COX-2 expression predicts worse breast cancer prognosis and does not modify the association with aspirin

Aspirin Use and Survival Among Patients With Breast Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Previous meta-analyses have indicated that aspirin could affect breast cancer outcomes, particularly when taken post-diagnostically. However, several recent studies appear to show little to no association between aspirin use and breast cancer mortality, all-cause mortality, or recurrence.

AIMS

This study aims to conduct an updated systematic review and meta-analysis on the associations of pre-diagnostic and post-diagnostic aspirin use with the aforementioned breast cancer outcomes. It also looks, through subgroup analyses and meta-regressions, at a range of variables that could explain the associations between aspirin use and breast cancer outcomes.

RESULTS

In total, 24 papers and 149 860 patients with breast cancer were included. Pre-diagnostic aspirin use was not associated with breast-cancer-specific mortality (HR 0.98, 95% CI, 0.80-1.20, P = .84) or recurrence (HR 0.94, 95% CI, 0.88-1.02, P = .13). Pre-diagnostic aspirin was associated with non-significantly higher all-cause mortality (HR 1.27, 95% CI, 0.95-1.72, P = .11). Post-diagnostic aspirin was not significantly associated with all-cause mortality (HR 0.87, 95% CI, 0.71-1.07, P = .18) or recurrence (HR 0.89, 95% CI, 0.67-1.16, P = .38). Post-diagnostic aspirin use was significantly associated with lower breast-cancer-specific mortality (HR 0.79, 95% CI, 0.64-0.98, P = .032).

CONCLUSIONS

The only significant association of aspirin with breast cancer outcomes is lower breast-cancer-specific mortality in patients who used aspirin post-diagnostically. However, factors such as selection bias and high inter-study heterogeneity mean that this result should not be treated as conclusive, and more substantial evidence such as that provided by RCTs is needed before any decisions on new clinical uses for aspirin should be made.

Dual-target inhibitors based on COX-2: a review from medicinal chemistry perspectives

Inhibitors of COX-2 constitute a class of anti-inflammatory analgesics, showing potential against certain types of cancer. However, such inhibitors are associated with cardiovascular toxicity. Moreover, although single-target molecules possess specificity for particular targets, they often lead to poor safety, low efficacy and drug resistance due to compensatory mechanisms. A new generation of dual-target drugs that simultaneously inhibit COX-2 and another target is showing strong potential to treat cancer or reduce adverse cardiac effects. The present perspective focuses on the structure and functions of COX-2, and its role as a therapeutic target. It also explores the current state and future possibilities for dual-target strategies from a medicinal chemistry perspective.

Aspirin Affects MDA-MB-231 Vesicle Production and Their Capacity to Induce Fibroblasts towards a Pro-Invasive State

Long-term administration of aspirin (ASA, acetylsalicylic acid) in oncogenic patients has been related to a reduction in cancer risk incidence, but its precise mechanism of action is unclear. The activation of cancer-associated fibroblasts (CAFs) is a key element in tumor progression and can be triggered by cancer-derived extracellular vesicles (EVs). Targeting the communication between cancer cells and the surrounding tumor microenvironment (TME) may control cancer progression. Our aim was to investigate the effect of ASA on breast cancer cells, focusing on EV secretion and their effect on the biological properties of CAFs. As a result, ASA was shown to reduce the amount and alter the size distribution of EVs produced by MDA-MB-231 tumor cells. Fibroblasts stimulated with EVs derived from MDA-MB-231 treated with ASA (EV-ASA) showed a lower expression of alpha-smooth muscle actin (α-SMA), matrix metalloproteinase-2 (MMP2) but not fibroblast activation protein (FAP) in respect to the ones stimulated with EVs from untreated breast cancer cells (EV-CTR). Furthermore, invasion assays using a three-dimensional (3D) fibroblast spheroid model showed reduced MDA-MB-231 invasion towards fibroblast spheroids pretreated with EV-ASA as compared to spheroids prepared with EV-CTR-stimulated fibroblasts. This suggests that ASA partially inhibits the ability of tumor EVs to stimulate CAFs to promote cancer invasion. In conclusion, ASA can interfere with tumor communication by reducing EV secretion by breast tumor cells as well as by interfering with their capacity to stimulate fibroblasts to become CAFs.

Associations of aspirin and other anti-inflammatory medications with breast cancer risk by the status of COX-2 expression

BACKGROUND

We investigated the associations of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) with breast cancer risk by the status of COX-2 protein expression.

METHODS

This study included 421 cases and 3,166 controls from a nested case-control study within the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII) cohorts. Information on medication use was first collected in 1980 (NHS) and 1989 (NHSII) and was updated biennially. Medication use was defined as none, past or current; average cumulative dose and frequency were calculated for all past or current users using data collected from all biannual questionnaires preceding the reference date. Immunochemistry for COX-2 expression was performed using commercial antibody (Cayman Chemical and Thermo Fisher Scientific). We used polychotomous logistic regression to quantify associations of aspirin and NSAIDs with the risk of COX2+ and COX2- breast cancer tumors, while adjusting for known breast cancer risk factors. All tests of statistical significance were two-sided.

RESULTS

In multivariate analysis, we found no differences in associations of the aspirin exposures and NSAIDs with breast cancer risk by COX2 expression status. In stratified analyses by COX2 status, significant associations of these medications with breast cancer risk were observed for dosage of aspirin among current users in COX2- tumors (OR for > 5 tablets per week vs. none 1.71, 95% CI 1.01-2.88, p-trend 0.04). Regular aspirin use was marginally associated with the risk of COX2- tumors (p-trend = 0.06).

CONCLUSIONS

Our findings suggested no differences in associations of aspirin and other NSAIDs with COX2+ and COX2- tumors.

Patients with Invasive Lobular Carcinoma Show a Significant Increase in IRS-4 Expression Compared to Infiltrative Ductal Carcinoma—A Histopathological Study

Background and Objectives: Breast cancer (BC) is the first diagnosed type of cancer and the second leading cause of cancer-related mortality in women. In addition, despite the improvement in treatment and survival in these patients, the global prevalence and incidence of this cancer are rising, and its mortality may be different according to the histological subtype. Invasive lobular carcinoma (ILC) is less common but entails a poorer prognosis than infiltrative ductal carcinoma (IDC), exhibiting a different clinical and histopathological profile. Deepening study on the molecular profile of both types of cancer may be of great aid to understand the carcinogenesis and progression of BC. In this sense, the aim of the present study was to explore the histological expression of Insulin receptor substrate 4 (IRS-4), cyclooxygenase 2 (COX-2), Cyclin D1 and retinoblastoma protein 1 (Rb1) in patients with ILC and IDC. Patients and Methods: Thus, breast tissue samples from 45 patients with ILC and from 45 subjects with IDC were analyzed in our study. Results: Interestingly, we observed that IRS-4, COX-2, Rb1 and Cyclin D1 were overexpressed in patients with ILC in comparison to IDC. Conclusions: These results may indicate a differential molecular profile between both types of tumors, which may explain the clinical differences among ILC and IDC. Further studies are warranted in order to shed light onto the molecular and translational implications of these components, also aiding to develop a possible targeted therapy to improve the clinical management of these patients.

Implementing subtype-specific pre-clinical models of breast cancer to study pre-treatment aspirin effects

Backgorund

Prior data suggest pre‐diagnostic aspirin use impacts breast tumour biology and patient outcome. Here, we employed faithful surgical resection models of HER2+ and triple‐negative breast cancer (TNBC), to study outcome and response mechanisms across breast cancer subtypes.

