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)

We determined whether concurrent blockage of vascular endothelial growth factor (VEGF) receptor and epidermal growth factor (EGF) receptor signaling by two novel tyrosine kinase inhibitors, PTK 787 and PKI 166, respectively, can inhibit angiogenesis and, hence, the growth and metastasis of human pancreatic carcinoma in nude mice. Highly metastatic human pancreatic carcinoma L3.6pl cells were injected into the pancreas of nude mice. Seven days later, groups of mice began receiving oral doses of PTK 787 and PKI 166 three times weekly. Some groups of mice also received i.p. injections of gemcitabine twice a week. The mice were necropsied when the control mice became moribund. Treatment with PTK 787 and PKI 166, with gemcitabine alone, or with the combination of PTK 787, PKI 166, and gemcitabine produced 69, 50, and 97% reduction in the volume of pancreatic tumors, respectively. Administration of protein tyrosine kinase inhibitors and gemcitabine also significantly decreased the incidence of lymph node and liver metastasis. The therapeutic efficacy directly correlated with a decrease in circulating proangiogenic molecules (VEGF, interleukin-8), a decrease in microvessel density, a decrease in proliferating cell nuclear antigen staining, and an increase in apoptosis of tumor cells and endothelial cells. Therapies produced by combining gemcitabine with either PKI 166 or PTK 787 were similar to those produced by combining gemcitabine with both PKI 166 and PTK 787. These results suggest that blockade of either epidermal growth factor receptor or VEGF receptor signaling combined with chemotherapy provides an effective approach to the therapy of pancreatic cancer.
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PMID:Blockade of vascular endothelial growth factor receptor and epidermal growth factor receptor signaling for therapy of metastatic human pancreatic cancer. 1192 16

Pancreatic cancer has a very poor prognosis and is a common cause of cancer death in the Western world. Certain genetic alterations may be important in the prognosis of pancreatic cancer. Activation mutations in the K- ras oncogene occur in around 90% of pancreatic cancers, and the overexpression of growth factors epidermal growth factor (EGF), transforming growth factor (TGF)alpha, TGFbetas 1-3, acidic fibroblast growth factor (aFGF), basic FGF (bFGF), and growth factor receptors c-erbB-2 and -3 and TGFRbetas 1-3 is common. High mutation levels of cell cycle control genes such as p53, p16, p21, SMAD4, and cyclin D1 are found, and there is abnormal expression of apoptotic genes, such as bcl-2, bcl-XL, and bax. The expression of several of these growth factors and their receptors has been found to be associated with poorly differentiated tumors of an advanced stage and decreased survival. However, the inactivation and loss of expression of p16, p53, and p21, and the expression of several apoptotic genes, such as bax and bcl-2, have not been found to be of any prognostic significance. The expression of wild type p53, however, may predict responsiveness to chemotherapy. TGFbeta1 expression has been shown to be associated with longer survival in patients with pancreatic cancer. Two studies (including our own) have found bcl-XL expression to be significantly associated with poor survival. These and newer molecular markers may prove to be important in the choice of future therapies for pancreatic cancer.
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PMID:Molecular prognostic markers in pancreatic cancer. 1202 93

Pancreatic cancer has one of the poorest prognoses of all gastrointestinal malignancies. Today, it is the fourth or fifth leading cause of cancer-related deaths in Western industrialized countries, and the incidence has been increasing throughout the past decades. Insensitivity to growth-inhibitory and apoptotic signals as well as self-sufficiency of growth-promoting factors are hallmarks of the pathogenesis of this malignancy. In pancreatic cancer, a variety of growth factors and their receptors are expressed at increased levels. For example, the concomitant presence of the epidermal growth factor (EGF) receptor and its ligand EGF is associated with enhanced tumor aggressiveness and shorter survival following tumor resection. Furthermore, a number of other growth factors and their receptors, such as nerve growth factor and its receptor, are overexpressed in pancreatic cancer and contribute to its malignant phenotype. Besides factors which directly promote cell proliferation, a variety of other factors such as galectins are upregulated, which influences the tumor environment and the invasiveness of pancreatic cancer cells. In addition, tumor suppressor genes such as KAI1 are expressed at reduced levels, thereby enhancing the ability of pancreatic cells to form metastases. A complex disturbance of factors is present in pancreatic cancer, resulting in a distinct growth advantage which clinically results in rapid tumor progression and poor patient survival.
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PMID:Pancreatic cancer: factors regulating tumor development, maintenance and metastasis. 1212 Feb 31

