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)

The study was aimed to investigate the effects of emodin on the proliferation and apoptosis of adriamycin-resistant HL-60/ADR cells, and to explore the underlying mechanism. The cell viability and colony formation were detected by MTT assay and colony formation assay respectively. Apoptotic cells were tested by means of cell cycle analysis, mitochondrial transmembrane potential levels, caspase-3 activity detection, Annexin V FITC/PI staining and TUNEL labeling. RT-PCR was used to analyze the bcl-2 and c-myc mRNA expressions. The protein expressions of Bcl-2, c-Myc and caspase-3 precursor were determined by Western blot. The results showed that HL-60/ADR cell growth was significantly inhibited by emodin in dose and time dependent manners. Cell colony formation obviously decreased with IC50 5.79 micromol/L. G0/G1 phase cell population increased while G2/M phase cells decreased in 40 and 80 micromol/L groups compared with control group (p < 0.01), and no significant difference of cell cycle was observed in 20 micromol/L group (p > 0.05). The typical hypo-diploid peak (apoptotic peak) appeared in each dose group. The levels of mitochondrial transmembrane potential of HL-60/ADR cells decreased and caspase-3 activity increased when incubated with emodin for 12 and 24 hours respectively. Apoptosis occurred in a dose-dependent manner, and its earlier and later stages were identified by Annexin-V FITC/PI staining and TUNEL labeling methods respectively. The expressions of bcl-2, c-myc mRNA and Bcl-2, c-Myc, caspase-3 precursor protein were all down-regulated in a time-dependent manner after treatment with emodin at different times. It is concluded that emodin efficiently inhibits growth and induces apoptosis on HL-60/ADR cells, which may be related with the down-regulation of mitochondrial transmembrane potential and expressions of bcl-2 and c-myc, as well as up-regulation of caspase-3 activity.
 ...
PMID:[Inhibitory effects of emodin on drug-resistant HL-60/ADR cell proliferation and its induction of apoptosis]. 1795 69

We investigated the relationship between the resistance to the proapoptotic action of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and cellular prion protein (PrPc) function, using the TRAIL-sensitive MCF-7 human breast adenocarcinoma cell line and two TRAIL-resistant sublines: 2101 and MCF-7/ADR. All of the cell lines tested expressed TRAIL-R1 and TRAIL-R2. TRAIL decoy receptors were not detected, suggesting that the resistance of 2101 and MCF-7/ADR cells, strongly expressing PrPc, to TRAIL-mediated cell death was independent from the expression of TRAIL receptors and death-inducing signaling complex formation. Down-regulation of PrPc by small interfering RNA increased the sensitivity of Adriamycin- and TRAIL-resistant cells to TRAIL, but not to epirubicin/Adriamycin. TRAIL-mediated apoptosis in PrPc knocked-down cells was associated with caspase processing, Bid cleavage, and Mcl-1 degradation. In addition, an increased sensitivity of apoptosis-resistant cells to TRAIL after PrPc silencing was not associated with the increased recruitment of receptors and intracellular signaling molecule to the death-inducing signaling complex. Bcl-2 expression was substantially decreased after PrPc knock-down but the levels of Bcl-X(L) and Mcl-1 were not affected. The down-regulation of Bcl-2 was concomitant with Bax delocalization. Our findings support the notion that silencing of PrPc facilitates the activation of proapoptotic Bax by down-regulation of Bcl-2 expression, thereby abolishing the resistance of breast cancer cells to TRAIL-induced apoptosis.
 ...
PMID:Silencing of prion protein sensitizes breast adriamycin-resistant carcinoma cells to TRAIL-mediated cell death. 1800 36

