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

The Mr 52,000 cathepsin-D-like protease induced by estrogens in MCF7 human breast cells was assayed in 182 primary breast cancer cytosols prepared for receptor assays from pre- and post-menopausal patients. Using two solid-phase sandwich immunoenzymatic assays, we quantified the total Mr 52,000 cathepsin D (52K-cath-D) (the Mr 52,000 precursor protein and its Mr 48,000 and 34,000 processed forms) and the Mr 52,000 precursor alone. The value of total 52K-cath-D varied between 3 and 165 pmol/mg protein and the proportion of the precursor varied from 0 to 28% of total 52K-cath-D. There was no correlation between the concentrations of 52K-cath-D and estrogen receptor, but the estrogen receptor status (greater than or less than 10 fmol/mg protein) was correlated to the 52K-cath-D status (greater than or less than 15 pmol/mg protein) according to the chi 2 test (P less than 0.001). The correlation with progesterone receptor concentrations and status was low (r = 0.43) and absent, respectively. There was no correlation with Scarff and Bloom stages, tumor size, or patient's age. The percentage of patients with invaded lymph nodes was significantly higher (80%) in the subgroup with the highest total 52K-cath-D levels (greater than or equal to 42 pmol/mg protein), representing only 12% of the population but not in the total population. On the basis of this prospective study, before clinical follow-up can be evaluated, we conclude that in the total population examined, the 52K-cath-D concentration was only correlated with estrogen receptor status, but not with any other prognostic parameter.
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PMID:Immunoenzymatic assay of Mr 52,000 cathepsin D in 182 breast cancer cytosols: low correlation with other prognostic parameters. 327 97

The estrogen-induced 52K protein secreted by human breast cancer cells is a lysosomal protease recently identified as a pro-cathepsin D by sequencing several cDNA clones isolated from MCF7 cells (Augereau et al., Mol. Endocr.). Using one of these clones, we detected, in MCF7 cells, a 2.2 kb mRNA whose level was rapidly increased 4- to 10-fold by estradiol, but not by other classes of steroids. Other mitogens, such as epidermal growth factor and insulin, also induced the 2.2 kb mRNA in a dose-dependent manner. Induction with epidermal growth factor was as rapid but was 2- to 3-fold lower than with estradiol. Antiestrogens had no effect on the 52K-cathepsin-D mRNA in MCF7 cells, but became estrogen agonists in two antiestrogen-resistant sublines R27 and LY2. The use of transcription and translation inhibitors and nuclear run-on experiments indicate that estradiol enhances transcription of the 52K-cathepsin-D gene in MCF7 cells.
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PMID:Estrogens and growth factors induce the mRNA of the 52K-pro-cathepsin-D secreted by breast cancer cells. 328 24

In an attempt to understand the mechanism by which estrogens stimulate cell proliferation and mammary carcinogenesis, metastatic human breast cancer cell lines (MCF7, ZR75-1) were found to secrete a 52,000 dalton (52K) protein under estrogen stimulation. Following its purification to homogeneity, the 52K protein was identified as a secreted procathepsin-D-like aspartyl protease bearing mannose-6-phosphate signals. This precursor displays an in vitro autocrine mitogenic activity on estrogen-deprived MCF7 cells and is able to degrade basement membrane and proteoglycans following its autoactivation. The total protease (52K + 48K and 34K) was detected and assayed by monoclonal antibodies and was found to be highly concentrated in proliferative and cystic mastopathies. In breast cancer, its cytosolic concentration appears to be correlated more to tumor invasiveness than to hormone responsiveness. The mRNA of the 52K protease accumulates rapidly following estradiol treatment, as was shown by Northern blot analysis with cloned cDNA. The 52K cathepsin-D-like protease is the first example of a lysosomal protease induced by estrogens in cancer cells. Results obtained using different approaches suggest that two cysteinyl cathepsins are also related to cell transformation and invasiveness. It has been proposed that cathepsin-B is involved in breast cancer and metastatic melanoma, and its regulation by estrogen has been shown in the rat uterus. Cathepsin-L corresponds to the major excreted protein (MEP) whose synthesis and secretion are markedly increased by transformation of NIH 3T3 cells with Ki ras and are regulated by several growth factors. In addition to secreted autocrine growth factors and to other proteases (plasminogen activator, collagenase), lysosomal cathepsins may therefore play an important role in the process of tumor growth and invasion as long as their precursor is secreted abundantly.
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PMID:Estrogen-induced lysosomal proteases secreted by breast cancer cells: a role in carcinogenesis? 331 45

