Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protein product of the bcl-2 gene is though to be involved in inhibition of apoptosis; it may therefore be important in the modulation of hormonal/anti-hormonal responsiveness exhibited by tumours. This study immunocytochemically investigates (i) relationships between bcl-2 protein expression in primary breast cancers and other markers of prognostic and therapeutic value and (ii) associations of the bcl-2 protein with breast cancer responsiveness to endocrine therapy. The bcl-2 protein was found within the tumour epithelial cell cytoplasm of 32/46 breast cancer specimens; inter-patient staining was heterogeneous. Immunostaining for steroid hormone receptors was strongly associated with that for the bcl-2 protein, and it is thus possible that this protein, like progesterone receptor, is under oestrogen regulation via oestrogen receptor. The protein was inversely related to 2 markers of endocrine insensitivity, epidermal growth factor receptor (EGFR) and c-erbB-2 oncoprotein, while no associations were observed with either transforming growth factor (TGF)-alpha or Ki-67 proliferative status. A highly significant relationship was observed between response to endocrine therapy and the presence of bcl-2 protein. Indeed, bcl-2 immunostaining proved to be a more accurate predictor of response than oestrogen receptor status. Patients with elevated bcl-2 immunostaining (particularly those who coexpressed high oestrogen receptor levels) appeared to derive the greatest benefit from endocrine therapy. Our results are paradoxical since it was expected that the bcl-2 protein would counteract the tumour inhibitory effects of endocrine therapies as it is thought to prevent programmed cell death.
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PMID:Immunocytochemical localization of BCL-2 protein in human breast cancers and its relationship to a series of prognostic markers and response to endocrine therapy. 796 Feb 34

As the prognostic significance of the three most frequently amplified oncogenes in breast cancer (c-myc, int-2/FGF3, and c-erbB-2/neu) is still unclear, and as the amplification of these genes appears to be mutually exclusive, we investigated the prognostic significance of oncogene amplification per se by multivariate analysis in a group of 112 primary human breast cancer cases. Amplification of at least one gene (c-myc, int-2/FGF3, or c-erbB-2/neu), progesterone receptor status, and pathological tumor size were the only independent variables predictive of metastasis-free survival. Moreover, we constructed prognostic profiles by computing risks associated with the three parameters predictive of poor survival and discriminated high-, moderate-, and low-risk categories.
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PMID:Oncogene amplification per se: an independent prognostic factor in human breast cancer. 799 60

In 199 breast cancers, HER-2/neu amplification was analyzed by Southern blotting (149 cases) and by slot blotting (149 cases), with 99 cases studied using both techniques. There were 18.8% amplified tumors (> or = 2 copies) by Southern blotting and 15.4% by slot blotting. The difference in the percentages of amplified tumors was not statistically significant (p = 0.44). There was a correlation between HER-2/neu amplification and the SBR grade (p = 0.046): this correlation relied on the absence of amplification in the GI tumors. In a subset study, the negativity of the progesterone receptor content was correlated with HER-2/neu amplification in the node positive (p = 0.02), the pre-menopausal (p = 0.04) and the pre-menopausal node positive (p = 0.002) patients. In the literature as in our results, amplification appears to be correlated with poor prognostic factors. However, in a subgroup with most of the favorable prognostic factors: positive estrogen and progesterone receptor contents and node negativity, the frequency of amplified tumors (19.4%, n = 67) was the same as that observed in the whole group (16.6%, n = 199). This result may suggest that the HER-2/neu amplification could act as an independent prognostic factor.
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PMID:Human breast cancer: correlation study between HER-2/neu amplification and prognostic factors in an unselected population. 809 88

The authors studied 30 consecutive archival cases of pure breast carcinoma in situ (CIS) for estrogen receptor (ER), progesterone receptor (PR), and c-erbB-2 oncogene product. Clinical factors of age and menstrual status and histologic features of tumor type and nuclear grade were determined. Some 77% represented ductal CIS, with 10% noninvasive papillary, and 13% lobular CIS. A total of 22 of 30 (73%) were ER+ and 19 (63%) were PR+; 24 (80%) were c-erbB-2+ with 11 (37%) showing strong staining; 75% of the ER-PR group had tumors of NG 3, versus 14% for the ER+PR+ plus ER+PR- groups. Nonstatistically significant trends correlating the strongly positive oncogene group with PM status, receptor negativity, and high nuclear grade were noted. The overall rate of receptor positivity, as well as the correlation with nuclear grade, is similar to that in invasive carcinomas c-erbB-2 protein expression shows a higher rate in in situ than is reported for invasive tumors, and shows a tendency to be expressed more strongly in tumors with other features of poor prognosis. Therefore, these factors may also have prognostic significance in CIS. Continued followup of this population to recurrence may provide further insight.
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PMID:Estrogen and progesterone receptor and c-erbB-2 oncoprotein analysis in pure in situ breast carcinoma: an immunohistochemical study. 809 77

