UNIPROT:P04626 - FACTA Search

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

Query: UNIPROT:P04626 (erbB-2)
5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclooxygenase (COX)-2-derived prostaglandins (PGs) are thought to contribute to tumor growth and resistance to radiation therapy. COX-2 protein expression is increased in many tumors including those of the breast. COX-2-derived PGs have been shown to protect cells from radiation damage. This study evaluated the role of COX-2-derived PG in radiation treatment by using the NMF11.2 mammary tumor cell line originally obtained from HER-2/neu mice that overexpress HER-2/neu. We determined whether the effects of the COX-2 inhibitor SC236 on cell growth, radiation-induced PGE2 production and COX expression, cell cycle redistribution, and vascular endothelial growth factor (VEGF) were acting through COX-2-dependent mechanisms. The NMF11.2 cells expressed both COX-1 and COX-2 protein and mRNA. The radiation treatment alone led to a dose-dependent increase in the levels of COX-2 mRNA and COX-2 protein, which was associated with an increase in the production of PGE2 and prostacyclin (PGI2). Treating NMF11.2 cells with high concentrations (20 microM) of SC236 for 48 h reduced the radiation-induced increase in COX-2 activity and also decreased cell growth. SC236 (20 microM) increased the accumulation of the cells in the radiosensitive G2-M phase of the cell cycle. However, a low concentration (5 microM) of SC236 was adequate to reduce COX-2 activity. The lower concentration of SC236 (5 microM) also decreased cell growth after a longer incubation period (96 h) and, in combination with a 2 or 5 Gy dose, led to an accumulation of cells in G2-M phase. Restoring PG to control values in cells treated with 5 microM SC236 prevented the growth inhibition and G2-M cell cycle arrest. Radiation treatment of NMF11.2 cells also increased VEGF protein expression and VEGF secretion in a dose-dependent manner, which was blocked in those cells pretreated with 20 microM SC236 but not in those pretreated with 5 microM SC236. These findings indicate that the COX-2 inhibitor SC236 reduced cell growth and arrested cells in the G2-M phase of the cell cycle by mechanisms that are both dependent and independent of PG production while its effects on VEGF appear to be independent of COX-2.
...
PMID:Cyclooxygenase (COX)-2-dependent effects of the inhibitor SC236 when combined with ionizing radiation in mammary tumor cells derived from HER-2/neu mice. 1507 85

Head and neck squamous cell carcinomas (HNSCC) are characterized by a marked propensity for local invasion and cervical lymph node metastasis. The aim of this study was to investigate the expression of epidermal growth factor receptor (EGFR), c-erbB-2, vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) in tumor samples of 91 HNSCC patients, and to study a possible correlation to various clinico-pathologic parameters. The expression of EGFR, c-erbB-2, VEGF, MMP-2, -3 and -9 was analyzed in the same paraffin embedded tissue by semi-quantitative immunohistochemical staining. High expression of EGFR, c-erbB-2, MMP-2 or -9 was associated with advanced clinical stages, nodal metastases and tumor-stages. However, high expression of VEGF or MMP-3 was not associated with any clinico-pathologic parameters except significant correlation between VEGF and the tumor site. There were significant correlations between EGFR, c-erbB-2, MMP-2 and -9 in HNSCC patients. Conversely, no correlation was found between VEGF or MMP-3 and the other markers. However, significant correlation was found between MMP-3 or -9 and VEGF. The results indicate that the expression of EGFR, c-erbB-2, VEGF or MMPs play an important role in tumor growth, invasion and metastasis in HNSCC. The authors conclude that EGFR, c-erbB-2, MMP-2 and -9 could be good independent prognostic markers, but not VEGF and MMP-3.
...
PMID:Expression of c-erbB receptors, MMPs and VEGF in squamous cell carcinoma of the head and neck. 1525 82

