77 research outputs found

    DIRECT EFFECTS OF VEGF/VEGF-R TARGETING AGENTS ON COLON CANCER CELLS

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    Anti-angiogenic therapies targeting vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) are important treatments for a number of human malignancies, including colorectal cancers. However, there is increasing evidence that VEGF/VEGF-R inhibitors promote the adaptive and evasive resistance of tumor cells to the therapies. The mechanism by which the cancer cells become resistant remains unclear. One potential mechanism is that VEGF/VEGF-R blockers directly act on tumor cells independently of anti-angiogenic effects. In this study, the direct effects of an anti-VEGF antibody (bevacizumab) and a VEGF-R tyrosine kinase inhibitor (sunitinib) on the evasive adaptation of colon cancer cells were compared. HCT116 and RKO human colon cancer cell lines were chronically exposed (3 months) to bevacizumab or sunitinib in vitro to establish bevacizumab- and sunitinib-adapted cells, respectively. Transwell migration and invasion assays, western blotting, reverse transcription-quantitative polymerase chain reaction, co-immunoprecipitation analysis, cell survival assays and ELISAs were conducted to analyze the adapted cells. Compared with the control vehicle-treated cells, the two cell models exhibited increased migration and invasion activities to different degrees and through different mechanisms. The bevacizumab-adapted cells, but not in the sunitinib-adapted cells, exhibited redundantly increased expression levels of VEGF/VEGF-R family members, including VEGF-A, placental growth factor, VEGF-C, VEGF-R1 and VEGF-R3. In addition, the phosphorylation levels of VEGF-R1 and VEGF-R3 were increased in the bevacizumab-adapted cells compared with the control cells. Thus, the inhibition of VEGF-R1 and VEGF-R3 decreased the evasive activities of the cells, suggesting that they remained dependent on redundant VEGF/VEGF-R signaling. By contrast, the sunitinib-adapted cells exhibited increased neuropilin-1 (NRP1) expression levels compared with the control cells. In the sunitinib-adapted cells, NRP1 interacted with phosphorylated cMet, and the cMet activation was dependent on NRP1. Thus, NRP1 or cMet blockade suppressed the evasive activation of the sunitinib-adapted cells. These results suggest that the sunitinib-adapted cells switched from a VEGF-R-dependent pathway to an alternative NRP1/cMet-dependent one. The findings of the present study indicate that VEGF/VEGF-R inhibitors directly act on colon cancer cells and activate their evasive adaptation via different mechanisms

    Antiangiogenic agent sunitinib induces epithelial to mesenchymal transition and accelerates motility of colorectal cancer cells

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    Although vascular endothelial growth factor receptor (VEGF-R)-targeted antiangiogenic agents are important treatment for a number of human malignancies, there is accumulating evidence that the therapies may promote disease progression, such as invasion and metastasis. How tumors become to promote their evasiveness remains fully uncertain. One of possiblemechanisms for the adaptationmay be a direct effect of VEGF-R inhibitors on tumor cells expressing VEGF-R. To elucidate a direct effect of VEGF-R-targeting drug (sunitinib), we established a human colorectal cancer cell model adapted to sunitinib. The sunitinib-conditioned cells showed a significant increase in cellular motility and migration activities, compared to the vehicle-treated control cells. Consistent with the phenotype, the sunitinib-conditioned cells decreased the expression levels of E-cadherin (an epithelial marker), while significantly increased the levels of Slug and Zeb1 (mesenchymal markers). Expression profiles of VEGF-R in the sunitinib-conditioned cells showed that only neuropilin-1 (NRP1) expression was significantly increased among all VEGF-R tested. Blockade of NRP1 using its antagonist clearly repressed the migration activationin sunitinib-conditioned cells, but not in the control cells. These results suggest that inhibition of VEGF-R on colorectal cancer cells can drive the epithelial-mesenchymal transition, leading to activation of cell motility in an NRP1-dependent manner

