Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.3.44 (P-glycoprotein)
 13,344 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD44 variants carrying sequences encoded by exon v6 are preferentially expressed in metastatic animal cancer cell lines. CD44v6 overexpression correlates tumor dedifferentiation and progression in some human carcinomas, but the relationship of CD44v6 overexpression with metastatic behavior of tumor observed in animal models is controversial, particularly in breast carcinomas. The discrepancies probably result from analytical bias. We investigated CD44v6 and CD44s expression in 218 frozen samples of primary breast carcinomas. Immunocytochemical procedure was performed under optimal technical conditions using commercially available 2F-10 monoclonal antibody (MAb), a microprocessor-controlled automated device (Ventana Medical Systems, Tucson, AZ), and quantitative evaluation of results by processing digitized-colored microscopic images (SAMBA, Grenoble, France). CD44v6 expression in tissue sections was shown to be independent of the patient age, tumor size, histological types and grades, and the lymph node status. CD44v6 expression was also independent of the expression of molecules endowed with poor prognostic significance detected by MAbs (anti-p53, anti-c-erb B-2 protein, MIB1) on consecutive sections. No significant relationship could be evidenced either between CD44v6 expression, and CD31 involved stromal angiogenesis and cathepsin D. Finally, CD44v6 was independent of markers of hormone dependence (estrogen and progesterone receptors, pS2) and of multidrug resistance (P-glycoprotein). Similar results were observed with anti-CD44s. We conclude that the true prognostic significance of CD44v6 overexpression still remains to be shown under rigorous technical conditions (frozen samples, well-documented MAbs, and optimal standardization of procedure using automation and quantitative analysis) providing data appropriate for further correlation with long-term patient follow-up.
 ...
PMID:Automated and quantitative immunocytochemical assays of CD44v6 in breast carcinomas. 904 92

The reduction of E-cadherin expression, which is involved in the initial step of invasion and metastasis of cancer, was investigated in 218 human breast carcinomas. Quantitative immunohistochemical assays (ICAs) were performed on frozen sections. Quantitation was assessed by processing digitized microscopic images of immunoreactions using a computerized system of image analysis (SAMBA). The results were correlated with clinicopathological data and quantitative immunodetection of other molecules. E-cadherin expression was significantly (P < 0.001) stronger in ductal carcinomas than in lobular carcinomas and stronger (P < 0.01) in low grades than in high grades, but E-cadherin was independent of lymph node status and tumour size. Also an inverse significant (P < 0.01) relationship was observed between E-cadherin expression on tissue sections and positive immunoreactions with anti-P53, MIB1 (growth fraction), and anti-c-erb-B2 product. Conversely, strong positive and anti-E-cadherin immunoreactions correlated with strong positive anti-ER and anti-PR immunoreactions (P < 0.01). No relationship was observed between E-cadherin and the results of quantitative ICAs of cathepsin D, CD31, and P-glycoprotein, assessed on consecutive sections from the same frozen tissue samples. The results show that preserved E-cadherin expression correlates with high degree of tumour differentiation, low proliferative activity, and low expression of prognostic markers. The deregulation of E-cadherin is independent of other steps of tumour invasion, such as protease digestion of extracellular matrix and angiogenesis.
 ...
PMID:E-cadherin quantitative immunocytochemical assays in breast carcinomas. 915 15

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.
 ...
PMID:ELAM selectin expression in breast carcinomas detected by automated and quantitative immunohistochemical assays. 953 26

VLA2 is thought to be involved in the metastatic process in malignant tumours, in particular in carcinomatous cell adhesion to vessel basement membrane. VLA2 expression was immunohistochemically investigated in 204 breast carcinomas. Frozen tissue sections were probed with monoclonal anti-VLA2 using automated (Ventana ES 320 System) and quantitative (SAMBA 2005 image processor) immunoperoxidase. A positive anti-VLA2 immunoreaction was observed in 48 tumours (23.5%), within epithelial carcinomatous cells. The VLA2-positive surface in tumours varied from 3% to 20% (mean 8.75, S.D. 7.17) and was correlated with histoprognostic indicators and tumour expression of various antigens detected using the same method as that for VLA2. The results show that VLA2 immunoexpression was independent of the tumour size, grade, type and aneuploidy, and of the nodal status. VLA2 significantly correlated with ELAM, VCAM, VLA3 and P-glycoprotein (P-gp) (P < 0.01) and inversely correlated with cathepsin D (P < 0.001), but was independent of Ki67/MIB1, p53, bcl-2, c-erbB-2, E cadherin, CD44v, CD31, oestrogen and progesterone receptors' (ER, PR) antigenic sites and pS2. The exact role, if any, of VLA2 in tumour cell dissemination remains to be elucidated and the clinical relevance of VLA2 immunodetection in breast carcinomas requires further investigation of the correlation between VLA2 immunocytochemical expression and patients' outcome and response to chemotherapy.
 ...
PMID:VLA2 integrin expression in breast carcinomas evaluated by automated and quantitative immunohistochemistry. 964 45