Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.22 (cdc2)
 8,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Agaricus blazei is well known as a traditional medicinal mushroom and it has been shown to exhibit immunostimulatory and anti-cancer activity. However, the cellular and molecular mechanism of cell cycle arrest and apoptosis of cancer cells is poorly understood. In this study, we have investigated whether A. blazei extract (ABE) exerts anti-proliferative and apoptotic effects on human gastric epithelial AGS cells. It was found that ABE could inhibit cell growth in a dose-dependent manner, which was associated with the arrest of G2/M phase and the induction of apoptotic cell death. Flow cytometric analysis showed that ABE could cause an arrest at the G2/M phase of the cell cycle, which is closely correlated to decreased cyclin B1 and cdc2 levels. Furthermore, this compound induced apoptosis through up-regulation of Bax and the activation of caspases with down-regulation of XIAP and cIAP-1, but not cIAP-2, and a capase-3 inhibitor could block cell death and apoptotic body formation. These data clearly indicate that ABE-induced apoptosis is associated with caspase-3 activation. In summary, the growth inhibition of ABE is highly related to cell cycle arrest at the G2/M phase and the induction of caspase-3-dependent apoptosis in human gastric epithelial AGS cells.
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PMID:Induction of G2/M arrest and apoptosis in human gastric epithelial AGS cells by aqueous extract of Agaricus blazei. 1708 60

Acute treatment with kainate 30 mg/kg (KA) produced behavioral alterations and reactive gliosis. However, it did not produce major death of mouse hippocampal neurons, indicating that concentrations were not cytotoxic. KA caused rapid and temporal Erk phosphorylation (at 6h) and Akt dephosphorylation (1-3 days). Concomitantly, the activation of GSK3beta was increased 1-3 days after KA. After 7 days, a reduction in GSK3beta activation was observed. Caspase-3 activity increased, but to a lesser extent than calpain activation (measured by fluorimetry and calpain-cleaved alpha-spectrin). As calpain is involved in cdk5 activation, and cdk5 is related to GSK3beta, the cdk5/p25 pathway was examined. Results showed that the p25/p35 ratio in KA-injected mice for 3 days was 73.6% higher than control levels. However, no changes in cdk5 expression were detected. Both Western blot and immunohistochemistry against p-Tau(Thr(231)) indicated an increase at this phosphorylated site of tau protein. Indeed an increase in p-Tau(Ser(199)) and p-Tau(Ser(396)) was observed by Western blot. Our results demonstrate that tau hyperphosphorylation, induced by KA, is due to an increase in GSK3beta/cdk5 activity in combination with an inactivation of Akt. This indicates that the calpain/cdk5 pathway for tau phosphorylation has a potential role in delayed apoptotic death evoked by excitotoxicity. Moreover, the subsequent activation of caspase and calpain proteases leads to dephosphorylation of tau, thus increasing microtubular destructuration. Taken together, our results provide new insights in the activation of several kinase-pathways implicated in cytoskeletal alterations that are a common feature of neurodegenerative diseases.
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PMID:Kainate induces AKT, ERK and cdk5/GSK3beta pathway deregulation, phosphorylates tau protein in mouse hippocampus. 1711 46

Tumor cells express HYAL1 hyaluronidase, which degrades hyaluronic acid. HYAL1 expression in bladder cancer cells promotes tumor growth, invasion, and angiogenesis. We previously described five alternatively spliced variants of HYAL1 that encode enzymatically inactive proteins. The HYAL1-v1 variant lacks a 30-amino acid sequence that is present in HYAL1. In this study, we examined whether HYAL1-v1 expression affects bladder cancer growth and invasion by stably transfecting HT1376 bladder cancer cells with a HYAL1-v1 cDNA construct. Although HYAL1-v1 transfectants expressed equivalent levels of enzymatically active HYAL1 protein when compared with vector transfectants, their conditioned medium had 4-fold less hyaluronidase activity due to a noncovalent complex formed between HYAL1 and HYAL1-v1 proteins. HYAL1-v1 transfectants grew 3- to 4-fold slower due to cell cycle arrest in the G(2)-M phase and increased apoptosis. In HYAL1-v1 transfectants, cyclin B1, cdc2/p34, and cdc25c levels were > or =2-fold lower than those in vector transfectants. The increased apoptosis in HYAL1-v1 transfectants was due to the extrinsic pathway involving Fas and Fas-associated death domain up-regulation, caspase-8 activation, and BID cleavage, leading to caspase-9 and caspase-3 activation and poly(ADP-ribose) polymerase cleavage. When implanted in athymic mice, HYAL1-v1-expressing tumors grew 3- to 4-fold slower and tumor weights at day 35 were 3- to 6-fold less than the vector tumors (P < 0.001). Whereas vector tumors were infiltrating and had high mitoses and microvessel density, HYAL1-v1 tumors were necrotic, infiltrated with neutrophils, and showed low mitoses and microvessel density. Therefore, HYAL-v1 expression may negatively regulate bladder tumor growth, infiltration, and angiogenesis.
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PMID:HYAL1-v1, an alternatively spliced variant of HYAL1 hyaluronidase: a negative regulator of bladder cancer. 1714 67