To study the molecular mechanism of inhibition of angiogenesis in HER-2/neu-overexpressing breast cancer by genistein, HER-2/neu negative expression breast cancer MCF-7 cells were transfected with HER-2/neu to establish HER-2/neu-overexpressing MCF-7 cells (named MCF-7/HER-2). Expression of vascular endothelial growth factor (VEGF), urokinase-type plasminogen activator (uPA), matrix metalloproteinase-2,9 (MMP-2,9) in MCF-7, MCF-7/HER-2 as well as genistein-treated MCF-7/HER-2 were measured by immunocytochemistry and Western blot. We found that the expression of VEGF, MMP-2,9 and uPA in MCF-7/HER-2 cells were highter than that in MCF-7 cells, those angiogenesis related factors expression in MCF-7/HER-2 cells significantly decreased after treatment with genistein. Genistein could inhibit expression of angiogenesis-related factors VEGF, MMP-2,9 and uPA in HER-2/neu-overexpressing breast cancer cells, and this may be part of molecular mechanism of its anti-angiogenesis in HER-2/neu-overexpressing breast cancer.
...
PMID:[Effect of genistein on expression of angiogenesis related factors in HER-2/neu-overexpressing breast cancer cells]. 1532 30

The effects of HER-2/neu overexpression on the tumor microenvironment in an aggressive breast cancer xenograft model were investigated. These studies focused on tumors derived following the subcutaneous injection of MDA-MB-435/LCC6 cells transfected with human c-erbB2 (LCC6(HER-2)) into SCID-Rag2M mice. LCC6(HER-2) tumors were more viable (H&E-stained tumor sections) than isogenic vector control tumors (LCC6(Vector)). Correspondingly, a 2.7-fold increase in trypan blue-excluding cells (P = 0.00056) and a 4.8-fold increase in clonogenic cells (P = 0.00146) were noted in cell suspensions derived from disaggregated LCC6(HER-2) versus LCC6(Vector) tumors. Tumor sections stained with the antibody detecting 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)-acetamide (EF5), a marker of hypoxia, showed a greater fraction of hypoxic tissue in LCC6(HER-2) tumors compared with control tumors. Flow cytometric analyses based on viable tumor cells (DNA content >/= 2N) in cell suspensions from disaggregated tumors confirmed that there were significantly more EF5-positive cells (i.e., hypoxic) in LCC6(HER-2) than in LCC6(Vector) tumors (16.41 +/- 8.1% and 5.96 +/- 4.1%, respectively; P = 0.0015). Protein levels of phosphorylated (Ser(536)) nuclear factor-kappaB p65 were significantly elevated in LCC6(HER-2) tumors (P = 0.00048), and a trend in increased hypoxia-inducible factor-1alpha protein levels was observed in LCC6(HER-2) compared with LCC6(Vector) tumors. Despite the substantial viable hypoxic cell fraction and a 1.7-fold increase of vascular endothelial growth factor protein (P = 0.05) in LCC6(HER-2) tumors, no significant differences were found (P > 0.05) between LCC6(HER-2) and LCC6(Vector) vasculature (CD31 staining and Hoechst 33342 perfusion). These results suggest that HER-2/neu overexpression may be linked with overall increased tumor viability and a significant increase in the population of viable hypoxic cells, which is not due to differences in tumor vascularization.
...
PMID:HER-2/neu overexpression increases the viable hypoxic cell population within solid tumors without causing changes in tumor vascularization. 1556 77

Her-2/neu (erbB-2) oncogene overexpression is associated with increased tumor progression and metastasis. Fatty acid synthase (FAS), the key lipogenic enzyme responsible for the endogenous synthesis of fatty acids, has been shown to be one of the genes regulated by Her-2/neu at the level of transcription, translation, and biosynthetic activity. Interestingly, we recently established that both pharmacological inhibition of FAS activity and silencing of FAS gene expression specifically suppress Her-2/neu oncoprotein expression and tyrosine-kinase activity in breast and ovarian Her-2/neu overexpressors. Unraveling the functional organization of this novel bi-directional molecular connection between Her-2/neu and FAS-dependent neoplastic lipogenesis is a major challenge that the field is only beginning to take on. Considering that Her-2/neu overexpression correlates with increased expression of the hypoxia inducible factor-1alpha (HIF-1alpha), which, in a mitogen-activated protein kinase (MAPK)-dependent manner, plays a key role in the expression of several genes including cytokines such as vascular endothelial growth factor (VEGF), we hypothesized that FAS blockade should result in a concomitant down-regulation of VEGF. Unexpectedly, the specific inhibition of the de novo fatty acid synthesis with the small-molecule inhibitor of FAS activity C75 resulted in a dramatic dose-dependent enhancement (up to 500% increase) of VEGF secretion in Her-2/neu-overexpressing SK-Br3, BT-474, and SKOV3 cancer cells. Concurrently, FAS blockade drastically activated MAPK and promoted further a prominent accumulation of HIF-1alpha in Her-2/neu overexpressors. Moreover, U0126-induced inhibition of MAPK activity completely abolished C75-induced up-regulation of HIF-1alpha expression and VEGF secretion, whereas it did not modulate C75-induced down-regulation of Her-2/neu oncogene. Importantly, RNA interference (RNAi)-mediated silencing of the FAS gene recapitulated C75's effects by up-regulating VEGF secretion, MAPK activation and HIF-1alpha expression. Therefore, it appears that perturbation of cancer-associated endogenous fatty metabolism triggers a "hypoxia-like" (oxygen-independent) condition that actively rescues Her-2/neu-dependent MAPK --> HIP-1alpha --> VEGF cascade. It is tempting to suggest that an intact FAS-catalyzed endogenous fatty acid metabolism is a necessary metabolic adaptation to support the enhanced ability of Her-2/neu-overexpressing cancer cells to survive cellular hypoxia in a HIF-alpha-dependent manner.
...
PMID:Does endogenous fatty acid metabolism allow cancer cells to sense hypoxia and mediate hypoxic vasodilatation? Characterization of a novel molecular connection between fatty acid synthase (FAS) and hypoxia-inducible factor-1alpha (HIF-1alpha)-related expression of vascular endothelial growth factor (VEGF) in cancer cells overexpressing her-2/neu oncogene. 1566 79

