Mechanisms underlying aspirin-mediated growth inhibition and apoptosis induction of cyclooxygenase-2 negative colon cancer cell line SW480

Aspirin reprogrammes colorectal cancer cell metabolism and sensitises to glutaminase inhibition

BACKGROUND

To support proliferation and survival within a challenging microenvironment, cancer cells must reprogramme their metabolism. As such, targeting cancer cell metabolism is a promising therapeutic avenue. However, identifying tractable nodes of metabolic vulnerability in cancer cells is challenging due to their metabolic plasticity. Identification of effective treatment combinations to counter this is an active area of research. Aspirin has a well-established role in cancer prevention, particularly in colorectal cancer (CRC), although the mechanisms are not fully understood.

METHODS

We generated a model to investigate the impact of long-term (52 weeks) aspirin exposure on CRC cells, which has allowed us comprehensively characterise the metabolic impact of long-term aspirin exposure (2-4mM for 52 weeks) using proteomics, Seahorse Extracellular Flux Analysis and Stable Isotope Labelling (SIL). Using this information, we were able to identify nodes of metabolic vulnerability for further targeting, investigating the impact of combining aspirin with metabolic inhibitors in vitro and in vivo.

RESULTS

We show that aspirin regulates several enzymes and transporters of central carbon metabolism and results in a reduction in glutaminolysis and a concomitant increase in glucose metabolism, demonstrating reprogramming of nutrient utilisation. We show that aspirin causes likely compensatory changes that render the cells sensitive to the glutaminase 1 (GLS1) inhibitor-CB-839. Of note given the clinical interest, treatment with CB-839 alone had little effect on CRC cell growth or survival. However, in combination with aspirin, CB-839 inhibited CRC cell proliferation and induced apoptosis in vitro and, importantly, reduced crypt proliferation in Apcfl/fl mice in vivo.

CONCLUSIONS

Together, these results show that aspirin leads to significant metabolic reprogramming in colorectal cancer cells and raises the possibility that aspirin could significantly increase the efficacy of metabolic cancer therapies in CRC.

Genomic and epigenomic responses to aspirin in human colonic organoids

Aspirin (ASA) is a proven chemoprotective agent for colorectal cancer, though mechanisms underlying these effects are incompletely understood. Human organoids are an ideal system to study genomic and epigenomic host-environment interactions. We use human colonic organoids to profile ASA responses on genome-wide gene expression and chromatin accessibility. Human colonic organoids from one individual were cultured and treated in triplicate with 3 mM ASA or vehicle control (DMSO) for 24 h. Gene expression and chromatin accessibility were measured using RNA- and ATAC-sequencing, respectively. Differentially expressed genes were analyzed using DESeq2. Top genes were validated by qPCR. Gene set enrichment was performed by SetRank. Differentially accessible peaks were analyzed using DiffBind and edgeR. Peak annotation and differential transcription factor motifs were determined by HOMER and diffTF. The results showed robust transcriptional responses to ASA with significant enrichment for fatty acid oxidation and peroxisome proliferator-activated receptor (PPAR) signaling that were validated in independent organoid lines. A large number of differentially accessible chromatin regions were found in response to ASA with significant enrichment for Fos, Jun, and Hnf transcription factor motifs. Integrated analysis of epigenomic and genomic treatment responses highlighted gene regions that could mediate ASA's specific effects in the colon including those involved in chemoprotection and/or toxicity. Assessment of chromatin accessibility and transcriptional responses to ASA yielded new observations about genome-wide effects in the colon facilitated by application of human colonic organoids. This framework can be applied to study colonic ASA responses between individuals and populations in future studies.

Ethanol Extract of Pomegranate (Punica granatum) Peel in Increasing the Expression of Caspase-3 in DSS-Induced Mice

Background

Colorectal cancer (CRC) is a malignancy derived from the glandular epithelial cells in the colon. Patients with inflammatory bowel disease (IBD) are more likely to develop CRC. Cancer proliferation is characterized by the loss of inhibition of apoptosis, which involves caspase-3 activation. This study examined the effects of the pomegranate peel extract on the expression of caspase-3 in mice crypt cells induced by dextran sodium sulfate (DSS) 2%.

Methods

The experimental study was done in six groups. All treatments were done in 42 days. The groups were all induced by DSS through water drinking, except for the normal group, which was only given water. The treatments given included the pomegranate extract in two doses (240 mg and 480 mg/kg bw/day), aspirin, and ellagic acid. The specimens were then fixated and stained for the immunohistochemistry scoring for the expression of caspase-3, which was then analyzed statistically.

