Kosuke Watari

Kyushu University, Hukuoka, Fukuoka, Japan

Are you Kosuke Watari?

Claim your profile

Publications (19)77.68 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Most NSCLC patients with EGFR mutations benefit from treatment with EGFR-TKIs, but the clinical efficacy of EGFR-TKIs is limited by the appearance of drug resistance. Multiple kinase inhibitors of EGFR family proteins such as afatinib have been newly developed to overcome such drug resistance. We established afatinib-resistant cell lines after chronic exposure of activating EGFR mutation-positive PC9 cells to afatinib. Afatinib-resistant cells showed following specific characteristics as compared to PC9: [1] Expression of EGFR family proteins and their phosphorylated molecules was markedly downregulated by selection of afatinib resistance; [2] Expression of FGFR1 and its ligand FGF2 was alternatively upregulated; [3] Treatment with anti-FGF2 neutralizing antibody blocked enhanced phosphorylation of FGFR in resistant clone; [4] Both resistant clones showed collateral sensitivity to PD173074, a small-molecule FGFR-TKIs, and treatment with either PD173074 or FGFR siRNA exacerbated suppression of both afatinib-resistant Akt and Erk phosphorylation when combined with afatinib; [5] Expression of twist was markedly augmented in resistant sublines, and twist knockdown specifically suppressed FGFR expression and cell survival. Together, enhanced expression of FGFR1 and FGF2 thus plays as an escape mechanism for cell survival of afatinib-resistant cancer cells, that may compensate the loss of EGFR-driven signaling pathway.
    Oncotarget 03/2014; · 6.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Tumors formed by a highly metastatic human lung cancer cell line are characterized by activated signaling via vascular endothelial growth factor (VEGF)-C through its receptor (VEGFR-3) and aggressive lymph node metastasis. In this study, we examined how these highly metastatic cancers acquired aggressive lymph node metastasis. Compared with their lower metastatic counterparts, the highly metastatic tumors formed by this cell line expressed higher amounts of interleukin (IL)-1α, with similarly augmented expression of IL-1α and IL-1β by tumor stromal cells and of VEGF-A and VEGF-C by tumor-associated macrophages. These tumor-associated macrophages were mainly of the M2 type. Administration of a macrophage-targeting drug suppressed the production of these potent angiogenic and lymphangiogenic factors, resulting in decreased tumor growth, angiogenesis, lymphangiogenesis, and lymph node metastasis. In Matrigel plug assays, the highly metastatic cells formed tumors that were extensively infiltrated by M2-type macrophages and exhibited enhanced angiogenesis and lymphangiogenesis. All of these responses were suppressed by the IL-1 receptor (IL-1R) antagonist anakinra. Thus, the IL-1α-driven inflammatory activation of angiogenesis and lymphangiogenesis seems to provide a highly metastatic tumor microenvironment favorable for lymph node metastasis through cross-talk with macrophages. Accordingly, the IL-1R/M2-type macrophage axis may be a good therapeutic target for patients with this form of lung cancer.
    PLoS ONE 01/2014; 9(6):e99568. · 3.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cytological diagnosis of respiratory disease has become important, not only for histological typing using immunocytochemistry (ICC) but also for molecular DNA analysis of cytological material. The aim of this study was to investigate the fixation effect of SurePath preservative fluids. Human lung cancer PC9 and 11-18 cell lines, and lung adenocarcinoma cells in pleural effusion, were fixed in CytoRich Blue, CytoRich Red, 15% neutral-buffered formalin, and 95% ethanol, respectively. PC9 and 11-18 cell lines were examined by ICC with epidermal growth factor receptor (EGFR) mutation-specific antibodies, the EGFR mutation DNA assay, and fluorescence in situ hybridization. The effect of antigenic storage time was investigated in lung adenocarcinoma cells in pleural effusion by ICC using the lung cancer detection markers. PC9 and 11-18 cell lines in formalin-based fixatives showed strong staining of EGFR mutation-specific antibodies and lung cancer detection markers by ICC as compared with ethanol-based fixatives. DNA preservation with CytoRich Blue and CytoRich Red was superior to that achieved with 95% ethanol and 15% neutral-buffered formalin fixatives, whereas EGFR mutations by DNA assay and EGFR gene amplification by fluorescence in situ hybridization were successfully identified in all fixative samples. Although cytoplasmic antigens maintained high expression levels, expression levels in nuclear antigens fell as storage time increased. These results indicate that CytoRich Red is not only suitable for ICC with EGFR mutation-specific antibodies, but also for DNA analysis of cytological material, and is useful in molecular testing of lung cancer, for which various types of analyses will be needed in future. Cancer (Cancer Cytopathol) 2013. © 2013 American Cancer Society.
