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)

Various types of tumors show aberrant expression and overexpression of epidermal growth factor (EGF) receptor and the degree of receptor expression correlates with a malignant phenotype in many epithelial tumors. However, in vitro evidence supporting the advantageous role of receptor overexpression is deficient. In this study, we compared the effects of exogenous EGF on the cell colony morphology in monolayer and collagen gel culture between HSC-1 squamous carcinoma cells overexpressing EGF receptor and their revertant subline cells. These cells formed coherent cell colonies under routine culture conditions, but addition of EGF induced dissociation of cell colonies within 24 h in the parent HSC-1 cells, though not in the subline cells. Since the colony dissociation apparently involved loss of cell-cell adhesion, we also studied the effects of EGF on E-cadherin expression and its function. Cell aggregation assays showed that EGF reduced E-cadherin function dose-dependently in the parent cells, but not in the subline cells. However, immunoblotting analysis and ELISA showed the absence of downregulation or degradation of E-cadherin. Instead, EGF tyrosine phosphorylated cadherin/catenin complex components including beta-catenin and increased the detergent solubility of E-cadherin in the parent cells. These results suggest that EGF modified the functional association between E-cadherin and actin filament through tyrosine phosphorylation of the cadherin/catenin complex and thereby made the adhesion molecule incompetent. Our results indicate that the ligand activation of overexpressed EGF receptor impairs E-cadherin-mediated cell-cell adhesion and causes dissociation of the squamous carcinoma cell colonies, which facilitates tumor cell invasion in vivo. This might be relevant to the advantageous role of EGF receptor overexpression in malignant phenotype of epithelial tumor cells.
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PMID:Ligand activation of overexpressed epidermal growth factor receptor results in colony dissociation and disturbed E-cadherin function in HSC-1 human cutaneous squamous carcinoma cells. 863 95

ELAM is an E-Selectin adhesion molecule involved in the inflammatory process but it is also thought to potentially participate in the development of blood borne metastases, by facilitating tumour cell adhesion to vessels wall. ELAM expression in tumours was immunohistochemically investigated in 203 breast carcinomas. Frozen tissue sections were probed with monoclonal anti ELAM (Clone 1.2B6) using automated and quantitative immunoperoxidase systems. A positive anti-ELAM immunoreaction was observed in 113 tumours (57%). The mean surface of positive tumours varied from 3% to 50% (mean = 11.75%, SD = 8.7) and was correlated with histoprognostic indicators and tumour expression of various antigens detected according to the same method as ELAM. The results showed that ELAM immunoexpression was independent of the tumour size, grade and type and of the nodal status but significantly increased parallel to patients' age (p<0. 01). ELAM expression was independent of Ki-67/MIB1, anti-P53 and anti-Bcl2, anti-CD44v, anti-c-erbB-2, anti-CD31, anti-RE/RP, anti-PS2, and anti-VLA3 immunoreactions. But ELAM expression correlated with that of the VCAM vascular cell adhesion molecule (p=0.0004), VLA2 (p<0.0001), P-glycoprotein (p=0.025), and of Cathepsin D to a lower degree (p=0.06) and inversely correlated with E-cadherin (p=0.03). The results suggest that endothelial cell activation is independent of tumour cell proliferative activity and of stromal angiogenesis and that the precise role and regulation of ELAM in tumours remains to be elucidated. Also the clinical relevance of ELAM immunohistochemical expression requires further investigation and correlation with patients' follow-up.
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PMID:ELAM selectin expression in breast carcinomas detected by automated and quantitative immunohistochemical assays. 953 26

Metallothionein (MT) is a low molecular weight, cysteine-rich, zinc-binding protein that may have a function in cellular repair processes, growth and differentiation. Using a monoclonal antibody (E9) to metallothionein, we investigated the immunohistochemical expression of MT in routinely fixed and paraffin-embedded tissue from 98 cases of female breast carcinomas. The MT expression was studied in comparison with the expression of the basement membrane (BM) antigens (type IV collagen, laminin), fibronectin, cathepsin D, adhesion molecule CD44, p53 protein, the pRb, c-erbB-2 oncoprotein, EGFR, stromelysin-1, proliferation indices (Ki-67, PCNA), steroid receptor content as well as with other conventional clinicopathological parameters of breast cancer. Strong MT expression was observed in the majority of tumour cells in 18.4% of tumours, focal MT positivity in 13.3% and almost complete lack of MT expression in 68.4% of cases (mean value 33.36 +/- 26.36). The MT expression in carcinoma cells was strongly associated with the DCIS component of the tumour (p < 0.0001). High values of MT were correlated with low steroid receptor status (p = 0.08 for ER receptor and p = 0.019 for PgR receptor content). MT positive cases were correlated with stromelysin-1 expression (p = 0.059) and cathepsin D (p = 0.058). These findings suggest that MT expression is characteristic of the early phase of breast carcinogenesis, possibly regulated by hormones, and could be a new potential prognostic marker in breast cancer.
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PMID:Immunohistochemical localization of metallothionein in human breast cancer in comparison with cathepsin D, stromelysin-1, CD44, extracellular matrix components, P53, Rb, C-erbB-2, EGFR, steroid receptor content and proliferation. 1047 Jan 61

