Mechanism Of Aspirin Research Articles

Aspirin enhances radio/chemo-therapy sensitivity in C. elegans by inducing germ cell apoptosis and suppresses RAS overactivated tumorigenesis via mtROS-mediated DNA damage and MAPK pathway

Previous studies have demonstrated that combination therapy involving radiotherapy and aspirin decreases the survival rate of cancer cells. However, the mechanism by which aspirin exerts its radiation sensitization effect at the in vivo level remains largely unclear. In this study, we employed Caenorhabditis elegans (C. elegans) as a model organism to investigate the effect of aspirin combined with radio/chemo-therapy on tumors at the individual level. Here, we illustrate that high-dose aspirin increases the expression of genes involved in core apoptosis pathways (egl-1, ced-9, ced-4 and ced-3) and induces germ cell apoptosis in C. elegans through mitochondrial outer membrane permeabilization (MOMP) and elevation of reactive oxygen species (ROS) levels. Crucially, aspirin-induces ROS upregulates the expression of genes critical for DNA damage response (hus-1, clk-2 and cep-1) and genes involved in MAPK pathways (lin-45, mek-2, mpk-1, sek-1 and pmk-1), thereby mediating the enhanced sensitivity of radio/chemo-therapy by aspirin. Notably, aspirin fails to induce germ cell apoptosis and enhance radio/chemo-therapy in C. elegans lacking the expression of each of those genes. Furthermore, in a C. elegans tumor-like symptom model, aspirin enhances radio/chemo-therapy sensitivity through ROS induction. However, low-dose aspirin can diminish the apoptotic signal of reproductive cells in C. elegans and exert anti-inflammatory effects. Our research results suggest that the tumor-suppressive and radio/chemo-therapy sensitizing effects of aspirin provide robust experimental evidence for improving the clinical efficacy of tumor radio/chemo-therapy and deepening our understanding of aspirin's mechanism of action in cancer.

Aspirin prevents colorectal cancer by regulating the abundance of Enterococcus cecorum and TIGIT+Treg cells

Although aspirin can reduce the incidence of colorectal cancer (CRC), there is still uncertainty about its significance as a treatment for CRC, and the mechanism of aspirin in CRC is not well understood. In this study, we used aspirin to prevent AOM/DSS-induced CRC in mice, and the anti-CRC efficacy of aspirin was assessed using haematoxylin and eosin (H&E) staining and by determining the mouse survival rate and tumour size. 16S rDNA sequencing, flow cytometry (FCM), and Western blotting were also conducted to investigate the changes in the gut microbiota, tumour immune microenvironment, and apoptotic proteins, respectively. The results demonstrated that aspirin significantly exerted anti-CRC effects in mice. According to 16S rDNA sequencing, aspirin regulated the composition of the gut microbiota and dramatically reduced the abundance of Enterococcus cecorum. FCM demonstrated that there were more CD155 tumour cells and CD4 + CD25 + Treg cells showed increased TIGIT levels. Moreover, increased TIGIT expression on Treg cells is associated with reduced Treg cell functionality. Importantly, the inhibition of Treg cells is accompanied by the promotion of CD19 + GL-7 + B cells, CD8 + T cells, CD4 + CCR4 + Th2 cells, and CD4 + CCR6 + Th17 cells. Overall, aspirin prevents colorectal cancer by regulating the abundance of Enterococcus cecorum and TIGIT + Treg cells.

Low-dose aspirin for the prevention of atherosclerotic cardiovascular disease.

During the past 30 years, several developments have occurred in the antiplatelet field, including the role of aspirin in primary prevention of atherosclerotic cardiovascular disease. There have been several attempts to develop antiplatelet drugs more effective and safer than aspirin and a shift in emphasis from efficacy to safety, advocating aspirin-free antiplatelet regimens after percutaneous coronary intervention. Evidence supporting a chemopreventive effect of low-dose aspirin against colorectal (and other digestive tract) cancer has also strengthened. The aim of this article is to revisit the role of aspirin in the prevention of atherothrombosis across the cardiovascular risk continuum, in view of developments in the antiplatelet field. The review will offer a clinical perspective on aspirin's mechanism of action, pharmacokinetics, and pharmacodynamics. This will be followed by a detailed discussion of its clinical efficacy and safety.

Optimizing aspirin dose for colorectal cancer patients through deep phenotyping using novel biomarkers of drug action.

