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Biomedical subjects

T C Hsieh

Publications and source records attributed to T C Hsieh.

10 recordsLinked to original sources
PubMed1995

Growth modulation of human prostatic cancer cells by interleukin-1 and interleukin-1 receptor antagonist.

The effects of interleukin-1 (IL-1 alpha or IL 1 beta) on androgen-dependent LNCaP and androgen-independent JCA-1 human prostatic cancer cell proliferation were investigated. IL-1 alpha or IL-1 beta induced a dose dependent growth reduction by 50-80% as determined by cell cycle phase distribution, cell number and clonal growth in short and long term cultures. IL-1 negated the androgen growth effect on equal molar basis but the androgen receptors were not blocked by IL-1. The presence of intracellular IL-1 receptors was detected by flow cytometry and the IL-1 mediated growth reduction could be blocked with a 500 fold excess of the IL-1 receptor antagonist (hIL-1ra), revealing a growth control involving IL-1, HIL-1ra, androgen and their receptors.

Cell Division↗
PubMed1995

Growth regulation and cellular changes during differentiation of human prostatic cancer LNCaP cells as induced by T lymphocyte-conditioned medium.

Human prostatic epithelial cells from an androgen-dependent LNCaP cell line were examined in response to conditioned medium (CM) derived from phytohemagglutinin (PHA)-stimulated lymphocytes. Addition of CM caused a greater than 70% reduction of cell proliferation by cell counting and cell cycle. These cells showed G1 phase arrest and the clonogenicity was reduced. The growth-modulating effect was dose-dependent and not due to cell lysis or apoptosis. The binding of androgen to androgen receptor on these cells showed approximately 50% reduction, underlining a proliferation reduction mechanism. The prostate-specific antigen (PSA) was downregulated to approximately 75% during the process. Cell morphology showed dendritic processes extending from cytoplasm and other neuroendocrine cell characteristics. The expression of several cytoskeleton and intracellular proteins increased as determined by immunostaining on slides and by ELISA procedures. These included vimentin, correlating to cell shape changes, cytokeratins 8 and 18, associated with differentiated cell types of prostate epithelia, and neuron-specific enolase and serotonin, associated with neuroendocrine cells. From these cellular changes, we can infer that the cell growth was modulated along with induction of terminal differentiation. Activated T cells were demonstrated to be important in providing the modulating activity. This growth modulator was semipurified and had an estimated molecular weight 13,000 to 24,000 Da. The activity was determined to be distinct from TGF, TNF, and some commonly known lymphokines. The interaction between lymphoid and prostatic cells in growth and development is described.

Biomarkers↗
PubMed1995

Growth attenuation in a human prostate cell line mediated by a phorbol ester.

Human prostatic cancer cells JCA-1 were induced with a phorbol ester 12-o-tetradecanoylphorbol-13-acetate (TPA), and cell growth differentiation were analyzed. Within hours of exposure to TPA, cell proliferation decreased and reached approximately 80% reduction after 3 days, as determined by [3H]thymidine incorporation and cell counting. Cell cycle analysis revealed a blocking of cells entering into the replicating S and G2M phases from the G1 phase. The TPA induced cells had a reduced growth rate but remained viable. The growth-modulating activity of TPA was similarly observed with LNCaP cells. Agarose gel electrophoresis of the chromosomal DNA from induced cells exhibited a non-fragmented pattern excluding the possibility of cell apoptosis. In parallel to the growth reduction, the TPA induced cells became larger in size showing dendrite like cytoplasmic extensions. Furthermore, JCA-1 cells treated with TPA acquired the expression of cytokeratin 18 and increased the expression of actin and vimentin by 300%. These results indicate an induced growth reduction accompanied by cellular differentiation of the prostatic cancer cells.

Cell Cycle↗
PubMed1990

Induction of tumor necrosis factor and cytotoxicity by macrophages exposed to lactoperoxidase and microperoxidase.

Peroxidases are involved in a number of cytotoxic reactions. Murine thioglycollate-induced peritoneal macrophages were exposed to either lactoperoxidase or microperoxidase in vitro. At a concentration of 17.7 microM, both of these enzymes induced between 100 and 200 units of tumor necrosis factor (TNF) per 0.1 ml. Furthermore, these substances were able to stimulate macrophages to kill 3T12 target cells in a dose dependent manner at concentrations of 0.177 microM to 17.7 microM. Per cent cytotoxicity varied from 20% up to 75% at the higher concentrations. It was concluded that these enzymes can induce macrophages to secrete TNF and become activated to the cytotoxic state.

Animals↗
PubMed1989

Peroxidases enhance macrophage-mediated cytotoxicity via induction of tumor necrosis factor.

Tumor necrosis factor (TNF) is a monokine which is involved in macrophage-mediated cytotoxicity (MMC). We have previously reported that peroxidases can activate thioglycollate-induced macrophages to the tumoricidal state in vitro. The present study was undertaken in an attempt to correlate peroxidase-induced MMC with production of TNF. Horseradish peroxidase (HRP) was used as the principal model for these studies. Resident and thioglycollate-induced macrophages exposed to peroxidases were examined for both MMC against 3T12 cells and production of TNF. Thioglycollate-induced macrophages exposed to HRP, bovine lactoperoxidase, or human myeloperoxidase demonstrated enhanced secretion of TNF. When exposed to HRP, both resident and thioglycollate-induced macrophages secreted significant amounts of TNF and acquired the ability to lyse 3T12 cells. However, resident macrophages were considerably less efficient in both their cytotoxic activity and TNF secretion. Macrophage-mediated cytotoxicity was eliminated by the addition of specific antisera to TNF. In addition, replacement of culture supernatants within 24 hr after exposure of the macrophages to HRP increased tumor cell killing in the absence of additional detectable TNF production, suggesting that other factors may be involved in peroxidase-induced MMC. These results indicate that TNF is intimately associated with peroxidase-induced MMC and suggest a possible role for peroxidases as immunomodulators via augmentation of macrophage capacities and functions.

