Kenta Kishimoto

Kobe University, Kōbe-shi, Hyogo-ken, Japan

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Publications (15)24.82 Total impact

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    ABSTRACT: Decoy receptor 3 (DcR3) is a soluble secreted protein that belongs to the tumor necrosis factor receptor (TNFR) superfamily. DcR3 inhibits the Fas ligand (FasL)/Fas apoptotic pathway by binding to FasL, competitively with Fas receptor. Previous studies have reported that overexpression of DcR3 has been detected in various human malignancies and that DcR3 functions as a 'decoy' for FasL to inhibit FasL-induced apoptosis. In addition, recent studies have revealed that DcR3 has 'non-decoy' functions to promote tumor cell migration and invasion, suggesting that DcR3 may play important roles in tumor progression by decoy and non-decoy functions. We have previously reported that overexpression of DcR3 was observed in human malignant fibrous histiocytoma (MFH), however, the roles of DcR3 in MFH have not been studied. In the present study, to elucidate the roles of DcR3 in tumor progression of MFH, we examined the effects of DcR3 inhibition on cell apoptosis, migration and invasion in human MFH cells. siRNA knockdown of DcR3 enhanced the FasL-induced apoptotic activity and significantly decreased cell migration and invasion with a decrease in the activation of phosphatidylinositol 3 kinase (PI3K)/Akt and matrix metalloproteinase (MMP)-2. The findings in this study strongly suggest that DcR3 plays important roles in tumor progression of human MFH by decoy as well as non-decoy functions and that DcR3 may serve as a potent therapeutic target for human MFH.
    International Journal of Oncology 06/2013; · 2.66 Impact Factor
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    ABSTRACT: Osteosarcoma (OS) is a primary malignancy of the bone, with a tendency to metastasize early. Despite intensive chemotherapy and surgical resection, more than 30% of patients develop distant metastases, and the prognosis of patients with metastases is essentially poor. Members of the protein kinase D (PKD) family are serine/threonine kinases, and have been studied in various cancers. Among the three different isoforms of this family, PKD1 is one of the best understood for its role in human malignancies; however, its role in musculoskeletal tumors has not been studied. In the present study, we investigated the role of PKD1 in human OS. We first analyzed PKD1 mRNA expression in human musculoskeletal tumor tissue samples by quantitative real-time PCR. PKD1 expression in OS samples was significantly lower than that in benign schwannoma samples, and this was correlated with metastatic potential. In in vitro studies, overexpression of PKD1 by plasmid transfection decreased OS cell invasion, migration and proliferation, and significantly decreased matrix metalloproteinase (MMP)2 mRNA expression. Conversely, siRNA knockdown of PKD1 increased invasion, migration and proliferation of OS cells, and MMP2 expression was markedly increased. Furthermore, overexpression of PKD1 significantly reduced in vivo tumor growth of OS cells. These results demonstrated that low expression of PKD1 may contribute to increased cell invasion, migration and proliferation ability of human OS. Taken together, our findings strongly suggest that PKD1 may negatively regulate the malignant potential of human OS, and may be a therapeutic target for human OS in the clinical setting.
    International Journal of Oncology 03/2012; 40(6):1839-48. · 2.66 Impact Factor
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    ABSTRACT: Mitochondria play an essential role in cellular energy metabolism and apoptosis. Previous studies have demonstrated that decreased mitochondrial biogenesis is associated with cancer progression. In mitochondrial biogenesis, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) regulates the activities of multiple nuclear receptors and transcription factors involved in mitochondrial proliferation. Previously, we showed that overexpression of PGC-1α leads to mitochondrial proliferation and induces apoptosis in human malignant fibrous histiocytoma (MFH) cells in vitro. We also demonstrated that transcutaneous application of carbon dioxide (CO(2)) to rat skeletal muscle induces PGC-1α expression and causes an increase in mitochondrial proliferation. In this study, we utilized a murine model of human MFH to determine the effect of transcutaneous CO(2) exposure on PGC-1α expression, mitochondrial proliferation and cellular apoptosis. PGC-1α expression was evaluated by quantitative real-time PCR, while mitochondrial proliferation was assessed by immunofluorescence staining and the relative copy number of mitochondrial DNA (mtDNA) was assessed by real-time PCR. Immunofluorescence staining and DNA fragmentation assays were used to examine mitochondrial apoptosis. We also evaluated the expression of mitochondrial apoptosis related proteins, such as caspases, cytochorome c and Bax, by immunoblot analysis. We show that transcutaneous application of CO(2) induces PGC-1α expression, and increases mitochondrial proliferation and apoptosis of tumor cells, significantly reducing tumor volume. Proteins involved in the mitochondrial apoptotic cascade, including caspase 3 and caspase 9, were elevated in CO(2) treated tumors compared to control. We also observed an enrichment of cytochrome c in the cytoplasmic fraction and Bax protein in the mitochondrial fraction of CO(2) treated tumors, highlighting the involvement of mitochondria in apoptosis. These data indicate that transcutaneous application of CO(2) may represent a novel therapeutic tool in the treatment of human MFH.
