Etodolac Enhances the Radiosensitivity of Irradiated HT-29 Human Colorectal Cancer Cells.

BACKGROUND: Radioresistance is found to be the main therapeutic restriction in colorectal radiation therapy. The aim of this study was to investigate the synergistic effect of Etodolac (ET) and ionizing radiation on human colorectal cancer cells. METHODS: Pretreated HT-29 cells with ET were exposed to ionizing radiation. The radiosensitizing effect of ET was evaluated using MTT, flow cytometry, and clonogenic assay. The amount of nitrite oxide (NO) in irradiated cells was also measured with the Griess reagent. RESULTS: The present study found that pretreatment of HT-29 cells with ET decreases their survival and colony formation. Higher concentrations of ET cause total apoptosis and an increase in NO levels in irradiated cells. CONCLUSION: Applying ET in a concentration-dependent manner had an incremental effect on the amount of apoptosis and cell death induced by radiation.

A comparative study: the prospective influence of nanovectors in leveraging the chemopreventive potential of COX-2 inhibitors against skin cancer.

INTRODUCTION: This study was conducted to elucidate the chemopreventive potential, cytotoxic, and suppression of cellular metastatic activity of etodolac (ETD)-loaded nanocarriers. METHODS: To esteem the effect of charge and composition of the nanovectors on their performance, four types of vectors namely, negative lipid nanovesicles; phosalosomes (N-Phsoms), positive phosalosomes (P-Phsoms), nanostructured lipid carriers (NLCs) and polymeric alginate polymer (AlgNPs) were prepared and compared. ETD was used as a model cyclo-oxygenase-2 (COX-2) inhibitor to evaluate the potency of these nanovectors to increase ETD permeation and retention through human skin and cytotoxicity against squamous cell carcinoma cell line (SCC). Moreover, the chemopreventive activity of ETD nanovector on mice skin cancer model was evaluated. RESULTS: Among the utilized nanovectors, ETD-loaded N-Phsoms depicted spherical vesicles with the smallest particle size (202.96±2.37 nm) and a high zeta potential of -24.8±4.16 mV. N-Phsoms exhibited 1.5, and 3.6 folds increase in the ETD amount deposited in stratum corneum, epidermis and dermis. Moreover, cytotoxicity studies revealed a significant cytotoxic potential of such nanovector with IC50=181.76 compared to free ETD (IC50=982.75), correlated to enhanced cellular internalization. Its efficacy extended to a reduction in the relative tumor weight with 1.70 and 1.51-fold compared to positive control and free ETD, that manifested by a 1.72-fold reduction in both COX-2 and proliferating cell nuclear antigen mRNA (PCNA-mRNA) levels and 2.63-fold elevation in caspase-3 level in skin tumors relative to the positive control group with no hepato-and nephrotoxicity. CONCLUSION: Encapsulation of ETD in nanovector enhances its in-vitro and in-vivo anti-tumor activity and opens the door for encapsulation of more relevant drugs.

Synthesis, anticancer activity, and molecular modeling of etodolac-thioether derivatives as potent methionine aminopeptidase (type II) inhibitors.

A series of (R,S)-1-{[5-(substituted)sulfanyl-4-substituted-4H-1,2,4-triazole-3-yl]methyl}-1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indoles (5a-v) were designed and synthesized using a five-step synthetic protocol that involves substituted benzyl chlorides and (R,S)-5-[(1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-yl)methyl]-4-substituted-2,4-dihydro-3H-1,2,4-triazole-3-thiones in the final step. The synthesized derivatives were evaluated for cytotoxicity and anticancer activity in vitro using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric method against VERO, HEPG2 (human hepatocellular liver carcinoma), SKOV3 (ovarian carcinoma), MCF7 (human breast adenocarcinoma), PC3 and DU145 (prostate carcinoma) cells at 10-5 M (10 µM) for 24 h. Compounds 5d and 5h showed the best biological potency against the SKOV3 cancer cell line (IC50 = 7.22 and 5.10 µM, respectively) and did not display cytotoxicity toward VERO cells compared to etodolac. Compounds 5k, 5s, and 5v showed the most potent biological activity against the PC3 cancer cell line (IC50 = 8.18, 3.10, and 4.00 µM, respectively) and did not display cytotoxicity. Moreover, these compounds were evaluated for caspase-3, -9, and -8 protein expression and activation in the apoptosis pathway for 6, 12, and 24 h, which play a key role in the treatment of cancer. In this study, we also investigated the apoptotic mechanism and molecular modeling of compounds 5k and 5v on the methionine aminopeptidase (type II) enzyme active site in order to get insights into the binding mode and energy.