The epidermal growth factor (EGF) receptor (EGFR) family consists of four transmembrane tyrosine kinases that undergo homodimerization and heterodimerization. Pancreatic cancers overexpress these receptors. To examine the effects of EGFR blockade on pancreatic cancer cell mitogenesis in relation to activation of specific signaling pathways, four pancreatic cancer cell lines were infected with an adenoviral vector encoding a truncated EGFR (AdtrEGFR), and activation of signaling was assessed with the mitogen-activated protein kinase (MAPK) kinase inhibitors PD98059 and U0126, the p38 MAPK inhibitor SB203580, and the c-Jun NH2-terminal kinase inhibitor SP600125. In all four cell lines, AdtrEGFR markedly attenuated EGF and heparin-binding EGF-dependent cell growth, EGFR family tyrosine phosphorylation, and phosphorylation of MAPK, c-Jun NH2-terminal kinase, p38 MAPK, and activating transcription factor 2. AdtrEGFR did not alter fibroblast growth factor 2 actions on mitogenesis. In ASPC-1, PANC-1, and T3M4 cells, PD98059 and U0126 inhibited MAPK kinase activation but not EGF-stimulated mitogenesis, whereas SB203580 inhibited EGF-stimulated mitogenesis, p38 MAPK activation, and MAPK-activated protein kinase 2 activation, without attenuating the mitogenic effect of insulin-like growth factor 1. In contrast, in COLO-357 cells, PD98059, and U0126, but not SB203580, inhibited EGF-stimulated mitogenesis, whereas SP600125 did not alter the mitogenic actions of EGF in any of the cell lines. Thus, EGF promotes proliferation via the MAPK in COLO-357 cells but via p38 MAPK in ASPC-1, PANC-1, and T3M4 cells, and whereas EGFR activation leads to the activation of all four members of the EGFR family in these cells, downstream signaling is efficiently blocked by AdtrEGFR.
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PMID:Multiple mitogenic pathways in pancreatic cancer cells are blocked by a truncated epidermal growth factor receptor. 1235 75

The ERBB2 gene is overexpressed in 30% of breast cancers and this has been correlated with poor prognosis. ERBB2 is upregulated in other cancers such as prostate, pancreas, colon and ovary. In breast cancer cells, the mechanisms leading to ERBB2 gene overexpression are increased transcription and gene amplification. In these cancers, AP-2 transcription factors are involved in ERBB2 overexpression, and AP-2 levels are correlated with p185(c-)(erbB-2) levels. In this work, we wanted to know if the same molecular mechanisms are responsible for the ERBB2 upregulation in non-breast cancers. We compared ERBB2 gene copy number, p185(c-)(erbB-2) and mRNA levels with AP-2 levels in several ovary, prostate, colon and pancreas cancer cells. A moderate expression of erbB-2 mRNA and protein were observed in some cells without gene amplification. In contrast to breast cancer cells, AP-2 factors were absent or low in some non-breast cells which did express ERBB2. It is thus likely that AP-2 is not a major player in the increased levels of erbB-2 transcripts in non-breast cancer cells. The transcriptional activity of the ERBB2 promoter in colon and ovary cancer cells was estimated using reporter vectors. The results showed that the promoter regions involved in ERBB2 gene overexpression in breast cancer cells are different from those that lead to the gene upregulation in colon and ovary cancers. In conclusion, our results indicate that different transcriptional and post-transcriptional mechanisms are responsible for the increased levels of erbB-2 transcript and protein in breast and non-breast cancer cells.
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PMID:Different mechanisms are implicated in ERBB2 gene overexpression in breast and in other cancers. 1294 24

Hedgehog signalling--an essential pathway during embryonic pancreatic development, the misregulation of which has been implicated in several forms of cancer--may also be an important mediator in human pancreatic carcinoma. Here we report that sonic hedgehog, a secreted hedgehog ligand, is abnormally expressed in pancreatic adenocarcinoma and its precursor lesions: pancreatic intraepithelial neoplasia (PanIN). Pancreata of Pdx-Shh mice (in which Shh is misexpressed in the pancreatic endoderm) develop abnormal tubular structures, a phenocopy of human PanIN-1 and -2. Moreover, these PanIN-like lesions also contain mutations in K-ras and overexpress HER-2/neu, which are genetic mutations found early in the progression of human pancreatic cancer. Furthermore, hedgehog signalling remains active in cell lines established from primary and metastatic pancreatic adenocarcinomas. Notably, inhibition of hedgehog signalling by cyclopamine induced apoptosis and blocked proliferation in a subset of the pancreatic cancer cell lines both in vitro and in vivo. These data suggest that this pathway may have an early and critical role in the genesis of this cancer, and that maintenance of hedgehog signalling is important for aberrant proliferation and tumorigenesis.
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PMID:Hedgehog is an early and late mediator of pancreatic cancer tumorigenesis. 1673 83

