Building C(sp3)-rich complexity by combining cycloaddition and C-C cross-coupling reactions.

Prized for their ability to rapidly generate chemical complexity by building new ring systems and stereocentres1, cycloaddition reactions have featured in numerous total syntheses2 and are a key component in the education of chemistry students3. Similarly, carbon-carbon (C-C) cross-coupling methods are integral to synthesis because of their programmability, modularity and reliability4. Within the area of drug discovery, an overreliance on cross-coupling has led to a disproportionate representation of flat architectures that are rich in carbon atoms with orbitals hybridized in an sp2 manner5. Despite the ability of cycloadditions to introduce multiple carbon sp3 centres in a single step, they are less used6. This is probably because of their lack of modularity, stemming from the idiosyncratic steric and electronic rules for each specific type of cycloaddition. Here we demonstrate a strategy for combining the optimal features of these two chemical transformations into one simple sequence, to enable the modular, enantioselective, scalable and programmable preparation of useful building blocks, natural products and lead scaffolds for drug discovery.

Synthesis of a Polycyclic Halichondrin C1-C14 Fragment via Intermolecular Oxy-Michael/ Trans-Ketalization.

Syntheses of a crystalline polycyclic halichondrin C1-C14 building block starting from a d-gulono-1,4-lactone-derived intermediate in the current Halaven manufacturing process are described. Key features of the syntheses include an acid-catalyzed tandem intermolecular oxy-Michael/intramolecular trans-ketalization reaction and stereoselective Kishi reductions.

E7766, a Macrocycle-Bridged Stimulator of Interferon Genes (STING) Agonist with Potent Pan-Genotypic Activity.

A strategy for creating potent and pan-genotypic stimulator of interferon genes (STING) agonists is described. Locking a bioactive U-shaped conformation of cyclic dinucleotides by introducing a transannular macrocyclic bridge between the nucleic acid bases leads to a topologically novel macrocycle-bridged STING agonist (MBSA). In addition to substantially enhanced potency, the newly designed MBSAs, exemplified by clinical candidate E7766, exhibit broad pan-genotypic activity in all major human STING variants. E7766 is shown to have potent antitumor activity with long lasting immune memory response in a mouse liver metastatic tumor model. Two complementary stereoselective synthetic routes to E7766 are also described.

Synthesis of the Halichondrin C1-C15 Fragment from a Halaven C27-C35 Byproduct: Stereospecific Intramolecular Kishi Reduction.

A byproduct from a Halaven C27-C35 manufacturing process was transformed into a crystalline halichondrin C1-C15 building block by employing a stereospecific intramolecular Kishi reduction as the key step.

Targeting the Golgi apparatus to overcome acquired resistance of non-small cell lung cancer cells to EGFR tyrosine kinase inhibitors.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (EGFR-TKIs) were demonstrated to provide survival benefit in patients with non-small cell lung cancer (NSCLC) harboring activating mutations of EGFR; however, emergence of acquired resistance to EGFR-TKIs has been shown to cause poor outcome. To overcome the TKI resistance, drugs with different mode of action are required. We previously reported that M-COPA (2-methylcoprophilinamide), a Golgi disruptor, suppressed the growth of gastric cancers overexpressing receptor tyrosine kinases (RTKs) such as hepatocyte growth factor receptor (MET) via downregulating their cell surface expression. In this study, we examined the antitumor effect of M-COPA on NSCLC cells with TKI resistance. As a result, M-COPA effectively downregulated cell surface EGFR and its downstream signals, and finally exerted in vivo antitumor effect in NSCLC cells harboring secondary (T790M/del19) and tertiary (C797S/T790M/del19) mutated EGFR, which exhibit acquired resistance to first- and third generation EGFR-TKIs, respectively. M-COPA also downregulated MET expression potentially involved in the acquired resistance to EGFR-TKIs via bypassing the EGFR pathway blockade. These results provide the first evidence that targeting the Golgi apparatus might be a promising therapeutic strategy to overcome the vicious cycle of TKI resistance in EGFR-mutated NSCLC cells via downregulating cell surface RTK expression.

[Nursing images appearing in elementary school textbooks under the 7th national curriculum].

PURPOSE: The purpose of this study was to identify the nursing images appearing in elementary school textbooks. METHOD: This study targeted 130 textbooks of 13 subjects under the 7th national curriculum for elementary schools as of December 2005. Nursing-related texts, photographs, and illustrations in the textbooks were analyzed by using a content analysis method. As for the textbook analysis, two coders thoroughly read the textbooks to record nursing-related content per coding paper, respectively. RESULT: The total number of nursing-related content appearing in 130 textbooks of 13 subjects was 70. More nursing-related content was exhibited in the photograph and illustration domain(N=57, 81.4%) than in the text domain(N=13, 18.6%). Nursing-related content(N=70) appeared in the order of nursing activities with 56(80.0%), nursing as a job with 10(14.3%), and others with 4(5.7%). As for the nursing image of nursing-related content, positive images were most with 30(42.9%), followed by negative images with 21(30.0%), and neutral images with 19(27.1%). CONCLUSION: Nursing-related content was dealt with too little, and dependent nursing activities such as medication, and assisting roles for doctor's examinations and treatments mainly appeared. Also, the main activity place was a hospital. To introduce proper and adequate nursing activities to the students, various types of nursing-related data and material should be distributed to front line schools, teachers, main authors, and publishing companies.

Prins Reaction of Homoallenyl Alcohols: Access to Substituted Pyrans in the Halichondrin Series.

Prins reaction of homoallenyl alcohols with aldehyde dimethylacetals in the presence of methoxyacetic acid directly affords tetrasubstituted pyrans relevant to halichondrins with complete control of the C27 stereogenic center. Regioselective Tsuji reduction of the resultant allylic acetates stereoselectively establishes the C25 stereogenic center and C26 exocyclic olefin. Building upon these findings, we achieved concise access to the halichondrin C14-C38 and eribulin C14-C35 fragments.

