Celecoxib induces apoptosis by inhibiting 3-phosphoinositide-dependent protein kinase-1 activity in the human colon cancer HT-29 cell line

Synergistic celecoxib and dimethyl-celecoxib combinations block cervix cancer growth through multiple mechanisms

OBJECTIVE

The synergistic inhibitory effect of celecoxib (CXB) and dimethyl-celecoxib (DMC) plus paclitaxel (PA) or cisplatin (CP) on human cervix HeLa and SiHa cells was assessed at multiple cellular levels in order to elucidate the biochemical mechanisms triggered by the synergistic drug combinations.

METHODS

The effect of CXB (5 μM)/CP (2 μM) or CXB (5 μM)/PA (15 μM) and DMC (15 μM)/CP (5 μM) or DMC (15 μM)/PA (20 μM) for 24 h was assayed on cancer cell proliferation, energy metabolism, mitophagy, ROS production, glycoprotein-P activity, DNA stability and apoptosis/necrosis.

RESULTS

Drug combinations synergistically decreased HeLa and SiHa cell proliferation (>75%) and arrested cellular cycle by decreasing S and G2/M phases as well as the Ki67 content (HeLa) by 7.5-30 times. Cell viability was preserved (>90%) and no apparent effects on non-cancer cell growth were observed. Mitochondrial and glycolytic protein contents (44-95%) and ΔΨm (45-50%) in HeLa cells and oxidative phosphorylation and glycolysis fluxes (70-90%) in HeLa and SiHa cells were severely decreased, which in turn promoted a drastic fall in the ATP supply (85-88%). High levels of mitophagy proteins in HeLa cells and active mitochondrial digestion in HeLa and SiHa cells was observed. Mitochondrial fission and microtubule proteins were also affected. Intracellular ROS content (2-2.3-fold) and ROS production was stimulated (2.3-4 times), whereas content and activity of glycoprotein-P (45-85%) were diminished. DNA fragmentation was not observed and apoptosis/necrosis was not detected suggesting that cell death could be mainly associated to mitophagy induction.

CONCLUSIONS

CXB or DMC combination with canonical chemotherapy may be a promising chemotherapy strategy against cervical cancer growth, because it can selectively block multiple cell processes including inhibition of energy pathways and in consequence ATP-dependent processes such as cell proliferation, glycoprotein-P activity, ROS production and mitophagy, with no apparent effects on non-cancer cells.

Causal relationship between anti-inflammatory drugs and cancer: a pan-cancer study with Mendelian randomization

Background

Numerous epidemiological studies have elucidated the intricate connection between inflammation and cancer, highlighting how sustained inflammatory responses can fuel carcinogenesis by fostering proliferation, angiogenesis, and metastasis, while dampening immune responses and sensitivity to chemotherapy. Previous clinical investigations have underscored the potential of anti-inflammatory medications in either preventing or mitigating tumor formation. Here, the causal relationship between anti-inflammatory drugs and cancer was further explored through Mendelian randomization studies.

Methods

Employing Mendelian randomization, we scrutinized the causal links between three anti-inflammatory drugs-NSAIDs, Aspirin, and Anilide-and 37 types of cancer. We primarily utilized inverse variance weighting (IVW) as the primary analytical approach to delineate the causal association between these drugs and cancer types. Concurrently, sensitivity analyses were conducted to ascertain the absence of horizontal pleiotropy and heterogeneity.

Results

Our investigation revealed a discernible causal relationship between certain anti-inflammatory drugs and a subset of cancers, albeit without a pervasive impact across all cancer types. Specifically, NSAIDs exhibited a risk-reducing effect on non-small cell lung cancer (OR: 0.76, 95% CI: 0.59-0.97, p-value: 0.03) and gastric cancer (OR: 0.57, 95% CI: 0.34-0.98, p-value: 0.04). Conversely, aspirin was associated with an increased risk of oral malignant tumors (OR: 2.18, 95% CI: 1.13-4.21, p-value: 0.02). Notably, no statistically significant findings were observed for anilide drugs (p < 0.05).

Conclusion

We identified several cancers with potential causal links to NSAIDs, including non-small cell lung cancer and gastric cancer. Despite our extensive analysis, we did not identify a substantial causal relationship between the use of anti-inflammatory drugs and the development of various cancers.

The relationship between nonsteroidal anti-inflammatory drugs and cancer incidence: An umbrella review

Several clinical and preclinical studies have shown that nonsteroidal anti-inflammatory drugs (NSAIDs), particularly aspirin, reduce the incidence of various cancer types. However, there is still a lack of literature evaluating the overall association between multiple cancer morbidities and NSAIDs. Thus, we conducted an umbrella review to evaluate the quality of evidence, validity, and biases of the existing systematic reviews and meta-analyses on the relationships between NSAIDS and multiple tumor incidence outcomes. We found that NSAIDs might be associated with a decreased risk of several cancers, including the central nervous system, breast, esophageal, gastric, head and neck, hepatocellular, cholangiocarcinoma, colorectal, endometrial, lung, ovary, prostate, and pancreatic cancers, but regular intake of any dose of non-aspirin NSAIDs (NA-NSAIDs) could increase the incidence of kidney cancer. However, most of included studies are evaluated as low quality according to our evidence assessment. Furthermore, due to the potential side effects, such as hemorrhage, digestive symptoms and peptic ulcer, it is still not recommend to use NSAIDs regularly to prevent cancers.

Investigation of mitochondrial targeting ability of sydnones and sydnonimines and mitochondria-targeted delivery of celecoxib

Mitochondria are considered to be a promising target in cancer diagnosis and therapeutics. Recently, sydnone and sydnonimine, as mesoionic bioorthogonal reagents, have been used in cell labeling and drug delivery. Here we investigated the mitochondrial targeting ability of sydnones and sydnonimines for the first time. Experimental results show that sydnone and sydnonimine themselves have high mitochondrial distribution. However, the introduction of a phenyl group into the C₄ position of sydnone dramatically decreases the mitochondrial affinity. In addition, we took advantage of mitochondrial targeting ability and click-and-release reaction of sydnonimine to evaluate anticancer activities of in-mitochondria delivery of celecoxib against HeLa and HepG2 cells, indicating that celecoxib-induced cancer cell death may not involve mitochondria-related pathway.

Targeting cancer-related inflammation with non-steroidal anti-inflammatory drugs: Perspectives in pharmacogenomics

Inflammatory processes are essential for innate immunity and contribute to carcinogenesis in various malignancies, such as colorectal cancer, esophageal cancer and lung cancer. Pharmacotherapies targeting inflammation have the potential to reduce the risk of carcinogenesis and improve therapeutic efficacy of existing anti-cancer treatment. Non-steroidal anti-inflammatory drugs (NSAIDs), comprising a variety of structurally different chemicals that can inhibit cyclooxygenase (COX) enzymes and other COX-independent pathways, are originally used to treat inflammatory diseases, but their preventive and therapeutic potential for cancers have also attracted researchers' attention. Pharmacogenomic variability, including distinct genetic characteristics among different patients, can significantly affect pharmacokinetics and effectiveness of NSAIDs, which might determine the preventive or therapeutic success for cancer patients. Hence, a more comprehensive understanding in pharmacogenomic characteristics of NSAIDs and cancer-related inflammation would provide new insights into this appealing strategy. In this review, the up-to-date advances in clinical and experimental researches targeting cancer-related inflammation with NSAIDs are presented, and the potential of pharmacogenomics are discussed as well.

