SARS-CoV-2, a β-coronavirus, has rapidly spread across the world, highlighting its high transmissibility, but the underlying morphogenesis and pathogenesis remain poorly understood. Here, we characterize the replication dynamics, cell tropism and morphogenesis of SARS-CoV-2 in organotypic human airway epithelial (HAE) cultures. SARS-CoV-2 replicates efficiently and infects both ciliated and secretory cells in HAE cultures. In comparison, HCoV-NL63 replicates to lower titers and is only detected in ciliated cells. SARS-CoV-2 shows a similar morphogenetic process as other coronaviruses but causes plaque-like cytopathic effects in HAE cultures. Cell fusion, apoptosis, destruction of epithelium integrity, cilium shrinking and beaded changes are observed in the plaque regions. Taken together, our results provide important insights into SARS-CoV-2 cell tropism, replication and morphogenesis.

Although crizotinib demonstrates robust efficacy in anaplastic lymphoma kinase (ALK)-positive non-small-cell lung carcinoma patients, progression during treatment eventually develops. Resistant patient samples revealed a variety of point mutations in the kinase domain of ALK, including the L1196M gatekeeper mutation. In addition, some patients progress due to cancer metastasis in the brain. Using structure-based drug design, lipophilic efficiency, and physical-property-based optimization, highly potent macrocyclic ALK inhibitors were prepared with good absorption, distribution, metabolism, and excretion (ADME), low propensity for p-glycoprotein 1-mediated efflux, and good passive permeability. These structurally unusual macrocyclic inhibitors were potent against wild-type ALK and clinically reported ALK kinase domain mutations. Significant synthetic challenges were overcome, utilizing novel transformations to enable the use of these macrocycles in drug discovery paradigms. This work led to the discovery of 8k (PF-06463922), combining broad-spectrum potency, central nervous system ADME, and a high degree of kinase selectivity.

The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly pathogenic respiratory virus with pathogenic mechanisms that may be driven by innate immune pathways. The goal of this study is to characterize the expression of the structural (S, E, M, N) and accessory (ORF 3, ORF 4a, ORF 4b, ORF 5) proteins of MERS-CoV and to determine whether any of these proteins acts as an interferon antagonist. Individual structural and accessory protein-coding plasmids with an N-terminal HA tag were constructed and transiently transfected into cells, and their native expression and subcellular localization were assessed using Wes tern blotting and indirect immunofl uorescence. While ORF 4b demonstrated majorly nuclear localization, all of the other proteins demonstrated cytoplasmic localization. In addition, for the fi rst time, our experiments revealed that the M, ORF 4a, ORF 4b, and ORF 5 proteins are potent interferon antagonists. Further examination revealed that the ORF 4a protein of MERS-CoV has the most potential to counteract the antiviral effects of IFN via the inhibition of both the interferon production (IFN-β promoter activity, IRF-3/7 and NF-κB activation) and ISRE promoter element signaling pathways. Together, our results provide new insights into the function and pathogenic role of the structural and accessory proteins of MERS-CoV.

Coronaviruses (CoVs) act as cross-species viruses and have the potential to spread rapidly into new host species and cause epidemic diseases. Despite the severe public health threat of severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome CoV (MERS-CoV), there are currently no drugs available for their treatment; therefore, broad-spectrum inhibitors of emerging and endemic CoVs are urgently needed. To search for effective inhibitory agents, we performed high-throughput screening (HTS) of a 2,000-compound library of approved drugs and pharmacologically active compounds using the established genetically engineered human CoV OC43 (HCoV-OC43) strain expressing Renilla luciferase (rOC43-ns2Del-Rluc) and validated the inhibitors using multiple genetically distinct CoVs in vitro. We screened 56 hits from the HTS data and validated 36 compounds in vitro using wild-type HCoV-OC43. Furthermore, we identified seven compounds (lycorine, emetine, monensin sodium, mycophenolate mofetil, mycophenolic acid, phenazopyridine, and pyrvinium pamoate) as broad-spectrum inhibitors according to their strong inhibition of replication by four CoVs in vitro at low-micromolar concentrations. Additionally, we found that emetine blocked MERS-CoV entry according to pseudovirus entry assays and that lycorine protected BALB/c mice against HCoV-OC43-induced lethality by decreasing viral load in the central nervous system. This represents the first demonstration of in vivo real-time bioluminescence imaging to monitor the effect of lycorine on the spread and distribution of HCoV-OC43 in a mouse model. These results offer critical information supporting the development of an effective therapeutic strategy against CoV infection. IMPORTANCE Currently, there is no approved therapy to treat coronavirus infection; therefore, broad-spectrum inhibitors of emerging and endemic CoVs are needed. Based on our high-throughput screening assay using a compound library, we identified seven compounds with broad-spectrum efficacy against the replication of four CoVs in vitro. Additionally, one compound (lycorine) was found to protect BALB/c mice against HCoV-OC43-induced lethality by decreasing viral load in the central nervous system. This inhibitor might offer promising therapeutic possibilities for combatting novel CoV infections in the future.

