Ken-ichi Nagai

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Although cancer is a disease with genetic and epigenetic origins, the possible effects of reprogramming by defined factors remain to be fully understood. We studied the effects of the induction or inhibition of cancer-related genes and immature status-related genes whose alterations have been reported in gastrointestinal cancer cells. Retroviral-mediated(More)
BACKGROUND We recently reported that gastrointestinal (GI) cancer cells can be reprogrammed to a pluripotent state by the ectopic expression of defined embryonic stem (ES)-like transcriptional factors. The induced pluripotent cancer (iPC) cells from GI cancer were sensitized to chemotherapeutic agents and differentiation-inducing treatment during a(More)
Heat stress on Madin-Darby canine kidney cells increased ceramide content to 187% at 40 degrees C for 24 h, and the de novo synthesis from serine increased to 146%. Glucosylceramide (GlcCer) and galactosylceramide (GalCer) synthesis from ceramide, the first glycosylation step of sphingolipid metabolism in kidney cells, increased to 290% (GalCer) and 143%(More)
BACKGROUND Previous reports have demonstrated that SNAI1 plays a role in epithelial-mesenchymal transition (EMT) through the suppression of CDH1. Its role in the pathology and regulation of EMT expression to chemoresistance in colorectal cancer (CRC) has not yet been fully elucidated. METHODS Immunohistochemistry was performed to evaluate the expression(More)
Proximal-rich tubules were prepared from rat kidneys by using collagenase treatment. The isolated rat renal tubules were compared with the intact kidney on the following characteristics. (1) Composition of the sulfoglycolipid. (2) Sulfoglycolipid metabolism based on incorporation of [35S]sulfate or some properties of sulfoglycolipid metabolism, including(More)
Patterns and contents of major acidic glycosphingolipids in the kidney of three marine mammalian species, the Steller sea lion (Pinnipedia), the rough-toothed dolphin and the broad-beaked dolphin (Odontoceti), were examined, and compared with those of terrestrial mesic mammals. The profile of major acidic glycosphingolipids was not significantly different(More)
Incorporation of (35)S-sulfate into the polar molecular species of sulfoglycolipids (SM4s) in Madin-Darby canine kidney cells increased in a hypertonic medium (500 mOsm/L) supplemented with sodium chloride. The unknown sulfoglycolipid (SX) was identified as GlcCer sulfate based on the results of TLC, GLC, and mass spectra. The synthesis of SX increased in(More)
Effects of a glycolytic (glucose) and a gluconeogenic renal nutritional substrate (glutamine) on metabolic turnover of sulfolipids, determined as [(35)S]sulfate incorporation, were compared in renal tubules prepared from well-fed rats. The results showed that the effects of glucose and glutamine, at nearly physiological serum concentration, are quite(More)
A convenient tool for studying metabolism of seminolipid in testis was developed by using mouse isolated seminiferous tubules prepared by collagenase treatment. Because more than 99% of [35S]sulfate-incorporation was distributed in seminolipid, its metabolism in seminiferous tubules can be analyzed without disturbance of the other sulfolipids in this assay(More)
Verots S3 and Vero317 cells were shown by metabolic labeling with (35)S-sulfate to contain many more sulfoglycosphingolipids than original Vero cells derived from African green monkey kidney. The activity of galactosyl ceramide sulfotransferase (GST) was shown to be 89- and 92-fold higher in Vero317 cells and Verots S3 cells, respectively, than that of the(More)