No abstract

Nitric oxide-donating nonsteroidal anti-inflammatory drugs (NO-NSAIDs) are an emergent class of pharmaceutical derivatives with promising utility as cancer chemopreventive agents. Aspirin and sulindac have been shown to be effective in selecting for cells with reduced microsatellite instability (MSI) that is inherent in mismatch repair (MMR)-deficient hereditary nonpolyposis colorectal cancer (HNPCC) cells. The effect of NO-NSAIDs on MSI in MMR-deficient HNPCC cells is unknown. Here, we have examined genetically defined MMRdeficient murine embryo fibroblasts, murine colonocytes, and isogenic human HNPCC tumor cell lines treated with acetylsalicylic acid (aspirin; ASA) and three isomeric derivatives of NO-aspirin (NO-ASA). The MSI profiles were determined and compared with the Bethesda Criteria. We found that the ASA-and NO-ASA-treated MMR-deficient cell lines displayed a dose-dependent suppression of MSI that appeared as early as 8 weeks and gradually increased to include up to 67% of the microsatellite sequences examined after 19 to 20 weeks of continuous treatment. Residual resistance to microsatellite stabilization was largely confined to mononucleotide repeat sequences. Control (MMR-proficient) cells showed no changes in microsatellite status with or without treatment. The relative dose-dependent stabilization selection was: ortho-NO-ASA % para-NO-ASA > meta-NO-ASA J ASA. Moreover, the doses required for stabilization by the orthoand para-NO-ASA were 300-to 3,000-fold lower than ASA. These results suggest that NO-ASA derivatives may be more effective at suppressing MSI in MMR-deficient cell lines than ASA and should be considered for chemopreventive trials with HNPCC carriers. [Cancer Res 2007;67(22):10966-75]

No abstract

Administration of thymosin fraction V to NZB/NZW F1 mice, an animal model for human SLE, accelerated the appearance of proteinuria and anti‐nDNA antibodies, increased deposition of immunoglobulins in kidneys, and significantly shortened survivals. Although the addition of thymosin to in vitro cultures of spleen and lymph node cells from thymosin‐treated mice increased DNA synthesis in response to stimulation with Con A, in vivo treatment with thymosin did not affect the Con A response. There was no effect on in vitro responses to PHA or LPS, or on IgM antibody formation to SRBC (T cell dependent) or SSS III (T cell independent) immunizations. Antibodies to thymosin or contamination of our thymosin preparations with nucleic acids could not be demonstrated. The acceleration of autoimmune disease produced by thymosin treatment could not be explained by alteration of the T and B cell functions studied.