Tackling Surgical Morbidity and Mortality through Modifiable Risk Factors in Cancer Patients

Despite advances in surgical techniques, surgical morbidity and mortality remain important public health problems. Postoperative complications often lead to greater morbidity and mortality, as well as increased length of hospital stay and medical costs. Therefore, a reduction in postoperative complications is particularly important with regard to positive long-term outcomes in patients with cancer. To improve patients' postoperative prognosis, it is necessary to screen for and focus on modifiable risk factors and their subsequent resolution. Recently, it was reported that nutritional status, inflammation and surgical approaches are related to postoperative morbidity and mortality. Therefore, in this review article, we describe the current evidence regarding modifiable risk factors influencing surgical morbidity and mortality as well as future directions for improved postoperative management in cancer patients.

NSAIDs and Cancer Resolution: New Paradigms beyond Cyclooxygenase

Acute inflammation or resolved inflammation is an adaptive host defense mechanism and is self-limiting, which returns the body to a state of homeostasis. However, unresolved, uncontrolled, or chronic inflammation may lead to various maladies, including cancer. Important evidence that links inflammation and cancer is that nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, reduce the risk and mortality from many cancers. The fact that NSAIDs inhibit the eicosanoid pathway prompted mechanistic drug developmental work focusing on cyclooxygenase (COX) and its products. The increased prostaglandin E2 levels and the overexpression of COX-2 in the colon and many other cancers provided the rationale for clinical trials with COX-2 inhibitors for cancer prevention or treatment. However, NSAIDs do not require the presence of COX-2 to prevent cancer. In this review, we highlight the effects of NSAIDs and selective COX-2 inhibitors (COXIBs) on targets beyond COX-2 that have shown to be important against many cancers. Finally, we hone in on specialized pro-resolving mediators (SPMs) that are biosynthesized locally and, in a time, -dependent manner to promote the resolution of inflammation and subsequent tissue healing. Different classes of SPMs are reviewed, highlighting aspirin's potential in triggering the production of these resolution-promoting mediators (resolvins, lipoxins, protectins, and maresins), which show promise in inhibiting cancer growth and metastasis.

CircRNA ANXA2 Promotes Lung Cancer Proliferation and Metastasis by Upregulating PDPK1 Expression

Lung cancer is a common malignant tumor that seriously threatens human health. It has become the top malignant tumor in terms of morbidity and mortality. In recent years, circRNA, a special noncoding RNA molecule, has attracted considerable interest. This study focused on the role of circRNA ANXA2 (circANXA2) in lung cancer and the molecular mechanism of cancer promotion. Real-time quantitative PCR (RT-PCR) was used in detecting the expression abundance of circANXA2 in different lung cancer cells and tissues. The subcellular localization of circANXA2 was detected through fluorescence in situ hybridization. circANXA2 expression was knocked down through siRNA. CCK-8, clone formation assay, and TUNEL assay were used in evaluating the effects of circANXA2 on cell proliferation, clone formation ability, and apoptosis. The role of circANXA2 in tumor proliferation was further verified in vivo using the tumor transplantation model in nude mice. The molecular mechanism of circANXA2 was investigated with luciferase activity assay and RT-PCR. The expression abundance of circANXA2 is high in lung cancer cell lines and tissues. Knocking down of circANXA2 inhibits the proliferation and clonogenesis of the lung cancer cells. Knocking down circANXA2 promotes apoptosis. circANXA2 further affects downstream PDPK1 expression by regulating miR-33a-5p and thereby affecting the malignancy of the lung cancer cells. circANXA2 inhibits miR-33a-5p activity by directly interacting with miR-33a-5p. circANXA2 regulates the transcription of the miR-33a-5p downstream target gene PDPK1 and affects the malignant progression of lung cancer.

Modulation of endothelium function by fatty acids

The endothelium acts as the barrier that prevents circulating lipids such as lipoproteins and fatty acids into the arterial wall; it also regulates normal functioning in the circulatory system by balancing vasodilation and vasoconstriction, modulating the several responses and signals. Plasma lipids can interact with endothelium via different mechanisms and produce different phenotypes. Increased plasma-free fatty acids (FFAs) levels are associated with the pathogenesis of atherosclerosis and cardiovascular diseases (CVD). Because of the multi-dimensional roles of plasma FFAs in mediating endothelial dysfunction, increased FFA level is now considered an essential link in the onset of endothelial dysfunction in CVD. FFA-mediated endothelial dysfunction involves several mechanisms, including dysregulated production of nitric oxide and cytokines, metaflammation, oxidative stress, inflammation, activation of the renin-angiotensin system, and apoptosis. Therefore, modulation of FFA-mediated pathways involved in endothelial dysfunction may prevent the complications associated with CVD risk. This review presents details as to how endothelium is affected by FFAs involving several metabolic pathways.

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.

In Silico Approach Using Free Software to Optimize the Antiproliferative Activity and Predict the Potential Mechanism of Action of Pyrrolizine-Based Schiff Bases

In the current study, a simple in silico approach using free software was used with the experimental studies to optimize the antiproliferative activity and predict the potential mechanism of action of pyrrolizine-based Schiff bases. A compound library of 288 Schiff bases was designed based on compound 10, and a pharmacophore search was performed. Structural analysis of the top scoring hits and a docking study were used to select the best derivatives for the synthesis. Chemical synthesis and structural elucidation of compounds 16a–h were discussed. The antiproliferative activity of 16a–h was evaluated against three cancer (MCF7, A2780 and HT29, IC₅₀ = 0.01–40.50 μM) and one normal MRC5 (IC₅₀ = 1.27–24.06 μM) cell lines using the MTT assay. The results revealed the highest antiproliferative activity against MCF7 cells for 16g (IC₅₀ = 0.01 μM) with an exceptionally high selectivity index of (SI = 578). Cell cycle analysis of MCF7 cells treated with compound 16g revealed a cell cycle arrest at the G₂/M phase. In addition, compound 16g induced a dose-dependent increase in apoptotic events in MCF7 cells compared to the control. In silico target prediction of compound 16g showed six potential targets that could mediate these activities. Molecular docking analysis of compound 16g revealed high binding affinities toward COX-2, MAP P38α, EGFR, and CDK2. The results of the MD simulation revealed low RMSD values and high negative binding free energies for the two complexes formed between compound 16g with EGFR, and CDK2, while COX-2 was in the third order. These results highlighted a great potentiality for 16g to inhibit both CDK2 and EGFR. Taken together, the results mentioned above highlighted compound 16g as a potential anticancer agent.

Review: Schistosoma mansoni phosphatidylinositol 3 kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signaling pathway

Schistosoma mansoni worms are under a milieu of external and internal signaling pathways. The life-cycle stages are exposed to enormous stimuli within the mammalian and the snail hosts and as free-living stages in the fresh water. Furthermore, there is a unique interplay between the male and the female worms involving many stimuli from the male essential for full development of the female. PI3K/Akt/mTOR is an evolutionarily divergent signal transduction pathway universal to nearly every multicellular organism. This work reviews the Schistosoma mansoni PI3K/Akt/mTOR signal pathways and the involvement of the signal in the worms' physiology concerning the uptake of glucose, reproduction and survival. The inhibitors of the signal pathway used against Schistosoma mansoni were summarized. Given the importance of the PI3K/Akt/mTOR signal pathway, its inhibition could be a promising control strategy against schistosomiasis.

