Abstract 1853: The Chk1 inhibitor, SRA737, synergizes with niraparib to kill cancer cells via multiple cell death pathways

Author(s):  
Laurence Booth ◽  
Jane Roberts ◽  
Andrew Poklepovic ◽  
Ryan J. Hansen ◽  
Bryan Strouse ◽  
...  
eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
William Putzbach ◽  
Quan Q Gao ◽  
Monal Patel ◽  
Stijn van Dongen ◽  
Ashley Haluck-Kangas ◽  
...  

Over 80% of multiple-tested siRNAs and shRNAs targeting CD95 or CD95 ligand (CD95L) induce a form of cell death characterized by simultaneous activation of multiple cell death pathways preferentially killing transformed and cancer stem cells. We now show these si/shRNAs kill cancer cells through canonical RNAi by targeting the 3’UTR of critical survival genes in a unique form of off-target effect we call DISE (death induced by survival gene elimination). Drosha and Dicer-deficient cells, devoid of most miRNAs, are hypersensitive to DISE, suggesting cellular miRNAs protect cells from this form of cell death. By testing 4666 shRNAs derived from the CD95 and CD95L mRNA sequences and an unrelated control gene, Venus, we have identified many toxic sequences - most of them located in the open reading frame of CD95L. We propose that specific toxic RNAi-active sequences present in the genome can kill cancer cells.


2017 ◽  
Author(s):  
William Putzbach ◽  
Quan Q. Gao ◽  
Monal Patel ◽  
Stijn van Dongen ◽  
Ashley Haluck-Kangas ◽  
...  

AbstractOver 80% of multiple tested siRNAs and shRNAs targeting CD95 or CD95 ligand (CD95L) induce a form of cell death characterized by simultaneous activation of multiple cell death pathways preferentially killing transformed and cancer stem cells. We now show these si/shRNAs kill cancer cells through canonical RNAi by targeting the 3’UTR of critical survival genes in a unique form of off-target effect we call DISE (death induced by survival gene elimination). Drosha and Dicer deficient cells, devoid of most miRNAs, are hypersensitive to DISE, suggesting cellular miRNAs protect cells from this form of cell death. By testing 4666 shRNAs derived from the CD95 and CD95L mRNA sequences and an unrelated control gene, Venus, we have identified many toxic sequences - most of them located in the open reading frame of CD95L. We propose that using specific toxic RNAi-active sequences present in the genome can kill cancer cells.


Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3976 ◽  
Author(s):  
Sameera Omar Mohammed Saeed Balhamar ◽  
Neena Gopinathan Panicker ◽  
Shaima Akhlaq ◽  
Mohammed Mansoor Qureshi ◽  
Waqar Ahmad ◽  
...  

This study systematically analyzed the anticancer potential of Acridocarpus orientalis (AO), a traditional medicinal plant of the Arabian Peninsula/East Africa known for its anti-inflammatory and pain relief properties. Tests of serial organic fractions from methanolic extracts of its leaves and stems revealed that only some fractions showed anti-proliferative potential with the dichloromethane fraction from leaves (AOD (L)) showing the most cytotoxic effect against both breast (MCF-7 and MDA-MB-231) and cervical (HeLa) cancer cell lines. The n-butanol fraction from the stems (AOB (S)), on the other hand, was more effective against cervical cancer cells and did not harm the normal cells. Further characterization of the mode of cell killing revealed that AOD (L) depended more on non-apoptotic pathways for its cytotoxicity in breast cancer cells, while it could activate some apoptosis and necroptosis in HeLa cells. The AOB (S) fraction could primarily activate apoptosis and some necroptosis in HeLa cells. Both fractions perturbed autophagy, but in a dissimilar manner. Thus, different parts of A. orientalis revealed variable potential to induce cell death in cancer cells via apoptotic and non-apoptotic pathways, making A. orientalis a valuable plant for the exploration of anticancer bioactive reagents, some of which may be protective for normal cells.


2021 ◽  
Vol 13 (604) ◽  
pp. eabb1069
Author(s):  
Yuping Fan ◽  
Yan Teng ◽  
Fabien Loison ◽  
Aiming Pang ◽  
Anongnard Kasorn ◽  
...  

Clinical outcomes from granulocyte transfusion (GTX) are disadvantaged by the short shelf life and compromised function of donor neutrophils. Spontaneous neutrophil death is heterogeneous and mediated by multiple pathways. Leveraging mechanistic knowledge and pharmacological screening, we identified a combined treatment, caspases–lysosomal membrane permeabilization–oxidant–necroptosis inhibition plus granulocyte colony-stimulating factor (CLON-G), which altered neutrophil fate by simultaneously targeting multiple cell death pathways. CLON-G prolonged human and mouse neutrophil half-life in vitro from less than 1 day to greater than 5 days. CLON-G–treated aged neutrophils had equivalent morphology and function to fresh neutrophils, with no impairment to critical effector functions including phagocytosis, bacterial killing, chemotaxis, and reactive oxygen species production. Transfusion with stored CLON-G–treated 3-day-old neutrophils enhanced host defenses, alleviated infection-induced tissue damage, and prolonged survival as effectively as transfusion with fresh neutrophils in a clinically relevant murine GTX model of neutropenia-related bacterial pneumonia and systemic candidiasis. Last, CLON-G treatment prolonged the shelf life and preserved the function of apheresis-collected human GTX products both ex vivo and in vivo in immunodeficient mice. Thus, CLON-G treatment represents an effective and applicable clinical procedure for the storage and application of neutrophils in transfusion medicine, providing a therapeutic strategy for improving GTX efficacy.


2021 ◽  
Vol 55 (1) ◽  
pp. 235-263
Author(s):  
Daichao Xu ◽  
Chengyu Zou ◽  
Junying Yuan

The receptor-interacting protein kinase 1 (RIPK1) is recognized as a master upstream regulator that controls cell survival and inflammatory signaling as well as multiple cell death pathways, including apoptosis and necroptosis. The activation of RIPK1 kinase is extensively modulated by ubiquitination and phosphorylation, which are mediated by multiple factors that also control the activation of the NF-κB pathway. We discuss current findings regarding the genetic modulation of RIPK1 that controls its activation and interaction with downstream mediators, such as caspase-8 and RIPK3, to promote apoptosis and necroptosis. We also address genetic autoinflammatory human conditions that involve abnormal activation of RIPK1. Leveraging these new genetic and mechanistic insights, we postulate how an improved understanding of RIPK1 biology may support the development of therapeutics that target RIPK1 for the treatment of human inflammatory and neurodegenerative diseases.


2019 ◽  
Vol 33 (10) ◽  
pp. 10680-10691 ◽  
Author(s):  
Myles R. McCrary ◽  
Michael Q. Jiang ◽  
Michelle M. Giddens ◽  
James Y. Zhang ◽  
Sharon Owino ◽  
...  

FEBS Open Bio ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 798-810 ◽  
Author(s):  
Siwei Liu ◽  
Bilin Liang ◽  
Huiting Jia ◽  
Yuhan Jiao ◽  
Zhongqiu Pang ◽  
...  

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