NIPBL 5'UTR Mutation: A Molecular Switch in Cohesin Complex- Related CdLS

Cornelia de Lange Syndrome (CdLS) is a prevalent cohesinopathy, frequently arising from mutations in genes encoding components of the cohesin complex, with NIPBL being the most commonly affected. This study aimed to investigate the consequences of a 5' untranslated region (UTR) mutation (c.-467 C > T) in the NIPBL gene on gene expression, cohesin complex integrity, and cellular development. Utilizing CRISPR/Cas9 technology, we generated a heterozygous cell line harboring the NIPBL 5'UTR mutation and employed a suite of molecular biology techniques, including RNA secondary structure prediction, luciferase reporter assays, and RT-pcr, to evaluate the mutation's impact. Our findings indicate that the 5'UTR mutation introduces an additional upstream open reading frame (uORF), resulting in diminished mRNA and protein expression levels of NIPBL . This reduction in NIPBL expression correlated with a downregulation of RAD21, a pivotal component of the cohesin complex, and a decrease in nuclear β-catenin levels, thereby affecting cell proliferation. This study elucidates that the 5'UTR mutation in NIPBL contributes to CdLS by disrupting gene expression and cellular processes, underscoring the significance of 5'UTR elements in the regulation of gene expression and the potential ramifications of sequence variations within this region. Our results advance the understanding of the molecular mechanisms underlying CdLS and may inform the development of targeted therapeutic interventions.