Proteomics analysis of meclofenamic acid-treated small cell lung carcinoma cells revealed changes in cellular energy metabolism for cancer cell survival.

Small cell lung carcinoma (SCLC) is a highly aggressive cancer with low survival rate. Although initial response to chemotherapy in SCLC patients is well-rated, the treatments applied after the disease relapses are not successful. Drug resistance is accepted to be one of the main reasons for this failure. Therefore, there is an urgent need for new treatment strategies for SCLC. Meclofenamic acid, a nonsteroidal anti-inflammatory drug, has been shown to have anticancer effects on various types of cancers via different mechanisms. The aim of this study was to investigate the alterations that meclofenamic acid caused on a SCLC cell line, DMS114 using the tools of proteomics namely two-dimensional gel electrophoresis coupled to MALDI-TOF/TOF and nHPLC coupled to LC-MS/MS. Among the proteins identified by both methods, those showing significantly altered expression levels were evaluated using bioinformatics databases, PANTHER and STRING. The key altered metabolism upon meclofenamic acid treatment appeared to the cellular energy metabolism. Glycolysis was suppressed, whereas mitochondrial activity and oxidative phosphorylation were boosted. The cells underwent metabolic reprogramming to adapt into their new environment for survival. Metabolic reprogramming is known to cause drug resistance in several cancer types including SCLC. The identified differentially regulated proteins in here associated with energy metabolism hold value as the potential targets to overcome drug resistance in SCLC treatment.

Phase I/II trial of meclofenamate in progressive MGMT-methylated glioblastoma under temozolomide second-line therapy-the MecMeth/NOA-24 trial.

BACKGROUND: Glioblastoma is the most frequent and malignant primary brain tumor. Even in the subgroup with O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and favorable response to first-line therapy, survival after relapse is short (12 months). Standard therapy for recurrent MGMT-methylated glioblastoma is not standardized and may consist of re-resection, re-irradiation, and chemotherapy with temozolomide (TMZ), lomustine (CCNU), or a combination thereof. Preclinical results show that meclofenamate (MFA), originally developed as a nonsteroidal anti-inflammatory drug (NSAID) and registered in the USA, sensitizes glioblastoma cells to temozolomide-induced toxicity via inhibition of gap junction-mediated intercellular cytosolic traffic and demolishment of tumor microtube (TM)-based network morphology. METHODS: In this study, combined MFA/TMZ therapy will be administered (orally) in patients with first relapse of MGMT-methylated glioblastoma. A phase I component (6-12 patients, 2 dose levels of MFA + standard dose TMZ) evaluates safety and feasibility and determines the dose for the randomized phase II component (2 × 30 patients) with progression-free survival as the primary endpoint. DISCUSSION: This study is set up to assess toxicity and first indications of efficacy of MFA repurposed in the setting of a very difficult-to-treat recurrent tumor. The trial is a logical next step after the identification of the role of resistance-providing TMs in glioblastoma, and results will be crucial for further trials targeting TMs. In case of favorable results, MFA may constitute the first clinically feasible TM-targeted drug and therefore might bridge the idea of a TM-targeted therapeutic approach from basic insights into clinical reality. TRIAL REGISTRATION: EudraCT 2021-000708-39 . Registered on 08 February 2021.

Carcinoma-astrocyte gap junctions promote brain metastasis by cGAMP transfer.

Brain metastasis represents a substantial source of morbidity and mortality in various cancers, and is characterized by high resistance to chemotherapy. Here we define the role of the most abundant cell type in the brain, the astrocyte, in promoting brain metastasis. We show that human and mouse breast and lung cancer cells express protocadherin 7 (PCDH7), which promotes the assembly of carcinoma-astrocyte gap junctions composed of connexin 43 (Cx43). Once engaged with the astrocyte gap-junctional network, brain metastatic cancer cells use these channels to transfer the second messenger cGAMP to astrocytes, activating the STING pathway and production of inflammatory cytokines such as interferon-α (IFNα) and tumour necrosis factor (TNF). As paracrine signals, these factors activate the STAT1 and NF-κB pathways in brain metastatic cells, thereby supporting tumour growth and chemoresistance. The orally bioavailable modulators of gap junctions meclofenamate and tonabersat break this paracrine loop, and we provide proof-of-principle that these drugs could be used to treat established brain metastasis.

