Hidetoshi Sumimoto

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The mitogen-activated protein kinase (MAPK) pathway is frequently activated in human cancers, leading to malignant phenotypes such as autonomous cellular proliferation. Here, we demonstrate a novel role of the activated MAPK pathway in immune evasion by melanoma cells with the mutation of BRAF, which encodes a MAPKKs, (BRAF(V600E)). MEK inhibitor U0126 or(More)
An increased production of reactive oxygen species (ROS) could contribute to the development of diabetic nephropathy. NAD(P)H oxidase might be an important source of ROS production in kidney as reported in blood vessels. In this study, we show the increased expression of essential subunits of NAD(P)H oxidase, NOX4 and p22phox, in the kidney of diabetic(More)
UNLABELLED It is unclear how hepatic adiponectin resistance and sensitivity mediated by the adiponectin receptor, AdipoR2, contributes to the progression of nonalcoholic steatohepatitis (NASH). The aim of this study was to examine the roles of hepatic AdipoR2 in NASH, using an animal model. We fed C57BL/6 mice a methionine-deficient and choline-deficient(More)
Recent studies have uncovered various pleiotrophic effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase-inhibiting drugs (statins). Several studies have identified a beneficial effect of statins on diabetic nephropathy; however, the molecular mechanisms are unclear. In this study, we show that statin ameliorates nephropathy in db/db mice, a rodent(More)
Cancer-induced immunosuppression is a major problem as it reduces the anti-tumor effects of immunotherapies. In cancer tissues, cancer cells, immune cells, and other stromal cells interact and create an immunosuppressive microenvironment through a variety of immunosuppressive factors. Some cancer subpopulations such as cancer cells undergoing(More)
BACKGROUND RNA interference (RNAi) is a phenomenon in which expression of an individual gene can be specifically silenced by introducing a double-stranded RNA, one complementary to the gene, into cells. This phenomenon can be observed in mammalian cells when small interfering RNAs (siRNAs) are used, and is receiving attention as the most powerful tool for(More)
A growing body of evidence has shown that oxidative stress may be involved in the development of vascular complications associated with diabetes. However, the molecular mechanism for increased reactive oxygen species (ROS) production in diabetes remains uncertain. Among various possible mechanisms, attention have increasingly been paid to NAD(P)H oxidase as(More)
Oncogenic mutations of molecules involved in the mitogen-activated protein kinase (MAPK) pathways provide signals mediating both tumor growth and invasion in various cancers including melanomas. BRAF somatic mutations, found in 66% of melanomas, have NIH3T3 transforming ability with the elevated kinase activity in vitro. We attempted to mediate RNA(More)
RNAi is a useful tool for functional analysis of genes and developing a potential therapeutic strategy for various diseases including cancers. RNAi can be applied in various forms. HIV vectors are useful for the stable transduction of genes to both replicating and quiescent cells with a broad host tropism, and have been developed for basic and clinical(More)
Myeloid cell leukemia-1 (Mcl-1) is an anti-apoptotic protein that regulates apoptosis sensitivity in a variety of cell types. Here we evaluate the roles of Mcl-1 in chemotherapy-associated apoptosis in gastric cancer cells. In addition, our study examined whether Mcl-1 contributed to apoptosis resistance in so-called cancer stem cell (CSC)-like populations(More)