The Role of Epithelial to Mesenchymal Transition in Human Amniotic Membrane Rupture.

Context: Biochemical weakening of the amnion is a major factor preceding preterm premature rupture of membranes (PPROMs), leading to preterm birth. Activation of matrix metalloproteinases (MMPs) is known to play a key role in collagen degradation of the amnion; however, epithelial to mesenchymal transition (EMT) that is also induced by MMP activation has not been investigated as a mechanism for amnion weakening. Objective: To measure amniotic EMT associated with vaginal delivery (VD) compared with unlabored cesarean sections (CSs), and to assess changes in amniotic mechanical strength with pharmacologic inhibitors and inducers of EMT, thus testing the hypothesis that EMT is a key biochemical event that promotes amniotic rupture. Findings: (1) Amnions taken from VD contained a significantly increased number of mesenchymal cells relative to epithelial cells compared with unlabored CS by fluorescence-activated cell sorting analysis (60% vs 10%); (2) tumor necrosis factor (TNF)-α stimulation of amniotic epithelial cells increased expression of the mesenchymal marker vimentin after 2 days; (3) EMT inhibitor, etodolac, significantly increased the time and mechanical pressure required to rupture the amnion; and (4) TNF-α and another pharmacologic EMT inducer, ethacridine, decreased the time and mechanical pressure required for amnion rupture, further confirming that the mesenchymal phenotype significantly weakens the amnion. Conclusions: This work demonstrated amniotic cell EMT was associated with labor and EMT decreased the tensile strength of the amnion. These findings suggest a role for EMT in the pathophysiology of PPROM and may provide a basis for development of therapies to prevent preterm labor.

Effect of etodolac hydrazone, a new compound synthesised from etodolac, on spermatozoon quality, testicular lipid peroxidation, apoptosis and spermatozoon DNA integrity.

The aim of this study was to investigate the effect of etodolac hydrazone (EH), a new compound synthesised from etodolac, on spermatozoon quality, testicular lipid peroxidation, apoptosis and spermatozoon DNA integrity in rats. Group 1 (n = 8) received 1 ml dimethyl sulfoxide (DMSO) daily (Control); group 2 (n = 8) was treated with 5 mg kg(-1)  day(-1) EH, dissolved in 1 ml DMSO (EH-5); and group 3 (n = 8) was treated with 10 mg kg(-1)  day(-1) EH, dissolved in 1 ml DMSO (EH-10). All administrations were performed by gavage and maintained for 8 weeks. Both doses of EH administration caused significant decreases in absolute and relative weights of testis, whole epididymis, right cauda epididymis, and spermatozoon motility, spermatozoon count in comparison with the control group. Only 10 mg kg(-1)  day(-1) EH administration caused significant decreases in absolute and relative weights of seminal vesicles and serum testosterone level, and significant increases in testicular lipid peroxidation level, and numbers of TUNEL+ apoptotic germ cells and spermatozoa with damaged DNA along with some histopathological damages when compared to the control group. However, body and ventral prostate weight, and testicular antioxidant markers (glutathione, glutathione-peroxidase and catalase), were unaffected significantly by both doses of EH administration. In conclusion, two different doses of EH, in particular its high dose, damage to testicular spermatogenic cells and spermatozoon DNA and, it decreases spermatozoon motility, count and testosterone level in healthy rats.

A window-of-opportunity biomarker study of etodolac in resectable breast cancer.

