Brazilin is a natural product inhibitor of the NLRP3 inflammasome

Excessive or aberrant NLRP3 inflammasome activation has been implicated in the progression and initiation of many inflammatory conditions; however, currently no NLRP3 inflammasome inhibitors have been approved for therapeutic use in the clinic. Here we have identified that the natural product brazilin effectively inhibits both priming and activation of the NLRP3 inflammasome in cultured murine macrophages, a human iPSC microglial cell line and in a mouse model of acute peritoneal inflammation. Through computational modeling, we predict that brazilin can adopt a favorable binding pose within a site of the NLRP3 protein which is essential for its conformational activation. Our results not only encourage further evaluation of brazilin as a therapeutic agent for NLRP3-related inflammatory diseases, but also introduce this small-molecule as a promising scaffold structure for the development of derivative NLRP3 inhibitor compounds.

A Selective Review and Virtual Screening Analysis of Natural Product Inhibitors of the NLRP3 Inflammasome

The NLRP3 inflammasome is currently an exciting target for drug discovery due to its role in various inflammatory diseases; however, to date, no NLRP3 inhibitors have reached the clinic. Several studies have used natural products as hit compounds to facilitate the design of novel selective NLRP3 inhibitors. Here, we review selected natural products reported in the literature as NLRP3 inhibitors, with a particular focus on those targeting gout. To complement this survey, we also report a virtual screen of the ZINC20 natural product database, predicting favored chemical features that can aid in the design of novel small molecule NLRP3 inhibitors.

SAR of Novel 3-Arylisoquinolinones: meta-Substitution on the Aryl Ring Dramatically Enhances Antiproliferative Activity through Binding to Microtubules

A set of meta-substituted 3-arylisoquinolinones have been identified that show substantial cytotoxicity in breast, liver, lung and colon cancer cell lines; these are up to 700-fold more active than the corresponding para analogues. These compounds were initially proposed as inhibitors of N-ribosyl dihydronicotinamide (NRH): quinone oxidoreductase 2 (NQO2) but were found to be inactive against the enzyme. Instead, COMPARE analysis suggested that 6-fluoro-3-(meta-fluorophenyl)isoquinolin-1(2H)-one (4) could mimic colchicine and interact with microtubules, a recognized target for cancer therapy. Subsequent docking, molecular dynamics simulations, and free energy analysis further suggested that compound 4 bound well into the colchicine-binding pocket of tubulin. Indeed, 4 suppressed tubulin polymerization, caused G₂/M cell cycle arrest, and induced apoptosis. Also, 4 inhibited the formation of endothelial cell capillary-like tubes and further disrupted the structure of preestablished tubes; the effects were not observed with para analogue 5. In accordance with this, the computed free energy of binding of 5 to tubulin was lower in magnitude than that for 4 and appeared to arise in part from the inability of the para substituent to occupy a tubulin subpocket, which is possible in the meta orientation. In conclusion, the antiproliferative potential of the novel 3-arylisoquinolinones is markedly influenced by a subtle change in the structure (meta versus para). The meta-substituted isoquinolinone 4 is a microtubule-destabilizing agent with potential tumor-selectivity and antiangiogenic and vascular disrupting features.

Synthesis and anticancer activity of novel quinazolinone-based rhodanines

Background

Rhodanines and quinazolinones have been reported to possess various pharmacological activities.

Results

A novel series of twenty quinazolinone-based rhodanines were synthesized via Knoevenagel condensation between 4-[3-(substitutedphenyl)-3,4-dihydro-4-oxoquinazolin-2-yl)methoxy]substituted-benzaldehydes and rhodanine. Elemental and spectral analysis were used to confirm structures of the newly synthesized compounds. The newly synthesized compounds were biologically evaluated for in vitro cytotoxic activity against the human fibrosarcoma cell line HT-1080 as a preliminary screen using the MTT assay.

