Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human prostatic acid phosphatase (PAcP) was used as a valuable surrogate marker for monitoring prostate cancer prior to the availability of prostate-specific antigen (PSA). Even though the level of PAcP is increased in the circulation of prostate cancer patients, its intracellular level and activity are greatly diminished in prostate cancer cells. Recent advances in understanding the function of the cellular form of PAcP (cPAcP) have shed some light on its role in prostate carcinogenesis, which may have potential applications for prostate cancer therapy. It is now evident that cPAcP functions as a neutral protein tyrosine phosphatase (PTP) in prostate cancer cells and dephosphorylates HER-2/ErbB-2/Neu (HER-2: human epidermal growth factor receptor-2) at the phosphotyrosine (p-Tyr) residues. Dephosphorylation of HER-2 at its p-Tyr residues results in the down-regulation of its specific activity, which leads to decreases in growth and tumorigenicity of those cancer cells. Conversely, decreased cPAcP expression correlates with hyperphosphorylation of HER-2 at tyrosine residues and activation of downstream extracellular signal-regulated kinase (ERK)/mitogen activated protein kinase (MAPK) signaling, which results in prostate cancer progression as well as androgen-independent growth of prostate cancer cells. These in vitro results on the effect of cPAcP on androgen-independent growth of prostate cancer cells corroborate the clinical findings that cPAcP level is greatly decreased in advanced prostate cancer and provide insights into one of the molecular mechanisms involved in prostate cancer progression. Results from experiments using xenograft animal models further indicate a novel role of cPAcP as a tumor suppressor. Future studies are warranted to clarify the use of cPAcP as a therapeutic agent in human prostate cancer patients.
 ...
PMID:Cellular prostatic acid phosphatase: a protein tyrosine phosphatase involved in androgen-independent proliferation of prostate cancer. 1632 23

The immunoexpression of prostate-specific antigen in breast cancers has been well established, but the role of this extra-prostate PSA appears to be a complex, poorly understood and of doubtful prognostic value. In this context, our aim was to evaluate PSA in breast carcinomas and to compare the results with several established prognostic markers of breast cancer: estrogen and progesterone receptors status, HER2/neu status, histological type of tumor, grade of differentiation, stage, tumor size, nodal and menopausal status. We have immunohistochemically assessed 53 breast carcinomas for PSA, ER, PR and oncoprotein HER2/neu status. The relationship between the clinical and histopathological markers was analyzed by chi-square test. In the present study PSA was expressed in 60.3% of cases, and we have found a significant correlation with the histological type and HER2/neu negative status in premenopausal women. No statistically significant difference was found between PSA positivity and menopausal status of the patients, nodal status, estrogen and progesterone receptors, HER2/neu status in postmenopausal patients, tumor size or histological grade. We conclude that in our study PSA can not be considered as a valuable independent prognostic factor in breast carcinoma. As long as the majorities of PSA positive carcinomas were small in size, early stage, better and moderately differentiated, HER2/neu negative and 70% of ER/PR positive carcinomas expressed PSA, it might be useful as a marker for a subset of breast cancers with better prognosis, which could respond to endocrine therapy, in correlation with other prognostic markers.
 ...
PMID:Prostate-specific antigen value as a marker in breast cancer. 1657 73

Prevention trials showed that selenium reduced prostate cancer incidence by 50%, establishing selenium as a promising chemopreventive agent for prostate cancer. Selenium inhibited human prostate cancer cell growth, blocked cell cycle progression at multiple transition points, and induced apoptotic cell death. Previous studies showed a novel mechanism of selenium anticancer action in which selenium markedly reduces androgen signaling and androgen receptor (AR)-mediated gene expression, including prostate-specific antigen (PSA), in human prostate cancer cells. The molecular mechanisms of selenium-mediated down-regulation of AR signaling are not clear. In this study, a systemic approach was taken to examine the modification of androgen signaling by selenium in human prostate cancer cells. In addition to reduced AR mRNA expression, selenium was found to initially increase the stability of AR mRNA within 6 hours while decreasing the stability of AR mRNA after 8 hours. Selenium increased AR protein degradation and reduced AR nuclear localization. Scatchard analysis indicated that selenium did not affect ligand binding to AR in LNCaP cells. Chromatin immunoprecipitation analyses showed that DHT increased the recruitment of AR and coactivators, such as SRC-1 and TIF-2, to the promoter of the PSA gene, and that recruitment was greatly diminished in the presence of 5 micromol/L selenium. On the other hand, selenium enhanced the recruitment of corepressors, such as SMRT, to the promoter of the PSA gene. Taken together, these results suggest that selenium disrupts AR signaling at multiple stages, including AR mRNA expression, mRNA stability, protein degradation, nuclear translocation, and recruitment of coregulators.
 ...
PMID:Mechanisms of selenium down-regulation of androgen receptor signaling in prostate cancer. 1664 61