We recently reported that gallic acid is a major active agent responsible for grape seed extract activity in DU145 human prostate carcinoma cells. The present study was conducted to examine its efficacy and associated mechanism. Gallic acid treatment of DU145 cells resulted in a strong cell growth inhibition, cell cycle arrest, and apoptotic death in a dose- and time-dependent manner, together with a decrease in cyclin-dependent kinases and cyclins but strong induction in Cip1/p21. Additional mechanistic studies showed that gallic acid induces an early Tyr(15) phosphorylation of cell division cycle 2 (cdc2). Further upstream, gallic acid also induced phosphorylation of both cdc25A and cdc25C via ataxia telangiectasia mutated (ATM)-checkpoint kinase 2 (Chk2) activation as a DNA damage response evidenced by increased phospho-histone 2AX (H2A.X) that is phosphorylated by ATM in response to DNA damage. Time kinetics of ATM phosphorylation, together with those of H2A.X and Chk2, was in accordance with an inactivating phosphorylation of cdc25A and cdc25C phosphatases and cdc2 kinase, suggesting that gallic acid increases cdc25A/C-cdc2 phosphorylation and thereby inactivation via ATM-Chk2 pathway following DNA damage that induces cell cycle arrest. Caffeine, an ATM/ataxia telangiectasia-rad3-related inhibitor, reversed gallic acid-caused ATM and H2A.X phosphorylation and cell cycle arrest, supporting the role of ATM pathway in gallic acid-induced cell cycle arrest. Additionally, gallic acid caused caspase-9, caspase-3, and poly(ADP)ribose polymerase cleavage, but pan-caspase inhibitor did not reverse apoptosis, suggesting an additional caspase-independent apoptotic mechanism. Together, this is the first report identifying gallic acid efficacy and associated mechanisms in an advanced and androgen-independent human prostate carcinoma DU145 cells, suggesting future in vivo efficacy studies with this agent in preclinical prostate cancer models.
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PMID:Gallic acid causes inactivating phosphorylation of cdc25A/cdc25C-cdc2 via ATM-Chk2 activation, leading to cell cycle arrest, and induces apoptosis in human prostate carcinoma DU145 cells. 1717 33

Epidemiological studies have indicated that increased consumption of cruciferous vegetables is associated with a statistically significant reduction in the risk for cancers. The major bioactive agent in these vegetables is a class of sulfur-containing glycosides called glucosinolates. Isothiocyanates, derivatives of glucosinolates, have been shown to possess anticancer properties in a variety of tumor cell lines. In this study, we evaluated the antigrowth, cell cycle modulation and proapoptotic effects of isothiocyanate iberin in human neuroblastoma cells. Treatment of neuroblastoma cells with iberin resulted in a dose- and time-dependent inhibition of growth, increased cytotoxicity, and G1 or G2 cell cycle arrest depending upon cell type. The iberin-induced cell cycle arrest in neuroblastoma cells was associated with inhibition of expression of Cdk2, Cdk4, and Cdk6 proteins. Fluorescence microscopic analysis of DNA-staining patterns with DAPI revealed an increase in apoptotic cell death in iberin-treated cells as compared with control cells. FLICA staining showed that iberin induced apoptosis, and this apoptotic induction was found to be associated with the activation of caspase-9, caspase-3, and PARP. These findings suggest that the anticancer efficacy of iberin is mediated via induction of cell cycle arrest and apoptosis in human neuroblastoma cells and has strong potential for development as a therapeutic agent against cancer.
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PMID:Iberin induces cell cycle arrest and apoptosis in human neuroblastoma cells. 1727 80