Observational data show that nonsteroidal anti-inflammatory drug (NSAID) use is associated with a lower rate of breast cancer. We evaluated the effect of etodolac, an FDA-approved NSAID reported to inhibit cyclooxygenase (COX) enzymes and the retinoid X receptor alpha (RXR), on rationally identified potential biomarkers in breast cancer. Patients with resectable breast cancer planned for initial management with surgical resection were enrolled and took 400 mg of etodolac twice daily prior to surgery. Protein and gene expression levels for genes related to COX-2 and RXRα were evaluated in tumor samples from before and after etodolac exposure. Thirty subjects received etodolac and 17 subjects were assayed as contemporaneous or opportunistic controls. After etodolac exposure mean cyclin D1 protein levels, assayed by immunohistochemistry, decreased (P = 0.03). Notably, pre- versus post cyclin D1 gene expression change went from positive to negative with greater duration of etodolac exposure (r = -0.64, P = 0.01). Additionally, etodolac exposure was associated with a significant increase in COX-2 gene expression levels (fold change: 3.25 [95% CI: 1.9, 5.55]) and a trend toward increased ß-catenin expression (fold change: 2.03 [95% CI: 0.93, 4.47]). In resectable breast cancer relatively brief exposure to the NSAID etodolac was associated with reduced cyclin D1 protein levels. Effect was also observed on cyclin D1 gene expression with decreasing levels with longer durations of drug exposure. Increased COX-2 gene expression was seen, possibly due to compensatory feedback. These data highlight the utility of even small clinical trials with access to biospecimens for pharmacodynamic studies.

Anti-cancer and anti-hepatitis C virus NS5B polymerase activity of etodolac 1,2,4-triazoles.

Arachidonic acid is an unsaturated fatty acid liberated from phospholipids of cell membranes. NSAIDs are known as targets of cyclooxygenase enzyme (COX-1, COX-2 and COX-3) in arachidonic acid metabolism. This mechanism of COX-2 in carcinogenesis causes cancer. In addition, COX-2 plays a role in the early stages of hepatocarcinogenesis. Hepatitis C virus (HCV) infection is cause of liver cirrhosis and hepatocellular carcinoma (HCC). The aim of our study was to improve effective agents against HCV. A novel series of new etodolac 1,2,4-triazoles derivatives (4a-h) have been synthesized and investigated for their activity against HCV NS5B polymerase. Compound 4a was found to be the most active with IC(50) value of 14.8 µM. In accordance with these results, compound 4a was screened for anti-cancer activity on liver cancer cell lines (Huh7, Mahlavu, HepG2, FOCUS). Compound 4a showed anti-cancer activity against Huh7 human hepatoma cell line with IC(50) value of 4.29 µM. Therefore, compound 4a could be considered as a new anti-cancer and anti-HCV lead compound.

Impact of N-acetylcysteine and etodolac treatment on systolic and diastolic function in a rat model of myocardial steatosis induced by high-fat-diet.

OBJECTIVES: Obesity is a worldwide problem, leading to cardiomyopathy. Oxidative stress and inflammation have been reported to play significant roles in developing obesity cardiomyopathy. N-acetylcysteine is a glutathione prodrug that preserves liver against steatosis via constraining the production of reactive oxygen species. Etodolac is a nonsteroidal anti-inflammatory drug which has been demonstrated to protect liver against fibrosis. The aim of the present study was to evaluate and compare the effects of N-acetylcysteine and etodolac on impaired cardiac functions due to high-fat-diet (HFD) induced myocardial steatosis in rats. MATERIAL AND METHODS: Thirty-two male Sprague-Dawley rats were randomly divided into four groups. Control group was maintained on standard-rat-basic-diet (SD) for 20 weeks, while HFD was given to three study groups for 20 weeks. Then N-acetylcysteine was given to one of the study groups (HFD+NAC), and etodolac to another group (HFD+ETD) as a supplement for 4 weeks while all groups were continued on SD. At the end of the study periods, hearts were examined by Langendorff technique and rat livers were evaluated histologically. RESULTS: HFD and HFD+ETD groups presented with significantly higher steatosis and fibrosis in liver compared to other groups. HFD+NAC preserved diastolic functions. Also HFD+NAC and HFD+ETD groups had significantly better systolic funtions than HFD group. CONCLUSIONS: Obesity is associated with diastolic dysfunction rather than systolic dysfunction. NAC may protect the heart against diastolic dysfunction due to obesity. NAC and etodolac treatment improve systolic function, even in the absence of systolic dysfunction.

