An Integrative Meta-analysis of MicroRNAs in Hepatocellular Carcinoma

We aimed to shed new light on the roles of microRNAs （miRNAs） in liver cancer using an integrative in silico bioinformatics analysis. A new protocol for target prediction and functional analysis is presented and applied to the 26 highly differentially deregulated miRNAs in hepatocellular carcinoma. This framework comprises： （1） the overlap of prediction results by four out of five target prediction tools, including TargetScan, PicTar, miRanda, DIANA-microT and miRDB （combining machine-learning, alignment, interaction energy and statistical tests in order to minimize false positives）, （2） evidence from previous microarray analysis on the expression of these targets, （3） gene ontology （GO） and pathway enrichment analysis of the miRNA targets and their pathways and （4） linking these results to oncogenesis and cancer hallmarks. This yielded new insights into the roles of miRNAs in cancer hallmarks. Here we presented several key targets and hundreds of new targets that are significantly enriched in many new cancer-related hallmarks. In addition, we also revealed some known and new oncogenic pathways for liver cancer. These included the famous MAPK, TGFβ and cell cycle pathways. New insights were also provided into Wnt signaling, prostate cancer, axon guidance and oocyte meiosis pathways. These signaling and developmental pathways crosstalk to regulate stem cell transformation and implicate a role of miRNAs in hepatic stem cell deregulation and cancer development. By analyzing their complete interactome, we proposed new categorization for some of these miRNAs as either tumor-suppressors or oncomiRs with dual roles. Therefore some of these miRNAs may be addressed as therapeutic targets or used as therapeutic agents. Such dual roles thus expand the view of miRNAs as active maintainers of cellular homeostasis.     

New quinoxaline 1,4-di-N-oxides. Part 1: Hypoxia-selective cytotoxins and anticancer agents derived from quinoxaline 1,4-di-N-oxides

Hypoxic cells which are common feature of solid tumors are resistant to both anticancer drugs and radiation therapy. Thus, the identification of drugs with the selective toxicity toward hypoxic cells is an important target in anticancer chemotherapy. Tirapazamine has been shown to be an efficient and selective cytotoxin after bioreductive activation in hypoxic cells which is thought to be due to the presence of the 1,4-di-N-oxide. A new series of quinoxaline 1,4-di-N-oxides and fused quinoxaline di-N-oxides were synthesized and evaluated for hypoxic-cytotoxic activity on EAC cell line. Compound 10a was the most potent cytotoxin IC(50) 0.9 microg/mL, potency 75 microg/mL, and was approximately 15 times more selective cytotoxin (HCR>111) than 3-aminoquinoxaline-2-carbonitrile which has been used as a standard (HCR>7.5). Compounds 4 and 3a,b were more selective than the standard. In addition, antitumor activity against Hepg2 (liver) and U251 (brain) human cell lines was evaluated, compounds 9c and 8a were the most active against Hepg2 with IC(50) values 1.9 and 2.9 microg/mL, respectively, however, all the tested compounds were nontoxic against U251 cell line.     

Role of cell-mediated immunity in the resistance to experimental sporotrichosis in mice

The in vitro activity of several new imidazoles, cloconazole, sulconazole, butoconazole, isoconazole and fenticonazole, were compared with those of amphothericin B, flucytosine, and three azoles: econazole, miconazole and ketoconazole against isolates of pathogenic Candida. A total of 186 clinical isolates of 10 species of the genus Candida and two culture collection strains were tested by an agar-dilution technique. Isoconazole was the most active azole, followed by butoconazole and sulconazole. Differences between some of the species in their susceptibility to the antifungal agents were noted. Sulconazole and cloconazole had the highest activity in vitro against 106 isolates of C. albicans. Butoconazole and isoconazole were also very active against isolates of C. albicans, and were the most active azole compounds against 80 isolates of Candida spp.     

