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Sample records for induced paclitaxel resistance

  1. TXNDC17 promotes paclitaxel resistance via inducing autophagy in ovarian cancer.

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    Zhang, Song-Fa; Wang, Xin-Yu; Fu, Zhi-Qin; Peng, Qiao-Hua; Zhang, Jian-Yang; Ye, Feng; Fu, Yun-Feng; Zhou, Cai-Yun; Lu, Wei-Guo; Cheng, Xiao-Dong; Xie, Xing

    2015-01-01

    Paclitaxel is recommended as a first-line chemotherapeutic agent against ovarian cancer, but drug resistance becomes a major limitation of its success clinically. The key molecule or mechanism associated with paclitaxel resistance in ovarian cancer still remains unclear. Here, we showed that TXNDC17 screened from 356 differentially expressed proteins by LC-MS/MS label-free quantitative proteomics was more highly expressed in paclitaxel-resistant ovarian cancer cells and tissues, and the high expression of TXNDC17 was associated with poorer prognostic factors and exhibited shortened survival in 157 ovarian cancer patients. Moreover, paclitaxel exposure induced upregulation of TXNDC17 and BECN1 expression, increase of autophagosome formation, and autophagic flux that conferred cytoprotection for ovarian cancer cells from paclitaxel. TXNDC17 inhibition by siRNA or enforced overexpression by a pcDNA3.1(+)-TXNDC17 plasmid correspondingly decreased or increased the autophagy response and paclitaxel resistance. Additionally, the downregulation of BECN1 by siRNA attenuated the activation of autophagy and cytoprotection from paclitaxel induced by TXNDC17 overexpression in ovarian cancer cells. Thus, our findings suggest that TXNDC17, through participation of BECN1, induces autophagy and consequently results in paclitaxel resistance in ovarian cancer. TXNDC17 may be a potential predictor or target in ovarian cancer therapeutics.

  2. An antimitotic and antivascular agent BPR0L075 overcomes multidrug resistance and induces mitotic catastrophe in paclitaxel-resistant ovarian cancer cells.

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    Xiaolei Wang

    Full Text Available Paclitaxel plays a major role in the treatment of ovarian cancer; however, resistance to paclitaxel is frequently observed. Thus, new therapy that can overcome paclitaxel resistance will be of significant clinical importance. We evaluated antiproliferative effects of an antimitotic and antivascular agent BPR0L075 in paclitaxel-resistant ovarian cancer cells. BPR0L075 displays potent and broad-spectrum cytotoxicity at low nanomolar concentrations (IC50 = 2-7 nM against both parental ovarian cancer cells (OVCAR-3, SKOV-3, and A2780-1A9 and paclitaxel-resistant sublines (OVCAR-3-TR, SKOV-3-TR, 1A9-PTX10, regardless of the expression levels of the multidrug resistance transporter P-gp and class III β-tubulin or mutation of β-tubulin. BPR0L075 blocks cell cycle at the G2/M phase in paclitaxel-resistant cells while equal concentration of paclitaxel treatment was ineffective. BPR0L075 induces cell death by a dual mechanism in parental and paclitaxel-resistant ovarian cancer cells. In the parental cells (OVCAR-3 and SKOV-3, BPR0L075 induced apoptosis, evidenced by poly(ADP-ribose polymerase (PARP cleavage and DNA ladder formation. BPR0L075 induced cell death in paclitaxel-resistant ovarian cancer cells (OVCAR-3-TR and SKOV-3-TR is primarily due to mitotic catastrophe, evidenced by formation of giant, multinucleated cells and absence of PARP cleavage. Immunoblotting analysis shows that BPR0L075 treatment induced up-regulation of cyclin B1, BubR1, MPM-2, and survivin protein levels and Bcl-XL phosphorylation in parental cells; however, in resistant cells, the endogenous expressions of BubR1 and survivin were depleted, BPR0L075 treatment failed to induce MPM-2 expression and phosphorylation of Bcl-XL. BPR0L075 induced cell death in both parental and paclitaxel-resistant ovarian cancer cells proceed through caspase-3 independent mechanisms. In conclusion, BPR0L075 displays potent cytotoxic effects in ovarian cancer cells with a potential to overcome

  3. DUSP1 induces paclitaxel resistance through the regulation of p-glycoprotein expression in human ovarian cancer cells.

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    Kang, Yu-Seon; Seok, Hyun-Jeong; Jeong, Eun-Jeong; Kim, Yuna; Yun, Seok-Joong; Min, Jeong-Ki; Kim, Sun Jin; Kim, Jang-Seong

    2016-09-01

    The heterogeneity and genetic instability of ovarian cancer cells often lead to the development of drug resistance, closely related with the increased cancer-related mortality. In this study, we investigated the role of dual-specificity phosphatase 1 (DUSP1) in the development of the resistance in human ovarian cancer cells against paclitaxel. Overexpression of DUSP1 in HeyA8 human ovarian cancer cells (HeyA8-DUSP1) up-regulated the expression of the drug efflux pump, p-glycoprotein. Consequently, HeyA8-DUSP1 cells are highly resistant to paclitaxel, with the resistance comparable to that of a multi-drug resistance cell line (HeyA8-MDR). Moreover, over expression of DUSP1 significantly increased the activation of p38 MAPK, leaving the activation of ERK1/2 and JNK1/2 unaffected. Pharmacological suppression of p38 MAPK activity prevents the up-regulation of p-glycoprotein expression and the consequent resistance against paclitaxel in HeyA8-DUSP1 cells. By contrast, HeyA8-MDR cells expressed a significantly higher level of DUSP1, but treatment with small interference RNA against DUSP1 significantly suppressed the expression of p-glycoprotein and the resistance against paclitaxel in HeyA8-MDR cells. Ectopic expression of MKK3, an upstream activator of p38 MAPK, significantly up-regulated the expression of p-glycoprotein and increased the consequent resistance against paclitaxel in HeyA8 cells. Collectively, these data indicated that DUSP1 may induce the resistance against paclitaxel through the p38 MAPK-mediated overexpression of p-glycoprotein in human ovarian cancer cells.

  4. Cathepsin L upregulation-induced EMT phenotype is associated with the acquisition of cisplatin or paclitaxel resistance in A549 cells.

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    Han, Mei-Ling; Zhao, Yi-Fan; Tan, Cai-Hong; Xiong, Ya-Jie; Wang, Wen-Juan; Wu, Feng; Fei, Yao; Wang, Long; Liang, Zhong-Qin

    2016-12-01

    Cathepsin L (CTSL), a lysosomal acid cysteine protease, is known to play important roles in tumor metastasis and chemotherapy resistance. In this study we investigated the molecular mechanisms underlying the regulation of chemoresistance by CTSL in human lung cancer cells. Human lung cancer A549 cells, A549/PTX (paclitaxel-resistant) cells and A549/DDP (cisplatin-resistant) cells were tested. The resistance to cisplatin or paclitaxel was detected using MTT and the colony-formation assays. Actin remodeling was observed with FITC-Phalloidin fluorescent staining or immunofluorescence. A wound-healing assay or Transwell assay was used to assess the migration or invasion ability. The expression of CTSL and epithelial and mesenchymal markers was analyzed with Western blotting and immunofluorescence. The expression of EMT-associated transcription factors was measured with Western blotting or q-PCR. BALB/c nude mice were implanted subcutaneously with A549 cells overexpressing CTSL, and the mice were administered paclitaxel (10, 15 mg/kg, ip) every 3 d for 5 times. Cisplatin or paclitaxel treatment (10-80 ng/mL) induced CTSL expression in A549 cells. CTSL levels were much higher in A549/PTX and A549/DDP cells than in A549 cells. Silencing of CTSL reversed the chemoresistance in A549/DDP and A549/TAX cells, whereas overexpression of CTSL attenuated the sensitivity of A549 cells to cisplatin or paclitaxel. Furthermore, A549/DDP and A549/TAX cells underwent morphological and cytoskeletal changes with increased cell invasion and migration abilities, accompanied by decreased expression of epithelial markers (E-cadherin and cytokeratin-18) and increased expression of mesenchymal markers (N-cadherin and vimentin), as well as upregulation of EMT-associated transcription factors Snail, Slug, ZEB1 and ZEB2. Silencing of CTSL reversed EMT in A549/DDP and A549/TAX cells; In contrast, overexpression of CTSL induced EMT in A549 cells. In xenograft nude mouse model, the mice implanted

  5. Loss of PKCδ Induces Prostate Cancer Resistance to Paclitaxel through Activation of Wnt/β-Catenin Pathway and Mcl-1 Accumulation.

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    Flores, M Luz; Castilla, Carolina; Gasca, Jessica; Medina, Rafael; Pérez-Valderrama, Begoña; Romero, Francisco; Japón, Miguel A; Sáez, Carmen

    2016-07-01

    Prostate cancer is the leading cause of cancer-related death among men in developed countries. Although castration therapy is initially effective, prostate cancers progress to hormone-refractory disease and in this case taxane-based chemotherapy is widely used. Castration-resistant prostate cancer cells often develop resistance to chemotherapy agents and the search for new therapeutic strategies is necessary. In this article, we demonstrate that PKCδ silencing favors mitotic arrest after paclitaxel treatment in PC3 and LNCaP cells; however, this is associated with resistance to paclitaxel-induced apoptosis. In prostate cancer cells, PKCδ seems to exert a proapoptotic role, acting as a negative regulator of the canonical Wnt/β-catenin pathway. PKCδ silencing induces activation of Wnt/β-catenin pathway and the expression of its target genes, including Aurora kinase A, which is involved in activation of Akt and both factors play a key role in GSK3β inactivation and consequently in the stabilization of β-catenin and antiapoptotic protein Mcl-1. We also show that combined treatments with paclitaxel and Wnt/β-catenin or Akt inhibitors improve the apoptotic response to paclitaxel, even in the absence of PKCδ. Finally, we observe that high Gleason score prostate tumors lose PKCδ expression and this correlates with higher activation of β-catenin, inactivation of GSK3β, and higher levels of Aurora kinase A and Mcl-1 proteins. These findings suggest that targeting Wnt/β-catenin or Akt pathways may increase the efficacy of taxane chemotherapy in advanced human prostate cancers that have lost PKCδ expression. Mol Cancer Ther; 15(7); 1713-25. ©2016 AACR.

  6. The extracellular matrix protein TGFBI induces microtubule stabilization and sensitizes ovarian cancers to paclitaxel.

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    Ahmed, Ahmed Ashour; Mills, Anthony D; Ibrahim, Ashraf E K; Temple, Jillian; Blenkiron, Cherie; Vias, Maria; Massie, Charlie E; Iyer, N Gopalakrishna; McGeoch, Adam; Crawford, Robin; Nicke, Barbara; Downward, Julian; Swanton, Charles; Bell, Stephen D; Earl, Helena M; Laskey, Ronald A; Caldas, Carlos; Brenton, James D

    2007-12-01

    The extracellular matrix (ECM) can induce chemotherapy resistance via AKT-mediated inhibition of apoptosis. Here, we show that loss of the ECM protein TGFBI (transforming growth factor beta induced) is sufficient to induce specific resistance to paclitaxel and mitotic spindle abnormalities in ovarian cancer cells. Paclitaxel-resistant cells treated with recombinant TGFBI protein show integrin-dependent restoration of paclitaxel sensitivity via FAK- and Rho-dependent stabilization of microtubules. Immunohistochemical staining for TGFBI in paclitaxel-treated ovarian cancers from a prospective clinical trial showed that morphological changes of paclitaxel-induced cytotoxicity were restricted to areas of strong expression of TGFBI. These data show that ECM can mediate taxane sensitivity by modulating microtubule stability.

  7. Targeting of apoptotic pathways by SMAC or BH3 mimetics distinctly sensitizes paclitaxel-resistant triple negative breast cancer cells.

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    Panayotopoulou, Effrosini G; Müller, Anna-Katharina; Börries, Melanie; Busch, Hauke; Hu, Guohong; Lev, Sima

    2017-02-06

    Standard chemotherapy is the only systemic treatment for triple-negative breast cancer (TNBC), and despite the good initial response, resistance remains a major therapeutic obstacle. Here, we employed a High-Throughput Screen to identify targeted therapies that overcome chemoresistance in TNBC. We applied short-term paclitaxel treatment and screened 320 small-molecule inhibitors of known targets to identify drugs that preferentially and efficiently target paclitaxel-treated TNBC cells. Among these compounds the SMAC mimetics (BV6, Birinapant) and BH3-mimetics (ABT-737/263) were recognized as potent targeted therapy for multiple paclitaxel-residual TNBC cell lines. However, acquired paclitaxel resistance through repeated paclitaxel pulses result in desensitization to BV6, but not to ABT-263, suggesting that short- and long-term paclitaxel resistance are mediated by distinct mechanisms. Gene expression profiling of paclitaxel-residual, -resistant and naïve MDA-MB-231 cells demonstrated that paclitaxel-residual, as opposed to -resistant cells, were characterized by an apoptotic signature, with downregulation of anti-apoptotic genes (BCL2, BIRC5), induction of apoptosis inducers (IL24, PDCD4), and enrichment of TNFα/NF-κB pathway, including upregulation of TNFSF15, coupled with cell-cycle arrest. BIRC5 and FOXM1 downregulation and IL24 induction was also evident in breast cancer patient datasets following taxane treatment. Exposure of naïve or paclitaxel-resistant cells to supernatants of paclitaxel-residual cells sensitized them to BV6, and treatment with TNFα enhanced BV6 potency, suggesting that sensitization to BV6 is mediated, at least partially, by secreted factor(s). Our results suggest that administration of SMAC or BH3 mimetics following short-term paclitaxel treatment could be an effective therapeutic strategy for TNBC, while only BH3-mimetics could effectively overcome long-term paclitaxel resistance.

  8. Paclitaxel-induced apoptosis is BAK-dependent, but BAX and BIM-independent in breast tumor.

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    Anna V Miller

    Full Text Available Paclitaxel (Taxol-induced cell death requires the intrinsic cell death pathway, but the specific participants and the precise mechanisms are poorly understood. Previous studies indicate that a BH3-only protein BIM (BCL-2 Interacting Mediator of cell death plays a role in paclitaxel-induced apoptosis. We show here that BIM is dispensable in apoptosis with paclitaxel treatment using bim(-/- MEFs (mouse embryonic fibroblasts, the bim(-/- mouse breast tumor model, and shRNA-mediated down-regulation of BIM in human breast cancer cells. In contrast, both bak (-/- MEFs and human breast cancer cells in which BAK was down-regulated by shRNA were more resistant to paclitaxel. However, paclitaxel sensitivity was not affected in bax(-/- MEFs or in human breast cancer cells in which BAX was down-regulated, suggesting that paclitaxel-induced apoptosis is BAK-dependent, but BAX-independent. In human breast cancer cells, paclitaxel treatment resulted in MCL-1 degradation which was prevented by a proteasome inhibitor, MG132. A Cdk inhibitor, roscovitine, blocked paclitaxel-induced MCL-1 degradation and apoptosis, suggesting that Cdk activation at mitotic arrest could induce subsequent MCL-1 degradation in a proteasome-dependent manner. BAK was associated with MCL-1 in untreated cells and became activated in concert with loss of MCL-1 expression and its release from the complex. Our data suggest that BAK is the mediator of paclitaxel-induced apoptosis and could be an alternative target for overcoming paclitaxel resistance.

  9. A new 2α,5α,10β,14β-tetraacetoxy-4(20,11-taxadiene (SIA derivative overcomes paclitaxel resistance by inhibiting MAPK signaling and increasing paclitaxel accumulation in breast cancer cells.

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    Mei Mei

    Full Text Available Tumor resistance due to multiple mechanisms seriously hinders the efficacy of chemotherapy drugs such as paclitaxel. The most widely studied P-glycoprotein inhibitors still have limited ability to reverse resistance in the clinic. In this study, NPB304, a novel Sinenxan A (SIA derivative, was found to significantly sensitize resistant breast cancer cells to paclitaxel in vitro and in vivo. Treatment with NPB304 increased paclitaxel-induced apoptosis in a p53-dependent manner through PARP cleavage. Importantly, NPB304 enhanced the antitumor effect of paclitaxel in resistant breast tumor xenografts in nude mice without significantly affecting weight loss. NPB304 regulated cell resistance through inhibition of MAPK pathway components, including p-ERK and p-p38. Moreover, NPB304 increased paclitaxel accumulation by affecting P-gp function. In addition to increasing Rhodamine 123 accumulation, NPB304 promoted bidirectional permeability but decreased the efflux ratio of paclitaxel in a Caco-2 monolayer model, thereby increasing the intracellular concentration of paclitaxel. Similarly, NPB304 increased the concentration of paclitaxel in the resistant tumor tissue. Hence, NPB304 is a novel compound that promotes the sensitization of resistant cells to paclitaxel through multiple mechanisms and has the potential for use in combination therapies to treat resistant breast cancer.

  10. A new 2α,5α,10β,14β-tetraacetoxy-4(20),11-taxadiene (SIA) derivative overcomes paclitaxel resistance by inhibiting MAPK signaling and increasing paclitaxel accumulation in breast cancer cells.

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    Mei, Mei; Xie, Dan; Zhang, Yi; Jin, Jing; You, Feng; Li, Yan; Dai, Jungui; Chen, Xiaoguang

    2014-01-01

    Tumor resistance due to multiple mechanisms seriously hinders the efficacy of chemotherapy drugs such as paclitaxel. The most widely studied P-glycoprotein inhibitors still have limited ability to reverse resistance in the clinic. In this study, NPB304, a novel Sinenxan A (SIA) derivative, was found to significantly sensitize resistant breast cancer cells to paclitaxel in vitro and in vivo. Treatment with NPB304 increased paclitaxel-induced apoptosis in a p53-dependent manner through PARP cleavage. Importantly, NPB304 enhanced the antitumor effect of paclitaxel in resistant breast tumor xenografts in nude mice without significantly affecting weight loss. NPB304 regulated cell resistance through inhibition of MAPK pathway components, including p-ERK and p-p38. Moreover, NPB304 increased paclitaxel accumulation by affecting P-gp function. In addition to increasing Rhodamine 123 accumulation, NPB304 promoted bidirectional permeability but decreased the efflux ratio of paclitaxel in a Caco-2 monolayer model, thereby increasing the intracellular concentration of paclitaxel. Similarly, NPB304 increased the concentration of paclitaxel in the resistant tumor tissue. Hence, NPB304 is a novel compound that promotes the sensitization of resistant cells to paclitaxel through multiple mechanisms and has the potential for use in combination therapies to treat resistant breast cancer.

  11. Overexpression of centrosomal protein Nlp confers breast carcinoma resistance to paclitaxel.

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    Zhao, Weihong; Song, Yongmei; Xu, Binghe; Zhan, Qimin

    2012-02-01

    Nlp (ninein-like protein), an important molecule involved in centrosome maturation and spindle formation, plays an important role in tumorigenesis and its abnormal expression was recently observed in human breast and lung cancers. In this study, the correlation between overexpression of Nlp and paclitaxel chemosensitivity was investigated to explore the mechanisms of resistance to paclitaxel and to understand the effect of Nlp upon apoptosis induced by chemotherapeutic agents. Nlp expression vector was stably transfected into breast cancer MCF-7 cells. With Nlp overexpression, the survival rates, cell cycle distributions and apoptosis were analyzed in transfected MCF-7 cells by MTT test and FCM approach. The immunofluorescent assay was employed to detect the changes of microtubule after paclitaxel treatment. Immunoblotting analysis was used to examine expression of centrosomal proteins and apoptosis associated proteins. Subsequently, Nlp expression was retrospectively examined with 55 breast cancer samples derived from paclitaxel treated patients. Interestingly, the survival rates of MCF-7 cells with Nlp overexpressing were higher than that of control after paclitaxel treatment. Nlp overexpression promoted G2-M arrest and attenuated apoptosis induced by paclitaxel, which was coupled with elevated Bcl-2 protein. Nlp expression significantly lessened the microtubule polymerization and bundling elicited by paclitaxel attributing to alteration on the structure or dynamics of β-tubulin but not on its expression. The breast cancer patients with high expression of Nlp were likely resistant to the treatment of paclitaxel, as the response rate in Nlp negative patients was 62.5%, whereas was 58.3 and 15.8% in Nlp (+) and Nlp (++) patients respectively (p = 0.015). Nlp expression was positive correlated with those of Plk1 and PCNA. These findings provide insights into more rational chemotherapeutic regimens in clinical practice, and more effective approaches might be

  12. The microtubule-stabilizing agent discodermolide competitively inhibits the binding of paclitaxel (Taxol) to tubulin polymers, enhances tubulin nucleation reactions more potently than paclitaxel, and inhibits the growth of paclitaxel-resistant cells.

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    Kowalski, R J; Giannakakou, P; Gunasekera, S P; Longley, R E; Day, B W; Hamel, E

    1997-10-01

    The lactone-bearing polyhydroxylated alkatetraene (+)-discodermolide, which was isolated from the sponge Discodermia dissoluta, induces the polymerization of purified tubulin with and without microtubule-associated proteins or GTP, and the polymers formed are stable to cold and calcium. These effects are similar to those of paclitaxel (Taxol), but discodermolide is more potent. We confirmed that these properties represent hypernucleation phenomena; we obtained lower tubulin critical concentrations and shorter polymers with discodermolide than paclitaxel under a variety of reaction conditions. Furthermore, we demonstrated that discodermolide is a competitive inhibitor with [3H]paclitaxel in binding to tubulin polymer, with an apparent Ki value of 0.4 microM. Multidrug-resistant human colon and ovarian carcinoma cells overexpressing P-glycoprotein, which are 900- and 2800-fold resistant to paclitaxel, respectively, relative to the parental lines, retained significant sensitivity to discodermolide (25- and 89-fold more resistant relative to the parental lines). Ovarian carcinoma cells that are 20-30-fold more resistant to paclitaxel than the parental line on the basis of expression of altered beta-tubulin polypeptides retained nearly complete sensitivity to discodermolide. The effects of discodermolide on the reorganization of the microtubules of Potorous tridactylis kidney epithelial cells were examined at different times. Intracellular microtubules were reorganized into bundles in interphase cells much more rapidly after discodermolide treatment compared with paclitaxel treatment. A variety of spindle aberrations were observed after treatment with both drugs. The proportions of the different types of aberration were different for the two drugs and changed with the length of drug treatment.

  13. Establishment of a paclitaxel resistant human breast cancer cell strain (MCF-7/Taxol) and intracellular paclitaxel binding protein analysis.

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    Zuo, K-Q; Zhang, X-P; Zou, J; Li, D; Lv, Z-W

    2010-01-01

    Multidrug resistance of tumours is one of the most important factors that leads to chemotherapy failure. A multidrug-resistant breast cancer cell line, MCF-7/Taxol, was established from the drug-sensitive parent cell line MCF-7. The biological properties of MCF-7/Taxol, including its drug resistance profile and profile of paclitaxel binding proteins, were analysed and compared with the parent cell line. A number of paclitaxel binding proteins were present in MCF-7 cells but absent from MCF-7/Taxol cells, namely heat shock protein 90, actinin and dermcidin precursor. The identification of differential paclitaxel binding proteins between the multidrug-resistant MCF-7/Taxol cell line and the parent drug-sensitive cell line MCF-7 provides insight into possible mechanisms involved in resistance to these chemotherapy drugs.

  14. Paclitaxel induces apoptosis in human gastric carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Hai-Bo Zhou; Ju-Ren Zhu

    2003-01-01

    AIM: To investigate the apoptosis in gastric cancer cells induced by paclitaxel, and the relation between this apoptosis and expression of Bcl-2 and Bax.METHODS: In in vitro experiments, MTT assay was used to determine the cell growth inhibitory rate. Transmission electron microscope and TUNEL staining method were used to quantitatively and qualitively detect the apoptosis status of gastric cancer cell line SGC-7901 before and after the paditaxel treatment. Immunohistochemical staining was used to detect the expression of apoptosis-regulated gene Bcl-2and Bax.RESULTS: Paclitaxel inhibited the growth of gastric cancer cell line SGC-7901 in a dose-and time-dependent manner.Paclitaxel induced SGC-7901 cells to undergo apoptosis with typically apoptotic characteristics, including morphological changes of chromatin condensation, chromatin crescent formation, nucleus fragmentation and apoptotic body formation. Paclitaxel could reduce the expression of apoptosis-regulated gene Bcl-2, and improve the expression of apoptosis-regulated gene Bax.CONCLUSION: Paclitaxel is able to induce the apoptosis in gastric cancer. This apoptosis may be mediated by downexpression of apoptosis-regulated gene Bcl-2 and upexpression of apoptosis-regulated gene Bax.

  15. Paclitaxel-induced activation of murine peritoneal macrophage in vitro

    Institute of Scientific and Technical Information of China (English)

    Li Zhongxiang; Wang Fufeng; Qiao Yuhuan

    2004-01-01

    Objective: To study the effects of paclitaxel on macrophage activation. Methods:Mouse macrophages were isolated by peritoneal lavage and cultured in RPMI 1640 medium according to the following groups: paclitaxel (5μmol/L) group, IFN-γ (5U/L) group, paclitaxel (5μmol/L) and IFN-γ (5U/L) combination group, and control group(without paclitaxel and IFNγ) .24 hours later, supematants were collected for nitric oxide(NO) assessment using the Griess reagent, and ttanor necrosis factor-α(TNF-α) assessment using the enzyme linked immunosorbent assay. Antibody-dependent cell-mediated cytotoxicity(ADCC) of the macrophages was assessed using the method of hemoglobin-enzyme release assay (Hb-ERA). Results: Paclitaxel induced the production of higher levels of NO(8.86 ± 1.16μmol/L) and TNF-α(120.2 ± 10.2pg/ml) ,and enhanced the ADCC of macrophages[ (20.61 + 1.13)% ]. The differences were significant compared with the control group[no NO and TNF-α detected,ADCC (15.37 + 1.93)% ](P < 0.01). Paclitaxel and IFN-γ in combination induced the production of higher levels of NO(22.85 ± 0.91μmol/L) and TNF-α(358.6 ± 27 .5pg/ml), and enhanced the ADCC of macrophages[ (42.49 + 3.09) % ]. The differences were significant compared with paclitaxel or IFN-γ[NO 8.09 ± 1.13μmol/L, TNF-α1 24.8 + 9.6pg/ml, ADCC(23.32 ± 2.63) % ] alone (P<0.01). Conclusion: These findings indicate that paclitaxel can promote NO and TNF-α production,enhance ADCC of macrophages, and induce macrophage activation. The active effects are more significant with paclitaxel and IFN-γcombination.

  16. hGBP-1 Expression Predicts Shorter Progression-Free Survival in Ovarian Cancers, While Contributing to Paclitaxel Resistance

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    Wadi, Suzan; Tipton, Aaron R.; Trendel, Jill A.; Khuder, Sadik A.; Vestal, Deborah J.

    2017-01-01

    Ovarian cancer is the gynecological cancer with the poorest prognosis. One significant reason is the development of resistance to the chemotherapeutic drugs used in its treatment. The large GTPase, hGBP-1, has been implicated in paclitaxel resistance in ovarian cell lines. Forced expression of hGBP-1 in SKOV3 ovarian cancer cells protects them from paclitaxel-induced cell death. However, prior to this study, nothing was known about whether hGBP-1 was expressed in ovarian tumors and whether its expression correlated with paclitaxel resistance. hGBP-1 is expressed in 17% of ovarian tumors from patients that have not yet received treatment. However, at least 80% of the ovarian tumors that recurred after therapies that included a tax-ane, either paclitaxel or docetaxel, were positive for hGBP-1. In addition, hGBP-1 expression predicts a significantly shorter progression-free survival in ovarian cancers. Based on these studies, hGBP-1 could prove to be a potential biomarker for paclitaxel resistance in ovarian cancer. PMID:28090373

  17. Overcoming paclitaxel resistance in uterine endometrial cancer using a COX-2 inhibitor.

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    Hasegawa, Kiyoshi; Ishikawa, Kunimi; Kawai, Satoshi; Torii, Yutaka; Kawamura, Kyoko; Kato, Rina; Tsukada, Kazuhiko; Udagawa, Yasuhiro

    2013-12-01

    Cyclooxygenase (COX)-2 inhibitors have been reported to potentially modulate the resistance of cancer cells to chemotherapeutic drugs by affecting multidrug resistance 1 (MDR1) expression. In the present study, we investigated the association between COX-2 and MDR1 expression in endometrial cancers and evaluated the effects of the COX-2 inhibitor, etodolac, in combination with paclitaxel on paclitaxel-resistant endometrial cancer cells. The relationship between COX-2 and MDR1 mRNA expression was examined by quantitative PCR in 36 endometrial cancer specimens. The paclitaxel-resistant cell line OMC-2P was established from OMC-2 cells. Paclitaxel (1 µg/ml) with or without etodolac (10 µg/ml) was added to OMC-2 and OMC-2P cells, and COX-2 and MDR1 mRNA expression levels were examined. The concentration of prostaglandin E2 (PGE2) in the supernatant of each cell line was examined by enzyme-linked immunosorbent assay. The function of MDR1 was determined by intracellular accumulation of rhodamine 123 using flow cytometry, and the concentration of intracellular paclitaxel was determined by high-performance liquid chromatography. We found a positive relationship between COX-2 and MDR1 mRNA expression in endometrial cancer. Both COX-2 mRNA expression and PGE2 production were elevated in resistant OMC-2P cells when compared to non-resistant OMC-2 cells. Additionally, MDR1 mRNA expression was markedly upregulated in OMC-2P cells. In OMC-2 cells, COX-2 and MDR1 mRNA levels were significantly upregulated by paclitaxel treatment and downregulated by co-administration with etodolac. In OMC-2P cells, COX-2 mRNA expression was also significantly upregulated by paclitaxel treatment and tended to be downregulated by co-administration with etodolac. Moreover, co-administration of paclitaxel and etodolac suppressed the induction of MDR1 mRNA. Rhodamine 123 efflux was increased in OMC-2P cells when compared to the efflux in the OMC-2 cells and was increased in response to paclitaxel

  18. Lin28 mediates paclitaxel resistance by modulating p21, Rb and Let-7a miRNA in breast cancer cells.

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    Kezhen Lv

    Full Text Available Resistance to chemotherapy is a major obstacle for the effective treatment of cancers. Lin28 has been shown to contribute to tumor relapse after chemotherapy; however, the relationship between Lin28 and chemoresistance remained unknown. In this study, we investigated the association of Lin28 with paclitaxel resistance and identified the underlying mechanisms of action of Lin28 in human breast cancer cell lines and tumor tissues. We found that the expression level of Lin28 was closely associated with the resistance to paclitaxel treatment. The T47D cancer cell line, which highly expresses Lin28, is more resistant to paclitaxel than the MCF7, Bcap-37 or SK-BR-3 cancer cell lines, which had low-level expression of Lin28. Knocking down of Lin28 in Lin28 high expression T47D cells increased the sensitivity to paclitaxel treatment, while stable expression of Lin28 in breast cancer cells effectively attenuated the sensitivity to paclitaxel treatment, resulting in a significant increase of IC50 values of paclitaxel. Transfection with Lin28 also significantly inhibited paclitaxel-induced apoptosis. We also found that Lin28 expression was dramatically increased in tumor tissues after neoadjuvant chemotherapy or in local relapse or metastatic breast cancer tissues. Moreover, further studies showed that p21, Rb and Let-7 miRNA were the molecular targets of Lin28. Overexpression of Lin28 in breast cancer cells considerably induced p21 and Rb expression and inhibited Let-7 miRNA levels. Our results indicate that Lin28 expression might be one mechanism underlying paclitaxel resistance in breast cancer, and Lin28 could be a potential target for overcoming paclitaxel resistance in breast cancer.

  19. Lin28 mediates paclitaxel resistance by modulating p21, Rb and Let-7a miRNA in breast cancer cells.

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    Lv, Kezhen; Liu, Liqun; Wang, Linbo; Yu, Jiren; Liu, Xiaojiao; Cheng, Yongxia; Dong, Minjun; Teng, Rongyue; Wu, Linjiao; Fu, Peifen; Deng, Wuguo; Hu, Wenxian; Teng, Lisong

    2012-01-01

    Resistance to chemotherapy is a major obstacle for the effective treatment of cancers. Lin28 has been shown to contribute to tumor relapse after chemotherapy; however, the relationship between Lin28 and chemoresistance remained unknown. In this study, we investigated the association of Lin28 with paclitaxel resistance and identified the underlying mechanisms of action of Lin28 in human breast cancer cell lines and tumor tissues. We found that the expression level of Lin28 was closely associated with the resistance to paclitaxel treatment. The T47D cancer cell line, which highly expresses Lin28, is more resistant to paclitaxel than the MCF7, Bcap-37 or SK-BR-3 cancer cell lines, which had low-level expression of Lin28. Knocking down of Lin28 in Lin28 high expression T47D cells increased the sensitivity to paclitaxel treatment, while stable expression of Lin28 in breast cancer cells effectively attenuated the sensitivity to paclitaxel treatment, resulting in a significant increase of IC50 values of paclitaxel. Transfection with Lin28 also significantly inhibited paclitaxel-induced apoptosis. We also found that Lin28 expression was dramatically increased in tumor tissues after neoadjuvant chemotherapy or in local relapse or metastatic breast cancer tissues. Moreover, further studies showed that p21, Rb and Let-7 miRNA were the molecular targets of Lin28. Overexpression of Lin28 in breast cancer cells considerably induced p21 and Rb expression and inhibited Let-7 miRNA levels. Our results indicate that Lin28 expression might be one mechanism underlying paclitaxel resistance in breast cancer, and Lin28 could be a potential target for overcoming paclitaxel resistance in breast cancer.

  20. (-)-Epigallocatechin-3-gallate decreases thrombin/paclitaxel-induced endothelial tissue factor expression via the inhibition of c-Jun terminal NH2 kinase phosphorylation

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    Wang, Huang-Joe [Institute of Biotechnology, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan (China); Division of Cardiology, Department of Medicine, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan (China); Lo, Wan-Yu [Department of Medical Research, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan (China); Graduate Integration of Chinese and Western Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan (China); Lu, Te-Ling [School of Pharmacy, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan (China); Huang, Haimei, E-mail: hmhuang@life.nthu.edu.tw [Institute of Biotechnology, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan (China)

    2010-01-01

    Patients with paclitaxel-eluting stents are concerned with stent thrombosis caused by premature discontinuation of dual antiplatelet therapy or clopidogrel resistance. This study investigates the effect of (-)-epigallocatechin-3-gallate (EGCG) on the expression of thrombin/paclitaxel-induced endothelial tissue factor (TF) expressions in human aortic endothelial cells (HAECs). EGCG was nontoxic to HAECs at 6 h up to a concentration of 25 {mu}mol/L. At a concentration of 25 {mu}mol/L, EGCG pretreatment potently inhibited both thrombin-stimulated and thrombin/paclitaxel-stimulated endothelial TF protein expression. Thrombin and thrombin/paclitaxel-induced 2.6-fold and 2.9-fold increases in TF activity compared with the control. EGCG pretreatment caused a 29% and 38% decrease in TF activity on thrombin and thrombin/paclitaxel treatment, respectively. Real-time polymerase chain reaction (PCR) showed that thrombin and thrombin/paclitaxel-induced 3.0-fold and 4.6-fold TF mRNA expressions compared with the control. EGCG pretreatment caused an 82% and 72% decrease in TF mRNA expression on thrombin and thrombin/paclitaxel treatment, respectively. The c-Jun terminal NH2 kinase (JNK) inhibitor SP600125 reduced thrombin/paclitaxel-induced TF expression. Furthermore, EGCG significantly inhibited the phosphorylation of JNK to 49% of thrombin/paclitaxel-stimulated HAECs at 60 min. Immunofluorescence assay did not show an inhibitory effect of EGCG on P65 NF-{kappa}B nuclear translocation in the thrombin/paclitaxel-stimulated endothelial cells. In conclusion, EGCG can inhibit TF expression in thrombin/paclitaxel-stimulated endothelial cells via the inhibition of JNK phosphorylation. The unique property of EGCG may be used to develop a new drug-eluting stent by co-coating EGCG and paclitaxel.

  1. Characterization of acquired paclitaxel resistance of breast cancer cells and involvement of ABC transporters.

    Science.gov (United States)

    Němcová-Fürstová, Vlasta; Kopperová, Dana; Balušíková, Kamila; Ehrlichová, Marie; Brynychová, Veronika; Václavíková, Radka; Daniel, Petr; Souček, Pavel; Kovář, Jan

    2016-11-01

    Development of taxane resistance has become clinically very important issue. The molecular mechanisms underlying the resistance are still unclear. To address this issue, we established paclitaxel-resistant sublines of the SK-BR-3 and MCF-7 breast cancer cell lines that are capable of long-term proliferation in 100nM and 300nM paclitaxel, respectively. Application of these concentrations leads to cell death in the original counterpart cells. Both sublines are cross-resistant to doxorubicin, indicating the presence of the MDR phenotype. Interestingly, resistance in both paclitaxel-resistant sublines is circumvented by the second-generation taxane SB-T-1216. Moreover, we demonstrated that it was not possible to establish sublines of SK-BR-3 and MCF-7 cells resistant to this taxane. It means that at least the tested breast cancer cells are unable to develop resistance to some taxanes. Employing mRNA expression profiling of all known human ABC transporters and subsequent Western blot analysis of the expression of selected transporters, we demonstrated that only the ABCB1/PgP and ABCC3/MRP3 proteins were up-regulated in both paclitaxel-resistant sublines. We found up-regulation of ABCG2/BCRP and ABCC4 proteins only in paclitaxel-resistant SK-BR-3 cells. In paclitaxel-resistant MCF-7 cells, ABCB4/MDR3 and ABCC2/MRP2 proteins were up-regulated. Silencing of ABCB1 expression using specific siRNA increased significantly, but did not completely restore full sensitivity to both paclitaxel and doxorubicin. Thus we showed a key, but not exclusive, role for ABCB1 in mechanisms of paclitaxel resistance. It suggests the involvement of multiple mechanisms in paclitaxel resistance in tested breast cancer cells.

  2. Short exposure to paclitaxel induces multipolar spindle formation and aneuploidy through promotion of acentrosomal pole assembly

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Paclitaxel is a widely used microtubule drug and cancer medicine. Here we report that by short exposure to paclitaxel at a low dose, multipolar spindles were induced in mitotic cells without centrosome amplification. Both TPX2 depletion and Aurora-A overexpression antagonized the multipolarity. Live cell imaging showed that some paclitaxel-treated cells accomplished multipolar cell division and a portion of the daughter cells went on to the next round of mitosis. The surviving cells grew into clones with varied genome content. The results indicated that an aneuploidy population could be induced by short exposure to paclitaxel at a low dose, implicating potential side effects of paclitaxel.

  3. Delayed Paclitaxel-Trastuzumab-Induced Interstitial Pneumonitis in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Omalkhair Abulkhair

    2011-04-01

    Full Text Available Pneumonitis is a rare but serious complication associated with paclitaxel and/or trastuzumab treatment. We report a 51-year-old female patient with locally advanced breast cancer who presented with shortness of breath, fever, dry cough and pulmonary infiltrates. She had been treated without complications for 10 weeks with paclitaxel (Taxol® and trastuzumab (Herceptin® as neoadjuvant therapy, with complete clinical and pathological response. Infections and cardiomyopathy were excluded as causes of her symptoms. Bronchoscopy and biopsy were performed and a diagnosis of drug-induced interstitial pneumonitis was made. After treatment with steroids, the patient showed a significant response in less than 24 h; she was discharged home without the need for oxygen less than 48 h after therapy initiation. Although no causative association could be found between either trastuzumab or paclitaxel and this patient’s pulmonary syndrome, the potential for such toxicity should be considered, especially as paclitaxel/trastuzumab is a vey common combination therapy for breast cancer.

  4. Paeonol reverses paclitaxel resistance in human breast cancer cells by regulating the expression of transgelin 2.

    Science.gov (United States)

    Cai, Jiangxia; Chen, Siying; Zhang, Weipeng; Hu, Sasa; Lu, Jun; Xing, Jianfeng; Dong, Yalin

    2014-06-15

    Paclitaxel (PTX) is a first-line antineoplastic drug that is commonly used in clinical chemotherapy for breast cancer treatment. However, the occurrence of drug resistance in chemotherapeutic treatment has greatly restricted its use. There is thus an urgent need to find ways of reversing paclitaxel chemotherapy resistance in breast cancer. Plant-derived agents have great potential in preventing the onset of the carcinogenic process and enhancing the efficacy of mainstream antitumor drugs. Paeonol, a main compound derived from the root bark of Paeonia suffruticosa, has various biological activities, and is reported to have reversal drug resistance effects. This study established a paclitaxel-resistant human breast cancer cell line (MCF-7/PTX) and applied the dual-luciferase reporter gene assay, MTT assay, flow cytometry, transfection assay, Western blotting and the quantitative real-time polymerase chain reaction (qRT-PCR) to investigate the reversing effects of paeonol and its underlying mechanisms. It was found that transgelin 2 may mediate the resistance of MCF-7/PTX cells to paclitaxel by up-regulating the expressions of the adenosine-triphosphate binding cassette transporter proteins, including P-glycoprotein (P-gp), multidrug resistance associated protein 1 (MRP1), and breast cancer resistance protein (BCRP). Furthermore, the ability of paeonol to reverse paclitaxel resistance in breast cancer was confirmed, with a superior 8.2-fold reversal index. In addition, this study found that paeonol down-regulated the transgelin 2-mediated paclitaxel resistance by reducing the expressions of P-gp, MRP1, and BCRP in MCF-7/PTX cells. These results not only provide insight into the potential application of paeonol to the reversal of paclitaxel resistance, thus facilitating the sensitivity of breast cancer chemotherapy, but also highlight a potential role of transgelin 2 in the development of paclitaxel resistance in breast cancer.

  5. The potent microtubule-stabilizing agent (+)-discodermolide induces apoptosis in human breast carcinoma cells--preliminary comparisons to paclitaxel.

    Science.gov (United States)

    Balachandran, R; ter Haar, E; Welsh, M J; Grant, S G; Day, B W

    1998-01-01

    (+)-Discodermolide, a sponge-derived natural product, stabilizes microtubules more potently than paclitaxel despite the lack of any obvious structural similarities between the drugs. It competitively inhibits the binding of paclitaxel to tubulin polymers, hypernucleates microtubule assembly more potently than paclitaxel, and inhibits the growth of paclitaxel-resistant ovarian and colon carcinoma cells. Because paclitaxel shows clinical promise for breast cancer treatment, its effects in a series of human breast cancer cells were compared to those of (+)-discodermolide. Growth inhibition, cell and nuclear morphological, and electrophoretic and flow cytometric analyses were performed on (+)-discodermolide-treated MCF-7 and MDA-MB231 cells. (+)-Discodermolide potently inhibited the growth of both cell types (IC50 Discodermolide-treated cells exhibited condensed and highly fragmented nuclei. Flow cytometric comparison of cells treated with either drug at 10 nM, a concentration well below that achieved clinically with paclitaxel, showed both caused cell cycle perturbation and induction of a hypodiploid cell population. (+)-Discodermolide caused these effects more extensively and at earlier time points. The timing and type of high molecular weight DNA fragmentation induced by the two agents was consistent with induction of apoptosis. The results suggest that (+)-discodermolide has promise as a new chemotherapeutic agent against breast and other cancers.

  6. ABCB1 (MDR1) induction defines a common resistance mechanism in paclitaxel- and olaparib-resistant ovarian cancer cells.

    Science.gov (United States)

    Vaidyanathan, Aparajitha; Sawers, Lynne; Gannon, Anne-Louise; Chakravarty, Probir; Scott, Alison L; Bray, Susan E; Ferguson, Michelle J; Smith, Gillian

    2016-08-09

    Clinical response to chemotherapy for ovarian cancer is frequently compromised by the development of drug-resistant disease. The underlying molecular mechanisms and implications for prescription of routinely prescribed chemotherapy drugs are poorly understood. We created novel A2780-derived ovarian cancer cell lines resistant to paclitaxel and olaparib following continuous incremental drug selection. MTT assays were used to assess chemosensitivity to paclitaxel and olaparib in drug-sensitive and drug-resistant cells±the ABCB1 inhibitors verapamil and elacridar and cross-resistance to cisplatin, carboplatin, doxorubicin, rucaparib, veliparib and AZD2461. ABCB1 expression was assessed by qRT-PCR, copy number, western blotting and immunohistochemical analysis and ABCB1 activity assessed by the Vybrant and P-glycoprotein-Glo assays. Paclitaxel-resistant cells were cross-resistant to olaparib, doxorubicin and rucaparib but not to veliparib or AZD2461. Resistance correlated with increased ABCB1 expression and was reversible following treatment with the ABCB1 inhibitors verapamil and elacridar. Active efflux of paclitaxel, olaparib, doxorubicin and rucaparib was confirmed in drug-resistant cells and in ABCB1-expressing bacterial membranes. We describe a common ABCB1-mediated mechanism of paclitaxel and olaparib resistance in ovarian cancer cells. Optimal choice of PARP inhibitor may therefore limit the progression of drug-resistant disease, while routine prescription of first-line paclitaxel may significantly limit subsequent chemotherapy options in ovarian cancer patients.

  7. Salvianolic acid A reverses paclitaxel resistance in human breast cancer MCF-7 cells via targeting the expression of transgelin 2 and attenuating PI3 K/Akt pathway.

    Science.gov (United States)

    Cai, Jiangxia; Chen, Siying; Zhang, Weipeng; Zheng, Xiaowei; Hu, Sasa; Pang, Chengsen; Lu, Jun; Xing, Jianfeng; Dong, Yalin

    2014-10-15

    Chemotherapy resistance represents a major problem for the treatment of patients with breast cancer and greatly restricts the use of first-line chemotherapeutics paclitaxel. The purpose of this study was to investigate the role of transgelin 2 in human breast cancer paclitaxel resistance cell line (MCF-7/PTX) and the reversal mechanism of salvianolic acid A (SAA), a phenolic active compound extracted from Salvia miltiorrhiza. Western blotting and real-time quantitative polymerase chain reaction (qRT-PCR) indicated that transgelin 2 may mediate paclitaxel resistance by activating the phosphatidylinositol 3-kinase (PI3 K)/Akt signaling pathway to suppress MCF-7/PTX cells apoptosis. The reversal ability of SAA was confirmed by MTT assay and flow cytometry, with a superior 9.1-fold reversal index and enhancement of the apoptotic cytotoxicity induced by paclitaxel. In addition, SAA effectively prevented transgelin 2 and adenosine-triphosphate binding cassette transporter (ABC transporter) including P-glycoprotein (P-gp), multidrug resistance associated protein 1 (MRP1), and breast cancer resistance protein (BCRP) up-regulation and exhibited inhibitory effect on PI3 K/Akt signaling pathway in MCF-7/PTX cells. Taken together, SAA can reverse paclitaxel resistance through suppressing transgelin 2 expression by mechanisms involving attenuation of PI3 K/Akt pathway activation and ABC transporter up-regulation. These results not only provide insight into the potential application of SAA in reversing paclitaxel resistance, thus facilitating the sensitivity of breast cancer chemotherapy, but also highlight a potential role of transgelin 2 in the development of paclitaxel resistance in breast cancer.

  8. Rescue of tau-induced synaptic transmission pathology by paclitaxel

    Directory of Open Access Journals (Sweden)

    Hdas eErez

    2014-02-01

    Full Text Available Behavioral and electrophysiological studies of Alzheimer’s disease (AD and other tauopathies have revealed that the onset of cognitive decline correlates better with synaptic dysfunctions than with hallmark pathologies such as extracellular amyloid-β plaques, intracellular hyperphosphorylated tau or neuronal loss. Recent experiments have also demonstrated that anti-cancer microtubule-stabilizing drugs can rescue tau-induced behavioral decline and hallmark neuron pathologies. Nevertheless, the mechanisms underlying tau-induced synaptic dysfunction as well as those involved in the rescue of cognitive decline by microtubules stabilizing drugs remain unclear. Here we began to study these mechanisms using the glutaminergic sensory-motoneuron synapse derived from Aplysia ganglia, electrophysiological methods, the expression of mutant-human-tau (mt-htau either pre- or post-synaptically and the antimitotic drug paclitaxel. Expression of mt-htau in the presynaptic neurons led to reduced excitatory postsynaptic potential (EPSP amplitude generated by rested synapses within 3 days of mt-htau expression, and to deeper levels of homosynaptic depression. mt-htau-induced synaptic weakening correlated with reduced releasable presynaptic vesicle pools as revealed by the induction of asynchronous neurotransmitter release by hypertonic sucrose solution. Paclitaxel totally rescued tau-induced synaptic weakening by maintaining the availability of the presynaptic vesicle stores. Postsynaptic expression of mt-htau did not impair the above described synaptic-transmission parameters for up to 5 days. Along with earlier confocal microscope observations from our laboratory, these findings suggest that tau-induced synaptic dysfunction is the outcome of impaired axoplasmic transport and the ensuing reduction in the releasable presynaptic vesicle stores rather than the direct effects of mt-htau or paclitaxel on the synaptic release mechanisms.

  9. Paclitaxel-induced peripheral neuropathy increases substance P release in rat spinal cord.

    Science.gov (United States)

    Chiba, Terumasa; Oka, Yusuke; Kambe, Toshie; Koizumi, Naoya; Abe, Kenji; Kawakami, Kazuyoshi; Utsunomiya, Iku; Taguchi, Kyoji

    2016-01-05

    Peripheral neuropathy is a common adverse effect of paclitaxel treatment. The major dose-limiting side effect of paclitaxel is peripheral sensory neuropathy, which is characterized by painful paresthesia of the hands and feet. To analyze the contribution of substance P to the development of paclitaxel-induced mechanical hyperalgesia, substance P expression in the superficial layers of the rat spinal dorsal horn was analyzed after paclitaxel treatment. Behavioral assessment using the von Frey test and the paw thermal test showed that intraperitoneal administration of 2 and 4mg/kg paclitaxel induced mechanical allodynia/hyperalgesia and thermal hyperalgesia 7 and 14 days after treatment. Immunohistochemistry showed that paclitaxel (4mg/kg) treatment significantly increased substance P expression (37.6±3.7% on day 7, 43.6±4.6% on day 14) in the superficial layers of the spinal dorsal horn, whereas calcitonin gene-related peptide (CGRP) expression was unchanged. Moreover, paclitaxel (2 and 4mg/kg) treatment significantly increased substance P release in the spinal cord on day 14. These results suggest that paclitaxel treatment increases release of substance P, but not CGRP in the superficial layers of the spinal dorsal horn and may contribute to paclitaxel-induced painful peripheral neuropathy.

  10. Identification of the first inhibitor of the GBP1:PIM1 interaction. Implications for the development of a new class of anticancer agents against paclitaxel resistant cancer cells.

    Science.gov (United States)

    Andreoli, Mirko; Persico, Marco; Kumar, Ajay; Orteca, Nausicaa; Kumar, Vineet; Pepe, Antonella; Mahalingam, Sakkarapalayam; Alegria, Antonio E; Petrella, Lella; Sevciunaite, Laima; Camperchioli, Alessia; Mariani, Marisa; Di Dato, Antonio; Novellino, Ettore; Scambia, Giovanni; Malhotra, Sanjay V; Ferlini, Cristiano; Fattorusso, Caterina

    2014-10-09

    Class III β-tubulin plays a prominent role in the development of drug resistance to paclitaxel by allowing the incorporation of the GBP1 GTPase into microtubules. Once in the cytoskeleton, GBP1 binds to prosurvival kinases such as PIM1 and initiates a signaling pathway that induces resistance to paclitaxel. Therefore, the inhibition of the GBP1:PIM1 interaction could potentially revert resistance to paclitaxel. A panel of 44 4-azapodophyllotoxin derivatives was screened in the NCI-60 cell panel. The result is that 31 are active and the comparative analysis demonstrated specific activity in paclitaxel-resistant cells. Using surface plasmon resonance, we were able to prove that NSC756093 is a potent in vitro inhibitor of the GBP1:PIM1 interaction and that this property is maintained in vivo in ovarian cancer cells resistant to paclitaxel. Through bioinformatics, molecular modeling, and mutagenesis studies, we identified the putative NSC756093 binding site at the interface between the helical and the LG domain of GBP1. According to our results by binding to this site, the NSC756093 compound is able to stabilize a conformation of GBP1 not suitable for binding to PIM1.

  11. Severe hyponatremia caused by nab-paclitaxel-induced syndrome of inappropriate antidiuretic hormone secretion

    Science.gov (United States)

    Neuzillet, Cindy; Babai, Samy; Kempf, Emmanuelle; Pujol, Géraldine; Rousseau, Benoît; Le-Louët, Hervé; Christophe Tournigand

    2016-01-01

    Abstract Incidence of pancreatic ductal adenocarcinoma (PDAC) is increasing. Most patients have advanced disease at diagnosis and therapeutic options in this setting are limited. Gemcitabine plus nab-paclitaxel regimen was demonstrated to increase survival compared with gemcitabine monotherapy and is therefore indicated as first-line therapy in patients with metastatic PDAC and performance status Eastern Cooperative Oncology Group (ECOG) 0-2. The safety profile of gemcitabine and nab-paclitaxel combination includes neutropenia, fatigue, and neuropathy as most common adverse events of grade 3 or higher. No case of severe hyponatremia associated with the use of nab-paclitaxel for the treatment of PDAC has been reported to date. We report the case of a 72-year-old Caucasian man with a metastatic PDAC treated with gemcitabine and nab-paclitaxel regimen, who presented with a severe hyponatremia (grade 4) caused by a documented syndrome of inappropriate antidiuretic hormone secretion (SIADH). This SIADH was attributed to nab-paclitaxel after a rigorous imputability analysis, including a rechallenge procedure with dose reduction. After dose and schedule adjustment, nab-paclitaxel was pursued without recurrence of severe hyponatremia and with maintained efficacy. Hyponatremia is a rare but potentially severe complication of nab-paclitaxel therapy that medical oncologists and gastroenterologists should be aware of. Nab-paclitaxel-induced hyponatremia is manageable upon dose and schedule adaptation, and should not contraindicate careful nab-paclitaxel reintroduction. This is of particular interest for a disease in which the therapeutic options are limited. PMID:27368013

  12. Role of cytochrome P450 2C8*3 (CYP2C8*3) in paclitaxel metabolism and paclitaxel-induced neurotoxicity

    DEFF Research Database (Denmark)

    Lee, Mi-Young; Apellániz-Ruiz, María; Johansson, Inger

    2015-01-01

    AIM: The CYP2C8*3 allele has been suggested as a risk factor for paclitaxel-induced neuropathy but the data hitherto published are conflicting. MATERIALS & METHODS: In total 435 patients were investigated with respect to maximum neuropathy grade and accumulated paclitaxel dose. The enzymatic prop...

  13. Acquisition of paclitaxel resistance is associated with a more aggressive and invasive phenotype in prostate cancer.

    Science.gov (United States)

    Kim, John J; Yin, Bo; Christudass, Christhunesa S; Terada, Naoki; Rajagopalan, Krithika; Fabry, Ben; Lee, Danielle Y; Shiraishi, Takumi; Getzenberg, Robert H; Veltri, Robert W; An, Steven S; Mooney, Steven M

    2013-06-01

    Drug resistance is a major limitation to the successful treatment of advanced prostate cancer (PCa). Patients who have metastatic, castration-resistant PCa (mCRPC) are treated with chemotherapeutics. However, these standard therapy modalities culminate in the development of resistance. We established paclitaxel resistance in a classic, androgen-insensitive mCRPC cell line (DU145) and, using a suite of molecular and biophysical methods, characterized the structural and functional changes in vitro and in vivo that are associated with the development of drug resistance. After acquiring paclitaxel-resistance, cells exhibited an abnormal nuclear morphology with extensive chromosomal content, an increase in stiffness, and faster cytoskeletal remodeling dynamics. Compared with the parental DU145, paclitaxel-resistant (DU145-TxR) cells became highly invasive and motile in vitro, exercised greater cell traction forces, and formed larger and rapidly growing tumors in mouse xenografts. Furthermore, DU145-TxR cells showed a discrete loss of keratins but a distinct gain of ZEB1, Vimentin and Snail, suggesting an epithelial-to-mesenchymal transition. These findings demonstrate, for the first time, that paclitaxel resistance in PCa is associated with a trans-differentiation of epithelial cell machinery that enables more aggressive and invasive phenotype and portend new strategies for developing novel biomarkers and effective treatment modalities for PCa patients. Copyright © 2012 Wiley Periodicals, Inc.

  14. Effect of Thai plant extracts on P-glycoprotein function and viability in paclitaxel-resistant HepG2 cells.

    Science.gov (United States)

    Kawami, Masashi; Yumoto, Ryoko; Nagai, Junya; Junyaprasert, Varaporn Buraphacheep; Soonthornchareonnon, Noppamas; Patanasethanont, Denpong; Sripanidkulchai, Bung-orn; Takano, Mikihisa

    2010-01-01

    The effects of ethanol extracts from Thai plants on P-glycoprotein (P-gp) function and cell viability were examined using paclitaxel-resistant HepG2 (PR-HepG2) cells. KP018 from Ellipeiopsis cherrevensis and AT80 from Ancistrocladus tectorius increased both rhodamine 123, a typical P-gp substrate, and [(3)H]paclitaxel uptake in PR-HepG2 cells. However, some extracts such as MT80 from Microcos tomentosa increased rhodamine 123, but not [(3)H]paclitaxel, uptake, while MM80 from Micromelum minutum increased only [(3)H]paclitaxel uptake. Thus, the effects of extracts of Thai plants on rhodamine 123 uptake were not necessarily the same as those on [(3)H]paclitaxel uptake. Purified compounds such as bergapten did not affect the uptake of either substrate. KP018, AT80, and MM80 increased [(3)H]paclitaxel uptake and decreased the cell viability in a concentration-dependent manner. Among these extracts, KP018 showed the most potent cytotoxicity. The cytotoxic potency of KP018 on PR-HepG2 cells was similar to that on wild-type HepG2 cells, and was not potentiated by verapamil. At concentrations resulting in no cytotoxicity, AT80 and MM80 potentiated paclitaxel-induced cytotoxicity in PR-HepG2 cells. These results indicate that K018 may be a useful source to search for a new anticancer drug, while AT80 and MM80 may be useful as modulators of P-gp-mediated multidrug resistance in cancer cells.

  15. Drug-induced immune hemolytic anemia associated with albumin-bound paclitaxel.

    Science.gov (United States)

    Thomas, Roby; Shillingburg, Alexandra

    2015-08-01

    Drug-induced immune hemolytic anemia (DIIHA) is rare, with only 1 patient in 1 million affected by the condition.1 Garratty identified 125 drugs indicated in DIIHA of which 11% were antineoplastic agents, and neither paclitaxel nor albumin-bound paclitaxel were included.2 In addition, we did not find any reports in our own search of the literature. Taxanes are known to cause anemia as a result of their myelosuppressive effects, but an immune hemolysis is rare. To our knowledge, we present here the first case of DIIHA with nab-paclitaxel.

  16. Prevention of Paclitaxel-Induced Neuropathy Through Activation of the Central Cannabinoid Type 2 Receptor System

    Science.gov (United States)

    Naguib, Mohamed; Xu, Jijun J.; Diaz, Philippe; Brown, David L.; Cogdell, David; Bie, Bihua; Hu, Jianhua; Craig, Suzanne; Hittelman, Walter N.

    2012-01-01

    Background Peripheral neuropathy is a major dose-limiting toxicity of chemotherapy, especially after multiple courses of paclitaxel. The development of paclitaxel-induced neuropathy is associated with the activation of microglia followed by the activation and proliferation of astrocytes, and the expression and release of proinflammatory cytokines in the spinal dorsal horn. Cannabinoid type 2 (CB2) receptors are expressed in the microglia in neurodegenerative disease models. Methods To explore the potential of CB2 agonists for preventing paclitaxel-induced neuropathy, we designed and synthesized a novel CB2-selective agonist, namely MDA7. The effect of MDA7 in preventing paclitaxel-induced allodynia was assessed in rats and in CB2+/+ and CB2–/– mice. We hypothesize that the CB2 receptor functions in a negative-feedback loop and that early MDA7 administration can blunt the neuroinflammatory response to paclitaxel and prevent mechanical allodynia through interference with specific signaling pathways. Results We found that MDA7 prevents paclitaxel-induced mechanical allodynia in rats and mice in a dose- and time-dependent manner without compromising paclitaxel's antineoplastic effect. MDA7's neuroprotective effect was absent in CB2-/- mice and was blocked by CB2 antagonists, suggesting that MDA7's action directly involves CB2 receptor activation. MDA7 treatment was found to interfere with early events in the paclitaxel-induced neuroinflammatory response as evidenced by relatively reduced Toll-like receptor and CB2 expression in the lumbar spinal cord, reduced levels of extracellular signal regulated kinase 1/2 activity, reduced numbers of activated microglia and astrocytes, and reduced secretion of proinflammatory mediators in vivo and in in vitro models. Conclusions Our findings suggest an innovative therapeutic approach to prevent chemotherapy-induced neuropathy and may permit more aggressive use of active chemotherapeutic regimens with reduced long-term sequelae

  17. Low expression of SLOOP associated with paclitaxel resistance in ovarian cancer cell line

    Institute of Scientific and Technical Information of China (English)

    GAO Jian-hua; HE Zhi-juan; WANG Qi; LI Xin; LI Yi-xuan; LIU Min; ZHENG Jian-hua; TANG Hua

    2008-01-01

    Background Recent studies indicate that Sl 00P expression may be a biomarker that can predict the success of cancer chemotherapy. Whether it is relevant to chemOtherapeutics in ovarian cancer is unknown.In this study,we investigated the association of S1OOP expression with paclitaxel sensitivity in ovarian cancer cell lines.Methods We measured S1 OOP expression and paclitaxel resistance profiles in parent SKOV3 and OVCAH3 cell lines.Then,the two cell lines were transiently transfected with SlOOP siRNA.We also constructed an OVCAR3 cell clone that stably overexpressed SIOOP The effect of S100P expression level on the survival of cells exposed to paclitaxel was measured using the MTT assav.S1OOP expression was evaluated by semi-quantitative RT.PCR and Western blotting.Significance of differences was calculated using independent samples t-test and one way analysis of variance(ANOVA).Results Lower S1 00P expression was associated with a survival advantage in OVCAR3 cells exposed to paclitaxel;the survival advantage in SKOV3 cells was smaller Presistance to paclitaxel in ovarian cancer cell lines.S100P expression thus might be a marker that can predict the effectiveness of paclitaxel based chemotherapy.Such a marker could be helpful in improving individual medication regimens for ovarian cancer patients.

  18. Overcoming paclitaxel resistance in lung cancer cells via dual inhibition of stathmin and Bcl-2.

    Science.gov (United States)

    Han, Zheng-Xiang; Wang, Hong-Mei; Jiang, Guan; Du, Xiu-Ping; Gao, Xiang-Yang; Pei, Dong-Sheng

    2013-06-01

    Lung cancer is the leading cause of death from malignancy in people and over 85% of these patients eventually die from disseminated disease. Paclitaxel (TAX) is widely used as an antimicrotubule agent for the treatment of lung cancer. Unfortunately, the resistance to this antimicrotubule agent occurs frequently. Stathmin (STMN1) is a ubiquitous microtubule destabilizing protein linked to cancer and cell health and its expression level often correlates with cancer stage progression and prognosis for survival. Overexpression of the antiapoptotic protein Bcl-2 has been shown to prolong drug-induced growth arrest, potentially inducing resistance. In this study, we used a short hairpin RNA (shRNA) approach to evaluate the effect of STMN1 and Bcl-2 downregulation in the sensitivity to TAX in lung cancer cells. We achieved significant downregulation of STMN1 and Bcl-2 mRNA and protein expression by a combination of double shRNA treatment strategy. Our experimental data showed that inhibition of STMN1 and Bcl-2 expression with RNA interference can sensitize lung cancer cells to TAX. These findings suggest a novel approach to improve the efficacy of certain antimicrotubule agents against lung cancer by regulating the function of STMN1 and Bcl-2.

  19. Drug-induced subacute cutaneous lupus erythematosus associated with nab-paclitaxel therapy.

    Science.gov (United States)

    Lamond, N W D; Younis, T; Purdy, K; Dorreen, M S

    2013-10-01

    Drug-induced lupus erythematosus (dile) syndromes are documented complications of chemotherapeutic agents, including paclitaxel. Subacute cutaneous lupus erythematosus (scle) is a distinct dile syndrome presenting with characteristic annular or papulosquamous skin lesions in a photosensitive distribution with associated high anti-ssa titres. Previously, dile syndromes complicating paclitaxel therapy have been attributed to polyethoxylated castor oil (Kolliphor EL: BASF, Ludwigshafen, Germany), the biologic solvent included in the drug's original formulation (Taxol: Bristol-Myers Squibb, Montreal, QC), rather than the parent chemotherapy molecule. Here, we report a characteristic case of drug-induced scle complicating treatment with nanoparticle albumin bound (nab)-paclitaxel (Abraxane: Celgene, Summit, NJ, U.S.A.), a solvent-free taxane formulation. The pertinent English-language literature is also discussed. This case report is the first to link solvent-free paclitaxel with scle, and it suggests that the parent molecule is responsible for the reaction.

  20. Differentially expressed proteins in human breast cancer cells sensitive and resistant to paclitaxel.

    Science.gov (United States)

    Pavlikova, Nela; Bartonova, Irena; Dincakova, Lucia; Halada, Petr; Kovar, Jan

    2014-08-01

    The resistance of cancer cells to chemotherapeutic drugs represents a major problem in cancer treatment. Despite all efforts, mechanisms of resistance have not yet been elucidated. To reveal proteins that could be involved in resistance to taxanes, we compared protein expression in whole cell lysates of SK-BR-3 breast cancer cells sensitive to paclitaxel and in lysates of the same line with acquired resistance to paclitaxel. The resistant SK-BR-3 cell line was established in our lab. Protein separation was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectro-metry. With these techniques we identified four proteins with different expression in resistant SK-BR-3 cells, i.e., serpin B3, serpin B4, heat shock protein 27 (all three upregulated) and cytokeratin 18 (downregulated). Observed changes were confirmed using western blot analysis. This study suggests new directions worthy of further study in the effort to reveal the mechanism of resistance to paclitaxel in breast cancer cells.

  1. Inhibition of Notch signaling in combination with paclitaxel reduces platinum-resistant ovarian tumor growth

    Directory of Open Access Journals (Sweden)

    Jolijn W Groeneweg

    2014-07-01

    Full Text Available Introduction: Ovarian cancer (OvCa is the most lethal gynecologic malignancy in the United States because of chemoresistant recurrent disease. Our objective was to investigate the efficacy of inhibiting the Notch pathway with a gamma-secretase inhibitor (GSI in an OvCa patient derived xenograft (PDX model as a single agent therapy and in combination with standard chemotherapy.Methods: Immunocompromised mice bearing xenografts derived from clinically platinum sensitive human ovarian serous carcinomas were treated with vehicle, GSI (MRK-003 alone, paclitaxel and carboplatin (P/C alone, or the combination of GSI and P/C. Mice bearing platinum resistant xenografts were given GSI with or without paclitaxel. Gene transcript levels of the Notch pathway target Hes1 were analyzed using RT-PCR. Notch1 and Notch3 protein levels were evaluated. The Wilcoxon rank-sum test was used to assess significance between the different treatment groups. Results: Expression of Notch1 and 3 was variable. GSI alone decreased tumor growth in two of three platinum sensitive ovarian tumors (p < 0.05, as well as in one of three platinum sensitive tumors (p = 0.04. The combination of GSI and paclitaxel was significantly more effective than GSI alone and paclitaxel alone in all platinum resistant ovarian tumors (all p <0.05. The addition of GSI did not alter the effect of P/C in platinum sensitive tumors. Interestingly, although the response of each tumor to chronic GSI exposure did not correlate with its endogenous level of Notch expression, GSI did negatively affect Notch signaling in an acute setting.Conclusions: Inhibiting the Notch signaling cascade with a GSI reduces primary human xenograft growth in vivo. GSI synergized with conventional cytotoxic chemotherapy only in the platinum resistant OvCa models with single agent paclitaxel. These findings suggest inhibition of the Notch pathway in concert with taxane therapy may hold promise for treatment of platinum resistant OvCa.

  2. Differentially expressed proteins in human MCF-7 breast cancer cells sensitive and resistant to paclitaxel.

    Science.gov (United States)

    Pavlíková, Nela; Bartoňová, Irena; Balušíková, Kamila; Kopperova, Dana; Halada, Petr; Kovář, Jan

    2015-04-10

    Resistance of cancer cells to chemotherapeutic agents is one of the main causes of treatment failure. In order to detect proteins potentially involved in the mechanism of resistance to taxanes, we assessed differences in protein expression in MCF-7 breast cancer cells that are sensitive to paclitaxel and in the same cells with acquired resistance to paclitaxel (established in our lab). Proteins were separated using two-dimensional electrophoresis. Changes in their expression were determined and proteins with altered expression were identified using mass spectrometry. Changes in their expression were confirmed using western blot analysis. With these techniques, we found three proteins expressed differently in resistant MCF-7 cells, i.e., thyroid hormone-interacting protein 6 (TRIP6; upregulated to 650%), heat shock protein 27 (HSP27; downregulated to 50%) and cathepsin D (downregulated to 28%). Silencing of TRIP6 expression by specific siRNA leads to decreased number of grown resistant MCF-7 cells. In the present study we have pointed at some new directions in the studies of the mechanism of resistance to paclitaxel in breast cancer cells.

  3. PLGA nanoparticles codeliver paclitaxel and Stat3 siRNA to overcome cellular resistance in lung cancer cells

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    Su WP

    2012-08-01

    Full Text Available Wen-Pin Su,1,2 Fong-Yu Cheng,3 Dar-Bin Shieh,3–6 Chen-Sheng Yeh,5–7 Wu-Chou Su1,2,81Graduate Institute of Clinical Medicine, College of Medicine, National Cheng Kung University; 2Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University; 3Institute of Oral Medicine, College of Medicine, National Cheng Kung University; 4Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University; 5Advanced Optoelectronic Technology Center; 6Center for Frontier Materials and Micro/Nano Science and Technology, and 7Department of Chemistry, National Cheng Kung University; 8Cancer Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.Abstract: Background: Effective cancer chemotherapy remains an important issue in cancer treatment, and signal transducer and activator of transcription-3 (Stat3 activation leads to cellular resistance of anticancer agents. Polymers are ideal vectors to carry both chemotherapeutics and small interfering ribonucleic acid (siRNA to enhance antitumor efficacy. In this paper, poly(lactic-co-glycolic acid (PLGA nanoparticles loaded with paclitaxel and Stat3 siRNA were successfully synthesized, and their applications in cancer cells were investigated.Methods: Firstly, paclitaxel was enclosed by PLGA nanoparticles through solvent evaporation. They were then coated with cationic polyethylenimine polymer (PLGA-PEI-TAX, enabling it to carry Stat3 siRNA on its surface through electrostatic interactions (PLGA-PEI-TAX-S3SI. The size, zeta potential, deliver efficacy, and release profile of the PLGA nanocomplexes were characterized in vitro. The cellular uptake, intracellular nanoparticle trajectory, and subsequent cellular events were evaluated after treatment with various PLGA nanocomplexes in human lung cancer A549 cells and A549-derived paclitaxel-resistant

  4. Prediction of paclitaxel resistance in breast cancer: is CYP1B1*3 a new factor of influence?

    Science.gov (United States)

    Gehrmann, Mathias; Schmidt, Markus; Brase, Jan C; Roos, Peter; Hengstler, Jan G

    2008-07-01

    This article focuses on the recent findings by Marsh and colleagues, and also discusses recent findings with regards to breast cancer. Taxanes are amongst the most active agents in the treatment of breast cancer. However, many tumors are intrinsically resistant. Therefore, it would be an enormous progress, if factors could be identified that reliably differentiate between taxane-sensitive and -resistant patients. Marsh and colleagues analyzed the CYP1B1*3 (Val432Leu) polymorphism in patients with high-risk stage III and IV breast cancer, who received dose-intense paclitaxel in combination with doxorubicin and cyclophosphamide. They report for the first time that patients with two leucine alleles in codon 432 of CYP1B1 experience a longer progression-free survival compared with patients with the Val/Leu or Val/Val genotypes. If confirmed in independent cohorts CYP1B1*3 may prove to be an important factor that helps to differentiate between paclitaxel-sensitive and resistant breast cancer patients. However, the mechanism behind the association between CYP1B1*3 and prognosis of paclitaxel-treated patients remains unclear. Several studies provide strong evidence that CYP1B1 does not influence tumor progression independently from paclitaxel chemotherapy, and that CYP1B1 itself does not alter paclitaxel resistance. In addition, CYP1B1 mRNA expression does not correlate with paclitaxel sensitivity of primary tumor cells. Although still speculative, a possible explanation is an association between CYP1B1*3 with still unknown factors that, on their part, influence paclitaxel sensitivity. In the future, studies with SNP chips and studies on the transcriptome, proteome and metabolome level should be performed in order to identify signatures differentiating between paclitaxel-sensitive and -resistant patients.

  5. Dual blockade of phosphatidylinositol 3'-kinase and mitogen-activated protein kinase pathways overcomes paclitaxel-resistance in colorectal cancer.

    Science.gov (United States)

    Xu, Rui; Nakano, Kenji; Iwasaki, Hironori; Kumagai, Michiaki; Wakabayashi, Rie; Yamasaki, Akio; Suzuki, Hiroyuki; Mibu, Ryuichi; Onishi, Hideya; Katano, Mitsuo

    2011-07-28

    Paclitaxel, one of key drugs to treat a wide range of malignancies, exhibits relative low sensitivity for colorectal cancer. The present study was to examine whether and how phosphatidylinositol 3'-kinase (PI3K) signals affect the sensitivity of colorectal cancer to paclitaxel. Four colorectal cancer cell lines were exposed to paclitaxel in the presence of PI3K signal inhibitors, such as LY294002, siRNA for Akt, or rapamycin, with or without MAPK inhibitor, PD98059. Cell viability and apoptosis were determined by MTT assay, cell cycle analysis in flow cytometer and Hoechst nuclear staining. To analyze the PI3K activity, the expression in phosphorylated Akt and downstream effectors of p70S6 kinase (S6K) were evaluated by Western blot analysis. Paclitaxel alone (5-10 nM) did not induce the apoptosis in all four cell lines. Although LY294002 alone did not affect the cell viability, it suppressed the Akt and S6K activities and induced the sub-G1 arrest/apoptosis when paclitaxel was co-administered, as well as the Akt siRNA and rapamycin did. Simultaneous blockade of PI3K and MAPK pathways more suppressed the S6K activity and further increased the apoptosis. In conclusion, PI3K is involved in low susceptibility of colorectal cancer to paclitaxel and dual PI3K/MAPK targeting agents may evolve a new paclitaxel-based chemotherapy for colorectal cancer.

  6. Enhanced combination therapy effect on paclitaxel-resistant carcinoma by chloroquine co-delivery via liposomes

    Directory of Open Access Journals (Sweden)

    Gao MH

    2015-10-01

    Full Text Available Menghua Gao,1 Yuzhen Xu,1 Liyan Qiu2,3 1College of Pharmaceutical Sciences, 2Ministry of Education (MOE Key Laboratory of Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 3Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Abstract: A novel composite liposomal system co-encapsulating paclitaxel (PTX with chloroquine phosphate (CQ was designed for treating PTX-resistant carcinoma. It was confirmed that liposomal CQ can sensitize PTX by means of autophagy inhibition and competitively binding with multidrug-resistance transporters. Furthermore, according to the in vitro cytotoxicity and apoptosis assay, real-time observation of cellular uptake, and in vivo tissue distribution study, co-encapsulation of PTX and CQ in liposomes was validated as superior to the mixture of PTX liposome plus CQ liposome due to the simultaneous delivery and synergetic effect of the two drugs. Consequently, this composite liposome achieved significantly stronger anticancer efficacy in vivo than the PTX liposome plus CQ liposome mixture. This study helps to guide and enlighten ongoing and future clinical trials about the optimal administration modes for drug combination therapy. Keywords: paclitaxel, chloroquine, liposome, drug resistance, combination therapy

  7. Minoxidil is a potential neuroprotective drug for paclitaxel-induced peripheral neuropathy

    Science.gov (United States)

    Chen, Yi-Fan; Chen, Li-Hsien; Yeh, Yu-Min; Wu, Pei-Ying; Chen, Yih-Fung; Chang, Lian-Yun; Chang, Jang-Yang; Shen, Meng-Ru

    2017-01-01

    Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment. No medication has been shown to be effective in the treatment of CIPN. This study aims to integrate the image-based high-content screening, mouse behavior models and mechanistic cell-based assays to discover potential neuroprotective drugs. Among screened compounds, minoxidil showed the most potent neuroprotective effect against paclitaxel, with regard to neurite outgrowth of dorsal root ganglia (DRG). Minoxidil protected mice from thermal insensitivity and alleviated mechanical allodynia in paclitaxel-treated mice. The ultrastructure and quantified G-ratio of myelin integrity of sciatic nerve tissues supported the observations in mouse behavioral tests. The mechanistic study on DRG neurons suggested that minoxidil suppressed neuroinflammation and remodeled the dysregulation of intracellular calcium homeostasis provoked by paclitaxel. Importantly, minoxidil showed a synergistic anti-tumor effect with paclitaxel both in tumor xenograft models of cervical and breast cancer. Interestingly, the quantitative assays on hair length and hair growth both exhibited that minoxidil significantly improved the hair quality after chemotherapy. Since minoxidil is a drug approved by the Food and Drug Administration (FDA), the safety and biocompatibility are well documented. The immediate next step is to launch an early-stage clinical trial intending to prevent CIPN by minoxidil. PMID:28349969

  8. Lansoprazole induces sensitivity to suboptimal doses of paclitaxel in human melanoma.

    Science.gov (United States)

    Azzarito, Tommaso; Venturi, Giulietta; Cesolini, Albino; Fais, Stefano

    2015-01-28

    Tumor acidity is now considered an important determinant of drug-resistance and tumor progression, and anti-acidic approaches, such as Proton Pump inhibitors (PPIs), have demonstrated promising antitumor and chemo-sensitizing efficacy. The main purpose of the present study was to evaluate the possible PPI-induced sensitization of human melanoma cells to Paclitaxel (PTX). Our results show that PTX and the PPI Lansoprazole (LAN) combination was extremely efficient against metastatic melanoma cells, as compared to the single treatments, both in vitro and in vivo. We also showed that acidity plays an important role on the anti-tumor activity of these drugs, being detrimental for PTX activity, while crucial for the synergistic effect of PTX following pretreatment with LAN, due to its nature of pro-drug needing protonation for a full activation. We obtained straightforward results in a human melanoma xenograft model combining well tolerated LAN doses with suboptimal and poorly toxic doses of PTX. With this study we provide a clear evidence that the PPI LAN may be included in new combined therapy of human melanoma together with low doses of PTX.

