Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of EGFR family and steroid hormone receptors was examined in a series of 40 cases of pure ductal carcinoma in situ (DCIS) of the breast by immunohistochemical staining of paraffin-embedded sections. Hematoxylin and eosin-stained sections were used to classify the tumors according to the published criteria by Holland et al. (Holland R, Peterse JL, Millis RR, et al. Semin Diagn Pathol. 1994;1 1:167-180). Of the tumors 48% were immunoreactive for EGFR, 63% for c-erbB-2, 78% for c-erbB-3, 95% for c-erbB-4, 88% for estrogen receptor (ER) and 80% for progesterone receptor (PR). Statistically significant association between histological grade (differentiation) and c-erbB-2 protein expression was seen (p <.001). In addition, expression of c-erbB-4 protein was associated with c-erbB-2 (p=.004), c-erbB-3 (p=.058), ER (p=.002) and PR (p=.004). It is concluded that c-erbB-2 expression in DCIS is associated with high-grade pathological features, and a higher c-erbB-2 expression is seen in DCIS than in invasive breast carcinomas. A possible association between extensive expression of c-erbB-4 and steroid hormone receptors in proliferative and premalignant breast epithelial cells and the c-erbB-2 expression in DCIS and invasive breast carcinomas is discussed.
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PMID:Expression of EGFR family and steroid hormone receptors in ductal carcinoma in situ of the breast. 1175 15

The recent cloning of a second estrogen receptor (ER), designated ERbeta, has prompted a reevaluation of the role of ERs in breast cancer. We have developed and validated a real-time RT-PCR assay to quantify ERalpha and ERbeta gene expression at the mRNA level in a series of 131 patients with unilateral invasive primary breast cancer. Although ERbeta expression showed wide variations in tumor tissues, its range (nearly three orders of magnitude) was smaller than that of ERalpha (nearly four orders of magnitude), suggesting that ERbeta is more tightly controlled than ERalpha. We observed a negative correlation between ERalpha and ERbeta expression. 'ERalpha-negative' tumors (containing very low ERalpha mRNA levels) were associated with SBR histopathological grade III, RB1 underexpression and ERBB2 overexpression, confirming that ERalpha negativity delineates poorly differentiated tumors. The amount of ERalpha mRNA (but not that of ERbeta mRNA) increased with age and was consequently higher in postmenopausal patients' tumors. Expression of ERalpha (but not that of ERbeta) also correlated strongly with progesterone receptor (PR) and PS2 expression, suggesting that ERalpha has stronger transcriptional activity than ERbeta towards genes containing an ERE (estrogen response element) in their promoters. Interestingly, we found a negative correlation between the expression of ERbeta (but not ERalpha) and CCND1, which contains an AP1 element but not an ERE in its promoter. Taken together, these data confirm that ERalpha and ERbeta play different roles in breast cancer, partly by mediating the transcription of various genes via different types of DNA enhancer. PR and PS2 seem to be mainly ERalpha-responsive genes, whereas CCND1 may be mainly ERbeta-responsive. Our findings also underline the need for a reliable method, providing full range of quantitative values, to determine ERalpha and ERbeta status in the clinical setting.
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PMID:Quantification of estrogen receptor alpha and beta expression in sporadic breast cancer. 1178 24

