Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. HER-2/neu has been widely studied in breast cancer. In this review, the association of HER-2/neu gene and protein abnormalities studied by Southern and slot blotting, immunohistochemistry, enzyme immunoassays, and fluorescence in situ hybridization with prognosis in breast cancer is studied in depth by review of a series of 47 published studies encompassing more than 15,000 patients. The relative advantages of gene amplification assays and frozen/fresh tissue immunohistochemistry over paraffin section immunohistochemistry are discussed. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The potential value of HER-2/neu status for the prediction of response to therapy in breast cancer is presented in the light of a series of recently published studies showing a range of impact on the outcome of patients treated with hormonal, cytotoxic, and radiation therapies. The evidence that HER-2/neu gene and protein abnormalities in breast cancer predict resistance to tamoxifen therapy and relative sensitivity to chemotherapy regimens including adriamycin is presented. The review will also evaluate the status of serum-based testing for circulating the HER-2/neu receptor protein and its ability to predict disease outcome and therapy response. In the final section, the review will briefly present preliminary data concerning the use of antibody-based therapies directed against the HER-2/neu protein and their potential to become a new modality for breast cancer treatment. The recently presented phase III clinical trial evidence that systemic administration of anti-HER2 antibodies (Herceptin), alone and in combination with cytotoxic chemotherapy in patients with HER-2/neu overexpressing primary tumors, can increase the time to recurrence and overall response rates in metastatic breast cancer is reviewed.
 ...
PMID:The HER-2/neu oncogene in breast cancer: prognostic factor, predictive factor, and target for therapy. 983 67

Overexpression of the HER-2/neu proto-oncogene, which encodes the tyrosine kinase receptor p185neu, has been observed in tumors from breast cancer patients. We demonstrated previously that emodin, a tyrosine kinase inhibitor, suppresses tyrosine kinase activity in HER-2/neu-overexpressing breast cancer cells and preferentially represses transformation phenotypes of these cells in vitro. In the present study, we examined whether emodin can inhibit the growth of HER-2/neu-overexpressing tumors in mice and whether emodin can sensitize these tumors to paclitaxel, a commonly used chemotherapeutic agent for breast cancer patients. We found that emodin significantly inhibited tumor growth and prolonged survival in mice bearing HER-2/neu-overexpressing human breast cancer cells. Furthermore, the combination of emodin and paclitaxel synergistically inhibited the anchorage-dependent and -independent growth of HER-2/neu-overexpressing breast cancer cells in vitro and synergistically inhibited tumor growth and prolonged survival in athymic mice bearing s.c. xenografts of human tumor cells expressing high levels of p185neu. Both immunohistochemical staining and Western blot analysis showed that emodin decreases tyrosine phosphorylation of HER-2/neu in tumor tissue. Taken together, our results suggest that the tyrosine kinase activity of HER-2/neu is required for tumor growth and chemoresistance and that tyrosine kinase inhibitors such as emodin can inhibit the growth of HER-2/neu-overexpressing tumors in mice and also sensitize these tumors to paclitaxel. The results may have important implications in chemotherapy for HER-2/neu-overexpressing breast tumors.
 ...
PMID:Tyrosine kinase inhibitor emodin suppresses growth of HER-2/neu-overexpressing breast cancer cells in athymic mice and sensitizes these cells to the inhibitory effect of paclitaxel. 1003 84

IGF1 and IGF2 are circulating peptide hormones and locally-acting growth factors with both paracrine and autocrine functions. IGF1 and IGF2 signal through a common tyrosine kinase receptor, the insulin-like growth factor 1 receptor (IGF1R), and have mitogenic, cell survival, and insulin-like actions that are essential for embryogenesis, post-natal growth physiology, and breast development. The activities of IGF1 and 2 are tightly-regulated by a network of binding proteins and targeted degradation mechanisms. This complex regulatory system is disrupted in breast cancer, leading to excess IGF1R signaling. Evidence for this statement includes: a) breast cancers are infiltrated with IGF2 expressing stromal cells; b) mannose 6-phosphate/IGF2 receptor (M6P/IGF2R) is mutated in breast cancer, leading to loss of IGF2 degradation; c) IGF1R is overexpressed by malignant breast epithelial cells, and in some cases IGF1R is amplified; and d) complex changes in IGF binding protein expression occur during breast cancer progression which most likely also affect IGF1 and 2 signaling. The clinical importance of these epigenetic and genetic changes has recently been stressed by the finding that IGF1R signaling alters the apoptotic response of breast cancer cells to genotoxic stress and, in addition, IGF1R activation sensitizes cells to estrogen by inducing phosphorylation of the estrogen receptor. As a consequence of these findings, we propose that IGF analysis of breast cancer samples should shift from prognostic studies to an evaluation of IGF ligands, receptors, and binding proteins as resistance/sensitivity markers for radiation, chemotherapy, and endocrine therapy.
Breast Cancer Res Treat 1998
PMID:Insulin-like growth factors in human breast cancer. 1006 81

