Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Knowledge about genetic alterations specific to the metastatic process and chemoresistance in neuroblastoma is progressing steadily. Low or no CD44 expression, increased NM23 expression and specific mutations of the 5' coding regions of NM23 are distinct features of aggressive, metastatic neuroblastoma. MYCN down-regulates Class I HLA antigen expression in many neuroblastoma cell lines and, in turn, may be regulated by a suppressor gene. The MYCN amplified human neuroblastoma cell line, IGR-N-91, established in vitro, metastasises in the nude mouse and has exhibited co-activation of MYCN and PGY1, resulting from direct activation of the oncoprotein on the PGY1 promoter. In this model, the MYCN product activates angiogenesis, the dissemination process and chemoresistance via specific genes (PGY1 and GST3). MYCN, like the BCL-2 and TP53 products, may also play a key role in apoptosis. The implication of these genes in the potential for metastasis and chemoresistance in neuroblastoma is discussed.
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PMID:Genetic alterations associated with metastatic dissemination and chemoresistance in neuroblastoma. 757 68

The distribution of PECAM-1/CD31 molecule was investigated in 133 breast carcinomas using monoclonal antibody and frozen sections. Anti-CD31 labels endothelial cells and reflects stromal angiogenesis. The CD31 immunoreactivity was evaluated by computer-assisted analysis of digitized microscopic images. The automatic screening of the whole preparation and the measurements of the mean CD31 immunostained surface was performed in each case. A similar procedure was achieved for p53, cathepsin D, P-gp, pHER-2/neu, Ki67, pS2 estrogen and progesterone antigenic sites immunodetection. The image analysis of positive CD31 surface was variable, ranging from 4% to 33% (mean 14.7%, SD = 5.43). The CD31 positive surface correlated (P < .01) with the Nottingham prognostic index, but not with the tumor size, the node status, the tumor grade, nor with the patient age. Also the CD31 immunoreactivity was independent of the pHER-2/neu, Ki67 antigen, p53, ER, PR and pS2 immunodetectable expression in tumors, but correlates with that of cathepsin D (P = .024) and P-gp (P = .028), which reflects the multi-drug resistance capacity of tumor cells. In conclusion, CD31 positive vessels assessed on frozen sections by image analysis constitute an excellent method of evaluating tumor stromal angiogenesis, and can be further used for clinical purposes. The results also suggest that the CD31/PECAM molecule may be involved in the spread of tumor by interacting with extracellular matrix lysis that results from the tumor cell proteasic activity and with multidrug resistance.
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PMID:CD31 quantitative immunocytochemical assays in breast carcinomas. Correlation with current prognostic factors. 772 41

Expression of the bcl-2 gene was investigated in 218 human breast carcinomas by immunohistochemical analysis. Immunodetections were assessed using (1) frozen sections, (2) documented commercially available monoclonal antibody (bcl-2/124, Dako), (3) automation of immunoperoxidase technique (Ventana) and (4) quantitative evaluation of results by image analysis (SAMBA) and statistical analysis of quantitative data (BMDP software). Bcl-2 protein expression was correlated with current prognostic indicators and with molecular markers detected by the same procedure as for Bcl-2. It was shown that Bcl-2 expression is not related to patients' age, tumour size and type or lymph node status, but an inverse relationship was observed between Bcl-2 and tumour grade (P < 0.0001). An inverse relationship was also observed between Bcl-2 expression and p53 (P < 0.0001), Ki67/MIB1 antigen- (P = 0.0012), and P-gp- (P = 0.002) positive immunoreactions. In contrast, anti-Bcl-2 positive reaction was significantly associated with ER-positive (P < 0.001) and with ER/PR-positive or ER/PR/pS2-positive immunoreactions (P < or = 0.005). Bcl-2 expression was independent of CD31 and cathepsin D expression. Thus, Bcl-2 protein, thought to be antiapoptotic, exhibits parodoxical expression in human breast carcinomas. It is strongly detected in low-grade tumours (well-differentiated) with low (MIB1) growth fraction, but is independent of the tumour progression (size, node status, CD31, and cathepsin D). Bcl-2 acting on apoptosis is related to p53 gene abnormalities in breast carcinomas. Bcl-2 protein expression may also be involved in response to endocrine therapy (associated to ER/PR/pS2 positive immunoreactions) and probably with chemoresistance mechanisms (inverse relationship with P-gp).
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PMID:Automated and quantitative immunocytochemical assays of Bcl-2 protein in breast carcinomas. 925 1