Method

NOD/SCID mice were implanted with HER2+ MDA‐MB‐231/LN/2‐4/H2N, trastuzumab‐resistant HER2+ HCC1954 or a TNBC patient‐derived xenograft (PDX). A daily low‐dose aspirin regimen commenced until primary tumours reached ~250 mm³ and subsequently resected. MDA‐MB‐231/LN/2‐4/H2N mice were monitored for metastasis utilising imaging. To interrogate the survival benefit of pre‐treatment aspirin, 3 weeks post‐resection, HCC1954/TNBC animals received standard‐of‐care (SOC) chemotherapy for 6 weeks. Primary tumour response to aspirin was interrogated using immunohistochemistry.

Results

Aspirin delayed time to metastasis in MDA‐MB‐231/LN/2‐4/H2N xenografts and decreased growth of HER2⁺/TNBC primary tumours. Lymphangiogenic factors and lymph vessels number were decreased in HER2⁺ tumours. However, no survival benefit was seen in aspirin pre‐treated animals (HCC1954/TNBC) that further received adjuvant SOC, compared with animals treated with SOC alone. In an effort to study mechanisms responsible for the observed reduction in lymphangiogenesis in HER2⁺ BC we utilised an in vitro co‐culture system of HCC1954 tumour cells and mesenchymal stromal cells (MSC). Aspirin abrogated the secretion of VEGF‐C in MSCs and also decreased the lymph/angiogenic potential of the MSCs and HCC1954 by tubule formation assay. Furthermore, aspirin decreased the secretion of uPA in HCC1954 cells potentially diminishing its metastatic capability.

Conclusion

Our data employing clinically relevant models demonstrate that aspirin alters breast tumour biology. However, aspirin may not represent a robust chemo‐preventative agent in the HER2⁺ or TNBC setting.

Metformin suppresses breast cancer growth via inhibition of cyclooxygenase-2

Pre-clinical and on-going trials have indicated the advantage of using metformin as an anticancer drug alone or in combination with other chemotherapeutics for the treatment of patients with breast cancer. However, the mechanisms by which metformin attenuates tumorigenesis remain to be further elucidated. The present study investigated the anticancer effects of metformin in breast cancer and identified potential molecular targets of metformin using western blotting and immunohistochemical analysis. Metformin significantly decreased tumor cell proliferation in vitro and suppressed tumor growth in vivo. Moreover, it induced the activation of AMP-induced protein kinase and suppression of phosphorylated-eukaryotic translation initiation factor 4E-binding protein 1 (p-4E-BP1), a downstream effector of the mTOR signaling pathway, and decreased cyclin D1 levels in in vitro and in vivo experimental models. Additionally, metformin inhibited cyclooxygenase (COX)-2 expression. Clinically, high expression levels of COX-2 and p-4E-BP1 in tissues of patients with breast cancer were significantly associated with enhanced lymphatic metastasis and distant metastasis. Thus, the current data suggested that metformin may have potential value as a synergistic therapy targeting both the COX-2 and mTOR signaling pathways.

The Therapeutic Potential of Regulatory T Cells: Challenges and Opportunities

Regulatory T cells (Tregs) are an immunosuppressive subgroup of CD4+ T cells which are identified by the expression of forkhead box protein P3 (Foxp3). The modulation capacity of these immune cells holds an important role in both transplantation and the development of autoimmune diseases. These cells are the main mediators of self-tolerance and are essential for avoiding excessive immune reactions. Tregs play a key role in the induction of peripheral tolerance that can prevent autoimmunity, by protecting self-reactive lymphocytes from the immune reaction. In contrast to autoimmune responses, tumor cells exploit Tregs in order to prevent immune cell recognition and anti-tumor immune response during the carcinogenesis process. Recently, numerous studies have focused on unraveling the biological functions and principles of Tregs and their primary suppressive mechanisms. Due to the promising and outstanding results, Tregs have been widely investigated as an alternative tool in preventing graft rejection and treating autoimmune diseases. On the other hand, targeting Tregs for the purpose of improving cancer immunotherapy is being intensively evaluated as a desirable and effective method. The purpose of this review is to point out the characteristic function and therapeutic potential of Tregs in regulatory immune mechanisms in transplantation tolerance, autoimmune diseases, cancer therapy, and also to discuss that how the manipulation of these mechanisms may increase the therapeutic options.

S-nitrosylated and non-nitrosylated COX2 have differential expression and distinct subcellular localization in normal and breast cancer tissue

Immunohistochemical (IHC) staining in breast cancer shows both gain and loss of COX2 expression with disease risk and progression. We investigated four common COX2 antibody clones and found high specificity for purified human COX2 for three clones; however, recognition of COX2 in cell lysates was clone dependent. Biochemical characterization revealed two distinct forms of COX2, with SP21 recognizing an S-nitrosylated form, and CX229 and CX294 recognizing non-nitrosylated COX2 antigen. We found S-nitrosylated and non-nitrosylated COX2 occupy different subcellular locations in normal and breast cancer tissue, implicating distinct synthetic/trafficking pathways and function. Dual stains of ~2000 breast cancer cases show early-onset breast cancer had increased expression of both forms of COX2 compared to postmenopausal cases. Our results highlight the strengths of using multiple, highly characterized antibody clones for COX2 IHC studies and raise the prospect that S-nitrosylation of COX2 may play a role in breast cancer biology.

Targeting Lipid Peroxidation for Cancer Treatment

Cancer is one of the highest prevalent diseases in humans. The chances of surviving cancer and its prognosis are very dependent on the affected tissue, body location, and stage at which the disease is diagnosed. Researchers and pharmaceutical companies worldwide are pursuing many attempts to look for compounds to treat this malignancy. Most of the current strategies to fight cancer implicate the use of compounds acting on DNA damage checkpoints, non-receptor tyrosine kinases activities, regulators of the hedgehog signaling pathways, and metabolic adaptations placed in cancer. In the last decade, the finding of a lipid peroxidation increase linked to 15-lipoxygenases isoform 1 (15-LOX-1) activity stimulation has been found in specific successful treatments against cancer. This discovery contrasts with the production of other lipid oxidation signatures generated by stimulation of other lipoxygenases such as 5-LOX and 12-LOX, and cyclooxygenase (COX-2) activities, which have been suggested as cancer biomarkers and which inhibitors present anti-tumoral and antiproliferative activities. These findings support the previously proposed role of lipid hydroperoxides and their metabolites as cancer cell mediators. Depletion or promotion of lipid peroxidation is generally related to a specific production source associated with a cancer stage or tissue in which cancer originates. This review highlights the potential therapeutical use of chemical derivatives to stimulate or block specific cellular routes to generate lipid hydroperoxides to treat this disease.

Erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers and fatty acid synthase: a nested case-control study

BACKGROUND

Previous studies of fatty acids and breast cancer risk have shown mixed results, which may be due in part to tumor heterogeneity. Prior research has also illustrated an important role of specific fatty acids in immune regulation, T cell function, and inflammation, indicating that the effects of specific fatty acids on breast cancer risk may vary by tumor expression of immuno-inflammatory markers. We therefore aimed to evaluate the relationships between prediagnostic erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers (CD4, CD8, CD20, CD163, COX-2) and fatty acid synthase (FAS).

METHODS

We conducted a matched case-control study nested within the Nurses' Health Study II (n = 235 cases and 235 controls). Blood samples were collected from 1996 to 1999. Tumor tissue blocks were collected for cases diagnosed after blood collection and through 2006. Unconditional nominal polytomous logistic regression adjusted for matching factors and potential confounders was used to assess whether associations between fatty acids and breast cancer risk varied by tumor expression subtype, ascertained via immunohistochemistry. Odds ratios (OR) and 95% confidence intervals (CI) were estimated separately by tumor expression subtype using unconditional logistic regression.