Development of PET Radioligands Targeting COX-2 for Colorectal Cancer Staging, a Review of in vitro and Preclinical Imaging Studies

Colorectal cancer (CRC) is the second most common cause of cancer death, making early diagnosis a major public health challenge. The role of inflammation in tumorigenesis has been extensively explored, and among the identified markers of inflammation, cyclooxygenase-2 (COX-2) expression seems to be linked to lesions with a poor prognosis. Until now, COX-2 expression could only be accessed by invasive methods, mainly by biopsy. Imaging techniques such as functional Positron Emission Tomography (PET) could give access to in vivo COX-2 expression. This could make the staging of the disease more accurate and would be of particular interest in the exploration of the first metastatic stages. In this paper, we review recent progress in the development of COX-2 specific PET tracers by comparing the radioligands' characteristics and highlighting the obstacles that remain to be overcome in order to achieve the clinical development of such a radiotracer, and its evaluation in the management of CRC.

Effect of celecoxib against different developmental stages of experimental Schistosoma mansoni infection

Due to the high prevalence of schistosomiasis and the wide use of praziquantel solely for mass drug administration to control the disease, there is a great concern about the potential emergence of reduced susceptibility strains. This, together with the concern that praziquantel is ineffective against juvenile worms highlight the importance of developing an alternative anti-schistosomal drug. Using nonsteroidal anti-inflammatory drugs against schistosome infection is considerable. The present study evaluated the effect of oral administration of five days celecoxib regimen (20 mg/kg/day) against different developmental stages of Schistosoma mansoni infection. This regimen induced significant reduction in worm burden, tissue egg count, individual female fecundity and the mean percentage of immature and mature eggs with increased mean percentage of dead eggs. More importantly, celecoxib was more potent than praziquantel in all these parasitological parameters (except in the worm burden when given against the adult stage where the difference was statistically non-significant). Scanning and transmission electron microscopy of the adult worms revealed severe tegumental damage, laceration of the muscular layers and oedema of the syncytial layer. There was disruption of the testicular, ovarian and vitelline glandular tissues with signs of apoptosis and abnormalities of the spermatozoa and the oocytes. Additionally, celecoxib induced reduction in the number and the size of the hepatic granulomata and also amelioration of the hepatic tissue pathology.

Celecoxib induces apoptosis through Akt inhibition in 5-fluorouracil-resistant gastric cancer cells

Gastric cancer is the fifth leading cause of cancer and a global public health problem. 5-Fluorouracil (5-FU) is the primary drug chosen for the treatment of advanced gastric cancer, but acquired cancer drug resistance limits its effectiveness and clinical use. Proliferation assays showed that a gastric carcinoma cell line, AGS and 5-FU-resistant AGS cells (AGS FR) treated with 3-100 μM 5-FU for 48 h or 72 h showed different sensitivities to 5-FU. Immunoblot assay demonstrated that AGS FR cells expressed more COX-2 and PGE₂-cognated receptor EP2 than AGS cells. AGS FR cells considerably produced PGE₂ than AGS upon stimulation with 5-FU. These results suggest that COX-2 expression is associated with 5-FU resistance. Unlike AGS FR cells, AGS cells showed increased levels of both cleaved caspase-3 and Bax following 5-FU treatment. Treatment of cells with the COX-2 selective inhibitor celecoxib induced cell death of AGS FR cells in a time- and concentration-dependent manner. FACS analysis showed that celecoxib at high doses caused apoptotic cell death, demonstrating a concentration-dependent increase in the cell populations undergoing early apoptosis and late apoptosis. This apoptotic induction was strongly supported by the expression profiles of apoptosis- and survival-associated proteins in response to celecoxib; pro-apoptotic cellular proteins increased while expressions of COX-2 and p-Akt were downregulated in a concentration-dependent manner. An increase in PTEN expression was accompanied with downregulation of p-Akt. Based on the data that downregulation of COX-2 was correlated with the concentrations of celecoxib, COX-2 may play a key role in celecoxib-induced cell death of AGS FR cells. Butaprost, the EP2 agonist, promoted proliferative activity of AGS FR cells in a concentration-dependent manner compared with AGS cells. In cells exposed to butaprost, expressions of COX-2 and p-Akt were increased in a concentration-dependent manner with concomitantly reduced PTEN levels. Taken together, 5-FU-resistance in gastric cancer is correlated with COX-2 expression, and therefore the selective inhibition of COX-2 leads to suppression of cell proliferation of AGS FR cells. Modulation of COX-2 expression and its catalytic activity may be a potential therapeutic strategy to overcome 5-FU-resistant gastric cancer.

Novel Thiosemicarbazones Sensitize Pediatric Solid Tumor Cell-Types to Conventional Chemotherapeutics through Multiple Molecular Mechanisms

Simple Summary

Combination of chemotherapeutics for the treatment of childhood cancer can lead to the use of lower cytotoxic drug doses and better therapeutic tolerability (i.e., lower side effects) for patients. We discovered novel molecular targets of two lead thiosemicarbazone agents of the di-2-pyridylketone thiosemicarbazone class. These molecular targets include: cyclooxygenase, the DNA repair protein, O6-methylguanine DNA methyltransferase, mismatch repair proteins, and topoisomerase 2α. This research also identifies promising synergistic interactions of these thiosemicarbazones particularly with the standard chemotherapeutic, celecoxib.

Abstract

Combining low-dose chemotherapies is a strategy for designing less toxic and more potent childhood cancer treatments. We examined the effects of combining the novel thiosemicarbazones, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), or its analog, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), with the standard chemotherapies, celecoxib (CX), etoposide (ETO), or temozolomide (TMZ). These combinations were analyzed for synergism to inhibit proliferation of three pediatric tumor cell-types, namely osteosarcoma (Saos-2), medulloblastoma (Daoy) and neuroblastoma (SH-SY5Y). In terms of mechanistic dissection, this study discovered novel thiosemicarbazone targets not previously identified and which are important for considering possible drug combinations. In this case, DpC and Dp44mT caused: (1) up-regulation of a major protein target of CX, namely cyclooxygenase-2 (COX-2); (2) down-regulation of the DNA repair protein, O⁶-methylguanine DNA methyltransferase (MGMT), which is known to affect TMZ resistance; (3) down-regulation of mismatch repair (MMR) proteins, MSH2 and MSH6, in Daoy and SH-SY5Y cells; and (4) down-regulation in all three cell-types of the MMR repair protein, MLH1, and also topoisomerase 2α (Topo2α), the latter of which is an ETO target. While thiosemicarbazones up-regulate the metastasis suppressor, NDRG1, in adult cancers, it is demonstrated herein for the first time that they induce NDRG1 in all three pediatric tumor cell-types, validating its role as a potential target. In fact, siRNA studies indicated that NDRG1 was responsible for MGMT down-regulation that may prevent TMZ resistance. Examining the effects of combining thiosemicarbazones with CX, ETO, or TMZ, the most promising synergism was obtained using CX. Of interest, a positive relationship was observed between NDRG1 expression of the cell-type and the synergistic activity observed in the combination of thiosemicarbazones and CX. These studies identify novel thiosemicarbazone targets relevant to childhood cancer combination chemotherapy.