Non-Hodgkin's lymphomas (NHL) are B-cell malignancies which generally present molecular abnormalities, such as bcl-2 translocation t(14; 18) predominantly in the follicular subgroup. Other molecular events have been described in NHL, including p53 gene mutation and overexpression of one chemoresistance mechanism, the multidrug resistance system, P-glycoprotein (MDR 1/P-gp). In this study, we analysed samples from 44 NHL patients with the presence of the bcl-2 major breakpoint region (MBR) rearrangement in 29 and without in 15. Immunochemical analysis revealed that 39 samples were positive for bcl-2 protein expression in tumoral cells (88.6%). Seventeen (38.6%) patients expressed P-gp and 9 (20.5%) expressed p53 proteins. Eleven patients expressed both bcl-2 and P-gp proteins, four expressed bcl-2 and p53 proteins whereas four expressed bcl-2, p53 and P-gp proteins. Our results confirm the importance of p53 expression as a key prognostic factor, and no objective response (OR) was found in patients with p53 positivity. MBR rearrangement was not associated with poor response to chemotherapy (62.1% OR in MBR positive patients v. 60% OR in MBR negative patients). The clinical impact of P-gp cannot be identified because no relationship was observed between P-gp expression and prognosis (58.8% OR in P-gp positive patients v. 63% OR in P-gp negative patients).
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PMID:MBR rearrangement and P-glycoprotein expression are not independent prognostic factors like p53 protein in malignant lymphoma. 968 Dec 18

Expression of vascular cell adhesion molecules (VCAM) in tumors is associated with endothelial cell activation and may facilitate adherence of carcinomatous cells to the vessel wall, promoting bloodborne metastases. Expression of VCAM was investigated in 202 breast carcinomas using automated (Ventana System) and quantitative (SAMBA image analyzer) immunoperoxidase staining of frozen sections. Positive VCAM immunoreactivity was observed in 83 tumors (41%) (mean immunostained surface, 12.4%; SD, 10.5). The mean area of immunostaining was correlated with clinical and pathologic prognostic indicators and with the immunohistochemical expression in tissue sections of various indicators of cell proliferation, metastatic potential, and drug resistance or sensitivity, evaluated according to the same method. There was no correlation of VCAM immunoreactivity with tumor size, type, or grade or with nodal status. Also, no significant correlation was observed between VCAM and MIB1/Ki67, p53, Bcl-2, E cadherin, CD44v, cathepsin D, CD31, P-gp, ER, PR, or pS2. However, VCAM immunoreactivity was significantly correlated with ELAM and VLA2 (P = .001) and VLAs (P = .008) expression. The results suggest that VCAM expression in breast carcinoma tissue sections is likely not a prognostic indicator. Its practical clinical relevance, if any, must be established by correlation with patients' outcomes and tumor sensitivity to drugs.
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PMID:VCAM (IGSF) adhesion molecule expression in breast carcinomas detected by automated and quantitative immunocytochemical assays. 974 2

Several mechanisms of resistance to chemotherapy have been identified among the agents that are commonly used in the systemic treatment of patients with esophageal cancer: paclitaxel, platinum, and 5-FU. A recent study from our laboratory evaluated the initial endoscopic biopsy material from patients who subsequently underwent trimodality therapy, including chemotherapy with cisplatin and 5-FU, radiation therapy, and surgery. IHC analysis was performed on seven markers of chemotherapy or radiation therapy resistance: P-gp, GST-pi, MT (platinum inhibitors); EGF-R, TGF-alpha, erb-B2 (activation of cell growth cascade); and p53 (interferes with chemotherapy-induced apoptosis). In this study, elevated expression of GST-pi and P-gp were associated with decreased survival and may be markers of treatment resistance. Expression of erb-B2 was associated with enhanced survival and may be a marker of treatment sensitivity. Assessment of the probability of chemoresistance of a particular tumor using the expression of molecular biologic markers may allow for the selection of a more favorable chemotherapeutic agent. Furthermore, understanding the mechanisms of resistance, including the mechanisms of DNA repair, may provide insight into mechanisms to reverse or to inhibit resistance to chemotherapy. DNA repair mechanisms are used by cells to protect themselves against mutagens and carcinogens. DNA repair inhibitors may increase the mutagenicity associated with DNA damage and may prove to be an ineffective oncologic treatment strategy; however, the possibility exists that DNA repair inhibition may improve the efficacy of anticancer agents, and this should be tested. The value of this strategy may be in allowing treatment doses to be decreased and lessening side effects while maintaining therapeutic efficacy.
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PMID:Molecular biology of esophageal cancer. 1096 50

