Targeting thiol isomerase activity with zafirlukast to treat ovarian cancer from the bench to clinic.

Thiol isomerases, including PDI, ERp57, ERp5, and ERp72, play important and distinct roles in cancer progression, cancer cell signaling, and metastasis. We recently discovered that zafirlukast, an FDA-approved medication for asthma, is a pan-thiol isomerase inhibitor. Zafirlukast inhibited the growth of multiple cancer cell lines with an IC50 in the low micromolar range, while also inhibiting cellular thiol isomerase activity, EGFR activation, and downstream phosphorylation of Gab1. Zafirlukast also blocked the procoagulant activity of OVCAR8 cells by inhibiting tissue factor-dependent Factor Xa generation. In an ovarian cancer xenograft model, statistically significant differences in tumor size between control vs treated groups were observed by Day 18. Zafirlukast also significantly reduced the number and size of metastatic tumors found within the lungs of the mock-treated controls. When added to a chemotherapeutic regimen, zafirlukast significantly reduced growth, by 38% compared with the mice receiving only the chemotherapeutic treatment, and by 83% over untreated controls. Finally, we conducted a pilot clinical trial in women with tumor marker-only (CA-125) relapsed ovarian cancer, where the rate of rise of CA-125 was significantly reduced following treatment with zafirlukast, while no severe adverse events were reported. Thiol isomerase inhibition with zafirlukast represents a novel, well-tolerated therapeutic in the treatment of ovarian cancer.

Remimazolam: A Novel Option for Procedural Sedation in High Risk Patients.

PURPOSE: The purpose of this drug review was to explore the safety and efficacy of the newly approved benzodiazepine, remimazolam, in order to evaluate its place in therapy. SUMMARY: Remimazolam has a faster onset of action and recovery time than midazolam when given as single IV doses. Additionally, it has no known CYP450 interactions that would contribute to drug-drug interactions. Patients with severe hepatic impairment may require dose titration as well as the elderly who should be closely monitored. Although remimazolam vials should be protected from light and must be reconstituted immediately before use, the reconstituted vial may be stored for later use at room temperature for up to 8 hours. Remimazolam is more expensive than current options used in practice, as such individual institutional formulary and provider preference will require review to see if its advantages are worth the additional cost and to determine its place in therapy. CONCLUSION: Remimazolam is a novel option when choosing a benzodiazepine for procedural sedation that has pharmacokinetic and pharmacodynamic advantages when compared to other commonly prescribed sedatives. Remimazolam has proved superior to midazolam when analyzing drug-drug interactions, onset, and time to alertness. Remimazolam also has a shorter elimination half-life and decreased volume of distribution when compared to midazolam.

Zafirlukast is a broad-spectrum thiol isomerase inhibitor that inhibits thrombosis without altering bleeding times.

BACKGROUND AND PURPOSE: Multiple members of the thiol isomerase (TI) family of enzymes are present in and released by platelets. Inhibition of these enzymes results in diminished platelet responses, aggregation, adhesion and thrombus formation. Recently, the therapeutic potential of TI inhibition has been recognised and drug-development technologies were used to identify selective small molecule inhibitors. To date, few pan-TI inhibitors have been characterised and the most studied, bacitracin, is known to be nephrotoxic, which prohibits its systemic therapeutic usage. EXPERIMENTAL APPROACH: We therefore sought to identify novel broad-spectrum inhibitors of these enzymes and test their effects in vivo. A total of 3,641 compounds were screened for inhibitory effects on the redox activity of ERp5, protein disulphide isomerase (PDI), ERp57, ERp72 and thioredoxin in an insulin turbidity assay. Of the lead compounds identified, zafirlukast was selected for further investigation. KEY RESULTS: When applied to platelets, zafirlukast diminished platelet responses in vitro. Zafirlukast was antithrombotic in murine models of thrombosis but did not impair responses in a model of haemostasis. Since TIs are known to modulate adhesion receptor function, we explored the effects of zafirlukast on cell migration. This was inhibited independently of cysteinyl LT receptor expression and was associated with modulation of cell-surface free thiol levels consistent with alterations in redox activity on the cell surface. CONCLUSION AND IMPLICATIONS: We identify zafirlukast to be a novel, potent, broad-spectrum TI inhibitor, with wide-ranging effects on platelet function, thrombosis and integrin-mediated cell migration. Zafirlukast is antithrombotic but does not cause bleeding.