We have previously described a secreted glycoprotein of mol. wt 52,000 (52-kDa protein) which is induced by estrogen in some human breast cancer cell lines. This protein has been identified as the proenzyme of a lysosomal cathepsin-D-like protease which is secreted in large proportions in breast cancer cells. To determine which information may be generated by this marker when detected in mammary tumors, in comparison with hormone receptors, we used monoclonal antibodies interacting specifically with the 52-kDa protein and its related cellular processed products (mols. wts 48 and 34 kDa). A high concentration of this protein has been shown in proliferative ductal mastopathies and cysts, suggesting its value in detecting high-risk mastopathies. We now present the immunoperoxidase distribution of this protein in breast carcinoma compared to the cytosolic hormone receptors assayed in parallel. In 232 breast cancers, no correlation was found between the cellular 52-kDa protein content and cytosolic estrogen or progesterone receptor concentrations. This absence of correlation was also shown by the constitutive production of this protein by estrogen-receptor-negative breast cancer cell lines and confirmed by double immunostaining of breast cancer cell aspirates showing a dissociation between the cytoplasmic staining of this 52-kDa lysosomal protease and the nuclear staining of the estrogen receptor. These clinical results, associated with the in vitro mitogenic and proteolytic activities of this protein, strongly suggest that the 52-kDa protein staining in tissue is associated with tumor proliferation and/or invasion, rather than with hormone responsiveness.
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PMID:Immunohistochemical distribution of the 52-kDa protein in mammary tumors: a marker associated with cell proliferation rather than with hormone responsiveness. 332 May 36

We have studied estrogen-regulated proteins in an attempt to understand the mechanism by which estrogens stimulate cell proliferation and mammary carcinogenesis. In estrogen receptor positive human breast cancer cell lines (MCF7, ZR75-1) estrogens specifically increase the production into the culture medium of a 52,000 daltons (52K) glycoprotein. Several high affinity monoclonal antibodies to the partially purified secretory 52K protein have allowed to purify to homogeneity this protein and its cellular processed products. The 52K protein has been identified as the secreted precursor of a cathepsin-D like protease bearing mannose-6-phosphate signals and routed to lysosomes via mannose-6-phosphate receptor. The protease is mitogenic in vitro on estrogen deprived MCF7 cells and is able to degrade basement membrane and proteoglycans following its activation. The cellular related proteins, as detected by immunohistochemistry and immunoassay are more concentrated in proliferative mammary ducts than in resting ducts and their concentration in breast cancer cytosol appears to be more correlated with lymph nodes invasion and disease free survival (with S. Thorpe, Copenhagen) than with the estrogen receptor (RE) level. The protein is also produced constitutively by RE-negative cell lines, while in some antiestrogen resistant variants, it becomes inducible by tamoxifen, contrary to the wild type MCF7 cells. Cloning of its cDNA in lambda gt11 has allowed to show that the mRNA is rapidly induced by estrogens and to sequence the protein and compare it to that of the normal human kidney cathepsin-D.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The estrogen-regulated 52K-cathepsin-D in breast cancer: from biology to clinical applications. 365 55

Proteolytic and sialyltransferase activities were determined in extracts of 65 human primary breast tumors, 6 lymph node metastases, 6 fibroadenomas and 27 normal tissues. Using proteins and synthetic selective substrates, we observed the presence of collagen-peptidases, plasminogen activator, cathepsin-B and cathepsin-D-like enzymes, and sialyltransferase. No active or trypsin-activatable type-IV collagenase activity was detected. Although individual variations between tumors were large, proteinase and sialyltransferase contents were significantly elevated in malignant breast tissues. Enzyme activities were found to be related to the epithelial volume of the tumor. No significant correlation was found between the proteinase or sialyltransferase activities and the degree of differentiation of the tumor cells, or the degree to which tumors had metastasized to regional lymph nodes. Since large variations of enzyme levels apparently reflect the heterogeneity of epithelial cell densities in tumor samples, proteolytic or sialyltransferase activities cannot therefore be used as a measure of quantitative evaluation of invasive properties in breast cancer.
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PMID:Proteinases and sialyltransferase in human breast tumors. 632 71