Conclusions

All the target compounds were active, displaying IC₅₀ values roughly in the range of 10–60 µM. Structure–activity relationship study revealed that bulky, hydrophobic, and electron withdrawing substituents at the para-position of the quinazolinone 3-phenyl ring as well as methoxy substitution on the central benzene ring, enhance cytotoxic activity. The four most cytotoxic compounds namely, 45, 43, 47, and 37 were further tested against two human leukemia cell lines namely, HL-60 and K-562 and showed cytotoxic activity in the low micromolar range with compound 45 being the most active, having IC₅₀ values of 1.2 and 1.5 μM, respectively. Interestingly, all four compounds were devoid of cytotoxicity against normal human fibroblasts strain AG01523, indicating that the synthesized rhodanines may be selectively toxic against cancer cells. Mechanistic studies revealed that the most cytotoxic target compounds exhibit pro-apoptotic activity and trigger oxidative stress in cancer cells.

Adrenocortical carcinoma: patterns of care and role of adjuvant radiation therapy-a population-based study and review of the literature

PURPOSE

We reviewed the experience of a tertiary cancer centre in the management of adrenocortical carcinoma (acc) treated over 40 years. We also searched the literature for guidelines related to the treatment of acc and for evidence for adjuvant radiation therapy (rt).

METHODS

In a retrospective chart review, acc patients treated between January 1974 and December 2013 were identified, and patient demographics and tumour characteristics were extracted. Outcomes data, including dates and sites of failure, vital status, and cause of death, were collected. Overall survival was estimated using the Kaplan- Meier method. A medline search using PubMed, Ovid, and embase was used to review the literature about the role of rt and any available management guidelines for acc.

RESULTS

Of 81 patients identified during the chart review, 39 had confirmed acc. In 32 patients, surgical resection was performed, including in 2 patients with M1 disease. Of those 32 patients, 16 received adjuvant systemic treatment (mitotane or concurrent chemoradiation). Only 6 patients received adjuvant rt, of whom 3 are still alive (2 living with distant failure). At a median follow-up of 3.8 years, 28 patients had died (72%), 10 were living (26%), and 1 had been lost to follow-up. Of the 22 patients for whom failure data were available, 2 experienced local failure, and the rest, distant failure.

CONCLUSIONS

The current data are insufficient to make treatment recommendations. Use of collaborative databases and consensus about diagnostic and therapeutic guidelines are warranted for better identification of optimum management. Adjuvant rt could be a reasonable option for R1 disease, but further research is needed.

Multidisciplinary management of cancer patients: chasing a shadow or real value? An overview of the literature

PURPOSE

Multidisciplinary cancer conferences (mccs) are designed to optimize patient outcomes. It appears intuitive that mccs are essential to clinical decision-making and patient management; however, it is unclear whether that belief is supported by evidence. Our objectives were to assess the currently published literature addressing the impact of mccs on clinical decision-making and patient outcomes.

METHODS

Ovid medline was searched from 1950 to June 2010 using these keywords: "multidisciplinary/interdisciplinary/clinical meeting$/conference$/round$/team$," "decision making," "neoplasms$/cancer$/oncology/tumo(u)r conference$/board$/meeting$," "multidisciplinary/interdisciplinary cancer conference$/meeting$." All trials, guidelines, metaanalyses, reviews, and prospective and retrospective studies were included.

RESULTS

The keywords retrieved 595 abstracts, and 30 manuscripts were obtained. Most of the studies assessed the impact of mccs on clinical decision-making rather than on patient outcomes.

CONCLUSIONS

Available evidence supports the belief that mccs significantly influence clinical decision-making and treatment recommendations. In contrast, scant evidence suggests that mccs improve patient outcomes. Unfortunately, the current literature is substantially heterogeneous and therefore does not allow for firm conclusions.

Tc-99m diethylenetriamine pentaacetic acid (DTPA) renal function reserve estimation: is it a reliable predictive tool for assessment of preclinical renal involvement in scleroderma patients?