  9. Cell Division Cycle 6 Promotes Mitotic Slippage and Contributes to Drug Resistance in Paclitaxel-Treated Cancer Cells.

    Science.gov (United States)

    He, Yue; Yan, Daoyu; Zheng, Dianpeng; Hu, Zhiming; Li, Hongwei; Li, Jinlong

    2016-01-01

    Paclitaxel (PTX) is an antimitotic drug that possesses potent anticancer activity, but its therapeutic potential in the clinic has been hindered by drug resistance. Here, we report a mechanism by which cancer cells can exit from the PTX-induced mitotic arrest, i.e. mitotic slippage, and avoid subsequent death resulting in drug resistance. In cells experiencing mitotic slippage, Cdc6 protein level was significantly upregulated, Cdk1 activity was inhibited, and Cohesin/Rad21 was cleaved as a result. Cdc6 depletion by RNAi or Norcantharidin inhibited PTX-induced Cdc6 up-regulation, maintained Cdk1 activity, and repressed Cohesin/Rad21 cleavage. In all, this resulted in reduced mitotic slippage and reversal of PTX resistance. Moreover, in synchronized cells, the role of Cdc6 in mitotic exit under PTX pressure was also confirmed. This study indicates that Cdc6 may promote mitotic slippage by inactivation of Cdk1. Targeting of Cdc6 may serve as a promising strategy for enhancing the anticancer activity of PTX.

  10. Effect of ω-conotoxin MVIIA and Phα1β on paclitaxel-induced acute and chronic pain.

    Science.gov (United States)

    Rigo, Flávia K; Dalmolin, Gerusa D; Trevisan, Gabriela; Tonello, Raquel; Silva, Mariane A; Rossato, Mateus F; Klafke, Jonatas Z; Cordeiro, Marta do N; Castro Junior, Célio J; Montijo, Danuza; Gomez, Marcus V; Ferreira, Juliano

    2013-12-01

    The treatment with the chemotherapeutic agent paclitaxel produces a painful peripheral neuropathy, and is associated with an acute pain syndrome in a clinically significant number of patients. However, no standard therapy has been established to manage the acute pain or the chronic neuropathic pain related to paclitaxel. In the present study, we evaluated the analgesic potential of two N-type voltage-gated calcium channel (VGCC) blockers, ω-conotoxin MVIIA and Phα1β, on acute and chronic pain induced by paclitaxel. Adult male rats were treated with four intraperitoneal injections of paclitaxel (1+1+1+1mg/kg, in alternate days) and the development of mechanical hyperalgesia was evaluated 24h (acute painful stage) or 15days (chronic painful stage) after the first paclitaxel injection. Not all animals showed mechanical hyperalgesia 24h after the first paclitaxel injection, but those that showed developed a more intense mechanical hyperalgesia at the chronic painful stage. Intrathecal administration (i.t.) of ω-conotoxin MVIIA (3-300pmol/site) or Phα1β (10-300pmol/site) reduced the mechanical hyperalgesia either at the acute or at the chronic painful stage induced by paclitaxel. When administered at the acute painful stage, ω-conotoxin MVIIA (300pmol/site, i.t.) and Phα1β (300pmol/site, i.t.) prevented the worsening of chronic mechanical hyperalgesia. Furthermore, Phα1β (30-300pmol/site, i.t.) elicited less adverse effects than ω-conotoxin MVIIA (10-300 pmol/site, i.t.). Taken together, our data evidence the involvement of N-type VGCC in pain sensitization induced by paclitaxel and point out the potential of Phα1β as a safer alternative than ω-conotoxin MVIIA to treat the pain related to paclitaxel.

  11. Resistance to paclitaxel in a cisplatin-resistant ovarian cancer cell line is mediated by P-glycoprotein.

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    Britta Stordal

    Full Text Available The IGROVCDDP cisplatin-resistant ovarian cancer cell line is also resistant to paclitaxel and models the resistance phenotype of relapsed ovarian cancer patients after first-line platinum/taxane chemotherapy. A TaqMan low-density array (TLDA was used to characterise the expression of 380 genes associated with chemotherapy resistance in IGROVCDDP cells. Paclitaxel resistance in IGROVCDDP is mediated by gene and protein overexpression of P-glycoprotein and the protein is functionally active. Cisplatin resistance was not reversed by elacridar, confirming that cisplatin is not a P-glycoprotein substrate. Cisplatin resistance in IGROVCDDP is multifactorial and is mediated in part by the glutathione pathway and decreased accumulation of drug. Total cellular glutathione was not increased. However, the enzyme activity of GSR and GGT1 were up-regulated. The cellular localisation of copper transporter CTR1 changed from membrane associated in IGROV-1 to cytoplasmic in IGROVCDDP. This may mediate the previously reported accumulation defect. There was decreased expression of the sodium potassium pump (ATP1A, MRP1 and FBP which all have been previously associated with platinum accumulation defects in platinum-resistant cell lines. Cellular localisation of MRP1 was also altered in IGROVCDDP shifting basolaterally, compared to IGROV-1. BRCA1 was also up-regulated at the gene and protein level. The overexpression of P-glycoprotein in a resistant model developed with cisplatin is unusual. This demonstrates that P-glycoprotein can be up-regulated as a generalised stress response rather than as a specific response to a substrate. Mechanisms characterised in IGROVCDDP cells may be applicable to relapsed ovarian cancer patients treated with frontline platinum/taxane chemotherapy.

  12. Enhanced combination therapy effect on paclitaxel-resistant carcinoma by chloroquine co-delivery via liposomes.

    Science.gov (United States)

    Gao, Menghua; Xu, Yuzhen; Qiu, Liyan

    2015-01-01

    A novel composite liposomal system co-encapsulating paclitaxel (PTX) with chloroquine phosphate (CQ) was designed for treating PTX-resistant carcinoma. It was confirmed that liposomal CQ can sensitize PTX by means of autophagy inhibition and competitively binding with multidrug-resistance transporters. Furthermore, according to the in vitro cytotoxicity and apoptosis assay, real-time observation of cellular uptake, and in vivo tissue distribution study, co-encapsulation of PTX and CQ in liposomes was validated as superior to the mixture of PTX liposome plus CQ liposome due to the simultaneous delivery and synergetic effect of the two drugs. Consequently, this composite liposome achieved significantly stronger anticancer efficacy in vivo than the PTX liposome plus CQ liposome mixture. This study helps to guide and enlighten ongoing and future clinical trials about the optimal administration modes for drug combination therapy.

  13. CYP1B1 enhances the resistance of epithelial ovarian cancer cells to paclitaxel in vivo and in vitro.

    Science.gov (United States)

    Zhu, Zhuangyan; Mu, Yaqin; Qi, Caixia; Wang, Jian; Xi, Guoping; Guo, Juncheng; Mi, Ruoran; Zhao, Fuxi

    2015-02-01

    Ovarian cancer (OC) is the most frequent cause of mortality among gynecological malignancies, with a 5-year survival rate of approximately 30%. The standard regimen for OC therapy includes a platinum agent combined with a taxane, to which the patients frequently acquire resistance. Resistance arises from the oxidation of anticancer drugs by CYP1B1, a cytochrome P450 enzyme overexpressed in malignant OC. The aim of the present study was to determine the role of CYP1B1 expression in the drug resistance of OC to the taxane, paclitaxel (PTX). Immunohistochemical staining was used to assess CYP1B1 expression in a panel of ovarian samples (53 primary cancer samples, 14 samples of metastastic cancer, 30 benign tumor samples and 19 normal tissue samples). Semi-quantitative RT-PCR was also performed to determine CYP1B1 expression in several OC cell lines. Finally, we used proliferation and toxicity assays, as well as a mouse xenograft model using nude mice to determine whether α-naphthoflavone (ANF), a CYP1B1 specific inhibitor, reduces resistance to PTX. CYP1B1 was overexpressed in the samples from primary and metastatic loci of epithelial ovarian cancers. In some cell lines, PTX induced CYP1B1 expression, which resulted in drug resistance. Exposure to ANF reduced drug resistance and enhanced the sensitivity of OC cells to PTX in vitro and in vivo. The expression profile of CYP1B1 suggests that it has the potential to be a useful diagnostic marker and prognostic factor for malignant OC. The inhibition of CYP1B1 expression by specific agents may provide a novel therapeutic strategy for the treatment of patients resistant to PTX and may improve the prognosis of these patients.

  14. Dynamic long-term microstructural and ultrastructural alterations in sensory nerves of rats of paclitaxel-induced neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    Wu Yuan; Li Jun; Zhou Junfei; Feng Yi

    2014-01-01

    Background Paclitaxel,as a first line anti-neoplastic compound,frequently produces long-term pain after tumors have been treated.Clinical manifestations are varied and non-specific.Pathology of the nervous system during the development of the neuropathic pain is unclear.Thus,eady diagnosis and treatment is often unsatisfying for patients.This study aimed to promote considerate understanding of the structural alteration of sensory nerves.Methods All rats were simply randomized into 3 groups:paclitaxel group,vehicle group and saline group.An established rat model of paclitaxel-induced peripheral neuropathy (2 mg/kg) was chosen for our research,behavior tests were operated during the procedure of 56 days.All rats were sampled on days 0,3,7,28 and 56.The hind paw plantar skin,sciatic nerves,dorsal root ganglion and attached fibers,and lumbar spinal cord were processed for light and electron microscopy.The differences among 3 groups were analyzed with one-way analysis of vadance (ANOVA).Results We affirmed that paclitaxel-induced mechano-aliodynia and mechano-hyperalgesia occured after a 3-7-day delay,and this pain peaked at day 28 and persisted to day 56.Paclitaxel and vehicle treatment both evoked thermalhyperalgesia.Paclitaxel-induced axonal and myelin sheath degeneration was evident.At days 3 and 7,significant increases in atypical mitochondria in both myelinated axons and C-fibers of paclitaxel-treated nerves indicated that injured mitochondria correlated to specific paclitaxel-induced neuropathic pain,and the abnormity sustained till day 56.Microtubule was unaffected in myelinated axons or C-fibers in paclitaxel-or vehicle-treated rats.Significant increase of G ratio was evident with paclitaxel injection at days 7 and 28.Conclusion Our research suggests a causal role for axonal degeneration,abnormalities in axonal mitochondria,and structural modification of axonal microtubules in paclitaxel-induced neuropathic pain,and the abnormal mitochondria could be connected

  15. Nociceptor beta II, delta, and epsilon isoforms of PKC differentially mediate paclitaxel-induced spontaneous and evoked pain.

    Science.gov (United States)

    He, Ying; Wang, Zaijie Jim

    2015-03-18

    As one of the most effective and frequently used chemotherapeutic agents, paclitaxel produces peripheral neuropathy (paclitaxel-induced peripheral neuropathy or PIPN) that negatively affects chemotherapy and persists after cancer therapy. The mechanisms underlying this dose-limiting side effect remain to be fully elucidated. This study aimed to investigate the role of nociceptor protein kinase C (PKC) isoforms in PIPN. Employing multiple complementary approaches, we have identified a subset of PKC isoforms, namely βII, δ, and ϵ, were activated by paclitaxel in the isolated primary afferent sensory neurons. Persistent activation of PKCβII, PKCδ, and PKCϵ was also observed in the dorsal root ganglion neurons after chronic treatment with paclitaxel in a mouse model of PIPN. Isoform-selective inhibitors of PKCβII, PKCδ, and PKCϵ given intrathecally dose-dependently attenuated paclitaxel-induced mechanical allodynia and heat hyperalgesia. Surprisingly, spinal inhibition of PKCβII and PKCδ, but not PKCϵ, blocked the spontaneous pain induced by paclitaxel. These data suggest that a subset of nociceptor PKC isoforms differentially contribute to spontaneous and evoked pain in PIPN, although it is not clear whether PKCϵ in other regions regulates spontaneous pain in PIPN. The findings can potentially offer new selective targets for pharmacological intervention of PIPN.

  16. Assessment of paclitaxel induced sensory polyneuropathy with "Catwalk" automated gait analysis in mice.

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    Petra Huehnchen

    Full Text Available Neuropathic pain as a symptom of sensory nerve damage is a frequent side effect of chemotherapy. The most common behavioral observation in animal models of chemotherapy induced polyneuropathy is the development of mechanical allodynia, which is quantified with von Frey filaments. The data from one study, however, cannot be easily compared with other studies owing to influences of environmental factors, inter-rater variability and differences in test paradigms. To overcome these limitations, automated quantitative gait analysis was proposed as an alternative, but its usefulness for assessing animals suffering from polyneuropathy has remained unclear. In the present study, we used a novel mouse model of paclitaxel induced polyneuropathy to compare results from electrophysiology and the von Frey method to gait alterations measured with the Catwalk test. To mimic recently improved clinical treatment strategies of gynecological malignancies, we established a mouse model of dose-dense paclitaxel therapy on the common C57Bl/6 background. In this model paclitaxel treated animals developed mechanical allodynia as well as reduced caudal sensory nerve action potential amplitudes indicative of a sensory polyneuropathy. Gait analysis with the Catwalk method detected distinct alterations of gait parameters in animals suffering from sensory neuropathy, revealing a minimized contact of the hind paws with the floor. Treatment of mechanical allodynia with gabapentin improved altered dynamic gait parameters. This study establishes a novel mouse model for investigating the side effects of dose-dense paclitaxel therapy and underlines the usefulness of automated gait analysis as an additional easy-to-use objective test for evaluating painful sensory polyneuropathy.

  17. Salvianolic acid A reverses the paclitaxel resistance and inhibits the migration and invasion abilities of human breast cancer cells by inactivating transgelin 2.

    Science.gov (United States)

    Zheng, Xiaowei; Chen, Siying; Yang, Qianting; Cai, Jiangxia; Zhang, Weipeng; You, Haisheng; Xing, Jianfeng; Dong, Yalin

    2015-01-01

    Multidrug resistance and tumor migration and invasion are the major obstacles to effective breast cancer chemotherapy, but the underlying molecular mechanisms remain unclear. This study investigated the potential of transgelin 2 and salvianolic acid A to modulate the resistance and the migration and invasion abilities of paclitaxel-resistant human breast cancer cells (MCF-7/PTX). MCF-7/PTX cells were found to exhibit not only a high degree of resistance to paclitaxel, but also strong migration and invasion abilities. Small interfering RNA-mediated knockdown of TAGLN2 sensitized the MCF-7/PTX cells to paclitaxel, and inhibited their migration and invasion abilities. In addition, we also observed that combined salvianolic acid A and paclitaxel treatment could reverse paclitaxel resistance, markedly inhibit tumor migration and invasion, and suppress the expression of transgelin 2 in MCF-7/PTX cells. These findings indicate that salvianolic acid A can reverse the paclitaxel resistance and inhibit the migration and invasion abilities of human breast cancer cells by down-regulating the expression of transgelin 2, and hence could be useful in breast cancer treatments.

  18. Salvianolic acid A reverses the paclitaxel resistance and inhibits the migration and invasion abilities of human breast cancer cells by inactivating transgelin 2

    Science.gov (United States)

    Zheng, Xiaowei; Chen, Siying; Yang, Qianting; Cai, Jiangxia; Zhang, Weipeng; You, Haisheng; Xing, Jianfeng; Dong, Yalin

    2015-01-01

    Multidrug resistance and tumor migration and invasion are the major obstacles to effective breast cancer chemotherapy, but the underlying molecular mechanisms remain unclear. This study investigated the potential of transgelin 2 and salvianolic acid A to modulate the resistance and the migration and invasion abilities of paclitaxel-resistant human breast cancer cells (MCF-7/PTX). MCF-7/PTX cells were found to exhibit not only a high degree of resistance to paclitaxel, but also strong migration and invasion abilities. Small interfering RNA-mediated knockdown of TAGLN2 sensitized the MCF-7/PTX cells to paclitaxel, and inhibited their migration and invasion abilities. In addition, we also observed that combined salvianolic acid A and paclitaxel treatment could reverse paclitaxel resistance, markedly inhibit tumor migration and invasion, and suppress the expression of transgelin 2 in MCF-7/PTX cells. These findings indicate that salvianolic acid A can reverse the paclitaxel resistance and inhibit the migration and invasion abilities of human breast cancer cells by down-regulating the expression of transgelin 2, and hence could be useful in breast cancer treatments PMID:26176734

  19. Role of granulocyte colony-stimulating factor in paclitaxel-induced intestinal barrier breakdown and bacterial translocation in rats

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chi; XU Yang-guang; DUAN Xue-ning; LIU Yin-hua; ZHAO Jian-xin; XU Ling; YE Jing-ming

    2011-01-01

    Background Chemotherapy causes breakdown of the intestinal barrier, which may lead to bacterial translocation. Paclitaxel, an anti-tubulin agent, has many side effects; however, its effect on the intestinal barrier is unknown. Previous studies show that granulocyte colony-stimulating factor (G-CSF) plays an important role in modulating intestinal barrier function, but these studies are not conclusive. Here, we investigated the effects of paclitaxel on the intestinal barrier, and whether G-CSF could prevent paclitaxel-induced bacterial translocation.Methods Twenty-four male Sprague-Dawley rats were divided into three groups: control group, paclitaxel group and paclitaxel + G-CSF group. Intestinal permeability was measured by the urinary excretion rates of lactulose and mannitol administered by gavage. The mesenteric lymph nodes, spleen and liver were aseptically harvested for bacterial culture. Endotoxin levels and white blood cell (WBC) counts were measured and bacterial quantification performed using relative real-time PCR. Jejunum samples were also obtained for histological observation. Intestinal apoptosis was evaluated using a fragmented DNA assay and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick end-labeling staining. One-way analysis of variance and Fisher's exact test were used to compare differences between groups.Results Paclitaxel induced apoptosis in 12.5% of jejunum villus cells, which was reduced to 3.8% by G-CSF treatment. Apoptosis in the control group was 0.6%. Paclitaxel treatment also resulted in villus atrophy, increased intestinal permeability and a reduction in the WBC count. G-CSF treatment resulted in increased villus height and returned WBC counts to normal levels. No bacterial translocation was detected in the control group, whereas 6/8,8/8, and 8/8 rats in the paclitaxel group were culture-positive in the liver, spleen and mesenteric lymph nodes, respectively. Bacterial translocation was

  20. Paclitaxel and carboplatin in the treatment of small-cell lung cancer patients resistant to cyclophosphamide, doxorubicin, and etoposide : A non-cross-resistant schedule

    NARCIS (Netherlands)

    Groen, HJM; Fokkema, E; Biesma, B; Kwa, B; van Putten, JWG; Postmus, PE; Smit, EF

    1999-01-01

    Purpose: To evaluate the efficacy of paclitaxel and carboplatin (PC) in small-cell lung cancer (SCLC) patients resistant to cyclophasphamide, doxorubicin, and etoposide (CDE). Patients and Methods: We performed a phase II study with PC in SCLC patients who relapsed within 3 months after first-line t

  1. Paclitaxel-loaded star-shaped copolymer nanoparticles for enhanced malignant melanoma chemotherapy against multidrug resistance

    Science.gov (United States)

    Su, Yongsheng; Hu, Jian; Huang, Zhibin; Huang, Yubin; Peng, Bingsheng; Xie, Ni; Liu, Hui

    2017-01-01

    Malignant melanoma (MM) is the most dangerous type of skin cancer with annually increasing incidence and death rates. However, chemotherapy for MM is restricted by low topical drug concentration and multidrug resistance. In order to surmount the limitation and to enhance the therapeutic effect on MM, a new nanoformulation of paclitaxel (PTX)-loaded cholic acid (CA)-functionalized star-shaped poly(lactide-co-glycolide) (PLGA)-D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (NPs) (shortly PTX-loaded CA-PLGA-TPGS NPs) was fabricated by a modified method of nanoprecipitation. The particle size, zeta potential, morphology, drug release profile, drug encapsulation efficiency, and loading content of PTX-loaded NPs were detected. As shown by confocal laser scanning, NPs loaded with coumarin-6 were internalized by human melanoma cell line A875. The cellular uptake efficiency of CA-PLGA-TPGS NPs was higher than those of PLGA NPs and PLGA-TPGS NPs. The antitumor effects of PTX-loaded NPs were evaluated by the MTT assay in vitro and by a xenograft tumor model in vivo, demonstrating that star-shaped PTX-loaded CA-PLGA-TPGS NPs were significantly superior to commercial PTX formulation Taxol®. Such drug delivery nanocarriers are potentially applicable to the improvement of clinical MM therapy. PMID:28293102

  2. CSE1L/CAS, a microtubule-associated protein, inhibits taxol (paclitaxel)-induced apoptosis but enhances cancer cell apoptosis induced by various chemotherapeutic drugs.

    Science.gov (United States)

    Liao, Ching-Fong; Luo, Shue-Fen; Shen, Tzu-Yun; Lin, Chin-Huang; Chien, Jung-Tsun; Du, Shin-Yi; Jiang, Ming-Chung

    2008-03-31

    CSE1L/CAS, a microtubule-associated, cellular apoptosis susceptibility protein, is highly expressed in various cancers. Microtubules are the target of paclitaxel-induced apoptosis. We studied the effects of increased or reduced CAS expression on cancer cell apoptosis induced by chemotherapeutic drugs including paclitaxel. Our results showed that CAS overexpression enhanced apoptosis induced by doxorubicin, 5-fluorouracil, cisplatin, and tamoxifen, but inhibited paclitaxel-induced apoptosis of cancer cells. Reductions in CAS produced opposite results. CAS overexpression enhanced p53 accumulation induced by doxorubicin, 5-fluorouracil, cisplatin, tamoxifen, and etoposide. CAS was associated with alpha-tubulin and beta-tubulin and enhanced the association between alpha-tubulin and beta-tubulin. Paclitaxel can induce G2/M phase cell cycle arrest and microtubule aster formation during apoptosis induction, but CAS overexpression reduced paclitaxel-induced G2/M phase cell cycle arrest and microtubule aster formation. Our results indicate that CAS may play an important role in regulating the cytotoxicities of chemotherapeutic drugs used in cancer chemotherapy against cancer cells.

  3. Prevention of Paclitaxel-induced allodynia by Minocycline: Effect on loss of peripheral nerve fibers and infiltration of macrophages in rats

    Directory of Open Access Journals (Sweden)

    Xin Wen-Jun

    2010-11-01

    Full Text Available Abstract Background Although paclitaxel is a frontline antineoplastic agent for treatment of solid tumors, the paclitaxel-evoked pain syndrome is a serious problem for patients. There is currently no valid drug to prevent or treat the paclitaxel-induced allodynia, partly due to lack of understanding regarding the cellular mechanism. Studies have shown that minocycline, an inhibitor of microglia/macrophage, prevented neuropathic pain and promoted neuronal survival in animal models of neurodegenerative disease. Recently, Cata et al also reported that minocycline inhibited allodynia induced by low-dose paclitaxel (2 mg/kg in rats, but the mechanism is still unclear. Results Here, we investigate by immunohistochemistry the change of intraepidermal nerve fiber (IENF in the hind paw glabrous skin, expression of macrophage and activating transcription factor 3 (ATF3 in DRG at different time points after moderate-dose paclitaxel treatment (cumulative dose 24 mg/kg; 3 × 8 mg/kg in rats. Moreover, we observe the effect of minocycline on the IENF, macrophages and ATF3. The results showed that moderate-dose paclitaxel induced a persisted, gradual mechanical allodynia, which was accompanied by the loss of IENF in the hind paw glabrous skin and up-regulation of macrophages and ATF3 in DRG in rats. The expressions of ATF3 mainly focus on the NF200-positive cells. More importantly, we observed that pretreatment of minocycline at dose of 30 mg/kg or 50 mg/kg, but not 5 mg/kg, prevented paclitaxel-evoked allodynia. The evidence from immunohistochemistry showed that 30 mg/kg minocycline rescued the degeneration of IENF, attenuated infiltration of macrophages and up-regulation of ATF3 induced by paclitaxel treatment in rats. Conclusions Minocycline prevents paclitaxel-evoked allodynia, likely due to its inhibition on loss of IENF, infiltration of macrophages and up-regulation of ATF3 in rats. The finding might provide potential target for preventing paclitaxel-induced

  4. Paclitaxel Injection

    Science.gov (United States)

    ... with other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to treat ovarian cancer (cancer that ... cancer, and lung cancer. Paclitaxel injection with polyoxyethylated castor oil is also used to treat Kaposi's sarcoma (a ...

  5. MDR1 siRNA loaded hyaluronic acid-based CD44 targeted nanoparticle systems circumvent paclitaxel resistance in ovarian cancer

    Science.gov (United States)

    Yang, Xiaoqian; Lyer, Arun K.; Singh, Amit; Choy, Edwin; Hornicek, Francis J.; Amiji, Mansoor M.; Duan, Zhenfeng

    2015-02-01

    Development of multidrug resistance (MDR) is an almost universal phenomenon in patients with ovarian cancer, and this severely limits the ultimate success of chemotherapy in the clinic. Overexpression of the MDR1 gene and corresponding P-glycoprotein (Pgp) is one of the best known MDR mechanisms. MDR1 siRNA based strategies were proposed to circumvent MDR, however, systemic, safe, and effective targeted delivery is still a major challenge. Cluster of differentiation 44 (CD44) targeted hyaluronic acid (HA) based nanoparticle has been shown to successfully deliver chemotherapy agents or siRNAs into tumor cells. The goal of this study is to evaluate the ability of HA-PEI/HA-PEG to deliver MDR1 siRNA and the efficacy of the combination of HA-PEI/HA-PEG/MDR1 siRNA with paclitaxel to suppress growth of ovarian cancer. We observed that HA-PEI/HA-PEG nanoparticles can efficiently deliver MDR1 siRNA into MDR ovarian cancer cells, resulting in down-regulation of MDR1 and Pgp expression. Administration of HA-PEI/HA-PEG/MDR1 siRNA nanoparticles followed by paclitaxel treatment induced a significant inhibitory effect on the tumor growth, decreased Pgp expression and increased apoptosis in MDR ovarian cancer mice model. Our findings suggest that CD44 targeted HA-PEI/HA-PEG/MDR1 siRNA nanoparticles can serve as a therapeutic tool with great potentials to circumvent MDR in ovarian cancer.

  6. Coadministration of indomethacin and minocycline attenuates established paclitaxel-induced neuropathic thermal hyperalgesia: Involvement of cannabinoid CB1 receptors.

    Science.gov (United States)

    Parvathy, Subramanian S; Masocha, Willias

    2015-06-18

    Taxanes such as paclitaxel, which are chemotherapeutic drugs, cause dose-dependent painful neuropathy in some patients. We investigated whether coadministration of minocycline and indomethacin produces antinociceptive effects in mice with paclitaxel-induced neuropathic thermal hyperalgesia and if the cannabinoid system is involved. Previously, we reported that coadministration of these two drugs results in antinociception against inflammatory pain at doses where either drug alone lack significant activity. In the current study, we observed that treatment of female mice with indomethacin or minocycline alone did not affect established paclitaxel-induced thermal hyperalgesia, whereas coadministration of the two drugs attenuated it. In male mice indomethacin had some antihyperalgesic activity, whilst minocycline did not. Coadministration of the two drugs had supraadditive antihyperalgesic activity in male mice. Administration of a cannabinoid CB1 receptor antagonist AM 251 blocked the antihyperalgesic effects of the combination of minocycline and indomethacin in both male and female mice. In conclusion our results indicate that coadministration of minocycline and indomethacin abrogates established paclitaxel-induced neuropathic thermal hyperalgesia in mice, and the potentiation of the antinociceptive effects of this combination involves the cannabinoid system.

  7. Paclitaxel-induced hyperalgesia modulates negative affective component of pain and NR1 receptor expression in the frontal cortex in rats.

    Science.gov (United States)

    Noda, Kazuko; Akita, Hisanao; Ogata, Masanori; Saji, Makoto

    2014-03-01

    Paclitaxel, one of the chemotherapeutic agents clinically used to treat several types of cancer, produces side effects such as peripheral neuropathy, sensory abnormalities, and hyperalgesia. Since hyperalgesia remains after cessation of paclitaxel therapy and becomes chronic, we hypothesize that alteration in memory and the cognitive process of pain underlies hyperalgesia. To test this hypothesis, we examined whether drug-induced hyperalgesia alters the affective component of pain and the NMDA-NR1 and mGluR1 receptors as a mediator for signal transmission and memory of pain. Mechanical sensitivity was measured by von Frey filament test after intraperitoneal injection of paclitaxel in rats. Paclitaxel-induced hyperalgesia was confirmed over almost the entire 14-day period of observation after the treatment. The effect of paclitaxel-induced hyperalgesia on the affective component of pain was assessed using pain-induced place aversion. The formalin-induced conditioned place aversion was completely abolished in the paclitaxel-treated rats. Immunoblot analysis of NR1 and mGluR1 protein levels in various brain regions was performed after paclitaxel treatment. Treatment reduced only the NR1 expression within the frontal cortex. These results suggest that the hypofunction of memory processes with the reduced NMDA receptors in the frontal cortex might be involved in the expression of abnormal emotional behaviors accompanied by hyperalgesia.

  8. Intraperitoneal delivery of a novel liposome-encapsulated paclitaxel redirects metabolic reprogramming and effectively inhibits cancer stem cells in Taxol(®)-resistant ovarian cancer.

    Science.gov (United States)

    Shen, Yao-An; Li, Wai-Hou; Chen, Po-Hung; He, Chun-Lin; Chang, Yen-Hou; Chuang, Chi-Mu

    2015-01-01

    Taxol(®) remained as the mainstay therapeutic agent in the treatment of ovarian cancer, however recurrence rate is still high. Cancer stem cells (CSCs) represent a subset of cells in the bulk of tumors and play a central role in inducing drug resistance and recurrence. Furthermore, cancer metabolism has been an area under intensive investigation, since accumulating evidence has shown that CSCs and cancer metabolism are closely linked, an effect named as metabolic reprogramming. In this work, we aimed to investigate the impacts of a novel liposome-encapsulated paclitaxel (Nano-Taxol) on the stemness phenotype and metabolic reprogramming. A paclitaxel-resistant cell line (TR) was established at first. Tumor growth was induced in the mice peritoneal cavity by inoculation of TR cells. A 2x2 factorial experiment was designed to test the therapeutic efficacy in which factor 1 represented the comparison of drugs (Taxol(®) versus Nano-Taxol), while factor 2 represented the delivery route (intravenous versus intraperitoneal delivery). In this work, we found that intraperitoneal delivery of Nano-Taxol redirects metabolic reprogramming, from glycolysis to oxidative phosphorylation, and effectively suppresses cancer stem cells. Also, intraperitoneal delivery of Nano-Taxol led to a significantly better control of tumor growth compared with intravenous delivery of Taxol(®) (current standard treatment). This translational research may serve as a novel pathway for the drug development of nanomedicine. In the future, this treatment modality may be extended to treat several relevant cancers that have been proved to be suitable for the loco-regional delivery of therapeutic agents, including colon cancer, gastric cancer, and pancreatic cancer.

  9. Chitosan/pshRNA Plasmid Nanoparticles Targeting MDR1 Gene Reverse Paclitaxel Resistance in Ovarian Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Yan YANG; Zehua WANG; Minfang LI; Shi LU

    2009-01-01

    In order to investigate the effect of chitosan/pshR.NA plasmid nanoparticles targeting MDRI genes on the resistance of A2780/TS cells to paclitaxel,chitosan/pshRNA plasmid nanoparticles were synthesized by means of a complex coacervation technique and transfected into A2780/TS cells.The cells transfected with MDR1-targeted chitosan/pshRNA plasmid nanoparticles were experimental cells and the cells transfected with chitosan/pGPU6/GFP/Neo no-load plasmid nanoparticles served as negative control cells.Morphological features of the nanoparticles were observed under transmission electron microscope (TEM).MDR1 mRNA expression was assessed by RT-PCR.Half-inhibitory concentration (IC50) of paclitaxel for A2780/TS cells was determined by MTT method.TEM showed that the nanoparticles were round-shaped,smooth in surface and the diameters varied from 80 to 120 nm.The MDR1 mRNA in the transfected cells was significantly decreased by 17.6%,27.8% and 52.6% on the post-transfection day 2,4 and 7 when compared with that in A2780/TS cells control (P<0.05).MTT assay revealed that the relative reversal efficiency was increased over time and was 29.6%,51.2% and 61.3% respectively in the transfected cells 2,4,7 days after transfection and IC50 (0.197±0.003,0.144±0.001,0.120±0.004) were decreased with difference being significant when compared with that in A2780/TS (0.269±0.003) cells control (P<0.05).It was concluded that chitosan/pshRNA plasmid nanoparticles targeting MDR1 can effectively reverse the paclitaxel resistance in A2780/TS cells in a time-dependent manner.

  10. CYP3A4*22 genotype and systemic exposure affect paclitaxel-induced neurotoxicity

    NARCIS (Netherlands)

    A.J.M. de Graan (Anne-Joy); L. Elens (Laure); J.A. Sprowl (Jason); A. Sparreboom (Alex); L.E. Friberg (Lena); B. van der Holt (Bronno); P.J. de Raaf (Pleun); P. de Bruijn (Peter); F.K. Engels (Frederike); F.A.L.M. Eskens (Ferry); E.A.C. Wiemer (Erik); J. Verweij (Jaap); A.H.J. Mathijssen (Ron); R.H.N. van Schaik (Ron)

    2013-01-01

    textabstractPurpose: Paclitaxel is used for the treatment of several solid tumors and displays a high interindividual variation in exposure and toxicity. Neurotoxicity is one of the most prominent side effects of paclitaxel. This study explores potential predictive pharmacokinetic and

  11. Inositol hexaphosphate and paclitaxel: symbiotic treatment of oral cavity squamous cell carcinoma.

    Science.gov (United States)

    Janus, Seth C; Weurtz, Beverly; Ondrey, Frank G

    2007-08-01

    Nuclear factor (NF)-kappaB is an early response gene that has been associated with head and neck squamous cell cancer (HNSCC) progression. NF-kappaB activation is induced by some chemotherapy agents, including paclitaxel. The activation of this gene can be correlated with apoptosis resistance. Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate. NF-kappaB levels were evaluated in oral cavity HNSCC lines after treatment with paclitaxel and IP6, alone and in combination. Resulting levels of cell death and apoptosis were assessed, and conclusions are drawn regarding a possible synergistic relationship between paclitaxel and IP6. NF-kappaB activation in cancer cells treated with paclitaxel and IP6, alone and in combination, was measured by transient transfection, and results were interpreted by luminometry. Cell proliferation of treated cells was measured by MTT assay. Cell viability and apoptosis of cancer cells treated with paclitaxel and IP6 combinations were quantitated by trypan blue staining and Caspase-Glo 3/7 assay, respectively. IP6 was observed to significantly downregulate NF-kappaB activation in both NA and CA-9-22 oral cavity HNSCC cell lines. Paclitaxel treatments caused increased NF-kappaB activation in the same cell lines. IP6 was observed to mitigate paclitaxel-induced NF-kappaB activation in the CA-9-22 cell line. IP6, when combined with paclitaxel, reduces CA-9-22 cell proliferation, increases cell death, and increases apoptosis, when compared with treatment with paclitaxel alone. IP6 reduces paclitaxel induced NF-kappaB activation and increases paclitaxel-mediated cell killing and apoptosis. As a well-tolerated and safe supplement, IP6 deserves further study in the treatment of oral cavity squamous cell carcinoma.

  12. Resistance to first line platinum paclitaxel chemotherapy in serous epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Steffensen, Karina Dahl; Smoter, Marta; Waldstrøm, Marianne

    2014-01-01

    of sensitivity to platinum/paclitaxel treatment. The primary aim of the study was to investigate whether ERCC1 and Tau protein expression correlates with patient outcome in newly diagnosed epithelial ovarian cancer (EOC) patients. Formalin-fixed, paraffin-embedded tissue sections from 227 newly diagnosed EOC...

  13. Systematic evaluation of multifunctional paclitaxel-loaded polymeric mixed micelles as a potential anticancer remedy to overcome multidrug resistance.

    Science.gov (United States)

    Zhang, Jiulong; Zhao, Xiufeng; Chen, Qing; Yin, Xiaoyi; Xin, Xiu; Li, Kexin; Qiao, Mingxi; Hu, Haiyang; Chen, Dawei; Zhao, Xiuli

    2017-03-01

    Multidrug resistance (MDR) of tumor cells is becoming the main reason for the failure of chemotherapy and P-glycoprotein (P-gp) mediated drug efflux has demonstrated to be the key factor for MDR. To address this issue, a novel pH-responsive mixed micelles drug delivery system composed of dextran-g-poly(lactide-co-glycolide)-g-histidine (HDP) and folate acid-D-α-tocopheryl polyethylene glycol 2000 (FA-TPGS2K) copolymers has been designed for the delivery of antitumor agent, paclitaxel (PTX) via FA-receptor mediated cell endocytosis, into PTX-resistant breast cancer MCF-7 cells (MCF-7/PTX). PTX-loaded FA-TPGS2K/HDP mixed micelles were characterized to have a small size distribution, high loading content and excellent pH-responsive drug release profiles. Compared with HDP micelles, FA-TPGS2K/HDP mixed micelles showed a higher cytotoxicity against MCF-7 and MCF-7/PTX cells due to the synergistic effect of FA-receptor mediated cell endocytosis, pH-responsive drug release and TPGS mediated P-gp inhibition. P-gp expression level, ATP content and mitochondrial membrane potential change have been measured, the results indicated blank FA-TPGS2K/HDP mixed micelles could inhibit the P-gp activity by reducing the mitochondrial membrane potential and depleting ATP content but not down-regulating the P-gp expression. In vivo antitumor activities demonstrated FA-TPGS2K/HDP mixed micelles could reach higher antitumor activity compared with HDP micelles for MCF-7/PTX tumor cells. Histological assay also indicated that FA-TPGS2K/HDP mixed micelles showed strongly apoptosis inducing effect, anti-proliferation effect and anti-angiogenesis effect. All these evidences demonstrated this pH-sensitive FA-TPGS2K/HDP micelle-based drug delivery system is a promising approach for overcoming MDR. In this work, a novel FA-TPGS2K copolymer has been synthesized and used it to construct mixed micelles with HDP copolymer to overcome MDR effect. Furthermore, a series in vitro and in vivo evaluations

  14. Synergistic effect of a novel cyclic pentadepsipeptide, neoN-methylsansalvamide, and paclitaxel on human multidrug resistance cancer cell lines.

    Science.gov (United States)

    Lee, Hee-Seok; Phat, Chanvorleak; Choi, Sang-Un; Lee, Chan

    2013-06-01

    NeoN-methylsansalvamide is a novel low-molecular-weight cyclic pentadepsipeptide that exerts cytotoxic effects on various human cancer cell lines. Its structural analysis using liquid chromatography mass/mass spectrometry showed the cyclic structure sequence -phenylalanine-leucine-valine-N-methylleucine-leucic acid-. The intrinsic cytotoxic and multidrug resistance reversal effects of neoN-methylsansalvamide were evaluated on the human cancer cell lines MES-SA and HCT15 as well as on their multidrug resistance sublines (MES-SA/DX5 and HCT15/CL05, respectively) using the sulforhodamine B assay. The EC50 values of paclitaxel for MES-SA, HCT15, and for the multidrug resistance sublines MES-SA/DX5 and HCT15/CL05 were 1.00±0.20, 0.85±0.63, 10.00±0.53, and >1000 nmol/l, respectively. However, the EC50 values for paclitaxel including 3 μmol/l neoN-methylsansalvamide for MES-SA/DX5, HCT15, and HCT15/CL02 were 1.58±0.12, 0.10±0.02, and 288.40±21.02 nmol/l, respectively. The in-vitro multidrug resistance reversal activity of neoN-methylsansalvamide was similar to that of the control verapamil. These finding suggests that a novel cyclic pentadepsipeptide, neoN-methylsansalvamide, is effective in reversing multidrug resistance in vitro, and this activity may be a major applicable biological function of this compound.

  15. Gene expression and pathway analysis of ovarian cancer cells selected for resistance to cisplatin, paclitaxel, or doxorubicin

    Directory of Open Access Journals (Sweden)

    Sherman-Baust Cheryl A

    2011-12-01

    Full Text Available Abstract Background Resistance to current chemotherapeutic agents is a major cause of therapy failure in ovarian cancer patients, but the exact mechanisms leading to the development of drug resistance remain unclear. Methods To better understand mechanisms of drug resistance, and possibly identify novel targets for therapy, we generated a series of drug resistant ovarian cancer cell lines through repeated exposure to three chemotherapeutic drugs (cisplatin, doxorubicin, or paclitaxel, and identified changes in gene expression patterns using Illumina whole-genome expression microarrays. Validation of selected genes was performed by RT-PCR and immunoblotting. Pathway enrichment analysis using the KEGG, GO, and Reactome databases was performed to identify pathways that may be important in each drug resistance phenotype. Results A total of 845 genes (p Conclusions Ovarian cancer cells develop drug resistance through different pathways depending on the drug used in the generation of chemoresistance. A better understanding of these mechanisms may lead to the development of novel strategies to circumvent the problem of drug resistance.

  16. Rapid tumor necrosis and massive hemorrhage induced by bevacizumab and paclitaxel combination therapy in a case of advanced breast cancer

    Directory of Open Access Journals (Sweden)

    Ono M

    2013-10-01

    Full Text Available Mayu Ono, Tokiko Ito, Toshiharu Kanai, Koichi Murayama, Hiroshi Koyama, Kazuma Maeno, Yasuhiro Mochizuki, Asumi Iesato, Toru Hanamura, Toshihiro Okada, Takayuki Watanabe, Ken-ichi ItoDivision of Breast and Endocrine Surgery, Department of Surgery (II, Shinshu University School of Medicine, Matsumoto, JapanAbstract: Bevacizumab when combined with chemotherapy exerts significant activity against many solid tumors through tumor angiogenesis inhibition; however, it can induce severe side effects. We report the rare case of a 27-year-old premenopausal woman with locally advanced breast cancer that was marked by rapid tumor necrosis followed by massive hemorrhage shortly after bevacizumab and paclitaxel administration. On the basis of histopathological examination of a biopsy specimen and computed tomography findings, she was diagnosed with stage IV estrogen and progesterone receptor-negative and human epidermal growth factor receptor type 2-positive breast cancer with multiple organ metastases when she had entered gestational week 24. Cyclophosphamide, Adriamycin®, fluorouracil therapy was initiated, but multiple liver metastases continued to progress. A healthy fetus was delivered by induced delivery and trastuzumab-based treatment was initiated. Although the multiple liver metastases were controlled successfully by trastuzumab combined with paclitaxel, the primary tumor continued to expand even after subsequent administration of three other treatment regimens including anti-human epidermal growth factor receptor type 2 agents and cytotoxic drugs. To inhibit primary tumor growth, a combination therapy with paclitaxel and bevacizumab was subsequently initiated. Following therapy initiation, however, the large tumor occupying the patient's entire left breast became necrotic and ulcerated rapidly. Furthermore, massive hemorrhage from the tumor occurred 5 weeks after bevacizumab-based therapy initiation. Although hemostasis was achieved by manual

  17. Astrocyte activation in the anterior cingulate cortex and altered glutamatergic gene expression during paclitaxel-induced neuropathic pain in mice

    Directory of Open Access Journals (Sweden)

    Willias Masocha

    2015-10-01

    Full Text Available Spinal astrocyte activation contributes to the pathogenesis of paclitaxel-induced neuropathic pain (PINP in animal models. We examined glial fibrillary acidic protein (GFAP; an astrocyte marker immunoreactivity and gene expression of GFAP, glutamate transporters and receptor subunits by real time PCR in the anterior cingulate cortex (ACC at 7 days post first administration of paclitaxel, a time point when mice had developed thermal hyperalgesia. The ACC, an area in the brain involved in pain perception and modulation, was chosen because changes in this area might contribute to the pathophysiology of PINP. GFAP transcripts levels were elevated by more than fivefold and GFAP immunoreactivity increased in the ACC of paclitaxel-treated mice. The 6 glutamate transporters (GLAST, GLT-1 EAAC1, EAAT4, VGLUT-1 and VGLUT-2 quantified were not significantly altered by paclitaxel treatment. Of the 12 ionotropic glutamate receptor subunits transcripts analysed 6 (GLuA1, GLuA3, GLuK2, GLuK3, GLuK5 and GLuN1 were significantly up-regulated, whereas GLuA2, GLuK1, GLuK4, GLuN2A and GLuN2B were not significantly altered and GLuA4 was lowly expressed. Amongst the 8 metabotropic receptor subunits analysed only mGLuR8 was significantly elevated. In conclusion, during PINP there is astrocyte activation, with no change in glutamate transporter expression and differential up-regulation of glutamate receptor subunits in the ACC. Thus, targeting astrocyte activation and the glutamatergic system might be another therapeutic avenue for management of PINP.

  18. Weekly paclitaxel in escalating doses in a patient with anthracycline-resistant, triple-negative, metastatic breast cancer with severe liver dysfunction

    Directory of Open Access Journals (Sweden)

    Ajay Gupta

    2012-01-01

    Full Text Available Liver dysfunction in a patient with anthracycline-resistant breast cancer and liver metastases with poor performance status (PS represents a serious situation. Taxanes are the drugs of choice, but once the transaminase enzyme levels are raised more than 10-times the upper limit of normal (>10 ULN, paclitaxel administration is contraindicated. We present the report of one such case who had a gratifying response to escalating doses of weekly paclitaxel thus suggesting that even patients with severe liver dysfunction can derive benefits from such a strategy. The patient, a 54-year-old lady with breast cancer metastatic to the liver and bones and previous receipt of anthracycline-based therapy, presented to us with a PS of 3. Her liver functions (LFT were: serum bilirubin 2.2 mg% (0.3-1.1 mg%, aspartate aminotransferase 375 IU/L (0-25 IU/L, alanine aminotransferase 369 IU/L (0-35 IU/L and alkaline phosphatase 363 IU/L (38-126 IU/L. She was started on weekly paclitaxel 20 mg/m 2 and zoledronate. After the first dose, the LFTs rose marginally but the skin lesions stabilized. Dose was subsequently escalated to 40 mg/m 2 . At the end of the 10th week, her PS improved to 1 and the disease showed a partial response. LFTs improved markedly. However, 5 days after the administration of the 13 th dose, the disease progressed and paclitaxel had to be discontinued. It is possible to derive maximum palliative benefit with escalating doses of weekly paclitaxel even in patients whose liver functions are deranged with transaminase levels (>10 ULN and in whom conventional administration of paclitaxel is contraindicated.

  19. Paclitaxel Induced MDS and AML: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Udit Bhaskar Bhatnagar

    2016-01-01

    Full Text Available Therapy related acute myelogenous leukemia (AML and myelodysplastic syndromes (MDS have been classically linked to alkylating agents and topoisomerase inhibitors. They constitute about 1% of all AMLs. There is less evidence on association of taxanes (paclitaxel and docetaxel with these myeloid neoplasms. We present a case of paclitaxel therapy related acute myelogenous leukemia after treatment of endometrial cancer with a regimen containing paclitaxel and carboplatin. A 63-year-old female underwent surgery followed by a total of 6 cycles of chemotherapy with carboplatin and paclitaxel. Six months after last cycle of chemotherapy, she was diagnosed with myelodysplastic syndrome with refractory anemia and excess blasts. Six weeks later, she had worsening anemia and thrombocytopenia which prompted a bone marrow biopsy which revealed acute myelomonocytic leukemia. A thorough literature review revealed 12 other case reports where taxanes have been implicated in the development of therapy related myeloid neoplasm. Based on the timeline of events in our patient, paclitaxel is the likely culprit in the pathogenesis of this myeloid neoplasm. This rare but significantly grave adverse effect should be kept in consideration when deciding on treatment options for gynecological malignancies.

  20. A Hyperresponsive HPA Axis May Confer Resilience Against Persistent Paclitaxel-Induced Mechanical Hypersensitivity.

    Science.gov (United States)

    Kozachik, Sharon L; Page, Gayle G

    2016-05-01

    Paclitaxel (PAC) treatment is associated with persistent, debilitating neuropathic pain that affects the hands and feet. Female sex and biological stress responsivity are risk factors for persistent pain, but it is unclear whether these important biologically based factors confer risk for PAC-induced neuropathic pain. To determine the relative contributions of sex and hypothalamic-pituitary-adrenal (HPA)-axis stress responsivity to PAC-induced mechanical hypersensitivity, we employed a PAC protocol consisting of three, 2-week cycles of every-other-day doses of PAC 1 mg/kg versus saline (Week 1) and recovery (Week 2), totaling 42 days, in mature male and female Fischer 344, Lewis, and Sprague Dawley (SD) rats, known to differ in HPA axis stress responsivity. Mechanical sensitivity was operationalized using von Frey filaments, per the up-down method. Among PAC-injected rats, SD rats exhibited significantly greater mechanical hypersensitivity relative to accumulative PAC doses compared to Fischer 344 rats. Lewis rats were not significantly different in mechanical hypersensitivity from SD or Fischer 344 rats. At the end of the protocol, PAC-injected SD rats exhibited profound mechanical hypersensitivity, whereas the PAC-injected Fischer 344 rats appeared relatively resilient to the long-term effects of PAC and exhibited mechanical sensitivity that was not statistically different from their saline-injected counterparts. Sex differences were mixed and noted only early in the PAC protocol. Moderate HPA axis stress responsivity may confer additional risk for the painful effects of PAC. If these findings hold in humans, clinicians may be better able to identify persons who may be at increased risks for developing neuropathic pain during PAC therapy.

  1. Modulation of the sphingolipid rheostat is involved in paclitaxel resistance of the human prostate cancer cell line PC3-PR.

    Science.gov (United States)

    Aoyama, Yuka; Sobue, Sayaka; Mizutani, Naoki; Inoue, Chisato; Kawamoto, Yoshiyuki; Nishizawa, Yuji; Ichihara, Masatoshi; Kyogashima, Mamoru; Suzuki, Motoshi; Nozawa, Yoshinoti; Murate, Takashi

    2017-04-29

    Taxoids are anti-cancer drugs frequently used to treat solid tumors, but they are sometimes ineffective and tumors may become resistant to their action. Here, we examined the involvement of sphingolipid metabolic enzymes in paclitaxel (PTX) resistance using a human prostate cancer cell line, PC3, and its PTX-resistant subline, PC3-PR. PTX (20 nM) suppressed cell proliferation and increased various ceramide species in PC3, but not PC3-PR, cells. PC3-PR contained higher S1P levels than did PC3, regardless of PTX treatment. Western blotting revealed that PC3-PR cells expressed higher levels of sphingosine kinase 1 (SPHK1) and glucosylceramide synthase (GCS) but lower levels of acid sphingomyelinase (ASMase) and neutral sphingomyelinase 2 than did PC3 cells. Inhibition of SPHK1 using siRNA or a pharmacological inhibitor decreased S1P levels in PC3-PR cells and inhibited proliferation in the presence or absence of PTX, suggesting that SPHK1 is at least partially responsible for PTX resistance. Similarly, GCS inhibitors (PDMP and PPMP) increased cellular ceramides and suppressed the proliferation of PC3-PR. However, inhibition of proteasome function or histone deacetylase activity increased SMase and ceramide levels and suppressed PC3-PR proliferation. These results suggest that modulation of metabolic enzyme expression and alteration of the sphingolipid rheostat protects cancer cells against PTX. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Disulfiram targets cancer stem-like cells and reverses resistance and cross-resistance in acquired paclitaxel-resistant triple-negative breast cancer cells

    Science.gov (United States)

    Liu, P; Kumar, I S; Brown, S; Kannappan, V; Tawari, P E; Tang, J Z; Jiang, W; Armesilla, A L; Darling, J L; Wang, W

    2013-01-01

    Background: Triple-negative breast cancer (TNBC) has significantly worse prognosis. Acquired chemoresistance remains the major cause of therapeutic failure of TNBC. In clinic, the relapsed TNBC is commonly pan-resistant to various drugs with completely different resistant mechanisms. Investigation of the mechanisms and development of new drugs to target pan-chemoresistance will potentially improve the therapeutic outcomes of TNBC patients. Methods: In this study, 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT), combination index (CI)–isobologram, western blot, ALDEFLUOR analysis, clonogenic assay and immunocytochemistry were used. Results: The chemoresistant MDA-MB-231PAC10 cells are highly cross-resistant to paclitaxel (PAC), cisplatin (CDDP), docetaxel and doxorubicin. The MDA-MB-231PAC10 cells are quiescent with significantly longer doubling time (64.9 vs 31.7 h). This may be caused by high expression of p21Waf1. The MDA-MB-231PAC10 cells express high aldehyde dehydrogenase (ALDH) activity and a panel of embryonic stem cell-related proteins, for example, Oct4, Sox2, Nanog and nuclealisation of HIF2α and NF-κBp65. We have previously reported that disulfiram (DS), an antialcoholism drug, targets cancer stem cells (CSCs) and enhances cytotoxicity of anticancer drugs. Disulfiram abolished CSC characters and completely reversed PAC and CDDP resistance in MDA-MB-231PAC10 cells. Conclusion: Cancer stem cells may be responsible for acquired pan-chemoresistance. As a drug used in clinic, DS may be repurposed as a CSC inhibitor to reverse the acquired pan-chemoresistance. PMID:24008666

  3. Multiplicity of acquired cross-resistance in paclitaxel-resistant cancer cells is associated with feedback control of TUBB3 via FOXO3a-mediated ABCB1 regulation

    Science.gov (United States)

    Aldonza, Mark Borris D.; Hong, Ji-Young; Alinsug, Malona V.; Song, Jayoung; Lee, Sang Kook

    2016-01-01

    Acquired drug resistance is a primary obstacle for effective cancer therapy. The correlation of point mutations in class III β-tubulin (TUBB3) and the prominent overexpression of ATP-binding cassette P-glycoprotein (ABCB1), a multidrug resistance gene, have been protruding mechanisms of resistance to microtubule disruptors such as paclitaxel (PTX) for many cancers. However, the precise underlying mechanism of the rapid onset of cross-resistance to an array of structurally and functionally unrelated drugs in PTX-resistant cancers has been poorly understood. We determined that our established PTX-resistant cancer cells display ABCB1/ABCC1-associated cross-resistance to chemically different drugs such as 5-fluorouracil, docetaxel, and cisplatin. We found that feedback activation of TUBB3 can be triggered through the FOXO3a-dependent regulation of ABCB1, which resulted in the accentuation of induced PTX resistance and encouraged multiplicity in acquired cross-resistance. FOXO3a-directed regulation of P-glycoprotein (P-gp) function suggests that control of ABCB1 involves methylation-dependent activation. Consistently, transcriptional overexpression or downregulation of FOXO3a directs inhibitor-controlled protease-degradation of TUBB3. The functional PI3K/Akt signaling is tightly responsive to FOXO3a activation alongside doxorubicin treatment, which directs FOXO3a arginine hypermethylation. In addition, we found that secretome factors from PTX-resistant cancer cells with acquired cross-resistance support a P-gp-dependent association in multidrug resistance (MDR) development, which assisted the FOXO3a-mediated control of TUBB3 feedback. The direct silencing of TUBB3 reverses induced multiple cross-resistance, reduces drug-resistant tumor mass, and suppresses the impaired microtubule stability status of PTX-resistant cells with transient cross-resistance. These findings highlight the control of the TUBB3 response to ABCB1 genetic suppressors as a mechanism to reverse the

  4. 子宫内膜癌CYP1 B1的表达对紫杉醇耐药性的影响%The influence of CYP1B1 expression in endometrial cancer on paclitaxel resistance

    Institute of Scientific and Technical Information of China (English)

    刘媛媛

    2016-01-01

    Objective To investigate the association between expression of CYPIB 1 in endometrial cancer cells and paclitaxel -resistance .Methods Endometrial cancer cell line Ishikevawa as the research object ,using TCDD induce expression of CYP 1B1 in Ish-ikevawa,observe the effect of paclitaxel on the cytotoxic effects after CYP 1BI expression.Measured by RT -PCR after induction of CYP1B1 mRNA levels,using immunochemical staining and Western blotting assay protein expression of CYPIBI ,MTS colorimetric de-termination of paclitaxel on inhibition strength of cell proliferation .Results TCDD can induce Ishikevawa cells expressing CYP 1B1,its mRNA and protein expression levels of TCDD concentrations demonstrate a significant dose -dependent manner ( P<0.05).When the cells were treated with TCDD Ishikevawa induced CYP 1B1,paclitaxel concentration in a 0.01 0.1μg /mL,the inhibition rates of pacli-taxel decreased significantly compared with the control group ( P<0.05).Conclusion CYP1B1 expression may result in cells resist-ant to paclitaxel .%目的:探讨子宫内膜细胞CYPIB1表达与紫衫醇耐药产生的相关性。方法以子宫内膜癌细胞系Ishikevawa为研究对象,经TCDD诱导Ishikevawa表达CYP1B1,观察CYP1BI表达后对紫衫醇药物的细胞毒效应的影响。采用RT-PCR测定诱导后CYP1B1 mRNA水平,采用细胞免疫化学染色和蛋白印迹技术测定诱导后CYPIBI蛋白水平,MTS比色法测定紫衫醇对细胞增殖的抑制强度。结果 TCDD可诱导Ishikevawa 细胞表达CYP1B1,其mRNA和蛋白表达水平与TCDD浓度具有明显的剂量依赖性( P<0.05)。当Ishikevawa细胞经TCDD诱导表达CYP1B1后,紫衫醇浓度在0.01~0.1μg/mL时,紫杉醇对Ishikevawa细胞的抑制率与对照组相比明显下降( P<0.05)。结论 CYP1B1表达后可导致细胞产生对紫杉醇耐药。

  5. Paclitaxel-induced hollow toenail%紫杉醇致双足趾甲空洞

    Institute of Scientific and Technical Information of China (English)

    朱建辉; 邵喜英; 王增

    2015-01-01

    A 32-year-old woman with breast cancer received a postoperative adjuvant chemotherapy with epirubicin plus cyclophosphamide followed by paclitaxel.The drug regimen of paclitaxel was intravenous infusion 120 mg once a week.On the day 6 after the first cycle of paclitaxel treatment, the patient developed bilateral big toenail hollowness, the aperture was about 2 mm.She was given the second cycle of paclitaxel according to the original plan.Six days later, the hollow toenail was worsened with slight pain.Paclitaxel was stopped.Mecobalamin, erythromycin ointment and keeping warm of feet were applied.Four days later,the pain was reduced, and the toenail hollowness did not continue to enlarge.%1例32岁乳腺癌患者术后接受表柔比星联合环磷酰胺方案序贯紫杉醇化疗.应用紫杉醇(120 mg,1次/周静脉滴注)第1周期后第6天,患者出现双足大拇趾甲空洞,孔径约2 mm.按原方案行紫杉醇第2周期化疗.6d后,趾甲空洞变大,略有疼痛感.停用紫杉醇.给予双足保暖,并口服甲钴胺和外用红霉素软膏.4d后,患者足部疼痛感减轻,空洞未再增大.

  6. Paclitaxel-resistant HeLa cells have up-regulated levels of reactive oxygen species and increased expression of taxol resistance gene 1.

    Science.gov (United States)

    Bi, Wenxiang; Wang, Yuxia; Sun, Gaoying; Zhang, Xiaojin; Wei, Yongqing; Li, Lu; Wang, Xiaoyuan

    2014-07-01

    This study is to establish a paclitaxel (PTX)-resistant human cervical carcinoma HeLa cell line (HeLa/PTX) and to investigate its redox characteristics and the expression of taxol resistance gene 1 (Txr1). HeLa cells were treated with PTX and effects of PTX on cell proliferation were detected through cell counting and the MTT assay. Levels of cellular reactive oxygen species (ROS), reduced glutathione (GSH), and oxidized glutathione (GSSG) as well as the ratio of GSH to GSSG were measured by the 2,7-difluorescein diacetate (DCFH-DA) method and the 5,5'dithiobis(2-nitrobenzoic acid) (DTNB) method. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined by the nitrite formation method, the molybdate colorimetric method, and the DTNB colorimetric method, respectively. The level of Txr1 mRNA was determined by real-time PCR. Compared with the regular HeLa cells, HeLa/PTX cells were larger in size and had more cytoplasmic granules. The population doubling time for HeLa/PTX cells was 1.32 times of that of HeLa cells (PHeLa cells with a resistance index of 122.69. HeLa/PTX cells had higher levels of ROS (PHeLa cells. HeLa/PTX cells, with higher levels of ROS and Txr1 mRNA expression, are more resistant to PTX than HeLa cells.

  7. Preventative and therapeutic effects of a GABA transporter 1 inhibitor administered systemically in a mouse model of paclitaxel-induced neuropathic pain

    Science.gov (United States)

    Parvathy, Subramanian S.

    2016-01-01

    Background There is a dearth of drugs to manage a dose-limiting painful peripheral neuropathy induced by paclitaxel in some patients during the treatment of cancer. Gamma-aminobutyric acid transporter-1 (GAT-1) whose expression is increased in the brain and spinal cord during paclitaxel-induced neuropathic pain (PINP) might be a potential therapeutic target for managing PINP. Thus, our aim was to evaluate if systemic administration of a GAT-1 inhibitor ameliorates PINP. Methods The reaction latency to thermal stimuli (hot plate test; at 55 °C) and cold stimuli (cold plate test; at 4 °C) of female BALB/c mice was recorded before and after intraperitoneal treatment with paclitaxel, its vehicle, and/or a selective GAT-1 inhibitor NO-711. The effects of NO-711 on motor coordination were evaluated using the rotarod test at a constant speed of 4 rpm or accelerating mode from 4 rpm to 40 rpm over 5 min. Results The coadministration of paclitaxel with NO-711 3 mg/kg prevented the development of paclitaxel-induced thermal hyperalgesia and cold allodynia at day 7 after drug treatment. NO-711 at 3 mg/kg produced antihyperalgesic activity up to 1 h and antiallodynic activity up to 2 h in mice with established paclitaxel-induced thermal hyperalgesia and cold allodynia. No motor deficits were observed with NO-711 at a dose of 3 mg/kg, whereas a higher dose 5 mg/kg caused motor impairment and reduced mean time spent on the rotarod at a constant speed of 4 rpm. However, at a rotarod accelerating mode from 4 rpm to 40 rpm over 5 min, NO-711 3 mg/kg caused motor impairment up to 1 h, but had recovered by 2 h. Conclusions These results show that systemic administration of the GAT-1 inhibitor NO-711 has preventative and therapeutic activity against paclitaxel-induced thermal hyperalgesia and cold allodynia. NO-711’s antiallodynic effects, but not antihyperalgesic effects, were independent of its motor impairment/sedation properties. Thus, low doses of GAT-1 inhibitors

  8. Synergistic Effects of Apigenin and Paclitaxel on Apoptosis of Cancer Cells

    Science.gov (United States)

    Diao, Ying; Lu, Changyan; Fu, Jin; Luo, Lan; Yin, Zhimin

    2011-01-01

    Background It was well known that the clinical use of chemotherapeutic drugs is restricted by severe adverse reactions and drug resistances. Thus it is necessary to figure out a strategy to increase the specific anti-tumor efficiency of chemotherapeutic drugs. Apigenin, a kind of flavonoids, has been reported to possess anticancer activities with very low cytotoxicity to normal tissue. Methodology/Principal Findings Our results from cell viability assay, western-blots and TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay demonstrated the synergistic pro-apoptotic effects of a low dose of apigenin and paclitaxel in human cancer cell lines. To analyze the underlying mechanism, we examined reactive oxygen species (ROS) staining after cells were treated with a combination of apigenin and paclitaxel, or each of them alone. Data from flow-cytometry showed that superoxides but not reduction of peroxides accumulated in HeLa cells treated with apigenin or a combination of apigenin and paclitaxel. Apigenin and paclitaxel-induced HeLa cell apoptosis was related to the level of ROS in cells. We further evaluated activity and protein level of superoxide dismutase (SOD). Apigenin significantly inhibited SOD activity but did not alter the SOD protein level suggesting that apigenin promoted ROS accumulation through suppressing enzyme activity of SOD. Addition of Zn2+, Cu2+ and Mn2+ to cell lysates inhibited apigenin's effects on SOD activity. At the same time, data from caspase-2 over-expression and knocked-down experiments demonstrated that caspase-2 participated in apigenin and paclitaxel-induced HeLa cell apoptosis. Conclusions/Significance Taken together, our study demonstrated that apigenin can sensitize cancer cells to paclitaxel induced apoptosis through suppressing SOD activity, which then led to accumulation of ROS and cleavage of caspase-2, suggesting that the combined use of apigenin and paclitaxel was an effective way to decrease the dose of paclitaxel taken

  9. Synergistic effects of apigenin and paclitaxel on apoptosis of cancer cells.

    Directory of Open Access Journals (Sweden)

    Yimiao Xu

    Full Text Available BACKGROUND: It was well known that the clinical use of chemotherapeutic drugs is restricted by severe adverse reactions and drug resistances. Thus it is necessary to figure out a strategy to increase the specific anti-tumor efficiency of chemotherapeutic drugs. Apigenin, a kind of flavonoids, has been reported to possess anticancer activities with very low cytotoxicity to normal tissue. METHODOLOGY/PRINCIPAL FINDINGS: Our results from cell viability assay, western-blots and TdT-mediated dUTP-biotin nick end labeling (TUNEL assay demonstrated the synergistic pro-apoptotic effects of a low dose of apigenin and paclitaxel in human cancer cell lines. To analyze the underlying mechanism, we examined reactive oxygen species (ROS staining after cells were treated with a combination of apigenin and paclitaxel, or each of them alone. Data from flow-cytometry showed that superoxides but not reduction of peroxides accumulated in HeLa cells treated with apigenin or a combination of apigenin and paclitaxel. Apigenin and paclitaxel-induced HeLa cell apoptosis was related to the level of ROS in cells. We further evaluated activity and protein level of superoxide dismutase (SOD. Apigenin significantly inhibited SOD activity but did not alter the SOD protein level suggesting that apigenin promoted ROS accumulation through suppressing enzyme activity of SOD. Addition of Zn(2+, Cu(2+ and Mn(2+ to cell lysates inhibited apigenin's effects on SOD activity. At the same time, data from caspase-2 over-expression and knocked-down experiments demonstrated that caspase-2 participated in apigenin and paclitaxel-induced HeLa cell apoptosis. CONCLUSIONS/SIGNIFICANCE: Taken together, our study demonstrated that apigenin can sensitize cancer cells to paclitaxel induced apoptosis through suppressing SOD activity, which then led to accumulation of ROS and cleavage of caspase-2, suggesting that the combined use of apigenin and paclitaxel was an effective way to decrease the dose

  10. Oxaliplatin, a potent inhibitor of survivin, enhances paclitaxel-induced apoptosis and mitotic catastrophe in colon cancer cells.

    Science.gov (United States)

    Fujie, Yujiro; Yamamoto, Hirofumi; Ngan, Chew Yee; Takagi, Akimitsu; Hayashi, Taro; Suzuki, Rei; Ezumi, Koji; Takemasa, Ichiro; Ikeda, Masataka; Sekimoto, Mitsugu; Matsuura, Nariaki; Monden, Morito

    2005-08-01

    Clinical studies have demonstrated that oxaliplatin, a novel platinum derivative, is a potent chemotherapeutic agent, especially when combined with other reagents. The aim of the present study was to explore the mechanism of such action. Using colon cancer cell lines, we examined changes in cell cycle, apoptosis and mitotic catastrophe induced by oxaliplatin and/or paclitaxel. Oxaliplatin at its IC(50) induced apoptosis and cell cycle arrest at G(2)-M phase. Western blot analyses indicated that oxaliplatin decreased mitosis-commencing protein cdc2 and anti-apoptotic proteins, phospho-Bcl(2) and Bcl-xl in the three colon cancer cells tested. Since cdc2 stabilizes survivin, a putative IAP (inhibitor of apoptosis) family member, through phosphorylation of Thr34, we examined the level of survivin and found a marked decrease due to oxaliplatin. This finding is of particular interest because survivin is a promising molecular target against various human cancers and a key molecule involved in both apoptosis and mitotic catastrophe. When used in combination with paclitaxel (taxol), a putative apoptosis-inducing reagent, the isobologram indicated that the taxol-oxaliplatin sequence or taxol plus oxaliplatin had synergic or additive effects, while the oxaliplatin-taxol sequence resulted in a prominent antagonism. The taxol-oxaliplatin sequence caused marked growth inhibition of DLD1 and SW480 cells, possibly due to upregulation of apoptotic and non-apoptotic pathways, respectively. Morphological surveys indicated that the non-apoptotic process could be mitotic catastrophe. Our results suggest that oxaliplatin that potently inhibited survivin may exert outstanding cytotoxic effects when combined with certain chemoreagents through enhancement of apoptosis and mitotic catastrophe.

  11. A novel paclitaxel-loaded poly(d,l-lactide-co-glycolide)-Tween 80 copolymer nanoparticle overcoming multidrug resistance for lung cancer treatment.

    Science.gov (United States)

    Yuan, Xun; Ji, Wenxiang; Chen, Si; Bao, Yuling; Tan, Songwei; Lu, Shun; Wu, Kongming; Chu, Qian

    2016-01-01

    Drug resistance has become a main obstacle for the effective treatment of lung cancer. To address this problem, a novel biocompatible nanoscale package, poly(d,l-lactide-co-glycolide)-Tween 80, was designed and synthesized to overcome paclitaxel (PTX) resistance in a PTX-resistant human lung cancer cell line. The poly(d,l-lactide-co-glycolide) (PLGA)-Tween 80 nanoparticles (NPs) could efficiently load PTX and release the drug gradually. There was an increased level of uptake of PLGA-Tween 80 in PTX-resistant lung cancer cell line A549/T, which achieved a significantly higher level of cytotoxicity than both PLGA NP formulation and Taxol(®). The in vivo antitumor efficacy also showed that PLGA-Tween 80 NP was more effective than Taxol(®), indicating that PLGA-Tween 80 copolymer was a promising carrier for PTX in resistant lung cancer.

  12. Automated Synthesis of 18F Analogue of Paclitaxel (PAC): [18F]Paclitaxel (FPAC)

    OpenAIRE

    2006-01-01

    A positron-emitting paclitaxel (PAC) derivative could allow in-vivo measurement of multidrug resistance in tumors and, therefore, predict a potential chemotherapeutic benefit to patients. [18F]Paclitaxel was produced using a 2-reaction vessel automated synthesizer followed by HPLC purification. Optimized reaction conditions resulted in radiochemical yields of 21.2 ± 9.6% at end of bombardment, radiochemical purity > 99%, and specific activity of 159 ± 43 GBq/μmol. [18F]Paclitaxel activities o...

  13. Biodegradable mixed MPEG-SS-2SA/TPGS micelles for triggered intracellular release of paclitaxel and reversing multidrug resistance

    Science.gov (United States)

    Dong, Kai; Yan, Yan; Wang, Pengchong; Shi, Xianpeng; Zhang, Lu; Wang, Ke; Xing, Jianfeng; Dong, Yalin

    2016-01-01

    In this study, a type of multifunctional mixed micelles were prepared by a novel biodegradable amphiphilic polymer (MPEG-SS-2SA) and a multidrug resistance (MDR) reversal agent (d-α-tocopheryl polyethylene glycol succinate, TPGS). The mixed micelles could achieve rapid intracellular drug release and reversal of MDR. First, the amphiphilic polymer, MPEG-SS-2SA, was synthesized through disulfide bonds between poly (ethylene glycol) monomethyl ether (MPEG) and stearic acid (SA). The structure of the obtained polymer was similar to poly (ethylene glycol)-phosphatidylethanolamine (PEG-PE). Then the mixed micelles, MPEG-SS-2SA/TPGS, were prepared by MPEG-SS-2SA and TPGS through the thin film hydration method and loaded paclitaxel (PTX) as the model drug. The in vitro release study revealed that the mixed micelles could rapidly release PTX within 24 h under a reductive environment because of the breaking of disulfide bonds. In cell experiments, the mixed micelles significantly inhibited the activity of mitochondrial respiratory complex II, also reduced the mitochondrial membrane potential, and the content of adenosine triphosphate, thus effectively inhibiting the efflux of PTX from cells. Moreover, in the confocal laser scanning microscopy, cellular uptake and 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assays, the MPEG-SS-2SA/TPGS micelles achieved faster release and more uptake of PTX in Michigan Cancer Foundation-7/PTX cells and showed better antitumor effects as compared with the insensitive control. In conclusion, the biodegradable mixed micelles, MPEG-SS-2SA/TPGS, could be potential vehicles for delivering hydrophobic chemotherapeutic drugs in MDR cancer therapy. PMID:27785018

  14. Extracellular Vesicle-Mediated Reversal of Paclitaxel Resistance in Prostate Cancer

    Science.gov (United States)

    Wang, Justin Q.; DeChalus, Austin; Chatterjee, Devin N.; Keller, Evan T.; Mizokami, Atsushi; Camussi, Giovanni; Mendelsohn, Andrew R.; Renzulli, Joseph F.; Quesenberry, Peter J.; Chatterjee, Devasis

    2017-01-01

    Prostate cancer (PCa) is the most common solid tumor in males and the second leading cause of cancer-related deaths in males in the United States. The current first line therapy for metastatic PCa is androgen deprivation therapy and is initially effective against the disease. However, castrate resistant prostate cancer (CRPC) develops in many men within 18–36 months, rendering this treatment ineffective. Chemotherapy, with a class of drugs known as taxanes is the standard-of-care cytotoxic option in metastatic castrate resistant PCa (mCRPC). However, the overall survival advantage for chemotherapy in mCRPC is only 2.2 months and the cancer cells often become resistant to these drugs as well. Once patients fail chemotherapy the progression to death is inevitable. Extracellular vesicles (EVs) are involved in cell signaling and play a role in cancer progression. Previous work has demonstrated that EVs are involved in the development of drug resistance in cancer cells. We report the reversal of taxane resistance and tumorigenic phenotype in PCa cells after EVs treatment. This study suggests that EVs represent a potentially novel therapeutic treatment option for CRPC. PMID:27279238

  15. Gene expression profile of sodium channel subunits in the anterior cingulate cortex during experimental paclitaxel-induced neuropathic pain in mice

    Science.gov (United States)

    2016-01-01

    Paclitaxel, a chemotherapeutic agent, causes neuropathic pain whose supraspinal pathophysiology is not fully understood. Dysregulation of sodium channel expression, studied mainly in the periphery and spinal cord level, contributes to the pathogenesis of neuropathic pain. We examined gene expression of sodium channel (Nav) subunits by real time polymerase chain reaction (PCR) in the anterior cingulate cortex (ACC) at day 7 post first administration of paclitaxel, when mice had developed paclitaxel-induced thermal hyperalgesia. The ACC was chosen because increased activity in the ACC has been observed during neuropathic pain. In the ACC of vehicle-treated animals the threshold cycle (Ct) values for Nav1.4, Nav1.5, Nav1.7, Nav1.8 and Nav1.9 were above 30 and/or not detectable in some samples. Thus, comparison in mRNA expression between untreated control, vehicle-treated and paclitaxel treated animals was done for Nav1.1, Nav1.2, Nav1.3, Nav1.6, Nax as well as Navβ1–Navβ4. There were no differences in the transcript levels of Nav1.1–Nav1.3, Nav1.6, Nax, Navβ1–Navβ3 between untreated and vehicle-treated mice, however, vehicle treatment increased Navβ4 expression. Paclitaxel treatment significantly increased the mRNA expression of Nav1.1, Nav1.2, Nav1.6 and Nax, but not Nav1.3, sodium channel alpha subunits compared to vehicle-treated animals. Treatment with paclitaxel significantly increased the expression of Navβ1 and Navβ3, but not Navβ2 and Navβ4, sodium channel beta subunits compared to vehicle-treated animals. These findings suggest that during paclitaxel-induced neuropathic pain (PINP) there is differential upregulation of sodium channels in the ACC, which might contribute to the increased neuronal activity observed in the area during neuropathic pain. PMID:27896032

  16. Gene expression profile of sodium channel subunits in the anterior cingulate cortex during experimental paclitaxel-induced neuropathic pain in mice

    Directory of Open Access Journals (Sweden)

    Willias Masocha

    2016-11-01

    Full Text Available Paclitaxel, a chemotherapeutic agent, causes neuropathic pain whose supraspinal pathophysiology is not fully understood. Dysregulation of sodium channel expression, studied mainly in the periphery and spinal cord level, contributes to the pathogenesis of neuropathic pain. We examined gene expression of sodium channel (Nav subunits by real time polymerase chain reaction (PCR in the anterior cingulate cortex (ACC at day 7 post first administration of paclitaxel, when mice had developed paclitaxel-induced thermal hyperalgesia. The ACC was chosen because increased activity in the ACC has been observed during neuropathic pain. In the ACC of vehicle-treated animals the threshold cycle (Ct values for Nav1.4, Nav1.5, Nav1.7, Nav1.8 and Nav1.9 were above 30 and/or not detectable in some samples. Thus, comparison in mRNA expression between untreated control, vehicle-treated and paclitaxel treated animals was done for Nav1.1, Nav1.2, Nav1.3, Nav1.6, Nax as well as Navβ1–Navβ4. There were no differences in the transcript levels of Nav1.1–Nav1.3, Nav1.6, Nax, Navβ1–Navβ3 between untreated and vehicle-treated mice, however, vehicle treatment increased Navβ4 expression. Paclitaxel treatment significantly increased the mRNA expression of Nav1.1, Nav1.2, Nav1.6 and Nax, but not Nav1.3, sodium channel alpha subunits compared to vehicle-treated animals. Treatment with paclitaxel significantly increased the expression of Navβ1 and Navβ3, but not Navβ2 and Navβ4, sodium channel beta subunits compared to vehicle-treated animals. These findings suggest that during paclitaxel-induced neuropathic pain (PINP there is differential upregulation of sodium channels in the ACC, which might contribute to the increased neuronal activity observed in the area during neuropathic pain.

  17. Acute pancreatitis induced by paclitaxel and carboplatin therapy in an ovarian cancer patient.

    Science.gov (United States)

    Shintani, D; Yoshida, H; Imai, Y; Fujiwara, K

    2016-01-01

    A 46-year-old female was treated with a regimen of paclitaxel and carboplatin (TC therapy) as adjuvant chemotherapy for Stage IC ovarian adenocarcinoma. There was no severe toxicity except for grade 3 neutropenia during the first four cycles of TC therapy. However, she developed acute pancreatitis at 14 days after fifth cycle. TC therapy is commonly associated with adverse effects such as myelosuppression, hypersensitivity, alopecia, and peripheral neuropathy, but acute pancreatitis has rarely been reported. Ovarian cancer patients often present with nausea and abdominal pain, which are the same symptoms of pancreatitis. It is very important to keep in mind that acute pancreatitis may be concealed in these common symptoms of ovarian cancer during and after TC therapy. Because acute pancreatitis is fatal complication and quitting the drug usually leads to complete cure. The authors report an uncommon case in which TC therapy may have caused acute pancreatitis.