RESULTS

Associations between fatty acids and breast cancer risk did not vary substantially by tumor CD4, CD20, CD163, or COX-2. However, n-3 polyunsaturated fatty acids (PUFAs) were inversely associated with CD8^low but not CD8^high cancers (CD8^low OR_{T3 vs T1} = 0.45, 95% CI 0.23-0.87, P_trend = 0.02; CD8^high OR_{T3 vs T1} = 1.19, 95% CI 0.62-2.26, P_trend = 0.62; P_het = 0.04). n-6 PUFAs were suggestively inversely associated with CD8^high but not CD8^low cancers (CD8^high OR_{T3 vs T1} = 0.61, 95% CI 0.32-1.14, P_trend = 0.11; CD8^low OR_{T3 vs T1} = 1.63, 95% CI 0.87-3.04, P_trend = 0.12; P_het = 0.02). Trans fatty acids were positively associated with FAS^high but not FAS^low tumors (FAS^high OR_{T3 vs T1} = 2.94, 95% CI 1.46-5.91, P_trend = 0.002; FAS^low OR_{T3 vs T1} = 0.99, 95% CI 0.52-1.92, P_trend = 0.97; P_het = 0.01).

CONCLUSION

Results indicate that the effects of n-3 PUFAs, n-6 PUFAs, and trans fatty acids on breast cancer risk may vary by tumor tissue expression subtypes. Findings suggest potential immuno-modulatory and FAS-mediated mechanisms.

Limited Proteolysis of Cyclooxygenase-2 Enhances Cell Proliferation

Accumulating evidence suggests that the cyclooxygenase-2 (COX-2) enzyme has additional catalytic-independent functions. Here we show that COX-2 appears to be cleaved in mouse and human tumors, which led us to hypothesize that COX-2 proteolysis may play a role in cell proliferation. The data presented herein show that a K598R point mutation at the carboxyl-terminus of COX-2 causes the appearance of several COX-2 immunoreactive fragments in nuclear compartments, and significantly enhances cell proliferation. In contrast, insertion of additional mutations at the border of the membrane-binding and catalytic domains of K598R COX-2 blocks fragment formation and prevents the increase in proliferation. Transcriptomic analyses show that K598R COX-2 significantly affects the expression of genes involved in RNA metabolism, and subsequent proteomics suggest that it is associated with proteins that regulate mRNA processing. We observe a similar increase in proliferation by expressing just that catalytic domain of COX-2 (ΔNT- COX-2), which is completely devoid of catalytic activity in the absence of its other domains. Moreover, we show that the ΔNT- COX-2 protein also interacts in the nucleus with β-catenin, a central regulator of gene transcription. Together these data suggest that the cleavage products of COX-2 can affect cell proliferation by mechanisms that are independent of prostaglandin synthesis.

Different associations of tumor PIK3CA mutations and clinical outcomes according to aspirin use among women with metastatic hormone receptor positive breast cancer

Introduction

The relationships among PIK3CA mutations, medication use and tumor progression remains poorly understood. Aspirin use post-diagnosis may modify components of the PI3K pathway, including AKT and mTOR, and has been associated with lower risk of breast cancer recurrence and mortality. We assessed time to metastasis (TTM) and survival with respect to aspirin use and tumor PIK3CA mutations among women with metastatic breast cancer.

Methods

Patients with hormone receptor positive, HER2 negative (HR+/HER2-) metastatic breast cancer treated in 2009–2016 who received tumor genotyping were included. Aspirin use between primary and metastatic diagnosis was extracted from electronic medical records. TTM and survival were estimated using Cox proportional hazards regression.

Results

Among 267 women with metastatic breast cancer, women with PIK3CA mutated tumors had longer TTM than women with PIK3CA wildtype tumors (7.1 vs. 4.7 years, p = 0.008). There was a significant interaction between PIK3CA mutations and aspirin use on TTM (p = 0.006) and survival (p = 0.026). PIK3CA mutations were associated with longer TTM among aspirin non-users (HR = 0.60 95% CI:0.44–0.82 p = 0.001) but not among aspirin users (HR = 1.57 0.86–2.84 p = 0.139). Similarly, PIK3CA mutations were associated with reduced mortality among aspirin non-users (HR = 0.70 95% CI:0.48–1.02 p = 0.066) but not among aspirin users (HR = 1.75 95% CI:0.88–3.49 p = 0.110).

Conclusions

Among women who develop metastatic breast cancer, tumor PIK3CA mutations are associated with slower time to progression and mortality only among aspirin non-users. Larger studies are needed to confirm this finding and examine the relationship among aspirin use, tumor mutation profile, and the overall risk of breast cancer progression.

The relationship between exposure to particulate matter and breast cancer incidence and mortality: A meta-analysis

BACKGROUND

Particulate matter (PM) acts as an environment pollutant and thus plays a vital role in the development of human lung cancer. Whether PM is a risk factor for breast cancer (BC) morbidity and mortality, however, is not clear. Recently, several studies have reported inconsistent results for the association between PM and BC risk. This meta-analysis examines the indefinite relationship between exposure to PM and BC morbidity and mortality.

METHODS

Based on a search of Pubmed, Embase, Web of Science and Cochrane Library, the hazard ratio (HR) and 95% confidence interval (CI) were extracted and analyzed by Review Manager 5.3 and Stata14.0 to estimate the association between PM and BC morbidity and mortality. The heterogeneity for the included studies was evaluated using a Chi-square test and the I statistic. Forest plot was used to illustrate the pooled HR and mean difference. A Funnel plot, Begg test, and Egger test were performed to explore the publication bias between the included studies.All analyses were based on previous published studies, thus, no ethical approval and patient consent are required.

RESULTS

A total of 14 of 284 publications with 1,004,128 BC cases were gathered. The analysis showed each 10 μg/m of PM2.5 (diameter ≤2.5 μm) was associated with 1.17 (95% CI: 1.05-1.30, P = .004) fold risk BC mortality, and each 10 μg/m of PM10 (diameter ≤10 μm) was associated with 1.11 (95% CI: 1.02-1.21, P = .021) fold risk BC mortality. However, neither PM10 nor PM2.5 was found to be significantly associated with BC morbidity. Publication bias was detected in studies on PM2.5 and BC mortality.

CONCLUSIONS

Our study suggests that PM exposure may raise the mortality but not the morbidity of BC. Still, further studies may be necessary to confirm this finding.

Growth inhibitory effects of PC-NSAIDs on human breast cancer subtypes in cell culture

The potential role of non-steroidal anti-inflammatory drug (NSAID) therapy in the prevention and treatment of cancer has generated considerable research interest. Phosphatidylcholine (PC)-associated NSAIDs decrease the gastrointestinal side effects of NSAID therapy, and may be more effective than traditional NSAIDs in limiting tumor growth. In the present study, human cells representing three major breast cancer subtypes were cultured with aspirin, indomethacin and PC-associated forms of each drug, with PC alone as a control. All tested drugs decreased the tumor cell number after 8 days of culture, with PC-NSAIDs having the greatest inhibitory effect, and NSAIDs alone, particularly aspirin, having the least effect. PC alone was effective in limiting the proliferation of all cell lines, suggesting that the two components of PC-NSAIDs have an additive effect. The ELISA results did not support a strong role for inhibition of cyclooxygenase enzymes in the decrease in cancer cell proliferation, which may account for the limited effectiveness of aspirin alone. PC-NSAIDs, particularly indomethacin-PC, are attractive candidate drugs in the prevention and treatment of different types of breast cancer, including triple negative breast cancer.

Prediagnosis aspirin use, DNA methylation, and mortality after breast cancer: A population-based study

BACKGROUND

The authors hypothesized that epigenetic changes may help to clarify the underlying biologic mechanism linking aspirin use to breast cancer prognosis. To the authors' knowledge, this is the first epidemiologic study to examine whether global methylation and/or tumor promoter methylation of breast cancer-related genes interact with aspirin use to impact mortality after breast cancer.

