The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Nakamasa Hayashi - One of the best experts on this subject based on the ideXlab platform.
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combination of a stat3 inhibitor and an mtor inhibitor against a temozolomide resistant Glioblastoma Cell Line
Cancer Genomics & Proteomics, 2017Co-Authors: Haruo Miyata, Tadashi Ashizawa, Akira Iizuka, Takashi Sugino, Nakamasa Hayashi, Ryota Kondou, Chizu Nonomura, Kenichi Urakami, Akira Asai, Koichi MitsuyaAbstract:Background Temozolomide-resistant (TMZ-R) Glioblastoma is very difficult to treat, and a novel approach to overcome resistance is needed. Materials and methods The efficacy of a combination treatment of STAT3 inhibitor, STX-0119, with rapamycin was investigated against our established TMZ-resistant U87 Cell Line. Results The growth-inhibitory effect of the combination treatment was significant against the TMZ-R U87 Cell Line (IC50: 78 μM for STX-0119, 30.5 μM for rapamycin and 11.3 μM for combination of the two). Western blotting analysis demonstrated that the inhibitory effect of STX-0119 on S6 and 4E-BP1 activation through regulation of YKL-40 expression occurred in addition to the inhibitory effect of rapamycin against the mTOR pathway. Conclusion These results suggest that the STAT3 pathway is associated with the mTOR downstream pathway mediated by YKL-40 protein, and the combination therapy of the STAT3 inhibitor and rapamycin could be worth developing as a novel therapeutic approach against TMZ-resistant relapsed gliomas.
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ykl 40 downregulation is a key factor to overcome temozolomide resistance in a Glioblastoma Cell Line
Oncology Reports, 2014Co-Authors: Yasuto Akiyama, Tadashi Ashizawa, Masaru Komiyama, Haruo Miyata, Chie Oshita, Maho Omiya, Akira Iizuka, Akiko Kume, Takashi Sugino, Nakamasa HayashiAbstract:The frequent recurrence of Glioblastoma multiforme (GBM) after standard treatment with temozolomide (TMZ) is a crucial issue to be solved in the clinical field. O6‑methylguanine‑DNA methyltransferase (MGMT) is considered one of the major mechanisms involved in TMZ resistance. However, some important mechanisms for TMZ resistance other than MGMT have recently been identified. In the present study, we established a TMZ-resistant (TMZ-R) U87 Glioblastoma Cell Line in vitro and in vivo and investigated novel targeting molecules other than MGMT in those Cells. The TMZ-R U87 Glioblastoma Cell Line was established in vitro and in vivo. TMZ-R U87 Cells showed a more invasive activity and a shorter survival time in vivo. Gene expression analysis using DNA microarray and quantitative PCR (qPCR) demonstrated that YKL‑40, MAGEC1 and MGMT mRNA expression was upregulated 100-, 83- and 6-fold, respectively in the TMZ-R U87 Cell Line. Western blot analysis and qPCR demonstrated that STAT3 phosphorylation, STAT3 target genes and stem Cell and mesenchymal marker genes were upregulated to a greater extent in the TMZ‑resistant Cell Line. Notably, short hairpin (sh)RNA‑based inhibition against the YKL‑40 gene resulted in moderate growth inhibition in the resistant Cells in vitro and in vivo. Additionally, YKL‑40 gene inhibition exhibited significant suppression of the invasive activity and particularly partially restored the sensitivity to TMZ. Therefore, YKL‑40 may be a novel key molecule in addition to MGMT, that is responsible for TMZ resistance in Glioblastoma Cell Lines and could be a new target to overcome TMZ resistance in recurrent Glioblastomas in the future.
