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Human Colon Carcinoma Cell Line (human + colon_carcinoma_cell_line)
Selected Abstracts2,-Deoxyadenosine causes apoptotic cell death in a human colon carcinoma cell lineJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 6 2003Michela Giannecchini Abstract The combination of 2,-deoxyadenosine and 2,-deoxycoformycin is toxic for the human colon carcinoma cell line LoVo. In this study we investigated the mode of action of the two compounds and have found that they promote apoptosis. The examination by fluorescence microscopy of the cells treated with the combination revealed the characteristic morphology associated with apoptosis, such as chromatin condensation and nuclear fragmentation. The occurrence of apoptosis was also confirmed by the release of cytochrome c and the proteolytic processing of procaspase-3 in cells subjected to the treatment. To exert its triggering action on the apoptotic process, 2,-deoxyadenosine enters the cells through an equilibrative nitrobenzyl-thioinosine-insensitive carrier, and must be phosphorylated by intracellular kinases. Indeed, in the present work we demonstrate by analysis of the intracellular metabolic derivatives of 2,-deoxyadenosine that, as suggested by our previous findings, in the incubation performed with 2,-deoxyadenosine and 2,-deoxycoformycin, an appreciable amount of dATP was formed. Conversely, when also an inhibitor of adenosine kinase was added to the incubation mixture, dATP was not formed, and the toxic and apoptotic effect of the combination was completely reverted. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:329,337, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10095 [source] Transcellular transport of genistein, a soybean-derived isoflavone, across human colon carcinoma cell line (Caco-2)BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 1 2001Masataka Oitate Abstract Genistein, a soybean-derived isoflavone, is thought to have an anticarcinogenic action, but little is known about the cellular mechanisms of its intestinal absorption. This study was designed to investigate the absorption mechanisms of genistein using human colon carcinoma cell line, Caco-2 cells. The apical-to-basolateral transcellular transport of genistein across a Caco-2 cell monolayer was significantly greater than that in the opposite direction. An uptake experiment revealed that cellular uptake of genistein by Caco-2 cells was concentrative. The transcellular transport of genistein was saturable and temperature-dependent, and was inhibited by other flavonoids such as rutin, quercetin, (+)-catechin and (,)-epicatechin. These results suggest that genistein is transported across Caco-2 cells by a carrier-mediated system, located on the apical membrane. Copyright © 2001 John Wiley & Sons, Ltd. [source] Rectal washout with cytotoxic solution can be extended to the whole colonBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 12 2002P. P. Mariani Background: Rectal irrigation with a cytotoxic agent does not kill viable intraluminal cancer cells proximal to the primary tumour. To prevent implantation of these cells at the time of restorative proctectomy, the feasibility of retrograde whole-colon irrigation just before surgery was explored. Methods: The cytotoxic efficacy of different combinations of povidone,iodine (PVPI) and Gastrografin was tested with the trypan blue exclusion test on a human colon carcinoma cell line (SW620) in vitro. Subsequently, a retrograde whole-colon lavage with PVPI 5 per cent and Gastrografin 12 per cent was performed in 14 euthyroid, non-allergic patients with colorectal cancer using a colostomy irrigation set. Thyroid function and mucosal damage were assessed. Results: It took 2 min and approximately 1 litre of infused solution to reach the caecum in all patients. The solution was 100 per cent tumoricidal in vitro and remained so after colonic irrigation. Total serum tri-iodothyronine (T3) levels decreased and those of reverse T3 increased, but normalized after 1 week. Superficial epithelial desquamation was observed shortly after irrigation; however, complete restoration occurred within 7 days. Conclusion: A rectal washout can easily be extended to a retrograde irrigation of the whole colon in elective colorectal cancer surgery. This may help to prevent anastomotic and local recurrence due to implantation of viable exfoliated tumour cells. © 2002 British Journal of Surgery Society Ltd [source] Group IID heparin-binding secretory phospholipase A2 is expressed in human colon carcinoma cells and human mast cells and up-regulated in mouse inflammatory tissuesFEBS JOURNAL, Issue 11 2002Makoto Murakami Group IID secretory phospholipase A2 (sPLA2 -IID), a heparin-binding sPLA2 that is closely related to sPLA2 -IIA, augments stimulus-induced cellular arachidonate release in a manner similar to sPLA2 -IIA. Here we identified the residues of sPLA2 -IID that are responsible for heparanoid binding, are and therefore essential for cellular function. Mutating four cationic residues in the C-terminal portion of sPLA2 -IID resulted in abolition of its ability to associate with cell surface heparan sulfate and to enhance stimulus-induced delayed arachidonate release, cyclooxygenase-2 induction, and prostaglandin generation in 293 cell transfectants. As compared with several other group II subfamily sPLA2s, which were equally active on A23187- and IL-1-primed cellular membranes, sPLA2 -IID showed apparent preference for A23187-primed membranes. Several human colon carcinoma cell lines expressed sPLA2 -IID and sPLA2 -X constitutively, the former of which was negatively regulated by IL-1. sPLA2 -IID, but not other sPLA2 isozymes, was expressed in human cord blood-derived mast cells. The expression of sPLA2 -IID was significantly altered in several tissues of mice with experimental inflammation. These results indicate that sPLA2 -IID may be involved in inflammation in cell- and tissue-specific manners under particular conditions. 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