COX-Independent Mechanisms of Cancer Chemoprevention by Anti-Inflammatory Drugs

Roles of prostaglandins in immunosuppression

Prostaglandins (PGs) play a crucial and multifaceted role in various physiological processes such as intercellular signaling, inflammation regulation, neurotransmission, vasodilation, vasoconstriction, and reproductive functions. The diversity and biological significance of these effects are contingent upon the specific types or subtypes of PGs, with each PG playing a crucial role in distinct physiological and pathological processes. Particularly within the immune system, PGs are essential in modulating the function of immune cells and the magnitude and orientation of immune responses. Hence, a comprehensive comprehension of the functions PG signaling pathways in immunosuppressive regulation holds substantial clinical relevance for disease prevention and treatment strategies. The manuscript provides a review of recent developments in PG signaling in immunosuppressive regulation. Furthermore, the potential clinical applications of PGs in immunosuppression are also discussed. While research into the immunosuppressive effects of PGs required further exploration, targeted therapies against their immunosuppressive pathways might open new avenues for disease prevention and treatment.

Celecoxib and sulindac sulfide elicit anticancer effects on PIK3CA-mutated head and neck cancer cells through endoplasmic reticulum stress, reactive oxygen species, and mitochondrial dysfunction

Gain-of-function mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) catalytic subunit alpha gene (PIK3CA) is a significant factor in head and neck cancer (HNC). Patients with HNC harboring PIK3CA mutations receive therapeutic benefits from the use of non-steroidal anti-inflammatory drugs (NSAIDs). However, the molecular mechanisms underlying these effects remain unknown. Here, we examined the Detroit562 and FaDu cell lines as HNC models with and without a hyperactive PIK3CA mutation (H1047R), respectively, regarding their possible distinct responses to the NSAIDs celecoxib and sulindac sulfide (SUS). Detroit562 cells exhibited relatively high PI3K/Akt pathway-dependent cyclooxygenase-2 (COX-2) expression, associated with cell proliferation. Celecoxib treatment restricted cell proliferation and upregulated endoplasmic reticulum (ER) stress-related markers, including GRP78, C/EBP-homologous protein, activating transcription factor 4, death receptor 5, and reactive oxygen species (ROS). These effects were much stronger in Detroit562 cells than in FaDu cells and were largely COX-2-independent. SUS treatment yielded similar results. Salubrinal (an ER stress inhibitor) and N-acetyl-L-cysteine (a ROS scavenger) prevented NSAID-induced ROS generation and ER stress, respectively, indicating crosstalk between ER and oxidative stress. In addition, celecoxib and/or SUS elevated cleaved caspase-3 levels, Bcl-2-associated X protein/Bcl-2-interacting mediator of cell death expression, and mitochondrial damage, which was more pronounced in Detroit562 than in FaDu cells. Salubrinal and N-acetyl-L-cysteine attenuated celecoxib-induced mitochondrial dysfunction. Collectively, our results suggest that celecoxib and SUS efficiently suppress activating PIK3CA mutation-harboring HNC progression by inducing ER and oxidative stress and mitochondrial dysfunction, leading to apoptotic cell death, further supporting NSAID treatment as a useful strategy for oncogenic PIK3CA-mutated HNC therapy.

Synthesis, characterization, molecular modeling studies, and biological evaluation of metal piroxicam complexes (M = Ni(II), Pt(IV), Pd(II), Ag(I)) as antibacterial and anticancer agents

Four piroxicam metal complexes; NiL2 , PtL2 , PdL2 , and AgL were synthesized and characterized by different techniques with enhanced antibacterial and anticancer activity. Regarding in vitro antimicrobial activity, complex NiL2 displayed potent antibacterial effect against Escherichia coli and Pseudomonas aeruginosa that was 1.9-folds higher than piroxicam (minimum inhibitory concentration [MIC] = 31.85, 65.32 µM), respectively. In case of G+ve bacteria, complex PtL2 had potent activity on Staphylococcus aureus which was 2.1-folds higher than piroxicam (MIC = 43.12 µM), while activity of complex AgL against Enterococcus faecalis was threefolds higher than piroxicam (MIC = 74.57 µM. Complexes PtL2 and PdL2 exhibited higher inhibition of DNA gyrase than piroxicam (IC50  = 6.21 µM) in the range of 1.9-1.7-folds. The in vitro antiproliferative activity depicted that all investigated complexes showed better cytotoxic effect than piroxicam, specifically Pt and Pd complexes which had lower IC50 values than piroxicam on human liver cancer cell line HepG2 by 1.8 and 1.7-folds, respectively. While Pd and Ag complexes showed 2 and 1.6-folds better effect on human colon cancer cell line HT-29 compared with piroxicam. Molecular modeling studies including docking on Stranded DNA Duplex (1juu) and DNA gyrase enzyme (1kzn) that gave good insight about interaction of complexes with target molecules, calculation of electrostatic potential map and global reactivity descriptors were performed.

The Protective Effect of Sanggenol L Against DMBA-induced Hamster Buccal Pouch Carcinogenesis Induces Apoptosis and Inhibits Cell Proliferative Signalling Pathway

BACKGROUND

Oral squamous cell carcinoma (OSCC) has a poor prognosis when treated with surgery and chemotherapy. Therefore, a new therapy and preventative strategy for OSCC and its underlying mechanisms are desperately needed. The purpose of this study was to examine the chemopreventive effects of sanggenol L on oral squamous cell carcinoma (OSCC). The research focused on molecular signalling pathways in 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.

AIM

The purpose of this study was to look at the biochemical and chemopreventive effects of sanggenol L on 7,12-dimethylbenz(a)anthracene (DMBA)-induced HBP (hamster buccal pouch) carcinogenesis via cell proliferation and the apoptotic pathway.

METHODS

After developing squamous cell carcinoma, oral tumours continued to progress leftward into the pouch 3 times per week for 10 weeks while being exposed to 0.5 % reactive DMBA three times per week. Tumour growth was caused by biochemical abnormalities that induced inflammation, increased cell proliferation, and decreased apoptosis.

RESULTS

Oral sanggenol L (10 mg/kg bw) supplementation with cancer-induced model DMBApainted hamsters prevented tumour occurrences, improved biochemistry, inhibited inflammatory markers, decreased cell proliferation marker expression of tumour necrosis factor-alpha (TNF- α), nuclear factor (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and induced apoptosis.

CONCLUSION

Sanggenol L could be developed into a new medicine for the treatment of oral carcinogenesis.

Targeted degrader technologies as prospective SARS-CoV-2 therapies

COVID-19 remains a severe public health threat despite the WHO declaring an end to the public health emergency in May 2023. Continual development of SARS-CoV-2 variants with resistance to vaccine-induced or natural immunity necessitates constant vigilance as well as new vaccines and therapeutics. Targeted protein degradation (TPD) remains relatively untapped in antiviral drug discovery and holds the promise of attenuating viral resistance development. From a unique structural design perspective, this review covers antiviral degrader merits and challenges by highlighting key coronavirus protein targets and their co-crystal structures, specifically illustrating how TPD strategies can refine existing SARS-CoV-2 3CL protease inhibitors to potentially produce superior protease-degrading agents.

Sulindac sulfide as a non-immune suppressive γ-secretase modulator to target triple-negative breast cancer

Introduction

Triple-negative breast cancer (TNBC) comprises a heterogeneous group of clinically aggressive tumors with high risk of recurrence and metastasis. Current pharmacological treatment options remain largely limited to chemotherapy. Despite promising results, the efficacy of immunotherapy and chemo-immunotherapy in TNBC remains limited. There is strong evidence supporting the involvement of Notch signaling in TNBC progression. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Notch inhibitors, including g-secretase inhibitors (GSIs), are quite effective in preclinical models of TNBC. However, the success of GSIs in clinical trials has been limited by their intestinal toxicity and potential for adverse immunological effects, since Notch plays key roles in T-cell activation, including CD8 T-cells in tumors. Our overarching goal is to replace GSIs with agents that lack their systemic toxicity and ideally, do not affect tumor immunity. We identified sulindac sulfide (SS), the active metabolite of FDA-approved NSAID sulindac, as a potential candidate to replace GSIs.

Methods

We investigated the pharmacological and immunotherapeutic properties of SS in TNBC models in vitro, ex-vivo and in vivo.

Results

We confirmed that SS, a known γ-secretase modulator (GSM), inhibits Notch1 cleavage in TNBC cells. SS significantly inhibited mammosphere growth in all human and murine TNBC models tested. In a transplantable mouse TNBC tumor model (C0321), SS had remarkable single-agent anti-tumor activity and eliminated Notch1 protein expression in tumors. Importantly, SS did not inhibit Notch cleavage in T- cells, and the anti-tumor effects of SS were significantly enhanced when combined with a-PD1 immunotherapy in our TNBC organoids and in vivo.

Discussion

Our data support further investigation of SS for the treatment of TNBC, in conjunction with chemo- or -chemo-immunotherapy. Repurposing an FDA-approved, safe agent for the treatment of TNBC may be a cost-effective, rapidly deployable therapeutic option for a patient population in need of more effective therapies.

