2013年1月1日星期二

JAK-STAT pathway modulates the roles of iNOS and COX-2 in the cytoprotection of early phase of hydrogen peroxide preconditioning against apoptosis induced by oxidative stress.

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JAK-STAT pathway modulates the roles of iNOS and COX-2 in the cytoprotection of early phase of hydrogen peroxide preconditioning against apoptosis induced by oxidative stress.

Neurosci Lett. 2012 Nov 7;529(2):166-71

Authors: Yu H, Liu Z, Zhou H, Dai W, Chen S, Shu Y, Feng J

Abstract
Our previous studies have demonstrated that preconditioning with hydrogen peroxide (H(2)O(2)) activated the JAK-STAT pathway that played an important role in the cytoprotection, and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mediated the late phase of cytoprotection induced by high concentration of H(2)O(2) after preconditioning. Here we sought to identify the downstream targets of the JAK-STAT axis that mediated H(2)O(2) preconditioning and the expression of iNOS and COX-2 in the early phase of H(2)O(2) preconditioning. It was shown that (1) Preconditioning with H(2)O(2) at 100 ?mol/L for 90 min in PC12 cells induced significant expression of iNOS and COX-2. (2) Pretreatment with the iNOS inhibitor AG (10 ?mol/L) or the COX-2 inhibitor NS-398 (10 ?mol/L) respectively 20min before H(2)O(2) preconditioning not only inhibits the increased expression of iNOS or COX-2 but also abrogates the protective effects of H(2)O(2) preconditioning against apoptosis induced by oxidative stress. (3) Pretreatment with the JAK inhibitor AG-490 (10 ?mol/L) 20 min before H(2)O(2) preconditioning obviously inhibits the up-regulation of iNOS or COX-2 induced by H(2)O(2) preconditioning. These results suggested that JAK-STAT pathway modulates the roles of iNOS and COX-2 in the cytoprotection of early phase of H(2)O(2) preconditioning.

PMID: 22995181 [PubMed - indexed for MEDLINE]

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Safety and efficacy of everolimus after kidney and hematopoietic stem cell transplantation.

Safety and efficacy of everolimus after kidney and hematopoietic stem cell transplantation.

Ann Transplant. 2012 Dec 31;17(4):52-8

Authors: Keller F, Wiesner S, Bunjes D, Hartmann B, Schmitt M

Abstract
Background: The aim of this retrospective study was to investigate the efficacy of everolimus at our institution and to report incidence and type of side effects in patients who underwent kidney transplantation or hematopoietic stem cell transplantation (HSCT). Material/Methods: Electronic medical records were evaluated for 122 patients (76 men and 46 women) treated with everolimus between January 2000 and January 2009. Of these patients, 81 had undergone kidney transplantation (mean age: 56�12 years) and 41 patients were treated with HSCT (mean age: 47�11 years). Results: Everolimus was discontinued in a total of 53% of patients (n=64) with no difference observed in kidney transplant recipients vs. stem cell transplanted patients (p=0.85). In one half of the patients, cessation of the drug was due to a lack of long-term efficacy (n=32). In the other half, everolimus was discontinued due to side effects (n=32). However, patients with side effects had no elevated everolimus concentrations (5.5�2.3 vs. 5.2�1.7 ng/ml; p=0.39). Pneumonitis (n=5) or proteinuria over 1.5 g per day (n=13) were only observed in kidney transplant patients, while polyomavirus-induced cystitis (n=3) and thrombotic thrombocytopenic purpura (n=7) were only observed in stem cell transplanted patients. Conclusions: Everolimus was an effective immunosuppressive agent in half of the patients. A quarter of all patients developed side effects resulting in discontinuation of the drug. The profile of side effects in kidney recipients clearly differs from hematopoietic stem cell transplanted patients.

PMID: 23274324 [PubMed - in process]

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Comparison of Paclitaxel-Eluting Stents (Taxus) and Everolimus-Eluting Stents (Xience) in Left Main Coronary Artery Disease With 3 Years Follow-Up (from the ESTROFA-LM Registry).

Comparison of Paclitaxel-Eluting Stents (Taxus) and Everolimus-Eluting Stents (Xience) in Left Main Coronary Artery Disease With 3 Years Follow-Up (from the ESTROFA-LM Registry).