We have previously shown that high levels of HER-2/neu protein were overexpressed in human Ewing's sarcoma cells (TC71, SK-ES1) relative to normal human osteoblasts. The purpose of this study was to determine whether herceptin alone or in combination with chemotherapeutic agents could inhibit the growth of Ewing's sarcoma in vitro and in vivo. Western blot analysis showed that the protein levels of HER-2/neu were decreased following herceptin treatment. Cell growth was also inhibited by herceptin in a dose-dependent manner with an IC(50) of 4 mg/mL in TC71 and SK-ES1 cell line, whereas human immunoglobin had no effect. Northern blot and ELISA showed the RNA expression and protein levels of vascular endothelial growth factor were also inhibited by herceptin treatment with no alteration in HIF-1alpha protein and topoisomerase IIalpha expression. Furthermore, Ewing's sarcoma tumor growth was significantly delayed by 100 mg/kg herceptin treatment in our Ewing's sarcoma xenograft mouse model. Combining taxol with herceptin resulted in additive cytotoxicity, whereas herceptin-etoposide, doxorubicin, and 9-nitrocamptothecin combinations did not. Taxol-herceptin enhanced growth inhibition in TC71 cells in vitro compared with either agent alone. Ewing's sarcoma growth was also delayed in vivo and mean tumor size was significantly lower in mice treated with herceptin plus taxol than in those receiving taxol or herceptin alone. These data suggest that herceptin in combination with taxol may be a therapeutic option in the treatment of Ewing's sarcoma.
...
PMID:Herceptin down-regulates HER-2/neu and vascular endothelial growth factor expression and enhances taxol-induced cytotoxicity of human Ewing's sarcoma cells in vitro and in vivo. 1575 27

The proangiogenic vascular endothelial growth factor-A (VEGF) is essential for the development of new tumor vessels. ZD6474 is a novel inhibitor of VEGF receptor-2 (VEGFR-2) tyrosine kinase activity, which also has additional activity against epidermal growth factor (EGF) receptor tyrosine kinase. The antitumor activity of different schedules of ZD6474 in a clinically relevant, metastasizing, murine renal cell carcinoma (RENCA) model was evaluated in this study. RENCA cells were inoculated into the left kidney of 24 mice (day 0). Daily ZD6474 (50 mg/kg p.o.) treatment was initiated 1 day or 10 days after tumor cell inoculation and continued until day 21. Following treatment, kidney weight and volume were assessed and blood vessel density determined by CD31 staining. Visible metastases in the lungs, spleen, and lymph nodes were quantified using a dissection microscope. In an additional study, animals were treated according to the same regimen and quantitative three-dimensional microvascular corrosion casting was performed to enable detailed assessment of the tumor vascular architecture. Therapy initiated on day 1 or day 10 resulted in a 79% and 59% reduction in primary tumor volume, a 79% and 60% reduction in the number of lung metastases, and a 58% and 59% reduction in vessel density of primary tumors compared with the control group, respectively. Corrosion casting proved a 5.4- and 3.2-fold lower vascular volume compared with untreated tumors, observations that paralleled with significant architectural alterations. In this RENCA model, ZD6474 was a highly active inhibitor of tumor angiogenesis, primary tumor growth and tumor metastasis.
...
PMID:The VEGF receptor tyrosine kinase inhibitor, ZD6474, inhibits angiogenesis and affects microvascular architecture within an orthotopically implanted renal cell carcinoma. 1588 78