Factors associated with consent for organ donation: a retrospective population-based study

Background:Optimizing the approach to and consent of potential organ donors maximizes patient autonomy and the availability of organs for transplants. We set out to identify modifiable factors associated with donation consent.Methods:We conducted a retrospective cohort study of consecutive adults (≥ 18 yr) referred for organ donation in Ontario between April 2013 and June 2019. We analyzed patient clinical data and demographics, data on substitute decision-makers and characteristics of the donation consent approach. Study outcomes were consent for organ donation and approach rate. We evaluated independent associations between consent and approach-and system-level factors.Results:We identified 34 837 referrals for organ donation, of which 6548 (18.8%) substitute decision-makers were approached for consent. Of these, 3927 (60.0% of approaches) consented for organ donation and 1883 (48.0% of consents) patients proceeded to be organ donors. The most common reason substitute decision-makers were not approached for consent in a case with donation potential was a late referral by the health care team (45.2%). Modifiable factors independently associated with consent included a telephone approach for consent (adjusted odds ratio [OR] 0.46, 95% confidence interval [CI] 0.35–0.58) and a collaborative approach by a physician and donation coordinator (adjusted OR 1.26, 95% CI 1.01–1.59).Interpretation:Consent for organ donation was associated with several modifiable factors. Organizations should target interventions to ensure timely referrals to organ donation organizations, increase in-person consent approaches and increase physician participation in the approach process.

Many people die on transplant waiting lists because the demand for organs outstrips supply. Almost 4500 people are on organ transplant waiting lists in Canada. Despite public support for organ donation across Canada,¹ donation rates vary between 8.8 and 21.2 donors per million population, ² and a substantial pool of potential donors is not being realized. ^2,3 The identification, referral and approach of potential donors can be facilitated by policy, legislation and best practices, ^3,4 although the efficacy of interventions is variable across jurisdictions.^5,6 Some comprehensive interventions to increase donor numbers have not changed consent rates,⁷ suggesting that the consent approach process may be a target for improvement.Substitute decision-makers play an important role in the organ donation process, even in jurisdictions with donation consent registries or opt-out consent systems. Substitute decision-makers are almost always asked permission for organ donation, even when there is a registered donation consent,⁸ and their consent rates vary widely.⁹ Substitute decision-makers faced with consent decisions often do so in emotionally charged circumstances, and many do not know the explicit wishes of the patient.¹⁰ Given this context, the process of obtaining consent and the supports provided may have a substantial impact on the decision. Practices have been identified that improve consent rates from substitute decision-makers,¹¹ and these are routinely performed by large, high-performing organ donation organizations. Several epidemiological studies have identified nonmodifiable factors associated with donation consent (e.g., race, age, socioeconomic status and education).^12–15 The persistent variability in consent rates suggests that other modifiable factors may influence a substitute decision-maker’s decision to consent.We aimed to identify modifiable approach-and system-level factors that were associated with positive consent for organ donation in Ontario, Canada.     

Seasonal changes in serum leptin of the feral raccoon (Procyon lotor) determined by canine-leptin-specific ELISA

Several reports have been published on blood leptin concentrations in feral animals, including members of the Carnivora, using a commercially available multi-species radioimmunoassay (RIA) kit with anti-human leptin antibody. However, we observed weak immunoreactivity between recombinant canine leptin and anti-human leptin antibody, suggesting a limitation in the applicability of the RIA kit for leptin assays in Carnivora species. We tested the applicability of RIA and sandwich enzyme-linked immunosorbent assay (ELISA) with anti-canine leptin antibody to assay blood leptin in the dog (Canis familiaris) and the raccoon (Procyon lotor). When RIA was used for recombinant canine leptin and dog sera, values were much lower than those determined by ELISA at higher concentrations (>10 ng/ml), while rather higher at lower concentrations (<2 ng/ml). A similar discrepancy between the two methods was found for serum leptin concentrations in raccoons. Clear seasonal variations were observed by ELISA, but not by RIA, with high values in autumn (3.46+/-0.45 ng/ml) and low values in spring and summer (0.71+/-0.07 ng/ml). Serum leptin concentrations in raccoons correlated positively with their body weight (r=0.753) and body mass index (r=0.755), corroborating our previous findings of a strong positive correlation between serum leptin concentrations and body fat content in dogs. Thus, the canine leptin ELISA is useful for assays of dog and raccoon leptin, and blood leptin is a good marker of nutritional condition in the species of Carnivora assayed in this study.     