A selective cyclooxygenase-2 inhibitor (Etodolac) prevents spontaneous biliary tumorigenesis in a hamster bilioenterostomy model.

BACKGROUND: Secondary biliary carcinomas are associated with persistent reflux cholangitis after bilioenterostomy. Cyclooxygenase-2 (COX-2) has been a target for cancer prevention. The aim of this study was to evaluate the chemopreventive efficacy of long-term treatment with a selective COX-2 inhibitor medication during the natural course after bilioenterostomy without chemical induction. METHODS: Syrian golden hamsters which underwent choledochojejunostomy were randomly divided into two groups: the control group (n = 31), which was fed a normal diet, and the etodolac group (n = 33), which was fed 0.01% etodolac (a selective COX-2 inhibitor) mixed in the meal. The hamsters were killed at the postoperative weeks 20-39, 40-59, 60-79, or 80-100. Biliary neoplasms, cholangitis, proliferating cell nuclear antigen labeling index (PCNA-LI) of the biliary epithelium, and prostaglandin E2 (PGE2) production were evaluated. RESULTS: The occurrence rates of biliary neoplasm were 43.8 and 15.2% in the control and etodolac groups, respectively (p < 0.05). The incidence of biliary neoplasm increased as time progressed in the control group, whereas it remained at a low level throughout the experimental period in the etodolac group. PGE2 products tended to be lower in the etodolac group, and PCNA-LI was significantly lower in the etodolac group (p < 0.01). These results suggest that the medication etodolac suppresses cell proliferation of the biliary epithelium, thereby preventing biliary carcinogenesis. CONCLUSIONS: Etodolac is expected to prevent secondary biliary carcinogenesis caused by persistent reflux cholangitis after bilioenterostomy.

Overexpression of cyclooxygenase-2 in malignant peripheral nerve sheath tumor and selective cyclooxygenase-2 inhibitor-induced apoptosis by activating caspases in human malignant peripheral nerve sheath tumor cells.

BACKGROUND: Cyclooxygenase-2 (COX-2) is a key enzyme in the conversion of arachidonic acid to prostanoids, and its activation is associated with carcinogenesis as well as inflammation. The antitumor effect of selective COX-2 inhibitors has been noted in various malignancies. Malignant peripheral nerve sheath tumor (MPNST) is a rare and aggressive soft tissue sarcoma for which effective treatments have not yet been established. The purpose of this study was to investigate a potential therapeutic role of COX-2 in MPNST. METHODS: We evaluated the expression of COX-2 in 44 cases of high-grade MPNST using immunohistochemical staining and compared the staining results with the characteristics and outcome of the patients. We also investigated the antitumor effect of etodolac, a selective COX-2 inhibitor, on MPNST cells in vitro using the MPNST cell line, FMS-1. RESULTS: Overexpression of COX-2 (≥50% positive cells) was observed in 29 cases (65.9%), was significantly associated with a poor overall survival (P = 0.0495), and was considered an independent risk factor for a poor outcome by the results of both univariate and multivariate analysis. Etodolac induced apoptosis of FMS-1 cells through the activation of caspase-8, -9, and -3. Moreover, several caspase inhibitors significantly inhibited etodolac-induced apoptosis. CONCLUSIONS: Selective COX-2 inhibitors including etodolac had an antitumor effect on MPNST cells, and their use holds promise as a novel therapeutic strategy for patients with MPNST to improve their prognoses.

Usefulness of selective COX-2 inhibitors as therapeutic agents against canine mammary tumors.

