Anti-angiogenic effects of differentiation-inducing factor-1 involving VEGFR-2 expression inhibition independent of the Wnt/β-catenin signaling pathway

<p>Abstract</p> <p>Background</p> <p>Differentiation-inducing factor-1 (DIF-1) is a putative morphogen that induces cell differentiation in <it>Dictyostelium discoideum</it>. DIF-1 inhibits proliferation of various mammalian tumor cells by suppressing the canonical Wnt/β-catenin signaling pathway. To assess the potential of a novel cancer chemotherapy based on the pharmacological effect of DIF-1, we investigated whether DIF-1 exhibits anti-angiogenic effects <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p>DIF-1 not only inhibited the proliferation of human umbilical vein endothelial cells (HUVECs) by restricting cell cycle in the G₀/G₁phase and degrading cyclin D1, but also inhibited the ability of HUVECs to form capillaries and migrate. Moreover, DIF-1 suppressed VEGF- and cancer cell-induced neovascularization in Matrigel plugs injected subcutaneously to murine flank. Subsequently, we attempted to identify the mechanism behind the anti-angiogenic effects of DIF-1. We showed that DIF-1 strongly decreased vascular endothelial growth factor receptor-2 (VEGFR-2) expression in HUVECs by inhibiting the promoter activity of human VEGFR-2 gene, though it was not caused by inhibition of the Wnt/β-catenin signaling pathway.</p> <p>Conclusion</p> <p>These results suggested that DIF-1 inhibits angiogenesis both <it>in vitro </it>and <it>in vivo</it>, and reduction of VEGFR-2 expression is involved in the mechanism. A novel anti-cancer drug that inhibits neovascularization and tumor growth may be developed by successful elucidation of the target molecules for DIF-1 in the future.</p

Truncated SSX Protein Suppresses Synovial Sarcoma Cell Proliferation by Inhibiting the Localization of SS18-SSX Fusion Protein

Synovial sarcoma is a relatively rare high-grade soft tissue sarcoma that often develops in the limbs of young people and induces the lung and the lymph node metastasis resulting in poor prognosis. In patients with synovial sarcoma, specific chromosomal translocation of t(X; 18) (p11.2; q11.2) is observed, and SS18-SSX fusion protein expressed by this translocation is reported to be associated with pathogenesis. However, role of the fusion protein in the pathogenesis of synovial sarcoma has not yet been completely clarified. In this study, we focused on the localization patterns of SS18-SSX fusion protein. We constructed expression plasmids coding for the full length SS18-SSX, the truncated SS18 moiety (tSS18) and the truncated SSX moiety (tSSX) of SS18-SSX, tagged with fluorescent proteins. These plasmids were transfected in synovial sarcoma SYO-1 cells and we observed the expression of these proteins using a fluorescence microscope. The SS18-SSX fusion protein showed a characteristic speckle pattern in the nucleus. However, when SS18-SSX was co-expressed with tSSX, localization of SS18-SSX changed from speckle patterns to the diffused pattern similar to the localization pattern of tSSX and SSX. Furthermore, cell proliferation and colony formation of synovial sarcoma SYO-1 and YaFuSS cells were suppressed by exogenous tSSX expression. Our results suggest that the characteristic speckle localization pattern of SS18-SSX is strongly involved in the tumorigenesis through the SSX moiety of the SS18-SSX fusion protein. These findings could be applied to further understand the pathogenic mechanisms, and towards the development of molecular targeting approach for synovial sarcoma

全脳型Creutzfeldt-Jakob病の1剖検例 : 特にその眼球病変について

1年7か月の経過をとり,臨床的に全脳型Creutzfeld-Jakob病と考えられていた症例を剖検した.脳は重量が695gで,び漫性に萎縮していた.眼球には肉眼的には変化はなかった.病理組織学的には大脳,小脳皮質,基底核,視床などに海綿状態,神経細胞の変性と脱落,原形質性アストロサイトの増殖,脂肪顆粒細胞の出現を認めた.大脳白質から中脳被蓋,橋にかけては広範に変性し,原形質性アストロサイトの増殖,脂肪顆粒細胞の出現を認めた.網膜では周辺網膜の外顆粒層に細胞脱落と空胞化,外網状層の変性,神経節細胞の変性と脱落,神経線維層の粗鬆化がみられた.本例の白質病変は皮質と同様の基質の変化,アストロサイトの増殖,脂肪顆粒細胞の出現などがみられたことより一次性変化と思われた.網膜の細胞脱落,空胞化,基質の粗鬆化なども大脳の変化と同様と思われ,網膜病変は一次性変化と考えられた.A case of the panencephalopathic type of Creutzfeldt-Jakob disease was reported. The patient was a 59-year-old female, who was admitted in July 1982 because of gait disturbance, hallucination, left hemiparesis and Gegenhalten of the left upper extremity. In September 1982 she developed akinetic mutism which lasted until her terminal stage. She died in February 1984 after a course of one year and seven months. The brain weighed 695 g and showed diffuse atrophy. Microscopically, there was marked atrophy and loss of neurons, and proliferations of protoplasmic astrocytes throughout the cerebral and cerebellar cortex, basal ganglia and thalamus. The cerebral white matter, tegmentum of the midbrain, pons, optic nerves, optic chiasm and optic tracts showed diffuse destruction of myelins and axons with fat granule cells and astrocytic proliferations. Loss of the outer nuclear layer of the retina was more prominent in the peripheral area than in the central area. The outer plexiform layer showed a remarkable vacuolization especially in the posterior region. Retinal ganglion cells showed degenerative changes and occasional loss. In this case, white matter involvements and ocular lesions were thought to be the primary degenerative changes of Creutzfeldt-Jakob disease

Multistep Ion Channel Remodeling and Lethal Arrhythmia Precede Heart Failure in a Mouse Model of Inherited Dilated Cardiomyopathy

Background: Patients with inherited dilated cardiomyopathy (DCM) frequently die with severe heart failure (HF) or die suddenly with arrhythmias, although these symptoms are not always observed at birth. It remains unclear how and when HF and arrhythmogenic changes develop in these DCM mutation carriers. In order to address this issue, properties of the myocardium and underlying gene expressions were studied using a knock-in mouse model of human inherited DCM caused by a deletion mutation DK210 in cardiac troponinT. Methodology/Principal Findings: By 1 month, DCM mice had already enlarged hearts, but showed no symptoms of HF and a much lower mortality than at 2 months or later. At around 2 months, some would die suddenly with no clear symptoms of HF, whereas at 3 months, many of the survivors showed evident symptoms of HF. In isolated left ventricular myocardium (LV) from 2 month-mice, spontaneous activity frequently occurred and action potential duration (APD) was prolonged. Transient outward (Ito) and ultrarapid delayed rectifier K + (IKur) currents were significantly reduced in DCM myocytes. Correspondingly, down-regulation of Kv4.2, Kv1.5 and KChIP2 was evident in mRNA and protein levels. In LVs at 3-months, more frequent spontaneous activity, greater prolongation of APD and further down-regulation in above K + channels were observed. At 1 month, in contrast, infrequent spontaneous activity and down-regulation of Kv4.2, but not Kv1.5 or KChIP2, were observed