Volatile Components of Roasted Chufa-tubers

The desmutagenic activities of some vegetable and fruit juices to the mutagenicity of 2-tert-butyl-p-quinone (t-BQ) were assayed by the Ames test using Salmonella typhimurium TA 100. t-BQ is a strong mutagen and is produced from butylated hydroxyanisole when treated with nitrite under acidic conditions. The juices of sweet pepper, lemon, tomato, orange, strawberry, melon, and kiwi fruit reduced the mutagenicity of t-BQ, the desmutagenic activities being proportionally related to the content of the sulfhydryl group contained in these juices. The authentic sulfhydryl compounds, glutathione, pantetheine and dithiothreitol, were then tested for their desmutagenicity against t-BQ by the induced-mutation frequency method, and they were proved responsible for the desmutagenicity. Glutathione reduced half of the t-BQ to 2-tert-butyl-hydroquinone during the desmutagenic reaction, the other half being suggested to have been a conjugated compound between glutathione and t-BQ.     

Dual Drug Targeting of Mutant Bcr‐Abl Induces Inactive Conformation: New Strategy for the Treatment of Chronic Myeloid Leukemia and Overcoming Monotherapy Resistance

Bcr‐Abl is an oncogenic fusion protein which expression enhances tumorigenesis, and has been highly associated with chronic myeloid leukemia (CML). Acquired drug resistance in mutant Bcr‐Abl has enhanced pathogenesis with the use of single therapy agents such as nilotinib. Moreover, allosteric targeting has been identified to consequentially inhibit Bcr‐Abl activity, which led to the recent development of ABL‐001 (asciminib) that selectively binds the myristoyl pocket. Experimental studies have revealed that the combination of nilotinib and ABL‐001 induced a ‘bent’ conformation in the C‐terminal helix of Bcr‐Abl; a benchmark of inhibition, thereby exhibiting a greater potency in the treatment of CML, surmounting the setbacks of drug resistance, disease regression and relapse. Therefore, we report the first account of the dynamics and conformational analysis of oncogenic T334I Bcr‐Abl by dual targeting. Our findings revealed that unlike in the Bcr‐Abl‐Nilotinib complex, dual targeting by both inhibitors induced the bent conformation in the C‐terminal helix that varied with time. This was coupled with significant alteration in Bcr‐Abl stability, flexibility, and compactness and an overall structural re‐orientation inwards towards the hydrophobic core, which reduced the solvent‐exposed residues indicative of protein folding. This study will facilitate allosteric targeting and the design of more potent allosteric inhibitors for resistive target proteins in cancer.     

Phylogenetic,toxigenic and virulence profiles of <Emphasis Type="Italic">Alternaria</Emphasis> species causing leaf blight of tomato in Egypt

Species of Alternaria are serious plant pathogens, causing major losses on a wide range of crops. Leaf blight symptoms were observed on tomato leaves, and samples were collected from various regions. Isolation was done from symptomatic tomato leaves, and 15 representatives were selected from a collection of 65 isolates of Alternaria species. The virulence of Alternaria isolates was investigated on detached leaves (DL) and whole plants of tomato cv. Super strain B. A phylogenetic analysis was performed based on three partial gene regions, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the RNA polymerase second largest subunit (RPB2) and the Alternaria major allergen gene (Alt a 1). The potentiality of Alternaria isolates to produce toxins was also investigated on the basis of thin-layer chromatography (TLC). Our investigations revealed that Alternaria isolates showed different levels of virulence either on tomato plants or DL. Based on the phylogeny of three genes, Alternaria isolates encompassed two species of small-spored morphospecies: A. alternata (14 isolates) and A. arborescens (single isolate). The produced toxins varied among Alternaria isolates with tenuazonic acid (TeA) being the most abundant mycotoxin produced by most isolates. This study highlighted on other Alternaria species in Egypt that might represent a serious concern for tomato producers as causal agents of leaf blight over other species, i.e. A. solani.