Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:A9QXG9 (bcl-2)
 7,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine whether the expression of p53, p21, bcl-2 or Ki-67 in cancer cells is predictive of chemosensitivity, immunohistochemical examination of these factors and chemosensitivity assays were performed on colon and gastric cancer specimens. Chemosensitivity tests were performed using CDDP, 5-FU, MMC, or ADR and inhibition rate (IR) was calculated by MTT assay. Before exposure to anticancer drugs, the samples were investigated immunohistochemically for expression of the above factors and after anticancer drug exposure by TUNNEL staining, for the presence of apoptotic cells. With 5-FU and MMC, the apoptotic index was well correlated with IR, so their effects were related to apoptosis. Moreover, with these two agents, the p53 labeling index (LI) was inversely correlated with IR and p21-LI showed a good correlation with IR. We therefore concluded that immunohistochemical studies for p53 and p21 were useful for predicting the chemosensitivities of colon and gastric cancer to MMC and 5-FU.
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PMID:Correlation of immunohistochemical p53 labeling index with inhibition rate in chemosensitivity test in gastric and colon cancer. 1129 39

B-cell chronic lymphocytic leukemia (CLL) is the most common type of leukemia diagnosed in the Western Hemisphere and remains incurable with currently available therapy. In an attempt to identify new potential therapy for CLL, we explored the pre-clinical activity of gemcitabine in human B-CLL cells (n =11). Mononuclear cell isolates were exposed to varying concentrations of gemcitabine (0.01-100 microM) for 4, 24, and 96 h. Viability, as determined by the tetrazolium salt (MTT) assay, after a 4 h incubation with gemcitabine declined in 6 of 8 (75%) evaluable patients at a concentration < 30 microM (a physiologically attainable level), and 3 of 8 of the B-CLL cells had an LC50 (concentration where 50% loss of viability is observed) < 30 microM. At 4 days of drug exposure, 82% (9/11) of patients had an LC50 < 30 microM. Annexin-V/propidium iodine staining demonstrated apoptosis in CLL cells exposed to 30 microM of gemcitabine. Examination of changes in apoptosis related proteins demonstrated no significant change in bcl-2, bax or p53 protein expression with gemcitabine (23 microM) at 4, 24, or 48 h. These data demonstrate that gemcitabine has pre-clinical activity in B-CLL and supports its exploration as a single agent and in combination with other active agents in this disease.
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PMID:Gemcitabine demonstrates in vitro activity against human B-cell chronic lymphocytic leukemia. 1133 14

Aspirin- and non-steroidal anti-inflammatory drug (NSAID)-induced apoptosis is one of the important mechanisms for their anti-tumour effect in gastric cancer. We aimed at determining the role of bcl-2 family proteins and caspases in the apoptotic process. Gastric cancer cell lines AGS (wild-type p53) and MKN-28 (mutant p53) were used. Cell proliferation was measured by MTT assay. Apoptosis was determined by acridine orange staining. Protein expressions were determined by western blotting. Aspirin and indomethacin inhibited cell proliferation and induced apoptosis in both cells. AGS cells were more sensitive compared with MKN-28 cells. The pro-apoptotic proteins bax and bak were overexpressed after treatment, while the protein level of bcl-2 remained unchanged. Apoptosis was accompanied by an increase in caspase-3 activity and cleavage of caspase-3 and poly(ADP-ribose) polymerase. Inhibition of caspase-3 rescued aspirin-induced apoptosis. Our results suggest that one of the major pathways which mediates the anti-tumour response of aspirin and indomethacin in gastric cancer cells is through up-regulation of bax and bak and activation of caspase-3. Bax and bak are important in the chemoprevention of gastric cancer.
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PMID:Non-steroidal anti-inflammatory drugs induce apoptosis in gastric cancer cells through up-regulation of bax and bak. 1153 60

