Kumamoto University

About: Kumamoto University is a education organization based out in Kumamoto, Kumamoto, Japan. It is known for research contribution in the topics: Cancer & Population. The organization has 19602 authors who have published 35513 publications receiving 901260 citations. The organization is also known as: Kumamoto Daigaku.

Mechanism and biological significance of CD44 cleavage

Abstract: There are multiple steps in the metastasis of cancer cells. Tumor cells must first detach from the tumor mass and invade the surrounding extracellular matrix (ECM). In this step, cell surface adhesion molecules play an important role in the interaction between the cells and their microenvironments. CD44 is an adhesion molecule that interacts with hyaluronic acid (HA) and is implicated in a wide variety of physiological and pathological processes. Recently, proteolytic cleavages of CD44 have been emerging as key regulatory events for the CD44 dependent cell-matrix interaction and signaling pathway. CD44 undergoes sequential proteolytic cleavages in the ectodomain and intramembranous domain, resulting in the release of a CD44 intracellular domain (ICD) fragment. The ectodomain cleavage of CD44 is triggered by multiple stimulations and contributes to the regulation of cell attachment to and migration on HA matrix. The ectodomain cleavage subsequently induces the intramembranous cleavage, which is mediated by presenilin (PS)-dependent gamma -secretase. The intramembranous cleavage generates CD44ICD, which acts as a signal transduction molecule; it is translocated to the nucleus and activates transcription. An understanding of the underlying mechanism of these cleavages of CD44 could provide novel therapeutic targets for cancer cell invasion and metastasis.

Emx1 and Emx2 functions in development of dorsal telencephalon

Abstract: The genes Emx1 and Emx2 are mouse cognates of a Drosophila head gap gene, empty spiracles, and their expression patterns have suggested their involvement in regional patterning of the forebrain. To define their functions we introduced mutations into these loci. The newborn Emx2 mutants displayed defects in archipallium structures that are believed to play essential roles in learning, memory and behavior: the dentate gyrus was missing, and the hippocampus and medial limbic cortex were greatly reduced in size. In contrast, defects were subtle in adult Emx1 mutant brain. In the early developing Emx2 mutant forebrain, the evagination of cerebral hemispheres was reduced and the roof between the hemispheres was expanded, suggesting the lateral shift of its boundary. Defects were not apparent, however, in the region where Emx1 expression overlaps that of Emx2, nor was any defect found in the early embryonic forebrain caused by mutation of the Emx1 gene, of which expression principally occurs within the Emx2-positive region. Emx2 most likely delineates the palliochoroidal boundary in the absence of Emx1 expression during early dorsal forebrain patterning. In the more lateral region of telencephalon, Emx2-deficiency may be compensated for by Emx1 and vice versa. Phenotypes of newborn brains also suggest that these genes function in neurogenesis corresponding to their later expressions.

Transforming growth factor beta induces IgA production and acts additively with interleukin 5 for IgA production.

Abstract: Effects of transforming growth factor beta (TGF-beta) on IgA production by LPS-stimulated B cells have been studied. TGF-beta itself could augment polyclonal IgA production in concomitant inhibition of polyclonal IgM and IgG1 production. Furthermore, TGF-beta and IL-5 additively augmented IgA production. TGF-beta exerted its activity early in the culture (by 2 d in a 5-d culture) and IL-5 was required late in the culture. Surface IgA- (sIgA-) B cells responded to TGF-beta for the development of IgA-secreting cells. By contrast, sIgA+ B cells, but not sIgA- B cells, responded to IL-5 for IgA production. These results suggest that TGF-beta has a differential role in the induction of IgA production from IL-5 on murine-activated B cells.

Focal liver masses: characterization with diffusion-weighted echo-planar MR imaging.

Abstract: PURPOSE: To evaluate diffusion-weighted echo-planar magnetic resonance (MR) imaging for improving the specificity of characterization of liver tumors. MATERIALS AND METHODS: Diffusion-weighted echo-planar imaging was performed with a 1.5-T whole-body imager with use of a body phased-array coil in 51 patients with 59 hepatic masses (41 malignant tumors, nine hemangiomas, and nine cysts). Apparent diffusion coefficient (ADC) values were obtained with two motion-probing gradients (b = 30 and 1,200 sec/mm2) during each of the breath-hold periods, and an ADC map was constructed. The T2 was derived from spin-echo echo-planar images with echo times of 47 and 99 msec. RESULTS: The ADC value of malignant masses (1.04 x 10(-3) mm2/sec) was significantly lower (P < .01) than that of benign masses (hemangiomas [1.95 x 10(-3) mm2/sec] and cysts [3.05 x 10(-3) mm2/sec]), although the T2s showed considerable overlap. A small amount of overlap in ADC values occurred among malignant tumors, hemangiomas, and cysts. ADC val...