Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04155 (pS2)
 1,234 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A human tamoxifen-resistant mammary carcinoma, MaCa 3366/TAM, originating from a sensitive parental xenograft 3366 was successfully established by treatment of tumour-bearing nude mice with 1-50 mg kg(-1) tamoxifen for 3 years during routine passaging. Both tumours did not differ significantly in OR- and PR-positivity, however, when compared with the sensitive tumour line, the mean OR content of the TAM-resistant subline is slightly lower. An OR-upregulation following withdrawal of oestradiol treatment was observed in the parental tumours but not in the resistant xenografts. Following long-term treatment with tamoxifen, the histological pattern of the breast carcinoma changed. The more differentiated structures being apparent after treatment with 17beta-oestradiol in the original 3366 tumour were not induced in the resistant line. Tamoxifen failed to induce a tumour growth inhibition in comparison to the tamoxifen-sensitive line. The pure anti-oestrogen, ICI 182 780, revealed cross-resistance. Sequence analysis of the hormone-binding domain of the OR of both lines showed no differences, suggesting that either mutations in other regions of the OR are involved in the TAM-resistance phenotype or that mechanisms outside of this protein induced this phenotype. Oestrogen and anti-oestrogen regulate pS2 and cathepsin D expression in 3366 tumours as in the human breast cancer cell line MCF-7. The resistant 3366/TAM tumours have lost this regulation. The established breast cancer xenografts 3366 and 3366/TAM offer the possibility of investigating mechanisms of anti-oestrogen resistance in an in vivo situation. They can be used to test novel approaches to prevent, or to overcome, this resistance in a clinically related manner.
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PMID:Development and characterization of a tamoxifen-resistant breast carcinoma xenograft. 1083

Chromatin restricts the accessibility of DNA to regulatory factors; its remodeling over the regulatory regions contributes to the control of gene expression. An increasing number of evidence links defects in chromatin remodeling machinery and cancer. Our aim is to elucidate the role of chromatin structure in the control of the expression of hormone-induced genes in breast cell lines estrogen-dependent or -independent for growth. Mammary tumor growth is controlled by steroid hormones via their nuclear receptor and by growth factors via tyrosine kinase receptors. 50 % of these tumors elude to hormonal control. This limits the anti-estrogen therapy. As a model, we have analyzed in several cell lines the chromatin organization of the regulatory regions of two genes, pS2 that is associated with a good prognostic, and cathepsin D (catD) that is a bad prognostic marker. The expression of the two genes is estrogen-regulated in estrogen-dependent cell line MCF7. In contrast in the hormone-independent cell line MDA MB 231, pS2 is not expressed and catD is constitutively expressed. Within the regulatory regions of pS2 gene, we have localized two regions that undergo a hormone-dependent change in chromatin structure in MCF7 cells but not in MDA MB 231. The lack of chromatin remodeling in MDA MB 231 cells is not due to the absence of expression of the estrogen receptor in the cell line. The expression of pS2 gene can be correlated with chromatin remodeling over the regulatory regions of pS2 gene. In contrast catD regulatory regions did not display hormone-dependent changes in chromatin structure, suggesting that hormone regulation takes place within regions with a constitutively open chromatin structure.
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PMID:[Chromatin remodeling in estrogen-dependent and independent human breast cancer cell lines]. 1089 64

In order to search for novel estrogen-responsive genes, we performed serial analysis of gene expression (SAGE) for estrogen-treated MCF-7 human breast cancer cells. SAGE analysis of 31,000 and 30,856 tags from non-treated and 17 beta-estradiol (E2)-treated cells for 24 h, respectively, facilitated the identification of 15,037 different transcripts. Comparison of these two SAGE libraries indicated a remarkable similarity in expression profiles. Among the identified transcripts, four genes were found to be markedly increased for E2-treated cells compared with control cells. Three of the transcripts were cathepsin D, pS2 and high mobility group 1 protein, which have been described as estrogen-inducible genes. The fourth gene was WISP-2 (Wnt-1 inducible signaling pathway protein 2) which has recently been reported as an up-regulated gene in the mammary epithelial cell line C57 MG transformed by the Wnt-1 oncogene. The increase in WISP-2 mRNA was completely prevented by co-incubation with a pure anti-estrogen ICI 182,780, but not by coincubation with cycloheximide, indicating that WISP-2 is directly regulated by the estrogen receptor. The WISP-2 gene was also induced by treating with environmental estrogens, such as bisphenol-A or nonylphenol. This study represents the first comprehensive gene expression analysis of estrogen-treated human breast cancer cells.
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PMID:WISP-2 as a novel estrogen-responsive gene in human breast cancer cells. 1094 50