  18. Biodegradable mixed MPEG-SS-2SA/TPGS micelles for triggered intracellular release of paclitaxel and reversing multidrug resistance

    Directory of Open Access Journals (Sweden)

    Dong K

    2016-10-01

    Full Text Available Kai Dong,1 Yan Yan,2 Pengchong Wang,2 Xianpeng Shi,2 Lu Zhang,2 Ke Wang,2 Jianfeng Xing,2 Yalin Dong1 1Department of Pharmacy, The First Affiliated Hospital of Xi’an Jiaotong University, 2School of Pharmacy, Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China Abstract: In this study, a type of multifunctional mixed micelles were prepared by a novel biodegradable amphiphilic polymer (MPEG-SS-2SA and a multidrug resistance (MDR reversal agent (D-α-tocopheryl polyethylene glycol succinate, TPGS. The mixed micelles could achieve rapid intracellular drug release and reversal of MDR. First, the amphiphilic polymer, MPEG-SS-2SA, was synthesized through disulfide bonds between poly (ethylene glycol monomethyl ether (MPEG and stearic acid (SA. The structure of the obtained polymer was similar to poly (ethylene glycol-phosphatidylethanolamine (PEG-PE. Then the mixed micelles, MPEG-SS-2SA/TPGS, were prepared by MPEG-SS-2SA and TPGS through the thin film hydration method and loaded paclitaxel (PTX as the model drug. The in vitro release study revealed that the mixed micelles could rapidly release PTX within 24 h under a reductive environment because of the breaking of disulfide bonds. In cell experiments, the mixed micelles significantly inhibited the activity of mitochondrial respiratory complex II, also reduced the mitochondrial membrane potential, and the content of adenosine triphosphate, thus effectively inhibiting the efflux of PTX from cells. Moreover, in the confocal laser scanning microscopy, cellular uptake and 3-(4,5-dimethyl-thiazol-2-yl-2,5-diphenyl-tetrazolium bromide assays, the MPEG-SS-2SA/TPGS micelles achieved faster release and more uptake of PTX in Michigan Cancer Foundation-7/PTX cells and showed better antitumor effects as compared with the insensitive control. In conclusion, the biodegradable mixed micelles, MPEG-SS-2SA/TPGS, could be potential vehicles for delivering hydrophobic chemotherapeutic drugs in

  19. Synthesis of Paclitaxel Analogs

    OpenAIRE

    Xu, Zhibing

    2010-01-01

    Paclitaxel is one of the most successful anti-cancer drugs, particularly in the treatment of breast cancer and ovarian cancer. For the investigation of the interaction between paclitaxel and MD-2 protein, and development of new antagonists for lipopolysaccharide, several C10 A-nor-paclitaxel analogs have been synthesized and their biological activities have been evaluated. In order to reduce the myelosuppression effect of the paclitaxel, several C3â ² and C4 paclitaxel analogs have been synth...

  20. A3 adenosine receptor agonist prevents the development of paclitaxel-induced neuropathic pain by modulating spinal glial-restricted redox-dependent signaling pathways.

    Science.gov (United States)

    Janes, Kali; Esposito, Emanuela; Doyle, Timothy; Cuzzocrea, Salvatore; Tosh, Dillip K; Jacobson, Kenneth A; Salvemini, Daniela

    2014-12-01

    Chemotherapy-induced peripheral neuropathy accompanied by chronic neuropathic pain is the major dose-limiting toxicity of several anticancer agents including the taxane paclitaxel (Taxol). A critical mechanism underlying paclitaxel-induced neuropathic pain is the increased production of peroxynitrite in spinal cord generated in response to activation of the superoxide-generating enzyme, NADPH oxidase. Peroxynitrite in turn contributes to the development of neuropathic pain by modulating several redox-dependent events in spinal cord. We recently reported that activation of the Gi/Gq-coupled A3 adenosine receptor (A3AR) with selective A3AR agonists (ie, IB-MECA) blocked the development of chemotherapy induced-neuropathic pain evoked by distinct agents, including paclitaxel, without interfering with anticancer effects. The mechanism or mechanisms of action underlying these beneficial effects has yet to be explored. We now demonstrate that IB-MECA attenuates the development of paclitaxel-induced neuropathic pain by inhibiting the activation of spinal NADPH oxidase and two downstream redox-dependent systems. The first relies on inhibition of the redox-sensitive transcription factor (NFκB) and mitogen activated protein kinases (ERK and p38) resulting in decreased production of neuroexcitatory/proinflammatory cytokines (TNF-α, IL-1β) and increased formation of the neuroprotective/anti-inflammatory IL-10. The second involves inhibition of redox-mediated posttranslational tyrosine nitration and modification (inactivation) of glia-restricted proteins known to play key roles in regulating synaptic glutamate homeostasis: the glutamate transporter GLT-1 and glutamine synthetase. Our results unravel a mechanistic link into biomolecular signaling pathways employed by A3AR activation in neuropathic pain while providing the foundation to consider use of A3AR agonists as therapeutic agents in patients with chemotherapy-induced peripheral neuropathy. Copyright © 2014

  1. Modulation of MDR1 and MRP3 gene expression in lung cancer cells after paclitaxel and carboplatin exposure.

    Science.gov (United States)

    Melguizo, Consolación; Prados, Jose; Luque, Raquel; Ortiz, Raúl; Caba, Octavio; Alvarez, Pablo J; Gonzalez, Beatriz; Aranega, Antonia

    2012-12-05

    Carboplatin-paclitaxel is a reference regimen in the treatment of locally advanced or disseminated non-small cell lung cancer (NSCLC). This paper discusses the multidrug resistance developed with this drug combination, which is one of the major obstacles to successful treatment. In order to understand and overcome the drug resistance pattern of NSCLC after carboplatin plus paclitaxel exposure, levels of mRNA expression of multidrug resistance 1 (MDR1) and multidrug resistance-associated protein 3 (MRP3) were investigated in primary NSCLC cell lines (A-549 and A-427) and a metastasis-derived NSCLC cell line (NODO). Our results showed that exposure of the three NSCLC lines to plasma concentrations of paclitaxel (5 μM) produced an increase in MDR1 expression, while MRP3 showed no alteration in expression. By contrast, the same cells exposed to carboplatin plasma concentrations (30 μM) showed overexpression of MRP3. In these cells, MDR1 showed no expression changes. Interestingly, the combination of both paclitaxel and carboplatin caused increased expression of the MDR1 drug resistance gene rather than the individual treatments. These results suggest that carboplatin and paclitaxel may induce drug resistance mediated by MDR1 and MRP3, which may be enhanced by the simultaneous use of both drugs.

  2. Modulation of MDR1 and MRP3 Gene Expression in Lung Cancer Cells after Paclitaxel and Carboplatin Exposure

    Directory of Open Access Journals (Sweden)

    Consolación Melguizo

    2012-12-01

    Full Text Available Carboplatin-paclitaxel is a reference regimen in the treatment of locally advanced or disseminated non-small cell lung cancer (NSCLC. This paper discusses the multidrug resistance developed with this drug combination, which is one of the major obstacles to successful treatment. In order to understand and overcome the drug resistance pattern of NSCLC after carboplatin plus paclitaxel exposure, levels of mRNA expression of multidrug resistance 1 (MDR1 and multidrug resistance-associated protein 3 (MRP3 were investigated in primary NSCLC cell lines (A-549 and A-427 and a metastasis-derived NSCLC cell line (NODO. Our results showed that exposure of the three NSCLC lines to plasma concentrations of paclitaxel (5 μM produced an increase in MDR1 expression, while MRP3 showed no alteration in expression. By contrast, the same cells exposed to carboplatin plasma concentrations (30 μM showed overexpression of MRP3. In these cells, MDR1 showed no expression changes. Interestingly, the combination of both paclitaxel and carboplatin caused increased expression of the MDR1 drug resistance gene rather than the individual treatments. These results suggest that carboplatin and paclitaxel may induce drug resistance mediated by MDR1 and MRP3, which may be enhanced by the simultaneous use of both drugs.

  3. Overexpression of stathmin is resistant to paclitaxel treatment in patients with non-small cell lung cancer.

    Science.gov (United States)

    Sun, Ruifang; Liu, Zhigang; Wang, Lumin; Lv, Weidong; Liu, Jia; Ding, Caixia; Yuan, Yong; Lei, Guangyan; Xu, Changfu

    2015-09-01

    Paclitaxel can exert therapeutic effects by interacting with microtubules. Stathmin and β-III-tubulin, which have impact on microtubule activity, are believed to be involved in the chemotherapy. The purpose of the present study was to evaluate the associations between stathmin and β-III-tubulin expression and treatment response and survivals in patients with non-small cell lung cancer (NSCLC). Two hundred thirty-eight patients who were treated by platinum-based chemotherapy were enrolled in this study, among them, 111 patients also received paclitaxel treatment. Formalin-fixed and paraffin-embedded tumor tissues were collected for messenger RNA (mRNA) and protein detection. We assessed the associations of the two molecules with treatment response and survival outcome. High level of stathmin exhibited poor response to chemotherapy (for mRNA, P = 0.041; for protein, P = 0.017). Overexpression of stathmin was associated with shorter overall survival (for mRNA, P = 0.012; for protein, P = 0.014) and progression-free survival (for mRNA, P = 0.039; for protein, P = 0.022). Of note, this association was only observed in patients who were treated by both platinum and paclitaxel. Similar effects were not observed for β-III-tubulin. The findings demonstrated that paclitaxel effect may be interfered with stathmin; overexpression of stathmin is a predictive marker for a worse prognosis in patients with NSCLC who were treated by both platinum and paclitaxel chemotherapy.

  4. Down-regulated βIII-tubulin Expression Can Reverse Paclitaxel Resistance in A549/Taxol Cells Lines

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    Yinling ZHUO

    2014-08-01

    Full Text Available Background and objective Chemotherapy drug resistance is the primary causes of death in patients with pulmonary carcinoma which make tumor recurrence or metastasis. β-tubulin is the main cell targets of anti-microtubule drug. Increased expression of βIII-tubulin has been implicated in non-small cell lung cancer (NSCLC cell lines. To explore the relationship among the expression level of βIII-tubulin and the sensitivity of A549/Taxolcell lines to Taxol and cell cycles and cell apoptosis by RNA interference-mediated inhibition of βIII-tubulin in A549/Taxol cells. Methods Three pairs of siRNA targetd βIII-tubulin were designed and prepared, which were transfected into A549/Taxol cells using LipofectamineTM 2000. We detected the expression of βIII-tubulin mRNA using Real-time fluorescence qRT-PCR. Tedhen we selected the most efficient siRNA by the expression of βIII-tubulin mRNA in transfected group. βIII-tubulin protein level were mesured by Western blot. The taxol sensitivity in transfected group were evaluated by MTT assay. And the cell apoptosis and cell cycles were determined by flow cytometry. Results βIII-tubulin mRNA levels in A549/Taxol cells were significantly decreased in transfected grop by Real-time qRT-PCR than control groups. And βIII-tubulin siRNA-1 sequence showed the highest transfection efficiency, which was (87.73±4.87% (P<0.01; Western blot results showed that the expressional level of BIII tublin protein was significantly down-reulated in the transfectant cells than thant in the control cells. By MTT assay, we showed that the inhibition ratio of Taxol to A549/Taxol cells transfeced was higher than that of control group (51.77±4.60% (P<0.01. The early apoptosis rate of A549/Taxol cells in transfected group were significantly higher than that of control group (P<0.01; G2-M content in taxol group obviously increased than untreated samples by the cell cycle (P<0.05. Conclusion βIII-tubulin down-regulated significantly

  5. Inhibition of glycogen synthase kinase 3β activity with lithium prevents and attenuates paclitaxel-induced neuropathic pain.

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    Gao, M; Yan, X; Weng, H-R

    2013-12-19

    Paclitaxel (taxol) is a first-line chemotherapy-drug used to treat many types of cancers. Neuropathic pain and sensory dysfunction are the major toxicities, which are dose-limiting and significantly reduce the quality of life in patients. Two known critical spinal mechanisms underlying taxol-induced neuropathic pain are an increased production of pro-inflammatory cytokines including interleukin-1β (IL-1β) and suppressed glial glutamate transporter activities. In this study, we uncovered that increased activation of glycogen synthase kinase 3beta (GSK3β) in the spinal dorsal horn was concurrently associated with increased protein expressions of GFAP, IL-1β and a decreased protein expression of glial glutamate transporter 1 (GLT-1), as well as the development and maintenance of taxol-induced neuropathic pain. The enhanced GSK3β activities were supported by the concurrently decreased AKT and mTOR activities. The changes of all these biomarkers were basically prevented when animals received pre-emptive lithium (a GSK3β inhibitor) treatment, which also prevented the development of taxol-induced neuropathic pain. Further, chronic lithium treatment, which began on day 11 after the first taxol injection, reversed the existing mechanical and thermal allodynia induced by taxol. The taxol-induced increased GSK3β activities and decreased AKT and mTOR activities in the spinal dorsal horn were also reversed by lithium. Meanwhile, protein expressions of GLT-1, GFAP and IL-1β in the spinal dorsal horn were improved. Hence, suppression of spinal GSK3β activities is a key mechanism used by lithium to reduce taxol-induced neuropathic pain, and targeting spinal GSK3β is an effective approach to ameliorate GLT-1 expression and suppress the activation of astrocytes and IL-1β over-production in the spinal dorsal horn.

  6. Paclitaxel and the dietary flavonoid fisetin: a synergistic combination that induces mitotic catastrophe and autophagic cell death in A549 non-small cell lung cancer cells.

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    Klimaszewska-Wisniewska, Anna; Halas-Wisniewska, Marta; Tadrowski, Tadeusz; Gagat, Maciej; Grzanka, Dariusz; Grzanka, Alina

    2016-01-01

    The use of the dietary polyphenols as chemosensitizing agents to enhance the efficacy of conventional cytostatic drugs has recently gained the attention of scientists and clinicians as a plausible approach for overcoming the limitations of chemotherapy (e.g. drug resistance and cytotoxicity). The aim of this study was to investigate whether a naturally occurring diet-based flavonoid, fisetin, at physiologically attainable concentrations, could act synergistically with clinically achievable doses of paclitaxel to produce growth inhibitory and/or pro-death effects on A549 non-small cell lung cancer cells, and if it does, what mechanisms might be involved. The drug-drug interactions were analyzed based on the combination index method of Chou and Talalay and the data from MTT assays. To provide some insights into the mechanism underlying the synergistic action of fisetin and paclitaxel, selected morphological, biochemical and molecular parameters were examined, including the morphology of cell nuclei and mitotic spindles, the pattern of LC3-II immunostaining, the formation of autophagic vacuoles at the electron and fluorescence microscopic level, the disruption of cell membrane asymmetry/integrity, cell cycle progression and the expression level of LC3-II, Bax, Bcl-2 and caspase-3 mRNA. Here, we reported the first experimental evidence for the existence of synergism between fisetin and paclitaxel in the in vitro model of non-small cell lung cancer. This synergism was, at least partially, ascribed to the induction of mitotic catastrophe. The switch from the cytoprotective autophagy to the autophagic cell death was also implicated in the mechanism of the synergistic action of fisetin and paclitaxel in the A549 cells. In addition, we revealed that the synergism between fisetin and paclitaxel was cell line-specific as well as that fisetin synergizes with arsenic trioxide, but not with mitoxantrone and methotrexate in the A549 cells. Our results provide rationale for

  7. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean, carn

  8. [A Case of Albumin-Bound Paclitaxel-Induced Peripheral Neuropathy without Exacerbation].

    Science.gov (United States)

    Uchiyama, Masanobu; Goto, Toshitaka; Ueno, Miho; Kakimoto, Hideki; Mashima, Kouta; Ikari, Yousuke; Takamatsu, Yasushi; Ogata, Kentaro; Kamimura, Hidetoshi

    2017-06-01

    Albumin-bound paclitaxel(nab-PTX)-associated neuropathy decreases the quality of life of cancer patients and leads to dose modification, discontinuation of chemotherapy, and occasionally dose-limiting toxicity. In the present case study, a 92- year-old female patient with peritoneal cancer of carcinomatous peritonitis and carcinomatous ascites was treated with carboplatin plus nab-PTX every 4 weeks as first-line chemotherapy, and a good response was achieved following 4 cycles of this regimen. However, the patient developed Grade 3 peripheral neuropathy and stopped the therapy. As a result, the peripheral neuropathy gradually improved. After 1 year, ascites appeared, and tumor marker(CA125)levels increased. We tried an 8-h infusion of nab-PTX to avoid peripheralneuropathy. After 4 cycles, a positive response was achieved without exacerbation of the peripheralneuropathy. Administering nab-PTX over shorter periods of time has generally led to increased peripheral neuropathy. The severity of peripheralneuropathy can be reduced with a longer infusion time.

  9. How Taxol/paclitaxel kills cancer cells.

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    Weaver, Beth A

    2014-09-15

    Taxol (generic name paclitaxel) is a microtubule-stabilizing drug that is approved by the Food and Drug Administration for the treatment of ovarian, breast, and lung cancer, as well as Kaposi's sarcoma. It is used off-label to treat gastroesophageal, endometrial, cervical, prostate, and head and neck cancers, in addition to sarcoma, lymphoma, and leukemia. Paclitaxel has long been recognized to induce mitotic arrest, which leads to cell death in a subset of the arrested population. However, recent evidence demonstrates that intratumoral concentrations of paclitaxel are too low to cause mitotic arrest and result in multipolar divisions instead. It is hoped that this insight can now be used to develop a biomarker to identify the ∼50% of patients that will benefit from paclitaxel therapy. Here I discuss the history of paclitaxel and our recently evolved understanding of its mechanism of action.

  10. A preliminary study of imaging paclitaxel-induced tumor apoptosis with 99Tcm-His10-Annexin V

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yu-min; WANG Feng; FANG Wei; HUA Zi-chun; WANG Zi-zheng; MENG Qing-le; YAN Jue

    2013-01-01

    Backgroud In tumors the process of apoptosis occurs over an interval of time after chemotherapy.It is important to determine the best time for detecting apoptosis by in vivo imaging.In this study,we evaluated the dynamics and feasibility of imaging non-small cell lung cancer (NSCLC) apoptosis induced by paclitaxel treatment using a 99Tcm-labeled Annexin V recombinant with ten consecutive histidines (His10-Annexin V) in a mouse model.Methods 99Tcm-His10-Annexin V was prepared by one step direct labeling; radio-chemical purity (RCP) and radio-stability was tested.The binding of 99Tcm-His10-Annexin V to apoptotic cells was validated in vitro using camptothecin-induced Jurkat cells.In vivo bio-distribution was determined in mice by dissection.The human H460 NSCLC tumor cell line (H460) tumor-bearing mice were treated with intravenous paclitaxel 24,48 and 72 hours later.99Tcm-His10-Annexin V was injected intravenously,and planar images were acquired at 2,4 and 6 hours post-injection on a dual-head gamma camera fitted with a pinhole collimator.Tumor-to-normal tissue ratios (T/NT) were calculated by ROI analysis and they reflected specific binding of 99Tcm-His10-Annexin V.Mice were sacrificed after imaging.Caspase-3,as the apoptosis detector,was determined by flow cytometry,and DNA fragmentation was analyzed by the terminal deoxynucleotidytransferase mediated dUTP nick-end labeling (TUNEL) assay.Nonspecific accumulation of protein was estimated using bovine serum albumin (BSA).The imaging data were correlated with TUNEL-positive nuclei and caspase-3 activity.Results 99Tcm-His10-Annexin V had a RCP >98% and high stability 2 hours after radio-labeling,and it could bind to apoptotic cells with high affinity.Bio-distribution of 99Tcm-His10-Annexin V showed predominant uptake in kidney,relatively low uptake in myocardium,liver and gastrointestinal tract,and rapid clearance from blood and kidney was observed.The T/NT was significantly increased after paclitaxel treatment

  11. Effect of sun ginseng potentiation on epirubicin and paclitaxel-induced apoptosis in human cervical cancer cells

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    Yingjia Lin

    2015-01-01

    Conclusion: SG significantly potentiated the anticancer activities of epirubicin and paclitaxel in a synergistic manner. These effects were associated with the increased mitochondrial accumulation of both Bax and Bak that led to an enhanced cytochrome c release, caspase-9/-3 activation, and apoptosis. Treating cancer cells by combining epirubicin and paclitaxel with SG may prove to be a novel strategy for enhancing the efficacy of the two drug types.

  12. Paclitaxel Through the Ages of Anticancer Therapy: Exploring Its Role in Chemoresistance and Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Anna Maria Barbuti

    2015-12-01

    Full Text Available Paclitaxel (Taxol® is a member of the taxane class of anticancer drugs and one of the most common chemotherapeutic agents used against many forms of cancer. Paclitaxel is a microtubule-stabilizer that selectively arrests cells in the G2/M phase of the cell cycle, and found to induce cytotoxicity in a time and concentration-dependent manner. Paclitaxel has been embedded in novel drug formulations, including albumin and polymeric micelle nanoparticles, and applied to many anticancer treatment regimens due to its mechanism of action and radiation sensitizing effects. Though paclitaxel is a major anticancer drug which has been used for many years in clinical treatments, its therapeutic efficacy can be limited by common encumbrances faced by anticancer drugs. These encumbrances include toxicities, de novo refraction, and acquired multidrug resistance (MDR. This article will give a current and comprehensive review of paclitaxel, beginning with its unique history and pharmacology, explore its mechanisms of drug resistance and influence in combination with radiation therapy, while highlighting current treatment regimens, formulations, and new discoveries.

  13. Comparative study among glutamine, acetyl-L-carnitine, vitamin-E and methylcobalamine for treatment of paclitaxel-induced peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Santu Mondal

    2014-01-01

    Full Text Available Context: One of the major toxicity of paclitaxel is peripheral neuropathy. Sensory components are affected more than motor and autonomic dysfunction. Aims: Acetyl-L-carnitine (ALC, methylcobalamine, vitamin E and glutamine have been used in various trials against placebos. With head on trials among these four drugs missing, this randomized study was conducted to compare the efficacy in relieving symptoms of paclitaxel induced peripheral neuropathy. Settings and Design : This single institutional, prospective, multi-arm, randomized study was conducted as per Helsinki protocol and with local ethical committee clearances. Materials and Methods: Patients of carcinomas of lung, breast and ovary recruited, would receive paclitaxel 175 mg/m 2 intravenous as 1 st or 2 nd line drug. They underwent randomization to any of four treatment arms: Arm A (vitamin E 400 mg OD day 1 of the cycle to 1 month after completion of clinical trial [CT]; Arm B (ALC 250 mg OD from day 1 to day 7 in each cycle of CT; Arm C (glutamine 10 mg TDS from day 2 to day 5 in each cycle and Arm D (methylcobalamine 500 μg TDS from day 1 of the first cycle to 1 month after completion of CT. All drugs were started at the onset of symptoms. CTCAE v 4.02 was used for assessments. Statistical Analysis Used : Changes in scores for sensory, motor and pain symptoms over the study period were compared using repeated measures of General Linear Model of SPSS version 17. Results : 22, 24, 21 and 23 patients were eligible for analysis in four arms. Vitamin E was producing comparable relief as methylcobalamine of peripheral neuropathy. Both vitamin E and methylcobalamine was superior to glutamine and ALC in relieving sensory, motor and pain symptoms. Glutamine and ALC had comparable effects. Conclusions: All four drugs were effective in the alleviation of symptoms with vitamin E and methylcobalaine more effective than glutamine and ALC in control of symptoms of paclitaxel induced peripheral

  14. Changes of Survivin mRNA and Protein Expression during Paclitaxel Treatment in Breast Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    XIONG Huihua; YU Shiying; ZHUANG Liang; XIONG Hua

    2007-01-01

    In order to investigate the role of antiapoptosis gene, survivin in the resistance to palcitaxel, the expression of survivin mRNA and protein in the process of paclitaxel treatment in breast cancer cell line MCF-7 was detected. MCF-7 cells were incubated with paclitaxel at different concentrations. The growth inhibition rate of MCF-7 was investigated by tetrazolium bromide (MTT) colorimetry. The change of apoptosis was detected by Annexin-V/PI methods. The changes in the expression of survivin mRNA and protein were studied by reverse transcription polymerase chain reaction (RT-PCR) and Western-blot assay respectively. The growth inhibition rate of MCF-7 was increased in a concentration- and time-dependent manner. Paclitaxel of higher concentration could effectively induce apoptosis in MCF-7 cells after 48 h, while the expression of survivin was increased at early time (within 6 h) and decreased after 24 h regardless of treatment concentrations of paclitaxel. It suggested that tumor cells might evade the paclitaxel-induced cell cycle arrest and apoptosis by increasing the level of survivin at early treatment time.

  15. Synergistic effect of folate-mediated targeting and verapamil-mediated P-gp inhibition with paclitaxel -polymer micelles to overcome multi-drug resistance.

    Science.gov (United States)

    Wang, Feihu; Zhang, Dianrui; Zhang, Qiang; Chen, Yuxuan; Zheng, Dandan; Hao, Leilei; Duan, Cunxian; Jia, Lejiao; Liu, Guangpu; Liu, Yue

    2011-12-01

    Multidrug resistance (MDR) in tumor cells is a significant obstacle for successful cancer chemotherapy. Overexpression of drug efflux transporters such as P-glycoprotein (P-gp) is a key factor contributing to the development of tumor drug resistance. Verapamil (VRP), a P-gp inhibitor, has been reported to be able to reverse completely the resistance caused by P-gp. For optimal synergy, the drug and inhibitor combination may need to be temporally colocalized in the tumor cells. Herein, we investigated the effectiveness of simultaneous and targeted delivery of anticancer drug, paclitaxel (PTX), along with VRP, using DOMC-FA micelles to overcome tumor drug resistance. The floate-functionalized dual agent loaded micelles resulted in the similar cytotoxicity to PTX-loaded micelles/free VRP combination and co-administration of two single-agent loaded micelles, which was higher than that of PTX-loaded micelles. Enhanced therapeutic efficacy of dual agent micelles could be ascribe to increased accumulation of PTX in drug-resistant tumor cells. We suggest that the synergistic effect of folate receptor-mediated internalization and VRP-mediated overcoming MDR could be beneficial in treatment of MDR solid tumors by targeting delivery of micellar PTX into tumor cells. As a result, the difunctional micelle systems is a very promising approach to overcome tumor drug resistance. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  16. Optimizing anticancer drug treatment in pregnant cancer patients: pharmacokinetic analysis of gestation-induced changes for doxorubicin, epirubicin, docetaxel and paclitaxel.

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    van Hasselt, J G C; van Calsteren, K; Heyns, L; Han, S; Mhallem Gziri, M; Schellens, J H M; Beijnen, J H; Huitema, A D R; Amant, F

    2014-10-01

    Pregnant patients with cancer are increasingly treated with anticancer drugs, although the specific impact of pregnancy-induced physiological changes on the pharmacokinetics (PK) of anticancer drugs and associated implications for optimal dose regimens remains unclear. Our objectives were to quantify changes in PK during pregnancy for four frequently used anticancer agents doxorubicin, epirubicin, docetaxel and paclitaxel, and to determine associated necessary dose adjustments. A pooled analysis of PK data was carried out for pregnant (Pr) and nonpregnant (NPr) patients for doxorubicin (n = 16 Pr/59 NPr), epirubicin (n = 14 Pr/57 NPr), docetaxel (n = 3 Pr/32 NPr) and paclitaxel (n = 5 Pr/105 NPr). Compartmental nonlinear mixed effect models were used to describe the PK and gestational effects. Subsequently, we derived optimized dose regimens aiming to match to the area under the concentration-time curve (AUC) in nonpregnant patients. The effect of pregnancy on volumes of distribution for doxorubicin, epirubicin, docetaxel and paclitaxel were estimated as fold-change of change of 1.1 (RSE 9%), 1.19 (RSE 7%) and 1.92 (RSE 21%) were, respectively, estimated on CL. Calculated dose adjustment requirements for doxorubicin, epirubicin, docetaxel and paclitaxel were +5.5%, +8.0%, +16.9% and +37.8%, respectively. Estimated changes in infusion duration were marginal (changes during pregnancy. The suggested dose adaptations should only be implemented after conduct of further confirmatory studies of the PK during pregnancy. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. The maintenance of cisplatin- and paclitaxel-induced mechanical and cold allodynia is suppressed by cannabinoid CB2 receptor activation and independent of CXCR4 signaling in models of chemotherapy-induced peripheral neuropathy

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    Deng Liting

    2012-09-01

    Full Text Available Abstract Background Chemotherapeutic agents produce dose-limiting peripheral neuropathy through mechanisms that remain poorly understood. We previously showed that AM1710, a cannabilactone CB2 agonist, produces antinociception without producing central nervous system (CNS-associated side effects. The present study was conducted to examine the antinociceptive effect of AM1710 in rodent models of neuropathic pain evoked by diverse chemotherapeutic agents (cisplatin and paclitaxel. A secondary objective was to investigate the potential contribution of alpha-chemokine receptor (CXCR4 signaling to both chemotherapy-induced neuropathy and CB2 agonist efficacy. Results AM1710 (0.1, 1 or 5 mg/kg i.p. suppressed the maintenance of mechanical and cold allodynia in the cisplatin and paclitaxel models. Anti-allodynic effects of AM1710 were blocked by the CB2 antagonist AM630 (3 mg/kg i.p., but not the CB1 antagonist AM251 (3 mg/kg i.p., consistent with a CB2-mediated effect. By contrast, blockade of CXCR4 signaling with its receptor antagonist AMD3100 (10 mg/kg i.p. failed to attenuate mechanical or cold hypersensitivity induced by either cisplatin or paclitaxel. Moreover, blockade of CXCR4 signaling failed to alter the anti-allodynic effects of AM1710 in the paclitaxel model, further suggesting distinct mechanisms of action. Conclusions Our results indicate that activation of cannabinoid CB2 receptors by AM1710 suppresses both mechanical and cold allodynia in two distinct models of chemotherapy-induced neuropathic pain. By contrast, CXCR4 signaling does not contribute to the maintenance of chemotherapy-induced established neuropathy or efficacy of AM1710. Our studies suggest that CB2 receptors represent a promising therapeutic target for the treatment of toxic neuropathies produced by cisplatin and paclitaxel chemotherapeutic agents.

  18. Molecular mechanism of indirubin-3'-monoxime and Matrine in the reversal of paclitaxel resistance in NCI-H520/TAX25 cell line

    Institute of Scientific and Technical Information of China (English)

    LUO Su-xia; DENG Wen-ying; WANG Xin-feng; L(U) Hui-fang; HAN Li-li; CHEN Bei-bei; CHEN Xiao-bing

    2013-01-01

    Background Multidrug resistance (MDR) is a main reason for paclitaxel (TAX) treatment failure.Indirubin-3'-monoxime (IRO) and Matrine are traditional Chinese medicines,which may reverse the resistance of tumor cells to some chemotherapy drugs,but the relationship between paclitaxel resistance and Matrine is still unclear.The aim of this study was to explore the potential molecular mechanism of IRO and Matrine in reversal of TAX resistance.Methods In this study,MTT assay was used to measure the non-cytotoxic dosage of IRO and Matrine on NCI-H520/TAX25 cells and determine the reversal extent of TAX resistance under non-toxic doses.In addition,RT-PCR and Western blotting were used to evaluate the mRNA expression and the protein level of survivin,Oct-4,and Sox-2 in NCI-H520/FAX25 cells using semi-quantitative methods.Results There was no obvious inhibition on sensitive cell strains and drug-resistant strains,when the final concentration was at lest 4 μmol/L for IRO and 100 μmol/L for Matrine.So 4 μmol/L of IRO and 100 μmol/L of Matrine were considered as the reversal dosage.When 4 μmol/L of IRO or 100 μmol/L of Matrine were used together with TAX,the sensitivity to TAX increased evidently in NCI-H520/TAX2 cells; the reversal rate of IRO and Matrine was about 1.92 (43.56/22.6 nmol/L) and 1.74 (43.56/25.0 nmol/L),respectively.The mRNA expression and the protein level of survivin,Oct-4,and Sox-2 in NCI-H520/TAX25 decreased significantly (P <0.05) after addition of IRO or Matrine in TAX treatment,compared to that of TAX treatment alone.Conclusion The decrease in both mRNA expression and protein level of survivin,Oct-4,and Sox-2 might be the molecular mechanism,by which IRO and Matrine mediate the reversal of TAX resistance.

  19. Nanomedicine-nanoemulsion formulation improves safety and efficacy of the anti-cancer drug paclitaxel according to preclinical assessment.

    Science.gov (United States)

    Lee, King C; Maturo, Claudia; Rodriguez, Robert; Nguyen, Hoang-Lan; Shorr, Robert

    2011-08-01

    Paclitaxel is an important anticancer drug and is currently used to treat a variety of cancers, including ovarian carcinomas, breast cancer, non-small cell lung cancer, and AIDS-related Kaposi's sarcoma. The objectives of the studies were to assess and compare the safety and efficacy of EmPAC (a newly developed nanoemulsion formulation of paclitaxel) versus Taxol (the injectable formulation of paclitaxel involving the use of polyethylated or polyoxyl castor oil currently used in the clinic). The objectives were also to investigate the mechanism for the improved safety and efficacy of EmPAC over Taxol. These results showed that EmPAC had better anti-tumor efficacy than Taxol, according to in vitro cell culture studies and studies in animal tumor models. EmPAC had improved anti-tumor efficacy even in tumor cell lines that are known to be multi-drug resistant. Part of the mechanism of action for the improved efficacy may be related to EmPAC inducing greater cellular uptake of paclitaxel into tumor cells than Taxol did, according to the in vitro cell culture radioactive-labeled studies and in vitro cell culture antibody studies. It may also partly be because EmPAC delivered more paclitaxel to the tumor mass than Taxol, while the delivery of paclitaxel to other tissues (e.g., blood, muscle, liver, spleen, kidney and lung) were similar between the two formulations of paclitaxel, according to studies in animals with tumor xenograft. EmPAC also had better safety than Taxol according to toxicology studies in rabbits. This may be because EmPAC does not contain the toxic ingredients used in formulating Taxol (such as polyethylated or polyoxyl castor oil). These results support the clinical development of the nanoemulsion formulation of paclitaxel.

  20. Ototoxicity of paclitaxel in rat cochlear organotypic cultures

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    Dong, Yang [Shanghai University of Traditional Chinese Medicine, Shanghai 201203 (China); Center for Hearing and Deafness, University at Buffalo, NY 14214 (United States); Ding, Dalian; Jiang, Haiyan [Center for Hearing and Deafness, University at Buffalo, NY 14214 (United States); Shi, Jian-rong [Shanghai University of Traditional Chinese Medicine, Shanghai 201203 (China); Salvi, Richard [Center for Hearing and Deafness, University at Buffalo, NY 14214 (United States); Roth, Jerome A., E-mail: jaroth@buffalo.edu [Department of Pharmacology and Toxicology, University at Buffalo, NY 14214 (United States)

    2014-11-01

    Paclitaxel (taxol) is a widely used antineoplastic drug employed alone or in combination to treat many forms of cancer. Paclitaxel blocks microtubule depolymerization thereby stabilizing microtubules and suppressing cell proliferation and other cellular processes. Previous reports indicate that paclitaxel can cause mild to moderate sensorineural hearing loss and some histopathologic changes in the mouse cochlea; however, damage to the neurons and the underlying cell death mechanisms are poorly understood. To evaluate the ototoxicity of paclitaxel in more detail, cochlear organotypic cultures from postnatal day 3 rats were treated with paclitaxel for 24 or 48 h with doses ranging from 1 to 30 μM. No obvious histopathologies were observed after 24 h treatment with any of the paclitaxel doses employed, but with 48 h treatment, paclitaxel damaged cochlear hair cells in a dose-dependent manner and also damaged auditory nerve fibers and spiral ganglion neurons (SGN) near the base of the cochlea. TUNEL labeling was negative in the organ of Corti, but positive in SGN with karyorrhexis 48 h after 30 μM paclitaxel treatment. In addition, caspase-6, caspase-8 and caspase-9 labeling was present in SGN treated with 30 μM paclitaxel for 48 h. These results suggest that caspase-dependent apoptotic pathways are involved in paclitaxel-induced damage of SGN, but not hair cells in cochlea. - Highlights: • Paclitaxel was toxic to cochlear hair cells and spiral ganglion neurons. • Paclitaxel-induced spiral ganglion degeneration was apoptotic. • Paclitaxel activated caspase-6, -8 and -8 in spiral ganglion neurons.

  1. Induction of tumor necrosis factor by bryostatin 1 is involved in synergistic interactions with paclitaxel in human myeloid leukemia cells.

    Science.gov (United States)

    Wang, Shujie; Wang, Zhiliang; Dent, Paul; Grant, Steven

    2003-05-01

    Interactions between the protein kinase C (PKC) activator/down-regulator bryostatin 1 and paclitaxel have been examined in human myeloid leukemia cells (U937) and in highly paclitaxel-resistant cells ectopically expressing a Bcl-2 phosphorylation loop-deleted protein (Delta Bcl-2). Treatment (24 hours) of wild-type cells with paclitaxel (eg, 5 to 20 nM) in combination with 10 nM bryostatin 1 induced a marked increase in mitochondrial damage (eg, cytochrome c and Smac/DIABLO [second mitochondria-derived activator of caspases/direct IAP binding protein with low pI] release), caspase activation, Bid cleavage, and apoptosis; moreover, bryostatin 1 circumvented the block to paclitaxel-induced mitochondrial injury and apoptosis conferred by ectopic expression of the loop-deleted protein. Coadministration of tumor necrosis factor (TNF) soluble receptors, or ectopic expression of CrmA or dominant-negative caspase-8, abrogated potentiation of paclitaxel-induced mitochondrial injury and apoptosis by bryostatin 1, implicating the extrinsic apoptotic pathway in this process. Similar events occurred in HL-60 leukemia cells. Potentiation of paclitaxel-induced apoptosis in wild-type and mutant cells by bryostatin 1 was associated with increases in TNF-alpha mRNA and protein and was mimicked by exogenous TNF-alpha. Coadministration of the selective PKC inhibitor GFX (1 microM) blocked the increase in TNF-alpha mRNA levels and apoptosis in bryostatin 1/paclitaxel-treated cells. Lastly, synchronization of cells in G(2)M increased their sensitivity to TNF-alpha-associated lethality. Collectively, these findings indicate that in U937 cells, bryostatin 1 promotes paclitaxel-mediated mitochondrial injury and apoptosis, and circumvents resistance to cell death conferred by loss of the Bcl-2 phosphorylation domain, through the PKC-dependent induction of TNF-alpha. They further suggest that this process is amplified by paclitaxel-mediated arrest of cells in G(2)M, where they are more

  2. Automated synthesis of 18F analogue of paclitaxel (PAC): [18F]Paclitaxel (FPAC).

    Science.gov (United States)

    Kalen, Joseph D; Hirsch, Jerry I; Kurdziel, Karen A; Eckelman, William C; Kiesewetter, Dale O

    2007-06-01

    A positron-emitting paclitaxel (PAC) derivative could allow in vivo measurement of multidrug resistance in tumors and, therefore, predict a potential chemotherapeutic benefit to patients. [18F]Paclitaxel was produced using a 2-reaction vessel automated synthesizer followed by HPLC purification. Optimized reaction conditions resulted in radiochemical yields of 21.2+/-9.6% at end of bombardment, radiochemical purity >99%, and specific activity of 159+/-43 G Bq/micromol. [18F]Paclitaxel activities of 1.33+/-0.729 G Bq (n=7) were obtained in sterile, pyrogen-free solution for IV administration.

  3. Automated synthesis of {sup 18}F analogue of paclitaxel (PAC): [{sup 18}F]Paclitaxel (FPAC)

    Energy Technology Data Exchange (ETDEWEB)

    Kalen, Joseph D. [Molecular Imaging Center, Department of Radiology, Virginia Commonwealth University, Richmond, VA (United States)]. E-mail: jdkalen@vcu.edu; Hirsch, Jerry I. [Molecular Imaging Center, Department of Radiology, Virginia Commonwealth University, Richmond, VA (United States); Kurdziel, Karen A. [Molecular Imaging Center, Department of Radiology, Virginia Commonwealth University, Richmond, VA (United States); Eckelman, William C. [Molecular Tracer, LLC, Bethesda, MD (United States); Kiesewetter, Dale O. [Positron Emission Tomography Radiochemistry Group, NIBIB, National Institute of Health, Bethesda, MD (United States)

    2007-06-15

    A positron-emitting paclitaxel (PAC) derivative could allow in vivo measurement of multidrug resistance in tumors and, therefore, predict a potential chemotherapeutic benefit to patients. [{sup 18}F]Paclitaxel was produced using a 2-reaction vessel automated synthesizer followed by HPLC purification. Optimized reaction conditions resulted in radiochemical yields of 21.2+/-9.6% at end of bombardment, radiochemical purity >99%, and specific activity of 159+/-43GBq/{mu}mol. [{sup 18}F]Paclitaxel activities of 1.33+/-0.729GBq (n=7) were obtained in sterile, pyrogen-free solution for IV administration.

  4. Pharmacological and small interference RNA-mediated inhibition of breast cancer-associated fatty acid synthase (oncogenic antigen-519) synergistically enhances Taxol (paclitaxel)-induced cytotoxicity.

    Science.gov (United States)

    Menendez, Javier A; Vellon, Luciano; Colomer, Ramon; Lupu, Ruth

    2005-05-20

    The relationship between breast cancer-associated fatty acid synthase (FAS; oncogenic antigen-519) and chemotherapy-induced cell damage has not been studied. We examined the ability of C75, a synthetic slow-binding inhibitor of FAS activity, to modulate the cytotoxic activity of the microtubule-interfering agent Taxol (paclitaxel) in SK-Br3, MDA-MB-231, MCF-7 and multidrug-resistant MDR-1 (P-Glycoprotein)-overexpressing MCF-7/AdrR breast cancer cells. When the combination of C75 with Taxol in either concurrent (C75 + Taxol 24 hr) or sequential (C75 24 hr --> Taxol 24 hr) schedules were tested for synergism, addition or antagonism using the isobologram and the median-effect plot analyses, co-exposure of C75 and Taxol mostly demonstrated synergistic effects, whereas sequential exposure to C75 followed by Taxol mainly showed additive or antagonistic interactions. Because the nature of the cytotoxic interactions was definitely schedule-dependent in MCF-7 cells, we next evaluated the effects of C75 on Taxol-induced apoptosis as well as Taxol-activated cell death and cell survival-signaling pathways in this breast cancer cell model. An ELISA for histone-associated DNA fragments demonstrated that C75 and Taxol co-exposure caused a synergistic enhancement of apoptotic cell death, whereas C75 pre-treatment did not enhance the apoptosis-inducing activity of Taxol. Co-exposure to C75 and Taxol induced a remarkable nuclear accumulation of activated p38 mitogen-activated protein kinase (p38 MAPK), which was accompanied by a synergistic nuclear accumulation of the p53 tumor-suppressor protein that was phosphorylated at Ser46, a p38 MAPK-regulated pro-apoptotic modification of p53. As single agents, FAS blocker C75 and Taxol induced a significant stimulation of the proliferation and cell survival mitogen-activated protein kinase extracellular signal-regulated kinase (ERK1/ERK2 MAPK) activity, whereas, in combination, they interfered with ERK1/ERK2 activation. Moreover, the

  5. Targeted Dual pH-Sensitive Lipid ECO/siRNA Self-Assembly Nanoparticles Facilitate In Vivo Cytosolic sieIF4E Delivery and Overcome Paclitaxel Resistance in Breast Cancer Therapy.

    Science.gov (United States)

    Gujrati, Maneesh; Vaidya, Amita M; Mack, Margaret; Snyder, Dayton; Malamas, Anthony; Lu, Zheng-Rong

    2016-11-01

    RNAi-mediated knockdown of oncogenes associated with drug resistance can potentially enhance the efficacy of chemotherapy. Here, we have designed and developed targeted dual pH-sensitive lipid-siRNA self-assembly nanoparticles, RGD-PEG(HZ)-ECO/siRNA, which can efficiently silence the oncogene, eukaryotic translation initiation factor 4E (eIF4E), and consequently resensitize triple-negative breast tumors to paclitaxel. The dual pH-sensitive function of these nanoparticles facilitates effective cytosolic siRNA delivery in cancer cells, both in vitro and in vivo. Intravenous injection of RGD-PEG(HZ)-ECO/siRNA nanoparticles (1.0 mg-siRNA/kg) results in effective gene silencing for at least one week in MDA-MB-231 tumors. In addition, treatment of athymic nude mice with RGD-PEG(HZ)-ECO/sieIF4E every 6 days for 6 weeks down-regulates the overexpression of eIF4E and resensitizes paclitaxel-resistant MDA-MB-231 tumors to paclitaxel, resulting in significant tumor regression at a low dose, with negligible side effects. Moreover, repeated injections of the RGD-PEG(HZ)-ECO/siRNA nanoparticles in immunocompetent mice result in minimal immunogenicity, demonstrating their safety and low toxicity. These multifunctional lipid/siRNA nanoparticles constitute a versatile platform of delivery of therapeutic siRNA for treating cancer and other human diseases. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Phase 2 study of canfosfamide in combination with pegylated liposomal doxorubicin in platinum and paclitaxel refractory or resistant epithelial ovarian cancer

    Directory of Open Access Journals (Sweden)

    Moore Carla L

    2010-03-01

    Full Text Available Abstract Background Canfosfamide is a novel glutathione analog activated by glutathione S-transferase P1-1. This study evaluated the safety and efficacy of canfosfamide in combination with pegylated liposomal doxorubicin (PLD in patients with platinum resistant ovarian cancer. Patients with platinum resistant ovarian carcinoma and measurable disease received canfosfamide at 960 mg/m2 in combination with PLD at 50 mg/m2, intravenously day 1 in every 28 day cycles until tumor progression or unacceptable toxicities. The primary endpoints were objective response rate (ORR and progression-free survival (PFS. Results Canfosfamide plus PLD combination therapy was administered at 960/50 mg/m2, respectively. Thirty-nine patients received a median number of 4 cycles (range 1.0-18.0. The ORR was 27.8% (95% CI, 14.2-45.2 with a disease stabilization rate of 80.6% (95% CI, 64.0-91.8 in the evaluable population. The CA-125 marker responses correlated with the radiological findings of complete response or partial response. The median PFS was 6.0 months (95% CI, 4.2-7.9 and median survival was 17.8 months. The combination was well tolerated. Myelosuppression was managed with dose reductions and growth factor support. Grade 3 febrile neutropenia was observed in 2 patients (5.1%. Non-hematologic adverse events occurred at the expected frequency and grade for each drug alone, with no unexpected or cumulative toxicities. Conclusions Canfosfamide in combination with PLD is well tolerated and active in platinum and paclitaxel refractory or resistant ovarian cancer. A randomized phase 3 study was conducted based on this supportive phase 2 study. Trial Registration This study was registered at www.clinicaltrials.gov: NCT00052065.

  7. [Administration of premedication with fexofenadine for paclitaxel-induced hypersensitive reactions in breast cancer patients complicated with closed-angle glaucoma].

    Science.gov (United States)

    Komatsubara, Kazuo; Miyoshi, Kyoko; Kogure, Yuuki; Matsuhisa, Tetsuaki; Eguchi, Hisae

    2010-01-01

    Paclitaxel (PTX) is one of the most important breast cancer treatment drugs. However, severe hypersensitivity reactions such as decreases in blood pressure and impaired breathing occur with high frequency. For the prevention of such hypersensitivity reactions, administration of a premedication composed of three components, diphenhydramine, ranitidine (or famotidine), and dexamethasone, has been advised in package insert information of medicine. Administration of diphenhydramine is difficult in breast cancer patients complicated with closed-angle glaucoma, because diphenhydramine has a weak anticholinergic adverse effect which can induce mydriasis and glaucoma attack. We studied the prevention of severe hypersensitivity reactions and of glaucoma attack in 2 breast cancer patients complicated with closed angle glaucoma at our hospital from April 2007 to March 2008. We switched from diphenhydramine to fexofenadine as the medicine to prevent hypersensitivity reactions. Hypersensitivity reactions were not observed throughout all courses in both patients, and no glaucoma attack was observed.

  8. Prodrug Strategies for Paclitaxel

    Directory of Open Access Journals (Sweden)

    Ziyuan Meng

    2016-05-01

    Full Text Available Paclitaxel is an anti-tumor agent with remarkable anti-tumor activity and wide clinical uses. However, it is also faced with various challenges especially for its poor water solubility and low selectivity for the target. To overcome these disadvantages of paclitaxel, approaches using small molecule modifications and macromolecule modifications have been developed by many research groups from all over the world. In this review, we discuss the different strategies especially prodrug strategies that are currently used to make paclitaxel more effective.

  9. Rhizobacterial exopolysaccharides elicit induced resistance on cucumber.

    Science.gov (United States)

    Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2008-06-01

    The role of exopolysaccharides (EPSs) from a plant growth-promoting rhizobacterium, Burkholderia gladioli IN26, on elicitation of induced systemic resistance was investigated. A purified EPS induced expression of PR- 1a::GUS on tobacco and elicited induced resistance against Colletotrichum orbiculare on cucumber. The maximum level of disease protection was noted when seeds were soaked in 200 ppm of the EPS. Our results indicate that EPS from specific rhizobacteria can elicit induced resistance and suggest that bacterial EPS might be a useful elicitor of resistance under field conditions.

  10. [Cytological Study in vitro on Co-delivery of siRNA and Paclitaxel within Solid Lipid Nanoparticles to Overcome Multidrug Resistance in Tumors].

    Science.gov (United States)

    Huang, Rui; Yao, Xinyu; Chen, Yuan; Sun, Xun; Lin, Yunzhu

    2016-02-01

    Multidrug resistance (MDR) remains the major obstacle to the success of clinical cancer chemotherapy. P-glycoprotein (P-gp), encoded by the MDR1, is an important part with complex mechanisms associated with the MDR. In order to overcome the MDR of tumors, we in the present experimental design incorporated small interfering RNA (siRNA) targeting MDR1 gene and anticancer drug paclitaxel (PTX) into the solid lipid nanoparticles (SLNs) to achieve the combinational therapeutic effects of genetherapy and chemotherapy. In this study, siRNA-PTX-SLNs were successfully prepared. The cytotoxicity of blank SLNs and siRNA-PTX-SLNs in MCF-7 cells and MCF-7/ADR cells were detected by MTT; and the uptake efficiency of PTX in MCF-7/ADR cells were detected via HPLC method; quantitative real-time PCR and flow cytometry were performed to investigate the silencing effect of siRNA-PTX- SLNs on MDR1 gene in MCF-7/ADR cells. The results showed that PTX loaded SLNs could significantly inhibit the growth of tumor cells, and more importantly, the MDR tumor cells treated with siRNA-PTX-SLNs showed the lowest viability. HPLC study showed that SLNs could enhance the cellular uptake for PTX. Meanwhile, siRNA delivered by SLNs significantly decreased the P-gp expression in MDR tumor cells, thus increased the cellular accumulation of rhodamine123 as a P-gp substrate. In conclusion, the MDR1 gene could be silenced by siRNA-PTX-SLNs, which could promote the growth inhibition efficiency of PTX on tumor cells, leading to synergetic effect on MDR tumor therapy.

  11. Paclitaxel-sensitization enhanced by curcumin involves down-regulation of nuclear factor-κB and Lin28 in Hep3B cells.

    Science.gov (United States)

    Zhou, Mingjie; Li, Zhaohui; Han, Ziwu; Tian, Nan

    2015-01-01

    Although paclitaxel is an effective chemotherapeutic drug used in the treatment of many tumors, hepatoma cells, in particular, are known to be highly resistant to it. Previously, we discovered that Lin28 was closely associated with resistance to paclitaxel in Hep3B cells. The nuclear factor-kappa B (NF-κB) transcription factor, which plays an important role in tumor survival, directly activates Lin28 expression through a binding site on the first intron. Curcumin, a non-toxic anti-inflammatory agent, inhibits NF-κB activity in vitro. In this study, we reported that a combination of curcumin and paclitaxel exhibited synergistic anti-proliferative and pro-apoptosis effects on Hep3B cells, and curcumin down-regulated paclitaxel-induced enhanced expression of Lin28 and NF-κB activation. Furthermore, our results revealed that curcumin reduced Lin28 levels via mechanisms directly mediated by inhibition of NF-κB activity. These mechanism-based observations evidence that curcumin enhances the sensitivity of hepatoma cells to paclitaxe, and strongly support the notion that paclitaxel in combination with curcumin may provide a superior therapeutic index for HCC chemotherapy.

  12. Covalent linkage of nanodiamond-paclitaxel for drug delivery and cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Kuang-Kai; Wang, Chi-Ching; Chao, Jui-I [Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30013, Taiwan (China); Zheng, Wen-Wei; Lo, Yu-Shiu; Chen, Chinpiao [Department of Chemistry, National Dong Hwa University, Hualien 97401, Taiwan (China); Chiu, Yu-Chung; Cheng, Chia-Liang, E-mail: clcheng@mail.ndhu.edu.tw, E-mail: chinpiao@mail.ndhu.edu.tw, E-mail: jichao@faculty.nctu.edu.tw [Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan (China)

    2010-08-06

    A nanoparticle-conjugated cancer drug provides a novel strategy for cancer therapy. In this study, we manipulated nanodiamond (ND), a carbon nanomaterial, to covalently link paclitaxel for cancer drug delivery and therapy. Paclitaxel was bound to the surface of 3-5 nm sized ND through a succession of chemical modifications. The ND-paclitaxel conjugation was measured by atomic force microscope and nuclear magnetic resonance spectroscopy, and confirmed with infrared spectroscopy by the detection of deuterated paclitaxel. Treatment with 0.1-50 {mu}g ml{sup -1} ND-paclitaxel for 48 h significantly reduced the cell viability in the A549 human lung carcinoma cells. ND-paclitaxel induced both mitotic arrest and apoptosis in A549 cells. However, ND alone or denatured ND-paclitaxel (after treatment with strong alkaline solution, 1 M NaOH) did not induce the damage effects on A549 cells. ND-paclitaxel was taken into lung cancer cells in a concentration-dependent manner using flow cytometer analysis. The ND-paclitaxel particles were located in the microtubules and cytoplasm of A549 cells observed by confocal microscopy. Furthermore, ND-paclitaxel markedly blocked the tumor growth and formation of lung cancer cells in xenograft SCID mice. Together, we provide a functional covalent conjugation of ND-paclitaxel, which can be delivered into lung carcinoma cells and preserves the anticancer activities on the induction of mitotic blockage, apoptosis and anti-tumorigenesis.

  13. CYP1B1 enhances the resistance of epithelial ovarian cancer cells to paclitaxel in vivo and in vitro

    OpenAIRE

    ZHU, ZHUANGYAN; MU, YAQIN; QI, CAIXIA; WANG, JIAN; XI, GUOPING; GUO, JUNCHENG; Mi, Ruoran; ZHAO, FUXI

    2014-01-01

    Ovarian cancer (OC) is the most frequent cause of mortality among gynecological malignancies, with a 5-year survival rate of approximately 30%. The standard regimen for OC therapy includes a platinum agent combined with a taxane, to which the patients frequently acquire resistance. Resistance arises from the oxidation of anticancer drugs by CYP1B1, a cytochrome P450 enzyme overexpressed in malignant OC. The aim of the present study was to determine the role of CYP1B1 expression in the drug re...

  14. Additive effect of rikkunshito, an herbal medicine, on chemotherapy-induced nausea, vomiting, and anorexia in uterine cervical or corpus cancer patients treated with cisplatin and paclitaxel: results of a randomized phase II study (JORTC KMP-02)

    OpenAIRE

    Ohnishi, Shunsuke; Watari, Hidemichi; Kanno, Maki; Ohba, Yoko; Takeuchi, Satoshi; Miyaji, Tempei; Oyamada, Shunsuke; NOMURA, EIJI; Kato, Hidenori; Sugiyama, Toru; Asaka, Masahiro; Sakuragi, Noriaki; Yamaguchi, Takuhiro; Uezono, Yasuhito; Iwase, Satoru

    2017-01-01

    Objective Rikkunshito, an herbal medicine, is widely prescribed in Japan for the treatment of anorexia and functional dyspepsia, and has been reported to recover reductions in food intake caused by cisplatin. We investigated whether rikkunshito could improve chemotherapy-induced nausea and vomiting (CINV) and anorexia in patients treated with cisplatin. Methods Patients with uterine cervical or corpus cancer who were to receive cisplatin (50 mg/m2 day 1) and paclitaxel (135 mg/m2 day 0) as fi...

  15. Induced resistance in rice against insects.

    Science.gov (United States)

    Karban, R; Chen, Y

    2007-08-01

    Vaccinations are the mainstay of western preventive medicine, and they have been used to protect some crops against disease and insect pests. We consider rice as a model for protection using induced resistance since it is one of the most important staple crops and there have been significant new developments in: cross-resistance among rice insects, chemical pathways involved in induced resistance, sequencing the rice genome and expression of genes conferring resistance against rice insect pests. Insect attack has been found to cause lesions that kill planthopper eggs and early stages of gall midges. Damaged plants released volatiles that made them less likely to be chosen by planthoppers and more attractive to parasitoids. Chemical elicitors have been developed for dicotyledonous plants and these can induce resistance in rice, although rice does not fit models developed to explain signalling in dicots. For example, salicylic acid did not increase in rice after infection by pathogens and did not appear to be the mobile signal for induced resistance against pathogens although it was involved in induced responses to phloem-feeding insects. Jasmonic acid acted as a signal in some induced responses to pathogens as well as chewing insects. Many of the genes associated with induced resistance in rice have recently been mapped, and techniques are being developed to incorporate them into the genome of cultivated varieties. Attempts to control insect pests of rice will affect interactions with pathogens, predators and parasites, and other organisms in this agroecosystem.

  16. Insulin-like growth factor-1 attenuates apoptosis and protects neurochemical phenotypes of dorsal root ganglion neurons with paclitaxel-induced neurotoxicity in vitro.

    Science.gov (United States)

    Chen, Cheng; Bai, Xue; Bi, Yanwen; Liu, Guixiang; Li, Hao; Liu, Zhen; Liu, Huaxiang

    2017-02-01

    Paclitaxel (PT)-induced neurotoxicity is a significant problem associated with successful treatment of cancers. Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor and plays an important role in promoting axonal growth from dorsal root ganglion (DRG) neurons. Whether IGF-1 has protective effects on neurite growth, cell viability, neuronal apoptosis and neuronal phenotypes in DRG neurons with PT-induced neurotoxicity is still unclear. In this study, primary cultured rat DRG neurons were used to assess the effects of IGF-1 on DRG neurons with PT-induced neurotoxicity. The results showed that PT exposure caused neurite retraction in a dose-dependent manner. PT exposure caused a decrease of cell viability and an increase in the ratio of apoptotic cells which could be reversed by IGF-1. The percentage of calcitonin gene-related peptide immunoreactive (CGRP-IR) neurons and neurofilament (NF)-200-IR neurons, mRNA, and protein levels of CGRP and NF-200 decreased significantly after treatment with PT. IGF-1 administration had protective effects on CGRP-IR neurons, but not on NF-200-IR neurons. Either extracellular signal-regulated protein kinase (ERK1/2) inhibitor PD98059 or phosphatidylinositol 3-kinase (PI3 K) inhibitor LY294002 blocked the effect of IGF-1. The results imply that IGF-1 may attenuate apoptosis to improve neuronal cell viability and promote neurite growth of DRG neurons with PT-induced neurotoxicity. Moreover, these results support an important neuroprotective role of exogenous IGF-1 on distinct subpopulations of DRG neurons which is responsible for skin sensation. The effects of IGF-1 might be through ERK1/2 or PI3 K/Akt signaling pathways. These findings provide experimental evidence for IGF-1 administration to alleviate neurotoxicity of distinct subpopulations of DRG neurons induced by PT.

  17. Inducible clindamycin resistance in Staphylococcus species.

    Science.gov (United States)

    Afridi, Faisal Iqbal; Zeb, Mubarak; Hussain, Arif; Farooqi, Badar Jahan; Murtuza, Ghulam

    2014-07-01

    To determine the frequency of inducible clindamycin resistance in clinical isolates of Staphylococcus species by phenotypic D-test. Observational study. Ziauddin University Hospital, Karachi, from July to December 2011. Consecutive clinical isolates of Staphylococcus species were collected and identified by conventional microbiological techniques. Antimicrobial susceptibility testing and inducible clindamycin resistance was carried out by performing D-test using CLSI criteria. Methicillin resistance was detected by using Cefoxitin disk as a surrogate marker. Statistical analysis was performed by SPSS version-17. A total of 667 clinical isolates of Staphylococcus species were obtained during the study period. In these isolates, 177 (26.5%) were Staphylococcus aureus, and 490 (73.5%) were coagulase negative Staphylococci. The total frequency of inducible clindamycin resistance among isolates of Staphylococcus species was 120/667 (18%). Frequency of inducible clindamycin resistance among coagulase negative Staphylococci group and Staphylococcus aureus group were 18.57% and 16.38% respectively. Median age of patients in D-test positive group was 19.5 (1 - 54) years. The frequency of inducible clindamycin resistance among Staphylococcus species may differ in different hospital setup. Clinical microbiology laboratories should implement testing simple and effective D-test on all Staphylococcus species. D-test positive isolates should be reported clindamycin resistant to decrease treatment failure.

  18. Fe3O4 nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    Science.gov (United States)

    Yang, Cuiping; He, Xiangfeng; Chen, Junsong; Chen, Dengyu; Liu, Yunjing; Xiong, Fei; Shi, Fangfang; Dou, Jun; Gu, Ning

    2013-08-01

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe3O4 nanoparticles (PTX-NPs) with an average size range of 7.17 ± 1.31 nm on MM CSCs in vitro. The characteristics of CD138-CD34- cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138-CD34- cells were evaluated by a variety of assays in vitro. The results showed that the CD138-CD34- cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138-CD34- cells. PTX-NPs significantly inhibited CD138- CD34- cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138-CD34- phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138-CD34- CSCs. The findings may provide a guideline for PTX-NPs' treatment of MM CSCs in preclinical investigation.

  19. Fe{sub 3}O{sub 4} nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cuiping [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); He, Xiangfeng [Affiliated Tumor Hospital of Nantong University, Department of Medical Oncology (China); Chen, Junsong; Chen, Dengyu; Liu, Yunjing [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Xiong, Fei [Southeast University, School of Biological Science and Medical Engineering (China); Shi, Fangfang [Zhongda Hospital, Southeast University, Department of Oncology (China); Dou, Jun, E-mail: njdoujun@yahoo.com.cn [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Gu, Ning, E-mail: guning@seu.edu.cn [Southeast University, School of Biological Science and Medical Engineering (China)

    2013-08-15

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe{sub 3}O{sub 4} nanoparticles (PTX-NPs) with an average size range of 7.17 {+-} 1.31 nm on MM CSCs in vitro. The characteristics of CD138{sup -}CD34{sup -} cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138{sup -}CD34{sup -} cells were evaluated by a variety of assays in vitro. The results showed that the CD138{sup -}CD34{sup -} cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138{sup -}CD34{sup -} cells. PTX-NPs significantly inhibited CD138{sup -} CD34{sup -} cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138{sup -}CD34{sup -} phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138{sup -}CD34{sup -} CSCs. The findings may provide a guideline for PTX-NPs' treatment of MM CSCs in preclinical investigation.

  20. Harmine combined with paclitaxel inhibits tumor proliferation and induces apoptosis through down-regulation of cyclooxygenase-2 expression in gastric cancer

    Science.gov (United States)

    Yu, Xiao-Juan; Sun, Kun; Tang, Xiao-He; Zhou, Cun-Jin; Sun, Hui; Yan, Zhe; Fang, Ling; Wu, Hong-Wen; Xie, Yi-Kui; Gu, Bin

    2016-01-01

    Cyclooxygenase-2 (COX-2) serves an important role in the carcinogenesis and progression of gastric cancer. Harmine (HM) and paclitaxel (PTX) are reported as promising drug candidates for cancer therapy, but whether a synergistic anti-tumor effect of HM combined with PTX exists in human gastric cancer remains unknown. The present study evaluated the effects of HM and/or PTX on cell proliferation and apoptosis in a gastric cancer cell line, SGC-7901. HM and PTX inhibited cell proliferation in a dose-dependent manner. Both HM and PTX alone induced apoptosis in gastric cancer cells. The combination of HM and PTX exerted synergistic effects on proliferation inhibition and apoptosis induction in SGC-7901 cells, with down-regulation of COX-2, PCNA and Bcl-2 and up-regulation of Bax expression. The results indicated that combination chemotherapy using HM with PTX exerts an anti-tumor effect for treating gastric cancer. The combination of the two drugs inhibits gastric cancer development more effectively than each drug alone through down-regulation of COX-2 expression. PMID:27446381

  1. Paclitaxel Through the Ages of Anticancer Therapy: Exploring Its Role in Chemoresistance and Radiation Therapy

    OpenAIRE

    Anna Maria Barbuti; Zhe-Sheng Chen

    2015-01-01

    Paclitaxel (Taxol®) is a member of the taxane class of anticancer drugs and one of the most common chemotherapeutic agents used against many forms of cancer. Paclitaxel is a microtubule-stabilizer that selectively arrests cells in the G2/M phase of the cell cycle, and found to induce cytotoxicity in a time and concentration-dependent manner. Paclitaxel has been embedded in novel drug formulations, including albumin and polymeric micelle nanoparticles, and applied to many anticancer treatment ...

  2. AC1MMYR2 impairs high dose paclitaxel-induced tumor metastasis by targeting miR-21/CDK5 axis.

    Science.gov (United States)

    Ren, Yu; Zhou, Xuan; Yang, Juan-Juan; Liu, Xia; Zhao, Xiao-hui; Wang, Qi-xue; Han, Lei; Song, Xin; Zhu, Zhi-yan; Tian, Wei-ping; Zhang, Lun; Mei, Mei; Kang, Chun-sheng

    2015-07-01

    Paclitaxel (taxol) is a widely used chemo-drug for many solid tumors, while continual taxol treatment is revealed to stimulate tumor dissemination. We previously found that a small molecule inhibitor of miR-21, termed AC1MMYR2, had the potential to impair tumorigenesis and metastasis. The aim of this study was to investigate whether combining AC1MMYR2 with taxol could be explored as a means to limit tumor metastasis. Here we showed that abnormal activation of miR-21/CDK5 axis was associated with breast cancer lymph node metastasis, which was also contribute to high dose taxol-induced invasion and epithelial mesenchymal transition (EMT) in both breast cancer cell line MDA-MB-231 and glioblastoma cell line U87VIII. AC1MMYR2 attenuated CDK5 activity by functional targeting CDK5RAP1, CDK5 activator p39 and target p-FAK(ser732). A series of in vitro assays indicated that treatment of AC1MMYR2 combined with taxol suppressed tumor migration and invasion ability in both MDA-MB-231 and U87VIII cell. More importantly, combination therapy impaired high-dose taxol induced invadopodia, and EMT markers including β-catenin, E-cadherin and vimentin. Strikingly, a significant reduction of lung metastasis in mice was observed in the AC1MMYR2 plus taxol treatment. Taken together, our work demonstrated that AC1MMYR2 appeared to be a promising strategy in combating taxol induced cancer metastasis by targeting miR-21/CDK5 axis, which highlighted the potential for development of therapeutic modalities for better clinic taxol application.

  3. A phase II study of paclitaxel in heavily pretreated patients with small-cell lung cancer

    NARCIS (Netherlands)

    Smit, EF; Fokkema, E; Biesma, B; Groen, HJM; Snoek, W; Postmus, PE

    1998-01-01

    The purpose of the study was to delineate the efficacy and toxicity of paclitaxel (Taxol, Bristol Myers Squibb) in the treatment of drug resistant small-cell lung cancer (SCLC). Patients with SCLC relapsing within 3 months of cytotoxic therapy received paclitaxel 175 mg m(-2) intravenously over 3 h

  4. Induced disease resistance signaling in plants

    NARCIS (Netherlands)

    Verhagen, B.W.M.; Loon, L.C. van; Pieterse, C.M.J.

    2006-01-01

    To protect themselves from disease, plants have evolved sophisticated inducible defense mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signaling pathways controlling induced disease resistance is a major objective in resea

  5. [Evaluation of short-time premedication with d-chlorpheniramine maleate injection for paclitaxel-induced hypersensitivity reaction].

    Science.gov (United States)

    Harada, Tomohiko; Doi, Masakazu; Yamada, Yasuhiko; Akase, Tomohide

    2008-08-01

    Paclitaxel(referred to hereinafter as PTX )is used in ovarian cancer, non-small cell lung cancer, breast cancer, gastric cancer, and endometrial cancer with positive treatment result reports. However, severe allergic reactions such as decreases in blood pressure and impaired breathing occur with relatively high frequency. For the prevention of such allergic reactions, administration of a premedication composed of the three components, dexamethasone sodium phosphate injection, diphenhydramine hydrochloride tablet, and ranitidine hydrochloride injection solution(or injectable famodine), is advised in the appended documentation. Administration is difficult because, among these three components, only diphenhydramine hydrochloride is administered orally and thus must be provided through the internal medicine department. Particularly when this combined dosage is administered as outpatient chemotherapy, the doctor must prescribe diphenhydramine hydrochloride tablets, and the patient must not forget to bring them on the day in which chemotherapy is administered. Also, checks by the medical staff such as pharmacists and nurses are required, complicating the administration of this therapy further. Taking this situation into consideration, our hospital uses a short-time premedication method wherein d-Chlorpheniramine Maleate injections are substituted for diphenhydramine hydrochloride tablets, and the time required for premedication is reduced to 15 minutes. This study investigated the allergic reaction ratio to consider the safety and usefulness of the short-time premedication method used at our hospital. The chemotherapy regimens conducted for the subject patients were 9 cases of PTX+CBDCA, 6 cases of biweekly- PTX, and 5 cases of weekly-PTX. A total of 67 PTX injections were given, 15 of them being first-time administrations. The ratio of allergic/hypersensitivity reactions was 10.0%(2 cases in 20). The short-time premedication method using d-Chlorpheniramine Maleate

  6. Pharmacologic sensitivity of paclitaxel to its delivery vehicles drives distinct clinical outcomes of paclitaxel formulations.

    Science.gov (United States)

    Li, Yan; Chen, Nianhang; Palmisano, Maria; Zhou, Simon

    2015-04-01

    Paclitaxel, an effective antitumor agent, is formulated in various vehicles serving as carriers to deliver the hydrophobic paclitaxel to tissue. The approved formulations in the U.S. are paclitaxel formulated in Cremophor EL (currently known as Kolliphor EL) and nanoparticle albumin-bound paclitaxel (nab-paclitaxel). Despite having the same active ingredient (paclitaxel), different formulations produce distinct products with unique efficacy and safety profiles. A semimechanistic model was developed to describe the pharmacologic sensitivity of paclitaxel under different formulations. Circulating paclitaxel concentration data from patients treated with nab-paclitaxel or Cremophor EL-paclitaxel were analyzed in NONMEM using a semimechanistic model with simultaneous disposition of paclitaxel-carrier complexes and the total paclitaxel released from the complexes. The key factors driving paclitaxel exposure in circulation and peripheral tissues were explored via sensitivity analysis. The rapid decline of total paclitaxel concentration following intravenous administration of nab-paclitaxel and Cremophor EL-paclitaxel was attributed to rapid tissue distribution of the paclitaxel-carrier complexes, with minor contribution of free and protein-bound paclitaxel. Distribution of nab-paclitaxel to peripheral tissue was 4-fold faster and 10-fold more extensive than that of Cremophor EL-paclitaxel micelles, resulting in distinct tissue paclitaxel profiles. Sensitivity analyses showed the plasma paclitaxel-time profile was insensitive to the rapid rates of tissue distribution and decomposition of paclitaxel-carrier complexes but that the tissue distribution profile of paclitaxel was highly sensitive. Tissue distribution of paclitaxel is carrier complex system-dependent. Different delivery systems result in distinct tissue paclitaxel profiles but similar paclitaxel concentration-time profiles in plasma or blood, rendering the paclitaxel plasma profile a poor surrogate for its

  7. Rationalization of paclitaxel insensitivity of yeast β-tubulin and human βIII-tubulin isotype using principal component analysis

    Directory of Open Access Journals (Sweden)

    Das Lalita

    2012-08-01

    Full Text Available Abstract Background The chemotherapeutic agent paclitaxel arrests cell division by binding to the hetero-dimeric protein tubulin. Subtle differences in tubulin sequences, across eukaryotes and among β-tubulin isotypes, can have profound impact on paclitaxel-tubulin binding. To capture the experimentally observed paclitaxel-resistance of human βIII tubulin isotype and yeast β-tubulin, within a common theoretical framework, we have performed structural principal component analyses of β-tubulin sequences across eukaryotes. Results The paclitaxel-resistance of human βIII tubulin isotype and yeast β-tubulin uniquely mapped on to the lowest two principal components, defining the paclitaxel-binding site residues of β-tubulin. The molecular mechanisms behind paclitaxel-resistance, mediated through key residues, were identified from structural consequences of characteristic mutations that confer paclitaxel-resistance. Specifically, Ala277 in βIII isotype was shown to be crucial for paclitaxel-resistance. Conclusions The present analysis captures the origin of two apparently unrelated events, paclitaxel-insensitivity of yeast tubulin and human βIII tubulin isotype, through two common collective sequence vectors.

  8. Paclitaxel stimulates chromosomal fusion and instability in cells with dysfunctional telomeres: Implication in multinucleation and chemosensitization

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Woo, Seon Rang [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Department of Biochemistry, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kang, Chang-Mo [Laboratory of Cytogenetics and Tissue Regeneration, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Juhn, Kyoung-Mi; Ju, Yeun-Jin; Shin, Hyun-Jin; Joo, Hyun-Yoo; Park, Eun Ran; Park, In-chul; Hong, Sung Hee; Hwang, Sang-Gu [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Lee, Jung-Kee [Department of Life Science and Genetic Engineering, Paichai University, Daejeon 302-735 (Korea, Republic of); Kim, Hae Kwon [Department of Biotechnology, Seoul Woman' s University, Seoul 139-774 (Korea, Republic of); Cho, Myung-Haing [Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-74-2 (Korea, Republic of); Park, Gil Hong [Department of Biochemistry, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Lee, Kee-Ho, E-mail: khlee@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

    2011-01-14

    Research highlights: {yields} Paclitaxel serves as a stimulator of chromosomal fusion in cells in which telomeres are dysfunctional. {yields} Typical fusions involve p-arms, but paclitaxel-induced fusions occur between both q- and p-arms. {yields} Paclitaxel-stimulated fusions in cells in which telomeres are dysfunctional evoke prolonged G2/M cell cycle arrest and delay multinucleation. {yields} Upon telomere erosion, paclitaxel promotes chromosomal instability and subsequent apoptosis. {yields} Chromosomal fusion enhances paclitaxel chemosensitivity under telomere dysfunction. -- Abstract: The anticancer effect of paclitaxel is attributable principally to irreversible promotion of microtubule stabilization and is hampered upon development of chemoresistance by tumor cells. Telomere shortening, and eventual telomere erosion, evoke chromosomal instability, resulting in particular cellular responses. Using telomerase-deficient cells derived from mTREC-/-p53-/- mice, here we show that, upon telomere erosion, paclitaxel propagates chromosomal instability by stimulating chromosomal end-to-end fusions and delaying the development of multinucleation. The end-to-end fusions involve both the p- and q-arms in cells in which telomeres are dysfunctional. Paclitaxel-induced chromosomal fusions were accompanied by prolonged G2/M cell cycle arrest, delayed multinucleation, and apoptosis. Telomere dysfunctional cells with mutlinucleation eventually underwent apoptosis. Thus, as telomere erosion proceeds, paclitaxel stimulates chromosomal fusion and instability, and both apoptosis and chemosensitization eventually develop.

  9. Anti-nociceptive roles of the glia-specific metabolic inhibitor fluorocitrate in paclitaxel-evoked neuropathic pain.

    Science.gov (United States)

    Xu, Yongming; Cheng, Guangxia; Zhu, Yanrong; Zhang, Xin; Pu, Shaofeng; Wu, Junzhen; Lv, Yingying; Du, Dongping

    2016-10-01

    Paclitaxel (Taxol) is a powerful chemotherapy drug used in breast cancers, but it often causes neuropathic pain, leading to the early cessation of therapy and poor treatment outcomes. Approaches for the management of paclitaxel-induced neuropathic pain are urgently needed. The involvement of spinal astrocytes in the pathogenesis of paclitaxel-induced neuropathy has been reported, but little is known about the role of fluorocitrate (FC), a selective inhibitor of astrocyte activation, during neuropathic pain related to paclitaxel treatment. In this study, we investigated the effects of FC on paclitaxel-induced neuropathic pain. Glial fibrillary acidic protein (GFAP) expression was determined to assess astrocyte activation. To explore the mechanisms involved, the expression of glial glutamate transporter 1 (GLT-1) and the activation of mitogen-activated protein kinases in the spinal dorsal horn were analyzed. The results showed that paclitaxel decreased the mechanical nociceptive thresholds and increased GFAP expression, leading to spinal astrocyte activation. After paclitaxel treatment, GLT-1 was significantly down-regulated, and the phosphorylation of ERK1/2 and JNK were obviously up-regulated. However, paclitaxel treatment did not increase p38 phosphorylation. Additional studies showed that paclitaxel-evoked mechanical hypersensitivity was reduced by FC treatment. Moreover, FC treatment inhibited the activation of astrocytes and reversed the changes in GLT-1 expression and MAPK phosphorylation. Further study indicated that FC did not influence the antitumor effect of paclitaxel, suggesting that FC blocked paclitaxel-induced neuropathic pain without antagonizing its antitumor effect. Together, these results suggested that paclitaxel induced astrocyte-specific activation, which may contribute to mechanical allodynia and hyperalgesia, and that FC could be a potential therapeutic agent for paclitaxel-induced neuropathic pain. © The Author 2016. Published by Oxford

  10. Induced signals in resistive plate chambers

    CERN Document Server

    Riegler, W

    2002-01-01

    We derive theorems for induced signals on electrodes embedded in a medium with a position and frequency dependent permittivity $\\vep(\\vx,s)$ and conductivity $\\sigma(\\vx,s)$ that are connected with arbitrary discrete elements. The problem is treated using the quasi-static approximation of Maxwell's equations for weakly conducting media \\cite{melcher}\\cite{quasi}. The induced signals can be derived by time dependent weighting fields and potentials and the result is the same as the one given in \\cite{gatti}. We also show how these time dependent weighting fields can be derived from electrostatic solutions. Finally we will apply the results to Resistive Plate Chambers (RPCs) where we discuss the effects of the resistive plates and thin resistive layers on the signals induced on plane electrodes and strips.

