Licochalcone A regulates viral IRES activity to inhibit enterovirus replication.

Enterovirus D68 (EV-D68), belonging to the genus Enterovirus of the Picornavirus family, is an emerging pathogen that can cause neurological and respiratory diseases in children. However, there is little understanding of the pathogenesis of EV-D68, and no effective vaccine or drug for the prevention or treatment of the diseases caused by this virus is available. Autophagy is a cellular process that targets cytoplasmic proteins or organelles to the lysosomes for degradation. Enteroviruses strategically harness the host autophagy pathway to facilitate the completion of their life cycle. Therefore, we selected an autophagy compound library to screen for autophagy-related compounds that may affect viral growth. By using the neutralization screening assay, we identified a compound, 'licochalcone A' that significantly inhibited EV-D68 replication. To investigate the mechanism by which licochalcone A inhibits EV-D68 replication and to identify the viral life cycle stage it inhibits, the time-of-addition, viral attachment, viral entry, and dual-luciferase reporter assays were performed. The results of the time-of-addition assay showed that licochalcone A, a characteristic chalcone found in liquorice roots and widely used in traditional Chinese medicine, inhibits EV-D68 replication during the early stages of the viral life cycle, while those of the dual-luciferase reporter assay showed that licochalcone A does not regulate viral attachment and entry, but inhibits EV-D68 IRES-dependent translation. Licochalcone A also inhibited enterovirus A71 and coxsackievirus B3 but did not significantly inhibit dengue virus 2 or human coronavirus 229E replication. Licochalcone A regulates IRES translation to inhibit EV-D68 viral replication.

Cbl Negatively Regulates NLRP3 Inflammasome Activation through GLUT1-Dependent Glycolysis Inhibition.

Activation of the nod-like receptor 3 (NLRP3) inflammasomes is crucial for immune defense, but improper and excessive activation causes inflammatory diseases. We previously reported that Cbl plays a pivotal role in suppressing NLRP3 inflammasome activation by inhibiting Pyk2-mediated apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization. Here, we showed that Cbl dampened NLRP3 inflammasome activation by inhibiting glycolysis, as demonstrated with Cbl knockout cells and treatment with the Cbl inhibitor hydrocotarnine. We revealed that the inhibition of Cbl promoted caspase-1 cleavage and interleukin (IL)-1ß secretion through a glycolysis-dependent mechanism. Inhibiting Cbl increased cellular glucose uptake, glycolytic capacity, and mitochondrial oxidative phosphorylation capacity. Upon NLRP3 inflammasome activation, inhibiting Cbl increased glycolysis-dependent activation of mitochondrial respiration and increased the production of reactive oxygen species, which contributes to NLRP3 inflammasome activation and IL-1ß secretion. Mechanistically, inhibiting Cbl increased surface expression of glucose transporter 1 (GLUT1) protein through post-transcriptional regulation, which increased cellular glucose uptake and consequently raised glycolytic capacity, and in turn enhanced NLRP3 inflammasome activation. Together, our findings provide new insights into the role of Cbl in NLRP3 inflammasome regulation through GLUT1 downregulation. We also show that a novel Cbl inhibitor, hydrocortanine, increased NLRP3 inflammasome activity via its effect on glycolysis.

EFLA 945 restricts AIM2 inflammasome activation by preventing DNA entry for psoriasis treatment.

Psoriasis is a chronic inflammatory skin disease that affects about 2% of the general population. Activation of the Absent in Melanoma 2 (AIM2) inflammasome is crucial for immune defense, but it can also cause inflammatory and autoimmune diseases, including psoriasis. We currently lack an AIM2 inflammasome inhibitor that could be used therapeutically. Here, we show that EFLA 945, a safe product of red grape vine leaf extracts, can restrict AIM2 inflammasome activation. Mechanistically, EFLA945 prevents DNA entry into THP-1-derived macrophages, and thereby inhibits cytoplasmic DNA-dependent apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization, caspase-1 activation, and the secretion of interleukin (IL)-1ß and IL-18. The major phytochemicals of EFLA 945, resveratrol and peonidin 3-O-glucoside (P3G), appear to be the potential bioactive compounds responsible for its ability to restrict AIM2-dependent IL-1ß secretion. Importantly, in an in vivo mouse model, EFLA 945 attenuates imiquimod (IMQ)-induced psoriasis-related pro-inflammatory responses in topical psoriatic skin, including caspase-1 activation, IL-1ß maturation, and IL-17 production, and decreases the severity of psoriasis. Together, these results demonstrate that the safe natural product, EFLA 945, can restrict the AIM2 inflammasome activation through preventing DNA entry and may prove beneficial for treating psoriasis.