Chromatin restricts the accessibility of DNA to regulatory factors; its remodelling over the regulatory regions contributes to the control of gene expression. An increasing number of evidence links defects in chromatin remodelling machinery and cancer. Our aim is to elucidate the role of chromatin structure in the control of the expression of hormone-induced genes in breast cell lines oestrogen-dependent or -independent for growth. Mammary tumour growth is controlled by steroid hormones via their nuclear receptor and by growth factors via tyrosine kinase receptors. 50% of these tumours elude to hormonal control. This limits the anti-oestrogen therapy. As a model, we have analysed in several cell lines the chromatin organisation of the regulatory regions of two genes, pS2 that is associated with a good prognostic, and cathepsin D (catD) that is a bad prognostic marker. The expression of the two genes is oestrogen-regulated in oestrogen-dependent cell line MCF7. In contrast in the hormone-independent cell line MDA MB 231, pS2 is not expressed and catD is constitutively expressed. Within the regulatory regions of pS2 gene, we have localised two regions that undergo a hormone-dependent change in chromatin structure in MCF7 cells but not in MDA MB 231 and that can be correlated with gene expression. In contrast catD regulatory regions did not display hormone-dependent changes in chromatin structure, suggesting that hormone regulation takes place within regions with a constitutively open chromatin structure.
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PMID:Chromatin remodeling in hormone-dependent and -independent breast cancer cell lines. 1095 22

In order to investigate the possible hormone-dependence of CD44v6 in human breast cancer, we assayed the concentrations of this isoform in the membrane fraction of 168 invasive ductal carcinomas (IDC) and in 26 normal breast tissue samples, 18 fibradenomas (FAD), 3 fibrocystic disease specimens (FD), 7 mucinous carcinomas and 4 medullary carcinomas using the ELISA method. The results were compared with those of the estrogen (ER) and progesterone (PR) receptors, pS2, tissue type plasminogen activator (t-PA), cathepsin D, epidermal growth factor receptor (EGFR) and c-erbB2/neu oncoprotein concentrations. Menopausal status, size of the tumor in the cases of cancers, axillary lymph node involvement, histologic grade, ploidy, cellular synthesis phase, multifocality and multicentricity were also considered as variables. The cut-off value for CD44v6-positivity was set at 5 ng/mg prt. membrane protein content. 64/138 (38.1%) infiltrating ductal carcinomas scored positive. This was significantly higher than for the normal breast tissue (0/26; p: 0.0001), similar to that seen in the FAD (3/18), fibrocystic disease (0/3), infiltrating mucinous carcinomas (4/7) and lobular (3/15) and significantly lower than for the infiltrating medullary carcinomas (4/4; p: 0.027). There were no significant differences with the other groups of tissues studied. Furthermore, CD44v6-positive IDC showed significantly higher concentrations of ER, PR and cathepsin D and lower (p: 0.051) concentrations of EGFR when compared to their CD44v6-negative counterparts. The significant coexpression of ER, PR and cathepsin D seems to indicate a possible role for hormonal regulation of CD44v6 expression while the role of pS2 and t-PA, estrogen related proteins, was very reduced.
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PMID:[Expression of the adhesion molecule CD44v6 in infiltrating ductal carcinomas of the breast is associated with hormone dependence. Our experience with 168 cases]. 1106 11

The BRCA1 gene was previously found to inhibit the transcriptional activity of the estrogen receptor [ER-alpha] in human breast and prostate cancer cell lines. In this study, we found that breast cancer-associated mutations of BRCA1 abolish or reduce its ability to inhibit ER-alpha activity and that domains within the amino- and carboxyl-termini of the BRCA1 protein are required for the inhibition. BRCA1 inhibition of ER-alpha activity was demonstrated under conditions in which a BRCA1 transgene was transiently or stably over-expressed in cell lines with endogenous wild-type BRCA1 and in a breast cancer cell line that lacks endogenous functional BRCA1 (HCC1937). In addition, BRCA1 blocked the expression of two endogenous estrogen-regulated gene products in human breast cancer cells: pS2 and cathepsin D. The BRCA1 protein was found to associate with ER-alpha in vivo and to bind to ER-alpha in vitro, by an estrogen-independent interaction that mapped to the amino-terminal region of BRCA1 (ca. amino acid 1-300) and the conserved carboxyl-terminal activation function [AF-2] domain of ER-alpha. Furthermore, several truncated BRCA1 proteins containing the amino-terminal ER-alpha binding region blocked the ability of the full-length BRCA1 protein to inhibit ER-alpha activity. Our findings suggest that the amino-terminus of BRCA1 interacts with ER-alpha, while the carboxyl-terminus of BRCA1 may function as a transcriptional repression domain. Oncogene (2001) 20, 77 - 87.
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PMID:Role of direct interaction in BRCA1 inhibition of estrogen receptor activity. 1124 6

