Browsing by Subject "POTENT"

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  • Aly, Ashraf A.; El-Emary, Talaat; Mourad, Aboul-Fetouh E.; Alyan, Zainab Khallaf; Bräse, Stefan; Nieger, Martin (2019)
    5-Carbohydrazides and 5-carbonylazides of pyrazolo[3,4-b]pyridines are used to synthesize new heterocyclic derivatives. Some unexpected behaviors are observed in the reactions of the above two species. The structures of the obtained compounds are proved by spectroscopic studies together with elemental and X-ray structure analyses.
  • Hassan, Alaa A.; Mohamed, Nasr K.; El-Shaieb, Kamal M. A.; Tawfeek, Hendawy N.; Bräse, Stefan; Nieger, Martin (2019)
    2-Substituted hydrazinecarbothioamides and N ,2-disubstituted hydrazinecarbothioamides react in high yield with dimethyl acetylenedicarboxylate (DMAD) to give 4-oxo-Z-(thiazolidin-5-ylidene) acetate derivatives. Several mechanistic options involving interaction are presented. The structures of thiazolidin-4-ones have been unambiguously confirmed by single crystal X-ray crystallography. (C) 2014 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.
  • Kakkola, L.; Denisova, O. V.; Tynell, J.; Viiliainen, J.; Ysenbaert, T.; Matos, R. C.; Nagaraj, A.; Öhman, Tiina; Kuivanen, S.; Paavilainen, H.; Feng, L.; Yadav, B.; Julkunen, I.; Vapalahti, O.; Hukkanen, V.; Stenman, J.; Aittokallio, T.; Verschuren, E. W.; Ojala, P. M.; Nyman, T.; Saelens, X.; Dzeyk, K.; Kainov, D. E. (2013)
  • Bulanova, Daria; Ianevski, Aleksandr; Bugai, Andrii; Akimov, Yevhen; Kuivanen, Suvi; Paavilainen, Henrik; Kakkola, Laura; Nandania, Jatin; Turunen, Laura; Ohman, Tiina; Ala-Hongisto, Hanna; Pesonen, Hanna M.; Kuisma, Marika S.; Honkimaa, Anni; Walton, Emma L.; Oksenych, Valentyn; Lorey, Martina B.; Guschin, Dmitry; Shim, Jungmin; Kim, Jinhee; Than, Thoa T.; Chang, So Young; Hukkanen, Veijo; Kulesskiy, Evgeny; Marjomaki, Varpu S.; Julkunen, Ilkka; Nyman, Tuula A.; Matikainen, Sampsa; Saarela, Jani S.; Sane, Famara; Hober, Didier; Gabriel, Guelsah; De Brabander, Jef K.; Martikainen, Miika; Windisch, Marc P.; Min, Ji-Young; Bruzzone, Roberto; Aittokallio, Tero; Vaha-Koskela, Markus; Vapalahti, Olli; Pulk, Arto; Velagapudi, Vidya; Kainov, Denis E. (2017)
    Viral diseases remain serious threats to public health because of the shortage of effective means of control. To combat the surge of viral diseases, new treatments are urgently needed. Here we show that small-molecules, which inhibit cellular anti-apoptotic Bcl-2 proteins (Bcl-2i), induced the premature death of cells infected with different RNA or DNA viruses, whereas, at the same concentrations, no toxicity was observed in mock-infected cells. Moreover, these compounds limited viral replication and spread. Surprisingly, Bcl-2i also induced the premature apoptosis of cells transfected with viral RNA or plasmid DNA but not of mock-transfected cells. These results suggest that Bcl-2i sensitizes cells containing foreign RNA or DNA to apoptosis. A comparison of the toxicity, antiviral activity, and side effects of six Bcl-2i allowed us to select A-1155463 as an antiviral lead candidate. Thus, our results pave the way for the further development of Bcl-2i for the prevention and treatment of viral diseases.
