Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cystatin A (acid cysteine proteinase inhibitor; ACPI) is a natural inhibitor of cysteine proteinases. It has been suggested that an inverse correlation exists between cystatin A and malignant progression. We wanted to assess the biological and clinical significance of cystatin A in infiltrative breast carcinoma by immunohistochemical staining. Formalin-fixed paraffin-embedded material from 440 cases treated during the years 1988-1991 was used in the study. After exclusion of patients with disseminated disease at diagnosis, previous contralateral breast carcinoma, and absence of follow-up data, 384 patients could be included in the survival analysis. For immunohistochemical analysis of cystatin A, we used monoclonal cystatin A antibody WR-23/2/3/3, the binding of which was detected by the avidin-biotin-peroxidase method. Immunohistochemical analysis of Bcl-2 and p53 was also done, and mitotic activity was evaluated. Positive staining for cystatin A was found in 52 of 440 cases. The staining was irregular but showed irrefutably positive areas within neoplastic tissue. Most of the positive tumors were of the ductal infiltrative type, but two were mucinous carcinomas, one medullary and one squamous cell carcinoma. No lobular carcinomas showed positive staining. Focal cystatin A positivity was seen in myoepithelial cells of benign ducts. Occasional apoptotic bodies within the neoplasm showed strong positivity for cystatin A. Tumors positive for cystatin A were of larger size and had higher mitotic activity than cystatin A-negative tumors. Cystatin A was associated with negative Bcl-2 staining, but there was no statistically significant association between axillary lymph node status or p53 immunostaining. The risk for breast cancer-related death was significantly higher in patients with cystatin A-positive tumors than in those with cystatin A-negative ones. The risk increase was significant also in lymph node-negative patients. After adjusting for the effect of tumor size, histological grade, and lymph node status, cystatin A-positive patients still had a higher risk of death. Patients with cystatin A and p53 coexpression had a higher risk of death than the other patients. The findings reveal a new variant of aggressive breast cancer. This type of carcinoma may develop during tumor progression through genetic instability that allows cystatin A expression and gives growth advantage to a clone of tumor cells.
 ...
PMID:Cysteine proteinase inhibitor cystatin A in breast cancer. 945 85

Immunohistochemical expression of p53, Bc12, vimentin, and S100 protein-positive Langerhans cell was evaluated in 50 endometrial carcinomas (6 stage I, 14 stage II, 20 stage III, and 10 stage IV), in an attempt to use these markers as predictors of survival. Monoclonal antibodies to p53, Bcl-2, vimentin, and S100 proteins were applied to paraffin-embedded sections of endometrial adenocarcinoma, using the avidin-biotin peroxidase complex technique (ABC). All 20 patients with stage I and II carcinomas were alive with a mean follow-up of 3 years. Of 30 patients with stage III and IV carcinomas, 13 died of tumor (3-year survival, 57%; SE, 10%), eight were alive with tumor, and nine were alive with no evidence of tumor (mean follow-up, 46 months). Strong p53 positivity was present in 11 carcinomas (22%), including nine high-stage and two low-stage tumors. Bcl-2 positivity was identified in 33 tumors (66%). These tumors were mostly low stage; however, no correlation was found between Bcl-2 expression and prognosis. Vimentin positivity (P < .001), and tumor infiltration by a large number of S100 protein-positive Langerhans cells (P < .05) were associated with low-stage tumors. Vimentin was expressed in 23 carcinomas, including 70% of low-stage tumors and 20% of high-stage tumors. Most high-grade carcinomas were Langerhans cell depleted; most low-grade carcinomas showed >50 S100 protein-positive Langerhans cells/10 high-power fields. Our results indicate that Langerhans cell infiltration and vimentin positivity of tumor cells are favorable prognostic factors in endometrial carcinomas.
 ...
PMID:Prognostic significance of p53, bcl-2, vimentin, and S100 protein-positive Langerhans cells in endometrial carcinoma. 959 68