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effect of the stat3 inhibitor stx 0119 on the proliferation of a temozolomide resistant Glioblastoma Cell Line
International Journal of Oncology, 2014Co-Authors: Tadashi Ashizawa, Yasuto Akiyama, Masaru Komiyama, Haruo Miyata, Maho Omiya, Akira Iizuka, Akiko Kume, Takashi Sugino, Akira Asai, Nakamasa HayashiAbstract:Glioblastoma multiforme (GBM) is one of the most malignant and aggressive tumors and has a very poor prognosis, with a median survival time of less than 2 years. Once recurrence develops, there are few therapeutic approaches to control the growth of Glioblastoma. In particular, temozolomide (TMZ)-resistant (TMZ-R) GBM is very difficult to treat, and a novel approach to overcome resistance is eagerly awaited. Previously, we reported a novel small molecule inhibitor of STAT3 dimerization, STX-0119, as a cancer therapeutic. In the current study, the efficacy of STX-0119 was evaluated against our established TMZ-resistant U87 Cell Line using quantitative PCR-based gene expression analysis, in vitro assay and animal experiments. The growth inhibitory effect of STX-0119 on U87 and TMZ-R U87 Cells was moderate (IC₅₀, 34 and 45 µM, respectively). In particular, STX-0119 did not show significant inhibition of U87 tumor growth; however, it suppressed the growth of the TMZ-R U87 tumor in nude mice by more than 50%, and prolonged the median survival time compared to the control group. Quantitative PCR revealed that YKL-40, MAGEC1, MGMT, several EMT genes, mesenchymal genes and STAT3 target genes were upregulated, but most of those genes were downregulated by STX-0119 treatment. Furthermore, the invasive activity of TMZ-R U87 Cells was significantly inhibited by STX-0119. YKL-40 levels in TMZ-R U87 Cells and their supernatants were significantly decreased by STX-0119 administration. These results suggest that STX-0119 is an efficient therapeutic to overcome TMZ resistance in recurrent GBM tumors, and could be the next promising compound leading to survival prolongation, and YKL-40 may be a possible surrogate marker for STAT3 targeting.
Haruo Miyata - One of the best experts on this subject based on the ideXlab platform.
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combination of a stat3 inhibitor and an mtor inhibitor against a temozolomide resistant Glioblastoma Cell Line
Cancer Genomics & Proteomics, 2017Co-Authors: Haruo Miyata, Tadashi Ashizawa, Akira Iizuka, Takashi Sugino, Nakamasa Hayashi, Ryota Kondou, Chizu Nonomura, Kenichi Urakami, Akira Asai, Koichi MitsuyaAbstract:Background Temozolomide-resistant (TMZ-R) Glioblastoma is very difficult to treat, and a novel approach to overcome resistance is needed. Materials and methods The efficacy of a combination treatment of STAT3 inhibitor, STX-0119, with rapamycin was investigated against our established TMZ-resistant U87 Cell Line. Results The growth-inhibitory effect of the combination treatment was significant against the TMZ-R U87 Cell Line (IC50: 78 μM for STX-0119, 30.5 μM for rapamycin and 11.3 μM for combination of the two). Western blotting analysis demonstrated that the inhibitory effect of STX-0119 on S6 and 4E-BP1 activation through regulation of YKL-40 expression occurred in addition to the inhibitory effect of rapamycin against the mTOR pathway. Conclusion These results suggest that the STAT3 pathway is associated with the mTOR downstream pathway mediated by YKL-40 protein, and the combination therapy of the STAT3 inhibitor and rapamycin could be worth developing as a novel therapeutic approach against TMZ-resistant relapsed gliomas.