    Cancer Cytopathology 10/2013; · 4.43 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: EGFR kinase inhibitors including gefitinib and erlotinib exert potent therapeutic efficacy in non-small cell lung cancers harboring EGFR activating mutations. However, most patients ultimately develop resistance to these drugs. Here we report a novel mechanism of acquired resistance the reversal of which could clinical outcomes. In erlotinib-resistant lung cancer cells harboring activating EGFR mutations that we established, there was increased expression of Src, integrinβ1, α2, and α5 along with enhanced cell adhesion activity. Interestingly, RNAi-mediated silencing of integrinβ1 restored erlotinib sensitivity and reduced activation of Src and Akt after erlotinib treatment. Further, Src silencing inhibited Akt phosphorylation and cell growth, with this inhibitory effect further augmented by erlotinib treatment. Increased expression of integrinβ1, α5, and/or α2 was also observed in refractory tumor samples from lung cancer patients treated with erlotinib and/or gefitinib. Together, our findings identify the integrinβ1/Src/Akt signaling pathway as a key mediator of acquired resistance to EGFR-targeted anticancer drugs.
    Cancer Research 07/2013; · 9.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The expression of N-myc downstream-regulated gene 1 (NDRG1) was significantly correlated with tumor angiogenesis and malignant progression together with poor prognosis in gastric cancer. However, the underlying mechanism for the role of NDRG1 in the malignant progression of gastric cancer remains unknown. Here we examined whether and how NDRG1 could modulate tumor angiogenesis by human gastric cancer cells. We established NU/Cap12 and NU/Cap32 cells overexpressing NDRG1 in NUGC-3 cells which show lower tumor angiogenesis in vivo. Compared with parental NU/Mock3, NU/Cap12 and NU/Cap32 cells [1] induced higher tumor angiogenesis than NU/Mock3 cells accompanied by infiltration of tumor associated macrophages in mouse dorsal air sac assay and Matrigel plug assay; [2] showed much higher expression of CXC chemokines, MMP-1, and the potent angiogenic factor VEGF-A; [3] increased the expression of the representative inflammatory cytokine, IL-1α; [4] augmented JNK phosphorylation and nuclear expression of activator-protein 1 (AP-1). Further analysis demonstrated that knockdown of AP-1 (Jun and/or Fos) resulted in down-regulation of the expression of VEGF-A, CXC chemokines and MMP-1, and also suppressed expression of IL-1α in NDRG1-overexpressing cell lines. Treatment with IL-1 receptor antagonist (IL-1ra) resulted in down-regulation of JNK and c-Jun phosphorylation, and the expression of VEGF, CXC chemokines and MMP-1 expression in NU/Cap12 and NU/Cap32 cells. Finally, administration of IL-1ra suppressed both tumor angiogenesis and infiltration of macrophages by NU/Cap12 in vivo. Together, activation of JNK/AP-1 thus seems to promote tumor angiogenesis in relation to NDRG1-induced inflammatory stimuli by gastric cancer cells.
    Journal of Biological Chemistry 07/2013; · 4.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gene amplification of HER2/ErbB2 occurs in gastric cancer, and the therapeutic efficacy of the HER2-targeted antibody, trastuzumab, has recently been improved against HER2-positive advanced stomach cancer. Here we examined whether Y-box-binding protein-1 (YB-1) could selectively control HER2 gene expression and cellular sensitivity to epidermal growth factor receptor (EGFR) family protein-targeted drugs in human gastric cancer cells. HER2 expression was specifically downregulated by YB-1 silencing using its cognate siRNA, whereas there was less change in the expression of EGFR and HER3. A chromatin immunoprecipitation assay revealed the specific binding of YB-1 to its consensus sequence on the 5-regulatory region of HER2. YB-1 knockdown induced drug resistance to lapatinib, a dual EGFR and HER2 kinase inhibitor, and also to erlotinib, an EGFR kinase inhibitor. Moreover, phosphorylation of protein kinase B (Akt) was not markedly affected by lapatinib or erlotinib when YB-1 was silenced. Nuclear YB-1 expression was significantly (p=0.026) associated with HER2 expression, but not with EGFR or HER3, in patients with gastric cancer (n=111). The YB-1-HER2 axis might therefore be useful for the further development of personalized therapeutics against gastric cancer by HER2-targeted drugs.