    Regorafenib induces adaptive resistance of colorectal cancer cells via inhibition of vascular endothelial growth factor receptor

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    Recently, inhibition of tumor angiogenesis has become an important anti-cancer therapy. Tumor angiogenesis is regulated by multiple signaling pathways, including VEGF and VEGF receptor (VEGF-R), FGF and FGF receptor (FGF-R), and PDGF and PDGF receptor (PDGF-R) pathways. Thus, the antiangiogenic agents, such as regorafenib, simultaneously target those receptors on vascular endothelial cells. In addition to endothelial cells, cancer cells express the three receptors, suggesting that the antiangiogenic inhibitors affect tumor cells. In fact, we previously demonstrated that regorafenib directly acted on human colorectal cancer cells and accelerated their apoptosis resistance and migration capability. Thus, we here elucidated how regorafenib induced the malignant phenotypes in colorectal cancer cells. To identify the responsible receptor among the regorafenibtargeting proangiogenic receptors, we examined the effects of a potent selective inhibitor for VEGF-R, FGF-R or PDGF-R on apoptosis resistance and migration capability. We clarified that blockade of VEGF-R, but not FGF-R and PDGF-R, induced the malignant phenotypes. We confirmed that blocking of VEGF ligands derived from colorectal cancer cells also induced the phenotypes. These results suggest that regorafenib progressed the malignancy via prevention of autocrine and paracrine VEGF signaling in colorectal cancer cells

    DIRECT EFFECTS OF VEGF/VEGF-R TARGETING AGENTS ON COLON CANCER CELLS

    Get PDF
    Anti-angiogenic therapies targeting vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) are important treatments for a number of human malignancies, including colorectal cancers. However, there is increasing evidence that VEGF/VEGF-R inhibitors promote the adaptive and evasive resistance of tumor cells to the therapies. The mechanism by which the cancer cells become resistant remains unclear. One potential mechanism is that VEGF/VEGF-R blockers directly act on tumor cells independently of anti-angiogenic effects. In this study, the direct effects of an anti-VEGF antibody (bevacizumab) and a VEGF-R tyrosine kinase inhibitor (sunitinib) on the evasive adaptation of colon cancer cells were compared. HCT116 and RKO human colon cancer cell lines were chronically exposed (3 months) to bevacizumab or sunitinib in vitro to establish bevacizumab- and sunitinib-adapted cells, respectively. Transwell migration and invasion assays, western blotting, reverse transcription-quantitative polymerase chain reaction, co-immunoprecipitation analysis, cell survival assays and ELISAs were conducted to analyze the adapted cells. Compared with the control vehicle-treated cells, the two cell models exhibited increased migration and invasion activities to different degrees and through different mechanisms. The bevacizumab-adapted cells, but not in the sunitinib-adapted cells, exhibited redundantly increased expression levels of VEGF/VEGF-R family members, including VEGF-A, placental growth factor, VEGF-C, VEGF-R1 and VEGF-R3. In addition, the phosphorylation levels of VEGF-R1 and VEGF-R3 were increased in the bevacizumab-adapted cells compared with the control cells. Thus, the inhibition of VEGF-R1 and VEGF-R3 decreased the evasive activities of the cells, suggesting that they remained dependent on redundant VEGF/VEGF-R signaling. By contrast, the sunitinib-adapted cells exhibited increased neuropilin-1 (NRP1) expression levels compared with the control cells. In the sunitinib-adapted cells, NRP1 interacted with phosphorylated cMet, and the cMet activation was dependent on NRP1. Thus, NRP1 or cMet blockade suppressed the evasive activation of the sunitinib-adapted cells. These results suggest that the sunitinib-adapted cells switched from a VEGF-R-dependent pathway to an alternative NRP1/cMet-dependent one. The findings of the present study indicate that VEGF/VEGF-R inhibitors directly act on colon cancer cells and activate their evasive adaptation via different mechanisms

