Involvement of Mitochondrial Mechanisms and Cyclooxygenase-2 Activation in the Effect of Desethylamiodarone on 4T1 Triple-Negative Breast Cancer Line.

Novel compounds significantly interfering with the mitochondrial energy production may have therapeutic value in triple-negative breast cancer (TNBC). This criterion is clearly fulfilled by desethylamiodarone (DEA), which is a major metabolite of amiodarone, a widely used antiarrhythmic drug, since the DEA previously demonstrated anti-neoplastic, anti-metastasizing, and direct mitochondrial effects in B16F10 melanoma cells. Additionally, the more than fifty years of clinical experience with amiodarone should answer most of the safety concerns about DEA. Accordingly, in the present study, we investigated DEA's potential in TNBC by using a TN and a hormone receptor positive (HR+) BC cell line. DEA reduced the viability, colony formation, and invasive growth of the 4T1 cell line and led to a higher extent of the MCF-7 cell line. It lowered mitochondrial transmembrane potential and induced mitochondrial fragmentation. On the other hand, DEA failed to significantly affect various parameters of the cellular energy metabolism as determined by a Seahorse live cell respirometer. Cyclooxygenase 2 (COX-2), which was upregulated by DEA in the TNBC cell line only, accounted for most of 4T1's DEA resistance, which was counteracted by the selective COX-2 inhibitor celecoxib. All these data indicate that DEA may have potentiality in the therapy of TNBC.

Artificial Intelligence-Based Colorectal Polyp Histology Prediction by Using Narrow-Band Image-Magnifying Colonoscopy.

BACKGROUND/AIMS: We have been developing artificial intelligence based polyp histology prediction (AIPHP) method to classify Narrow Band Imaging (NBI) magnifying colonoscopy images to predict the hyperplastic or neoplastic histology of polyps. Our aim was to analyze the accuracy of AIPHP and narrow-band imaging international colorectal endoscopic (NICE) classification based histology predictions and also to compare the results of the two methods. METHODS: We studied 373 colorectal polyp samples taken by polypectomy from 279 patients. The documented NBI still images were analyzed by the AIPHP method and by the NICE classification parallel. The AIPHP software was created by machine learning method. The software measures five geometrical and color features on the endoscopic image. RESULTS: The accuracy of AIPHP was 86.6% (323/373) in total of polyps. We compared the AIPHP accuracy results for diminutive and non-diminutive polyps (82.1% vs. 92.2%; p=0.0032). The accuracy of the hyperplastic histology prediction was significantly better by NICE compared to AIPHP method both in the diminutive polyps (n=207) (95.2% vs. 82.1%) (p<0.001) and also in all evaluated polyps (n=373) (97.1% vs. 86.6%) (p<0.001). CONCLUSION: Our artificial intelligence based polyp histology prediction software could predict histology with high accuracy only in the large size polyp subgroup.

[Hemospray: a novel therapeutic option in the management of acute upper gastrointestinal bleeding]. / Hemospray: Új lehetoség az akut felso gastrointestinalis vérzések ellátásában.

INTRODUCTION: Early endoscopic diagnosis and endoscopic therapy are very important in cases of acute gastrointestinal bleeding. Hemospray is an inorganic powder with hemostatic properties recently proposed for the treatment of acute gastrointestinal bleeding. AIM: The aim of the authors was to report the first Hungarian experience obtained with Hemospray in patients with acute gastrointestinal bleeding. METHOD: During a 14-month period 10 acute upper gastrointestinal bleeder patients were treated endoscopically with Hemospray in 11 settings. In 5 patients previous endoscopic hemostatic methods failed and in the remaining 5 patients Hemospray was administrated as a first-line therapy. RESULTS: Primary hemostasis was achieved in 9 of the 10 patients treated with Hemospray. Two patients died during hospitalization (uncontrolled arterial bleeding in one patient and hepatic encephalopathy in the other one patient). Primary hemostasis and hemodynamic stability were achieved in each of the 4 patients who had thrombopenia. CONCLUSIONS: Hemospray as a rescue therapy may ensure primary hemostasis in severe acute gastrointestinal bleeding even in cases with thrombopenia.

Mucosal healing effect of mesalazine granules in naproxen-induced small bowel enteropathy.

