108 research outputs found

    Reevaluation of analytical methods for photogenerated singlet oxygen

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    The aim of the present study is to compare different analytical methods for singlet oxygen and to discuss an appropriate way to evaluate the yield of singlet oxygen photogenerated from photosensitizers. Singlet oxygen photogenerated from rose bengal was evaluated by electron spin resonance analysis using sterically hindered amines, spectrophotometric analysis of 1,3-diphenylisobenzofuran oxidation, and analysis of fluorescent probe (Singlet Oxygen Sensor Green®). All of the analytical methods could evaluate the relative yield of singlet oxygen. The sensitivity of the analytical methods was 1,3-diphenylisobenzofuran < electron spin resonance < Singlet Oxygen Sensor Green®. However, Singlet Oxygen Sensor Green® could be used only when the concentration of rose bengal was very low (<1 µM). In addition, since the absorption spectra of 1,3-diphenylisobenzofuran is considerably changed by irradiation of 405 nm laser, photosensitizers which are excited by light with a wavelength of around 400 nm such as hematoporphyrin cannot be used in the 1,3-diphenylisobenzofuran oxidation method. On the other hand, electron spin resonance analysis using a sterically hindered amine, especially 2,2,6,6-tetramethyl-4-piperidinol and 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide, had proper sensitivity and wide detectable range for the yield of photogenerated singlet oxygen. Therefore, in photodynamic therapy, it is suggested that the relative yield of singlet oxygen generated by various photosensitizers can be evaluated properly by electron spin resonance analysis

    Overexpression of GalNAc-transferase GalNAc-T3 Promotes Pancreatic Cancer Cell Growth

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    O-linked glycans of secreted and membrane bound proteins play an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation, and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc: polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins, and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in human pancreatic cancer tissues, and suppression of GalNAc-T3 significantly attenuates growth of pancreatic cancer cells in vitro and in vivo. In addition, suppression of GalNAc-T3 induces apoptosis of pancreatic cancer cells. Our results indicate that GalNAc-T3 is likely to be involved in pancreatic carcinogenesis. Modification of cellular glycosylation occurs in nearly all types of cancer as a result of alterations in the expression levels of glycosyltransferases. We report guanine nucleotide binding protein, alpha transducing activity polypeptide 1 (GNAT1) as a possible substrate protein of GalNAc-T3. GalNAc-T3 is associated with O-glycosylation of GNAT1, and affects the subcellular distribution of GNAT1. Knocking down endogenous GNAT1 significantly suppresses the growth/survival of PDAC cells. Our results imply that GalNAc-T3 contributes to the function of O-glycosylated proteins and thereby affects the growth and survival of pancreatic cancer cells. Thus, substrate proteins of GalNAc-T3 should serve as important therapeutic targets for pancreatic cancers

    Overexpression of GalNAc-transferase GalNAc-T3 Promotes Pancreatic Cancer Cell Growth

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    O-linked glycans of secreted and membrane bound proteins play an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation, and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc: polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins, and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in human pancreatic cancer tissues, and suppression of GalNAc-T3 significantly attenuates growth of pancreatic cancer cells in vitro and in vivo. In addition, suppression of GalNAc-T3 induces apoptosis of pancreatic cancer cells. Our results indicate that GalNAc-T3 is likely to be involved in pancreatic carcinogenesis. Modification of cellular glycosylation occurs in nearly all types of cancer as a result of alterations in the expression levels of glycosyltransferases. We report guanine nucleotide binding protein, alpha transducing activity polypeptide 1 (GNAT1) as a possible substrate protein of GalNAc-T3. GalNAc-T3 is associated with O-glycosylation of GNAT1, and affects the subcellular distribution of GNAT1. Knocking down endogenous GNAT1 significantly suppresses the growth/survival of PDAC cells. Our results imply that GalNAc-T3 contributes to the function of O-glycosylated proteins and thereby affects the growth and survival of pancreatic cancer cells. Thus, substrate proteins of GalNAc-T3 should serve as important therapeutic targets for pancreatic cancers

    Overexpression of GalNAc-transferase GalNAc-T3 Promotes Pancreatic Cancer Cell Growth

