Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:O76050 (neu)
 3,969 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We used an electron microscope to examine microvilli which appear on the surfaces of various tumor cells with high or low growth potential and/or metastatic ability. The results show that a greater number of microvilli appeared on the surfaces of tumor cells (QRpP and ERpP) which possess high growth potential than on tumor cells (QR and ER) with low growth potential. We also observed that microvilli were more abundant on the surface of highly metastatic clone cells, i.e. c-SST-2 (cl-2), mouse B16 melanoma (F-10) and human colon carcinoma (KM12SM) than on weakly metastatic clone cells, c-SST-2 (cl-4-2), B16 (F-1) and (KM12C). At the same time, more microvilli were observed on the surface of B16 BL6 cells, which were obtained from the metastatic site of the B16 F10 cells, than on the surface of the parent B16 F10 cells. Immunoelectron microscopy revealed that the c-neu oncogene product, which is closely related to an epidermal growth factor receptor, was positively stained in the microvilli of tumor cells (ERpP) with high growth potential and high metastatic ability, whereas the tumor cells (ER) with low growth potential and weak metastatic ability were not stained. These findings suggest that the increased presence of microvilli correlates closely with the growth potential and metastatic ability of tumor cells.
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PMID:Correlation between the presence of microvilli and the growth or metastatic potential of tumor cells. 197 29

The microbial product wortmannin has previously been shown to be a potent inhibitor of phosphatidylinositol-3-kinase. In view of the potential role of this enzyme in transduction of mitogenic signals, we determined the cytotoxic activity of wortmannin against several human tumor cell lines in vitro. The most sensitive lines included GC3 colon carcinoma, IGROV1 ovarian carcinoma, and CCRF-CEM leukemia (IC-50s ranging from 0.7-2.1 microM). The cytotoxicity of wortmannin was decreased approximately 10-fold by serum-free conditions. Wortmannin was generally less active in low passage human breast cancer cell lines that overexpress either epidermal growth factor receptor or Her2/neu. Wortmannin was also tested for in vivo antitumor activity against seven murine tumor and ten human tumor xenograft models. Activity (> 60% inhibition of tumor growth) was observed in only the C3H mammary carcinoma and the human BxPC-3 pancreatic carcinoma xenograft. In vivo antitumor activity did not correlate with in vitro sensitivity to wortmannin cytotoxicity.
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PMID:In vitro and in vivo antitumor activity of the phosphatidylinositol-3-kinase inhibitor, wortmannin. 765 91

The Her-2/neu oncogene encodes a Mr 185,000 transmembrane protein with homology to the epidermal growth factor receptor. It is overexpressed in 30-40% of breast and ovarian cancers, and this overexpression was shown to correlate with aggressiveness of malignancy and poor prognosis. Using tumor-associated lymphocytes isolated from patients with ovarian or breast cancer, several HLA-A2-restricted, Her-2/neu-derived peptides were identified. Further studies revealed that these tumor-associated CTLs can also lyse other tumors, including non-small cell lung and pancreatic cancer cells, suggesting that Her-2/neu epitopes are shared between several distinct types of epithelial tumors. To analyze whether Her-2/neu epitopes are tumor-associated antigens for renal cell carcinoma (RCC) and colon carcinoma, we induced Her-2/neu peptide-specific CTL responses by primary in vitro immunization and used these CTLs to determine the presentation of Her-2/neu epitopes on human tumor lines. Autologous dendritic cells (DCs) generated from peripheral blood monocytes were pulsed with Her-2/neu-derived peptides E75 and GP2 and used as antigen-presenting cells for CTL priming. High CTL activity toward peptide-pulsed targets was obtained after two weekly restimulations. CTLs induced with DCs generated in the presence of TNF-alpha elicited a higher cytotoxic activity when they were stimulated with the cognate peptide than did CTLs induced with DCs grown in granulocyte macrophage colony-stimulating factor and interleukin 4 alone. The cytotoxicity of induced CTLs was antigen specific and HLA-A2 restricted. Furthermore, these CTLs lysed, in a MHC- and antigen-restricted fashion, not only breast cancer cells but also colon carcinoma and RCC cell lines expressing Her-2/neu. The cytotoxic activity against tumor cells was blocked by cold HLA-A2-positive targets pulsed with the cognate peptide in cold target inhibition assay and by anti-HLA-A2 monoclonal Ab. These results suggest that epitopes derived from Her-2/neu protein might be attractive candidates for broadly applicable vaccines and may prove useful for adoptive immunotherapies designed for colon carcinoma or RCC.
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PMID:Her-2/neu-derived peptides are tumor-associated antigens expressed by human renal cell and colon carcinoma lines and are recognized by in vitro induced specific cytotoxic T lymphocytes. 948 28