Background: Low-dose aspirin's mechanism of action for preventing colorectal cancer (CRC) is still debated, and the optimal dose remains uncertain. We aimed to optimize the aspirin dose for cancer prevention in CRC patients through deep phenotyping using innovative biomarkers for aspirin's action. Methods: We conducted a Phase II, open-label clinical trial in 34 CRC patients of both sexes randomized to receive enteric-coated aspirin 100mg/d, 100mg/BID, or 300mg/d for 3 ± 1weeks. Biomarkers were evaluated in blood, urine, and colorectal biopsies at baseline and after dosing with aspirin. Novel biomarkers of aspirin action were assessed in platelets and colorectal tissues using liquid chromatography-mass spectrometry to quantify the extent of cyclooxygenase (COX)-1 and COX-2 acetylation at Serine 529 and Serine 516, respectively. Results: All aspirin doses caused comparable % acetylation of platelet COX-1 at Serine 529 associated with similar profound inhibition of platelet-dependent thromboxane (TX)A2 generation ex vivo (serum TXB2) and in vivo (urinary TXM). TXB2 was significantly reduced in CRC tissue by aspirin 300mg/d and 100mg/BID, associated with comparable % acetylation of COX-1. Differently, 100mg/day showed a lower % acetylation of COX-1 in CRC tissue and no significant reduction of TXB2. Prostaglandin (PG)E2 biosynthesis in colorectal tumors and in vivo (urinary PGEM) remained unaffected by any dose of aspirin associated with the variable and low extent of COX-2 acetylation at Serine 516 in tumor tissue. Increased expression of tumor-promoting genes like VIM (vimentin) and TWIST1 (Twist Family BHLH Transcription Factor 1) vs. baseline was detected with 100mg/d of aspirin but not with the other two higher doses. Conclusion: In CRC patients, aspirin 300mg/d or 100mg/BID had comparable antiplatelet effects to aspirin 100mg/d, indicating similar inhibition of the platelet's contribution to cancer. However, aspirin 300mg/d and 100mg/BID can have additional anticancer effects by inhibiting cancerous tissue's TXA2 biosynthesis associated with a restraining impact on tumor-promoting gene expression. EUDRACT number: 2018-002101-65. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT03957902.

Aspirin, Risk of Colorectal Cancer, & Genetic Risk-Letter.

We read with interest the study by Bakshi and colleagues in which they explored the association between genetic susceptibility to colorectal cancer and aspirin, using a 95-variant colorectal cancer polygenic risk score (PRS) in the participants of ASPREE (ASPirin in Reducing Events in the Elderly) trial (1). The ASPREE trial was a prospective double-blinded, placebo-controlled randomized trial in which 12,609 individuals of European descent ages ≥70 years were enrolled. They concluded that the 95-SNP PRS continues to identify individuals at higher risk of colorectal cancer, including individuals with no family history of colorectal cancer. Recently, Chen and colleagues, using data collected from a large population-based case–control study on colorectal cancer in Germany, analyzed PRS based on 140 colorectal cancer–related risk loci to quantify the genetic risk, reported that regular use of NSAIDs, including aspirin, was associated with significantly reduced colorectal cancer risk regardless of individual genetic profile (2). However, randomization of aspirin treatment in the ASPREE trial was not associated with a reduced incidence of colorectal cancer (P = 0.7).Also, a pooled analysis of two large U.S. cohort studies was published, the Nurses’ Health Study and Health Professionals Follow-up Study, with a total of 94,540 participants ages ≥70 years old (3). The analysis showed that initiating aspirin at an older age was not associated with a lower risk of colorectal cancer. In contrast, those who used aspirin before age 70 years and continued into their 70s or later had a reduced risk of colorectal cancer. A possible explanation is that a beneficial effect of aspirin for colorectal cancer requires at least 5 to 10 years of use (3).Over the last decades, aspirin has been an extensively prescribed drug with antiplatelet and anti-inflammatory effects (4). The mechanism of aspirin's possible anticancer effect is under investigation, but it is believed that it is through inhibiting catalytic enzymes COX-1 and COX-2 involved in prostaglandin synthesis. Therefore, in subjects taking aspirin, gut microbiome composition will shift toward a lower proportion of proinflammatory, colorectal cancer–predisposing bacteria (e.g., Fusobacteria) and a higher proportion of anti-inflammatory, colorectal cancer–protective bacteria (e.g., butyrate-producing bacteria; ref. 5).The recent study by Bakshi and colleagues and other recent high impacted trials on the effect of aspirin on cardiovascular disease and colorectal cancer risks have high translational values into the daily practice. However, there is a need for future preclinical and clinical trials on the impact of aspirin on gut microbiota and their metabolic and immunoregulatory potential.See the Response, p. 703No disclosures were reported.

