Dna Damage Induced By Nucleostemin Depletion, Along With Autophagy Abolish Differentiation Blockage in Kg1a Leukemia Cells

Background and aim: current therapeutic strategies are not completely successful in eradicating undifferentiated leukemic stem cells (lscs) and consequently, treatment of leukemia remains a medical challenge. a variety of stem-cell related genes, including nucleostemin (ns), are highly expressed in lscs, and these upregulated genes perform crucial roles in leukemogenesis and treatment of in acute myeloid leukemia (aml). here, we study the biological function of ns and its underlying mechanism in controlling proliferation and differentiation status of kg1a lscs. methods: ns was depleted by a specific small interference rna (sins). the growth inhibition and viability were evaluated by trypan blue exclusion test. the qpcr was performed using sybr green. autophagy was studied by western blotting (lc3 conversion) and real-time pcr (atg expression). cell apoptosis and cell cycle distribution were studied by flow cytometry. the expression of myelocytic differentiation marker of cd11b was evaluated by flow cytometry. the acidity of lysosomes and the accumulation of acidic vesicular organelles (avos) were evaluated by acridine orange stain. finally, dna damage was monitored by confocal microscopy. results: we showed that this nucleolar protein controls the proliferation and differentiation status of kg1a lscs. depletion of ns induced dna damage, arrested cell cycle, and elicited autophagy along with differentiation in kg1a cells. ns insufficiency led to the activation of the autophagy pathway, as evidenced by lc3 conversion and atgs expression. notably, pharmacological inhibition of autophagy by autophagy inhibitors 3-methyladenine decreased myeloid maturation in ns-depleted kg1a cells, through induction of persistent dna damage and finally apoptosis. conclusion: our data provided the evidence that induction of dna damage along with autophagy induced by ns depletion contributes to confer differentiation blockage of kg1a cells and suggest that ns targeting could be exploited for future therapeutic interventions based on the use of differentiation therapy agents in this malignancy.