Based largely on studies of cell lines in vitro and of transgenic mouse models, disruptions of transforming growth factor (TGF) beta signaling are thought to contribute to the development and progression of human breast cancer. However, whether and how TGF-beta signaling becomes disrupted during human breast cancer development in vivo remains largely unknown. To address this question, we have compared the patterns of expression and activation of the postreceptor components of the TGF-beta signaling pathway, the so-called Smads, in human breast cancer cell lines with those in breast carcinoma specimens. None of the breast carcinoma cell lines were growth arrested by TGF-beta in vitro. Each of the tumor cell lines expressed normal levels of Smad2 and -3. Moreover, TGF-beta treatment induced phosphorylation of Smad2 (Smad2P) in each of these lines, except those that lacked TGF-beta type II receptors. Moreover, only one of the cell lines failed to express Smad4. Among 456 cases of human breast carcinoma assembled in tissue microarrays, the majority (92%) expressed Smad2, Smad2P, as well as Smad4, indicating their ability to proliferate within a microenvironment that contains bioactive TGF-beta. Thirty cases (6.6%) failed to express Smad2P, suggesting the loss of TGF-beta receptor signaling. Nine cases (2%) failed to express Smad4, and 3 of these also failed to express Smad2P. Thus, the phenotypes of breast tumors in vivo paralleled that of human breast cancer cell lines in terms of Smad2P and Smad4 expression. Loss of Smad signaling was not associated with any particular histological subtype, histological or nuclear grade, estrogen- or progesterone receptor expression, or HER2/neu expression. Loss of Smad4 was inversely correlated with the presence of axillary lymph node metastases. Most importantly, among patients with stage II breast cancer, lack of Smad2P expression in the tumor was strongly associated with shorter overall survival. Finally, analysis of a small cohort of hereditary breast cancers failed to reveal any association between BRCA1 or BRCA2 genotype and alterations in Smad signaling.
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PMID:Alterations of Smad signaling in human breast carcinoma are associated with poor outcome: a tissue microarray study. 1180 1

Inflammatory breast carcinoma (IBC) is a rare but aggressive form of breast cancer. In this first-ever study, we investigated the role of nine prognostic markers' expression (estrogen receptor [ER], progesterone receptor [PR], p53, C-erbB-2, epidermal growth factor receptor [EGFR], cathepsin D [CD], proliferating cell nuclear antigen [PCNA], DNA ploidy, and S-phase fraction [SPF]) and disease outcome in IBC cases compared with the control group. A case control study of IBC was conducted on 40 test cases with two controls per case matching age, grade, and number of axillary lymph nodes sampled. During 7 years of this study, 10% of all patients with breast cancer had IBC. In this study, 84% of IBC cases showed positive axillary lymph nodes compared with 63% in control group. The expression of nine prognostic markers, that is, ER, PR, p53, C-erbB-2, EGFR, CD, PCNA, SPF, and DNA ploidy, was studied by immunohistochemistry and flow cytometry. Hormone receptor status showed an inverse correlation (p < 0.05). Among p53, C-erbB-2, EGFR, and CD in the IBC group, only p53 showed a significant correlation, with 70% positivity in IBC versus 48% positivity in the control group (p < 0.05). Much higher SPF and PCNA positivity was seen in the IBC group compared with the control group (p < 0.05). DNA ploidy also showed a significant correlation compared with the control group (p < 0.05). After a median follow up of 18 months, median overall survival in the IBC group was 1.8 years (range 0.6-5.8 years) compared with 3.0 years (range 2.5-7.0 years), with a p value of 0.0001.
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PMID:Case control study of prognostic markers and disease outcome in inflammatory carcinoma breast: a unique clinical experience. 1184 51

The extreme drug resistance (EDR) assay has not been widely studied in the setting of non-metastatic breast cancer. We evaluated the feasibility of performing the assay in 144 primary breast tumor specimens from two institutions by determining the rate of successful tumor culture for assays, number of drugs evaluated per assay, and time from tumor biopsy to receipt of results. We also sought to determine factors that are associated with assay success. An exploratory analysis was performed to detect possible associations between estrogen receptor (ER), progesterone receptor (PR) and HER2/NEU over-expression and extreme drug resistance demonstrated by the assay for specific chemotherapeutic agents. Of 144 tumor specimens submitted, tumor was successfully cultured for assay in 101(70%) of cases. A median of five drugs was evaluated per assay (range 2-9). Results were obtained in a median of 8 days (range 2-29). Young age, high tumor grade, PR negativity, and higher tumor submission weight were predictive for a successful assay. EDR was observed in 7-15% of tumors to doxorubicin, cyclophosphamide, 5-fluorouracil (5FU) and mitoxantrone, but EDR to paclitaxel was observed in 35%. Extreme drug resistance to 5-FU was associated with negative ER and PR status. There was a trend toward association between EDR to paclitaxel and HER2/NEU over-expression. The EDR assay may be successfully performed in the majority of tumors, and assay results are available in a timely fashion such that adjuvant treatment drug selection could be guided by results. These results may be helpful for designing possible future trials that evaluate the assay's role in adjuvant chemotherapy selection.
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PMID:Factors associated with success of the extreme drug resistance assay in primary breast cancer specimens. 1188 14