Aspirin reduces sFlt-1-mediated apoptosis of trophoblast cells in preeclampsia.

Preeclampsia (PE) is a hypertensive disorder that occurs during pregnancy. Low-dose aspirin is used to reduce the occurrence of early-onset PE; however, the mechanisms are not clear. The aim of this study was to reveal the underlying mechanism of aspirin in reducing sFlt-1-mediated apoptosis of trophoblast cells in PE. Serum sFlt-1 and sEng profiles and placental oxidative stress levels were significantly decreased in PE patients treated with aspirin compared with untreated patients without it, whereas serum PLGF and placental SOD profiles were increased in PE patients with aspirin. Aspirin attenuated the role of sFlt-1 in oxidative stress and endothelial dysfunction and reduced apoptosis of trophoblasts by inactivating the NF-κB signalling pathway in HTR-8/SVneo trophoblast cells. Blood pressure, urine protein, swelling of the villous vessels and mitochondrial parameters were noted to be much better after aspirin administrated to sFlt-1 treated pregnant mice. In conclusion, aspirin reverses the endothelial dysfunction and oxidative stress caused by sFlt-1 and thus reduces apoptosis of preeclamptic trophoblasts by inactivating NF-κB signalling pathway.

Effect of aspirin on hepatocellular carcinoma and its related mechanism

Aspirin, as a traditional non-steroidal anti-inflammatory drug, has therapeutic and preventive effects on gastrointestinal tumors. Hepatocellular carcinoma is one of the most common malignant tumors in the digestive tract, so it is necessary to find effective preventive and therapeutic measures. This article reviews the research progress and mechanism of aspirin on hepatocellular carcinoma with a view to provide references for future clinical treatment.

Aspirin Improves Nonalcoholic Fatty Liver Disease and Atherosclerosis through Regulation of the PPARδ-AMPK-PGC-1α Pathway in Dyslipidemic Conditions.

This study is aimed at elucidating how aspirin could systemically and simultaneously normalize nonalcoholic fatty liver disease (NAFLD) and atherosclerosis through both in vitro and in vivo studies in hyperlipidemic conditions. We evaluated the effects and mechanism of aspirin on the levels of various biomarkers related to NAFLD, atherosclerosis, and oxidative phosphorylation in cells and animals of hyperlipidemic conditions. The protein levels of biomarkers (PPARδ, AMPK, and PGC-1α) involved in oxidative phosphorylation in both the vascular endothelial and liver cells were elevated by the aspirin in hyperlipidemic condition. Also in the stimulation pathway of oxidative phosphorylation by aspirin, PPARδ was a superior regulator than AMPK and PGC-1α in HepG2 cells. In the vascular endothelial cells, the phosphorylated endothelial nitric oxide synthase level was increased by the treatment. The protein levels of biomarkers related to lipid synthesis were decreased by the treatment in the liver cells. In rabbits administered with cholesterol diet, the levels of triglyceride, HDL-cholesterol, and alanine amino transferase in serums were ameliorated by the aspirin treatment, the levels of ATP and TNFα were increased or decreased, respectively, by the aspirin in liver and aorta tissues, and mannose receptor and C-C chemokine receptor type 2 levels were increased or decreased by the aspirin in spleen, respectively. The elevated levels of macrophage antigen, angiotensin II type1 receptor, and lipid accumulation were decreased in both the liver and aorta tissues in the aspirin-treated group. In conclusion, aspirin can systemically and simultaneously ameliorate NAFLD and atherosclerosis by inhibiting lipid biosynthesis and inflammation and by elevating catabolic metabolism through the activation of the PPARδ-AMPK-PGC-1α pathway. Furthermore, aspirin may normalize atherosclerosis and NAFLD by modulating the mannose receptor and CCR2 in macrophages.