Deletions and amplifications are frequent alterations of the short arm of chromosome 8 associated with various types of cancers, including breast cancers. This indicates the likely presence of tumor suppressor genes and oncogenes. In the present study, we have used the expressed sequence tag (EST) map of 8p11-21 to assemble a set of available cDNAs representing genes from this region. DNA arrays were prepared for expression analysis and search for genes potentially involved in breast cancer. Underexpresion in tumoral breast cells (versus normal breast) was observed for 15 transcripts. Among these, the Frizzled-related gene FRP1/FRZB, was turned off in 78% of breast carcinomas, suggesting that the lack of its product may be associated with malignant transformation. Overexpression in tumoral breast cells was observed for 13 genes. The FGFR1 gene, that encodes a tyrosine kinase receptor for members of the fibroblast growth factor family, was identified as a good candidate for one amplification unit. Taken together, our results demonstrate that such a strategy can rapidly identify genes with an altered pattern of expression and provide candidate genes for malignancies.
 ...
PMID:Differential expression assay of chromosome arm 8p genes identifies Frizzled-related (FRP1/FRZB) and Fibroblast Growth Factor Receptor 1 (FGFR1) as candidate breast cancer genes. 1008 45

HER2/neu, a Mr 185,000 tyrosine kinase receptor that is overexpressed in breast cancer, undergoes proteolytic cleavage of its extracellular domain (ECD). In contrast with other membrane-bound proteins, including growth factor receptors, that are cleaved by a common machinery system, we show that HER2 cleavage is a slow process and is not activated by protein kinase C. Pervanadate, a general inhibitor of protein-tyrosine phosphatases, induces a rapid and potent shedding of HER2 ECD. The shedding of HER2 ECD is inhibited by the broad-spectrum metalloprotease inhibitors EDTA, TAPI-2, and batimastat. The tissue inhibitor of metalloproteases-1; an inhibitor of matrix metalloproteases that does not inhibit cleavage by the general protein kinase C-dependent shedding machinery, also inhibited HER2 ECD shedding, whereas tissue inhibitor of metalloproteases-2 did not. These data suggest that HER2 cleavage is a process regulated by an as-yet-unidentified distinct protease.
 ...
PMID:Cleavage of the HER2 ectodomain is a pervanadate-activable process that is inhibited by the tissue inhibitor of metalloproteases-1 in breast cancer cells. 1009 47

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. HER-2/neu has been widely studied in breast cancer. The potential value of HER-2/neu status for the prediction of disease outcome and response to therapy in breast cancer is presented in the light of a series of recently published studies showing a range of impact on the outcome of patients treated with hormonal, cytotoxic and radiation therapies. This review includes the application of serum-based HER-2/neu testing and the use of antibody-based therapies directed against the HER-2/neu protein and their potential to become a new modality for breast cancer treatment.
 ...
PMID:The HER-2/neu oncogene: prognostic factor, predictive factor and target for therapy. 1020 34

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. HER-2/neu has been widely studied in breast cancer. In this review, the association of HER-2/neu gene and protein abnormalities studied by Southern and slot blotting, immunohistochemistry, enzyme immunoassays, and fluorescence in situ hybridization with prognosis in breast cancer is studied in depth by review of a series of 47 published studies encompassing more than 15,000 patients. The relative advantages of gene amplification assays and frozen/fresh tissue immunohistochemistry over paraffin section immunohistochemistry are discussed. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The potential value of HER-2/neu status for the prediction of response to therapy in breast cancer is presented in the light of a series of recently published studies showing a range of impact on the outcome of patients treated with hormonal, cytotoxic, and radiation therapies. The evidence that HER-2/neu gene and protein abnormalities in breast cancer predict resistance to tamoxifen therapy and relative sensitivity to chemotherapy regimens including adriamycin is presented. The review will also evaluate the status of serum-based testing for circulating the HER-2/neu receptor protein and its ability to predict disease outcome and therapy response. In the final section, the review will briefly present preliminary data concerning the use of antibody-based therapies directed against the HER-2/neu protein and their potential to become a new modality for breast cancer treatment. The recently presented phase III clinical trial evidence that systemic administration of anti-HER2 antibodies (Herceptin®), alone and in combination with cytotoxic chemotherapy in patients with HER-2/neu overexpressing primary tumors, can increase the time to recurrence and overall response rates in metastatic breast cancer is reviewed.
 ...
PMID:The HER-2/neu Oncogene in Breast Cancer: Prognostic Factor, Predictive Factor, and Target for Therapy. 1038 10