    PLoS ONE 01/2012; 7(11):e49189. · 3.53 Impact Factor
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    ABSTRACT: Protein kinase Cδ (PKCδ), an isoform of PKC, has been shown to act as a critical mediator of tumor progression and apoptosis; however, its role in musculoskeletal tumors is still unknown. In the current study, we examined the expression of PKCδ in human musculoskeletal tumor tissue samples, and investigated the effects of siRNA downregulation of PKCδ on human malignant fibrous histiocytoma (MFH) cell proliferation, migration, and apoptosis, to elucidate its functional roles in musculoskeletal tumorigenesis. Of note, real-time PCR analysis revealed that mRNA expression of PKCδ in high-grade musculoskeletal MFH tumors was significantly lower than that in benign schwannomas. siRNA downregulation of PKCδ significantly increased human MFH cell proliferation and migration, and markedly suppressed apoptosis. These findings suggest that PKCδ has a negative effect on tumorigenesis and/or acts as a pro-apoptotic kinase in human MFH cells. The data presented here could be applied in the development of new therapeutic avenues, with the elevation of PKCδ expression being one potential strategy to prevent MFH progression. Thus, PKCδ may be a potent therapeutic target for human MFH.
    Oncology Reports 08/2011; 26(5):1221-6. · 2.30 Impact Factor
  • Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 06/2011; 21(4):e1-4. · 1.93 Impact Factor
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    ABSTRACT: A 20-year-old man presented with pain and recurrent hemarthrosis in the right knee. Magnetic resonance imaging of the knee showed a lesion with homogeneous low signal intensity on T1-weighted images and a heterogeneous, low to high signal intensity on T2-weighted images. At arthroscopy, the mass was located between the posterior cruciate ligament and the posterior knee joint capsule. The tumor was excised through a posterior approach and histologically diagnosed as a nodular fasciitis. Intra-articular nodular fasciitis is a very rare clinicopathologic entity. The current case showed the unique clinical feature of recurrent hemarthrosis at initial presentation, which has not been previously reported.
    Rheumatology International 03/2011; 32(6):1691-4. · 2.21 Impact Factor
  • European Journal of Cancer - EUR J CANCER. 01/2011; 47.
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    ABSTRACT: Bevacizumab is a specific inhibitor of angiogenesis and a neutralising antibody against vascular endothelial growth factor (VEGF). The effect of bevacizumab was evaluated on malignant fibrous histiocytoma (MFH) in vivo using an animal model. MFH cell line, NaraH, was implanted to athymic nude mice which were randomly divided into a treatment and a control group. The change in body weight and tumour volume were evaluated and immunohistochemical analysis was performed of microvessel density (MVD) and VEGF expression in the tumour tissue. Bevacizumab significantly induced inhibition of tumour growth, reducing tumour volume to 48% at the end of experiment. Intratumoural MVD was significantly decreased in the bevacizumab treatment group compared to the control group. A positive correlation was found between tumour volume and MVD. Bevacizumab suppressed MFH tumour growth by inhibiting tumoural angiogenesis. The current study suggests that bevacizumab may be a novel therapeutic agent for MFH.
    Anticancer research 09/2010; 30(9):3391-5. · 1.71 Impact Factor
  • Ejc Supplements - EJC SUPPL. 01/2010; 8(5):140-140.
  • Ejc Supplements - EJC SUPPL. 01/2010; 8(5):70-70.
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    ABSTRACT: Neutron-capture therapy with gadolinium (Gd-NCT) has therapeutic potential, especially that gadolinium is generally used as a contrast medium in magnetic resonance imaging (MRI). The accumulation of gadolinium in a human sarcoma cell line, malignant fibrosis histiocytoma (MFH) Nara-H, was visualized by the MRI system. The commercially available MRI contrast medium Gd-DTPA (Magnevist, dimeglumine gadopentetate aqueous solution) and the biodegradable and highly gadopentetic acid (Gd-DTPA)-loaded chitosan nanoparticles (Gd-nanoCPs) were prepared as MRI contrast agents. The MFH cells were cultured and collected into three falcon tubes that were set into the 3-tesra MRI system to acquire signal intensities from each pellet by the spin echo method, and the longitudinal relaxation time (T1) was calculated. The amount of Gd in the sample was measured by inductively coupled plasma atomic emission spectrography (ICP-AES). The accumulation of gadolinium in cells treated with Gd-nanoCPs was larger than that in cells treated with Gd-DTPA. In contrast, and compared with the control, Gd-DTPA was more effective than Gd-nanoCPs in reducing T1, suggesting that the larger accumulation exerted the adverse effect of lowering the enhancement of MRI. Further studies are warranted to gain insight into the therapeutic potential of Gd-NCT.
    Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine 04/2009; 67(7-8 Suppl):S355-8. · 1.09 Impact Factor
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    ABSTRACT: We present details of a case of intra-tendinous ganglion arising from the long head of the biceps at an unusual location. MRI scans have important implications for surgical planning and treatment. After excision of the ganglion, the tendon remaining could be repaired. Five months after surgery, there was no sign of recurrence.
    Skeletal Radiology 04/2008; 37(3):263-5. · 1.74 Impact Factor
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    ABSTRACT: Based on developmental fate and function, cartilage tissue is broadly classified into transient cartilage (e.g. growth plate, GP) and permanent cartilage (e.g. articular cartilage, AC). The former eventually disappears and is replaced by bone during the endochondral ossification process, whereas the latter retains its permanency. Osteo(chondro)clasts, multinucleated giant cells of the monocyte/macrophage lineage, are selectively induced in the GP during endochondral ossification and play central roles in the resorption of cartilagenous matrices. The aim of this study was to investigate the factors determining the GP-specific recruitment of osteo(chondro)clasts. We especially focused on the expression pattern of the receptor activator of NF-kappaB ligand (RANKL), an essential factor for osteo(chondro)clast differentiation, and on that of epigenetic and transcriptional factors affecting RANKL gene expression. Knee joints of male BALB/c mice aged 8 weeks were dissected and subjected to immunohistochemical analysis using anti-RANKL, Runx2, Dlx5 and Msx2 antibodies. The methylation status of the mouse RANKL gene promoter in both the GP and the AC was analyzed by sodium bisulfite mapping using microdissected mouse tissue. The expression of BMP-2, -3, -4, -6 and type X collagen mRNA was examined by in situ hybridization (ISH). At the boundary between the calcifying cartilage and the hypertrophic chondrocytes of the GP, RANKL-expressing chondrocytes overlapped those expressing Runx2, Dlx5 and Msx2, near numerous osteo(chondro)clasts. Although similar BMP-2 and -4 expression was observed in chondrocytes in both the GP and the AC as well as in maturing osteoblasts, a rather restricted BMP-6 expression pattern was observed in resting and proliferating chondrocytes in the GP. On the other hand, sodium bisulfite mapping showed that mostly non-CpG methylation was similarly scattered in a non-specific manner in chondrocytes in the GP and the AC. Taken together with the fact that putative Runx2 binding elements are located in the RANKL promoter, our data suggest that Runx2, an essential transcription factor for skeletal development, is also a key regulator of RANKL expression in chondrocytes in the GP. Furthermore, a selective and sequential expression of a subset of BMP and of transcription factors may define the expression pattern of RANKL through Runx2.
    Histochemie 06/2006; 125(5):593-602. · 2.61 Impact Factor
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    ABSTRACT: Medullary bone infarctions, which are believed to arise due to arterial obstructions in the bone, are usually asymptomatic and are noted incidentally in roentgenograms or bone scans performed for other reasons. We present two cases of acute bone infarctions that were found accidentally by magnetic resonance imaging (MRI). In both cases, conventional radiographs could not demonstrate any findings and the cases were clinically asymptomatic. The current two cases suggest that MRI shows various findings in bone infarctions.
    Clinical Imaging 32(2):147-51. · 0.65 Impact Factor
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    ABSTRACT: PKC412, formerly CGP41251, N-benzoylstaurosporine, was initially developed as a selective protein kinase C (PKC) inhibitor, and it preferentially inhibits conventional PKC family members. In this study, the expression of PKCa was examined in human osteosarcoma and MFH cell lines, and the inhibitory effect of PKC412 on the proliferation of the cell lines was evaluated. Three human osteosarcoma cell lines (KTHOS, MG63 and KHOS) and four human MFH cell lines (TNMY1, GBS-1, Nara-F and Nara-H) were used. The expression of PKCalpha and phosphorylated PKCalpha were analyzed using both Western blotting analysis and immunocytochemical analysis. The effect of PKC412 on cell proliferation was evaluated using the MTS assay technique. PKC412 inhibited cell proliferation of all seven cell lines in a dose- and time-dependent manner. Both Western blotting analysis and immunocytochemical analysis revealed that not only PKCalpha but also phosphorylated PKCalpha were expressed in all cell lines incubated with the culture medium without any stimuli. PKC412 suppressed phosphorylation of PKCalpha in all cell lines at a concentration of 1 microM. The inhibition of cell proliferation of the human osteosarcoma and MFH cell lines by PKC412 might be due to reduced PKCalpha activity. This suggests PKC412 might be a potent chemotherapeutic agent for human sarcomas.
    Anticancer research 28(2A):825-32. · 1.71 Impact Factor