Supplementary file 2_CircHIPK3 promotes the progression of B-cell acute lymphoblastic leukemia in children by binding to STAT3.docx

Background<p>Circular RNAs (circRNAs) have emerged as critical post-transcriptional regulators in hematological malignancies; however, the specific role and molecular mechanism of circHIPK3 in pediatric B-cell acute lymphoblastic leukemia (B-ALL) remain unexplored.</p>Methods<p>circHIPK3 expression was profiled in clinical B-ALL specimens and cell lines. The biological functions were evaluated using CCK-8, flow cytometry, and in vivo NOD/SCID xenograft models for leukemic infiltration assessment.

Mechanistic interactions were deciphered via RNA immunoprecipitation (RIP), RNA pull-down, and ubiquitination assays.</p>Results<p>CircHIPK3 was aberrantly upregulated in B-ALL tissues and cells, exhibiting exceptional stability and predominant cytoplasmic localization. CircHIPK3 silencing significantly impaired leukemic cell proliferation, induced G0/G1 cell cycle arrest, and triggered apoptosis. Mechanistically, we identified a direct physical association between cytoplasmic circHIPK3 and STAT3.