Novel carfilzomib-based combinations as potential therapeutic strategies for liposarcomas

10.1007/s00018-020-03620-wCellular and Molecular Life Sciences7841837-185

Signalling inhibition by ponatinib disrupts productive alternative lengthening of telomeres (ALT)

Alternative lengthening of telomeres (ALT) supports telomere maintenance in 10-15% of cancers, thus representing a compelling target for therapy. By performing anti-cancer compound library screen on isogenic cell lines and using extrachromosomal telomeric C-circles, as a bona fide marker of ALT activity, we identify a receptor tyrosine kinase inhibitor ponatinib that deregulates ALT mechanisms, induces telomeric dysfunction, reduced ALT-associated telomere synthesis, and targets, in vivo, ALT-positive cells. Using RNA-sequencing and quantitative phosphoproteomic analyses, combined with C-circle level assessment, we find an ABL1-JNK-JUN signalling circuit to be inhibited by ponatinib and to have a role in suppressing telomeric C-circles. Furthermore, transcriptome and interactome analyses suggest a role of JUN in DNA damage repair. These results are corroborated by synergistic drug interactions between ponatinib and either DNA synthesis or repair inhibitors, such as triciribine. Taken together, we describe here a signalling pathway impacting ALT which can be targeted by a clinically approved drug

Signalling inhibition by ponatinib disrupts productive alternative lengthening of telomeres (ALT)

The kinase inhibitor Ponatinib inhibits an ABL1-JUN signalling axis and alters telomere homeostasis, reduces telomere synthesis, and provokes telomere dysfunction in cancer cells which employ the alternative lengthening of telomeres mechanisms