    Get PDF
    O-linked glycans of secreted and membrane bound proteins play an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation, and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc: polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins, and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in human pancreatic cancer tissues, and suppression of GalNAc-T3 significantly attenuates growth of pancreatic cancer cells in vitro and in vivo. In addition, suppression of GalNAc-T3 induces apoptosis of pancreatic cancer cells. Our results indicate that GalNAc-T3 is likely to be involved in pancreatic carcinogenesis. Modification of cellular glycosylation occurs in nearly all types of cancer as a result of alterations in the expression levels of glycosyltransferases. We report guanine nucleotide binding protein, alpha transducing activity polypeptide 1 (GNAT1) as a possible substrate protein of GalNAc-T3. GalNAc-T3 is associated with O-glycosylation of GNAT1, and affects the subcellular distribution of GNAT1. Knocking down endogenous GNAT1 significantly suppresses the growth/survival of PDAC cells. Our results imply that GalNAc-T3 contributes to the function of O-glycosylated proteins and thereby affects the growth and survival of pancreatic cancer cells. Thus, substrate proteins of GalNAc-T3 should serve as important therapeutic targets for pancreatic cancers

    Probing the spin polarization of current by soft X-ray imaging of current-induced magnetic vortex dynamics

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    Time-resolved soft X-ray transmission microscopy is applied to image the current-induced resonant dynamics of the magnetic vortex core realized in a micronsized Permalloy disk. The high spatial resolution better than 25 nm enables us to observe the resonant motion of the vortex core. The result also provides the spin polarization of the current to be 0.67 +/-0.16 for Permalloy by fitting the experimental results with an analytical model in the framework of the spin-transfer torque.Comment: 13 pages, 3 figure

    Antisense RNA transcripts in the blood may be novel diagnostic markers for colorectal cancer

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    Numerous genetic studies have been conducted regarding the occurrence of colorectal cancer (CRC) and the prognosis using microarrays. However, adequate investigations into the diagnostic application of microarrays have yet to be performed. The simplicity and accuracy of diagnosis and prognosis tracking are important requirements for its processes, and the use of blood cells for diagnosis is considered to be suitable to meet these requirements. The patients involved in the study were 28 preoperative patients with CRC and 6 healthy individuals who served as controls. RNA was extracted from the blood cells of the patients and analyzed using a sense/antisense RNA custom microarray. In the patients with CRC, the expression levels of 20 sense RNA and 20 antisense RNA species were identified as being significantly altered compared with that of the healthy volunteers (P2.0). Cluster analysis of these RNA species revealed that the top 10 antisense RNAs significantly clustered patients with cancer and healthy individuals separately. Patients with stage I or II CRC exhibited significant changes in the expression levels of 33 sense and 39 antisense RNA species, as compared with healthy volunteers (P2.0). Cluster analysis demonstrated that patients with stage I or II CRC and healthy volunteers formed separate clusters only among the top 20 antisense RNA species. A tracking study of expression levels of haloacid dehalogenase‑like hydrolase domain‑containing 1 (HDHD1) antisense RNA was performed and a significant difference was identified between the CRC and healthy groups revealing that the levels at one week and three months following surgical removal of the cancerous tissue, decreased to almost same levels of the healthy individuals. The results of the current study indicate that HDHD1 antisense RNA may serve as a potential biomarker for the prognosis of CRC

    Endoscopic submucosal dissection of a minute intramucosal adenocarcinoma in Barrett\u27s esophagus.

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    A 73-year-old man with short segmental Barrett\u27s esophagus underwent esophagoscopy, and a slightly depressed, discolored lesion was found on the anterior wall of the lower esophagus. Under a provisional diagnosis of differentiated adenocarcinoma without local lymph node metastasis, endoscopic submucosal dissection (ESD) was carried out. En bloc resection with tumor-free lateral/basal margins was accomplished without complication. The resected area was 12 x 15 mm in size, whereas the neoplastic lesion was 4 x 4 mm. Histopathological examination confirmed intramucosal well-differentiated tubular adenocarcinoma without angiolymphatic invasion adjacent to the muscularis mucosae. Repeated esophagoscopy 6 months after ESD showed neither locally recurrent nor metachronous lesions. Considering that Barrett\u27s esophagus is a precancerous condition, one may recommend eradication of both the neoplastic and non-neoplastic lesion with using ESD.Without Figure
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