Anthracyclines and anthracenediones are well-known cancer chemotherapeutic agents but their uses are limited with cardiotoxicity and drug resistance. Several l- and d-form amino acids were introduced into the anthraquinone skeleton and numerous derivatives were synthesized for the evaluation of anticancer activity. The screening tests showed that WRC-213, an l-methionine conjugation, was the most effective derivative to inhibit proliferative effect of human androgen-independent prostate cancer PC-3 cells (IC50=50 nM). In an extension evaluation, WRC-213 displayed a potent anti-proliferative activity in various cancer cell lines, including non-small cell lung cancer A549, androgen-independent prostate cancer DU145, colorectal cancer HT-29, breast cancer MCF-7 and hepatocellular carcinoma Hep3B and HepG2. It induced cell-cycle arrest at S and G2, but not mitotic phase, in PC-3 cells. The comet assay revealed that induction of DNA damage and inhibition of topoisomerase II were the primary insults. After the checkpoint arrest of the cell-cycle, WRC-213 induced the mitochondria-mediated intrinsic apoptotic pathway, including Mcl-1 cleavage, Bcl-2 down-regulation and activation of caspase-9/caspase-3 cascades. Survivin degradation and caspase-2 activation also contributed to WRC-213-induced apoptosis. Moreover, the assessment of cytotoxicity in H9c2 cardiomyocytes and drug resistance in NCI/ADR-RES cells demonstrated that WRC-213 showed much lower cardiotoxicity and P-glycoprotein-related resistance than those of mitoxantrone, etoposide and doxorubicin. In conclusion, it is suggested that WRC-213 is a potential topoisomerase II inhibitor with reduced cardiotoxicity and drug resistance. It inhibits topoisomerase II activity and induces chromosomal DNA strand breaks, leading to S and G2 arrest of the cell-cycle and activation of mitochondria-mediated apoptotic pathways.
 ...
PMID:WRC-213, an l-methionine-conjugated mitoxantrone derivative, displays anticancer activity with reduced cardiotoxicity and drug resistance: identification of topoisomerase II inhibition and apoptotic machinery in prostate cancers. 1803 33

Doxorubicin, a widely used chemotherapeutic agent, can give rise to severe cardiotoxicity by inducing cardiomyocyte apoptosis. Dracocephalum rupestre Hance, a Chinese traditional herb, has therapeutic potential for cardiovascular diseases. Naringenin-7-O-glucoside is the main active constituent of D. rupestre and there is increasing interest in its therapeutic applications. The aim of this study was to evaluate the effects of naringenin-7-O-glucoside on cardiomyocyte apoptosis induced by doxorubicin. Cell viability was detected by MTT assay. Naringenin-7-O-glucoside (10, 20, and 40 microM) significantly enhanced cardiomyocyte proliferation relative to that of doxorubicin. Furthermore, naringenin-7-O-glucoside increased the protein levels of heme oxygenase-1 (HO-1) and Bcl-2 in cardiomyocytes (as detected by Western blotting) and suppressed the mRNA expression of caspase-3 and caspase-9 (as detected by RT-PCR). These results suggest that naringenin-7-O-glucoside has protective effects against doxorubicin-induced apoptosis, effects which could underlie the use of naringenin-7-O-glucoside therapeutic agent for treating or preventing cardiomyopathy associated with doxorubicin.
 ...
PMID:Protective effects of naringenin-7-O-glucoside on doxorubicin-induced apoptosis in H9C2 cells. 1815 51

The cardiotoxic effects of doxorubicin, a potent chemotherapeutic agent, have been linked to DNA damage, oxidative mitochondrial damage, and nuclear translocation of p53, but the exact molecular mechanisms causing p53 transactivation and doxorubicin-induced cardiomyopathy are not clear. The present study was carried out to determine whether extracellular signal-regulated kinases (ERKs), which are known to be activated by DNA damaging agents, are responsible for doxorubicin-induced p53 activation and oxidative mitochondrial damage in H9c2 cells. Cell death was measured by terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling, annexin V-fluorescein isothiocyanate, activation of caspase-9 and -3, and cleavage of poly(ADP-ribose) polymerase (PARP). We found that doxorubicin produced cell death in H9c2 cells in a time-dependent manner, beginning at 6 h, and these changes are associated decreased expression of Bcl-2, increases in Bax and p53 upregulated modulator of apoptosis-alpha expression, and collapse of mitochondria membrane potential. The changes in cell death and Bcl-2 family proteins, however, were preceded by earlier activation and nuclear translocation of ERKs, followed by increased phosphorylation at Ser15 and nuclear translocation of the phosphorylated p53. The functional importance of ERK1/2 and p53 in doxorubicin-induced toxicity was further demonstrated by the specific ERK inhibitor U-0126 and p53 inhibitor pifithrin (PFT)-alpha, which abrogated the changes in Bcl-2 family proteins and cell death produced by doxorubicin. U-0126 blocked the phosphorylation and nuclear translocation of both ERK1/2 and p53, whereas PFT-alpha blocked only the changes in p53. Doxorubicin and ERK inhibitors produced similar changes in ERK1/2-p53, PARP, and caspase-3 in neonatal rat cultured cardiomyocytes. Thus we conclude that ERK1/2 are functionally linked to p53 and that the ERK1/2-p53 cascade is the upstream signaling pathway responsible for doxorubicin-induced cardiac cell apoptosis. ERKs and p53 may be considered as novel therapeutic targets for the treatment of doxorubicin-induced cardiotoxicity.
 ...
PMID:ERKs/p53 signal transduction pathway is involved in doxorubicin-induced apoptosis in H9c2 cells and cardiomyocytes. 1877 51