Honokiol, an inducer of sirtuin-3, protects against non-steroidal anti-inflammatory drug-induced gastric mucosal mitochondrial pathology, apoptosis and inflammatory tissue injury

BACKGROUND AND PURPOSE

Mitochondrial oxidative stress, inflammation and apoptosis primarily underlie gastric mucosal injury caused by the widely used non-steroidal anti-inflammatory drugs (NSAIDs). Alternative gastroprotective strategies are therefore needed. Sirtuin-3 pivotally maintains mitochondrial structural integrity and metabolism while preventing oxidative stress; however, its relevance to gastric injury was never explored. Here, we have investigated whether and how sirtuin-3 stimulation by the phytochemical, honokiol, could rescue NSAID-induced gastric injury.

EXPERIMENTAL APPROACH

Gastric injury in rats induced by indomethacin was used to assess the effects of honokiol. Next-generation sequencing-based transcriptomics followed by functional validation identified the gastroprotective function of sirtuin-3. Flow cytometry, immunoblotting, qRT-PCR and immunohistochemistry were used measure effects on oxidative stress, mitochondrial dynamics, electron transport chain function, and markers of inflammation and apoptosis. Sirtuin-3 deacetylase activity was also estimated and gastric luminal pH was measured.

KEY RESULTS

Indomethacin down-regulated sirtuin-3 to induce oxidative stress, mitochondrial hyperacetylation, 8-oxoguanine DNA glycosylase 1 depletion, mitochondrial DNA damage, respiratory chain defect and mitochondrial fragmentation leading to severe mucosal injury. Indomethacin dose-dependently inhibited sirtuin-3 deacetylase activity. Honokiol prevented mitochondrial oxidative damage and inflammatory tissue injury by attenuating indomethacin-induced depletion of both sirtuin-3 and its transcriptional regulators PGC1α and ERRα. Honokiol also accelerated gastric wound healing but did not alter gastric acid secretion, unlike lansoprazole.

CONCLUSIONS AND IMPLICATIONS

Sirtuin-3 stimulation by honokiol prevented and reversed NSAID-induced gastric injury through maintaining mitochondrial integrity. Honokiol did not affect gastric acid secretion. Sirtuin-3 stimulation by honokiol may be utilized as a mitochondria-based, acid-independent novel gastroprotective strategy against NSAIDs.

First Generation of Antioxidant Precursors for Bioisosteric Se-NSAIDs: Design, Synthesis, and In Vitro and In Vivo Anticancer Evaluation

The introduction of selenium (Se) into organic scaffolds has been demonstrated to be a promising framework in the field of medicinal chemistry. A novel design of nonsteroidal anti-inflammatory drug (NSAID) derivatives based on a bioisosteric replacement via the incorporation of Se as diacyl diselenide is reported. The antioxidant activity was assessed using the DPPH radical scavenging assay. The new Se-NSAID derivatives bearing this unique combination showed antioxidant activity in a time- and dose-dependent manner, and also displayed different antiproliferative profiles in a panel of eight cancer cell lines as determined by the MTT assay. Ibuprofen derivative 5 was not only the most antioxidant agent, but also selectively induced toxicity in all the cancer cell lines tested (IC50 < 10 µM) while sparing nonmalignant cells, and induced apoptosis partially without enhancing the caspase 3/7 activity. Furthermore, NSAID derivative 5 significantly suppressed tumor growth in a subcutaneous colon cancer xenograft mouse model (10 mg/kg, TGI = 72%, and T/C = 38%) without exhibiting any apparent toxicity. To our knowledge, this work constitutes the first report on in vitro and in vivo anticancer activity of an unprecedented Se-NSAID hybrid derivative and its rational use for developing precursors for bioisosteric selenocompounds with appealing therapeutic applications.

Effects of selective cyclooxygenase-2 inhibitor robenacoxib on primary cells derived from feline injection-site sarcoma

Feline injection-site sarcomas (FISSs) are highly invasive malignant mesenchymal neoplasms that arise from injection sites in cats. Although the tumorigenesis of FISSs is still uncertain, there is a consensus that FISS is associated with chronic inflammation caused by irritation of injection-related trauma and foreign chemical substances. Chronic inflammation can provide a proper microenvironment for tumour development, which has been known as one of the risk factors of tumorigenesis in many tumours. To investigate the tumorigenesis of FISS and screen for its potential therapeutic targets, cyclooxygenase-2 (COX-2), an inflammation-enhancing enzyme, was selected as a target for this study. In vitro experiments using FISS- and normal tissue-derived primary cells and robenacoxib, a highly selective COX-2 inhibitor, were performed. The results demonstrated that expression of COX-2 could be detected in formalin-fixed and paraffin-embedded FISS tissues and FISS-derived primary cells. Cell viability, migration and colony formation of FISS-derived primary cells were inhibited, and cell apoptosis was enhanced by robenacoxib in a dose-dependent manner. However, susceptibility to robenacoxib varied in different lines of FISS primary cells and was not completely correlated with COX-2 expression. Our results suggest that COX-2 inhibitors could be potential adjuvant therapeutics against FISSs.

Kinases in cerebral cavernous malformations: Pathogenesis and therapeutic targets

Cerebral cavernous malformations (CCMs) are low-flow, hemorrhagic vascular lesions of the central nervous system of genetic origin, which can cause stroke-like symptoms and seizures. From the identification of CCM1, CCM2 and CCM3 as genes related to disease progression, molecular and cellular mechanisms for CCM pathogenesis have been established and the search for potential drugs to target CCM has begun. Broadly speaking, kinases are the major group signaling in CCM pathogenesis. These include the MEKK3/MEK5/ERK5 cascade, Rho/Rock signaling, CCM3/GCKIII signaling, PI3K/mTOR signaling, and others. Since the discovery of Rho/Rock in CCM pathogenesis, inhibitors for Rho signaling and subsequently other components in CCM signaling were discovered and applied in preclinical and clinical trials to ameliorate CCM progression. This review discusses the general aspects of CCM disease, kinase-mediated signaling in CCM pathogenesis and the current state of potential treatment options for CCM. It is suggested that kinase target drug development in the context of CCM might facilitate and meet the unmet requirement - a non-surgical option for CCM disease.

Cytotoxicity of Carvotacetones from Sphaeranthus africanus Against Cancer Cells and Their Potential to Induce Apoptosis

Three carvotacetones (1 - 3: ) isolated from Sphaeranthus africanus were screened in 60 cancer cell lines at the National Cancer Institute (NCI) within the Developmental Therapeutics Program (DTP). At the concentration of 10^-5 M, compound 1: (3,5-diangeloyloxy-7-hydroxycarvotacetone) turned out to be the most active compound against ACHN and UO-31 renal cancer cell lines with growth percent values of - 100% (all cells dead). Compound 2: (3-angeloyloxy-5-[2″,3″-epoxy-2″-methylbutanoyloxy]-7-hydroxycarvotacetone) showed strong effects in SK-MEL-5 melanoma and ACHN renal cancer cells with inhibition values of 93% and 97%, respectively. Compound 3: (3-angeloyloxy-5-[3″-chloro-2″-hydroxy-2″-methylbutanoyloxy]-7-hydroxy-carvotacetone) exhibited a quite strong effect on renal cancer cells with a growth inhibitory effect of 96% against ACHN and UO-31 cells. When treated with five different concentrations of 1: (1 × 10^-8, 1 × 10^-7, 1 × 10^-6, 1 × 10^-5, and 1 × 10^-4 M), HOP-92 cells were found to be most sensitive with GI₅₀, TGI, and LC₅₀ values of 0.17, 0.40, and 0.96 µM, respectively. When using the ApoTox-Glo triplex assay to evaluate the apoptosis inducing effects of seven carvotacetones isolated from S. africanus in CCRF-CEM cells, compounds 1:  - 6: increased caspase-3/7 activity with 1, 2: , and 4: (3-angeloyloxy-5,7-dihydroxycarvotacetone) exhibiting the highest activitiy, indicating induction of caspase-dependent apoptosis.

Phytochemical profile, antioxidant, cytotoxic and anti-inflammatory activities of stem bark extract and fractions of Ailanthus excelsa Roxb.: In vitro, in vivo and in silico approaches

This study aimed to assess the phytochemical composition, in vitro antioxidant, cytotoxicity, and in vivo anti-inflammatory activities of the methanolic extract of Ailanthus excelsa (Simaroubaceae) stem bark and its fractions. Quantitative phytochemical analysis revealed that methanolic extract and all fractions contained a high level of flavonoids (20.40-22.91 mg/g QE), phenolics (1.72-7.41 mg/g GAE), saponins (33.28-51.87 mg/g DE), and alkaloids (0.21-0.33 mg/g AE). The antioxidant potential was evaluated in vitro using a range of assays, i.e., DPPH•, ABTS radical scavenging ability, and total antioxidant capacity. The chloroform and ethyl acetate fractions showed stronger antioxidant activity than the methanol extract. In vitro cytotoxic activity was investigated in three human tumor cell lines (A-549, MCF7 and HepG2) using the SRB assay. In addition, the in vivo anti-inflammatory effect was assessed by carrageenan-induced paw edema in rats. The chloroform fraction showed a more pronounced effect by effectively controlling the growth with the lowest GI50 and TGI concentrations. The human lung cancer cell line (A-549) was found to be more sensitive to the chloroform fraction. Furthermore, the chloroform fraction exhibited significant anti-inflammatory activity at a dose of 200 mg/kg in the latter phase of inflammation. Besides, methanol extract and ethyl acetate fraction revealed a significant cytotoxic and anti-inflammatory effects. The chloroform fraction of stem bark showed a strong anti-inflammatory effect in experimental animals and significant COX-2 inhibitory potential in the in vitro experiments. GC-MS analysis of chloroform fraction identified the phytochemicals like caftaric acid, 3,4-dihydroxy phenylacetic acid, arachidonic acid, cinnamic acid, 3-hydroxyphenylvaleric acid, caffeic acid, hexadeconoic acid, and oleanolic acid. The in-silico results suggest that identified compounds have better affinity towards the selected targets, viz. the BAX protein (PDB ID: 1F16), p53-binding protein Mdm-2 (PDB ID: 1YCR), and topoisomerase II (PDB ID: 1QZR). Amongst all, caftaric acid exhibited the best binding affinity for all three targets. Thus, it can be concluded that caftaric acid in combination with other phenolic compounds, might be responsible for the studied activity. Additional in vivo and in vitro studies are required to establish their exact molecular mechanisms and consider them as lead molecules in developing of valuable drugs for treating oxidative stress-induced disorders, cancers, and inflammations.