Bcl-2 overexpression has been shown to be associated with several malignancies, including B-cell chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphomas (NHL), mainly low-grade and follicular in type. It has as yet not been described in hairy cell leukemia (HCL). In 30 patients with CLL and 14 with HCL who were consecutively selected for treatment with purine analogues (Fludarabine in CLL and 2-chloro-deoxy-adenosine in HCL), we evaluated bcl-2 oncoprotein expression in leukemic cells on marrow sections that were taken before treatment and stained immunohistochemically with a monoclonal antibody (Dakopatts 124 clone), by the avidin-biotin-peroxidase method. All samples were found to be bcl-2 positive, with a staining intensity that was moderate to strong in CLL and weak to moderate in HCL. 83% of CLL and 100% of HCL patients were responsive to purine analogues. These findings show that bcl-2 is overexpressed in almost all cases CLL and HCL and that bcl-2 overexpression does not predict a poor response to purine analogues, which are believed to induce apoptosis.
 ...
PMID:BCL-2 immunohistochemical evaluation in B-cell chronic lymphocytic leukemia and hairy cell leukemia before treatment with fludarabine and 2-chloro-deoxy-adenosine. 961 87

Thyroid toxicity of iodide excess has been demonstrated in animals fed with an iodide-rich diet; in vitro iodide is cytotoxic, inhibits cell growth, and induces morphological changes in thyroid cells of some species. In this study, we investigated the effect of iodide excess in an immortalized thyroid cell line (TAD-2) in primary cultures of human thyroid cells and in cells of nonthyroid origin. Iodide displayed a dose-dependent cytotoxicity in both TAD-2 and primary thyroid cells, although at different concentrations, whereas it had no effect on cells of nonthyroid origin. Thyroid cells treated with iodide excess underwent apoptosis, as evidenced by morphological changes, plasma membrane phosphatidylserine exposure, and DNA fragmentation. Apoptosis was unaffected by protein synthesis inhibition, whereas inhibition of peroxidase enzymatic activity by propylthiouracil completely blocked iodide cytotoxicity. During KI treatment, reactive oxygen species were produced, and lipid peroxide levels increased markedly. Inhibition of endogenous p53 activity did not affect the sensitivity of TAD-2 cells to iodide, and Western blot analysis demonstrated that p53, Bcl-2, Bcl-XL, and Bax protein expression did not change when cells were treated with iodide. These data indicate that excess molecular iodide, generated by oxidation of ionic iodine by endogenous peroxidases, induces apoptosis in thyroid cells through a mechanism involving generation of free radicals. This type of apoptosis is p53 independent, does not require protein synthesis, and is not induced by modulation of Bcl-2, Bcl-XL, or Bax protein expression.
 ...
PMID:Iodide excess induces apoptosis in thyroid cells through a p53-independent mechanism involving oxidative stress. 1065 Sep 40

Twelve human embryos and fetuses aged of 7-30 weeks of intrauterinal life were examined to determine the expression of bcl-2 gene in the developing kidney. Tissue samples were routinely processed and three-step indirect immunohistochemical method was used for the detection of Bcl-2 protein. End-point cytophotometry was performed with computer-controlled microscope photometer with a scanning table and the mean relative absorbance of the final product of peroxidase reaction was determined and taken as a measure of Bcl-2 expression. The morphometric evaluation was carried out from the TV display using Weibel s universal hexagonal raster and we determined the relative volume of Bcl-2 positive structures in the various zones of the embryonal kidney. The aim of our research was mapping of the Bcl-2 occurrence in the developing kidney of human embryos and fetuses. The Bcl-2 protein is involved in the regulation of apoptosis and its effect is antiapoptotic. The highest Bcl-2 expression was proved in the cells of metanephrogenic blastema. The lower occurrence of Bcl-2 positive cells was demonstrated in proximal tubules analges+ and it was almost on the borderline of detection in branches of ureteral bud. In the fetal period the marked Bcl-2 expression was maintained in the epithelial cells of proximal tubules analges.
 ...
PMID:Expression of BCL-2 in the developing kidney of human embryos and fetuses qualitative and quantitative study. 1074 26