Some node-negative breast cancer patients, with initially good prognosis, relapse from their cancer and are poorly identified. In the present study, based on prospective data of 197 tumors, we measured cathepsin D (cath D, n=197), pS2 protein (n=125), c-erbB-2 oncoprotein (n=100) and epidermal growth factor receptor (EGF-R, n=99) to better define the risk of relapse of node-negative patients in comparison with that defined by the clinical and histological factors. The median follow-up in surviving patients was 75 months. Univariate analysis indicated that patients with histological grade III tumors (the Scarff, Bloom and Richardson classification) had a much poorer prognosis than those with histological grade I or II tumors (P=0.0027 for relapse-free survival and P=0.0156 for overall survival). When the population of node-negative patients was divided by tertiles, high cath D levels showed a significant association with an early relapse (P=0.0316). Using cut-off values, patients with high cath D (> or =25 pmol/mg protein) or c-erbB-2 oncoprotein (> or =4 Human Neu Unit/microg protein) levels, had a significant worse relapse-free survival (P=0.0147 and 0.0417, respectively). No prognostic information was supported by pS2 protein or EGF-R measurements. In multivariate analysis, histological grade, cath D and c-erbB-2 oncoprotein remained independent predictors of recurrence (P=0.005, 0.0361 and 0.0321, respectively). By combining low levels of cath D and c-erbB-2 oncoprotein in histological grade I or II tumors, we identified a subgroup of patients with a 100% relapse-free survival probability at 6 years of follow-up. Moreover, the subgroup of patients with histological grade I or II tumors and high values of both cath D and c-erbB-2 oncoprotein showed a prognosis as poor as the subgroup defined by histological grade III alone, respectively 66% and 70% relapse-free survival at 6 years of follow-up. In conclusion, the combination of conventional prognostic factor (histological grade) and biochemical factors (cath D and c-erbB-2 oncoprotein) enabled us to identify, in this preliminary study, a subgroup of patients having an increased risk of relapse in a group (node-negative patients with low histological grade tumors) considered as good prognosis.
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PMID:Prognostic impact of cathepsin D and c-erbB-2 oncoprotein in a subgroup of node-negative breast cancer patients with low histological grade tumors. 1125 Nov 76

In order to study the association of histological grade (HG) with specific clinical and biological parameters which may influence the clinical behavior of infiltrating ductal carcinomas of the breast (IDC), we analyzed in 229 tissue samples the cytosolic concentrations of estrogen receptor (ER), progesterone receptor (PR), pS2, cathepsin D, hyaluronic acid (HA) and tissue-type plasminogen activator (t-PA), as well as those of the erbB2 oncoprotein, epidermal growth factor receptor (EGFR), HA, CD44v5 and CD44v6 in the cell membrane fraction. Likewise, we considered size, ploidy, S-phase fraction and axillary node involvement as variables of the study. The transition from HG1 to HG2 and from HG2 to HG3 was accompanied by a number of common features: global increase in size, greater number of tumors >2.0 cm, decrease in membrane hyaluronic acid concentrations, increased cell proliferation (S-phase >7%) and greater aneuploidy. Other events observed during the transition from HG2 to HG3 were a decrease in ER, PR, t-PA and cytosolic hyaluronic acid. These results led us to consider that HG is associated with certain clinical-biological changes that may help explain its value as a prognostic factor in breast carcinomas.
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PMID:Histological grade in breast cancer: association with clinical and biological features in a series of 229 patients. 1128 57

Breast cancer screening is important for the early detection of breast cancer. Tumors that become symptomatic in the screening interval are known as interval cancers but the reasons for their rapid progression are unknown. Estrogen receptor expression is lower in interval cancers suggesting that they may have reduced hormonal responsiveness. To investigate this hypothesis we have measured the expression of the estrogen receptor and three estrogen-responsive genes (cathepsin D, progesterone receptor, and TFF1) in screen-detected and interval breast cancers. The expression of the protease cathepsin D was not associated with estrogen receptor in either group of tumor. Progesterone receptor expression was highly correlated with that of the estrogen receptor in both groups of tumors but it was not expressed at significantly different levels in the two groups of tumors. Expression of TFF1, a cellular motogen, was correlated with estrogen receptor in screen-detected but not interval cancers and was expressed at markedly higher levels in interval breast tumors, the group that expresses lower levels of estrogen receptor. Interval cancers are characterized by high levels of expression of TFF1 and/or Ki67 suggesting that cell migration and cell division play important roles in the rapid progression of interval cancers. The observation that TFF1 expression in interval cancers tends to be estrogen-independent and that interval cancers have reduced estrogen receptor expression suggests they may have a reduced response to hormone therapy.
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PMID:High expression of the trefoil protein TFF1 in interval breast cancers. 1143 68

The paper presents recent data on the role of oncogenes and suppressive genes, receptors of steroidal hormones, secretory protein pS2, cathepsin D, urokinase and tissue plasminogen activators and their inhibitor PAI-I, polypeptide growth factors and somatostatin and their receptors in the evaluation of proliferative activity and drug therapy responses and in the prediction of disease and on the simultaneous estimation of the limited number of mutually complementing parameters that can characterize the proliferative activity of a tumor, its metastatic potential and sensitivity to different types of overall and regional regulation. The main task for investigators engaged in this area is to choose a qualitatively and quantitatively optimal ratio of molecular markers of breast cancer to evaluate the biological behavior of a tumor.
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PMID:[Modern prospects for molecular-biochemical methods for evaluating biological "behavior" of breast neoplasms]. 1167 60


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