    Molecular Cancer Therapeutics 02/2013; · 5.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Expression of N-myc downstream-regulated gene 1 (NDRG1)/Cap43 is a prognostic indicator of human malignancies according to the tumor type in which it occurs. We investigated how NDRG1/Cap43 could affect tumor growth and angiogenesis in non-small-cell lung cancer (NSCLC) in vivo using an animal experimental model, and also how it could affect tumor angiogenesis and prognosis in NSCLC patients. Knockdown of NDRG1/Cap43 in lung cancer cells using a specific small interfering RNA resulted in growth rates in culture that were similar to those of counterpart control cells, but decreased tumor growth rates in vivo markedly. Stable NDRG1/Cap43 knockdown did not induce consistent changes in the expression of Epidermal growth factor receptor (EGFR) family proteins and c-Met in two human lung cancer cell lines in vitro. However, cell lines with NDRG1/Cap43 knockdown showed markedly decreased production of the potent angiogenic factors vascular endothelial growth factor-A and interleukin-8. Cells with knockdown of NDRG1/Cap43 showed marked reduction of tumor-induced angiogenesis. Using immunohistochemistry, we examined 182 surgically resected specimens of NSCLC for expression of NDRG1/Cap43 and tumor angiogenesis. High microvessel density in the tumor was significantly associated with nuclear positivity for NDRG1/Cap43 in both adenocarcinoma (p = 0.003) and squamous cell carcinoma (p=0.041). For both adenocarcinoma (p = 0.031) and squamous cell carcinoma (p=0.034), the survival curve of patients negative for nuclear NDRG1/Cap43 expression differed significantly from that of patients who were positive. Therefore, the expression of NDRG1/Cap43 may be predictive of tumor angiogenesis and poor prognosis in NSCLC.
    Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 04/2012; 7(5):779-89. · 4.55 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Our recent study demonstrated that higher expression of N-myc downregulated gene 1 (NDRG1) is closely correlated with poor prognosis in gastric cancer patients. In this study, we asked whether NDRG1 has pivotal roles in malignant progression including metastasis of gastric cancer cells. By gene expression microarray analysis expression of NDRG1 showed the higher increase among a total of 3691 up-regulated genes in a highly metastatic gastric cancer cell line (58As1) than their parental low metastatic counterpart (HSC-58). The highly metastatic cell lines showed decreased expression of E-cadherin, together with enhanced expression of vimentin and Snail. This decreased expression of E-cadherin was restored by Snail knockdown in highly metastatic cell lines. We next established stable NDRG1 knockdown cell lines (As1/Sic50 and As1/Sic54) from the highly metastatic cell line, and both of these cell lines showed enhanced expression of E-cadherin and decreased expression of vimentin and Snail. And also, E-cadherin promoter-driven luciferase activity was found to be increased by NDRG1 knockdown in the highly metastatic cell line. NDRG1 knockdown in gastric cancer cell showed suppressed invasion of cancer cells into surround tissues, suppressed metastasis to the peritoneum and decreased ascites accumulation in mice with significantly improved survival rates. This is the first study to demonstrate that NDRG1 plays its pivotal role in the malignant progression of gastric cancer through epithelial mesenchymal transition.
