Transcription Factor MEF2B Promotes Cisplatin Resistance in Neuroblastoma by Upregulating CRABP1

Background Neuroblastoma (NB) is the most common extracranial solid tumor in children, associated with poor prognosis among high-risk patients. Cisplatin-based chemotherapy is a standard treatment approach; however, acquired resistance frequently leads to treatment failure. The role of Cellular Retinoic Acid Binding Protein 1 (CRABP1) and its regulatory mechanisms in cisplatin-resistant NB remain unclear. Objective This study aims to identify key genes driving cisplatin resistance in NB, elucidate their upstream transcriptional regulatory mechanisms, and evaluate their clinical prognostic value. Methods A cisplatin-resistant NB cell line (SK-N-BE(2)-CISR) was generated via gradual concentration induction and subjected to transcriptome sequencing. Differentially expressed genes (DEGs) were intersected with those related to patient mortality from public prognostic datasets (GSE16237 and GSE62564) to identify core candidate genes. Independent clinical cohorts (GSE181559 and E-MTAB-8248) were utilized to validate associations between candidate gene expression and clinical stage, survival outcomes, and prognostic predictive value. Upstream transcriptional regulators were identified through multi-dataset integration, promoter binding site prediction, and protein-DNA computational docking. Functional validation was subsequently performed in SK-N-BE(2), SK-N-SH, and SK-N-BE(2)-CISR cells, including quantitative real-time PCR (qRT-PCR), Western blotting, lentivirus-mediated CRABP1 knockdown, plasmid-mediated MEF2B overexpression rescue experiments, IC50 assays, and dual-luciferase reporter assays. Results CRABP1 was identified as a core gene significantly associated with both in vitro cisplatin resistance and poor patient prognosis. Its expression was significantly upregulated in deceased patients and advanced-stage (INSS 3/4) tumor tissues. High CRABP1 expression predicted shorter overall survival and exhibited robust prognostic accuracy (AUC > 0.8 in selected cohorts). Single-cell analysis of MYCN-amplified neuroblastoma revealed that CRABP1 is restrictedly expressed in a subset of neuroendocrine cells. In silico knockdown identified NYAP2 and VIP as key downstream effectors, implicating CRABP1 in the regulation of mitotic activity and translational programs. Bioinformatics analysis combined with computational modeling predicted direct binding of transcription factor MEF2B to the promoter region of CRABP1 (pTM = 0.84). Experimentally, MEF2B and CRABP1 were significantly upregulated at both mRNA and protein levels in cisplatin-resistant cells (P < 0.01). CRABP1 knockdown markedly reduced the IC50 of cisplatin in NB cells, whereas MEF2B overexpression partially restored CRABP1 expression and the drug-resistant phenotype. Dual-luciferase reporter assays confirmed that MEF2B directly activates the wild-type CRABP1 promoter, an effect abolished by site-directed mutation of the predicted binding motif. Conclusions This study reveals CRABP1 as a key molecule promoting cisplatin resistance and disease progression in NB, which is directly transactivated by transcription factor MEF2B, as experimentally confirmed by promoter reporter assays and functional rescue experiments. The MEF2B-CRABP1 axis may mediate resistance through multiple pathways, including metabolic reprogramming. These findings provide novel potential targets and a theoretical basis for improving prognosis prediction and reversing drug resistance in NB.