Identification of organic compounds from plants is of clinical significance because of the effect that they might have in patients with haematopoietic disorders. We studied the effect of the plant extract Justicia spicigera (Acanthaceae) in different haematopoietic cells: human leukaemic cell lines, umbilical cord blood cells, and mouse bone marrow cells. By examining colony formation and performing the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay it was shown that the plant extract of Justicia spicigera contains cytotoxic factors for leukaemic cells and has no proliferative activity on normal haematopoietic progenitor cells. Our results show that this plant extract induces apoptosis in the human leukaemia cell line TF-1, but not in the bcl-2 transfectant cell line TB-1. Similar results were obtained using a haemopoietic cell line 32D and 32DBcl2. The cultures of umbilical cord blood cells and mouse bone marrow that contain granulocyte-macrophage colony-stimulating factor (GM-CSF) do not proliferate or become terminally differentiated in the presence of the infusion of Justicia spicigera. GM-CSF that acts by abrogating programmed cell death is not sufficient to inhibit the apoptotic stimulus in TF-1 and 32D cells. Moreover mouse fibroblasts (3T3) and two cervical carcinoma cell lines CALO and INBL, undergo apoptosis in the presence of different concentrations of an infusion from the plant. Our data show that there is a strong correlation between the cytotoxic effect and cell proliferation. Together, these results indicate that the plant infusion of Justicia spicigera does not contain any haematopoietic activity, induces apoptosis inhibited by bcl-2 and is linked to cell proliferation.
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PMID:Cytotoxic activity of Justicia spicigera is inhibited by bcl-2 proto-oncogene and induces apoptosis in a cell cycle dependent fashion. 1174 62

The integrity of the retinal pigment epithelium, especially that of the macula is essential for the preservation of vision into old age. The chronic exposure to sunlight and peroxidized lipids from phagocytized photoreceptor outer segments imposes a high level of oxidative stress on the retinal tissues, which increases with age as antioxidant protection declines and therefore could accelerate apoptosis. Bcl-2 known to facilitate mitochondrial DNA repair and cellular survival in other tissues was overexpressed in a single clone of human retinal pigment epithelium cells after stable transfection with humanbcl-2 in rhoSFV-neoexpression factor. Near confluent cells (2nd-4th generation permanently bcl-2 transfected) were protected from mitochondrial dysfunction after exposure to H(2)O(2) up to 150 microM. With 200 microM H(2)O(2), function in transfected cells declined by only 25% control activity as determined by MTT reduction assays, compared to wild type and vector only transfected cells expressing normal bcl-2 levels. Similarly the bcl-2 -transfected cells were more resistant to mitochondrial DNA damage after H(2)O(2) treatment than the other groups and suffered 50% less damage after exposure to 200 microM H(2)O(2), as assayed by quantitative polymerase chain reaction assays. These data suggest that bcl-2 overexpression protects human RPE cells from mitochondrial respiratory dysfuction, mitochondrial DNA damage and promotes cellular survival in response to oxidative stress induced by H(2)O(2).
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PMID:Bcl-2 overexpression increases survival in human retinal pigment epithelial cells exposed to H(2)O(2). 1212 40

To investigate whether ethanol induces apoptosis in Leydig cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, terminal deoxynuclotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, DNA fragmentation assay, caspase-3 enzyme assay, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were performed on TM3 mouse Leydig cells. Through morphological and biochemical analyses, it was demonstrated that TM3 cells treated with ethanol at concentrations of 50 and 100 mM exhibit classical apoptotic features. In addition, it was shown that ethanol induces increases in levels of bax and caspase-3 and a decrease in bcl-2 expression. Based on the results, alcohol appears to activate specific intracellular death-related pathways leading to bax-dependant caspase-3 activation and the induction of apoptosis in Leydig cells.
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PMID:Alcohol induces apoptosis in TM3 mouse Leydig cells via bax-dependent caspase-3 activation. 1216 4

The aim of this paper was to evaluate the role of bcl-2 in the susceptibility of the MCF7 ADR human breast carcinoma line overexpressing the P-170 glycoprotein (P-170) to various drugs. The sensitivity to four multidrug resistance (MDR)-related drugs (doxorubicin (ADR), vincristine (VCR), vinblastine (VBL), actinomycin D (ACTD)) and three MDR-non-related drugs (cisplatin (DDP), bischloroethylnitrosourea (BCNU), 5-fluorouracil (5-FU)) was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay in three bcl-2-overexpressing clones obtained from the MCF7 ADR line. We found that the bcl-2-overexpressing clones show increased resistance to DDP and BCNU, while no difference to 5-FU were observed between the control cells and bcl-2 transfectants. Surprisingly, bcl-2-overexpressing clones displayed an increased sensitivity compared with the control cells to the MDR-related drugs ADR, VCR, VBL and ACTD. Focusing on DDP and ADR, we found that the increased resistance of the bcl-2 transfectants to DDP was correlated to their ability to prevent apoptosis, while the enhanced sensitivity to ADR was associated with an increased ADR accumulation and a decreased ADR efflux. Moreover, while bcl-2 overexpression does not induce changes in P-170 glycoprotein expression, it did induce a reduction of the adenosine triphosphate (ATP) levels and basal protein kinase C (PKC) activity, both of which have a crucial role in the regulation of the MDR phenotype. In conclusion, the effect of bcl-2 on antineoplastic sensitivity observed in this study underscores the idea that bcl-2 may have distinct biological effects depending on the anticancer drug used.
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PMID:Bcl-2 has differing effects on the sensitivity of breast cancer cells depending on the antineoplastic drug used. 1246 Jul 91

