Aspirin-induced nuclear translocation of NFκB and apoptosis in colorectal cancer is independent of p53 status and DNA mismatch repair proficiency

Substantial evidence indicates nonsteroidal anti-inflammatory drugs (NSAIDs) protect against colorectal cancer (CRC). However, the molecular basis for this anti-tumour activity has not been fully elucidated. We previously reported that aspirin induces signal-specific IκBα degradation followed by NFκB nuclear translocation in CRC cells, and that this mechanism contributes substantially to aspirin-induced apoptosis. We have also reported the relative specificity of this aspirin-induced NFκB-dependent apoptotic effect for CRC cells, in comparison to other cancer cell types. It is now important to establish whether there is heterogeneity within CRC, with respect to the effects of aspirin on the NFκB pathway and apoptosis. p53 signalling and DNA mismatch repair (MMR) are known to be deranged in CRC and have been reported as potential molecular targets for the anti-tumour activity of NSAIDs. Furthermore, both p53 and MMR dysfunction have been shown to confer resistance to chemotherapeutic agents. Here, we set out to determine the p53 and hMLH1 dependency of the effects of aspirin on NFκB signalling and apoptosis in CRC. We specifically compared the effects of aspirin treatment on cell viability, apoptosis and NFκB signalling in an HCT-116 CRC cell line with the p53 gene homozygously disrupted (HCT-116p53−/−) and an HCT-116 cell line rendered MMR proficient by chromosomal transfer (HCT-116+ch3), to the parental HCT-116 CRC cell line. We found that aspirin treatment induced apoptosis following IκBα degradation, NFκB nuclear translocation and repression of NFκB-driven transcription, irrespective of p53 and DNA MMR status. These findings are relevant for design of both novel chemopreventative agents and chemoprevention trials in CRC

Epigenomic analysis of aberrantly methylated genes in colorectal cancer identifies genes commonly affected by epigenetic alterations.

Methylation profiling based on bead-chip arrays is an effective method for screening aberrantly methylated genes in CRC. In addition, we identified novel methylated genes that are candidate diagnostic or prognostic markers for CRC

High-Density Genomic Scan with 50K SNP Arrays Reveals Existence of Cryptic Chromosomal Lesions and Germ Line Allelic Polymorphism That Might Determine Predisposition to MDS

Abstract Chromosomal damage is a hallmark of MDS. Inability to detect abnormal karyotype in a portion of MDS patients is consistent with the theory that large lesions may represent the extreme of possible DNA damage. Predisposition to MDS may be due to inherited defects; possibly, genes coding for detoxifying enzymes, DNA repair genes and immunogenetic factors could be involved and the risk can be multifactorial. To date studies dealing with complex pathogenesis of MDS have been based on empiric approaches allowing for very limited insights into the possibly complex genetic traits and DNA changes during evolution of the disease. Gene array technology facilitates detailed genomic analysis. We have applied 50K SNP Affymetrix arrays to the analysis of the MDS genome. The goal of our study was to establish the feasibility of this technology to study 2 separate aspects: i) to detect acquired cryptic chromosomal damage, ii) to investigate germ line allelic variants in MDS that could constitute predisposition factors. Our MDS cohort included 22 patients 15 RA/RS, 7 RAEB; 11 with typical cytogenetic abnormalities and 11 normal karyotypes. Using a threshold value 6 -log10(pval) we confirmed previously known changes in 8/11 patients. The remaining 3 showed multiple scattered lesions throughout affected chromosomes; false negatives were likely due to dilution by non-clonal cells. However, using a high density SNP scan, novel previously cryptic lesions contiguous over various chromosomal portions were found in 5/11 patients with normal metaphase cytogenetics and some patients with previously established defects. Chromosomes 5, 7 and 8 showed a higher number of smaller defects consistent with the pathogenesis of MDS; deletions within 7p14, 7p12.2 and 7q21.3 were found in 4 patients without obvious mononosomy 7. Similarly, deletions of various size within 5q12.3–35.5 were seen in 4/15 patients with low-grade MDS. Analysis of such defects within phenotypically defined subsets of patients may reveal possible consensus lesions or commonly affected genes. We also investigated the presence of putatively MDS-specific genotypes. Overrepresentation of otherwise rare SNP may suggest existence of cryptic changes involving adjacent portions of the genome. Globally SNP array allowed for classification of 55953 SNP in 22 patients. 28% were heterozygous, while 36% were homozygous for either variant. Complex analysis of such a large number of genotypes may allow for determination of potential associations between genetic makeup and clinical sub-entities. Based on the allelic frequencies of individual SNP in MDS group and controls, we have identified significantly overrepresented SNPs occurring in either homo- or heterozygous form. For example, FOXL1 SNP occurring at a frequency of 2.4% in homo- and heterozygote form in normals was found in 25% of patients, and 10% of patients were homozygous for a Semaphorin SNP present in only 0.015% of controls. Similarly, PARP variant showed an allelic frequency of 2.7 vs. 14% in controls and patients, respectively. In general, our study show the potential value of high density SNP arrays in precise analysis of clonal genomic lesions and/loss heterozygozity as well as complex genotypic profiles that may potentially contribute to inherited predisposition traits

Resistin in rheumatoid arthritis synovial tissue, synovial fluid and serum

BACKGROUND: Resistin is a newly identified adipocytokine which has demonstrated links between obesity and insulin resistance in rodents. In humans, proinflammatory properties of resistin are superior to its insulin resistance‐inducing effects. OBJECTIVES: To assess resistin expression in synovial tissues, serum and synovial fluid from patients with rheumatoid arthritis, osteoarthritis and spondylarthropathies (SpA), and to study its relationship with inflammatory status and rheumatoid arthritis disease activity. METHODS: Resistin expression and localisation in synovial tissue was determined by immunohistochemistry and confocal microscopy. Serum and synovial fluid resistin, leptin, interleukin (IL)1β, IL6, IL8, tumour necrosis factor α, and monocyte chemoattractant protein‐1 levels were measured. The clinical activity of patients with rheumatoid arthritis was assessed according to the 28 joint count Disease Activity Score (DAS28). RESULTS: Resistin was detected in the synovium in both rheumatoid arthritis and osteoarthritis. Staining in the sublining layer was more intensive in patients with rheumatoid arthritis compared with those with osteoarthritis. In rheumatoid arthritis, macrophages (CD68), B lymphocytes (CD20) and plasma cells (CD138) but not T lymphocytes (CD3) showed colocalisation with resistin. Synovial fluid resistin was higher in patients with rheumatoid arthritis than in those with SpA or osteoarthritis (both p<0.001). In patients with rheumatoid arthritis and SpA, serum resistin levels were higher than those with osteoarthritis (p<0.01). Increased serum resistin in patients with rheumatoid arthritis correlated with both CRP (r = 0.53, p<0.02), and DAS28 (r = 0.44, p<0.05), but not with selected (adipo) cytokines. CONCLUSION: The upregulated resistin at local sites of inflammation and the link between serum resistin, inflammation and disease activity suggest a role for resistin in the pathogenesis of rheumatoid arthritis