Interaction study with DNA/HSA, anti-topoisomerase IIα, cytotoxicity and in vitro antiproliferative evaluations and molecular docking of indole-thiosemicarbazone compounds

In this work we will discuss the antiproliferative evaluation and the possible mechanisms of action of indole-thiosemicarbazone compounds LTs with anti-inflammatory activity, previously described in the literature. In this perspective, some analyzes were carried out, such as the study of binding to human serum albumin (HSA) and to biological targets: DNA and human topoisomerase IIα (topo). Antiproliferative study was performed with DU-145, Jukart, MCF-7 and T-47D tumor lines and J774A.1, besides HepG2 macrophages and hemolytic activity. In the HSA interaction tests, the highest binding constant was 3.70 × 10⁶ M^-1, referring to LT89 and in the fluorescence, most compounds, except for LT76 and LT87, promoted fluorescent suppression with the largest Stern-Volmer constant for the LT88 3.55 × 10⁴. In the antiproliferative assay with DU-145 and Jurkat strains, compounds LT76 (0.98 ± 0.10/1.23 ± 0.32 μM), LT77 (0.94 ± 0.05/1.18 ± 0.08 μM) and LT87 (0.94 ± 0.12/0.84 ± 0.09 μM) stood out, due to their IC₅₀ values mentioned above. With the MCF-7 and T-47D cell lines, the lowest IC₅₀ was presented by LT81 with values of 0.74 ± 0.12 μM and 0.68 ± 0.10 μM, respectively, followed by the compounds LT76 and LT87. As well as the positive control amsacrine, the compounds LT76, LT81 and LT87 were able to inhibit the enzymatic action of human Topoisomerase IIα.

Novel Vulgarin Derivatives: Chemical Transformation, In Silico and In Vitro Studies

Vulgarin, an eudesmanolide sesquiterpene isolated from Artemisia judaica, was refluxed with iodine to produce two derivatives (1 and 2), which were purified and spectroscopically identified as naproxen methyl ester analogs. The reaction mechanism by which 1 and 2 were formed is explained using a sigmatropic reaction with a 1,3 shift. The scaffold hopping via lactone ring opening enabled the new derivatives of vulgarin (1 and 2) to fit well inside the COX-2 active site with ΔG of -7.73 and -7.58 kcal/mol, respectively, which was better than that of naproxen (ΔG of -7.04 kcal/mol). Moreover, molecular dynamic simulations showed that 1 was able to achieve a faster steady-state equilibrium than naproxen. The novel derivative 1 showed promising cytotoxic activities against HepG-2, HCT-116, MCF-7, and A-549 cancer cell lines compared to those of vulgarin and naproxen.

Carborane Analogues of Fenoprofen Exhibit Improved Antitumor Activity

Fenoprofen is a widely used nonsteroidal anti-inflammatory drug (NSAID) against rheumatoid arthritis, degenerative joint disease, ankylosing spondylitis and gout. Like other NSAIDs, fenoprofen inhibits the synthesis of prostaglandins by blocking both cyclooxygenase (COX) isoforms, COX-1 the "house-keeping" enzyme and COX-2 the induced isoform from pathological stimuli. Unselective inhibition of both COX isoforms results in many side effects, but off-target effects have also been reported. The steric modifications of the drugs could afford the desired COX-2 selectivity. Furthermore, NSAIDs have shown promising cytotoxic properties. The structural modification of fenoprofen using bulky dicarba-closo-dodecaborane(12) (carborane) clusters and the biological evaluation of the carborane analogues for COX inhibition and antitumor potential showed that the carborane analogues exhibit stronger antitumor potential compared to their respective aryl-based compounds.

Exploring the Nerve Regenerative Capacity of Compounds with Differing Affinity for PPARγ In Vitro and In Vivo

Damage to peripheral nerves can cause debilitating consequences for patients such as lifelong pain and disability. At present, no drug treatments are routinely given in the clinic following a peripheral nerve injury (PNI) to improve regeneration and remyelination of damaged nerves. Appropriately targeted therapeutic agents have the potential to be used at different stages following nerve damage, e.g., to maintain Schwann cell viability, induce and sustain a repair phenotype to support axonal growth, or promote remyelination. The development of therapies to promote nerve regeneration is currently of high interest to researchers, however, translation to the clinic of drug therapies for PNI is still lacking. Studying the effect of PPARγ agonists for treatment of peripheral nerve injures has demonstrated significant benefits. Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), has reproducibly demonstrated benefits in vitro and in vivo, suggested to be due to its agonist action on PPARγ. Other NSAIDs have demonstrated differing levels of PPARγ activation based upon their affinity. Therefore, it was of interest to determine whether affinity for PPARγ of selected drugs corresponded to an increase in regeneration. A 3D co-culture in vitro model identified some correlation between these two properties. However, when the drug treatments were screened in vivo, in a crush injury model in a rat sciatic nerve, the same correlation was not apparent. Further differences were observed between capacity to increase axon number and improvement in functional recovery. Despite there not being a clear correlation between affinity and size of effect on regeneration, all selected PPARγ agonists improved regeneration, providing a panel of compounds that could be explored for use in the treatment of PNI.

Systemic Nos2 Depletion and Cox inhibition limits TNBC disease progression and alters lymphoid cell spatial orientation and density

Antitumor immune polarization is a key predictor of clinical outcomes to cancer therapy. An emerging concept influencing clinical outcome involves the spatial location of CD8+ T cells, within the tumor. Our earlier work demonstrated immunosuppressive effects of NOS2 and COX2 tumor expression. Here, we show that NOS2/COX2 levels influence both the polarization and spatial location of lymphoid cells including CD8+ T cells. Importantly, elevated tumor NOS2/COX2 correlated with exclusion of CD8+ T cells from the tumor epithelium. In contrast, tumors expressing low NOS2/COX2 had increased CD8+ T cell penetration into the tumor epithelium. Consistent with a causative relationship between these observations, pharmacological inhibition of COX2 with indomethacin dramatically reduced tumor growth of the 4T1 model of TNBC in both WT and Nos2- mice. This regimen led to complete tumor regression in ∼20-25% of tumor-bearing Nos2- mice, and these animals were resistant to tumor rechallenge. Th1 cytokines were elevated in the blood of treated mice and intratumoral CD4+ and CD8+ T cells were higher in mice that received indomethacin when compared to control untreated mice. Multiplex immunofluorescence imaging confirmed our phenotyping results and demonstrated that targeted Nos2/Cox2 blockade improved CD8+ T cell penetration into the 4T1 tumor core. These findings are consistent with our observations in low NOS2/COX2 expressing breast tumors proving that COX2 activity is responsible for limiting the spatial distribution of effector T cells in TNBC. Together these results suggest that clinically available NSAID's may provide a cost-effective, novel immunotherapeutic approach for treatment of aggressive tumors including triple negative breast cancer.

Weight Loss and/or Sulindac Mitigate Obesity-associated Transcriptome, Microbiome, and Protumor Effects in a Murine Model of Colon Cancer

Obesity is associated with an increased risk of colon cancer. Our current study examines whether weight loss and/or treatment with the NSAID sulindac suppresses the protumor effects of obesity in a mouse model of colon cancer. Azoxymethane-treated male FVB/N mice were fed a low-fat diet (LFD) or high-fat diet (HFD) for 15 weeks, then HFD mice were randomized to remain on HFD (obese) or switch to LFD [formerly obese (FOb-LFD)]. Within the control (LFD), obese, and FOb-LFD groups, half the mice started sulindac treatment (140 ppm in the diet). All mice were euthanized 7 weeks later. FOb-LFD mice had intermediate body weight levels, lower than obese but higher than control (P < 0.05). Sulindac did not affect body weight. Obese mice had greater tumor multiplicity and burden than all other groups (P < 0.05). Transcriptomic profiling indicated that weight loss and sulindac each modulate the expression of tumor genes related to invasion and may promote a more antitumor immune landscape. Furthermore, the fecal microbes Coprobacillus, Prevotella, and Akkermansia muciniphila were positively correlated with tumor multiplicity and reduced by sulindac in obese mice. Coprobacillus abundance was also decreased in FOb-LFD mice. In sum, weight loss and sulindac treatment, alone and in combination, reversed the effects of chronic obesity on colon tumor multiplicity and burden. Our findings suggest that an investigation regarding the effects of NSAID treatment on colon cancer risk and/or progression in obese individuals is warranted, particularly for those unable to achieve moderate weight loss.