When activated, the serine/threonine kinase AKT mediates an antiapoptotic signal implicated in chemoresistance of various cancers. The mechanism(s) of AKT activation are unknown, though overexpression of HER-2/neu has been implicated in breast cancer. Therefore, we determined the incidence of activated AKT in human pancreatic cancer, whether HER-2/neu is involved in AKT activation, and if AKT activation is associated with biologic behaviour. HER-2/neu expression and AKT activation were examined in seven pancreatic cancer cell lines by Western blotting. The in vitro effect of HER-2/neu inhibition on AKT activation was similarly determined. Finally, 78 pancreatic cancer specimens were examined for AKT activation and HER-2/neu overexpression, and correlated with the clinical prognostic variable of histologic grade. HER-2/neu was overexpressed in two of seven cell lines; these two cell lines demonstrated the highest level of AKT activation. Inhibition of HER-2/neu reduced AKT activation in vitro. AKT was activated in 46 out of 78 (59%) of the pancreatic cancers; HER-2/neu overexpression correlated with AKT activation (P=0.015). Furthermore, AKT activation was correlated with higher histologic tumour grade (P=0.047). Thus, it is concluded that AKT is frequently activated in pancreatic cancer; this antiapoptotic signal may be mediated by HER-2/neu overexpression. AKT activation is associated with tumour grade, an important prognostic factor.
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PMID:Incidence, mechanism and prognostic value of activated AKT in pancreas cancer. 1464 46

A large number of data derived from molecular analyses support the hypothesis that human cancer is a genetic disease and a distinct subset of genes have been found to be genetically changed in most tumors. Molecular alterations in pancreatic cancer include: (1) oncogenes such as K-ras, c-myc, c-fos, and c-erbB-2; (2) tumor suppressor genes such as p53, p16, DPC4/SMAD4, and DCC; and (3) growth factors such as EGF, FGF, HGF, PDGF, VEGF, TGF-beta. Genetic alterations of K-ras and p53 are common in human pancreatic cancer, but the occurrence of pancreatic cancer is a multi-step phenomenon in which the accumulation of genetic changes is extremely important.
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PMID:[Recent advances in gene change of pancreatic cancer]. 1505 82

Pancreatic ductal carcinomas are thought to arise from precursor ductal lesions called pancreatic intra-epithelial neoplasias or PanINs. We report the case of a woman suffering from idiopathic chronic pancreatitis associated with PanINs lesions who developed six years later an invasive ductal carcinoma. Immunohistochemistry for p53, HER-2/neu and genetic analysis of K-ras oncogene were performed at different stages of disease and revealed that the PanINs and the carcinoma did not express p53 and HER-2/neu gene products whereas a K-ras mutation was present at the carcinoma stage. The relationship between cancer and chronic pancreatitis and the main difficulties concerning the early diagnostic of pancreatic cancer are discussed.
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PMID:From pancreatic intraepithelial neoplasia to cancer: a dramatic progression with K-ras status analysis. 1586 14

The aims of this study were to determine the effects of (a) combining the epidermal growth factor receptor (EGFR) blocker (erlotinib) and the cyclooxygenase-2 inhibitor (celecoxib) on cell growth and apoptosis in human pancreatic cancer cell lines, (b) baseline EGFR expression on the potentiation of erlotinib-induced apoptosis by celecoxib, and (c) the effects of the combination on the expression of the COX-2, EGFR, HER-2/neu, and nuclear factor-kappaB (NF-kappaB). Baseline expression of EGFR was determined by Western blot analysis in five human pancreatic cancer cell lines. BxPC-3, PANC-1, and HPAC had high EGFR and MIAPaCa had low EGFR. Cells were grown in culture and treated with erlotinib (1 and 10 micromol/L), celecoxib (1 and 10 micromol/L), and the combination. Growth inhibition was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and apoptosis was assayed by ELISA. Reverse transcriptase-PCR was used to evaluate COX-2 and EGFR mRNA. EGFR, COX-2, and HER-2/neu expression was determined by Western immunoblotting. Electrophoretic mobility shift assay was used to evaluate NF-kappaB activation. Growth inhibition and apoptosis were significantly (P < 0.05) higher in BxPC-3, HPAC, and PANC-1 cells treated with celecoxib and erlotinib than cells treated with either celecoxib or erlotinib. However, no potentiation in growth inhibition or apoptosis was observed in the MIAPaCa cell line with low expression of the EGFR. Significant down-regulation of COX-2 and EGFR expression was observed in the BxPC-3 and HPAC cells treated with the combination of erlotinib (1 micromol/L) and celecoxib (10 micromol/L) compared with celecoxib- or erlotinib-treated cells. Celecoxib significantly down-regulated HER-2/neu expression in BxPC-3 and HPAC cell lines. Significant inhibition of NF-kappaB activation was observed in BxPC-3 and HPAC cell lines treated with erlotinib and celecoxib. (a) Celecoxib can potentiate erlotinib-induced growth inhibition and apoptosis in pancreatic cell lines, (b) high baseline EGFR expression is a predictor of this potentiation, and (c) the down-regulation of EGFR, COX-2, and HER-2/neu expression and NF-kappaB inactivation contributes to the potentiation of erlotinib by celecoxib.
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PMID:Simultaneous targeting of the epidermal growth factor receptor and cyclooxygenase-2 pathways for pancreatic cancer therapy. 1637 9


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