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

The progression of human breast cancer is often associated with a loss of estrogen dependence for growth, a resistance to estrogen antagonists such as tamoxifen, and the metastatic spread of the disease to secondary sites. Cell lines developed from such advanced breast tumors are often metastatic in athymic mice, show a loss of estrogen receptor mRNA and protein (ER-), and do not respond to 17beta-estradiol. However many advanced human breast tumors do express significant amounts of ER transcript, especially when analyzed by more sensitive methods of detection including RT-PCR and Ribonuclease Protection Assay (RPA). No metastatic, ER+breast tumor cell line has previously existed to examine the role of ER in metastatic progression and acquired drug (tamoxifen) resistance. The GI-101A cell line was recently developed from a metastatic breast tumor xenograft and is both tumorogenic and metastatic to the lungs and lymph node when injected into athymic mice, a pattern similar to that seen in patients. While Western blot analysis initially indicated that GI-101A was ER-, analysis of ER mRNA by RT-PCR and RPA have demonstrated the expression of ER (as well as EGF receptor and neu oncogene) transcripts. Functional ER in GI-101A was confirmed by a clear growth response to 17beta-estradiol in culture. Optimal 17beta-estradiol concentrations were significantly lower for GI101A than for MCF-7 (1 n m as opposed to >/=10 n m), and GI-101A growth was inhibited at 17beta-estradiol concentrations above 10 n m. Unlike MCF-7 cells, GI-101A shows constitutive expression of pS2 protein in hormone depleted media with no apparent induction by 17beta-estradiol supplimentation, as well as a resistance to the anti-estrogen tamoxifen at concentrations up to 10 n m. Finally, ER transcripts which likely represent an alternately spliced ER variant which has previously been shown to encode a constitutively active ER protein have been detected in GI-101A at levels similar to the wild type transcript, and offer a possible mechanism for estrogen independence, tamoxifen resistance, and constitutive pS2 expression.
 ...
PMID:A metastatic breast tumor cell line, GI-101A, is estrogen receptor positive and responsive to estrogen but resistant to tamoxifen. 1032 49

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.
 ...
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

Our study attempts to determine the prognostic value of the quantitative measurement of the oncoprotein p185(Her-2/neu) in a group of patients with breast cancer and positive node involvement. In a series of 217 patients with breast cancer and positive nodes in whom the oncoprotein p185 was quantitatively determined by ELISA, we analyzed the clinico-pathological variables including age, menopausal status, tumor size, number of affected nodes, type and histology grade and the molecular variables such as the oestrogen and progesterone receptors (ER and PR, respectively), pS2 and Cathepsin D (CD). Using 260 fmol/mg protein as a cut-off point, 18% of the tumors presented as overexpressing p185. The p185 showed no relationship with any of the clinico-pathological variables studied except that its concentration was elevated in ductal and lobular histology types and in the moderate and poorly differentiated histology grades. With a median follow-up of 50 months (range 1-90), the univariate analysis of disease-free survival (DFS) and overall survival (OS) showed that the histology grade, tumor size, the number of infiltrated nodes, the p185 and the ER were the variables associated with the clinical course of the disease in the patients. In the multivariate analysis, however, only the tumor size, number of affected ganglia, the p185 and the ER remained associated with the clinical progression of the disease. The patients with p185 overexpression had a risk, not only of relapse but also death from the disease, of more than twice that of the patients who had normal p185 concentrations. When the p185 was divided into 3 categories based on +/-1 x SD above or below the mean, the patients with high and low p185 showed, in the univariate analysis, a similar relationship with DFS but not with OS. In the multivariate analysis, both with the DFS as with the OS, only a high p185 concentration retained its association with the clinical course of the disease in the patients. Our results suggest that by quantitatively determining (using ELISA) the p185 oncoprotein, groups of cancer patients of high risk could be better identified for more effective clinical management.
 ...
PMID:Prognostic value of the quantitative measurement of the oncoprotein p185(Her-2/neu) in a group of patients with breast cancer and positive node involvement. 1223 94

Antiestrogen therapy of ductal carcinoma in situ (DCIS) has become a more common option in reducing risk of developing invasive cancer. Previously, estrogen receptor alpha (ER-alpha) was evaluated as the only predictive factor. Immunohistochemical staining was performed for ER-alpha, estrogen receptor ER-beta, progesterone receptor (PR), pS2 and her-2/neu in 59 cases of ductal carcinoma in situ (DCIS). We observed a positive correlation between the expression of ER-alpha (p=0.003), PR (p<0.001) and histopathological grading. Of the DCIS, 61.5% of ER-beta positive (p=0.046) and 35.5% of PR positive samples showed a coexpression with pS2, whereas 72.1% of pS2 negative DCIS were also negative for ER-beta and 92.9% of PR negative DCIS were negative for pS2 (p=0.012). In contrast, 50.0% of her-2/neu negative DCIS expressed ER-beta receptor (p=0.052). We propose that there are subpopulations of DCIS which can be described by distinct endocrine-associated expression patterns.
 ...
PMID:Estrogen receptor alpha and beta, progesterone receptor, pS2 and HER-2/neu expression delineate different subgroups in ductal carcinoma in situ of the breast. 1537 87

