Takashi Sasayama

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Aurora family kinases contribute to regulation of mitosis. Using RNA interference in synchronized HeLa cells, we now show that Aurora-A is required for mitotic entry. We found that initial activation of Aurora-A in late G2 phase of the cell cycle is essential for recruitment of the cyclin B1-Cdk1 complex to centrosomes, where it becomes activated and(More)
MicroRNAs (miRNAs) are effective post-transcriptional regulators of gene expression and are important in many biological processes. Although the oncogenic and tumor suppressive functions of several miRNAs have been characterized, the role of miRNAs in mediating tumor invasion and migration remains largely unexplored. Recently, miR-10b was identified as an(More)
The Aurora (Ipl1)-related kinases are universal regulators of mitosis. We now show that Aurora-A, in addition to Aurora-B, regulates kinetochore function in human cells. A two-hybrid screen identified the kinetochore component CENP-A as a protein that interacts with Aurora-A. Aurora-A phosphorylated CENP-A in vitro on Ser-7, a residue also known to be(More)
CD44 is a widely distributed cell surface adhesion molecule and is implicated in diverse biological processes. However, the nature of intracellular signaling triggered by CD44 remains to be elucidated. Here, we show that CD44 undergoes sequential proteolytic cleavage in the ectodomain and intracellular domain, resulting in the release of a CD44(More)
MicroRNAs (miRs) are small, non-coding RNAs that regulate gene expression and contribute to cell proliferation, differentiation and metabolism. Our previous study revealed the extensive modulation of a set of miRs in malignant glioma. In that study, miR microarray analysis demonstrated the upregulation of microRNA-183 (miR-183) in glioblastomas. Therefore,(More)
Gene rearrangement in the form of an intragenic deletion is the primary mechanism of oncogenic mutation of the epidermal growth factor receptor (EGFR) gene in gliomas. However, the incidence of platelet-derived growth factor receptor-α (PDGFRA) gene rearrangement in these tumors is unknown. We investigated the PDGFRA locus in PDGFRA-amplified gliomas and(More)
BACKGROUND Various mitotic events are controlled by Cdc2-cyclin B and other mitotic kinases. Aurora/Ipl1-related mitotic kinases were proved to play key roles in mitotic progression in diverse lower organisms. Aurora-A is a mammalian counterpart of aurora/Ipl1-related kinases and is thought to be a potential oncogene. However, the regulation of aurora-A(More)
The diagnosis of primary central nervous system lymphoma (PCNSL) by radiographical examination is often difficult because of its similarity to other brain tumors. To test whether interleukin-10 (IL-10) and IL-6 can be used to distinguish PCNSL from other brain tumors that are radiographically similar, cerebrospinal fluid (CSF) levels of IL-10 and IL-6 were(More)
AIMS Primary central nervous system lymphoma (PCNSL) manifest aggressive clinical behaviour and have poor prognosis. Although constitutive activation of the nuclear factor-κB (NF-κB) pathway has been documented, knowledge about the genetic alterations leading to the impairment of the NF-κB pathway in PCNSLs is still limited. This study was aimed to unravel(More)
A 55-year-old woman presented with a rare xanthogranuloma of the sellar region after complaining of severe headache and visual disturbance 3 months previously. Clinical examination showed she was alert with early signs of bitemporal hemianopsia. Endocrinological examination revealed hypopituitarism. Magnetic resonance imaging showed an intrasellar mass(More)