    The malignant progression effects of regorafenib in human colon cancer cells

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    A number of anti-angiogenic drugs targeting vascular endothelial growth factor receptors (VEGF-R) have developed and enabled significant advances in cancer therapy including colorectal cancer. However, acquired resistance to the drugs occurs, leading to disease progression, such as invasion and metastasis. How tumors become the resistance and promote their malignancy remains fully uncertain. One of possible mechanisms for the resistance and the progression may be the direct effect of VEGF-R inhibitors on tumor cells expressing VEGF-R. We investigated here the direct effect of a VEGF-R-targeting agent, regorafenib, which is the first small molecule inhibitor of VEGF-Rs for the treatment of patients with colorectal cancer, on phenotype changes in colon cancer HCT116 cells. Treatment of cells with regorafenib for only 2 days activated cell migration and invasion, while vehicle-treated control cells showed less activity. Intriguingly, chronic exposure to regorafenib for 90 days dramatically increased migration and invasion activities and induced a resistance to hypoxia-induced apoptosis. These results suggest that loss of VEGF signaling in cancer cells may induce the acquired resistance to VEGF/VEGF-R targeting therapy by gaining two major malignant phenotypes, apoptosis resistance and activation of migration/invasion

    ハイヨウセイ キン イシュク オ フセグ コウユビキチンカ ペプチド Cblin Cbl-b inhibitor ノ コウキノウカ

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    Skeletal muscle atrophy caused by unloading is characterized by both decreased responsiveness to myogenic growth factors and increased proteolysis. In our previous studies, it has been shown that ubiquitin ligase Cbl-b interacted and degraded the IGF-1 signaling intermediate IRS-1. We also reported that a peptide mimetic of tyrosin608-phosphorylated IRS-1 (DGpYMP), named Cblin, Cbl-b inhibitor. However, Cblin may tend to be degraded by aminopeptidase in vivo. We aimed to confirm whether Cblin inhibiter muscle atrophy caused by glucocorticoids in mouse C2C12 myotubes, and effects of the modified Cblin N-terminus to prevent it from degradation. Pretreatment with Cblin significantly prevented the decrease in diameters of C2C12 myotubes treated with dexamethasone, and IRS-1 degradation, expression of atrogenes mRNA was repressed, and phosphorylation of Akt/mTOR was also protected. Moreover, the 50% inhibitory concentration of N -myristoylated Cblin and Cblin for Cbl-b-mediated IRS-1 ubiquitination was 35μM and 120μM, respectively. In addition, N -myristoylated Cblin significantly inhibited the dexamethasone-induced reduction of myotube diameter. Taken together, these results suggest that Cblin Cblin prevented the dexamethasone induced myotube atrophy, and N -myristoyled Cblin is more effective than nonmodified Cblin in prevention of muscle atrophy

    カレッジ・オブ・ファインアーツ(COFA)との大学間国際連携による先端的デザイン教育の研究および実践

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    カレッジ・オブ・ファインアーツ(COFA)との大学連携国際プロジェクトを基盤とした共同研究を行なった。研究の成果は「Future Crossing展」としてグランフロント大阪キュリオシティにおいて展示し、情報発信を行なった。インタラクションデザイン教育研究所(IDI)と岐阜県立情報科学芸術大学院大学(IAMAS)の協働による以下の5つのプロジェクトが展示された。1) Curating the city: Kobe2) Quattro libri3) Cinema obscura4) Do it together5) Everything you can imagine is real特に、「キュレーティング・ザ・シティ:神戸」は港湾都市というシドニーとの地政学的な共通点をテーマとした都市プロジェクトである。ヘイドン・ホワイトのメタヒストリーという概念からアイデアを得た過去と未来をつなぐ都市形成の方法論である。ビルディングタイプによって都市をカテゴライズするのではなく、異なる種類の都市の結節点をつないで都市ネットワークを構築する試みである。"Future Crossing" show also featured five IDI and IAMAS faculty projects in robotics, 3D printing, retooling old technologies and "curating the city" with an emphasis on using new technologies to cross over existing cultural boundaries and pre-set fields of inquiry to imagine new possibilities and future social realities.1)Curating the city: KobeThis project proposed in counterpoint to the City of Kobe’s more traditionalist urban planning schemes takes a hint from Hayden White’s Metahistory: grasping the city as a multilayered (past-present-future) time-space description in which functions are not categorised by building types, but rather as nodes for “vocabularies replete with diverse plots and rhetorics”. Information society “big data” can streamed through such nodes while simultaneously the built environment and physical structures can be more easily repurposed in the form of nodes for new urban networks.2) Quattro libri, 3) Cinema obscura, 4) Do it together, 5)Everything you can imagine is rea