METHODS

Prediagnosis aspirin use was assessed through in-person interviews within a population-based cohort of 1508 women diagnosed with a first primary breast cancer in 1996 and 1997. Global methylation in peripheral blood was assessed by long interspersed elements-1 (LINE-1) and the luminometric methylation assay. Promoter methylation of 13 breast cancer-related genes was measured in tumor by methylation-specific polymerase chain reaction and the MethyLight assay. Vital status was determined by the National Death Index through December 31, 2014 (N = 202/476 breast cancer-specific/all-cause deaths identified among 1266 women with any methylation assessment and complete aspirin data). Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs, and the likelihood ratio test was used to evaluate multiplicative interactions.

RESULTS

All-cause mortality was elevated among aspirin users who had methylated promotor of BRCA1 (HR, 1.67; 95% CI, 1.26-2.22), but not among those with unmethylated promoter of BRCA1 (HR, 0.99; 95% CI, 0.67-1.45; P for interaction ≤.05). Decreased breast cancer-specific mortality was observed among aspirin users who had unmethylated promotor of BRCA1 and PR and global hypermethylation of LINE-1 (HR, 0.60, 0.78, and 0.63, respectively; P for interaction ≤.05), although the 95% CIs included the null.

CONCLUSIONS

The current study suggests that the LINE-1 global methylation and promoter methylation of BRCA1 and PR in tumor may interact with aspirin use to influence mortality after breast cancer.

The Presence of Cyclooxygenase 2, Tumor-Associated Macrophages, and Collagen Alignment as Prognostic Markers for Invasive Breast Carcinoma Patients

Inflammation, and the organization of collagen in the breast tumor microenvironment, is an important mediator of breast tumor progression. However, a direct link between markers of inflammation, collagen organization, and patient outcome has yet to be established. A tumor microarray of 371 invasive breast carcinoma biopsy specimens was analyzed for expression of inflammatory markers, including cyclooxygenase 2 (COX-2), macrophages, and several collagen features in the tumor nest (TN) or the tumor-associated stroma (TS). The tumor microarray cohort included females, aged 18 to 80 years, with a median follow-up of 8.4 years. High expression of COX-2 (TN), CD68 (TS), and CD163 (TN and TS) predicted worse patient overall survival (OS). This notion was strengthened by the finding from the multivariate analysis that high numbers of CD163⁺ macrophages in the TS is an independent prognostic factor. Overall collagen deposition was associated with high stromal expression of COX-2 and CD163; however, total collagen deposition was not a predictor for OS. Conversely, local collagen density, alignment and perpendicular alignment to the tumor boundary (tumor-associated collagen signature-3) were predictors of OS. These results suggest that in invasive carcinoma, the localization of inflammatory cells and aligned collagen orientation predict poor patient survival. Additional clinical studies may help validate whether therapy with selective COX-2 inhibitors alters expression of CD68 and CD163 inflammatory markers.

Particulate Matter and Traffic-Related Exposures in Relation to Breast Cancer Survival

BACKGROUND

Although particulate matter (PM) has not been consistently associated with breast cancer risk, two studies have reported harmful associations for breast cancer survival. We examined PM exposures and breast cancer survival in two U.S.-based prospective cohort studies.

METHODS

The Nurses' Health Study (NHS) and NHSII are cohorts with detailed data on medical history, lifestyle factors, and causes of death. Women with Stage I-III breast cancer (n = 8,936) were followed through June 2014. Residential PM was estimated using spatio-temporal models. We performed Cox regression to estimate hazard ratios (HR) of breast cancer-specific mortality and all-cause mortality for 10 μg/m³ increases in post-diagnosis PM.

RESULTS

There were 1,211 breast cancer-specific deaths. Overall, PM was not associated with breast cancer-specific mortality [PM_2.5: HR, 1.09; 95% confidence interval (CI), 0.87-1.36; PM_2.5-10: HR, 1.03; 95% CI, 0.85-1.24; PM₁₀: HR, 1.05; 95% CI, 0.89-1.24], but was associated with modest increases in all-cause mortality (PM_2.5: HR, 1.12; 95% CI, 0.96-1.30; PM_2.5-10: HR, 1.12; 95% CI, 1.00-1.24; PM₁₀: HR, 1.09; 95% CI, 1.01-1.18). However, among participants with Stage I disease, PM_2.5 was associated with higher breast cancer-specific mortality (HR, 1.64; 95% CI, 1.11-2.43).

CONCLUSIONS

PM was not associated with breast cancer-specific death overall; however, higher PM was associated with all-cause mortality. Higher PM_2.5 was associated with higher breast cancer-specific mortality among patients with Stage I breast cancer even after adjustment.

IMPACT

Studies on ambient PM and breast cancer survival demonstrate that PM_2.5 may have broader health effects than previously recognized and warrants further research on breast tumor progression.

Substrate-inactivated cyclooxygenase-2 is disposed of by exosomes through the ER-Golgi pathway

Catalysis of arachidonic acid (AA) by cyclooxygenase-2 (COX-2) gives rise to a single product that serves as a precursor for all prostaglandins, which are central mediators of inflammation. Rapid up-regulation of COX-2 expression in response to pro-inflammatory stimuli is a well-characterized means of generating the large pool of prostaglandins necessary for inflammation. However, an efficient inflammatory process must also terminate rapidly and thus requires cessation of COX-2 enzymatic activity and removal of excess protein from the cell. Previous studies showed that COX-2 that has not been exposed to AA ('naive') degrades in the cellular proteasome. However, continuous exposure to AA induces suicide inactivation of COX-2 and its elimination no longer occurs in neither the proteasomal nor lysosomal machineries. In the present study, we show that either overexpressed or endogenously induced COX-2 is secreted via exosomes through the endoplasmic reticulum-Golgi pathway. We further find that excretion of COX-2 is significantly enhanced by prolonged exposure to AA. Genetic or chemical inhibition of COX-2 enzymatic activity has no effect on its secretion in the absence of substrate, but prevents the additional activity-dependent secretion. Finally, transfer of COX-2 to target cells only occurs in the absence of AA stimulation. Together, these results suggest that exosomal secretion of AA-activated COX-2 constitutes a means to remove damaged inactive COX-2 from the cell.

Therapeutic positioning of secretory acetylated APE1/Ref-1 requirement for suppression of tumor growth in triple-negative breast cancer in vivo

Triple-negative breast cancer (TNBC) represents a relatively small proportion of all BCs but a relatively large proportion of BC-related death. Thus, more effective therapeutic strategies are needed for the management of TNBC. We demonstrated that the stimulation of apoptosis by the binding of secreted acetylated-apurinic apyrimidinic endonuclease 1/redox factor-1 (Ac-APE1/Ref-1) to the receptor for advanced glycation end products (RAGE) was essential for TNBC cell death in response to hyperacetylation. The aim of the present study was to assess the potential therapeutic efficacy of secretory Ac-APE1/Ref-1 in orthotopic TNBC xenografts in vivo. We found that hyperacetylation in xenografts caused secretion of Ac-APE1/Ref-1 into the blood, where the factor bound directly to RAGE in hyperacetylated tumor tissues. Hyperacetylation in the TNBC xenografts induced strong inhibition of tumor growth and development, leading to apoptotic cell death, accompanied by increased RAGE expression and generation of reactive oxygen species. Tissues exhibited markedly higher counts of apoptotic bodies, a reduced proliferation index, and reduced neovascularization compared with control tumors. Ac-APE1/Ref-1-stimulated apoptosis was markedly reduced in RAGE-knockdown tumors compared with RAGE-overexpressing tumors, even in the presence of hyperacetylation. The function of secreted Ac-APE1/Ref-1 was confirmed in other hyperacetylated TNBCs xenografts using BT-549 and MDA-MB-468 cells, demonstrating its relevance as an anti-cancer molecule.