  11. LBA50 - Influence of concomitant clopidogrel consumption on development of paclitaxel-associated toxicity: A pharmacoepidemiological study

    DEFF Research Database (Denmark)

    K, Agergaard; Mau-Sørensen, M; Stage, Tore Bjerregaard

    LBA50 - Influence of concomitant clopidogrel consumption on development of paclitaxel-associated toxicity: A pharmacoepidemiological study Background Paclitaxel is mainly eliminated via metabolism by the liver enzyme CYP2C8. It has recently been demonstrated in vitro that glucuronidation converts...... clopidogrel to a metabolite, which is a strong inhibitor of CYP2C8. To determine if this interaction has clinical relevance, we investigated whether concomitant clopidogrel and paclitaxel was associated with severe paclitaxel toxicity, primarily peripheral sensory neuropathy. Methods Patients concomitantly...... treated with clopidogrel and paclitaxel were identified using treatment registers and the Danish National Database of Reimbursed Prescriptions (DNDRP). Each patient was matched using age and gender with two controls treated with low-dose aspirin and paclitaxel. Paclitaxel induced toxicity was evaluated...

  12. Rhizobacteria-mediated induced systemic resistance in Arabidopsis

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Ton, J.; Wees, A.C.M. van; Hase, S.; Léon-Kloosterziel, K.M.; Verhagen, B.W.M.; Pelt, J.A. van; Loon, L.C. van

    2002-01-01

    Selected strains of rhizosphere bacteria have been shown to reduce disease by activating a resistance mechanism in the plant called rhizobacteria-mediated induced systemic resistance (ISR). ISR resembles pathogen-induced systemic acquired resistance (SAR), in that both types of induced resistance re

  13. Induced systemic resistance by beneficial microbes

    NARCIS (Netherlands)

    Pieterse, Corné M J|info:eu-repo/dai/nl/113115113; Zamioudis, Christos|info:eu-repo/dai/nl/313964742; Berendsen, Roeland L.|info:eu-repo/dai/nl/304824151; Weller, David M.; van Wees, Saskia C M|info:eu-repo/dai/nl/185445373; Bakker, Peter A H M|info:eu-repo/dai/nl/074744623

    2014-01-01

    Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth-promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of patho

  14. Induced systemic resistance by beneficial microbes

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Zamioudis, C.; Berendsen, R.L.; Weller, D.M.; Van Wees, S.C.M.; Bakker, P.A.H.M.

    2014-01-01

    Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth–promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of patho

  15. Ghrelin- and GH-induced insulin resistance

    DEFF Research Database (Denmark)

    Vestergaard, Esben Thyssen; Krag, Morten B; Poulsen, Morten M

    2013-01-01

    Supraphysiological levels of ghrelin and GH induce insulin resistance. Serum levels of retinol-binding protein-4 (RBP4) correlate inversely with insulin sensitivity in patients with type 2 diabetes. We aimed to determine whether ghrelin and GH affect RBP4 levels in human subjects....

  16. Induced systemic resistance by beneficial microbes

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Zamioudis, C.; Berendsen, R.L.; Weller, D.M.; Van Wees, S.C.M.; Bakker, P.A.H.M.

    2014-01-01

    Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth–promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of patho

  17. Study on establishment of paclitaxel resistant osteosarcoma cell line MG63/Taxol and its biological characteristics%人成骨肉瘤MG63紫杉醇耐药细胞系建立及生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    吴文欣; 李维

    2015-01-01

    Objective To establish the paclitaxel(Taxol0 induced osteosarcoma MG63 drug resistance cell subline(MG63/Taxol )and to observe its biological characteristics. Methods Paclitaxel resistant human osteosarcoma cell subline (MG63/Tax-ol) was established by adopting large dose impact combined with small dose maintenance to induce MG63 cell line with Taxol as the inducer. The sensitivity of chemotherapy drugs for the MG63 and MG63/Taxol cell sublines were measured by the colony for-mation assay. The cell morphology change was observed through light microscopy. The proliferation ability of cell lines was mea-sured by growth curve. The cell stages were analyzed by flow cytometry. Results (1)Through 6-month induction,paclitaxel re-sistant osteosarcoma cell subline(MG63/Taxol)was established. (2)The resistant index of MG63/Taxol to Taxol was 10.55. MG63/Taxol also produced the various degrees of cross resistance to cisplatin , methotrexate and 5-Fu. (3)The cell morphology was ob-served through light microscopy. The MG63/Taxol cells were regular arranging, spindle shape and size consistent,MG63/Taxol cell subline was irregular arranging,size inconsistent and morphology showed triangle shape,multiangular shape and multi-nucle-ation.(4)The cell growth cure showed that MG63/Taxol cells grew slowly than the parent cells. (5)The cell cyclical analysis dis-played that the distribution of the G0/G1 stage cells was increased ,while the S stage cells were decreased. Conclusion (1)A pa-clitaxel resistant human osteosarcoma cell subline (MG63/Taxol) established by adopting the large dose impact combined with small dose maintenance(MG63)generates the cross resistance to cisplatin,methotrexate and 5-Fu in different degrees.(2)MG63/Taxol cell subline is significantly different from the parent cell MG63 in the aspects of cell morphology,cell growth curve and cell cycle distribution.%目的:建立紫杉醇(Taxol)诱导的人成骨肉瘤MG63耐药细胞株亚系MG63/Taxol,并观察

  18. Enhancement of paclitaxel and carboplatin therapies by CCL2 blockade in ovarian cancers

    Science.gov (United States)

    Moisan, Francois; Francisco, Edgar B.; Brozovic, Anamaria; Duran, George E.; Wang, Yan C.; Chaturvedi, Shalini; Seetharam, Shobha; Snyder, Linda A.; Doshi, Parul; Sikic, Branimir I.

    2016-01-01

    Ovarian cancer is associated with a leukocyte infiltrate and high levels of chemokines such as CCL2. We tested the hypothesis that CCL2 inhibition can enhance chemotherapy with carboplatin and paclitaxel. Elevated CCL2 expression was found in three non-MDR paclitaxel resistant ovarian cancer lines ES-2/TP, MES-OV/TP and OVCAR-3/TP, compared to parental cells. Mice xenografted with these cells were treated with the anti-human CCL2 antibody CNTO 888 and the anti-mouse MCP-1 antibody C1142, with and without paclitaxel or carboplatin. Our results show an additive effect of CCL2 blockade on the efficacy of paclitaxel and carboplatin. This therapeutic effect was largely due to inhibition of mouse stromal CCL2. We show that inhibition of CCL2 can enhance paclitaxel and carboplatin therapy of ovarian cancer. PMID:24816187

  19. Effect of paclitaxel along with di allyl sulfide on immuno competent cells, immune complexes and immunoglobulins changes in 7,12 Di Methyl Benz(A Anthracene induced skin cancer in wistar rats.

    Directory of Open Access Journals (Sweden)

    Muninathan N, Ursula Sampson, Prashanth Talikoti, Uma Maheshwari, Archana, Kumar

    2014-03-01

    Full Text Available Our recent studies have shown that naturally occurring dietary organo sulfure compounds such as di allyl sulfide and paclitaxel are capable of inhibiting polycyclic aromatic hydrocarbon (PAH metabolism and subsequent PAH-DNA adduct formation in Wistar rats. In this study these plant phenols were tested for their effects against PAHs and 7,12 Di Methyl Benz (A Anthracene -induced skin tumorigenesis in rats. Each compounds was evaluated as a possible anticarcinogen in an initiation and promotion and a complete skin tumorigenesis protocol. In the two-stage tumor protocol in Wistar rats using 7,12-dimethylbenz(aanthracene as the initiating agent followed by twice weekly applications of acetone as tumor promoter each plant compounds afforded significant protection against skin tumorigenicity. The protective effects were verified both by prolongation of latency period and by subsequent tumor development. Our results suggest that these plants compounds have substantial though variable potential for modifying the risk of skin tumorigenicity induced by a wide variety of chemicals and of these combinations of Paclitaxel and Di allyl sulfide was shown to have maximal chemo protective effects.

  20. Paclitaxel: new uses for an old drug

    Directory of Open Access Journals (Sweden)

    Zhang D

    2014-02-01

    Full Text Available Dongshan Zhang,1,2 Ruhao Yang,1 Shixuan Wang,2 Zheng Dong1,2 1Departments of Emergency Medicine and Nephrology, Second Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China; 2Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University and Charlie Norwood VA Medical Center, Augusta, GA, USA Abstract: Paclitaxel (Taxol, one of the most important anticancer drugs, has been used for therapy of different types of cancers. Mechanistically, paclitaxel arrests cell cycle and induces cell death by stabilizing microtubules and interfering with microtubule disassembly in cell division. Recently, it has been found that low-dose paclitaxel seems promising in treating non-cancer diseases, such as skin disorders, renal and hepatic fibrosis, inflammation, axon regeneration, limb salvage, and coronary artery restenosis. Future studies need to understand the mechanisms underlying these effects in order to design therapies with specificity. Keywords: taxol inflammation, fibrosis, coronary artery restenosis, limb salvage, kidney

  1. Acute non-ST elevation myocardial infarction following paclitaxel administration for ovarian carcinoma: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Kajal Shah

    2012-01-01

    Full Text Available We report a case of an acute non-ST elevation myocardial infarction (AMI induced by paclitaxel in a patient with ovarian cancer. A 45-year-old premenopausal lady without any co-morbidity was started on the first cycle of neoadjuvant chemotherapy with paclitaxel-based regimen for advanced stage ovarian cancer. The patient developed chest pain 3 h after paclitaxel infusion with characteristic electrocardiographic changes of antero-apical myocardial infarction. The patient recovered on conservative medical management with reversion of electrocardiogram (ECG changes. Cardiac ischemia and myocardial infarction, possibly due to coronary vasospasm, are rare adverse effects of paclitaxel with reported incidence of 0.26%. We have reported a case of paclitaxel-induced myocardial infarction with reversible cardiac dysfunction. The possibility of myocardial infarction should be considered in patients who develop chest pain or other symptoms after paclitaxel infusion.

  2. MicroRNA-143 replenishment re-sensitizes colorectal cancer cells harboring mutant, but not wild-type, KRAS to paclitaxel treatment.

    Science.gov (United States)

    Fei, Bing-Yuan; Wang, Xiu-Ying; Fang, Xue-Dong

    2016-05-01

    Colorectal cancer (CRC) global incidence is one of the highest among cancers. The KRAS gene has been shown as a robust biomarker for poor prognosis and drug resistance. MicroRNA-143 (miR-143) and let-7 are families of tumor suppressor microRNAs that are often downregulated in CRC, especially with coexistent KRAS mutations. In order to evaluate if miR-143 and/or let-7b replenishment would re-sensitize CRC cells to paclitaxel treatment, we investigated in effect of miR-143 and let-7b replenishments on sensitivity to paclitaxel treatment in KRAS mutant LoVo and wild-type SW48 CRC cell lines. Our results showed that miR-143, but not let-7b, increased sensitization of KRAS mutant tumor cells to paclitaxel. Furthermore, transfection of miR-143, but not let-7b, mimic negatively regulated the expression of mutant but not wild-type KRAS. Combination of miR-143 mimic and paclitaxel induced the onset of apoptosis, and reverted in vitro metastatic properties (migration and invasion) in KRAS mutant tumor cells. MiR-143 thus can be used as a chemosensitizer for the treatment of KRAS mutant tumors and warrants further investigations in in vitro and pre-clinical in vivo models.

  3. Induced Systemic Resistance and the Rhizosphere Microbiome

    OpenAIRE

    Bakker, Peter A. H. M.; Doornbos, Rogier F.; Christos Zamioudis; Berendsen, Roeland L; Pieterse, Corné M. J.

    2013-01-01

    Microbial communities that are associated with plant roots are highly diverse and harbor tens of thousands of species. This so-called microbiome controls plant health through several mechanisms including the suppression of infectious diseases, which is especially prominent in disease suppressive soils. The mechanisms implicated in disease suppression include competition for nutrients, antibiosis, and induced systemic resistance (ISR). For many biological control agents ISR has been recognized...

  4. The Effect of Protein Kinase C Modulation with Bryostatin 1 on Paclitaxel-Induced Growth Inhibition and Apoptosis in Human Breast Cancer Cell Lines

    Science.gov (United States)

    1999-01-01

    need for new therapies is critical. These studies evaluated the therapeutic potential of a novel agent, the protein kinase C modulator, Bryostatin 1 in...agents to determine synergistic combinations. The combination of bryostatin 1 and paclitaxel was studied in four breast cancer cell lines utilizing...fluorouracil, & vinorelbine) were also tested in combination with bryostatin 1 using two breast cancer cell lines and three treatment schedules. Again, no

  5. Mechanisms of rhizobacteria-mediated induced systemic resistance

    NARCIS (Netherlands)

    Hase, S.; Pieterse, C.M.J.; Loon, L.C. van

    2001-01-01

    Some of non-pathogenic rhizosphere bacteria reduce disease by activating a resistance mechanism in the plant called rhizobacteria-mediated induced systemic resistance (ISR). Rhizobacteria-mediated ISR resembles classic pathogen-induced systemic acquired resistance (SAR) in that both types of induced

  6. Bacterial Gibberellins Induce Systemic Resistance of Plants

    Directory of Open Access Journals (Sweden)

    I. N. FEKLISTOVA

    2014-06-01

    Full Text Available It is generally agreed today that some rhizosphere bacteria can ensure induced systemic resistance to pathogens. In this paper we tested the ability of gibberellins produced by rhizosphere non-pathogenic bacteria Pseudomonas aurantiaca to induce systemic resistance to alternariosis agent – Alternaria brassicicola – in oilseed rape plants.Oilseed rape (Brássica nápus is one of the most promising oil-bearing croppers. It allows improving the supply of population with vegetable oil, animal and poultry industries with high quality vegetable protein. It is used for biofuel production as well.Gibberellin preparation was isolated from liquid culture of strain Pseudomonas aurantiaca grown in 250 mL of M9 medium (48 h, 28 °C under darkroom conditions. Gibberellins were extracted according procedure described by Tien et al. (1979. Gibberellins concentration in the medium was determined by fluorometric method.Elicitor activity of bacterial metabolites – gibberellins – was analyzed in model system of artificial inoculation of oilseed rape germs with phytopathogenic fungi Alternaria brassicicola. The elicitor action efficiency was evaluated on the 15th day of oilseed rape cultivation based on the percentage of leaf surface covered by necrotic lesions.Gibberellins were shown to induce systemic resistance resulted in decreasing of oil seed plants   vulnerability by 52.7%.It is known that under the unfavorable conditions plants synthesis the reactive oxygen intermediates   which activate destructive processes. One of the first organism reactions to stress action is the change of the lipid peroxidation level. It was shown that treatment of the soil with gibberellins resulted in decreasing of the lipid peroxidation level twofold.Gibberellins were shown to have a similar effect on permeability of cell membranes for free nucleotides. The permeability of cell membranes in leaves decreased 2.8-fold at room temperature. We suggest that gibberellins

  7. Induced Systemic Resistance and the Rhizosphere Microbiome

    Directory of Open Access Journals (Sweden)

    Peter A.H.M. Bakker

    2013-06-01

    Full Text Available Microbial communities that are associated with plant roots are highly diverse and harbor tens of thousands of species. This so-called microbiome controls plant health through several mechanisms including the suppression of infectious diseases, which is especially prominent in disease suppressive soils. The mechanisms implicated in disease suppression include competition for nutrients, antibiosis, and induced systemic resistance (ISR. For many biological control agents ISR has been recognized as the mechanism that at least partly explains disease suppression. Implications of ISR on recruitment and functioning of the rhizosphere microbiome are discussed.

  8. Induced systemic resistance by beneficial microbes.

    Science.gov (United States)

    Pieterse, Corné M J; Zamioudis, Christos; Berendsen, Roeland L; Weller, David M; Van Wees, Saskia C M; Bakker, Peter A H M

    2014-01-01

    Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth-promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of pathogens and insect herbivores. A wide variety of root-associated mutualists, including Pseudomonas, Bacillus, Trichoderma, and mycorrhiza species sensitize the plant immune system for enhanced defense without directly activating costly defenses. This review focuses on molecular processes at the interface between plant roots and ISR-eliciting mutualists, and on the progress in our understanding of ISR signaling and systemic defense priming. The central role of the root-specific transcription factor MYB72 in the onset of ISR and the role of phytohormones and defense regulatory proteins in the expression of ISR in aboveground plant parts are highlighted. Finally, the ecological function of ISR-inducing microbes in the root microbiome is discussed.

  9. Incidence of inducible clindamycin resistance in Staphylococcus pseudintermedius from dogs.

    Science.gov (United States)

    Gold, Randi M; Lawhon, Sara D

    2013-12-01

    Clindamycin is increasingly used to treat canine pyoderma. Eight of 608 Staphylococcus pseudintermedius isolates were positive for inducible clindamycin resistance by double-disk diffusion testing and PCR detection of ermB. Staphylococcus pseudintermedius isolates that are erythromycin resistant but clindamycin susceptible by in vitro antimicrobial susceptibility testing should be tested for inducible clindamycin resistance.

  10. Incidence of Inducible Clindamycin Resistance in Staphylococcus pseudintermedius from Dogs

    OpenAIRE

    Gold, Randi M.; Lawhon, Sara D.

    2013-01-01

    Clindamycin is increasingly used to treat canine pyoderma. Eight of 608 Staphylococcus pseudintermedius isolates were positive for inducible clindamycin resistance by double-disk diffusion testing and PCR detection of ermB. Staphylococcus pseudintermedius isolates that are erythromycin resistant but clindamycin susceptible by in vitro antimicrobial susceptibility testing should be tested for inducible clindamycin resistance.

  11. Protective effect of paclitaxel on injury of hippocampal neurons induced by cerebral ischemia-reperfusion%紫杉醇对脑缺血-再灌注诱导海马神经元损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    齐素华; 巩娟娟; 倪小宇

    2012-01-01

    目的 研究紫杉醇对脑缺血-再灌注(I-R)后海马神经元损伤的保护作用及分子机制.方法 SD大鼠随机分为假手术对照组(A组)、I-R对照组(B组)、1% DMSO溶剂处理组(C组)、紫杉醇8 μg/kg组(D组,缺血前30 min脑室注射),每组各10只.采用大鼠四动脉结扎全脑缺血模型,应用免疫印迹法检测紫杉醇对B细胞淋巴瘤-白血病2(Bcl-2)、半胱天冬氨酸蛋白酶3(Caspase-3)表达的影响.结果 与A组相比,B、C组Bcl-2及Caspase-3磷酸化表达增加(P<0.05),而D组Bcl-2及Caspase-3磷酸化表达较B组明显减少(P<0.05).结论 紫杉醇可能对脑I-R诱导海马神经元的损伤有保护作用;这种保护作用可能与Bcl-2、Caspase-3蛋白活性密切相关.%Objective To investigate the effect and molecular mechanism of paclitaxel on the injury of hippocampal neurons induced by cerebral ischemia-reperfusion(I-R). Methods SD rats were randomly divided into four groups of A(sham operation) ,B(I-R model) ,C(injection of 1% DMSO) and D(intraventricular injection of paclitaxel 8 μg/kg 30 min before ischemia) with 10 rats each. The cerebral ischemia model was established by four-vessel occlusion, and the expressions of B cell lymphoma/leukemia-2(Bcl-2) and cystein asparate proteinase-3(Caspase-3) were detected by Western blot Results Compared with group A, the phosphorylation of Bcl-2 and Caspase-3 was increased in groups of B and C(P<0. 05). However, the phosphorylation of Bcl-2 and Caspase-3 in group D was significantly lower than that in group B(P<0. 05). Conclusion Paclitaxel may protect I-R-induced injury of hippocampal neurons, which is probably related with the activation of Bcl-2 and Caspase-3.

  12. CB1 Knockout Mice Unveil Sustained CB2-Mediated Antiallodynic Effects of the Mixed CB1/CB2 Agonist CP55,940 in a Mouse Model of Paclitaxel-Induced Neuropathic Pain.

    Science.gov (United States)

    Deng, Liting; Cornett, Benjamin L; Mackie, Ken; Hohmann, Andrea G

    2015-07-01

    Cannabinoids suppress neuropathic pain through activation of cannabinoid CB1 and/or CB2 receptors; however, unwanted CB1-mediated cannabimimetic effects limit clinical use. We asked whether CP55,940 [(-)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3-hydroxypropyl)cyclohexanol], a potent cannabinoid that binds with similar affinity to CB1 and CB2 in vitro, produces functionally separable CB1- and CB2-mediated pharmacological effects in vivo. We evaluated antiallodynic effects, possible tolerance, and cannabimimetic effects (e.g., hypothermia, catalepsy, CB1-dependent withdrawal signs) after systemic CP55,940 treatment in a mouse model of toxic neuropathy produced by a chemotherapeutic agent, paclitaxel. The contribution of CB1 and CB2 receptors to in vivo actions of CP55,940 was evaluated using CB1 knockout (KO), CB2KO, and wild-type (WT) mice. Low-dose CP55,940 (0.3 mg/kg daily, i.p. ) suppressed paclitaxel-induced allodynia in WT and CB2KO mice, but not CB1KO mice. Low-dose CP55,940 also produced hypothermia and rimonabant-precipitated withdrawal in WT, but not CB1KO, mice. In WT mice, tolerance developed to CB1-mediated hypothermic effects of CP55,940 earlier than to antiallodynic effects. High-dose CP55,940 (10 mg/kg daily, i.p.) produced catalepsy in WT mice, which precluded determination of antiallodynic efficacy but produced sustained CB2-mediated suppression of paclitaxel-induced allodynia in CB1KO mice; these antiallodynic effects were blocked by the CB2 antagonist 6-iodopravadoline (AM630). High-dose CP55,940 did not produce hypothermia or rimonabant-precipitated withdrawal in CB1KO mice. Our results using the mixed CB1/CB2 agonist CP55,940 document that CB1 and CB2 receptor activations produce mechanistically distinct suppression of neuropathic pain. Our study highlights the therapeutic potential of targeting cannabinoid CB2 receptors to bypass unwanted central effects associated with CB1 receptor activation.

  13. Genetic analysis of induced systemic resistance in Arabidopsis thaliana: association between induced and basal resistance

    NARCIS (Netherlands)

    Ton, J.; Pieterse, C.M.J.; Loon, L.C. van

    1998-01-01

    Selected nonpathogenic rhizobacteria are able to elicit induced systemic resistance (ISR) in plants. Different ecotypes of Arabidopsis thaliana were screened for expression of ISR against infection by Pseudomonas syringae pv. tomato, after treatment of the roots with the nonpathogenic P. fluorescens

  14. Effect of a thiolated polymer on oral paclitaxel absorption and tumor growth in rats.

    Science.gov (United States)

    Föger, Florian; Malaivijitnond, Suchinda; Wannaprasert, Thanakul; Huck, Christian; Bernkop-Schnürch, Andreas; Werle, Martin

    2008-02-01

    The anticancer agent paclitaxel is currently commercially available only as an infusion due to its low oral bioavailability. An oral formulation would be highly beneficial for patients. Besides the low solubility, the main reason for the limited oral bioavailability of paclitaxel is that it is a substrate of the efflux pump P-glycoprotein (P-gp). Recently, it has been demonstrated that P-gp can be inhibited by thiolated polymers. In this study, an oral paclitaxel formulation based on thiolated polycarbophil was evaluated in vivo in wild-type rats and in mammary cancer-induced rats. The paclitaxel plasma level after a single administration of paclitaxel was observed for 12 h in healthy rats. Moreover, cancer-induced rats were treated weekly for 5 weeks with the novel formulation. It was demonstrated that (1) co-administration of thiolated polycarbophil significantly improved paclitaxel plasma levels, (2) a more constant pharmacokinetic profile could be achieved and (3) the tumor growth was reduced. These effects can most likely be attributed to P-gp inhibition. According to the achieved results, thiolated polymers are believed to be interesting tools for the delivery of P-gp substrates such as paclitaxel.

  15. FoxO3a transcriptional regulation of bim controls apoptosis in paclitaxel-treated breast cancer cell lines

    NARCIS (Netherlands)

    Sunters, A; de Mattos, SF; Stahl, M; Brosens, JJ; Zoumpoulidou, G; Saunders, CA; Coffer, PJ; Medema, RH; Coombes, RC; Lam, EWF

    2003-01-01

    Paclitaxel is used to treat breast cancers, but the mechanisms by which it induces apoptosis are poorly understood. Consequently, we have studied the role of the FoxO transcription factors in determining cellular response to paclitaxel. Western blotting revealed that in a panel of nine breast cancer

  16. FoxO3a transcriptional regulation of Bim controls apoptosis in paclitaxel-treated breast cancer cell lines

    NARCIS (Netherlands)

    Sunters, A.; Fernandez de Mattos, S.; Stahl, M.; Brosens, J.J.; Zoumpoulidou, G.; Saunders, C.A.; Coffer, P.J.; Medema, R.H.; Coombes, R.C.; Lam, E.W.-F.

    2003-01-01

    Paclitaxel is used to treat breast cancers, but the mechanisms by which it induces apoptosis are poorly understood. Consequently, we have studied the role of the FoxO transcription factors in determining cellular response to paclitaxel. Western blotting revealed that in a panel of nine breast cancer

  17. FoxO3a transcriptional regulation of bim controls apoptosis in paclitaxel-treated breast cancer cell lines

    NARCIS (Netherlands)

    Sunters, A; de Mattos, SF; Stahl, M; Brosens, JJ; Zoumpoulidou, G; Saunders, CA; Coffer, PJ; Medema, RH; Coombes, RC; Lam, EWF

    2003-01-01

    Paclitaxel is used to treat breast cancers, but the mechanisms by which it induces apoptosis are poorly understood. Consequently, we have studied the role of the FoxO transcription factors in determining cellular response to paclitaxel. Western blotting revealed that in a panel of nine breast cancer

  18. Molecular dynamics simulation and free energy landscape methods in probing L215H, L217R and L225M βI-tubulin mutations causing paclitaxel resistance in cancer cells.

    Science.gov (United States)

    Tripathi, Shubhandra; Srivastava, Gaurava; Sharma, Ashok

    2016-08-05

    Drug resistance poses a threatening challenge for mankind, as the development of resistance to already well-established drugs causes serious therapeutic problems. Resistance to paclitaxel (Ptxl), a complex diterpenoid working as microtubule stabilizer, is one such issue in cancer treatment. Microtubule stabilizer drugs, stabilises microtubules upon binding to β-tubulin subunit of tubulin heterodimer thus causing mitotic arrest leading to death of cancer cell. Leucine point mutations viz. L215H, L217R, and L225M were reported for Ptxl resistance in various cancers. In the current study, molecular mechanism of these resistance causing mutations was explored using molecular docking, molecular dynamics (MD) simulation, binding energy estimation (MMPBSA), free energy decomposition, principle component analysis (PCA) and free energy landscape (FEL) methods. A total of five systems including unbound βI-tubulin (Apo), docked wild+Ptxl, L215H+Ptxl, L217R+Ptxl and L225M+Ptxl were prepared, and 50 ns MD simulation was performed for each system. Binding energy estimation indicated that leucine mutation reduces the binding affinity of Ptxl in mutant types (MTs) as compared to wild type (WT). Further, in contrast to WT Ptxl interactions with the M-loop (PHE270-VAL286), S6-S7 loop and H9-H10 were significantly altered in MTs. Results showed that in MTs, Ptxl had weak interaction with M-loop residues, while having strong affinity with S6-S7 loop and H6-H7 loop. Moreover, PCA and FEL analysis revealed that M-loop flexible region (THR274-LEU284) was strongly bound with Ptxl in WT preventing its flexible movement and the causing factor for microtubule stabilization. In MTs due to poor interaction with Ptxl, M-loop flexible region retains its flexibility, therefore unable to stabilize microtubule. This study will give an insight into the importance of M-loop flexible region interaction with Ptxl for microtubule stabilization. In addition, it clearly provides the molecular basis of

  19. Snail-Induced Epithelial-to-Mesenchymal Transition Enhances P-gp-Mediated Multidrug Resistance in HCC827 Cells.

    Science.gov (United States)

    Tomono, Takumi; Yano, Kentaro; Ogihara, Takuo

    2017-09-01

    Overexpression and activation of P-glycoprotein (P-gp), which mediates efflux transport of various anticancer drugs in cancer cells, is associated with multidrug resistance (MDR). On the other hand, malignant cancer cells frequently undergo epithelial-to-mesenchymal transition (EMT), thereby acquiring high migratory mobility and invasive ability. Snail is a transcriptional factor that represses multiple other factors, and its overexpression is a trigger of EMT. Because both P-gp and Snail are involved in malignant evolution of cancer, in this work, we evaluated whether EMT induced by overexpression of Snail influences P-gp expression and activity. Snail-overexpressing cells showed downregulation of epithelial markers, E-cadherin, occludin, and claudin-1, and upregulation of mesenchymal markers, vimentin and ZEB1. Although Western blot analysis showed that P-gp expression levels were similar in Mock and Snail-overexpressing cells, the results of P-gp functional assays with P-gp substrates rhodamine123 and paclitaxel indicated that P-gp is activated in Snail-overexpressing cells. Indeed, Snail-overexpressing cells showed greater viability than Mock cells in the presence of paclitaxel. We observed caveolin-1 dephosphorylation and decreased growth factor receptor-bound protein 2 (GRB2) expression in Snail-overexpressing cells. These findings suggest a novel pathway leading to cancer MDR, in which Snail induces EMT concomitantly with a decrease in GRB2-mediated caveolin-1 phosphorylation, resulting in activation of P-gp. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  20. Effect of CD147 monoclonal antibody on paclitaxel resistance in HCE1 multicellular spheroids%CD147单克隆抗体对HCE1多细胞球体紫杉醇耐药的影响

    Institute of Scientific and Technical Information of China (English)

    胡芸; 吴宜林

    2011-01-01

    Objective To investigate the effect of CD147 monoclonal antibody (mAb) on the natural resistance to paclitaxel (TAX) in the human cervical cancer line ( HCE1 ) multicellular spheroid (HCE1/MCS) model and if CD147 mAb can reverse the HCE1/MCS resistance to TAX. Methods HCE1/MCS was obtained by liquid overlay and rotating technique. HCE1/MCS morphological changes were observed before or after the interference of CD147 mAb. The effects of TAX on HCE1/MCS (including inhibition ratio, IC50 and index of multicellular resistance) before or after CD147 mAb treatment were determined by the method of WST-1 and the inhibition ratio curve was mapped. Cell cycle and apoptosis were detected by flow cytometer (FCM). The expression of CD147 and P-gp of both HCE1/MC and HCE1/MCS was detected by immunocytochemistry. Results HCE1/MCS was established successfully. CD147 mAb could inhibit HCE1/MCS from forming spheroids. CD147 mAb could enhance the sensitivity of HCE1/MCS to TAX. IC50 in different concentrations of CD147 mAb (5,10,20 μg/mL) HCE1/MCS group were (40.31 ±3.73), (32.43 ±1.56), and (30.69 ±1.01) μg/mL. CD147 mAb resulted in Gi/G0 arrest in HCE1/ MCS. CD147 mAb of low concentrations (0- 10 μg/mL) caused a dose-dependent inhibition of HCE1/MCS (P < 0.05). Combined with TAX, CD147 mAb could also induce HCE1/MCS cell cycle arrest in both G1/S and G2/M stage. The expression of CD147 and P-gp was consistent in HCE1/MCS groups. Conclusion CD147 plays an important role in muliticellular resistance of cervical cancer and inhibition of CD147 can synergistically reverse the multicellular drug resistance (MCR) in cervical cancer. The MCR of HCE1/MCS mediated by CD147 is related to P-gp.%目的:研究CD147单克隆抗体在人宫颈鳞癌细胞株HCE1多细胞球体模型中对紫杉醇天然耐药的影响,探讨CD147单克隆抗体是否可以逆转HCE1多细胞球体天然耐药及其对P-糖蛋白(P-gp)的影响.方法:运用液体重叠法和旋转法建立HCE1多细胞球

  1. Liposomal paclitaxel formulations.

    Science.gov (United States)

    Koudelka, Stěpán; Turánek, Jaroslav

    2012-11-10

    Over the past three decades, taxanes represent one of the most important new classes of drugs approved in oncology. Paclitaxel (PTX), the prototype of this class, is an anti-cancer drug approved for the treatment of breast and ovarian cancer. However, notwithstanding a suitable premedication, present-day chemotherapy employing a commercial preparation of PTX (Taxol®) is associated with serious side effects and hypersensitivity reactions. Liposomes represent advanced and versatile delivery systems for drugs. Generally, both in vivo mice tumor models and human clinical trials demonstrated that liposomal PTX formulations significantly increase a maximum tolerated dose (MTD) of PTX which outperform that for Taxol®. Liposomal PTX formulations are in various stages of clinical trials. LEP-ETU (NeoPharm) and EndoTAG®-1 (Medigene) have reached the phase II of the clinical trials; Lipusu® (Luye Pharma Group) has already been commercialized. Present achievements in the preparation of various liposomal formulations of PTX, the development of targeted liposomal PTX systems and the progress in clinical testing of liposomal PTX are discussed in this review summarizing about 30 years of liposomal PTX development.

  2. Design, Synthesis and Applications of Hyaluronic Acid-Paclitaxel Bioconjugatesâ€

    Directory of Open Access Journals (Sweden)

    Rinaldo Marini Bettolo

    2008-02-01

    Full Text Available Paclitaxel (1a, a well known antitumor agent adopted mainly for the treatmentof breast and ovarian cancer, suffers from significant disadvantages such as low solubility,certain toxicity and specific drug-resistance of some tumor cells. To overcome theseproblems extensive research has been carried out. Among the various proposed strategies,the conjugation of paclitaxel (1a to a biocompatible polymer, such as hyaluronic acid(HA, 2, has also been considered. Coupling a bioactive compound to a biocompatiblepolymer offers, in general, many advantages such as better drug solubilization, betterstabilization, specific localization and controlled release. Hereafter the design, synthesisand applications of hyaluronic acid-paclitaxel bioconjugates are reviewed. An overview ofHA-paclitaxel combinations is also given.

  3. Paclitaxel/Taxol sensitivity in human renal cell carcinoma is not determined by the p53 status.

    Science.gov (United States)

    Reinecke, Petra; Kalinski, Thomas; Mahotka, Csaba; Schmitz, Michael; Déjosez, Marion; Gabbert, Helmut Erich; Gerharz, Claus Dieter

    2005-05-26

    In this study, we analyzed the role of the p53 status for paclitaxel/Taxol sensitivity in renal cell carcinomas (RCCs) of the clear cell type. Using immunohistochemistry, nuclear p53 accumulation could not be correlated to the paclitaxel/Taxol sensitivity. DNA sequencing detected a p53 gene mutation in two out of eight RCC cell lines, i.e. in exon 8 (cell line clearCa-6), and in exon 9 (cell line clearCa-5). No correlation, however, was found between the p53 status of our RCC cell lines and their paclitaxel/Taxol sensitivity as indicated by the IC50 values. However, paclitaxel-induced growth inhibition in paclitaxel-sensitive RCC cell lines was accompanied by an increase in apoptosis, irrespective of their p53 status. Although CD95 up-regulation was observed in renal cell carcinoma with wild-type p53 upon paclitaxel treatment, paclitaxel-induced apoptosis itself is triggered independently from the CD95 system. In conclusion, the p53 status cannot predict paclitaxel/Taxol sensitivity in RCC cell lines of the clear cell type.

  4. CD40L induces multidrug resistance to apoptosis in breast carcinoma and lymphoma cells through caspase independent and dependent pathways

    Directory of Open Access Journals (Sweden)

    Blay Jean-Yves

    2006-03-01

    Full Text Available Abstract Background CD40L was found to reduce doxorubicin-induced apoptosis in non Hodgkin's lymphoma cell lines through caspase-3 dependent mechanism. Whether this represents a general mechanism for other tumor types is unknown. Methods The resistance induced by CD40L against apoptosis induced by a panel of cytotoxic chemotherapeutic drugs in non Hodgkin's lymphoma and breast carcinoma cell lines was investigated. Results Doxorubicin, cisplatyl, etoposide, vinblastin and paclitaxel increased apoptosis in a dose-dependent manner in breast carcinoma as well as in non Hodgkin's lymphoma cell lines. Co-culture with irradiated L cells expressing CD40L significantly reduced the percentage of apoptotic cells in breast carcinoma and non Hodgkin's lymphoma cell lines treated with these drugs. In breast carcinoma cell lines, these 5 drugs induced an inconsistent increase of caspase-3/7 activity, while in non Hodgkin's lymphoma cell lines all 5 drugs increased caspase-3/7 activity up to 28-fold above baseline. Co-culture with CD40L L cells reduced (-39% to -89% the activation of caspase-3/7 induced by these agents in all 5 non Hodgkin's lymphoma cell lines, but in none of the 2 breast carcinoma cell lines. Co culture with CD40L L cells also blocked the apoptosis induced by exogenous ceramides in breast carcinoma and non Hodgkin's lymphoma cell lines through a caspase-3-like, 8-like and 9-like dependent pathways. Conclusion These results indicate that CD40L expressed on adjacent non tumoral cells induces multidrug resistance to cytotoxic agents and ceramides in both breast carcinoma and non Hodgkin's lymphoma cell lines, albeit through a caspase independent and dependent pathway respectively.

  5. Mechanisms of PGPR-induced resistance against pathogens

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1997-01-01

    Plant growth-promoting rhizobacteria can suppress diseases through antagonism between the bacteria and soilborne pathogens, as well as by inducing a systemic resistance in the plant against both root and foliar pathogens. Specific Pseudomonas strains induce systemic resistance in carnation, cucumber

  6. Inducible clindamycin resistance among clinical isolates of staphylococci

    Directory of Open Access Journals (Sweden)

    Ciraj A

    2009-01-01

    Full Text Available Introduction: Clinical failure of clindamycin therapy has been reported due to multiple mechanisms that confer resistance to macrolide, lincosamide and streptogramin antibiotics. This study was undertaken to detect the presence of inducible clindamycin resistance among clinical isolates of staphylococci. Materials and Methods: The detection of inducible clindamycin resistance was performed by D-test using erythromycin and clindamycin discs as per CDC guidelines. Results: Among the 244 clinical isolates of staphylococci studied, 32 (13.1% showed inducible clindamycin resistance and belonged to the MLSBi phenotype. Among the MLS B i phenotypes, 10 isolates were methicillin-resistant Staphylococcus aureus (38.4% of the total MRSA, 16 were methicillin-sensitive Staphylococcus aureus (12.9% of the total MSSA and 6 were coagulase-negative staphylococci (6.3% of the total CONS. Conclusion: The test for inducible resistance to clindamycin should be included in the routine antibiotic susceptibility testing, as it will help in guiding therapy.

  7. LBA50 - Influence of concomitant clopidogrel consumption on development of paclitaxel-associated toxicity: A pharmacoepidemiological study

    DEFF Research Database (Denmark)

    K, Agergaard; Mau-Sørensen, M; Stage, Tore Bjerregaard

    from medical charts by reviewers partially blinded to clopidogrel exposure. The association of clopidogrel use and development of paclitaxel induced neuropathy was evaluated over accumulated paclitaxel dose with censoring after 1500 mg using Cox-regression analysis with adjustment for high intensity......LBA50 - Influence of concomitant clopidogrel consumption on development of paclitaxel-associated toxicity: A pharmacoepidemiological study Background Paclitaxel is mainly eliminated via metabolism by the liver enzyme CYP2C8. It has recently been demonstrated in vitro that glucuronidation converts...... identified. Median age was 67 years, and 24 % of patients were male. The most frequent cancer types were breast cancer (35% and 30%), ovarian cancer (10% and 17%) in clopidogrel and aspirin users, respectively. At 1500 mg paclitaxel, 20 (42 %) and 27 (31 %) of the patients had developed CTCAE grade 2...

  8. Study on the relationship between drug resistance of Paclitaxel-resistant cell line in ovarian cancer and myeloid differentiation factor 88%卵巢癌紫杉醇耐药细胞耐药性和髓样分化因子88关系的研究

    Institute of Scientific and Technical Information of China (English)

    袁犁; 周琦; 徐发良; 李少林; 邹冬玲

    2012-01-01

    Objective:To investigate the biological characteristics of Paclitaxel-resistant cell line A2780/Taxol and parental cell A2780 of ovarian cancer and to discuss their relationship with myeloid differentiation factor 88(MyD88). Methods:CCK-8 assay was applied to detect the drug resistance and resistance index of A2780/Taxol and A2780 cell. Flow cytometry was used to test the cell cycle of A2780 and A2780/Taxol. Rhodamine 123(Rhl23) efflux was used and the expression of P-glycoprotein(P-gp) was evaluated. Western blot was used to detect the protein expressions of P-gp in A2780 and A2780/Taxol cell line. The expressions of MyD88 and P-gp were detected by immunocytochemistry. Results: Both cell lines had some changes in cell cycle. The G1 phase was longer in A2780/Taxol cell line compared with that in A2780 cell line,with statistical differences between the two groups(P<0.05). The results of CCK-8 showed that the IC50 of A2780/Taxol against Paclitaxel was (36.81 ± 2.05) μg/ml while that of A2780 against Pacli-taxel was (1.40 ±0.18) μg/ml. The resistance index of A2780/Taxol was 26.35. Mean fluorescence intensity in A2780/Taxol was significantly declined according to the results of Rhl23 assay. The expressions of P-gp and MyD88 were significantly higher in A2780/ Taxol cell line than in A2780 cell line detected by Western blot and immunocytochemistry. Conclusions: A2780/Taxol cell line is confirmed to be drug resistant. The expression of MyD88 is closely related with Paclitaxel-resistance.so it can be used for basic research of Paclitaxel-resistance.%目的:研究卵巢癌亲本A2780细胞与卵巢癌紫杉醇耐药细胞A2780/Taxol生物学特性及与髓样分化因子(Myeloid differentiation factor 88,MyD88)的关系.方法:应用CCK-8法检测A2780细胞和A2780/Taxol细胞的耐药性和耐药指数,采用流式细胞法检测A2780和A2780/Taxol细胞的细胞周期.应用罗丹明123(Rhodamine 123,Rh123)排出实验测定P-糖蛋

  9. [Effects of paclitaxel and gefitinib on the proliferation and cell cycle of human lung adenocarcinoma cell SPC-A1.].

    Science.gov (United States)

    Jia, Gang; Zhang, Weimin; Zhou, Juan; Zhu, Zhixia

    2008-06-20

    Previous clinical trials showed that there was no clinical benefit in the treatment of advanced non-small cell lung cancer when chemotherapy combined with gefitinib. The present study aims to assess the sequential administration of paclitaxel and gefitinib on the cell proliferation of lung adenocarcinoma cell SPC-A1 and to explore its mechanism by observing their effects on the cell cycle. The expression of EGFR mRNA and EGFR protein were examined by RT-PCR and western blotting respectively. MTT was used to measure the cell proliferation of SPC-A1 cells. Cell cycle was detected by flow cytometry. Both EGFR mRNA and EGFR protein were overexpressed in SPC-A1 cells. From 1*10(-14) M to 1*10(-6) M, both paclitaxel and gefitinib inhibited the cell proliferation of SPC-A1 cells in a dose-dependent and time-dependent manner in vitro . The effects of paclitaxel in combination with gefitinib on cell proliferation depended on the sequence. No significant additive effects on cell proliferation was found when they were used simultaneously or gefitinib was added before paclitaxel. However, sequential administration of gefitinib following paclitaxel can remarkably enhanced the effect of paclitaxel on the cell proliferation of SPC-A1 cells. Cell cycle studies showed that paclitaxel and gefitinib induced G2/M and G0/G1 arrest respectively. The G0/G1 arrest was observed when paclitaxel and gefitinib was used simultaneously or gefitinib was added before paclitaxel. In contrast, sequential administration of gefitinib following paclitaxel induced G2/M arrest. Both paclitaxel and gefitinib inhibits the cell proliferation of SPC-A1 cells. The additive effects on cell proliferation are sequential-dependent. The concomitant and the sequential treatment of gefitinib followed by paclitaxel exert no significant additive effects on the cell proliferation and resulted in the accumulation of cells in G0/G1 phase, which may decrease the effectiveness of paclitaxel in subsequent cycles. The

  10. Antagonistic effect of oridonin on paclitaxel-resistance of ovarian cancer cells and its mechanism%冬凌草甲素对卵巢癌细胞紫杉醇耐药性的拮抗作用及其机制研究

    Institute of Scientific and Technical Information of China (English)

    王汉楚; 沙丽晓; 陈小燕; 周莉; 郑飞云

    2012-01-01

    protein expression of NF-kB in ovarian cancer cells. HO-8910PM/PIX cells were sc injected into nude mice to establish ovarian xenograft tumor model. Eight weeks after implantation, the inhibitory effect on growth of xenograft tumor in nude mice was observed. Immunohistochemistry was used to detect the positive expression of NF-kB in the tumor tissues. Results The proliferation of HO-8910PM/PIX cells was significantly inhibited by oridonin with a concentration correlation. Apoptotic rate induced by oridonin was markedly higher than that in the control group. However, pretreated with TPA, the apoptosis induced by oridonin was significantly attenuated. Compared to HO-8910PM cells, NF-kB protein expression in HO-8910PM/PIX cells was obversly up-regulated, which could be inhibited by oridonin. Oridonin could significantly inhibit the growth of xenograft tumor in nude mice and weaken the positive expression of NF-kB in xenograft tumor tissues. Conclusion Oridonin has antagonistic effect on paclitaxel-resistance of human ovarian cancer cells both in vivo and in vitro, which may be related to the down-regulation of NF-kB expression.

  11. The study of low dose of paclitaxel repress hypoxia-inducible factor-1α expression in Hela cells under hypoxic conditions%小剂量紫杉醇对乏氧Hela细胞HIF-1α抑制作用的研究

    Institute of Scientific and Technical Information of China (English)

    梁玲霞; 田晓予; 王瑞芳; 王盈; 李世朋

    2014-01-01

    目的:探讨小剂量紫杉醇对乏氧Hela细胞HIF-1α的抑制作用。方法:细胞乏氧模型采用四甲基偶氮唑蓝( MTT)快速比色法检测细胞增殖率。细胞免疫荧光法和Western blot检测Hela细胞HIF-1α的表达。结果:紫杉醇使Hela细胞的增殖率降低,但乏氧状态下的Hela细胞增殖率明显高于正常状态下的细胞,两者相比差异有统计学意义( P<0.05)。不同浓度紫杉醇可使乏氧状态下的Hela细胞绿色荧光减弱,且呈浓度依赖性。结论:紫杉醇对乏氧和常氧状态下Hela细胞均有抑制作用,乏氧使Hela细胞对紫杉醇有一定的抵抗作用。紫杉醇对乏氧状态下的Hela细胞HIF-1α的表达有抑制作用,呈浓度依赖性。%Objective:To investigate whether paclitaxel can inhabit HIF-1α expression in Hela cells under hy-poxia conditions. Methods:The hypoxia model of Hela,MTT assay was used to analyze cells proliferation rate,immu-nofluorescence and Western blot was used to observe the expression of HIF-1α in Hela cells. Results:Paclitaxel make the proliferation ratio of Hela cells down,in the state of hypoxia,the proliferation ratio of Hela cells was signifi-cantly higher than normoxia,there was statistically significant difference between two groups(P<0. 05). Different concentration of paclitaxel can make the green fluorescence reduced,and it has dose-dependent effect. Conclusion:Paclitaxel can inhabit the proliferation of Hela cells under normoxia and hypoxia conditions. Hypoxia Hela cells have a certain resistance to paclitaxel. Paclitaxel inhibit HIF-1αexpression in hypoxia Hela cells,and it has dose-depend-ent effect.

  12. Resveratrol down-regulates survivin and induces apoptosis in human multidrug-resistant SPC-A-1/CDDP cells.

    Science.gov (United States)

    Zhao, Weiguo; Bao, Pengtao; Qi, Haowen; You, Houcheng

    2010-01-01

    We studied the effect of resveratrol treatment on multidrug-resistant human non-small cell lung cancer cells. Human multidrug-resistant SPC-A-1/CDDP cells were treated with resveratrol at a concentration of 25, 50, or 100 microM in in vitro studies and nude mice were implanted with multidrug-resistant SPC-A-1/and fed a special diet that included resveratrol at a dose of either 1 g/kg/day or 3 g/kg/day in in vivo studies. No adverse toxicological effects of resveratrol treatment were observed. The rate of cell proliferation, apoptosis ratio, cell cycle phase distribution, IC50 values of cisplatin, gefitinib, and paclitaxel, implanted tumour volume, and expression of survivin in resveratrol-treated and control mice were then determined. Resveratrol significantly inhibited the proliferation of SPC-A-1/CDDP cells, induced apoptosis, arrested the cell cycle phase between G0-G1 and S phase or at the G2/M phase, decreased the IC50 values of multiple chemotherapeutic drugs, and showed anti-tumour effects in nude mice that had been implanted with SPC-A-1/CDDP cells. In additional, resveratrol affected the proliferation of SPC-A-1/CDDP cells in a dose- and time-dependent manner. Expression of survivin in SPC-A-1/CDDP cells decreased after they were treated with all concentrations of resveratrol and resveratrol was also found to have a dose-dependent effect on survivin expression. Resveratrol can induce apoptosis in multidrug-resistant human NSCLC SPC-A-1/CDDP cells by down-regulating the expression of survivin.

  13. Radiation-induced cisplatin resistance in two human cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Eichholtz-Wirth, H.; Stotzer, O. [GSF-Institute of Radiobiology and Cytometry, Neuherberg (Germany); Marx, K. [Medical Clin. III, University, Munich (Germany)

    1997-03-01

    Cisplatin resistance has been induced in human HT-29 and HeLa cells after low-dose fractionated {gamma}-irradiation. The drug resistance is modest and does not confer cross-resistance to irradiation. Alterations that were recently shown to correlate with radiation-induced cisplatin resistance in murine cells are not involved in the resistant HeLa-C3 cells. Scavengers, such as GSH or metallothioneins are unchanged and there is no alteration of the cGMP transduction pathway. Preliminary results in HeLa-C3 cells indicate that resistance is associated with differences of the apoptotic pathway, with enhancement of the p53 suppressor protein after cisplatin treatment but unchanged bcl-2 protein expression. (authors)

  14. The transcriptome of rhizobacteria-induced systemic resistance in Arabidopsis

    NARCIS (Netherlands)

    Verhagen, B.W.M.; Glazebrook, J.; Zhu, T.; Chang, H.-S.; Loon, L.C. van; Pieterse, C.M.J.

    2004-01-01

    Plants develop an enhanced defensive capacity against a broad spectrum of plant pathogens after colonization of the roots by selected strains of nonpathogenic, fluorescent Pseudomonas spp. In Arabidopsis thaliana, this rhizobacteria-induced systemic resistance (ISR) functions independently of salicy

  15. Induced resistance in Arabidopsis and radish; involvement of PR proteins

    OpenAIRE

    HOFFLAND, E.; Pieterse, C. M. J.; Bik, L.; Pelt, J.A. van

    1995-01-01

    This paper demonstrates that Pseudomonas fluorescens strain WCS417 and salicylic acid can induce systemic resistance in radish and Arabidopsis thaliana against Fusarium oxysporum. In neither of the two plant species this induction is associated with induction of PRs. This indicates that PR-accumulation is not a prerequisite for induction of systemic resistance.

  16. Mechanisms of macrophage activation in obesity-induced insulin resistance

    OpenAIRE

    Odegaard, Justin I.; Chawla, Ajay

    2008-01-01

    Chronic inflammation is now recognized as a key step in the pathogenesis of obesity-induced insulin resistance and type 2 diabetes mellitus. This low-grade inflammation is mediated by the inflammatory (classical) activation of recruited and resident macrophages that populate metabolic tissues, including adipose tissue and liver. These findings have led to the concept that infiltration and activation of adipose tissue macrophages is causally linked to obesity-induced insulin resistance. Studie...

  17. Clopidogrel paclitaxel drug-drug interaction

    DEFF Research Database (Denmark)

    Agergaard, K; Mau-Sørensen, M; Bjerregaard Stage, T

    2017-01-01

    Paclitaxel is mainly eliminated by CYP2C8 in the liver. CYP2C8 is strongly inhibited by the clopidogrel metabolite acyl-β-D-glucuronide. To determine if this interaction has clinical relevance, we identified 48 patients treated with clopidogrel and paclitaxel using databases and a prescription re...

  18. Taxomyces andreanae : A Presumed Paclitaxel Producer Demystified?

    NARCIS (Netherlands)

    Staniek, Agata; Woerdenbag, Herman J.; Kayser, Oliver

    2009-01-01

    The 1990s brought an abundance of reports on paclitaxel-producing endophytes, initially heralded as a discovery having tremendous implications for cancer therapy. As the vision of large-scale fermentation tanks producing vast quantities of relatively inexpensive paclitaxel and novel taxanes has fade

  19. Development of a Nanocrystalline Paclitaxel Formulation for Hipec Treatment

    NARCIS (Netherlands)

    De Smet, Lieselotte; Colin, Pieter; Ceelen, Wim; Bracke, Marc; Van Bocxlaer, Jan; Remon, Jean Paul; Vervaet, Chris

    2012-01-01

    To develop a nanocrystalline paclitaxel formulation with a high paclitaxel-to-stabilizer ratio which can be used for hyperthermic intraperitoneal chemotherapy (HIPEC). Paclitaxel (PTX) nanocrystals were prepared via wet milling using Pluronic F127(A (R)) as stabilizer. The suitability of paclitaxel

  20. Inducible, transferable resistance to vancomycin in Enterococcus faecium, D399.

    Science.gov (United States)

    Shlaes, D M; Al-Obeid, S; Shlaes, J H; Boisivon, A; Williamson, R

    1989-04-01

    Enterococcus faecium D399 was isolated from the blood and peritoneal abscess of a patient with intraabdominal sepsis. The patient had not been treated with vancomycin, but the strain was found to be resistant with a MIC of 1000 mg/l. Resistance was inducible and transferable (probably by conjugation) to JH2-2, and correlated with induction of synthesis of a 39 kDa protein. This mechanism appears to be identical to that previously described for E. faecalis A256, suggesting that dissemination of this form of glycopeptide resistance has already occurred. The resistance phenotype of D399, however, differed somewhat from that found in other enterococcal strains with inducible resistance.

  1. Occurrence and characterization of inducible clindamycin resistance in canine methicillin-resistant Staphylococcus pseudintermedius.

    Science.gov (United States)

    Chanchaithong, Pattrarat; Prapasarakul, Nuvee

    2016-02-01

    This study aimed to detect inducible clindamycin (iCLI) resistance in Staphylococcus pseudintermedius isolated from dogs in Thailand using D-zone testing. Strains that were iCLI-resistant were characterized by molecular typing and antibiogram and were detected in 10/200 S. pseudintermedius isolates (5%) from 7/41 dogs (17%). All were methicillin-resistant S. pseudintermedius (MRSP) and demonstrated multidrug resistance. The iCLI-resistant MRSP contained erm(B) and had identical or closely related DNA fingerprint patterns by pulsed-field gel electrophoresis. All iCLI-resistant MRSP strains belonged to the same clonal complex 112 (sequence types 111 and 112) by multilocus sequence typing. To avoid misinterpretation of clindamycin susceptibility, D-zone testing is recommended to promote rational antimicrobial selection and limit the clonal expansion of multidrug resistant bacteria.

  2. STAT3-dependent TXNDC17 expression mediates Taxol resistance through inducing autophagy in human colorectal cancer cells.

    Science.gov (United States)

    Zhang, Zhongde; Wang, Aihua; Li, Hui; Zhi, Hui; Lu, Feng

    2016-06-10

    Taxol (paclitaxel) is one of the taxane class of anticancer drugs as a first-line chemotherapeutic agent against many cancers including colorectal cancer, breast cancer, non-small cell lung cancer, ovarian cancer and so on. It is verified to induce cytotoxicity in a concentration and time-dependent manner. Numerous novel formulations of Taxol have been remanufactured for better therapeutic effect. Though Taxol works as a common anticancer drug for a long time in clinical practice, drug resistance is a major limitation of its long-term administration. In-depth research on drug resistance is still in progress and researchers have made some achievements, however, the mechanism or key molecule related to Taxol resistance in colorectal cancer still remains to be explored. In the present study, we observed that the high expression of TXNDC17 (thioredoxin domain containing 17) was associated with Taxol resistance in colorectal cancer cells. And TXNDC17 mediated Taxol resistance was related with increased basal autophagy level. Taxol exposure induced high levels of phospho-STAT3 (Tyr 705) and TXNDC17; and increase of basal autophagy in colorectal cancer cells. TXNDC17 overexpression cells obtained Taxol resistance and a high level of autophagy, and it is not surprising that stable downregulation of TXNDC17 accordingly reversed these phenomena. Interestingly, STAT3 could similarly work as TXNDC17 in spite of slighter effect compared to TXNDC17. And it has been proved that phospho-STAT3 (Tyr 705) possesses transcriptional regulation activity through forming dimmers. Many research revealed that transcription factor STAT3 affected more than 1000 gene products, and TXNDC17 is predicted to be a target gene of STAT3 at UCSC database. For the first time, we found STAT3 could bind promoter region of TXNDC17 (-623 bp to -58 bp relative to the transcription start site (TSS)) for regulating its expression. These results suggest the possibility that TXNDC17 could play an important role

  3. Paclitaxel tumor priming promotes delivery and transfection of intravenous lipid-siRNA in pancreatic tumors.

    Science.gov (United States)

    Wang, Jie; Lu, Ze; Wang, Junfeng; Cui, Minjian; Yeung, Bertrand Z; Cole, David J; Wientjes, M Guillaume; Au, Jessie L-S

    2015-10-28

    The major barrier for using small interfering RNA (siRNA) as cancer therapeutics is the inadequate delivery and transfection in solid tumors. We have previously shown that paclitaxel tumor priming, by inducing apoptosis, expands the tumor interstitial space, improves the penetration and dispersion of nanoparticles and siRNA-lipoplexes in 3-dimensional tumor histocultures, and promotes the delivery and transfection efficiency of siRNA-lipoplexes under the locoregional setting in vivo (i.e., intraperitoneal treatment of intraperitoneal tumors). The current study evaluated whether tumor priming is functional for systemically delivered siRNA via intravenous injection, which would subject siRNA to several additional delivery barriers and elimination processes. We used the same pegylated cationic (PCat)-siRNA lipoplexes as in the intraperitoneal study to treat mice bearing subcutaneous human pancreatic Hs766T xenograft tumors. The target gene was survivin, an inducible chemoresistance gene. The results show single agent paclitaxel delayed tumor growth but also significantly induced the survivin protein level in residual tumors, whereas addition of PCat-siSurvivin completely reversed the paclitaxel-induced survivin and enhanced the paclitaxel activity (p<0.05). In comparison, PCat-siSurvivin alone did not yield survivin knockdown or antitumor activity, indicating the in vivo effectiveness of intravenous siRNA-mediated gene silencing requires paclitaxel cotreatment. Additional in vitro studies showed that paclitaxel promoted the cytoplasmic release of siGLO, a 22 nucleotide double-stranded RNA that has no mRNA targets, from its PCat lipoplex and/or endosomes/lysosomes. Taken together, our earlier and current data show paclitaxel tumor priming, by promoting the interstitial transport and cytoplasmic release, is critical to promote the delivery and transfection of siRNA in vivo. In addition, because paclitaxel has broad spectrum activity and is used to treat multiple types

  4. Heritability of rhizobacteria-mediated induced systemic resistance and basal resistance in Arabidopsis

    NARCIS (Netherlands)

    Ton, J.; Davison, S.; Loon, L.C. van; Pieterse, C.M.J.

    2001-01-01

    Selected strains of non-pathogenic rhizobacteria have the ability to trigger an induced systemic resistance (ISR) response in plants. In Arabidopsis, rhizobacteria-mediated ISR has been extensively studied, using Pseudomonas fluorescens WCS417r as the inducing agent and P. syringae pv. tomato DC3000

  5. A randomized phase I trial of nanoparticle albumin-bound paclitaxel with or without mifepristone for advanced breast cancer

    OpenAIRE

    Nanda, Rita; Stringer-Reasor, Erica M.; Saha, Poornima; Kocherginsky, Masha; Gibson, Jean; Libao, Bernadette; Hoffman, Philip C.; Obeid, Elias; Merkel, Douglas E.; Khramtsova, Galina; Skor, Maxwell; Krausz, Thomas; Cohen, Ronald N.; Ratain, Mark J.; Fleming, Gini F.

    2016-01-01

    Purpose Glucocorticoid receptor (GR) overexpression is associated with poor prognosis ER-negative breast cancer. GR antagonism with mifepristone increases chemotherapy-induced breast cancer cell death, therefore we conducted a phase I clinical trial of mifepristone and nab-paclitaxel in advanced breast cancer. Methods A novel randomized phase I design was used to assess the effect of mifepristone on nab-paclitaxel pharmacokinetics and toxicity. Patients were randomized to placebo or mifeprist...

  6. Induced systemic resistance (ISR) in plants: mechanism of action.

    Science.gov (United States)

    Choudhary, Devendra K; Prakash, Anil; Johri, B N

    2007-12-01

    Plants possess a range of active defense apparatuses that can be actively expressed in response to biotic stresses (pathogens and parasites) of various scales (ranging from microscopic viruses to phytophagous insect). The timing of this defense response is critical and reflects on the difference between coping and succumbing to such biotic challenge of necrotizing pathogens/parasites. If defense mechanisms are triggered by a stimulus prior to infection by a plant pathogen, disease can be reduced. Induced resistance is a state of enhanced defensive capacity developed by a plant when appropriately stimulated. Systemic acquired resistance (SAR) and induced systemic resistance (ISR) are two forms of induced resistance wherein plant defenses are preconditioned by prior infection or treatment that results in resistance against subsequent challenge by a pathogen or parasite. Selected strains of plant growth-promoting rhizobacteria (PGPR) suppress diseases by antagonism between the bacteria and soil-borne pathogens as well as by inducing a systemic resistance in plant against both root and foliar pathogens. Rhizobacteria mediated ISR resembles that of pathogen induced SAR in that both types of induced resistance render uninfected plant parts more resistant towards a broad spectrum of plant pathogens. Several rhizobacteria trigger the salicylic acid (SA)-dependent SAR pathway by producing SA at the root surface whereas other rhizobacteria trigger different signaling pathway independent of SA. The existence of SA-independent ISR pathway has been studied in Arabidopsis thaliana, which is dependent on jasmonic acid (JA) and ethylene signaling. Specific Pseudomonas strains induce systemic resistance in viz., carnation, cucumber, radish, tobacco, and Arabidopsis, as evidenced by an enhanced defensive capacity upon challenge inoculation. Combination of ISR and SAR can increase protection against pathogens that are resisted through both pathways besides extended protection to a

  7. Glial Reactivity in Resistance to Methamphetamine-Induced Neurotoxicity

    OpenAIRE

    Friend, Danielle M.; Keefe, Kristen A

    2013-01-01

    Neurotoxic regimens of methamphetamine (METH) result in reactive microglia and astrocytes in striatum. Prior data indicate that rats with partial dopamine (DA) loss resulting from prior exposure to METH are resistant to further decreases in striatal DA when re-exposed to METH 30 days later. Such resistant animals also do not show an activated microglia phenotype, suggesting a relation between microglial activation and METH-induced neurotoxicity. To date, the astrocyte response in such resista...

  8. Peltier-Effect-Induced Correction to Ohmic Resistance

    Science.gov (United States)

    Cheremisin, M. V.

    2001-02-01

    The standard ohmic measurements by means of two extra leads contain an additional thermal correction to resistance. The current results in heating(cooling) at first(second) sample contact due to Peltier effect. The contacts temperatures are different. The measured voltage is the sum of the ohmic voltage swing and Peltier effect induced thermopower which is linear on current. As a result, the thermal correction to resistance measured exists at $I\\to 0$. The correction should be in comparison with ohmic resistance. Above some critical frequency dependent on thermal inertial effects the thermal correction disappears.

  9. The development of a quantitative and qualitative method based on UHPLC-QTOF MS/MS for evaluation paclitaxel-tetrandrine interaction and its application to a pharmacokinetic study.

    Science.gov (United States)

    Li, Dan; Cao, Zhonglian; Liao, Xueling; Yang, Ping; Liu, Li

    2016-11-01

    Paclitaxel is a broad-spectrum anti-cancer drug by targeting microtubulin. However, multidrug resistant (MDR) makes its clinical application more difficult and results in failure of chemotherapy. Tetrandrine as a potential multidrug resistant modulator could be combined with other anti-cancer drugs. In this study, ultra-performance liquid chromatography (UHPLC) combined with quadrupole time-of-flight mass spectrometry (QTOF) was applied to simultaneously qualitative and quantitative analysis of paclitaxel for the pharmacokinetic studies while combined with tetrandrine. This method was developed based on non-target screening mode IDA (Information Dependent Acquisition). As a result, the validated range was 0.25-64ng/ml (30µl plasma) for paclitaxel. Totally 33 metabolites of paclitaxel and tetrandine were identified in vivo and in vitro. The main metabolites of PTX were dose-dependent decreased with different amounts of tetrandine co-administration no matter in vivo and in vitro, the exposure of PTX increased in pharmacokinetic study. The verified method is sensitive accurate and effective for the simultaneous determination of paclitaxel and its metabolites in blood, urine and live microsome incubation samples and it was successfully applied to evaluate the pharmacokinetics and drug-drug interaction between paclitaxel and tetrandine. Furthermore, a biosensor technology, surface plasmon resonance (SPR) analysis was applied to preliminary evaluate the competitive protein binding of multiple components. The SPR analysis indicated that the affinity between 6-hydroxy-paclitaxel and micotubulin is similar to that between paclitaxel and micotubulin, and tetrandrine also does not form a competitive combination with paclitaxel. For human, 6-hydroxy-paclitaxel is the one of main metabolites of paclitaxel, so the results suggested that tetrandine has an influence on the metabolite of paclitaxel, but tetrandine and the main metabolites of PTX probably do not affect PTX

  10. 白蛋白结合型紫杉醇联合贝伐珠单抗治疗复发性卵巢癌的临床分析%Albumin type combined with paclitaxel plus beacizumab bead sheet resistance for the treatment of recurrent ovarian cancer

    Institute of Scientific and Technical Information of China (English)

    陈杰; 陈春婷; 关慧; 董丽娜; 刘睿敏

    2016-01-01

    Objective:To study the curative effect of type albumin in combination with paclitaxel plus beacizumab bead sheet resistance in the treatment of recurrent ovarian cancer adverse reaction and survival conditions.Methods:We used type albumin in combination with paclitaxel plus beacizumab bead sheet resistance to treatment of 78 cases of recurrent ovarian cancer.1st day type albumin in combination with paclitaxel 260mg/m2 ,beacizumab bead sheet re-sistance to 15mg/m2 ,21d for a cycle.Results:All 78 patients can be evaluated curative effect,no complete remission cases,partial in 9 cases,stable in 42 cases,27 cases,effective rate was 11.5%(9 /78),the clinical benefit rate was 65.4%(51 /78).The main adverse reactions were bone marrow suppression,gastrointestinal tract reaction,fatigue, hair loss,peripheral nerve toxicity,skin rashes,high blood pressure,muscle aches.More adverse reactions were level I and level II,the side effects can be tolerated,no treatment -related death.Conclusion:The combination of albumin type paclitaxel plus beacizumab bead sheet resistance in the treatment of recurrent ovarian cancer can obtain better curative effect,adverse reactions can be tolerated,but still needs further research.%目的:探讨白蛋白结合型紫杉醇联合贝伐珠单抗治疗复发性卵巢癌疗效、不良反应和生存情况。方法:选取经病理学诊断为卵巢上皮癌患者78例,既往使用过紫杉类、吉西他滨等药物治疗后进展,接受白蛋白结合型紫杉醇联合贝伐珠单抗方案治疗。具体方案:第1天接受白蛋白结合型紫杉醇260mg/m2、第2天接受贝伐珠单抗15mg/m2,21d 为1个周期,每个周期评价不良反应,2个周期评价疗效。结果:78例患者均可进行疗效评价,无完全缓解病例,部分缓解9例,稳定42例,进展27例,有效率为11.5%(9/78),临床获益率为65.4%(51/78)。主要不良反应为骨髓抑制、消化道反应、乏力、脱

  11. Inducible resistance to Fas—mediated apoptosis in B cells

    Institute of Scientific and Technical Information of China (English)

    ROTHSTEINTHOMASL

    2000-01-01

    Apoptosis produced in B cells through Fas(APO-1,CD95) triggering is regulated by signals derived from other surface receptors:CD40 engagement produces upregulation of Fas expression and marked susceptibility to Fas-induced cell death,whereas antigen receptor engagement,or IL-4R engagement,inhibits Fas killing and in so doing induces a state of Fas-resistance,even in otherwise sensitive,CD40-stimulated targets.Surface immunoglobulin and IL-4R utilize at least partially distinct path ways to produce Fas-resistance that differentially depend on PKC and STAT6,respectively.Further,surface immunoglobulin signaling for inducible Fas-resistance bypasses Btk,requires NF-κB,and entails new macromolecular synthesis.Terminal effectors of B cell Fas-resistance include the known anti-apoptotic gene products,Bcl-XL and FLIP,and a novel anti-apoptotic gene that encodes FAIM (Fas Apoptosis Inhibitory Molecule).faim was identified by differential display and exists in two alternatively spliced forms;faim-S is broadly expressed,but faim-L expression is tissue-specific.The FAIM sequence is highly evolu tionarily conserved,suggesting an important role for this molecule throughout phylogeny.Inducible resistance to Fas killing is hypothesized to protect foreign antigen-specific B cells during potentially hazardous interactions with FasL-bearing T cells,whereas autoreactive B cells fail to become Fas-resistant and are deleted via Fas-dependent cytotoxicity.Inadvertent or aberrant acquisition of Fas-resistance may permit autoreactive B cells to escape Fas deletion,and malignant lymphocytes to impede anti-tumor immunity.

  12. Inducible resistance to Fas-mediated apoptosis in B cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Apoptosis produced in B cells through Fas (APO-1, CD95) triggering is regulated by signals derived from other surface receptors: CD40 engagement produces upregulation of Fas expression and marked susceptibility to Fas-induced cell death, whereas antigen receptor engagement, or IL-4R engagement, inhibits Fas killing and in so doing induces a state of Fas-resistance, even in otherwise sensitive, CD40-stimulated targets. Surface immunoglobulin and IL-4R utilize at least partially distinct pathways to produce Fas-resistance that differentially depend on PKC and STAT6, respectively. Further, surface immunoglobulin signaling for inducible Fas-resistance bypasses Btk, requires NF-кB, and entails new macromolecular synthesis. Terminal effectors of B cell Fas-resistance include the known anti-apoptotic gene products, Bcl-xL and FLIP, and a novel anti-apoptotic gene that encodes FAIM (Fas Apoptosis Inhibitory Molecule). faim was identified by differential display and exists in two alternatively spliced forms; faim-S is broadly expressed, but faim-L expression is tissue-specific. The FAIM sequence is highly evolutionarily conserved, suggesting an important role for this molecule throughout phylogeny. Inducible resistance to Fas killing is hypothesized to protect foreign antigen-specific B cells during potentially hazardous interactions with FasL-bearing T cells, whereas autoreactive B cells fail to become Fas-resistant and are deleted via Fas-dependent cytotoxicity. Inadvertent or aberrant acquisition of Fas-resistance may permit autoreactive B cells to escape Fas deletion, and malignant lymphocytes to impede anti-tumor immunity.

  13. Paclitaxel Albumin-stabilized Nanoparticle Formulation

    Science.gov (United States)

    This page contains brief information about paclitaxel albumin-stabilized nanoparticle formulation and a collection of links to more information about the use of this drug, research results, and ongoing clinical trials.

  14. Optimizing anticancer drug treatment in pregnant cancer patients : pharmacokinetic analysis of gestation-induced changes for doxorubicin, epirubicin, docetaxel and paclitaxel

    NARCIS (Netherlands)

    van Hasselt, J G C; van Calsteren, K; Heyns, L; Han, S; Mhallem Gziri, M; Schellens, J H M; Beijnen, J H; Huitema, A D R; Amant, F

    2014-01-01

    BACKGROUND: Pregnant patients with cancer are increasingly treated with anticancer drugs, although the specific impact of pregnancy-induced physiological changes on the pharmacokinetics (PK) of anticancer drugs and associated implications for optimal dose regimens remains unclear. Our objectives wer

  15. Optimizing anticancer drug treatment in pregnant cancer patients : pharmacokinetic analysis of gestation-induced changes for doxorubicin, epirubicin, docetaxel and paclitaxel

    NARCIS (Netherlands)

    van Hasselt, J G C; van Calsteren, K; Heyns, L; Han, S; Mhallem Gziri, M; Schellens, J H M|info:eu-repo/dai/nl/073926272; Beijnen, J H|info:eu-repo/dai/nl/071919570; Huitema, A D R; Amant, F

    2014-01-01

    BACKGROUND: Pregnant patients with cancer are increasingly treated with anticancer drugs, although the specific impact of pregnancy-induced physiological changes on the pharmacokinetics (PK) of anticancer drugs and associated implications for optimal dose regimens remains unclear. Our objectives

  16. Optimizing anticancer drug treatment in pregnant cancer patients : pharmacokinetic analysis of gestation-induced changes for doxorubicin, epirubicin, docetaxel and paclitaxel

    NARCIS (Netherlands)

    van Hasselt, J G C; van Calsteren, K; Heyns, L; Han, S; Mhallem Gziri, M; Schellens, J H M; Beijnen, J H; Huitema, A D R; Amant, F

    2014-01-01

    BACKGROUND: Pregnant patients with cancer are increasingly treated with anticancer drugs, although the specific impact of pregnancy-induced physiological changes on the pharmacokinetics (PK) of anticancer drugs and associated implications for optimal dose regimens remains unclear. Our objectives wer

  17. Oxygen-carbon nanotubes as a chemotherapy sensitizer for paclitaxel in breast cancer treatment.

    Directory of Open Access Journals (Sweden)

    Yongkun Wang

    Full Text Available To study the in vivo and in vitro effects of adding oxygen carbon nanotubes (CNTs to chemotherapy for breast cancer.MCF-7 and SK-BR-3 breast cancer cells were co-cultured with paclitaxel and then exposed to oxygen-CNTs under hypoxic conditions. Cell proliferation, viability, and apoptosis rate were analyzed. Hypoxia-inducible factor-1 alpha (HIF-1α expression was measured using reverse transcription-polymerase chain reaction (RT-PCR and western blot. Nude mice were used as a human breast cancer model to explore the impact of oxygen-CNTs on the in vivo chemotherapeutic effect of paclitaxel.Oxygen-CNTs had no significant effects on the growth of breast cancer cells under normoxia and hypoxia. However, in the hypoxic environment, oxygen-CNTs significantly enhanced the inhibitory effect of paclitaxel on cell proliferation, as well as the apoptosis rate. Under hypoxia, downregulation of HIF-1α and upregulation of caspase-3, caspase-8, caspase-9, LC3 and Beclin-1 were observed when paclitaxel was combined with oxygen-CNT. Furthermore, addition of oxygen-CNTs to chemotherapy was found to significantly reduce tumor weight in the tumor-bearing mice model.Oxygen-CNTs can significantly increase the chemotherapeutic effect of paclitaxel on breast cancer cells. Oxygen-CNTs may be a potential chemosensitizer in breast cancer therapy.

  18. The chemotherapeutic agent paclitaxel selectively impairs learning while sparing source memory and spatial memory.

    Science.gov (United States)

    Smith, Alexandra E; Slivicki, Richard A; Hohmann, Andrea G; Crystal, Jonathon D

    2017-03-01

    Chemotherapeutic agents are widely used to treat patients with systemic cancer. The efficacy of these therapies is undermined by their adverse side-effect profiles such as cognitive deficits that have a negative impact on the quality of life of cancer survivors. Cognitive side effects occur across a variety of domains, including memory, executive function, and processing speed. Such impairments are exacerbated under cognitive challenges and a subgroup of patients experience long-term impairments. Episodic memory in rats can be examined using a source memory task. In the current study, rats received paclitaxel, a taxane-derived chemotherapeutic agent, and learning and memory functioning was examined using the source memory task. Treatment with paclitaxel did not impair spatial and episodic memory, and paclitaxel treated rats were not more susceptible to cognitive challenges. Under conditions in which memory was not impaired, paclitaxel treatment impaired learning of new rules, documenting a decreased sensitivity to changes in experimental contingencies. These findings provide new information on the nature of cancer chemotherapy-induced cognitive impairments, particularly regarding the incongruent vulnerability of episodic memory and new learning following treatment with paclitaxel.

  19. Importance of inducible multidrug resistance 1 expression in HL-60 cells resistant to gemtuzumab ozogamicin.

    Science.gov (United States)

    Matsumoto, Taichi; Jimi, Shiro; Hara, Shuuji; Takamatsu, Yasushi; Suzumiya, Junji; Tamura, Kazuo

    2012-07-01

    Resistance to gemtuzumab ozogamicin (GO) hampers the effective treatment of refractory acute myeloid leukemia (AML). To clarify the mechanism of resistance to GO, HL-60 cells were persistently exposed to GO in order to establish GO-resistant HL-60 (HL-60/GOR) cells. Multidrug resistance 1 (MDR-1) was strongly expressed in HL-60/GOR cells, but not in HL-60 cells. Although withdrawal of GO after the chronic exposure of HL-60/GOR cells to this compound gradually decreased MDR-1 expression to trace levels, reintroducing GO restored high MDR-1 expression in HL-60/GOR cells, but not in HL-60 cells. These results indicate that HL-60/GOR cells acquired the ability to induce MDR-1 expression in response to GO. U0126, a MEK1/2 inhibitor, prevented GO-inducible MDR-1 expression and abrogated GO resistance in HL-60/GOR cells. These results suggest that in the clinical use of GO, inducible MDR-1 expression in tumor cells should be investigated before treatment with GO. If the cells are positive then MEK1/2 inhibitors may be effective in overcoming resistance to GO.

  20. Effects of stathmin 1 silencing by siRNA on sensitivity of esophageal cancer cells Eca-109 to paclitaxel.

    Science.gov (United States)

    Zhu, H W; Jiang, D; Xie, Z Y; Zhou, M H; Sun, D Y; Zhao, Y G

    2015-12-29

    We investigated the effects of stathmin 1 (STMN1) silencing by small interfering (siRNA) on the sensitivity of esophageal cancer cells Eca-109 to paclitaxel. STMN1 siRNA was transiently transfected into Eca-109 cells. The effects of transfection were detected by quantitative polymerase chain reaction and western blotting. The effects of STMN1 silencing by siRNA on the sensitivity of esophageal cancer cells Eca-109 to paclitaxel was tested by MTT and colony formation assays. Hoechst 33258 nuclear staining was used to investigate the differences in Eca-109 cell apoptosis induced by paclitaxel. STMN1 siRNA was successfully transfected and the expression of STMN1 was inhibited. The sensitivity of STMN1 siRNA-transfected Eca-109 cells to paclitaxel was significantly increased (P < 0.01). The apoptosis of Eca-109 cells significantly increased following treatment with paclitaxel (P < 0.01). STMN1 silencing by siRNA may enhance the sensitivity of esophageal cancer cells Eca-109 to paclitaxel and induce apoptosis.