Block of gap junctions eliminates aberrant activity and restores light responses during retinal degeneration.

Retinal degeneration leads to progressive photoreceptor cell death, resulting in vision loss. Subsequently, inner retinal neurons develop aberrant synaptic activity, compounding visual impairment. In retinal ganglion cells, light responses driven by surviving photoreceptors are obscured by elevated levels of aberrant spiking activity. Here, we demonstrate in rd10 mice that targeting disruptive neuronal circuitry with a gap junction antagonist can significantly reduce excessive spiking. This treatment increases the sensitivity of the degenerated retina to light stimuli driven by residual photoreceptors. Additionally, this enhances signal transmission from inner retinal neurons to ganglion cells, potentially allowing the retinal network to preserve the fidelity of signals either from prosthetic electronic devices, or from cells optogenetically modified to transduce light. Thus, targeting maladaptive changes to the retina allows for treatments to use existing neuronal tissue to restore light sensitivity, and to augment existing strategies to replace lost photoreceptors.

Effects of meclofenamic acid on limbic epileptogenesis in mice kindling models.

The most avid goal for antiepileptic drugs (AEDs) development today is to discover potential agents to prevent epilepsy or slow the process of epileptogenesis. Accumulating evidence reveals that gap junctions in the brain may be involved in epileptogenesis. Meclofenamic acid (MFA), a gap junction blocker, has not yet been applied in epileptogenic models to test whether it has antiepileptogenic or disease-modifying properties or not. In this study, we investigated the effects of MFA on limbic epileptogenesis in amygdaloid kindling and hippocampus rapid kindling models in mice. We found that intracerebroventricular (i.c.v., 2 µl) administration of either dose of MFA (100 µM, 1mM or 100mM) 15 min prior daily kindling stimulus decreased seizure stage, shortened the after-discharge duration (ADD) and increased the number of stimulations required to elicit stage 5 seizure. MFA also prevented the establishment of post-kindling enhanced amygdala excitability, evident as the increase of afterdischarge threshold (ADT) compared with pre-kindling values. Furthermore, MFA retarded kindling acquisition in mice hippocampus rapid kindling model as well, which demonstrated that the antiepileptogenic effects of MFA were not specific to the amygdala but also occur in other limbic structures such as the hippocampus. Our results confirm that MFA can slow the limbic epileptogenesis in both amygdaloid kindling and hippocampus rapid kindling models, and indicate that MFA may be a potential drug that has antiepileptogenic or disease-modifying properties.

Antitumor effect of meclofenamic acid on human androgen-independent prostate cancer: a preclinical evaluation.

PURPOSE: Prostate cancer is a worldwide public health problem and its treatment continues to be a therapeutic challenge especially in patients with metastatic androgen-independent cancer. Inflammation is a process that has been involved in the origin of this cancer and its inhibition has been postulated as a prophylactic and therapeutic strategy. The present study evaluated two non-steroidal anti-inflammatory drugs (meclofenamic acid and mefenamic acid) that have been studied very little in regard to cancer treatment. METHODS: In vitro, the cytotoxic effects of meclofenamic acid and mefenamic acid were determined in human prostate cancer cell lines (LNCaP: androgen-dependent; and PC3: androgen-independent). In vivo trials were divided into two phases; meclofenamic acid toxicity was initially determined at different doses (0, 5, 10 and 20 mg/kg/day/25 days) in BALB/c mice, after which a trial using non-toxic doses was carried out to evaluate the antitumor efficacy of the drug in a PC3/nude-mouse model of human androgen-independent prostate cancer. RESULTS: In vitro trials showed that only meclofenamic acid is highly cytotoxic in neoplastic prostate cells. The 5 and 10 mg/kg/day/25 day doses did not cause relevant toxicity in the BALB/c mouse trial, and so both doses were used in the nude-mouse model of cancer trial. This latter trial showed that meclofenamic acid significantly reduces tumor growth, prolongs survival, and is even capable of generating total tumor regression in up to 25% of mice treated at high dose. CONCLUSIONS: Meclofenamic acid was shown to be a potential antineoplastic agent for both androgen-dependent and androgen-independent prostate cancer.