Celecoxib and Afatinib synergistic enhance radiotherapy sensitivity on human non-small cell lung cancer A549 cells

PURPOSE

Radioresistance is highly correlated with radiotherapy failure in clinical cancer treatment. In the current study, we sought to examine the efficacy of Celecoxib and Afatinib co-treatment as radiosensitizers in the management of non-small cell lung cancer (NSCLC) A549 cells.

MATERIALS AND METHODS

Generally, A549 cells were cultured with the treatment of Celecoxib and/or Afatinib for 24 h. Then, the cells were exposed to irradiation at 2 Gy/min for 1 min. After the end of treatment, cell viability, clonogenic survival, apoptosis and Prostaglandin E2 (PGE2) Elisa assays were performed. Transcriptional levels of Cyclooxygenase-2 (COX-2) affected by Celecoxib and/or Afatinib were measured by RT-qPCR. Posttranscriptional level of epidermal growth factor receptor (EGFR)-related gene was measured by Western blotting analysis.

RESULTS

Here, we, for the first time, reported that the co-treatment of Celecoxib and Afatinib regulates the resistance of NSCLC A549 cells to radiation. The co-treatment of Celecoxib and Afatinib sensitized radiotherapy through the radiation-induced loss of cell viability and colony formation, as well as apoptosis. Mechanistically, Celecoxib and Afatinib-treated cells showed the inhibition of COX-2 and EGFR expression, which may be responsible for the A549 cells' increased resistance to radiation.

CONCLUSION

Our results suggested that Celecoxib and Afatinib regulate cell sensitivity to apoptosis, and thus modulate the resistance of NSCLC to radiation.

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.

Celecoxib substituted biotinylated poly(amidoamine) G3 dendrimer as potential treatment for temozolomide resistant glioma therapy and anti-nematode agent

Glioblastoma multiforme (GBM) is a one of the most widely diagnosed and difficult to treat type of central nervous system tumors. Resection combined with radiotherapy and temozolomide (TMZ) chemotherapy prolongs patients' survival only for 12 - 15 months after diagnosis. Moreover, many patients develop TMZ resistance, thus important is search for a new therapy regimes including targeted drug delivery. Most types of GBM reveal increased expression of cyclooxygenase-2 (COX-2) and production of prostaglandin E2 (PGE₂), that are considered as valuable therapeutic target. In these studies, the anti-tumor properties of the selective COX-2 inhibitor celecoxib (CXB) and biotinylated third generation of the poly(amidoamine) dendrimer substituted with 31 CXB residues (G3BC31) on TMZ -resistant U-118 MG glioma cell line were examined and compared with the effect of TMZ alone including viability, proliferation, migration and apoptosis, as well as the cellular expression of COX-2, ATP level, and PGE₂ production. Confocal microscopy analysis with the fluorescently labeled G3BC31 analogue has shown that the compound was effectively accumulated in U-118 MG cells in time-dependent manner and its localization was confirmed in lysosomes but not nuclei. G3BC31 reveal much higher cytotoxicity for U-118 MG cells at relatively low concentrations in the range of 2-4 µM with compared to CBX alone, active at 50-100 µM. This was due to induction of apoptosis and inhibition of proliferation and migration. Observed effects were concomitant with reduction of PGE₂ production but independent of COX-2 expression. We suggest that investigated conjugate may be a promising candidate for therapy of TMZ-resistant glioblastoma multiforme, although applicable in local treatment, since our previous study of G3BC31 did not demonstrate selectivity against glioma cells compared to normal human fibroblasts. However, it has to be pointed that in our in vivo studies conducted with model organism, Caenorhabditis elegans indicated high anti-nematode activity of G3BC31 in comparison with CXB alone that confirms of usefulness of that organism for estimation of anti-cancer drug toxicity.

Celecoxib Prevents Doxorubicin-Induced Multidrug Resistance in Canine and Mouse Lymphoma Cell Lines

Background: Treatment of malignancies is still a major challenge in human and canine cancer, mostly due to the emergence of multidrug resistance (MDR). One of the main contributors of MDR is the overexpression P-glycoprotein (Pgp), which recognizes and extrudes various chemotherapeutics from cancer cells. Methods: To study mechanisms underlying the development of drug resistance, we established an in vitro treatment protocol to rapidly induce Pgp-mediated MDR in cancer cells. Based on a clinical observation showing that a 33-day-long, unplanned drug holiday can reverse the MDR phenotype of a canine diffuse large B-cell lymphoma patient, our aim was to use the established assay to prevent the emergence of drug resistance in the early stages of treatment. Results: We showed that an in vitro drug holiday results in the decrease of Pgp expression in MDR cell lines. Surprisingly, celecoxib, a known COX-2 inhibitor, prevented the emergence of drug-induced MDR in murine and canine lymphoma cell lines. Conclusions: Our findings suggest that celecoxib could significantly improve the efficiency of chemotherapy by preventing the development of MDR in B-cell lymphoma.

The inflammatory microenvironment in vestibular schwannoma

Vestibular schwannomas are tumors arising from the vestibulocochlear nerve at the cerebellopontine angle. Their proximity to eloquent brainstem structures means that the pathology itself and the treatment thereof can be associated with significant morbidity. The vast majority of these tumors are sporadic, with the remainder arising as a result of the genetic syndrome Neurofibromatosis Type 2 or, more rarely, LZTR1-related schwannomatosis. The natural history of these tumors is extremely variable, with some tumors not displaying any evidence of growth, others demonstrating early, persistent growth and a small number growing following an extended period of indolence. Emerging evidence now suggests that far from representing Schwann cell proliferation only, the tumor microenvironment is complex, with inflammation proposed to play a key role in their growth. In this review, we provide an overview of this new evidence, including the role played by immune cell infiltration, the underlying molecular pathways involved, and biomarkers for detecting this inflammation in vivo. Given the limitations of current treatments, there is a pressing need for novel therapies to aid in the management of this condition, and we conclude by proposing areas for future research that could lead to the development of therapies targeted toward inflammation in vestibular schwannoma.

Celecoxib enhances the sensitivity of non-small-cell lung cancer cells to radiation-induced apoptosis through downregulation of the Akt/mTOR signaling pathway and COX-2 expression

The current study aimed to identify the radiosensitizing effect of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, in combination with radiotherapy in non-small-cell lung cancer (NSCLC) cells. The combination of celecoxib potentiated radiation-induced apoptosis; however, no changes in cell cycle distribution and number of phosphorylated histone H2AX foci were detected, indicating a DNA damage-independent mechanism. In an in vivo mouse model, the tumor size was significantly decreased in the group combining celecoxib with radiation compared with the radiation only group. Phosphorylation of protein kinase B (Akt) and mammalian target of rapamycin (mTOR), as well as expression of COX-2 were significantly downregulated in cells treated with the combination of celecoxib and radiation compared with the radiation only group. The result indicated that celecoxib exhibits radiosensitizing effects through COX-2 and Akt/mTOR-dependent mechanisms. Induction the Akt/mTOR signaling pathway promotes radioresistance in various cancers, including NSCLC. Therefore, the current study suggested the therapeutic potential of combination therapy of celecoxib and radiation in the prevention of radioresistance.