Results

The H-scores of each treatment group were 213.23 ± 8.32 (DSS group), 243.81 ± 18.69 (normal group), 226.10 ± 12.38 (pomegranate peel extract of 240 mg/kg/d), 238.84 ± 15.81 (pomegranate peel extract of 480 mg/kg/d), 227.47 ± 12.15 (aspirin), and 224.01 ± 18.39 (ellagic acid). Statistical differences were found in one-way analysis of variance (ANOVA) and post hoc analysis among the DSS group, normal group, and dose 2 group (pomegranate peel extract of 480 mg/kg/day).

Conclusions

The ethanol extract of pomegranate was able to induce apoptosis, which was demonstrated by the increase of caspase-3 expression.

Current Studies of Aspirin as an Anticancer Agent and Strategies to Strengthen its Therapeutic Application in Cancer

Aspirin has emerged as a promising intervention in cancer in the past decade. However, there are existing controversies regarding the anticancer properties of aspirin as its mechanism of action has not been clearly defined. In addition, the risk of bleeding in the gastrointestinal tract from aspirin is another consideration that requires medical and pharmaceutical scientists to work together to develop more potent and safe aspirin therapy in cancer. This review presents the most recent studies of aspirin with regard to its role in cancer prevention and treatment demonstrated by highlighted clinical trials, mechanisms of action as well as approaches to develop aspirin therapy best beneficial to cancer patients. Hence, this review provides readers with an overview of aspirin research in cancer that covers not only the unique features of aspirin, which differentiate aspirin from other non-steroidal anti-inflammatory drugs (NSAIDs), but also strategies that can be used in the development of drug delivery systems carrying aspirin for cancer management. These studies convey optimistic messages on the continuing efforts of the scientist on the way of developing an effective therapy for patients with a low response to current cancer treatments.

Antagonism between salicylate and the cAMP signal controls yeast cell survival and growth recovery from quiescence

Aspirin and its main metabolite salicylate are promising molecules in preventing cancer and metabolic diseases. S. cerevisiae cells have been used to study some of their effects: (i) salicylate induces the reversible inhibition of both glucose transport and the biosyntheses of glucose-derived sugar phosphates, (ii) Aspirin/salicylate causes apoptosis associated with superoxide radical accumulation or early cell necrosis in MnSOD-deficient cells growing in ethanol or in glucose, respectively. So, treatment with (acetyl)-salicylic acid can alter the yeast metabolism and is associated with cell death. We describe here the dramatic effects of salicylate on cellular control of the exit from a quiescence state. The growth recovery of long-term stationary phase cells was strongly inhibited in the presence of salicylate, to a degree proportional to the drug concentration. At high salicylate concentration, growth reactivation was completely repressed and associated with a dramatic loss of cell viability. Strikingly, both of these phenotypes were fully suppressed by increasing the cAMP signal without any variation of the exponential growth rate. Upon nutrient exhaustion, salicylate induced a premature lethal cell cycle arrest in the budded-G2/M phase that cannot be suppressed by PKA activation. We discuss how the dramatic antagonism between cAMP and salicylate could be conserved and impinge common targets in yeast and humans. Targeting quiescence of cancer cells with stem-like properties and their growth recovery from dormancy are major challenges in cancer therapy. If mechanisms underlying cAMP-salicylate antagonism will be defined in our model, this might have significant therapeutic implications.

TGF-β1 mediates the effects of aspirin on colonic tumor cell proliferation and apoptosis

Previous studies have demonstrated that aspirin serves an important role in chemoprevention and the suppression of colorectal cancer (CRC); however, the underlying mechanisms for this inhibition by aspirin remain unclear. Aspirin is capable of promoting apoptosis through prostaglandin-dependent orprostaglandin-independent signaling pathways. In the prostaglandin-dependent pathways, inhibition of cyclooxygenase (COX), particularly COX-2, is the primary mechanism known to be involved in aspirin-induced CRC suppression. Previous studies have implicated prostaglandin-independent signaling pathways and certain associated proteins, including SOX7, in aspirin-induced CRC suppression. In the present study, a newly-characterized association between aspirin, transforming growth factor (TGF)-β1 and CRC inhibition was identified. Specifically, aspirin triggers CRC cell apoptosis by inducing the secretion of TGF-β1, and the increased TGF-β1 then leads to apoptosis and proliferation inhibition in CRC cells.

