The effect of peroxisome proliferator-activated receptor-gamma ligand on urological cancer cells

Peroxisome proliferator activator-receptor (PPAR)-gamma ligand induces growth arrest of cancer cells through apoptosis. In this study, we examined the effects of PPAR-gamma inhibitors on cell proliferation in renal cell carcinoma (RCC), bladder tumor (BT), and prostatic carcinoma (PC) cell lines. We investigated the inhibitory effect of PPAR-gamma ligands, troglitazone and 15-deoxy-Delta12,14-prostaglandin J2 (15dPGJ2) on RCC, BT and PC-derived cell lines using MTT assay and Hoechst staining. PPAR-gamma ligands (troglitazone and 15dPGJ2) induced the reduction of cell viability with the half-maximal concentration of growth inhibition of RCC, BT, and PC cell lines. Furthermore, counting cells at days 1, 2 and 3, clearly showed marked inhibition of cell proliferation using troglitazone and 15dPGJ2. All PPAR-gamma inhibitors stopped the growth of all RCC, BT and PC cells. Cells treated with PPAR-gamma inhibitors showed chromatin condensation, cellular shrinkage, small membrane-bound bodies (apoptotic bodies), and cytoplasmic condensation. These cellular changes were typically redundant characteristics of apoptosis. PPAR-gamma ligands may mediate potent antiproliferative effects against RCC, BT and PC cells through differentiation. Thus, PPAR-gamma may become a new target in treatment of urological tumors.     

Deposition of complement protein C3b on mixed self-assembled monolayers carrying surface hydroxyl and methyl groups studied by surface plasmon resonance

Since complement activation is recognized as a common response of the host defense system when an artificial medical device is applied to a patient, great effort has been devoted to studies on the interaction of the complement system with artificial materials. However, some uncertainties remain, partially because of the lack of well characterized surfaces and suitable analytic methods for study of the surface phenomena that occur on artificial materials under physiologic conditions. In this study, we employed self-assembled monolayers (SAMs) and the surface plasmon resonance (SPR) technique to study interactions of the serum complement with well characterized surfaces. Self-assembled monolayers carrying various concentrations of hydroxyl groups were prepared using 11-mercapto-1-undecanol (C11-OH) and one of n-nonanethiol, n-dodecanethiol, and n-hexadecanethiol. The amount of NHS deposition on the SAMs increased with increasing C11-OH content of the SAMs, and the amount of anti-C3b antibody immobilization formed on the NHS deposition layers increased with increasing C11-OH content of the SAMs. These results clearly demonstrate that a large amount of C3b, produced through the activation of the complement system, binds covalently to and is adsorbed by hydroxyl-group-rich surfaces. The combination of SAMs and the SPR technique is suitable for studying the interaction of the complement system with solid surfaces, and the results should give basic information needed for a rational design of biocompatible surfaces on synthetic materials.     

Relationship between lipoxygenase and human testicular cancer

The metabolism of arachidonic acid by either the cyclooxygenase (COX) or lipoxygenase (LOX) pathway generates eicosanoids, which have been implicated in the pathogenesis of a variety of human diseases, including cancer. They are now believed to play important roles in tumor promotion, progression, and metastasis, and the involvement of LOX expression and function in tumor growth and metastasis has been reported in human tumor cell lines. Expressions of 5-LOX and 12-LOX in human testicular cancer (TC), and normal testis (NT) tissues were examined, as well as effects of their inhibitors on cell proliferation in TC cell line. Expressions of 5-LOX and 12-LOX were detected by immunohistochemistry. Effects of LOX inhibitors on TC cell growth were examined by MTT assay. While 5-LOX and 12-LOX expressions were slightly detected in NT tissues, expressions of 5-LOX and 12-LOX were significant detected in TC tissues by immunohistochemistry. The LOX inhibitors inhibited the growth of TC cells. LOX is induced in TC, and results may suggest that LOXs are essential for cell growth of TC cells.     

Axonal trajectory of single group Ia and Ib fibers in the cat spinal cord

Intracellular staining with HRP of physiologically identified group Ia and Ib afferent fibers in the adult cat lumbosacral cord revealed that group Ia and Ib fibers take a similar course in the dorsal funiculus, but the collaterals emerging from them show a different topographical distribution and a different mode of branching in the gray matter. Ia collaterals terminate in laminae VI, VII, IX, and sometimes VIII, whereas Ib collaterals terminate only in lamina VI, or both VI and IX. In lamina IX, two large motor-type neurons received terminations of both Ia and Ib fibers at the same time.     

Kupffer cell-mediated cytotoxicity against hepatoma cells occurs through production of nitric oxide and adhesion via ICAM-1/CD18

Rat Kupffer cell (KC)-mediated cytotoxicity against both thesyngeneic hepatoma cell line AH70 and hepatocytes was evaluatedby changes in mitochondrial function, and the possible roleof ICAM-1/CD18 in the interaction between the cells was studied.Rhodamine 123 fluorescence, a marker of the mitochondrial membranepotential, decreased in AH70 cells after co-culture with KC,while that in hepatocytes was unchanged by co-culture. Thisdecrease was blocked by anti-ICAM-1, anti-CD18 and the Inhibitionof nitric oxide synthesis. Cytometric studies demonstrated thatICAM-1 expression on AH70 cells increased after addition ofIFN-, IL-1ß, tumor necrosis factor (TNF)- or KC, whilein hepatocytes ICAM-1 was not increased. Anti-ICAM-1 pretreatmentinhibited the increase in ICAM-1 expression and the decreasein rhodamine 123 fluorescence on AH70 cells after co-culturewith KC. CD18 on KC was increased only after co-culture withAH70. TNF- but not IFN- was detected in the supernatant of co-culturebetween KC and AH70 cells, and this production was partiallyinhibited by anti-ICAM-1 and anti-CD18. The activity of Induciblenitric oxide synthase in Kupffer cells and the levels of nitritesand nitrates in the co-culture supernatant increased over time,and this increase was attenuated either by addition of NO synthesisinhibitors, anti-ICAM-1 or anti-CD18. These results indicatethat the rat KC causes mitochondrial dysfunction in cancer cellsvia the production of NO and cell-to-cell adhesion via ICAM-1/CD18has an Important role in this cytotoxic process.     

GM1, a ganglioside that specifically enhances immunoglobulin production and proliferation in human plasma cells

The effects of gangliosides on human plasma cell responses were studied. Among the various gangliosides tested, only GM1 enhanced immunoglobulin (Ig) production and proliferation in the human plasma cell lines, IM-9 and AF-10, while other gangliosides (GM2, GM3, GD1a, GD1b, GD3, GT1b, and GQ1b) had no effect. Among the various cytokines tested, including interleukin (IL)-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12, IL-13, interferon (IFN)-α and IFN-γ, only IL-6 enhanced Ig production and proliferation in IM-9 and AF-10 cells. However, the enhancement of plasma cell responses by GM1 was specific and was not mediated by IL-6, since GM1 activity was blocked by anti-GM1 monoclonal antibody (mAb), but not by control IgM, anti-IL-6 Ab or the anti-IL-6 receptor mAb, PM1. Conversely, the enhancement by IL-6 was blocked by anti-IL-6 Ab and PM1, but not by anti-GM1 mAb. GM1, but not other gangliosides, also enhanced Ig production and proliferation in freshly separated plasma cells from patients with plasma cell leukemia and in plasma cells generated in vitro. These actions of GM1 were specifically blocked by anti-GM1 mAb, but not by anti-IL-6 Ab or PM1. These results indicate that GM1 may be an important regulator of plasma cell responses.