AR (androgen receptor) and PSA (prostate-specific antigen) are involved in the pathogenesis of breast cancer, but their role is not clearly defined. The purpose of this study was to analyze by immunohistochemistry the AR and PSA (prostate-specific antigen) expression in 156 female breast carcinomas and to correlate the results with some histopathological parameters, like ER (estrogen receptor), PR (progesterone receptor), HER2/neu, nodal and metastasis status, histological type and grade. ARs and PSA were expressed in 112/156 (72%) and respectively in 61/156 (39%) of cases and we found a positive correlation between AR and PSA expression in breast carcinomas (p<0.0002). We also found an association between the histological type of the tumor and AR (p<0.001), respectively PSA (p=0.01) and between AR and the grade of differentiation (p=0.007) and the nodal status (p=0.02). No correlations were found between the metastasis status and AR or PSA. 47.3% (53/112) of AR-positive cases and 46% (28/61) of PSA-positive cases were ER-negative. High frequency of AR (87.5%) and PSA (75%) expression was found in medullary carcinomas and 53% of lobular invasive carcinomas co-expressed AR and PSA. We found an inverse correlation between HER2/neu and PSA (p=0.05). Although most of the PSA-positive carcinomas were lymph node-negative, well and moderately differentiated, we did not find any statistically significant correlations between these parameters and PSA expression. Our study confirms that ARs are commonly expressed in breast cancer and the expression of PSA and AR are highly correlated. Moreover, all the lobular carcinomas and the majority of medullary carcinomas co-expressed AR and PSA, the majority of AR-positive carcinomas were lymph node-negative, well and moderately differentiated, and large number of ER-negative carcinomas expressed AR and PSA.
 ...
PMID:Immunohistochemical expression of androgen receptor and prostate-specific antigen in breast cancer. 1697 95

YKL-40 is produced by cancer cells and tumour-associated macrophages. YKL-40 may play a role in cancer cell proliferation, differentiation, survival, invasiveness, metastasis, in angiogenesis and the inflammation and remodelling of the extracellular matrix surrounding the tumour. Serum YKL-40 is a biomarker of prognosis, confirmed in 13 different types of cancer including > 2500 patients. Highest serum YKL-40 is found in patients with metastatic cancer with the shortest recurrence-free interval and shortest overall survival. Serum YKL-40 provides independent information compared with clinical characteristics and biomarkers, such as HER2, carcinoembryonic antigen, CA-125, prostate-specific antigen and lactate dehydrogenase. The authors hypothesise that inhibition of YKL-40 by monoclonal antibodies either directly or towards its receptor may be as efficient a cancer therapeutic as the monoclonal antibodies against HER2, HER1, vascular endothelial growth factor and CD20. Drugs inhibiting YKL-40 should be explored as new cancer therapeutics.
 ...
PMID:Is YKL-40 a new therapeutic target in cancer? 1722 36

Treatment of prostate cancer (CaP) patients frequently involves androgen ablation, but resistance often develops and androgen-insensitive tumors emerge. The molecular basis for the development of refractory CaP that grows in an androgen-independent manner is poorly understood, but alterations in growth factor signaling pathways are likely to be involved. We examined the growth factor modulation of androgen-receptor element (ARE)-inducible luciferase reporter gene activity and consequent DNA synthesis as a measure of proliferative growth in androgen-dependent LNCaP or androgen-independent PC3 or DU145 CaP cells. The synthetic androgen R1881 stimulated ARE-inducible reporter gene activity and prostate-specific antigen expression in LNCaP cells and the MEK/ERK inhibitor U0126 or the anti-androgen bicalutamide (casodex) prevented both of these responses. Activated V12-Ha-Ras expression in LNCaP cells also stimulated ARE-inducible gene transcription, and U0126 or the farnesyltransferase inhibitor FTI-277 but not bicalutamide blocked this. ARE-inducible reporter gene activity was elevated already in PC3 cells, and ERK was constitutively activated in serum-starved LNCaP or DU145 cells. U0126 inhibited each of these responses and also inhibited DNA synthesis in all 3 CaP cell lines. These results demonstrate that chronic stimulation of the Ras-MEK-ERK signaling pathway can sustain ARE-inducible gene transcription and growth of CaP cells, and suggests that components of this pathway may offer targets for cancer therapy.
 ...
PMID:Ras-MEK-ERK signaling cascade regulates androgen receptor element-inducible gene transcription and DNA synthesis in prostate cancer cells. 1741 12