Doxorubicin is an important component of combination therapy for muscle-invasive urinary bladder cancer. Treatment with this topoisomerase II poison is able to interfere with cell cycle progression and lead to cancer cell death. Using FACS analysis, Western immunoblotting and semi-quantitative RT-PCR, we studied the effects of doxorubicin on cell cycle progression and apoptosis, and also explored the possibility of using groups of genes as biomarkers of prognosis and/or response to doxorubicin treatment in human urinary bladder cancer cells. Doxorubicin induced dose-dependent G2/M and/or G1/S cell cycle arrest, followed by grade- and dose-dependent reduction in the amount of the cytosolic trimeric form of FasL, activation of Caspase-8, Caspase-9, Caspase-3, cleavage of PARP, Lamin A/C, Bcl-XL/S and interestingly Hsp90, and finally cell death. Data presented here also suggest the use of the expression patterns of Cyclin-E2, Cyclin-F, p63, p73, FasL, TRAIL, Tweak, Tweak-R, XAF-1, OPG and Bok genes for identification of the differentiation grade, and Cyclin-B2, GADD45A, p73, FasL, Bik, Bim, TRAIL, Fas, Tweak-R, XAF-1, Bcl-2, Survivin, OPG, DcR2 and Bcl-XL genes for the detection of response to doxorubicin in human bladder cancer cells.
 ...
PMID:Grade-dependent effects on cell cycle progression and apoptosis in response to doxorubicin in human bladder cancer cell lines. 1908 86

Doxorubicin is one of the most effective agents used in the treatment of various tumors. Its use is restricted by the development of resistance to apoptosis, the mechanism of which is not fully understood. Nuclear transcription factor kappaB (NF-kappaB) has been shown both to block apoptosis and to promote cell proliferation, and hence has been considered as an important target for anticancer drug development. We found that in wild type and Dox-revertant MCF-7 cells, Doxorubicin induced NF-kappaB was transient and Dox-resistant cells showed high basal activity of NF-kappaB and expression of genes dependent on it. Moreover, in resistant cells Doxorubicin was unable to induce apoptosis as detected by assays for reactive oxygen intermediates generation, lipid peroxidation, cytotoxicity, PARP degradation and Bcl-2 expression. High basal expressions of multi-drug resistant protein and transglutaminase were found in Dox-resistant cells and inhibition of NF-kappaB decreased those amounts and also sensitized these cells by Doxorubicin. These observations collectively suggest that high NF-kappaB activity confers resistance to Doxorubicin and its inhibition potentiates apoptosis. This study indicates that NF-kappaB plays an important role in chemoresistance and establishes the fact that inhibition of NF-kappaB will be a novel approach in chemotherapy.
 ...
PMID:Inhibition of constitutive activity of nuclear transcription factor kappaB sensitizes doxorubicin-resistant cells to apoptosis. 2372 Aug 33