Among 843 cases of breast cancer, p53 oncoprotein was detected by the monoclonal antibody (MoAb) Pab-1801 in only 13%. Low-grade carcinomas (tubular, mucinous, papillary, and invasive cribriform types) did not express p53 protein, but it was observed in 4.2% of infiltrating lobular carcinomas (6 of 140 cases) and 50% of pure medullary carcinomas (5 of 10 cases). In intermediate-grade neoplasms, no correlation was seen between p53 status and other putative determinants of a poor prognosis. The latter included high tumor stage, lymph nodal involvement, high growth fraction (as determined by labeling with the MoAb Ki-67), negative results for estrogen receptor (ER) and progesterone receptor (PR) proteins, and amplification of the c-erbB-2 oncogene product in the neoplastic cells. Ninety-nine of 640 (15.5%) cases of high-grade, invasive, ductal breast carcinoma, however, showed an inverse relationship between expression of p53 protein and positive results for ER/PR proteins and a direct correlation with large tumor size, Ki-67-determined growth fraction, and amplification of c-erbB-2 oncopeptide. All of the latter associations were highly significant statistically. The authors conclude that mutant p53 protein may serve a prognostic role in a subset of cases of invasive ductal mammary carcinoma.
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PMID:Relationship between p53 expression and other prognostic factors in human breast carcinoma. An immunohistochemical study. 837 28

Estrogen receptor positive ovarian cancer is often refractile to antiestrogen therapy. Here we describe the SKOV3 human ovarian carcinoma cell line as an in vitro model for estrogen and antiestrogen resistant ovarian cancer. While SKOV3 cells expressed estrogen receptor (ER) mRNA and protein at a similar level as the estrogen responsive T47D breast carcinoma cell line, their growth was not responsive to estradiol (E2) and was not inhibited by the antiestrogens OH-tamoxifen and ICI 164,384. The ER in SKOV3 cells was normal with respect to apparent Kd for binding with E2, E2 regulation of a transiently transfected ERE driven reporter gene, and E2 stimulation of expression of the early growth response genes c-myc and c-fos. However, the SKOV3 cells exhibited no expression of the progesterone receptor gene (PR) even after addition of E2, and the protein products of the estrogen responsive genes HER-2/neu and cathepsin D were expressed at constitutive levels that were not regulated by E2. Therefore, estrogen resistance in these cells may be a result of constitutive expression and loss of E2 regulation of selected growth regulatory gene products rather than a defect in estrogen activation of ER as a transcriptional regulator.
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PMID:SKOV3 ovarian carcinoma cells have functional estrogen receptor but are growth-resistant to estrogen and antiestrogens. 854 Dec 24

The neu/erbB-2/HER-2 proto-oncogene is amplified and/or overexpressed in up to 30% of mammary carcinomas and has been variably correlated with poor prognosis. The signaling activity of the encoded receptor tyrosine kinase is regulated by interactions with other type 1 receptors and their ligands. We have used a novel approach, phosphorylation-sensitive anti-Neu antibodies, to quantify signaling by Neu and epidermal growth factor receptor in a panel of frozen sections of mammary carcinoma specimens. We also determined the relationship of Neu, phosphorylated Neu (and epidermal growth factor receptor), and phosphotyrosine to the expression of Neu-related receptors (epidermal growth factor receptor, HER-3, and HER-4) and to prognostic factors (estrogen and progesterone receptor). We found that tyrosine phosphorylation of Neu (and hence signaling activity) is highly variable among mammary carcinomas. Neu and HER-4 were associated with divergent correlates, suggesting that they have profoundly different biological activities. These results have implications for etiology of mammary carcinoma for clinical evaluation of mammary carcinoma patients, and for development of Neu-targeted therapeutic strategies.
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PMID:Type 1 receptor tyrosine kinases are differentially phosphorylated in mammary carcinoma and differentially associated with steroid receptors. 857 17