Cell migration depends mainly on actin polymerization and intracellular organization, which are influenced by a vast variety of actin binding proteins (ABPs). Regulation of ABP activity is mediated by second messengers such as phosphoinositides and calcium. Signaling via these second messengers is initiated and regulated by membrane receptors, e.g., receptor tyrosine kinases (RTKs), and by adhesion molecule interactions (e.g., integrins and selectins) and focal adhesion kinases. A major role in steering second-messenger signaling and thus in actin cytoskeleton reorganization and motility of cancer cells is played by the RTK c-erbB-2. This occurs through a number of signaling pathways which involve mainly enzymes, e.g., phospholipase Cgamma1 and GTPases, which modify signaling molecules. Furthermore large multiprotein complexes including actin-related protein 2/3, Wiskott-Aldrich syndrome protein, profilin, and capping protein among others play an important role in regulating actin reorganization. The complex picture of the mode of actin reorganization, which is involved in tumor cell migration, is slowly emerging from the mists of cellular signaling pathways, but this is still by no means a clear view.
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PMID:Cancer cell motility--on the road from c-erbB-2 receptor steered signaling to actin reorganization. 1177 34

Occult disseminated tumor cells are the major cause of relapse in patients with primary operable breast cancer but detection and characterization of these few cells is difficult. Applying immunohistochemistry, an immunomagnetic enrichment technique (IET) and immunocytochemistry (IC), we studied 58 breast cancer patients without overt metastases for the frequency of cytokeratin-positive (CK+) bone marrow (BM) cells coexpressing the epithelial adhesion molecule 17-1A (EpCAM) and c-erbB-2 and analyzed the primary tumor for these antigens as a strategy for additional immunotherapy. The primary tumors were analyzed for the target antigens by a pathologist. Dissemination of CK+ cells was studied in 4-6 x 10(6) BM cells by IC alone. For characterization of CK+ cells, 10-15 x 10(6) BM cells were incubated with microbeads coupled to antibodies detecting the target antigens, labelled cells were separated on selection columns and the positively (BM cells carrying the target antigen) and negatively (BM cells without target antigen) selected fractions were stained for CK+ cells. The effectiveness of these methods was confirmed in cell culture models. 17-1A was detected in all primary tumors and c-erbB-2 overexpression (2+, 3+) was found in 25/58 tissue samples. In total, analyzing 15-20 x 10(6) BM cells in each patient, the detection rate for CK+ cells in the BM was 69% (40/58 patients). Interestingly, analysis of the positive and negative enrichment fractions showed that the 17-1A antigen was coexpressed on CK+ cells in only 6 patients and c-erbB-2/CK+ cells were found in only one patient. Although 17-1A and c-erbB-2 were frequently detected in the primary tumor, these antigens were rarely expressed on CK+ BM cells. Whether the applied IET is not able to detect low amounts of these target antigens has to be clarified. Nevertheless, applying cell-cycle independent protocols in clinical trials requires careful elucidation of those patients who might benefit from these therapies.
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PMID:Rare expression of target antigens for immunotherapy on disseminated tumor cells in breast cancer patients without overt metastases. 1461 76

Endometrial adenocarcinoma is the most common malignant neoplasm of the female genital tract and, despite its relative frequency, the molecular events that contribute to the development and progression of the lesion remain poorly understood. The normal human endometrium is characterized by hormone-dependent variations during the menstrual cycle. This tightly controlled system is disturbed in endometrial hyperplasia and carcinomas and a series of changes initiate and promote progression towards the malignant phenotype. These changes can be subdivided into discrete steps, involving activation of oncogenes, inactivation of tumour suppressor genes, deregulation of cell cycle regulators or other proteins involved in tumour invasion and progression. Immunohistochemical expression of different biomarkers such as hormone receptor status (ER, PR), proliferation associated indices (PCNA, MIB1), oncogene (c-erbB-2), tumour suppressor gene products (pRb, p53 protein), cell cycle related proteins (cyclin D1, cyclin E, p21/WAF1), anti-apoptotic protein (bcl-2), adhesion molecule (CD44s), proteolytic enzyme (cathepsin D), heat shock protein (hsp27) and metallothionein (MT) has shown the contribution of these molecules to endometrial carcinogenesis in a hormone-dependent or independent manner as an early or late event. In addition, these biomarkers seem to be correlated with tumour differentiation or myometrial invasion, and therefore could be considered as indicators of the biological behaviour of endometrial carcinoma. Furthermore, the interrelationships of these molecular markers show that these genetic dysregulations could be implicated in the control of cell proliferation and differentiation, and thereby in the multistep process of endometrial carcinogenesis.
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PMID:Immunohistochemical tumour markers in endometrial carcinoma. 1612 80