Vanillin extracted from Proso and Barnyard millets induce apoptotic cell death in HT-29 human colon cancer cell line

In the present study, we hypothesized that the active compound extracted from Proso and Barnyard millets inhibits cell proliferation and apoptosis induction in colon cancer cell line. The bioactive compounds from these millets were purified by supercritical fluid extraction and their structure was elucidated using spectroscopic methods. Extracted bioactive components from these millets were similar in chemical structure to the phenolic aldehyde-Vanillin [4-Hydroxy-3-methoxybenzaldehyde]. Cell proliferative effect was assessed by MTT assay using HT-29 cell line. Compound 1 significantly inhibited the proliferation of HT-29 cells when treated with concentrations of 250 µg/ml and 1,000 µg/ml for 48 h, while compound 2 moderately inhibited the proliferation of the HT-29 cell line at the same concentration and time period. Cytotoxic activity of extracted compounds by the release of lactate dehydrogenase confirms that these compounds were not toxic to the cells at 250 µg/ml of compounds 1 and 2. In addition, flow cytometry results show a significant cell arrest in the G0/G1 phase and increase in the apoptotic cells in sub G0 phase, in a dose-dependent manner when compared with the control. The conclusion of this study suggests that the anticancer property of these millets is mediated through the presence of vanillin.

Diclofenac induced apoptosis via altering PI3K/Akt/MAPK signaling axis in HCT 116 more efficiently compared to SW480 colon cancer cells

Diclofenac is a preferential cyclooxygenase 2 inhibitor (COX-2) and member of non-steroidal anti-inflammatory drugs (NSAIDs). Inflammation is one of the main reason of poor prognosis of colon cancer cases; thereby NSAIDs are potential therapeutic agents in colon cancer therapy. In this study, our aim to understand the potential molecular targets of diclofenac, which may propose new therapeutic targets in HCT 116 (wt p53) and SW480 (mutant p53R273H) colon cancer cells. For this purpose, we identified different response against diclofenac treatment through expression profiles of PI3K/Akt/MAPK signaling axis. Our hypothesis was diclofenac-mediated apoptosis is associated with inhibition of PI3K/Akt/MAPK signaling axis. We found that sub-cytotoxic concentration of diclofenac (400 µM) promoted further apoptosis in HCT 116 cells compared to SW480 colon cancer cells. Diclofenac triggered dephosphorylation of PTEN, PDK, Akt, which led to inhibition of PI3K/Akt survival axis in HCT 116 colon cancer cells. However, diclofenac showed lesser effect in SW480 colon cancer cells. In addition, diclofenac further activated p44/42, p38 and SAPK/JNK in HCT 116 cells compared to SW480 cells.

Sequential treatment with celecoxib and bortezomib enhances the ER stress-mediated autophagy-associated cell death of colon cancer cells

Treatment with celecoxib and bortezomib as single chemotherapeutic agents reduces the viability and proliferation of colorectal cancer cells. The use of these agents in combination with other chemotherapeutic agents is usually associated with adverse effects. In the present study, a combination of celecoxib and bortezomib was investigated for potential synergistic effects in colon cancer cells. The sequential exposure to celecoxib with bortezomib synergistically induced apoptotic death in human colon cancer cells compared with groups treated with a single drug or other drug combinations. c-Jun N-terminal kinase/p38-mitogen-activated protein kinase-induced endoplasmic reticulum (ER) stress through serial exposure to celecoxib and bortezomib may have induced the intracellular Ca²⁺ release, leading to the generation of autophagosomes in p53-expressing HCT-116 cells. Targeted inhibition of p53 activity or ER stress or treatment with the Ca²⁺-chelating agent BAPTA-AM suppressed the ER stress-mediated Ca²⁺ release and apoptosis. Although p53^-/- HCT-116 cells were less sensitive to sequential treatment with celecoxib and bortezomib, co-localization of autophagosomes was detected in the absence of CCAAT-enhancer-binding protein homologous protein expression. Treatment of p53^-/- HCT-116 cells with BAPTA-AM did not inhibit apoptosis following serial treatment with celecoxib and bortezomib. These results suggest that the order of drug administration is important in treating cancer and that the sequential treatment with celecoxib and bortezomib enhances the ER stress-mediated autophagy-associated cell death of colon cancer cells, regardless of p53 expression.

Design, Synthesis and Biological Activity Evaluation of S-Substituted 1H-5-Mercapto-1,2,4-Triazole Derivatives as Antiproliferative Agents in Colorectal Cancer

Colon cancer is a widespread pathology with complex biochemical etiology based on a significant number of intracellular signaling pathways that play important roles in carcinogenesis, tumor proliferation and metastasis. These pathways function due to the action of key enzymes that can be used as targets for new anticancer drug development. Herein we report the synthesis and biological antiproliferative evaluation of a series of novel S-substituted 1H-3-R-5-mercapto-1,2,4-triazoles, on a colorectal cancer cell line, HT-29. Synthesized compounds were designed by docking based virtual screening (DBVS) of a previous constructed compound library against protein targets, known for their important role in colorectal cancer signaling: MEK1, ERK2, PDK1, VEGFR2. Among all synthesized structures, TZ55.7, which was retained as a possible PDK1 (phospholipid-dependent kinase 1) inhibitor, exhibited the most significant cytotoxic activity against HT-29 tumor cell line. The same compound alongside other two, TZ53.7 and TZ3a.7, led to a significant cell cycle arrest in both sub G0/G1 and G0/G1 phase. This study provides future perspectives for the development of new agents containing the 1,2,4-mercapto triazole scaffold with antiproliferative activities in colorectal cancer.

The potential to treat lung cancer via inhalation of repurposed drugs

Lung cancer is a highly invasive and prevalent disease with ineffective first-line treatment and remains the leading cause of cancer death in men and women. Despite the improvements in diagnosis and therapy, the prognosis and outcome of lung cancer patients is still poor. This could be associated with the lack of effective first-line oncology drugs, formation of resistant tumors and non-optimal administration route. Therefore, the repurposing of existing drugs currently used for different indications and the introduction of a different method of drug administration could be investigated as an alternative to improve lung cancer therapy. This review describes the rationale and development of repositioning of drugs for lung cancer treatment with emphasis on inhalation. The review includes the current progress of repurposing non-cancer drugs, as well as current chemotherapeutics for lung malignancies via inhalation. Several potential non-cancer drugs such as statins, itraconazole and clarithromycin, that have demonstrated preclinical anti-cancer activity, are also presented. Furthermore, the potential challenges and limitations that might hamper the clinical translation of repurposed oncology drugs are described.

Autophagy inhibition enhances celecoxib-induced apoptosis in osteosarcoma

Osteosarcoma (OS) is the most prevalent bone malignancy in childhood and adolescence, with highly aggressive and early systemic metastases. Here, we reported that celecoxib, a selective COX-2 inhibitor in the NSAID class, exhibits strong antitumor activity in dose dependent manner in two OS cell lines-143B and U2OS. We showed that celecoxib inhibits OS cell growth, causes G0/G1-phase arrest, modulates apoptosis and autophagy and reduces migration in OS cells. In addition, the results of fluorescent mitochondrial probe JC-1 test indicated that the mitochondrial pathway mediates celecoxib-induced apoptosis. Significantly, the autophagy inhibitor CQ combined with celecoxib causes greater cell proliferation inhibition and apoptosis. Pharmacologic inhibition of autophagy with another potent autophagy inhibitor SAR405 also enhances celecoxib-mediated suppression of cell viability. These results were confirmed with shRNAs targeting the autophagy-related gene Atg5. In OS tumor xenografts in vivo, celecoxib also presents antitumor activity. Taken together, our results shed light on the function and mechanism of antitumor action of celecoxib for treatment of OS patients.