Am J Cardiol. 2012 Dec 27;

Authors: De la Torre Hernandez JM, Alfonso F, Recalde AS, Jimenez Navarro MF, Perez de Prado A, Hernandez F, Abdul-Jawad Altisent O, Roura G, Camarero TG, Elizaga J, Rivero F, Gimeno F, Calvi�o R, Moreu J, Bosa F, Rumoroso JR, Bullones JA, Gallardo A, Fernandez Diaz JA, Ruiz Arroyo JR, Aragon V, Masotti M, ESTROFA-LM Study Group

Abstract
Evidence regarding therapy with drug-eluting stents in the left main coronary artery (LM) is based mostly on trials performed with first-generation drug-eluting stents. The aim of this study was to evaluate long-term clinical outcomes after treatment for unprotected LM disease with paclitaxel-eluting stents (PES) and everolimus-eluting stents (EES). The ESTROFA-LM is a multicenter retrospective registry including consecutive patients with unprotected LM disease treated with PES or EES. A total of 770 patients have been included at 21 centers, 415 with treated PES and 355 with EES. Treatment with 2 stents was more frequent with PES (17% vs 10.4%, p�= 0.007), whereas intravascular ultrasound was more frequently used with EES (35.2% vs 26%, p�= 0.006). The 3-year death and infarction survival rates were 86.1% for PES and 87.3% for EES (p�= 0.50) and for death, infarction, and target lesion revascularization were 83.6% versus 82% (p�= 0.60), respectively. Definite or probable thrombosis was 1.6% for PES and 1.4% for EES (p�= 0.80). The use of 2 stents, age, diabetes, and acute coronary syndromes were independent predictors of mortality. In the subgroup of distal lesions, the use of intravascular ultrasound was an independent predictor of better outcome. Comparison of propensity score-matched groups did not yield differences between the 2 stents. In conclusion, the results of this multicenter registry show comparable safety and efficacy at 3 years for PES and EES in the treatment of LM disease. The use of bifurcation stenting techniques in distal lesions was a relevant independent predictor for events. The use of intravascular ultrasound appears to have a positive impact on patients treated for LM distal disease.

PMID: 23273715 [PubMed - as supplied by publisher]

dovitinib dna-pk coxinhibitors

Tetraploidization increases sensitivity to Aurora B kinase inhibition.

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Tetraploidization increases sensitivity to Aurora B kinase inhibition.

Cell Cycle. 2012 Jul 1;11(13):2567-77

Authors: Marxer M, Foucar CE, Man WY, Chen Y, Ma HT, Poon RY

Abstract
Aurora kinases are overexpressed in many cancers and are targets for anticancer drugs. The yeast homolog of Aurora B kinase, IPL1, was found to be a ploidy-specific lethality gene. Given that polyploidization is a common feature of many cancers, we hypothesized polyploidization also sensitizes mammalian cells to inhibition of Aurora kinases. Using two models of apparent diploid vs. tetraploid cell lines (one based on the hepatocellular carcinoma cell line Hep3B and another on untransformed mouse fibroblasts), we found that tetraploid cells were more sensitive to Aurora B inhibition than their diploid counterparts. Apoptosis could be induced in tetraploid cells by two different Aurora B inhibitors. Furthermore, tetraploid cells were sensitive to Aurora B inhibition but were not affected by Aurora A inhibition. Interestingly, the underlying mechanism was due to mitotic slippage and the subsequent excessive genome reduplication. In support of this, abolition of cytokinesis with dihydrocytochalasin B resulted in similar effects on tetraploid cells as Aurora B inhibition. These results indicate that inhibition of Aurora B or cytokinesis can promote apoptosis effectively in polyploid cancer cells.

PMID: 22722494 [PubMed - in process]

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2012年12月31日星期一

A translocator protein ligand PK11195 shows antigrowth activity in human choriocarcinoma cells.

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A translocator protein ligand PK11195 shows antigrowth activity in human choriocarcinoma cells.

Tumour Biol. 2012 Oct;33(5):1505-10

Authors: Takai N, Kira N, Ishii T, Yoshida T, Nishida M, Nishida Y, Nasu K, Takano M, Midori H, Koga S, Narahara H

Abstract
The potential anticancer agent 1-(2-chlorophenyl-N-methylpropyl)-3-isoquinolinecarboxamide (PK11195), a translocator protein ligand (initially described as a ligand for the peripheral benzodiazepine receptor), induces apoptosis in some lines of human tumor cells. We investigated the effect of PK11195 in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of PK11195, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. A WST-1 assay showed that BeWo cells were sensitive to the growth inhibitory effect of PK11195. In contrast, the nonsite selective ligand diazepam has a little effect on these cells. Cell cycle analysis indicated that exposure to PK11195 decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine, by the loss of mitochondrial transmembrane potential, and by antibodies directed against histones from fragmented DNA. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. These results suggest that PK11195 may serve as a therapeutic agent for the treatment of choriocarcinoma.

