be of use in the characterization and subdivision of breast cancer.
 ...
PMID:Keratin expression in the normal breast and in breast carcinoma. 171 6

It is not known how tightly regulation of cytokeratin (CK) protein expression is correlated with transcriptional activity in breast cancer. The level of control of CK expression in the normal mammary gland and in breast cancer has been assessed by combining in situ hybridization with riboprobes, and with immunohistochemistry using monospecific antibodies. In normal mammary gland, luminal cells showed abundant hybridization with complementary RNA (cRNA) probes for CK7, CK8, CK18, and CK19. Proteins of these CKs were correspondingly distributed except for that of CK19, which showed a heterogeneous staining. In primary carcinomas, both messenger RNAs (mRNAs) and proteins of CK8 and CK18 were generally expressed to a degree similar to that of normal epithelia, but a lower level of mRNA and protein of CK18 was observed in metastatic carcinomas. Reduced expression of CK7 and CK14 was observed in all carcinomas, and the correlation between mRNA and protein for these two cytokeratins was unbalanced, whereas the expression of CK19 mRNA and the proportion of its protein-positive cells were increased. The results suggest that these major CKs in normal mammary gland epithelia are regulated at the transcriptional level except for CK19, which is partially under the posttranscriptional control. The alterations observed in breast cancer are not only reflected by the reduced or increased expression of individual cytokeratins, but characterized by partial loss of the normal regulation of cytokeratin expression.
 ...
PMID:Expression of cytokeratin messenger RNA versus protein in the normal mammary gland and in breast cancer. 876 13

Cell-surface activation of plasminogen may be important in diseases that involve cellular migration, including atherosclerosis and tumour invasion/metastasis. Cytokeratin 8 (CK 8) has been identified as a plasminogen-binding protein expressed on the external surfaces of hepatocytes and breast carcinoma cells [Hembrough, Vasudevan, Allietta, Glass and Gonias (1995) J. Cell Sci. 108, 1071-1082]. In this investigation, we demonstrate that a soluble form of CK 8 is released into the culture medium of breast cancer cell lines. The released CK 8 is in the form of variably sized polymers that bind plasminogen and promote the activation of [Glu1]plasminogen and [Lys78]plasminogen by single-chain tissue-type plasminogen activator (sct-PA). To assess the mechanism by which CK 8 promotes plasminogen activation, CK 8 was purified from rat hepatocytes and immobilized in microtitre plates. Immobilized CK 8 bound 125I-plasminogen and 125I-sct-PA in a specific and saturable manner. The KDs were 160 +/- 40 nM and 250 +/- 48 nM, respectively. Activation of plasminogen bound to immobilized CK 8 was accelerated compared with plasminogen in solution, as determined using a coupled-substrate fluorescence assay and SDS/PAGE. The ability of CK 8 to promote plasminogen activation may be important in the pericellular spaces surrounding breast cancer cells and at the cell surface.
 ...
PMID:Cytokeratin 8 released by breast carcinoma cells in vitro binds plasminogen and tissue-type plasminogen activator and promotes plasminogen activation. 876 Mar 60

We report the pathological characteristics of a variant of mammary endocrine tumour, predominantly formed from cytologically bland spindle cells. This neoplasm grows as a red, well defined mass lacking the usual macroscopical characteristics of breast cancer. Within smoothly contoured aggregates arranged in an insular pattern, delicate capillaries and collagen bundles support the neoplastic epithelial cells. Most of the tumour cells possess a slender spindle shape and form a solid or fenestrated sheet, but a few appear cuboidal and create glands. Immunohistochemical studies demonstrate that the spindle cells and the glandular cells constitute a single population. Both types of cells stain for neuroendocrine markers (chromogranin, synaptophysin, and CD 57), carcinoembryonic antigen, keratin 8/18, S-100 protein, and receptors for oestrogen and progesterone. Many of the tumour cells possess argyrophilic granules, and electron microscopy may reveal dense core granules.
 ...
PMID:Spindle cell endocrine carcinoma of the mammary gland. 879 35

Cytokeratin 8 (CK 8) has been identified on the external surfaces of viable, unpermeabilized epithelial cells (Hembrough, T. A., Vasudevan, J., Allietta, M. M., Glass, W. F., and Gonias, S. L. (1995) J. Cell Sci. 108, 1071-1082). In this study, we demonstrated that CK 8 is the major plasminogen-binding protein in plasma membrane fractions isolated from three breast cancer cell lines, BT20, MCF-7, and MDA-MB-157. To assess the function of CK 8 as a plasminogen receptor, monoclonal antibody 1E8 was raised against the carboxyl-terminal 12 amino acids of CK 8. The 1E8 epitope was present on the external surfaces of breast cancer cells, as determined by immunofluorescence microscopy. 125I-1E8 bound to MCF-7 cells; the maximum binding capacity (1.5 x 10(6) sites per cell) was comparable with that determined for plasminogen. When MCF-7 cells were incubated with Fab fragments of 1E8, specific 125I-plasminogen binding was decreased up to 82%. Specific plasminogen binding was decreased up to 67%, even when the unbound 1E8 Fab was removed by washing the cells prior to adding 125I-plasminogen. Preincubation with 1E8 Fab decreased plasminogen binding to BT20 and MDA-MB-157 cells, although to a lesser extent than with MCF-7 cells. Plasminogen activation by tissue-type plasminogen activator was greatly accelerated, due to a large decrease in Km, when the plasminogen was bound to MCF-7 cells. Pretreatment with 1E8 Fab decreased the rate of plasminogen activation by up to 83%, implicating CK 8 in the MCF-7 cell-accelerated reaction. These studies identify cell-surface CK 8 as a major plasminogen receptor in breast cancer cells and as a required component for the rapid activation of cell-associated plasminogen by tissue-type plasminogen activator.
 ...
PMID:Cell-surface cytokeratin 8 is the major plasminogen receptor on breast cancer cells and is required for the accelerated activation of cell-associated plasminogen by tissue-type plasminogen activator. 881 Mar 46