Data regarding young age as an independent prognostic factor have been conflicting. We investigated this variable in 696 premenopausal Vietnamese and Chinese women with operable breast cancer who participated in a clinical trial of adjuvant surgical oophorectomy and tamoxifen. Tumor size and axillary lymph node status did not vary with age. Women < 35 years had a greater fraction of histologic grade III tumors (P = 0.06), and in the two thirds of patients with available data, in women < 35 years, there was a lower percentage of estrogen- and progesterone receptor-positive tumors and a higher percentage of HER2/neu-positive tumors (P > 0.14 for each group). In univariate analyses, compared to women > or = 45 years, women < 35 years and 35-39 years were at greater risk for death (P = 0.002 and P = 0.023, respectively), and compared to women > or = 40, women < 40 were at greater risk of death (P = 0.002). Multivariate analyses supported a conclusion that younger age was an independent adverse prognostic factor for survival (P = 0.005, age as a continuous variable). Kaplan-Meier analyses in all patients and in oophorectomy and tamoxifen-treated patients, but not in observation-only patients, showed statistically significant poorer disease-free and overall survival in women < 40 years compared to those > or = 40 years. Thus, despite efficacy of the combined adjuvant hormonal therapy, younger age was a risk factor for poorer survival.
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PMID:Young age as an adverse prognostic factor in premenopausal women with operable breast cancer. 1189 61

A differential display method was used to study genes the expression of which is altered during growth inhibition induced by medroxyprogesterone acetate (MPA). A transcript of G-protein-coupled receptor 30 (GPR30) was upregulated by MPA in estrogen-treated MCF-7 breast cancer cells. Northern-blot analysis showed a progestin-specific primary target gene, which was enhanced by progesterone and different progestins, but not by dihydrotestosterone or dexamethasone, and which was abrogated by antiprogestin RU486. The dose-dependent and time-dependent increase in GPR30 mRNA expression correlated with MPA-induced growth inhibition in MCF-7 cells. Additionally, GPR30 upregulation by progestin correlated with growth inhibition when a comparison was made between different breast cancer cell lines. The ERK1/ERK2 pathway is capable of inducing progesterone receptor-dependent and ligand-dependent transcription. Thus we sought to establish whether different MAPK pathway inhibitors affect progestin-induced GPR30 mRNA regulation. The regulation of GPR30 was independent of ERK pathway activation, but the p38 pathway inhibitor induced GPR30 expression, which suggested a potential gene regulation pathway. These data demonstrate a new progestin target gene, the expression of which correlates with growth inhibition.
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PMID:Progestin upregulates G-protein-coupled receptor 30 in breast cancer cells. 1202 86