The impact of aspirin use on breast cancer subtype and clinical course

BACKGROUND

The use of aspirin has been associated with improved survival in patients with breast cancer, but the results have been mixed. We aim to analyze the impact of aspirin use before or after breast cancer diagnosis on breast cancer clinical characteristics and outcomes.

MATERIALS AND METHODS

We performed a single-institution, retrospective analysis of 1113 women diagnosed with operable breast cancer between 1995 and 2015. Patients were grouped according to their aspirin use: never (944), before diagnosis (79), and after diagnosis (90). Clinical variables, overall survival (OS), and disease-free survival (DFS) were compared between groups.

RESULTS

Women using aspirin before diagnosis were older, more likely to be black, and to have associated medical comorbidities than patients in other groups (all P <0.001). These patients were also more likely to present with hormone receptor-negative cancers, including triple-negative breast cancer (P = 0.002). Aspirin use before diagnosis was associated with a worse OS in univariate and multivariate analyses (both P <0.001), but there were no other differences in OS or DFS related to aspirin use.

CONCLUSIONS

Despite a potential impact on tumor subtype in patients using aspirin before their breast cancer diagnosis, aspirin use does not appear to alter breast cancer-related survival.

Role of Aspirin in Breast Cancer Survival

Chemotherapy and hormonal therapy have significantly decreased breast cancer mortality, although with considerable side effects and financial costs. In the USA, over three million women are living after a breast cancer diagnosis and are eager for new treatments that are low in toxicity and cost. Multiple observational studies have reported improved breast cancer survival with regular aspirin use. Furthermore, pooled data from five large randomized trials of aspirin for cardiovascular disease showed that subjects on aspirin had decreased risk of cancer mortality and decreased risk of metastatic cancer. Although the potential mechanism for aspirin preventing breast cancer is not known, possible pathways may involve platelets, inflammation, cyclooxygenase (COX) 2, hormones, or PI3 kinase. This review article summarizes the current epidemiologic and clinical trial evidence as well as possible underlying mechanisms that justify current phase III randomized trials of aspirin to improve breast cancer survival.

Clinicopathological and prognostic significance of COX-2 immunohistochemical expression in breast cancer: a meta-analysis

The prognostic significance of COX-2 in patients with breast cancer remains controversial. The aims of our meta-analysis are to evaluate its association with clinicopathological characteristics and prognostic value in patients with breast cancer. PubMed, EMBASE, Web of Science, the Ovid Database and Grey literature were systematically searched up to May 2016. Twenty-one studies including 6739 patients with breast cancer were analyzed. The meta-analysis indicated that the incidence difference of COX-2 expression was significant when comparing the lymph node positive group to negative group (OR = 1.76, 95% CI [1.30, 2.39]) and the tumor size ≥ 2cm group to the tumor size < 2cm group (OR = 1.71, 95% CI [1.22, 2.39]). None of other clinicopathological parameters such as the ER status, PR status, HER2 status and the vascular invasion status were associated with COX-2 overexpression. The detection of COX-2 was significantly correlated with the disease-free survival (DFS) of patients (HR = 1.58, 95% CI [1.23, 2.03]) and the overall survival (OS) of patients (HR = 1.51, 95% CI [1.31, 1.72]). Our meta-analysis demonstrates that the presence of high levels of COX-2 is associated with poor prognosis for breast cancer patients and predicts bigger tumor size and lymph node metastasis.

Aspirin induces Beclin-1-dependent autophagy of human hepatocellular carcinoma cell

Aspirin not only reduces the incidence of hepatocellular carcinoma (HCC) but also plays a synergistic role with chemotherapy for HCC treatment. However, the underlying mechanisms remain incompletely elucidated. Given that autophagy triggers cancer cell death, the present study examined the autophagic effect of aspirin on HCC cells. Results showed that aspirin increased LC3II/LC3I ratio, decreased p62 expression, and enhanced autophagic flux (autophagosome and autolysosome puncta) in Hep3B, HepG2, or SMMC-7721 cells, reflecting the autophagy of HCC cells. The autophagic effects of aspirin depended on Beclin-1 expression. Aspirin disrupted the interaction between Bcl-2 and Beclin-1. In addition to activating the AMP-activated protein kinase, c-Jun N-terminal kinase, and Glycogen synthase kinase-3 pathways, aspirin inhibited the mammalian-target-of rapamycin-S6K1/4E-BP1 signaling. Aspirin induced autophagy of HCC cell. This study contributes to understanding the chemoprotective and inhibitory effects of aspirin on HCC development.

Employing mesenchymal stem cells to support tumor-targeted delivery of extracellular vesicle (EV)-encapsulated microRNA-379

Adult Mesenchymal Stem Cells (MSCs) have a well-established tumor-homing capacity, highlighting potential as tumor-targeted delivery vehicles. MSCs secrete extracellular vesicle (EV)-encapsulated microRNAs, which play a role in intercellular communication. The aim of this study was to characterize a potential tumor suppressor microRNA, miR-379, and engineer MSCs to secrete EVs enriched with miR-379 for in vivo therapy of breast cancer. miR-379 expression was significantly reduced in lymph node metastases compared to primary tumor tissue from the same patients. A significant reduction in the rate of tumor formation and growth in vivo was observed in T47D breast cancer cells stably expressing miR-379. In more aggressive HER2-amplified HCC-1954 cells, HCC-379 and HCC-NTC tumor growth rate in vivo was similar, but increased tumor necrosis was observed in HCC-379 tumors. In response to elevated miR-379, COX-2 mRNA and protein was also significantly reduced in vitro and in vivo. MSCs were successfully engineered to secrete EVs enriched with miR-379, with the majority found to be of the appropriate size and morphology of exosomal EVs. Administration of MSC-379 or MSC-NTC cells, or EVs derived from either cell population, resulted in no adverse effects in vivo. While MSC-379 cells did not impact tumor growth, systemic administration of cell-free EVs enriched with miR-379 was demonstrated to have a therapeutic effect. The data presented support miR-379 as a potent tumor suppressor in breast cancer, mediated in part through regulation of COX-2. Exploiting the tumor-homing capacity of MSCs while engineering the cells to secrete EVs enriched with miR-379 holds exciting potential as an innovative therapy for metastatic breast cancer.

COX-2 expression in ovarian cancer: an updated meta-analysis

The prognostic role of COX-2 expression in ovarian cancer patients has been studied for years, while results remain controversial. Thus we performed a meta-analysis to evaluate the prognostic impact of COX-2 expression on survival of ovarian cancer patients. The databases PubMed, Embase and CNKI were searched. Summary hazard ratio (HR) and 95% confidence intervals (CIs) were calculated to analyze the correlations between COX-2 expression and overall survival (OS), and disease-free survival (DFS). A total of 1,867 patients from 18 studies were enrolled in the final analysis. The results showed that patients with higher COX-2 expression had a poor OS (HR: 1.48; 95% CI: 1.19-1.85) and DFS (HR: 1.81, 95% CI: 1.28-2.55). Subgroup analysis showed that there had significant associations between COX-2 expression and survival rate in most of the subgroups. Furthermore, there were significant associations between COX-2 expression and several clinical parameters such as FIGO stage, histological type and age. These results showed the patients with higher COX-2 expression had a significantly poorer survival rate, COX-2 expression had the potential to be a prognostic marker of ovarian cancer.

Prognostic genes of breast cancer revealed by gene co-expression network analysis

The aim of the present study was to identify genes that may serve as markers for breast cancer prognosis by constructing a gene co-expression network and mining modules associated with survival. Two gene expression datasets of breast cancer were downloaded from ArrayExpress and genes from these datasets with a coefficient of variation >0.5 were selected and underwent functional enrichment analysis with the Database for Annotation, Visualization and Integration Discovery. Gene co-expression networks were constructed with the WGCNA package in R. Modules were identified from the network via cluster analysis. Cox regression was conducted to analyze survival rates. A total of 2,669 genes were selected, and functional enrichment analysis of them revealed that they were mainly associated with the immune response, cell proliferation, cell differentiation and cell adhesion. Seven modules were identified from the gene co-expression network, one of which was found to be significantly associated with patient survival time. Expression status of 144 genes from this module was used to cluster patient samples into two groups, with a significant difference in survival time revealed between these groups. These genes were involved in the cell cycle and tumor protein p53 signaling pathway. The top 10 hub genes were identified in the module. The findings of the present study could advance the understanding of the molecular pathogenesis of breast cancer.