Cyclooxygenase-2 (COX-2) is a key enzyme for converting arachidonic acids to prostanoids, which are known to be induced during inflammation and cancer initiation. Previously, it has been reported that COX inhibitors, such as aspirin, reduce the incidence of human colorectal cancer; therefore, it is widely believed that COX-2 is a potential therapeutic and chemoprevention target for several types of human cancer. However, whether selective COX-2 inhibitors have antitumor effects against canine mammary tumor cells remains unclear. In the present study, to elucidate the antitumor effect of selective COX-2 inhibitors against canine mammary tumors, we investigated the antitumor effects of meloxicam, etodolac and celecoxib using COX-2-expressing canine mammary tumor (CF33) cells. We analyzed the effects of selective COX-2 inhibitors on COX-2 protein expression levels in CF33 cells. Celecoxib (100 µM) was found to induce downregulation of COX-2 protein expression. We examined the effect of selective COX-2 inhibitors on CF33 cell proliferation. All the selective COX-2 inhibitors suppressed CF33 cell growth. Specifically, etodolac and celecoxib inhibited cell proliferation via a decrease in S-phase cells and an increase in G0/G1 arrest. We examined the apoptotic effect of selective COX-2 inhibitors on CF33 cells. Our data suggested that etodolac and celecoxib induced apoptosis in CF33 cells. In particular, celecoxib led to apoptosis mediated by the activation of the mitochondrial apoptosis pathway, including the upregulation of BAX expression, downregulation of Bcl-2 expression and activation of caspase-3/7. Furthermore, celecoxib increased the percentages of cells in both early apoptosis and late apoptosis. Our results revealed that celecoxib induced apoptosis and cell cycle arrest in CF33 cells. The data suggested that celecoxib is the most viable candidate as a therapeutic agent for the treatment of canine mammary tumors. Furthermore, our findings provide the first indication that COX-2 inhibition can provide a new therapeutic strategy for treating canine mammary tumors.

Etodolac activates and desensitizes transient receptor potential ankyrin 1.

The transient receptor potential ankyrin 1 (TRPA1) channel is well known as a sensor to environmental irritant compounds, cold, and endogenous proalgesic agents. TRPA1 is expressed on sensory neurons and is involved in pain modulation. Etodolac is a cyclooxygenase (COX)-2 inhibitor that belongs to the class of nonsteroidal anti-inflammatory drugs (NSAIDs). A recent study indicates that etodolac inhibits allyl isothiocyanate (AITC)-induced calcium influx in heterologous HEK293 cells and sensory neurons. To examine whether and how etodolac modulates the TRPA1 channels, we applied etodolac to TRPA1-transfected HEK293 cells or rat dorsal root ganglion (DRG) neurons and recorded the currents using the whole-cell patch clamp technique. We found that etodolac at higher doses could activate and then desensitize TRPA1 channels in heterologous expressing HEK293 cells as well as in DRG neurons. The etodolac-induced currents were significantly attenuated in cysteine residues mutated human TRPA1-transfected HEK293 cells. Interestingly, application of etodolac at drug plasma levels in clinical usage did not induce significant TRPA1 currents but reduced the subsequent AITC-induced currents to 25% in HEK293 cells expressing TRPA1. Moreover, no modulatory effect of etodolac on TRPA1 was detected in the cysteine mutant cells. These data indicate a novel mechanism of the anti-inflammatory and analgesic clinical effects of etodolac, which may be involved with its direct activation and the subsequent desensitization of TRPA1 through the covalent modification of cysteine residues.

Cyclooxygenase-2 inhibition blocks M2 macrophage differentiation and suppresses metastasis in murine breast cancer model.