Drug repositioning and pharmacophore identification in the discovery of hookworm MIF inhibitors.

The screening of bioactive compound libraries can be an effective approach for repositioning FDA-approved drugs or discovering new pharmacophores. Hookworms are blood-feeding, intestinal nematode parasites that infect up to 600 million people worldwide. Vaccination with recombinant Ancylostoma ceylanicum macrophage migration inhibitory factor (rAceMIF) provided partial protection from disease, thus establishing a "proof-of-concept" for targeting AceMIF to prevent or treat infection. A high-throughput screen (HTS) against rAceMIF identified six AceMIF-specific inhibitors. A nonsteroidal anti-inflammatory drug (NSAID), sodium meclofenamate, could be tested in an animal model to assess the therapeutic efficacy in treating hookworm disease. Furosemide, an FDA-approved diuretic, exhibited submicromolar inhibition of rAceMIF tautomerase activity. Structure-activity relationships of a pharmacophore based on furosemide included one analog that binds similarly to the active site, yet does not inhibit the Na-K-Cl symporter (NKCC1) responsible for diuretic activity.

Embryo transfer induces a subclinical endometritis in recipient mares which can be prevented by treatment with non-steroid anti-inflammatory drugs.

We tested the hypothesis that subclinical endometritis occurs after embryo transfer (ET) in the horse. Recipient mares were treated with meclofenamic acid (M) or flunixin meglumin (F) after ET or were left untreated (n=9 per group). Embryos were re-collected 4 days after transfer. Endometrial biopsies were taken for histology and analysis of cyclooxygenase-2 (COX-2) by immunohistochemistry and for PCR. Bacteriological swabs were collected from the uterus and lavage fluid of donor and recipient mares. Progesterone and prostaglandin F(2alpha) release was analysed in recipient mares after ET. Four days after ET, four embryos were recovered from group M and three from group F and untreated mares, each. The number of polymorph nuclear neutrophils was reduced in treated mares (p<0.05). Expression of mRNA for inflammatory cytokines did not differ between groups. In group M, expression of endometrial prostaglandin-E-synthase was higher than in group F (p<0.05). Three out of nine control mares underwent preterm luteolysis (p<0.05 vs. treatment groups), prostaglandin release (p<0.05) and the number of COX-2 positive cells (p<0.01) were significantly higher than in treated mares. Only few bacteriological swabs were positive. In conclusion, treatment of embryo recipient mares with non-steroid anti-inflammatory drugs inhibits the inflammatory response of the endometrium after ET. Meclofenamic acid may have advantages in comparison to flunixin meglumin due to a different influence on prostaglandin synthesis that may not result in inhibition of embryonic mobility.

Use of carprofen for the treatment of pain and inflammation in dogs.

Most studies of nonsteroidal anti-inflammatory drugs (NSAID) do not demonstrate appreciable differences in efficacy. As awareness of the adverse effects associated with NSAID use increases, safety is becoming the primary concern among physicians when selecting NSAID for use by their human patients. However, veterinarians may be less aware of the safety concerns associated with NSAID use. A wide range of NSAID is used to treat human beings with osteoarthrits; however, it is imperative to remember that dogs are especially sensitive to these drugs, and reports of serious, and occasionally fatal, complications are numerous. Carprofen is a propionic acid-derived NSAID that has anti-inflammatory, analgesic, and antipyretic activity. In animals, carprofen is as potent as indomethacina and more potent than aspirin or phenlbutazone, but carprofen appears to be safer than most other NSAID.

Cyclooxygenase products contribute to endothelin-induced pulmonary hypertension and altered lung mechanics in sheep.

Endothelins have potent biological effect in vivo which may, in part, be mediated by stimulation of cyclooxygenase metabolism of arachidonic acid. We administered endothelins (ETs) intravenously to chronically instrumented awake sheep with and without pretreatment with meclofenamate (n = 8). 30 micrograms doses of ET-1, ET-2, and ET-3 caused similar degrees of acute elevation of pulmonary artery pressure (PPA), reduction of the dynamic compliance of the lungs (Cdyn), and increases in lung lymph flow. Pretreatment with meclofenamate inhibited the rise in PPA and reduction in Cdyn, but had no effect on lung lymph flow. We conclude that the biological effects of the endothelins on PPA and Cdyn, but not lung fluid balance, are mediated in part by cyclooxygenase products of arachidonic acid metabolism.