Amiodarone (AMD) is one of the most effective antiarrhythmic drugs available. However, its use is often limited by side-effects, mainly hypo- or hyperthyroidism. As AMD displays direct toxic effect on different cell types, we investigated the cytotoxic effect of AMD and its main metabolite, desethylamiodarone (DEA), in thyroid (TAD-2) and nonthyroid (HeLa) cell lines. Both AMD and DEA displayed a dose-dependent toxicity in TAD-2 and HeLa cells, although DEA was more effective. Both TAD-2 and HeLa cells underwent apoptosis, as evidenced by plasma membrane phosphatidylserine exposure and DNA fragmentation. Inhibition of protein synthesis with cycloheximide and inhibition of endogenous peroxidase activity with propylthiouracil did not affect this AMD- and DEA-induced apoptosis in TAD-2 cells. Western blot analysis did not display variations in the expression of p53, Bcl-2, Bcl-XL, and Bax proteins during the treatment with AMD and DEA. Generation of reactive oxygen species, investigated by flow cytometry with dichlorofluorescein diacetate, did not show the production of free radicals during drug treatment. Furthermore, Western blot analysis of cytosolic and mitochondrial fractions prepared from AMD-treated cells demonstrated that AMD induces the release of cytochrome c into the cytosol from the mitochondria. These data indicate that AMD induces cytochrome c release from mitochondria, triggering apoptosis through an iodine-independent mechanism, and that this process is not mediated by modulation of p53, Bcl-2, Bcl-XL, or Bax protein expression and does not involve the generation of free radicals.
 ...
PMID:Amiodarone induces cytochrome c release and apoptosis through an iodine-independent mechanism. 1109 75

Using models of serum deprivation and 1-methyl-4-phenylpyridinium (MPP(+)), we investigated the mechanism by which thioredoxin (Trx) exerts its antiapoptotic protection in human neuroblastoma cells (SH-SY5Y) and preconditioning-induced neuroprotection. We showed that SH-SY5Y cells are highly sensitive to oxidative stress and responsive to both extracellularly administered and preconditioning-induced Trx. Serum deprivation and MPP(+) produced an elevation in the hydroxyl radicals, malondialdehyde and 4-hydroxy-2,3-nonenal (HNE), causing the cells to undergo mitochondria-mediated apoptosis. Trx in the submicromolar range blocked the observed apoptosis via a multiphasic protection mechanism that includes the suppression of cytochrome c release (most likely via the induction of Bcl-2), the inhibition of procaspase-9 and procaspase-3 activation, and the elevated level of Mn-SOD. The reduced form of Trx suppresses the serum-free-induced hydroxyl radicals, lipid peroxidation, and apoptosis, indicating that H(2)O(2) is removed by Trx peroxidase. The participation of Trx in preconditioning-induced neuroprotection is supported by the observation that inhibition of Trx synthesis with antisense oligonucleotides or of Trx reductase drastically reduced the hormesis effect. This effect of Trx-mediated hormesis against oxidative stress-induced apoptosis is striking. It induced a 30-fold shift in LD(50) in the MPP(+)-induced neurotoxicity.
 ...
PMID:The roles of thioredoxin in protection against oxidative stress-induced apoptosis in SH-SY5Y cells. 1175 90

We have analyzed by immunocytochemistry the p53 and Bcl-2 proteins expression in 49 patients with B-ALL, T-ALL and AML at the time of initial diagnosis. The diagnosis was based on morphologic and cytochemical criteria and on immunophenotyping. To demonstrate the p53 protein expression, p53 specific mouse antihuman immunoreagent clone DO-1 that recognizes both wild and mutated p53 protein was used. To detect Bcl-2 a monoclonal antibody that recognizes the 26-kD Bcl-2 protein was applied. For evaluation of both proteins a sensitive Immunotech detection kit based on peroxidase labeled streptavidin biotin reagent was utilized. The patients were divided according to the presence or absence of both, nuclear p53 and cytoplasmic Bcl-2 proteins. A relative low frequency of p53 protein expression in B- and T-lineage acute lymphoblastic leukemia has been shown at diagnosis. In AML cases, the frequency of p53 expression was higher than that in ALL. Bcl-2 protein immunoreactivity has been found in the majority of acute leukemia patients. The marked heterogeneity in the percentage of p53 and Bcl-2 positive cells in individual patients was observed. Comparative analysis of the distinct acute leukemia subtypes according to the percentage of p53 and Bcl-2 positive cells showed no significant differences except for p53 protein positivity in relation between T-ALL and AML cases. The samples from healthy subjects used as a control exhibited very low proportion of positively stained cells and significantly differed from p53 as well as Bcl-2 positive cases. p53 and Bcl-2 positivity have not been significantly affected neither by age, sex nor WB C counts. Association between myeloid cells maturation and proportion of p53 and Bcl-2 positive cells was observed. Noteworthy was the inverse relation between the higher proportion of p53 positive cells and low Bcl-2 positivity in some cases of acute leukemia. Although our preliminary results need to be confirmed in a larger group of patients, immunocytochemical analysis of p53 and Bcl-2 proteins, indicators of cell alterations, may help to identify risk patients requiring intensive therapy.
 ...
PMID:Expression of p53 and bcl-2 proteins in acute leukemias: an immunocytochemical study. 1194 43