Cyclin-dependent kinases (Cdk) and their associated pathways represent some of the most attractive targets for the development of anticancer therapeutics. Based on antitumor activity in animal models, a variety of Cdk inhibitors are undergoing clinical evaluation either as a single agent or in combination with other approved drugs. In our anticancer drug discovery program, a novel series of flavones have been synthesized for evaluation against the activity of Cdk4-D1. This enzyme catalyzes the phosphorylation of retinoblastoma protein, thus inhibiting its function. We have identified a series of potent Cdk4-D1 inhibitors with IC(50) below 250 nmol/L. In this report, we have described the properties of one of the best compound, P276-00 of the flavone's series. P276-00 shows 40-fold selectivity toward Cdk4-D1, compared with Cdk2-E. The specificity toward 14 other related and unrelated kinases was also determined. P276-00 was found to be more selective with IC(50)s <100 nmol/L for Cdk4-D1, Cdk1-B, and Cdk9-T1, as compared with other Cdks, and less selective for non-Cdk kinases. It showed potent antiproliferative effects against various human cancer cell lines, with an IC(50) ranging from 300 to 800 nmol/L and was further compared for its antiproliferative activity against cancer and normal fibroblast cell lines. P276-00 was found to be highly selective for cancer cells as compared with normal fibroblast cells. To delineate its mechanism of action, the effect of P276-00 on cell cycle proteins was studied in human breast cancer cell line (MCF-7) and human non-small cell lung carcinoma (H-460). A significant down-regulation of cyclin D1 and Cdk4 and a decrease in Cdk4-specific pRb Ser(780) phosphorylation was observed. P276-00 produced potent inhibition of Cdk4-D1 activity that was found to be competitive with ATP and not with retinoblastoma protein. The compound also induced apoptosis in human promyelocytic leukemia (HL-60) cells, as evidenced by the induction of caspase-3 and DNA ladder studies. These data suggest that P276-00 has the potential to be developed as an anti-Cdk chemotherapeutic agent.
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PMID:In vitro antitumor properties of a novel cyclin-dependent kinase inhibitor, P276-00. 1736 86

Cardiotoxin III (CTX III), a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom, may have a potentiality as a structural template for rational drug design in killing cancer cells. Treatment of K562 cells with 0.3 microM of CTX III resulted in G2/M phase cell cycle arrest that was associated with a marked decline in protein levels of G2/M regulatory proteins including cyclin A, cyclin B1, Cdk2 and Cdc25C. In contrast to no effect on the phosphorylation of ERK, p38 MAPK and Akt, an activation of JNK was noted when K562 cells were exposed to CTX III. CTX III-mediated G2/M phase arrest and apoptosis were reduced by treatment with the JNK-specific inhibitor SP600125, but not by ERK and p38MAPK inhibitors. Further investigation showed that the specific JNK inhibitor, SP600125, reduced the activation of caspase-3, caspase-9, and reversed the decline in the expression of cyclin B1. Taken together, our data show for the first time that JNK, but not ERK, p38MAPK or Akt signaling, plays an important role in CTX III-mediated G2/M arrest and apoptosis in K562 cancer cells.
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PMID:Involvement of c-jun N-terminal kinase in G2/M arrest and caspase-mediated apoptosis induced by cardiotoxin III (Naja naja atra) in K562 leukemia cells. 1736 2

Silymarin and, one of its constituents, silibinin exert strong efficacy against prostate cancer (PCA); however, anticancer efficacy and associated mechanisms of other components of silymarin, which is a mixture of flavonolignans, are largely unknown. Here we have assessed the anticancer efficacy of two pure compounds isosilybin B and isosilybin A, isolated from silymarin, in human prostate carcinoma LNCaP and 22Rv1 cells. Isosilybin B and isosilybin A treatment resulted in growth inhibition and cell death together with a strong G(1) arrest and apoptosis in both the cell lines. In the studies examining changes in cell cycle and apoptosis regulators, isosilybin B and isosilybin A resulted in a decrease in the levels of both cyclins (D1, D3, E and A) and cyclin-dependent kinases (Cdk2, Cdk4 and cell division cycle 25A), but caused an increase in p21, p27 and p53 levels, except in 22Rv1 cells where isosilybin B caused a decrease in p21 protein level. Isosilybin B- and isosilybin A-induced apoptosis was accompanied with an increase in the cleavage of poly (ADP-ribose) polymerase, caspase-9 and caspase-3 and a decrease in survivin levels. Compared with LNCaP and 22Rv1 cells, the antiproliferative and cytotoxic potentials of isosilybin B and isosilybin A were of much lesser magnitude in non-neoplastic human prostate epithelial PWR-1E cells suggesting the transformation-selective effect of these compounds. Together, this study for the first time identified that isosilybin B and isosilybin A, two diastereoisomers isolated from silymarin, have anti-PCA activity that is mediated via cell cycle arrest and apoptosis induction.
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PMID:Isosilybin B and isosilybin A inhibit growth, induce G1 arrest and cause apoptosis in human prostate cancer LNCaP and 22Rv1 cells. 1738 12

