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Antitumor Properties (antitumor + property)
Selected AbstractsSynthesis, Structure, and Antitumor Properties of Platinum(IV) Complexes with Aminonitroxyl Radicals.CHEMINFORM, Issue 37 2003V. D. Sen Abstract For Abstract see ChemInform Abstract in Full Text. [source] The Influence of Lactobacillus brevis on Ornithine Decarboxylase Activity and Polyamine Profiles in Helicobacter pylori -Infected Gastric MucosaHELICOBACTER, Issue 2 2004Michele Linsalata ABSTRACT Background., Functional probiotics may prevent Helicobacter pylori infection, and some evidence suggests that they also possess antitumor properties. Lactobacillus brevis (CD2) is a functional Lactobacillus strain with peculiar biochemical features, essentially related to the activity of arginine deiminase. This enzyme catalyzes the catabolism of arginine and affects the biosynthesis of polyamines (putrescine, spermidine, and spermine). Polyamines are polycations found in high concentrations in both normal and neoplastic cells. Our aims were: 1, to assess whether oral administration of L. brevis (CD2) affects H. pylori survival in the human gastric mucosa; 2, to evaluate the effects of L. brevis (CD2) on polyamine biosynthesis in gastric biopsies from H. pylori- positive patients. Materials and Methods., For 3 weeks before endoscopy, 22 H. pylori- positive dyspeptic patients randomly received (ratio 1 : 1) high oral doses of L. brevis (CD2) or placebo. Before and after treatment, H. pylori infection was determined by urea breath test (UBT). In gastric biopsies, ornithine decarboxylase activity and polyamine levels were, respectively, evaluated by a radiometric technique and high-pressure liquid chromatography (HPLC). Results.,L. brevis (CD2) treatment did not eradicate H. pylori. However, a reduction in the UBT delta values occurred, suggesting a decrease in intragastric bacterial load. Significantly, L. brevis (CD2) induced a decrease in gastric ornithine decarboxylase activity and polyamine levels. Conclusions., Our data support the hypothesis that L. brevis (CD2) treatment decreases H. pylori colonization, thus reducing polyamine biosynthesis. Alternatively, the arginine deiminase activity following L. brevis (CD2) administration might cause arginine deficiency, preventing polyamine generation from gastric cells. [source] Analysis of gene expression profiles in human HL-60 cell exposed to cantharidin using cDNA microarrayINTERNATIONAL JOURNAL OF CANCER, Issue 2 2004Jun-Ping Zhang Abstract Cantharidin is a natural toxin that has antitumor properties and causes leukocytosis as well as increasing sensitivity of tumor cells resistant to other chemotherapeutic agents. There is limited information, however, on the molecular pharmacological mechanisms of cantharidin on human cancer cells. We have used cDNA microarrays to identify gene expression changes in HL-60 promyeloid leukemia cells exposed to cantharidin. Cantharidin-treated cells not only decreased expression of genes coding for proteins involved in DNA replication (e.g., DNA polymerase delta), DNA repair (e.g., FANCG, ERCC), energy metabolism (e.g., isocitrate dehydrogenase alpha, ADP/ATP translocase), but also decreased expression of genes coding for proteins that have oncogenic activity (e.g., c-myc, GTPase) or show tumor-specific expression (e.g., phosphatidylinositol 3-kinase). In contrast, these treated cells overexpressed several genes that encode intracellular and secreted growth-inhibitory proteins (e.g., BTG2, MCP-3) as well as proapoptotic genes (e.g., ATL-derived PMA-responsive peptide). Our findings suggest that alterations in specific genes functionally related to cell proliferation or apoptosis may be responsible for cantharidin-mediated cytotoxicity. We also found that exposure of HL-60 cells to cantharidin resulted in the decreased expression of multidrug resistance-associated protein genes (e.g., ABCA3, MOAT-B), suggesting that cantharidin may be used as an oncotherapy sensitizer, and the increased expression of genes in modulating cytokine production and inflammatory response (e.g., NFIL-3, N-formylpeptide receptor), which may partly explain the stimulating effects on leukocytosis. Our data provide new insight into the molecular mechanisms of cantharidin. © 2003 Wiley-Liss, Inc. [source] Expression of intercellular adhesion molecule (ICAM)-1 or ICAM-2 is critical in determining sensitivity of pancreatic cancer cells to cytolysis by human ,,-T cells: Implications in the design of ,,-T-cell-based immunotherapies for pancreatic cancerJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2009Zhiyong Liu Abstract Background and Aims:, ,,-T cells can recognize and kill malignant cells, particularly those