Comparison of NSAIDs activity in COX-2 expressing and non-expressing 2D and 3D pancreatic cancer cell cultures

Purpose

In this study, we evaluated the anticancer activity of non-steroidal anti-inflammatory drugs (NSAIDs) in BxPC-3 and MIA PaCa-2 pancreatic cancer cell cultures.

Methods

To test the effect of compounds on the viability of cells, the MTT assay was used. The activity of NSAIDs in 3D cell cultures was evaluated by measuring the size change of spheroids. The type of cell death was identified by cell staining with Hoechst 33342 and propidium iodide. To evaluate the effect on the colony-forming ability of cancer cells, the clonogenic assay was used.

Results

Five out of seven tested NSAIDs reduced the viability of BxPC-3 and MIA PaCa-2 cancer cells. Fenamates were more active against cyclooxygenase-2 expressing BxPC-3 than cyclooxygenase-2 non-expressing MIA PaCa-2 cell line. Fenamates and coxibs exerted higher activity in monolayer cultured cells, whereas salicylates were more active in 3D cultures. Fenamates and coxibs induced dose-dependent apoptosis and necrosis. NSAIDs also inhibited the colony-forming ability of cancer cells. Meclofenamic acid, niflumic acid, and parecoxib possessed higher activity on BxPC-3, and celecoxib possessed higher activity on MIA PaCa-2 cell colony formation.

Conclusion

Our results show that fenamates, coxibs, and salicylates possess anticancer activity on human pancreatic cancer BxPC-3 and MIA PaCa-2 cell cultures.

Biological and pharmacological effects of hexahydrocurcumin, a metabolite of curcumin

Curcumin, one of the most precious pharmacologically relevant natural products, has gained considerable attention among scientists for decades because of its multi-pharmacological activities in the clinical. However, critical studies on its pharmacological and toxicological activities are needed to understand how this compound can have these biological functions considering its poor oral bioavailability and the low plasma concentration. Moreover, curcumin undergoes extensive and rapid metabolism in vivo, indicating that the pharmacological activity of consuming curcumin might be mediated partly by its metabolites. And as one of the major curcumin metabolites, hexahydrocurcumin (HHC), exhibits similar or more potent bioactivity than curcumin by in vitro and in vivo studies, such as antioxidant, anti-inflammatory, antitumor and cardiovascular protective properties, which may provide important information for us to have a profound comprehension of the effectiveness of curcumin. This review mainly summarizes the current knowledge and underlying molecular mechanisms of the biological activities of HHC and its potential effects on the development of various human diseases.

Celecoxib and sulindac inhibit TGF-β1-induced epithelial-mesenchymal transition and suppress lung cancer migration and invasion via downregulation of sirtuin 1

The non-steroidal anti-inflammatory drugs (NSAIDs) celecoxib and sulindac have been reported to suppress lung cancer migration and invasion. The class III deacetylase sirtuin 1 (SIRT1) possesses both pro- and anticarcinogenic properties. However, its role in inhibition of lung cancer cell epithelial-mesenchymal transition (EMT) by NSAIDs is not clearly known. We attempted to investigate the potential use of NSAIDs as inhibitors of TGF-β1-induced EMT in A549 cells, and the underlying mechanisms of suppression of lung cancer migration and invasion by celecoxib and sulindac. We demonstrated that celecoxib and sulindac were effective in preventing TGF-β1-induced EMT, as indicated by upregulation of the epithelial marker, E-cadherin, and downregulation of mesenchymal markers and transcription factors. Moreover, celecoxib and sulindac could inhibit TGF-β1-enhanced migration and invasion of A549 cells. SIRT1 downregulation enhanced the reversal of TGF-β1-induced EMT by celecoxib or sulindac. In contrast, SIRT1 upregulation promoted TGF-β1-induced EMT. Taken together, these results indicate that celecoxib and sulindac can inhibit TGF-β1-induced EMT and suppress lung cancer cell migration and invasion via downregulation of SIRT1. Our findings implicate overexpressed SIRT1 as a potential therapeutic target to reverse TGF-β1-induced EMT and to prevent lung cancer cell migration and invasion.

Curcumol potentiates celecoxib-induced growth inhibition and apoptosis in human non-small cell lung cancer

Combinatorial therapies that target multiple signaling pathways may provide improved therapeutic responses over monotherapies. Celecoxib and curcumol are two highly hydrophobic drugs which show bioavailability problems due to their poor aqueous solubility. In the present study, we evaluated the effects of celecoxib and curcumol alone and in combination on cell proliferation, invasion, migration, cell cycle and apoptosis induction in non-small cell lung cancer (NSCLC) cells using in vitro and in vivo experiments. Our data showed that the sensitivity of a combined therapy using low concentration of celecoxib and curcumol was higher than that of celecoxib or curcumol alone. Suppression of NF-κB transcriptional activity, activation of caspase-9/caspase-3, cell cycle G1 arrest, and inhibition of survival MAPK and PI3K/AKT signaling pathway contributed to the synergistic effects of this combination therapy for induction of apoptosis. Additionally, either celecoxib alone or in combination with curcumol inhibited NSCLC cell migration and invasion by suppressing FAK and matrix metalloproteinase-9 activities. Furthermore, the combined treatment reduced tumor volume and weight in xenograft mouse model, and significantly decreased tumor metastasis nodules in lung tissues by tail vein injection. Our results confirm and provide mechanistic insights into the prominent anti-proliferative activities of celecoxib and/or curcumol on NSCLC cells, which provide a rationale for further detailed preclinical and potentially clinical studies of this combination for the therapy of lung cancer.

Novel diphenylthiazole derivatives with multi-target mechanism: Synthesis, docking study, anticancer and anti-inflammatory activities

Over the last few decades, a growing body of studies addressed the anticancer activity of NSAIDs, particularly selective COX-2 inhibitors. However, their exact molecular mechanism is still unclear and is not fully investigated. In this regard, a novel series of compounds bearing a COXs privilege scaffold, diphenyl thiazole, was synthesized and evaluated for their anticancer activity against a panel of cancer cell lines. The most active compounds 10b, 14a,b, 16a, 17a,b and 18b were evaluated in vitro for COX-1/COX-2 inhibitory activity. These compounds were suggested to exert their anticancer activity through a multi-target mechanism based on their structural features. Thus, compounds 10b and 17b with the least IC₅₀ values in MTT assay were tested against three known anticancer targets; EGFR, BRAF and tubulin. Compounds 10b and 17b showed remarkable activity against EGFR with IC₅₀ values of 0.4 and 0.2μM, respectively and good activity against BRAF with IC₅₀ values of 1.3 and 1.7μM, respectively. In contrast, they showed weak activity in tubulin polymerization assay. The in vivo anti-inflammatory potential was assessed and interestingly, compound 17b was the most potent compound. Together, this study offers some important insights into the correlation between COXs inhibition and cancer treatment. Additionally, the results demonstrated the promising activity of these compounds with a multi-target mechanism as good candidates for further development into potential anticancer agents.