    インタラクションデザインの教育方法に関する研究/地域連携、企業連携、大学連携、学部・大学院連携を基盤とする実践的デザイン教育

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    本研究は、情報社会へと移行している現代における社会構造の変化と社会環境の変化に対応したこれからのデザインのあり方を研究し、その教育の基盤となるカリキュラムを開発、これを実践的に運営することを通して教育方法の構築を行うことを目的としている。 特に現代の情報環境において失われつつある人間の「身体」をテーマとして未来のデザインの枠組みを考えること、また「ポストデザイン」をテーマとしてこれからのデザイン領域の変化そのものを考えることを研究の中心におく。新しい教育方法の実践としては、国際ワークショップなどの開催、大学連携、企業連携を通じて教育方法の調査・研究を行う。また国内外のデザイン研究機関および教育組織と連携し、わが国におけるインタラクションデザインという新しいデザイン領域の教育研究拠点としての活動を行った。At IDI(Interaction Design Institute), we aim to investigate how design is to respond to contemporary society in transition to the post-industrial information age, to develop curricula basic to such learning, and to establish appropriate teaching methods through actual practice.One central theme of our research concerns the loss of "body experience" in today\u27s information environments and the shift from existing concepts of design itself to "post-design" ideas. Specifically, we have conducted man-machine experiments and published findings on robotic replication of movement using KINECT platform devices to visually collect and compile data on human motion.Likewise, another direction toward new educational practices involves holding international workshops in collaboration with IAMAS, the RCA in London and other progressive institutions both in Japan and abroad so as to share and improve methodologies across the field of design-related education

    Contrasting patterns of the 5S and 45S rDNA evolutions in the Byblis liniflora complex (Byblidaceae)

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    To clarify the evolutionary dynamics of ribosomal RNA genes (rDNAs) in the Byblis liniflora complex (Byblidaceae), we investigated the 5S and 45S rDNA genes through (1) chromosomal physical mapping by fluorescence in situ hybridization (FISH) and (2) phylogenetic analyses using the nontranscribed spacer of 5S rDNA (5S-NTS) and the internal transcribed spacer of 45S rDNA (ITS). In addition, we performed phylogenetic analyses based on rbcL and trnK intron. The complex was divided into 2 clades: B. aquatica–B. filifolia and B. guehoi–B. liniflora–B. rorida. Although members of the complex had conservative symmetric karyotypes, they were clearly differentiated on chromosomal rDNA distribution patterns. The sequence data indicated that ITS was almost homogeneous in all taxa in which two or four 45S rDNA arrays were frequently found at distal regions of chromosomes in the somatic karyotype. ITS homogenization could have been prompted by relatively distal 45S rDNA positions. In contrast, 2–12 5S rDNA arrays were mapped onto proximal/interstitial regions of chromosomes, and some paralogous 5S-NTS were found in the genomes harboring 4 or more arrays. 5S-NTS sequence type-specific FISH analysis showed sequence heterogeneity within and between some 5S rDNA arrays. Interlocus homogenization may have been hampered by their proximal location on chromosomes. Chromosomal location may have affected the contrasting evolutionary dynamics of rDNAs in the B. liniflora complex

    Search for single production of vector-like quarks decaying into Wb in pp collisions at s=8\sqrt{s} = 8 TeV with the ATLAS detector

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