Non-steroidal anti-inflammatory drugs fail to enhance healing of acute hamstring injuries treated with physiotherapy.

The effects of two non-steroidal anti-inflammatory drugs (NSAIDs), meclofenamate and diclofenac, in combination with physiotherapy modalities on the rate of healing of acute hamstring muscle tears were studied in a double-blind, placebo-controlled trial. Fourty-four of the 75 patients with this injury recruited were assessed and randomly allocated to one of three treatment groups: meclofenamate (100 mg 3 times a day), diclofenac (50 mg 3 times a day) and placebo. All patients received the same intensive physiotherapy treatment over the 7-day treatment period. Patient assessments were performed on days 1, 3 and 7 of the 7-day study period and included pain assessment (visual analogue scale), swelling measurement (thigh circumference measurement at the site of the muscle tear) and isokinetic muscle performance testing. Treatment produced a significant improvement in all measurements in all groups, but there was no difference in any measurement between groups. However, when only the more severe injuries were analysed, the reported pain score at day 7 was significantly lower in the placebo group than in either the meclofenamate group or the diclofenac group (P < 0.05). Hence this study did not find any additive effect on the healing of acute muscle injuries when meclofenamate or diclofenac was added to standard physiotherapeutic modalities. The study therefore does not support the use of NSAIDs in the treatment of acute hamstring muscle injuries.

Methods to prevent colonic injury in pelvic radiation.

PURPOSE: Radiation has become an adjunct in the treatment of pelvic malignancies. Attempts to prevent adjacent tissue injury have met with varying degrees of success, and the purpose of this study was to investigate potential radioprotective effects of an elemental diet, sodium meclofenamate, and vitamin A in an animal model of acute and chronic pelvic radiation previously described. METHODS: Female Sprague-Dawley rats, 200-250 grams, were anesthetized and then received 900 rads of pelvic radiation once per week for five weeks for a total of 4500 rads. Animals were divided into five groups. Treatment groups received radiation and elemental diet, radiation and vitamin A, radiation and sodium meclofenamate. Control animals received anesthesia only and no radiation. Vitamin A was given as a supplement to (662 IU/kg) standard rat chow. Elemental diet was given as a commercially available formula, whereas sodium meclofenamate was given as a postoperative supplement (5 mg/kg/day). All animals were given these treatments during the course of radiation therapy only. Histology of distal colon was measured at one week, five weeks, six months, and one year postradiation therapy. The distal two cm of colon were removed at necropsy and fixed in 10 percent formalin at each of the above time points. Histologic grade was determined by a previously described grading scale. RESULTS: Results showed a qualitative radiation injury that could be documented at one and five weeks postradiation. Elemental diet, vitamin A, and sodium meclofenamate prevented histologic changes that occurred at these time points. No difference in histologic grade was seen between any groups at six months and one year postradiation therapy. CONCLUSION: In summary, our model of pelvic radiation produces a definable radiation injury within the colon at one and five weeks postradiation. Use of elemental diet, vitamin A, and sodium meclofenamate prevented these changes.

Pentoxifylline and meclofenamic acid treatment reduces clinical manifestations in a murine model of AIDS.

C57/BL/6 mice infected with LP-BM5 MuLV virus developed an AIDS-like disease (MAIDS) with splenomegaly, leukopenia, thrombocytopenia, anemia, decreased numbers of helper/inducer and suppressor/cytotoxic T-cells and decreased production of interferon alpha. We have shown previously that HIV-associated Kaposi's sarcoma tissue contains high levels of prostaglandin E2 (PgE2), and this inhibits interferon synthesis through a cAMP-dependent second-messenger process. In this study we treated groups of MAIDS-infected mice with combinations of pentoxifylline, an agent which increases cAMP and inhibits phosphodiesterases, and sodium meclofenamic acid, a PgE2 inhibitor. Treated mice showed: 1) significantly higher total leukocyte and platelet counts, 2) higher total L3T4+ (helper/inducer) and Lyt-2+ (suppressor-cytotoxic) T-cell population. Pathologic examination also showed significantly less hepatosplenomegaly and lymphadenopathy in animals treated with pentoxifylline and meclofenamic acid. Partly, PgE2-induced suppression of interferon alpha production may mediate expression of retrovirus infection in this murine model of AIDS.