Taxanes are effective in the treatment of metastatic breast cancer. Docetaxel has been shown to be more potent than paclitaxel in inducing bcl-2 phosphorylation and apoptosis and is clinically active in some paclitaxel-resistant breast tumors. HER-2/neu overexpression has been shown to correlate with resistance to hormonal therapy as well as chemotherapy. Using a HER-2/neu transfected MCF-7 human breast cancer cell line, we investigated the role of HER-2/neu overexpression on resistance to paclitaxel and docetaxel treatment. A control vector transfected MCF-7 human breast cancer cell line (MCF/neo) and a HER-2/neu transfected MCF-7 line (MCF/18) were treated with various concentrations of docetaxel or paclitaxel. Cell number was assessed using the MTT tetrazolium dye assay. In the control vector transfected MCF/neo cell line, paclitaxel and docetaxel gave similar dose-dependent growth inhibition ( p = 0.175). In HER-2/neu transfected MCF/18 cells, docetaxel treatment resulted in a dose-dependent inhibition similar to that seen in MCF/neo cells. Paclitaxel, however, gave significantly less growth inhibition than docetaxel in the HER-2/neu overexpressing MCF/18 cells (p = 0.0003). These data suggest that HER-2/neu overexpression may contribute to paclitaxel resistance. In contrast, the cytotoxic effects of docetaxel in these breast carcinoma cells are not affected by HER-2/neu expression. Therefore, docetaxel may be the preferred taxane therapy in HER-2/neu overexpressing breast tumors.
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PMID:Decreased response to paclitaxel versus docetaxel in HER-2/neu transfected human breast cancer cells. 1257 25

The ubiquitin-proteasome pathway is the principal mechanism for the degradation of short-lived proteins in eukaryotic cells. Recently, proteasome inhibitors have been shown to induce apoptosis in many kinds of human malignant cells. In this study, the mechanism of apoptosis induced by proteasome inhibitor in leukemic cells was examined. Evaluated by MTT assay, treatment of leukemic cells with Z-LLL-CHO, a reversible proteasome inhibitor, induced cell death in a dose-dependent manner. Appearance of the sub G(0)/G(1) fraction of cell cycle observed in flow cytometry assay suggested the induction of apoptosis, which was further proved by typical DNA ladder and morphological study. Western blot displayed the cleavage of bcl-2 into a shortened 22 kD fragment and the decrease in the levels of caspase-3 precursor. A highly sensitive colorimetric assay was employed and the elevation of caspase-3 activity was detected in both cell lines after treatment with Z-LLL-CHO. By comparison, these results showed that the leukemic cell line M-07e and KG-1a, which both express bcl-2 at a relative high level, had different susceptibility to undergo apoptosis induced by Z-LLL-CHO, which possibly due to their different levels of expression and activation of caspase-3 precursor, as well as their different degree of bcl-2 cleavage after treated by Z-LLL-CHO.
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PMID:[Induction of Apoptosis in Leukemic Cells by Inhibiting the Ubiquitin-Proteasome Pathway and Its Possible Mechanism] 1257 13

The effects of different doses of nitric oxide (NO) on the proliferation and apoptosis of the cultured bovine trabecular meshwork (TM) cells were studied. L-arginine and NG-nitro-L-arginine methyl (L-NAME) were incubated with TM cells for 48 h. In the control group, no medicine was given. In the experimental groups, concentrations of L-arginine and L-NAME were 1 x 10(-7) mol/L, 1 x 10(-6) mol/L, 1 x 10(-5) mol/L, 1 x 10(-4) mol/L, 1 x 10(-3) mol/L and 1 x 10(-2) mol/L, respectively. NO2- in supernate, the proliferation and apoptosis of TM cells and mRNA expression of bcl-2 and bax were measured by Griess reagent, terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL), MTT assay and in situ hybridization, respectively. The results showed that L-arginine with concentration > or = 1 x 10(-4) mol/L could induce apoptosis of the TM cells and inhibit the proliferation of TM cells through increasing the NO levels, down-regulating bcl-2 mRNA expression and up-regulating bax mRNA expression; L-NAME with concentration > or = 1 x 10(-5) mol/L could induce the proliferation of the TM cells through suppressing the production of NO. It was concluded that NO in high level could induce apoptosis of the TM cells and suppress the proliferation of the TM cells.
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PMID:Effects of nitric oxide on proliferation and apoptosis of cultured bovine trabecular meshwork cells. 1265 90


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