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)

Extramammary Paget's disease is a particular form of skin cancer of unknown histogenesis. To look for the genetic defects underlying the pathogenesis of this tumour, we have examined loss of heterozygosity (LOH), p53 and human papillomavirus (HPV) status, and the expression of c-erbB-2 and bcl-2 proteins in 14 cases. Unexpectedly, no LOH was detected at several loci commonly lost in other human cancers (namely 3p, 9p, 9q, 13q, 16q, 17p, and 17q) in 12 tumours examined. Altered p53 protein expression was entirely or mostly negative in all 14 cases. Direct sequencing of exons 5-8 of the p53 gene in eight cases revealed no mutation. Polymerase chain reaction amplification of the L1 gene of human papillomavirus (HPV) did not detect the virus that could inactivate p53 and retinoblastoma tumour-suppressor gene products. As expected, c-erbB-2 proto-oncogene protein was overexpressed in six cases. The expression of bcl-2 was negative in all cases. The results presented in this study suggest that molecular events underlying extramammary Paget's disease differ from those of other common epithelial malignancies and that tumour-suppressor genes located in chromosome regions not examined in this study may be important.
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PMID:Tumour cells of extramammary Paget's disease do not show either p53 mutation or allelic loss at several selected loci implicated in other cancers. 932 50

Our previous study in extramammary Paget's disease showed neither p53 mutations nor allelic loss at selected loci implicated in other cancers, suggesting a pathogenesis of this skin cancer different from other common epithelial malignancies. To examine further the genetic defects in extramammary Paget's disease, we carried out molecular genetic analyses in 31 tumor samples obtained from 27 cases of extramammary Paget's disease without underlying malignancies. Immunohistochemistry using CB-11 monoclonal antibody revealed either membrane or cytoplasmic erbB-2 oncoprotein overexpression in none of the 13 primary in situ tumors, but in one recurrent in situ tumor, 10 of 13 invasive primary tumors and two of four lymph node metastases. Sensitive dual color fluorescence in situ hybridization analysis using probes for erbB-2 gene locus and chromosome 17 pericentromere, however, revealed different erbB-2 gene status in the erbB-2 overexpressing tumors. One recurrent in situ tumor and one lymph node metastasis showed definite gene amplification characterized by multiple scattered signals or a few large clustered erbB-2 signals, whereas four tumors with predominantly cytoplasmic erbB-2 overexpression were thought to have low-grade gene amplification. The remaining six tumors overexpressing erbB-2 showed no increase of erbB-2 copy numbers. No evidence of abnormal activation of the beta-catenin gene, a critical mediator of Wnt signaling pathway, in any tumor by immunohistochemical staining and by direct sequencing and reverse transcription-polymerase chain reaction analysis was found. Frequent overexpression of erbB-2 by either gene amplification or possible transcriptional activation in invasive primary tumors and metastases suggests an important part for this oncogene in the progression of extramammary Paget's disease.
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PMID:erbB-2 overexpression but no activation of beta-Catenin gene in extramammary Paget's disease. 1046 13

Ultraviolet (UV) irradiation causes human skin aging and skin cancer through the activation of matrix metalloproteinases (MMPs) which are responsible for the degradation of collagen and tumor progression in human skin. The molecular mechanisms of UV-induced MMPs are yet to be defined. Our previous studies and others suggest that i) the transient activation of cell surface receptors and subsequent activation of MAP kinase cascade contributes to the transcriptional up-regulation of MMPs; and ii) UV-induced expression of pro-inflammatory cytokines such as IL-1 beta and TNF-alpha may also account for the expression of MMPs. However, signaling pathway through which cytokines induce MMP expression remains to be unraveled. In this study, we investigated the pathway that leads to the IL-1 beta-induced up-regulation of MMP-1 in human keratinocytes. IL-1 beta activated epidermal growth factor (EGF) receptor in cultured human keratinocytes in a time- and dose-dependent manner. IL-1 beta-induced EGF receptor tyrosine phosphorylation started at 5 min and peaked at 10 min and remained elevated up to 40 min post IL-1 beta treatment. EGF receptor kinase inhibitor PD153035 and AG1478 inhibited IL-1 beta-induced EGF receptor tyrosine phosphorylation. To test the effect of EGF receptor transactivation on downstream components, we examined the ERK activation by IL-1 beta. We found that IL-1 beta-induced ERK phosphorylation, PD153035 and MEK inhibitor PD98059 blocked IL-1 beta-induced ERK activity. Furthermore, both inhibitors also dramatically reduced IL-1 beta-induced expression of c-jun and c-fos mRNA which are required for up-regulation of MMPs. EGF receptor kinase inhibitor PD153035 and AG1478 and MEK inhibitor PD98059 also blocked IL-1 beta induction of MMP-1 in cultured human keratinocytes. Collectively, our data indicate that IL-1 beta-induced expression of MMP-1 is mediated by transactivation of EGF receptor and through ERK pathway in human keratinocytes.
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PMID:Transmodulation of epidermal growth factor receptor mediates IL-1 beta-induced MMP-1 expression in cultured human keratinocytes. 1117 16

Exposure to the sun's UV radiation appears to be the most important environmental factor involved in the development of skin cancer. UVA is the major portion of UV radiation in sunlight and is considered to be a human carcinogen. In this study, we have investigated the delayed and sustained activation of ERK MAPK by UVA exposure. In parallel, a delayed Ras activation with a similar time course was observed after UVA exposure. The activated Ras was found to be localized in endomembranes such as the Golgi apparatus instead of plasma membranes. Expression of dominant negative Ras (N17Ras) abolished ERK activation by UVA. The presence of AG1478, an epidermal growth factor (EGF) receptor (EGFR) kinase inhibitor, had no effect on ERK or Ras activation, indicating that EGFR kinase activity is not involved in ERK activation by UVA. In contrast, protein kinase C (PKC) depletion by chronic 12-O-tetradecanoylphorbol-13-acetate treatment nearly abolished UVA-induced ERK and Ras activation. The presence of the Ca(2+)-dependent-PKC inhibitor Go6976 had a similar effect. These findings suggest that ERK activation by UVA is mediated by PKC in a Ras-dependent pathway. In addition, a gradual increase in intracellular calcium level after UVA exposure was detected by flow cytometry. The presence of the PLC inhibitor U73122 or the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N, N',N'-tetraacetic acid tetrakis (acetoxymethyl ester) (BAPTA-AM) blocked both ERK and Ras activation, suggesting that both PLC and calcium are required for ERK activation. Our findings demonstrated that, different from UVC and UVB, UVA-induced delayed and sustained ERK activation is EGFR kinase activity-independent, but PLC/calcium/PKC-mediated. The delayed and sustained ERK activation provides a survival signal to human HaCaT keratinocytes, which may serve as an important mechanism for cell transformation and potential skin carcinogenesis in vivo caused by UVA exposure.
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PMID:Delayed and sustained activation of extracellular signal-regulated kinase in human keratinocytes by UVA: implications in carcinogenesis. 1547 81