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ykl 40 downregulation is a key factor to overcome temozolomide resistance in a Glioblastoma Cell Line
Oncology Reports, 2014Co-Authors: Yasuto Akiyama, Tadashi Ashizawa, Masaru Komiyama, Haruo Miyata, Chie Oshita, Maho Omiya, Akira Iizuka, Akiko Kume, Takashi Sugino, Nakamasa HayashiAbstract:The frequent recurrence of Glioblastoma multiforme (GBM) after standard treatment with temozolomide (TMZ) is a crucial issue to be solved in the clinical field. O6‑methylguanine‑DNA methyltransferase (MGMT) is considered one of the major mechanisms involved in TMZ resistance. However, some important mechanisms for TMZ resistance other than MGMT have recently been identified. In the present study, we established a TMZ-resistant (TMZ-R) U87 Glioblastoma Cell Line in vitro and in vivo and investigated novel targeting molecules other than MGMT in those Cells. The TMZ-R U87 Glioblastoma Cell Line was established in vitro and in vivo. TMZ-R U87 Cells showed a more invasive activity and a shorter survival time in vivo. Gene expression analysis using DNA microarray and quantitative PCR (qPCR) demonstrated that YKL‑40, MAGEC1 and MGMT mRNA expression was upregulated 100-, 83- and 6-fold, respectively in the TMZ-R U87 Cell Line. Western blot analysis and qPCR demonstrated that STAT3 phosphorylation, STAT3 target genes and stem Cell and mesenchymal marker genes were upregulated to a greater extent in the TMZ‑resistant Cell Line. Notably, short hairpin (sh)RNA‑based inhibition against the YKL‑40 gene resulted in moderate growth inhibition in the resistant Cells in vitro and in vivo. Additionally, YKL‑40 gene inhibition exhibited significant suppression of the invasive activity and particularly partially restored the sensitivity to TMZ. Therefore, YKL‑40 may be a novel key molecule in addition to MGMT, that is responsible for TMZ resistance in Glioblastoma Cell Lines and could be a new target to overcome TMZ resistance in recurrent Glioblastomas in the future.
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effect of the stat3 inhibitor stx 0119 on the proliferation of a temozolomide resistant Glioblastoma Cell Line
International Journal of Oncology, 2014Co-Authors: Tadashi Ashizawa, Yasuto Akiyama, Masaru Komiyama, Haruo Miyata, Maho Omiya, Akira Iizuka, Akiko Kume, Takashi Sugino, Akira Asai, Nakamasa HayashiAbstract:Glioblastoma multiforme (GBM) is one of the most malignant and aggressive tumors and has a very poor prognosis, with a median survival time of less than 2 years. Once recurrence develops, there are few therapeutic approaches to control the growth of Glioblastoma. In particular, temozolomide (TMZ)-resistant (TMZ-R) GBM is very difficult to treat, and a novel approach to overcome resistance is eagerly awaited. Previously, we reported a novel small molecule inhibitor of STAT3 dimerization, STX-0119, as a cancer therapeutic. In the current study, the efficacy of STX-0119 was evaluated against our established TMZ-resistant U87 Cell Line using quantitative PCR-based gene expression analysis, in vitro assay and animal experiments. The growth inhibitory effect of STX-0119 on U87 and TMZ-R U87 Cells was moderate (IC₅₀, 34 and 45 µM, respectively). In particular, STX-0119 did not show significant inhibition of U87 tumor growth; however, it suppressed the growth of the TMZ-R U87 tumor in nude mice by more than 50%, and prolonged the median survival time compared to the control group. Quantitative PCR revealed that YKL-40, MAGEC1, MGMT, several EMT genes, mesenchymal genes and STAT3 target genes were upregulated, but most of those genes were downregulated by STX-0119 treatment. Furthermore, the invasive activity of TMZ-R U87 Cells was significantly inhibited by STX-0119. YKL-40 levels in TMZ-R U87 Cells and their supernatants were significantly decreased by STX-0119 administration. These results suggest that STX-0119 is an efficient therapeutic to overcome TMZ resistance in recurrent GBM tumors, and could be the next promising compound leading to survival prolongation, and YKL-40 may be a possible surrogate marker for STAT3 targeting.
Matthew Drill - One of the best experts on this subject based on the ideXlab platform.