The role of molecular markers predicting the response to cytotoxic chemotherapy is not established. A potential predictive factor, topoisomerase IIalpha, is a target for certain cytotoxic drugs, and its concentration has been shown to correlate with chemosensitivity in vitro. We evaluated expression of topo IIalpha immunohistochemically in 230 breast cancer samples and studied its association with known clinicopathological factors and factors previously shown to predict response to cytotoxic drugs. Topo IIalpha protein expression was found in 0.6 to 39.4% (10.6 +/- 7.9%, mean +/- SD) of breast carcinoma cells, whereas expression was undetectable in nonmalignant breast epithelium. Topo IIalpha protein expression correlated well with semi-quantitative mRNA in situ hybridization (P = 0.007). A significant association was found between the proportion of topo-IIalpha-positive cells and low estrogen and progesterone receptor content (P<0.0001), high grade (P<0.0001), DNA aneuploidy (P=0.003), and c-erbB-2 oncoprotein overexpression (P<0.0001). Topo IIalpha expression was not associated with clinical variables, such as age of the patient, primary tumor size, or axillary nodal status. A highly significant linear correlation was found between topo IIalpha and tumor proliferation rate (S-phase fraction, r=0.46; P<0.0001). Because hormone receptors, grade, and ploidy are associated with tumor proliferation rate, topo IIalpha expression was adjusted for S-phase fraction to reveal the proliferation-independent clinopathological associations. According to the analysis of co-variance, only aneuploidy (P=0.0003) and c-erb-2 overexpression (P=0.01) were associated with proliferation-adjusted expression of topo IIalpha. In conclusion, the close association of Topo IIalpha with other potential predictive factors (tumor proliferation rate, c-erbB-2 oncoprotein) suggests that topo IIalpha, having a defined role as a target for cytotoxic drugs, may be a valuable predictor of response to chemotherapy.
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PMID:Expression of topoisomerase IIalpha is associated with rapid cell proliferation, aneuploidy, and c-erbB2 overexpression in breast cancer. 866 91

We have assessed the multiple biological variables on breast carcinoma FNA specimens using a Cytoblock technique. The growth fraction (MIB1), oestrogen receptor (ER), progesterone receptor (PR), p53 mutant protein, c-erbB-2, epidermal growth factor receptor (EGFR), NCRC11/epithelial membrane antigen (EMA) and DNA plopidy were examined. Objective quantification using image analysis (CAS 200) was applied as appropriate. Fifty cases were examined in this preliminary study. Excellent correlation between the Cytoblock preparations and parallel tissue sections was seen. Of the cancers, 81% were aneuploid with only 19% diploid in character, but 67% of the carcinomas were of histological grade 3. The mean nuclear area staining with MIB1 was 31.3% and with ER was 26.7%. Twenty-four percent (24.1%) of the nuclear area showed immunoreactivity with PR. Significant EGFR and EMA, respectively. A significant association between histological grade of the resected tumours and both MIB1 (P = 0.04) and EGFR (P = 0.02) expression in the Cytoblock samples was seen. p53 (P = 0.03) and EGFR (P = 0.01) immunoreactivity showed an association with tumour size. EGFR (P = 0.04) immunostaining also showed a relationship with the lymph node status of the patient. The technique is, we believe, a useful one for the assessment of multiple variables on breast cytology specimens; these preliminary data suggest that some of these may be useful in predicting prognosis in breast cancer patients.
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PMID:The assessment of multiple variables on breast carcinoma fine needle aspiration (FNA) cytology specimens: method, preliminary results and prognostic associations. 878 69

Expression of the erbB-2 oncogene in breast cancer patients correlates with poor prognosis and failure of hormonal therapy. In this study, the effects of a putative erbB/HER ligand, gp30, on estrogen receptor (ER) concentration and activity was investigated in the estrogen receptor positive human breast cancer cells, BT474 and MCF-7, which express either high or low levels of erbB-2 and erbB-4, respectively. Treatment of cells with gp30 resulted in a decrease in the steady-state level of estrogen receptor protein by approximately 70-80%. The effect of gp30 on the concentration of ER was independent of serum in the media and was not inhibited by an epidermal growth factor receptor blocking antibody. In addition to the effect on ER protein, gp30 decreased the steady-state level of ER messenger RNA. Transcription run on experiments demonstrated that the decrease in ER expression was mediated by a decrease in ER gene transcription. The effect of gp30 on estrogen receptor activity was also investigated in this study. Treatment of cells with gp30 blocked estradiol induction of progesterone receptor. Inhibition was observed at the level of progesterone receptor protein, messenger RNA, and gene transcription. gp30 also blocked estradiol induction of pS2 gene transcription. In addition to its effects on progesterone receptor and pS2, gp30 blocked activation of an estrogen response element in a transient transfection assay and inhibited ER binding to its response element in a DNA mobility shift assay, suggesting a direct effect on the estrogen receptor. The effects of gp30 on estrogen receptor concentration and activity were independent of the level of erbB-2 and erbB-4 in the cell. These data show that gp30 regulates the concentration of ER and modulates ER activity.
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PMID:Regulation of estrogen receptor concentration and activity by an erbB/HER ligand in breast carcinoma cell lines. 882 92


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