Aspirin has a better effect on PIK3CA mutant colorectal cancer cells by PI3K/Akt/Raptor pathway

BackgroundAspirin, as a non-steroidal anti-inflammatory drug, can improve the survival rate of patients with colorectal cancer, while aspirin is effective in patients with PIK3CA mutant colorectal cancer (CRC). However, the mechanism of aspirin in the treatment of PIK3CA mutated CRC patients remains unclear.MethodsIn this study, immunohistochemistry was used to detect the expression levels of PI3K and Raptor in colorectal cancer patients with PIK3CA mutation and PIK3CA wild-type patients. To demonstrate that aspirin has a better effect on the CRC of PIK3CA mutations in association with the PI3K/Akt/Raptor pathway, we used aspirin to treat PIK3CA mutant CRC cells (HCT-116 and RKO). Subsequently, the CCK8 assay and flow cytometry assay were used to detect the apoptosis of PIK3CA mutant CRC cells before and after aspirin use. Western blot was used to detect the changes of PI3K/Akt/Raptor-associated protein, autophagy protein microtubule associated protein 1 light chain 3 alpha (MAP1LC3A, LC3), beclin 1 (BECN1) and apoptosis protein BCL2-associated X protein/ BCL2 apoptosis regulator (Bax/Bcl2), Caspase 3 after treatment of CRC cells with PIK3CA mutation by aspirin.ResultsPhosphoinositide-3-kinase (PI3K) and regulatory associated protein of MTOR complex 1 (Raptor) protein expression levels were higher in PIK3CA-mutant patients than in IK3CA wild-type patients. The expression of Bax/Bcl2 increased after treatment indicates that aspirin can induce apoptosis of PIK3CA-mutant CRC cells. The expression level of MAP1LC3 (LC3) in cells increases with the concentration of aspirin demonstrates that aspirin can induce autophagy in CRC cells. After 48 h of treatment with aspirin, the phosphorylation of eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1) and ribosomal protein S6 kinase B1 (S6K1) was reduced, cell proliferation has been inhibited. After treatment with aspirin, as phosphorylation of PI3K and Protein kinase B (PKB, Akt) was decreased, Raptor expression was also decreased.ConclusionAspirin can regulate the proliferation, apoptosis and autophagy of CRC cells through the PI3K/Akt/Raptor pathway, affecting PIK3CA-mutant CRC.

Could aspirin be a lifesaver for prostate cancer patients in prostate cancer-specific mortality?: an update systematic review and meta-analysis

BackgroundCurrently, clinical studies on the prognosis of prostate cancer (PC) taking aspirin were developing, but the precise mechanism of aspirin on tumor cells was still unclear. In addition, the conclusion that aspirin can improve the prognosis of PC patients continues to be controversial. Therefore, we collected comprehensive literatures and performed our study to explore the prognostic effect of aspirin on PC.MethodsA comprehensive literature search was performed in April 2019 based on PUBMED. EMBASE. Hazard Ratio (HR) as well as its 95% confidence interval (CIs) for prostate cancer specific mortality (PCSM) was extracted from eligible studies.ResultA total of 10 eligible articles were used in our study. The pooled results showed that PC patients who used aspirin or taking aspirin did not have lower PCSM than those who had not used (HR =0.89, 95% CI: 0.73–1.08, P>0.05). In subgroup analysis, we found that taking aspirin before diagnosis of prostate cancer and taking aspirin after diagnosis of prostate cancer did not have significant association with PCSM. (pre-diagnostic use, HR = 0.88, 95% CI: 0.72–1.06; post-diagnosis use, HR = 0.88, 95% CI: 0.67–1.17). In addition, we found no significant association between aspirin use or its duration and the risk of PCSM. Another important result demonstrated that aspirin use was not associated with risk of PSCM in either high risk (T ≥ 3 and/or Gleason score ≥ 8) or low risk PC patients(low-risk PC, HR = 1.05, 95% CI: 0.81–1.35; high-risk PC, HR = 0.97, 95% CI: 0.75–1.24).ConclusionOur results demonstrated that there was no significant association between aspirin use and the risk of PCSM. At the same time, the dosage and duration of aspirin use had no statistical influence on the risk of PCSM in high/low risk PC. Further studies are needed to confirm the findings.

Abstract 2965: Functionally informed genome-wide interaction analysis of nonsteroidal anti-inflammatory drugs on colorectal cancer risk