PMID: 22528948 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

A validated tumorgraft model reveals activity of dovitinib against renal cell carcinoma.

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A validated tumorgraft model reveals activity of dovitinib against renal cell carcinoma.

Sci Transl Med. 2012 Jun 6;4(137):137ra75

Authors: Sivanand S, Pe�a-Llopis S, Zhao H, Kucejova B, Spence P, Pavia-Jimenez A, Yamasaki T, McBride DJ, Gillen J, Wolff NC, Morlock L, Lotan Y, Raj GV, Sagalowsky A, Margulis V, Cadeddu JA, Ross MT, Bentley DR, Kabbani W, Xie XJ, Kapur P, Williams NS, Brugarolas J

Abstract
Most anticancer drugs entering clinical trials fail to achieve approval from the U.S. Food and Drug Administration. Drug development is hampered by the lack of preclinical models with therapeutic predictive value. Herein, we report the development and validation of a tumorgraft model of renal cell carcinoma (RCC) and its application to the evaluation of an experimental drug. Tumor samples from 94 patients were implanted in the kidneys of mice without additives or disaggregation. Tumors from 35 of these patients formed tumorgrafts, and 16 stable lines were established. Samples from metastatic sites engrafted at higher frequency than those from primary tumors, and stable engraftment of primary tumors in mice correlated with decreased patient survival. Tumorgrafts retained the histology, gene expression, DNA copy number alterations, and more than 90% of the protein-coding gene mutations of the corresponding tumors. As determined by the induction of hypercalcemia in tumorgraft-bearing mice, tumorgrafts retained the ability to induce paraneoplastic syndromes. In studies simulating drug exposures in patients, RCC tumorgraft growth was inhibited by sunitinib and sirolimus (the active metabolite of temsirolimus in humans), but not by erlotinib, which was used as a control. Dovitinib, a drug in clinical development, showed greater activity than sunitinib and sirolimus. The routine incorporation of models recapitulating the molecular genetics and drug sensitivities of human tumors into preclinical programs has the potential to improve oncology drug development.

PMID: 22674553 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

Constitutively active c-Met kinase in PC-3 cells is autocrine-independent and can be blocked by the Met kinase inhibitor BMS-777607.

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Constitutively active c-Met kinase in PC-3 cells is autocrine-independent and can be blocked by the Met kinase inhibitor BMS-777607.

BMC Cancer. 2012;12:198

Authors: Dai Y, Siemann DW

Abstract
BACKGROUND: The c-Met receptor tyrosine kinase is aberrantly activated in many solid tumors. In a prior study we showed that prostate cancer PC-3 cells exhibit constitutively activated c-Met without exogenous hepatocyte growth factor (HGF); however whether this characteristic is due to an endogenous HGF/c-Met autocrine loop remains controversial. In the current study we examined the response of PC-3 cells to an anti-HGF neutralizing antibody or a small molecule Met kinase inhibitor (BMS-777607).
METHODS: Cell scattering was tested by monitoring cell morphology after HGF stimulation. Cell migration was examined by both "wound-healing" and transwell assasy and invasion was detected by Matrigel-coated transwell assay. Proliferation, survival and anoikis were determined by MTT, colony formation and trypan blue exclusion assay, respectively. Gene and protein expression were assessed by real-time PCR and Western blot, respectively.
RESULTS: Although HGF mRNA could be detected in PC-3 cells, the molecular weight of secreted "HGF" protein was inconsistent with the functional recombinant HGF. Furthermore, conditioned medium from PC-3 cell cultures was ineffective at triggering either motogenic behavior or c-Met signaling in DU145, another prostate cancer cell line expressing c-Met but lacking basal c-Met activation. PC-3 cells also were not responsive to the anti-HGF neutralizing antibody in experiments assessing proliferation, migration, or c-Met signaling. BMS-777607 treatment with micromolar doses nonetheless led to significant inhibition of multiple PC-3 cell functions including proliferation, clonogenicity, migration and invasion. At the molecular level, BMS-777607 suppressed autophosphorylated c-Met and downstream c-Src and Akt pathways.
CONCLUSIONS: These results suggest that the constitutive c-Met activation in PC-3 is independent of autocrine stimulation. Because PC-3 cells were responsive to BMS-777607 but not the anti-HGF antibody, the findings also indicate that under circumstances where c-Met is constitutively hyperactive in the absence of functional HGF, targeting the c-Met receptor remains a viable therapeutic option to impede cancer progression.

PMID: 22639908 [PubMed - indexed for MEDLINE]

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