    PLoS ONE 01/2012; 7(7):e41312. · 3.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: N-myc downstream regulated gene-1 (NDRG1)/Cap43 regulates tumor growth and metastasis in various carcinomas. In this study we examined whether and how NDRG1/Cap43 modulates tumor growth by human hepatocellular carcinoma (HCC) cells. NDRG1/Cap43 cDNA was used to transfect HCC cell lines (KIM-1), and stable transfectants overexpressing NDRG1/Cap43 (KIM-1/Cap43) were obtained. Cell cycle analysis showed that KIM-1/Cap43 cells were arrested in the G0/G1 phase. Western blot analysis demonstrated an increase in p21 in KIM-1/Cap43 cells in culture under full confluency as compared with KIM-1/Mock. When KIM-1 cells, which are very low in NDRG1/Cap43 expression, were treated with mimosine, a G0/G1 cell cycle blocker, expression of NDRG1/Cap43 was induced in a dose dependent manner, together with p21 induction and CDK4 reduction. In vivo, KIM-1/Cap43 cells showed markedly decreased tumor growth rates compared with those of KIM-1/Mock. Immunohistochemical staining demonstrated markedly higher p21 labeling index in the KIM-1/Cap43 tumor than KIM-1/Mock tumor, and lower CDK4 and Ki-67 labeling index in the KIM-1/Cap43 than KIM-1/Mock. In order to confirm suppressive effects of NDRG1/Cap43, we further established a stable transfectant expressing NDRG1/Cap43 (HAK-1B/Cap43) using another HCC cell line, HAK-1B. Western blot analysis demonstrated an increase in p21 and a decrease in CDK4 in HAK-1B/Cap43 cells in culture under full confluency as compared with HAK-1B/Mock. HAK-1B/Cap43 also showed decreased tumor growth rates as compared with its control counterpart in vivo. NDRG1/Cap43 overexpression thus induced cell cycle arrest at the G0/G1 phase accompanied by increased p21 and decreased CDK4 expression in HCC cells. NDRG1/Cap43 might play a key role in the cell cycle control of G0/G1 in HCC cells.
    Cancer letters 11/2011; 310(1):25-34. · 4.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Ewing sarcoma-primitive neuroectodermal tumor (EWS) is associated with the most unfavorable prognosis of all primary musculoskeletal tumors. The objective of the present study was to investigate whether tumor-associated macrophages (TAMs) affect the development of EWS. TAMs were isolated from mouse xenografts using CD11b magnetic beads and examined for their cytokine expression and osteoclastic differentiation. To evaluate the role of TAMs in xenograft formation, liposome-encapsulated clodronate was used to deplete TAMs in mice. Macrophage infiltration and tumor microvascular density were histologically evaluated in 41 patients with EWS, and association with prognosis was examined using Kaplan-Meier survival analysis. In mouse EWS xenografts, TAMs expressed higher concentrations of cytokines including interleukin-6, keratinocyte-derived chemokine, and monocyte chemotactic protein-1. TAMs were more capable than normal monocytes of differentiating into tartrate-resistant acid phosphatase-positive giant cells. Depleting macrophages using liposome-encapsulated clodronate significantly inhibited development of EWS xenografts. In human EWS samples, higher levels of CD68-positive macrophages were associated with poorer overall survival. In addition, enhanced vascularity, increase in the amount of C-reactive protein, and higher white blood cell counts were also associated with poor prognosis and macrophage infiltration. TAMs seem to enhance the progression of EWS by stimulating both angiogenesis and osteoclastogenesis. Further investigation of the behavior of TAMs may lead to development of biologically targeted therapies for EWS.
    American Journal Of Pathology 09/2011; 179(3):1157-70. · 4.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Development of a novel type of angiogenesis inhibitor will be essential for further improvement of therapeutics against cancer patients. We examined whether an octahydronaphthalene derivative, AMF-26, which was screened as an inhibitor of intercellular adhesion molecule-1 (ICAM-1) production stimulated by inflammatory stimuli in vascular endothelial cells, could block angiogenesis in response to vascular endothelial growth factor (VEGF) and/or inflammatory cytokines. Low dose AMF-26 effectively inhibited the tumor necrosis factor-α (TNF-α)- or the interleukin-1β (IL-1β)-induced production of ICAM-1 in human umbilical vascular endothelial cells (HUVECs). We found that the TNF-α-induced phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) and nuclear translocation of p65 were impaired by AMF-26 in both endothelial cells and cancer cells. AMF-26 was found to inhibit the phosphorylation of VEGF receptor 1 (VEGFR1), VEGFR2 and the downstream signaling molecules Akt, extracellular signal-regulated kinase (ERK)1/2 stimulated by VEGF in HUVECs. Therefore, the VEGF-induced proliferation, migration and tube formation of vascular endothelial cells was highly susceptible to inhibition by AMF-26. Oral administration of AMF-26 significantly blocked VEGF- or IL-1β-induced angiogenesis in the mouse cornea, and also tumor angiogenesis and growth. Together, our results indicate that AMF-26 inhibits angiogenesis through suppression of both VEGFR1/2 and nuclear factor-κB (NF-κB) signaling pathways when stimulated by VEGF or inflammatory cytokines. AMF-26 could be a promising novel candidate drug for cancer treatments.