Abstract Background Regular use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) is associated with lower risk of colorectal cancer (CRC). Genome-wide interaction analysis (GxE) has identified a few variants that may modify the effects of NSAIDs on CRC risk. However, limited statistical power remains a concern. Restricting analyses by using functional genomic information to aggregate variants into biologically relevant sets can reduce the number of tests, thereby increasing statistical power. We tested the interactions between variant models of gene expression and NSAIDs use on CRC risk. Methods Functional weights of each variant were estimated using PrediXcan based on jointly measured transcriptomes and genomes data of transverse colon tissues from the Genotype-Tissue Expression (GTEx) Project for all genes with sufficient heritability (≥1%). A mixed-effects model was used to assess the GxE effects in a gene among 9,917 incident CRC cases and 10,533 controls from 17 (nested) case-control studies from the Colon Cancer Family Registry (CCFR) and Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). GxE analysis was done by modeling the interaction between predicted gene expression and NSAID use (fixed effects), and residual variant-specific GxE effects that are not accounted for (random effects). Regular user of aspirin and/or non-aspirin NSAIDs was compared to non-regular users. False discovery rate (FDR) was used to account for multiple comparison and FDR≤0.2 was considered genome-wide significant. Secondary analysis was performed on significant genes and duration of use among users. Results Regular use of aspirin was higher among controls (30.3%) compared to cases (24.3%). Among the 4,842 genes tested, SORD significantly modified the effect of regular use of aspirin on CRC risk (p-interaction = 1.45×10-5; FDR=0.07). The SORD gene encodes sorbitol dehydrogenase (SORD), which oxidizes sorbitol to fructose in the polyol pathway. Decreased SORD concentrations were previously observed to dramatically increase in colorectal adenoma cells when compared to normal mucosa cells, suggesting the involvement of dysregulated polyol metabolisms in colorectal tumorigenesis. However, the duration of aspirin use was not statistically significantly associated with SORD gene expression on CRC risk (p=0.149) among 5,560 aspirin users. No significant interactions were observed between genetically determined colon gene expression levels and any NSAID use or non-aspirin NSAID use at FDR<0.2. Conclusions Incorporating functional information, we discovered a novel gene that may interact with aspirin use to confer CRC risk. These findings provide preliminary support for new biological insights that could help understand the chemopreventive mechanisms of aspirin on CRC. We aim to replicate these findings in additional studies. Citation Format: Xiaoliang Wang, Yu-Ru Su, Andrew T. Chan, Stephanie Bien, Sonja I. Bernt, Hermann Brenner, Graham Casey, Jenny Chang-Claude, Steven J. Gallinger, Robert W. Haile, Tabitha A. Harrison, Michael Hoffmeister, Mark A. Jenkins, Amit Joshi, Yi Lin, Noralane M. Lindor, Loic Le Marchand, Hongmei Nan, Polly A. Newcomb, John D. Potter, Martha L. Slattery, Steve N. Thibodeau, Emily White, Li Hsu, Ulrike Peters. Functionally informed genome-wide interaction analysis of nonsteroidal anti-inflammatory drugs on colorectal cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2965.

Aspirin: 120 years of innovation. A report from the 2017 Scientific Conference of the International Aspirin Foundation, 14 September 2017, Charité, Berlin.

Acetylsalicylic acid was first synthesised by Dr FeIix Hoffman on 10th August 1897 and Aspirin was born. It quickly became the best-known pain killer in the world and in the 120 years since this event, aspirin has continued to attract interest, innovation and excitement. Set within the walls of the preserved ruins of Rudolf Virchow’s lecture hall at Charité, within Berlin’s Museum of Medical History, the International Aspirin Foundation’s 28th Scientific Conference served to facilitate international, multi-disease, multidisciplinary discussion about the current understanding of aspirin’s mechanisms of action and its utility in modern medicine as well as ideas for future research into its multifaceted applications to enhance global health.In addition to the delegates in Berlin, 300 medical doctors at the 19th Annual Scientific Congress of the Chinese Society of Cardiology were able to join the cardiology sessions from Taiyuan, Shangxi province via a live streaming link to and from China. This led to useful discussion and allowed a truly international perspective to the meeting.

Aspirin cooperates with p300 to activate the acetylation of H3K9 and promote FasL-mediated apoptosis of cancer stem-like cells in colorectal cancer

Cancer stem-like cells (CSCs) have been proposed as a key driving force of tumor growth and relapse in colorectal cancer (CRC), and therefore, they are promising targets for cancer therapy. Epidemiological evidence has suggested that the daily use of aspirin reduces overall mortality of CRC and the risk of distant metastasis. We investigated the effect and mechanism of aspirin on CSCs in CRC.Methods: The ratio of CSCs was analyzed after aspirin treatment both in a cell model and patient samples. Chemically modified aspirin and immunoprecipitation were adopted to detect the target proteins of aspirin. A locus-specific light-inducible epigenetic modification system based on CRISPR technology was constructed to verify the causal relationship in these molecular events. In vivo characterization was performed in a xenograft model.Results: We found that aspirin induces apoptosis in enriched colorectal CSCs, inhibits tumor progression, and enhances the anti-neoplastic effects of chemotherapeutic agents. Furthermore, aspirin directly interacts with p300 in the nucleus, promotes H3K9 acetylation, activates FasL expression, and induces apoptosis in colorectal CSCs. Notably, these effects of aspirin are absent in non-CSCs since H3K9 is hypermethylated in non-CSCs and the effects are not induced by other NSAIDs. In addition, aspirin can suppress oxaliplatin-enriched CSCs and serve as an adjuvant therapy.Conclusions: Taken together, we revealed a unique epigenetic and cox-independent pathway (p300-AcH3K9-FasL axis) by which aspirin eliminates colorectal CSCs. These findings establish an innovative framework of the therapeutic significance of aspirin.