Tumor cells are often associated with abundant macrophages that resemble the alternatively activated M2 subset. Tumor-associated macrophages (TAMs) inhibit anti-tumor immune responses and promote metastasis. Cyclooxygenase-2 (COX-2) inhibition is known to prevent breast cancer metastasis. This study hypothesized that COX-2 inhibition affects TAM characteristics potentially relevant to tumor cell metastasis. We found that the specific COX-2 inhibitor, etodolac, inhibited human M2 macrophage differentiation, as determined by decreased CD14 and CD163 expressions and increased TNFα production. Several key metastasis-related mediators, such as vascular endothelial growth factor-A, vascular endothelial growth factor-C, and matrix metalloproteinase-9, were inhibited in the presence of etodolac as compared to untreated M2 macrophages. Murine bone marrow derived M2 macrophages also showed enhanced surface MHCII IA/IE and CD80, CD86 expressions together with enhanced TNFα expressions with etodolac treatment during differentiation. Using a BALB/c breast cancer model, we found that etodolac significantly reduced lung metastasis, possibly due to macrophages expressing increased IA/IE and TNFα, but decreased M2 macrophage-related genes expressions (Ym1, TGFß). In conclusion, COX-2 inhibition caused loss of the M2 macrophage characteristics of TAMs and may assist prevention of breast cancer metastasis.

Synthesis, cytotoxicity, and pro-apoptosis activity of etodolac hydrazide derivatives as anticancer agents.

Etodolac hydrazide and a novel series of etodolac hydrazide-hydrazones 3-15 and etodolac 4-thiazolidinones 16-26 were synthesized in this study. The structures of the new compounds were determined by spectral (FT-IR, (1)H NMR, (13)C NMR, HREI-MS) methods. Some selected compounds were determined at one dose toward the full panel of 60 human cancer cell lines by the National Cancer Institute (NCI, Bethesda, USA). 2-(1,8-Diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-yl)acetic acid[(4-chlorophenyl)methylene]hydrazide 9 demonstrated the most marked effect on the prostate cancer cell line PC-3, with 58.24% growth inhibition at 10(-5) M (10 µM). Using the MTT colorimetric method, compound 9 was evaluated in vitro against the prostate cell line PC-3 and the rat fibroblast cell line L-929, for cell viability and growth inhibition at different doses. Compound 9 exhibited anticancer activity with an IC(50) value of 54 µM (22.842 µg/mL) against the PC-3 cells and did not display any cytotoxicity toward the L-929 rat fibroblasts, compared to etodolac. In addition, this compound was evaluated for caspase-3 and Bcl-2 activation in the apoptosis pathway, which plays a key role in the treatment of cancer.

Pharmacological inhibition of beta-catenin in hepatoblastoma cells.

PURPOSE: The proto-oncogene beta-catenin is linked to an abnormal activation of the Wnt/beta-catenin-pathway and shows mutations in 50-90 % of hepatoblastoma (HB). Corresponding, the recently published murine orthotopic HB model differs from the former subcutaneous model by nuclear beta-catenin distribution. As the nuclear localization of beta-catenin is considered to reflect a more aggressive tumor growth, the influence of beta-catenin inhibition on cell viability and drug-efficiency in HB cells was analyzed. METHODS: Beta-catenin distribution in HB cells was analyzed by immunofluorescence. The influence of beta-catenin inhibitors Celecoxib, Etodolac, ICG001, and MET kinase inhibitor (SU11274) alone and in combination with cisplatin (CDDP) on HB cell lines (HuH6, HepT1) was evaluated by cell viability assays and BrdU incorporation. RESULTS: Celecoxib and ICG001 reduced dose-dependently HB cell viability and decreased nuclear beta-catenin in cultivated HB cells. Etodolac was without influence at concentrations up to 100 µM. Combinations of Celecoxib or ICG001 with MET kinase inhibitor or CDDP resulted in additive reduction of cell viability. CONCLUSION: Pharmaceutical beta-catenin inhibitors can modulate the nuclear localization of beta-catenin and reduce cell viability of HB cells in vitro. These promising effects might optimize the outcome of high-risk HB. The orthotopic HB model is a suitable basis for further in vivo studies.

Cyclooxygenase 2 and prostaglandin E2 regulate the attachment of calcium oxalate crystals to renal epithelial cells.

