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

This study is the first to investigate the anticancer effect of isoobtusilactone A (IOA) in two human breast cancer cell lines, MCF-7 and MDA-MB-231. IOA exhibited effective cell growth inhibition by inducing cancer cells to undergo G(2)-M phase arrest and apoptosis. Further investigation revealed that IOA's inhibition of cell growth was also evident in a nude mice model. Cell cycle blockade was associated with increased levels of p21 and reduced amounts of cyclin B1, cyclin A, cdc2, and cdc25C. IOA also enhanced the levels of inactivated phosphorylated cdc2 and cdc25C. IOA triggered the mitochondrial apoptotic pathway, as indicated by a change in Bax/Bcl-2 ratios, resulting in mitochondrial membrane potential loss, cytochrome c release, and caspase-9 activation. We also found that the generation of reactive oxygen species (ROS) is a critical mediator in IOA-induced cell growth inhibition. Enhancement of ROS by IOA activated apoptosis signal-regulating kinase 1 (ASK1) resulted in the increased activation of c-Jun NH(2)-terminal kinase and p38. Antioxidants EUK8 and N-acetyl cystenine significantly decreased apoptosis by inhibiting the ASK1 dephosphorylation at Ser(967) and subsequently increased the interaction of ASK1 with thioredoxin or 14-3-3 proteins. Moreover, blocking ASK1 by small interfering RNA inhibition completely suppressed IOA-induced apoptosis. Taken together, these results imply a critical role for ROS and ASK1 in IOA's anticancer activity.
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PMID:Isoobtusilactone A induces cell cycle arrest and apoptosis through reactive oxygen species/apoptosis signal-regulating kinase 1 signaling pathway in human breast cancer cells. 1767 Dec 11

Genistein is a soy isoflavone with anti-tumor properties. Genistein-induced apoptosis involves Bcl-2 downregulation. However, overexpression of Bcl-2 in breast cancer has been associated with better prognosis and response to hormonal therapy. To examine genistein's effect on breast cancer cells with different Bcl-2 levels, we established control (MCF-7/PV) and Bcl-2 overexpressing MCF-7 (MCF-7/Bcl-2) cell lines and characterized genistein regulated apoptosis and cell cycle progression in these cells. Our results demonstrate that overexpression of Bcl-2 rendered MCF-7 cells more sensitive, rather than resistant, to genistein. We found that genistein induces enhanced cytochrome c release and mitochondrial membrane depolarization in MCF-7/Bcl-2 cells, as compared to control. We also found that genistein increases Bcl-2 levels and Bcl-2/Bax ratio in the mitochondrial fractions of MCF-7/Bcl-2 cells, suggesting that disturbed Bcl-2/Bax distribution may cause cytochrome c release and apoptosis in these cells. Cell cycle analysis indicated that genistein induces G0/G1 arrest in MCF-7/PV cells but increases in G2/M arrest in MCF-7/Bcl-2 cells. This was accompanied by modified responses of several cell cycle regulators, such as p21 and cyclin B1. Taken together, our results indicate that genistein-Bcl-2 interaction switches Bcl-2 from an anti-apoptotic protein into a proapoptotic protein, which involves disturbed Bcl-2/Bax distribution in mitochondria, increased cytochrome c release and modified cell cycle regulation.
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PMID:Bcl-2 overexpression sensitizes MCF-7 cells to genistein by multiple mechanisms. 1778 19