AIM: To investigate the effect of mesalazine granules on small intestinal injury induced by naproxen using capsule endoscopy (CE). METHODS: This was a single center, non-randomized, open-label, uncontrolled pilot study, using the PillCam SB CE system with RAPID 5 software. The Lewis Index Score (LIS) for small bowel injury was investigated to evaluate the severity of mucosal injury. Arthropathy patients with at least one month history of daily naproxen use of 1000 mg and proton pump inhibitor co-therapy were screened. Patients with a minimum LIS of 135 were eligible to enter the 4-wk treatment phase of the study. During this treatment period, 3 × 1000 mg/d mesalazine granules were added to ongoing therapies of 1000 mg/d naproxen and 20 mg/d omeprazole. At the end of the 4-wk combined treatment period, a second small bowel CE was performed to re-evaluate the enteropathy according to the LIS results. The primary objective of this study was to assess the mucosal changes after 4 wk of mesalazine treatment. RESULTS: A total of 18 patients (16 females), ranging in age from 46 to 78 years (mean age 60.3 years) were screened, all had been taking 1000 mg/d naproxen for at least one month. Eight patients were excluded from the mesalazine therapeutic phase of the study for the following reasons: the screening CE showed normal small bowel mucosa or only insignificant damages (LIS < 135) in five patients, the screening esophagogastroduodenoscopy revealed gastric ulcer in one patient, capsule technical failure and incomplete CE due to poor small bowel cleanliness in two patients. Ten patients (9 female, mean age 56.2 years) whose initial LIS reached mild and moderate-to-severe enteropathy grades (between 135 and 790 and ≥ 790) entered the 4-wk therapeutic phase and a repeat CE was performed. When comparing the change in LIS from baseline to end of treatment in all patients, a marked decrease was seen (mean LIS: 1236.4 ± 821.9 vs 925.2 ± 543.4, P = 0.271). Moreover, a significant difference between pre- and post-treatment mean total LIS was detected in 7 patients who had moderate-to-severe enteropathy gradings at the inclusion CE (mean LIS: 1615 ± 672 vs 1064 ± 424, P = 0.033). CONCLUSION: According to the small bowel CE evaluation mesalazine granules significantly attenuated mucosal injuries in patients with moderate-to-severe enteropathies induced by naproxen.

Mitigation of radiation injury by selective stimulation of the LPA(2) receptor.

Due to its antiapoptotic action, derivatives of the lipid mediator lysophosphatidic acid (LPA) provide potential therapeutic utility in diseases associated with programmed cell death. Apoptosis is one of the major pathophysiological processes elicited by radiation injury to the organism. Consequently, therapeutic explorations applying compounds that mimic the antiapoptotic action of LPA have begun. Here we present a brief account of our decade-long drug discovery effort aimed at developing LPA mimics with a special focus on specific agonists of the LPA(2) receptor subtype, which was found to be highly effective in protecting cells from apoptosis. We describe new evidence that 2-((3-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)propyl)thio)benzoic acid (GRI977143), a prototypic nonlipid agonist specific to the LPA(2) receptor subtype, rescues apoptotically condemned cells in vitro and in vivo from injury caused by high-dose γ-irradiation. GRI977143 shows the features of a radiomitigator because it is effective in rescuing the lives of mice from deadly levels of radiation when administered 24h after radiation exposure. Our findings suggest that by specifically activating LPA(2) receptors GRI977143 activates the ERK1/2 prosurvival pathway, effectively reduces Bax translocation to the mitochondrion, attenuates the activation of initiator and effector caspases, reduces DNA fragmentation, and inhibits PARP-1 cleavage associated with γ-irradiation-induced apoptosis. GRI977143 also inhibits bystander apoptosis elicited by soluble proapoptotic mediators produced by irradiated cells. Thus, GRI977143 can serve as a prototype scaffold for lead optimization paving the way to more potent analogs amenable for therapeutic exploration. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.

Virtual screening for LPA2-specific agonists identifies a nonlipid compound with antiapoptotic actions.

