Therapeutic SHPRH-146aa encoded by circ-SHPRH dynamically upregulates P21 to inhibit CDKs in neuroblastoma

Recent research has underscored the significance of circular RNA (circRNA) in various cancers, including neuroblastoma (NB). Specifically, circ-SHPRH, a distinct circRNA, has emerged as an inhibitor of tumor growth through its ability to sequester miRNAs or produce the SHPRH-146aa protein. To explore circ-SHPRH's involvement in NB and its potential application in gene therapy, this study examined its expression in 94 NB tissues and cell lines (SK-N-BE(2), SH-SY5Y, CHLA-255) using real-time PCR and fluorescence in situ hybridization (FISH). Functional assays encompassing both overexpression and knockdown experiments in NB cell lines, as well as in vivo investigations, were conducted. RNA-seq analysis revealed a correlation between circ-SHPRH and the P21 (CDKN1A) pathway, a pivotal cell cycle regulator. Validation through PCR and other techniques confirmed that circ-SHPRH upregulated P21 expression. Furthermore, the regulatory role of circ-SHPRH in the P21-CDK pathway was corroborated through SHPRH-146aa expression. Notably, adenovirus-mediated overexpression of circ-SHPRH effectively curbed NB tumor growth in NSG mice, while combining circ-SHPRH with everolimus exhibited potential for NB treatment. This study elucidates the remarkable significance of circ-SHPRH in NB and its prospective utility in gene therapy, thereby paving the way for innovative therapeutic approaches.