Chalcones (1,3-diphenyl-2-propenone) are cancer preventive food components found in a human diet rich in fruits and vegetables. In this study, we first report the chemopreventive effect of chalcone in two human bladder cancer cell lines: T24 and HT-1376. The results show that chalcone inhibits the proliferation of T24 and HT-1376 cells by inducing apoptosis and blocking cell cycle progression in the G2/M phase. Western blot assay showed that chalcone significantly increases the expression of p21 and p27 proteins, and decreases the levels of cyclin B1, cyclin A and Cdc2, thereby contributing to cell cycle arrest. In addition, chalcone increased the expression of Bax and Bak, but decreased the levels of Bcl-2 and Bcl-X(L) and subsequently triggered mitochondrial apoptotic pathway (release of cytochrome c and activation of caspase-9 and caspase-3). Our study suggests that the induction of mitochondrial pathway and inhibition of the nuclear factor kappa B survival system may play important roles in the antiproliferative activity of chalcone in T24 and HT-1376 cells.
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PMID:Chalcone arrests cell cycle progression and induces apoptosis through induction of mitochondrial pathway and inhibition of nuclear factor kappa B signalling in human bladder cancer cells. 1784 7

Norcantharidin (NCTD), a demethylated form of cantharidin, is currently used as an anticancer drug in China, but five newly synthesized derivatives have not been tested for antitumor efficacy. In this study, we investigated the in-vitro and in-vivo activity of five derivatives on Bel-7402, HeLa and PC-3M1E8 cell lines on a sulfarhodamine B assay. All of the derivatives showed significant antiproliferative activity, hence we elected to study further one of them, NCTD-Nd3II, in an in-vivo mouse model, and to examine its effects on cell cycle and protein expression. NCTD-Nd3II inhibited H22 tumors in mice in a dose-dependent manner with low toxicity. Flow cytometry results showed that apoptosis and G2/M cell cycle arrest contributed to the cytotoxic and cytostatic effects of NCTD-Nd3II. Further studies showed that Bax and p21 protein expression was upregulated, whereas cyclin B1, Cdc-2 and Bcl-2 protein expression was downregulated. Our findings show that NCTD-Nd3II might be a promising chemotherapeutic agent for hepatomas.
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PMID:Anticancer activity and mechanisms of norcantharidin-Nd3II on hepatoma. 1789 13

This study is the first to investigate the anticancer effect of plumbagin in human melanoma A375.S2 cells. Plumbagin exhibited effective cell growth inhibition by inducing cancer cells to undergo S-G2/M phase arrest and apoptosis. Further investigation revealed that plumbagin's inhibition of cell growth was also evident in a nude mice model. Blockade of cell cycle was associated with increased levels of p21, and reduced amounts of cyclin B1, cyclin A, Cdc2, and Cdc25C. Plumbagin also enhanced the levels of inactivated phosphorylated Cdc2 and Cdc25C. Plumbagin triggered the mitochondrial apoptotic pathway indicated by a change in Bax/Bcl-2 ratios, resulting in caspase-9 activation. We also found the generation of ROS is a critical mediator in plumbagin-induced cell growth inhibition. Plumbagin increased the activation of apoptosis signal-regulating kinase 1, JNK and extracellular signal-regulated kinase 1/2 (ERK1/2), but not p38. In addition, antioxidants vitamin C and catalase significantly decreased plumbagin-mediated c-Jun N-terminal kinase (JNK) activation and apoptosis. Moreover, blocking ERK and JNK by specific inhibitors suppressed plumbagin-triggered mitochondrial apoptotic pathway. Taken together, these results imply a critical role for ROS and JNK in the plumbagin's anticancer activity.
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PMID:Plumbagin induces cell cycle arrest and apoptosis through reactive oxygen species/c-Jun N-terminal kinase pathways in human melanoma A375.S2 cells. 1802 67

