Kyushu University

About: Kyushu University is a education organization based out in Fukuoka, Japan. It is known for research contribution in the topics: Population & Catalysis. The organization has 68284 authors who have published 135190 publications receiving 3055928 citations. The organization is also known as: Kyūshū Daigaku.

MicroRNA-21 modulates biological functions of pancreatic cancer cells including their proliferation, invasion, and chemoresistance.

Abstract: Due to the poor prognosis of pancreatic cancer, novel diagnostic modalities for early diagnosis and new therapeutic strategy are urgently needed. Recently, microRNA-21 (miR-21) was reported to be strongly overexpressed in pancreatic cancer as well as in other solid cancers. We investigated the functional roles of miR-21, which have not been fully elucidated in pancreatic cancer. miR-21 expression was assessed in pancreatic cancer cell lines (14 cancer cell lines, primary cultures of normal pancreatic epithelial cells and fibroblasts, and a human normal pancreatic ductal epithelial cell line) and pancreatic tissue samples (25 cancer tissues and 25 normal tissues) by quantitative real-time reverse transcription-PCR amplification. Moreover, we investigated the proliferation, invasion, and chemoresistance of pancreatic cancer cells transfected with miR-21 precursor or inhibitor. miR-21 was markedly overexpressed in pancreatic cancer cells compared with nonmalignant cells, and miR-21 in cancer tissues was much higher than in nonmalignant tissues. The cancer cells transfected with the miR-21 precursor showed significantly increased proliferation, Matrigel invasion, and chemoresistance for gemcitabine compared with the control cells. In contrast, inhibition of miR-21 decreased proliferation, Matrigel invasion, and chemoresistance for gemcitabine. Moreover, miR-21 positively correlated with the mRNA expression of invasion-related genes, matrix metalloproteinase-2 and -9, and vascular endothelial growth factor. These data suggest that miR-21 expression is increased in pancreatic cancer cells and that miR-21 contributes to the cell proliferation, invasion, and chemoresistance of pancreatic cancer.

Rho-kinase-mediated pathway induces enhanced myosin light chain phosphorylations in a swine model of coronary artery spasm.

Abstract: Objective: We recently demonstrated in our swine model of coronary artery spasm that enhanced myosin light chain (MLC) phosphorylations (both MLC mono- and diphosphorylations) play a central role in the pathogenesis of the spasm. However, the molecular mechanism for and the phosphorylation sites for the enhanced MLC phosphorylations were unknown. In the present study, we addressed these points using hydroxyfasudil, a novel inhibitor of protein kinases, which we found preferentially inhibits Rho-kinase. Methods: The specificity of the inhibitory effects of hydroxyfasudil on Rho-kinase, MLCK, MRCKβ and PKC were examined by kinase assay in vitro. The left porcine coronary artery was chronically treated with interleukin-1β (IL-1β, 2.5 μg). Two weeks after the operation, coronary artery vasomotion was examined both in vivo and in vitro. MLC phosphorylations were examined by Western blot analysis and the sites for the phosphorylations by anti-phosphorylated MLC antibodies that identified the monophosphorylation site as Ser19 and diphophorylation sites as Ser19/Thr18 of MLC. Results: Inhibitory effects of hydroxyfasudil was at least 100 times more potent for Rho-kinase as compared with other protein kinases tested. Intracoronary serotonin (10 μg/kg) caused coronary hyperconstriction at the IL-1β-treated site in vivo, which was dose-dependently inhibited by hydroxyfasudil ( p <0.01). The coronary segment taken from the spastic site also showed hypercontractions to serotonin in vitro, which were again dose-dependently inhibited by hydroxyfasudil ( p <0.01). Western blot analysis showed that MLC monophosphorylation was significantly greater in the spastic segment than in the control segment, while MLC diphosphorylation was noted only at the spastic segment ( p <0.01). The sites for the mono- and diphosphorylated MLC were identified as the monophosphorylated site Ser19 and diphosphorylated sites Ser19/Thr18 of MLC, respectively. Both types of MLC phosphorylations at the spastic segment were markedly inhibited by hydroxyfasudil ( p <0.01). Conclusion: These results indicate that hydroxyfasudil-sensitive Rho-kinase-mediated pathway appears to mediate the enhanced MLC phosphorylations (on Ser19 and Ser19/Thr18 residues) and plays a central role in the pathogenesis of coronary artery spasm.

High-efficiency organic light-emitting diodes utilizing thermally activated delayed fluorescence from triazine-based donor–acceptor hybrid molecules

Abstract: We have designed and synthesized a high-efficiency purely organic luminescent material, 2,4-bis{3-(9 H-carbazol-9-yl)-9 H-carbazol-9-yl}-6-phenyl-1,3,5-triazine (CC2TA) comprising the bicarbazole donor and phenyltriazine acceptor units, which is capable of emitting thermally activated delayed fluorescence. The molecular design of CC2TA allows spatial separation of HOMO and LUMO on the donor and acceptor fragments, respectively, leading to an exceptionally small singlet–triplet exchange energy (ΔEST = 0.06 eV) together with a high triplet energy. Furthermore, a high external electroluminescence quantum efficiency as high as 11% ± 1% has been achieved in the sky-blue organic light-emitting diodes employing CC2TA as an emitter.