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inhibition of purinergic p2x receptor 7 p2x7r decreases granulocyte macrophage colony stimulating factor gm csf expression in u251 Glioblastoma Cells
Scientific Reports, 2020Co-Authors: Matthew Drill, Kim L Powell, Liyen Katrina Kan, Nigel C Jones, Terence J Obrien, John A Hamilton, Mastura MonifAbstract:Glioblastoma is the most aggressive form of primary brain cancer, with a median survival of 12-15 months. The P2X receptor 7 (P2X7R) is upregulated in Glioblastoma and is associated with increased tumor Cell proliferation. The cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) is also upregulated in Glioblastoma and has been shown to have both pro- and anti-tumor functions. This study investigates the potential mechanism linking P2X7R and GM-CSF in the U251 Glioblastoma Cell Line and the therapeutic potential of P2X7R antagonism in this setting. P2X7R protein and mRNA was demonstrated to be expressed in the U251 Cell Line as assessed by immunocytochemistry and qPCR. Its channel function was intact as demonstrated by live Cell confocal imaging using a calcium indicator Fluo-4 AM. Inhibition of P2X7R using antagonist AZ10606120, decreased both GM-CSF mRNA (P < 0.05) and protein (P < 0.01) measured by qPCR and ELISA respectively. Neutralization of GM-CSF with an anti-GM-CSF antibody did not alter U251 Cell proliferation, however, P2X7R antagonism with AZ10606120 significantly reduced U251 Glioblastoma Cell numbers (P < 0.01). This study describes a novel link between P2X7R activity and GM-CSF expression in a human Glioblastoma Cell Line and highlights the potential therapeutic benefit of P2X7R inhibition with AZ10606120 in Glioblastoma.
Jasti S Rao - One of the best experts on this subject based on the ideXlab platform.
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restoration of tissue factor pathway inhibitor 2 in a human Glioblastoma Cell Line triggers caspase mediated pathway and apoptosis
Clinical Cancer Research, 2007Co-Authors: Joseph George, Christopher S Gondi, Dzung H Dinh, Meena Gujrati, Jasti S RaoAbstract:Purpose: The induction of apoptotic pathways in cancer Cells offers a novel and potentially useful approach to improve patient responses to conventional chemotherapy. Tissue factor pathway inhibitor-2 (TFPI-2) is a protease inhibitor that is abundant in the extraCellular matrix and highly expressed in noninvasive Cells but absent or undetectable in highly invasive human Glioblastoma Cells. Experimental Design: Using a recombinant adeno-associated viral vector carrying human TFPI-2 cDNA, we stably expressed TFPI-2 in U-251 Cells, a highly invasive human Glioblastoma Cell Line. Our previous studies showed that restoration of TFPI-2 in Glioblastomas effectively prevents Cell proliferation, angiogenesis, and tumor invasion. In this study, we determined whether TFPI-2 restoration could induce apoptosis through the caspase-mediated signaling pathway. Results: The results from nuclear chromatin staining, terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling assay, and fluorescence-activated Cell sorting analysis showed increased apoptosis in U-251 Cells after restoration of TFPI-2. Caspase-9 and caspase-3 activity assays showed increased activity, indicating enhanced apoptosis. Immunofluorescence for cleaved caspase-9 and caspase-3 depicted increased expression and colocalization of both molecules. Western blot analysis showed increased transcriptional activities of Fas ligand, tumor necrosis factor-α, Bax, Fas-associated death domain, and tumor necrosis factor receptor 1–associated death domain as well as elevated levels of cleaved caspases and poly(ADP-ribose) polymerase. Semiquantitative reverse transcription-PCR depicted increased expression of tumor necrosis factor-α and Fas ligand and the related death domains tumor necrosis factor receptor 1–associated death domain and Fas-associated death domain. Conclusions: Taken together, these results show that restoration of TFPI-2 activates both intrinsic and extrinsic caspase-mediated, proapoptotic signaling pathways and induces apoptosis in U-251 Cells. Furthermore, our study suggests that recombinant adeno-associated viral vector–mediated gene expression offers a novel tool for cancer gene therapy.