Long-term clinical observations and ongoing studies have shown antitumor effects of external Qi of Yan Xin Qigong (YXQG-EQ) that originated from traditional Chinese medicine (TCM). In order to understand the molecular mechanisms underlying the antitumor effects of YXQG-EQ, we investigate the effects of YXQG-EQ on growth and apoptosis in androgen-independent prostate cancer PC3 cells. We found that exposure to YXQG-EQ led to G2/M arrest associated with reduced cyclin B1 expression and apoptosis in PC3 cells. YXQG-EQ treatment inhibited constitutive and epidermal growth factor-induced Akt phosphorylation, basal and TNF-alpha-induced NF-kappaB activation, and downregulated anti-apoptotic Bcl-2 and Bcl-xL expression. In contrast, exposure to YXQG-EQ increased phosphorylation of Akt and Erk1/2 in human umbilical vein endothelial cells (HUVEC), and had no cytotoxic effect on either HUVEC or peripheral blood mononuclear cells (PBMC). These results indicate that YXQG-EQ has profound effects on growth and apoptosis of prostate cancer cells by targeting survival pathways including the Akt and NF-kappa B pathways.
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PMID:External Qi of Yan Xin Qigong induces G2/M arrest and apoptosis of androgen-independent prostate cancer cells by inhibiting Akt and NF-kappa B pathways. 1808 Aug 2

The c-Myb gene encodes a transcription factor required for proliferation and survival of normal myeloid progenitors and leukemic blast cells. Targeting of c-Myb by antisense oligodeoxynucleotides has suggested that myeloid leukemia blasts (including chronic myelogenous leukemia [CML]-blast crisis cells) rely on c-Myb expression more than normal progenitors, but a genetic approach to assess the requirement of c-Myb by p210(BCR/ABL)-transformed hematopoietic progenitors has not been taken. We show here that loss of a c-Myb allele had modest effects (20%-28% decrease) on colony formation of nontransduced progenitors, while the effect on p210(BCR/ABL)-expressing Lin(-) Sca-1(+) and Lin(-) Sca-1(+)Kit(+) cells was more pronounced (50%-80% decrease). Using a model of CML-blast crisis, mice (n = 14) injected with p210(BCR/ABL)-transduced p53(-/-)c-Myb(w/w) marrow cells developed leukemia rapidly and had a median survival of 26 days, while only 67% of mice (n = 12) injected with p210(BCR/ABL)-transduced p53(-/-)c-Myb(w/d) marrow cells died of leukemia with a median survival of 96 days. p210(BCR/ABL)-transduced c-Myb(w/w) and c-Myb(w/d) marrow progenitors expressed similar levels of the c-Myb-regulated genes c-Myc and cyclin B1, while those of Bcl-2 were reduced. However, ectopic Bcl-2 expression did not enhance colony formation of p210(BCR/ABL)-transduced c-Myb(w/d) Lin(-)Sca-1(+)Kit(+) cells. Together, these studies support the requirement of c-Myb for p210(BCR/ABL)-dependent leukemogenesis.
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PMID:Requirement of c-Myb for p210(BCR/ABL)-dependent transformation of hematopoietic progenitors and leukemogenesis. 1822 49

CUGBP2, a translation inhibitor, induces colon cancer cells to undergo apoptosis. Mcl-1, an antiapoptotic Bcl-2 family protein, interferes with mitochondrial activation to inhibit apoptosis. Here, we have determined the effect of CUGBP2 on Mcl-1 expression. We developed a HCUG2 cell line by stably expressing CUGBP2 in the HCT-116 colon cancer cells. HCUG2 cells demonstrate decreased levels of proliferation and increased apoptosis, compared with HCT-116 cells. Flow cytometry analysis demonstrated higher levels of cells in the G(2)-M phase. Western blot analyses demonstrated that there was decreased Bcl-2 and Mcl-1 protein but increased expression of Bax, cyclin B1, and Cdc2. Immunocytochemistry also demonstrated increased levels of cyclin B1 and Cdc2 in the nucleus of HCUG2 cells. However, there was colocalization of phosphorylated histone H3 with transferase-mediated dUTP nick-end labeling (TUNEL). Furthermore, immunostaining for alpha-tubulin demonstrated that there was disorganization of microtubules. These data suggest that CUGBP2 expression in HCUG2 cells induces the cells to undergo apoptosis during the G(2)-M phase of the cell cycle. We next determined the mechanism of CUGBP2-mediated reduction in Mcl-1 expression. Mcl-1 protein, but not Mcl-1 mRNA, was lower in HCUG2 cells, suggesting translation inhibition. CUGBP2 binds to Mcl-1 3'-untranslated region (3'-UTR) both in vitro and in HCUG2 cells. Furthermore, CUGBP2 increased the stability of both endogenous Mcl-1 and luciferase mRNA containing the Mcl-1 3'-UTR. However, luciferase protein expression from the luciferase-Mcl-1 3'-UTR mRNA was suppressed. Taken together, these data demonstrate that CUGBP2 inhibits Mcl-1 expression by inhibiting Mcl-1 mRNA translation, resulting in driving the cells to apoptosis during the G(2) phase of the cell cycle.
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PMID:Translation inhibition during cell cycle arrest and apoptosis: Mcl-1 is a novel target for RNA binding protein CUGBP2. 1829 81

