Investigation of the anticancer effect of simultaneouslyapplying RNA-Based P53 activation and MDM2 inhibition indifferent cancer cell lines carrying wild-type P53

The p53–MDM2 axis is a central regulator of cellular stress responses, and its dysregulation contributes to tumor development and therapeutic resistance. This study investigated a dual RNA-based strategy designed to modulate this axis in A549 and HCT116 cancer cell lines harboring wild-type p53. The approach involved activating p53 transcription through small activating RNA (sap53) while simultaneously suppressing its negative regulator MDM2 using small interfering RNA (siMDM2), both delivered within a cationic lipid carrier. qPCR and Western blot analyses showed that sap53 increased p53 mRNA and protein levels, whereas siMDM2 efficiently reduced MDM2 expression and stabilized endogenous p53 by preventing its degradation. Combined treatment enhanced p53 accumulation more than single applications and led to strong induction of downstream targets p21 and PUMA, indicating activation of pathways governing cell-cycle arrest and apoptosis. Functional assays demonstrated that this dual strategy reduced cellular proliferation, with the combination group showing the most pronounced decrease in viability. Moreover, migration and invasion assays revealed a marked suppression of cellular motility, with the combined treatment exerting the strongest inhibitory effect, exhibiting that reinforced p53 signaling contributed to growth inhibition and reduced metastatic potential. MDM2 expression patterns reflected the balance between p53-driven transcriptional induction and siRNA-mediated suppression. Overall, these findings indicated that simultaneous p53 activation and MDM2 inhibition amplified p53 signaling, suppressed proliferation and mobility, and strengthened antitumor responses. Therefore, co-delivery of saRNA and siRNA in cationic lipid offered a promising RNA-based treatment strategy for tumors that retain functional p53.