Treatment with a new benzimidazole derivative bearing a pyrrolidine side chain overcomes sorafenib resistance in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Currently, sorafenib is the standard first-line drug for patients with advanced HCC. However, long-term exposure to sorafenib often results in reduced sensitivity of tumour cells to the drug, leading to acquired resistance. Therefore, developing new compounds to treat sorafenib resistance is urgently needed. Although benzimidazole and its derivatives have been reported to exert antimicrobial and antitumour effects, the anti-drug resistance potential of these molecules is still unknown. In this study, we established sorafenib-resistant (SR) cell lines and an acquired sorafenib resistance xenograft model. We showed that treatment with a benzimidazole derivative bearing a pyrrolidine side chain (compound 9a) inhibited the proliferation of SR cells by blocking the phosphorylation of AKT, p70S6 and the downstream molecule RPS6. In addition, caspase 3/PARP-dependent apoptotic signals were induced in 9a-treated cells. Regarding epithelial-mesenchymal transition (EMT) activities, 9a treatment significantly suppressed the migration of SR cells. In particular, the levels of EMT-related transcription factors (snail, slug and twist) and mesenchymal markers (vimentin and N-cadherin) were downregulated. In the acquired sorafenib resistance xenograft model, compound 9a administration decreased the growth of tumours with acquired sorafenib resistance and the expression of the HCC markers α-fetoprotein, glypican 3 and survivin. In conclusion, treatment with this compound may be a novel therapeutic strategy for patients with sorafenib resistance.

EBV-associated Burkitt lymphoma in Taiwan is not age-related.

This study retrospectively investigated 54 cases of sporadic Burkitt lymphoma in Taiwan with histopathology review, immunohistochemistry, Epstein-Barr virus (EBV) in situ hybridization (EBER) and fluorescence in situ hybridization (FISH). The great majority revealed typical immunophenotype and 89% (47/53) cases expressed myc protein. EBER was positive in 20% (11/54) of cases, more frequently with nodal presentation, but not significantly associated with age (pediatric vs. adult), abdominal vs. extra-abdominal presentation or overall survival (OS). MYC and IGH were rearranged in 94% (46/49) and 85% (41/48) of cases, respectively. The concordance rate between myc expression and MYC translocation was 83% (40/48). By univariate analysis, OS was statistically associated with age, with or without chemotherapy, central nervous system (CNS) involvement, CNS prophylaxis and leukemic transformation, but not gender, nodal vs. extranodal involvement, stage, immunohistochemistry, EBER, myc expression, MYC translocation or radiotherapy. By multivariate analysis, CNS involvement at presentation and administration of chemotherapy were statistically associated with OS.

Epstein-Barr virus is rarely associated with diffuse large B cell lymphoma in Taiwan and carries a trend for a shorter median survival time.

AIMS: Epstein-Barr virus (EBV)-positive diffuse large B cell lymphoma (DLBCL) of the elderly is characterised by frequent extranodal involvement, a morphological spectrum from polymorphous to monomorphous and a poor prognosis. The frequency is higher in Japan and Korea but lower in the West, while the status in Taiwan has not been reported yet. METHODS: We conducted a retrospective study of DLBCL in a single institute in Taiwan by immunohistochemistry and in situ hybridisation for EBV. RESULTS: Of the 424 consecutive DLBCL cases, 332 cases were studied for EBV. 15 (4.5%) were EBV-positive and 13 (3.9%) fulfil WHO criteria of EBV-positive DLBCL of the elderly with a median age of 75. Of these 15 cases, extranodal presentation occurred in 11 (73%) patients with predominance in the gastrointestinal tract and 6 (40%) were of germinal centre B cell phenotype. There was no difference between EBV-positive and -negative patients in terms of age, gender, nodal versus extranodal presentation, and immunophenotypical profile. EBV-positive patients showed a trend for a shorter median survival time (5.0 vs 39.3 months; p=0.058). Of all DLBCL patients, multivariable analysis revealed a significantly worse overall survival for patients older than 50 (p=0.001) and for those with bcl-6-negative tumours (p=0.003) but not with other clinicopathological factors including EBV status. CONCLUSIONS: EBV-positive DLBCL of the elderly is relatively rare in Taiwan, with an incidence intermediate between Japan/Korea and the West. Further studies are warranted to clarify the association of EBV and the clinicopathological features and the prognostic significance in patients with DLBCL.

