Effect of HS-mediated telomere disruption on Nalm6 cells

Nalm6 tumour cells were engineered with focused ultrasound (FUS)-controllable CRISPR (heat-inducible CRISPR) with telomere-targeting gRNA or control non-targeting (NT) gRNA, and either treated with heat shock (HS) or no HS (control, CT). We observed that a relatively short duration of HS (10 min) significantly inhibited the proliferation of the cells engineered with telomere FUS-CRISPR, but not that of the cells with NT FUS-CRISPR, suggesting that telomere disruption rather than hyperthermia itself suppressed cell growth. Bulk RNA-seq further revealed that FUS-CRISPR-mediated telomere disruption led to the upregulation of multiple genes associated with the stress response p53 signaling pathway and apoptotic process and the TNF family in the engineered cells to trigger cell cycle arrest. Overall design: Nalm6 cells engineered with telomere-targeting or NT FUS-CRISPR were subjected to 10 min HS or no treatment (CT). Total RNA was collected at 24, 48, and 96 h after HS using the RNA microprep kit (Zymo Research, R1050) and sent for bulk RNA-seq (Novogene).