Doxorubicin (DOX) is a highly effective antineoplastic drug. However, DOX-induced apoptosis in cardiomyocytes leads to irreversible degenerative cardiomyopathy and heart failure, which limits DOX clinical application. Leonurine is a special alkaloid for Herba leonuri, a traditional herb with cardioprotective effects. In current study, we investigated possible protective effects of Leonurine against DOX-induced cardiomyopathy in H9c2 cells. DOX-injured H9c2 cell model was made by application of 2 microM DOX. Leonurine was added to cells 2 h before DOX treatment. Pre-treated with Leonurine could attenuate DOX-induced apoptotic death of H9c2 cell, reduce MDA formation and intracellular Ca2+ overload. Leonurine also attenuated DOX-induced high expression of Bax, increased Bcl-2 expression in both protein and mRNA level. Myocardial mitochondrion is the target organelle of DOX-induced toxicity in cardiomyocytes. Leonurine moderated the dissipation of mitochondrial membrane potential (DeltaPsim) caused by DOX treatment. Our results indicated that Leonurine attenuated DOX-induced apoptosis in H9c2 cell by increasing anti-oxidant, anti-apoptotic ability and protecting mitochondrial function.
 ...
PMID:Herba leonurine attenuates doxorubicin-induced apoptosis in H9c2 cardiac muscle cells. 1935 31

Doxorubicin (Dox) is a commonly used drug to treat various types of cancers. Previously, we demonstrated that coupling Dox to cell-penetrating peptides (CPPs) represent a valuable strategy to overcome drug resistance in MDA-MB 231 breast cancer cells. In the present study, we evaluated the properties of these Dox conjugates (Dox-CPPs) in terms of apoptosis induction. Dox-CPPs were found to induce apoptotic death in MDA-MB 231 cells at a lower dose than that needed for unconjugated Dox. Cell death induction was associated with Bax oligomerisation, release of cytochrome c, caspase activation, chromatin condensation and internucleosomal degradation. However, whereas Bcl-2 overexpression was very potent in inhibiting apoptosis triggered by Dox, this anti-apoptotic protein was largely inefficient in preventing Dox-CPPs-induced apoptosis. These observations suggest that mitochondrial disruption is the main event in Dox-induced apoptotic signaling but that Dox-CPPs are probably able to trigger additional apoptotic pathways independent of mitochondrial events. Thus, the higher efficacy of Dox conjugated to CCPs in apoptosis induction might not be due exclusively to increased drug accumulation but also to the activation of multiple apoptotic pathways.
 ...
PMID:Efficient induction of apoptosis by doxorubicin coupled to cell-penetrating peptides compared to unconjugated doxorubicin in the human breast cancer cell line MDA-MB 231. 1952 55

Doxorubicin is known to have cumulative dose-dependent cardiotoxicity, and a tumor suppressor protein p53 has been implicated in the pathogenesis of doxorubicin cardiotoxicity. However, how p53 is induced by doxorubicin and mediates the cardiotoxic effects of doxorubicin remains elusive. In cultured cardiac myocytes, doxorubicin induced oxidative stress, DNA damage, ATM activation, and p53 induction. A free radical scavenger NAC attenuated all of these events, whereas an ATM kinase inhibitor wortmannin attenuated doxorubicin-induced ATM activation and p53 induction but not oxidative stress. Doxorubicin treatment in vivo also induced oxidative stress, DNA damage, ATM activation, and p53 accumulation. These observations suggest that p53 induction by doxorubicin is mediated by oxidative DNA damage-ATM pathway. Doxorubicin-induced contractile dysfunction and myocyte apoptosis in vivo were attenuated in heterozygous p53 deficient mice and cardiac-restricted Bcl-2 transgenic mice, suggesting that myocyte apoptosis plays a central role downstream of p53 in doxorubicin cardiotoxicity. We also tested whether pitavastatin exerts protective effects on doxorubicin cardiotoxicity. Pitavastatin attenuated doxorubicin-induced oxidative stress, DNA damage, ATM activation, p53 accumulation, and apoptosis in vitro. Pitavastatin also attenuated myocyte apoptosis and contractile dysfunction in vivo. The beneficial effects of pitavastatin were reversed by intermediate products of the mevalonate pathway that are required for the activation of Rac1, and Rac1 inhibitor exhibited cardioprotective effects comparable to those of pitavastatin. These data collectively suggest that doxorubicin-induced cardiotoxicity is mediated by oxidative DNA damage-ATM-p53-apoptosis pathway, and is attenuated by pitavastatin through its antioxidant effect involving Rac1 inhibition.
 ...
PMID:Chronic doxorubicin cardiotoxicity is mediated by oxidative DNA damage-ATM-p53-apoptosis pathway and attenuated by pitavastatin through the inhibition of Rac1 activity. 1966 Apr 69


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>