Aspirin Suppresses Growth in PI3K-Mutant Breast Cancer by Activating AMPK and Inhibiting mTORC1 Signaling

Despite the high incidence of oncogenic mutations in PIK3CA, the gene encoding the catalytic subunit of PI3K, PI3K inhibitors have yielded little clinical benefit for breast cancer patients. Recent epidemiologic studies have suggested a therapeutic benefit from aspirin intake in cancers harboring oncogenic PIK3CA Here, we show that mutant PIK3CA-expressing breast cancer cells have greater sensitivity to aspirin-mediated growth suppression than their wild-type counterparts. Aspirin decreased viability and anchorage-independent growth of mutant PIK3CA breast cancer cells independently of its effects on COX-2 and NF-κB. We ascribed the effects of aspirin to AMP-activated protein kinase (AMPK) activation, mTORC1 inhibition, and autophagy induction. In vivo, oncogenic PIK3CA-driven mouse mammary tumors treated daily with aspirin resulted in decreased tumor growth kinetics, whereas combination therapy of aspirin and a PI3K inhibitor further attenuated tumor growth. Our study supports the evaluation of aspirin and PI3K pathway inhibitors as a combination therapy for targeting breast cancer. Cancer Res; 77(3); 790-801. ©2016 AACR.

The prognostic impact of COX-2 expression in breast cancer depends on oral contraceptive history, preoperative NSAID use, and tumor size

The association between tumor cyclooxygenase 2 (COX-2) expression and breast cancer prognosis has been inconsistent. The purpose of this study was to evaluate the prognostic significance of COX-2 tumor expression according to adjuvant treatment, and potential effect modifications of non-steroid anti-inflammatory drug (NSAID) use, and other tumor and lifestyle factors. A prospective cohort of 1,116 patients with primary breast cancer in Lund, Sweden, included 2002-2012 was followed until June 2014 (median 5 years). Tumor-specific COX-2 expression was evaluated on tissue microarrays using immunohistochemistry. Associations between COX-2 intensity (negative, weak-moderate, high) and patient and tumor characteristics as well as prognosis were analyzed. Tumor-specific COX-2 expression was available for 911 patients and was significantly associated with higher age at diagnosis and less aggressive tumor characteristics. Higher COX-2 expression was associated with lower risk for breast cancer events during the first five years of follow-up, _adj HR 0.60 (95%CI: 0.37-0.97), per category. The association between COX-2 expression and prognosis was significantly modified by oral contraceptive (OC) use (P_interaction  = 0.048), preoperative NSAID use (P_interaction  = 0.009), and tumor size (P_interaction  = 0.039). COX-2 negativity was associated with increased risk for events during the first five years in ever OC users, _adj HR 1.94 (1.01-3.72) and during the 11-year follow-up in preoperative NSAID users, _adj HR 4.51 (1.18-11.44) as well as in patients with large tumors, _adj HR 2.57 (1.28-5.15). In conclusion, this study, one of the largest evaluating COX-2 expression in breast cancer, indicates that the prognostic impact of COX-2 expression depends on host factors and tumor characteristics.

Palbociclib inhibits epithelial-mesenchymal transition and metastasis in breast cancer via c-Jun/COX-2 signaling pathway

Palbociclib, a highly selective CDK4/6 inhibitor, has been shown to be a novel anti-tumor agent that suppresses breast cancer cell proliferation. However, its anti-metastasis activity remains controversial. In the present study, we evaluated whether palbociclib prevented breast cancer cell metastasis and revealed its regulatory mechanism. We found that palbociclib inhibited migration and invasion in the breast cancer cells MDA-MB-231 and T47D. The epithelial-mesenchymal transition (EMT) markers, vimentin and Snail, were down-regulated with palbociclib treatment. Moreover, we revealed that this inhibition was mediated by the c-Jun/COX-2 pathway. COX-2 was decreased after palbociclib treatment. The production of PGE2 was also reduced along with COX-2. Additionally, our data showed that c-Jun, a crucial transcriptional regulator of COX-2, was down-regulated by palbociclib. We found that palbociclib weakened the COX-2 promoter binding activity of c-Jun and prevented its translocation from the cytoplasm to cell nuclei. Bioluminescence imaging and tail intravenous injection were used to evaluate the anti-metastasis effect of palbociclib in vivo. The data demonstrated that palbociclib reduced breast cancer metastasis to the lung. These results therefore demonstrated that the anti-metastasis activity of palbociclib is mediated via the c-Jun/COX-2 signaling pathway by inhibiting EMT in breast cancer cells.

Origin, Methods, and Evolution of the Three Nurses' Health Studies

We have summarized the evolution of the Nurses' Health Study (NHS), a prospective cohort study of 121 700 married registered nurses launched in 1976; NHS II, which began in 1989 and enrolled 116 430 nurses; and NHS3, which began in 2010 and has ongoing enrollment. Over 40 years, these studies have generated long-term, multidimensional data, including lifestyle- and health-related information across the life course and an extensive repository of various biological specimens. We have described the questionnaire data collection, disease follow-up methods, biorepository resources, and data management and statistical procedures. Through integrative analyses, these studies have sustained a high level of scientific productivity and substantially influenced public health recommendations. We have highlighted recent interdisciplinary research projects and discussed future directions for collaboration and innovation.

Inflammatory networks underlying colorectal cancer

Inflammation is emerging as one of the hallmarks of cancer, yet its role in most tumors remains unclear. Whereas a minority of solid tumors are associated with overt inflammation, long-term treatment with non-steroidal anti-inflammatory drugs is remarkably effective in reducing cancer rate and death. This indicates that inflammation might have many as-yet-unrecognized facets, among which an indolent course might be far more prevalent than previously appreciated. In this Review, we explore the various inflammatory processes underlying the development and progression of colorectal cancer and discuss anti-inflammatory means for its prevention and treatment.

Breast cancer survival among young women: a review of the role of modifiable lifestyle factors

Almost 7 % of breast cancers are diagnosed among women age 40 years and younger in Western populations. Clinical outcomes among young women are worse. Early age-of-onset increases the risk of contralateral breast cancer, local and distant recurrence, and subsequent mortality. Breast cancers in young women (BCYW) are more likely to present with triple-negative (TNBC), TP53-positive, and HER-2 over-expressing tumors than among older women. However, despite these known differences in breast cancer outcomes and tumor subtypes, there is limited understanding of the basic biology, epidemiology, and optimal therapeutic strategies for BCYW. Several modifiable lifestyle factors associated with reduced risk of developing breast cancer have also been implicated in improved prognosis among breast cancer survivors of all ages. Given the treatment-related toxicities and the extended window for late effects, long-term lifestyle modifications potentially offer significant benefits to BCYW. In this review, we propose a model identifying three main areas of lifestyle factors (energy imbalance, inflammation, and dietary nutrient adequacy) that may influence survival in BCYW. In addition, we provide a summary of mechanisms of action and a synthesis of previous research on each of these topics.