Blocking COX-2 induces apoptosis and inhibits cell proliferation via the Akt/survivin- and Akt/ID3 pathway in low-grade-glioma

Approximately half of surgically-treated patients with low-grade-glioma (LGG) suffer recurrence or metastasis. Currently there is no effective drug treatment. While the selective COX-2 inhibitor celecoxib showed anti-neoplastic activity against several malignant tumors, its effects against LGG remain to be elucidated. Ours is the first report that the expression level of COX-2 in brain tissue samples from patients with LGG and in LGG cell lines is higher than in the non-neoplastic region and in normal brain cells. We found that celecoxib attenuated LGG cell proliferation in a dose-dependent manner. It inhibited the generation of prostaglandin E2 and induced apoptosis and cell-cycle arrest. We also show that celecoxib hampered the activation of the Akt/survivin- and the Akt/ID3 pathway in LGGs. These findings suggest that celecoxib may have a promising therapeutic potential and that the early treatment of LGG patients with the drug may be beneficial.

Celecoxib enhances anticancer effect of cisplatin and induces anoikis in osteosarcoma via PI3K/Akt pathway

Background

COX-2, an inducible enzyme, is associated with inflammatory diseases and carcinogenesis. Overexpression of COX-2 occurs in many human malignancies, including osteosarcoma. COX-2 positivity is form 67 to 92% in osteosarcoma, and COX-2 expresses 141-fold more in cancer stem cell spheres than daughter adherent cells. In our study, we have reported that celecoxib, a cyclooxygenase-2 inhibitor, induces apoptosis in human osteosarcoma cell line MG-63 via down-regulation of PI3K/Akt. It has been confirmed that celecoxib enhances apoptosis and cytotoxic effect of cisplatin, although the mechanism remains unclear.

Methods

We have attempted to identify the anti-proliferation of celecoxib, a selective COX-2 inhibitor, and the combination of celecoxib and cisplatin in MG-63 cells, and to explore the potential molecular mechanisms involved. MG-63 cells were treated with the combination of celecoxib and cisplatin or either agent alone for 48 h in serum-supplemented medium.

Results

MDR1, MRP1, BCRP and Trkb, E-cadherin, β-catenin were significantly downregulated in cells treated with the combination of celecoxib and cisplatin, and decreased β-catenin level was found in cells with wortmannin, a specific PI3K inhibitor.

Conclusion

Therefore, celecoxib enhances anticancer effect of cisplatin and induces anoikis in osteosarcoma, which may be PI3K/Akt-dependent, and MDR and β-catenin-related. PI3K may be at the center of the celecoxib effects, which play an essential role in the regulation of MDR and anoikis.

Prognostic significance of cyclooxygenase-2 expression in patients with hepatocellular carcinoma: a meta-analysis

INTRODUCTION

Cyclooxygenase-2 (COX-2) is believed to be an important enzyme in the carcinogenesis of hepatocellular carcinoma (HCC). However, it is still controversial whether COX-2 expression can be regarded as a prognostic factor for HCC patients. We performed a systematic review and meta-analysis of studies assessing the clinical and prognostic significance of COX-2 expression in HCC.

MATERIAL AND METHODS

Identification and review of publications assessing clinical or prognostic significance of COX-2 expression in HCC until November 1, 2014. A meta-analysis was performed to clarify the association between COX-2 expression and clinical outcomes.

RESULTS

A total of 11 publications met the criteria and included 943 cases. Analysis of these data showed that COX-2 expression was not significantly correlated with capsular formation (OR = 0.84, 95% confidence interval (CI): 0.46-1.55, p = 0.58), tumor TNM stage (OR = 0.73, 95% CI: 0.23-2.33, p = 0.59), vascular invasion (OR = 1.04, 95% CI: 0.25-4.35, p = 0.96), tumor size (OR = 0.78, 95% CI: 0.21-2.86, p = 0.71), or tumor differentiation degree (OR = 1.08, 95% CI: 0.42-2.79, p = 0.87). However, in the identified studies, COX-2 expression was strongly associated with high alpha-fetoprotein level (OR = 1.83, 95% CI: 1.01-3.33, p = 0.05), HBsAg status (OR = 1.85, 95% CI: 1.13-3.03, p = 0.01), decreased overall survival (relative risk (RR): 1.54, 95% CI: 1.18-2.02, p = 0.001) and decreased disease-free survival (RR = 1.49, 95% CI: 1.22-1.81, p < 0.001).

CONCLUSIONS

This meta-analysis shows that COX-2 expression in HCC is associated with decreased overall and disease-free survival and thus marks a worse prognosis. Nevertheless, more large sample and well-designed studies are warranted to confirm this finding.

Celecoxib enhances the inhibitory effect of 5-FU on human squamous cell carcinoma proliferation by ROS production

OBJECTIVES

The role of celecoxib in preventing and treating tumors has attracted broad attention in recent years because of its selective and specific inhibition of COX-2 activity. We investigated the inhibitory effects and mechanisms of celecoxib combined with 5-fluorouracil (5-FU) on proliferation of squamous cell carcinoma cells in vivo and in vitro.

STUDY DESIGN

Animal study and basic research.

METHODS

SNU-1041 and SNU-1076 squamous cell lines and an orthotopic tongue cancer mouse model were used to study growth inhibition with 5-FU enhanced by celecoxib. Sensitivity of cells to drug treatment was analyzed by the MTT assay, and generation of reactive oxygen species (ROS) was measured using dichlorofluorescein diacetate. Phosphorylation of AKT was detected by Western blotting. Survival analysis in the mouse model was assessed according to combination treatment with 5-FU and celecoxib.

RESULTS

Reactive oxygen species production in vitro was highest when celecoxib was administered 48 hours after 5-FU treatment. 5-FU-induced inhibition of cell proliferation was enhanced when combined with celecoxib, which was positively correlated with ROS production. Antioxidant treatment reversed 5-FU-inhibited cell proliferation by up to 60%. Cotreatment with celecoxib and 5-FU partially blocked AKT phosphorylation, although no significant changes in total AKT protein levels were detected. An increased survival time was observed in an orthotopic mouse model treated with a combination of celecoxib and 5-FU compared to treatment with either agent alone.

CONCLUSION

Celecoxib may have an enhanced anticancer effect in combination with 5-FU. Reactive oxygen species production may be a key mechanism in this combination therapy by inhibiting the AKT pathway.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 127:E117-E123, 2017.

Regulatory T Cells and Cancer: A Two-Sided Story

Regulatory T cells (Tregs) play pivotal roles in limiting the duration and magnitude of immune response against infectious agents and self-antigens. This is accomplished through contact-dependent and -independent mechanisms that involve crosstalk between Treg cells and other immune and tissue-specific cell types. The same machinery is employed by Tregs to regulate immune responses to cancer, limiting both pro-tumor inflammation and anti-tumor immunity. Factors produced by Treg cells also act directly on transformed epithelial cells and exert opposing effects during different stages of cancer development. Therefore, the immune regulatory cell population serves as a double-edged sword for the development, progression, and treatment of cancers. In this review, we summarize current knowledge on the roles of Treg lymphocytes during cancer development, as well as the underlying cellular and molecular mechanism.