The estrogen receptor alpha (ERalpha) signaling plays an essential role in breast cancer progression and endocrine therapy. Mitogen-activated protein kinase (MAPK/Erk1/2) has been implicated in ligand-independent activation of ER, resulting in the cross-talk between growth factor and ER mediated signaling. In this study, we examined the effect of the cross-talk on estradiol (E(2))-mediated signaling, tumor growth and its effect on anti-estrogen therapy. Our findings demonstrate that expression of constitutively activated mitogen activated kinase kinase (MEK1), an immediate upstream activator of MAPK in estrogen receptor positive MCF-7 breast cancer cells (MEK/MCF-7), showed an increase in ERalpha-driven transcriptional activation. In MEK/MCF-7 cells maximal transactivation levels were achieved in response to treatment with much lower E(2) concentrations (10(-10) M E(2)) when compared to MCF-7 control cells (10(-8) M E(2)). Furthermore, we have seen an increased association between ERalpha and its nuclear coactivators AIB1 or TIF-2, in MEK/MCF-7 cells relative to those seen in MCF-7 control cells. In addition, in vivo studies show that MEK/MCF-7 cell tumors are approximately threefold larger than those of MCF-7 cell, in the presence of E(2). Immunohistochemical staining demonstrates that progesterone receptor (PR) and pS2, two E(2)-regulated gene products, are significantly increased in MEK/MCF-7 cell tumors compared to those of MCF-7 control tumors, suggesting that activation of ERalpha by MAPK enhances the expression of E(2)-regulated genes and accelerates tumor growth. Remarkably, the antiestrogens tamoxifen and ICI 182,780, were shown both in vitro and in vivo studies to efficiently antagonize the stimulatory effects of E(2) on ER regulated transactivation and tumor growth in MEK/MCF-7 as well as MCF-7 cell lines. Taken together, these data suggest that MAPK/ER cross-talk enhances ERalpha-mediated signaling and accelerates E(2)-dependent tumor growth without diminishing sensitivity to the inhibitory effects of anti-estrogens.
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PMID:MAP kinase/estrogen receptor cross-talk enhances estrogen-mediated signaling and tumor growth but does not confer tamoxifen resistance. 1203 82

Preliminary results of a phase II study of gemcitabine plus trastuzumab in previously treated (up to 3 previous regimens) metastatic breast cancer patients are presented. Patients had histologically confirmed metastatic breast cancer, with 2+ or 3+ tumor HER2 expression. Treatment consisted of gemcitabine 1200 mg/m2 over 30 minutes intravenously on days 1 and 8 every 21 days, and trastuzumab 4 mg/kg over 90 minutes, followed by 2 mg/kg infused over 30 minutes weekly. Treatment was continued until disease progression or unacceptable toxicity occurred. Preliminary results are available on the first 38 patients enrolled. Median patient age was 53 years, 53% had estrogen receptor/progesterone receptor-positive disease, and HER2 staining was 2+ in 39% and 3+ in 61% of patients. There was a median of 3 previously administered (including adjuvant) chemotherapy regimens, and a median of 4.5 treatment cycles per patient has been administered so far. Twelve patients (32%) have had an objective partial response, with a median response duration of 8.6 months. Median time to disease progression is 6.7 months to date, with a median overall survival of 10.2 months. No unexpected toxicities or grade 4 nonhematologic toxicities have been observed; 2 patients developed grade 4 neutropenia and 1 patient had febrile neutropenia. Thus, gemcitabine/ trastuzumab resulted in an encouraging 32% response rate, given the heavily pretreated patient population. Tolerability was good overall, with no unexpected side effects observed.
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PMID:Phase II trial of gemcitabine plus trastuzumab in metastatic breast cancer patients previously treated with chemotherapy: preliminary results. 1205 40

Over-expression of the human epidermal growth factor receptor-2 (HER2/neu) has been observed in many cancers, and is associated with a poor prognosis. Recent adjuvant treatment with anti-HER2 monoclonal antibodies in breast cancer has increased the demand for an evaluation of the HER2/neu status in breast cancer. The aim of this study was to investigate the HER2/neu status in breast cancer by a real-time quantitative polymerase chain reaction (PCR) method using LightCycler (Roche Diagnostics, Mannheim, Germany). DNA samples from the fresh tumor tissues of 27 patients with breast cancer were analyzed in parallel using immunohistochemistry (IHC) and the other prognostic parameters including estrogen receptor, progesterone receptor, cytokeratin, and DNA ploidy. Ten (37%) out of 27 cases tested were positive for HER2/neu, while 16 (73%) out of 22 tested positive through an IHC study. The correlation between the DNA aneuploidy and the positive results for HER2/neu were only observed using the real-time PCR method (p < 0.05). There was no significant correlation between the HER2/neu status and the S-phase fractions of the DNA ploidy or other parameters. This study demonstrated that there is marked discordance in the results for the HER2/neu status according to the various methods used. Real-time quantitative PCR for HER2/neu appears to be clinically useful due to its simplicity and ability to produce rapid results.
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PMID:Evaluation of HER2/neu status by real-time quantitative PCR in breast cancer. 1208 41


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