Does the timing of aspirin administration influence its antiplatelet effect - review of literature on chronotherapy.

This publication is a summary of the multidirectional effects of aspirin and its role in modern medicine. The history of aspirin, or acetylsalicylic acid (ASA), and its use dates back to ancient times, although the substance in its pure form has been produced and sold since 1899. Initially it was used for its antipyretic, analgesic, and anti-inflammatory effects. Over the years many other benefits associated with the administration of ASA have been revealed. The mechanism of aspirin’s action was discovered thanks to the British pharmacologist and Nobel Prize winner Sir John Vane. Understanding the effects of acetylsalicylic acid, associated with the inhibition of cyclooxygenase and proinflammatory thromboxane A2 and with increased concentration of vasoprotective, antithrombotic prostacyclin, gave rise to the era of using small “cardiac” doses of ASA in cardiovascular diseases. In addition to the well-researched antiplatelet effect, other properties of ASA have been discovered, such as the non-COX-1 dependent improvement of endothelial function or the hypotensive effect after evening administration. According to the currently available knowledge, it is possible to speak of a pleiotropic effect of ASA and its use in the prevention of cardiovascular diseases, taking into account its anti-aggregation effect, circadian rhythms, and the principles of chronotherapy.

Exploratory plasma proteomic analysis in a randomized crossover trial of aspirin among healthy men and women.

Long-term use of aspirin is associated with lower risk of colorectal cancer and other cancers; however, the mechanism of chemopreventive effect of aspirin is not fully understood. Animal studies suggest that COX-2, NFκB signaling and Wnt/β-catenin pathways may play a role, but no clinical trials have systematically evaluated the biological response to aspirin in healthy humans. Using a high-density antibody array, we assessed the difference in plasma protein levels after 60 days of regular dose aspirin (325 mg/day) compared to placebo in a randomized double-blinded crossover trial of 44 healthy non-smoking men and women, aged 21–45 years. The plasma proteome was analyzed on an antibody microarray with ~3,300 full-length antibodies, printed in triplicate. Moderated paired t-tests were performed on individual antibodies, and gene-set analyses were performed based on KEGG and GO pathways. Among the 3,000 antibodies analyzed, statistically significant differences in plasma protein levels were observed for nine antibodies after adjusting for false discoveries (FDR adjusted p-value<0.1). The most significant protein was succinate dehydrogenase subunit C (SDHC), a key enzyme complex of the mitochondrial tricarboxylic acid (TCA) cycle. The other statistically significant proteins (NR2F1, MSI1, MYH1, FOXO1, KHDRBS3, NFKBIE, LYZ and IKZF1) are involved in multiple pathways, including DNA base-pair repair, inflammation and oncogenic pathways. None of the 258 KEGG and 1,139 GO pathways was found to be statistically significant after FDR adjustment. This study suggests several chemopreventive mechanisms of aspirin in humans, which have previously been reported to play a role in anti- or pro-carcinogenesis in cell systems; however, larger, confirmatory studies are needed.

The difference in association between aspirin use and other thrombocyte aggregation inhibitors and survival in patients with colorectal cancer

BackgroundSeveral studies have suggested that the association between aspirin and improved cancer survival is mediated through the mechanism of aspirin as thrombocyte aggregation inhibitors (TAI). The aim of this study was to provide epidemiological evidence for this mechanism assessing the association between overall survival and the use of aspirin and non-aspirin TAI in patients with colorectal cancer. MethodsIn this observational study, data from the Netherlands Comprehensive Cancer Organisation were linked to PHARMO Database Network. Patients using aspirin or aspirin in combination with non-aspirin TAI (dual users) were selected and compared with non-users. The association between overall survival and the use of (non-)aspirin TAI was analysed using Cox regression models with the use of (non-)aspirin TAI as a time-varying covariate. ResultsIn total, 9196 patients were identified with colorectal cancer and 1766 patients used TAI after diagnosis. Non-aspirin TAI were mostly clopidogrel and dipyridamole. Aspirin use was associated with a significant increased overall survival and hazard ratio (HR) 0.41 (95% confidence interval [CI] 0.37–0.47), and the use of non-aspirin TAI was not associated with survival of HR 0.92 (95% CI 0.70–1.22). Dual users did not have an improved overall survival when compared with patients using solely aspirin. ConclusionsAspirin use after diagnosis of colorectal cancer was associated with significantly lower mortality rates and this effect remained significant after adjusting for potential confounders. No additional survival benefit was observed in patients using both aspirin and another TAI.