Placement and Integration of Pathophysiology, Anatomy, and Physiology Within the Doctor of Pharmacy Curriculum.

Objective. To examine the placement of pathophysiology, anatomy, and physiology within the curricula of US pharmacy schools and colleges for variations in program length, prerequisites, institution type, geographic region, and establishment date.Methods. The websites of 146 pharmacy programs were examined for information related to pathophysiology, anatomy, and physiology courses and instruction. Eight programs listed uninterpretable or incomplete website data and were excluded, producing a final sample size of 138 programs. Data were analyzed to determine differences in curricular placement, credit hours, and integration.Results. The majority (65.3%) of pathophysiology courses were incorporated into the curriculum by integration, while some (14.5%) had both stand-alone and integrated pathophysiology courses. The remaining programs (20.2%) had stand-alone pathophysiology courses only. Of those with stand-alone pathophysiology courses, the mean number of credit hours was 5. Most programs (76.1%) required anatomy and/or physiology as a prerequisite or as part of the professional program, with significantly more public programs than private programs requiring it as a prerequisite (77.9% vs 48.6%).Conclusion. Pathophysiology is taught in diverse formats throughout US pharmacy schools, with the only consensus among programs being that it belongs in the professional curriculum. While the majority of programs teach pathophysiology as an integrated course, stand-alone courses are also common. There is also great diversity in the type of instruction used in anatomy and physiology courses. While every program requires students to complete anatomy and physiology courses, these are commonly taught as part of the professional curriculum or are prerequisites. Overall, there are few significant differences in the instruction of these subjects among US pharmacy schools.

Protein Disulfide Isomerases Regulate IgE-Mediated Mast Cell Responses and Their Inhibition Confers Protective Effects During Food Allergy.

The thiol isomerase, protein disulfide isomerase (PDI), plays important intracellular roles during protein folding, maintaining cellular function and viability. Recent studies suggest novel roles for extracellular cell surface PDI in enhancing cellular activation and promoting their function. Moreover, a number of food-derived substances have been shown to regulate cellular PDI activity and alter disease progression. We hypothesized that PDI may have similar roles during mast cell-mediated allergic responses and examined its effects on IgE-induced mast cell activity during cell culture and food allergy. Mast cells were activated via IgE and antigen and the effects of PDI inhibition on mast cell activation were assessed. The effects of PDI blockade in vivo were examined by treating mice with the irreversible PDI inhibitor, PACMA-31, in an ovalbumin-induced model of food allergy. The role of dietary PDI modulators was investigated using various dietary compounds including curcumin and quercetin-3-rutinoside (rutin). PDI expression was observed on resting mast cell surfaces, intracellularly, and in the intestines of allergic mice. Furthermore, enhanced secretion of extracellular PDI was observed on mast cell membranes during IgE and antigen activation. Insulin turbidimetric assays demonstrated that curcumin is a potent PDI inhibitor and pre-treatment of mast cells with curcumin or established PDI inhibitors such as bacitracin, rutin or PACMA-31, resulted in the suppression of IgE-mediated activation and the secretion of various cytokines. This was accompanied by decreased mast cell proliferation, FcεRI expression, and mast cell degranulation. Similarly, treatment of allergic BALB/c mice with PACMA-31 attenuated the development of food allergy resulting in decreased allergic diarrhea, mast cell activation, and fewer intestinal mast cells. The production of TH2-specific cytokines was also suppressed. Our observations suggest that PDI catalytic activity is essential in the regulation of mast cell activation, and that its blockade may benefit patients with allergic inflammation.