PREVENTION RELEVANCE

Obesity is a colon cancer risk and/or progression factor, but the underlying mechanisms are incompletely understood. Herein we demonstrate that obesity enhances murine colon carcinogenesis and expression of numerous tumoral procancer and immunosuppressive pathways. Moreover, we establish that weight loss via LFD and/or the NSAID sulindac mitigate procancer effects of obesity.

Carboranyl Analogues of Mefenamic Acid and Their Biological Evaluation

Mefenamic acid represents a widely used nonsteroidal anti-inflammatory drug (NSAID) to treat the pain of postoperative surgery and heavy menstrual bleeding. Like other NSAIDs, mefenamic acid inhibits the synthesis of prostaglandins by nonselectively blocking cyclooxygenase (COX) isoforms COX-1 and COX-2. For the improved selectivity of the drug and, therefore, reduced related side effects, the carborane analogues of mefenamic acid were evaluated. The ortho-, meta-, and para-carborane derivatives were synthesized in three steps: halogenation of the respective cluster, followed by a Pd-catalyzed B-N coupling and hydrolysis of the nitrile derivatives under acidic conditions. The COX inhibitory activity and cytotoxicity for different cancer cell lines revealed that the carborane analogues have stronger antitumor potential compared to their parent organic compound.

Activation of the transcription factor NRF2 mediates the anti-inflammatory properties of a subset of over-the-counter and prescription NSAIDs

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) enzymes and are ubiquitously used for their anti-inflammatory properties. However, COX inhibition alone fails to explain numerous clinical outcomes of NSAID usage. Screening commonly used NSAIDs in primary human and murine myeloid cells demonstrated that NSAIDs could be differentiated by their ability to induce growth/differentiation factor 15 (GDF15), independent of COX specificity. Using genetic and pharmacologic approaches, NSAID-mediated GDF15 induction was dependent on the activation of nuclear factor erythroid 2-related factor 2 (NRF2) in myeloid cells. Sensing by Cysteine 151 of the NRF2 chaperone, Kelch-like ECH-associated protein 1 (KEAP1) was required for NSAID activation of NRF2 and subsequent anti-inflammatory effects both in vitro and in vivo. Myeloid-specific deletion of NRF2 abolished NSAID-mediated tissue protection in murine models of gout and endotoxemia. This highlights a noncanonical NRF2-dependent mechanism of action for the anti-inflammatory activity of a subset of commonly used NSAIDs.

A chemoproteoinformatics approach demonstrates that aspirin increases sensitivity to MEK inhibition by directly binding to RPS5

MEK inhibitors are among the most successful molecularly targeted agents used as cancer therapeutics. However, to treat cancer more efficiently, resistance to MEK inhibitor-induced cell death must be overcome. Although previous genetic approaches based on comprehensive gene expression analysis or RNAi libraries led to the discovery of factors involved in intrinsic resistance to MEK inhibitors, a feasible combined treatment with the MEK inhibitor has not yet been developed. Here, we show that a chemoproteoinformatics approach identifies ligands overcoming the resistance to cell death induced by MEK inhibition as well as the target molecule conferring this resistance. First, we used natural products, perillyl alcohol and sesaminol, which induced cell death in combination with the MEK inhibitor trametinib, as chemical probes, and identified ribosomal protein S5 (RPS5) as their common target protein. Consistently, trametinib induced cell death in RPS5-depleted cancer cells via upregulation of the apoptotic proteins BIM and PUMA. Using molecular docking and molecular dynamics (MD) simulations, we then screened FDA- and EMA-approved drugs for RPS5-binding ligands and found that acetylsalicylic acid (ASA, also known as aspirin) directly bound to RPS5, resulting in upregulation of BIM and PUMA and induction of cell death in combination with trametinib. Our chemoproteoinformatics approach demonstrates that RPS5 confers resistance to MEK inhibitor-induced cell death, and that aspirin could be repurposed to sensitize cells to MEK inhibition by binding to RPS5.

Use of "Repurposed" Drugs in the Treatment of Epithelial Ovarian Cancer: A Systematic Review

Epithelial ovarian cancer has poor outcomes with standard therapy and limited options for treatment of recurrent disease. This systematic review summarizes the data on the clinical use of repurposed drugs. We searched for clinical studies using "repurposed" agents for the treatment of ovarian cancer in the following databases: PubMed, clinicaltrials.gov, Clinical Trial Registry of India, European Clinical Trials Registry, and Chinese Clinical Trial Registry. We excluded reviews, preclinical studies, and non-English language studies. We assessed the quality of included studies. The following agents/class of agents were included: statins, hydroxychloroquine, metformin, itraconazole, nonsteroidal anti-inflammatory drugs, vitamin D, proton pump inhibitors, beta-blockers, and sodium valproate. Only one randomized controlled trial investigated metformin, which found no benefit of metformin. However, this had a high risk of bias (no details of randomization). Among the observational studies, 70% were of high quality (Newcastle-Ottawa scale ≥7). Clinical benefit was seen for itraconazole, beta-blockers, metformin, statins, and proton pump inhibitors. Though multiple studies aim to repurpose agents in epithelial ovarian cancer, the most published literature is observational, and none are practice-changing. Given the solid preclinical data regarding the anticancer efficacy of these agents, well-designed clinical trials are urgently required.

NSAIDs Induce Proline Dehydrogenase/Proline Oxidase-Dependent and Independent Apoptosis in MCF7 Breast Cancer Cells

Non-steroidal anti-inflammatory drugs (NSAIDs) are considered in cancer therapy for their inhibitory effect on cyclooxygenase-2 (COX-2), which is overexpressed in most cancers. However, we found that NSAIDs as ligands of peroxisome proliferator-activated receptor-γ (PPARγ)-induced apoptosis independent of the COX-2 inhibition, and the process was mediated through activation of proline dehydrogenase/proline oxidase (PRODH/POX)-dependent generation of reactive oxygen species (ROS). This mitochondrial enzyme converts proline to ∆1-pyrroline-5-carboxylate (P5C) during which ATP or ROS is generated. To confirm the role of PRODH/POX in the mechanism of NSAID-induced apoptosis we obtained an MCF7 CRISPR/Cas9 PRODH/POX knockout breast cancer cell model (MCF7^POK-KO). Interestingly, the studied NSAIDs (indomethacin and diclofenac) in MCF7^POK-KO cells contributed to a more pronounced pro-apoptotic phenotype of the cells than in PRODH/POX-expressing MCF7 cells. The observed effect was independent of ROS generation, but it was related to the energetic disturbances in the cells as shown by an increase in the expression of AMPKα (sensor of cell energy status), GLUD1/2 (proline producing enzyme from glutamate), prolidase (proline releasing enzyme), PPARδ (growth supporting transcription factor) and a decrease in the expression of proline cycle enzymes (PYCR1, PYCRL), mammalian target of rapamycin (mTOR), and collagen biosynthesis (the main proline utilizing process). The data provide evidence that the studied NSAIDs induce PRODH/POX-dependent and independent apoptosis in MCF7 breast cancer cells.

Nonsteroidal Anti-Inflammatory Drugs as PPARγ Agonists Can Induce PRODH/POX-Dependent Apoptosis in Breast Cancer Cells: New Alternative Pathway in NSAID-Induced Apoptosis

Nonsteroidal anti-inflammatory drugs (NSAIDs) are considered to be therapeutics in cancer prevention because of their inhibitory effect on cyclooxygenases (COX), which are frequently overexpressed in many types of cancer. However, it was also demonstrated that NSAIDs provoked a proapoptotic effect in COX knocked-out cancer cells. Here, we suggest that this group of drugs may provoke antineoplastic activity through the activation of PPARγ, which induces proline dehydrogenase/proline oxidase (PRODH/POX)-dependent apoptosis. PRODH/POX is a mitochondrial enzyme that catalyzes proline degradation, during which ATP or reactive oxygen species (ROS) are generated. We have found that NSAIDs induced PRODH/POX and PPARγ expressions (as demonstrated by Western Blot or immunofluorescence analysis) and cytotoxicity (as demonstrated by MTT, cytometric assay, and DNA biosynthesis assay) in breast cancer MCF7 cells. Simultaneously, the NSAIDs inhibited collagen biosynthesis, supporting proline for PRODH/POX-induced ROS-dependent apoptosis (as demonstrated by an increase in the expression of apoptosis markers). The data suggest that targeting proline metabolism and the PRODH/POX–PPARγ axis can be considered a novel approach for breast cancer treatment.