  • Lindholm, Dan; Pham, Dan D.; Cascone, Annunziata; Eriksson, Ove; Wennerberg, Krister; Saarma, Mart (2016)
    Parkinson's disease (PD) is a progressive neurodegenerative disorder causing movement disabilities and several non-motor symptoms in afflicted patients. Recent studies in animal models of PD and analyses of brain specimen from PD patients revealed an increase in the level and activity of the non-receptor tyrosine kinase Abelson (c-Abl) in dopaminergic neurons with phosphorylation of protein substrates, such as alpha-synuclein and the E3 ubiquitin ligase, Parkin. Most significantly inhibition of c-Abl kinase activity by small molecular compounds used in the clinic to treat human leukemia have shown promising neuroprotective effects in cell and animal models of PD. This has raised hope that similar beneficial outcome may also be observed in the treatment of PD patients by using c-Abl inhibitors. Here we highlight the background for the current optimism, reviewing c-Abl and its relationship to pathophysiological pathways prevailing in PD, as well as discussing issues related to the pharmacology and safety of current c-Abl inhibitors. Clearly more rigorously controlled and well-designed trials are needed before the c-Abl inhibitors can be used in the neuroclinic to possibly benefit an increasing number of PD patients.
  • Tranter, Dale; Paatero, Anja O.; Kawaguchi, Shinsaku; Kazemi, Soheila; Serrill, Jeffrey D.; Kellosalo, Juho; Vogel, Walter K.; Richter, Uwe; Mattos, Daphne R.; Wan, Xuemei; Thornburg, Christopher C.; Oishi, Shinya; McPhail, Kerry L.; Ishmael, Jane E.; Paavilainen, Ville O. (2020)
    Coibamide A (CbA) is a marine natural product with potent antiproliferative activity against human cancer cells and a unique selectivity profile. Despite promising antitumor activity, the mechanism of cytotoxicity and specific cellular target of CbA remain unknown. Here, we develop an optimized synthetic CbA photoaffinity probe (photo-CbA) and use it to demonstrate that CbA directly targets the Sec61 alpha subunit of the Sec61 protein translocon. CbA binding to Sec61 results in broad substratenonselective inhibition of ER protein import and potent cytotoxicity against specific cancer cell lines. CbA targets a lumenal cavity of Sec61 that is partially shared with known Sec61 inhibitors, yet profiling against resistance conferring Sec61 alpha mutations identified from human HCT116 cells su ests a distinct binding mode for CbA. Specifically, despite conferring strong resistance to all previously known Sec61 inhibitors, the Sec61 alpha mutant R66I remains sensitive to CbA. A further unbiased screen for Sec61 alpha resistance mutations identified the CbA-resistant mutation S71P, which confirms nonidentical binding sites for CbA and apratoxin A and supports the susceptibility of the Sec61 plug region for channel inhibition. Remarkably, CbA, apratoxin A, and ipomoeassin F do not display comparable patterns of potency and selectivity in the NCI60 panel of human cancer cell lines. Our work connecting CbA activity with selective prevention of secretory and membrane protein biogenesis by inhibition of Sec61 opens up possibilities for developing new Sec61 inhibitors with improved druglike properties that are based on the coibamide pharmacophore.
  • Humisto, Anu; Herfindal, Lars; Jokela, Jouni; Karkman, Antti; Bjørnstad, Ronja; Choudhury, Romi R.; Sivonen, Kaarina (2015)
    Cyanobacteria are an inspiring source of bioactive secondary metabolites. These bioactive agents are a diverse group of compounds which are varying in their bioactive targets, the mechanisms of action, and chemical structures. Cyanobacteria from various environments, especially marine benthic cyanobacteria, are found to be rich sources for the search for novel bioactive compounds. Several compounds with anticancer activities have been discovered from cyanobacteria and some of these have succeeded to enter the clinical trials. Varying anticancer agents are needed to overcome increasing challenges in cancer treatments. Different search methods are used to reveal anticancer compounds from natural products, but cell based methods are the most common. Cyanobacterial bioactive compounds as agents against acute myeloid leukemia are not well studied. Here we examined our new results combined with previous studies of anti-leukemic compounds from cyanobacteria with emphasis to reveal common features in strains producing such activity. We report that cyanobacteria harbor specific anti-leukemic compounds since several studied strains induced apoptosis against AML cells but were inactive against non-malignant cells like hepatocytes. We noted that particularly benthic strains from the Baltic Sea, such as Anabaena sp., were especially potential AML apoptosis inducers. Taken together, this review and re-analysis of data demonstrates the power of maintaining large culture collections for the search for novel bioactivities, and also how anti-AML activity in cyanobacteria can be revealed by relatively simple and low-cost assays.