    International Journal of Cancer 08/2011; 131(2):310-21. · 6.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An anti-inflammatory enone fatty acid, (E)-9-oxooctadec-10-enoic acid (C10), was previously isolated from red alga (Gracilaria verrucosa). Of the many cellular signaling pathways activated in response to the inflammatory stimulus, lipopolysaccharide, the extracellular signal-regulated kinase 1/2, the stress-activated protein kinase/Jun N-terminal kinase and the nuclear factor-κB pathways were specifically blocked by C10 in the macrophage-like cell line, RAW264.7. In this study, we investigated the anti-angiogenic and anti-inflammatory activities of C10 in endothelial cells. C10 only partially inhibited the proliferation of human cancer cell lines at relatively high concentrations of over 20 μg/ml. However, C10 inhibited the proliferation of RAW264.7 cells and human umbilical vein endothelial cells (HUVECs) with half-maximal inhibitory concentration (IC50) values of 4-8 μg/ml. Both the proliferation and the migration of HUVECs induced by the vascular endothelial growth factor (VEGF) were markedly blocked by C10 with IC50 values of 2-3 μg/ml. The activation of nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor, α, by tumor necrosis factor-α or VEGF in these cells was also blocked by C10. Furthermore, in an in vivo model of angiogenesis in the mouse cornea, the neovascularization induced by VEGF was markedly inhibited by C10. The processes involved in inflammatory signaling, angiogenesis, and the development of malignancy in cancer are closely related, suggesting that C10 could be a useful lead compound for the development of novel anti-angiogenic therapies for cancer.
    International Journal of Oncology 02/2011; 38(2):493-501. · 2.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Expression of N-myc downstream regulated gene 1 (NDRG1)/Ca(2+)-associated protein 43 (Cap43) in cancer cells is a predictive marker of good or poor prognosis depending on tumor type. In this study, we examined whether NDRG1/Cap43 is a marker of good or poor prognosis in gastric cancer patients, and whether it is associated with tumor stromal responses, including angiogenesis and macrophage infiltration. The expression levels of NDRG1/Cap43, the number of CD68-positive macrophages and the CD34-positive microvessel density were analyzed by immunohistochemistry in 129 gastric cancer patients, including 65 with the intestinal type and 64 with the diffuse type. The expression of NDRG1/Cap43 in the nucleus and the membrane was evaluated. Nuclear NDRG1/Cap43 expression was found in 20/65 (30.8%) patients with the intestinal type and in 9/64 (14.1%) patients with the diffuse type of gastric cancer. Nuclear NDRG1/Cap43 expression was significantly associated with pathological stage in the intestinal type (P=0.002), but not in the diffuse type (P=0.039). Nuclear NDRG1/Cap43 expression was also closely associated with infiltrating macrophages (P=0.001) and tumor angiogenesis (P=0.001) in the intestinal type. Furthermore, nuclear NDRG1/Cap43 expression was associated with poor prognosis in both the intestinal (P=0.001) and the diffuse types of gastric cancer (P=0.047). By contrast, membranous NDRG1/Cap43 expression was not associated with the overall survival of gastric cancer patients with either the intestinal or diffuse type of gastric cancer. The expression of NDRG1/Cap43 in the nucleus may be a predictive biomarker for malignant progression in the intestinal type of gastric cancer, preferable to the expression of NDRG1/Cap43 in the membrane.