Polycomb repressive complex 2 (PRC2) mediates gene silencing through chromatin reorganization by methylation of histone H3 lysine 27 (H3K27). Overexpression of the complex and point mutations in the individual subunits of PRC2 have been shown to contribute to tumorigenesis. Several inhibitors of the PRC2 activity have shown efficacy in EZH2-mutated lymphomas and are currently in clinical development, although the molecular basis of inhibitor recognition remains unknown. Here we report the crystal structures of the inhibitor-bound wild-type and Y641N PRC2. The structures illuminate an important role played by a stretch of 17 residues in the N-terminal region of EZH2, we call the activation loop, in the stimulation of the enzyme activity, inhibitor recognition and the potential development of the mutation-mediated drug resistance. The work presented here provides new avenues for the design and development of next-generation PRC2 inhibitors through establishment of a structure-based drug design platform.

Middle East respiratory syndrome coronavirus (MERS-CoV) recently emerged as a severe worldwide public health concern. The virus is highly pathogenic, manifesting in infected patients with an approximately 50% fatality rate. It is known that the surface spike (S) proteins of coronaviruses mediate receptor recognition and membrane fusion, thereby playing an indispensable role in initiating infection. In this process, heptad repeats 1 and 2 (HR1 and HR2) of the S protein assemble into a complex called the fusion core, which represents a key membrane fusion architecture. To date, however, the MERS-CoV fusion core remains uncharacterized. In this study, we performed a series of biochemical and biophysical analyses characterizing the HR1/HR2 complexes of this novel virus. The HR sequences were variably truncated and then connected with a flexible amino acid linker. In each case, the recombinant protein automatically assembled into a trimer in solution, displaying a typical ␣-helical structure. One of these trimers was successfully crystallized, and its structure was solved at a resolution of 1.9 Å. A canonical 6-helix bundle, like those reported for other coronaviruses, was revealed, with three HR1 helices forming the central coiled-coil core and three HR2 chains surrounding the core in the HR1 side grooves. This demonstrates that MERS-CoV utilizes a mechanism similar to those of other class I enveloped viruses for membrane fusion. With this notion, we further identified an HR2-based peptide that could potently inhibit MERS-CoV fusion and entry by using a pseudotyped-virus system. These results lay the groundwork for future inhibitory peptidic drug design.

Background: Statistical data on the incidence, mortality, and burden of breast cancer and the relevant risk factors are valuable for policy-making. We aimed to estimate breast cancer incidence, deaths, and disability-adjusted life years (DALYs) by country, gender, age group, and social-demographic status between 1990 and 2017. Methods: We extracted breast cancer data from the 2017 Global Burden of Disease (GBD) study from 1990 through 2017 in 195 countries and territories. Data about the number of breast cancer incident cases, deaths, DALYs, and the age-standardized rates were collected. We also estimated the risk factors attributable to breast cancer deaths and DALYs using the comparative risk assessment framework of the GBD study. Results: In 2017, the global incidence of breast cancer increased to 1,960,681 cases. The high social-development index (SDI) quintile included the highest number of breast cancer death cases. Between 2007 and 2017, the ASDR of breast cancer declined globally, especially in high SDI and high middle SDI countries. The related DALYs were 17, 708,600 in 2017 with high middle SDI quintile as the highest contributor. Of the deaths and DALYs, alcohol use was the greatest contributor in most GBD regions and other contributors included high body mass index (BMI) and high fasting plasma glucose. Conclusion: The increasing global breast cancer burden is mainly observed in lower SDI countries; in higher SDI countries, the breast cancer burden tends to be relieving. Therefore, steps against attributable risk factors should be taken to reduce breast cancer burden in lower SDI countries.

The results show that LASP-1 might be a promising target in the treatment of patients with CRC with growth and metastasis of CRC.