Microarray Identification of Differential lncRNA AC002454.1 Expression in Pediatric Acute Leukemia and Its Oncogenic Effect in Leukemia Cells in vitro.

Objective: While long noncoding RNAs (lncRNAs) have emerged as critical regulators in hematological malignancies, their clinical significance in pediatric acute leukemia (AL) remains poorly characterized. This study aimed to (1) systematically profile differentially expressed lncRNAs (DE-lncRNAs) in pediatric AL through comparative analysis of bone marrow samples and (2) functionally characterize the oncogenic role of a top candidate, AC002454.1, to identify potential diagnostic markers and therapeutic targets.

Methods: Using Arraystar Human LncRNA Array V3.0, we analyzed bone marrow samples from 43 pediatric AL patients (21 ALL, 22 AML) and 21 healthy donors. Key DE-lncRNAs were validated by qRT-PCR, with AC002454.1 selected for functional investigation. In NB4 leukemic cells, we performed (1) lentiviral knockdown of AC002454.1, (2) cell proliferation assays (CCK-8), (3) cell cycle analysis (PI staining/flow cytometry), (4) apoptosis assessment (Annexin V-FITC/PI dual staining), and (5) Western blot for CDK6 regulation.

Results: Our qRT-PCR validation confirmed 97 differentially expressed lncRNAs (DE-lncRNAs), with lncRNA AC002454.1 showing the most significant differential expression between ALL and AML samples (P=0.040 and P=0.002, respectively, and particular elevation in AML). Functional studies demonstrated that AC002454.1 knockdown in NB4 cells led to (1) reduced cellular viability, (2) G2/M phase cell cycle arrest, and (3) increased apoptosis. Notably, AC002454.1 silencing also down-regulated CDK6 protein expression, suggesting a potential mechanistic link.

Conclusions: We identified AC002454.1 as a functionally significant lncRNA in pediatric AL, demonstrating its oncogenic role through the promotion of proliferation and inhibition of apoptosis in leukemic cells. These findings suggest its potential as both biomarker and therapeutic target.