  1. Metabolic acidosis-induced insulin resistance and cardiovascular risk.

    Science.gov (United States)

    Souto, Gema; Donapetry, Cristóbal; Calviño, Jesús; Adeva, Maria M

    2011-08-01

    Microalbuminuria has been conclusively established as an independent cardiovascular risk factor, and there is evidence of an association between insulin resistance and microalbuminuria, the former preceding the latter in prospective studies. It has been demonstrated that even the slightest degree of metabolic acidosis produces insulin resistance in healthy humans. Many recent epidemiological studies link metabolic acidosis indicators with insulin resistance and systemic hypertension. The strongly acidogenic diet consumed in developed countries produces a lifetime acidotic state, exacerbated by excess body weight and aging, which may result in insulin resistance, metabolic syndrome, and type 2 diabetes, contributing to cardiovascular risk, along with genetic causes, lack of physical exercise, and other factors. Elevated fruits and vegetables consumption has been associated with lower diabetes incidence. Diseases featuring severe atheromatosis and elevated cardiovascular risk, such as diabetes mellitus and chronic kidney failure, are typically characterized by a chronic state of metabolic acidosis. Diabetic patients consume particularly acidogenic diets, and deficiency of insulin action generates ketone bodies, creating a baseline state of metabolic acidosis worsened by inadequate metabolic control, which creates a vicious circle by inducing insulin resistance. Even very slight levels of chronic kidney insufficiency are associated with increased cardiovascular risk, which may be explained at least in part by deficient acid excretory capacity of the kidney and consequent metabolic acidosis-induced insulin resistance.

  2. Induced systemic resistance by plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Pelt, J.A. van; Verhagen, B.W.M.; Ton, J.; Wees, A.C.M. van; Léon-Kloosterziel, K.M.; Loon, L.C. van

    2003-01-01

    Rhizobacteria are present in large numbers on the root surface, where plant exudates and lysates provide nutrients. Selected strains of beneficial, plant growth-promoting rhizobacteria (PGPR) trigger a plant-mediated induced systemic resistance (ISR) response that is effective against a broad spectr

  3. Paclitaxel augments cytotoxic effect of photodynamic therapy using verteporfin in gastric and bile duct cancer cells.

    Science.gov (United States)

    Park, Seungwoo; Hong, Sung Pil; Oh, Tae Yoon; Bang, Seungmin; Chung, Jae Bock; Song, Si Young

    2008-07-01

    Photodynamic therapy (PDT) shows a limited antitumor effect in treating gastrointestinal tumors because of improper light penetration or insufficient photosensitizer uptake. The aim of this study was to evaluate the cytotoxic effect of PDT combined with paclitaxel on in vitro cancer cells. In vitro photodynamic therapy was performed in gastric cancer cells (NCI-N87) and bile duct cancer cells (YGIC-6B) using verteporfin (2 ug mL(-1)) and a PTH light source (1 000 W, Oriel Co.) with 665-675 nm narrow band pass filter. Cytotoxicity was compared using the MTT assay between cancer cells treated with PDT alone or pretreated with paclitaxel (IC(25)). Apoptotic changes were evaluated using DAPI staining, DNA fragmentation analysis, Annexin V-FITC apoptosis assay, cell cycle analysis, and western blots for cytochrome c, Bax, and Bid. The PDT-induced cytotoxicity was potentiated by pretreating with low dose paclitaxel (P cancer therapy.

  4. Lipid-induced insulin resistance: unravelling the mechanism

    Science.gov (United States)

    Samuel, Varman T; Petersen, Kitt Falk; Shulman, Gerald I

    2010-01-01

    Insulin resistance has long been associated with obesity. More than 40 years ago, Randle and colleagues postulated that lipids impaired insulin-stimulated glucose use by muscles through inhibition of glycolysis at key points. However, work over the past two decades has shown that lipid-induced insulin resistance in skeletal muscle stems from defects in insulin-stimulated glucose transport activity. The steatotic liver is also resistant to insulin in terms of inhibition of hepatic glucose production and stimulation of glycogen synthesis. In muscle and liver, the intracellular accumulation of lipids—namely, diacylglycerol—triggers activation of novel protein kinases C with subsequent impairments in insulin signalling. This unifying hypothesis accounts for the mechanism of insulin resistance in obesity, type 2 diabetes, lipodystrophy, and ageing; and the insulin-sensitising effects of thiazolidinediones. PMID:20609972

  5. Mechanisms of Induced Resistance in Barley Against Drechslera teres.

    Science.gov (United States)

    Lyngs Jørgensen, H J; Lübeck, P S; Thordal-Christensen, H; de Neergaard, E; Smedegaard-Petersen, V

    1998-07-01

    ABSTRACT Quantitative and qualitative histopathological methods and molecular analyses were used to study the mechanisms by which preinoculation with either of the nonbarley pathogens, Bipolaris maydis and Septoria nodorum, inhibited growth of Drechslera teres. Collectively, our data suggest that induced resistance is the principal mechanism responsible for impeding the pathogen. The enhancement of resistance in the host was primarily manifested during penetration by D. teres, and after penetration, where growth of D. teres ceased soon after development of infection vesicles. Thus, 24 h after pretreatment with B. maydis or S. nodorum, the penetration frequency from D. teres appressoria was reduced from 42.7% in the controls to 9.5 and 14.8%, respectively. The reductions were associated with increased formation of fluorescent papillae in induced cells (early defense reaction). The postpenetrational inhibition of D. teres completely stopped fungal growth and was apparently linked to an enhancement of multicellular hypersensitive responses in inducer-treated leaves (late defense reaction). Papillae formation and multicellular hypersensitive reactions were also observed in fully susceptible, noninduced control leaves, but they were inadequate to stop fungal progress. Northern blots from leaves treated with either inducer alone support the conclusion that induced resistance is involved in suppression of D. teres by increased formation of papillae and hypersensitive reactions. Thus, the blots showed strong expression of several defense response genes that are involved in these reactions in barley attacked by Erysiphe graminis f. sp. hordei.

  6. Inhibition of Hec1 expression enhances the sensitivity of human ovarian cancer cells to paclitaxel

    Institute of Scientific and Technical Information of China (English)

    Qing-qing MO; Ping-bo CHEN; Xin JIN; Qian CHEN; Lan TANG; Bei-bei WANG; Ke-zhen LI

    2013-01-01

    Aim:Hec1,a member of the Ndc80 kinetochore complex,is highly expressed in cancers.The aim of this study was to explore the role and mechanism of action of Hec1 with respect to the cytotoxicity of paclitaxel in ovarian cancer.Methods:Thirty ovarian cancer samples and 6 normal ovarian samples were collected.Hec1 expression in these samples was determined with immunohistochemistry.Ovarian cancer cell lines A2780,OV2008,C13K,SKOV3,and CAOV3 and A2780/Taxol were examined.Cell apoptosis and cell cycle analysis were detected with flow cytometric technique.siRNA was used to delete Hec1 in the cells.The expression of related mRNAs and proteins was measured using RT-PCR and Western blot analysis,respectively.Results:Hec1 expression was significantly higher in ovarian cancer samples than in normal ovarian samples,and was associated with paclitaxel-resistance and poor prognosis.Among the 6 ovarian cancer cell lines examined,Hec1 expression was highest in paclitaxelresistant A2780/Taxol cells,and lowest in A2780 cells.Depleting Hec1 in A2780/Taxol cells with siRNA decreased the IC5o value of paclitaxel by more than 10-fold (from 590±26.7 to 45.6±19.4 nmol/L).Depleting Hec1 in A2780 cells had no significant effect on the paclitaxel sensitivity.In paclitaxel-treated A2780/Taxol cells,depleting Hec1 significantly increased the cleaved PARP and Bax protein levels,and decreased the Bcl-xL protein level.Conclusion:Hec1 overexpression is associated with the progression and poor prognosis of ovarian cancer.Inhibition of Hec1 expression can sensitize ovarian cancer cells to paclitaxel.

  7. HSP72 protects against obesity-induced insulin resistance.

    Science.gov (United States)

    Chung, Jason; Nguyen, Anh-Khoi; Henstridge, Darren C; Holmes, Anna G; Chan, M H Stanley; Mesa, Jose L; Lancaster, Graeme I; Southgate, Robert J; Bruce, Clinton R; Duffy, Stephen J; Horvath, Ibolya; Mestril, Ruben; Watt, Matthew J; Hooper, Philip L; Kingwell, Bronwyn A; Vigh, Laszlo; Hevener, Andrea; Febbraio, Mark A

    2008-02-05

    Patients with type 2 diabetes have reduced gene expression of heat shock protein (HSP) 72, which correlates with reduced insulin sensitivity. Heat therapy, which activates HSP72, improves clinical parameters in these patients. Activation of several inflammatory signaling proteins such as c-jun amino terminal kinase (JNK), inhibitor of kappaB kinase, and tumor necrosis factor-alpha, can induce insulin resistance, but HSP 72 can block the induction of these molecules in vitro. Accordingly, we examined whether activation of HSP72 can protect against the development of insulin resistance. First, we show that obese, insulin resistant humans have reduced HSP72 protein expression and increased JNK phosphorylation in skeletal muscle. We next used heat shock therapy, transgenic overexpression, and pharmacologic means to overexpress HSP72 either specifically in skeletal muscle or globally in mice. Herein, we show that regardless of the means used to achieve an elevation in HSP72 protein, protection against diet- or obesity-induced hyperglycemia, hyperinsulinemia, glucose intolerance, and insulin resistance was observed. This protection was tightly associated with the prevention of JNK phosphorylation. These findings identify an essential role for HSP72 in blocking inflammation and preventing insulin resistance in the context of genetic obesity or high-fat feeding.

  8. Nab-Paclitaxel Plus Gemcitabine for Metastatic Pancreatic Cancer

    Science.gov (United States)

    A summary of results from a phase III trial that compared the combination of albumin-bound paclitaxel (nab-paclitaxel [Abraxane®]) and gemcitabine (Gemzar®) versus gemcitabine alone in patients with metastatic pancreatic cancer.

  9. Exercise and obesity-induced insulin resistance in skeletal muscle

    Directory of Open Access Journals (Sweden)

    Hyo-Bum Kwak

    2013-12-01

    Full Text Available The skeletal muscle in our body is a major site for bioenergetics and metabolism during exercise. Carbohydrates and fats are the primary nutrients that provide the necessary energy required to maintain cellular activities during exercise. The metabolic responses to exercise in glucose and lipid regulation depend on the intensity and duration of exercise. Because of the increasing prevalence of obesity, recent studies have focused on the cellular and molecular mechanisms of obesity-induced insulin resistance in skeletal muscle. Accumulation of intramyocellular lipid may lead to insulin resistance in skeletal muscle. In addition, lipid intermediates (e.g., fatty acyl-coenzyme A, diacylglycerol, and ceramide impair insulin signaling in skeletal muscle. Recently, emerging evidence linking obesity-induced insulin resistance to excessive lipid oxidation, mitochondrial overload, and mitochondrial oxidative stress have been provided with mitochondrial function. This review will provide a brief comprehensive summary on exercise and skeletal muscle metabolism, and discuss the potential mechanisms of obesity-induced insulin resistance in skeletal muscle.

  10. Absence of induced resistance in Agaricus bisporus against Lecanicillium fungicola.

    Science.gov (United States)

    Berendsen, Roeland L; Schrier, Niek; Kalkhove, Stefanie I C; Lugones, Luis G; Baars, Johan J P; Zijlstra, Carolien; de Weerdt, Marjanne; Wösten, Han A B; Bakker, Peter A H M

    2013-03-01

    Lecanicillium fungicola causes dry bubble disease and is an important problem in the cultivation of Agaricus bisporus. Little is known about the defense of mushrooms against pathogens in general and L. fungicola in particular. In plants and animals, a first attack by a pathogen often induces a systemic response that results in an acquired resistance to subsequent attacks by the same pathogen. The development of functionally similar responses in these two eukaryotic kingdoms indicates that they are important to all multi-cellular organisms. We investigated if such responses also occur in the interaction between the white button mushroom and L. fungicola. A first infection of mushrooms of the commercial A. bisporus strain Sylvan A15 by L. fungicola did not induce systemic resistance against a subsequent infection. Similar results were obtained with the A. bisporus strain MES01497, which was demonstrated to be more resistant to dry bubble disease. Apparently, fruiting bodies of A. bisporus do not express induced resistance against L. fungicola.

  11. Improvement of resistance to hydrogen induced cracking in electric resistance welded pipes fabricated with slit coils

    Science.gov (United States)

    Hong, Hyun Uk; Lee, Jong Bong; Choi, Ho Jin

    2009-02-01

    The optimization of electric resistance welding (ERW) conditions was studied to improve the resistance to hydrogen induced cracking (HIC) at the bondline in small diameter API X60 ERW pipes fabricated with slit coils. The results show that HIC is initiated preferentially at the elongated Si, Mn and Al-rich oxide inclusions, normally known as a penetrator on the bondline. However, no evidence was found of any centerline segregation effect. The HIC ratio increases with the fraction of penetrators at the bondline, regardless of the degrees of center segregation. Furthermore, for a satisfactory level of HIC resistance, the fraction of penetrators must be less than 0.03 % and most of the penetrators should be circular-shaped. The design of experimental (DOE) method was used to determine the optimum ERW condition for minimization of the penetrator ratio. Finally, guideline is suggested for the optimum ERW condition for achieving excellent HIC resistance.

  12. Resistance switching induced by electric fields in manganite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Villafuerte, M [Facultad de Ciencias Exactas y TecnologIa, Universidad Nacional de Tucuman, S. M. de Tucuman (Argentina); Juarez, G [Facultad de Ciencias Exactas y TecnologIa, Universidad Nacional de Tucuman, S. M. de Tucuman (Argentina); Duhalde, S [Dpto de Fisica, Facultad de IngenierIa, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Golmar, F [Dpto de Fisica, Facultad de IngenierIa, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Degreef, C L [Dpto de Fisica, Facultad de IngenierIa, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Heluani, S P [Facultad de Ciencias Exactas y TecnologIa, Universidad Nacional de Tucuman, S. M. de Tucuman (Argentina)

    2007-04-15

    In this work, we investigate the polarity-dependent Electric Pulses Induced Resistive (EPIR) switching phenomenon in thin films driven by electric pulses. Thin films of {sub 0.5}Ca{sub 0.5}MnO{sub 3} (manganite) were deposited by PLD on Si substrate. The transport properties at the interface between the film and metallic electrode are characterized in order to study the resistance switching. Sample thermal treatment and electrical field history are important to be considered for get reproducible EPIR effect. Carriers trapping at the interfaces are considered as a possible explanation of our results.

  13. Expression and significance of heparin binding-epidermal growth factor-like growth factor in paclitaxel-resistant ovarian cancer%肝素结合表皮生长因子在紫杉醇耐药卵巢上皮性癌细胞和组织中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    汤小晗; 卢美松; 李翠萍; 邓锁; 李萌

    2014-01-01

    均有统计学意义(P<0.01)。(2)体内实验结果:接种A2780和A2780/Taxol细胞的裸鼠移植瘤组织中HB-EGF蛋白的表达水平分别为(5.0±2.2)、(10.8±3.3)分,两者比较,差异有统计学意义(P<0.01)。A2780/Taxol+CRM197组肿瘤体积和肿瘤质量分别为(546±85)mm3和(0.56±0.09)g,明显低于A2780/Taxol组的(1840±145)mm3和(1.76±0.23)g,A2780+CRM197组肿瘤体积和肿瘤质量分别为(818±63)mm3和(0.74±0.15)g,明显低于A2780组的(1355±119)mm3和(1.31±0.27)g,分别比较,差异均有统计学意义(P<0.05)。A2780/Taxol+CRM197组的抑瘤率为68%,高于A2780+CRM197组的43%;A2780/Taxol+CRM197组的抑瘤率为68%,高于A2780+CRM197组的43%,分别比较,差异均有统计学意义(P<0.01)。结论紫杉醇耐药的卵巢癌细胞和组织中HB-EGF蛋白均高表达,与卵巢癌对紫杉醇的耐药性相关。抑制HB-EGF蛋白的表达可有效促进紫杉醇耐药卵巢癌细胞凋亡,抑制其生长。%Objective To examine the expression of heparin binding-epidermal growth factor-like growth factor (HB-EGF) in paclitaxel-resistant ovarian cancer and elucidate the relationship between HB-EGF and the resistance of ovarian cancer to paclitaxel. Methods The human ovarian carcinoma cell line A2780 and the paclitaxel-resistant human ovarian carcinoma cell line A2780/Taxol were cultured in vitro. Western blot was used to dectect the expression of HB-EGF protein in A2780 and A2780/Taxol groups. The A2780 cells were treated with cross-reacting material 197 (CRM197 and A2780 + CRM197 group) or dimethyl sulphoxide (DMSO;A2780 group), while the A2780/Taxol cells were treated with CRM197 (A2780/Taxol+CRM197 group) or DMSO (A2780/Taxol group). The effects of CRM197 on growth and proliferation was tested by methyl thiazolyl tetrazolium( MTT) and the results were showed as absorbance (A).The effects of CRM197 on cell cycles was tested by flow cytometry, while the effects of

  14. [The vitro research of effects of Beclin1 on paclitaxel-sensitivity in laryngeal carcinoma cell Hep-2].

    Science.gov (United States)

    Deng, Xiaocong; Yang, Xinming; Li, Shisheng

    2015-01-01

    Background: We detect the effects of Beclinl on paclitaxel-sensitivity in laryngeal carcinoma cell. This study used Hep-2, Hep-2-pcDNA3. 1, Hep-2-Beclinl as invitro model. The effect of paclitaxel on the proliferation and cell apoptosis of laryngeal cancer cell lines was evaluated by MTT assay and flow cytometry. The protein expression level of Akt and p-Akt was detected by Western blot. Result: After treated by paclitaxel, the inhibition rate was significantly higher in Hep-2-Beclin cells than in Hep-2-pcDNA3. 1 cells and Hep-2 cells (PHep-2, Hep-2-pcDNA3. 1, Hep-2-Beclinl were (23. 75 ± 2 3. 77) %, (21. 25 ± 4. 92) %, (32. 50 ± 5. 97) %, respectively. After dealing with 20µg/L paclitaxel, the apoptosis rate in Hep-2, Hep-2-pcDNA3. 1, Hep-2-Beclinl were (38. 75 ± 4. 79) %, (38. 75±6. 55) %, (50. 00±7. 26) %, respectively. Paclitaxel-induced apoptosis was higher in Hep-2-Beclin cells than in Hep-2-pcDNA3. 1 cells and Hep-2 cells (PHep-2-Beclin cells was lower than in Hep-2-pcDNA3. 1 cells and Hep-2 cells (P0. 05). Beclinl enhances paclitaxel-sensitivity by inhibition of PI3K/Akt pathway.

  15. Production of paclitaxel by Fusarium solani isolated from Taxus celebica

    Indian Academy of Sciences (India)

    B V S K Chakravarthi; Prasanta Das; Kalpana Surendranath; Anjali A Karande; Chelliah Jayabaskaran

    2008-06-01

    A fungus was isolated from the stem cuttings of Taxus celebica, which produced paclitaxel in liquid-grown cultures. The fungus was identified as Fusarium solani based on colony characteristics, morphology of conidia and the 26S rDNA sequence. Paclitaxel was identified by chromatographic and spectroscopic comparison with authentic paclitaxel and its cytotoxic activity towards Jurkat cells in vitro.

  16. Molecular mechanisms of paclitaxel and NM-3 on human gastric cancer in a severe combined immune deficiency mice orthotopic implantation model

    Institute of Scientific and Technical Information of China (English)

    Jin-Shui Zhu; Ming-Quan Song; Guo-Qiang Chen; Qin Li; Qun Sun; Qiang Zhang

    2007-01-01

    AIM: To explore the molecular mechanisms of action of paclitaxel and NM-3 on human gastric cancer in severe combined immune deficiency (SCID) mice.METHODS: Human gastric cancer cells SGC-7901 were implanted into SCID mice and mice were treated with paclitaxel and NM-3. The effects of paclitaxel and NM-3 on apoptosis of human gastric cancer cells were analyzed using flow cytometry, TUNEL assays, and DNA fragment analyses.RESULTS: Apoptosis of SGC-7901 cells was successfully induced by paclitaxel, NM-3, and the combination of paclitaxel and NM-3 24 h after injection as shown by the presence of apoptotic hypodiploid peaks on the flow cytometer before G1-S and a characteristic apoptotic band pattern in the DNA electrophoresis. The apoptotic rate detected by TUNEL assay was found to be significantly higher in the paclitaxel/NM-3 compared to the control group (38.5% ± 5.14% vs 13.2% ± 1.75%,P < 0.01).CONCLUSION: Paclitaxel in combination with NM-3 is able to induce apoptosis of the human gastric cancer cells in SCID mice effectively and synergistically.

  17. Inducible and Acquired Clarithromycin Resistance in the Mycobacterium abscessus Complex.

    Directory of Open Access Journals (Sweden)

    Marc Rubio

    Full Text Available Clarithromycin was considered the cornerstone for the treatment of Mycobacterium abscessus complex infections. Genetic resistance mechanisms have been described and many experts propose amikacin as an alternative. Nevertheless, clarithromycin has several advantages; therefore, it is necessary to identify the non-functional erm(41 allele to determine the most suitable treatment. The aims of this study were to characterize the molecular mechanisms of clarithromycin resistance in a collection of Mycobacterium abscessus complex isolates and to verify the relationship between these mechanisms and the antibiogram.Clinical isolates of M. abscessus complex (n = 22 from 16 patients were identified using four housekeeping genes (rpoB, secA1, sodA and hsp65, and their genetic resistance was characterized by studying erm(41 and rrl genes. Nine strains were recovered from the clinical isolates and subjected to E-test and microdilution clarithromycin susceptibility tests, with readings at 3, 7 and 14 days.We classified 11/16 (68.8% M. abscessus subsp. abscessus, 4/16 (25.0% M. abscessus subsp. bolletii, and 1/16 (6.3% M. abscessus subsp. massiliense. T28 erm(41 allele was observed in 8 Mycobacterium abscessus subps. abscessus and 3 Mycobacterium abscessus subsp. bolletii. One strain of M. abscessus subsp. bolletii had an erm(41 gene truncated and was susceptible to clarithromycin. No mutations were observed in rrl gene first isolates. In three patients, follow-up of initial rrl wild-type strains showed acquired resistance.Most clinical isolates of M. abscessus complex had inducible resistance to clarithromycin and total absence of constitutive resistance. Our findings showed that the acquisition of resistance mutations in rrl gene was associated with functional and non-functional erm(41 gene. Caution is needed when using erm(41 sequencing alone to identify M. abscessus subspecies. This study reports an acquired mutation at position 2057 of rrl gene

  18. 下调βIII-tubulin逆转肺腺癌A549/Taxol细胞株紫杉醇耐药%Down-regulatedβIII-tubulin Expression Can Reverse Paclitaxel Resistance in A549/Taxol Cells Lines

    Institute of Scientific and Technical Information of China (English)

    禚银玲; 郭其森

    2014-01-01

    Background and objective Chemotherapy drug resistance is the primary causes of death in patients with pulmonary carcinoma which make tumor recurrence or metastasis.β-tubulin is the main cell targets of anti-microtubule drug. Increased expression ofβIII-tubulin has been implicated in non-small cell lung cancer (NSCLC) cell lines. To explore the relationship among the expression level ofβIII-tubulin and the sensitivity of A549/Taxolcell lines to Taxol and cell cycles and cell apoptosis by RNA interference-mediated inhibition ofβIII-tubulin in A549/Taxol cells. Methods hTree pairs of siRNA targetdβIII-tubulin were designed and prepared, which were transfected into A549/Taxol cells using LipofectamineTM 2000. We detected the expression ofβIII-tubulin mRNA using Real-time lfuorescence qRT-PCR. Tedhen we selected the most eff-cient siRNA by the expression ofβIII-tubulin mRNA in transfected group.βIII-tubulin protein level were mesured by Western blot. hTe taxol sensitivity in transfected group were evaluated by MTT assay. And the cell apoptosis and cell cycles were deter-mined by lfow cytometry. Results βIII-tubulin mRNA levels in A549/Taxol cells were signiifcantly decreased in transfected grop by Real-time qRT-PCR than control groups. AndβIII-tubulin siRNA-1 sequence showed the highest transfection eff-ciency, which was (87.73±4.87)%(P<0.01);Western blot results showed that the expressional level of BIII tublin protein was signiifcantly down-reulated in the transfectant cells than thant in the control cells. By MTT assay, we showed that the inhibition ratio of Taxol to A549/Taxol cells transfeced was higher than that of control group (51.77±4.60)%(P<0.01). hTe early apopto-sis rate of A549/Taxol cells in transfected group were signiifcantly higher than that of control group (P<0.01);G2-M content in taxol group obviously increased than untreated samples by the cell cycle (P<0.05). Conclusion βIII-tubulin down-regulated signiifcantly sensitized NSCLC A549

  19. Optimizing chemically induced resistance in tomato against Botrytis cinerea

    DEFF Research Database (Denmark)

    Luna, Estrella; Beardon, Emily G; Ravnskov, Sabine

    2016-01-01

    Resistance-inducing chemicals can offer broad-spectrum disease protection in crops, but can also affect plant growth and interactions with plant-beneficial microbes. We have evaluated different application methods of ß-aminobutyric acid (BABA) and jasmonic acid (JA) for long-lasting induced...... resistance in tomato against Botrytis cinerea. In addition, we have studied non-target effects on plant growth and root colonization by arbuscular mycorrhizal fungi (AMF). Germinating seeds for one week in BABA- or JA-containing solutions promoted seed germination efficiency, did not affect plant growth...... repressed plant growth at higher concentrations of the chemicals, which was particularly pronounced in hydroponically grown plants after BABA treatment. Both seed coating with BABA, and seedling treatments with BABA or JA, did not affect AMF root colonization in soil-grown tomato. Our study has identified...

  20. Transcriptomics and knockout mutant analysis of rhizobacteria-mediated induced systemic resistance in Arabidopsis

    NARCIS (Netherlands)

    Verhagen, B.W.M.

    2004-01-01

    A classic example of induced resistance is triggered after infection by a necrotizing pathogen, rendering uninfected,distal parts more resistant to subsequent pathogen attack, and is often referred to as systemic acquired resistance (SAR). A phenotypically comparable type of induced resistance is tr

  1. HSP72 protects against obesity-induced insulin resistance

    OpenAIRE

    Chung, Jason; Nguyen, Anh-Khoi; Henstridge, Darren C.; Holmes, Anna G.; Chan, M. H. Stanley; Mesa, Jose L.; Lancaster, Graeme I.; Southgate, Robert J.; Bruce, Clinton R.; Duffy, Stephen J.; Horvath, Ibolya; Mestril, Ruben; Watt, Matthew J.; Hooper, Philip L.; Kingwell, Bronwyn A.

    2008-01-01

    Patients with type 2 diabetes have reduced gene expression of heat shock protein (HSP) 72, which correlates with reduced insulin sensitivity. Heat therapy, which activates HSP72, improves clinical parameters in these patients. Activation of several inflammatory signaling proteins such as c-jun amino terminal kinase (JNK), inhibitor of κB kinase, and tumor necrosis factor-α, can induce insulin resistance, but HSP 72 can block the induction of these molecules in vitro. Accordingly, we examined ...

  2. Prospects and challenges for practical application of rhizobacteria-mediated induced systemic resistance

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    2002-01-01

    Selected strains of plant growth-promoting rhizobacteria are able to induce a systemic resistance (ISR) in plants, which is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). The generally non-specific character of induced resistance constitutes an increase in the level o

  3. Phantom limb pain as a manifestation of paclitaxel neurotoxicity.

    Science.gov (United States)

    Khattab, J; Terebelo, H R; Dabas, B

    2000-07-01

    Paclitaxel is a chemotherapeutic agent with activity directed against several malignancies. It has multiple adverse effects including neurotoxicity. We describe 2 patients with prior amputation who experienced phantom limb pain (PLP) after receiving paclitaxel therapy. A third patient experienced disabling neurotoxicity in the extremity of a prior ulnar nerve and tendon transposition after receiving paclitaxel. This unique syndrome should be identified as a direct causal effect of paclitaxel. In this report, we review the pathophysiology of PLP and treatment options. Physicians should be aware that PLP can occur after initiation of paclitaxel.

  4. Intervention study of Cardioxane on Paclitaxel induced cardiac injury%右丙亚胺对紫杉醇心脏损伤的干预研究

    Institute of Scientific and Technical Information of China (English)

    霍燃; 臧爱民; 杨华; 王佳佳

    2013-01-01

    Aim: To investigate the protection effect of Dexrazoxane on Taxol induced cardiotoxicity. Methods: 64 Wister rats were randomly divided into four groups, group of negative control, group of Taxol only, group of Taxol and low-dose Dexrazoxane, group of Taxol and high-dose Dexrazoxane. The levels of cTnI and cTnT were detected at the end of 8 weeks and 16 weeks after different drug treatments, then the morphological features of myocardial cell patheological section were examined under inverted phase contrast microscopy. Results: Compared with negative control, the concentration of cTnI and cTnT were higher in the group of Taxol only at the end of 8 weeks, group of Taxol and Dexrazoxane was more effective than group of Taxol only to increase the cTnI and cTnT, but there was no statistically significance(P>0.05). At the end of 16 weeks,the concentration of cTnI and cTnT in the group of Taxol only were still higher than that in the group of negative control , group of Taxol and Dexrazoxane was still more effective than group of Taxol only to increase the cTnI and cTnT, which also has statistically significance (PO.05)。16周末紫杉醇组与空白对照组对比,血清cTnI、cTnI浓度升高,右丙亚胺组升高幅度高于紫杉醇组,差异有统计学意义(PO.05)。16周末紫杉醇组细胞及间质充血水肿,右丙亚胺组较紫杉醇重,病理积分高于紫杉醇组。结论右丙亚胺会加重单药紫杉醇所致的心脏毒性。

  5. Doxorubicin plus paclitaxel in advanced breast cancer

    DEFF Research Database (Denmark)

    Dombernowsky, P; Boesgaard, M; Andersen, E

    1997-01-01

    between administration of a short infusion of doxorubicin followed by a 3-hour infusion of paclitaxel was evaluated. Included were patients with metastatic breast cancer, who received doxorubicin 50 mg/m2 followed by paclitaxel 200 mg/m2 at intervals of 30 minutes, 4 hours, and 24 hours every 3 weeks......The combination of bolus doxorubicin and paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) as a 3-hour infusion is highly active in patients with metastatic breast cancer, but it has considerable cardiotoxicity. In this ongoing study, the potential effect of increasing the interval....... As of February 1997, 34 patients have been enrolled, two patients are too early to evaluate, and 13 are continuing treatment. The preliminary response rate is 69% (95% confidence interval, 50% to 84%), ranging from 60% to 80% within the three schedules. The main toxicities consisted of grade 3/4 neutropenia...

  6. Superior antitumor activity of nanoparticle albumin-bound paclitaxel in experimental gastric cancer.

    Directory of Open Access Journals (Sweden)

    Changhua Zhang

    Full Text Available Gastric cancer is the second common cause of cancer related death worldwide and lacks highly effective treatment for advanced disease. Nab-paclitaxel is a novel microtubule-inhibitory cytotoxic agent that has not been tested in gastric cancer as of yet. In this study, human gastric cancer cell lines AGS, NCI-N87 and SNU16 were studied. Nab-paclitaxel inhibited cell proliferation with an IC50 of 5 nM in SNU16, 23 nM in AGS and 49 nM in NCI-N87 cells after 72-hour treatment, which was lower than that of oxaliplatin (1.05 μM to 1.51 μM and epirubicin (0.12 μM to 0.25 μM. Nab-paclitaxel treatment increased expression of the mitotic-spindle associated phospho-stathmin irrespective of the baseline total or phosphorylated stathmin level, and induced mitotic cell death as confirmed through increased expression of cleaved-PARP and caspase-3. After a two-week nab-paclitaxel, oxaliplatin or epirubicin treatment, the average in vivo local tumor growth inhibition rate was 77, 17.2 and 21.4 percent, respectively (p = 0.002. Effects of therapy on tumoral proliferative and apoptotic indices corresponded with tumor growth inhibition data, while expression of phospho-stathmin also increased in tissues. There was an increase in median animal survival after nab-paclitaxel treatment (93 days compared to controls (31 days, p = 0.0007, oxaliplatin (40 days, p = 0.0007 or to docetaxel therapy (81 days, p = 0.0416. The strong antitumor activity of nab-paclitaxel in experimental gastric cancer supports such microtubule-inhibitory strategy for clinical application. Nab-paclitaxel benefits were observed independent from phosphorylated stathmin expression at baseline, putting into question the consideration of nab-paclitaxel use in gastric cancer based on this putative biomarker.

  7. Inflammation-induced microvascular insulin resistance is an early event in diet-induced obesity.

    Science.gov (United States)

    Zhao, Lina; Fu, Zhuo; Wu, Jing; Aylor, Kevin W; Barrett, Eugene J; Cao, Wenhong; Liu, Zhenqi

    2015-12-01

    Endothelial dysfunction and vascular insulin resistance usually coexist and chronic inflammation engenders both. In the present study, we investigate the temporal relationship between vascular insulin resistance and metabolic insulin resistance. We assessed insulin responses in all arterial segments, including aorta, distal saphenous artery and the microvasculature, as well as the metabolic insulin responses in muscle in rats fed on a high-fat diet (HFD) for various durations ranging from 3 days to 4 weeks with or without sodium salicylate treatment. Compared with controls, HFD feeding significantly blunted insulin-mediated Akt (protein kinase B) and eNOS [endothelial nitric oxide (NO) synthase] phosphorylation in aorta in 1 week, blunted vasodilatory response in small resistance vessel in 4 weeks and microvascular recruitment in as early as 3 days. Insulin-stimulated whole body glucose disposal did not begin to progressively decrease until after 1 week. Salicylate treatment fully inhibited vascular inflammation, prevented microvascular insulin resistance and significantly improved muscle metabolic responses to insulin. We conclude that microvascular insulin resistance is an early event in diet-induced obesity and insulin resistance and inflammation plays an essential role in this process. Our data suggest microvascular insulin resistance contributes to the development of metabolic insulin resistance in muscle and muscle microvasculature is a potential therapeutic target in the prevention and treatment of diabetes and its related complications. © 2015 Authors; published by Portland Press Limited.

  8. Identification and expression analysis of methyl jasmonate responsive ESTs in paclitaxel producing Taxus cuspidata suspension culture cells

    Directory of Open Access Journals (Sweden)

    Lenka Sangram K

    2012-04-01

    Full Text Available Abstract Background Taxol® (paclitaxel promotes microtubule assembly and stabilization and therefore is a potent chemotherapeutic agent against wide range of cancers. Methyl jasmonate (MJ elicited Taxus cell cultures provide a sustainable option to meet the growing market demand for paclitaxel. Despite its increasing pharmaceutical importance, the molecular genetics of paclitaxel biosynthesis is not fully elucidated. This study focuses on identification of MJ responsive transcripts in cultured Taxus cells using PCR-based suppression subtractive hybridization (SSH to identify genes involved in global pathway control. Results Six separate SSH cDNA libraries of paclitaxel-accumulating Taxus cuspidata P991 cell lines were constructed at three different post-elicitation time points (6h, 18h and 5 day to identify genes that are either induced or suppressed in response to MJ. Sequencing of 576 differentially screened clones from the SSH libraries resulted in 331 unigenes. Functional annotation and Gene Ontology (GO analysis of up-regulated EST libraries showed enrichment of several known paclitaxel biosynthetic genes and novel transcripts that may be involved in MJ-signaling, taxane transport, or taxane degradation. Macroarray analysis of these identified genes unravelled global regulatory expression of these transcripts. Semi-quantitative RT-PCR analysis of a set of 12 candidate genes further confirmed the MJ-induced gene expression in a high paclitaxel accumulating Taxus cuspidata P93AF cell line. Conclusions This study elucidates the global temporal expression kinetics of MJ responsive genes in Taxus suspension cell culture. Functional characterization of the novel genes identified in this study will further enhance the understanding of paclitaxel biosynthesis, taxane transport and degradation.

  9. Thiazole-valine peptidomimetic (TTT-28) antagonizes multidrug resistance in vitro and in vivo by selectively inhibiting the efflux activity of ABCB1

    Science.gov (United States)

    Wang, Yi-Jun; Patel, Bhargav A.; Anreddy, Nagaraju; Zhang, Yun-Kai; Zhang, Guan-Nan; Alqahtani, Saeed; Singh, Satyakam; Shukla, Suneet; Kaddoumi, Amal; Ambudkar, Suresh V.; Talele, Tanaji T.; Chen, Zhe-Sheng

    2017-01-01

    Multidrug resistance (MDR) attenuates the chemotherapy efficacy and increases the probability of cancer recurrence. The accelerated drug efflux mediated by ATP-binding cassette (ABC) transporters is one of the major MDR mechanisms. This study investigated if TTT-28, a newly synthesized thiazole-valine peptidomimetic, could reverse ABCB1-mediated MDR in vitro and in vivo. TTT-28 reversed the ABCB1-mediated MDR and increased the accumulation of [3H]-paclitaxel in ABCB1 overexpressing cells by selectively blocking the efflux function of ABCB1, but not interfering with the expression level and localization of ABCB1. Animal study revealed that TTT-28 enhanced the intratumoral concentration of paclitaxel and promoted apoptosis, thereby potently inhibiting the growth of ABCB1 overexpressing tumors. But TTT-28 did not induce the toxicity (cardiotoxicity/myelosuppression) of paclitaxel in mice. In this study, we synthesized and evaluated a novel selective inhibitor of ABCB1 (TTT-28) with high efficacy and low toxicity. The identification and characterization of this new thiazole-valine peptidomimetic will facilitate design and synthesis of a new generation of ABCB1 inhibitors, leading to further research on multidrug resistance and combination chemotherapy. Furthermore, the strategy that co-administer MDR-ABCB1 inhibitor to overcome the resistance of one FDA approved, widely used chemotherapeutic paclitaxel, may be promising direction for the field of adjuvant chemotherapy. PMID:28181548

  10. Recent Advances in Obesity-Induced Inflammation and Insulin Resistance

    Science.gov (United States)

    Tateya, Sanshiro; Kim, Francis; Tamori, Yoshikazu

    2013-01-01

    It has been demonstrated in rodents and humans that chronic inflammation characterized by macrophage infiltration occurs mainly in adipose tissue or liver during obesity, in which activation of immune cells is closely associated with insulin sensitivity. Macrophages can be classified as classically activated (M1) macrophages that support microbicidal activity or alternatively activated (M2) macrophages that support allergic and antiparasitic responses. In the context of insulin action, M2 macrophages sustain insulin sensitivity by secreting IL-4 and IL-10, while M1 macrophages induce insulin resistance through the secretion of proinflammatory cytokines, such as TNFα. Polarization of M1/M2 is controlled by various dynamic functions of other immune cells. It has been demonstrated that, in a lean state, TH2 cells, Treg cells, natural killer T cells, or eosinophils contribute to the M2 activation of macrophages by secreting IL-4 or IL-10. In contrast, obesity causes alteration of the constituent immune cells, in which TH1 cells, B cells, neutrophils, or mast cells induce M1 activation of macrophages by the elevated secretion of TNFα and IFNγ. Increased secretion of TNFα and free fatty acids from hypertrophied adipocytes also contributes to the M1 activation of macrophages. Since obesity-induced insulin resistance is established by macrophage infiltration and the activation of immune cells inside tissues, identification of the factors that regulate accumulation and the intracellular signaling cascades that define polarization of M1/M2 would be indispensable. Regulation of these factors would lead to the pharmacological inhibition of obesity-induced insulin resistance. In this review, we introduce molecular mechanisms relevant to the pathophysiology and review the most recent studies of clinical applications targeting chronic inflammation. PMID:23964268

  11. Genetic improvement of Trichoderma ability to induce systemic resistance

    Institute of Scientific and Technical Information of China (English)

    Ciliento R; Mach R L; Lorito M; Woo S L; Di Benedetto P; Ruocco M; Scala F; Soriente I; Ferraioli S; Brunner K; Zeilinger S

    2004-01-01

    @@ The beneficial applications of Trichoderma spp. in agriculture include not only the control of plant pathogens, but also the improvement of plant growth, micronutrient availability, and plant tolerance to abiotic stress. In addition, it has been suggested that these fungi are able to increase plant disease resistance by activating induced systemic resistance (ISR) . The mode of action of these beneficial fungi in the Trichoderma -plant-pathogen interaction are many, complex and not completely understood. Numerous lytic enzymes have been characterized, the encoding genes (ech42 gluc78,nag1 from T. atroviride strain P1) cloned, and their role in biocontrol demonstrated. The corresponding biocontrol-related inducible promoters have been used in a reporter system based on the Aspergillus niger glucose oxidase gene (goxA) to monitor biocontrol activity. Glucose oxidase catalyzes the oxygen-dependent oxidation of D-glucose to D-glucono-1, 5-lactone and hydrogen peroxide; this latter compound is known to have an antifungal effect and activate the plant defence cascade, thus increasing resistance to pathogen attack. T. atroviride P1 transformants with various promoters gox were tested as seed coating treatments on bean seeds planted in soil infested with a soilborne fungal pathogen. Successively, the emergent leaves were inoculated with a foliar pathogen to determine the effect of the GOX transformants on biocontrol and resistance to pathogen attack.Inoculations with the P1-GOX transformants not only reduced disease symptoms caused by a soil pathogen, but also the lesions of various foliar pathogens applied far from the Trichoderma colonization, thus activating ISR. A similar approach is being use to genetically improve T.harzianum T22, a rhizosphere competent and commercially marketed strain not transformed yet, by using four different gox gene constructs under the control of constitutive and inducible promoters.Plasmids have been introduced in Trichoderma by

  12. MUC1 induces drug resistance in pancreatic cancer cells via upregulation of multidrug resistance genes.

    Science.gov (United States)

    Nath, S; Daneshvar, K; Roy, L D; Grover, P; Kidiyoor, A; Mosley, L; Sahraei, M; Mukherjee, P

    2013-06-17

    MUC1 (CD227), a membrane tethered mucin glycoprotein, is overexpressed in >60% of human pancreatic cancers (PCs), and is associated with poor prognosis, enhanced metastasis and chemoresistance. The objective of this study was to delineate the mechanism by which MUC1 induces drug resistance in human (BxPC3 and Capan-1) and mouse (KCKO, KCM) PC cells. We report that PC cells that express high levels of MUC1 exhibit increased resistance to chemotherapeutic drugs (gemcitabine and etoposide) in comparison with cells that express low levels of MUC1. This chemo resistance was attributed to the enhanced expression of multidrug resistance (MDR) genes including ABCC1, ABCC3, ABCC5 and ABCB1. In particular, levels of MRP1 protein encoded by the ABCC1 gene were significantly higher in the MUC1-high PC cells. In BxPC3 and Capan-1 cells MUC1 upregulates MRP1 via an Akt-dependent pathway, whereas in KCM cells MUC1-mediated MRP1 upregulation is via an Akt-independent mechanism. In KCM, BxPC3 and Capan-1 cells, the cytoplasmic tail motif of MUC1 associates directly with the promoter region of the Abcc1/ABCC1 gene, indicating a possible role of MUC1 acting as a transcriptional regulator of this gene. This is the first report to show that MUC1 can directly regulate the expression of MDR genes in PC cells, and thus confer drug resistance.

  13. Drug-induced caspase 8 upregulation sensitises cisplatin-resistant ovarian carcinoma cells to rhTRAIL-induced apoptosis

    NARCIS (Netherlands)

    Duiker, E. W.; Meijer, A.; van der Bilt, A. R. M.; Meersma, G. J.; Kooi, N.; van der Zee, A. G. J.; de Vries, E. G.; de Jong, S.

    2011-01-01

    BACKGROUND: Drug resistance is a major problem in ovarian cancer. Triggering apoptosis using death ligands such as tumour necrosis factor-related apoptosis inducing ligand (TRAIL) might overcome chemoresistance. METHODS: We investigated whether acquired cisplatin resistance affects sensitivity to re

  14. Does farm fungicide use induce azole resistance in Aspergillus fumigatus?

    Science.gov (United States)

    Kano, Rui; Kohata, Erina; Tateishi, Akira; Murayama, Somay Yamagata; Hirose, Dai; Shibata, Yasuko; Kosuge, Yasuhiro; Inoue, Hiroaki; Kamata, Hiroshi; Hasegawa, Atsuhiko

    2015-02-01

    Azole resistance of Aspergillus fumigatus isolates has been reported worldwide and it would appear to be mainly due to a point mutation in the 14α-sterol demethylase (CYP51A) gene, which is the target enzyme for azoles. The mutation has been confirmed in isolates from patients who received long-term itraconazole (ITZ) therapy and from agricultural fields where high levels of azole fungicides were employed. However, the relationship between farm environments and azole-resistant A. fumigatus has not been fully studied. In this investigation, 50 isolates of A. fumigatus were obtained from a farm where tetraconazole has been sprayed twice a year for more than 15 years. The mean minimum inhibitory concentration (MIC) of isolates was 0.74 (0.19-1.5) mg/L against ITZ, which was below the medical resistance level of ITZ. The sequence of CYP51A from isolates indicated no gene mutations in isolates from the farm. Antifungal susceptibility of isolates to tetraconazole showed that spraying with tetraconazole did not induce resistance to tetraconazole or ITZ in A. fumigatus.

  15. Diet-Induced Obesity and the Mechanism of Leptin Resistance.

    Science.gov (United States)

    Engin, Atilla

    2017-01-01

    Leptin signaling blockade by chronic overstimulation of the leptin receptor or hypothalamic pro-inflammatory responses due to elevated levels of saturated fatty acid can induce leptin resistance by activating negative feedback pathways. Although, long form leptin receptor (Ob-Rb) initiates leptin signaling through more than seven different signal transduction pathways, excessive suppressor of cytokine signaling-3 (SOCS-3) activity is a potential mechanism for the leptin resistance that characterizes human obesity. Because the leptin-responsive metabolic pathways broadly integrate with other neurons to control energy balance, the methods used to counteract the leptin resistance has extremely limited effect. In this chapter, besides the impairment of central and peripheral leptin signaling pathways, limited access of leptin to central nervous system (CNS) through blood-brain barrier, mismatch between high leptin and the amount of leptin receptor expression, contradictory effects of cellular and circulating molecules on leptin signaling, the connection between leptin signaling and endoplasmic reticulum (ER) stress and self-regulation of leptin signaling has been discussed in terms of leptin resistance.

  16. Phase III trial of carboplatin plus paclitaxel with or without gemcitabine in first-line treatment of epithelial ovarian cancer

    DEFF Research Database (Denmark)

    du Bois, Andreas; Herrstedt, Jørn; Hardy-Bessard, Anne-Claire;

    2010-01-01

    One attempt to improve long-term survival in patients with advanced ovarian cancer was thought to be the addition of more non-cross-resistant drugs to platinum-paclitaxel combination regimens. Gemcitabine was among the candidates for a third drug....

  17. Unraveling rhizobacteria- and abscisic acid-induced pathogen resistance in rice (Oryza sativa L.)

    OpenAIRE

    De Vleesschauwer, David

    2008-01-01

    Induced disease resistance is the phenomenon by which plants exhibit a heightened level of resistance against pathogen infection after appropriate stimulation. In contrast to the relative wealth of information on inducible resistance responses in dicotyledoneous plants, our current understanding of the molecular machinery governing induced resistance in monocotyledoneous crops is still in its infancy. In light of aforementioned knowledge gap, this dissertation aimed to expand our knowledge on...

  18. Traumatic brain injury and obesity induce persistent central insulin resistance.

    Science.gov (United States)

    Karelina, Kate; Sarac, Benjamin; Freeman, Lindsey M; Gaier, Kristopher R; Weil, Zachary M

    2016-04-01

    Traumatic brain injury (TBI)-induced impairments in cerebral energy metabolism impede tissue repair and contribute to delayed functional recovery. Moreover, the transient alteration in brain glucose utilization corresponds to a period of increased vulnerability to the negative effects of a subsequent TBI. In order to better understand the factors contributing to TBI-induced central metabolic dysfunction, we examined the effect of single and repeated TBIs on brain insulin signalling. Here we show that TBI induced acute brain insulin resistance, which resolved within 7 days following a single injury but persisted until 28 days following repeated injuries. Obesity, which causes brain insulin resistance and neuroinflammation, exacerbated the consequences of TBI. Obese mice that underwent a TBI exhibited a prolonged reduction of Akt (also known as protein kinase B) signalling, exacerbated neuroinflammation (microglial activation), learning and memory deficits, and anxiety-like behaviours. Taken together, the transient changes in brain insulin sensitivity following TBI suggest a reduced capacity of the injured brain to respond to the neuroprotective and anti-inflammatory actions of insulin and Akt signalling, and thus may be a contributing factor for the damaging neuroinflammation and long-lasting deficits that occur following TBI. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  19. Inhibition of ceramide production reverses TNF-induced insulin resistance.

    Science.gov (United States)

    Grigsby, R J; Dobrowsky, R T

    2001-10-12

    Ceramide has been implicated as a mediator of insulin resistance induced by tumor necrosis factor-alpha (TNF) in adipocytes. Adipocytes contain numerous caveolae, sphingolipid and cholesterol-enriched lipid microdomains, that are also enriched in insulin receptor (IR). Since caveolae may be important sites for crosstalk between tyrosine kinase and sphingolipid signaling pathways, we examined the role of increased caveolar pools of ceramide in regulating tyrosine phosphorylation of the IR and its main substrate, insulin receptor substrate-1 (IRS-1). Neither exogenous short-chain ceramide analogs nor pharmacologic increases in endogenous caveolar pools of ceramide inhibited insulin-induced tyrosine phosphorylation of the IR and IRS-1. However, inhibition of TNF-induced caveolar ceramide production reversed the decrease in IR tyrosine phosphorylation in response to TNF. These results suggest that TNF-independent increases in caveolar pools of ceramide are not sufficient to inhibit insulin signaling but that in conjunction with other TNF-dependent signals, caveolar pools of ceramide are a critical component for insulin resistance by TNF.

  20. An Italian cost-effectiveness analysis of paclitaxel albumin (nab-paclitaxel) versus conventional paclitaxel for metastatic breast cancer patients: the COSTANza study

    Science.gov (United States)

    Lazzaro, Carlo; Bordonaro, Roberto; Cognetti, Francesco; Fabi, Alessandra; De Placido, Sabino; Arpino, Grazia; Marchetti, Paolo; Botticelli, Andrea; Pronzato, Paolo; Martelli, Elisa

    2013-01-01

    Purpose Paclitaxel albumin (nab-paclitaxel) is a nanoparticle albumin-bound paclitaxel formulation aimed at increasing therapeutic index in metastatic breast cancer. When compared to conventional paclitaxel, nab-paclitaxel has a reported longer time to progression, higher response, lower incidence of neutropenia, no need for premedication, shorter time of administration, and in pretreated metastatic breast cancer patients, extended overall survival. This study investigates the cost-effectiveness of nab-paclitaxel versus conventional paclitaxel for pretreated metastatic breast cancer patients in Italy. Materials and methods A Markov model with progression-free, progressed, and dead states was developed to estimate costs, outcomes, and quality adjusted life years over 5 years from the Italian National Health Service viewpoint. Patients were assumed to receive nab-paclitaxel 260 mg/m2 three times weekly or conventional paclitaxel 175 mg/m2 three times weekly. Data on health care resource consumption was collected from a convenience sample of five Italian centers. Resources were valued at Euro (€) 2011. Published utility weights were applied to health states to estimate the impact of response, disease progression, and adverse events on quality adjusted life years. Three sensitivity analyses tested the robustness of the base case incremental cost-effectiveness ratio (ICER). Results and conclusion Compared to conventional paclitaxel, nab-paclitaxel gains an extra 0.165 quality adjusted life years (0.265 life years saved) and incurs additional costs of €2506 per patient treated. This translates to an ICER of €15,189 (95% confidence interval: €11,891–€28,415). One-way sensitivity analysis underscores that ICER for nab-paclitaxel remains stable despite varying taxanes cost. Threshold analysis shows that ICER for nab-paclitaxel exceeds €40,000 only if cost per mg of conventional paclitaxel is set to zero. Probabilistic sensitivity analysis highlights that nab-paclitaxel

  1. Carboxylesterase-mediated insecticide resistance: Quantitative increase induces broader metabolic resistance than qualitative change.

    Science.gov (United States)

    Cui, Feng; Li, Mei-Xia; Chang, Hai-Jing; Mao, Yun; Zhang, Han-Ying; Lu, Li-Xia; Yan, Shuai-Guo; Lang, Ming-Lin; Liu, Li; Qiao, Chuan-Ling

    2015-06-01

    Carboxylesterases are mainly involved in the mediation of metabolic resistance of many insects to organophosphate (OP) insecticides. Carboxylesterases underwent two divergent evolutionary events: (1) quantitative mechanism characterized by the overproduction of carboxylesterase protein; and (2) qualitative mechanism caused by changes in enzymatic properties because of mutation from glycine/alanine to aspartate at the 151 site (G/A151D) or from tryptophan to leucine at the 271 site (W271L), following the numbering of Drosophila melanogaster AChE. Qualitative mechanism has been observed in few species. However, whether this carboxylesterase mutation mechanism is prevalent in insects remains unclear. In this study, wild-type, G/A151D and W271L mutant carboxylesterases from Culex pipiens and Aphis gossypii were subjected to germline transformation and then transferred to D. melanogaster. These germlines were ubiquitously expressed as induced by tub-Gal4. In carboxylesterase activity assay, the introduced mutant carboxylesterase did not enhance the overall carboxylesterase activity of flies. This result indicated that G/A151D or W271L mutation disrupted the original activities of the enzyme. Less than 1.5-fold OP resistance was only observed in flies expressing A. gossypii mutant carboxylesterases compared with those expressing A. gossypii wild-type carboxylesterase. However, transgenic flies universally showed low resistance to OP insecticides compared with non-transgenic flies. The flies expressing A. gossypii W271L mutant esterase exhibited 1.5-fold resistance to deltamethrin, a pyrethroid insecticide compared with non-transgenic flies. The present transgenic Drosophila system potentially showed that a quantitative increase in carboxylesterases induced broader resistance of insects to insecticides than a qualitative change. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Low-dose paclitaxel ameliorates fibrosis in the remnant kidney model by down-regulating miR-192.

    Science.gov (United States)

    Sun, Lin; Zhang, Dongshan; Liu, Fuyou; Xiang, Xudong; Ling, Guanghui; Xiao, Li; Liu, Yinghong; Zhu, Xuejing; Zhan, Ming; Yang, Yeyi; Kondeti, Vinay K; Kanwar, Yashpal S

    2011-11-01

    Transforming growth factor (TGF)-β has been shown to play a central role in the development of tubulointerstitial fibrosis, which can be corrected via treatment with paclitaxel. The biology of microRNA (miR) can be modulated by paclitaxel. We hypothesized that paclitaxel may attenuate renal fibrosis in a rat model of remnant kidney disease by inhibiting TGF-β induced-miRs. Rats in groups of 12 were subjected to 5/6 nephrectomy and received low-dose intraperitoneal injection of paclitaxel. Renal functions were assessed at 8 weeks. The TGF-β signalling cascade and ECM proteins were evaluated by real-time polymerase chain reaction (TRT-PCR) and immunofluorescence microscopy. Animals with remnant kidneys developed hypertension, which was not relieved with paclitaxel treatment. However, paclitaxel treatment resulted in dampening the proteinuric response, reduction in serum BUN, creatinine levels and urine protein : creatinine ratio and normalization of creatinine clearance. These effects were accompanied by the inhibition of Smad2/3 activation, attenuation of renal fibrosis and normalization of integrin-linked kinase (ILK), COL(I)A1, COL(IV)A2 and α-SMA expression. Also, paclitaxel down-regulated the expression of miR-192, miR-217 and miR -377, while miR-15 was up-regulated in the remnant kidney. In vitro, in tubular epithelial cells (NRK-52E), paclitaxel also inhibited TGF-β1-induced Smad2/3 activation and normalized ILK, COL(I)A1, COL(IV)A2 and α-SMA expression. Furthermore, ChIP analyses indicated that Taxol suppressed Smad3-mediated miR-192 transcriptional activity. Over-expression of miR-192 in NRK-52E mimicked the changes seen in the remnant kidney, while inclusion of miR-192 inhibitor in the culture medium blocked TGF-β1-induced COL(I)A1 and COL(IV)A2 expression, while ILK and α-SMA were unaffected. These data suggest that low-dose paclitaxel ameliorates renal fibrosis via modulating miR-192 pathobiology and TGF-β/Smad signalling. Copyright © 2011

  3. Efficacy and Tolerability of Weekly Paclitaxel in Combination with High-dose Toremifene Citrate in Patients with Metastatic Breast Cancer

    Directory of Open Access Journals (Sweden)

    Okita,Riki

    2009-08-01

    Full Text Available Toremifene citrate is expected to prevent drug resistance in cancer patients by inhibiting p-glycoprotein activity. The safety and efficacy of combination therapy with high-dose toremifene citrate and paclitaxel were investigated. Between December 2003 and June 2004, 15 women with a mean age of 53 years old with metastatic breast cancer were enrolled. The administration schedule was 80mg/m2 of paclitaxel given on Days 1, 8, and 15, and 120mg/day of toremifene citrate orally administered starting on Day 18. On Days 32 and 39, paclitaxel was concurrently administered again. Toxicities, response rate, and time to treatment failure were assessed. All patients had been treated with endocrine or chemotherapy. Grade 3 leukopenia occurred in 2 patients on the administration of paclitaxel alone, and grade 3 febrile neutropenia occurred in 1 patient given the combination therapy. There was no grade 3 or greater non-hematological toxicity. There was no complete response and 1 partial response, producing a response rate of 6.7%. Median time to treatment failure was 2.7 months. Combination therapy of paclitaxel and toremifene was safe and well tolerated with minimal toxicity. Further clinical trials targeting patients with functional p-glycoprotein are warranted.

  4. Gastrointestinal permeability in ovarian cancer and breast cancer patients treated with paclitaxel and platinum

    Directory of Open Access Journals (Sweden)

    Tichá Alena

    2007-08-01

    Full Text Available Abstract Background Combination of platinum derivatives with paclitaxel is currently the standard front line regimen for patients with epithelial ovarian carcinoma, and represents also an active regimen in patients with metastatic breast or unknown primary carcinomas. Measurement of intestinal permeability represents one of the potential methods of noninvasive laboratory assessment of gastrointestinal mucositis induced by chemotherapy, but little is known about intestinal permeability in patients treated with paclitaxel or platinum. Methods Intestinal permeability was assessed in 36 breast and ovarian cancer patients treated with paclitaxel/platinum combination by measuring, using capillary gas chromatography, urinary sucrose, lactulose, xylose and mannitol after oral challenge. The significance of differences during the therapy compared to pre-treatment values was studied by Wilcoxon paired test. The differences between groups of patient were studied by Mann-Whitney U test. Fisher exact test was used to compare the frequency in different subgroups. Results After administration of the first dose, a significant (p Conclusion A transient significant increase in lactulose/monosaccharide and sucrose/monosaccharide ratios was observed in ovarian and breast cancer patients treated with paclitaxel and platinum. Increased lactulose absorption, lactulose/mannitol, sucrose/mannitol and lactulose/xylose ratios were evident in patients with grade 3 or 4 toxicity, and increased baseline lactulose/mannitol ratio predicted serious toxicity.

  5. Hypoxia-inducible factor-1α induces multidrug resistance protein in colon cancer

    Directory of Open Access Journals (Sweden)

    Lv Y

    2015-07-01

    Full Text Available Yingqian Lv, Shan Zhao, Jinzhu Han, Likang Zheng, Zixin Yang, Li Zhao Department of Oncology, The Second Hospital, Hebei Medical University, Shijiazhuang, Hebei Province, People’s Republic of China Abstract: Multidrug resistance is the major cause of chemotherapy failure in many solid tumors, including colon cancer. Hypoxic environment is a feature for all solid tumors and is important for the development of tumor resistance to chemotherapy. Hypoxia-inducible factor (HIF-1α is the key transcription factor that mediates cellular response to hypoxia. HIF-1α has been shown to play an important role in tumor resistance; however, the mechanism is still not fully understood. Here, we found that HIF-1α and the drug resistance-associated gene multidrug resistance associated protein 1 (MRP1 were induced by treatment of colon cancer cells with the hypoxia-mimetic agent cobalt chloride. Inhibition of HIF-1α by RNA interference and dominant-negative protein can significantly reduce the induction of MRP1 by hypoxia. Bioinformatics analysis showed that a hypoxia response element is located at -378 to -373 bp upstream of the transcription start site of MRP1 gene. Luciferase reporter assay combined with mutation analysis confirmed that this element is essential for hypoxia-mediated activation of MRP gene. Furthermore, RNA interference revealed that HIF-1α is necessary for this hypoxia-driven activation of MRP1 promoter. Importantly, chromatin immunoprecipitation analysis demonstrated that HIF-1α could directly bind to this HRE site in vivo. Together, these data suggest that MRP1 is a downstream target gene of HIF-1α, which provides a potential novel mechanism for HIF-1α-mediated drug resistance in colon cancer and maybe other solid tumors as well. Keywords: hypoxia, hypoxia-inducible factor-1α, multidrug resistance associated protein, transcriptional regulation, chemotherapy tolerance

  6. Strain-induced negative differential resistance in ultrasmall carbon nanotube

    Science.gov (United States)

    Fang, Hui; Zhang, Fei-Peng; Ruan, Xing-Xiang; Huang, Can-Sheng; Jiang, Zhi-Nian; Peng, Jin-Yun; Wang, Ru-Zhi

    2017-08-01

    The transport properties in ultrasmall single-wall carbon nanotubes (SWCNTs) under tensile strain have been theoretically investigated. The regular negative differential resistance (NDR) induced by the strain undergoes a process from enhancement to weakening in the zigzag (3,0) SWCNT. The NDR achieves maximum with applying 4% tensile strain. Compared to the case of (3,0) SWCNT, that NDR cannot be manipulated by applying strain clearly in (4,0) and (5,0) ultrasmall SWCNTs with tensile strain lower than 10%. It proposes this strain-induced NDR effect to demonstrate the possibility of finding potential applications in SWCNT-based NDR nanodevices such as in memory devices, oscillators and fast switching devices.

  7. Autophagy is involved in doxorubicin induced resistance of human myeloma cell line RP-MI8226

    Institute of Scientific and Technical Information of China (English)

    潘耀柱

    2013-01-01

    Objective To explore the role of autophagy in doxorubicin (DOX) -induced resistance of human myeloma cell line RPMI8226.Methods We established doxorubicin induced resistant subline of myeloma cell line RPMI8226/DOX by drug concentration step-elevation method.Resistant index of DOX was measured by MTT

  8. Role of PTEN in TNFα induced insulin resistance

    Energy Technology Data Exchange (ETDEWEB)

    Bulger, David A. [Departments of Medicine and Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Medicine and Research Services, Veterans Association Medical Center, Memphis, TN 38104 (United States); Wellcome Trust Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ (United Kingdom); National Institute of Diabetes & Digestive & Kidney Disease, National Institutes of Health, Bethesda, MD 20892 (United States); Conley, Jermaine [Medicine and Research Services, Veterans Association Medical Center, Memphis, TN 38104 (United States); Conner, Spencer H.; Majumdar, Gipsy [Departments of Medicine and Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Medicine and Research Services, Veterans Association Medical Center, Memphis, TN 38104 (United States); Solomon, Solomon S., E-mail: ssolomon@uthsc.edu [Departments of Medicine and Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Medicine and Research Services, Veterans Association Medical Center, Memphis, TN 38104 (United States)

    2015-06-05

    Aims/hypothesis: PTEN may play a reversible role in TNFα induced insulin resistance, which has been linked to obesity-associated insulin resistance (IR). Methods: Western blots for PTEN and p-Akt were performed on H-411E liver cells incubated with insulin, TNFα, and in selected experiments VO-OHpic vanadium complex in the presence and absence of PTEN siRNA. Total PTEN was compared to β-actin loading control and p-Akt was compared to total Akt. Results: Western blot and Real Time RT-PCR experiments showed increased PTEN after TNFα treatment (p = 0.04); slightly decreased PTEN after insulin treatment; and slightly increased PTEN after insulin + TNFα treatment. PTEN siRNA markedly inhibited the TNFα-induced increase in PTEN (p < 0.01) without significantly changing the p-Akt levels. The vanadium complex, exhibiting insulin-like effects, also significantly prevented the TNFα-induced increase in PTEN. Combining insulin and VO-OHpic was additive, providing both proof of concept and insight into mechanism. Discussion: The PTEN increase due to TNFα treatment was reversible by both PTEN siRNA knockdown and VO-OHpic treatment. Thus, PTEN is identified as a potential new therapeutic target for reducing IR in Type 2 DM. - Highlights: • TNFα treatment induced a significant increase in PTEN in H-411E liver cells. • PTEN siRNA knockdown prevented this effect. • VO-OHpic (vanadium complex) treatment, like insulin, decreased PTEN protein levels. • Thus, PTEN is identified as a potential therapeutic target in DM Type 2.

  9. Is modulating virus virulence by induced systemic resistance realistic?

    Science.gov (United States)

    Faoro, Franco; Gozzo, Franco

    2015-05-01

    Induction of plant resistance, either achieved by chemicals (systemic acquired resistance, SAR) or by rhizobacteria (induced systemic resistance, ISR) is a possible and/or complementary alternative to manage virus infections in crops. SAR mechanisms operating against viruses are diverse, depending on the pathosystem, and may inhibit virus replication as well as cell-to-cell and long-distance movement. Inhibition is often mediated by salicylic acid with the involvement of alternative oxidase and reactive oxygen species. However, salicylate may also stimulate a separate downstream pathway, leading to the induction of an additional mechanism, based on RNA-dependent RNA polymerase 1-mediated RNA silencing. Thus, SAR and RNA silencing would closely cooperate in the defence against virus infection. Despite tremendous recent progress in the knowledge of SAR mechanisms, only a few compounds, including benzothiadiazole and chitosan have been shown to reduce the severity of systemic virus disease in controlled environment and, more modestly, in open field. Finally, ISR induction, has proved to be a promising strategy to control virus disease, particularly by seed bacterization with a mixture of plant growth-promoting rhizobacteria. However, the use of any of these treatments should be integrated with cultivation practices that reduce vector pressure by the use of insecticides, or by Bt crops.

  10. Spirulina protects against rosiglitazone induced osteoporosis in insulin resistance rats.

    Science.gov (United States)

    Gupta, Sumeet; Hrishikeshvan, H J; Sehajpal, Prabodh K

    2010-01-01

    The study was undertaken to assess the protective effect of Spirulina fusiformis extract against Rosiglitazone induced osteoporosis and pharmacodynamic effects of Rosiglitazone with Spirulina in treating hyperglycemia and hyperlipidemia of insulin resistance rat. For this aim, 30 Wistar albino rats were equally divided into five groups as control (C), diabetes mellitus (DM), diabetes mellitus+Rosiglitazone (DM+R), diabetes mellitus+Spirulina (DM+S), and diabetes mellitus+Rosiglitazone+Spirulina (DM+R+S). Serum glucose, triglyceride, HDL, LDL and insulin concentrations were estimated by routine standard methods in blood samples collected on 21th day. Integrity of the bone surface was examined by scanning electronic microscopy, and bone strength was measured by micro-hardness test on 45th day. A significant decrease in total bone mineral density was observed in group DM+R rats (pSpirulina administration. The intactness and integrity of the bone surface as well as the bone strength improved due to the high content of calcium and phosphorous in Spirulina. Besides, chromium and gamma-linoleic acid in Spirulina helped to decrease the fasting serum glucose, HDL, LDL and triglycerides levels in insulin resistance rats. These findings suggest that combination therapy of Rosiglitazone with Spirulina reduced the risk of osteoporosis in insulin resistance rats. Additionally, Spirulina complemented the antihyperglycemic and antilipidemic activity of Rosiglitazone. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  11. Cinnamaldehyde Derivative (CB-PIC Sensitizes Chemo-Resistant Cancer Cells to Drug-Induced Apoptosis via Suppression of MDR1 and its Upstream STAT3 and AKT Signalling

    Directory of Open Access Journals (Sweden)

    Jianzhong Xi

    2015-03-01

    Full Text Available Background/Aims: Our group reported that cinnamaldehyde derivative, (E-4-((2-(3-oxopop-1-enylphenoxymethylpyridinium malonic acid (CB-PIC induced apoptosis in hypoxic SW620 colorectal cancer cells via activation of AMP-activated protein kinase (AMPK and extracellular signal regulated kinase (ERK. Herein, sensitizing effect of CB-PIC was investigated in resistant cancer cells such as paclitaxel (PT resistant lung cancer cells (H460/PT, and Adriamycin (Adr resistant breast cancer (MCF7/Adr and colon cancer (HCT15/cos cells. Methods: Various drug resistant cell lines were treated with CB-PIC, and the signalling pathway and functional assay were explored by Western blot, Rhodamine assay, FACS, RT-PCR and MTT assay. Results: We found that CB-PIC effectively exerted cytotoxicity, increased sub G1 population and the cleaved form of poly (ADP-ribose polymerase (PARP and caspase 9 in drug resistant cancer cells. Furthermore, CB-PIC sensitized resistant cancer cells to adriamycin via downregulation of survival proteins such as survivin, Bcl-xL and Bcl-2, along with MDR1 suppression leading to accumulation of drug in the intracellular region. Of note, CB-PIC transcriptionally decreased MDR1 expression via suppression of STAT3 and AKT signalling in three resistant cancer cells with highly expressed P-glycoprotein. Nonetheless, CB-PIC did not affect transport activity of P-glycoprotein in a short time efflux assay, while epigallocatechin gallate (EGCG accumulated Rhodamine 123 into intracellular region of cell by direct inhibition of MDR1 transport activity. Conclusions: These data demonstrate that CB-PIC suppresses the P-glycoprotein expression through inhibition of STAT3 and AKT signalling to overcome drug resistance in chemo-resistant cancer cells as a potent chemotherapeutic sensitizer.

  12. Effect of bioagents and resistance inducers on grapevine crown gall

    Directory of Open Access Journals (Sweden)

    E. Biondi

    2010-01-01

    Full Text Available Bioagents and chemicals were applied to one-year old grafted vines (Ancelotta/420A in glasshouse and field experiments set up at the Vivai Cooperativi Rauscedo (VCR, Pordenone, Italy. In the glasshouse, holes were drilled in vines on the rootstock and the holes were charged with suspensions of different strains of Pseudomonas spp., and with the biofungicides BS-F4 and Serenade, both based on Bacillus subtilis, before inoculation with a vitopine Agrobacterium vitis strain. The growth retardant Regalis and the resistance inducer Bion were applied to the vines two weeks before inoculation with the pathogen. Six months after inoculation, disease incidence was lowest when BS-F4 had been applied. In the field trial, the vines were wounded by making a cut in the crown, after which they were dipped into the antagonist suspensions just before inoculation with the pathogen. In the two weeks before inoculation, the root systems of the vines were dipped into Regalis and Bion solutions at 7 day intervals. Only these resistance inducers and BS-F4 significantly reduced disease severity. The results indicate that a potential for defence against A. vitis may exist even in susceptible grapevine cultivars, and that this potential can be activated by diverse elicitors.

  13. Resistance induced component of management of diseases of grapevine

    Directory of Open Access Journals (Sweden)

    Jusciélio Barbosa

    2009-08-01

    Full Text Available The use of induced resistance presents as a viable alternative in the management of diseases of the vine. Accordingly, the objective of this study was to evaluate the efficiency of Agro Mos® and potassium phosphite in controlling diseases of grapevine under field conditions in the Valley San Francisco. O test was conducted under field conditions in the experimental area IFSertão Pernambucano, Petrolina, PE, using the cultivar Petit Sirah. The experimental design was in randomized blocks, composed of five treatments and five replicates: T1 - control; T2 - Cabrio Top® - CT (2kg ha-1; T3 - Agro Mos® - AM (3mL L-1; T4 - Fosfito de potássio - FP (4mL L-1; T5 - Agro Mos® - AM (3mL L-1 interleaved with the fungicide Cabrio Top® - CT (2kg ha-1. Each plot consisted of eight plants. Data were subjected to analysis of variance and averages compared by Tukey test at 5%. Conditions in which the experiment was developed, the use of potassium phosphite and Agro-Mos® promoted a significant reduction in the incidence of Plasmopara viticola and Uncinula necator.Key-words: resistance induced, Plasmopara viticola, Uncinula necator.

  14. Monomeric tartrate resistant acid phosphatase induces insulin sensitive obesity.

    Directory of Open Access Journals (Sweden)

    Pernilla Lång

    Full Text Available BACKGROUND: Obesity is associated with macrophage infiltration of adipose tissue, which may link adipose inflammation to insulin resistance. However, the impact of inflammatory cells in the pathophysiology of obesity remains unclear. Tartrate resistant acid phosphatase (TRAP is an enzyme expressed by subsets of macrophages and osteoclasts that exists either as an enzymatically inactive monomer or as an active, proteolytically processed dimer. PRINCIPAL FINDINGS: Using mice over expressing TRAP, we show that over-expression of monomeric, but not the dimeric form in adipose tissue leads to early onset spontaneous hyperplastic obesity i.e. many small fat cells. In vitro, recombinant monomeric, but not proteolytically processed TRAP induced proliferation and differentiation of mouse and human adipocyte precursor cells. In humans, monomeric TRAP was highly expressed in the adipose tissue of obese individuals. In both the mouse model and in the obese humans the source of TRAP in adipose tissue was macrophages. In addition, the obese TRAP over expressing mice exhibited signs of a low-grade inflammatory reaction in adipose tissue without evidence of abnormal adipocyte lipolysis, lipogenesis or insulin sensitivity. CONCLUSION: Monomeric TRAP, most likely secreted from adipose tissue macrophages, induces hyperplastic obesity with normal adipocyte lipid metabolism and insulin sensitivity.

  15. Molecular Mechanism of Local Drug Delivery with Paclitaxel-Eluting Membranes in Biliary and Pancreatic Cancer: New Application for an Old Drug

    Directory of Open Access Journals (Sweden)

    Sookhee Bang

    2015-01-01

    Full Text Available Implantation of self-expanding metal stents (SEMS is palliation for patients suffering from inoperable malignant obstructions associated with biliary and pancreatic cancers. Chemotherapeutic agent-eluting stents have been developed because SEMS are susceptible to occlusion by tumor in-growth. We reported recently that paclitaxel-eluting SEMS provide enhanced local drug delivery in an animal model. However, little is known about the molecular mechanisms by which paclitaxel-eluting stents attenuate tumor growth. We investigated the signal transduction pathways underlying the antiproliferative effects of a paclitaxel-eluting membrane (PEM implanted in pancreatic/cholangiocarcinoma tumor bearing nude mice. Molecular and cellular alterations were analyzed in the PEM-implanted pancreatic/cholangiocarcinoma xenograft tumors by Western blot, immunoprecipitation, and immunofluorescence. The quantities of paclitaxel released into the tumor and plasma were determined by liquid chromatography-tandem mass spectroscopy. Paclitaxel from the PEM and its diffusion into the tumor inhibited angiogenesis, which involved suppression of mammalian target of rapamycin (mTOR through regulation of hypoxia inducible factor (HIF-1 and increased apoptosis. Moreover, implantation of the PEM inhibited tumor-stromal interaction-related expression of proteins such as CD44, SPARC, matrix metalloproteinase-2, and vimentin. Local delivery of paclitaxel from a PEM inhibited growth of pancreatic/cholangiocarcinoma tumors in nude mice by suppressing angiogenesis via the mTOR and inducing apoptosis signal pathway.

  16. Enhanced antitumor effect of novel dual-targeted paclitaxel liposomes

    Energy Technology Data Exchange (ETDEWEB)

    Meng Shuyan; Su Bo; Li Wei; Ding Yongmei; Tang Liang; Zhou Wei; Song Yin; Li Heyan; Zhou Caicun, E-mail: caicunzhou@yahoo.com.cn [Cancer Institute of Tongji University School of Medicine, Shanghai Pulmonary Hospital, 507 Zhengmin Road, Shanghai (China)

    2010-10-15

    A novel dual-targeted peptide containing an alpha V integrins specific ligand and a neuropilin-1 specific motif was developed which showed an increased specific targeting affinity to tumors. Active dual-targeted liposomes were then produced with this peptide and exhibited greater binding activity than single-targeted liposomes in vitro. Paclitaxel entrapped in this formulation greatly increased the uptake of paclitaxel in the targeting cells and significantly suppressed the growth of HUVEC and A549 cells compared with general paclitaxel injections (Taxol) and single-targeted paclitaxel liposomes. The treatment of tumor xenograft models with dual-targeted paclitaxel liposomes also resulted in better tumor growth inhibition than any other treatment groups. Therefore, the dual-targeted paclitaxel liposomes prepared in the present study might be a more promising drug for cancer treatment. Furthermore, the dual-targeting approach may produce synergistic effects that can be applied in the development of new targeted drug delivery systems.

  17. Nrf2 inhibition reverses the resistance of cisplatin-resistant head and neck cancer cells to artesunate-induced ferroptosis

    Directory of Open Access Journals (Sweden)

    Jong-Lyel Roh

    2017-04-01

    Condensed abstract: Our results show the effectiveness and molecular mechanism of artesunate treatment on head and neck cancer (HNC. Artesunate selectively killed HNC cells but not normal cells by inducing an iron-dependent, ROS-accumulated ferroptosis. However, this effect may be suboptimal in some cisplatin-resistant HNCs because of Nrf2–antioxidant response element (ARE pathway activation. Inhibition of the Nrf2–ARE pathway increased artesunate sensitivity and reversed the ferroptosis resistance in resistant HNC cells.

  18. Cultured hypothalamic neurons are resistant to inflammation and insulin resistance induced by saturated fatty acids.

    Science.gov (United States)

    Choi, Sun Ju; Kim, Francis; Schwartz, Michael W; Wisse, Brent E

    2010-06-01

    Hypothalamic inflammation induced by high-fat feeding causes insulin and leptin resistance and contributes to the pathogenesis of obesity. Since in vitro exposure to saturated fatty acids causes inflammation and insulin resistance in many cultured cell types, we determined how cultured hypothalamic neurons respond to this stimulus. Two murine hypothalamic neuronal cell cultures, N43/5 and GT1-7, were exposed to escalating concentrations of saturated fatty acids for up to 24 h. Harvested cells were evaluated for activation of inflammation by gene expression and protein content. Insulin-treated cells were evaluated for induction of markers of insulin receptor signaling (p-IRS, p-Akt). In both hypothalamic cell lines, inflammation was induced by prototypical inflammatory mediators LPS and TNFalpha, as judged by induction of IkappaBalpha (3- to 5-fold) and IL-6 (3- to 7-fold) mRNA and p-IkappaBalpha protein, and TNFalpha pretreatment reduced insulin-mediated p-Akt activation by 30% (P saturated fatty acids on nonneuronal cells.