We investigated the effects of radiation on the expression of p53 protein and P-gp in breast cancer cells. Thirty-two preoperatively irradiated surgical specimens of stage I primary breast cancer were examined, and 39 surgical specimens of non-irradiated stage I breast cancer were selected as a control group. p53 and P-gp expression was detected by an immunohistochemical technique using rabbit polyclonal antibodies (RSP-53 and NCL-pGLYPp). The expression of p53 protein, defined as a nuclear immunoreaction in 20% or more of tumor cells, was detected in 4(13%) of the 32 cases in the irradiated group and 7 (18%) of the 39 cases in the non-irradiated group without any statistically significant difference. The expression of P-gp, defined as the presence of strong staining in more than 75% of the tumor cells, was detected in 19 (59%) of the cases in the irradiated group and 12(31%) of the cases in the non-irradiated group. P-gp expression was significantly higher in the former group than in the latter (P <0.05). There was no significant difference in P-gp expression between the stromal invasive component and the intraductal component in either the irradiated or the non-irradiated group. Radiotherapy possibly induces membranous P-gp expression in human breast cancer cells.
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PMID:Higher Level of P-glycoprotein Expression in Human Breast Cancer Cells after Radiation Therapy. 1109 39

A spontaneously EBV transformed follicular lymphoma (FL) cell line, Tat-1, was established from the lymph node biopsy specimen of a patient with B cell FL, grade 1 in transformation to high grade disease. Tat-1 cells expressed lymphoid markers and developed tumor masses in immunodeficient mice. Bcl-2, Bcl-X(L), Bax and p53 protein expression was revealed by Western blotting. Flow cytometric analysis confirmed P-gp expression. Cytogenetically, the Tat-1 cell line showed identical chromosomal alterations to that of the initial biopsy specimen, among which the most notable were the t(14;18) typical of FL and additional abnormalities involving chromosomes 1, 8 and 13. Multicolor FISH analysis delineated all abnormalities, including a t(1p;8q), a der(8)(8q24::14q32::18q21) and a der(13)(13q32::8q24::14q32::18q21). Further FISH investigations using a locus-specific probe cocktail containing c-myc, IgH and bcl-2 revealed fusion of these three loci on the derivatives 8 and 13, in addition to the derivative 14 IgH/bcl-2 fusion and an extra copy of c-myc on derivative chromosome 1. These results demonstrate an additional example of the deregulation of bcl-2 and c-myc expression through recombination with a single IgH enhancer region. The unusual molecular features of the Tat-1 cell line render it a unique tool for studies focused on cytogenetic alterations, expression of multidrug resistance phenotype and expression of anti-apoptotic proteins in FL.
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PMID:Establishment and comprehensive analysis of a new human transformed follicular lymphoma B cell line, Tat-1. 1184 Feb 95

Collagen gel droplet embedded culture-drug sensitivity test (CD-DST) is the newly developed in vitro chemosensitivity test that has several advantages over the conventional ones. The aim of the present study is to examine the clinical usefulness of this test in the prediction of response to chemotherapy in breast cancer patients. Seventy patients with primary (n = 45) or locally recurrent (n = 25) breast cancers were recruited, and each patient underwent tumor biopsy before chemotherapy. The biopsy specimens were used for CD-DST and immunohistological examination of 6 biological markers (P-gp, erbB2, p53, BCL2, MIB1 and ER-alpha). As chemotherapy, cyclophosphamide 600 mg/m(2) plus epirubicin 60 mg/m(2) q3w (CE, n = 28) or docetaxel 60 mg/m(2) q3w (DOC, n = 42) was given. Interpretable results using the CD-DST assay were obtained from 84.3% (59/70) of tumor specimens studied. Of the 18 tumors diagnosed as CE sensitive by CD-DST, 15 (83.3%) exhibited a response to CE therapy and none of the 5 tumors diagnosed as CE resistant by CD-DST exhibited a response to CE therapy. Of the 14 tumors diagnosed as DOC sensitive by CD-DST, 13 (92.9%) exhibited a response to DOC therapy and only one of the 22 tumors diagnosed as DOC resistant by CD-DST exhibited a response to DOC therapy. P-gp expression was found to exhibit a significant (p < 0.05) association with the resistance to CE therapy but not to DOC therapy. Diagnostic accuracy (72.7%) achieved by P-gp was lower than that (87.0%) achieved by CD-DST in CE therapy. Expressions of other biological markers (erbB2, p53, BCL2, MIB1 and ER-alpha) were not significantly associated with response to CE or DOC therapy. These results demonstrate that CD-DST can predict the response to CE and DOC therapy with a high accuracy in breast cancer patients and seems to be superior to the conventional predictors.
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PMID:Prediction of chemotherapeutic response by collagen gel droplet embedded culture-drug sensitivity test in human breast cancers. 1192 May 99

The resistant problem is the main restriction factor for clinical usage of taxol. The main mechanism of its resistance includes the high expression of P-gp, beta- and alpha-tubulin isotypes, the alteration expression of PKC, Bcl-2, p53, and ErbB2. The reversing method includes the use of analogues of taxol to reduce the expression of P-gp, or the use of antibody, immunotoxin, antisence oligonucleotide, and liposomes. The combination with other drugs can also be a method to reverse the resistance of taxol.
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PMID:[Development of research for drug-resistance mechanism of taxol]. 1245 28


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