M-COPA, a Golgi Disruptor, Inhibits Cell Surface Expression of MET Protein and Exhibits Antitumor Activity against MET-Addicted Gastric Cancers.

The Golgi apparatus is responsible for transporting, processing, and sorting numerous proteins in the cell, including cell surface-expressed receptor tyrosine kinases (RTK). The small-molecule compound M-COPA [2-methylcoprophilinamide (AMF-26)] disrupts the Golgi apparatus by inhibiting the activation of Arf1, resulting in suppression of tumor growth. Here, we report an evaluation of M-COPA activity against RTK-addicted cancers, focusing specifically on human gastric cancer (GC) cells with or without MET amplification. As expected, the MET-addicted cell line MKN45 exhibited a better response to M-COPA than cell lines without MET amplification. Upon M-COPA treatment, cell surface expression of MET was downregulated with a concurrent accumulation of its precursor form. M-COPA also reduced levels of the phosphorylated form of MET along with the downstream signaling molecules Akt and S6. Similar results were obtained in additional GC cell lines with amplification of MET or the FGF receptor FGFR2 MKN45 murine xenograft experiments demonstrated the antitumor activity of M-COPA in vivo Taken together, our results offer an initial preclinical proof of concept for the use of M-COPA as a candidate treatment option for MET-addicted GC, with broader implications for targeting the Golgi apparatus as a novel cancer therapeutic approach. Cancer Res; 76(13); 3895-903. ©2016 AACR.

Apratoxin A Shows Novel Pancreas-Targeting Activity through the Binding of Sec 61.

Apratoxin A is a natural product with potent antiproliferative activity against many human cancer cell lines. However, we and other investigators observed that it has a narrow therapeutic window in vivo Previous mechanistic studies have suggested its involvement in the secretory pathway as well as the process of chaperone-mediated autophagy. Still the link between the biologic activities of apratoxin A and its in vivo toxicity has remained largely unknown. A better understanding of this relationship is critically important for any further development of apratoxin A as an anticancer drug. Here, we describe a detailed pathologic analysis that revealed a specific pancreas-targeting activity of apratoxin A, such that severe pancreatic atrophy was observed in apratoxin A-treated animals. Follow-up tissue distribution studies further uncovered a unique drug distribution profile for apratoxin A, showing high drug exposure in pancreas and salivary gland. It has been shown previously that apratoxin A inhibits the protein secretory pathway by preventing cotranslational translocation. However, the molecule targeted by apratoxin A in this pathway has not been well defined. By using a (3)H-labeled apratoxin A probe and specific Sec 61α/ß antibodies, we identified that the Sec 61 complex is the molecular target of apratoxin A. We conclude that apratoxin A in vivo toxicity is likely caused by pancreas atrophy due to high apratoxin A exposure. Mol Cancer Ther; 15(6); 1208-16. ©2016 AACR.

EPZ011989, A Potent, Orally-Available EZH2 Inhibitor with Robust in Vivo Activity.

Inhibitors of the protein methyltransferase Enhancer of Zeste Homolog 2 (EZH2) may have significant therapeutic potential for the treatment of B cell lymphomas and other cancer indications. The ability of the scientific community to explore fully the spectrum of EZH2-associated pathobiology has been hampered by the lack of in vivo-active tool compounds for this enzyme. Here we report the discovery and characterization of EPZ011989, a potent, selective, orally bioavailable inhibitor of EZH2 with useful pharmacokinetic properties. EPZ011989 demonstrates significant tumor growth inhibition in a mouse xenograft model of human B cell lymphoma. Hence, this compound represents a powerful tool for the expanded exploration of EZH2 activity in biology.

Asymmetric Ni(II)/Cr(II)-mediated coupling reaction: stoichiometric process.

[reaction: see text] Via an X-ray analysis, the sulfonamide bearing R(1) = i-Pr, R(2) = Me, and R(3) = Me is shown to be a tridentate ligand to a Cr(III) salt. This class of ligands, represented by R(1) = t-Bu, R(2) = 2-naphthyl, and R(3) = Me, is effective to achieve an asymmetric Ni/Cr-mediated coupling reaction and, with the C14-C38 segment of halichondrins, its synthetic potential has been demonstrated. A possible mechanism is suggested for the process.

Asymmetric Ni(II)/Cr(II)-mediated coupling reaction: catalytic process.

[reaction: see text] The stable, crystalline Cr(III)/sulfonamide complex 1a is shown to be an effective catalyst for the Ni/Cr-mediated coupling reaction. A possible mechanism is suggested for the process. 1a is also effective for other Cr-mediated coupling reactions. With this catalyst, a concise and efficient synthesis of the C14-C26 segment of halichondrins has been developed.

[Analysis of nursing-related content portrayed in middle and high school textbooks under the national common basic curriculum in Korea].

PURPOSE: The purpose of this study was to analyze nursing-related content in middle, and high school textbooks under the National Common Basic Curriculum in Korea. METHODS: Nursing-related content from 43 middle school textbooks and 13 high school textbooks was analyzed. RESULTS: There were 28 items of nursing-related content in the selected textbooks. Among them, 13 items were in the 'nursing activity' area, 6 items were in the 'nurse as an occupation' area, 2 items were in the 'major and career choice' area, 6 items were 'just one word' and 1 item in 'others'. CONCLUSION: The main nursing related content which portrayed in the middle and high school textbooks were caring for patients (7 items accounting for 46.5%), nurses working in hospitals (6 items accounting for 21.4%). In terms of gender perspective, female nurses (15 items accounting for 53.6%) were most prevalent.