We investigated efficacy of gefitinib in hormone-refractory prostate cancer. Between March 2003 and December 2004, 23 patients with hormone-refractory prostate cancer were assigned to receive 250 mg oral gefitinib daily in addition to antiandrogen and luteinizing hormone-releasing hormone analogue for at least 2 months or until disease progression. Patients with progression stopped antiandrogen therapy, and received gefitinib and the luteinizing hormone-releasing hormone analogue. Serum HER2 and epidermal growth factor receptor extracellular domain were evaluated every 2 months. Gefitinib treatment did not result in any objective measurable response or responses in prostate-specific antigen. Median time to progression was 70 days (33-336). Median overall survival was 293 days (25-75 percentile: 235-349). HER2 extracellular domain mean value was 9.6 ng/ml (range 6.9-13.3) at basal time and was 10.1 (range 6.0-14.1) after 2 months. Epidermal growth factor receptor mean basal value was 51.0 ng/ml (range 41.4-75.3). After 2 months of treatment the mean value was 51.1 ng/ml (range 41.5-61.4). One patient had reduction in the pain score from baseline without an increase in the analgesic score. Four patients (17%) out of 23 had pain progression with an increase from baseline of at least 25% in the analgesic score. The study was discontinued before target accrual was reached owing to lack of efficacy of the drug. Our results do not support the efficacy of gefitinib in combination with endocrine treatment for hormone-refractory prostate cancer.
 ...
PMID:Gefitinib combined with endocrine manipulation in patients with hormone-refractory prostate cancer: quality of life and surrogate markers of activity. 1766 1

The expression of the WWOX tumor suppressor gene is lost or reduced in a large fraction of various cancers, including prostate cancer. We previously reported that Wwox overexpression induced apoptosis and suppressed prostate cancer growth in vitro and in vivo. In this study, pathways through which Wwox contributes to control of prostate cancer cell growth have been investigated. We found that Wwox interacts with Ap2gamma and prevents it from entering the nucleus to bind the ERBB2 promoter region to activate transcription of ERBB2, a mediator of androgen receptor activity and prostate cancer cell growth at limiting androgen concentration. Ectopic expression of Wwox reduced ErbB2 protein expression in vitro and expression of Wwox protein inversely correlated with expression of ErbB2 protein in prostate cancer tissues. Furthermore, Wwox suppressed Ap2gamma/ErbB2-induced prostate cancer cell growth and suppressed prostate-specific antigen secretion through interaction with Ap2gamma and down-modulation of ErbB2, an effect that required functional androgen receptor.
 ...
PMID:Wwox suppresses prostate cancer cell growth through modulation of ErbB2-mediated androgen receptor signaling. 1770 39

PSA (prostate-specific antigen), a serine protease with chymotrypsin-like activity is the most useful tumor marker for prostate cancer screening, diagnosis, prognosis and monitoring. The identification of PSA in normal and tumoral mammary gland was regarded as a curiosity, but the confirmation of PSA expression in the mammary gland by others teams of researchers and the identification of specific mRNA in tumors with PSA immunoexpression initiated new perspectives for studies. The aim of this study was to examine the prevalence of PSA in breast cancers and to evaluate the correlations between PSA expression and some clinicopathological markers. We analyzed the expression of PSA in series of consecutive breast carcinomas by immunohistochemistry and correlated the PSA expression with the histological type and grade, nodal and metastasis status, estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) and HER2/neu expression. PSA expression was observed in 44.5% of breast cancers, particularly in lobular types of carcinoma (p<0.0001). In univariate analysis, the expression of PSA was statistically correlated with AR (p<0.0001), PR (p=0.01) and inversely correlated with HER2/neu overexpression (p=0.008) and G3 (p=0.02). PSA did not significantly correlate with ER expression, lymph node and metastasis status. In multivariate analysis, PR was a moderate predictor (p=0.024) but the lobular type (p=0.000), AR (p=0.000), HER2/neu (p=0.002) and G3 (p=0.008) were strong predictors for PSA immunoexpression.
 ...
PMID:Prostate-specific antigen may serve as a pathological predictor in breast cancer. 1851 23

Targeted therapies present an interesting treatment option in prostate cancer. The aim of our study was to analyze the expression profile of several molecular markers that are candidates for targeted therapy in patients with progressive androgen-independent prostate cancer (AIPC). Based on the expression profile, the efficacy of a combination therapy with a signal transduction inhibitor (STI) and docetaxel was evaluated.Tumor tissue obtained from biopsy of the prostate or lymph node and visceral metastasis was analyzed for the immunohistochemical expression of epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor beta (PDGFRbeta), Her-2/neu, c-KIT, and vascular endothelial growth factor (VEGF). Patients with positive staining of one or more markers were treated with the corresponding STI and docetaxel.Fifty-one patients were included in the protocol, of whom 43 (84.3%) presented with progressive AIPC after first-line chemotherapy. Forty-six of these 51 patients (90.2%) showed expression of one or more of the analyzed markers. Expression of EGFR was found in 61.2%, PDGFRbeta in 57.1%, Her-2/neu in 16.3%, c-KIT in 25.0%, and VEGF in 74.5%. After request for cost coverage, 8/51 patients received the combination therapy and were evaluated for response. Four of the eight patients (50%) showed a decline in prostate-specific antigen of > or =50%, and median survival time was 13.5 months at a median follow-up of 23.6 (11-35) months.The results show that expression of molecular targets is found in about 90% of patients with AIPC. Based on the expression profile, an individual treatment strategy can be applied to each patient. Further clinical studies should determine the clinical efficacy of molecular targeted therapy in patients with AIPC.
 ...
PMID:[Feasibility of targeted therapy based on immunohistochemical expression analysis in androgen-independent prostate cancer]. 1867 46


<< Previous 1 2 3 4 5 Next >>