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inhibition of in vivo tumorigenicity and invasiveness of a human Glioblastoma Cell Line transfected with antisense upar vectors
Clinical & Experimental Metastasis, 1997Co-Authors: Shravan K Chintala, Sanjeeva Mohanam, Ziya L Gokaslan, Boyapati Venkaiah, Rolf Bjerkvig, Kazunari Oka, Garth L Nicolson, Raymond Sawaya, Jasti S RaoAbstract:Our previous studies showed that Glioblastomas express increased urokinase-type plasminogen activator receptors (uPARs) in comparison to low-grade gliomas (Yamamoto et al., Cancer Res., 54, 5016-5020, 1994). To explore whether downregulation of uPAR inhibits tumor formation and invasiveness, a human Glioblastoma Cell Line was transfected with a cDNA construct corresponding to 300 bp of the human uPAR's 5' end in an antisense orientation, resulting in a reduced number of uPA receptors. Co-culture studies with tumor spheroids and fetal rat brain aggregates showed that antisense SNB19-AS1 Cells expressing reduced uPAR failed to invade fetal rat brain aggregates. Intracerebral injection of SNB19-AS1 stable transfectants failed to form tumors and were negative for uPAR expression in nude mice. Thus uPAR appears in this model to be essential for tumorigenicity and invasion of Glioblastomas in vivo.
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in vitro inhibition of human Glioblastoma Cell Line invasiveness by antisense upa receptor
Oncogene, 1997Co-Authors: Sanjeeva Mohanam, Shravan K Chintala, Ziya L Gokaslan, Boyapati Venkaiah, Raymond Sawaya, Anuradha Bhattacharya, Douglas D Boyd, Jasti S RaoAbstract:The Cell surface urokinase-type plasminogen activator receptor (uPAR) has been shown to be a key molecule in regulating plasminogen-mediated extraCellular proteolysis. To investigate the role of uPAR in invasion of brain tumors, human Glioblastoma Cell Line SNB19 was stably transfected with a vector capable of expressing an antisense transcript complementary to the 300 base pair of the 5' end of the uPAR mRNA. Parental and stably transfected (vector, sense, and antisense) Cell Lines were analysed for uPAR mRNA transcript by Northern blot analysis, and receptor protein levels were measured by radioreceptor assays and Western blotting. Significant reduction of uPAR sites was observed in the antisense transfected Cell Lines. The levels of uPAR mRNA were significantly decreased in antisense clones compared to control, vector and sense clones. The invasive potential of the Cell Lines in vitro was measured by Matrigel invasion assay and migration of Cells from spheroids to monolayers. The antisense transfected Cells showed a markedly lower level of invasion and migration than the controls. The antisense clones were more adhesive to the ECM components compared to parental, vector and sense clones. All transfected (vector, sense and antisense) clones and parental Cells produced similar levels of uPA activity without any significant difference however, MMP-2 activity was decreased in antisense clones compared to controls. These results demonstrate that uPAR expression is critical for the invasiveness of human gliomas and down regulation of uPAR expression may be a feasible approach to decrease invasiveness.
Tadashi Ashizawa - One of the best experts on this subject based on the ideXlab platform.
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combination of a stat3 inhibitor and an mtor inhibitor against a temozolomide resistant Glioblastoma Cell Line
Cancer Genomics & Proteomics, 2017Co-Authors: Haruo Miyata, Tadashi Ashizawa, Akira Iizuka, Takashi Sugino, Nakamasa Hayashi, Ryota Kondou, Chizu Nonomura, Kenichi Urakami, Akira Asai, Koichi MitsuyaAbstract:Background Temozolomide-resistant (TMZ-R) Glioblastoma is very difficult to treat, and a novel approach to overcome resistance is needed. Materials and methods The efficacy of a combination treatment of STAT3 inhibitor, STX-0119, with rapamycin was investigated against our established TMZ-resistant U87 Cell Line. Results The growth-inhibitory effect of the combination treatment was significant against the TMZ-R U87 Cell Line (IC50: 78 μM for STX-0119, 30.5 μM for rapamycin and 11.3 μM for combination of the two). Western blotting analysis demonstrated that the inhibitory effect of STX-0119 on S6 and 4E-BP1 activation through regulation of YKL-40 expression occurred in addition to the inhibitory effect of rapamycin against the mTOR pathway. Conclusion These results suggest that the STAT3 pathway is associated with the mTOR downstream pathway mediated by YKL-40 protein, and the combination therapy of the STAT3 inhibitor and rapamycin could be worth developing as a novel therapeutic approach against TMZ-resistant relapsed gliomas.