  19. Preparation of paclitaxel-loaded microspheres with magnetic nanoparticles

    Institute of Scientific and Technical Information of China (English)

    CUI Sheng; SHEN Xiaodong; SHI Ruihua; LIN Benlan; CHEN Ping

    2007-01-01

    The objective of this paper was to prepare paclitaxel-loaded microspheres,a kind of target-orientation anticancer drug.The paclitaxel-loaded microspheres were prepared with magnetic Fe3O4 nanoparticles and taxo1.The morphology was characterized by scanning electron microscopy(SEM),and the average size and the size distribution were determined by a laser-size distributing instrument.High performance liquid chromatography(HPLC)was used to measure the paclitaxel content.Experimental results indicated that the effective drug loading and the entrapment ratio of paclitaxel-loaded microspheres were 1.83% and 92,62%,respectively.

  20. Identification of a locus in Arabidopsis controlling both the expression of rhizobacteria-mediated induced systemic resistance (ISR) and basal resistance against Pseudomonas syringae pv. tomato

    NARCIS (Netherlands)

    Ton, J.; Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Selected nonpathogenic rhizobacteria with biological disease control activity are able to elicit an induced systemic resistance (ISR) response that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Ten ecotypes of Arabidopsis thaliana were screened for their potential

  1. Jasmonate-responsive expression of paclitaxel biosynthesis genes in Taxus cuspidata cultured cells is negatively regulated by the bHLH transcription factors TcJAMYC1, TcJAMYC2 and TcJAMYC4

    Directory of Open Access Journals (Sweden)

    Sangram Keshari Lenka

    2015-02-01

    Full Text Available Taxus cell suspension culture is a sustainable technology for the industrial production of paclitaxel (Taxol®, a highly modified diterpene anti-cancer agent. The methyl jasmonate (MJ-mediated paclitaxel biosynthetic pathway is not fully characterized, making metabolic engineering efforts difficult. Here, promoters of seven genes (TASY, T5αH, DBAT, DBBT, PAM, BAPT and DBTNBT, encoding enzymes of the paclitaxel biosynthetic pathway were isolated and used to drive MJ-inducible expression of a GUS reporter construct in transiently transformed Taxus cells, showing that elicitation of paclitaxel production by MJ is regulated at least in part at the level of transcription. The paclitaxel biosynthetic pathway promoters contained a large number of E-box sites (CANNTG, similar to the binding sites for the key MJ-inducible transcription factor AtMYC2 from Arabidopsis thaliana. Three MJ-inducible MYC transcription factors similar to AtMYC2 (TcJAMYC1, TcJAMYC2 and TcJAMYC4 were identified in Taxus. Transcriptional regulation of paclitaxel biosynthetic pathway promoters by transient over expression of TcJAMYC transcription factors indicated a negative rather than positive regulatory role of TcJAMYCs on paclitaxel biosynthetic gene expression.

  2. Postharvest Chitosan Treatment Induces Resistance in Potato Against Fusarium sulphureum

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-juan; BI Yang; LI Yong-cai; HAN Rui-feng; GE Yong-hong

    2008-01-01

    The effects of chitosan treatment and inoculation on dry rot in tubers and slices of potato were studied. The results showed that chitosan treatment significantly reduced the lesion diameter of potato inoculated with Fusarium sulphureum.The treatment at 0.25% showed the best effect. Chitosan at 0.25% increased the activities of peroxidase and polyphenoloxidase, and the contents of flavonoid compounds and lignin in tissues. Increased activities of β-1,3-glucanase,and phenylalanine ammonialyase were observed, but there were no significant differences between the treated and the control. These findings suggested that the effects of chitosan could be associated with the induced resistance against Fusarium dry rot in potato.

  3. The rhizobacterial elicitor acetoin induces systemic resistance in Arabidopsis thaliana.

    Science.gov (United States)

    Rudrappa, Thimmaraju; Biedrzycki, Meredith L; Kunjeti, Sridhara G; Donofrio, Nicole M; Czymmek, Kirk J; Paré, Paul W; Bais, Harsh P

    2010-03-01

    The majority of plant growth promoting rhizobacteria (PGPR) confer plant immunity against a wide range of foliar diseases by activating plant defences that reduce a plant's susceptibility to pathogen attack. Here we show that Arabidopsis thaliana (Col-0) plants exposed to Bacillus subtilis strain FB17 (hereafter FB17), results in reduced disease severity against Pseudomonas syringae pv. tomato DC3000 (hereafter DC3000) compared to plants without FB17 treatment. Exogenous application of the B. subtilis derived elicitor, acetoin (3-hydroxy-2-butanone), was found to trigger induced systemic resistance (ISR) and protect plants against DC3000 pathogenesis. Moreover, B. subtilis acetoin biosynthetic mutants that emitted reduced levels of acetoin conferred reduced protection to A. thaliana against pathogen infection. Further analysis using FB17 and defense-compromised mutants of A. thaliana indicated that resistance to DC3000 occurs via NPR1 and requires salicylic acid (SA)/ethylene (ET) whereas jasmonic acid (JA) is not essential. This study provides new insight into the role of rhizo-bacterial volatile components as elicitors of defense responses in plants.

  4. Nonlinear magnetotransport theory and Hall induced resistance oscillations in graphene.

    Science.gov (United States)

    Gutiérrez-Jáuregui, R; Torres, M

    2014-06-11

    The quantum oscillations of nonlinear magnetoresistance in graphene that occur in response to a dc current bias are investigated. We present a theoretical model for the nonlinear magnetotransport of graphene carriers. The model is based on the exact solution of the effective Dirac equation in crossed electric and magnetic fields, while the effects of randomly distributed impurities are perturbatively added. To compute the nonlinear current effects, we develop a covariant formulation of the migration center theory. The current is calculated for short- and large-range scatterers. The analysis of the differential resistivity in the large magnetic field region, shows that the extrema of the Shubnikov de Hass oscillations invert when the dc currents exceed a threshold value. These results are in good agreement with experimental observations. In the small magnetic field regime, corresponding to large filling factors, the existence of Hall induced resistance oscillations are predicted for ultra clean graphene samples. These oscillations originate from Landau-Zener tunneling between Landau levels, that are tilted by the strong electric Hall field.

  5. Thiazolidinediones attenuate lipolysis and ameliorate dexamethasone-induced insulin resistance.

    Science.gov (United States)

    He, Jinhan; Xu, Chong; Kuang, Jiangying; Liu, Qinhui; Jiang, Hongfeng; Mo, Li; Geng, Bin; Xu, Guoheng

    2015-07-01

    Elevated levels of circulating free fatty acids induce insulin resistance and often occur in obese and diabetic conditions. One pharmacological basis for the antidiabetic effects of thiazolidinediones (TZDs) is that TZDs reduce levels of circulating FFAs by accelerating their uptake and reesterification from plasma into adipocytes. Here, we investigated whether TZDs affect adipose lipolysis, a process controlling triglyceride hydrolysis and FFA efflux to the bloodstream. The effects of TZDs on lipolysis were investigated in primary rat adipocytes in vitro and in rats in vivo. In rat primary adipocytes, the TZDs pioglitazone, rosiglitazone and troglitazone inhibited the lipolytic reaction dose- and time-dependently and in a post-receptor pathway by decreasing cAMP level and total lipase activity. TZDs increased the phosphorylation of Akt/protein kinase B, an action required for activating cyclic-nucleotide phosphodiesterase 3B, a major enzyme responsible for cAMP hydrolysis in adipocytes. Furthermore, rosiglitazone inhibited the lipolytic action in dexamethasone-stimulated adipocytes, thereby preventing the increased level of circulating FFAs, and ameliorated insulin resistance in vivo in dexamethasone-treated rats. TZDs may attenuate lipolysis and FFA efflux by activating Akt signaling to decrease cAMP level and hence reduce lipase activity in adipocytes. Inhibiting lipolysis and FFA efflux with TZDs could be a pharmacological basis by which TZDs antagonize diabetes, particularly in patients with hypercortisolemia or glucocorticoid challenge. Copyright © 2015. Published by Elsevier Inc.

  6. The miR-200 family differentially regulates sensitivity to paclitaxel and carboplatin in human ovarian carcinoma OVCAR-3 and MES-OV cells

    Science.gov (United States)

    Brozovic, Anamaria; Duran, George E.; Wang, Yan C; Francisco, E. Brian; Sikic, Branimir I.

    2015-01-01

    We studied the role of miRNA-200 family members in cellular sensitivity to paclitaxel and carboplatin, using two ovarian cancer cell lines, OVCAR-3 and MES-OV, and their paclitaxel resistant variants OVCAR-3/TP and MES-OV/TP. Both resistant variants display a strong epithelial-mesenchymal transition (EMT) phenotype, with marked decreases in expression of miR-200c and miR-141 in OVCAR-3/TP, and down-regulation of all five members of the miR-200 family in MES-OV/TP. Lentiviral transfection of inhibitors of miR-200c or miR-141 in parental OVCAR-3 triggered EMT and rendered the cells resistant to paclitaxel and carboplatin. Conversely, the infection of OVCAR-3/TP cells with retroviral particles carrying the miR-200ab429 and 200c141 clusters triggered a partial mesenchymal to epithelial transition (MET). This partial MET was not sufficient to re-sensitize OVCAR-3/TP cells to paclitaxel. However, the miR-200c/miR-141 cluster transfectants became 6-8× resistant to carboplatin, an unexpected result, whereas miR-200a/miR-200b/miR-429 had no effect. Transfecting the OVCAR-3/TP GFP cells with specific miRNA mimics confirmed these data. MiR-200c and miR-141 mimics conferred resistance to carboplatin in MES-OV/TP cells, similar to OVCAR-3/TP, but sensitized MES-OV to paclitaxel. Several genes involved in balancing oxidative stress were altered in OVCAR-3/TP 200c141 cells compared to controls. The miR-200 family plays major, cell-context dependent roles in regulating EMT and sensitivity to carboplatin and paclitaxel in OVCAR-3 and MES-OV cells. PMID:26025631

  7. Clinically Relevant Anticancer Polymer Paclitaxel Therapeutics

    Directory of Open Access Journals (Sweden)

    Danbo Yang

    2010-12-01

    Full Text Available The concept of utilizing polymers in drug delivery has been extensively explored for improving the therapeutic index of small molecule drugs. In general, polymers can be used as polymer-drug conjugates or polymeric micelles. Each unique application mandates its own chemistry and controlled release of active drugs. Each polymer exhibits its own intrinsic issues providing the advantage of flexibility. However, none have as yet been approved by the U.S. Food and Drug Administration. General aspects of polymer and nano-particle therapeutics have been reviewed. Here we focus this review on specific clinically relevant anticancer polymer paclitaxel therapeutics. We emphasize their chemistry and formulation, in vitro activity on some human cancer cell lines, plasma pharmacokinetics and tumor accumulation, in vivo efficacy, and clinical outcomes. Furthermore, we include a short review of our recent developments of a novel poly(L-g-glutamylglutamine-paclitaxel nano-conjugate (PGG-PTX. PGG-PTX has its own unique property of forming nano-particles. It has also been shown to possess a favorable profile of pharmacokinetics and to exhibit efficacious potency. This review might shed light on designing new and better polymer paclitaxel therapeutics for potential anticancer applications in the clinic.

  8. Stathmin potentiates vinflunine and inhibits Paclitaxel activity.

    Science.gov (United States)

    Malesinski, Soazig; Tsvetkov, Philipp O; Kruczynski, Anna; Peyrot, Vincent; Devred, François

    2015-01-01

    Cell biology and crystallographic studies have suggested a functional link between stathmin and microtubule targeting agents (MTAs). In a previous study we showed that stathmin increases vinblastine (VLB) binding to tubulin, and that conversely VLB increases stathmin binding to tubulin. This constituted the first biochemical evidence of the direct relationship between stathmin and an antimitotic drug, and revealed a new mechanism of action for VLB. The question remained if the observed interaction was specific for this drug or represented a general phenomenon for all MTAs. In the present study we investigated the binding of recombinant stathmin to purified tubulin in the presence of paclitaxel or another Vinca alkaloid, vinflunine, using Isothermal Titration Calorimetry (ITC). These experiments revealed that stathmin binding to tubulin is increased in the presence of vinflunine, whereas no signal is observed in the presence of paclitaxel. Further investigation using turbidity and co-sedimentation showed that stathmin inhibited paclitaxel microtubule-stabilizing activity. Taken together with the previous study using vinblastine, our results suggest that stathmin can be seen as a modulator of MTA activity and binding to tubulin, providing molecular explanation for multiple previous cellular and in vivo studies showing that stathmin expression level affects MTAs efficiency.

  9. Clinically Relevant Anticancer Polymer Paclitaxel Therapeutics

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Danbo [Biomedical Engineering and Technology Institute, Institutes for Advanced Interdisciplinary Research, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062 (China); Yu, Lei, E-mail: yu-lei@gg.nitto.co.jp [Biomedical Engineering and Technology Institute, Institutes for Advanced Interdisciplinary Research, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062 (China); Biomedical Group, Nitto Denko Technical Corporation, 501 Via Del Monte, Oceanside, CA 92058 (United States); Van, Sang [Biomedical Group, Nitto Denko Technical Corporation, 501 Via Del Monte, Oceanside, CA 92058 (United States)

    2010-12-23

    The concept of utilizing polymers in drug delivery has been extensively explored for improving the therapeutic index of small molecule drugs. In general, polymers can be used as polymer-drug conjugates or polymeric micelles. Each unique application mandates its own chemistry and controlled release of active drugs. Each polymer exhibits its own intrinsic issues providing the advantage of flexibility. However, none have as yet been approved by the U.S. Food and Drug Administration. General aspects of polymer and nano-particle therapeutics have been reviewed. Here we focus this review on specific clinically relevant anticancer polymer paclitaxel therapeutics. We emphasize their chemistry and formulation, in vitro activity on some human cancer cell lines, plasma pharmacokinetics and tumor accumulation, in vivo efficacy, and clinical outcomes. Furthermore, we include a short review of our recent developments of a novel poly(l-γ-glutamylglutamine)-paclitaxel nano-conjugate (PGG-PTX). PGG-PTX has its own unique property of forming nano-particles. It has also been shown to possess a favorable profile of pharmacokinetics and to exhibit efficacious potency. This review might shed light on designing new and better polymer paclitaxel therapeutics for potential anticancer applications in the clinic.

  10. Stathmin potentiates vinflunine and inhibits Paclitaxel activity.

    Directory of Open Access Journals (Sweden)

    Soazig Malesinski

    Full Text Available Cell biology and crystallographic studies have suggested a functional link between stathmin and microtubule targeting agents (MTAs. In a previous study we showed that stathmin increases vinblastine (VLB binding to tubulin, and that conversely VLB increases stathmin binding to tubulin. This constituted the first biochemical evidence of the direct relationship between stathmin and an antimitotic drug, and revealed a new mechanism of action for VLB. The question remained if the observed interaction was specific for this drug or represented a general phenomenon for all MTAs. In the present study we investigated the binding of recombinant stathmin to purified tubulin in the presence of paclitaxel or another Vinca alkaloid, vinflunine, using Isothermal Titration Calorimetry (ITC. These experiments revealed that stathmin binding to tubulin is increased in the presence of vinflunine, whereas no signal is observed in the presence of paclitaxel. Further investigation using turbidity and co-sedimentation showed that stathmin inhibited paclitaxel microtubule-stabilizing activity. Taken together with the previous study using vinblastine, our results suggest that stathmin can be seen as a modulator of MTA activity and binding to tubulin, providing molecular explanation for multiple previous cellular and in vivo studies showing that stathmin expression level affects MTAs efficiency.

  11. Lysophosphatidate induces chemo-resistance by releasing breast cancer cells from taxol-induced mitotic arrest.

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    Nasser Samadi

    Full Text Available BACKGROUND: Taxol is a microtubule stabilizing agent that arrests cells in mitosis leading to cell death. Taxol is widely used to treat breast cancer, but resistance occurs in 25-69% of patients and it is vital to understand how Taxol resistance develops to improve chemotherapy. The effects of chemotherapeutic agents are overcome by survival signals that cancer cells receive. We focused our studies on autotaxin, which is a secreted protein that increases tumor growth, aggressiveness, angiogenesis and metastasis. We discovered that autotaxin strongly antagonizes the Taxol-induced killing of breast cancer and melanoma cells by converting the abundant extra-cellular lipid, lysophosphatidylcholine, into lysophosphatidate. This lipid stimulates specific G-protein coupled receptors that activate survival signals. METHODOLOGY/PRINCIPAL FINDINGS: In this study we determined the basis of these antagonistic actions of lysophosphatidate towards Taxol-induced G2/M arrest and cell death using cultured breast cancer cells. Lysophosphatidate does not antagonize Taxol action in MCF-7 cells by increasing Taxol metabolism or its expulsion through multi-drug resistance transporters. Lysophosphatidate does not lower the percentage of cells accumulating in G2/M by decreasing exit from S-phase or selective stimulation of cell death in G2/M. Instead, LPA had an unexpected and remarkable action in enabling MCF-7 and MDA-MB-468 cells, which had been arrested in G2/M by Taxol, to normalize spindle structure and divide, thus avoiding cell death. This action involves displacement of Taxol from the tubulin polymer fraction, which based on inhibitor studies, depends on activation of LPA receptors and phosphatidylinositol 3-kinase. CONCLUSIONS/SIGNIFICANCE: This work demonstrates a previously unknown consequence of lysophosphatidate action that explains why autotaxin and lysophosphatidate protect against Taxol-induced cell death and promote resistance to the action of this

  12. Thermoresponsive Delivery of Paclitaxel by β-Cyclodextrin-Based Poly(N-isopropylacrylamide) Star Polymer via Inclusion Complexation.

    Science.gov (United States)

    Song, Xia; Wen, Yuting; Zhu, Jing-Ling; Zhao, Feng; Zhang, Zhong-Xing; Li, Jun

    2016-12-12

    Paclitaxel (PTX), a hydrophobic anticancer drug, is facing several clinical limitations such as low bioavailability and drug resistance. To solve the problems, a well-defined β-cyclodextrin-poly(N-isopropylacrylamide) star polymer was synthesized and used as a nanocarrier to improve the water solubility and aim to thermoresponsive delivery of PTX to cancer cells. The star polymer was able to form supramolecular self-assembled inclusion complex with PTX via host-guest interaction at room temperature, which is below the low critical solution temperature (LCST) of the star polymer, significantly improving the solubilization of PTX. At body temperature (above LCST), the phase transition of poly(N-isopropylacrylamide) segments induced the formation of nanoparticles, which greatly enhanced the cellular uptake of the polymer-drug complex, resulting in efficient thermoresponsive delivery of PTX. In particular, the polymer-drug complex exhibited better antitumor effects than the commercial formulation of PTX in overcoming the multi-drug resistance in AT3B-1 cells.

  13. An Italian cost-effectiveness analysis of paclitaxel albumin (nab-paclitaxel versus conventional paclitaxel for metastatic breast cancer patients: the COSTANza study

    Directory of Open Access Journals (Sweden)

    Lazzaro C

    2013-04-01

    Full Text Available Carlo Lazzaro,1 Roberto Bordonaro,2 Francesco Cognetti,3 Alessandra Fabi,3 Sabino De Placido,4 Grazia Arpino,4 Paolo Marchetti,5 Andrea Botticelli,5 Paolo Pronzato,6 Elisa Martelli7 1Studio di Economia Sanitaria, Milan, Italy; 2Public Hospital Trust Garibaldi, Catania, Italy; 3Istituto dei Tumori Regina Elena, Rome, Italy; 4School of Medicine, Federico II University, Naples, Italy; 5Department of Medical Oncology, School of Medicine, Sapienza University Hospital, Rome, Italy; 6Istituto di Ricovero e Cura a Carattere Scientifico, Azienda Ospedaliera Universitaria San Martino – Isituto Scientifico Tumori, Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy; 7Health Economics and Outcomes Research, Celgene Srl, Milan, Italy Purpose: Paclitaxel albumin (nab-paclitaxel is a nanoparticle albumin-bound paclitaxel formulation aimed at increasing therapeutic index in metastatic breast cancer. When compared to conventional paclitaxel, nab-paclitaxel has a reported longer time to progression, higher response, lower incidence of neutropenia, no need for premedication, shorter time of administration, and in pretreated metastatic breast cancer patients, extended overall survival. This study investigates the cost-effectiveness of nab-paclitaxel versus conventional paclitaxel for pretreated metastatic breast cancer patients in Italy. Materials and methods: A Markov model with progression-free, progressed, and dead states was developed to estimate costs, outcomes, and quality adjusted life years over 5 years from the Italian National Health Service viewpoint. Patients were assumed to receive nab-paclitaxel 260 mg/m2 three times weekly or conventional paclitaxel 175 mg/m2 three times weekly. Data on health care resource consumption was collected from a convenience sample of five Italian centers. Resources were valued at Euro (€ 2011. Published utility weights were applied to health states to estimate the impact of response, disease progression, and

  14. Downy mildew resistance induced by Trichoderma harzianum T39 in susceptible grapevines partially mimics transcriptional changes of resistant genotypes

    Directory of Open Access Journals (Sweden)

    Perazzolli Michele

    2012-11-01

    Full Text Available Abstract Background Downy mildew, caused by Plasmopara viticola, is one of the most severe diseases of grapevine and is commonly controlled by fungicide treatments. The beneficial microorganism Trichoderma harzianum T39 (T39 can induce resistance to downy mildew, although the molecular events associated with this process have not yet been elucidated in grapevine. A next generation RNA sequencing (RNA-Seq approach was used to study global transcriptional changes associated with resistance induced by T39 in Vitis vinifera Pinot Noir leaves. The long-term aim was to develop strategies to optimize the use of this agent for downy mildew control. Results More than 14.8 million paired-end reads were obtained for each biological replicate of T39-treated and control leaf samples collected before and 24 h after P. viticola inoculation. RNA-Seq analysis resulted in the identification of 7,024 differentially expressed genes, highlighting the complex transcriptional reprogramming of grapevine leaves during resistance induction and in response to pathogen inoculation. Our data show that T39 has a dual effect: it directly modulates genes related to the microbial recognition machinery, and it enhances the expression of defence-related processes after pathogen inoculation. Whereas several genes were commonly affected by P. viticola in control and T39-treated plants, opposing modulation of genes related to responses to stress and protein metabolism was found. T39-induced resistance partially inhibited some disease-related processes and specifically activated defence responses after P. viticola inoculation, causing a significant reduction of downy mildew symptoms. Conclusions The global transcriptional analysis revealed that defence processes known to be implicated in the reaction of resistant genotypes to downy mildew were partially activated by T39-induced resistance in susceptible grapevines. Genes identified in this work are an important source of markers

  15. A randomized phase I trial of nanoparticle albumin-bound paclitaxel with or without mifepristone for advanced breast cancer.

    Science.gov (United States)

    Nanda, Rita; Stringer-Reasor, Erica M; Saha, Poornima; Kocherginsky, Masha; Gibson, Jean; Libao, Bernadette; Hoffman, Philip C; Obeid, Elias; Merkel, Douglas E; Khramtsova, Galina; Skor, Maxwell; Krausz, Thomas; Cohen, Ronald N; Ratain, Mark J; Fleming, Gini F; Conzen, Suzanne D

    2016-01-01

    Glucocorticoid receptor (GR) overexpression is associated with poor prognosis ER-negative breast cancer. GR antagonism with mifepristone increases chemotherapy-induced breast cancer cell death, therefore we conducted a phase I clinical trial of mifepristone and nab-paclitaxel in advanced breast cancer. A novel randomized phase I design was used to assess the effect of mifepristone on nab-paclitaxel pharmacokinetics and toxicity. Patients were randomized to placebo or mifepristone for the first cycle; mifepristone was given to all for subsequent cycles. Nine patients were enrolled. All were found to have a twofold or greater increase in serum cortisol after mifepristone administration, reflecting effective GR inhibition. Neutropenia occurred at both nab-paclitaxel dose levels studied (100 and 80 mg/m(2)), and was easily managed with dose reduction and/or growth factor administration. Pharmacokinetic data suggest an interaction between nab-paclitaxel and mifepristone in some patients. Two patients had complete responses (CR), three partial responses (PR), one stable disease (SD), and three progressive disease (PD). Immunohistochemical staining for GR found six of nine tumors were GR-positive. All six GR-positive tumors were triple-negative at the time of recurrence. Of these six patients, two had CRs, two PRs, one SD, and one PD. GR appears to be a promising target in TNBC, and GR inhibition plus chemotherapy produces manageable toxicity. While neutropenia was observed in some, a nab-paclitaxel dose of 100 mg/m(2) plus mifepristone 300 mg was found to be tolerable, and a randomized phase II trial of nab-paclitaxel with/without mifepristone is planned in GR-positive advanced TNBC.

  16. New macrolides active against Streptococcus pyogenes with inducible or constitutive type of macrolide-lincosamide-streptogramin B resistance.

    OpenAIRE

    Fernandes, P B; Baker, W.R.; Freiberg, L A; Hardy, D. J.; McDonald, E J

    1989-01-01

    Macrolide-resistant bacteria can be classified as inducibly resistant or constitutively resistant. Inducibly resistant bacteria are resistant to 14-membered macrolides, such as erythromycin and clarithromycin (A-56268), but are susceptible to the 16-membered macrolides, such as tylosin and spiramycin, as well as to clindamycin. Constitutively resistant bacteria are resistant to macrolide-lincosamide-streptogramin B antibiotics. In this study, the MICs of several erythromycin and clarithromyci...

  17. Induced resistance in plants and the role of pathogenesis-related proteins

    NARCIS (Netherlands)

    Loon, L.C. van

    2001-01-01

    The nature of induced resistance Resistance, according to Agrios (1988) is the ability of an organism to exclude or overcome, completely or in some degree, the effect of a pathogen or other damaging factor. Disease resistance in plants is manifested by limited symptoms, reflecting the inability of t

  18. Apparent resistivity and spectral induced polarization in the submarine environment

    Directory of Open Access Journals (Sweden)

    HERCULES DE SOUZA

    2001-09-01

    Full Text Available Relatively few investigations have employed electrical methods in the submarine environment, which may be promising for mineral deposits or threatened by environmental problems. We have measured the electric field using both disk and bar electrodes in the sea water at three different levels: sea surface, seven meters deep, and sea bottom at a depth of ten meters, employing a 2 m spacing dipole-dipole array with 7 array spacings of investigation, and 13 values of frequencies at steps of (2N hertz, N = -2, -1, 0, 1, 2,.....10. The measurement allowed the analysis of the electric field as a function of frequency and spacing, and of the spectral induced polarization. Modelling and interpretation of the apparent resistivity yielded a good fit with previous drilling data. Analysis of the spectrum of the complex apparent resistivity and the comparison with equivalent circuits, provided information about the grain size, the mineral composition and the major induced polarization phenomenon occurring below the sea. Therefore the result of the present research show the feasibility of measuring the variation of seawater resistivity in situ, as well as the resistivity of sea bottom sediments.Relativamente poucas investigações têm empregado métodos elétricos no ambiente submarino, o qual pode ser promissor para depósitos minerais ou ameaçado por problemas ambientais. Nós medimos o campo elétrico usando eletrodos em forma de disco e de barra na água do mar, em três níveis distintos: superfície, sete metros de profundidade, e fundo do mar a dez metros de profundidade, empregando um dispositivo dipolo-dipolo com 2m de afastamento, 7 níveis de investigação e 13 valores de freqüência a intervalos de (2N hertz, N = -2, -1, 0, 1, 2, ... 10. A medida permitiu a análise do campo elétrico como uma função de freqüência e afastamento, e da polarização induzida espectral. A modelagem e a interpretação da resistividade aparente se ajustaram bem

  19. Induced systemic resistance in radish is not associated with accumulation of pathogenesis-related proteins

    NARCIS (Netherlands)

    Hoffland, E.; Pieterse, C.M.J.; Bik, L.; Pelt, J.A. van den

    1995-01-01

    The non-pathogenic Pseudomonas fluorescens strain WCS417r has been shown to induce systemic resistance in radish against Fusarium oxysporum f.sp. raphani. In this paper we investigate the involvement of pathogenesis-related (PR) proteins in this Pseudomonas-induced resistance. For comparison, salicy

  20. Growth hormone-induced insulin resistance in human subjects involves reduced pyruvate dehydrogenase activity

    DEFF Research Database (Denmark)

    Nellemann, Birgitte; Vendelbo, Mikkel H; Nielsen, Thomas S

    2014-01-01

    Insulin resistance induced by growth hormone (GH) is linked to promotion of lipolysis by unknown mechanisms. We hypothesized that suppression of the activity of pyruvate dehydrogenase in the active form (PDHa) underlies GH-induced insulin resistance similar to what is observed during fasting....

  1. IL-37 protects against obesity-induced inflammation and insulin resistance

    NARCIS (Netherlands)

    Ballak, Dov B.; Diepen, van Janna A.; Boekschoten, Mark; Muller, Michael; Kersten, Sander; Stienstra, Rinke

    2015-01-01

    Cytokines of the IL-1 family are important modulators of obesity-induced inflammation and the development of systemic insulin resistance. Here, we report that IL-37, a newly-described antiinflammatory member of the IL-1 family, affects obesity-induced inflammation and insulin resistance. IL-37

  2. Differential effectiveness of microbially induced resistance against herbivorous insects in Arabidopsis

    NARCIS (Netherlands)

    Oosten, V.R. van; Bodenhausen, N.; Reymond, P.; Pelt, J.A. van; Loon, L.C. van; Dicke, M.; Pieterse, C.M.J.

    2008-01-01

    Rhizobacteria–induced systemic resistance (ISR) and pathogen-induced systemic acquired resistance (SAR) have a broad, yet partly distinct, range of effectiveness against pathogenic microorganisms. Here, we investigated the effectiveness of ISR and SAR in Arabidopsis against the tissue-chewing insect

  3. [Advances in molecular mechanisms of bacterial resistance caused by stress-induced transfer of resistance genes--a review].

    Science.gov (United States)

    Sun, Dongchang; Wang, Bing; Zhu, Lihong

    2013-07-04

    The transfer of resistance gene is one of the most important causes of bacterial resistance. Recent studies reveal that stresses induce the transfer of antibiotic resistance gene through multiple mechanisms. DNA damage stresses trigger bacterial SOS response and induce the transfer of resistance gene mediated by conjugative DNA. Antibiotic stresses induce natural bacterial competence for transformation in some bacteria which lack the SOS system. In addition, our latest studies show that the general stress response regulator RpoS regulates a novel type of resistance gene transfer which is mediated by double-stranded plasmid DNA and occurs exclusively on the solid surface. In this review, we summarized recent advances in SOS dependent and independent stress-induced DNA transfer which is mediated by conjugation and transformation respectively, and the transfer of double-stranded plasmid DNA on the solid surface which is regulated by RpoS. We propose that future work should address how stresses activate the key regulators and how these regulators control the expression of gene transfer related genes. Answers to the above questions would pave the way for searching for candidate targets for controlling bacterial resistance resulted from the transfer of antibiotic genes.

  4. The importance of inducible clindamycin resistance in enterotoxin positive S. aureus isolated from clinical samples

    Directory of Open Access Journals (Sweden)

    Memariani M

    2009-07-01

    Full Text Available "nBackground: Clindamycin is a suitable antibiotic for treatment of skin and soft tissue infections. Moreover, it can suppress toxin production in many pathogenic bacteria such as S. aureus. There are two mechanisms of resistance in this antibiotic. Constitutive resistance can be detected by standard disk diffusion method but in the case of inducible resistance, D-test should be carried out. The main aim of this study is to determine prevalence of clindamycin inducible resistance among methicillin resistant and susceptible isolates of S. aureus isolated from different clinical samples. "nMethods: A total of 87 clinical isolates from clinical samples were collected. Methicillin resistance was determined using standard disk diffusion method. Subsequently, D-test was carried out according to CLSI guideline. Presence of the sea gene (enterotoxin A was detected by PCR using specific primers. "nResults: Out of 87 isolates, 18(20.7% were clindamycin inducible resistant while constitutive resistance was detected among 21(24.1% isolates. The 95% Confidence intervals for the proportion of inducible clindamycin resistance among clinical isolates of S. aureus was 12.2% to 29.2%. The inducible phenotype in MRSA isolates was more common than that of MSSA isolates (33.3% vs 5.1%.Significant differences were found between prevalence of inducible clindamycin resistance and type of infection (p=0.045. Importantly, there was a significant correlation between sea gene and the constitutive/inducible resistance (p<0.0001. "nConclusions: Due to the high prevalence of clindamycin inducible resistance among clinical isolates of S. aureus, we recommend D-test to avoid treatment failure.

  5. Transportan in nanocarriers improves skin localization and antitumor activity of paclitaxel

    Directory of Open Access Journals (Sweden)

    Pepe D

    2016-05-01

    Full Text Available Dominique Pepe,1 Vanessa FM Carvalho,2 Melissa McCall,1 Débora P de Lemos,2 Luciana B Lopes1,2 1Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY, USA; 2Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil Abstract: In this study, the ability of nanocarriers containing protein transduction domains (PTDs of various classes to improve cutaneous paclitaxel delivery and efficacy in skin tumor models was evaluated. Microemulsions (MEs were prepared by mixing a surfactant blend (polyoxyethylene 10 oleoyl ether, ethanol and propylene glycol, monocaprylin, and water. The PTD transportan (ME-T, penetratin (ME-P, or TAT (ME-TAT was added at a concentration of 1 mM to the plain ME. All MEs displayed nanometric size (32.3–40.7 nm and slight positive zeta potential (+4.1 mV to +6.8 mV. Skin penetration of paclitaxel from the MEs was assessed for 1–12 hours using porcine skin and Franz diffusion cells. Among the PTD-containing formulations, paclitaxel skin (stratum corneum + epidermis and dermis penetration at 12 hours was maximized with ME-T, whereas ME-TAT provided the lowest penetration (1.6-fold less. This is consistent with the stronger ability of ME-T to increase transepidermal water loss (2.4-fold compared to water and tissue permeability. The influence of PTD addition on the ME irritation potential was assessed by measuring interleukin-1α expression and viability of bioengineered skin equivalents. A 1.5- to 1.8-fold increase in interleukin-1α expression was induced by ME-T compared to the other formulations, but this effect was less pronounced (5.8-fold than that mediated by the moderate irritant Triton. Because ME-T maximized paclitaxel cutaneous localization while being safer than Triton, its efficacy was assessed against basal cell carcinoma cells and a bioengineered three-dimensional melanoma model. Paclitaxel-containing ME-T reduced

  6. Peroxynitrite mediates testosterone-induced vasodilation of microvascular resistance vessels.

    Science.gov (United States)

    Puttabyatappa, Yashoda; Stallone, John N; Ergul, Adviye; El-Remessy, Azza B; Kumar, Sanjiv; Black, Stephen; Johnson, Maribeth; Owen, Mary P; White, Richard E

    2013-04-01

    Our knowledge of how androgens influence the cardiovascular system is far from complete, and this lack of understanding is especially true of how androgens affect resistance vessels. Our aim was to identify the signaling mechanisms stimulated by testosterone (TES) in microvascular arteries and to understand how these mechanisms mediate TES-induced vasodilation. Mesenteric microvessels were isolated from male Sprague-Dawley rats. Tension studies demonstrated a rapid, concentration-dependent, vasodilatory response to TES that did not involve protein synthesis or aromatization to 17β-estradiol. Dichlorofluorescein fluorescence and nitrotyrosine immunoblot experiments indicated that TES stimulated peroxynitrite formation in microvessels, and functional studies demonstrated that TES-induced vasodilation was inhibited by scavenging peroxynitrite. As predicted, TES enhanced the production of both peroxynitrite precursors (i.e., superoxide and nitic oxide), and xanthine oxidase was identified as the likely source of TES-stimulated superoxide production. Functional and biochemical studies indicated that TES signaling involved activity of the phosphoinositide 3 (PI3) kinase-protein kinase B (Akt) cascade initiated by activation of the androgen receptor and culminated in enhanced production of cGMP and microvascular vasodilation. These findings, derived from a variety of analytical and functional approaches, provide evidence for a novel nongenomic signaling mechanism for androgen action in the microvasculature: TES-stimulated vasodilation mediated primarily by peroxynitrite formed from xanthine oxidase-generated superoxide and NO. This response was associated with activation of the PI3 kinase-Akt signaling cascade initiated by activation of the androgen receptor. We propose this mechanism could account for TES-stimulated cGMP production in microvessels and, ultimately, vasodilation.

  7. Effects of Combination of Thiazolidinediones with Melatonin in Dexamethasone-induced Insulin Resistance in Mice

    OpenAIRE

    Ghaisas, M. M.; Ahire, Y. S.; P R Dandawate; Gandhi, S.P; Mule, M.

    2011-01-01

    In type 2 Diabetes, oxidative stress plays an important role in development and aggregation of insulin resistance. In the present study, long term administration of the dexamethasone led to the development of insulin resistance in mice. The effect of thiazolidinediones pioglitazone and rosiglitazone, with melatonin on dexamethasone-induced insulin resistance was evaluated in mice. Insulin resistant mice were treated with combination of pioglitazone (10 mg/kg/day, p.o.) or rosiglitazone (5 mg/...

  8. Anaesthesia generates neuronal insulin resistance by inducing hypothermia

    Directory of Open Access Journals (Sweden)

    Sutherland Calum

    2008-10-01

    Full Text Available Abstract Background Anaesthesia is commonly employed prior to surgical investigations and to permit icv injections in rodents. Indeed it is standard practise in many studies examining the subsequent actions of hormones and growth factors on the brain. Recent evidence that the basal activity of specific intracellular signalling proteins can be affected by anaesthesia prompted us to examine the effect of anaesthesia not only on the basal activity but also the insulin sensitivity of the major insulin signalling pathways. Results We find that urethane- and ketamine-induced anaesthesia results in rapid activation of the phosphatidylinositol (PI 3-kinase-protein kinase B (PKB signalling pathway in the brain, increases tau phosphorylation while at the same time reducing basal activity of the Ras-ERK pathway. Subsequent injection of insulin does not alter the activity of either the PI 3-kinase or ERK signalling pathways, indicating a degree of neuronal molecular insulin resistance. However, if body temperature is maintained during anaesthesia then there is no alteration in the basal activity of these signalling molecules. Subsequent response of both pathways to insulin injection is restored. Conclusion The data is consistent with a hypothermia related alteration in neuronal signalling following anaesthesia, and emphasises the importance of maintaining the body temperature of rodents when monitoring insulin (or growth factor/neurotrophic agent action in the brain of anesthetised rodents.

  9. Tumor therapy with a urokinase plasminogen activator-activated anthrax lethal toxin alone and in combination with paclitaxel

    Science.gov (United States)

    Wein, Alexander N.; Liu, Shihui; Zhang, Yi; McKenzie, Andrew T.; Leppla, Stephen H.

    2013-01-01

    PA-U2, an engineered anthrax protective antigen that is activated by urokinase was combined with wild-type lethal factor in the treatment of Colo205 colon adenocarcinoma in vitro and B16-BL6 mouse melanoma in vitro and in vivo. This therapy was also tested in combination with the small molecule paclitaxel, based on prior reports suggesting synergy between ERK1/2 inhibition and chemotherapeutics. Colo205 was sensitive to PA-U2/LF while B16-BL6 was not. For the combination treatment of B16-BL6, paclitaxel showed a dose response in vitro, but cells remained resistant to PA-U2/LF even in the presence of paclitaxel. In vivo, each therapy slowed tumor progression, and an additive effect between the two was observed. Since LF targets tumor vasculature while paclitaxel is an anti-mitotic, it is possible the agents were acting against different cells in the stroma, precluding a synergistic effect. The engineered anthrax toxin PA-U2/LF warrants further development and testing, possibly in combination with an anti-angiogenesis therapy such as sunitinib or sorafinib. PMID:22843210

  10. Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer

    Science.gov (United States)

    2015-10-01

    AWARD NUMBER: W81XWH-13-1-0163 TITLE: Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer...15Sep2014 - 14Sep2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-13-1-0163 Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced...Annual Progress Report W81XWH-13-1-0163 Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer

  11. Amiodarone-induced Hypothyroidism with EPO-resistant Anemia in a Patient with Chronic Renal Failure

    OpenAIRE

    Peter M.S. Chang; Yee-Yung Ng

    2008-01-01

    The overall incidence of amiodarone-induced thyroid dysfunction ranges from 2% to 24%. One third to half of patients with hypothyroidism have anemia due to some decrease in normal red blood cell mass and erythropoietin (EPO) resistance. Therefore, for patients with chronic renal disease under medication with amiodarone, early regular thyroid function test should be checked in order to avoid amiodarone-induced hypothyroidism and EPO-resistant anemia. If amiodarone-induced hypothyroidism and EP...

  12. Phenotypes and Genotypes of Erythromycin-Resistant Streptococcus pyogenes Strains in Italy and Heterogeneity of Inducibly Resistant Strains

    OpenAIRE

    Giovanetti, Eleonora; Montanari, Maria Pia; Mingoia, Marina; Varaldo, Pietro Emanuele

    1999-01-01

    A total of 387 clinical strains of erythromycin-resistant (MIC, ≥1 μg/ml) Streptococcus pyogenes, all isolated in Italian laboratories from 1995 to 1998, were examined. By the erythromycin-clindamycin double-disk test, 203 (52.5%) strains were assigned to the recently described M phenotype, 120 (31.0%) were assigned to the inducible macrolide, lincosamide, and streptogramin B resistance (iMLS) phenotype, and 64 (16.5%) were assigned to the constitutive MLS resistance (cMLS) phenotype. The ind...

  13. Identifying clinically relevant drug resistance genes in drug-induced resistant cancer cell lines and post-chemotherapy tissues.

    Science.gov (United States)

    Tong, Mengsha; Zheng, Weicheng; Lu, Xingrong; Ao, Lu; Li, Xiangyu; Guan, Qingzhou; Cai, Hao; Li, Mengyao; Yan, Haidan; Guo, You; Chi, Pan; Guo, Zheng

    2015-12-01

    Until recently, few molecular signatures of drug resistance identified in drug-induced resistant cancer cell models can be translated into clinical practice. Here, we defined differentially expressed genes (DEGs) between pre-chemotherapy colorectal cancer (CRC) tissue samples of non-responders and responders for 5-fluorouracil and oxaliplatin-based therapy as clinically relevant drug resistance genes (CRG5-FU/L-OHP). Taking CRG5-FU/L-OHP as reference, we evaluated the clinical relevance of several types of genes derived from HCT116 CRC cells with resistance to 5-fluorouracil and oxaliplatin, respectively. The results revealed that DEGs between parental and resistant cells, when both were treated with the corresponding drug for a certain time, were significantly consistent with the CRG5-FU/L-OHP as well as the DEGs between the post-chemotherapy CRC specimens of responders and non-responders. This study suggests a novel strategy to extract clinically relevant drug resistance genes from both drug-induced resistant cell models and post-chemotherapy cancer tissue specimens.

  14. The Akt inhibitor MK-2206 enhances the cytotoxicity of paclitaxel (Taxol) and cisplatin in ovarian cancer cells.

    Science.gov (United States)

    Lin, Ying-Hsi; Chen, Bert Yu-Hung; Lai, Wei-Ting; Wu, Shao-Fu; Guh, Jih-Hwa; Cheng, Ann-Lii; Hsu, Lih-Ching

    2015-01-01

    Abnormalities in the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway are commonly observed in human cancers and contribute to chemotherapy resistance. Combination therapy, involving the use of molecular targeted agents and traditional cytotoxic drugs, may represent a promising strategy to lower resistance and enhance cytotoxicity. Here, we demonstrate the efficacy of an Akt inhibitor, MK-2206, in increasing the cytotoxic effect of either paclitaxel (Taxol) or cisplatin against the ovarian cancer cell lines SKOV3 (with constitutively active Akt) and ES2 (with inactive Akt). Sequential treatment of Taxol or cisplatin, followed by MK-2206, induced a synergistic inhibition of cell proliferation and effectively promoted cell death, either by inhibiting the phosphorylation of Akt and its downstream effectors 4E-BP1 and p70S6K in SKOV3 cells or by restoring p53 levels, which were downregulated after Taxol or cisplatin treatment, in ES2 cells. Combination treatment also downregulated the pro-survival protein Bcl-2 in both SKOV3 and ES2 cells, which may have contributed to cell death. In addition, we discovered that Taxol/MK-2206 or cisplatin/MK-2206 combination treatment resulted in significant enhancement of intracellular reactive oxygen species (ROS) induced by MK-2206, in both SKOV3 and ES2 cells; however, MK-2206-induced growth inhibition was reversed by a ROS scavenger only in ES2 cells. MK-2206 also suppressed DNA repair, particularly in SKOV3 cells. Taken together, our results demonstrate that the Akt inhibitor MK-2206 enhances the efficacy of cytotoxic agents in both Akt-active and Akt-inactive ovarian cancer cells but through different mechanisms.

  15. Advances in induced resistance by natural compounds: towards new options for woody crop protection

    Directory of Open Access Journals (Sweden)

    Eugenio Llorens

    Full Text Available ABSTRACT: The activation of defensive responses of plants is a promising tool for controlling pests in conventional agriculture. Over the last few years, several compounds have been studied to protect crops from pests, without displaying direct toxicity for pathogenic organisms. These compounds have the ability to induce a priming state on the plants that results in resistance (or tolerance against subsequent infection by a pathogen. In terms of molecular response, induced plant defense involves a broad number of physical and biochemical changes such as callose deposition or phenolic compounds, activation of salicylic and/or jasmonic acid pathways or synthesis of defense-related enzymes. Despite the large number of studies performed to ascertain the physiological and biochemical basis of induced resistance, only a few resistance-activating compounds have been studied as a real alternative to classic means of control and the studies geared towards incorporating induced resistance into disease management programs are relatively rare. The incorporation of natural resistance inducer in pest management programs of woody crops, alone or in combination with classical methods, could be a reliable method for reducing the amount of chemical residues in the environment. In this review, we discuss the current knowledge of induced resistance in woody crops, focusing on the mode of action of compounds authorized for conventional agriculture. We conclude by discussing the environmental and economic advantages of applying resistance inducers to conventional agriculture with special emphasis on natural compounds.

  16. Hypersensitivity reaction studies of a polyethoxylated castor oil-free, liposome-based alternative paclitaxel formulation.

    Science.gov (United States)

    Wang, Hongbo; Cheng, Guang; Du, Yuan; Ye, Liang; Chen, Wenzhong; Zhang, Leiming; Wang, Tian; Tian, Jingwei; Fu, Fenghua

    2013-03-01

    The commercial drug paclitaxel (Taxol) may introduce hypersensitivity reactions associated with the polyethoxylated castor oil-ethanol solvent. To overcome these problems, we developed a polyethoxylated castor oil-free, liposome-based alternative paclitaxel formulation, known as Lipusu. In this study, we performed in vitro and in vivo experiments to compare the safety profiles of Lipusu and Taxol, with special regard to hypersensitivity reactions. First, Swiss mice were used to determine the lethal dosages, and then to evaluate hypersensitivity reactions, followed by histopathological examination and enzyme-linked immunosorbent assays (ELISAs) of serum SC5b-9 and lung histamine. Additionally, healthy human serum was used to analyze in vitro complement activation. Finally, an MTT assay was used to determine the in vitro anti-proliferation activity. Our data clearly showed that Lipusu displayed a much higher safety margin and did not induce hypersensitivity or hypersensitivity-related lung lesions, which may be associated with the fact that Lipusu did not activate complement or increase histamine release in vivo. Moreover, Lipusu did not promote complement activation in healthy human serum in vitro, and demonstrated anti-proliferative activity against human cancer cells, similar to that of Taxol. Therefore, the improved formulation of paclitaxel, which exhibited a much better safety profile and comparable cytotoxic activity to Taxol, may bring a number of benefits to cancer patients.

  17. CHK1 Inhibition Radiosensitizes Head and Neck Cancers to Paclitaxel-Based Chemoradiotherapy.

    Science.gov (United States)

    Barker, Holly E; Patel, Radhika; McLaughlin, Martin; Schick, Ulrike; Zaidi, Shane; Nutting, Christopher M; Newbold, Katie L; Bhide, Shreerang; Harrington, Kevin J

    2016-09-01

    Head and neck squamous cell carcinoma (HNSCC) is a leading cause of cancer-related deaths, with increasingly more cases arising due to high-risk human papillomavirus (HPV) infection. Cisplatin-based chemoradiotherapy is a standard-of-care for locally advanced head and neck cancer but is frequently ineffective. Research into enhancing radiation responses as a means of improving treatment outcomes represents a high priority. Here, we evaluated a CHK1 inhibitor (CCT244747) as a radiosensitiser and investigated whether a mechanistically rational triple combination of radiation/paclitaxel/CHK1 inhibitor delivered according to an optimized schedule would provide added benefit. CCT244747 abrogated radiation-induced G2 arrest in the p53-deficient HNSCC cell lines, HN4 and HN5, causing cells to enter mitosis with unrepaired DNA damage. The addition of paclitaxel further increased cell kill and significantly reduced tumor growth in an HN5 xenograft model. Importantly, a lower dose of paclitaxel could be used when CCT244747 was included, therefore potentially limiting toxicity. Triple therapy reduced the expression of several markers of radioresistance. Moreover, the more radioresistant HN5 cell line exhibited greater radiation-mediated CHK1 activation and was more sensitive to triple therapy than HN4 cells. We analyzed CHK1 expression in a panel of head and neck tumors and observed that primary tumors from HPV(+) patients, who went on to recur postradiotherapy, exhibited significantly stronger expression of total, and activated CHK1. CHK1 may serve as a biomarker for identifying tumors likely to recur and, therefore, patients who may benefit from concomitant treatment with a CHK1 inhibitor and paclitaxel during radiotherapy. Clinical translation of this strategy is under development. Mol Cancer Ther; 15(9); 2042-54. ©2016 AACR.

  18. Three-dimensional induced polarization data inversion for complex resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Commer, M.; Newman, G.A.; Williams, K.H.; Hubbard, S.S.

    2011-03-15

    The conductive and capacitive material properties of the subsurface can be quantified through the frequency-dependent complex resistivity. However, the routine three-dimensional (3D) interpretation of voluminous induced polarization (IP) data sets still poses a challenge due to large computational demands and solution nonuniqueness. We have developed a flexible methodology for 3D (spectral) IP data inversion. Our inversion algorithm is adapted from a frequency-domain electromagnetic (EM) inversion method primarily developed for large-scale hydrocarbon and geothermal energy exploration purposes. The method has proven to be efficient by implementing the nonlinear conjugate gradient method with hierarchical parallelism and by using an optimal finite-difference forward modeling mesh design scheme. The method allows for a large range of survey scales, providing a tool for both exploration and environmental applications. We experimented with an image focusing technique to improve the poor depth resolution of surface data sets with small survey spreads. The algorithm's underlying forward modeling operator properly accounts for EM coupling effects; thus, traditionally used EM coupling correction procedures are not needed. The methodology was applied to both synthetic and field data. We tested the benefit of directly inverting EM coupling contaminated data using a synthetic large-scale exploration data set. Afterward, we further tested the monitoring capability of our method by inverting time-lapse data from an environmental remediation experiment near Rifle, Colorado. Similar trends observed in both our solution and another 2D inversion were in accordance with previous findings about the IP effects due to subsurface microbial activity.

  19. Mechanisms of Resistance to Cabazitaxel

    Science.gov (United States)

    Duran, George E.; Wang, Yan C.; Francisco, E. Brian; Rose, John C.; Martinez, Francisco J.; Coller, John; Brassard, Diana; Vrignaud, Patricia; Sikic, Branimir I.

    2015-01-01

    We studied mechanisms of resistance to the novel taxane cabazitaxel in established cellular models of taxane resistance. We also developed cabazitaxel-resistant variants from MCF-7 breast cancer cells by stepwise selection in drug alone (MCF-7/CTAX) or drug plus the transport inhibitor PSC-833 (MCF-7/CTAX-P). Among multidrug resistant (MDR) variants, cabazitaxel was relatively less cross-resistant than paclitaxel and docetaxel (15 vs. 200-fold in MES-SA/Dx5 and 9 vs. 60-fold in MCF-7/TxT50, respectively). MCF-7/TxTP50 cells that were negative for MDR but had 9-fold resistance to paclitaxel were also 9-fold resistant to cabazitaxel. Selection with cabazitaxel alone (MCF-7/CTAX) yielded 33-fold resistance to cabazitaxel, 52-fold resistance to paclitaxel, activation of ABCB1, and 3-fold residual resistance to cabazitaxel with MDR inhibition. The MCF-7/CTAX-P variant did not express ABCB1, nor did it efflux rhodamine-123, BODIPY-labeled paclitaxel, and [3H]-docetaxel. These cells are hypersensitive to depolymerizing agents (vinca alkaloids and colchicine), have reduced baseline levels of stabilized microtubules, and impaired tubulin polymerization in response to taxanes (cabazitaxel or docetaxel) relative to MCF-7 parental cells. Class III β-tubulin (TUBB3) RNA and protein were elevated in both MCF-7/CTAX and MCF-7/CTAX-P. Decreased BRCA1 and altered epithelial-mesenchymal transition (EMT) markers are also associated with cabazitaxel resistance in these MCF-7 variants, and may serve as predictive biomarkers for its activity in the clinical setting. In summary, cabazitaxel resistance mechanisms include MDR (although at a lower level than paclitaxel and docetaxel), and alterations in microtubule dynamicity, as manifested by higher expression of TUBB3, decreased BRCA1, and by the induction of EMT. PMID:25416788

  20. Bisphosphonates Inhibit Stellate Cell Activity and Enhance Antitumor Effects of Nanoparticle Albumin Bound-Paclitaxel in Pancreatic Ductal Adenocarcinoma

    Science.gov (United States)

    Gonzalez-Villasana, Vianey; Rodriguez-Aguayo, Cristian; Arumugam, Thiruvengadam; Cruz-Monserrate, Zobeida; Fuentes-Mattei, Enrique; Deng, Defeng; Hwang, Rosa F.; Wang, Huamin; Ivan, Cristina; Garza, Raul Joshua; Cohen, Evan; Gao, Hui; Armaiz-Pena, Guillermo N.; Monroig-Bosque, Paloma del C.; Philip, Bincy; Rashed, Mohammed H.; Aslan, Burcu; Erdogan, Mumin Alper; Gutierrez-Puente, Yolanda; Ozpolat, Bulent; Reuben, James M.; Sood, Anil K.; Logsdon, Craig; Lopez-Berestein, Gabriel

    2014-01-01

    Pancreatic stellate cells (PSCs) have been recognized as the principal cells responsible for the production of fibrosis in PDAC. Recently PSCs have been noted to share characteristics with cells of monocyte-macrophage lineage (MML cells). Thus, we tested whether PSCs could be targeted with the nitrogen-containing bisphosphonates (NBPs) [pamidronate (Pam) or zoledronic acid (ZA)], which are potent MML cell inhibitors. In addition, we tested NBPs treatment combination with nanoparticle albumin-bound paclitaxel (nab-paclitaxel) to enhance antitumor activity. In vitro we observed that PSCs possess α-naphthyl butyrate esterase (ANBE) enzyme activity, a specific marker of MML cells. Moreover NBPs inhibited PSCs proliferation, activation, release of macrophage chemoattractant protein-1 (MCP-1) and type I collagen expression. NBPs also induced PSC apoptosis and cell cycle arrest in the G1 phase. In vivo, NBPs inactivated PSCs; reduced fibrosis; inhibited tumor volume, tumor weight, peritoneal dissemination, angiogenesis, and cell proliferation; and increased apoptosis in an orthotopic murine model of PDAC. These in vivo antitumor effects were enhanced when NBPs were combined with nab-paclitaxel but not gemcitabine (Gem). Our study suggests that targeting PSCs and tumor cells with NBPs in combination with nab-paclitaxel may be a novel therapeutic approach to PDAC. PMID:25193509

  1. Inducible clindamycin resistance in Staphylococcus aureus isolates recovered from Mashhad, Iran

    Directory of Open Access Journals (Sweden)

    Najmeh seifi

    2012-06-01

    Full Text Available Background and Objectives: Staphylococcus aureus is an important agent in hospital and community-associated infections, causing high morbidity and mortality. Introduction of the new antimicrobial classes for this pathogen is usually followed by the emergence of resistant strains through multiple mechanisms. For instance, resistance to clindamycin (CLI, can be constitutive or inducible. Inducible clindamycin resistance which may lead to treatment failure can simply be identified by performing D-test. The aim of this study was to determine the prevalence of inducible clindamycin resistance among Staphylococcus aureus isolates by D-test method.Materials and Methods: This was a cross-sectional study conducted on 254 non-duplicated S. aureus isolates in Imam Reza hospital of Mashhad during 2010. Susceptibility to oxacillin, cefoxitin, erythromycin and clindamycin was performed by disk agar diffusion method according to CLSI guidelines and D-shaped clindamycin susceptibility patterns where considered as D-test positive (D+.Results: Of 211 S. aureus isolates 88 (37.82% were methicillin resistant. It was found that of 88 MRSA isolates, 78 (88.63% were erythromycin (ERY resistant and 46 (52.27% were CLI resistant. ERY and CLI resistance in MSSA strains was 21.95% and 11.96% respectively. Inducible clindamycin resistance was detected in 18 (20.45% MRSA isolates. 47(53.40% of MRSA isolates and 9 (7.32% of MSSA showed constitutive MLSB phenotype.Conclusion: In conclusion, we found a high prevalence of inducible clindamycin resistance phenotype in our region. We recommend that whenever clindamycin is intended for S. aureus infections, D-test should be performed to facilitate the optimal treatment of patients.Keywords: Staphylococcus aureus, clindamycin, Inducible resistance

  2. STX140, but not paclitaxel, inhibits mammary tumour initiation and progression in C3(1/SV40 T/t-antigen transgenic mice.

    Directory of Open Access Journals (Sweden)

    Florence Meyer-Losic

    Full Text Available Despite paclitxael's clinical success, treating hormone-refractory breast cancer remains challenging. Paclitaxel has a poor pharmacological profile, characterized by a low therapeutic index (TIX caused by severe dose limiting toxicities, such as neutropenia and peripheral neuropathy. Consequently, new drugs are urgently required. STX140, a compound previously shown to have excellent efficacy against many tumors, is here compared to paclitaxel in three translational in vivo breast cancer models, a rat model of peripheral neuropathy, and through pharmacological testing. Three different in vivo mouse models of breast cancer were used; the metastatic 4T1 orthotopic model, the C3(1/SV40 T-Ag model, and the MDA-MB-231 xenograft model. To determine TIX and pharmacological profile of STX140, a comprehensive dosing regime was performed in mice bearing MDA-MD-231 xenografts. Finally, peripheral neuropathy was examined using a rat plantar thermal hyperalgesia model. In the 4T1 metastatic model, STX140 and paclitaxel significantly inhibited primary tumor growth and lung metastases. All C3(1/SV40 T-Ag mice in the control and paclitaxel treated groups developed palpable mammary cancer. STX140 blocked 47% of tumors developing and significantly inhibited growth of tumors that did develop. STX140 treatment caused a significant (P<0.001 survival advantage for animals in early and late intervention groups. Conversely, in C3(1/SV40 T-Ag mice, paclitaxel failed to inhibit tumor growth and did not increase survival time. Furthermore, paclitaxel, but not STX140, induced significant peripheral neuropathy and neutropenia. These results show that STX140 has a greater anti-cancer efficacy, TIX, and reduced neurotoxicity compared to paclitaxel in C3(1/SV40 T-Ag mice and therefore may be of significant benefit to patients with breast cancer.

  3. EFFICACY AND MODES OF ACTION OF RESISTANCE INDUCERS ON TWO WHEAT SPECIES AGAINST MYCOSPHAERELLA GRAMINICOLA.

    Science.gov (United States)

    Somai-Jemmali, L; Randoux, B; Siah, A; Ors, M; Halama, P; Reignault, Ph; Hamada, W

    2014-01-01

    Plant resistance inducers could be an alternative to conventional fungicides to control in a more durable and environmentally friendly manner fungal pathogens. Here, we tested the protection efficacy and the modes of action of four resistance inducers (R1, R2, R3 and R4) against the causal agent of Septoria tritici blotch, Mycosphaerella graminicola, the most frequently occurring pathogen on wheat crops worldwide. The four inducers were tested on two wheat cultivars, Premio (a French bread wheat cultivar) and Karim (a Tunisian durum wheat cultivar), each inoculated with a bread-wheat or a durum-wheat adapted isolate; respectively. All inducers exhibited in the greenhouse a significant protection level on both cultivars regarding disease symptoms (necrosis and chlorosis) and sporulation (pycnidium density). The most efficient inducer was R3 which showed 84% symptom reduction, while the less efficient one was R2 with only a 39% reduction. None of the studied inducers showed direct biocide effect against the fungus, except R4 which displayed a significant in planta inhibition of spore germination. Further investigations revealed that all inducers elicited the plant defence enzymes peroxidase and lipoxygenase, but the activity levels varied depending on the considered inducer. In addition, the effect of resistance inducers on the infection process and the fungal cell-wall degrading enzymes xylanases and glucanases was also investigated. Our study allowed us to find out four efficient resistance inducers on wheat against M. graminicola and to establish data about the modes of action of these inducers.

  4. Chemotherapy induces adaptive drug resistance and metastatic potentials via phenotypic CXCR4-expressing cell state transition in ovarian cancer

    Science.gov (United States)

    Lee, Hyun Hee; Bellat, Vanessa

    2017-01-01

    Ovarian cancer (OVC) patients who receive chemotherapy often acquire drug resistance within one year. This can lead to tumor reoccurrence and metastasis, the major causes of mortality. We report a transient increase of a small distinctive CXCR4High/CD24Low cancer stem cell population (CXCR4High) in A2780 and SKOV-3 OVC cell lines in response to cisplatin, doxorubicin, and paclitaxel, treatments. The withdrawal of the drug challenges reversed this cell-state transition. CXCR4High exhibits dormancy in drug resistance and mesenchymal-like invasion, migration, colonization, and tumor formation properties. The removal of this cell population from a doxorubicin-resistant A2780 lineage (A2780/ADR) recovered the sensitivity to drug treatments. A cytotoxic peptide (CXCR4-KLA) that can selectively target cell-surface CXCR4 receptor was further synthesized to investigate the therapeutic merits of targeting CXCR4High. This peptide was more potent than the conventional CXCR4 antagonists (AMD3100 and CTCE-9908) in eradicating the cancer stem cells. When used together with cytotoxic agents such as doxorubicin and cisplatin, the combined drug-peptide regimens exhibited a synergistic cell-killing effect on A2780, A2780/ADR, and SKOV-3. Our data suggested that chemotherapy could establish drug-resistant and tumor-initiating properties of OVC via reversible CXCR4 cell state transition. Therapeutic strategies designed to eradicate rather than antagonize CXCR4High might offer a far-reaching potential as supportive chemotherapy. PMID:28196146

  5. Broad-spectrum acquired resistance in barley induced by the Pseudomonas pathosystem shares transcriptional components with Arabidopsis systemic acquired resistance.

    Science.gov (United States)

    Colebrook, E H; Creissen, G; McGrann, G R D; Dreos, R; Lamb, C; Boyd, L A

    2012-05-01

    Inducible resistance responses play a central role in the defense of plants against pathogen attack. Acquired resistance (AR) is induced alongside defense toward primary attack, providing broad-spectrum protection against subsequent pathogen challenge. The localization and molecular basis of AR in cereals is poorly understood, in contrast with the well-characterized systemic acquired resistance (SAR) response in Arabidopsis. Here, we use Pseudomonas syringae as a biological inducer of AR in barley, providing a clear frame of reference to the Arabidopsis-P. syringae pathosystem. Inoculation of barley leaf tissue with the nonadapted P. syringae pv. tomato avrRpm1 (PstavrRpm1) induced an active local defense response. Furthermore, inoculation of barley with PstavrRpm1 resulted in the induction of broad-spectrum AR at a distance from the local lesion, "adjacent" AR, effective against compatible isolates of P. syringae and Magnaporthe oryzae. Global transcriptional profiling of this adjacent AR revealed similarities with the transcriptional profile of SAR in Arabidopsis, as well as transcripts previously associated with chemically induced AR in cereals, suggesting that AR in barley and SAR in Arabidopsis may be mediated by analogous pathways.

  6. PeaT1-induced systemic acquired resistance in tobacco follows salicylic acid-dependent pathway.

    Science.gov (United States)

    Zhang, Wei; Yang, Xiufen; Qiu, Dewen; Guo, Lihua; Zeng, Hongmei; Mao, Jianjun; Gao, Qiufeng

    2011-04-01

    Systemic acquired resistance (SAR) is an inducible defense mechanism which plays a central role in protecting plants from pathogen attack. A new elicitor, PeaT1 from Alternaria tenuissima, was expressed in Escherichia coil and characterized with systemic acquired resistance to tobacco mosaic virus (TMV). PeaT1-treated plants exhibited enhanced systemic resistance with a significant reduction in number and size of TMV lesions on wild tobacco leaves as compared with control. The quantitative analysis of TMV CP gene expression with real-time quantitative PCR showed there was reduction in TMV virus concentration after PeaT1 treatment. Similarly, peroxidase (POD) activity and lignin increased significantly after PeaT1 treatment. The real-time quantitative PCR revealed that PeaT1 also induced the systemic accumulation of pathogenesis-related gene, PR-1a and PR-1b which are the markers of systemic acquired resistance (SAR), NPR1 gene for salicylic acid (SA) signal transduction pathway and PAL gene for SA synthesis. The accumulation of SA and the failure in development of similar level of resistance as in wild type tobacco plants in PeaT1 treated nahG transgenic tobacco plants indicated that PeaT1-induced resistance depended on SA accumulation. The present work suggested that the molecular mechanism of PeaT1 inducing disease resistance in tobacco was likely through the systemic acquired resistance pathway mediated by salicylic acid and the NPR1 gene.

  7. Study on the Resistance Induced by Salicylic Acid Against Phytophthora capsici in Pepper (Capsicum annuum)

    Institute of Scientific and Technical Information of China (English)

    MAO Ai-jun; WANG Yong-jian; FENG Lan-xiang; GENG San-sheng; XU Yong

    2005-01-01

    Pepper Phytophthora blight caused by Phytophthora capsici L. is the most destructive disease for reducing pepper yields in the world. Building up varietal resistance and induced resistance to the disease are of agricultural importance. In this paper, the disease resistance induced by salicylic acid (SA) against P. capsici were studied by using four hot pepper lines with different resistant abilities and one P. capsici strain with middle pathogenicity. Results show that SA could induce significantly the resistance of pepper seedlings to P. capsici, but CaC12, KH2PO4 and VAM couldn't. SA at a relative low concentration from 0.15 to 0.3 g L-1 had no antifungal activity in vitro against P. capsici. That means the disease resistant enhancement of the plants treated with SA is due to the induction effect, but not the antifungal effect of SA. About 1 to 5 days internal between SA-treatment and challenge inoculation was sufficient to induce the disease resistance of hot pepper. The resistance could remain more than 20 days after treatment with SA.

  8. Hepatocyte Toll-like receptor 4 regulates obesity-induced inflammation and insulin resistance

    Science.gov (United States)

    Chronic low-grade inflammation is a hallmark of obesity and thought to contribute to the development of obesity-related insulin resistance. Toll-like receptor 4 (Tlr4) is a key mediator of pro-inflammatory responses. Mice lacking Tlr4s are protected from diet-induced insulin resistance and inflammat...

  9. Novel free paclitaxel-loaded poly(L-γ-glutamylglutamine–paclitaxel nanoparticles

    Directory of Open Access Journals (Sweden)

    Danbo Yang

    2011-01-01

    Full Text Available Danbo Yang1, Sang Van2, Xinguo Jiang3, Lei Yu1,21Biomedical Engineering and Technology Institute, Institutes for Advanced Interdisciplinary Research, East China Normal University, Shanghai, People's Republic of China; 2Biomedical Group, Nitto Denko Technical Corporation, Oceanside, CA, USA; 3School of Pharmacy, Fudan University, Shanghai, People's Republic of ChinaAbstract: The purpose of this study was to develop a novel formulation of paclitaxel (PTX that would improve its therapeutic index. Here, we combined a concept of polymer–PTX drug conjugate with a concept of polymeric micelle drug delivery to form novel free PTX-loaded poly(L-γ-glutamylglutamine (PGG–PTX conjugate nanoparticles. The significance of this drug formulation emphasizes the simplicity, novelty, and flexibility of the method of forming nanoparticles that contain free PTX and conjugated PTX in the same drug delivery system. The results of effectively inhibiting tumor growth in mouse models demonstrated the feasibility of the nanoparticle formulation. The versatility and potential of this dual PTX drug delivery system can be explored with different drugs for different indications. Novel and simple formulations of PTX-loaded PGG–PTX nanoparticles could have important implications in translational medicines.Keywords: paclitaxel, polymeric micelle, poly(L-γ-glutamylglutamine–paclitaxel, nanoconjugate, nanoparticles

  10. Mycorrhiza-induced resistance: more than the sum of its parts?

    OpenAIRE

    Cameron, D.D.; Neal, A.L.; van Wees, S.C.M.; Ton, J.

    2013-01-01

    Plants can develop an enhanced defensive capacity in response to infection by arbuscular mycorrhizal fungi (AMF). This ‘mycorrhiza-induced resistance’ (MIR) provides systemic protection against a wide range of attackers and shares characteristics with systemic acquired resistance (SAR) after pathogen infection and induced systemic resistance (ISR) following root colonisation by non-pathogenic rhizobacteria. It is commonly assumed that fungal stimulation of the plant immune system is solely re...

  11. Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer

    Science.gov (United States)

    2016-12-01

    AWARD NUMBER: W81XWH-12-1-0529 TITLE: Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-12-1-0529 Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer 5b...of the next generation anti-androgens such as enzalutamide and abiraterone (Abi) for advanced prostate cancer therapy, we attempted to evaluate

  12. ANTIDIABETIC AND HYPOLIPIDEMIC ACTIVITY OF GYMNEMA SYLVESTRE IN DEXAMETHASONE INDUCED INSULIN RESISTANCE IN ALBINO RATS

    OpenAIRE

    Hemanth Kumar V, Nagendra Nayak IM , Shobha V Huilgol, Saeed M Yendigeri , Narendar K

    2015-01-01

    Background: Gymnema sylvestre plant was widely used for medicinal purpose. The plant leaves were traditionally used to treat diabetes. Aim: To determine the antidiabetic and hypolipidemic activity of Gymnema sylvestre in dexamethasone induced insulin resistance in Albino rats. Objectives: The present study was undertaken to evaluate antidiabetic and hypolipidemic activity of Gymnema sylvestre leaf aqueous extract against dexamethasone induced insulin resistance in Albino rats. Materials and M...

  13. Reiterative and interruptive signaling in induced plant resistance to chewing insects.

    Science.gov (United States)

    Kim, Jinwon; Quaghebeur, Hélène; Felton, Gary W

    2011-09-01

    Our understanding of induced resistance against herbivores has grown immeasurably during the last several decades. Based upon the emerging literature, we argue that induced resistance represents a continuum of phenotypes that is determined by the plant's ability to integrate multiple suites of signals of plant and herbivore origin. We present a model that illustrates the range of signals arising from early detection through herbivore feeding, and then through subsequent plant generations.

  14. Inclusion Complex of Paclitaxel in Hydroxypropyl-β-cyclodextrin

    Institute of Scientific and Technical Information of China (English)

    CHEN Yue; ZHOU Yu-lai; REN Yong; YAN Wei-qun

    2005-01-01

    @@ Introduction Paclitaxel (as Taxol) is a kind of diterpenoid natural product[1] extracted from Chinese yew. It has been reported to have high anti-tumor effects, such as the activity against oophorama, mammary cancer, encephaloma, cervical carcinoma, and non- small-cell lung carcinoma[2-5]. One of the major problems of paclitaxel applied to therapy is its extremely low solubility in water[6]. In addition, paclitaxel is administered as a slow infusion in a vehicle consisting of Cremophor EL (polyoxyethylated castor oil ). However, Cremophor has been observed to cause severe, occasionally fatal hypersensitivity reactions in animals and humans[7].Therefore, paclitaxel therapy includes a prophylactic regimen of antihistamines and corticosteroids[8] , along with a prolonged infusion time to reduce the severity and incidence of hypersensitivity reactions. Because of the reasons mentioned above, currently its preparation needs to be improved further[9].

  15. Inducing Fungus-Resistance into Plants through Biotechnology

    OpenAIRE

    Wani, Shabir Hussain

    2010-01-01

    Plant diseases are caused by a variety of plant pathogens including fungi, and their management requires the use of techniques like transgenic technology, molecular biology, and genetics. There have been attempts to use gene technology as an alternative method to protect plants from microbial diseases, in addition to the development of novel agrochemicals and the conventional breeding of resistant cultivars. Various genes have been introduced into plants, and the enhanced resistance against f...

  16. Fentanyl Enhances Hepatotoxicity of Paclitaxel via Inhibition of CYP3A4 and ABCB1 Transport Activity in Mice.

    Directory of Open Access Journals (Sweden)

    Jing-Dun Xie

    Full Text Available Fentanyl, a potent opioid analgesic that is used to treat cancer pain, is commonly administered with paclitaxel in advanced tumors. However, the effect of fentanyl on the hepatotoxicity of paclitaxel and its potential mechanism of action is not well studied. The purpose of this study was to investigate the effect of fentanyl on the hepatotoxicity of paclitaxel and its potential mechanisms of action. Pharmacokinetic parameters of paclitaxel were tested using reversed phase high-performance liquid chromatography (RP-HPLC. Aspartate transaminase (AST, alanine aminotransferase (ALT, and mouse liver histopathology were examined. Moreover, the cytotoxicity of anti-carcinogens was examined using 1-(4, 5-dimethylthiazol-2-yl-3,5-diphenylformazan (MTT, and the intracellular accumulation of doxorubicin and rhodamine 123 was detected by flow cytometry. Furthermore, the expression of ABCB1 and the activity of ABCB1 ATPase and CYP3A4 were also examined. In this study, the co-administration of fentanyl and paclitaxel prolonged the half-life (t1/2 of paclitaxel from 1.455 hours to 2.344 hours and decreased the clearance (CL from 10.997 ml/h to 7.014 ml/h in mice. Fentanyl significantly increased the levels of ALT in mice to 88.2 U/L, which is more than 2-fold higher than the level detected in the control group, and it increased the histological damage in mouse livers. Furthermore, fentanyl enhanced the cytotoxicity of anti-carcinogens that are ABCB1 substrates and increased the accumulation of doxorubicin and rhodamine 123. Additionally, fentanyl stimulated ABCB1 ATPase activity and inhibited CYP3A4 activity in the liver microsomes of mice. Our study indicates that the obvious hepatotoxicity during this co-administration was due to the inhibition of CYP3A4 activity and ABCB1 transport activity. These findings suggested that the accumulation-induced hepatotoxicity of paclitaxel when it is combined with fentanyl should be avoided.

  17. Hemocompatibility of folic-acid-conjugated amphiphilic PEG-PLGA copolymer nanoparticles for co-delivery of cisplatin and paclitaxel: treatment effects for non-small-cell lung cancer.

    Science.gov (United States)

    He, Zelai; Shi, Zengfang; Sun, Wenjie; Ma, Jing; Xia, Junyong; Zhang, Xiangyu; Chen, Wenjun; Huang, Jingwen

    2016-06-01

    In this study, we used folic-acid-modified poly(ethylene glycol)-poly(lactic-co-glycolic acid) (FA-PEG-PLGA) to encapsulate cisplatin and paclitaxel (separately or together), and evaluated their antitumor effects against lung cancer; this study was conducted in order to investigate the antitumor effects of the co-delivery of cisplatin and paclitaxel by a targeted drug delivery system. Blood compatibility assays and complement activation tests revealed that FA-PEG-PLGA nanoparticles did not induce blood hemolysis, blood clotting, or complement activation. The results also indicated that FA-PEG-PLGA nanoparticles had no biotoxic effects, the drug delivery system allowed controlled release of the cargo molecules, and the co-delivery of cisplatin and paclitaxel efficiently induces cancer cell apoptosis and cell cycle retardation. In addition, co-delivery of cisplatin and paclitaxel showed the ability to suppress xenograft lung cancer growth and prolong the survival time of xenografted mice. These results implied that FA-PEG-PLGA nanoparticles can function as effective carriers of cisplatin and paclitaxel, and that co-delivery of cisplatin and paclitaxel by FA-PEG-PLGA nanoparticles results in more effective antitumor effects than the combination of free-drugs or single-drug-loaded nanoparticles.

  18. Inducing resistance: a summary of papers presented at the First International Symposium on Induced Resistance to Plant Diseases, Corfu, May 2000

    NARCIS (Netherlands)

    Hammerschmidt, R.; Métraux, J.-P.; Loon, L.C. van

    2001-01-01

    The First International Symposium on Induced Resistance to Plant Diseases, organized by Eris Tjamos, brought together over 150 participants to discuss the complexities, questions and future direction of research on the mechanisms by which plants can become better able to defend themselves against pa

  19. Repurposing of phentolamine as a potential anticancer agent against human castration-resistant prostate cancer: A central role on microtubule stabilization and mitochondrial apoptosis pathway.

    Science.gov (United States)

    Ho, Chen-Hsun; Hsu, Jui-Ling; Liu, Shih-Ping; Hsu, Lih-Ching; Chang, Wei-Ling; Chao, Chuck C-K; Guh, Jih-Hwa

    2015-09-01

    Drug repurposing of phentolamine, an α-adrenoceptor antagonist, as an anticancer agent has been studied in human castration-resistant prostate cancer (CRPC). Cell proliferation was examined by sulforhodamine B and CFSE staining assays. Cell cycle progression and mitochondrial membrane potential (ΔΨm) were detected by flow cytometric analysis. Protein expression was detected by Western blotting. Effect on tubulin/microtubule was determined using confocal immunofluorescence microscopic examination, microtubule assembly detection, tubulin turbidity assay, and binding assay. Several assessments were used to characterize apoptotic signaling pathways and combinatory effect. Phentolamine induced anti-proliferative effect in PC-3 and DU-145, two CRPC cell lines, and P-glycoprotein (P-gp) overexpressing cells. This effect was not significantly reduced in paclitaxel-resistant cells. Rhodamine 123 efflux assay showed that phentolamine was not a P-gp substrate. Phentolamine induced mitotic arrest of the cell cycle and formation of hyperdiploid cells, followed by an increase of apoptosis. Mitotic arrest was confirmed by cyclin B1 up-regulation, Cdk1 activation, and a dramatic increase of mitotic protein phosphorylation. Both in vitro and cellular identification demonstrated that phentolamine, similar to paclitaxel, induced tubulin polymerization and formation of multiple nuclei. Besides, it did not compete with paclitaxel binding on tubulin. Phentolamine induced the phosphorylation and degradation of Bcl-2 and Bcl-xL, two anti-apoptotic Bcl-2 family members, and the loss of ΔΨm indicating the induction of mitochondrial damage. It ultimately induced the activation of caspase-9, -8, and -3 and apoptotic cell death. Moreover, combination treatment with phentolamine and paclitaxel caused a synergistic apoptosis. The data suggest that phentolamine is a potential anticancer agent. In contrast to a wide variety of microtubule disrupting agents, phentolamine induces microtubule

  20. FFA-induced adipocyte inflammation and insulin resistance: involvement of ER stress and IKKβ pathways.

    Science.gov (United States)

    Jiao, Ping; Ma, Jie; Feng, Bin; Zhang, Hao; Diehl, J Alan; Chin, Y Eugene; Yan, Weiqun; Xu, Haiyan

    2011-03-01

    Free-fatty acids (FFAs) are well-characterized factor for causing production of inflammatory factors and insulin resistance in adipocytes. Using cultured adipocytes, we demonstrate that FFAs can activate endoplasmic reticulum (ER) stress pathway by examination of ER stress sensor activation and marker gene expression. Chemical chaperone tauroursodeoxycholic acid (TUDCA) can reduce FFA-induced adipocyte inflammation and improve insulin signaling whereas overexpression of spliced X-box protein 1 (XBP-1s) only attenuates FFA-induced inflammation. PKR-like eukaryotic initiation factor 2α kinase (PERK) is one of the three major ER stress sensor proteins and deficiency of PERK alleviates FFA-induced inflammation and insulin resistance. The key downstream target of FFA-induced ER stress is IκB kinase β (IKKβ), a master kinase for regulating expression of inflammatory genes. Deficiency of PERK attenuates FFA-induced activation of IKKβ and deficiency of IKKβ alleviates FFA-induced inflammation and insulin resistance. Consistently, overexpression of IKKβ in 3T3-L1 CAR adipocytes causes inflammation and insulin resistance. In addition, IKKβ overexpression has profound effect on adipocyte lipid metabolism, including inhibition of lipogenesis and promotion of lipolysis. Furthermore, increased endogenous IKKβ expression and activation is also observed in isolated primary adipocytes from mice injected with lipids or fed on high-fat diet (HFD) acutely. These results indicate that ER stress pathway is a key mediator for FFA-induced inflammation and insulin resistance in adipocytes with PERK and IKKβ as the critical signaling components.