Aspirin therapy reduces the ability of platelets to promote colon and pancreatic cancer cell proliferation: Implications for the oncoprotein c-MYC

Aspirin, an anti-inflammatory and antithrombotic drug, has become the focus of intense research as a potential anticancer agent owing to its ability to reduce tumor proliferation in vitro and to prevent tumorigenesis in patients. Studies have found an anticancer effect of aspirin when used in low, antiplatelet doses. However, the mechanisms through which low-dose aspirin works are poorly understood. In this study, we aimed to determine the effect of aspirin on the cross talk between platelets and cancer cells. For our study, we used two colon cancer cell lines isolated from the same donor but characterized by different metastatic potential, SW480 (nonmetastatic) and SW620 (metastatic) cancer cells, and a pancreatic cancer cell line, PANC-1 (nonmetastatic). We found that SW480 and PANC-1 cancer cell proliferation was potentiated by human platelets in a manner dependent on the upregulation and activation of the oncoprotein c-MYC. The ability of platelets to upregulate c-MYC and cancer cell proliferation was reversed by an antiplatelet concentration of aspirin. In conclusion, we show for the first time that inhibition of platelets by aspirin can affect their ability to induce cancer cell proliferation through the modulation of the c-MYC oncoprotein.

Design, synthesis and biological evaluation of hybrids of β-carboline and salicylic acid as potential anticancer and apoptosis inducing agents

A novel series of hybrids (7a-l, 8a-l) from β-carboline and salicylic acid (SA) were designed and synthesized, and their in vitro biological activities were evaluated. Most of the hybrids displayed potent antiproliferative activity against five cancer cell lines in vitro, showing potencies superior to 5-FU and harmine. In particular, compound 8h selectively inhibited proliferation of liver cancer SMMC-7721 cells but not normal liver LO2 cells, and displayed greater inhibitory selectivity than intermediate 5h and SA. 8h also induced cancer cell apoptosis in an Annexin V-FITC/propidium iodide flow cytometry assay, and triggered the mitochondrial/caspase apoptosis by decreasing mitochondrial membrane potential which was associated with up-regulation of Bax, down-regulation of Bcl-2 and activation levels of the caspase cascade in a concentration-dependent manner. Our findings suggest that the β-carboline/SA hybrids may hold greater promise as therapeutic agents for the intervention of human cancers.

SOX7 is involved in aspirin-mediated growth inhibition of human colorectal cancer cells

AIM: To confirm the role of sex-determining region Y-box 7 (Sox7) in aspirin-mediated growth inhibition of COX-independent human colorectal cancer cells.

METHODS: The cell survival percentage was examined by MTT (Moto-nuclear cell direc cytotoxicity) assay. SOX7 expression was assessed by using reverse transcription-polymerase chain reaction and Western blotting. SB203580 was used to inhibit the p38MAPK signal pathway. SOX7 promoter activity was detected by Luciferase reporter assay.

RESULTS: SOX7 was upregulated by aspirin and was involved in aspirin-mediated growth inhibition of SW480 human colorectal cancer cells. The p38MAPK pathway played a role in aspirin-induced SOX7 expression, during which the AP1 transcription factors c-Jun and c-Fos upregulated SOX7 promoter activities.

RESULTS: SOX7 is upregulated by aspirin and is involved in aspirin-mediated growth inhibition of human colorectal cancer SW480 cells.

Inflammation and colorectal cancer: does aspirin affect the interaction between cancer and immune cells?

The effect of aspirin on colon-cancer-cell-induced cytokine secretion by peripheral blood mononuclear cells (PBMC) was examined. Aspirin was added to human colon cancer cells (HT-29 and RKO) or to PBMC incubated separately or jointly. The secretion of IFNγ, IL-6, and IL-10 induced by HT-29 cells was decreased, that of IL-1β was slightly increased, whereas IL-1ra production was not affected. With RKO cells, aspirin reduced IL-6, IL-1ra, and IL-10 synthesis and enhanced IFNγ secretion, while IL-1β remained unchanged. Conditioned media from colon cancer cells incubated without or with aspirin stimulated cytokine productions by PBMC similarly, suggesting that aspirin acts on the cell-to-cell interaction between cancer cells and PBMC. The results indicate that aspirin alter the balance between pro- and anti-inflammatory cytokines generated by interaction between colon cancer and immune cells disclosing an additional role of the drug in affecting inflammation-induced colon cancer.

Inflammation and colorectal cancer: does aspirin affect the interaction between cancer and immune cells?

The effect of aspirin on colon-cancer-cell-induced cytokine secretion by peripheral blood mononuclear cells (PBMC) was examined. Aspirin was added to human colon cancer cells (HT-29 and RKO) or to PBMC incubated separately or jointly. The secretion of IFNγ, IL-6, and IL-10 induced by HT-29 cells was decreased, that of IL-1β was slightly increased, whereas IL-1ra production was not affected. With RKO cells, aspirin reduced IL-6, IL-1ra, and IL-10 synthesis and enhanced IFNγ secretion, while IL-1β remained unchanged. Conditioned media from colon cancer cells incubated without or with aspirin stimulated cytokine productions by PBMC similarly, suggesting that aspirin acts on the cell-to-cell interaction between cancer cells and PBMC. The results indicate that aspirin alter the balance between pro- and anti-inflammatory cytokines generated by interaction between colon cancer and immune cells disclosing an additional role of the drug in affecting inflammation-induced colon cancer.

