Globotriaosyl Ceramide and Globoside as Major Glycolipid Components of Fibroblasts in Scirrhous Gastric Carcinoma Tissues

Scirrhous gastric cancer is characteristic in that cancer cells proliferate and invade with prominent fibrosis. To search for the expression of specific carbohydrate chains in scirrhous gastric cancer, we have examined the glycosphingolipid composition of scirrhous cancer tissues (n=10) in comparison with that of non-scirrhous cancer tissues (n=10) by means of two-dimensional thin layer chromatography, followed by fast atom bombardment mass spectrometry of the individual glycolipids and immunostaining analysis. The major neutral glycosphingolipids from scirrhous gastric cancer tissues were identified as ceramide monohexoside, ceramide dihexoside, globotriaosyl ceramide (Gb₃) and globoside (Gb₄), while the major acidic glycosphingolipids were II³ Neu-Acα-LacCer, II³ NeuAcα₂-LacCer and sulfatide. Relative concentrations of Gb₃ and Gb₄ in scirrhous gastric cancer tissues (Gb₃+ Gb₄=58%) were two times higher than those in non-scirrhous gastric cancer tissues (29%). Orthotopic fibroblasts cloned from scirrhous gastric cancer tissues showed similar high concentrations of Gb₃ and Gb₄ to scirrhous gastric cancer tissues. Furthermore, immunohistochemical study revealed that Gb₃ and Gb₄ were expressed intensely on the fibroblasts. On the other hand, analysis of glycosphingolipids in four scirrhous gastric cancer cell lines yielded the following results. i) The contents of Gb₃ and Gb₄ were low (6%), compared with orthotopic fibroblasts (62%). ii) Significant amounts of Le^a (pentaglycosylceramide) and Le^b (hexa- and heptaglycosylceramides), which could not be detected in scirrhous cancer tissues, were observed. The results show that the major neutral glycosphingolipids such as Gb₃ and Gb₄ of scirrhous gastric cancer tissues were derived from orthotopic fibroblasts and not from the cancer cells.     

Increased Sensitivity to Long-term 5-Fluorouracil Exposure of Human Colon Cancer HT-29 Cells Resistant to Short-term Exposure

A 5-fluorouracil (5-FU)-resistant subline of human colon cancer HT-29 cells was developed by repeated 1-h exposure in vitro to 5-FU. This subline (HT-29/5-FU/S) had 8-fold resistance to 5-FU in a 1-h exposure assay. However, it had rather increased sensitivity to 5-FU when assayed after a continuous 96-h exposure to it. Significantly less 5-fluorouridine-5'-triphosphate was produced in the resistant cells, leading to a lower level of 5-FU incorporation into the cellular RNA. The reduced activity of orotate phosphoribosyltransferase might explain these results. In contrast, the HT-29/5-FU/S cells were more sensitive to the inhibition of in situ thymidylate synthase (TS) by 5-FU than were the parent cells. The lower in situ TS activity may have made HT-29/5-FU/S cells more sensitive to TS inhibition by 5-FU as compared with the parent cells. The fact that HT-29/5-FU/S was more resistant to short-term 5-FU exposure but more sensitive to long-term exposure than the parent line confirmed the existence of different modes of action of 5-FU, depending on the exposure time.     

Caspase-3 activation and inflammatory responses in rat hippocampus inoculated with a recombinant adenovirus expressing the Alzheimer amyloid precursor protein

To elucidate the mechanism of neuronal death in Alzheimer's disease, we investigated the effects of overexpression of wild-type Alzheimer amyloid precursor protein (APP) on neuronal cells and glial cells in vivo. When an APP695-expressing adenovirus was injected into the dorsal hippocampal region, a number of neurons in remote areas were positively stained with anti-APP monoclonal antibody, and underwent severe degeneration from 3 to 7 days after viral inoculation. Most degenerating neurons were immunopositive with both APP and activated caspase-3, but some neurons that expressed activated caspase-3 were not expressing APP from 7 to 14 days after virus injection. In the neighborhood of the degenerating neurons, activated microglia/macrophages, which were identified by the phenotypic marker C3bi receptor (CD11b/c; OX-42), were observed, and some of them appeared to phagocytose the caspase-3-immunopositive degenerating neurons. In addition to microglia/macrophages, infiltrating leukocytes expressing CD45 or CD4 were also detected. These results suggest that the increased accumulation of APP induced not only caspase-3-mediated death machinery, but also inflammatory responses including microglial activation. These inflammatory responses might cause further neurodegeneration through the alternative pathway that might activate the caspase-3-mediated death machinery without APP expression.     

Cervical inflammatory cytokines and other markers in the cervical mucus of pregnant women with lower genital tract infection.

OBJECTIVE: To evaluate concentrations of interleukin (IL)-6, IL-8, lactoferrin (LF), and alpha defencine (alpha-DF) in the cervical mucus of pregnant women and analyze their relation to cervicitis and bacterial vaginosis (BV). METHODS: Cervical mucus samples were obtained from August 2003 through May 2004 from 157 women who were between the 6th and 36th week of an uncomplicated singleton pregnancy. All women were delivered at term, 69 without BV or cervicitis, 9 with BV, and 79 with cervicitis. RESULTS: Interleukin 8, LF, and mu-DF concentrations were higher in women with cervicitis (0.81 +/- 0.36 pg/mL, 14.8+/-12.3 microg/mL, and 0.60 +/- 0.49 microg/mL) than in women without BV or cervicitis (0.35 +/- 0.34 pg/mL, 8.0 +/- 11.0 microg/mL, and 0.15 +/- 0.12 microg/mL). Interleukin 6 concentration was higher in women with BV (0.26 +/- 0.32 pg/mL) than in women without BV or cervicitis (0.09 +/- 0.15 pg/mL) or in women with cervicitis (0.12 +/- 0.18 pg/mL). CONCLUSIONS: Higher levels of inflammatory cytokines in the cervical mucus of pregnant women may lead to early detection of lower genital tract infection.