OBJECTIVE: To determine the roles of endogenous cyclooxygenase 2 and prostaglandin E(2) in crystal-cell binding, which is considered to be an important step in the development of intratubular nephrocalcinosis. METHODS: An expression plasmid for human cyclooxygenase 2 was introduced into Madin-Darby canine kidney cells using the lipofection method. Cyclooxygenase activity was measured using thin-layer chromatography, and the prostaglandin E(2) concentration was determined with an enzyme immunoassay. In addition, crystal attachment was evaluated with a liquid scintillation counter using [(14)C] calcium oxalate monohydrate crystals, and immunohistochemistry and an enzyme immunoassay were used to analyze and quantify the expression of hyaluronan, a crystal-binding molecule. RESULTS: Cyclooxygenase 2-overexpressing Madin-Darby canine kidney cells produced about 10-fold more prostaglandin E(2) than wild-type Madin-Darby canine kidney cells, and their hyaluronan production was also upregulated. The attachment of calcium oxalate monohydrate crystals to cyclooxygenase 2-overexpressing Madin-Darby canine kidney cells was significantly reduced compared with their attachment to wild-type and mock-transfected Madin-Darby canine kidney cells. Pre-incubation of the cyclooxygenase 2-overexpressing cells, as well as the mock-transfected and wild-type cells with the cyclooxygenase 2 selective inhibitor etodolac, increased the cellular attachment of calcium oxalate monohydrate crystals in a dose-dependent manner. CONCLUSIONS: These findings suggest that cyclooxygenase 2 expression and the resultant increase in endogenous prostaglandin E(2), leading to increased hyaluronan production, help to prevent nephrocalcinosis by inhibiting the attachment of calcium oxalate monohydrate crystals to the surface of renal epithelial cells.

The effect of ß-adrenergic blockade and COX-2 inhibition on healing of colon, muscle, and skin in rats undergoing colonic anastomosis.

OBJECTIVE: COX inhibitors and ß-adrenergic blockers were recently shown to reduce cancer progression in animal models through various mechanisms. These include the prevention of immune suppression during the critical perioperative period, and the preclusion of direct promoting effects of catecholamines and prostaglandins on malignant tissue growth. To assess the safety of such pharmacological treatments in the context of oncologic surgery, the current study evaluates wound healing efficacy in the skin, muscle, and colon tissues in rats undergoing colonic anastomosis. METHODS: F344 rats were treated daily with a COX-2 inhibitor (etodolac), a ß-adrenergic blocker (propranolol), both drugs or vehicles. All rats underwent skin punch biopsy, and half were also subjected to laparotomy and colonic anastomosis. Tensile strength of the abdominal wall and colonic bursting pressure were assessed on Days 3, 7, and 30 postoperatively, and skin biopsy site healing was scored on Days 2, 4, and 6 postoperatively. RESULTS: None of the drug treatments produced any deleterious effects along the expected course of tissue healing. On Day 30, colon bursting pressure showed an abnormal strengthening in animals undergoing anastomosis compared to non-operated animals, across all drug treatments. This abnormal strengthening was attenuated by etodolac. In the skin, surgery reduced healing rate, irrespective of drug treatments. CONCLUSIONS: Effective doses of etodolac and propranolol caused no negative effects on wound healing processes in rats. The apparent safety of such treatments, together with their potential clinical benefits, suggests the incorporation of these treatments in oncologic patients undergoing curative tumor resection.

Etodolac improves 5-FU sensitivity of head and neck cancer cells through inhibition of thymidylate synthase.

BACKGROUND: 5-Fluorouracil (5-FU) is widely used in the treatment of head and neck squamous cell carcinoma (HNSCC). However, development of drug resistance is one of the major causes of HNSCC treatment failure. The goal of this study was to investigate the mechanism of 5-FU resistance and to develop a novel combination therapy with another agent which sensitizes cells to 5-FU. MATERIALS AND METHODS: A 5-FU-resistant cell line, UM-SCC-23F/R, was developed from UM-SCC-23 cells. We determined sensitivities to 5-FU, etodolac and a combination treatment and also analyzed the expressions of cyclooxygenase-2 (COX-2) and thymidylate synthase (TS). RESULTS: Selective COX-2 inhibitor, etodolac, sensitized UM-SCC-23F/R cells to 5-FU. Expression of COX-2 decreased after etodolac treatment in both cell lines. While overexpression of TS was observed in UM-SCC-23F/R cells, etodolac inhibited TS expression, suggesting that the sensitizing effect induced by etodolac depends on TS suppression. CONCLUSION: We demonstrate for the first time an important inhibitory effect of etodolac on TS expression leading to sensitization to 5-FU in 5-FU-resistant cells. Our data suggest that TS inhibition can be accomplished by this routinely used nonsteroidal anti-inflammatory drug, and this may have a role as novel effective cancer treatment for 5-FU-resistant cancer.