of epithelial origin, through mechanisms which do not require the recognition of tumor-specific antigens (innate immune response). This natural ability of ,,-T cells to kill tumor cells in a tumor antigen-independent manner provides a strong rationale for developing clinical trials designed to exploit the innate antitumor properties of ,,-T cells. Methods:,In vitro studies were carried out to asses the sensitivity of pancreatic cancer cells (MIA PaCa2, BxPC-3, PANC-1) to killing by ex vivo expanded human ,,-T cells. Results:, The capacity of ,,-T cells to bind to as well as to kill pancreatic cancer cells correlated with the degree of surface expression of key intercellular adhesion molecules (ICAM) present on pancreatic cancer cells. Moreover, pancreatic cancer cells expressing neither ICAM-1 nor ICAM-2 were bound poorly by ,,-T cells and were found to be resistant to ,,-T-cell killing. However, upon transfection of resistant cells with ICAM-1 or ICAM-2, ,,-T cells were then able to bind to and subsequently kill these cells. Conclusion:,In vitro, the expression of ICAM-1 or ICAM-2 on human pancreatic cancer cells is critically important in determining the extent to which these cells are sensitive to killing by human ,,-T cells. Accordingly, in ongoing and future clinical studies using ,,-T cells for the treatment of a variety of epithelial-derived solid tumors,including pancreatic cancer,interventions intended to modulate ICAM expression on tumor cells may become important adjuncts to ,,-T-cell-based immunotherapies. [source] In Vitro culture studies of FlorEssence® on human tumor cell linesPHYTOTHERAPY RESEARCH, Issue 2 2005Joseph Tai Abstract FlorEssence® (FE) is an herbal tea widely used by patients to treat chronic conditions in North America, particularly cancer patients during chemo- and radiation therapy. Although individual components of FE have antioxidant, antiestrogenic, immunostimulant and antitumor properties, in vitro evidence of anticancer activity for the herbal tea itself is still lacking. We studied the antiproliferative effect of FE on MCF7 and MDA-MB-468 human breast cancer, and Jurkat and K562 leukemia cell lines. We found that FE significantly inhibited the proliferation of both breast and leukemia cells in vitro only at high concentrations, with 50% inhibition of MDA-MB-468 cells at about 1[sol ]20 dilution, Jurkat cells at about 1[sol ]10 dilution and MCF7 and K562 cells at less than 1[sol ]10 dilution. Flow cytometry analysis showed that treatment with a high concentration of FE induced G2[sol ]M arrest in MCF7 and Jurkat cells, with also an increased SubG0[sol ]G1 fraction in MCF7 cells. MDA-MB-468 cells showed a significantly increased Sub G0[sol ]G1 fraction after treatment with 1[sol ]10 dilution of FE while the cell cycle of K562 was unaffected. When MCF7 and MDA-MB-468 breast cancer cells were treated with a combination of FE with either paclitaxel or cisplatin, results showed that only the combination of 1[sol ]20 dilution of FE with 0.5 µM cisplatin resulted in a small but significantly higher MCF7 cell survival than 0.5 µM cisplatin treatment alone. FE at 1[sol ]20 and 1[sol ]50 dilutions did not affect the antiproliferative properties of these two commonly used chemotherapeutic agents. The results suggest that FE at high concentrations show differential inhibitory effect on different human cancer cell lines. Further studies are needed to assess the biological activities of FE. Copyright © 2005 John Wiley & Sons, Ltd. [source] Analysis of pyridoquinoline derivatives by liquid chromatography/atmospheric pressure chemical ionization mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2001Y. Picó A method using liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (LC/APCI-MS) has been developed for the characterization and determination of pyridoquinoline derivatives 4,6-bis(dimethylaminoethylamino)-2,8,10-trimethylpyrido[3,2-g]quinoline, 4,6-bis(dimethylaminoethoxy)-2,8,10-trimethylpyrido[3,2-g]quinoline and 4,6-bis[(dimethylaminoethyl)thio]-2,8,10-trimethylpyrido[3,2-g] quinoline, all with potential antitumor properties. LC separation was performed on a conventional C18 column using a binary mobile phase composed of acetonitrile and 50,mM aqueous ammonium formate at pH 3. The APCI mass spectra obtained showed that proton addition giving [M,+,H]+ was the common mode of ionization to the amino- and thiopyridoquinolines, whereas the alkoxypyridoquinoline was identified by the main formation of the [M,,,(C2H3)N(CH3)2,+,H]+, followed by the [M,+,H]+ ion. The LC separation conditions and MS detection parameters were optimized for the determination. The analytical method was also applied to the determination of these pyridoquinoline derivatives