Phytomedicine polypharmacology: Cancer therapy through modulating the tumor microenvironment and oxylipin dynamics

Integrative approaches in cancer therapy have recently been extended beyond the induction of cytotoxicity to controlling the tumor microenvironment and modulating inflammatory cascades and pathways such as lipid mediator biosynthesis and their dynamics. Profiling of important lipid messengers, such as oxylipins, produced as part of the physiological response to pharmacological stimuli, provides a unique opportunity to explore drug pharmacology and the possibilities for molecular management of cancer physiopathology. Whereas single targeted chemotherapeutic drugs commonly lack efficacy and invoke drug resistance and/or adverse effects in cancer patients, traditional herbal medicines are seen as bright prospects for treating complex diseases, such as cancers, in a systematic and holistic manner. Understanding the molecular mechanisms of traditional medicine and its bioactive chemical constituents may aid the modernization of herbal remedies and the discovery of novel phytoagents for cancer management. In this review, systems-based polypharmacology and studies to develop multi-target drugs or leads from phytomedicines and their derived natural products that may overcome the problems of current anti-cancer drugs, are proposed and summarized.

Aspirin and Colorectal Cancer Prevention and Treatment: Is It for Everyone?

There is now a considerable body of data supporting the hypothesis that aspirin could be effective in the prevention and treatment of colorectal cancer, and a number of phase III randomised controlled trials designed to evaluate the role of aspirin in the treatment of colorectal cancer are ongoing. Although generally well tolerated, aspirin can have adverse effects, including dyspepsia and, infrequently, bleeding. To ensure a favourable balance of benefits and risks from aspirin, a more personalised assessment of the advantages and disadvantages is required. Emerging data suggest that tumour PIK3CA mutation status, expression of cyclo-oxygenase-2 and human leukocyte antigen class I, along with certain germline polymorphisms, might all help to identify individuals who stand to gain most. We review both the underpinning evidence and current data, on clinical, molecular and genetic biomarkers for aspirin use in the prevention and treatment of colorectal cancer, and discuss the opportunities for further biomarker research provided by ongoing trials.

New Insights on COX-2 in Chronic Inflammation Driving Breast Cancer Growth and Metastasis

The medicinal use of aspirin stretches back to ancient times, before it was manufactured in its pure form in the late 19th century. Its accepted mechanistic target, cyclooxygenase (COX), was discovered in the 1970s and since this landmark discovery, the therapeutic application of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has increased dramatically. The most significant benefits of NSAIDs are in conditions involving chronic inflammation (CI). Given the recognized role of CI in cancer development, the use of long-term NSAID treatment in the prevention of cancer is an enticing possibility. COX-2 is a key driver of CI, and here we review COX-2 expression as a predictor of survival in various cancer types, including breast. Obesity and post-partum involution are natural inflammatory states that are associated with increased breast cancer risk. We outline the COX-2 mediated mechanisms contributing to the growth of cancers. We dissect the cellular mechanism of epithelial-mesenchymal transition (EMT) and how COX-2 may induce this to facilitate tumor progression. Finally we examine the potential regulation of COX-2 by c-Myb, and the possible interplay between c-Myb/COX-2 in proliferation, and hypoxia inducible factor-1 alpha (HIF1α)/COX-2 in invasive pathways in breast cancer.

Targeting the COX-2 Pathway to Improve Therapeutic Response in the Obese Breast Cancer Patient Population

Multiple studies have demonstrated that obesity is associated with a worse outcome for all breast cancer subtypes and that obese breast cancer patients do not respond as well as normal weight patients to aromatase inhibitor treatment and chemotherapy. While a number of mechanisms have been proposed to explain this link, recent studies have provided evidence that elevated local cyclooxygenase-2 (COX-2) expression and the resulting increase in prostaglandin E2 (PGE2) production may play an important role. COX-2 upregulation in breast tumors is associated with a poor prognosis, a connection generally attributed to PGE2's direct effects on apoptosis and invasion as well as its stimulation of pre-adipocyte aromatase expression and subsequent estrogen production. Research in this area has provided a strong foundation for the hypothesis that COX-2 signaling is involved in the obesity-breast cancer link, and further study regarding the role of COX-2 in this link is warranted.

Down-regulation of cyclooxygenase-2 (COX-2) by cannabidiolic acid in human breast cancer cells

Metastases are known to be responsible for approximately 90% of breast cancer-related deaths. Cyclooxygenase-2 (COX-2) is involved not only in inflammatory processes, but also in the metastasis of cancer cells; it is expressed in 40% of human invasive breast cancers. To comprehensively analyze the effects of cannabidiolic acid (CBDA), a selective COX-2 inhibitor found in the fiber-type cannabis plant (Takeda et al., 2008), on COX-2 expression and the genes involved in metastasis, we performed a DNA microarray analysis of human breast cancer MDA-MB-231 cells, which are invasive breast cancer cells that express high levels of COX-2, treated with CBDA for 48 hr at 25 µM. The results obtained revealed that COX-2 and Id-1, a positive regulator of breast cancer metastasis, were down-regulated (0.19-fold and 0.52-fold, respectively), while SHARP1 (or BHLHE41), a suppressor of breast cancer metastasis, was up-regulated (1.72-fold) and CHIP (or STUB1) was unaffected (1.03-fold). These changes were confirmed by real-time RT-PCR analyses. Taken together, the results obtained here demonstrated that i) CBDA had dual inhibitory effects on COX-2 through down-regulation and enzyme inhibition, and ii) CBDA may possess the ability to suppress genes that are positively involved in the metastasis of cancer cells in vitro.

Low expression of microRNA-143 is related to degenerative scoliosis possibly by regulation of cyclooxygenase-2 expression

AIMS

This study is to determine if expression level of microRNA-143 (miR-143) and cyclooxygenase-2 (COX-2) are related to the occurrence and development of degenerative scoliosis.

METHODS

A total of 30 patients with degenerative scoliosis, 30 patients with adolescent idiopathic scoliosis were enrolled in this study. For control, 30 patients with spinal burst fractures were also enrolled in this study. Real-time PCR and western blotting was performed to measure the expression levels of COX-2 in intervertebral disc tissues, peripheral blood and cerebrospinal. Expression levels of miR-143 in intervertebral disc tissues, peripheral blood and cerebrospinal were detected by real-time PCR.

RESULTS

The expression levels of COX-2 were increased in intervertebral disc tissues, peripheral blood and cerebrospinal of patients with degenerative scoliosis when compared with those of patients with adolescent idiopathic scoliosis and spinal burst fractures (P < 0.05). However, the expression levels of miR-143 were decreased in intervertebral disc tissues, peripheral blood and cerebrospinal of patients with degenerative scoliosis when compared with those of patients with adolescent idiopathic scoliosis and spinal burst fractures (P < 0.05).

CONCLUSIONS

COX-2 is highly expressed whereas miR-143 is lowly expressed in patients with degenerative scoliosis. Decreased expression of miR-143 may be related to the aggravation of degenerative scoliosis by regulation of COX-2.

Association between aspirin use and mortality in breast cancer patients: a meta-analysis of observational studies

Previous studies have examined the effect of aspirin intake on the mortality in breast cancer, but the results are inconsistent. A meta-analysis was performed to assess the association with all available studies. Relevant studies were identified by searching PubMed and EMBASE to November 2014. We calculated the summary relative risks (RRs) and 95 % confidence intervals (CIs) using random-effects models. For this meta-analysis, eight cohort studies and two nested case-control studies were included. The analysis included 26,931 participants for postdiagnosis aspirin use and 673,453 participants for prediagnosis aspirin use, followed up over a period of between 2.6 and 30 years. The results showed that patients who used aspirin after diagnosis had a RR of 0.73 (95 % CI = 0.54-0.98, P = 0.04) for breast cancer-specific mortality compared to those who did not use aspirin. Those who used aspirin after diagnosis (vs. non-users) had a RR of 0.84 (95 % CI = 0.63-1.12, P = 0.24) for all-cause mortality. Prediagnostic exposure to aspirin was associated with neither breast cancer-specific mortality (RR = 1.04, 95 % CI = 0.75-1.45, P = 0.80) nor all-cause mortality (RR = 1.04, 95 % CI = 0.61-1.78, P = 0.89). Significant heterogeneity among included studies may be due to a single study, after removing which the significant association between postdiagnosis aspirin use and breast cancer-specific mortality disappeared; however, prediagnosis aspirin use achieved a borderline significant association with risk of all-cause mortality (RR = 0.81, 95 % CI = 0.68-0.97, P = 0.03). In conclusion, aspirin use might has, if any, only a small effect on the survival of breast cancer patients based on current evidence.