Lysophosphatidic acid (LPA) is a highly potent endogenous lipid mediator that protects and rescues cells from programmed cell death. Earlier work identified the LPA2 G protein-coupled receptor subtype as an important molecular target of LPA mediating antiapoptotic signaling. Here we describe the results of a virtual screen using single-reference similarity searching that yielded compounds 2-((9-oxo-9H-fluoren-2-yl)carbamoyl)benzoic acid (NSC12404), 2-((3-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)propyl)thio)benzoic acid (GRI977143), 4,5-dichloro-2-((9-oxo-9H-fluoren-2-yl)carbamoyl)benzoic acid (H2L5547924), and 2-((9,10-dioxo-9,10-dihydroanthracen-2-yl)carbamoyl) benzoic acid (H2L5828102), novel nonlipid and drug-like compounds that are specific for the LPA2 receptor subtype. We characterized the antiapoptotic action of one of these compounds, GRI977143, which was effective in reducing activation of caspases 3, 7, 8, and 9 and inhibited poly(ADP-ribose)polymerase 1 cleavage and DNA fragmentation in different extrinsic and intrinsic models of apoptosis in vitro. Furthermore, GRI977143 promoted carcinoma cell invasion of human umbilical vein endothelial cell monolayers and fibroblast proliferation. The antiapoptotic cellular signaling responses were present selectively in mouse embryonic fibroblast cells derived from LPA(1&2) double-knockout mice reconstituted with the LPA2 receptor and were absent in vector-transduced control cells. GRI977143 was an effective stimulator of extracellular signal-regulated kinase 1/2 activation and promoted the assembly of a macromolecular signaling complex consisting of LPA2, Na⁺ - H⁺ exchange regulatory factor 2, and thyroid receptor interacting protein 6, which has been shown previously to be a required step in LPA-induced antiapoptotic signaling. The present findings indicate that nonlipid LPA2-specific agonists represent an excellent starting point for development of lead compounds with potential therapeutic utility for preventing the programmed cell death involved in many types of degenerative and inflammatory diseases.

(S)-FTY720-vinylphosphonate, an analogue of the immunosuppressive agent FTY720, is a pan-antagonist of sphingosine 1-phosphate GPCR signaling and inhibits autotaxin activity.

FTY720 (Fingolimod), a synthetic analogue of sphingosine 1-phosphate (S1P), activates four of the five EDG-family S1P receptors and is in a phase-III clinical study for the treatment of multiple sclerosis. (S)-FTY720-phosphate (FTY720-P) causes S1P(1) receptor internalization and targeting to the proteasomal degradative pathway, and thus functions as an antagonist of S1P(1) by depleting the functional S1P(1) receptor from the plasma membrane. Here we describe the pharmacological characterization of two unsaturated phosphonate enantiomers of FTY720, (R)- and (S)-FTY720-vinylphosphonate. (R)-FTY720-vinylphosphonate was a full agonist of S1P(1) (EC(50) 20+/-3 nM). In contrast, the (S) enantiomer failed to activate any of the five S1P GPCRs and was a full antagonist of S1P(1,3,4) (K(i) 384 nM, 39 nM, and 1190 nM, respectively) and a partial antagonist of S1P(2), and S1P(5). Both enantiomers dose-dependently inhibited lysophospholipase D (recombinant autotaxin) with K(i) values in the low micromolar range, although with different enzyme kinetic mechanisms. When injected into mice, both enantiomers caused transient peripheral lymphopenia. (R)- and (S)-FTY720-vinylphosphonates activated ERK1/2, AKT, and exerted an antiapoptotic effect in camptothecin-treated IEC-6 intestinal epithelial cells, which primarily express S1P(2) transcripts and traces of S1P(5). (S)-FTY720-vinylphosphonate is the first pan-antagonist of S1P receptors and offers utility in probing S1P responses in vitro and in vivo. The biological effects of the (R)- and (S)-FTY720-vinylphosphonate analogues underscore the complexity of FTY720 cellular targets.

Prevalent role of Akt and ERK activation in cardioprotective effect of Ca(2+) channel- and beta-adrenergic receptor blockers.