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ykl 40 downregulation is a key factor to overcome temozolomide resistance in a Glioblastoma Cell Line
Oncology Reports, 2014Co-Authors: Yasuto Akiyama, Tadashi Ashizawa, Masaru Komiyama, Haruo Miyata, Chie Oshita, Maho Omiya, Akira Iizuka, Akiko Kume, Takashi Sugino, Nakamasa HayashiAbstract:The frequent recurrence of Glioblastoma multiforme (GBM) after standard treatment with temozolomide (TMZ) is a crucial issue to be solved in the clinical field. O6‑methylguanine‑DNA methyltransferase (MGMT) is considered one of the major mechanisms involved in TMZ resistance. However, some important mechanisms for TMZ resistance other than MGMT have recently been identified. In the present study, we established a TMZ-resistant (TMZ-R) U87 Glioblastoma Cell Line in vitro and in vivo and investigated novel targeting molecules other than MGMT in those Cells. The TMZ-R U87 Glioblastoma Cell Line was established in vitro and in vivo. TMZ-R U87 Cells showed a more invasive activity and a shorter survival time in vivo. Gene expression analysis using DNA microarray and quantitative PCR (qPCR) demonstrated that YKL‑40, MAGEC1 and MGMT mRNA expression was upregulated 100-, 83- and 6-fold, respectively in the TMZ-R U87 Cell Line. Western blot analysis and qPCR demonstrated that STAT3 phosphorylation, STAT3 target genes and stem Cell and mesenchymal marker genes were upregulated to a greater extent in the TMZ‑resistant Cell Line. Notably, short hairpin (sh)RNA‑based inhibition against the YKL‑40 gene resulted in moderate growth inhibition in the resistant Cells in vitro and in vivo. Additionally, YKL‑40 gene inhibition exhibited significant suppression of the invasive activity and particularly partially restored the sensitivity to TMZ. Therefore, YKL‑40 may be a novel key molecule in addition to MGMT, that is responsible for TMZ resistance in Glioblastoma Cell Lines and could be a new target to overcome TMZ resistance in recurrent Glioblastomas in the future.
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effect of the stat3 inhibitor stx 0119 on the proliferation of a temozolomide resistant Glioblastoma Cell Line
International Journal of Oncology, 2014Co-Authors: Tadashi Ashizawa, Yasuto Akiyama, Masaru Komiyama, Haruo Miyata, Maho Omiya, Akira Iizuka, Akiko Kume, Takashi Sugino, Akira Asai, Nakamasa HayashiAbstract:Glioblastoma multiforme (GBM) is one of the most malignant and aggressive tumors and has a very poor prognosis, with a median survival time of less than 2 years. Once recurrence develops, there are few therapeutic approaches to control the growth of Glioblastoma. In particular, temozolomide (TMZ)-resistant (TMZ-R) GBM is very difficult to treat, and a novel approach to overcome resistance is eagerly awaited. Previously, we reported a novel small molecule inhibitor of STAT3 dimerization, STX-0119, as a cancer therapeutic. In the current study, the efficacy of STX-0119 was evaluated against our established TMZ-resistant U87 Cell Line using quantitative PCR-based gene expression analysis, in vitro assay and animal experiments. The growth inhibitory effect of STX-0119 on U87 and TMZ-R U87 Cells was moderate (IC₅₀, 34 and 45 µM, respectively). In particular, STX-0119 did not show significant inhibition of U87 tumor growth; however, it suppressed the growth of the TMZ-R U87 tumor in nude mice by more than 50%, and prolonged the median survival time compared to the control group. Quantitative PCR revealed that YKL-40, MAGEC1, MGMT, several EMT genes, mesenchymal genes and STAT3 target genes were upregulated, but most of those genes were downregulated by STX-0119 treatment. Furthermore, the invasive activity of TMZ-R U87 Cells was significantly inhibited by STX-0119. YKL-40 levels in TMZ-R U87 Cells and their supernatants were significantly decreased by STX-0119 administration. These results suggest that STX-0119 is an efficient therapeutic to overcome TMZ resistance in recurrent GBM tumors, and could be the next promising compound leading to survival prolongation, and YKL-40 may be a possible surrogate marker for STAT3 targeting.