Statins, aspirin and risk of venous thromboembolic events in breast cancer patients

Venous thromboembolic events (VTE's) are associated with decreased survival in breast cancer patients. Studies suggested that statins reduce the risk of VTE's in the general population. Low dose Aspirin reduces risk of VTE's in high risk populations. The Breast Cancer in Northern Israel Study is a case-control study of consecutive breast cancer cases diagnosed in northern Israel and matched controls. The present analysis was limited to cases with breast cancer enrolled in the study. Data was extracted from Clalit Health Services (CHS) database and from computerized pharmacy records. Out of 3,585 patients enrolled, 261 (7.3%) had a VTE during median follow up of 4.2 years. The 1 and 2 year cumulative incidence was 2.64 and 3.65%. 55.7% of patients used statins, predominantly simvastatin (75.8%). 44.5% used aspirin. In multivariate analysis neither statins nor aspirin use was associated with a reduced risk for a VTE. Unadjusted HR for statin and aspirin was 1.461 (1.018-2.096) and 1.293 (0.846-1.976), respectively, and the adjusted HR were 0.86 (0.648-1.14) and 1.013 (0.737-1.392). Results were similar when only simvastatin use was assessed. Metastatic disease, chemotherapy, age, BMI and presence of comorbidities were significantly associated with risk of VTE's. Our study is the first to look at the effect of statins and aspirin on the incidence of VTE's in patients with breast cancer. In our cohort, statin and aspirin use did not decrease the risk for a VTE. Our results might be explained by use of low potency statins (simvastatin and pravastatin) and by alternate mechanisms for VTE formation in patients with cancer.

Recent prediagnostic aspirin use, lymph node involvement, and 5-year mortality in women with stage I-III breast cancer: a nationwide population-based cohort study

Lymph node-positive breast tumors are more likely to express COX2 than node-negative tumors. In preclinical studies, COX2 inhibition prevents breast tumor spread to lymph nodes. Therefore, we examined the association between recent (1 year) prediagnostic use of aspirin (COX1/COX2 inhibitor), lymph node involvement at breast cancer diagnosis, and breast cancer-specific mortality. Women with stage I-III breast cancer diagnosed from 2001 to 2006 (N = 2,796) were identified from Ireland's National Cancer Registry. These data were linked to prescription refill and mammographic screening databases. Relative risks (RR) were estimated for associations between prediagnostic aspirin use and lymph node-positive status at diagnosis. HRs were estimated for associations between pre- and postdiagnostic aspirin use and 5-year mortality, stratified by lymph node status. Women with prediagnostic aspirin use were statistically significantly less likely to present with a lymph node-positive tumor than nonusers [RR = 0.89; 95% confidence interval (CI), 0.81-0.97], particularly those with larger (Pinteraction = 0.036), progesterone receptor (PR)-negative (Pinteraction < 0.001) or estrogen receptor (ER)-negative (Pinteraction = 0.056) tumors. The magnitude of this association increased with dose (Ptrend < 0.01) and dosing intensity (Ptrend < 0.001) and was similar in women with or without screen-detected tumors (Pinteraction = 0.70). Prediagnostic aspirin use was associated with lower 5-year breast cancer-specific mortality among women with lymph node-negative tumors (HR, 0.55; 95% CI, 0.33-0.92) but not node-positive tumors (HR, 0.91; 95% CI, 0.37-1.22). Tests for effect-modification were, however, not statistically significant (Pinteraction = 0.087). Postdiagnostic aspirin use was not associated with breast cancer-specific mortality (HR, 0.99; 95% CI, 0.68-1.45). Our findings indicate that recent prediagnostic aspirin use is protective against lymph node-positive breast cancer. This is a plausible explanation for reductions in breast cancer mortality reported in observational studies of aspirin use.

Prognostic influence of cyclooxygenase-2 protein and mRNA expression in node-negative breast cancer patients

Background

Cyclooxygenases (COX) play a key role in prostaglandin metabolism and are important for tumor development and progression. The aim of this study was to analyze the prognostic impact of COX-2 expression in a cohort of lymph node-negative breast cancer patients not treated in the adjuvant setting.

Methods

COX-2 expression was determined by immunohistochemistry (IHC) in tumor tissue of 193 node-negative breast cancer patients. Additionally, mRNA expression was determined in corresponding tumor samples using microarray based gene-expression data. Univariate and multivariate Cox regression analyses adjusted for age at diagnosis, tumor size, histological grade, human epithelial growth factor receptor 2 (HER2), estrogen receptor (ER) and progesterone receptor (PR) were performed to evaluate the association of both COX-2 protein and mRNA expression with survival. Survival rates were determined by the Kaplan-Meier method. Correlations between COX-2 expression and established prognostic factors were analyzed using the Chi-square test. A potential correlation between COX-2 protein expression and COX-2 mRNA expression was assessed utilizing the Kruscal-Wallis-H-test.

Results

COX-2 protein expression was positive in 24.9% of the breast cancer samples. Univariate analysis showed that COX-2 protein expression was associated with shorter disease-free survival (DFS) (P = 0.0001), metastasis-free survival (MFS) (P = 0.002) as well as breast cancer specific overall survival (OS) (P = 0.043). In multivariate analysis COX-2 expression retained its significance independent of established prognostic factors for shorter DFS (P < 0.001, HR = 2.767, 95% CI = 1.563-4.901) and for inferior MFS (P = 0.002, HR = 2.7, 95% CI = 1.469-5.263) but not for OS (P = 0.096, HR = 1.929, 95% CI = 0.889-4.187). In contrast, COX-2 mRNA expression was not related to survival and failed to show a correlation with protein expression (P = 0.410).

Conclusions

The present findings support the hypothesis that COX-2 protein but not mRNA expression is associated with an unfavorable outcome in node-negative breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-952) contains supplementary material, which is available to authorized users.

Hypoxia promotes 786-O cells invasiveness and resistance to sorafenib via HIF-2α/COX-2

Accumulating evidences indicated that hypoxia-induced factors and COX-2 play a important role in tumorigenesis in various human cancer. Yet, the relationship between HIFs and COX-2 in human renal cancer remains unclear. The present study was to examine the role of HIFs and COX-2 in the invasiveness and the resistance to target agent in renal cancer cell line (786-O). In 786-O cells, hypoxia induced the increase in the protein expression of HIF1 and HIF2. We also demonstrate that hypoxia up-regulated the protein expression of COX-2 and Snail, but down-regulation of E-cadherin expression in 786-O cells promoted the invasiveness of 786-O cells and enhanced the resistance of 786-O cells to sorafenib. siRNA target to HIF1α, HIF2α and NS398, a selective inhibitor of COX-2, were used in this study. Only siRNA-HIF2α significantly suppressed the protein expression of HIF2 and COX-2, then decreased the invasive ability and resistance of 786-O cells to sorafenib under hypoxia. NS398 attenuated the increase in invasive cells number and the IC50 value of sorafenib induced by hypoxia. In conclusion, our results demonstrated that hypoxia promoted the invasiveness and resistance of 786-O cells to sorafenib via HIF2 and COX-2 and induced the activation of Snail/E-cadherin, suggesting that a signalling mechanism involving HIF2/COX2 modulates invasiveness and resistance to sorafenib in 786-O cells under hypoxia.