scholarly journals Induction and transmission of oncogene-induced senescence

Author(s):  
Nattaphong Rattanavirotkul ◽  
Kristina Kirschner ◽  
Tamir Chandra

Abstract Senescence is a cellular stress response triggered by diverse stressors, including oncogene activation, where it serves as a bona-fide tumour suppressor mechanism. Senescence can be transmitted to neighbouring cells, known as paracrine secondary senescence. Secondary senescence was initially described as a paracrine mechanism, but recent evidence suggests a more complex scenario involving juxtacrine communication between cells. In addition, single-cell studies described differences between primary and secondary senescent end-points, which have thus far not been considered functionally distinct. Here we discuss emerging concepts in senescence transmission and heterogeneity in primary and secondary senescence on a cellular and organ level.

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii62-ii62
Author(s):  
Sreepradha Sridharan ◽  
Arif Harmanci ◽  
Robert Siddaway ◽  
Tara Dobson ◽  
Jyothishmathi Swaminathan ◽  
...  

Abstract Diffuse Intrinsic Pontine Glioma (DIPG) is an incurable pediatric brain tumor of the pons and brainstem. Therefore, there is a desperate need for new therapeutics. Genomic profiling of tumors identified a highly prevalent dominant negative somatic mutation at lysine (K)-27 in histone genes HIST1H3B and H3F3A. Clonal evolution modeling suggests these mutations are truncal, and studies have demonstrated their contribution to tumorigenesis. ONC201, a first-in-class DRD2 antagonist and ClpP agonist is an anticancer drug developed by Oncoceutics, which targets the unfolded protein response (UPR) and integrated stress response (ISR) signaling and is actively being investigated in patients with recurrent H3 K27M-mutant gliomas. In adults with recurrent glioma, single agent studies showed benign-safety, no dose-limiting toxicities and a durable objective response when administered orally. In addition, intra-tumoral drug levels exceeded therapeutic thresholds, and induced tumor cell apoptosis. Based on this and response seen in a pediatric patient with DIPG for whom compassionate use of ONC201 was approved, a multi-arm, non-randomized multi-institutional Phase I clinical trial (NCT03416530) is actively accruing patients. However, the strength of UPR and ISR in DIPGs and their effect on DIPG response to ONC201 is not known. Our group employed bulk/single cell transcriptomic and single cell proteomic approaches to demonstrate substantial heterogeneity in UPR and ISR signaling in human DIPG samples. Consistent with this, DIPG cell lines exhibited considerable variability in sensitivity to ONC201. Single cell profiling identified tumor sub-populations with significant proliferative capacity even after ONC201 exposure. Incomplete response promotes recurrence. To target these cells, we performed a synthetic lethality screen with a library of 360 FDA-approved CNS penetrant compounds, which identified HDAC inhibitors and DNA damage-inducing chemotherapy as having synergy with ONC201. Thus, we suggest that tumor heterogeneity impacts sensitivity to ONC201 and that this can be reduced by combination treatments.


Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 99
Author(s):  
Shweta Devi ◽  
Vijay Kumar ◽  
Sandeep Kumar Singh ◽  
Ashish Kant Dubey ◽  
Jong-Joo Kim

Neurodegenerative disorders, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), are the most concerning disorders due to the lack of effective therapy and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress, which combats with stress conditions. Environmental stress/toxicity weakened the cellular stress response which results in cell damage. Small molecules, such as flavonoids, could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways, such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the potential role of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.


BIOspektrum ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 390-393
Author(s):  
F.-Nora Vögtle

AbstractThe majority of mitochondrial proteins are encoded in the nuclear genome, so that the nearly entire proteome is assembled by post-translational preprotein import from the cytosol. Proteomic imbalances are sensed and induce cellular stress response pathways to restore proteostasis. Here, the mitochondrial presequence protease MPP serves as example to illustrate the critical role of mitochondrial protein biogenesis and proteostasis on cellular integrity.


2021 ◽  
Vol 22 (6) ◽  
pp. 2941
Author(s):  
Marisa Pereira ◽  
Diana R. Ribeiro ◽  
Miguel M. Pinheiro ◽  
Margarida Ferreira ◽  
Stefanie Kellner ◽  
...  

Transfer RNA (tRNA) molecules contain various post-transcriptional modifications that are crucial for tRNA stability, translation efficiency, and fidelity. Besides their canonical roles in translation, tRNAs also originate tRNA-derived small RNAs (tsRNAs), a class of small non-coding RNAs with regulatory functions ranging from translation regulation to gene expression control and cellular stress response. Recent evidence indicates that tsRNAs are also modified, however, the impact of tRNA epitranscriptome deregulation on tsRNAs generation is only now beginning to be uncovered. The 5-methyluridine (m5U) modification at position 54 of cytosolic tRNAs is one of the most common and conserved tRNA modifications among species. The tRNA methyltransferase TRMT2A catalyzes this modification, but its biological role remains mostly unexplored. Here, we show that TRMT2A knockdown in human cells induces m5U54 tRNA hypomodification and tsRNA formation. More specifically, m5U54 hypomodification is followed by overexpression of the ribonuclease angiogenin (ANG) that cleaves tRNAs near the anticodon, resulting in accumulation of 5′tRNA-derived stress-induced RNAs (5′tiRNAs), namely 5′tiRNA-GlyGCC and 5′tiRNA-GluCTC, among others. Additionally, transcriptomic analysis confirms that down-regulation of TRMT2A and consequently m5U54 hypomodification impacts the cellular stress response and RNA stability, which is often correlated with tiRNA generation. Accordingly, exposure to oxidative stress conditions induces TRMT2A down-regulation and tiRNA formation in mammalian cells. These results establish a link between tRNA hypomethylation and ANG-dependent tsRNAs formation and unravel m5U54 as a tRNA cleavage protective mark.


Science ◽  
2021 ◽  
Vol 371 (6533) ◽  
pp. 1059-1063 ◽  
Author(s):  
D. Dipon Ghosh ◽  
Dongyeop Lee ◽  
Xin Jin ◽  
H. Robert Horvitz ◽  
Michael N. Nitabach

Color detection is used by animals of diverse phyla to navigate colorful natural environments and is thought to require evolutionarily conserved opsin photoreceptor genes. We report that Caenorhabditis elegans roundworms can discriminate between colors despite the fact that they lack eyes and opsins. Specifically, we found that white light guides C. elegans foraging decisions away from a blue-pigment toxin secreted by harmful bacteria. These foraging decisions are guided by specific blue-to-amber ratios of light. The color specificity of color-dependent foraging varies notably among wild C. elegans strains, which indicates that color discrimination is ecologically important. We identified two evolutionarily conserved cellular stress response genes required for opsin-independent, color-dependent foraging by C. elegans, and we speculate that cellular stress response pathways can mediate spectral discrimination by photosensitive cells and organisms—even by those lacking opsins.


Author(s):  
V. Calabrese ◽  
C. Cornelius ◽  
V. Leso ◽  
A. Trovato-Salinaro ◽  
B. Ventimiglia ◽  
...  

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