Monitoring Signaling by the p75NTR Receptor Utilizing a Caspase-3 Activation Assay Amenable to Small-Molecule Screening

2012 ◽  
Vol 10 (4) ◽  
pp. 353-364
Author(s):  
J. Michael Bradshaw ◽  
Lan Nguyen ◽  
William Wallace ◽  
Calvin Li ◽  
John-Michael Sauer ◽  
...  
2019 ◽  
Author(s):  
Michael Oschmann ◽  
Linus Johansson Holm ◽  
Oscar Verho

Benzofurans are everywhere in nature and they have been extensively studied by medicinal chemists over the years because of their chemotherapeutic and physiological properties. Herein, we describe a strategy that can be used to access elaborate benzo-2-carboxamide derivatives, which involves a synthetic sequence of 8-aminoquinoline directed C–H arylations followed by transamidations. For the directed C–H arylations, Pd catalysis was used to install a wide range of aryl and heteroaryl substituents at the C3 position of the benzofuran scaffold in high efficiency. Directing group cleavage and further diversification of the C3-arylated benzofuran products were then achieved in a single synthetic operation through the utilization of a two-step transamidation protocol. By bocylating the 8-aminoquinoline amide moiety of these products, it proved possible to activate them towards aminolysis with different amine nucleophiles. Interestingly, this aminolysis reaction was found to proceed efficiently without the need of any additional catalyst or additive. Given the high efficiency and modularity of this synthetic strategy, it constitute a very attractive approach for generating structurally-diverse collections of benzofuran derivatives for small molecule screening.


2020 ◽  
Vol 20 (6) ◽  
pp. 930-942 ◽  
Author(s):  
Imran Khan ◽  
Sadaf Mahfooz ◽  
Irfan A. Ansari

Background: In recent years, natural products have received great attention for cancer prevention owing to their various health benefits, noticeable lack of toxicity and side effects, and the limitations of chemotherapeutic agents. Andrographolide, a labdane diterpenoid is a principal bioactive constituent of Andrographis paniculata Nees, exhibits significant anticancer activity. Objective: The efficacy of andrographolide on colon cancer cells is yet to be elucidated completely. Therefore, we investigated the anticancer efficiency of andrographolide in colon cancer DLD1 cell line. Methods: Antiproliferative activity of andrographolide on DLD1 cells was evaluated by MTT assay, LDH release assay, morphological analysis and colony formation assay. Induction of apoptosis was determined by DAPI staining, Annexin V-FITC staining assay, and caspase-3 activation assay. Role of andrographolide induced cellular reactive oxygen species (ROS) and its association with apoptosis induction in DLD1 cells was elucidated by DCFDA dye. Synergistic ability of andrographolide with 5- fluorouracil (5-FU) and paclitaxel (PTX) was evaluated by MTT assay. Results: Results of the present study indicated that andrographolide declined cell viability of DLD1 cells in a concentration and time-dependent manner. Andrographolide induced apoptosis via nuclear condensation, phosphatidylserine externalization and caspase-3 activation. It also augmented cellular ROS levels which were in turn associated with apoptosis induction in DLD1 cells. Moreover, andrographolide displayed synergistic activity with 5-FU and PTX against DLD1 cells. Conclusion: The present study showed that andrographolide demonstrated antiproliferative and apoptotic properties, moreover it also displayed synergistic effect with chemotherapeutic drugs in colon cancer DLD1 cells.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii200-ii200
Author(s):  
Stephen Skirboll ◽  
Natasha Lucki ◽  
Genaro Villa ◽  
Naja Vergani ◽  
Michael Bollong ◽  
...  

Abstract INTRODUCTION Glioblastoma multiforme (GBM) is the most aggressive form of primary brain cancer. A subpopulation of multipotent cells termed GBM cancer stem cells (CSCs) play a critical role in tumor initiation and maintenance, drug resistance, and recurrence following surgery. New therapeutic strategies for the treatment of GBM have recently focused on targeting CSCs. Here we have used an unbiased large-scale screening approach to identify drug-like small molecules that induce apoptosis in GBM CSCs in a cell type-selective manner. METHODS A luciferase-based survival assay of patient-derived GBM CSC lines was established to perform a large-scale screen of ∼one million drug-like small molecules with the goal of identifying novel compounds that are selectively toxic to chemoresistant GBM CSCs. Compounds found to kill GBM CSC lines as compared to control cell types were further characterized. A caspase activation assay was used to evaluate the mechanism of induced cell death. A xenograft animal model using patient-derived GBM CSCs was employed to test the leading candidate for suppression of in vivo tumor formation. RESULTS We identified a small molecule, termed RIPGBM, from the cell-based chemical screen that induces apoptosis in primary patient-derived GBM CSC cultures. The cell type-dependent selectivity of RIPGBM appears to arise at least in part from redox-dependent formation of a proapoptotic derivative, termed cRIPGBM, in GBM CSCs. cRIPGBM induces caspase 1-dependent apoptosis by binding to receptor-interacting protein kinase 2 (RIPK2) and acting as a molecular switch, which reduces the formation of a prosurvival RIPK2/TAK1 complex and increases the formation of a proapoptotic RIPK2/caspase 1 complex. In an intracranial GBM xenograft mouse model, RIPGBM was found to significantly suppress tumor formation. CONCLUSIONS Our chemical genetics-based approach has identified a small molecule drug candidate and a potential drug target that selectively targets cancer stem cells and provides an approach for the treatment of GBMs.


2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Warren R.J.D. Galloway ◽  
David R. Spring

AbstractMedicinal chemistry research has traditionally focused upon a limited set of biological targets. Many other human disease-related targets have been termed ‘undruggable’ as they have proved largely impervious to modulation by small molecules. However, it is becoming increasingly evident that such targets can indeed be modulated; they are simply being challenged with the wrong types of molecules. Traditionally, screening libraries were composed of large numbers of structurally similar compounds. However, library size is not everything; the structural diversity of the library, which is largely dictated by the range of molecular scaffolds present, is crucial. Diversity-oriented synthesis (DOS) generates small molecule libraries with high levels of scaffold, and thus structural, diversity. Such collections should provide hits against a broad range of targets with high frequency, including ‘undruggable’ targets. Examples in the area of scaffold diversity generation taken from the author’s laboratories are given.


2021 ◽  
Vol 20 ◽  
pp. S48
Author(s):  
M. Ensinck ◽  
L. De Keersmaecker ◽  
M. Nijs ◽  
A.S. Ramalho ◽  
K. De Boeck ◽  
...  

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