Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have tested the hypothesis that the mechanism of platelet-derived growth factor (PDGF) and phorbol diester action to decrease the apparent affinity of the epidermal growth factor (EGF) receptor is the phosphorylation of the EGF receptor at the Ca2+/phospholipid-dependent protein kinase (protein kinase C) phosphorylation site, threonine 654. Protein kinase C-deficient cells were prepared by prolonged incubation of human fibroblasts with phorbol diester. Addition of phorbol diesters to these cells fails to regulate EGF receptor affinity or threonine 654 phosphorylation. In contrast, PDGF treatment of both control and protein kinase C-deficient fibroblasts causes a decrease in the apparent affinity of the EGF receptor and an increase in threonine 654 phosphorylation. Thus, the ability of PDGF or phorbol diester to modulate EGF receptor affinity occurs only when threonine 654 phosphorylation is increased. The stoichiometry of threonine 654 phosphorylation associated with a 50% decrease in the binding of 125I-EGF to high affinity sites was 0.15 versus 0.3 mol of phosphate per mole of EGF receptor when 32P-labeled fibroblasts are treated with PDGF or phorbol diester, respectively. It is concluded that EGF receptor phosphorylation at threonine 654 can be regulated by PDGF independently of protein kinase C, substoichiometric phosphorylation of the total EGF receptor pool at threonine 654 is caused by maximally effective concentrations of PDGF, and different extents of phosphorylation of EGF receptors at threonine 654 are observed for maximally effective concentrations of PDGF and phorbol diester, respectively. The data are consistent with the hypothesis that a specific subpopulation of EGF receptors that exhibit high affinity for EGF are regulated by threonine 654 phosphorylation.
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PMID:Stimulation of epidermal growth factor receptor threonine 654 phosphorylation by platelet-derived growth factor in protein kinase C-deficient human fibroblasts. 310 61

Stimulation of epidermal growth factor (EGF) receptor by ligands such as transforming growth factor (TGF) alpha may be associated with cell proliferation or transformation in both nevocytes and keratinocytes. Previously, EGF receptors have been identified within a variety of pigmented lesions, suggesting a possible responsiveness to ligands such as TGF alpha. In the present study, we characterize the intralesional expression and distribution of immunoreactive TGF alpha protein by avidin-biotin immunoperoxidase localization in benign nevi, congenital nevi, dysplastic nevi, and malignant melanomas. In situ hybridization techniques with TGF alpha riboprobes confirmed the constitutive production of TGF alpha in all types of pigmented lesions. The localization of TGF alpha expression to nevocytes when coupled with the previous reports of expression in basal keratinocytes suggests the possibility of either an autocrine mechanism of action for TGF alpha or a paracrine interplay of TGF alpha between keratinocytes and nevocytes within melanocytic lesions. An increase in immunoreactive TGF alpha in nevocytes was noted in both benign and dysplastic nevi from dysplastic nevus patients, as compared to benign nevi from normal patients. Congenital nevi and malignant melanomas showed an intermediate and variable level of TGF alpha immunoreactivity. When coupled with previous studies the data suggest linkage of the TGF alpha/EGF receptor pathway in the evolution of melanocytic lesions.
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PMID:Expression and distribution of transforming growth factor-alpha within melanocytic lesions. 796 61

In this study the expression of epidermal growth factor receptor (EGFR) and c-erbB-2, c-erbB-3 and c-erbB-4 oncogenes were investigated in gestational trophoblastic diseases and normal first trimester placenta. Furthermore, the possibility that macrophage (IL-1 alpha, IL-1 beta, TNF) and lymphocyte (IL-2, gamma-IFN, GM-CSF) cytokines effects are mediated by changes in EGFR expression were studied. Paraffin sections of 16 cases of partial mole, 25 cases of complete mole, 10 cases of gestational choriocarcinoma and 11 cases of therapeutic abortion were studied immunohistochemically for EGFR, c-erbB-2, c-erbB-3 and c-erbB-4 proteins. The presence of EGFR mRNA was studied using in situ hybridization. JEG-3 human choriocarcinoma cells were incubated with varying concentrations of interleukin 1-alpha, interleukin 1-beta, interleukin 2, gamma-interferon, granulocyte-macrophage colony stimulating factor and tumor necrosis factor-alpha, and the expression of EGFR was measured by radioimmunoassay using a murine monoclonal antibody with specificity for EGFR. Staining for EGFR was detected immunohistochemically in all cell type in gestational trophoblastic diseases and normal placenta. The levels of expression of EGFR in choriocarcinoma and syncytiotrophoblasts and cytotrophoblasts in complete mole were significantly greater than those in syncytiotrophoblasts and cytotrophoblasts in both normal placenta and partial mole (p < 0.01, p < 0.01). The immunoreactivity of c-erbB-2 was significantly stronger in choriocarcinoma and extravillous trophoblast in complete mole than that in extravillous trophoblast in partial mole and normal placenta (p < 0.02, p < 0.01, respectively). Strong immunostaining for EGFR (p = 0.02) and c-erbB-3 (p < 0.01) in extravillous trophoblasts of complete mole was found to be significantly correlated with the development of persistent postmolar gestational trophoblastic tumor. Macrophage-derived cytokines IL-1 alpha, IL-1 beta and TNF significantly suppressed cell growth; this was associated with a significant increase in EGFR expression. The lymphocyte (IL-2, gamma-IFN, GM-CSF) cytokines had no significant effect on either EGFR expression or cell growth. These findings support the concept that cytokines may act as paracrine mediators of autocrine processes involved in choriocarcinoma cell growth regulation by modulating growth factor receptor expression. The EGFR-related family of oncogenes may be important in the pathogenesis and prognosis of gestational trophoblastic diseases.
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PMID:[The c-erbB-related oncoproteins in normal placenta and in gestational trophoblastic diseases (in vitro study)]. 1142 88

Hereditary cancer syndromes provide excellent models for molecular genetic studies that may aid significantly in case detection, surveillance, and management. Ultimately, molecularly based designer pharmaceuticals may emerge from this research, such as the case of trastuzumab (Herceptin) in HER-2/neu positive breast cancer, and imatinib (Gleevec) in chronic myelocytic leukemia and gastrointestinal stromal tumors. Importantly, these molecular findings may fuel significant clues to cancer control. This background is mentioned since surveillance and management of pancreatic cancer, a major concern of this manuscript, has been uniformly unsuccessful as evidenced by the close correspondence between its incidence and its mortality. Yet knowledge about its genetic and molecular pathology will hopefully ameliorate this vexing problem. One molecular genetic clue is the recently identified palladin mutation in two pancreatic cancer prone families. However, caution must be used toward the palladin mutation, as several recent publications have questioned its significance as a pancreatic cancer causing mutation. We provide a concise description of pancreatic cancer in concert with malignant melanoma in the familial atypical multiple mole melanoma (FAMMM) syndrome as a potential preventive model. This knowledge should help clinicians and basic scientists seize on the opportunity to develop more sensitive and specific screening and management programs in this disease; while a relatively small subset of pancreatic cancer may be readily identifiable through its FAMMM phenotype, coupled with its CDKN2A mutation, this hereditary disorder, given a keen knowledge of its natural history and molecular genetics, may prove to be an effective clinical preventive model.
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PMID:Pancreatic cancer and the FAMMM syndrome. 1799 82