Up-Regulation of Cyclooxygenase-2 (COX-2) Expression by Temozolomide (TMZ) in Human Glioblastoma (GBM) Cell Lines

TMZ-resistance remains a main limitation in glioblastoma (GBM) treatment. TMZ is an alkylating agent whose cytotoxicity is modulated by O6-methylguanine-DNA methyltransferase (MGMT), whose expression is determined by MGMT gene promoter methylation status. The inflammatory marker COX-2 has been implicated in GBM tumorigenesis, progression, and stemness. COX-2 inhibitors are considered a GBM add-on treatment due to their ability to increase TMZ-sensitivity. We investigated the effect of TMZ on COX-2 expression in GBM cell lines showing different COX-2 levels and TMZ sensitivity (T98G and U251MG). β-catenin, MGMT, and SOX-2 expression was analyzed. The effects of NS398, COX-2 inhibitor, alone or TMZ-combined, were studied evaluating cell proliferation by the IncuCyte^® system, cell cycle/apoptosis, and clonogenic potential. COX-2, β-catenin, MGMT, and SOX-2 expression was evaluated by RT-PCR, Western blotting, and immunofluorescence and PGE2 by ELISA. Our findings, sustaining the role of COX-2/PGE2 system in TMZ-resistance of GBM, show, for the first time, a relevant, dose-dependent up-regulation of COX-2 expression and activity in TMZ-treated T98G that, in turn, correlated with chemoresistance. Similarly, all the COX-2-dependent signaling pathways involved in TMZ-resistance also resulted in being up-modulated after treatment with TMZ. NS398+TMZ was able to reduce cell proliferation and induce cell cycle arrest and apoptosis. Moreover, NS398+TMZ counteracted the resistance in T98G preventing the TMZ-induced COX-2, β-catenin, MGMT, and SOX-2 up-regulation.

Aspirin Inhibition of Group VI Phospholipase A2 Induces Synthetic Lethality in AAM Pathway Down-Regulated Gingivobuccal Squamous Carcinoma

Background: To elucidate the role of iPLA2/PLA2G6 in gingivobuccal squamous cell carcinoma (GB-SCC) and to ascertain the synthetic lethality-based chemoprevention role of aspirin in arachidonic acid metabolism (AAM) pathway down-regulated GB-SCC. Methods: The in vitro efficacy of aspirin on GB-SCC cells (ITOC-03 and ITOC-04) was assessed by cell proliferation, colony formation, apoptosis, cell migration, cell cycle assay and RNA-seq, while inhibition of PLA2G6 and AAM pathway components was affirmed by qPCR, Western blot and immunofluorescence staining. The in vivo effect of aspirin was evaluated using NOD-SCID mice xenografts and immunohistochemical analysis. Results: We found that aspirin, which has been reported to act through the COX pathway, is inhibiting PLA2G6, and thereby the COX and LOX components of the AAM pathway. The findings were validated using PLA2G6 siRNA and immunohistochemical marker panel. Moreover, a pronounced effect in ITOC-04 cells and xenografts implied aspirin-induced synthetic lethality in the AAM pathway down-regulated GB-SCC. Conclusions: This study reveals that aspirin induces the anti-tumor effect by a previously unrecognized mechanism of PLA2G6 inhibition. In addition, the effect of aspirin is influenced by the baseline AAM pathway status and could guide precision prevention clinical trials of AAM pathway inhibitors.

Modulating Properties of Piroxicam, Meloxicam and Oxicam Analogues against Macrophage-Associated Chemokines in Colorectal Cancer

The mechanisms underlying the antineoplastic effects of oxicams have not been fully elucidated. We aimed to assess the effect of classic and novel oxicams on the expression/secretion of macrophage-associated chemokines (RTqPCR/Luminex xMAP) in colorectal adenocarcinoma cells, and on the expression of upstream the non-steroidal anti-inflammatory drug (NSAID)-activated genes NAG1, NFKBIA, MYD88, and RELA, as well as at the chemokine profiling in colorectal tumors. Meloxicam downregulated CCL4 9.9-fold, but otherwise the classic oxicams had a negligible/non-significant effect. Novel analogues with a thiazine ring substituted with arylpiperazine and benzoyl moieties significantly modulated chemokine expression to varying degree, upregulated NAG1 and NFKBIA, and downregulated MYD88. They inhibited CCL3 and CCL4, and their effect on CCL2 and CXCL2 depended on the dose and exposure. The propylene linker between thiazine and piperazine nitrogens and one arylpiperazine fluorine substituent characterized the most effective analogue. Only CCL19 and CXCL2 were not upregulated in tumors, nor was CXCL2 in tumor-adjacent tissue compared to normal mucosa. Compared to adjacent tissue, CCL4 and CXCL2 were upregulated, while CCL2, CCL8, and CCL19 were downregulated in tumors. Tumor CCL2 and CCL7 increased along with advancing T and CCL3, and CCL4 along with the N stage. The introduction of arylpiperazine and benzoyl moieties into the oxicam scaffold yields effective modulators of chemokine expression, which act by upregulating NAG1 and interfering with NF-κB signaling.

NSAIDs: Old Acquaintance in the Pipeline for Cancer Treatment and Prevention─Structural Modulation, Mechanisms of Action, and Bright Future

The limitations of current chemotherapeutic drugs are still a major issue in cancer treatment. Thus, targeted multimodal therapeutic approaches need to be strategically developed to successfully control tumor growth and prevent metastatic burden. Inflammation has long been recognized as a hallmark of cancer and plays a key role in the tumorigenesis and progression of the disease. Several epidemiological, clinical, and preclinical studies have shown that traditional nonsteroidal anti-inflammatory drugs (NSAIDs) exhibit anticancer activities. This Perspective reports the most recent outcomes for the treatment and prevention of different types of cancers for several NSAIDs alone or in combination with current chemotherapeutic drugs. Furthermore, an extensive review of the most promising structural modifications is reported, such as phospho, H₂S, and NO releasing-, selenium-, metal complex-, and natural product-NSAIDs, among others. We also provide a perspective about the new strategies used to obtain more efficient NSAID- or NSAID derivative- formulations for targeted delivery.

Comparative Cancer Cell Signaling in Muscle-Invasive Urothelial Carcinoma of the Bladder in Dogs and Humans

Muscle-invasive urothelial carcinoma (MIUC) is the most common type of bladder malignancy in humans, but also in dogs that represent a naturally occurring model for this disease. Dogs are immunocompetent animals that share risk factors, pathophysiological features, clinical signs and response to chemotherapeutics with human cancer patients. This review summarizes the fundamental pathways for canine MIUC initiation, progression, and metastasis, emerging therapeutic targets and mechanisms of drug resistance, and proposes new opportunities for potential prognostic and diagnostic biomarkers and therapeutics. Identifying similarities and differences between cancer signaling in dogs and humans is of utmost importance for the efficient translation of in vitro research to successful clinical trials for both species.

Combination therapy with cannabidiol and chemotherapeutics in canine urothelial carcinoma cells

Background

Canine urothelial carcinoma is the most common form of canine bladder cancer. Treatment with chemotherapy has variable response rates leading to most dogs succumbing to their disease within a year. Cannabidiol is an emerging treatment within the field of oncology. In reported in vivo studies, cannabidiol has induced apoptosis, reduced cell migration, and acted as a chemotherapy sensitizer in various human tumor types. The aim of this study was to characterize the effects of cannabidiol on canine urothelial carcinoma cell viability and apoptosis as both a single agent and in combination with chemotherapy in vitro.

Results

Cannabidiol reduced cell viability and induced apoptosis in canine urothelial cells as determined by crystal violet viability assay and annexin V/propidium iodide flow cytometry. Furthermore, combinations of cannabidiol with mitoxantrone and vinblastine chemotherapy yielded significantly reduced cell viability and increased apoptosis compared to single agent treatment alone. The drug interactions were deemed synergistic based on combination index calculations. Conversely, the combination of cannabidiol and carboplatin did not result in decreased cell viability and increased apoptosis compared to single agent treatment. Combination index calculations suggested an antagonistic interaction between these drugs. Finally, the combination of the non-steroidal anti-inflammatory drug piroxicam with cannabidiol did not significantly affect cell viability, although, some cell lines demonstrated decreased cell viability when mitoxantrone was combined with piroxicam.

Conclusions

Cannabidiol showed promising results as a single agent or in combination with mitoxantrone and vinblastine for treatment of canine urothelial carcinoma cells. Further studies are justified to investigate whether these results are translatable in vivo.

Synthesis, potential antitumor activity, cell cycle analysis, and multitarget mechanisms of novel hydrazones incorporating a 4-methylsulfonylbenzene scaffold: a molecular docking study

Hydrazone is a bioactive pharmacophore that can be used to design antitumor agents. We synthesised a series of hydrazones (compounds 4–24) incorporating a 4-methylsulfonylbenzene scaffold and analysed their potential antitumor activity. Compounds 6, 9, 16, and 20 had the most antitumor activity with a positive cytotoxic effect (PCE) of 52/59, 27/59, 59/59, and 59/59, respectively, while compounds 5, 10, 14, 15, 18, and 19 had a moderate antitumor activity with a PCE of 11/59–14/59. Compound 20 was the most active and had a mean 50% cell growth inhibition (GI₅₀) of 0.26 µM. Compounds 9 and 20 showed the highest inhibitory activity against COX-2, with a half-maximal inhibitory concentration (IC₅₀) of 2.97 and 6.94 μM, respectively. Compounds 16 and 20 significantly inhibited EGFR (IC₅₀ = 0.2 and 0.19 μM, respectively) and HER2 (IC₅₀ = 0.13 and 0.07 μM, respectively). Molecular docking studies of derivatives 9, 16, and 20 into the binding sites of COX-2, EGFR, and HER2 were carried out to explore the interaction mode and the structural requirements for antitumor activity.