    Experimental and therapeutic medicine 01/2011; 2(3):471-479. · 0.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Four new cembrane diterpenes (1-4) and fifteen known cembranoids (5-19) were isolated from an Okinawan soft coral Lobophytum crassum. The structures of these four new cembranoids were determined on the basis of spectroscopic evidence. In particular, the absolute stereochemistry of 1, 2, 5 and 6 were elucidated by the application of the modified Mosher's method and circular dichroism (CD) spectral data. The inhibitory effects of some isolates were evaluated on nitric oxide (NO) production against a murine macrophage-like cell line (Raw 264.7). Cembranoids consisting of alpha-methylene-gamma-lactone, exhibited the significant effect on NO production.
    Chemical & pharmaceutical bulletin 09/2010; 58(9):1203-9. · 1.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Thymidine phosphorylase (TP), an enzyme catalyzing the reversible phospholysis of thymidine, deoxyuridine and their analogs at their respective bases and 2-deoxyribose-1-phosphate, thus promoting angiogenesis, is often expressed in macrophages present in tumor stroma. In this study, we investigated whether infiltration of TP-positive macrophages as well as tumor-associated macrophages affected tumor angiogenesis. TP was expressed in human macrophage-like cells, but not in gastric cancer cells in culture. The expression level of TP, the number of infiltrating CD68+ and CD163+ macrophages, and microvessel density (MVD) in the tumor were further analyzed by immunohistochemistry in 111 patients with gastric cancer. Biostatistical analysis of digitized data obtained by image analysis showed that TP expression was significantly correlated with the number of infiltrating macrophages and MVD in intestinal type gastric cancer (p<0.05). The number of infiltrating macrophages was also correlated with MVD in both the intestinal and diffuse types (p<0.05). An increased number of CD68+ macrophages was significantly associated with poor outcome in patients with intestinal type (p<0.001), but not diffuse type cancer. TP could be a specific marker enzyme that is expressed in tumor-infiltrating macrophages, being associated with tumor angiogenesis and poor prognosis in patients with intestinal-type gastric cancer.
    Oncology Reports 08/2010; 24(2):405-15. · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have recently reported that N-myc downstream-regulated gene 1 (NDRG1)/Ca(2+)-associated protein with a molecular mass of 43kDa (Cap43) suppresses angiogenesis and tumor growth of pancreatic cancer through marked decreases in both the expression of CXC chemokines and phosphorylation of a NF-kappaB signaling molecule, inhibitor of kappaB kinase (IkappaBalpha). NDRG1/Cap43 is phosphorylated at serine/threonine sites in its C-terminal domain by serum- and glucocorticoid-regulated kinase 1 (SGK1). In this study, we attempted to clarify the domain or site of NDRG1/Cap43 responsible for its suppression of CXC chemokine expression in pancreatic cancer cells. Expression of the deletion constructs CapDelta2 [deletion of amino acids (AA) 130-142] and CapDelta4 [deletion of AA 180-294] as well as the wild-type full sequence of NDRG1/Cap43 (F-Cap), suppressed the production of CXC chemokines such as Groalpha/CXCL1 and ENA-78/CXCL5, whereas no or low suppression was observed in cell expressing the CapDelta5 mutant [deletion of AA 326-350] and CapDelta6 mutant [deletion of AA 326-394]. We further introduced mutations at the serine and threonine sites at 328 [T328A], 330 [S330A] and 346 [T346A], which are susceptible to phosphorylation by SGK1, and also constructed double mutants [T328A, S330A], [T328A, T346A] and [S330A, T346A]. Expression of all these mutants, with the exception of [S330A, T346A], suppressed the production of CXC chemokine to similar levels as their wild-type counterpart. IkappaBalpha was found to be specifically phosphorylated by this double mutant [S330A, T346A] and the CapDelta5 mutant at levels comparable to that induced in their wild-type counterpart. Phosphorylation of NDRG1/Cap43 at both serine330 and threonine346 is required for its suppressive action on the NF-kappaB signaling pathway and CXC chemokine expression in pancreatic cancer cells.