Clinical characteristics and treatment outcomes of lung adenocarcinomas with discrepant EGFR mutation testing results derived from PCR-direct sequencing and real-time PCR-based assays.

INTRODUCTION: Detection of epidermal growth factor receptor (EGFR) mutation has become the most critical molecular test in managing patients with advanced lung adenocarcinoma. Whether patients with discrepant EGFR mutation results determined by low- and high-sensitivity methods have different clinical outcomes with EGFR tyrosine kinase inhibitor (TKI) treatment needs to be further evaluated. METHODS: Genomic DNA from serial lung adenocarcinoma samples that were EGFR wild-type determined by direct sequencing (DS) were reanalyzed using Scorpion/Amplification Refractory Mutation System (ARMS). The outcomes with EGFR-TKI treatment among patients with discrepant EGFR mutation results between DS and Scorpion/ARMS versus patients with EGFR mutations detected by DS were studied. RESULTS: Of the 130 tumors studied, 28 (21.5%) were found to have EGFR mutations by Scorpion/ARMS. Discrepant EGFR mutation testing results were more common in samples from nonsmokers than in samples from smokers (30.7% versus 9.1%; p = 0.003) and in pleural than in nonpleural samples (62.5% versus 18.9%; p = 0.012). There was no significant difference in the abundance of cancer cells in region(s) selected for testing (26.2% in tumor cell percentage ≤50 versus 16.9% in tumor cell percentage >50; p = 0.201). During EGFR-TKI treatment, the progression-free survival in patients with discrepant EGFR mutation results was similar to those with EGFR mutations detected by DS (median, 13.4 versus 10.9 months; p = 0.225). CONCLUSIONS: DS overlooked EGFR mutation in a significant number of lung adenocarcinoma patients. These patients could have obtained the same benefit from EGFR-TKI when a high-sensitivity method such as Scorpion/ARMS was applied.

Molecular diagnostic algorithm for epidermal growth factor receptor mutation detection in Asian lung adenocarcinomas: comprehensive analyses of 445 Taiwanese patients with immunohistochemistry, PCR-direct sequencing and Scorpion/ARMS methods.

BACKGROUND AND OBJECTIVE: Therapeutic responses of lung adenocarcinoma patients to tyrosine kinase inhibitors (TKIs) of epidermal growth factor receptor (EGFR) are closely associated with activating mutations within the EGFR tyrosine kinase domain. Screening activating EGFR mutations prior to selection for therapeutic strategy has been considered extremely valuable for clinical management of lung adenocarcinoma patients in Asian countries including Taiwan, where the EGFR mutation rate is higher than in the rest of the world. Currently there is no consensus on the method of choice to assess EGFR mutations in tumour tissue. METHODS: We enrolled 445 lung adenocarcinoma patients for analysis of tumour EGFR mutations using polymerase chain reaction (PCR)-direct sequencing, scorpion/amplified refractory mutation system (ARMS) technology and immunohistochemistry with mutation-specific antibodies. RESULTS: Two hundred forty-five patients (245/445; 55%) were found to harbour activating EGFR mutations using PCR-direct sequencing method, with a majority of patients (233/245; 95%) carrying exon 19 deletion or p.L858R point mutations. One hundred three of 200 patients were negative for EGFR mutations from PCR-direct sequencing were further analysed using Scorpion/ARMS technology. Up to 30% of the PCR-direct sequencing negative patients turned out to be positive in the Scorpion/ARMS EGFR mutation tests. For immunohistochemistry analysis of EGFR mutations, the p.E746_A750del specific antibody showed a sensitivity of 57% and a specificity of 100% for exon 19 deletions while the p.L858R point mutation specific antibody showed a sensitivity of 68% and a specificity of 95%. CONCLUSIONS: Based on this study, we proposed an algorithm for comprehensive and efficient testing of EGFR mutations on lung adenocarcinoma patients in Asia.

Effective palette indexing for image compression using self-organization of Kohonen feature map.

The process of limited-color image compression usually involves color quantization followed by palette re-indexing. Palette re-indexing could improve the compression of color-indexed images, but it is still complicated and consumes extra time. Making use of the topology-preserving property of self-organizing Kohonen feature map, we can generate a fairly good color index table to achieve both high image quality and high compression, without re-indexing. Promising experiment results will be presented.