Prognosis of systemic sclerosis (SSc) depends on internal organ involvement. We assessed the value of renal function reserve (RFR) for the detection of preclinical nephropathy in scleroderma. Thirty SSc patients with normal serum creatinine and 30 healthy controls were included. Medsger disease severity score, glomerular filtration rate (GFR), and microalbuminuria were measured. Tc-99m DTPA was utilized for GFR measurement at baseline and after oral protein overload (stimulated GFR). RFR was calculated as the percentile increase of stimulated GFR. SSc patients had lower means of baseline GFR (P=0.001), stimulated GFR (P=0.004), RFR (P=0.046), and higher microalbuminuria (P=0.009) than controls. According to baseline GFR, SSc patients showed three categories-normal baseline GFR (n=12), hyperfiltration GFR (n=3), and reduced baseline GFR (n=15). In the former category, RFR was normal in 6/12 patients and abnormal in the remainders (50%). Hyperfiltration patients and those with reduced baseline GFR showed abnormal RFR. A statistically significant negative association was found between microalbuminuria versus stimulated GFR and RFR (r= -0.5, P=0.007 and r= -0.45, P=0.013, respectively). The majority of SSc patients with abnormal RFR had disease duration of ≥48 months (60% vs. 20%, P=0.008). All SSc patients with pulmonary hypertension had abnormal RFR, while reduced baseline GFR was noted in only 60%. A significant negative correlation was found between reduced baseline GFR and cumulative dose of corticosteroids in SSc patients (r= -0.4, P=0.022). RFR estimation could be a useful predictive marker for preclinical renal involvement in SSc patients so that early prophylactic measures and therapy modifications could be considered.

Eastern Canadian Colorectal Cancer Consensus Conference: setting the limits of resectable disease

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Montreal, Quebec, October 22-24, 2009. Health care professionals involved in the care of patients with colorectal cancer participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management colorectal cancer, such as the management of hepatic and pulmonary metastases, the role of monoclonal antibodies to the epidermal growth factor receptor, and the benefits and safety of chemotherapy in elderly patients. The management of gastrointestinal neuroendocrine tumours and gastric cancer are also discussed.

Suitability of using multileaf collimator (MLC) for photon field matching

This study evaluated and presented the results on the suitability of using a Siemens double-focused multileaf collimator (MLC) for photon field matching. The study was conducted using film-based dosimetry for measurements and a Theraplan Plus (version 3.8) treatment planning system (TPS) for planning comparisons and additional field matching investigations. In this study, it was found that the double-focused MLC field matching closely resembled that of the independent jaws, with the exception that the MLC had a nonuniform match line-a--match line formed by a different size leaf pair gap--overlap at a different join-up position. In addition, it was found that the dose change varied linearly with the MLC leaf pair gap-overlap (from 3-mm gap to 3-mm overlap) by 11 +/- 1%/mm. Using intrafraction "feathering" of the junction, a reduction of the dose change from 11 +/- 1%/mm to 6.5 +/- 1%/mm occurred when the junction was moved once and from 11 +/- 1%/mm to 4 +/- 1%/mm when moved twice. Based on the results, the study suggested that MLC positioning error tolerances of +/-2 mm might be too large for photon field matching. On the other hand, a combination of reducing the tolerance to +/-1 mm and intrafraction junction moves (twice by +/-1 cm off matching axis) could reduce the maximum peak height--trough low at the junction to within a required range of -5 to +7% in planning target volume (PTV) dose heterogeneity.

Prophylaxis of radiation-associated mucositis in conventionally treated patients with head and neck cancer: a double-blind, phase III, randomized, controlled trial evaluating the clinical efficacy of an antimicrobial lozenge using a validated mucositis scoring system

PURPOSE

Mucositis occurs in almost all patients treated with radiotherapy for head and neck cancer. The aim of this multicenter, double-blind, prospective, randomized trial was to evaluate the clinical efficacy of an economically viable antimicrobial lozenge (bacitracin, clotrimazole, and gentamicin [BcoG]) in the alleviation of radiation-induced mucositis in patients with head and neck cancer.