Efficacy of meclofenamate sodium (Meclomen) in the treatment of rapidly progressive periodontitis.

This 6-month, double-blind, controlled clinical trial determined the efficacy of the non-steroidal anti-inflammatory drug, meclofenamate sodium (Meclomen), as an adjunct to scaling and root planing in the treatment of rapidly progressive periodontitis (RPP). 22 subjects (7 male, 15 female) aged 36.5 +/- 7.88 years with RPP and disease-active sites as determined by pretreatment bone scan had standardized radiographs at baseline and 6 months, and clinical measurements at baseline, 3 and 6 months. Following full-mouth scaling and root planing, subjects were randomly assigned to either a placebo, 50 or 100 mg meclofenamate sodium bid group. Bone change over the 6-month period as assessed by subtraction radiography was the primary efficacy determinant. Specialized software was used to isolate the lesion from the subtraction image and to measure bone change along the root surface. ANOVA using the subject as the unit of analysis revealed a significant dose response (p < 0.001) with the placebo group having a mean bone loss of 0.42 +/- 0.06 mm and the low and high dose groups having mean bone gains of 0.07 +/- 0.05 and 0.20 +/- 0.07 mm, respectively. These findings indicate that meclofenamate sodium may be a useful adjunct in the treatment of rapidly progressive periodontitis.

[A comparative evaluation of the remission from acute lumbar-sciatic pain following treatment with meclofenamic acid and naproxen]. / Valutazione comparativa sulla remissione del dolore lombosciatalgico acuto dopo trattamento con acido meclofenamico e naprossene.

This study was performed to assess the analgesic effect and the onset of action of meclofenamic acid compared with naproxene in patients affected by acute lumbar-sciatic pain. Thirty patients of both sexes were randomly allocated to 2 groups of 15 patients each; the first group was treated with meclofenamic acid (200 mg b.i.d.) and the second with naproxene (500 mg b.i.d.). Both drugs were administered as suppositories for a week. The intensity of pain, both at rest and after movement, was assessed by means of analogic scales at basal time and 15, 30, 60, 180, 360 minutes, 4 and 8 days after the first administration. Both types of pain were significantly decreased with respect to basal values in meclofenamic acid group (P < 0.01), 60 minutes after onset of treatment, while in the naproxene group the effect was later. Moreover the analgesic effect was significantly greater in the meclofenamic acid group with respect to the naproxene group, after 15 minutes for pain at rest (P < 0.05) and after 30 minutes for pain after movement (P < 0.02). Similarly, after 4 and 8 days, both types of pain improved to a larger extent in the meclofenamic acid group with respect to the naproxene group (P < 0.05 after four days and P < 0.01 after eight days). This study has shown that meclofenamic acid has greater efficacy and faster analgesic effect than naproxene. Meclofenamic acid has proved to be a drug of choice in the treatment of slight to moderate musculo-skeletal pain syndromes.

An attempt at real prophylaxis of primary dysmenorrhea: comparison between meclofenamate sodium and naproxen sodium.

Dysmenorrhea is a widespread phenomenon, affecting mainly young nulliparous women, often inducing difficulties in study or in work. Its pathogenesis involves a release of local vasoconstrictors like Prostaglandins and Leukotrienes. Modern therapy is based firstly on the administration of prostaglandin-Synthetase Inhibitors or Contraceptive Pills, with the aim of reducing the menstrual excess of pain inducing substances. In order to achieve more efficacy, on the basis of the already proven effectiveness of the Non Steroid Anti-Inflammatory Drugs (NSAID)s in this field, we recently set out to prevent dysmenorrhea in a double-blind randomized study with Meclofenamate Sorium and Naproxen Sodium. Through the observation of the drop in Basal Body Temperature which usually precedes menstrual flow, we were able to instruct our patients in the earlier recognition of impending menstrual onset, leading to earlier prevention of Prostaglandin and Leukotriene release. Meclofenamate Sodium in particular led to considerable pain reduction, with very good patient compliance and without significant complications, probably of its additional receptor effect.