    Biochemical and Biophysical Research Communications 04/2010; 396(2):376-81. · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Y-box binding protein-1 (YB-1) plays pivotal roles in acquisition of global drug resistance and cell growth promotion through transcriptional activation of genes for both drug resistance and growth factor receptors. In this study, we investigated whether YB-1 is involved in regulation of the cell cycle and cell proliferation of human cancer cells. Treatment with YB-1 siRNA caused a marked suppression of cell proliferation and expression of a cell cycle related gene, CDC6 by cancer cells. Of cell cycle of cancer cells, S phase content was specifically reduced by knockdown of YB-1. The overexpression of CDC6 abrogated this inhibition of both cell proliferation and S phase entry. ChIP assay demonstrated that YB-1 binds to a Y-box located in the promoter region of the CDC6 gene. Expression of cyclin D1, CDK1 and CDK2 was also reduced with increased expression of p21(Cip1) and p16(INK4A) when treated with YB-1 siRNA. Furthermore, the nuclear YB-1 expression was significantly associated with the level of CDC6 nuclear expression in patients with breast cancer. In conclusion, YB-1 plays an important role in cell cycle progression at G1/S of human cancer cells. YB-1 thus could be a potent biomarker for tumour growth and cell cycle in its close association with CDC6.
    European journal of cancer (Oxford, England: 1990) 03/2010; 46(5):954-65. · 4.12 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The close association of inflammation, angiogenesis and cancer progression is now highlighted, and in this study we especially focused on a close association of inflammation and lymphangiogenesis. We found that proinflammatory cytokine, interleukin-1beta (IL-1beta), could induce lymphangiogenesis in mouse cornea through enhanced production of potent lymphangiogenic factors, VEGF-A, VEGF-C and VEGF-D. IL-1beta-induced lymphangiogenesis, but not angiogenesis, was inhibited by administration of a selective anti-VEGF receptor-3 (VEGFR-3) neutralizing antibody. And in mouse cornea we observed recruitment of monocyte/macrophages and neutrophils by IL-1beta implanted cornea. Depletion of macrophages by a bisphosphonate encapsulated in liposomes inhibited this IL-1beta-induced lymphangiogenesis and also up-regulation of VEGF-A, VEGF-C, and VEGF-D. Furthermore, IL-1beta-induced lymphangiogenesis and angiogenesis were suppressed by NF-kappaB inhibition with marked suppression of VEGF-A, VEGF-C, and VEGF-D expression.
    Biochemical and Biophysical Research Communications 11/2008; 377(3):826-31. · 2.41 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The focus of the present study was whether and how infiltrating macrophages play a role in angiogenesis and the growth of cancer cells in response to the inflammatory cytokine interleukin (IL)-1beta. Lewis lung carcinoma cells overexpressing IL-1beta grew faster and induced greater neovascularization than a low IL-1beta-expressing counterpart in vivo. When macrophages were depleted using clodronate liposomes, both neovascularization and tumor growth were reduced in the IL-1beta-expressing tumors. Co-cultivation of IL-1beta-expressing cancer cells with macrophages synergistically augmented neovascularization and the migration of vascular endothelial cells. In these co-cultures, production of the angiogenic factors vascular endothelial growth factor-A and IL-8, monocyte chemoattractant protein-1, and matrix metalloproteinase-9 were increased markedly. The production of these factors, induced by IL-1beta-stimulated lung cancer cells, was blocked by a nuclear factor (NF)-kappaB inhibitor, and also by the knockdown of p65 (NF-kappaB) and c-Jun using small interference RNA, suggesting involvement of the transcription factors NF-kappaB and AP-1. These results demonstrated that macrophages recruited into tumors by monocyte chemoattractant protein-1 and other chemokines could play a critical role in promoting tumor growth and angiogenesis, through interactions with cancer cells mediated by inflammatory stimuli.
    Cancer Science 01/2008; 98(12):2009-18. · 3.48 Impact Factor

Publication Stats

209 Citations
77.68 Total Impact Points

Institutions

  • 2008–2014
    • Kyushu University
      • • Graduate School of Pharmaceutical Sciences
      • • Faculty of Pharmaceutical Sciences
      Hukuoka, Fukuoka, Japan
  • 2008–2012
    • Kurume University
      • • Division of Respirology, Neurology, and Rheumatology
      • • Department of Diagnostic Pathology
      • • Research Center for Innovative Cancer Therapy
      Куруме, Fukuoka, Japan