ALTering cancer by triggering telomere replication stress through the stabilization of promoter G-quadruplex in SMARCAL1 Journal Article


Authors: Panda, S.; Roychowdhury, T.; Dutta, A.; Chakraborty, S.; Das, T.; Chatterjee, S.
Article Title: ALTering cancer by triggering telomere replication stress through the stabilization of promoter G-quadruplex in SMARCAL1
Abstract: Most of the human cancers are dependent on telomerase to extend the telomeres. But ∼10% of all cancers use a telomerase-independent, homologous recombination mediated pathway called alternative lengthening of telomeres (ALT). Due to the poor prognosis, ALT status is not being considered yet in the diagnosis of cancer. No such specific treatment is available to date for ALT positive cancers. ALT positive cancers are dependent on replication stress to deploy DNA repair pathways to the telomeres to execute homologous recombination mediated telomere extension. SMARCAL1 (SWI/SNF related, matrix-associated, actin-dependent regulator of chromatin, subfamily A-like 1) is associated with the ALT telomeres to resolve replication stress thus providing telomere stability. Thus, the dependency on replication stress regulatory factors like SMARCAL1 made it a suitable therapeutic target for the treatment of ALT positive cancers. In this study, we found a significant downregulation of SMARCAL1 expression by stabilizing the G-quadruplex (G4) motif found in the promoter of SMARCAL1 by potent G4 stabilizers, like TMPyP4 and BRACO-19. SMARCAL1 downregulation led toward the increased localization of PML (promyelocytic leukemia) bodies in ALT telomeres and triggered the formation of APBs (ALT-associated promyelocytic leukemia bodies) in ALT positive cell lines, increasing telomere replication stress and DNA damage at a genomic level. Induction of replication stress and hyper-recombinogenic phenotype in ALT positive cells mediated by G4 stabilizing molecules already highlighted their possible application as a new therapeutic window to target ALT positive tumors. In accordance with this, our study will also provide a valuable insight toward the development of G4-based ALT therapeutics targeting SMARCAL1. © 2024 American Chemical Society.
Keywords: promoter region; genetics; dna replication; neoplasm; neoplasms; telomere; metabolism; cell line, tumor; promoter regions, genetic; tumor cell line; dna helicases; dna helicase; g-quadruplexes; guanine quadruplex; telomere homeostasis; humans; human; smarcal1 protein, human
Journal Title: ACS Chemical Biology
Volume: 19
Issue: 7
ISSN: 1554-8929
Publisher: American Chemical Society  
Date Published: 2024-07-19
Start Page: 1433
End Page: 1439
Language: English
DOI: 10.1021/acschembio.4c00285
PUBMED: 38959478
PROVIDER: scopus
DOI/URL:
Notes: Source: Scopus
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