Celecoxib repurposing in cancer therapy: molecular mechanisms and nanomedicine-based delivery technologies

While cancer remains a significant global health problem, advances in cancer biology, deep understanding of its underlaying mechanism and identification of specific molecular targets allowed the development of new therapeutic options. Drug repurposing poses several advantages as reduced cost and better safety compared with new compounds development. COX-2 inhibitors are one of the most promising drug classes for repurposing in cancer therapy. In this review, we provide an overview of the detailed mechanism and rationale of COX-2 inhibitors as anticancer agents and we highlight the most promising research efforts on nanotechnological approaches to enhance COX-2 inhibitors delivery with special focus on celecoxib as the most widely studied agent for chemoprevention or combined with chemotherapeutic and herbal drugs for combating various cancers.

COXIBs and 2,5-dimethylcelecoxib counteract the hyperactivated Wnt/β-catenin pathway and COX-2/PGE2/EP4 signaling in glioblastoma cells

BACKGROUND

Glioblastoma (GBM) is the deadliest and the most common primary brain tumor in adults. The invasiveness and proliferation of GBM cells can be decreased through the inhibition of Wnt/β-catenin pathway. In this regard, celecoxib is a promising agent, but other COXIBs and 2,5-dimethylcelecoxib (2,5-DMC) await elucidation. Thus, the aim of this study was to analyze the impact of celecoxib, 2,5-DMC, etori-, rofe-, and valdecoxib on GBM cell viability and the activity of Wnt/β-catenin pathway. In addition, the combination of the compounds with temozolomide (TMZ) was also evaluated. Cell cycle distribution and apoptosis, MGMT methylation level, COX-2 and PGE2 EP4 protein levels were also determined in order to better understand the molecular mechanisms exerted by these compounds and to find out which of them can serve best in GBM therapy.

METHODS

Celecoxib, 2,5-DMC, etori-, rofe- and valdecoxib were evaluated using three commercially available and two patient-derived GBM cell lines. Cell viability was analyzed using MTT assay, whereas alterations in MGMT methylation level were determined using MS-HRM method. The impact of COXIBs, in the presence and absence of TMZ, on Wnt pathway was measured on the basis of the expression of β-catenin target genes. Cell cycle distribution and apoptosis analysis were performed using flow cytometry. COX-2 and PGE2 EP4 receptor expression were evaluated using Western blot analysis.

RESULTS

Wnt/β-catenin pathway was attenuated by COXIBs and 2,5-DMC irrespective of the COX-2 expression profile of the treated cells, their MGMT methylation status, or radio/chemoresistance. Celecoxib and 2,5-DMC were the most cytotoxic. Cell cycle distribution was altered, and apoptosis was induced after the treatment with celecoxib, 2,5-DMC, etori- and valdecoxib in T98G cell line. COXIBs and 2,5-DMC did not influence MGMT methylation status, but inhibited COX-2/PGE2/EP4 pathway.

CONCLUSIONS

Not only celecoxib, but also 2,5-DMC, etori-, rofe- and valdecoxib should be further investigated as potential good anti-GBM therapeutics.

A Combined Proteomics and Mendelian Randomization Approach to Investigate the Effects of Aspirin-Targeted Proteins on Colorectal Cancer

BACKGROUND

Evidence for aspirin's chemopreventative properties on colorectal cancer (CRC) is substantial, but its mechanism of action is not well-understood. We combined a proteomic approach with Mendelian randomization (MR) to identify possible new aspirin targets that decrease CRC risk.

METHODS

Human colorectal adenoma cells (RG/C2) were treated with aspirin (24 hours) and a stable isotope labeling with amino acids in cell culture (SILAC) based proteomics approach identified altered protein expression. Protein quantitative trait loci (pQTLs) from INTERVAL (N = 3,301) and expression QTLs (eQTLs) from the eQTLGen Consortium (N = 31,684) were used as genetic proxies for protein and mRNA expression levels. Two-sample MR of mRNA/protein expression on CRC risk was performed using eQTL/pQTL data combined with CRC genetic summary data from the Colon Cancer Family Registry (CCFR), Colorectal Transdisciplinary (CORECT), Genetics and Epidemiology of Colorectal Cancer (GECCO) consortia and UK Biobank (55,168 cases and 65,160 controls).

RESULTS

Altered expression was detected for 125/5886 proteins. Of these, aspirin decreased MCM6, RRM2, and ARFIP2 expression, and MR analysis showed that a standard deviation increase in mRNA/protein expression was associated with increased CRC risk (OR: 1.08, 95% CI, 1.03-1.13; OR: 3.33, 95% CI, 2.46-4.50; and OR: 1.15, 95% CI, 1.02-1.29, respectively).

CONCLUSIONS

MCM6 and RRM2 are involved in DNA repair whereby reduced expression may lead to increased DNA aberrations and ultimately cancer cell death, whereas ARFIP2 is involved in actin cytoskeletal regulation, indicating a possible role in aspirin's reduction of metastasis.

IMPACT

Our approach has shown how laboratory experiments and population-based approaches can combine to identify aspirin-targeted proteins possibly affecting CRC risk.

Optimization of Erlotinib Plus Sulindac Dosing Regimens for Intestinal Cancer Prevention in an Apc-Mutant Model of Familial Adenomatous Polyposis (FAP)

A clinical trial in patients with familial adenomatous polyposis (FAP) demonstrated that sulindac plus erlotinib (SUL+ERL) had good efficacy in the duodenum and colon, but toxicity issues raised concerns for long-term prevention. We performed a biomarker study in the polyposis in rat colon (Pirc) model, observing phosphorylated Erk inhibition in colon polyps for up to 10 days after discontinuing ERL+SUL administration. In a follow-up study lasting 16 weeks, significant reduction of colon and small intestine (SI) tumor burden was detected, especially in rats given 250 ppm SUL in the diet plus once-a-week intragastric dosing of ERL at 21 or 42 mg/kg body weight (BW). A long-term study further demonstrated antitumor efficacy in the colon and SI at 52 weeks, when 250 ppm SUL was combined with once-a-week intragastric administration of ERL at 10, 21, or 42 mg/kg BW. Tumor-associated matrix metalloproteinase-7 (Mmp7), tumor necrosis factor (Tnf), and early growth response 1 (Egr1) were decreased at 16 weeks by ERL+SUL, and this was sustained in the long-term study for Mmp7 and Tnf. Based on the collective results, the optimal dose combination of ERL 10 mg/kg BW plus 250 ppm SUL lacked toxicity, inhibited molecular biomarkers, and exhibited effective antitumor activity. We conclude that switching from continuous to once-per-week ERL, given at one-quarter of the current therapeutic dose, will exert good efficacy with standard-of-care SUL against adenomatous polyps in the colon and SI, with clinical relevance for patients with FAP before or after colectomy. PREVENTION RELEVANCE: This investigation concludes that switching from continuous to once-per-week erlotinib, given at one-quarter of the current therapeutic dose, will exert good efficacy with standard-of-care sulindac against adenomatous polyps in the colon and small intestine, with clinical relevance for patients with FAP before or after colectomy.

Identification of an irreversible PPARγ antagonist with potent anticancer activity

Melanoma is responsible for most skin cancer deaths, and its incidence continues to rise year after year. Different treatment options have been developed for melanoma depending on the stage of the disease. Despite recent advances in immuno- and targeted therapies, advanced melanoma remains incurable and thus an urgent need persists for safe and more effective melanoma therapeutics. In this study, we demonstrate that a novel compound MM902 (3-(3-(bromomethyl)-5-(4-(tert-butyl) phenyl)-1H-1,2,4-triazol-1-yl) phenol) exhibited potent efficacies in inhibiting the growth of different cancer cells, and suppressed tumor growth in a mouse xenograft model of malignant melanoma. Beginning with MM902 instead of specific targets, computational similarity- and docking-based approaches were conducted to search for known anticancer drugs whose structural features match MM902 and whose pharmacological target would accommodate an irreversible inhibitor. Peroxisome proliferator-activated receptor (PPAR) was computationally identified as one of the pharmacological targets and confirmed by in vitro biochemical assays. MM902 was shown to bind to PPARγ in an irreversible mode of action and to function as a selective antagonist for PPARγ over PPARα and PPARδ. It is hoped that MM902 will serve as a valuable research probe to study the functions of PPARγ in tumorigenesis and other pathological processes.

Visceral Obesity and Its Shared Role in Cancer and Cardiovascular Disease: A Scoping Review of the Pathophysiology and Pharmacological Treatments

The association between obesity, cancer and cardiovascular disease (CVD) has been demonstrated in animal and epidemiological studies. However, the specific role of visceral obesity on cancer and CVD remains unclear. Visceral adipose tissue (VAT) is a complex and metabolically active tissue, that can produce different adipokines and hormones, responsible for endocrine-metabolic comorbidities. This review explores the potential mechanisms related to VAT that may also be involved in cancer and CVD. In addition, we discuss the shared pharmacological treatments which may reduce the risk of both diseases. This review highlights that chronic inflammation, molecular aspects, metabolic syndrome, secretion of hormones and adiponectin associated to VAT may have synergistic effects and should be further studied in relation to cancer and CVD. Reductions in abdominal and visceral adiposity improve insulin sensitivity, lipid profile and cytokines, which consequently reduce the risk of CVD and some cancers. Several medications have shown to reduce visceral and/or subcutaneous fat. Further research is needed to investigate the pathophysiological mechanisms by which visceral obesity may cause both cancer and CVD. The role of visceral fat in cancer and CVD is an important area to advance. Public health policies to increase public awareness about VAT's role and ways to manage or prevent it are needed.