Vascular endothelial growth factor (VEGF) and its receptor Flk-1/KDR play an important role in vascular permeability and tumor angiogenesis. Prompted by the hypothesis that VEGF/Flk-1 system may have regulatory roles in breast carcinogenesis, we investigated the expression of Flk-1 in 141 invasive breast carcinomas in correlation with clinical and immunohistochemical prognostic parameters, including proliferation indices like Ki-67 and Topoisomerase IIalpha (Topo-IIalpha). The immunohistochemical avidin-biotin-peroxidase method was performed on paraffin sections for the detection of Flk-1, p53, Bcl-2, c-erbB-2, Ki-67, Topo-IIalpha, ER, and PR. Flk-1 was detected in 91 of 141 (64.5%) of invasive breast carcinomas showing a widespread cytoplasmic expression in most of the neoplastic cells. Flk-1 expression was correlated with the menopausal status (P = 0.051) of the patient and the nuclear grade of the invasive breast carcinoma (P = 0.003), but demonstrated no correlation with histologic grade, stage, and patient survival. It is interesting that Flk-1 expression demonstrated a significant correlation with 2 well-established proliferation indices, Ki-67 (P = 0.037) and topo-IIalpha (P = 0.009), whereas there was no correlation with the expression of ER, PR, p53, Bcl-2, and c-erbB-2. Moreover, Flk-1 expression showed an inverse correlation with TIMP-1 mRNA localization in intratumoral stromal cells (P = 0.013). In conclusion, the significant correlation of Flk-1 expression in invasive breast carcinomas with proliferation indices like Ki-67 and topo-IIalpha suggests that VEGF may exert a growth factor activity on mammary cancer cells through its receptor Flk-1. On the other hand, the inverse correlation of Flk-1 with TIMP-1 mRNA in intratumoral stromal cells supports the notion that TIMP-1 may have an inhibitory role on angiogenesis.
 ...
PMID:Expression of the vascular endothelial growth factor receptor-2/Flk-1 in breast carcinomas: correlation with proliferation. 1245 8

Motoneurons in the spinal nucleus of the bulbocavernosus (SNB) and their target muscles, bulbocavernosus and levator ani (BC/LA), constitute an androgen-sensitive neuromuscular system. Testosterone regulates SNB soma size, SNB dendritic length, and BC/LA muscle mass in adult male rats. Recent evidence indicates that the cell death-regulatory protein, Bcl-2, may also play a role in adult neural plasticity. The present study examined whether gonadal hormones and/or the Bcl-2 protein influence the morphology of the SNB neuromuscular system in adult B6D2F1 mice. In Experiment 1, adult wild-type and Bcl-2 overexpressing males were castrated and implanted with silastic capsules containing testosterone or left blank. Six weeks after castration, cholera toxin-horseradish peroxidase was injected into the BC muscle to label SNB dendrites. Animals were killed 48 h later, and BC/LA muscle mass, SNB soma size, and SNB dendritic arbors were examined. In Experiment 2, wild-type and Bcl-2 overexpressing males were castrated or sham castrated, implanted with testosterone-filled or blank capsules, and examined 12 weeks later. In both experiments, BC/LA muscle mass and SNB soma size were significantly reduced in castrates receiving blank capsules. Surprisingly, however, there was no effect of hormone manipulation on any of several measures of dendritic length. Thus, the dendritic morphology of SNB motoneurons appears to be relatively insensitive to circulating androgen levels in B6D2F1 mice. Bcl-2 overexpression did not influence BC/LA muscle mass, SNB soma size, or SNB dendritic length, indicating that the morphology of this neuromuscular system and the response to castration are not altered by forced expression of the Bcl-2 protein.
 ...
PMID:Castration reduces motoneuron soma size but not dendritic length in the spinal nucleus of the bulbocavernosus of wild-type and BCL-2 overexpressing mice. 1238 67


1 2 3 4 5 Next >>