Androgen receptor (AR) is known to be expressed in approximately 70 to 90% of invasive breast cancers, but there are still conflicting data in terms of AR expression in ductal carcinoma in situ (DCIS). The aim of this study was to evaluate AR expression in DCIS and to compare these results with nuclear grading and with other common endocrine-related markers. On this basis the authors performed immunohistochemical staining for estrogen receptor (ER)-alpha and ER-beta, progesterone receptor (PR), pS2, her-2/neu, and AR in 59 cases of DCIS (24 low grade, 5 intermediate grade, 30 high grade). They found a strong correlation of expression of ER-alpha (P=0.003), PR (P<0.0001), and nuclear grading. For AR expression, 44.1% of all DCIS were positive, but there was no correlation between nuclear grading (P=0.535) and the expression of the other factors. The authors conclude that AR expression in DCIS is not correlated with nuclear grading and with the expression of other known endocrine-related markers such as ER-alpha and -beta, PR, pS2, and her-2/neu. The immunohistochemical assessment of AR status, therefore, may not help in providing a more objective way of classifying DCIS.
 ...
PMID:Androgen receptor expression in ductal carcinoma in situ of the breast: not a helpful marker for classification such as estrogen receptor alpha and progesterone receptor. 1572 90

Tamoxifen resistance is common for estrogen receptor alpha (ERalpha) positive breast cancer. Second-line therapies include aromatase inhibitors or fulvestrant. We have shown previously that fulvestrant reversed 17beta-estradiol-induced tumor regression of tamoxifen-stimulated MCF-7 xenografts (MCF-7TAMLT) treated for >5 years with tamoxifen in athymic mice and paradoxically stimulated growth. We investigated mechanisms responsible for growth by fulvestrant in the presence of physiologic estradiol and therapeutic strategies in vivo. The results demonstrated that only estradiol increased expression of the estrogen-responsive genes, c-myc, igf-1, cathepsin D, and pS2 mRNAs, in MCF-7E2 and MCF-7TAMLT tumors. Tamoxifen or fulvestrant decreased the estradiol-induced increase of these mRNAs in both tumor models. However, tyrosine-phosphorylated HER2/ neu, HER3, phospho-extracellular-regulated kinase-1/2 (ERK-1/2), and phospho-glycogen synthetase kinase 3alpha (GSK3alpha) and beta proteins were increased in MCF-7TAMLT tumors treated with fulvestrant compared to estradiol, control, or tamoxifen. Phospho-HER2/neu interacted with HER3 protein in MCF-7TAMLT tumors. In order to determine whether the functional interaction of HER2/neu with HER3 is critical for growth of fulvestrant-stimulated MCF-7TAMLT tumors, pertuzumab (an antibody that blocks HER2/neu-HER3 interaction) was used in an in vivo xenograft growth assay. Only growth of fulvestrant-treated MCF-7TAMLT xenografts was decreased significantly by 37.2% in response to pertuzumab (P=0.004). Pertuzumab specifically decreased the interaction of HER2/neu protein with HER3 in fulvestrant-stimulated MCF-7TAMLT tumors. These results suggested growth of MCF-7TAMLT tumors by tamoxifen or fulvestrant is potentially independent of ERalpha transcriptional activity as evidenced by lack of induction of four estrogen-responsive genes. The results suggested that growth of MCF-7TAMLT tumors treated with fulvestrant in the presence of physiologic estradiol is in part mediated through enhanced signaling from the HER2/neu-HER3 pathway as pertuzumab partially inhibited growth and the interaction of HER2/neu with HER3 in vivo.
 ...
PMID:Role for HER2/neu and HER3 in fulvestrant-resistant breast cancer. 1720 34

A series (n = 322) of breast carcinomas was investigated from 1991 to 1993 using digital image analysis. Nuclear morphometry and DNA content, and AgNORs were evaluated on cell imprints from fresh tissue samples which were further stored frozen (-80-degrees-C). Data were correlated to morphological prognostic factors and immunocytochemical expression of cell markers assessed on frozen sections and evaluated by densitometry after image analysis processing. Nuclear morphometric parameters, DNA nuclear content and AgNORs were independent from the tumor size, histological grades, and the tumor content of immunodetectable pHER-2/neu, Cathepsin D, ER, PR, pS2, and p53. But, DNA index and hyperploidy degree correlated with the mitosis index (p < 0.01) and Ki67 immunostaining (p = 0.003, p < 0.0001) whereas the shape factor and nucleus large diameter correlated with the degree of cell anisocytosis (p < 0.01). Nuclear surface and large diameter were greater in ductal carcinomas (p = 0.028) and in comedocarcinomas (p < 0.001) than in lobular carcinomas. These results suggest that image analysis processing provides accurate data to refine histoprognostic grading and additional parameters to evaluate tumor proliferative activity.
 ...
PMID:Digital image-analysis of nuclear morphometry, DNA-ploidy and AgNORs in breast-carcinoma cell imprints. 2157 58

pS2 expression was studied in 212 breast carcinomas. Immunocytochemical assays (ICAs) were performed on frozen sections and evaluated by digital image analysis. pS2 immunostaining was compared in frozen sections and paraffin sections. The pS2 positivity was observed in 45% of the cases on frozen sections. But in pS2 positive tumors, the tumor surface which was immunostained was small (m=14.3%). In 22% of immunoreactive tumors the positive surface was 5% or less. In contrast to frozen sections, the pS2 positivity on paraffin sections could not be evaluated by image analysis system because of the background. No significant correlation was observed between pS2 expression and patient age, tumor size, histological type and grade, nor with lymph node status. The pS2 positivity was significantly correlated to ER and PR positive immunodetection on frozen sections. But pS2 was independent from pHER-2/neu and cathepsin expression whereas there was a significant inverse relationship between pS2 and Ki67. This study shows that pS2-ICAs on frozen sections and image analysis are optimal and standardized conditions for the evaluation of pS2 expression in breast carcinomas, and suitable for selecting patients for hormone therapy.
 ...
PMID:Quantitative imaging of ps2 immunocytochemical assays in breast carcinomas. 2157 75


<< Previous 1 2