Biomedical subjects

Sanae Kabata Ikehara

Publications and source records attributed to Sanae Kabata Ikehara.

4 recordsLinked to original sources

PubMed2006

A polymorphism of C-to-T substitution at -31 IL1B is associated with the risk of advanced gastric adenocarcinoma in a Japanese population.

Proinflammatory cytokine gene polymorphisms have been demonstrated to associate with gastric cancer risk, of which IL1B-31T/C and -511C/T changes have been well investigated due to the possibility that they may alter the IL1B transcription. The signal transduction target upon interleukin 1 beta (IL1beta) stimulation, the nuclear factor of kappa B (NFkappaB) activation, supports cancer development, signal transduction in which is mediated by FS-7 cell-associated cell surface antigen (FAS) signaling. Based on recent papers describing the prognostic roles of the polymorphisms and the NFkappaB functions on cancer development, we sought to determine if Japanese gastric cancer patients were affected by the IL1B -31/-511 and FAS-670 polymorphisms. A case-control study was conducted on incident gastric adenocarcinoma patients (n=271) and age-gender frequency-matched control subjects (n=271). We observed strong linkage disequilibrium between the T allele at -511 and the C allele at -31 and between the C allele at -511 and the T allele at -31 in IL1B in both the cases and controls (R (2)=0.94). Neither IL1B-31, -511 nor FAS-670 polymorphisms showed significantly different risks of gastric adenocarcinoma. Though FAS-670 polymorphisms did not show any significant difference, the proportion of subjects with IL1B-31TT (or IL1B-511CC) increased according to stage (trend P=0.019). In particular, subjects with stage IV had a two times higher probability of having either IL1B-31TT (or IL1B-511CC) genotype compared with stage I subjects. These observations suggest that IL1B-31TT and IL1B-511CC are associated with disease progression.

Adenocarcinoma↗

PubMed2006

A carbohydrate recognition-based drug delivery and controlled release system using intraperitoneal macrophages as a cellular vehicle.

The lymphoid tissue in the omentum, at the so-called milky spots, is known as an initial place for disseminated cancer cells to develop into solid tumors. In the present study, i.p. macrophages significantly took up oligomannose-coated liposomes (OMLs) that were injected into the peritoneal cavity, and then gradually accumulated in the omentum and the other lymphoid tissues within 24 hours of i.p. injection of OMLs. When 5-fluorouracil (5-FU) was encapsulated in the OMLs, >60% of administered 5-FU accumulated in the omentum. Treatment of macrophages at 39 degrees C for 30 minutes led to the release of 5-FU from the macrophages, suggesting that controlled release from macrophages could be achieved by mild hyperthermia. We encased magnetic nanoparticles, which are known to convert electromagnetic energy to heat in the OMLs to achieve in vivo hyperthermia at the site. Using this system in a mouse i.p. metastasis model, we successfully controlled tumor development by coadministration of OML-encased 5-FU and OML-encased magnetic nanoparticles, followed by treatment with an alternating magnetic field. No apparent reduction was seen in tumor growth with the administration of OML-encased magnetic nanoparticles or OML-encased 5-FU alone. Thus, we have established the use of i.p. macrophages as a novel drug delivery system for the control of cancer metastatic to milky spots.

Animals↗

PubMed2006

Apical Golgi localization of N,N'-diacetyllactosediamine synthase, beta4GalNAc-T3, is responsible for LacdiNAc expression on gastric mucosa.

beta1,4-N-acetylgalactosaminyltransferase III (beta4GalNAc-T3), which was recently cloned and identified, exhibits GalNAc transferase activity toward a GlcNAcbeta residue with beta1,4-linkage, forming the N,N'-diacetyllactosediamine, GalNAcbeta1,4GlcNAc (LacdiNAc or LDN). Though LacdiNAc has not been found in the gastric mucosa, a large amount of transcript was detected in our previous study. To increase our knowledge of beta4GalNAc-T3 expression and its product LacdiNAc, we examined the exact localization of beta4GalNAc-T3 in human gastric mucosa using a newly developed antibody, monoclonal antibody (mAb) K1356. This antibody specifically detected the enzyme that transfected the beta4GalNAc-T3 gene into MKN45 cells, and the terminal betaGalNAc epitope yielded on the cell surface was recognized by a lectin, Wisteria floribunda agglutinin (WFA). beta4GalNAc-T3 was localized in the supra-nuclear region of surface mucous cells in gastric mucosa, and WFA positively stained the mucins secreted by the cells. In contrast, in the cells of the glandular compartment in the fundic glands and a few cells in the pyloric glands, beta4GalNAc-T3 was observed in the basolateral position of the nucleus, where no WFA reactivity was detected. The anti-Tn (GalNAcalpha-O-Ser/Thr) antibody staining did not overlap with the WFA staining. By measuring the binding activity of WFA using automated frontal affinity chromatography (FAC), we found WFA to bind most strongly LacdiNAc among the sugar chains examined. Neither beta4GalNAc-T3 nor WFA-positive staining was detected in intestinal metaplastic cells. These results suggest that the supra-nuclear expression of beta4GalNAc-T3 is essential for the formation of LacdiNAc on the surface mucous cells and that LacdiNAc and beta4GalNAc-T3 are novel differentiation markers of surface mucous cells in the gastric mucosa.

Antigens, Differentiation↗

PubMed2004

Negative regulation of T cell receptor signaling by Siglec-7 (p70/AIRM) and Siglec-9.

Siglec-7 (p70/AIRM) and Siglec-9 are "CD33"-related siglecs expressed on natural killer (NK) cells and subsets of peripheral T cells. Like other inhibitory NK cell receptors, they contain immunoglobulin receptor family tyrosine-based inhibitory motifs in their cytoplasmic domains, and Siglec-7 has been demonstrated to negatively regulate NK cell activation. Based on reports of the presence of these siglecs on T cells, we sought to determine if they are capable of modulating T cell receptor (TCR) signaling using Jurkat T cells stably and transiently transfected with Siglec-7 or Siglec-9. Following either pervanadate stimulation or TCR engagement, both Siglecs exhibited increased tyrosine phosphorylation and recruitment of SHP-1. Effects of Siglec-7 and -9 were also evident in downstream events in the signaling pathway. Both siglecs reduced phosphorylation of Tyr319 on ZAP-70, known to play a pivotal role in up-regulation of gene transcription following TCR stimulation. There was also a corresponding decreased transcriptional activity of nuclear factor of activated T cells (NFAT) as determined using a luciferase reporter gene. Like all siglecs, Siglec-7 and -9 recognize sialic acid-containing glycans of glycoproteins and glycolipids as ligands. Mutation of the conserved Arg in the ligand binding site of Siglec-7 (Arg124) or Siglec-9 (Arg120) resulted in reduced inhibitory function in the NFAT/luciferase transcription assay, suggesting that ligand binding is required for optimal inhibition of TCR signaling. The combined results demonstrate that both Siglec-7 and Siglec-9 are capable of negative regulation of TCR signaling and that ligand binding is required for optimal activity.

Amino Acid Motifs↗