in fetal calf serum using liquid-liquid extraction with dichloromethane. Acceptable recovery values were obtained, ranging between 45 and 98%. Copyright © 2001 John Wiley & Sons, Ltd. [source] Synthesis, X-ray powder structure analysis and biological properties of a mononuclear Cu(II) complex of N-2-hydroxyhippuric acidAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2009Soumya Basu Abstract A mononuclear copper (II) complex of N-2-hydroxyhippuric acid (2HHA), [Cu(HA)(H2O)2], has been synthesized and characterized by spectroscopic and X-ray powder diffraction studies. Crystal structure of [Cu(HA)(H2O)2] reveals a distorted square-pyramidal geometry around the metal center. The crystal packing in the complex exhibits a three-dimensional framework formed by intermolecular O; H···O and CH···O hydrogen bonds. Toxicity and antitumor properties of the complex have been studied in vivo. The complex, capable of depleting glutathione (GSH) at nontoxic doses, may be utilized to sensitize drug-resistant cells where resistance is due to an elevated level of GSH. Copyright © 2009 John Wiley & Sons, Ltd. [source] Gold (III) porphyrin complexes induce apoptosis and cell cycle arrest and inhibit tumor growth in colon cancerCANCER, Issue 19 2009Shuiping Tu MD Abstract BACKGROUND: Gold (III) compounds have exhibited favorable antitumor properties both in vitro and in vivo. In a previous study, the authors reported that the novel gold (III) complex 1a (gold 1a) exhibited strong cytotoxicity in some tumor cell lines. In the current study, the effect of gold 1a was investigated on colon cancer cells. METHODS: The cytotoxicity of gold 1a was determined by using the 3-(4,5-dimethyl-2-thihazyl)-2,5-diphenyl-2H-tetrazolium bromide method. Flow cytometry was used to detect apoptosis and cell cycle. The expression of protein was evaluated by Western blot assay. Tumor growth in vivo was evaluated in nude mice. RESULTS: Gold 1a exhibited marked cytotoxic effects in vitro to human colon cancer, and the concentration of drug required to inhibit cell growth by 50% compared with control (IC50) values ranged from 0.2 ,M to 3.4 ,M, which represented 8.7-fold to 20.8-fold greater potency than that of cisplatin. Gold 1a significantly induced apoptosis and cell cycle arrest and cleaved caspase 3, caspase 7, and poly(ADP-ribose) polymerase; released cytochrome C, and up-regulated p53, p21, p27, and Bax. In vivo, intraperitoneal injection of gold 1a at doses of 1.5 mg/kg and 3.0 mg/kg significantly inhibited tumor cell proliferation, induced apoptosis, and suppressed colon cancer tumor growth. An acute toxicology study indicated that gold 1a at effective antitumor concentrations did not cause any toxic side effects in mice. CONCLUSIONS: The current results suggested that gold 1a may be a new potential therapeutic drug for colon cancer. Cancer 2009. © 2009 American Cancer Society. [source] Expression of cyclic guanosine monophosphate-dependent protein kinase in metastatic colon carcinoma cells blocks tumor angiogenesisCANCER, Issue 7 2008In-Kiu Kwon PhD Abstract BACKGROUND Type 1 cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) reportedly has exhibited antitumor properties, and its expression is down-regulated in many tumors. METHODS The authors recently demonstrated that PKG re-expression in metastatic colon carcinoma cells results in decreased tumorigenesis: In the current study, they addressed that mechanism. RESULTS Over-expression of PKG in SW620 cells produced smaller, more apoptotic subcutaneous tumors in athymic mice, but the observed effect of PKG expression on growth and apoptosis in vitro was minimal. Closer examination of the subcutaneous xenografts revealed highly vascular tumors produced by the parental SW620 cells, which contrasted greatly with the PKG-expressing tumors, in which cell growth was limited to "islands" surrounding CD31-positive cells. The idea that PKG expression was associated with reduced tumor angiogenesis was supported by decreased levels of vascular endothelial growth factor in these tumors compared with tumors that were derived from parental SW620 cells. Investigation of potential mechanisms revealed that PKG expression was associated with reduced levels of ,-catenin compared with parental cells. Moreover, this effect of exogenous PKG on ,-catenin expression in SW620 cells also occurred in vitro, where the decrease was associated with reduced T-cell factor-dependent transcription. CONCLUSIONS Together the findings indicated that PKG down-regulation in colon cancer cells is important for optimal tumor angiogenesis and that regulation of ,-catenin expression may be important to this process. Cancer 2008. © 2008 American Cancer Society. [source] | |||||||||||||||||||||||||