In vitro and in vivo inhibitory effect of three Cox-2 inhibitors and epithelial-to-mesenchymal transition in human bladder cancer cell lines.

BACKGROUND: Although the anti-tumour effect of cyclooxygenase-2 (Cox-2) inhibitors in invasive bladder cancer has been confirmed, its mechanisms of action are unclear. Recently, the concept of an epithelial-to-mesenchymal transition (EMT) promoting carcinoma progression has been suggested, and a key feature of the EMT is the downregulation of E-cadherin. In this study, we investigated the effect of Cox-2 inhibitors on reversal EMT and tumour growth inhibition in bladder cancer cells. METHODS: We used three Cox-2 inhibitors, etodolac, celecoxib and NS-398 and three human bladder cancer cell lines, T24, 5637 and KK47, in this study. T24 xenograft tumour mouse model was used in the in vivo study. RESULTS: Within the clinical drug concentrations, only etodolac showed the in vitro growth inhibition in T24 not in the other cell lines. Etodolac reduced SNAIL mRNA and vimentin cell surface expression, and induced E-cadherin mRNA and E-cadherin cell surface expression, in T24. Etodolac also most strongly inhibited the cell migration of T24 in vitro and showed the highest tumour growth inhibition in T24 tumour in vivo. CONCLUSION: Etodolac at clinical doses exhibited induced in vitro and in vivo anti-tumour effects and reversal effect of EMT in T24. These results suggest that etodolac is a good candidate for an anti-tumour or chemopreventive reagent for high-grade bladder cancer.

Improving postoperative immune status and resistance to cancer metastasis: a combined perioperative approach of immunostimulation and prevention of excessive surgical stress responses.

BACKGROUND: Surgical procedures, including primary tumor resection, have been suggested to suppress immune competence and to promote postoperative infections and cancer metastasis. Catecholamines and prostaglandins were recently implicated in these processes, and in directly promoting tumor angiogenesis and invasion. OBJECTIVE: To examine the integration of 2 complementary approaches to reduce postoperative immunosuppression and metastatic progression: (1) perioperative immunostimulation with CpG-C and (2) pharmacological blockade of the tumor-promoting and immunosuppressing effects of catecholamines and prostaglandins, using propranolol (P) and etodolac (E), respectively. METHODS: F344 rats were treated before surgery with CpG-C, P+E, both interventions, or vehicles, and were intravenously inoculated with syngeneic MADB106 mammary adenocarcinoma cells. Blood was withdrawn, marginating-pulmonary leukocytes were harvested, and NK activity and lung MADB106 tumor retention were assessed. In addition, C57BL/6 mice were implanted with syngeneic B16F10.9 melanoma cells. When tumors reached 100 mm, mice were treated with CpG-C/vehicle, and 24 hours later the tumor was excised along with P+E/vehicle treatment. Recurrence-free survival was monitored thereafter. RESULTS: Each of the regimens alone, CpG-C or P+E, showed improvement in most indices examined, including improved long-term recurrence-free survival rates. Most importantly, the combined treatment yielded additive or synergistic effects, further improving tumor clearance from the lungs and enhancing NK numbers and cytotoxicity via different, but complimentary, mechanisms. CONCLUSIONS: Treatment aimed at perioperative enhancement of CMI and simultaneous inhibition of excessive catecholamine and prostaglandin responses, employing CpG-C, propranolol, and etodolac, could be successful in limiting postoperative immunosuppression and metastatic progression, more so than each treatment alone.