Efficacy of meclofenamate sodium versus placebo in headache and craniofacial pain.

Twenty patients were enrolled in a double-blind, placebo-controlled crossover study of meclofenamate sodium in headache and craniofacial pain. There were four observation periods of 15 days each: Period 1 was a wash-out period. In period 2, subjects were randomly assigned to a 15-day regimen of taking two capsules a day of 100mg meclofenamate sodium (group 1) or placebo (group 2). In period 3, group 1 was switched to placebo and group 2 to meclofenamate sodium for the next 15 days. Lastly, the patients took no medication for a further 15 days (period 4). A thermographic record of the craniofacial and neck areas was taken at the end of periods 1 and 4. A record of the pressure threshold and tissue compliance at different sites of the craniofacial, neck and shoulder areas was taken at the end of each period. During the trial, number and duration of painful events were recorded daily by the patients, and the level of pain evaluated on a visual analog scale. Mean data were analyzed for significant difference by ANOVA and paired t-test. During the meclofenamate sodium period, there was a significant decrease of days with painful events compared to the wash-out period in group 1 and compared to the placebo period in group 2. In the majority of patients, the meclofenamate sodium period scored lowest or second-lowest after the follow-up period in mean pain intensity. Data for pressure threshold, although not significant, were indicative of a possible increase during and after intake of meclofenamate sodium.(ABSTRACT TRUNCATED AT 250 WORDS)

Longterm drug therapy for rheumatoid arthritis in seven rheumatology private practices: I. Nonsteroidal antiinflammatory drugs.

The probability of continuation of a particular nonsteroidal antiinflammatory drug (NSAID) over 5 years was estimated for 1,775 courses taken by 532 patients with rheumatoid arthritis treated in 7 rheumatology private practices. Similar results were seen for 15 different NSAID--48% of courses were continued at 12 months, 36% at 24 months, and 20% at 60 months. Only acetylated salicylates, other than plain aspirin, were continued significantly longer than any of the other NSAID. The probability of continuation of plain aspirin was similar to other NSAID, including nonacetylated salicylates and nonsalicylate NSAID. The first NSAID taken by an individual patient was continued only marginally longer than the 4th NSAID taken by the same patient. While most NSAID courses were not continued for long periods, 20% were continued for longer than 5 years, suggesting effective longterm results in this minority of courses.

Effects of sodium meclofenamate on postoperative pain following periodontal surgery.

The analgesic activity of single doses of meclofenamate (100 mg) was compared to aspirin (500 mg) and to placebo on 99 outpatients with moderate to severe pain following periodontal surgery under double-blind conditions. Pain intensity differences scores (PID) at the first, second, and third hour after the ingestion of the first capsule of each medication were used to determine the analgesic efficacy of the studied drugs. Kruskal Wallis test followed by the Mann-Whitney rank sum test were used in the statistical analysis of results. Meclofenamate was statistically superior to placebo and superior to aspirin in the second hour of evaluation, while aspirin was not superior to placebo during the 3-hour period of pain evaluation. It is concluded that meclofenamate is a non-steroidal antiinflammatory drug with interesting analgesic properties which can be used as directed as an alternative to aspirin or acetaminophen for the control of postoperative pain following periodontal surgery.

Double blind randomized controlled trial of sodium meclofenamate (Meclomen) and diclofenac sodium (Voltaren): post validation reapplication of the WOMAC Osteoarthritis Index.

Following several years of development and validation, we applied the WOMAC Osteoarthritis Index as the principal outcome measure in a double blind randomized parallel trial of Meclomen (100 mg po tid) and Voltaren (25 mg po tid). Statistically significant improvements in clinical status were noted in both treatment groups. At the doses studied, between drug differences favoring Meclomen were observed in pain and stiffness, no difference being noted in physical function. No significant between drug difference was noted in tolerability at these same doses. Our study also demonstrated that the relative efficiency of WOMAC was similar to that of the Lequesne and Doyle indices. Finally, we defined the standard deviation necessary to calculate sample size for future studies using the WOMAC index, both for studies based on static scores and those based on change scores.