The proto-oncogene neu (HER2 or c-erbB2) is overexpressed with or without gene amplification in 20-30% of breast cancers. In patients, neu amplification or overexpression in breast and ovarian cancer correlates with poor prognosis and tumor resistance to chemotherapy. neu-induced transformation can be reversed by the suppression of neu gene transcription. To further understand how neu gene transcription is regulated and to identify a possible transcriptional repressor(s) of neu, we identified a negative regulatory element known previously to be located within a 1-kilobase (kb) DNA fragment of an unknown sequence, upstream of the proximal neu gene promoter. One of several DNA fragments subcloned from this region suppressed transcriptional activity of the proximal neu gene promoter. Sequencing of the 1-kb fragment confirmed the location of the repressor element to be between an AluI and a RsaI sites, around 1.4 kb upstream to the translation start site. Various deletions were introduced into the AluI-RsaI fragment and subcloned into both the native neu promoter and a heterologous thymidine kinase promoter. Subsequent transfections and reporter gene assays in cell lines of various tissues of origin confirmed and narrowed the repressor activity to a 120-base pair NlaIV-MslI fragment located between -1385 and -1266. Importantly, specific protein binding activity to this element could be detected with nuclear extracts isolated from these cell lines. In contrast, a 28-base pair MslI-RsaI fragment (-1265 to -1238), located immediately 3' of the putative repressor element, was found to form protein-DNA complexes with only nuclear extracts isolated from a colon carcinoma cell line. This specific protein binding activity correlated with a previously unknown transcriptional stimulatory activity only in this cell line.
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PMID:Characterization of a repressor element and a juxtaposed tissue-restricted activator element located on the distal neu gene promoter. 1069 68

We report the immunological characterization of three colon carcinoma cell lines, COLO 205, SW620 and SW403, which we selected to combine with cytokine-secreting fibroblasts for the development of an allogeneic tumour cell vaccine. The cell lines expressed HLA-A2 as well as shared tumour-associated antigens (TAAs) representative of colon carcinomas: CEA, Ep-CAM, MUC1, HER2/neu and MAGE antigens. They did not secrete high levels of the immunosuppressive factors TGF-beta, IL-10 or prostaglandins. The lines presented TAAs in a manner recognized by immune effector cells, which was demonstrated by the lysis of SW620 by HLA-A2-restricted anti-p53 cytotoxic T lymphocytes (CTL). COLO 205 and SW620 were genetically modified to express the co-stimulatory molecule CD80 (B7.1), which increased the ability of the cells to stimulate CTL in vitro. CTL clones derived from HLA-A2+ peripheral blood mononuclear cells stimulated with the CD80-expressing lines lysed the stimulator cell and an HLA-A2+ colon cancer cell line, but did not lyse an isogeneic fibroblast line or an HLA-A2- colon cancer cell line. CTL clones derived from colon carcinoma patients immunized with an allogeneic vaccine containing these lines demonstrated killing of autologous tumour cells, the vaccine cell lines and other HLA-A2+ colon cancer cell lines, but not fibroblasts isogeneic to certain of the target cell lines. Our studies demonstrate that these colon carcinoma cell lines express shared TAAs that can induce CTLs which recognize and lyse other colon carcinoma cells, and support the continued clinical evaluation of the CD80 gene modified allogeneic colon cell/cytokine-secreting fibroblast carcinoma vaccine.
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PMID:Antigenic and immunologic characterization of an allogeneic colon carcinoma vaccine. 1210 28

We have previously reported that the antibody fusion proteins anti-HER2/neu IgG3 fused to IL-12 [(IL-12)-IgG3] or GM-CSF [IgG3-(GM-CSF)] independently or in combination are effective anti-tumor agents against D2F2/E2 murine mammary cancer cells expressing human HER2/neu in the peritoneum. Importantly, the long-term survivors were immune to the subcutaneous challenge with D2F2/E2 and the parental D2F2 not expressing HER2/neu. We now show that these long-term survivors also exhibit significant protection against subsequent subcutaneous challenge with the murine colon carcinoma CT26-HER2/neu, and later against subcutaneous challenge with the parental CT26. These results suggest that the long-term systemic protection against mammary cancer elicited by treatment with antibody-cytokine fusion proteins can be extended to prevent the growth of a tumor from different origin expressing HER2/neu, and that this protection is not limited to this antigen alone, since it also prevented the growth of the parental tumor cells.
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PMID:Long-term immunity elicited by antibody-cytokine fusion proteins protects against sequential challenge with murine mammary and colon malignancies. 1731 Mar 81