Permanent human tumor cell lines are an important tool for the study of breast cancer. Two new breast cancer cell lines (BrCa-MZ-01 and BrCa-MZ-02) were isolated from a solid tumor and a pleural effusion, respectively. One cell line was established from a medullary carcinoma, the other from a ductal carcinoma. These cells exhibit ultrastructural and immunohistochemical features of epithelial cells of mammary origin. Intermediate filament and cytokeratin typing showed a clear predominance of the simple-epithelial cytokeratins CK 8, CK 18 and CK 19, although the expression was reduced in comparison to the hormone receptor-positive reference cell lines MCF-7 and ZR-75-1. Both cell lines produced slow-growing tumors after subcutaneous (s.c.) transplantation of 1 x 10(7) viable tumor cells into nude mice. The cell line BrCa-MZ-01 expresses the estrogen and progesterone receptor, whereas the cell line BrCa-MZ-02 remains negative. Both cell lines are positive for secretion of platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta), whereas interleukin-6 (IL-6) is only secreted by the cell line BrCa-MZ-02.
 ...
PMID:Differential characteristics of two new tumorigenic cell lines of human breast carcinoma origin. 966 5

We used a combination of 4 monoclonal antibodies (BM7, BM8 against MUC1, 5D3 against CK8,18,19 and HEA125 against human epithelial antigen) and a sensitive immunocytochemical staining using cytospin preparation to identify breast tumor cells in leukapheresis products (LP). This assay allowed detection of one tumor cell in 1x10(6) mononuclear cells (MC). In clinical specimens, tumor cells were detected in LP from 6 of 42 (14.3%) patients in the adjuvant treatment group, from 2 of 11 (18.2%) patients in the neoadjuvant treatment group and from 9 of 43 (20.1%) in the group of patients with metastatic disease. Tumor cell counts ranged from 0.25-5 cells in 1x10(6) normal cells per LP. The median tumor cell concentration was higher in specimens from patients with metastatic disease (median=0.96) than in specimens from patients in the adjuvant and neoadjuvant treatment groups (median=0.5 and 0.75). No significant differences between the epithelial cell positive group and the epithelial cell negative group with respect to tumor size, lymph nodes involvement, tumor grade, histological type and receptor were found. We conclude that immunocytochemical staining of cytospin preparation is a sensitive and simple method to detect and quantitate breast cancer cells in LP.
 ...
PMID:Detection of tumor cells in leukapheresis products from patients with breast cancer using immunocytochemical staining method. 1076 40

The purpose of the present study was to characterize primitive epithelial progenitor populations present in adult normal human mammary tissue using a combination of flow cytometry and in vitro colony assay procedures. Three types of human breast epithelial cell (HBEC) progenitors were identified: luminal-restricted, myoepithelial-restricted and bipotent progenitors. The first type expressed epithelial cell adhesion molecule (EpCAM), alpha6 integrin and MUC1 and generated colonies composed exclusively of cells positive for the luminal-associated markers keratin 8/18, keratin 19, EpCAM and MUC1. Bipotent progenitors produced colonies containing a central core of cells expressing luminal markers surrounded by keratin 14+ myoepithelial-like cells. Single cell cultures confirmed the bipotentiality of these progenitors. Their high expression of alpha6 integrin and low expression of MUC1 suggests a basal position of these cells in the mammary epithelium in vivo. Serial passage in vitro of an enriched population of bipotent progenitors demonstrated that only myoepithelial-restricted progenitors could be readily generated under the culture conditions used. These results support a hierarchical branching model of HBEC progenitor differentiation from a primitive uncommitted cell to luminal- and myoepithelial-restricted progenitors.
Breast Cancer Res Treat 2001 May
PMID:Characterization of bipotent mammary epithelial progenitor cells in normal adult human breast tissue. 1151 70

Invasiveness and the capacity of tumor cells to form distant metastases are important cellular characteristics associated with a poor prognosis in breast cancer patients. In an approach to find genes that are potentially involved in these processes, RNA species showing different abundance in RNA pools from 12 invasive and 13 noninvasive mammary carcinoma-derived cell lines have been identified by hybridization to cDNA microarrays. CD24, keratin 19, keratin 8, GOB-4 and ezrin-radixin-moesin-binding phosphoprotein 50 were found to be preferentially expressed by noninvasive cells whereas vimentin was confirmed as a characteristic of invasive cells. Only differences in expression higher than 3-fold evident in three independent hybridization experiments were considered significant. For all cell lines, expression of mRNA coding for the adhesion molecule CD24, previously suggested to play an important role during tumor progression to more invasive phenotypes, has been quantified by real-time RT-PCR. Flow-cytometric analyses confirmed that CD24 mRNA reflects the amount of cell surface CD24 (Spearman R = 0.88, p = 10(-6)). CD24 mRNA was found to be absent or weakly expressed in 9/12 (75%) invasive cell lines compared to 3/13 (23%) noninvasive cell lines. The correlation between CD24 expression and invasiveness was calculated to be highly significant with chi2 = 6.74 and p = 0.0094. Future analyses of primary breast carcinomas are warranted to define the role of CD24 in future diagnostic and therapeutic approaches.
 ...
PMID:Expression profiling of mammary carcinoma cell lines: correlation of in vitro invasiveness with expression of CD24. 1221 94


1 2 3 4 5 6 Next >>