We studied cardioprotective as well as Akt and extracellular signal-activated kinase (ERK) activating effect of a Ca(2+) antagonist and a beta-adrenergic receptor blocker during ischemia-reperfusion, and compared these properties of the substances with that of a poly(ADP-ribose) polymerase (PARP) inhibitor used as a positive control throughout the experiments. Langendorff-perfused isolated rat hearts were subjected to 25 min global ischemia followed by 45 min reperfusion, and recovery of energy metabolism as well as functional cardiac parameters were monitored. Although to varying extents, all substances improved recovery of creatine phosphate, ATP, intracellular pH, and reutilization of inorganic phosphate. These favorable changes were accompanied by improved recovery of heart function parameters and reduced infarct size. In addition and again to varying extents, all studied substances decreased oxidative damage (lipid peroxidation and protein oxidation), and activated Akt, glycogen synthase kinase (GSK)-3beta, and ERK1/2. Correlation between cardioprotective and kinase activating effectivity of the compounds proved to be statistically significant. Physiological significance of these kinase activations was established by demonstrating that inhibition of Akt by LY294002 and ERK1/2 by PD98059 compromised the cardioprotective effect of all the substances studied. In conclusion, we demonstrated for the first time that activation of phosphatidylinositol-3-kinase (PI-3K)-Akt and ERK2 pathways significantly contributed to cardioprotective effects of a Ca(2+) antagonist and a beta-adrenergic receptor blocker. Furthermore, we found a strong correlation between cardioprotective and kinase-activating potencies of the substances studied (Verapamil, Metoprolol and two PARP inhibitors), which indicated the potentiality of these kinases as drug-targets in the therapy of ischemic heart disease.

Effect of L-2286, a poly(ADP-ribose)polymerase inhibitor and enalapril on myocardial remodeling and heart failure.

Increased activation of poly(ADP-ribose) polymerase (PARP) enzyme has been implicated in the pathogenesis of acute and chronic myocardial dysfunction. We have demonstrated the protective effect of PARP inhibitors against postinfarction myocardial remodeling and heart failure. The primary aim of our recent work was to compare the effect and efficacy of a potent PARP-inhibitor (L-2286) to enalapril, a widely used angiotensin-converting enzyme (ACE) inhibitor. in experimental heart failure model. Both L-2286 and enalapril were tested in a rat model of chronic heart failure after isoproterenol-induced myocardial infarction. After a 12-week treatment period, echocardiography was performed, cardiac hypertrophy and interstitial collagen deposition were assessed, and the phosphorylation state of Akt-1/GSK-3beta pathway as well as the PKC and MAPK kinases were determined. Both PARP and ACE inhibition reduced the progression of postinfarction heart failure by attenuating cardiac hypertrophy and interstitial fibrosis. More importantly, PARP inhibition increased the activity of the prosurvival signal transduction factors (Akt-1/GSK-3beta pathway, PKCepsilon). Due to these effects, L-2286 improved the systolic left ventricular function. Enalapril treatment exerted a similar, but weaker protective effect against postinfarction myocardial remodeling and heart failure. In conclusion, we demonstrated in an experimental heart failure model that L-2286 decreased the postinfarction myocardial remodeling more effectively than enalapril treatment.

Vitrectomy with internal limiting membrane removal for clinically significant macular oedema.

BACKGROUND: Little has been published on internal limiting membrane (ILM) removal for clinically significant macular oedema (CSME) in eyes not improving following maximal laser treatment. METHODS: Retrospective review of the charts and intraoperative video films of 30 consecutive eyes of 27 patients undergoing vitrectomy, ILM peeling, and gas tamponade by a single surgeon. RESULTS: The average patient was 52 years old; 56% were males. The oedema was caused by diabetes in 87% of the eyes, 42% of which had proliferative disease. The oedema was diffuse in 16 eyes (53%) and cystoid (CME) in 14 (47%). In 21% of eyes, spontaneous vitreous detachment was present or the eye had already undergone vitrectomy. All but one eye had at least 6 months of follow-up (mean 12 months). The oedema resolved completely in 26 eyes (90%) and partially in 3 eyes (10%). The visual acuity improved at least two Snellen lines in 19 eyes (66%) and one line in 4 eyes (14%); the average improvement was 4 lines. The acuity was unchanged in three eyes (10%) and worsened in three eyes (10%), all due to cataract. Among the 14 eyes with CME, 11 (79%) became completely dry and the visual acuity improved in 11 eyes (79%). No ILM-related complication was encountered in any eye. CONCLUSIONS: Vitrectomy with ILM peeling is a promising approach to eyes with CSME. It appears to offer visual improvement at a much higher rate than laser therapy and with a longer-lasting effect than that of intravitreal triamcinolone. A larger study is necessary to confirm these preliminary findings.