We studied the immunohistochemical expression of HER-2/neu, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), estrogen receptor (ER), and progesterone receptor (PR) in uterine cervical small cell and large cell neuroendocrine carcinomas (SCNECs and LCNECs) from 24 patients seen at The University of Texas M.D. Anderson Cancer Center. The objectives were to determine their expression and prognostic role in survival. Twenty-three cases (95.8%) expressed VEGF. The tumors expressing EGFR, HER-2/neu, and COX-2 were modest in numbers: eight (33.3%), 10 (41.7%), and seven (29.2%), respectively. Only one tumor (4.2%) expressed ER, and only two tumors (8.3%) expressed PR. No significant differences in the expression of these factors were found between SCNECs and LCNECs or between stage I and stage II-III tumors. The median overall survival was 21.1 months (95% confidence interval [CI], 17.2-25.0 months). Only HER-2/neu expression was significantly associated with survival. Patients with negative HER-2/neu expression tumors had significantly shorter survival than those whose tumors were positive, 14.2 months (95% CI, 10.6-17.7 months) versus 33.1 months (95% CI, 0-76.92 months) (P = 0.03). There was a trend toward worse survival in patients with EGFR expression, but this finding was not significant. The combination of negative HER-2/neu expression and positive EGFR expression had the worst impact on survival.
...
PMID:Expression of HER-2/neu, epidermal growth factor receptor, vascular endothelial growth factor, cyclooxygenase-2, estrogen receptor, and progesterone receptor in small cell and large cell neuroendocrine carcinoma of the uterine cervix: a clinicopathologic and prognostic study. 1601 19

Therapeutic options in the treatment of metastatic colorectal cancer have recently been expanded by the introduction of two new monoclonal antibodies: bevacizumab and cetuximab. These antibodies were the proof of principle of two exciting new antitumor strategies: antiangiogenesis and inhibition of epidermal growth factor (EGF) receptor. Bevacizumab binds to vascular endothelial growth factor and thus blocks its angiogenic effects. In a randomized phase III trial bevacizumab in combination with irinotecan + 5-fluorouracil/leucovorin (IFL) was compared to chemotherapy alone as first-line treatment. The combination showed a superior response rate, a prolonged progression-free and overall survival. Cetuximab binds to the EGF receptor and thus inhibits its activation by its natural ligand. In a randomized phase II trial irinotecan refractory patients were treated with cetuximab alone or cetuximab plus irinotecan. The combination showed a response rate of 22,5% and a prolonged progression-free survival identifying cetuximab as an important new option for this patient group.
...
PMID:[Which role do new therapeutic options play in palliative care of colorectal cancer?]. 1622 55

The aim of this study was to analyze the association between vascular endothelial growth factor (VEGF) expression on tumor cells and other clinicopathologic parameters in breast cancer that could give additional information on its prognostic significance. Immunohistochemical analysis of expression of VEGF, estrogen (ER) and progesterone receptor (PR), HER-2/neu, and Ki67 was performed in 233 breast cancers. VEGF expression estimated semiquantitatively was correlated with all the above-mentioned parameters as well as with clinicopathologic characteristics of breast cancer such as menopausal status of patients, tumor size, histologic and nuclear grade, vascular invasion, and lymph node status. Most of the tumor cells and some stromal components expressed VEGF. A higher percentage of VEGF-positive tumor cells was present in premenopausal patients and in ER-negative tumors. In postmenopausal patients tumors with a higher expression of VEGF were associated not only with ER-negative but also with HER-2/neu-positive tumor cells. These ER-negative tumors were characterized by a higher proliferative activity. Angiogenic switch as well as proliferative activity of breast cancer cells probably are unfavorably dependent on estrogen activity. This negative correlation between VEGF expression and ER status may not only shed more light on tumor biology but may also have future therapeutic implications.
...
PMID:VEGF expression is associated with negative estrogen receptor status in patients with breast cancer. 1650 35

<< Previous 1 2 3 4 5 6 Next >>