Multiple genetic aberrations in human gliomas contribute to their highly infiltrative and rapid growth characteristics. Focal adhesion kinase (FAK) regulates tumor migration and invasion. Insulin-like growth factor-I receptor (IGF-IR), whose expression correlates with tumor grade, is involved in proliferation and survival. We hypothesized that inhibiting the phosphorylation of FAK and IGF-IR by NVP-TAE226 (hereafter called TAE226), a novel dual tyrosine kinase inhibitor of FAK and IGF-IR, would suppress the growth and invasion of glioma cells. In culture, TAE226 inhibited extracellular matrix-induced autophosphorylation of FAK (Tyr(397)). TAE226 also inhibited IGF-I-induced phosphorylation of IGF-IR and activity of its downstream target genes such as MAPK and Akt. TAE226 retarded tumor cell growth as assessed by a cell viability assay and attenuated G(2)-M cell cycle progression associated with a decrease in cyclin B1 and phosphorylated cdc2 (Tyr(15)) protein expression. TAE226 treatment inhibited tumor cell invasion by at least 50% compared with the control in an in vitro Matrigel invasion assay. Interestingly, TAE226 treatment of tumor cells containing wild-type p53 mainly exhibited G(2)-M arrest, whereas tumor cells bearing mutant p53 underwent apoptosis. Induction of apoptosis by TAE226 was substantiated by detection of caspase-3/7 activation and poly(ADP-ribose) polymerase cleavage and by an Annexin V apoptosis assay. More importantly, TAE226 treatment significantly increased the survival rate of animals in an intracranial glioma xenograft model. Collectively, these data show that blocking the signaling pathways of FAK and IGF-IR with TAE226 has the potential to be an efficacious treatment for human gliomas.
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PMID:Inhibition of both focal adhesion kinase and insulin-like growth factor-I receptor kinase suppresses glioma proliferation in vitro and in vivo. 1743 Nov 14

In the course of screening for anticancer agents, a novel active compound, F3-2-5, was isolated from culture broth of Streptomyces sp., KACC91015. Its structure was identified using nuclear magnetic resonance, mass spectrometry, and molecular modeling experiments, and confirmed by total synthesis. The growth of various human cancer cell lines was inhibited in a dose-dependent manner by 0.06-0.48 mM F3-2-5 over 24 h. Its IC(50) values were estimated at 37 microM on HeLa, 72 microM on A549, and 190 microM on HT-29 cells. However, F3-2-5 had no antiproliferative effect on normal lymphocytes and normal fibroblasts used as controls. Moreover, it affected cell cycle regulation and caused apoptosis of the HeLa cells; chromatin condensation and DNA fragmentation were observed in cells exposed to 80 microM F3-2-5. Western blot analysis revealed that F3-2-5 inhibited phosphorylation of retinoblastoma protein (pRb) and reduced expression of cyclin-dependent kinase-4 and -6, and cyclin D1 and E, while levels of p53 and p21(WAF1/CIP1) increased. Taken together, these findings show that F3-2-5 inhibits proliferation of HeLa cells by inducing G(1) phase arrest as a consequence of inhibition of pRb phosphorylation following up-regulation of p21(WAF1/CIP1) and p53. Furthermore, apoptosis in HeLa cells treated with F3-2-5 was associated with an increase in Bax and p53, leading to release of cytochrome c, activation of caspase-3, and -8, and cleavage of poly (ADP-ribose) polymerase.
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PMID:Novel anticancer agent, benzyldihydroxyoctenone, isolated from Streptomyces sp. causes G1 cell cycle arrest and induces apoptosis of HeLa cells. 1743 36


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