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. The association of HER-2/neu gene and protein abnormalities with prognosis in breast cancer is presented by considering a series of 52 published studies including more than 16,000 patients. The relative advantages and disadvantages of Southern blot testing, polymerase chain reaction amplification, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed with immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The importance of HER-2/neu protein overexpression in ductal carcinoma in situ, and HER-2/neu protein status in uncommon breast diseases in female patients and breast cancer in male patients are also considered. The potential value of HER-2/neu protein status for the prediction of response to therapy in breast cancer is presented for standard hormonal therapy, cytotoxic chemotherapy, and radiation therapy. Also evaluated is the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response. Finally, preliminary data concerning use of antibody-based therapies directed against HER-2/neu protein and their potential use in breast cancer treatment are considered.
 ...
PMID:HER-2/neu (c-erb-B2) gene and protein in breast cancer. 1039 1

Angiopoietin-1 (Ang-1) is required for developing vessels, and its absence leads to defects in vessel remodeling. Ang-1 has been identified as the ligand for the tyrosine kinase receptor Tie-2, which is expressed specifically on endothelial cells and early hematopoietic cells. In studying the role of Tie-2 and Ang-1 in megakaryocytopoiesis, 3 alternatively spliced species of Ang-1 mRNA (Ang-1.3 kb, Ang-0.9 kb, and Ang-0.7 kb) were identified in addition to the full-length Ang-1 (Ang-1.5 kb), in the megakaryocyte cell line CHRF by reverse transcription-polymerase chain reaction (RT-PCR), and then cloned and sequenced. The expression of 3 alternatively spliced isoforms of Ang-1 was confirmed by RT-PCR using specific primer pairs derived from junction sites and the 3' end of Ang-1 cDNA, and it was further demonstrated by nuclease protection assay, Northern blotting, and immunoblotting in CHRF cells. Expression of the Ang-1.3 kb isoform was also detected in human primary fibroblast cell line FS4, breast cancer cell line MDAMB-468, and CD34(+)CD41(+) cells of fetal liver and platelets. The function of the 1.5-kb, 1.3-kb, and 0.9-kb isoforms was examined. Recombinant proteins Ang-1.5 and 0.9 kb bind strongly to the recombinant Tie-2 receptor (Tie-2-Fc), whereas the 1.3-kb isoform does not. The Ang-1.3 kb isoform binds to the 1.5-kb isoform. Ang-1. 5 kb, but not the 1.3-kb and 0.9-kb isoforms, induces tyrosine phosphorylation of Tie-2 in human umbilical vein endothelial cells. These data suggest that isoforms 1.3 kb and 0.9 kb could serve as dominant negative molecules for the full-length Ang-1. The possible involvement of the newly identified Ang-1 isoforms in angiogenesis and in growth and differentiation of hematopoietic progenitor cells provides a greater complexity to these processes. (Blood. 2000;95:1993-1999)
 ...
PMID:Identification of a family of alternatively spliced mRNA species of angiopoietin-1. 1070 66

The c-erbB-2 proto-oncogene encodes a transmembrane protein tyrosine kinase receptor of 185 kDa (p185) and has been associated with several types of human cancers. In human breast cancer, overexpression of p185 occurs in 15-30% of cases, correlates with poor prognostic factors and characterizes breast cancers with a more aggressive behavior. Overexpression of p185 is usually associated with c-erbB-2 amplification, though it may occur independently and thus define subpopulations of breast cancers which might be of clinical interest. p185 expression is usually detected by immunohistochemistry (IHC) and few studies have been carried out to evaluate the p185 content of breast cancers with an ELISA technique. In this context, we showed, in 106 breast cancer samples, that p185 was expressed at high levels in 13.2%, intermediate levels in 55.7% and negative ones in 31.1% of cases. All p185 positive samples showed a c-erbB-2 oncogene amplification while none of the p185 negative samples and only 4% of p185 imtermediate samples had an amplification of c-erbB-2. p185 expression is significantly correlated with the negativity of estrogen and progestrone receptors, with high levels of cathepsin D and in some conditions with axillary nodal involvement. Thus, using the p185 ELISA assay, the c-erbB-2 status of breast cancers can be defined and moreover a subset can be discriminated which is characterized by intermediate levels of p185 and absence of c-erbB-2 amplification. The quantitative approach towards p185 in breast cancers affords the possibility of identifying more appropriately patients with high or low risk and thus permits adaptation of therapeutic regimens.
Breast Cancer Res Treat 2000 Sep
PMID:Relevance of p185 HER-2/neu oncoprotein quantification in human primary breast carcinoma. 1109 92


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>