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.

CD44 cleavage induced by a membrane-associated metalloprotease plays a critical role in tumor cell migration.

Abstract: CD44 is a cell surface receptor for hyaluronate, a component of the extracellular matrix (ECM). Although CD44 has been implicated in tumor invasion and metastasis, the molecular mechanisms remain to be elucidated. Here we find that CD44 expressed in cancer cells is cleaved at the membrane-proximal region of the ectodomain and the membrane-bound cleavage product can be detected using an antibody against the cytoplasmic domain of CD44. Furthermore, we report that CD44 cleavage is mediated by a membrane-associated metalloprotease expressed in cancer cells. A tissue inhibitor of metalloproteases-1 (TIMP-1), as well as metalloprotease inhibitors, inhibit CD44 cleavage in the cell-free assay. Contrary, serine protease inhibitors enhance CD44 cleavage, and the enhancement can be prevented by pretreatment with a metalloprotease inhibitor. Thus, CD44 cleavage is regulated by an intricate balance between some proteases and their inhibitors. Interestingly, treatment with the metalloprotease blocker 1,10-phenanthroline, which strongly prevent the CD44 cleavage, suppressed RERF-LC-OK lung cancer cell migration on a hyaluronate substrate, but not on several other substrates. These results suggest that CD44 cleavage plays a critical role in an efficient cell-detachment from a hyaluronate substrate during the cell migration and consequently promotes CD44-mediated cancer cell migration. Our present data indicate that CD44, not only ECM per se, is one of the targets of pericellular proteolysis involved in tumor invasion and metastasis.

The murine homolog of SALL4, a causative gene in Okihiro syndrome, is essential for embryonic stem cell proliferation, and cooperates with Sall1 in anorectal, heart, brain and kidney development

Abstract: Mutations in SALL4, the human homolog of the Drosophila homeotic gene spalt (sal), cause the autosomal dominant disorder known as Okihiro syndrome. In this study, we show that a targeted null mutation in the mouse Sall4 gene leads to lethality during peri-implantation. Growth of the inner cell mass from the knockout blastocysts was reduced, and Sall4-null embryonic stem (ES) cells proliferated poorly with no aberrant differentiation. Furthermore, we demonstrated that anorectal and heart anomalies in Okihiro syndrome are caused by Sall4 haploinsufficiency and that Sall4/Sall1 heterozygotes exhibited an increased incidence of anorectal and heart anomalies, exencephaly and kidney agenesis. Sall4 and Sall1 formed heterodimers, and a truncated Sall1 caused mislocalization of Sall4 in the heterochromatin; thus, some symptoms of Townes-Brocks syndrome caused by SALL1 truncations could result from SALL4 inhibition.

Sarcopenia Is a Negative Prognostic Factor After Curative Resection of Colorectal Cancer

Abstract: Skeletal muscle depletion (sarcopenia) is closely associated with limited physical ability and high mortality. This study was performed to evaluate the prognostic significance of skeletal muscle depletion in patients with resectable stage I–III colorectal cancer (CRC). We conducted a retrospective analysis of 220 consecutive patients with stage I–III CRC who underwent curative resection. The skeletal muscle cross-sectional area was measured by preoperative computed tomography. The lowest sex-specific quartile of skeletal muscle mass was classified as sarcopenia. Factors contributing to recurrence-free survival (RFS) were analyzed by univariate and multivariate Cox proportional hazard models. Of 220 patients who met our inclusion criteria, 55 (25 %) had sarcopenia. The median follow-up duration was 41.4 months. Patients with sarcopenia were younger and had higher carcinoembryonic antigen levels than patients without sarcopenia. RFS and overall survival (OS) were significantly shorter in patients with sarcopenia than those without (5-year RFS, 56 vs. 79 %, log-rank p = 0.006; 5-year OS, 68 vs. 85 %, log-rank p = 0.015). Multivariate Cox regression analysis revealed that sarcopenia was independently associated with shorter RFS (hazard ratio [HR] 2.176; 95 % confidence interval [CI] 1.200–3.943; p = 0.010) and OS (HR 2.270; 95 % CI 1.147–4.494; p = 0.019). The influence of sarcopenia on patient outcome was modified by age at surgery (p value for interaction = 0.026); sarcopenia was associated with a poor prognosis, especially in young patients (log-rank p < 0.001). Sarcopenia negatively impacts survival in patients undergoing curative resection for stage I–III CRC.

Head and backbone of the Early Cambrian vertebrate Haikouichthys

Abstract: Agnathan fish hold a key position in vertebrate evolution, especially regarding the origin of the head and neural-crest-derived tissue. In contrast to amphioxus, lampreys and other vertebrates possess a complex brain and placodes that contribute to well-developed eyes, as well as auditory and olfactory systems. These sensory sytems were arguably a trigger to subsequent vertebrate diversifications. However, although they are known from skeletal impressions in younger Palaeozoic agnathans, information about the earliest records of these systems has been largely wanting. Here we report numerous specimens of the Lower Cambrian vertebrate Haikouichthys ercaicunensis, until now only known from the holotype. Haikouichthys shows significant differences from other fossil agnathans: key features include a small lobate extension to the head, with eyes and possible nasal sacs, as well as what may be otic capsules. A notochord with separate vertebral elements is also identifiable. Phylogenetic analysis indicates that this fish lies within the stem-group craniates. Although Haikouichthys somewhat resembles the ammocoete larva of modern lampreys, this is because of shared general craniate characters; adult lampreys and hagfishes (the cyclostomes if monophyletic) are probably derived in many respects.