NSAIDs, Mitochondria and Calcium Signaling: Special Focus on Aspirin/Salicylates

Aspirin (acetylsalicylic acid) is a well-known nonsteroidal anti-inflammatory drug (NSAID) that has long been used as an anti-pyretic and analgesic drug. Recently, much attention has been paid to the chemopreventive and apoptosis-inducing effects of NSAIDs in cancer cells. These effects have been thought to be primarily attributed to the inhibition of cyclooxygenase activity and prostaglandin synthesis. However, recent studies have demonstrated unequivocally that certain NSAIDs, including aspirin and its metabolite salicylic acid, exert their anti-inflammatory and chemopreventive effects independently of cyclooxygenase activity and prostaglandin synthesis inhibition. It is becoming increasingly evident that two potential common targets of NSAIDs are mitochondria and the Ca²⁺ signaling pathway. In this review, we provide an overview of the current knowledge regarding the roles of mitochondria and Ca²⁺ in the apoptosis-inducing effects as well as some side effects of aspirin, salicylates and other NSAIDs, and introducing the emerging role of L-type Ca²⁺ channels, a new Ca²⁺ entry pathway in non-excitable cells that is up-regulated in human cancer cells.

NSAIDs and the colon

PURPOSE OF REVIEW

To better understand the effects of NSAIDs on the colon.

RECENT FINDINGS

An epidemiological study has confirmed that NSAIDs increase the risk of hospitalizations for lower gastrointestinal complications, though the estimated rate of hospitalization was lower than that for upper gastrointestinal complications. Proton-pump inhibitors were associated with reduction in hospitalizations for upper but not lower gastrointestinal complications. Current research on cyclooxygenase (COX) inhibition in patient and animal models suggests that COX-1 and COX-2 may have different roles in the exacerbation of inflammatory bowel disease. Epidemiological research on the chemoprevention of colorectal cancer with aspirin suggests that the positive effect of risk reduction is only observed after long-term treatment. The search for targets of chemopreventive drugs is ongoing. COX-2 inhibition still seems preferred option, as the effects observed with aspirin (the only chemopreventive agent with some apparent future) are more profound only in tumors and cells expressing COX-2. Other molecules such as nitric oxide NSAIDs, especially nitric oxide aspirin, are under intensive experimental research.

SUMMARY

NSAID use increases the risk of hospitalizations due to complications in the lower gastrointestinal tract. By inhibiting COX-2 or other tumorigenic targets, NSAIDs, especially aspirin or new aspirin derivates, may prevent colon cancer in selected populations.

As2O3 and Aspirin induce apoptosis of human gastric cancer cells SGC-7901

AIM: To investigate the effect of As₂O₃ and Aspirin on apoptosis of human gastric carcinoma cells SGC-7901 and to explore its possible mechanism.

METHODS: SGC-7901 cells were incubated in different concentrations of drugs, and then were divided into six groups: control group, Aspirin (2 mmol/L) group, Aspirin (1 mmol/L) group, As₂O₃ (4 μmol/L) group, As₂O₃ (2 μmol/L) group, and As₂O₃ (2 μmol/L) + Aspirin (1 mmol/L) group. 72 hours after the treatment, apoptosis rates in each group were analyzed using flow cytometry. The expressions of Bcl-2 and Bax protein were measured by immunocytochemistry assay.

RESULTS: Flow cytometry analysis revealed statistically significant difference between 2 μmol/L As₂O₃ + 1 mmol/L Aspirin group and control group, 1 mmol/L Aspirin group, 2 μmol/L As₂O₃ group (P < 0.05), while there was no statistically significant difference between 2 μmol/L As₂O₃ + 1 mmol/L Aspirin group and 4 μmol/L As₂O₃ group, 2 mmol/L Aspirin group. Immunocytochemistry showed that there was down-regulated expression of Bcl-2 protein and up-regulated expression of Bax protein in 2 μmol/L As₂O₃ + 1 mmol/L Aspirin group. Statistically significant difference was observed between 2 μmol/L As₂O₃+ 1 mmol/L Aspirin group and control group, 1 mmol/L Aspirin group, 2 μmol/L As₂O₃ group (50.21% ± 5.94% vs 91.65% ± 11.51%, 88.66% ± 10.53%, 89.27% ± 9.84%; 40.72% ± 9.54% vs 21.03% ± 4.32%, 23.07% ± 6.23%, 22.67% ± 3.16%, allP < 0.05).

CONCLUSION: As₂O₃ and Aspirin induce apoptosis of gastric cancer cells SGC-7901 possibly through suppressing Bcl-2 protein or enhancing Bax protein. Combination of As₂O₃ and Aspirin produces obvious synergistic effect.