Celecoxib induces apoptosis but up-regulates VEGF via endoplasmic reticulum stress in human colorectal cancer in vitro and in vivo

PURPOSE

In our previous study, we found that celecoxib, a kind of COX-2 inhibitor, led to cell apoptosis while up-regulating the expression of vascular endothelial growth factor (VEGF) in colorectal cancer HCT116 cells (COX-2 deficient), and endoplasmic reticulum (ER) stress was involved in the mechanism. Thus, we would like to explore whether these results are universal for other colorectal cancer cells, especially for COX-2-expressing ones, and whether the results in vitro and in vivo are matched.

METHODS

HT29 cells (COX-2 expressing) were treated with celecoxib under different conditions to evaluate cell apoptosis, VEGF expression and the activation of ER stress. HT29 and HCT116 xenograft tumor models were established to evaluate anti-tumor effects and verify the experiment results we obtained in vitro.

RESULTS

Celecoxib (≥60 µM) up-regulated the expression of ER stress markers (GRP78 and CHOP) and induced cell apoptosis accompanying with a correlated increased expression of VEGF in HT29 cells. Celecoxib-induced gene expression and cell apoptosis were inhibited by an ER stress inhibitor, PBA. In xenograft models, celecoxib treatment inhibited tumor growth with increased GRP78 and VEGF, which was consistent with the results in vitro.

CONCLUSIONS

Celecoxib, both in vitro and in vivo, induced apoptosis of colorectal cancer cells but increased the VEGF levels at the same time in a COX-2-independent manner, namely by activating ER stress. The increased VEGF would impair the effect of celecoxib and bring drug resistant; hence, the optimal schedule of the combination of celecoxib with anti-VEGF drugs needs to be explored.

Unraveling the role of the Target of Rapamycin signaling in sphingolipid metabolism

Sphingolipids are important bioactive molecules that regulate basic aspects of cellular metabolism and physiology, including cell growth, adhesion, migration, senescence, apoptosis, endocytosis, and autophagy in yeast and higher eukaryotes. Since they have the ability to modulate the activation of several proteins and signaling pathways, variations in the relative levels of different sphingolipid species result in important changes in overall cellular functions and fate. Sphingolipid metabolism and their route of synthesis are highly conserved from yeast to mammalian cells. Studies using the budding yeast Saccharomyces cerevisiae have served in many ways to foster our understanding of sphingolipid dynamics and their role in the regulation of cellular processes. In the past decade, studies in S. cerevisiae have unraveled a functional association between the Target of Rapamycin (TOR) pathway and sphingolipids, showing that both TOR Complex 1 (TORC1) and TOR Complex 2 (TORC2) branches control temporal and spatial aspects of sphingolipid metabolism in response to physiological and environmental cues. In this review, we report recent findings in this emerging and exciting link between the TOR pathway and sphingolipids and implications in human health and disease.

Simultaneous targeting of 5-LOX-COX and EGFR blocks progression of pancreatic ductal adenocarcinoma

Cyclooxygenase-2 (COX-2), 5-Lipoxygenase (5-LOX), and epidermal growth factor receptor (EGRF) are over-expressed in human pancreatic ductal adenocarcinoma (PDAC). Using next-generation sequencing (NGS) analysis, we show significant increase in COX-2, 5-LOX, and EGFR expression during PDAC progression. Targeting complementary pathways will achieve better treatment efficacy than a single agent high-dose strategy that could increase risk of side effects and tumor resistance. To target COX-2, 5-LOX, and EGFR simultaneously, we tested effects of licofelone (dual 5-LOX-COX inhibitor), and gefitinib (EGFR inhibitor), individually and in combination, on pancreatic intraepithelial neoplasms (PanINs) and their progression to PDAC using genetically engineered mice. Individually, licofelone (L) and gefitinib (G) significantly inhibited incidence of PDAC in male (72% L, 90% G, p < 0.0001) and female (90% L, 85% G, p < 0.0001) mice. The combination drug treatment produced complete inhibition of PDAC in both genders. Pancreata of mice receiving combination treatment showed significantly fewer Dclk1-positive cancer stem-like cells, inhibition of COX-2, 5-LOX, PCNA, EGFR and β-catenin expression (p < 0.05-0.0002), increased p21 expression. Significant changes in tumor immune responses and desmoplastic reaction was observed by NGS analysis in combination treatment (p < 0.05). In summary, early simultaneous targeting of 5-LOX-COX- and EGFR pathways may provide additive inhibitory effects leading to complete suppression of PDAC.

Use of Cyclo-Oxygenase Inhibitors Is Not Associated with Clinical Relapse in Inflammatory Bowel Disease: A Case-Control Study

Patients with inflammatory bowel disease (IBD) often have associated conditions, for which anti-inflammatory medication with cyclo-oxygenase (COX) inhibitors may be helpful. The current evidence is conflicting regarding the role of COX-inhibitors in causing relapse in IBD. This case-control study examined the association between the use of COX inhibitors and relapse of IBD. Logistic regression was used to analyse the relationship between COX-inhibitors and IBD relapse. Overall COX inhibitor use (combined non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 agents) had a negative association with relapse of IBD (adjusted OR 0.26, 95% CI 0.09–0.80). This negative association was confined to ulcerative colitis (UC) (adjusted OR = 0.06, 95% CI 0.01–0.50) and no association was found in Crohn’s disease (CD) patients (adjusted OR 1.25, 95% CI 0.18–7.46). The significant negative association between UC relapse and medication use was also seen with non-specific NSAIDs. Selective COX-2 inhibitor use was rare but non-significantly more common in stable patients. There was no association between low-dose aspirin or paracetamol use and relapse of CD or UC. We conclude that COX-inhibitor use was not associated with an increased risk of relapse in UC or CD, and may be protective in UC. Where indicated, NSAIDs should not be withheld from IBD patients.

Targeting cells of the myeloid lineage attenuates pain and disease progression in a prostate model of bone cancer

Tumor cells frequently metastasize to bone where they can generate cancer-induced bone pain (CIBP) that can be difficult to fully control using available therapies. Here, we explored whether PLX3397, a high-affinity small molecular antagonist that binds to and inhibits phosphorylation of colony-stimulating factor-1 receptor, the tyrosine-protein kinase c-Kit, and the FMS-like tyrosine kinase 3, can reduce CIBP. These 3 targets all regulate the proliferation and function of a subset of the myeloid cells including macrophages, osteoclasts, and mast cells. Preliminary experiments show that PLX3397 attenuated inflammatory pain after formalin injection into the hind paw of the rat. As there is an inflammatory component in CIBP, involving macrophages and osteoclasts, the effect of PLX3397 was explored in a prostate model of CIBP where skeletal pain, cancer cell proliferation, tumor metastasis, and bone remodeling could be monitored in the same animal. Administration of PLX3397 was initiated on day 14 after prostate cancer cell injection when the tumor was well established, and tumor-induced bone remodeling was first evident. Over the next 6 weeks, sustained administration of PLX3397 attenuated CIBP behaviors by approximately 50% and was equally efficacious in reducing tumor cell growth, formation of new tumor colonies in bone, and pathological tumor-induced bone remodeling. Developing a better understanding of potential effects that analgesic therapies have on the tumor itself may allow the development of therapies that not only better control the pain but also positively impact disease progression and overall survival in patients with bone cancer.