Animals↗
PubMed1987

Occurrence of an unusual amount of an odd-numbered fatty acid in glycosphingolipids from human cataracts.

Human cataractous glycosphingolipids were isolated and purified according to previously established procedures. Fatty acid analyses of the purified glycosphingolipid revealed the presence of a significant amount of an odd-chain fatty acid. This was confirmed by methane (CH4) chemical ionization mass spectrometry, which showed characteristic ions at m/z 397, 425, 437, and 365. These ions facilitated the determination of molecular weight and the assignment of C25:0 (n-pentacosanoic acid) to this fatty acid in question. This may be the first time that such an unusual distribution of a single odd-chain fatty acid has been shown to occur in glycosphingolipid from any tissue.

Brain↗
PubMed1986

Structures of the asparagine-linked sugar chains of laminin.

This investigation describes the isolation and characterization of oligosaccharides of the basement membrane glycoprotein, laminin. Pronase-released glycopeptides of isolated laminin, from a mouse Engelbreth-Holm-Swarm tumor, were fractionated using a combination of gel permeation chromatography and Con A-Sepharose affinity chromatography. The glycopeptides were analyzed for sugar linkage patterns by methylation analysis. Glycopeptides and hydrazine-released oligosaccharides were further analyzed using endo-beta-galactosidase, endo-beta-N-acetylglucosaminidase H and specific exoglycosidases in conjunction with calibrated gel permeation chromatography. Based on these experiments, murine tumor laminin was shown to contain asparagine-linked oligosaccharides with the following structures: bi-, tri- and tetraantennary complex-type oligosaccharides; polylactosaminyl side chains containing Gal(beta 1----4)GlcNAc(beta 1----3) repeating units attached to the trimannose core portion of the bi-, tri- and tetraantennary complex-type oligosaccharides; unusual complex-type oligosaccharides terminated at the nonreducing end with sialic acid, alpha-galactose, beta-galactose and beta-N-acetylglucosamine; alpha-galactosyl residues linked to N-acetyllactosamine sequences; high-mannose-type oligosaccharides. These results, in conjunction with analytical data, indicate that most of the carbohydrate of this laminin is N-linked to asparagine and that there are about 43 such N-linked oligosaccharides per laminin molecule.

Animals↗
PubMed1981

Glycophosphoceramides from plants. Purification and characterization of a novel tetrasaccharide derived from tobacco leaf glycolipids.

A glycophosphoceramide concentrate prepared from tobacco leaves was shown to contain a mixture of related lipids (Kaul, K., and Lester, R. L. (1975) Plant Physiol. 55, 120-129; Kaul, K., and Lester, R. L. (1978) Biochemistry 17, 3569-3575) with the simplest and most abundant components having the structure GlcN(+/- Ac)(alpha 1 leads to 4)GlcUA(alpha 1 leads to 2)myoinositol-1-O-phosphorylceramide (Hsieh, T. C.-Y., Kaul, K., Laine, R. A., and Lester, R. L. (1978) Biochemistry 17, 3575-3579). To determine the structure of the more complex members of this series, a mixture of oligosaccharides was prepared from a carboxyl-reduced glycophosphoceramide concentrate by alkali-catalyzed hydrolysis and alkaline phosphatase treatment. A combination of reverse-phase high pressure liquid chromatography (Wells, G. B., and Lester, R. L. (1979) Anal. Biochem. 97, 184-190), normal-phase high pressure liquid chromatography, and thin layer chromatography were used to resolve several oligosaccharides as acetylated derivatives. Products of methylation analysis, CrO3 oxidation, and deacetylation-deamination were identified using chemical ionization mass spectrometry to give the following novel structures. A major tetrasaccharide was completely characterized as Gal(alpha 1 leads to 4)GlcNAc(alpha 1 leads to 4)GlcUA(alpha 1 leads to 2)myoinositol. An additional structure of a minor tetrasaccharide was partially characterized as GlcNAc(alpha 1 leads to 4)GlcUA(alpha 1 leads to ?)myoinositol(O leads from 1 alpha)Man. These are representatives of a class of acidic glycolipids from plants, possibly analogous to the acidic gangliosides found in animal cell membranes.

Carbohydrate Conformation↗
PubMed1978

Structure of a major glycophosphoceramide from tobacco leaves, PSL-I: 2-deoxy-2-acetamido-D-glucopyranosyl(alpha1 leads to 4)-D-glucuronopyranosyl(alpha1 leads to 2)myoinositol-1-O-phosphoceramide.

The chemical structure of a major glycophosphoceramide from tobacco leaves, called PSL-I [K. Kaul and R. L. Lester (1975), Plant Physiol. 55, 120], has now been characterized as 2-deoxy-2-acetamido-D-glucopyranosyl(alpha1 leads to 4)D-glucuronopyranosyl(alpha1 leads to 2)myoinositol-1-O-phosphoceramide. Sites of glycoside linkage were determined by (1) methylation analysis on a trisaccharide isolated by degradation of carboxyl-reduced PSL-I and (2) periodate oxidation experiments on PSL-I. The resulting products were identified with gas chromatography/mass spectrometry. Anomeric configurations were determined by resistance of the sugars in the peracetylated trisaccharide to chromium trioxide treatment.

Glycosphingolipids↗