Abstract 5244: Effects of chronic low dose aspirin treatment in the mouse AOM/DSS model of colon carcinogenesis

Abstract Although early detection and treatment of colorectal cancer (CRC) have improved in recent years, it remains a significant healthcare problem with high morbidity and mortality. Published data indicate that long-term intake of low dose aspirin reduces the risk of CRC, however the molecular mechanisms underlying this effect are still unclear. The aim of this study was to investigate the efficacy of low dose equivalent aspirin treatment in a mouse colon carcinogenesis model, including evaluation of potential mechanistic contributors. An initial PK/PD study in healthy mice indicated that aspirin 25 mg/kg/day given via drinking water had a similar PD effect - reduction in plasma thromboxane B2 (TXB2), as an indicator of cyclooxygenase-1 (COX-1) inhibition - as did 5-day low-dose aspirin treatment (100 mg/day) in healthy human volunteers. Male and female C57BL/6J mice were treated with the carcinogen azoxymethane (AOM) 10 mg/kg once i.p. combined with three 5-day cycles (at 14 day intervals) of dextran sodium sulphate (DSS) 2% in drinking water. Aspirin treatment was started concomitant with AOM administration and continued for 12 weeks, at which time the data outlined below were obtained. Aspirin 25 mg/kg/day significantly reduced tumor burden in 3 independent experiments (total tumor number reduced by 43 - 51%; tumor area per mouse reduced by 59 - 65%; mean tumor area reduced by 22 - 27%). Increasing the dose to 50 mg/kg/day did not show better inhibition of tumorigenesis. Aspirin-induced reduction in tumorigenesis in this model was accompanied by reduction in systemic plasma TXB2 by about 70%, indicating reduced platelet activation. TXB2 production by colon explants was also reduced, by 30-50%. Aspirin treatment reduced inflammatory activity (fecal blood; IL-1β and IL-6 production by colon explant cultures; iNOS-positive tumor macrophage infiltration). Immunohistological analysis of tumor tissue showed no reduction in proliferation (BrdU staining) by aspirin but there was a trend towards increased apoptosis (caspase-3 positive cells) and a significant reduction in CD31-positive microvessel density. Aspirin treatment did not result in significant modulation of the Wnt/β-catenin, NF-κB or HIF-1 pathways as assessed by mRNA expression of several of their target genes in tumor tissue. The results show that aspirin can inhibit tumor development in this established model of colon carcinogenesis, primarily by reducing tumor number with a less marked effect on the size of individual tumors. This effect is associated with COX-1 inhibition of a similar magnitude to that seen with low dose aspirin in humans. The influence of aspirin on intestinal inflammation and platelet activation as well as on tumor cell apoptosis and tumor angiogenesis might all contribute to the beneficial effects seen in this model. Additional studies are planned to further elucidate aspirin's mechanism of action in inhibiting tumor development. Citation Format: Nadine Rohwer, Anja Kuehl, Dieter Zopf, Fiona M. McDonald, Karsten-Heinrich Weylandt. Effects of chronic low dose aspirin treatment in the mouse AOM/DSS model of colon carcinogenesis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5244.

Abstract 4284: Exploratory plasma proteomic analysis in a randomized cross-over trial of aspirin among healthy individuals