Thymosin-beta-4 (TB4) as an actin-sequestering peptide has been detected outside of cells in blood plasma or in wound fluid. TB4 induces tumor metastasis and paclitaxel resistance, which is the most significant obstacle to successful therapy in tumors. Here we investigated the inhibitory effect of TB4 peptides on tumor cell death by paclitaxel. The effect of TB4 peptides was assayed by the measurement of caspase-3 activity, G2/M arrest, and Bcl-2 phosphorylation. Cell survival rate was increased and caspase-3 activity was decreased by the treatment with TB4 peptides. In contrast, small interfering RNA (siRNA) of TB4 inhibited cell viability and augmented caspase-3 activity. Significant changes in Bcl-2 phosphorylation were detected by TB4 peptide treatment or by the overexpression of TB4 gene in Hela cells. The reduced population in G2/M phase by TB4 peptide treatment was correlated with the decreased expression of cyclin B1. The data were confirmed in gastric tumor cell lines, SNU 638 (low TB4 level) and SNU 668 (high TB4 level), which were established from clinically isolated gastric tumors. In conclusion, soluble TB4 peptides produced in cancer cells could be an obstacle to treat tumors with paclitaxel. Therefore, TB4 could be a novel target to control paclitaxel resistance.
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PMID:Actin-sequestering protein, thymosin-beta-4 (TB4), inhibits caspase-3 activation in paclitaxel-induced tumor cell death. 1830 30

Cucurbitacins are compounds isolated from various plant families, which have been used as folk medicines for centuries in countries such as India and China because of their wide spectrum of pharmacological activities such as cytotoxic, anti-inflammatory, and anticancer effects. Accumulated evidences have shown that cucurbitacin B inhibits the growth of numerous human cancer cell lines and tumor xenografts. To determine whether cucurbitacin B can inhibit the growth of laryngeal squamous cell carcinoma, in the present study we investigated the antitumor effect of cucurbitacin B on Hep-2 cells. Hep-2 cells were treated with different concentrations of cucurbitacin B for different time. Cell proliferation, cell cycle distribution, and cell apoptosis were evaluated using MTT assay, flow cytometry, and fluorescent microscopy. It was found that cucurbitacin B exhibited significant efficacy in growth inhibition, cell cycle arrest at G2/M phase, and apoptosis induction in a dose- and time-dependent manner. Measuring the modulation of regulators in the cell cycle, apoptosis and signal transductions by Western blot analysis showed that the effect of cucurbitacin B was due to suppression of the expression of p-STAT3, Bcl-2, and cyclin B1. Moreover, in vivo studies were performed in a mouse xenograft model, where cucurbitacin B inhibited tumor growth in a dose-dependent manner. In conclusion, the antitumor effect of cucurbitacin B on Hep-2 cells was due to the induction of cell cycle arrest as well as apoptosis. The possible mechanisms underlying the action might be attributed to the suppression of STAT3 phosphorylation. This investigation suggests a potential clinical application of cucurbitacin B for the treatment of laryngeal cancer patients.
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PMID:Inhibitory effects of cucurbitacin B on laryngeal squamous cell carcinoma. 1830 9


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