  1. Amiodarone-induced Hypothyroidism with EPO-resistant Anemia in a Patient with Chronic Renal Failure

    Directory of Open Access Journals (Sweden)

    Peter M.S. Chang

    2008-11-01

    Full Text Available The overall incidence of amiodarone-induced thyroid dysfunction ranges from 2% to 24%. One third to half of patients with hypothyroidism have anemia due to some decrease in normal red blood cell mass and erythropoietin (EPO resistance. Therefore, for patients with chronic renal disease under medication with amiodarone, early regular thyroid function test should be checked in order to avoid amiodarone-induced hypothyroidism and EPO-resistant anemia. If amiodarone-induced hypothyroidism and EPO-resistant anemia occur in patients with chronic renal failure, early thyroxine should be given instead of waiting for spontaneous recovery by amiodarone discontinuation only. Here, we report a patient with chronic renal failure who developed EPO-resistant anemia after amiodarone treatment for arrhythmia. The hemoglobin level responded to EPO therapy rapidly after thyroxine administration and amiodarone discontinuation.

  2. Mycorrhiza-induced resistance: more than the sum of its parts?

    Science.gov (United States)

    Cameron, Duncan D; Neal, Andrew L; van Wees, Saskia C M; Ton, Jurriaan

    2013-10-01

    Plants can develop an enhanced defensive capacity in response to infection by arbuscular mycorrhizal fungi (AMF). This 'mycorrhiza-induced resistance' (MIR) provides systemic protection against a wide range of attackers and shares characteristics with systemic acquired resistance (SAR) after pathogen infection and induced systemic resistance (ISR) following root colonisation by non-pathogenic rhizobacteria. It is commonly assumed that fungal stimulation of the plant immune system is solely responsible for MIR. In this opinion article, we present a novel model of MIR that integrates different aspects of the induced resistance phenomenon. We propose that MIR is a cumulative effect of direct plant responses to mycorrhizal infection and indirect immune responses to ISR-eliciting rhizobacteria in the mycorrhizosphere.

  3. IL-37 protects against obesity-induced inflammation and insulin resistance

    NARCIS (Netherlands)

    Ballak, D.B.; Diepen, van J.A.; Moschen, A.R.; Jansen, H.; Hijmans, A.; Groenhof, G.J.; Leenders, F.; Bufler, P.; Boekschoten, M.V.

    2014-01-01

    Cytokines of the IL-1 family are important modulators of obesity-induced inflammation and the development of systemic insulin resistance. Here we show that IL-1 family member ¿IL-37, recently characterized as an anti-inflammatory cytokine, ameliorates obesity-induced inflammation and insulin resista

  4. IL-37 protects against obesity-induced inflammation and insulin resistance

    NARCIS (Netherlands)

    Ballak, D.B.; Diepen, J.A. van; Moschen, A.R.; Jansen, H.J.; Hijmans, A.G.; Groenhof, G.J.; Leenders, F.; Bufler, P.; Boekschoten, M.V.; Muller, M; Kersten, S.; Li, S.; Kim, S.; Eini, H.; Lewis, E.C.; Joosten, L.A.; Tilg, H.; Netea, M.G.; Tack, C.J.; Dinarello, C.A.; Stienstra, R.

    2014-01-01

    Cytokines of the IL-1 family are important modulators of obesity-induced inflammation and the development of systemic insulin resistance. Here we show that IL-1 family member IL-37, recently characterized as an anti-inflammatory cytokine, ameliorates obesity-induced inflammation and insulin

  5. IL-37 protects against obesity-induced inflammation and insulin resistance

    NARCIS (Netherlands)

    Ballak, D.B.; Diepen, van J.A.; Moschen, A.R.; Jansen, H.; Hijmans, A.; Groenhof, G.J.; Leenders, F.; Bufler, P.; Boekschoten, M.V.

    2014-01-01

    Cytokines of the IL-1 family are important modulators of obesity-induced inflammation and the development of systemic insulin resistance. Here we show that IL-1 family member ¿IL-37, recently characterized as an anti-inflammatory cytokine, ameliorates obesity-induced inflammation and insulin

  6. IL-37 protects against obesity-induced inflammation and insulin resistance

    NARCIS (Netherlands)

    Ballak, D.B.; Diepen, van J.A.; Moschen, A.R.; Jansen, H.; Hijmans, A.; Groenhof, G.J.; Leenders, F.; Bufler, P.; Boekschoten, M.V.

    2014-01-01

    Cytokines of the IL-1 family are important modulators of obesity-induced inflammation and the development of systemic insulin resistance. Here we show that IL-1 family member ¿IL-37, recently characterized as an anti-inflammatory cytokine, ameliorates obesity-induced inflammation and insulin resista

  7. Role of diacylglycerol activation of PKCθ in lipid-induced muscle insulin resistance in humans

    Science.gov (United States)

    Szendroedi, Julia; Yoshimura, Toru; Phielix, Esther; Koliaki, Chrysi; Marcucci, Mellissa; Zhang, Dongyan; Jelenik, Tomas; Müller, Janette; Herder, Christian; Nowotny, Peter; Shulman, Gerald I.; Roden, Michael

    2014-01-01

    Muscle insulin resistance is a key feature of obesity and type 2 diabetes and is strongly associated with increased intramyocellular lipid content and inflammation. However, the cellular and molecular mechanisms responsible for causing muscle insulin resistance in humans are still unclear. To address this question, we performed serial muscle biopsies in healthy, lean subjects before and during a lipid infusion to induce acute muscle insulin resistance and assessed lipid and inflammatory parameters that have been previously implicated in causing muscle insulin resistance. We found that acute induction of muscle insulin resistance was associated with a transient increase in total and cytosolic diacylglycerol (DAG) content that was temporally associated with protein kinase (PKC)θ activation, increased insulin receptor substrate (IRS)-1 serine 1101 phosphorylation, and inhibition of insulin-stimulated IRS-1 tyrosine phosphorylation and AKT2 phosphorylation. In contrast, there were no associations between insulin resistance and alterations in muscle ceramide, acylcarnitine content, or adipocytokines (interleukin-6, adiponectin, retinol-binding protein 4) or soluble intercellular adhesion molecule-1. Similar associations between muscle DAG content, PKCθ activation, and muscle insulin resistance were observed in healthy insulin-resistant obese subjects and obese type 2 diabetic subjects. Taken together, these data support a key role for DAG activation of PKCθ in the pathogenesis of lipid-induced muscle insulin resistance in obese and type 2 diabetic individuals. PMID:24979806

  8. Assessing the oseltamivir-induced resistance risk and implications for influenza infection control strategies

    Directory of Open Access Journals (Sweden)

    Hsieh NH

    2017-07-01

    Full Text Available Nan-Hung Hsieh,1 Yi-Jun Lin,2 Ying-Fei Yang,2 Chung-Min Liao2 1Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA; 2Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan Background: Oseltamivir-resistant mutants with higher drug resistance rates and low transmission fitness costs have not accounted for influenza (subtype viruses. Predicting the impacts of neuraminidase inhibitor therapy on infection rates and transmission of drug-resistant viral strains requires further investigation.Objectives: The purpose of this study was to assess the potential risk of oseltamivir-induced resistance for influenza A (H1N1 and A (H3N2 viruses.Materials and methods: An immune-response-based virus dynamic model was used to best fit the oseltamivir-resistant A (H1N1 and A (H3N2 infection data. A probabilistic risk assessment model was developed by incorporating branching process-derived probability distribution of resistance to estimate oseltamivir-induced resistance risk.Results: Mutation rate and sensitive strain number were key determinants in assessing resistance risk. By increasing immune response, antiviral efficacy, and fitness cost, the spread of resistant strains for A (H1N1 and A (H3N2 were greatly decreased. Probability of resistance depends most strongly on the sensitive strain number described by a Poisson model. Risk of oseltamivir-induced resistance increased with increasing the mutation rate for A (H1N1 only. The ≥50% of resistance risk induced by A (H1N1 and A (H3N2 sensitive infected cells were 0.4 (95% CI: 0.28–0.43 and 0.95 (95% CI 0.93–0.99 at a mutation rate of 10−6, respectively. Antiviral drugs must be administrated within 1–1.5 days for A (H1N1 and 2–2.5 days for A (H3N2 virus infections to limit viral production.Conclusion: Probabilistic risk assessment of antiviral drug-induced

  9. Gefitinib circumvents hypoxia-induced drug resistance by the modulation of HIF-1alpha.

    Science.gov (United States)

    Rho, Jin Kyung; Choi, Yun Jung; Lee, Jin Kyung; Ryoo, Baek-Yeol; Na, Im Ii; Yang, Sung Hyun; Kim, Cheol Hyeon; Yoo, Young Do; Lee, Jae Cheol

    2009-03-01

    Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcriptional factor which is activated by hypoxia and associated with cell survival, proliferation and drug resistance. Recent studies have shown that the down-stream molecules of the epidermal growth factor receptor (EGFR) signal are involved in the hypoxia-dependent or -independent HIF-1alpha protein accumulation. Thus, we hypothesized that an EGFR-TK inhibitor, gefitinib, might circumvent the hypoxia-induced drug resistance via the regulation of HIF-1alpha expression. In our data, treatment of gefitinib suppressed induced HIF-1alpha by hypoxia. This action of gefitinib was caused by reduced protein stability without any change in the level of HIF-1alpha mRNA. The effect of gefitinib on down-regulation of HIF-1alpha was reversed by transfection of constitutively active form of Akt. The cellular response to gefitinib was similar in both normoxia and hypoxia condition. However, the response to conventional chemotherapeutic drugs decreased >50% under hypoxia condition and they did not change HIF-1alpha expression. In addition, the suppression of HIF-1alpha using siRNA overcame partially hypoxia-induced drug resistance. In conclusion, gefitinib was able to circumvent hypoxia-induced drug resistance suggesting that the effective suppression of HIF-1alpha by the inhibition of EGFR-Akt pathway may overcome the hypoxia-induced drug resistance.

  10. The ability of single sex infections of Schistosoma japonicum to induce resistance to reinfection in mice.

    Science.gov (United States)

    Moloney, N A; Hinchcliffe, P; Webbe, G

    1986-09-01

    In four experiments, mice harbouring an average 50, 76 or over 200 Schistosoma japonicum female worms were not resistant when challenged six to eight weeks after infection. The female worms from these single sex infections were stunted and immature (average length 4.6 mm) and induced no overt pathology in the host. Male worm burdens of 60, 135 or 140 also induced little or no resistance to challenge in the host. The males from these single sex infections were fully grown for their age (average length 9 mm) and burdens of 135 or 140 induced distended hepatic portal veins and marked deposition of pigment in the livers of infected mice.

  11. The relationship between basal and induced resistance in Arabidopsis

    NARCIS (Netherlands)

    Ton, J.; Pieterse, C.M.J.; Loon, L.C. van

    2006-01-01

    Plants are constantly exposed to potentially pathogenic micro-organisms. They possess an extensive array of passive and active defense mechanisms, and only a small proportion of micro-organisms are capable of infecting the plant and causing disease. Plant resistance can be broadly defined as the pla

  12. Rhizobacteria-mediated induced systemic resistence in Arabidopsis

    NARCIS (Netherlands)

    Ton, J.

    2001-01-01

    Upon primary pathogen attack, plants activate a diverse array of defense mechanisms at the site of primary infection. Besides this so-called basal resistance, plants have also the ability to enhance their defensive capacity against future pathogen attack. There are at least two types of biolog

  13. Signalling in rhizobacteria-induced systemic resistance in Arabidopsis thaliana

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Wees, A.C.M. van; Ton, J.; Pelt, J.A. van; Loon, L.C. van

    2002-01-01

    To protect themselves from disease, plants have evolved sophisticated defence mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signalling pathways controlling disease resistance is a major objective in research on plant-path

  14. A review on the mechanisms of blood-flow restriction resistance training-induced muscle hypertrophy.

    Science.gov (United States)

    Pearson, Stephen John; Hussain, Syed Robiul

    2015-02-01

    It has traditionally been believed that resistance training can only induce muscle growth when the exercise intensity is greater than 65% of the 1-repetition maximum (RM). However, more recently, the use of low-intensity resistance exercise with blood-flow restriction (BFR) has challenged this theory and consistently shown that hypertrophic adaptations can be induced with much lower exercise intensities (training being demonstrated by numerous studies, the underlying mechanisms responsible for such effects are not well defined. Metabolic stress has been suggested to be a primary factor responsible, and this is theorised to activate numerous other mechanisms, all of which are thought to induce muscle growth via autocrine and/or paracrine actions. However, it is noteworthy that some of these mechanisms do not appear to be mediated to any great extent by metabolic stress but rather by mechanical tension (another primary factor of muscle hypertrophy). Given that the level of mechanical tension is typically low with BFR resistance exercise (adaptations reported with BFR resistance training. However, despite the low level of mechanical tension, it is plausible that the effects induced by the primary factors (mechanical tension and metabolic stress) are, in fact, additive, which ultimately contributes to the adaptations seen with BFR resistance training. Exercise-induced mechanical tension and metabolic stress are theorised to signal a number of mechanisms for the induction of muscle growth, including increased fast-twitch fibre recruitment, mechanotransduction, muscle damage, systemic and localised hormone production, cell swelling, and the production of reactive oxygen species and its variants, including nitric oxide and heat shock proteins. However, the relative extent to which these specific mechanisms are induced by the primary factors with BFR resistance exercise, as well as their magnitude of involvement in BFR resistance training-induced muscle hypertrophy

  15. Cross-resistance to fluconazole induced by exposure to the agricultural azole tetraconazole: an environmental resistance school?

    Science.gov (United States)

    Rocha, Marcos Fábio Gadelha; Alencar, L P; Paiva, M A N; Melo, Luciana Magalhães; Bandeira, Silviane Praciano; Ponte, Y B; Sales, Jamille Alencar; Guedes, G M M; Castelo-Branco, D S C M; Bandeira, T J P G; Cordeiro, R A; Pereira-Neto, W A; Brandine, G S; Moreira, José Luciano Bezerra; Sidrim, José Júlio Costa; Brilhante, Raimunda Sâmia Nogueira

    2016-05-01

    This study aimed to investigate the influence of tetraconazole and malathion, both used in agricultural activities, on resistance to fluconazole, itraconazole and voriconazole in Candida parapsilosis ATCC 22019. The susceptibility to tetraconazole, malathion, fluconazole, itraconazole and voriconazole, through broth microdilution. Then, 12 independent replicates, were separated and exposed to four treatment groups, each one containing three replicates: G1: tetraconazole; G2: malathion; G3: fluconazole (positive control); G4: negative control. Replicates from G1, G2 and G3, were exposed to weekly increasing concentrations of tetraconazole, malathion and fluconazole, respectively, ranging from MIC/2 to 32 × MIC, throughout 7 weeks. The exposure to tetraconazole, but not malathion, decreased susceptibility to clinical azoles, especially fluconazole. The tetraconazole-induced fluconazole resistance is partially mediated by the increased activity of ATP-dependent efflux pumps, considering the increase in antifungal susceptibility after the addition of the efflux pump inhibitor, promethazine, and the increase in rhodamine 6G efflux and CDR gene expression in the G1 replicates. Moreover, MDR expression was only detected in G1 and G3 replicates, suggesting that MDR pumps are also involved in tetraconazole-induced fluconazole resistance. It is noteworthy that tetraconazole and fluconazole-treated replicates behaved similarly, therefore, resistance to azoles of clinical use may be a consequence of using azoles in farming activities.

  16. Allergen exposure induces adipose tissue inflammation and insulin resistance.

    Science.gov (United States)

    Jung, Chien-Cheng; Tsai, Yau-Sheng; Chang, Chih-Ching; Cheng, Tsun-Jen; Chang, Ching-Wen; Liu, Ping-Yen; Chiu, Yi-Jen; Su, Huey-Jen

    2014-11-01

    This study investigates whether exposure to allergen elicits insulin resistance as a result of adipose tissue inflammation. Male C57BL/6 mice were challenged with ovalbumin (OVA) allergen for 12 weeks, and blood and adipose tissue samples were collected at 24h after the last challenge. Levels of adhesion molecules, fasting insulin, fasting glucose, and adipokines in the blood were analyzed, and fasting homeostasis model assessment was applied to determine insulin resistance (HOMA-IR). The expression of pro- and anti-inflammatory genes in dissected adipose tissues was analyzed by real-time RT-PCR. Our results showed that OVA exposure increased insulin resistance as well as resistin and E-selectin, but reduced adiponectin in the serum. Resistin level was significantly correlated with HOMA-IR. Moreover, in adipose tissues of OVA-challenged mice, the pro-inflammatory M1 genes were more abundant while the anti-inflammatory M2 genes were less than those of PBS-treated mice. The expressional changes of both M1 and M2 genes were significantly associated with serum levels of adiponectin, resistin, and E-selectin. Hematoxylin and eosin (HE) and immunohistochemistry (IHC) stain also showed that there was more obvious inflammation in OVA-challenged mice. In conclusion, the current study suggests the relationship between allergen-elicited adipose tissue inflammation and circulating inflammatory molecules, which are possible mediators for the development of insulin resistance. Therefore, we propose that allergen exposure might be one risk factor for insulin resistance. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Paclitaxel Drug-eluting Tracheal Stent Could Reduce Granulation Tissue Formation in a Canine Model

    Directory of Open Access Journals (Sweden)

    Ting Wang

    2016-01-01

    Conclusions: The paclitaxel-eluting stent could safely reduce the granulation tissue formation after stent implantation in vivo, suggesting that the paclitaxel-eluting tracheal stent might be considered for potential use in humans in the future.

  18. Breast cancer cells with acquired antiestrogen resistance are sensitized to cisplatin-induced cell death

    DEFF Research Database (Denmark)

    Yde, Christina Westmose; Gyrd-Hansen, Mads; Lykkesfeldt, Anne E

    2007-01-01

    for future breast cancer treatment. In this study, we have investigated the effect of the chemotherapeutic compound cisplatin using a panel of antiestrogen-resistant breast cancer cell lines established from the human breast cancer cell line MCF-7. We show that the antiestrogen-resistant cells...... with parental MCF-7 cells. Our data show that Bcl-2 can protect antiestrogen-resistant breast cancer cells from cisplatin-induced cell death, indicating that the reduced expression of Bcl-2 in the antiestrogen-resistant cells plays a role in sensitizing the cells to cisplatin treatment.......Antiestrogens are currently used for treating breast cancer patients who have estrogen receptor-positive tumors. However, patients with advanced disease will eventually develop resistance to the drugs. Therefore, compounds effective on antiestrogen-resistant tumors will be of great importance...

  19. Prenylated Chalcone 2 Acts as an Antimitotic Agent and Enhances the Chemosensitivity of Tumor Cells to Paclitaxel

    Directory of Open Access Journals (Sweden)

    Joana Fonseca

    2016-07-01

    Full Text Available We previously reported that prenylated chalcone 2 (PC2, the O-prenyl derivative (2 of 2′-hydroxy-3,4,4′,5,6′-pentamethoxychalcone (1, induced cytotoxicity of tumor cells via disruption of p53-MDM2 interaction. However, the cellular changes through which PC2 exerts its cytotoxic activity and its antitumor potential, remain to be addressed. In the present work, we aimed to (i characterize the effect of PC2 on mitotic progression and the underlying mechanism; and to (ii explore this information to evaluate its ability to sensitize tumor cells to paclitaxel in a combination regimen. PC2 was able to arrest breast adenocarcinoma MCF-7 and non-small cell lung cancer NCI-H460 cells in mitosis. All mitosis-arrested cells showed collapsed mitotic spindles with randomly distributed chromosomes, and activated spindle assembly checkpoint. Live-cell imaging revealed that the compound induced a prolonged delay (up to 14 h in mitosis, culminating in massive cell death by blebbing. Importantly, PC2 in combination with paclitaxel enhanced the effect on cell growth inhibition as determined by cell viability and proliferation assays. Our findings demonstrate that the cytotoxicity induced by PC2 is mediated through antimitotic activity as a result of mitotic spindle damage. The enhancement effects of PC2 on chemosensitivity of cancer cells to paclitaxel encourage further validation of the clinical potential of this combination.

  20. Prenylated Chalcone 2 Acts as an Antimitotic Agent and Enhances the Chemosensitivity of Tumor Cells to Paclitaxel.

    Science.gov (United States)

    Fonseca, Joana; Marques, Sandra; Silva, Patrícia M A; Brandão, Pedro; Cidade, Honorina; Pinto, Madalena M; Bousbaa, Hassan

    2016-07-29

    We previously reported that prenylated chalcone 2 (PC2), the O-prenyl derivative (2) of 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone (1), induced cytotoxicity of tumor cells via disruption of p53-MDM2 interaction. However, the cellular changes through which PC2 exerts its cytotoxic activity and its antitumor potential, remain to be addressed. In the present work, we aimed to (i) characterize the effect of PC2 on mitotic progression and the underlying mechanism; and to (ii) explore this information to evaluate its ability to sensitize tumor cells to paclitaxel in a combination regimen. PC2 was able to arrest breast adenocarcinoma MCF-7 and non-small cell lung cancer NCI-H460 cells in mitosis. All mitosis-arrested cells showed collapsed mitotic spindles with randomly distributed chromosomes, and activated spindle assembly checkpoint. Live-cell imaging revealed that the compound induced a prolonged delay (up to 14 h) in mitosis, culminating in massive cell death by blebbing. Importantly, PC2 in combination with paclitaxel enhanced the effect on cell growth inhibition as determined by cell viability and proliferation assays. Our findings demonstrate that the cytotoxicity induced by PC2 is mediated through antimitotic activity as a result of mitotic spindle damage. The enhancement effects of PC2 on chemosensitivity of cancer cells to paclitaxel encourage further validation of the clinical potential of this combination.

  1. Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains in Italy and heterogeneity of inducibly resistant strains.

    Science.gov (United States)

    Giovanetti, E; Montanari, M P; Mingoia, M; Varaldo, P E

    1999-08-01

    A total of 387 clinical strains of erythromycin-resistant (MIC, >/=1 microg/ml) Streptococcus pyogenes, all isolated in Italian laboratories from 1995 to 1998, were examined. By the erythromycin-clindamycin double-disk test, 203 (52.5%) strains were assigned to the recently described M phenotype, 120 (31.0%) were assigned to the inducible macrolide, lincosamide, and streptogramin B resistance (iMLS) phenotype, and 64 (16.5%) were assigned to the constitutive MLS resistance (cMLS) phenotype. The inducible character of the resistance of the iMLS strains was confirmed by comparing the clindamycin MICs determined under normal testing conditions and those determined after induction by pregrowth in 0.05 microg of erythromycin per ml. The MICs of erythromycin, clarithromycin, azithromycin, josamycin, spiramycin, and the ketolide HMR3004 were then determined and compared. Homogeneous susceptibility patterns were observed for the isolates of the cMLS phenotype (for all but one of the strains, HMR3004 MICs were 0.5 to 8 microg/ml and the MICs of the other drugs were >128 microg/ml) and those of the M phenotype (resistance only to the 14- and 15-membered macrolides was recorded, with MICs of 2 to 32 microg/ml). Conversely, heterogeneous susceptibility patterns were observed in the isolates of the iMLS phenotype, which were subdivided into three distinct subtypes designated iMLS-A, iMLS-B, and iMLS-C. The iMLS-A strains (n = 84) were highly resistant to the 14-, 15-, and 16-membered macrolides and demonstrated reduced susceptibility to low-level resistance to HMR3004. The iMLS-B strains (n = 12) were highly resistant to the 14- and 15-membered macrolides, susceptible to the 16-membered macrolides (but highly resistant to josamycin after induction), and susceptible to HMR3004 (but intermediate or resistant after induction). The iMLS-C strains (n = 24) had lower levels of resistance to the 14- and 15-membered macrolides (with erythromycin MICs increasing two to four times after

  2. Overcoming Hypoxic-Resistance of Tumor Cells to TRAIL-Induced Apoptosis through Melatonin

    Directory of Open Access Journals (Sweden)

    You-Jin Lee

    2014-07-01

    Full Text Available A solid tumor is often exposed to hypoxic or anoxic conditions; thus, tumor cell responses to hypoxia are important for tumor progression as well as tumor therapy. Our previous studies indicated that tumor cells are resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL-induced cell apoptosis under hypoxic conditions. Melatonin inhibits cell proliferation in many cancer types and induces apoptosis in some particular cancer types. Here, we examined the effects of melatonin on hypoxic resistant cells against TRAIL-induced apoptosis and the possible mechanisms of melatonin in the hypoxic response. Melatonin treatment increased TRAIL-induced A549 cell death under hypoxic conditions, although hypoxia inhibited TRAIL-mediated cell apoptosis. In a mechanistic study, hypoxia inducible factor-1α and prolyl-hydroxylase 2 proteins, which increase following exposure to hypoxia, were dose-dependently down-regulated by melatonin treatment. Melatonin also blocked the hypoxic responses that reduced pro-apoptotic proteins and increased anti-apoptotic proteins including Bcl-2 and Bcl-xL. Furthermore, melatonin treatment reduced TRAIL resistance by regulating the mitochondrial transmembrane potential and Bax translocation. Our results first demonstrated that melatonin treatment induces apoptosis in TRAIL-resistant hypoxic tumor cells by diminishing the anti-apoptotic signals mediated by hypoxia and also suggest that melatonin could be a tumor therapeutic tool by combining with other apoptotic ligands including TRAIL, particularly in solid tumor cells exposed to hypoxia.

  3. CDK5 Regulates Paclitaxel Sensitivity in Ovarian Cancer Cells by Modulating AKT Activation, p21Cip1- and p27Kip1-Mediated G1 Cell Cycle Arrest and Apoptosis.

    Directory of Open Access Journals (Sweden)

    Shu Zhang

    Full Text Available Cyclin-dependent kinase 5 (CDK5 is a cytoplasmic serine/ threonine kinase. Knockdown of CDK5 enhances paclitaxel sensitivity in human ovarian cancer cells. This study explores the mechanisms by which CDK5 regulates paclitaxel sensitivity in human ovarian cancers. Multiple ovarian cancer cell lines and xenografts were treated with CDK5 small interfering RNA (siRNA with or without paclitaxel to examine the effect on cancer cell viability, cell cycle arrest and tumor growth. CDK5 protein was measured by immunohistochemical staining of an ovarian cancer tissue microarray to correlate CDK5 expression with overall patient survival. Knockdown of CDK5 with siRNAs inhibits activation of AKT which significantly correlates with decreased cell growth and enhanced paclitaxel sensitivity in ovarian cancer cell lines. In addition, CDK5 knockdown alone and in combination with paclitaxel induced G1 cell cycle arrest and caspase 3 dependent apoptotic cell death associated with post-translational upregulation and nuclear translocation of TP53 and p27(Kip1 as well as TP53-dependent transcriptional induction of p21(Cip1 in wild type TP53 cancer cells. Treatment of HEYA8 and A2780 wild type TP53 xenografts in nu/nu mice with CDK5 siRNA and paclitaxel produced significantly greater growth inhibition than either treatment alone. Increased expression of CDK5 in human ovarian cancers correlates inversely with overall survival. CDK5 modulates paclitaxel sensitivity by regulating AKT activation, the cell cycle and caspase-dependent apoptosis. CDK5 inhibition can potentiate paclitaxel activity in human ovarian cancer cells.

  4. Fluoroquinolone-induced gene transfer in multidrug-resistant Salmonella

    Science.gov (United States)

    Fluoroquinolones are broad spectrum antibiotics that inhibit bacterial DNA gyrase and topoisomerase activity. Bacterial exposure to fluoroquinolones can cause DNA damage and induce a bacterial SOS response to stimulate repair of damaged DNA. Certain prophages (integrated in bacterial chromosomes) ...

  5. Lipid-induced insulin resistance does not impair insulin access to skeletal muscle.

    Science.gov (United States)

    Kolka, Cathryn M; Richey, Joyce M; Castro, Ana Valeria B; Broussard, Josiane L; Ionut, Viorica; Bergman, Richard N

    2015-06-01

    Elevated plasma free fatty acids (FFA) induce insulin resistance in skeletal muscle. Previously, we have shown that experimental insulin resistance induced by lipid infusion prevents the dispersion of insulin through the muscle, and we hypothesized that this would lead to an impairment of insulin moving from the plasma to the muscle interstitium. Thus, we infused lipid into our anesthetized canine model and measured the appearance of insulin in the lymph as a means to sample muscle interstitium under hyperinsulinemic euglycemic clamp conditions. Although lipid infusion lowered the glucose infusion rate and induced both peripheral and hepatic insulin resistance, we were unable to detect an impairment of insulin access to the lymph. Interestingly, despite a significant, 10-fold increase in plasma FFA, we detected little to no increase in free fatty acids or triglycerides in the lymph after lipid infusion. Thus, we conclude that experimental insulin resistance induced by lipid infusion does not reduce insulin access to skeletal muscle under clamp conditions. This would suggest that the peripheral insulin resistance is likely due to reduced cellular sensitivity to insulin in this model, and yet we did not detect a change in the tissue microenvironment that could contribute to cellular insulin resistance. Copyright © 2015 the American Physiological Society.

  6. Nox2 Mediates Skeletal Muscle Insulin Resistance Induced by a High Fat Diet*

    Science.gov (United States)

    Souto Padron de Figueiredo, Alvaro; Salmon, Adam B.; Bruno, Francesca; Jimenez, Fabio; Martinez, Herman G.; Halade, Ganesh V.; Ahuja, Seema S.; Clark, Robert A.; DeFronzo, Ralph A.; Abboud, Hanna E.; El Jamali, Amina

    2015-01-01

    Inflammation and oxidative stress through the production of reactive oxygen species (ROS) are consistently associated with metabolic syndrome/type 2 diabetes. Although the role of Nox2, a major ROS-generating enzyme, is well described in host defense and inflammation, little is known about its potential role in insulin resistance in skeletal muscle. Insulin resistance induced by a high fat diet was mitigated in Nox2-null mice compared with wild-type mice after 3 or 9 months on the diet. High fat feeding increased Nox2 expression, superoxide production, and impaired insulin signaling in skeletal muscle tissue of wild-type mice but not in Nox2-null mice. Exposure of C2C12 cultured myotubes to either high glucose concentration, palmitate, or H2O2 decreases insulin-induced Akt phosphorylation and glucose uptake. Pretreatment with catalase abrogated these effects, indicating a key role for H2O2 in mediating insulin resistance. Down-regulation of Nox2 in C2C12 cells by shRNA prevented insulin resistance induced by high glucose or palmitate but not H2O2. These data indicate that increased production of ROS in insulin resistance induced by high glucose in skeletal muscle cells is a consequence of Nox2 activation. This is the first report to show that Nox2 is a key mediator of insulin resistance in skeletal muscle. PMID:25825489

  7. Go-6976 Reverses Hyperglycemia-Induced Insulin Resistance Independently of cPKC Inhibition in Adipocytes

    Science.gov (United States)

    Robinson, Katherine A.; Hegyi, Krisztina; Hannun, Yusuf A.; Buse, Maria G.; Sethi, Jaswinder K.

    2014-01-01

    Chronic hyperglycemia induces insulin resistance by mechanisms that are incompletely understood. One model of hyperglycemia-induced insulin resistance involves chronic preincubation of adipocytes in the presence of high glucose and low insulin concentrations. We have previously shown that the mTOR complex 1 (mTORC1) plays a partial role in the development of insulin resistance in this model. Here, we demonstrate that treatment with Go-6976, a widely used “specific” inhibitor of cPKCs, alleviates hyperglycemia-induced insulin resistance. However, the effects of mTOR inhibitor, rapamycin and Go-6976 were not additive and only rapamycin restored impaired insulin-stimulated AKT activation. Although, PKCα, (but not –β) was abundantly expressed in these adipocytes, our studies indicate cPKCs do not play a major role in causing insulin-resistance in this model. There was no evidence of changes in the expression or phosphorylation of PKCα, and PKCα knock-down did not prevent the reduction of insulin-stimulated glucose transport. This was also consistent with lack of IRS-1 phosphorylation on Ser-24 in hyperglycemia-induced insulin-resistant adipocytes. Treatment with Go-6976 did inhibit a component of the mTORC1 pathway, as evidenced by decreased phosphorylation of S6 ribosomal protein. Raptor knock-down enhanced the effect of insulin on glucose transport in insulin resistant adipocytes. Go-6976 had the same effect in control cells, but was ineffective in cells with Raptor knock-down. Taken together these findings suggest that Go-6976 exerts its effect in alleviating hyperglycemia-induced insulin-resistance independently of cPKC inhibition and may target components of the mTORC1 signaling pathway. PMID:25330241

  8. Chaos-induced resistivity of collisionless magnetic reconnection in the presence of a guide field

    Science.gov (United States)

    Shang, Meng; Wu, De-Jin; Chen, Ling; Chen, Peng-Fei

    2017-01-01

    One of the most puzzling problems in astrophysics is to understand the anomalous resistivity in collisionless magnetic reconnection that is believed extensively to be responsible for the energy release in various eruptive phenomena. The magnetic null point in the reconnecting current sheet, acting as a scattering center, can lead to chaotic motions of particles in the current sheet, which is one of the possible mechanisms for anomalous resistivity and is called chaos-induced resistivity. In many interesting cases, however, instead of the magnetic null point, there is a nonzero magnetic field perpendicular to the merging field lines, usually called the guide field, whose effect on chaos-induced resistivity has been an open problem. By use of the test particle simulation method and statistical analysis, we investigate chaos-induced resistivity in the presence of a constant guide field. The characteristics of particle motion in the reconnecting region, in particular, the chaotic behavior of particle orbits and evolving statistical features, are analyzed. The results show that as the guide field increases, the radius of the chaos region increases and the Lyapunov index decreases. However, the effective collision frequency, and hence the chaos-induced resistivity, reach their peak values when the guide field approaches half of the characteristic strength of the reconnection magnetic field. The presence of a guide field can significantly influence the chaos of the particle orbits and hence the chaos-induced resistivity in the reconnection sheet, which decides the collisionless reconnection rate. The present result is helpful for us to understand the microphysics of anomalous resistivity in collisionless reconnection with a guide field.

  9. Go-6976 reverses hyperglycemia-induced insulin resistance independently of cPKC inhibition in adipocytes.

    Directory of Open Access Journals (Sweden)

    Katherine A Robinson

    Full Text Available Chronic hyperglycemia induces insulin resistance by mechanisms that are incompletely understood. One model of hyperglycemia-induced insulin resistance involves chronic preincubation of adipocytes in the presence of high glucose and low insulin concentrations. We have previously shown that the mTOR complex 1 (mTORC1 plays a partial role in the development of insulin resistance in this model. Here, we demonstrate that treatment with Go-6976, a widely used "specific" inhibitor of cPKCs, alleviates hyperglycemia-induced insulin resistance. However, the effects of mTOR inhibitor, rapamycin and Go-6976 were not additive and only rapamycin restored impaired insulin-stimulated AKT activation. Although, PKCα, (but not -β was abundantly expressed in these adipocytes, our studies indicate cPKCs do not play a major role in causing insulin-resistance in this model. There was no evidence of changes in the expression or phosphorylation of PKCα, and PKCα knock-down did not prevent the reduction of insulin-stimulated glucose transport. This was also consistent with lack of IRS-1 phosphorylation on Ser-24 in hyperglycemia-induced insulin-resistant adipocytes. Treatment with Go-6976 did inhibit a component of the mTORC1 pathway, as evidenced by decreased phosphorylation of S6 ribosomal protein. Raptor knock-down enhanced the effect of insulin on glucose transport in insulin resistant adipocytes. Go-6976 had the same effect in control cells, but was ineffective in cells with Raptor knock-down. Taken together these findings suggest that Go-6976 exerts its effect in alleviating hyperglycemia-induced insulin-resistance independently of cPKC inhibition and may target components of the mTORC1 signaling pathway.

  10. Inducible expression eliminates the fitness cost of vancomycin resistance in enterococci.

    Science.gov (United States)

    Foucault, Marie-Laure; Depardieu, Florence; Courvalin, Patrice; Grillot-Courvalin, Catherine

    2010-09-28

    Inducible vancomycin resistance in enterococci is due to a sophisticated mechanism that combines synthesis of cell wall peptidoglycan precursors with low affinity for glycopeptides and elimination of the normal target precursors. Although this dual mechanism, which involves seven genes organized in two operons, is predicted to have a high fitness cost, resistant enterococci have disseminated worldwide. We have evaluated the biological cost of VanB-type resistance due to acquisition of conjugative transposon Tn1549 in Enterococcus faecium and Enterococcus faecalis. Because fitness was dependent on the integration site of Tn1549, an isogenic set of E. faecalis was constructed to determine the cost of inducible or constitutive expression of resistance or of carriage of Tn1549. A luciferase gene was inserted in the integrase gene of the transposon to allow differential quantification of the strains in cocultures and in the digestive tract of gnotobiotic mice. Both in vitro and in vivo, carriage of inactivated or inducible Tn1549 had no cost for the host in the absence of induction by vancomycin. In contrast, induced or constitutively resistant strains not only had reduced fitness but were severely impaired in colonization ability and dissemination among mice. These data indicate that tight regulation of resistance expression drastically reduces the biological cost associated with vancomycin resistance in Enterococcus spp. and accounts for the widespread dissemination of these strains. Our findings are in agreement with the observation that regulation of expression is common in horizontally acquired resistance and represents an efficient evolutionary pathway for resistance determinants to become selectively neutral.

  11. Injury-Induced Insulin Resistance in Adipose Tissue

    OpenAIRE

    Williams, Vanessa L.; Martin, Rachel E.; Franklin, John L.; Hardy, Robert. W.; Messina, Joseph L.

    2012-01-01

    Hyperglycemia and insulin resistance are common findings in critical illness. Patients in the surgical ICU are frequently treated for this ‘critical illness diabetes’ with intensive insulin therapy, resulting in a substantial reduction in morbidity and mortality. Adipose tissue is an important insulin target tissue, but it is not known whether adipose tissue is affected by critical illness diabetes. In the present study, a rodent model of critical illness diabetes was used to determine whethe...

  12. Development of herbicide resistant crops through induced mutations

    Directory of Open Access Journals (Sweden)

    Muhammad Rizwan

    2015-11-01

    Full Text Available Herbicide resistance is an innate characteristic of crop plants. It enables them to survive and propagate even in the presence of lethal doses of herbicides in the surroundings. Genetic tolerance in crops towards herbicides may have several benefits. It may increases safety margins between weed and crop sensitivity and also expands applicability of a particular herbicide. Besides, it can also lower the operating cost for weed control as compared to manual weeding and crop rotation which is normally prohibited by herbicide persistence. Herbicide resistant crops are developed through transformation of a plant with either native or mutant resistant genes, seed mutagenesis, plant cell or tissue culture and through other traditional plant breeding techniques. Seed mutagenesis is a non-transgenic approach, which is found to be most economical and perfect approach. Moreover, all commercial herbicide tolerant crops were derived from single nucleotide substitution of genes and trait can be incorporated into elite varieties because of incomplete dominance and non-pleiotropic effect of the alleles of all commercial herbicide tolerant mutations.

  13. New macrolides active against Streptococcus pyogenes with inducible or constitutive type of macrolide-lincosamide-streptogramin B resistance.

    Science.gov (United States)

    Fernandes, P B; Baker, W R; Freiberg, L A; Hardy, D J; McDonald, E J

    1989-01-01

    Macrolide-resistant bacteria can be classified as inducibly resistant or constitutively resistant. Inducibly resistant bacteria are resistant to 14-membered macrolides, such as erythromycin and clarithromycin (A-56268), but are susceptible to the 16-membered macrolides, such as tylosin and spiramycin, as well as to clindamycin. Constitutively resistant bacteria are resistant to macrolide-lincosamide-streptogramin B antibiotics. In this study, the MICs of several erythromycin and clarithromycin analogs against macrolide-susceptible and macrolide-resistant Streptococcus pyogenes strains were determined. Four 11,12-carbamate analogs of clarithromycin had lower MICs than erythromycin did against S. pyogenes with the inducible or constitutive type of macrolide-lincosamide-streptogramin B resistance. Five 11,12-carbonate analogs of erythromycin with modifications at the 4" position of cladinose had lower MICs than did erythromycin against S. pyogenes with the constitutive type of resistance, and one of these compounds, which had a naphthyl-glycyl substitution at the 4" position, had a lower MIC than erythromycin against both the inducibly resistant and constitutively resistant strains. Two analogs of erythromycin with a modification on the 4" position of cladinose had lower MICs than erythromycin did against the constitutively resistant organisms but not against the inducibly resistant organisms. Thus, 14-membered macrolides can be modified so as to confer a low MIC when tested in vitro.

  14. STX140, but not paclitaxel, inhibits mammary tumour initiation and progression in C3(1)/SV40 T/t-antigen transgenic mice.

    Science.gov (United States)

    Meyer-Losic, Florence; Newman, Simon P; Day, Joanna M; Reed, Michael J; Kasprzyk, Philip G; Purohit, Atul; Foster, Paul A

    2013-01-01

    Despite paclitxael's clinical success, treating hormone-refractory breast cancer remains challenging. Paclitaxel has a poor pharmacological profile, characterized by a low therapeutic index (TIX) caused by severe dose limiting toxicities, such as neutropenia and peripheral neuropathy. Consequently, new drugs are urgently required. STX140, a compound previously shown to have excellent efficacy against many tumors, is here compared to paclitaxel in three translational in vivo breast cancer models, a rat model of peripheral neuropathy, and through pharmacological testing. Three different in vivo mouse models of breast cancer were used; the metastatic 4T1 orthotopic model, the C3(1)/SV40 T-Ag model, and the MDA-MB-231 xenograft model. To determine TIX and pharmacological profile of STX140, a comprehensive dosing regime was performed in mice bearing MDA-MD-231 xenografts. Finally, peripheral neuropathy was examined using a rat plantar thermal hyperalgesia model. In the 4T1 metastatic model, STX140 and paclitaxel significantly inhibited primary tumor growth and lung metastases. All C3(1)/SV40 T-Ag mice in the control and paclitaxel treated groups developed palpable mammary cancer. STX140 blocked 47% of tumors developing and significantly inhibited growth of tumors that did develop. STX140 treatment caused a significant (Ptumor growth and did not increase survival time. Furthermore, paclitaxel, but not STX140, induced significant peripheral neuropathy and neutropenia. These results show that STX140 has a greater anti-cancer efficacy, TIX, and reduced neurotoxicity compared to paclitaxel in C3(1)/SV40 T-Ag mice and therefore may be of significant benefit to patients with breast cancer.

  15. Physiological Stress-Induced Drug Resistance and its Reversal

    Science.gov (United States)

    2004-07-01

    resistance but does shift the dose response curve . • Demonstrate that p53 status does not alter sensitization to drug by NFkB inhibitors such as PGA1...Figure 13). The presence of p53 (ON) shifts the dose response curve to the right but the response remains the same. PGA1 pretreatment, sensitizes...shift the dose response curve . • Demonstrate that p53 status does not alter sensitization to drug by NFkB inhibitors such as PGA1. • Demonstrated that

  16. Glioblastoma stem cells resistant to temozolomide-induced autophagy

    Institute of Scientific and Technical Information of China (English)

    FU Jun; LIU Zhi-gang; LIU Xiao-mei; CHEN Fu-rong; SHI Hong-liu; PANG Jesse Chung-sean; NG Ho-keung; CHEN Zhong-ping

    2009-01-01

    Background Recent studies have demonstrated the existence of a small fraction of cells with features of primitive neural progenitor cells and tumor-initiating function in brain tumors. These cells might represent primary therapeutic target for complete eradication of the tumors. This study aimed to determine the resistant phenotype of glioblastoma stem cells (GSCs) to temozolomide (TMZ) and to explore the possible molecular mechanisms underlying TMZ resistance.Methods Freshly resected glioblastoma specimen was collected and magnetic isolation of GSCs was carded out using the Miltenyi Biotec CD133 Celt isolation kit. The cytotoxic effect of TMZ on CD133+ and CD133- glioblastoma cells was determined by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Autophagy-related proteins (Beclin-1, LC3 and Atg5) and cleaved caspase-3 (p17) were analyzed by Westem blotting. Immunofluorescent staining was used to detect Atg5, glial fibrillary acidic protein (GFAP) and CD133 expression in glioblastoma cells. Statistical analysis was carried out using SPSS 10.0 software. For all tests, the level of statistical significance was set at P <0.05.Results CD133+ glioblastoma cells exhibited neurosphere-like growth in vitro and high expression of CD133 stem cell marker. The growth-inhibiting rate in CD133- glioblastoma cells treated with 5 or 50 pmol/L TMZ was significantly higher than that in CD133+ glioblastoma cells ((14.36±3.75)% vs (2.54±1.36)% or (25.95±5.25)% vs (2.72±1.84)%, respectively, P <0.05). Atg5, LC3-ll and Beclin-1 levels were significantly lower in CD133+ glioblastoma cells than those in autologous CD133- cells after TMZ treatment (P <0.05). Caspase-3 was mildly activated only in CD133- glioblastoma cells after exposure to TMZ (P <0.05). Immunofluorescent staining revealed elevated expression of Atg5 in GFAP* cells following TMZ treatment.Conclusions The GSCs display strong capability of tumor's resistance to TMZ. This resistance is

  17. Effects of PV Module Soiling on Glass Surface Resistance and Potential-Induced Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter; Button, Patrick; Hendrickson, Alex; Spataru, Sergiu; Glick, Stephen

    2015-06-14

    The goals of the project were: Determine applicability of transmission line method (TLM) to evaluate sheet resistance of soils on module glass;
    Evaluate various soils on glass for changes in surface resistance and their ability to promote potential-induced degradation with humidity (PID);
    Evaluate PID characteristics, rate, and leakage current increases on full-size mc-Si modules associated with a conductive soil on the surface.

  18. Personalized prediction of EGFR mutation-induced drug resistance in lung cancer

    OpenAIRE

    Wang, Debby D.; Weiqiang Zhou; Hong Yan; Maria Wong; Victor Lee

    2013-01-01

    EGFR mutation-induced drug resistance has significantly impaired the potency of small molecule tyrosine kinase inhibitors in lung cancer treatment. Computational approaches can provide powerful and efficient techniques in the investigation of drug resistance. In our work, the EGFR mutation feature is characterized by the energy components of binding free energy (concerning the mutant-inhibitor complex), and we combine it with specific personal features for 168 clinical subjects to construct a...

  19. 11beta-hydroxysteroid dehydrogenase type 1 regulates glucocorticoid-induced insulin resistance in skeletal muscle.

    LENUS (Irish Health Repository)

    Morgan, Stuart A

    2009-11-01

    Glucocorticoid excess is characterized by increased adiposity, skeletal myopathy, and insulin resistance, but the precise molecular mechanisms are unknown. Within skeletal muscle, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts cortisone (11-dehydrocorticosterone in rodents) to active cortisol (corticosterone in rodents). We aimed to determine the mechanisms underpinning glucocorticoid-induced insulin resistance in skeletal muscle and indentify how 11beta-HSD1 inhibitors improve insulin sensitivity.

  20. SOCS-1 deficiency does not prevent diet-induced insulin resistance

    DEFF Research Database (Denmark)

    Emanuelli, Brice; Macotela, Yazmin; Boucher, Jérémie

    2008-01-01

    Obesity is associated with inflammation and increased expression of suppressor of cytokine signaling (SOCS) proteins, which inhibit cytokine and insulin signaling. Thus, reducing SOCS expression could prevent the development of obesity-induced insulin resistance. Using SOCS-1 knockout mice, we...... investigated the contribution of SOCS-1 in the development of insulin resistance induced by a high-fat diet (HFD). SOCS-1 knockout mice on HFD gained 70% more weight, displayed a 2.3-fold increase in epididymal fat pads mass and increased hepatic lipid content. This was accompanied by increased mRNA expression...... of leptin and the macrophage marker CD68 in white adipose tissue and of SREBP1c and FAS in liver. HFD also induced hyperglycemia in SOCS-1 deficient mice with impairment of glucose and insulin tolerance tests. Thus, despite the role of SOCS proteins in obesity-related insulin resistance, SOCS-1 deficiency...

  1. Mycorrhiza-induced resistance: more than the sum of its parts?

    Science.gov (United States)

    Cameron, Duncan D.; Neal, Andrew L.; van Wees, Saskia C.M.; Ton, Jurriaan

    2014-01-01

    Plants can develop an enhanced defensive capacity in response to infection by arbuscular mycorrhizal fungi (AMF). This ‘mycorrhiza-induced resistance’ (MIR) provides systemic protection against a wide range of attackers and shares characteristics with systemic acquired resistance (SAR) after pathogen infection and induced systemic resistance (ISR) following root colonisation by non-pathogenic rhizobacteria. It is commonly assumed that fungal stimulation of the plant immune system is solely responsible for MIR. In this opinion article, we present a novel model of MIR that integrates different aspects of the induced resistance phenomenon. We propose that MIR is a cumulative effect of direct plant responses to mycorrhizal infection and indirect immune responses to ISR-eliciting rhizobacteria in the mycorrhizosphere. PMID:23871659

  2. NK cells link obesity-induced adipose stress to inflammation and insulin resistance.

    Science.gov (United States)

    Wensveen, Felix M; Jelenčić, Vedrana; Valentić, Sonja; Šestan, Marko; Wensveen, Tamara Turk; Theurich, Sebastian; Glasner, Ariella; Mendrila, Davor; Štimac, Davor; Wunderlich, F Thomas; Brüning, Jens C; Mandelboim, Ofer; Polić, Bojan

    2015-04-01

    An important cause of obesity-induced insulin resistance is chronic systemic inflammation originating in visceral adipose tissue (VAT). VAT inflammation is associated with the accumulation of proinflammatory macrophages in adipose tissue, but the immunological signals that trigger their accumulation remain unknown. We found that a phenotypically distinct population of tissue-resident natural killer (NK) cells represented a crucial link between obesity-induced adipose stress and VAT inflammation. Obesity drove the upregulation of ligands of the NK cell-activating receptor NCR1 on adipocytes; this stimulated NK cell proliferation and interferon-γ (IFN-γ) production, which in turn triggered the differentiation of proinflammatory macrophages and promoted insulin resistance. Deficiency of NK cells, NCR1 or IFN-γ prevented the accumulation of proinflammatory macrophages in VAT and greatly ameliorated insulin sensitivity. Thus NK cells are key regulators of macrophage polarization and insulin resistance in response to obesity-induced adipocyte stress.

  3. Herbivore-induced resistance against microbial pathogens in Arabidopsis

    NARCIS (Netherlands)

    Vos, de M.; Zaanen, van W.; Koornneef, A.; Korzelius, J.P.; Dicke, M.; Loon, van L.C.; Pieterse, C.M.J.

    2006-01-01

    Caterpillars of the herbivore Pieris rapae stimulate the production of jasmonic acid (JA) and ethylene (ET) in Arabidopsis (Arabidopsis thaliana) and trigger a defense response that affects insect performance on systemic tissues. To investigate the spectrum of effectiveness of P. rapae-induced resis

  4. Electrode-induced digital-to-analog resistive switching in TaO x -based RRAM devices.

    Science.gov (United States)

    Li, Xinyi; Wu, Huaqiang; Bin Gao; Wu, Wei; Wu, Dong; Deng, Ning; Cai, Jian; Qian, He

    2016-07-29

    In RRAM devices, electrodes play a significant role during the switching process. In this paper, different top electrodes are used for TaO y /Ta2O5-x /AlO σ triple-oxide-layer devices. Top electrode-induced digital resistive switching to analog resistive switching was observed. For Pt top electrode (TE) devices, abrupt digital resistive switching behavior was observed, while Al TE devices showed gradual analog resistive switching behavior. Devices with various AlO σ thicknesses and sizes were fabricated and characterized to evaluate the reliability of the analog resistive switching. The physical mechanisms responsible for this electrode-induced resistive switching behavior were discussed.

  5. p38丝裂原活化蛋白激酶通路对紫杉醇诱发细胞凋亡中γ-氨基丁酸B型受体表达变化的影响%Effects of p38 mitogen-activated protein kinase pathway on changes of γ-aminobutyric acid B receptors expression in paclitaxel-induced apoptosis

    Institute of Scientific and Technical Information of China (English)

    金子; 王秀丽; 吴川; 赵爽; 李昭; 柴潇潇

    2015-01-01

    Objective To investigate the effects of p38 mitogen-activated protein kinase (p38MAPK) pathway on changes of γ-aminobutyric acid B receptors (GABAs receptors) expression in paclitaxel-induced apoptosis by giving p38MAPK inhibitor (SB203580) and the and molecular mechanism.Methods The primarily cultured hippocampal neurons which had been cultivated for 5 days in vitro were randomly selected,and the density was about 1 × 109/L.These neurons were separately given different concentrations of paclitaxel (0,0.01,0.10,1.00,10.00 μmol/L).The changes of hippocampal neuronral inhibitory rate (n =3) and apoptosis rate (n =4) were detected by methyl thiazol tetrazolium (MTT) method and flow cytometry.As a result,the optimal concentration of paclitaxel to induce apoptosis was determined.Hippocampal neurons were cultured for other 5 days,selected,and randomly divided into four groups:control group (group C),10 μmol/L SB203580 group (K group),the optimal concentration of paclitaxel group (N),10 μmol/L SB203580 + the optimal concentration of paclitaxel group (K + N group).All of the hippocampal neurons were cultured for 24 h,and the medicine volume in each group was consistent.The GABAB receptors and nuclear factor-κB (NF-κB) expression in the hippocampal neurons was detected by Western blotting (n =3).Results Effect of paclitaxel on the viability of hippocampal neurons had duration and concentration interaction (F =6.127,P < 0.05).According to the results of MTT method (n =3) and flow cytometry (n =4),the apoptosis rate had a significant difference among each group (F =64.523,P < 0.05),and then calculated the optimal concentration of paclitaxel-induced apoptosis was 1 μmol/L[The early apoptosis rate was (48.63 ± 5.76)%].As compared with group C (n =3),the expression of GABAB receptors and NF-κB protein was significantly up-regulated in both N group and K + N group (P <0.05),and that of GABAB receptors and NF-κB protein was down-regulated in K group (P < 0

  6. Induced electromagnetic stirring behavior in a resistance spot weld nugget

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A multi-physics hybrid numerical model,which couples electric,magnetic,thermal and flow fields,was used to investigate electromagnetic stirring behavior in a resistance spot weld nugget.The differences of two kinds of different excitation inputs,i.e.,a sinusoidal current and its root-mean-square(RMS) value,were studied to examine if they could produce equivalent electromagnetic stirring effects in the weld nugget.Research showed that the two types of current inputs could produce almost identical fluid flow and heat transfer patterns and consistent evolution of flow and thermal fields in the nugget.At the end of the welding cycles,the maximum flow velocity and temperature between the two inputs differed by 11.6% and 0.3%,respectively.Therefore,the RMS current can be assumed to produce an approximately equivalent electromagnetic stirring effect with the sinusoidal current,and can be used in the future research to greatly improve the solution efficiency of the electromagnetic stirring behavior in the resistance spot weld nugget.

  7. A human model of dietary saturated fatty acid induced insulin resistance.

    Science.gov (United States)

    Koska, Juraj; Ozias, Marlies K; Deer, James; Kurtz, Julie; Salbe, Arline D; Harman, S Mitchell; Reaven, Peter D

    2016-11-01

    Increased consumption of high-fat diets is associated with the development of insulin resistance and type 2 diabetes. Current models to study the mechanisms of high-fat diet-induced IR in humans are limited by their long duration or low efficacy. In the present study we developed and characterized an acute dietary model of saturated fatty acid-enriched diet induced insulin resistance. High caloric diets enriched with saturated fatty acids (SFA) or carbohydrates (CARB) were evaluated in subjects with normal and impaired glucose tolerance (NGT or IGT). Both diets were compared to a standard eucaloric American Heart Association (AHA) control diet in a series of crossover studies. Whole body insulin resistance was estimated as steady state plasma glucose (SSPG) concentrations during the last 30min of a 3-h insulin suppression test. SSPG was increased after a 24-h SFA diet (by 83±74% vs. control, n=38) in the entire cohort, which was comprised of participants with NGT (92±82%, n=22) or IGT (65±55%, n=16) (all pinsulin resistance in both NGT and IGT subjects. Insulin resistance persisted overnight after the last SFA meal and was attenuated by one day of a healthy diet. This model offers opportunities for identifying early mechanisms and potential treatments of dietary saturated fat induced insulin resistance. Published by Elsevier Inc.

  8. A review on the molecular mechanisms involved in insulin resistance induced by organophosphorus pesticides.

    Science.gov (United States)

    Lasram, Mohamed Montassar; Dhouib, Ines Bini; Annabi, Alya; El Fazaa, Saloua; Gharbi, Najoua

    2014-08-01

    There is increasing evidence reporting that organophosphorus pesticides (OPs) impair glucose homeostasis and cause insulin resistance and type 2 diabetes. Insulin resistance is a complex metabolic disorder that defies explanation by a single etiological pathway. Formation of advanced glycation end products, accumulation of lipid metabolites, activation of inflammatory pathways and oxidative stress have all been implicated in the pathogenesis of insulin resistance. Ultimately, these molecular processes activate a series of stress pathways involving a family of serine kinases, which in turn have a negative effect on insulin signaling. Experimental and clinical data suggest an association between these molecular mechanisms and OPs compounds. It was first reported that OPs induce hyperglycemia. Then a concomitant increase of blood glucose and insulin was pointed out. For some years only, we have begun to understand that OPs promote insulin resistance and increase the risk of type 2 diabetes. Overall, this review outlines various mechanisms that lead to the development of insulin resistance by OPs exposure.

  9. [Resistance acquisition via the bacterial SOS response: the inducive role of antibiotics].

    Science.gov (United States)

    Da Re, Sandra; Ploy, Marie-Cécile

    2012-02-01

    After the euphoria of the antibiotic discovery and their tremendous action on bacterial infections outcomes, arrives a period of fear with the continuous emergence of bacteria that are resistant to almost all antibiotic treatments. It is becoming essential to better understand antibiotic resistance mechanisms to find new approaches to prevent the worldwide problem of multiresistance. The role of antibiotics on the direct induction of resistance acquisition is known. Recent studies have shown that some antibiotics, by inducing the bacterial SOS response, global repair response after DNA damages, are involved on a broader level in the induction, acquisition and dissemination of resistances in bacteria. We discuss here the role of antibiotics in resistance acquisition via the SOS response through several examples and the interest of identifying the SOS response regulators as the future targets of new families of antimicrobial molecules.

  10. Physiological and biochemical characteristics of laboratory induced mutants of Botrytis cinerea with resistance to fluazinam.

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    Shao, Wenyong; Zhang, Yu; Ren, Weichao; Chen, Changjun

    2015-01-01

    Botrytis cinerea is a necrotrophic and filamentous fungus with a high risk of developing resistance to fungicides. The pyridinamine fungicide fluazinam has been reported to have excellent activity against B. cinerea and better effect on controlling gray mold. In this study, the physiological and biochemical characteristics of laboratory-induced mutants of B. cinerea with resistance to fluazinam has been investigated. Compared to the wild-type strains, the fluazinam-resistant mutants had a significant decrease in respiratory rate, glycerol, oxalate, and ATP contents, and an increase in ATPase activity and sensitivity to osmotic pressure, but did not differ in cell membrane permeability. Sequencing indicated that two parental strains and four resistant mutants were identical in the nucleotide sequence of F-ATPase gene. These results will enrich our understanding of the resistance mechanism of B. cinerea to fluazinam.

  11. Nab-paclitaxel for the treatment of breast cancer: efficacy, safety, and approval

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    Iwase H

    2011-07-01

    Full Text Available Yutaka Yamamoto1, Ichiro Kawano2, Hirotaka Iwase11Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan; 2Department of Surgery, Asahino General Hospital, Kumamoto, JapanAbstract: Nanoparticle albumin-bound paclitaxel (nab-paclitaxel is a novel formulation of paclitaxel that does not require solvents such as polyoxyethylated castor oil and ethanol. Use of these solvents has been associated with toxic response, including hypersensitivity reactions and prolonged sensory neuropathy, as well as a negative impact in relation to the therapeutic index of paclitaxel. nab-paclitaxel displays greater antitumor activity and less toxicity than solvent-base paclitaxel. In a phase I trial of single nab-paclitaxel, the maximum tolerated dose was 300 mg/m2 with the dose limiting toxicities being sensory neuropathy, stomatitis, and superficial keratopathy. In the metastatic setting, a pivotal comparative randomized phase III study demonstrated that nab-paclitaxel (at 260 mg/m2 over 30 minutes infusion without premedication every 3 weeks mediated a superior objective response rate and prolonged time to progression compared with solvent-based paclitaxel (at 175 mg/m2 over a 3-hour injection with standard premedication. The nab-paclitaxel-treated group showed a higher incidence of sensory neuropathy than the solvent-based paclitaxel group. However, these adverse side effects rapidly resolved after interruption of treatment and dose reduction. Weekly administration of nab-paclitaxel was also more active and displayed less toxicity compared with 100 mg/m2 docetaxel given triweekly. Nab-paclitaxel has already been approved in 42 countries for the treatment of metastatic breast cancer previously treated with anthracycline, based on confirmation of the efficacy and manageable toxicity in the metastatic setting. This review summarizes the most relevant knowledge on nab-paclitaxel for treating breast cancer

  12. Inhibition of P-Glycoprotein Mediated Efflux of Paclitaxel by Coumarin Derivatives in Cancer Stem Cells: An In Silico Approach.

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    Tripathi, Anushree; Misra, Krishna

    2016-01-01

    P-glycoprotein (P-gp) is well known to cause multidrug resistance (MDR) in cancer cells. This MDR leads to cancer recurrence which is a major obstacle in cancer treatment. High P-gp expression has been observed in the population of cancer stem cells (CSCs) having self-renewal potential. Early detection and inhibition of these CSCs is directly beneficial to cancer treatment. In this study coumarin derivatives are used to inhibit efflux process and thereby enhance bioavailability of various drugs like paclitaxel (PTX). This drug is most commonly used for the treatment of cancers of breast, ovary, head and neck. Coumarin derivatives can be used to reduce the growth of breast cancer stem cells through P-gp mediated efflux inhibition and paclitaxel bioavailability enhancement. With the use of computational approaches including molecular docking simulation and pharmacophore study, few coumarin derivatives have been found to be more potential inhibitors of P-gp mediated efflux. Based on high affinity inhibitors, new coumarin derivatives have been designed and docked at active site cavity of P-gps. Some newly designed coumarin derivatives were found to be more potent due to their higher binding affinity towards target protein. The finding that newly designed coumarins can be exploited for inhibition of P-gp mediated efflux in order to enhance paclitaxel bioavailability and can inhibit breast cancer stem cell growth is significant for designing potent anticancer drugs.

  13. Exercise protects against diet-induced insulin resistance through downregulation of protein kinase Cβ in mice.

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    Xiaoquan Rao

    Full Text Available Physical exercise is an important and effective therapy for diabetes. However, its underlying mechanism is not fully understood. Protein kinase Cβ (PKCβ has been suggested to be involved in the pathogenesis of obesity and insulin resistance, but the role of PKCβ in exercise-induced improvements in insulin resistance is completely unknown. In this study, we evaluated the involvement of PKCβ in exercise-attenuated insulin resistance in high-fat diet (HFD-fed mice. PKCβ(-/- and wild-type mice were fed a HFD with or without exercise training. PKC protein expression, body and tissue weight change, glucose and insulin tolerance, metabolic rate, mitochondria size and number, adipose inflammation, and AKT activation were determined to evaluate insulin sensitivity and metabolic changes after intervention. PKCβ expression decreased in both skeletal muscle and liver tissue after exercise. Exercise and PKCβ deficiency can alleviate HFD-induced insulin resistance, as evidenced by improved insulin tolerance. In addition, fat accumulation and mitochondrial dysfunction induced by HFD were also ameliorated by both exercise and PKCβ deficiency. On the other hand, exercise had little effect on PKCβ(-/- mice. Further, our data indicated improved activation of AKT, the downstream signal molecule of insulin, in skeletal muscle and liver of exercised mice, whereas PKCβ deficiency blunted the difference between sedentary and exercised mice. These results suggest that downregulation of PKCβ contributes to exercise-induced improvement of insulin resistance in HFD-fed mice.

  14. IL-33 facilitates endocrine resistance of breast cancer by inducing cancer stem cell properties.

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    Hu, Haiyan; Sun, Jiaxing; Wang, Chunhong; Bu, Xiangmao; Liu, Xiangping; Mao, Yan; Wang, Haibo

    2017-02-16

    Breast cancers with estrogen receptor (ER) expressions account for the majority of all clinical cases. Due to hormone therapy with tamoxifen, prognoses of patients with ER-positive breast cancer are significantly improved. However, endocrine resistance to tamoxifen is common and inevitable, leading to compromised efficacy of hormone therapy. Herein, we identify a crucial role of IL-33 in inducing endocrine resistance of breast cancer. IL-33 overexpression in breast cancer cells results in resistance to tamoxifen-induced tumor growth inhibition, while IL-33 knockdown corrects this problem. Mechanistically, IL-33 induces breast cancer stem cell properties evidenced by mammosphere formation and xenograft tumorigenesis, as well as expression of cancer stem cell genes including ALDH1A3, OCT4, NANOG and SOX2. In breast cancer patients, higher serum IL-33 levels portend advanced clinical stages, poorly differentiated cancer cells and tumor recurrence. IL-33 expression levels in patients' freshly isolated breast cancer cells predicts tamoxifen resistance and cancer stem cell features in individual patient. Collectively, IL-33 induces endocrine resistance of breast cancer by promoting cancer stem cell properties. These findings provide novel mechanisms connecting IL-33 with cancer pathogenesis and pinpoint IL-33 as a promising target for optimizing hormone therapy in clinical practice.

  15. Evaluation of plant resistance inducers on different winter soft wheat cultivars against Septoria leaf blotch.

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    Ors, M; Siah, A; Randoux, B; Selim, S; Boizet, F; Couleaud, G; Maumene, C; Halama, P; Reignault, Ph

    2012-01-01

    Septoria tritici blotch (STB) caused by Mycosphaerella graminicola (anamorph: Zymoseptoria tritici) is one of the most devastating foliar diseases on bread wheat (Triticum aestivum L.). Because of the emergence of fungal strains highly resistant to mainly used fungicides and the deleterious impacts of these fungicides on the environment, development of alternative control strategies to protect wheat crops against STB is needed. The induction of plant resistance by elicitors is likely to be a helpful alternative. Our study aims at characterizing the efficiency of potential resistance inducers towards STB in three bread wheat cultivars differing in their resistance levels to the pathogen: Alixan (susceptible), Premio (moderately resistant) and Altigo (resistant). These cultivars were inoculated under controlled and semi-controlled conditions with the pathogenic M. graminicolo strain T01193 in order to assess the protective effect of three potential resistance inducers against the disease. Moreover, the direct antifungal effect bf these products was evaluated in vitro at different concentrations in order to verify their potential biocide activity. Furthermore, cytological analyses were performed in order to determine the effects of these products on the fungal infection process and to compare these effects among the three wheat cultivars. Finally, reactive oxygen species metabolism was investigated in the three cultivars during their interaction with T01193 by measuring peroxidase activity.

  16. Mesenchymal Stem Cell-Induced Doxorubicin Resistance in Triple Negative Breast Cancer

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    Dar-Ren Chen

    2014-01-01

    Full Text Available Triple negative breast cancer (TNBC is an aggressive histological subtype with limited treatment options and a worse clinical outcome compared with other breast cancer subtypes. Doxorubicin is considered to be one of the most effective agents in the treatment of TNBC. Unfortunately, resistance to this agent is common. In some drug-resistant cells, drug efflux is mediated by adenosine triphosphate-dependent membrane transporter termed adenosine triphosphate-binding cassette (ABC transporter, which can drive the substrates across membranes against concentration gradient. In the tumor microenvironment, upon interaction with mesenchymal stem cells (MSCs, tumor cells exhibit altered biological functions of certain gene clusters, hence increasing stemness of tumor cells, migration ability, angiogenesis, and drug resistance. In our present study, we investigated the mechanism of TNBC drug resistance induced by adipose-derived MSCs. Upon exposure of TNBC to MSC-secreted conditioned medium (CM, noticeable drug resistance against doxorubicin with markedly increased BCRP protein expression was observed. Intracellular doxorubicin accumulation of TNBC was also decreased by MSC-secreted CM. Furthermore, we found that doxorubicin resistance of TNBC was mediated by IL-8 presented in the MSC-secreted CM. These findings may enrich the list of potential targets for overcoming drug resistance induced by MSCs in TNBC patients.

  17. Mesenchymal stem cell-induced doxorubicin resistance in triple negative breast cancer.

    Science.gov (United States)

    Chen, Dar-Ren; Lu, Dah-Yuu; Lin, Hui-Yi; Yeh, Wei-Lan

    2014-01-01

    Triple negative breast cancer (TNBC) is an aggressive histological subtype with limited treatment options and a worse clinical outcome compared with other breast cancer subtypes. Doxorubicin is considered to be one of the most effective agents in the treatment of TNBC. Unfortunately, resistance to this agent is common. In some drug-resistant cells, drug efflux is mediated by adenosine triphosphate-dependent membrane transporter termed adenosine triphosphate-binding cassette (ABC) transporter, which can drive the substrates across membranes against concentration gradient. In the tumor microenvironment, upon interaction with mesenchymal stem cells (MSCs), tumor cells exhibit altered biological functions of certain gene clusters, hence increasing stemness of tumor cells, migration ability, angiogenesis, and drug resistance. In our present study, we investigated the mechanism of TNBC drug resistance induced by adipose-derived MSCs. Upon exposure of TNBC to MSC-secreted conditioned medium (CM), noticeable drug resistance against doxorubicin with markedly increased BCRP protein expression was observed. Intracellular doxorubicin accumulation of TNBC was also decreased by MSC-secreted CM. Furthermore, we found that doxorubicin resistance of TNBC was mediated by IL-8 presented in the MSC-secreted CM. These findings may enrich the list of potential targets for overcoming drug resistance induced by MSCs in TNBC patients.

  18. Peroxisome proliferator-activated receptor-gamma agonists suppress tissue factor overexpression in rat balloon injury model with paclitaxel infusion.

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    Jun-Bean Park

    Full Text Available The role and underlying mechanisms of rosiglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-γ agonist, on myocardial infarction are poorly understood. We investigated the effects of this PPAR-γ agonist on the expression of tissue factor (TF, a primary molecule for thrombosis, and elucidated its underlying mechanisms. The PPAR-γ agonist inhibited TF expression in response to TNF-α in human umbilical vein endothelial cells, human monocytic leukemia cell line, and human umbilical arterial smooth muscle cells. The overexpression of TF was mediated by increased phosphorylation of mitogen-activated protein kinase (MAPK, which was blocked by the PPAR-γ agonist. The effective MAPK differed depending on each cell type. Luciferase and ChIP assays showed that transcription factor, activator protein-1 (AP-1, was a pivotal target of the PPAR-γ agonist to lower TF transcription. Intriguingly, two main drugs for drug-eluting stent, paclitaxel or rapamycin, significantly exaggerated thrombin-induced TF expression, which was also effectively blocked by the PPAR-γ agonist in all cell types. This PPAR-γ agonist did not impair TF pathway inhibitor (TFPI in three cell types. In rat balloon injury model (Sprague-Dawley rats, n = 10/group with continuous paclitaxel infusion, the PPAR-γ agonist attenuated TF expression by 70±5% (n = 4; P<0.0001 in injured vasculature. Taken together, rosiglitazone reduced TF expression in three critical cell types involved in vascular thrombus formation via MAPK and AP-1 inhibitions. Also, this PPAR-γ agonist reversed the paclitaxel-induced aggravation of TF expression, which suggests a possibility that the benefits might outweigh its risks in a group of patients with paclitaxel-eluting stent implanted.

  19. Class III β-tubulin overexpression within the tumor microenvironment is a prognostic biomarker for poor overall survival in ovarian cancer patients treated with neoadjuvant carboplatin/paclitaxel.

    Science.gov (United States)

    Roque, Dana M; Buza, Natalia; Glasgow, Michelle; Bellone, Stefania; Bortolomai, Ileana; Gasparrini, Sara; Cocco, Emiliano; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Rutherford, Thomas J; Schwartz, Peter E; Santin, Alessandro D

    2014-01-01

    Critics have suggested that neoadjuvant chemotherapy (NACT) followed by interval debulking may select for resistant clones or cancer stem cells when compared to primary cytoreduction. β-tubulins are chemotherapeutic targets of taxanes and epothilones. Class III β-tubulin overexpression has been linked to chemoresistance and hypoxia. Herein, we describe changes in class III β-tubulin in patients with advanced ovarian carcinoma in response to NACT, in relationship to clinical outcome, and between patients who underwent NACT versus primary debulking; we characterize in vitro chemosensitivity to paclitaxel/patupilone of cell lines established from this patient population, and class III β-tubulin expression following repeated exposure to paclitaxel. Using immunohistochemistry, we observed among 22 paired specimens obtained before/after NACT decreased expression of class III β-tubulin following therapy within stroma (p=0.07), but not tumor (p=0.63). Poor median overall survival was predicted by high levels of class III β-tubulin in both tumor (HR 3.66 [1.11,12.05], p=0.03) and stroma (HR 4.53 [1.28,16.1], p=0.02). Class III β-tubulin expression by quantitative-real-time-polymerase-chain-reaction was higher among patients who received NACT (n=12) compared to primary cytoreduction (n=14) (mean±SD fold-change: 491.2±115.9 vs. 224.1±55.66, p=0.037). In vitro subculture with paclitaxel resulted in class III β-tubulin upregulation, however, cell lines that overexpressed class III β-tubulin remained sensitive to patupilone. Overexpression of class III β-tubulin in patients dispositioned to NACT may thus identify an intrinsically aggressive phenotype, and predict poor overall survival and paclitaxel resistance. Decreases in stromal expression may represent normalization of the tumor microenvironment following therapy. Epothilones warrant study for patients who have received neoadjuvant carboplatin and paclitaxel.

  20. Predictive and prognostic impact of TP53 mutations and MDM2 promoter genotype in primary breast cancer patients treated with epirubicin or paclitaxel.

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    Ranjan Chrisanthar

    Full Text Available BACKGROUND: TP53 mutations have been associated with resistance to anthracyclines but not to taxanes in breast cancer patients. The MDM2 promoter single nucleotide polymorphism (SNP T309G increases MDM2 activity and may reduce wild-type p53 protein activity. Here, we explored the predictive and prognostic value of TP53 and CHEK2 mutation status together with MDM2 SNP309 genotype in stage III breast cancer patients receiving paclitaxel or epirubicin monotherapy. EXPERIMENTAL DESIGN: Each patient was randomly assigned to treatment with epirubicin 90 mg/m(2 (n = 109 or paclitaxel 200 mg/m(2 (n = 114 every 3rd week as monotherapy for 4-6 cycles. Patients obtaining a suboptimal response on first-line treatment requiring further chemotherapy received the opposite regimen. Time from last patient inclusion to follow-up censoring was 69 months. Each patient had snap-frozen tumor tissue specimens collected prior to commencing chemotherapy. PRINCIPAL FINDINGS: While TP53 and CHEK2 mutations predicted resistance to epirubicin, MDM2 status did not. Neither TP53/CHEK2 mutations nor MDM2 status was associated with paclitaxel response. Remarkably, TP53 mutations (p = 0.007 but also MDM2 309TG/GG genotype status (p = 0.012 were associated with a poor disease-specific survival among patients having paclitaxel but not patients having epirubicin first-line. The effect of MDM2 status was observed among individuals harbouring wild-type TP53 (p = 0.039 but not among individuals with TP53 mutated tumors (p>0.5. CONCLUSION: TP53 and CHEK2 mutations were associated with lack of response to epirubicin monotherapy. In contrast, TP53 mutations and MDM2 309G allele status conferred poor disease-specific survival among patients treated with primary paclitaxel but not epirubicin monotherapy.

  1. Chemotherapy-related amenorrhea after adjuvant paclitaxel-trastuzumab (APT trial).

    Science.gov (United States)

    Ruddy, Kathryn J; Guo, Hao; Barry, William; Dang, Chau T; Yardley, Denise A; Moy, Beverly; Marcom, P Kelly; Albain, Kathy S; Rugo, Hope S; Ellis, Matthew J; Shapira, Iuliana; Wolff, Antonio C; Carey, Lisa A; Overmoyer, Beth A; Hudis, Clifford; Krop, Ian E; Burstein, Harold J; Winer, Eric P; Partridge, Ann H; Tolaney, Sara M

    2015-06-01

    Chemotherapy-related amenorrhea (CRA) is associated with infertility and menopausal symptoms. Learning how frequently paclitaxel and trastuzumab cause amenorrhea is important. Most other adjuvant breast cancer therapies induce CRA in approximately 50 % of all premenopausal recipients [1]. 410 patients enrolled on the APT Trial, a single-arm phase 2 adjuvant study of 12 weeks of paclitaxel and trastuzumab followed by nine months of trastuzumab monotherapy. Eligible patients had ≤3 cm node-negative HER2 + breast cancers. Premenopausal enrollees were asked to complete menstrual surveys every 3-12 months for 72 months. Women who responded to at least one survey at least 15 months after chemotherapy initiation (and who did not undergo hysterectomy and/or bilateral oophorectomy or receive ovarian suppressing medications prior to 15 months) were included in this analysis. A participant was defined as having amenorrhea in follow-up if her self-reported last menstrual period at last follow-up was greater than 12 months prior to the survey. Among the 64 women in the evaluable population (median age at study entry 44 years, range 27-52 years), the median time between chemotherapy initiation and last menstrual survey was 51 months (range 16-79). 18 of 64 women (28 %, 95 % CI 18-41 %) were amenorrheic at that time point. Amenorrhea rates among premenopausal women treated with adjuvant paclitaxel and trastuzumab for early stage breast cancer appear lower than those seen historically with standard alkylator-based breast cancer regimens. Future studies are needed to understand the impact of this regimen on related issues of fertility and menopausal symptoms.