Expression of an acidic lysosomal protease, cathepsin-D (CD), was analysed immunohistochemically in a series of 151 breast carcinomas with special reference to its prognostic significance, Strong expression of CD was detected in 22% of cases. This intense expression was significantly associated with a number of established prognostic factors, including the non-ductal type of carcinoma (p = 0.0243) and metastases at the time of diagnosis (p = 0.0068). On the other hand, high expression of CD was not related to the lymph-node status, tumour size, ER/PR content or histological grade. Patients with CD overexpression has a significantly lower survival probability (p = 0.0478) than did the patients with low expression of this protease. The relationship between the high expression of CD and short disease-free survival was almost significant (p = 0.0519). Intense immunostaining of CD was associated with a significantly impaired disease outlook in patients with confirmed lymph node metastasis (N+) (p = 0.0137) but not in those with negative lymph nodes (N-) (p = 0.0620). In Cox's multivariate analysis, expression of CD had no independent prognostic value over the conventional prognostic factors. The results suggest that expression of CD is of borderline significance in evaluating the intrinsic malignancy of female breast cancer in general. The potential of CD as a prognostic factor in specific subgroups of breast cancers will be the subject of further studies.
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PMID:Prognostic value of cathepsin-D expression in female breast cancer. 764 22

Amplification of c-myc and c-erb beta-2 (HER-2/neu) proto-oncogenes were analyzed in breast cancer tissues obtained from 100 patients without lymph node involvement (N-). An amplification of the c-myc gene was detected in four cases and a c-erb beta-2 (HER-2/neu) amplification in eight cases. The frequency of these abnormalities were compared to classical prognostic parameters as well as to new biological prognostic markers (cellular cycle, cathepsin-D and pS2 protein). Most of altered tumors were associated to some classical poor prognostic factors such as: steroid receptor-negative tumors, poorly differentiated tumors, high histoprognostic grade and tumor cell density. In contrast, no relation was found with new biological parameters. The analyses of these data in relation to clinical evolution will be of interest to evaluate their prognostic value.
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PMID:[Amplification of c-myc and c-erbbeta-2(HER-2/neu) in breast cancer without axillary lymph node metastasis: correlation with other prognostic parameters]. 770 67

The expression of three lysosomal cysteine proteases was examined in a lowly metastatic, MCF-7 human breast cancer cell line and its highly metastatic, Adriamycin-resistant variant, MCF-7/AdrR. While levels of cathepsin H activity were similar in all cell lines at each stage of growth, intracellular cathepsin B and L activities were highest in MCF-7/AdrR. These high levels were accompanied by growth-related increases in acid/pepsin-activatable cathepsin activity in the culture medium. Analyses of endogenous cathepsin B inhibitor activity in control and heat-treated cell homogenates after fractionation by fast protein liquid chromatography suggested that alterations in cystatin-like, cysteine protease inhibitor activities contribute to increased levels of cathepsin activities in metastatic MCF-7/AdrR cells.
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PMID:Characterization of cysteine proteases and their endogenous inhibitors in MCF-7 and adriamycin-resistant MCF-7 human breast cancer cells. 786 Feb 23

In breast cancer, axillary lymph node invasiveness is the major prognostic factor in predicting relapse and metastasis. Nevertheless, since 30% of node-negative tumours also relapse, it is necessary to develop other independent prognostic factors. Oncogene amplification and overexpression as well as the level of cathepsin-D have been proposed as additional prognostic factors. Recent studies suggest that the acidic lysosomal proteinase cath-D, present in all cells and known to be secreted in breast cancer cells, may be implicated in the process of tumour invasion and metastasis. We have compared the cytosolic cath-D level with the amplification and the overexpression of the oncogenes c-myc and c-erb-b-2 in 62 breast carcinomas (52 primary and 10 metastatic). Using a cut-off level of 60 pmol/mg protein, the status of cath-D showed a positive correlation with c-myc amplification (P = 0.01) or overexpression (P = 0.02). In contrast, no correlation was found between cath-D and c-erb-B-2 amplification or overexpression. Also, no correlation was found between cath-D and established prognostic factors such as node invasiveness, steroid receptors, grade and menopausal status. Nevertheless, a weak correlation was found between cath-D levels and tumour status (P = 0.05). In conclusion, in breast cancer, a high cytosolic cath-D concentration is more frequent in tumours with c-myc amplification and overexpression but is dissociated from c-erb-B-2 amplification or overexpression, suggesting that the determination of cath-D, as well as the latter two markers, will have an additional prognostic value.
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PMID:Cathepsin-D and c-erb-B 2 have an additive prognostic value for breast cancer patients. 790 24


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