Ibuprofen disrupts a WNK1/GSK3β/SRPK1 protein complex required for expression of tumor-related splicing variant RAC1B in colorectal cells

A major risk factor promoting tumor development is chronic inflammation and the use of nonsteroidal anti-inflammatory drugs (NSAID), including ibuprofen, can decrease the risk of developing various types of cancer, including colorectal cancer (CRC). Although the molecular mechanism behind the antitumor properties of NSAIDs has been largely attributed to inhibition of cyclooxygenases (COXs), several studies have shown that the chemopreventive properties of ibuprofen also involve multiple COX-independent effects. One example is its ability to inhibit the alternative splicing event generating RAC1B, which is overexpressed in a specific subset of BRAF-mutated colorectal tumors and sustains cell survival. Here we describe the mechanism by which ibuprofen prevents RAC1B alternative splicing in a BRAF mutant CRC cell line: it leads to decreased translocation of SRPK1 and SRSF1 to the nucleus and is regulated by a WNK1/GSK3β/SRPK1 protein kinase complex. Surprisingly, we demonstrate that ibuprofen does not inhibit the activity of any of the involved kinases but rather promotes disassembly of this regulatory complex, exposing GSK3β serine 9 to inhibitory phosphorylation, namely by AKT, which results in nuclear exclusion of SRPK1 and SRSF1 hypophosphorylation. The data shed new light on the biochemical mechanisms behind ibuprofen’s action on alternative spliced RAC1B and may support its use in personalized approaches to CRC therapy or chemoprevention regimens.

Deuteration versus ethylation - strategies to improve the metabolic fate of an 18F-labeled celecoxib derivative

The inducible isoenzyme cyclooxygenase-2 (COX-2) is closely associated with chemo-/radioresistance and poor prognosis of solid tumors. Therefore, COX-2 represents an attractive target for functional characterization of tumors by positron emission tomography (PET). In this study, the celecoxib derivative 3-([¹⁸F]fluoromethyl)-1-[4-(methylsulfonyl)phenyl]-5-(p-tolyl)-1H-pyrazole ([¹⁸F]5a) was chosen as a lead compound having a reported high COX-2 inhibitory potency and a potentially low carbonic anhydrase binding tendency. The respective deuterated analog [D₂,¹⁸F]5a and the fluoroethyl-substituted derivative [¹⁸F]5b were selected to study the influence of these modifications with respect to COX inhibition potency in vitro and metabolic stability of the radiolabeled tracers in vivo. COX-2 inhibitory potency was found to be influenced by elongation of the side chain but, as expected, not by deuteration. An automated radiosynthesis comprising ¹⁸F-fluorination and purification under comparable conditions provided the radiotracers [¹⁸F]5a,b and [D₂,¹⁸F]5a in good radiochemical yields (RCY) and high radiochemical purity (RCP). Biodistribution and PET studies comparing all three compounds revealed bone accumulation of ¹⁸F-activity to be lowest for the ethyl derivative [¹⁸F]5b. However, the deuterated analog [D₂,¹⁸F]5a turned out to be the most stable compound of the three derivatives studied here. Time-dependent degradation of [¹⁸F]5a,b and [D₂,¹⁸F]5a after incubation in murine liver microsomes was in accordance with the data on metabolism in vivo. Furthermore, metabolites were identified based on UPLC-MS/MS.

The aim of this study is to investigate the influence of deuteration and elongation on an ¹⁸F-labeled COX-2 inhibitor with focus on metabolic stability to develop suitable COX-2 targeting radiotracers.

The molecular mechanisms of celecoxib in tumor development

BACKGROUND

Clinical studies have shown that celecoxib can significantly inhibit the development of tumors, and basic experiments and in vitro experiments also provide a certain basis, but it is not clear how celecoxib inhibits tumor development in detail.

METHODS

A literature search of all major academic databases was conducted (PubMed, China National Knowledge Internet (CNKI), Wan-fang, China Science and Technology Journal Database (VIP), including the main research on the mechanisms of celecoxib on tumors.

RESULTS

Celecoxib can intervene in tumor development and reduce the formation of drug resistance through multiple molecular mechanisms.

CONCLUSION

Celecoxib mainly regulates the proliferation, migration, and invasion of tumor cells by inhibiting the cyclooxygenases-2/prostaglandin E2 signal axis and thereby inhibiting the phosphorylation of nuclear factor-κ-gene binding, Akt, signal transducer and activator of transcription and the expression of matrix metalloproteinase 2 and matrix metalloproteinase 9. Meanwhile, it was found that celecoxib could promote the apoptosis of tumor cells by enhancing mitochondrial oxidation, activating mitochondrial apoptosis process, promoting endoplasmic reticulum stress process, and autophagy. Celecoxib can also reduce the occurrence of drug resistance by increasing the sensitivity of cancer cells to chemotherapy drugs.

A novel plausible mechanism of NSAIDs-induced apoptosis in cancer cells: the implication of proline oxidase and peroxisome proliferator-activated receptor

Although pharmaco-epidemiological studies provided evidence for the anticancer potential of non-steroidal anti-inflammatory drugs (NSAIDs), the mechanism of their anti-cancer activity is not known. Several lines of evidence suggest that proline dehydrogenase/proline oxidase (PRODH/POX) may represent a target for NSAIDs-dependent anti-cancer activity. PRODH/POX catalyzes conversion of proline into Δ1-pyrroline-5-carboxylate releasing ATP or reactive oxygen species for autophagy/apoptosis. Since NSAIDs are ligands of peroxisome proliferator-activated receptor (PPARs) and PPARs are implicated in PRODH/POX-dependent apoptosis we provided a hypothesis on the mechanism of NSAIDs-induced apoptosis in cancer cells.

L-Arginine/Nitric Oxide Pathway Is Altered in Colorectal Cancer and Can Be Modulated by Novel Derivatives from Oxicam Class of Non-Steroidal Anti-Inflammatory Drugs

L-arginine/nitric oxide pathway metabolites are altered in colorectal cancer (CRC). We evaluated underlying changes in pathway enzymes in 55 paired tumor/tumor-adjacent samples and 20 normal mucosa using quantitative-PCR and assessed the impact of classic and novel oxicam analogues on enzyme expression and intracellular metabolite concentration (LC-MS/MS) in Caco-2, HCT116, and HT-29 cells. Compared to normal mucosa, ARG1, PRMT1, and PRMT5 were overexpressed in both tumor and tumor-adjacent tissue and DDAH2 solely in tumor-adjacent tissue. Tumor-adjacent tissue had higher expression of ARG1, DDAH1, and DDAH2 and lower NOS2 than patients-matched tumors. The ARG1 expression in tumors increased along with tumor grade and reflected lymph node involvement. Novel oxicam analogues with arylpiperazine moiety at the thiazine ring were more effective in downregulating DDAHs and PRMTs and upregulating ARG2 than piroxicam and meloxicam. An analogue distinguished by propylene linker between thiazine's and piperazine's nitrogen atoms and containing two fluorine substituents was the strongest inhibitor of DDAHs and PRMTs expression, while an analogue containing propylene linker but no fluorine substituents was the strongest inhibitor of ARG2 expression. Metabolic reprogramming in CRC includes overexpression of DDAHs and PRMTs in addition to ARG1 and NOS2 and is not restricted to tumor tissue but can be modulated by novel oxicam analogues.

Esophageal Squamous Cell Carcinoma Is Accompanied by Local and Systemic Changes in L-arginine/NO Pathway

The L-arginine/NO pathway holds promise as a source of potential therapy target and biomarker; yet, its status and utility in esophageal squamous cell carcinoma (ESCC) is unclear. We aimed at quantifying pathway metabolites in sera from patients with ESCC (n = 61) and benign conditions (n = 62) using LC-QTOF-MS and enzyme expression in esophageal tumors and matched noncancerous samples (n = 40) using real-time PCR with reference to ESCC pathology and circulating immune/inflammatory mediators, quantified using Luminex xMAP technology. ESCC was associated with elevated systemic arginine and asymmetric dimethylarginine. Citrulline decreased and arginine bioavailability increased along with increasing ESCC advancement. Compared to adjacent tissue, tumors overexpressed ODC1, NOS2, PRMT1, and PRMT5 but had downregulated ARG1, ARG2, and DDAH1. Except for markedly higher NOS2 and lower ODC1 in tumors from M1 patients, the pathology-associated changes in enzyme expression were subtle and present also in noncancerous tissue. Both the local enzyme expression level and systemic metabolite concentration were related to circulating inflammatory and immune mediators, particularly those associated with eosinophils and those promoting viability and self-renewal of cancer stem cells. Metabolic reprogramming in ESCC manifests itself by the altered L-arginine/NO pathway. Upregulation of PRMTs in addition to NOS2 and ODC1 and the pathway link with stemness-promoting cytokines warrants further investigation.