  2. Effect of multidrug resistance 1/P-glycoprotein on the hypoxia-induced multidrug resistance of human laryngeal cancer cells.

    Science.gov (United States)

    Li, Dawei; Zhou, Liang; Huang, Jiameng; Xiao, Xiyan

    2016-08-01

    In a previous study, it was demonstrated that hypoxia upregulated the multidrug resistance (MDR) of laryngeal cancer cells to chemotherapeutic drugs, with multidrug resistance 1 (MDR1)/P-glycoprotein (P-gp) expression also being upregulated. The present study aimed to investigate the role and mechanism of MDR1/P-gp on hypoxia-induced MDR in human laryngeal carcinoma cells. The sensitivity of laryngeal cancer cells to multiple drugs and cisplatin-induced apoptosis was determined by CCK-8 assay and Annexin-V/propidium iodide staining analysis, respectively. The accumulation of rhodamine 123 (Rh123) in the cells served as an estimate of drug accumulation and was evaluated by flow cytometry (FCM). MDR1/P-gp expression was inhibited using interference RNA, and the expression of the MDR1 gene was analyzed using reverse transcription-quantitative polymerase chain reaction and western blotting. As a result, the sensitivity to multiple chemotherapeutic agents and the apoptosis rate of the hypoxic laryngeal carcinoma cells increased following a decrease in MDR1/P-gp expression (PP-gp markedly increased intracellular Rh123 accumulation (PP-gp serves an important role in regulating hypoxia-induced MDR in human laryngeal carcinoma cells through a decrease in intracellular drug accumulation.

  3. Systemic resistance to gray mold induced in tomato by benzothiadiazole and Trichoderma harzianum T39.

    Science.gov (United States)

    Harel, Yael Meller; Mehari, Zeraye Haile; Rav-David, Dalia; Elad, Yigal

    2014-02-01

    Gray mold (Botrytis cinerea) is an important disease of tomato (Solanum lycopersicum). This study examined defense-related gene expression involved in the resistance to B. cinerea that is induced in tomato plants by benzothiadiazole and Trichoderma harzianum T39 soil drench. In whole plants, transcriptional changes related to salicylic acid and ethylene were induced by the application of a 0.01% benzothiadiazole solution, whereas changes related to jasmonic acid were induced by the application of a 0.4% T39 suspension. On detached leaves, soil treatment by T39 led to enhanced resistance to B. cinerea infection that was proportional to the concentration of the T39 suspension. By 5 days after pathogen inoculation, the plants that had received the 0.04% T39 drench exhibited 62% less severe disease than the untreated plants. The 0.4% T39 drench led to an 84% reduction in disease severity. Observations of B. cinerea infection in leaves harvested from plants grown in the treated soils revealed that drenching with a T39 suspension induces systemic resistance against B. cinerea and primes salicylic acid- and ethylene-related gene expression in a manner proportional to the concentration of the biocontrol agent. Benzothiadiazole treatment induced resistance to gray mold independently of salicylic acid and led to strong priming of two genes known to be involved in defense against B. cinerea, Pti5 and PI2.

  4. Evolutionary change from induced to constitutive expression of an indirect plant resistance.

    Science.gov (United States)

    Heil, Martin; Greiner, Sabine; Meimberg, Harald; Krüger, Ralf; Noyer, Jean-Louis; Heubl, Günther; Linsenmair, K Eduard; Boland, Wilhelm

    2004-07-08

    Induced plant resistance traits are expressed in response to attack and occur throughout the plant kingdom. Despite their general occurrence, the evolution of such resistances has rarely been investigated. Here we report that extrafloral nectar, a usually inducible trait, is constitutively secreted by Central American Acacia species that are obligately inhabited by ants. Extrafloral nectar is secreted as an indirect resistance, attracting ants that defend plants against herbivores. Leaf damage induces extrafloral nectar secretion in several plant species; among these are various Acacia species and other Fabaceae investigated here. In contrast, Acacia species obligately inhabited by symbiotic ants nourish these ants by secreting extrafloral nectar constitutively at high rates that are not affected by leaf damage. The phylogeny of the genus Acacia and closely related genera indicate that the inducibility of extrafloral nectar is the plesiomorphic or 'original' state, whereas the constitutive extrafloral nectar flow is derived within Acacia. A constitutive resistance trait has evolved from an inducible one, obviously in response to particular functional demands.

  5. PD-1 blockade induces responses by inhibiting adaptive immune resistance

    Science.gov (United States)

    Tumeh, Paul C.; Harview, Christina L.; Yearley, Jennifer H.; Shintaku, I. Peter; Taylor, Emma J. M.; Robert, Lidia; Chmielowski, Bartosz; Spasic, Marko; Henry, Gina; Ciobanu, Voicu; West, Alisha N.; Carmona, Manuel; Kivork, Christine; Seja, Elizabeth; Cherry, Grace; Gutierrez, Antonio; Grogan, Tristan R.; Mateus, Christine; Tomasic, Gorana; Glaspy, John A.; Emerson, Ryan O.; Robins, Harlan; Pierce, Robert H.; Elashoff, David A.; Robert, Caroline; Ribas, Antoni

    2014-01-01

    Therapies that target the programmed death-1 (PD-1) receptor have shown unprecedented rates of durable clinical responses in patients with various cancer types.1–5 One mechanism by which cancer tissues limit the host immune response is via upregulation of PD-1 ligand (PD-L1) and its ligation to PD-1 on antigen-specific CD8 T-cells (termed adaptive immune resistance).6,7 Here we show that pre-existing CD8 T-cells distinctly located at the invasive tumour margin are associated with expression of the PD-1/PD-L1 immune inhibitory axis and may predict response to therapy. We analyzed samples from 46 patients with metastatic melanoma obtained before and during anti-PD1 therapy (pembrolizumab) using quantitative immunohistochemistry, quantitative multiplex immunofluorescence, and next generation sequencing for T-cell receptors (TCR). In serially sampled tumours, responding patients showed proliferation of intratumoural CD8+ T-cells that directly correlated with radiographic reduction in tumour size. Pre-treatment samples obtained from responding patients showed higher numbers of CD8, PD1, and PD-L1 expressing cells at the invasive tumour margin and inside tumours, with close proximity between PD-1 and PD-L1, and a more clonal TCR repertoire. Using multivariate analysis, we established a predictive model based on CD8 expression at the invasive margin and validated the model in an independent cohort of 15 patients. Our findings indicate that tumour regression following therapeutic PD-1 blockade requires pre-existing CD8+ T cells that are negatively regulated by PD-1/PD-L1 mediated adaptive immune resistance. PMID:25428505

  6. Determination of paclitaxel in southern yew tree by HPLC

    Institute of Scientific and Technical Information of China (English)

    施树云; 周春山

    2003-01-01

    Paclitaxel in southern yew tree was quantitatively determined by high performance liquid chromatography(HPLC) with ODS-C18 column. A mixture of CH3OH-H2O-CH3COOH(volume ratio: 55 : 44: 1) is used as mo-bile phase and UV detection is carried out at 227 nm, and the column temperature is 20℃. The results show thatthere is a good linear relationship between the area of paclitaxel and the concentration of the sample in the range 50-500 mg/L for paclitaxel. The corresponding regression equation is Y=13 021.7+ 1.01 × 106 X, r=0. 999 0. The av-erage recovery is 95. 3% and the relative standard deviation is 2.08%.

  7. Hyaluronic Acid- Paclitaxel: Antitumor Efficacy against CD44(+ Human Ovarian Carcinoma Xenografts

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    Edmond Auzenne

    2007-06-01

    Full Text Available Numerous human tumor types, including ovarian cancer, display a significant expression of the CD44 family of cell surface proteoglycans. To develop tumortargeted drugs, we have initially evaluated whether the CD44 ligand hyaluronic acid (HA could serve as a backbone for paclitaxel (TXL prodrugs. HA-TXL was prepared by modification of previous techniques. The in vitro cytotoxicity of HA-TXL against the CD44(+ human ovarian carcinoma cell lines SKOV-3ip and NMP-1 could be significantly blocked by preincubation with a molar excess of free HA. Female nude mice bearing intraperitoneal implants of NMP-1 cells were treated intraperitoneally with a single sub-maximum tolerated dose dose of HA-TXL or with multiple-dose regimens of paclitaxel (Taxol; Mead Johnson, Princeton, NJ to determine the effects of these regimens on host survival and intraperitoneal tumor burden, with the latter being assessed by magnetic resonance imaging. NMP-1 xenograffs were highly resistant to Taxol regimens, as host survival was only nominally improved compared to controls (T/C ∼ 120, whereas singledose HA-TXL treatment significantly improved survival in this model (T/C ∼ 140; P = .004. In both NMP-1 and SKOV-3ip models, MR images of abdomens of HA-TXL-treated mice obtained shortly before controls required humane sacrifice revealed markedly reduced tumor burdens compared to control mice. This study is among the first to demonstrate that HA-based prodrugs administered locoregionally have antitumor activity in vivo.

  8. Two Cases of Mastectomy after Paclitaxel + Bevacizumab Therapy for Locally Advanced Breast Cancer

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    Chika Shinoda

    2014-05-01

    Full Text Available Introduction: Locally advanced breast cancer (LABC deteriorates the quality of life (QOL of the affected patients. Combination chemotherapy or extended chemotherapy is considered to help to shrink local lesions. Case 1: A 71-year-old female with a history of tympanitis and cystitis with methicillin-resistant Staphylococcus aureus (MRSA visited our hospital. There was a tumor of 7 cm in diameter in her right breast with skin ulceration. Paclitaxel + bevacizumab therapy was started, and after five cycles of therapy, a mastectomy with axillary dissection was performed. Chemotherapy with anthracycline was avoided for fear of activating the MRSA. After the operation, the patient's wound opened. However, it naturally epithelialized. Case 2: A 41-year-old female visited our hospital due to a tumor of 8 cm in diameter in her right breast with skin ulceration. Four cycles of paclitaxel + bevacizumab therapy were started, and her tumor almost disappeared during the first cycle. Then, doxorubicin + cyclophosphamide therapy was performed for four cycles, and a mastectomy with axillary dissection was performed. Her postoperative course was good. Discussion: Chemotherapy with bevacizumab or extended chemotherapy is generally not considered to contribute to a survival improvement. However, such therapy contributes in increasing the response to chemotherapy, and should be considered for patients with LABC to shrink the local lesions and improve the QOL.

  9. Osmotic stress sensitizes naturally resistant cells to TNF-alpha-induced apoptosis.

    Science.gov (United States)

    Franco, D L; Nojek, I M; Molinero, L; Coso, O A; Costas, M A

    2002-10-01

    Most cells are naturally resistant to TNF-alpha-induced cell death and become sensitized when NF-kappaB transactivation is blocked or in the presence of protein synthesis inhibitors that prevent the expression of anti-apoptotic genes. In this report we analyzed the role of osmotic stress on TNF-alpha-induced cell death. We found that it sensitizes the naturally resistant HeLa cells to TNF-alpha-induced apoptosis, with the involvement of an increase in the activity of several kinases, the inhibition of Bcl-2 expression, and a late increase on NF-kappaB activation. Cell death occurs regardless of the enhanced NF-kappaB activity, whose inhibition produces an increase in apoptosis. The inhibition of p38 kinase, also involved in NF-kappaB activation, significantly increases the effect of osmotic stress on TNF-alpha-induced cell death.

  10. Anesthesia with propofol induces insulin resistance systemically in skeletal and cardiac muscles and liver of rats

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Yoshikazu; Fukushima, Yuji; Kaneki, Masao [Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Shriners Hospitals for Children, Harvard Medical School, Boston, MA 02114 (United States); Martyn, J.A. Jeevendra, E-mail: jmartyn@partners.org [Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Shriners Hospitals for Children, Harvard Medical School, Boston, MA 02114 (United States)

    2013-02-01

    Highlights: ► Propofol, as a model anesthetic drug, induced whole body insulin resistance. ► Propofol anesthesia decreased glucose infusion rate to maintain euglycemia. ► Propofol decreased insulin-mediated glucose uptake in skeletal and cardiac muscles. ► Propofol increased hepatic glucose output confirming hepatic insulin resistance. -- Abstract: Hyperglycemia together with hepatic and muscle insulin resistance are common features in critically ill patients, and these changes are associated with enhanced inflammatory response, increased susceptibility to infection, muscle wasting, and worsened prognosis. Tight blood glucose control by intensive insulin treatment may reduce the morbidity and mortality in intensive care units. Although some anesthetics have been shown to cause insulin resistance, it remains unknown how and in which tissues insulin resistance is induced by anesthetics. Moreover, the effects of propofol, a clinically relevant intravenous anesthetic, also used in the intensive care unit for sedation, on insulin sensitivity have not yet been investigated. Euglycemic hyperinsulinemic clamp study was performed in rats anesthetized with propofol and conscious unrestrained rats. To evaluate glucose uptake in tissues and hepatic glucose output [{sup 3}H]glucose and 2-deoxy[{sup 14}C]glucose were infused during the clamp study. Anesthesia with propofol induced a marked whole-body insulin resistance compared with conscious rats, as reflected by significantly decreased glucose infusion rate to maintain euglycemia. Insulin-stimulated tissue glucose uptake was decreased in skeletal muscle and heart, and hepatic glucose output was increased in propofol anesthetized rats. Anesthesia with propofol induces systemic insulin resistance along with decreases in insulin-stimulated glucose uptake in skeletal and heart muscle and attenuation of the insulin-mediated suppression of hepatic glucose output in rats.

  11. UV-induced DNA damage promotes resistance to the biotrophic pathogen Hyaloperonospora parasitica in Arabidopsis.

    Science.gov (United States)

    Kunz, Bernard A; Dando, Paige K; Grice, Desma M; Mohr, Peter G; Schenk, Peer M; Cahill, David M

    2008-10-01

    Plant innate immunity to pathogenic microorganisms is activated in response to recognition of extracellular or intracellular pathogen molecules by transmembrane receptors or resistance proteins, respectively. The defense signaling pathways share components with those involved in plant responses to UV radiation, which can induce expression of plant genes important for pathogen resistance. Such intriguing links suggest that UV treatment might activate resistance to pathogens in normally susceptible host plants. Here, we demonstrate that pre-inoculative UV (254 nm) irradiation of Arabidopsis (Arabidopsis thaliana) susceptible to infection by the biotrophic oomycete Hyaloperonospora parasitica, the causative agent of downy mildew, induces dose- and time-dependent resistance to the pathogen detectable up to 7 d after UV exposure. Limiting repair of UV photoproducts by postirradiation incubation in the dark, or mutational inactivation of cyclobutane pyrimidine dimer photolyase, (6-4) photoproduct photolyase, or nucleotide excision repair increased the magnitude of UV-induced pathogen resistance. In the absence of treatment with 254-nm UV, plant nucleotide excision repair mutants also defective for cyclobutane pyrimidine dimer or (6-4) photoproduct photolyase displayed resistance to H. parasitica, partially attributable to short wavelength UV-B (280-320 nm) radiation emitted by incubator lights. These results indicate UV irradiation can initiate the development of resistance to H. parasitica in plants normally susceptible to the pathogen and point to a key role for UV-induced DNA damage. They also suggest UV treatment can circumvent the requirement for recognition of H. parasitica molecules by Arabidopsis proteins to activate an immune response.

  12. Mitochondrial aldehyde dehydrogenase obliterates insulin resistance-induced cardiac dysfunction through deacetylation of PGC-1α

    Science.gov (United States)

    Hu, Nan; Ren, Jun; Zhang, Yingmei

    2016-01-01

    Insulin resistance contributes to the high prevalence of type 2 diabetes mellitus, leading to cardiac anomalies. Emerging evidence depicts a pivotal role for mitochondrial injury in oxidative metabolism and insulin resistance. Mitochondrial aldehyde dehydrogenase (ALDH2) is one of metabolic enzymes detoxifying aldehydes although its role in insulin resistance remains elusive. This study was designed to evaluate the impact of ALDH2 overexpression on insulin resistance-induced myocardial damage and mechanisms involved with a focus on autophagy. Wild-type (WT) and transgenic mice overexpressing ALDH2 were fed sucrose or starch diet for 8 weeks and cardiac function and intracellular Ca2+ handling were assessed using echocardiographic and IonOptix systems. Western blot analysis was used to evaluate Akt, heme oxygenase-1 (HO-1), PGC-1α and Sirt-3. Our data revealed that sucrose intake provoked insulin resistance and compromised fractional shortening, cardiomyocyte function and intracellular Ca2+ handling (p 0.05), mitochondrial injury (elevated ROS generation, suppressed NAD+ and aconitase activity, p < 0.05 for all), the effect of which was ablated by ALDH2. In vitro incubation of the ALDH2 activator Alda-1, the Sirt3 activator oroxylin A and the histone acetyltransferase inhibitor CPTH2 rescued insulin resistance-induced changes in aconitase activity and cardiomyocyte function (p < 0.05). Inhibiting Sirt3 deacetylase using 5-amino-2-(4-aminophenyl) benzoxazole negated Alda-1-induced cardioprotective effects. Taken together, our data suggest that ALDH2 serves as an indispensable cardioprotective factor against insulin resistance-induced cardiomyopathy with a mechanism possibly associated with facilitation of the Sirt3-dependent PGC-1α deacetylation. PMID:27634872

  13. Identification of new biomarker candidates for glucocorticoid induced insulin resistance using literature mining

    Directory of Open Access Journals (Sweden)

    Fleuren Wilco WM

    2013-02-01

    Full Text Available Abstract Background Glucocorticoids are potent anti-inflammatory agents used for the treatment of diseases such as rheumatoid arthritis, asthma, inflammatory bowel disease and psoriasis. Unfortunately, usage is limited because of metabolic side-effects, e.g. insulin resistance, glucose intolerance and diabetes. To gain more insight into the mechanisms behind glucocorticoid induced insulin resistance, it is important to understand which genes play a role in the development of insulin resistance and which genes are affected by glucocorticoids. Medline abstracts contain many studies about insulin resistance and the molecular effects of glucocorticoids and thus are a good resource to study these effects. Results We developed CoPubGene a method to automatically identify gene-disease associations in Medline abstracts. We used this method to create a literature network of genes related to insulin resistance and to evaluate the importance of the genes in this network for glucocorticoid induced metabolic side effects and anti-inflammatory processes. With this approach we found several genes that already are considered markers of GC induced IR, such as phosphoenolpyruvate carboxykinase (PCK and glucose-6-phosphatase, catalytic subunit (G6PC. In addition, we found genes involved in steroid synthesis that have not yet been recognized as mediators of GC induced IR. Conclusions With this approach we are able to construct a robust informative literature network of insulin resistance related genes that gave new insights to better understand the mechanisms behind GC induced IR. The method has been set up in a generic way so it can be applied to a wide variety of disease networks.

  14. Artesunate induces ROS-mediated apoptosis in doxorubicin-resistant T leukemia cells.

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    Thomas Efferth

    Full Text Available BACKGROUND: A major obstacle for successful cancer treatment often is the development of drug resistance in cancer cells during chemotherapy. Therefore, there is an urgent need for novel drugs with improved efficacy against tumor cells and with less toxicity on normal cells. Artesunate (ART, a powerful anti-malarial herbal compound, has been shown to inhibit growth of various tumor cell lines in vitro and of xenografted Kaposi's sarcoma in mice in vivo. However, the molecular mechanisms by which ART exerts its cytotoxicity have not been elucidated. The ART-class of anti-malarial compounds is attractive due to their activity against multidrug-resistant Plasmodium falciparum and Plasmodium vivax strains. Another salient feature of these compounds is the lack of severe side effects in malaria patients. METHODOLOGY AND PRINCIPAL FINDINGS: In this study, we used T-cell leukemias as a model system to study the molecular mechanisms of ART-induced apoptosis. The most typical anticancer drugs are DNA intercalators such as Doxorubicin. To investigate drug sensitivity and resistance, we chose a Doxorubicin-resistant leukemia cell line and investigated the killing effect of ART on these cells. We show that ART induces apoptosis in leukemic T cells mainly through the mitochondrial pathway via generation of reactive oxygen species (ROS, a mechanism different from Doxorubicin. This is confirmed by the fact that the antioxidant N-Acetyle-Cysteine (NAC could completely block ROS generation and, consequently, inhibited ART-induced apoptosis. Therefore, ART can overcome the Doxorubicin-resistance and induce the Doxorubicin-resistant leukemia cells to undergo apoptosis. We also show that ART can synergize with Doxorubicin to enhance apoptotic cell death in leukemic T cells. This synergistic effect can be largely explained by the fact that ART and Doxorubicin use different killing mechanisms. CONCLUSIONS: Our studies raise the possibility to develop ART in

  15. Inducible Clindamycin Resistant Staphylococcus aureus in Iran: A Systematic Review and Meta-analysis

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    Ahmadreza Zarifian

    2015-11-01

    Full Text Available Introduction: Staphylococcus aureus is a prominent human pathogen. One of the drugs used in the treatment of staphylococcal infections (particularly infections of skin and soft tissue, is clindamycin. Resistance to clindamycin includes two types: inducible and constitutive. Routine laboratory methods of antibiotic susceptibility testing cannot detect the inducible type and D- test is required for its detection. The purpose of this systematic review was to determine the relative prevalence of this type of resistance in Iran.Methods: Search terms "inducible clindamycin resistant", "D-test", "Staphylococcus aureus" and "Iran" were used to find relevant articles in PubMed, Google Scholar and two Persian search engines. Also, the abstracts of the recent national microbiology congresses were checked.All studies used D-test to find iMLSB  (inducible macrolide, lincosamide and streptograminB resistance phenotype among clinical isolates (not nasal swabs of S. aureus, were included. In order to perform meta-analysis, we used “comprehensive meta-analysis” software (ver. 2.Results: In total, 9 articles and 8 abstracts related to the topic of the study were found. Random effects meta-analyses showed a pooled estimate for percentage of iMLSB  phenotype among 2683 samples of S. aureus was about 10% (95% confidence interval: 0.07-0.12. Using the fixed effect model, the odds of positive iMLSB  in methicillin-resistant S. aureus was about 5 times more likely to occur in comparison with methicillin-susceptible S. aureus (95% CI: 3.49 to 7.76.Conclusion: Fortunately, the relative frequency of inducible resistance to clindamycin in our country is relatively low. However, we believe that D-test should be performed for all erythromicin-resistant  isolates  in  order  to  identify  inducible  resistance  to  clindamycin.Moreover, reevaluation of inducible reistance to clindamycin in forthcoming years is highly recommended.

  16. Mechanisms involved in biocontrol and plant induced resistance by Trichoderna asperellun (T.harzianum T-203)

    Institute of Scientific and Technical Information of China (English)

    Chet I; Shoresh M; Yedidia I; Viterbo A

    2004-01-01

    @@ Growing awareness of the environmental damage caused by the use of chemical substances for plant disease control in agriculture has raised the need to study biological alternatives, such as activating the defense response of plant crops by inducers not toxic to the environment. Trichoderna spp. are effective biocontrol agents for a number of soilborne pathogens, and are also known for their ability to enhance plant growth and to induce systemic resistance (ISR) in plants.

  17. A study of process induced voids in resistance welding of thermoplastic composites

    OpenAIRE

    Shi, H.; Fernandez Villegas, I.; Bersee, H.E.N.

    2015-01-01

    Void formation in resistance welding of woven fabric reinforced thermoplastic composites was investigated. Void contents were measured using optical microscopy and digital image process. Un-even void distributions were observed in the joints, and more voids were found in the middle of the joints than the edges. A higher welding pressure was shown to help reduce the void generation. The mechanisms of void formation, in particular fibre de-compaction induced voids and residual moisture induced ...

  18. Optical imaging of radiation-induced metabolic changes in radiation-sensitive and resistant cancer cells

    Science.gov (United States)

    Alhallak, Kinan; Jenkins, Samir V.; Lee, David E.; Greene, Nicholas P.; Quinn, Kyle P.; Griffin, Robert J.; Dings, Ruud P. M.; Rajaram, Narasimhan

    2017-06-01

    Radiation resistance remains a significant problem for cancer patients, especially due to the time required to definitively determine treatment outcome. For fractionated radiation therapy, nearly 7 to 8 weeks can elapse before a tumor is deemed to be radiation-resistant. We used the optical redox ratio of FAD/(FAD+NADH) to identify early metabolic changes in radiation-resistant lung cancer cells. These radiation-resistant human A549 lung cancer cells were developed by exposing the parental A549 cells to repeated doses of radiation (2 Gy). Although there were no significant differences in the optical redox ratio between the parental and resistant cell lines prior to radiation, there was a significant decrease in the optical redox ratio of the radiation-resistant cells 24 h after a single radiation exposure (p=0.01). This change in the redox ratio was indicative of increased catabolism of glucose in the resistant cells after radiation and was associated with significantly greater protein content of hypoxia-inducible factor 1 (HIF-1α), a key promoter of glycolytic metabolism. Our results demonstrate that the optical redox ratio could provide a rapid method of determining radiation resistance status based on early metabolic changes in cancer cells.

  19. MiR-197 induces Taxol resistance in human ovarian cancer cells by regulating NLK.

    Science.gov (United States)

    Zou, Dongling; Wang, Dong; Li, Rong; Tang, Ying; Yuan, Li; Long, Xingtao; Zhou, Qi

    2015-09-01

    Chemotherapy is the preferred therapeutic approach for the therapy of advanced ovarian cancer, but 5-year survival rate remains low due to the development of drug resistance. Increasing evidence has documented that microRNAs (miRNAs) act important roles in drug resistance in a variety types of cancer. However, the roles of miRNA in regulating Taxol resistance in ovarian cancer and the detailed mechanism are less reported. We used Taqman probe stem loop real-time PCR to accurately measure the levels of miR-197 in normal ovarian cells, ovarian cancer cells, and Taxol-resistant ovarian cancer cells and found that miR-197 was significantly increased in Taxol-resistant ovarian cancer cells. Enforced expression of miR-197 can promote Taxol resistance, cell proliferation, and invasion of ovarian cancer cells. Meanwhile, repression of miR-197 in ovarian cancer cells can sensitize its response to Taxol and also induced attenuated cell proliferation and invasion ability. Furthermore, investigation of the detailed mechanism showed that the promotion of miR-197 on drug resistance in ovarian cancer cells was partially mediated by downregulating NLK, a negative regulator of WNT signaling pathway. Taken together, our work first demonstrated that miR-197 can confer drug resistance to Taxol, by regulating tumor suppressor, NLK expression in ovarian cancer cells.

  20. Src mutation induces acquired lapatinib resistance in ERBB2-amplified human gastroesophageal adenocarcinoma models.

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    Yong Sang Hong

    Full Text Available ERBB2-directed therapy is now a routine component of therapy for ERBB2-amplified metastatic gastroesophageal adenocarcinomas. However, there is little knowledge of the mechanisms by which these tumors develop acquired resistance to ERBB2 inhibition. To investigate this question we sought to characterize cell line models of ERBB2-amplified gastroesophageal adenocarcinoma with acquired resistance to ERBB2 inhibition. We generated lapatinib-resistant (LR subclones from an initially lapatinib-sensitive ERBB2-amplified esophageal adenocarcinoma cell line, OE19. We subsequently performed genomic characterization and functional analyses of resistant subclones with acquired lapatinib resistance. We identified a novel, acquired SrcE527K mutation in a subset of LR OE19 subclones. Cells with this mutant allele harbour increased Src phosphorylation. Genetic and pharmacologic inhibition of Src resensitized these subclones to lapatinib. Biochemically, Src mutations could activate both the phosphatidylinositol 3-kinase and mitogen activated protein kinase pathways in the lapatinib-treated LR OE19 cells. Ectopic expression of SrcE527K mutation also was sufficient to induce lapatinib resistance in drug-naïve cells. These results indicate that pathologic activation of Src is a potential mechanism of acquired resistance to ERBB2 inhibition in ERBB2-amplified gastroesophageal cancer. Although Src mutation has not been described in primary tumor samples, we propose that the Src hyperactivation should be investigated in the settings of acquired resistance to ERBB2 inhibition in esophageal and gastric adenocarcinoma.

  1. Optical imaging of radiation-induced metabolic changes in radiation-sensitive and resistant cancer cells.

    Science.gov (United States)

    Alhallak, Kinan; Jenkins, Samir V; Lee, David E; Greene, Nicholas P; Quinn, Kyle P; Griffin, Robert J; Dings, Ruud P M; Rajaram, Narasimhan

    2017-06-01

    Radiation resistance remains a significant problem for cancer patients, especially due to the time required to definitively determine treatment outcome. For fractionated radiation therapy, nearly 7 to 8 weeks can elapse before a tumor is deemed to be radiation-resistant. We used the optical redox ratio of FAD / ( FAD + NADH ) to identify early metabolic changes in radiation-resistant lung cancer cells. These radiation-resistant human A549 lung cancer cells were developed by exposing the parental A549 cells to repeated doses of radiation (2 Gy). Although there were no significant differences in the optical redox ratio between the parental and resistant cell lines prior to radiation, there was a significant decrease in the optical redox ratio of the radiation-resistant cells 24 h after a single radiation exposure ( p = 0.01 ). This change in the redox ratio was indicative of increased catabolism of glucose in the resistant cells after radiation and was associated with significantly greater protein content of hypoxia-inducible factor 1 ( HIF - 1 ? ), a key promoter of glycolytic metabolism. Our results demonstrate that the optical redox ratio could provide a rapid method of determining radiation resistance status based on early metabolic changes in cancer cells.

  2. Free paclitaxel loaded PEGylated-paclitaxel nanoparticles: preparation and comparison with other paclitaxel systems in vitro and in vivo.

    Science.gov (United States)

    Lu, Jingkai; Chuan, Xingxing; Zhang, Hua; Dai, Wenbing; Wang, Xinglin; Wang, Xueqing; Zhang, Qiang

    2014-08-25

    Previously, PEGylated paclitaxel (PEG-PTX) was found not favorable as a polymer prodrug because of its poor antitumor efficiency. But surprisingly, it was found in our study that PEG-PTX could form a novel nanoparticle system with free PTX. To address how this system works, we compared PTX loaded PEG-PTX nanoparticles (PEG-PTX/PTX) with PTX loaded PEG-PLA micelles (PEG-PLA/PTX) or PTX injection available (Taxol(®)) in vitro and in vivo. Firstly, it was found that PEG-PTX/PTX was more stable in aqueous solution than PEG-PLA/PTX in terms of PTX crystal formation and drug release. Then it was demonstrated that coumarin loaded PEG-PTX nanoparticles had a much higher uptake in MCF-7 cells compared to coumarin loaded PEG-PLA micelles. The in vivo imaging study revealed that DIR or DID (near infrared fluorescent substances) loaded PEG-PTX nanoparticles distributed more in tumors in MCF-7 tumor bearing mice than DIR or DID loaded PEG-PLA micelles and solvent system of Taxol(®). In the efficacy study with MCF-7 tumor bearing mice, PEG-PTX/PTX showed significantly higher antitumor activity than PEG-PLA/PTX at the same PTX dosage. At the dose of 10mg free PTX per kg, PEG-PTX/PTX displayed similar efficacy as Taxol(®) but less toxicity evaluated by the loss of body weight. With the increase of free PTX to 15 mg/kg, PEG-PTX/PTX showed significantly better efficacy than Taxol(®). In conclusion, with favorable characteristics in stability, cellular uptake, cytotoxicity, biodistribution, safety and efficacy, PEG-PTX/PTX seems highly potential as a nanocarrier for PTX delivery.

  3. Resistance to exercise-induced weight loss: compensatory behavioral adaptations.

    Science.gov (United States)

    Melanson, Edward L; Keadle, Sarah Kozey; Donnelly, Joseph E; Braun, Barry; King, Neil A

    2013-08-01

    In many interventions that are based on an exercise program intended to induce weight loss, the mean weight loss observed is modest and sometimes far less than what the individual expected. The individual responses are also widely variable, with some individuals losing a substantial amount of weight, others maintaining weight, and a few actually gaining weight. The media have focused on the subpopulation that loses little weight, contributing to a public perception that exercise has limited utility to cause weight loss. The purpose of the symposium was to present recent, novel data that help explain how compensatory behaviors contribute to a wide discrepancy in exercise-induced weight loss. The presentations provide evidence that some individuals adopt compensatory behaviors, that is, increased energy intake and/or reduced activity, that offset the exercise energy expenditure and limit weight loss. The challenge for both scientists and clinicians is to develop effective tools to identify which individuals are susceptible to such behaviors and to develop strategies to minimize their effect.

  4. Silvicultural Attempts to Induce Browse Resistance in Conifer Seedlings

    Directory of Open Access Journals (Sweden)

    Bruce A. Kimball

    2011-01-01

    Full Text Available A multiyear study was conducted to determine if soil amendment combined with topical application of elemental sulfur could be employed to reduce deer browse damage to four conifer species. Fertilizer and sulfur were applied to conifer seedlings at seven sites near Corvallis, OR. Growth and browse damage data were collected for all seedlings over a period of 17 months. Additionally, foliar concentrations of monoterpenes and simple carbohydrates were assessed in western redcedar (Thuja plicata seedlings over a period of three years. Fertilization and sulfur treatments had a moderate impact on growth and no influence on browse damage or the chemical responses. Over the course of the study, browse damage diminished while foliar monoterpene concentrations increased in redcedar. It appears that silvicultural manipulation via sulfur application and/or soil amendment cannot accelerate or alter the ontogenetical changes that may naturally defend seedlings against mammalian herbivores. In a brief trial with captive deer, redcedar browse resistance was influenced by seedling maturation, but not monoterpene content. Other maturation effects may yield significant browse protection to young seedlings.

  5. Mycorrhiza-induced resistance and priming of plant defenses.

    Science.gov (United States)

    Jung, Sabine C; Martinez-Medina, Ainhoa; Lopez-Raez, Juan A; Pozo, Maria J

    2012-06-01

    Symbioses between plants and beneficial soil microorganisms like arbuscular-mycorrhizal fungi (AMF) are known to promote plant growth and help plants to cope with biotic and abiotic stresses. Profound physiological changes take place in the host plant upon root colonization by AMF affecting the interactions with a wide range of organisms below- and above-ground. Protective effects of the symbiosis against pathogens, pests, and parasitic plants have been described for many plant species, including agriculturally important crop varieties. Besides mechanisms such as improved plant nutrition and competition, experimental evidence supports a major role of plant defenses in the observed protection. During mycorrhiza establishment, modulation of plant defense responses occurs thus achieving a functional symbiosis. As a consequence of this modulation, a mild, but effective activation of the plant immune responses seems to occur, not only locally but also systemically. This activation leads to a primed state of the plant that allows a more efficient activation of defense mechanisms in response to attack by potential enemies. Here, we give an overview of the impact on interactions between mycorrhizal plants and pathogens, herbivores, and parasitic plants, and we summarize the current knowledge of the underlying mechanisms. We focus on the priming of jasmonate-regulated plant defense mechanisms that play a central role in the induction of resistance by arbuscular mycorrhizas.

  6. Transcriptional Profiles Uncover Aspergillus flavus-Induced Resistance in Maize Kernels

    Directory of Open Access Journals (Sweden)

    Zhi-Yuan Chen

    2011-06-01

    Full Text Available Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and through storage. Previous studies have highlighted the constitutive production of proteins involved in maize kernel resistance against A. flavus’ infection. However, little is known about induced resistance nor about defense gene expression and regulation in kernels. In this study, maize oligonucleotide arrays and a pair of closely-related maize lines varying in aflatoxin accumulation were used to reveal the gene expression network in imbibed mature kernels in response to A. flavus’ challenge. Inoculated kernels were incubated 72 h via the laboratory-based Kernel Screening Assay (KSA, which highlights kernel responses to fungal challenge. Gene expression profiling detected 6955 genes in resistant and 6565 genes in susceptible controls; 214 genes induced in resistant and 2159 genes induced in susceptible inoculated kernels. Defense related and regulation related genes were identified in both treatments. Comparisons between the resistant and susceptible lines indicate differences in the gene expression network which may enhance our understanding of the maize-A. flavus interaction.

  7. An inducible fusaric acid tripartite efflux pump contributes to the fusaric acid resistance in Stenotrophomonas maltophilia.

    Directory of Open Access Journals (Sweden)

    Rouh-Mei Hu

    Full Text Available BACKGROUND: Fusaric acid (5-butylpicolinic acid, a mycotoxin, is noxious to some microorganisms. Stenotrophomonas maltophilia displays an intrinsic resistance to fusaric acid. This study aims to elucidate the mechanism responsible for the intrinsic fusaric acid resistance in S. maltophilia. METHODOLOGY: A putative fusaric acid resistance-involved regulon fuaR-fuaABC was identified by the survey of the whole genome sequence of S. maltophilia K279a. The fuaABC operon was verified by reverse transcriptase-PCR. The contribution of the fuaABC operon to the antimicrobial resistance was evaluated by comparing the antimicrobials susceptibility between the wild-type strain and fuaABC knock-out mutant. The regulatory role of fuaR in the expression of the fuaABC operon was assessed by promoter transcription fusion assay. RESULTS: The fuaABC operon was inducibly expressed by fusaric acid and the inducibility was fuaR dependent. FuaR functioned as a repressor of the fuaABC operon in absence of a fusaric acid inducer and as an activator in its presence. Overexpression of the fuaABC operon contributed to the fusaric acid resistance. SIGNIFICANCE: A novel tripartite fusaric acid efflux pump, FuaABC, was identified in this study. Distinct from the formally classification, the FuaABC may constitute a new type of subfamily of the tripartite efflux pump.

  8. Unaltered Prion Pathogenesis in a Mouse Model of High-Fat Diet-Induced Insulin Resistance.

    Directory of Open Access Journals (Sweden)

    Caihong Zhu

    Full Text Available Epidemiological, clinical, and experimental animal studies suggest a strong correlation between insulin resistance and Alzheimer's disease. In fact, type-2 diabetes is considered an important risk factor of developing Alzheimer's disease. In addition, impaired insulin signaling in the Alzheimer's disease brain may promote Aβ production, impair Aβ clearance and induce tau hyperphosphorylation, thereby leading to deterioration of the disease. The pathological prion protein, PrPSc, deposits in the form of extracellular aggregates and leads to dementia, raising the question as to whether prion pathogenesis may also be affected by insulin resistance. We therefore established high-fat diet-induced insulin resistance in tga20 mice, which overexpress the prion protein. We then inoculated the insulin-resistant mice with prions. We found that insulin resistance in tga20 mice did not affect prion disease progression, PrPSc deposition, astrogliosis or microglial activation, and had no effect on survival. Our study demonstrates that in a mouse model, insulin resistance does not significantly contribute to prion pathogenesis.

  9. High throughput atmospheric pressure plasma-induced graft polymerization for identifying protein-resistant surfaces.

    Science.gov (United States)

    Gu, Minghao; Kilduff, James E; Belfort, Georges

    2012-02-01

    Three critical aspects of searching for and understanding how to find highly resistant surfaces to protein adhesion are addressed here with specific application to synthetic membrane filtration. They include the (i) discovery of a series of previously unreported monomers from a large library of monomers with high protein resistance and subsequent low fouling characteristics for membrane ultrafiltration of protein-containing fluids, (ii) development of a new approach to investigate protein-resistant mechanisms from structure-property relationships, and (iii) adaptation of a new surface modification method, called atmospheric pressure plasma-induced graft polymerization (APP), together with a high throughput platform (HTP), for low cost vacuum-free synthesis of anti-fouling membranes. Several new high-performing chemistries comprising two polyethylene glycol (PEG), two amines and one zwitterionic monomers were identified from a library (44 commercial monomers) of five different classes of monomers as strong protein-resistant monomers. Combining our analysis here, using the Hansen solubility parameters (HSP) approach, and data from the literature, we conclude that strong interactions with water (hydrogen bonding) and surface flexibility are necessary for producing the highest protein resistance. Superior protein-resistant surfaces and subsequent anti-fouling performance was obtained with the HTP-APP as compared with our earlier HTP-photo graft-induced polymerization (PGP).

  10. Extracellular DNA chelates cations and induces antibiotic resistance in Pseudomonas aeruginosa biofilms.

    Directory of Open Access Journals (Sweden)

    Heidi Mulcahy

    2008-11-01

    Full Text Available Biofilms are surface-adhered bacterial communities encased in an extracellular matrix composed of DNA, bacterial polysaccharides and proteins, which are up to 1000-fold more antibiotic resistant than planktonic cultures. To date, extracellular DNA has been shown to function as a structural support to maintain Pseudomonas aeruginosa biofilm architecture. Here we show that DNA is a multifaceted component of P. aeruginosa biofilms. At physiologically relevant concentrations, extracellular DNA has antimicrobial activity, causing cell lysis by chelating cations that stabilize lipopolysaccharide (LPS and the outer membrane (OM. DNA-mediated killing occurred within minutes, as a result of perturbation of both the outer and inner membrane (IM and the release of cytoplasmic contents, including genomic DNA. Sub-inhibitory concentrations of DNA created a cation-limited environment that resulted in induction of the PhoPQ- and PmrAB-regulated cationic antimicrobial peptide resistance operon PA3552-PA3559 in P. aeruginosa. Furthermore, DNA-induced expression of this operon resulted in up to 2560-fold increased resistance to cationic antimicrobial peptides and 640-fold increased resistance to aminoglycosides, but had no effect on beta-lactam and fluoroquinolone resistance. Thus, the presence of extracellular DNA in the biofilm matrix contributes to cation gradients, genomic DNA release and inducible antibiotic resistance. DNA-rich environments, including biofilms and other infection sites like the CF lung, are likely the in vivo environments where extracellular pathogens such as P. aeruginosa encounter cation limitation.

  11. Effects of Combination of Thiazolidinediones with Melatonin in Dexamethasone-induced Insulin Resistance in Mice.

    Science.gov (United States)

    Ghaisas, M M; Ahire, Y S; Dandawate, P R; Gandhi, S P; Mule, M

    2011-11-01

    In type 2 Diabetes, oxidative stress plays an important role in development and aggregation of insulin resistance. In the present study, long term administration of the dexamethasone led to the development of insulin resistance in mice. The effect of thiazolidinediones pioglitazone and rosiglitazone, with melatonin on dexamethasone-induced insulin resistance was evaluated in mice. Insulin resistant mice were treated with combination of pioglitazone (10 mg/kg/day, p.o.) or rosiglitazone (5 mg/kg/day, p.o.) with melatonin 10 mg/kg/day p.o. from day 7 to day 22. In the biochemical parameters, the serum glucose, triglyceride levels were significantly lowered (Pmelatonin. There was also, significant increased (Pmelatonin and decreased hyperglycemia induced insulin resistance by thiazolidinediones. The glucose uptake in the isolated hemidiaphragm of mice was significantly increased in combination treated groups (PM and RM) than dexamethasone alone treated mice as well as individual (pioglitazone, rosiglitazone, melatonin) treated groups probably via increased in expression of GLUT-4 by melatonin and thiazolidinediones as well as increased in insulin sensitivity by thiazolidinediones. Hence, it can be concluded that combination of pioglitazone and rosiglitazone, thiazolidinediones, with melatonin may reduces the insulin resistance via decreased in oxidative stress and control on hyperglycemia.

  12. Haemophilus influenzae induces a potentiated increase in guinea-pig pulmonary resistance to histamine

    NARCIS (Netherlands)

    Folkerts, G.; Nijkamp, F.P.

    1985-01-01

    The human respiratory pathogen Haemophilus influenzae (H.i.) induced bronchial hyperreactivity to histamine (1.0–8.0 μg/100 g b.w. i.v.) in vivo in anaesthetized spontaneously breathing guinea-pigs. This hyperreactivity was caused by a potentiated increase in pulmonary resistance. Decreases in dynam

  13. Isoorientin reverts TNF-α-induced insulin resistance in adipocytes activating the insulin signaling pathway.

    Science.gov (United States)

    Alonso-Castro, Angel Josabad; Zapata-Bustos, Rocio; Gómez-Espinoza, Guadalupe; Salazar-Olivo, Luis A

    2012-11-01

    Isoorientin (ISO) is a plant C-glycosylflavonoid with purported antidiabetic effects but unexplored mechanisms of action. To gain insight into its antidiabetic mechanisms, we assayed nontoxic ISO concentrations on the 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2-deoxy-d-glucose (2-NBDG) uptake by murine 3T3-F442A and human sc adipocytes. In insulin-sensitive adipocytes, ISO stimulated the 2-NBDG uptake by 210% (murine) and 67% (human), compared with insulin treatment. Notably, ISO also induced 2-NBDG uptake in murine (139%) and human (60%) adipocytes made resistant to insulin by treatment with TNF-α, compared with the incorporation induced in these cells by rosiglitazone. ISO induction of glucose uptake in adipocytes was abolished by inhibitors of the insulin signaling pathway. These inhibitors also blocked the proper phosphorylation of insulin signaling pathway components induced by ISO in both insulin-sensitive and insulin-resistant adipocytes. Additionally, ISO stimulated the transcription of genes encoding components of insulin signaling pathway in murine insulin-sensitive and insulin-resistant adipocytes. In summary, we show here that ISO exerts its antidiabetic effects by activating the insulin signaling pathway in adipocytes, reverts the insulin resistance caused in these cells by TNF-α by stimulating the proper phosphorylation of proteins in this signaling pathway, and induces the expression of genes encoding these proteins.

  14. IL-37 protects against obesity-induced inflammation and insulin resistance.

    Science.gov (United States)

    Ballak, Dov B; van Diepen, Janna A; Moschen, Alexander R; Jansen, Henry J; Hijmans, Anneke; Groenhof, Gert-Jan; Leenders, Floris; Bufler, Philip; Boekschoten, Mark V; Müller, Michael; Kersten, Sander; Li, Suzhao; Kim, SooHyun; Eini, Hadar; Lewis, Eli C; Joosten, Leo A B; Tilg, Herbert; Netea, Mihai G; Tack, Cees J; Dinarello, Charles A; Stienstra, Rinke

    2014-09-03

    Cytokines of the IL-1 family are important modulators of obesity-induced inflammation and the development of systemic insulin resistance. Here we show that IL-1 family member IL-37, recently characterized as an anti-inflammatory cytokine, ameliorates obesity-induced inflammation and insulin resistance. Mice transgenic for human IL-37 (IL-37tg) exhibit reduced numbers of adipose tissue macrophages, increased circulating levels of adiponectin and preserved glucose tolerance and insulin sensitivity after 16 weeks of HFD. In vitro treatment of adipocytes with recombinant IL-37 reduces adipogenesis and activates AMPK signalling. In humans, elevated steady-state IL-37 adipose tissue mRNA levels are positively correlated with insulin sensitivity and a lower inflammatory status of the adipose tissue. These findings reveal IL-37 as an important anti-inflammatory modulator during obesity-induced inflammation and insulin resistance in both mice and humans, and suggest that IL-37 is a potential target for the treatment of obesity-induced insulin resistance and type 2 diabetes.

  15. Characterization of Arabidopsis enhanced disease susceptibility mutants that are affected in systemically induced resistance

    NARCIS (Netherlands)

    Ton, J.; Vos, M. de; Robben, C.; Buchala, Anthony; Métraux, Jean-Pierre; Loon, L.C. van; Pieterse, C.M.J.

    2002-01-01

    In Arabidopsis, the rhizobacterial strain Pseudomonas fluorescens WCS417r triggers jasmonate (JA)- and ethylene (ET)-dependent induced systemic resistance (ISR) that is effective against different pathogens. Arabidopsis genotypes unable to express rhizobacteria-mediated ISR against the bacterial pat

  16. Genetic mapping shows intraspecific variation and transgressive segregation for caterpillar-induced aphid resistance in maize

    Science.gov (United States)

    Plants in nature have inducible defenses that sometimes lead to targeted resistance against particular herbivores, but susceptibility to others. The metabolic diversity and genetic resources available for maize (Zea mays) make this a suitable system for a mechanistic study of within- species variati...

  17. Improving the antitumor activity of squalenoyl-paclitaxel conjugate nanoassemblies by manipulating the linker between paclitaxel and squalene.

    Science.gov (United States)

    Caron, Joachim; Maksimenko, Andrei; Wack, Séverine; Lepeltier, Elise; Bourgaux, Claudie; Morvan, Estelle; Leblanc, Karine; Couvreur, Patrick; Desmaële, Didier

    2013-01-01

    A series of new lipid prodrugs of paclitaxel, which can be formulated as nanoassemblies, are described. These prodrugs which are designed to overcome the limitations due to the systemic toxicity and low water solubility of paclitaxel consist of a squalene chain bound to the 2'-OH of paclitaxel through a 1,4-cis,cis-dienic linker. This design allows the squalene-conjugates to self-assemble as nanoparticular systems while preserving an efficient release of the free drug, thanks to the dienic spacer. The size, steric hindrance, and functional groups of the spacer have been modulated. All these prodrugs self-assemble into nanosized aggregates in aqueous solution as characterized by dynamic light scattering and transmission electron microscopy and appear stable in water for several days as determined by particle size measurement. In vitro biological assessment shows that these squalenoyl-paclitaxel nanoparticles display notable cytotoxicity on several tumor cell lines including A549 lung cell line, colon cell line HT-29, or KB 3.1 nasopharyngeal epidermoid cell line. The cis,cis-squalenyl-deca-5,8-dienoate prodrug show improved activity over simple 2'-squalenoyl-paclitaxel prodrug highlighting the favourable effect of the dienic linker. The antitumor efficacy of the nanoassemblies constructed with the more active prodrugs has been investigated on human lung (A549) carcinoma xenograft model in mice. The prodrug bearing the cis,cis-deca-5,8-dienoyl linker shows comparable antitumor efficacy to the parent drug, but reveals a much lower subacute toxicity as seen in body weight loss. Thus, nanoparticles with the incorporated squalenoyl paclitaxel prodrug may prove useful for replacement of the toxic Cremophor EL.

  18. Functional and morphological effects of resistance exercise on disuse-induced skeletal muscle atrophy.

    Science.gov (United States)

    Nicastro, H; Zanchi, N E; Luz, C R da; Lancha, A H

    2011-11-01

    Abstract quality of life. Since there is no currently effective and safe treatment available for skeletal muscle atrophy, the search for new alternatives is necessary. Resistance exercise (RE) seems to be an important tool in the treatment of disuse-induced skeletal muscle atrophy by promoting positive functional (strength and power) and structural (hypertrophy and phenotypic changes) adaptive responses. Human and animal studies using different types of resistance exercise (flywheel, vascular occlusion, dynamic, isometric, and eccentric) have obtained results of great importance. However, since RE is a complex phenomenon, lack of strict control of its variables (volume, frequency, intensity, muscle action, rest intervals) limits the interpretation of the impact of the manipulation on skeletal muscle remodeling and function under disuse. The aim of this review is to critically describe the functional and morphological role of resistance exercise in disuse-induced skeletal muscle atrophy with emphasis on the principles of training.

  19. Reduction of insulinotropic properties of GLP-1 and GIP after glucocorticoid-induced insulin resistance

    DEFF Research Database (Denmark)

    Eriksen, Marie; Jensen, David H; Tribler, Siri

    2015-01-01

    AIMS/HYPOTHESIS: We evaluated the insulinotropic properties of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) in healthy individuals at risk of developing type 2 diabetes before and after glucocorticoid-induced insulin resistance. METHODS: Nineteen healthy....... In addition, first-phase insulin responses were determined at 7 mmol/l and 15 mmol/l and second-phase insulin responses at 7 mmol/l. RESULTS: After dexamethasone treatment, all 19 participants had increased insulin resistance (HOMA-IR and insulin sensitivity index [M/I] values) and 2 h plasma glucose...... concentrations, while beta cell function indices generally increased according to the increased resistance. First-phase insulin responses induced by GLP-1 and GIP at 7 mmol/l and maximal beta cell secretory capacity did not differ before and after dexamethasone, while second-phase responses to 7 mmol/l and first...

  20. Preharvest L-arginine treatment induced postharvest disease resistance to Botrysis cinerea in tomato fruits.

    Science.gov (United States)

    Zheng, Yang; Sheng, Jiping; Zhao, Ruirui; Zhang, Jian; Lv, Shengnan; Liu, Lingyi; Shen, Lin

    2011-06-22

    L-arginine is the precursor of nitric oxide (NO). In order to examine the influence of L-arginine on tomato fruit resistance, preharvest green mature tomato fruits (Solanum lycopersicum cv. No. 4 Zhongshu) were treated with 0.5, 1, and 5 mM L-arginine. The reduced lesion size (in diameter) on fruit caused by Botrytis cinerea, as well as activities of phenylalanine ammonia-lyase (PAL), Chitinase (CHI), β-1,3-glucanase (GLU), and polyphenoloxidase (PPO), was compared between L-arginine treated fruits and untreated fruits. We found that induced resistance increased and reached the highest level at 3-6 days after treatment. Endogenous NO concentrations were positively correlated with PAL, PPO, CHI, and GLU activities after treatment with Pearson coefficients of 0.71, 0.94, 0.97, and 0.87, respectively. These results indicate that arginine induces disease resistance via its effects on NO biosynthesis and defensive enzyme activity.

  1. Resistance to acetaminophen-induced hepatotoxicity in glutathione S-transferase Mu 1-null mice.

    Science.gov (United States)

    Arakawa, Shingo; Maejima, Takanori; Fujimoto, Kazunori; Yamaguchi, Takashi; Yagi, Masae; Sugiura, Tomomi; Atsumi, Ryo; Yamazoe, Yasushi

    2012-01-01

    We investigated the role of glutathione S-transferases Mu 1 (GSTM1) in acetaminophen (APAP)-induced hepatotoxicity using Gstm1-null mice. A single oral administration of APAP resulted in a marked increase in plasma alanine aminotransferase accompanied by hepatocyte necrosis 24 hr after administration in wild-type mice, but its magnitude was unexpectedly attenuated in Gstm1-null mice. Therefore, it is suggested that Gstm1-null mice are resistant to APAP-induced hepatotoxicity. To examine the mechanism of this resistance in Gstm1-null mice, we measured phosphorylation of c-jun N-terminal kinase (JNK), which mediates the signal of APAP-induced hepatocyte necrosis, by Western blot analysis 2 and 6 hr after APAP administration. A marked increase in phosphorylated JNK was observed in wild-type mice, but the increase was markedly suppressed in Gstm1-null mice. Therefore, it is suggested that suppressed phosphorylation of JNK may be a main mechanism of the resistance to APAP-induced hepatotoxicity in Gstm1-null mice, although other possibilities of the mechanism cannot be eliminated. Additionally, phosphorylation of glycogen synthase kinase-3β and mitogen-activated protein kinase kinase 4, which are upstream kinases of JNK in APAP-induced hepatotoxicity, were also suppressed in Gstm1-null mice. A decrease in liver total glutathione 2 hr after APAP administration, which is an indicator for exposure to N-acetyl-p-benzoquinoneimine, the reactive metabolite of APAP, were similar in wild-type and Gstm1-null mice. In conclusion, Gstm1-null mice are considered to be resistant to APAP-induced hepatotoxicity perhaps by the suppression of JNK phosphorylation. This study indicates the novel role of GSTM1 as a factor mediating the cellular signal for APAP-induced hepatotoxicity.

  2. Preparation, characterization, and in vitro targeted delivery of folate-decorated paclitaxel-loaded bovine serum albumin nanoparticles

    Directory of Open Access Journals (Sweden)

    Dongmei Zhao

    2010-09-01

    Full Text Available Dongmei Zhao, Xiuhua Zhao, Yuangang Zu, Jialei Li, Yu Zhang, Ru Jiang, Zhonghua ZhangKey Laboratory of Forest Plant Ecology, Northeast Forestry University, Ministry of Education, Harbin, Heilongjiang, ChinaAbstract: Paclitaxel (Taxol® is an important anticancer drug in clinical use for treatment of a variety of cancers. Because of its low solubility, it is formulated in high concentration in Cremophor EL® which induces hypersensitivity reactions. In this study, targeted delivery of paclitaxel-loaded nanoparticles was prepared by a desolvation procedure, crosslinked on the wall material of bovine serum albumin, and subsequently decorated by folic acid. The characteristics of the nanoparticles, such as amount of folate conjugation, surface morphology, drug entrapment efficiency, drug loading efficiency, and release kinetics were investigated in vitro. The targeting effect was investigated in vitro by cancer cell uptake of fluorescein isothiocyanate-labeled nanoparticles. The spherical nanoparticles obtained were negatively charged with a zeta potential of about -30 mV, and characterized around 210 nm with a narrow size distribution. Drug entrapment efficiency and drug loading efficiency were approximately 95.3% and 27.2%, respectively. The amount of folate conjugation was 9.22 µg/mg of bovine serum albumin. The folate-decorated nanoparticles targeted a human prostate cancer cell line effectively.Keywords: paclitaxel, bovine serum albumin, folate, nanoparticles, target delivery

  3. Silymarin induces insulin resistance through an increase of phosphatase and tensin homolog in Wistar rats.

    Directory of Open Access Journals (Sweden)

    Kai-Chun Cheng

    Full Text Available BACKGROUND AND AIMS: Phosphatase and tensin homolog (PTEN is a phosphoinositide phosphatase that regulates crucial cellular functions, including insulin signaling, lipid and glucose metabolism, as well as survival and apoptosis. Silymarin is the active ingredient in milk thistle and exerts numerous effects through the activation of PTEN. However, the effect of silymarin on the development of insulin resistance remains unknown. METHODS: Wistar rats fed fructose-rich chow or normal chow were administered oral silymarin to identify the development of insulin resistance using the homeostasis model assessment of insulin resistance and hyperinsulinemic- euglycemic clamping. Changes in PTEN expression in skeletal muscle and liver were compared using western blotting analysis. Further investigation was performed in L6 cells to check the expression of PTEN and insulin-related signals. PTEN deletion in L6 cells was achieved by small interfering ribonucleic acid transfection. RESULTS: Oral administration of silymarin at a dose of 200 mg/kg once daily induced insulin resistance in normal rats and enhanced insulin resistance in fructose-rich chow-fed rats. An increase of PTEN expression was observed in the skeletal muscle and liver of rats with insulin resistance. A decrease in the phosphorylation of Akt in L6 myotube cells, which was maintained in a high-glucose condition, was also observed. Treatment with silymarin aggravated high-glucose-induced insulin resistance. Deletion of PTEN in L6 cells reversed silymarin-induced impaired insulin signaling and glucose uptake. CONCLUSIONS: Silymarin has the ability to disrupt insulin signaling through increased PTEN expression. Therefore, silymarin should be used carefully in type-2 diabetic patients.

  4. Pressure Induced Polymorphic Phase Transition of Natural Metamorphic Kalsilite; Electrical Resistivity and Infrared Spectroscopic Investigations

    Directory of Open Access Journals (Sweden)

    G. Parthasarathy

    2015-10-01

    Full Text Available We report here pressure dependence of the electrical resistivity of natural kalsilite (K0.998Na0.002Al0.998Fe0.002SiO4 from a granulite facies terrain in southern India. The electrical resistivity of kalsilite was measured with four probe technique up to 7.5 GPa at room temperature. The electrical resistivity decreases continuously with the increase of pressure up to 3.7 GPa, where there is a discontinuous drop in the electrical resistivity by 14%–16% indicating a first order transition. Further increase of pressure does not induce any phase transition up to 7.5 GPa at room temperature. Fourier transform infrared (FTIR spectroscopy of the kalsilite sample at various pressures indicates that the observed transition is reversible in nature.

  5. Inhibition of ceramide synthesis ameliorates glucocorticoid-, saturated-fat-, and obesity-induced insulin resistance.

    Science.gov (United States)

    Holland, William L; Brozinick, Joseph T; Wang, Li-Ping; Hawkins, Eric D; Sargent, Katherine M; Liu, Yanqi; Narra, Krishna; Hoehn, Kyle L; Knotts, Trina A; Siesky, Angela; Nelson, Don H; Karathanasis, Sotirios K; Fontenot, Greg K; Birnbaum, Morris J; Summers, Scott A

    2007-03-01

    Insulin resistance occurs in 20%-25% of the human population, and the condition is a chief component of type 2 diabetes mellitus and a risk factor for cardiovascular disease and certain forms of cancer. Herein, we demonstrate that the sphingolipid ceramide is a common molecular intermediate linking several different pathological metabolic stresses (i.e., glucocorticoids and saturated fats, but not unsaturated fats) to the induction of insulin resistance. Moreover, inhibition of ceramide synthesis markedly improves glucose tolerance and prevents the onset of frank diabetes in obese rodents. Collectively, these data have two important implications. First, they indicate that different fatty acids induce insulin resistance by distinct mechanisms discerned by their reliance on sphingolipid synthesis. Second, they identify enzymes required for ceramide synthesis as therapeutic targets for combating insulin resistance caused by nutrient excess or glucocorticoid therapy.

  6. Di-octyl phthalate induced altered host resistance: Viral and protozoal models in mice

    Energy Technology Data Exchange (ETDEWEB)

    Dogra, R.K.S.; Khanna, S.; Srivastava, S.N.; Shukla, L.; Shanker, R. (Industrial Toxicology Research Centre, Lucknow (India)); Chandra, K.; Chandra, S.; Katiyar, J.C. (Central Drug Research Institute, Lucknow (India))

    1989-01-01

    Among industrially important chemicals, the effect of phthalate ester plasticizers on host resistance and immune surveillance to disease has not been well studied. Our recent studies with Di-ccetyl phthalate (DOP) have demonstrated lymphoid organotoxicity, alteration in the functioning of immune system and altered host resistance to a hookworm parasite (Nippostrongylus brasiliensis) in rodents. These observations suggested that DOP, probably through its effect on immune system, could result in altered host resistance to infection. The present studies were, therefore, undertaken to further assess the altered host resistance in DOP treated mice when challenged with either a virus (encephalomyocarditis) or a protozoal (plasmodium) infection, to delineate the possible contribution of phthalate-induced state of immunomodulation to infections.

  7. Magnetically induced nonvolatile magnetoresistance and resistance memory effect in phase-separated manganite thin films

    Science.gov (United States)

    Li, Qian; Cao, Qingqi; Wang, Dunhui; Du, Youwei

    2017-03-01

    We report the observation of magnetically induced resistance memory effect in a typical electronic phase-separated manganite La5/8‑x Pr x Ca3/8MnO3 (x  =  0.3) thin film. In the hysteresis region of metal-to-insulator transition, the resistance exhibits a sharp drop with the application of magnetic field and maintains the low resistance state after the removal of field, showing a nonvolatile magnetoresistance effect. The high resistance state can be recovered until the temperature is warmed. More explicit measurements at the hysteresis region exhibit the non-volatility and irreversibility of magnetoresistance, which can be ascribed to the percolative feature in the electronic phase-separated manganite. The origin and potential applications of these interesting effects are discussed.

  8. The Innate Immune Signaling System as a Regulator of Disease Resistance and Induced Systemic Resistance Activity Against Verticillium dahliae.

    Science.gov (United States)

    Gkizi, Danai; Lehmann, Silke; L'Haridon, Floriane; Serrano, Mario; Paplomatas, Epaminondas J; Métraux, Jean-Pierre; Tjamos, Sotirios E

    2016-04-01

    In the last decades, the plant innate immune responses against pathogens have been extensively studied, while biocontrol interactions between soilborne fungal pathogens and their hosts have received much less attention. Treatment of Arabidopsis thaliana with the nonpathogenic bacterium Paenibacillus alvei K165 was shown previously to protect against Verticillium dahliae by triggering induced systemic resistance (ISR). In the present study, we evaluated the involvement of the innate immune response in the K165-mediated protection of Arabidopsis against V. dahliae. Tests with Arabidopsis mutants impaired in several regulators of the early steps of the innate immune responses, including fls2, efr-1, bak1-4, mpk3, mpk6, wrky22, and wrky29 showed that FLS2 and WRKY22 have a central role in the K165-triggered ISR, while EFR1, MPK3, and MPK6 are possible susceptibility factors for V. dahliae and bak1 shows a tolerance phenomenon. The resistance induced by strain K165 is dependent on both salicylate and jasmonate-dependent defense pathways, as evidenced by an increased transient accumulation of PR1 and PDF1.2 transcripts in the aerial parts of infected plants treated with strain K165.

  9. Induced systemic resistance in cucumber and Arabidopsis thaliana by the combination of Trichoderma harzianum Tr6 and Pseudomonas sp.

    NARCIS (Netherlands)

    Alizadeh, H.; Behboudi, K.; Amadzadeh, M.; Javan-Nikkhah, M.; Zamioudis, C; Pieterse, C.M.J.; Bakker, P.A.H.M.

    2013-01-01

    Trichoderma species and fluorescent Pseudomonas spp. have been reported to induce systemic resistance in plants. In this study the effectiveness of a combination of these biological control agents on the efficacy of induced resistance was investigated in cucumber and the model plant Arabidopsis thal

  10. Pomegranate seed oil, a rich source of punicic acid, prevents diet-induced obesity and insulin resistance in mice.

    NARCIS (Netherlands)

    Vroegrijk, I.O.; Diepen, J.A. van; Berg, S.; Westbroek, I.; Keizer, H.; Gambelli, L.; Hontecillas, R.; Bassaganya-Riera, J.; Zondag, G.C.; Romijn, J.A.; Havekes, L.M.; Voshol, P.J.

    2011-01-01

    BACKGROUND: Pomegranate seed oil has been shown to protect against diet induced obesity and insulin resistance. OBJECTIVE: To characterize the metabolic effects of punicic acid on high fat diet induced obesity and insulin resistance. DESIGN: High-fat diet or high-fat diet with 1% Pomegranate seed oi

  11. Changes in chemical composition related to fungal infection and induced resistance in carnation and radish investigated by pyrolysis mass spectrometry

    NARCIS (Netherlands)

    Steijl, Harko; Niemann, G.J.; Boon, J.J.

    2002-01-01

    Pseudomonas fluorescens WCR 417r induces systemic resistance in radish roots challenged by Fusarium oxysporum f. sp. raphani and, incidentally, in carnation stems challenged by Fusarium oxysporum f. sp. dianthi. The induced systemic resistance is not associated with accumulation of pathogenesis-rela

  12. Pomegranate seed oil, a rich source of punicic acid, prevents diet-induced obesity and insulin resistance in mice.

    NARCIS (Netherlands)

    Vroegrijk, I.O.; Diepen, J.A. van; Berg, S.; Westbroek, I.; Keizer, H.; Gambelli, L.; Hontecillas, R.; Bassaganya-Riera, J.; Zondag, G.C.; Romijn, J.A.; Havekes, L.M.; Voshol, P.J.

    2011-01-01

    BACKGROUND: Pomegranate seed oil has been shown to protect against diet induced obesity and insulin resistance. OBJECTIVE: To characterize the metabolic effects of punicic acid on high fat diet induced obesity and insulin resistance. DESIGN: High-fat diet or high-fat diet with 1% Pomegranate seed oi

  13. Pomegranate seed oil, a rich source of punicic acid, prevents diet-induced obesity and insulin resistance in mice.

    NARCIS (Netherlands)

    Vroegrijk, I.O.; Diepen, J.A. van; Berg, S.; Westbroek, I.; Keizer, H.; Gambelli, L.; Hontecillas, R.; Bassaganya-Riera, J.; Zondag, G.C.; Romijn, J.A.; Havekes, L.M.; Voshol, P.J.

    2011-01-01

    BACKGROUND: Pomegranate seed oil has been shown to protect against diet induced obesity and insulin resistance. OBJECTIVE: To characterize the metabolic effects of punicic acid on high fat diet induced obesity and insulin resistance. DESIGN: High-fat diet or high-fat diet with 1% Pomegranate seed

  14. Free fatty acid-induced hepatic insulin resistance is attenuated following lifestyle intervention in obese individuals with impaired glucose tolerance

    DEFF Research Database (Denmark)

    Haus, Jacob M; Solomon, Thomas; Marchetti, Christine M

    2010-01-01

    The objective of the study was to examine the effects of an exercise/diet lifestyle intervention on free fatty acid (FFA)-induced hepatic insulin resistance in obese humans.......The objective of the study was to examine the effects of an exercise/diet lifestyle intervention on free fatty acid (FFA)-induced hepatic insulin resistance in obese humans....

  15. Adaptive response of rat pancreatic β-cells to insulin resistance induced by monocrotophos: Biochemical evidence.

    Science.gov (United States)

    Nagaraju, Raju; Rajini, Padmanabhan Sharda

    2016-11-01

    Our previous findings clearly suggested the role of duration of exposure to monocrotophos (MCP) in the development of insulin resistance. Rats exposed chronically to MCP developed insulin resistance with hyperinsulinemia without overt diabetes. In continuation of this vital observation, we sought to delineate the biochemical mechanisms that mediate heightened pancreatic β-cell response in the wake of MCP-induced insulin resistance in rats. Adult rats were orally administered (0.9 and 1.8mg/kgb.w/d) MCP for 180days. Terminally, MCP-treated rats exhibited glucose intolerance, hyperinsulinemia, and potentiation of glucose-induced insulin secretion along with elevated levels of circulating IGF1, free fatty acids, corticosterone, and paraoxonase activity. Biochemical analysis of islet extracts revealed increased levels of insulin, malate, pyruvate and ATP with a concomitant increase in activities of cytosolic and mitochondrial enzymes that are known to facilitate insulin secretion and enhanced shuttle activities. Interestingly, islets from MCP-treated rats exhibited increased insulin secretory potential ex vivo compared to those isolated from control rats. Further, MCP-induced islet hypertrophy was associated with increased insulin-positive cells. Our study demonstrates the impact of the biological interaction between MCP and components of metabolic homeostasis on pancreatic beta cell function/s. We speculate that the heightened pancreatic beta cell function evidenced may be mediated by increased IGF1 and paraoxonase activity, which effectively counters insulin resistance induced by chronic exposure to MCP. Our findings emphasize the need for focused research to understand the confounding environmental risk factors which may modulate heightened beta cell functions in the case of organophosphorus insecticide-induced insulin resistance. Such an approach may help us to explain the sharp increase in the prevalence of type II diabetes worldwide. Copyright © 2016 Elsevier

  16. Determinants of Pseudomonas putida WCS358 involved in inducing systemic resistance in plants.

    Science.gov (United States)

    Meziane, Hamid; VAN DER Sluis, Ientse; VAN Loon, Leendert C; Höfte, Monica; Bakker, Peter A H M

    2005-03-01

    SUMMARY Pseudomonas putida WCS358 is a plant growth-promoting rhizobacterium originally isolated from the rhizosphere of potato. It can suppress soil-borne plant diseases by siderophore-mediated competition for iron, but it has also been reported to result in induced systemic resistance (ISR) in Arabidopsis thaliana. Bacterial determinants of this strain involved in inducing systemic resistance in Arabidopsis were investigated using a Tn5 transposon mutant defective in biosynthesis of the fluorescent siderophore pseudobactin, a non-motile Tn5 mutant lacking flagella, and a spontaneous phage-resistant mutant lacking the O-antigenic side chain of the lipopolysaccharides (LPS). When using Pseudomonas syringae pv. tomato as the challenging pathogen, purified pseudobactin, flagella and LPS all triggered ISR. However, the mutants were all as effective as the parental strain, suggesting redundancy in ISR-triggering traits in WCS358. The Botrytis cinerea-tomato, B. cinerea-bean and Colletotrichum lindemuthianum-bean model systems were used to test further the potential of P. putida WCS358 to induce ISR. Strain WCS358 significantly reduced disease development in all three systems, indicating that also on tomato and bean WCS358 can trigger ISR. In both tomato and bean, the LPS mutant had lost the ability to induce resistance, whereas the flagella mutant was still effective. In bean, the pseudobactin mutant was still effective, whereas this mutant has lost its effectivity in tomato. In both bean and tomato, flagella isolated from the parental strain were not effective, whereas LPS or pseudobactin did induce systemic resistance.

  17. Induce systemic resistance in lupine against root rot diseases.

    Science.gov (United States)

    Ali, Abeer A; Ghoneem, K M; El-Metwally, M A; Abd El-Hai, K M

    2009-02-01

    Root rot caused by soil borne pathogenic fungi is the most sever disease attacks lupine plants. Isolation trials from diseased plants in some areas of Dakahlia Province (Egypt) was carried out. Rhizoctonia solani and Fusarium solani proved to be the most dominant isolates. Meanwhile, Fusarium oxysporum and Sclerotium rolfsii were less frequent. Efficacies of some plant resistance elicitors viz.: chitosan (CHI), Salicylic Acid (SA) and hydroquinone (HQ) in comparing to the fungicide Rhizolex T-50 as seed treatments showed significant reduction in the fungal growth in vitro. Chitosan at 8 g L(-1) and fungicide completely inhibited the growth of all isolated fungi, while SA at 1.4 g L(-1) and HQ at 1.2 g L(-1) inhibited the growth of Fusarium solani and F. oxysporum, respectively. The greenhouse experiments showed that S. rolfesii (No. 6) and R. solani (No. 2) followed by F. solani (No. 5) and F. oxysporum (No. 9) were the most aggressive root rot fungi. Soaking susceptible lupine seeds (Giza 1) in each one of the three selected elicitors showed a significant reduction in seedlings mortality. CHI at 8 g L(-1) was superior in increasing the percentage of healthy plants to record 72.5, 80.9, 62.7and 64.3%, when seeds were grown in soil infested with of F. solani, F. oxysporum, R. solani and S. rolfesii, respectively. These results were confirmed under field conditions in two different locations i.e., Tag El-Ezz and El-Serow Research Stations. CHI 8 g L(-1) proved to be the best elicitor after fungicide, in reducing lupine root rot disease. It showed 41 and 60% reduction in the plants mortality comparing to 56.37 and 69.13% in case of Rhizolex-T in Tag El-Ezz and El-Serow locations, respectively. The treatments were accompanied with a significant increase in lupine growth parameters, yield components and physiological aspects. Application of CHI at 8 g L(-1) or HQ at 1.2 g L(-1) was the most potent in this respect as compared to check treatment.

  18. Salinomycin induces apoptosis in cisplatin-resistant colorectal cancer cells by accumulation of reactive oxygen species.

    Science.gov (United States)

    Zhou, Jin; Li, Pu; Xue, Xiaofeng; He, Songbing; Kuang, Yuting; Zhao, Hong; Chen, Shaoji; Zhi, Qiaoming; Guo, Xiaobo

    2013-10-24

    Postoperative chemotherapy for Colorectal cancer (CRC) patients is not all effective and the main reason might lie in cancer stem cells (CSCs). Emerging studies showed that CSCs overexpress some drug-resistance related proteins, which efficiently transport the chemotherapeutics out of cancer cells. Salinomycin, which considered as a novel and an effective anticancer drug, is found to have the ability to kill both CSCs and therapy-resistant cancer cells. To explore the potential mechanisms that salinomycin could specifically target on therapy-resistant cancer cells in colorectal cancers, we firstly obtained cisplatin-resistant (Cisp-resistant) SW620 cells by repeated exposure to 5 μmol/l of cisplatin from an original colorectal cancer cell line. These Cisp-resistant SW620 cells, which maintained a relative quiescent state (G0/G1 arrest) and displayed stem-like signatures (up-regulations of Sox2, Oct4, Nanog, Klf4, Hes1, CD24, CD26, CD44, CD133, CD166, Lgr5, ALDH1A1 and ALDH1A3 mRNA expressions) (p 0.05), but could induce cell death process (p GSH-PX activities (p cisplatin-resistant colorectal cancer cells.

  19. Environmental azole fungicide, prochloraz, can induce cross-resistance to medical triazoles in Candida glabrata.

    Science.gov (United States)

    Faria-Ramos, Isabel; Tavares, Pedro R; Farinha, Sofia; Neves-Maia, João; Miranda, Isabel M; Silva, Raquel M; Estevinho, Letícia M; Pina-Vaz, Cidalia; Rodrigues, Acácio G

    2014-11-01

    Acquisition of azole resistance by clinically relevant yeasts in nature may result in a significant, yet undetermined, impact in human health. The main goal of this study was to assess the development of cross-resistance between agricultural and clinical azoles by Candida spp. An in vitro induction assay was performed, for a period of 90 days, with prochloraz (PCZ) - an agricultural antifungal. Afterward, the induced molecular resistance mechanisms were unveiled. MIC value of PCZ increased significantly in all Candida spp. isolates. However, only C. glabrata developed cross-resistance to fluconazole and posaconazole. The increased MIC values were stable. Candida glabrata azole resistance acquisition triggered by PCZ exposure involved the upregulation of the ATP binding cassette multidrug transporter genes and the transcription factor, PDR1. Single mutation previously implicated in azole resistance was found in PDR1 while ERG11 showed several synonymous single nucleotide polymorphisms. These results might explain why C. glabrata is so commonly less susceptible to clinical azoles, suggesting that its exposure to agricultural azole antifungals may be associated to the emergence of cross-resistance. Such studies forward potential explanations for the worldwide increasing clinical prevalence of C. glabrata and the associated worse prognosis of an infection by this species.

  20. Differential effectiveness of microbially induced resistance against herbivorous insects in Arabidopsis.

    Science.gov (United States)

    Van Oosten, Vivian R; Bodenhausen, Natacha; Reymond, Philippe; Van Pelt, Johan A; Van Loon, L C; Dicke, Marcel; Pieterse, Corné M J

    2008-07-01

    Rhizobacteria-induced systemic resistance (ISR) and pathogen-induced systemic acquired resistance (SAR) have a broad, yet partly distinct, range of effectiveness against pathogenic microorganisms. Here, we investigated the effectiveness of ISR and SAR in Arabidopsis against the tissue-chewing insects Pieris rapae and Spodoptera exigua. Resistance against insects consists of direct defense, such as the production of toxins and feeding deterrents and indirect defense such as the production of plant volatiles that attract carnivorous enemies of the herbivores. Wind-tunnel experiments revealed that ISR and SAR did not affect herbivore-induced attraction of the parasitic wasp Cotesia rubecula (indirect defense). By contrast, ISR and SAR significantly reduced growth and development of the generalist herbivore S. exigua, although not that of the specialist P. rapae. This enhanced direct defense against S. exigua was associated with potentiated expression of the defense-related genes PDF1.2 and HEL. Expression profiling using a dedicated cDNA microarray revealed four additional, differentially primed genes in microbially induced S. exigua-challenged plants, three of which encode a lipid-transfer protein. Together, these results indicate that microbially induced plants are differentially primed for enhanced insect-responsive gene expression that is associated with increased direct defense against the generalist S. exigua but not against the specialist P. rapae.