sulindac-sulfide and Adenomatous-Polyposis-Coli

Colorectal cancer (CRC) is the second leading cause of cancer death in the USA. Accumulation of beta-catenin protein is nearly ubiquitous in colon adenomas and cancers, presumably due to mutations in the APC or beta-catenin genes that inhibit proteasome-dependent degradation of beta-catenin protein. Substantial clinical, epidemiological, and animal evidence indicate that sulindac and other non-steroidal anti-inflammatory drugs (NSAIDs) prevent the development of CRC. The mechanisms by which sulindac exerts its potent growth inhibitory effects against colon tumor cells are incompletely understood, but down-regulation of beta-catenin has been suggested as one potential mechanism. The goal of this study was to determine the mechanism of beta-catenin protein down-regulation by sulindac metabolites. Treatment of human colon cancer cell lines with apoptotic concentrations of sulindac metabolites (sulindac sulfide, sulindac sulfone) induced a dose- and time-dependent inhibition of beta-catenin protein expression. Inhibition of proteasome activity with MG-132 partially blocked the ability of sulindac sulfide and sulindac sulfone to inhibit beta-catenin protein expression. Pretreatment with the caspase inhibitor z-VAD-fmk blocked morphological signs of apoptosis as well as caspase cleavage, and also partially prevented beta-catenin degradation by sulindac metabolites. These effects occurred in cells with bi-allelic APC mutation (SW480), with wild-type APC but mono-allelic beta-catenin mutation (HCT116) and in cells that lack expression of either COX-1 or -2 (HCT15). These results indicate that loss of beta-catenin protein induced by sulindac metabolites is COX independent and at least partially due to reactivation of beta-catenin proteasome degradation and partially a result of caspase activation during the process of apoptosis.

Topics: Adenomatous Polyposis Coli; Antineoplastic Agents; Apoptosis; beta Catenin; Caspase 3; Caspase Inhibitors; Caspases; Cell Nucleus; Colonic Neoplasms; Cysteine Endopeptidases; Cysteine Proteinase Inhibitors; Cytoskeletal Proteins; Down-Regulation; Enzyme Inhibitors; Humans; Leupeptins; Multienzyme Complexes; Proteasome Endopeptidase Complex; Signal Transduction; Sulindac; Trans-Activators; Tumor Cells, Cultured

Sulindac, a non-steroidal anti-inflammatory drug (NSAID), is effective in treating intestinal adenomas in humans with Familial Adenomatous Polyposis (FAP) and in preventing intestinal tumors in the C57Bl/6J-Min+ (Min) mouse, an animal model of FAP. Sulindac is a prodrug metabolized by the liver and intestinal flora to a sulfone, which has no anti-inflammatory activity, and a sulfide, which is the active anti-inflammatory metabolite. In this study, we determined which of these metabolites is responsible for the anti-tumor effect of sulindac in Min mice. Min mice were treated with either sulindac sulfone or sulindac sulfide (0.5 +/- 0.1 mg/day). Min mice and homozygous C57Bl/6J-(+/+) normal litter-mates lacking the Apc mutation (+/+) were used as controls. At 110 days of age, all mice were euthanized and their intestinal tracts examined. Control Min mice had 33.2 +/- 6.6 tumors per mouse compared to 0.6 +/- 0.3 tumors for sulindac sulfide-treated Min mice (P < 0.001) and 21.9 +/- 4.5 tumors per mouse for sulindac sulfone-treated Min mice (P > 0.05). Decreased enterocyte apoptosis was observed in Min control mice and Min mice treated with sulindac sulfone. Sulindac sulfide restored to normal the level of apoptosis in the mucosa of Min animals and decreased levels of PGE2 in the small intestine of treated Min animals by 59% (P < 0.001). These data suggest that the anti-tumor effect of sulindac in Apc-deficient animals is mediated by the sulfide metabolite and correlates with suppression of tissue prostaglandin synthesis.

Topics: Adenomatous Polyposis Coli; Animals; Anti-Inflammatory Agents, Non-Steroidal; Anticarcinogenic Agents; Apoptosis; Female; Genes, APC; Heterozygote; Intestinal Mucosa; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Prodrugs; Sulindac

Sulindac is a non-steroidal anti-inflammatory drug which induces regression of colonic polyps in patients with familial adenomatous polyposis. Animal and in vitro studies have shown that both the sulphide metabolite of sulindac, which is able to inhibit cyclo-oxygenase, and the sulphone metabolite, which lacks this ability, are able to inhibit the growth of colonic carcinoma cells. The exact mechanism by which these effects occurs is not known.. To examine the effect of sulindac sulphide and sulindac sulphone on the expression of APC messenger RNA (mRNA), and on the proliferation of colonic carcinoma cells in vitro.. The colonic carcinoma cell line LIM 1215 was treated with sulindac sulphide and sulindac sulphone (10 microM or 100 microM) for 24 hours. Total RNA was extracted and APC mRNA was quantitated using competitive reverse transcription polymerase chain reaction. Measurements of cell number, cell proliferation, and prostaglandin E2 concentrations were also made.. A significant increase in APC mRNA was observed after treatment with 10 microM of both sulindac sulphide and sulindac sulphone (control: 37.2 (19.7); 10 microM sulindac sulphide: 129 (112.8); 10 microM sulindac sulphone: 207.7 (102.9) pg/(g total RNA) (p < 0.05). Prostaglandin E2 concentrations were significantly reduced after treatment with sulindac sulphide, but not after sulindac sulphone. Both agents produced a dose dependent reduction in cell numbers and cell proliferation, which was more noticeable after treatment with sulindac sulphide.. Both sulindac sulphide and sulindac sulphone inhibit the growth of carcinoma cells in vitro and cause an increase in APC mRNA. The effect of these agents on colonic carcinogenesis is not mediated entirely by means of an inhibition of prostaglandin biosynthesis.

Topics: Adenomatous Polyposis Coli; Adenomatous Polyposis Coli Protein; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Base Sequence; Cell Division; Cytoskeletal Proteins; Dinoprostone; Gene Expression Regulation, Neoplastic; Humans; Intestinal Mucosa; Molecular Sequence Data; Polymerase Chain Reaction; RNA, Messenger; Sulindac; Tumor Cells, Cultured