  • Liu, Liwei; Herfindal, Lars; Jokela, Jouni; Shishido, Tania Keiko; Wahlsten, Matti; Doskeland, Stein Ove; Sivonen, Kaarina (2014)
  • Song, Yun-Qing; Weng, Zi-Miao; Dou, Tong-Yi; Finel, Moshe; Wang, Ya-Qiao; Ding, Le-Le; Jin, Qiang; Wang, Dan-Dan; Fang, Sheng-Quan; Cao, Yun-Feng; Hou, Jie; Ge, Guang-Bo (2019)
    Magnolol, the most abundant bioactive constituent of the Chinese herb Magnolia officinalis, has been found with multiple biological activities, including anti-oxidative, anti-inflammatory and enzyme-regulatory activities. In this study, the inhibitory effects and inhibition mechanism of magnolol on human carboxylesterases (hCEs), the key enzymes responsible for the hydrolytic metabolism of a variety of endogenous esters as well as ester-bearing drugs, have been well-investigated. The results demonstrate that magnolol strongly inhibits hCE1-mediated hydrolysis of various substrates, whereas the inhibition of hCE2 by magnolol is substrate-dependent, ranging from strong to moderate. Inhibition of intracellular hCE1 and hCE2 by magnolol was also investigated in living HepG2 cells, and the results showed that magnolol could strongly inhibit intracellular hCE1, while the inhibition of intracellular hCE2 was weak. Inhibition kinetic analyses and docking simulations revealed that magnolol inhibited both hCE1 and hCE2 in a mixed manner, which could be partially attributed to its binding at two distinct ligand-binding sites in each carboxylesterase, including the catalytic cavity and the regulatory domain. In addition, the potential risk of the metabolic interactions of magnolol via hCE1 inhibition was predicted on the basis of a series of available pharmacokinetic data and the inhibition constants. All these findings are very helpful in deciphering the metabolic interactions between magnolol and hCEs, and also very useful for avoiding deleterious interactions via inhibition of hCEs.
  • Kazemi, Soheila; Kawaguchi, Shinsaku; Badr, Christian E.; Mattos, Daphne R.; Ruiz-Saenz, Ana; Serrill, Jeffrey D.; Moasser, Mark M.; Dolan, Brian P.; Paavilainen, Ville O.; Oishi, Shinya; McPhail, Kerry L.; Ishmael, Jane E. (2021)
    Coibamide A is a potent cancer cell toxin and one of a select group of natural products that inhibit protein entry into the secretory pathway via a direct inhibition of the Sec61 protein translocon. Many Sec61 client proteins are clinically relevant drug targets once trafficked to their final destination in or outside the cell, however the use of Sec61 inhibitors to block early biosynthesis of specific proteins is at a pre-clinical stage. In the present study we evaluated the action of coibamide A against human epidermal growth factor receptor (HER, ErbB) proteins in representative breast and lung cancer cell types. HERs were selected for this study as they represent a family of Sec61 clients that is frequently dysregulated in human cancers, including coibamide-sensitive cell types. Although coibamide A inhibits biogenesis of a broad range of Sec61 substrate proteins in a presumed substrate nonselective manner, endogenous HER3 (ErbB-3) and EGFR (ErbB-1) proteins were more sensitive to coibamide A, and the related Sec61 inhibitor apratoxin A, than HER2 (ErbB-2). Despite this rank order of sensitivity (HER3 > EGFR > HER2), Sec61-dependent inhibition by coibamide A was sufficient to decrease cell surface expression of HER2. We report that coibamide Aor apratoxin A-mediated block of HER3 entry into the secretory pathway is unlikely to be mediated by the HER3 signal peptide alone. HER3 (G11L/S15L), that is fully resistant to the highly substrate-selective cotransin analogue CT8, was more resistant than wild-type HER3 but only at low coibamide A (3 nM) concentrations; HER3 (G11L/S15L) expression was inhibited by higher concentrations of either natural product. Timeand concentration-dependent decreases in HER protein expression induced a commensurate reduction in AKT/MAPK signaling in breast and lung cancer cell types and loss in cell viability. Coibamide A potentiated the cytotoxic efficacy of small molecule kinase inhibitors lapatinib and erlotinib in breast and lung cancer cell types, respectively. These data indicate that natural product modulators of Sec61 function have value as chemical probes to interrogate HER/ErbB signaling in treatment-resistant human cancers.