Abstract Background: Long-term use of aspirin is associated with lower colorectal cancer (CRC) incidence; however, the mechanism of the chemopreventive effect of aspirin is not fully understood. Animal studies suggest that COX-2, NFκB signaling and Wnt/β-catenin pathways may play a role, but no clinical trials have systematically evaluated the biological response to aspirin in healthy humans. Methods: We assessed the difference in plasma protein levels after 60 days of regular dose aspirin (325 mg/day) compared to placebo in a randomized, double-blinded, placebo-controlled, cross-over trial of 44 healthy non-smoking men and women, aged 21-45 years. Plasma proteomics was analyzed on an antibody microarray with ∼3,000 full-length antibodies, printed in triplicate. Moderated paired t-test was performed on individual antibodies, and gene set analyses were performed for KEGG and GO pathways. Results: Among the 3,387 antibodies, significant differences in plasma protein levels were observed for 267 antibodies (p&amp;lt;0.05), the most significant protein being a transcription-factor regulator belonging to a steroid receptor family and found to be differentially expressed in colon cancer cells. Other significant proteins are involved in multiple oncogenic pathways related to colon tumorigenesis. In the pathway analysis, 4 KEGG (among 138) and 69 GO (among 1,089) pathways were found to be significant (p&amp;lt;0.05), including natural killer (NK) cell-mediated cytotoxicity, butanoate metabolism and Wnt signaling pathways. Pathways that modulate cellular protein binding to steroid receptors were also significantly different between aspirin treatment and placebo (p&amp;lt;0.05). None of the results remained statistically significant after correction for multiple testing. Conclusion: Several proteins and pathways, which have previously been reported as playing a role in colorectal carcinogenesis in vitro were found to be differentially expressed after aspirin treatment vs. placebo in healthy human subjects. This study suggests several chemopreventive mechanisms of aspirin; however, larger, confirmatory studies are needed. Citation Format: Xiaoliang Wang, Yuzheng Zhang, Ali Shojaie, Paul D. Lampe, Lisa Levy, Ulrike Peters, John D. Potter, Emily White, Johanna W. Lampe. Exploratory plasma proteomic analysis in a randomized cross-over trial of aspirin among healthy individuals. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4284.

Prediagnostic aspirin use and mortality in women with stage I to III breast cancer: A cohort study in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

There is a body of evidence indicating that aspirin may reduce the risk of cancer mortality. However, to the authors' knowledge, the optimal exposure timing and mechanism of action remain unclear. In the current study, the authors investigated associations between prediagnostic aspirin use and breast cancer-specific mortality in a US population. Postmenopausal women diagnosed with stage I to III breast cancer (1993-2009) were identified (2925 women with a total of 18,073 person-years) from the National Cancer Institute's Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Prediagnostic aspirin use (1274 women) was identified from study questionnaires. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs) for associations between aspirin use and breast cancer-specific mortality. Effect modification by lymph node status was evaluated. Prediagnostic aspirin use was not found to be associated with lower breast cancer-specific mortality (HR, 0.95; 95% CI, 0.68-1.31 [P = .74]). In analyses stratified by lymph node status, aspirin use was found to be associated with lower breast cancer-specific mortality among women with lymph node-negative tumors (HR, 0.54; 95% CI, 0.32-0.93 [P = 0.02]), but not those with lymph node-positive tumors (HR, 1.41; 95% CI, 0.92-2.16 [P = 0.11]). Tests for interaction were found to be statistically significant (P for interaction =.006). No association was noted between aspirin use and lymph node status. Prediagnostic aspirin use was not found to be associated with a reduction in breast cancer-specific mortality overall. However, effect modification by lymph node status was observed and mortality was found to be reduced by approximately one-half among aspirin users with lymph node-negative disease. This represents a clinically significant reduction in breast cancer mortality. These findings contribute to the understanding of aspirin's mechanism of action in breast cancer. However, further etiologic research to understand this association is warranted. Cancer 2016;122:2067-75. © 2016 American Cancer Society.

Proteome-wide prediction of targets for aspirin: new insight into the molecular mechanism of aspirin.

Besides its anti-inflammatory, analgesic and anti-pyretic properties, aspirin is used for the prevention of cardiovascular disease and various types of cancer. The multiple activities of aspirin likely involve several molecular targets and pathways rather than a single target. Therefore, systematic identification of these targets of aspirin can help us understand the underlying mechanisms of the activities. In this study, we identified 23 putative targets of aspirin in the human proteome by using binding pocket similarity detecting tool combination with molecular docking, free energy calculation and pathway analysis. These targets have diverse folds and are derived from different protein family. However, they have similar aspirin-binding pockets. The binding free energy with aspirin for newly identified targets is comparable to that for the primary targets. Pathway analysis revealed that the targets were enriched in several pathways such as vascular endothelial growth factor (VEGF) signaling, Fc epsilon RI signaling and arachidonic acid metabolism, which are strongly involved in inflammation, cardiovascular disease and cancer. Therefore, the predicted target profile of aspirin suggests a new explanation for the disease prevention ability of aspirin. Our findings provide a new insight of aspirin and its efficacy of disease prevention in a systematic and global view.