PATIENTS AND METHODS

One hundred thirty-seven eligible patients were randomized to treatment with either antimicrobial lozenge (69 patients) or placebo lozenge (68 patients). The primary end point of the study was the time to development of severe mucositis from the start of radiotherapy. Secondary end points included severity and duration of mucositis, pain measurement, radiation therapy interruption, and quality of life. Mucositis was scored using a validated mucositis scoring system.

RESULTS

Toxicity profiles were similar between the two arms of the study. The median time to development of severe mucositis from the start of radiotherapy was 3.61 weeks on BCoG and 3.96 weeks on placebo (P =.61). There were no statistically significant differences between the arms in the extent of severe mucositis as measured by physician, in oral toxicities as recorded by patients, or in radiotherapy delays.

CONCLUSION

This study was conducted on the basis of a pilot study that demonstrated the BCoG lozenge to be tolerable and microbiologically efficacious. A validated mucositis scoring system was used. However, in this group of patients treated with conventional radiotherapy, the lozenge did not impact significantly on the severity of mucositis. Whether such a lozenge would be beneficial in treatment situations where rate of severe mucositis is higher (ie, in patients treated with unconventional fractionation or with concomitant chemotherapy) is unknown.

Adjuvant and adjunctive chemotherapy in the management of squamous cell carcinoma of the head and neck region. A meta-analysis of prospective and randomized trials

PURPOSE

Using the technique of meta-analysis, we aim to illustrate the potential benefit, or lack of it, in adding chemotherapy to locoregional definitive treatment in a prospective randomized setting.

PATIENTS AND METHODS

Mantel-Haenszel summary analyses were used to test 42 prospective and properly randomized trials for statistically significant differences in the proportion with side effects and in the proportion with response to treatment between the experimental treatment arm (including chemotherapy) and control arm (local definitive treatment only) of the study. Summarized estimates of relative risks of side effects and relative proportions of positive responses were obtained using the summarizing options in PROC FREQ in the SAS computer package. In 25 of 42 studies, sufficient survival information was available to estimate the effect of chemotherapy on the rate of dying per person per unit of time.

RESULTS

Chemotherapy, when added to local definitive treatment, was found to increase toxicity. This increase is statistically significant. The relative proportion of side effects was 2.17, with a 95% confidence interval of 1.84 to 2.56 and P less than .001. Addition of chemotherapy to local treatment has reduced the mortality rate for treated patients by 11% in the total group (all 25 studies), with a 95% confidence interval of 1% to 19%. This reduction means that at the time 50% of patients in the control arm were still alive, 54% of patients who received chemotherapy would be expected to be alive. Concurrent treatment (11 studies) has reduced the mortality rate by 22%, with a 95% confidence interval of 8% to 33%, which means that at the time 50% of patients in the control arm were still alive, 58% of patients who received chemotherapy would be expected to be alive.

CONCLUSION

Addition of chemotherapy to local definitive treatment has significantly increased the morbidity of treatment as well as the chance of initial tumor response and local control. A statistically significant improvement in survival was found for the simultaneous use of chemotherapy and local definitive treatment.

Phase II trial of carboplatin and vinblastine in advanced squamous-cell carcinoma of the head and neck

A chemotherapy regimen consisting of carboplatin and vinblastine was given to 30 patients with recurrent or previously untreated, locally advanced squamous carcinoma of the head and neck region. The main aim of the study was to assess the toxicity of this regimen, the feasibility of its outpatient administration and the tumour response. A total of ten patients (33%) achieved an objective response, including two who achieved a complete response. The combination offered useful palliation for patients with recurrent disease; it was well tolerated and can be given on an outpatient basis. This regimen could be combined with other active agents such as methotrexate or bleomycin.