Biological effects of selective COX-2 inhibitor NS398 on human glioblastoma cell lines

Background

Cyclooxygenase-2 (COX-2), an inflammation-associated enzyme, has been implicated in tumorigenesis and progression of glioblastoma (GBM). The poor survival of GBM was mainly associated with the presence of glioma stem cells (GSC) and the markedly inflammatory microenvironment. To further explore the involvement of COX-2 in glioma biology, the effects of NS398, a selective COX-2 inhibitor, were evaluated on GSC derived from COX-2 expressing GBM cell lines, i.e., U87MG and T98G, in terms of neurospheres' growth, autophagy, and extracellular vesicle (EV) release.

Methods

Neurospheres' growth and morphology were evaluated by optical and scanning electron microscopy. Autophagy was measured by staining acidic vesicular organelles. Extracellular vesicles (EV), released from neurospheres, were analyzed by transmission electron microscopy. The autophagic proteins Beclin-1 and LC3B, as well as the EV markers CD63 and CD81, were analyzed by western blotting. The scratch assay test was used to evaluate the NS398 influence on GBM cell migration.

Results

Both cell lines were strongly influenced by NS398 exposure, as showed by morphological changes, reduced growth rate, and appearance of autophagy. Furthermore, the inhibitor led to a functional change of EV released by neurospheres. Indeed, EV secreted by NS398-treated GSC, but not those from control cells, were able to significantly inhibit adherent U87MG and T98G cell migration and induced autophagy in recipient cells, thus leading to effects quite similar to those directly caused by NS398 in the same cells.

Conclusion

Despite the intrinsic diversity and individual genetic features of U87MG and T98G, comparable effects were exerted by the COX-2 inhibitor NS398 on both GBM cell lines. Overall, our findings support the crucial role of the inflammatory-associated COX-2/PGE2 system in glioma and glioma stem cell biology.

Synthesis, antitumor activity, and molecular docking study of 2-cyclopentyloxyanisole derivatives: mechanistic study of enzyme inhibition

A series of 24 compounds was synthesised based on a 2-cyclopentyloxyanisole scaffold 3–14 and their in vitro antitumor activity was evaluated. Compounds 4a, 4b, 6b, 7b, 13, and 14 had the most potent antitumor activity (IC₅₀ range: 5.13–17.95 μM), compared to those of the reference drugs celecoxib, afatinib, and doxorubicin. The most active derivatives 4a, 4b, 7b, and 13 were evaluated for their inhibitory activity against COX-2, PDE4B, and TNF-α. Compounds 4a and 13 potently inhibited TNF-α (IC₅₀ values: 2.01 and 6.72 μM, respectively) compared with celecoxib (IC₅₀=6.44 μM). Compounds 4b and 13 potently inhibited COX-2 (IC₅₀ values: 1.08 and 1.88 μM, respectively) comparable to that of celecoxib (IC₅₀=0.68 μM). Compounds 4a, 7b, and 13 inhibited PDE4B (IC₅₀ values: 5.62, 5.65, and 3.98 μM, respectively) compared with the reference drug roflumilast (IC₅₀=1.55 μM). The molecular docking of compounds 4b and 13 with the COX-2 and PDE4B binding pockets was studied.

Highlights

Antitumor activity of new synthesized cyclopentyloxyanisole scaffold was evaluated.

The powerful antitumor 4a, 4b, 6b, 7b & 13 were assessed as COX-2, PDE4B & TNF-α inhibitors.

Compounds 4a, 7b, and 13 exhibited COX-2, PDE4B, and TNF-α inhibition.

Compounds 4b and 13 showed strong interactions at the COX-2 and PDE4B binding pockets.

Fleszar M, Bednarz-Misa I, Lewandowski Ł, Szczuka I, Kempiński R, Neubauer K. Transcriptional and Metabolomic Analysis of L-Arginine/Nitric Oxide Pathway in Inflammatory Bowel Disease and Its Association with Local Inflammatory and Angiogenic Response: Preliminary Findings

L-arginine/nitric oxide pathway in Crohn's disease (CD) and ulcerative colitis (UC) is poorly investigated. The aim of current study is to quantify pathway serum metabolites in 52 CD (40 active), 48 UC (33 active), and 18 irritable bowel syndrome patients and 40 controls using mass spectrometry and at determining mRNA expression of pathway-associated enzymes in 91 bowel samples. Arginine and symmetric dimethylarginine decreased (p < 0.05) in active-CD (129 and 0.437 µM) compared to controls (157 and 0.494 µM) and active-UC (164 and 0.52 µM). Citrulline and dimethylamine increased (p < 0.05) in active-CD (68.7 and 70.9 µM) and active-UC (65.9 and 73.9 µM) compared to controls (42.7 and 50.4 µM). Compared to normal, CD-inflamed small bowel had downregulated (p < 0.05) arginase-2 by 2.4-fold and upregulated dimethylarginine dimethylaminohydrolase (DDAH)-2 (1.5-fold) and arginine N-methyltransferase (PRMT)-2 (1.6-fold). Quiescent-CD small bowel had upregulated (p < 0.05) arginase-2 (1.8-fold), DDAH1 (2.9-fold), DDAH2 (1.5-fold), PRMT1 (1.5-fold), PRMT2 (1.7-fold), and PRMT5 (1.4-fold). Pathway enzymes were upregulated in CD-inflamed/quiescent and UC-inflamed colon as compared to normal. Compared to inflamed, quiescent CD-colon had upregulated DDAH1 (5.7-fold) and ornithine decarboxylase (1.6-fold). Concluding, the pathway is deregulated in CD and UC, also in quiescent bowel, reflecting inflammation severity and angiogenic potential. Functional analysis of PRMTs and DDAHs as potential targets for therapy is warranted.

Biological and Spectroscopic Investigations of New Tenoxicam and 1.10-Phenthroline Metal Complexes

In the present work, tenoxicam (H₂Ten) reacted with Mn(II), Co(II), Ni(II), Cu(II) and Zn (II) ions in the presence of 1.10-phenthroline (Phen), forming new mixed ligand metal complexes. The properties of the formed complexes were depicted by elemental analyses, infrared, electronic spectra, proton nuclear magnetic resonance (¹H NMR), mass spectrometry, thermogravimetric (TGA) and differential thermogravimetric (DTG) analysis, molar conductance and magnetic moment. IR spectra demonstrated that H₂Ten acted as a neutral bidentate ligand, coordinated to the metal ions via the pyridine-N and carbonyl group of the amide moiety, and Phen through the nitrogen atoms. Kinetic thermodynamics parameters activation energy (E*), enthalpy of activation (ΔH*), entropy of activation (ΔS*), Gibbs, free energy (ΔG*) associated to the complexes have been evaluated. Antibacterial screening of the compounds was carried out in vitro against Clavibacter michiganensis, Xanthomonas campestris and Bacillus megaterium. Antifungal activity was performed in vitro against Monilinia fructicola, Penicillium digitatum and Colletotrichum acutatum. The possible phytotoxic effect of the studied compounds was also investigated on Solanum lycopersicum (tomatoes) and Lepidium sativum (garden cress) seeds. The anticancer activity was screened against cell cultures of HCT-116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and MCF-7 (human breast adenocarcinoma).

Prostanoid receptor genes confer poor prognosis in head and neck squamous cell carcinoma via epigenetic inactivation

Background

Chronic inflammation is a risk factor for head and neck squamous cell carcinoma (HNSCC) and other diseases. Prostanoid receptors are clearly involved in the development of many types of cancer. However, their role is not simple and is poorly understood in HNSCC.

Methods

Methylation profiles of prostanoid receptor family genes were generated for tumour samples obtained from 274 patients with HNSCC, including 69 hypopharynx, 51 larynx, 79 oral cavity, and 75 oropharynx tumour samples, by quantitative methylation-specific PCR. Promoter methylation was then evaluated with respect to various clinical characteristics and patient survival.

Results

The mean number of methylated genes per sample was 2.05 ± 2.59 (range 0 to 9). Promoters of PTGDR1, PTGDR2, PTGER1, PTGER2, PTGER3, PTGER4, PTGFR, PTGIR, and TBXA2R were methylated in 43.8%, 18.2%, 25.5%, 17.5%, 41.2%, 8.0%, 19.3%, 20.4%, and 11.3% of the samples, respectively. Methylation indices for prostanoid receptor family genes tended to be higher as the number of TET methylation events increased. Patients with 5–9 methylated genes had a significantly lower survival rate than that of patients with 0–4 methylated genes (log-rank test, P= 0.007). In multivariate analyses, PTGDR1 methylation was most highly correlated with recurrence in patients with hypopharyngeal cancer (P = 0.014). A similar correlation was observed for PTGER4 in patients with laryngeal cancer (P = 0.046). Methylation of the PTGIR and TBXA2R promoters was positively correlated with recurrence in oropharyngeal cancer (P = 0.028 and P = 0.006, respectively). Moreover, Patients with 5–9 methylated genes were extremely lower of 5hmC levels (P = 0.035) and was correlated with increasing expression of DNMT3A and DNMT3B (P < 0.05 and P < 0.05, respectively).

Conclusion

We characterised the relationship between the methylation status of prostanoid receptor genes and recurrence in HNSCC. These results provide new perspectives for the development of molecular targeted treatment approaches.