Development of a Dual Gene-Targeted Multi-Sirna with Branched Structure and Its Role in the Therapy of Liver Cancer

<b>Background:</b> Hepatocellular carcinoma (HCC) remains a major global health challenge with limited therapeutic options. Although RNA interference (RNAi) enables precise gene silencing, its clinical application is restricted by siRNA instability, inefficient cellular uptake, and the requirement for potentially toxic delivery carriers. To address these limitations, a dual-targeted branched siRNA nanostructure (GT-multi-siRNA) was developed to simultaneously silence two HCC-related oncogenes, GP73 and hTERT. <b>Methods:</b> GT-multi-siRNA was synthesized in <i>Escherichia coli</i> and characterized for particle size, stability, Dicer processing efficiency, intracellular retention, and cytotoxicity. Its therapeutic effects were evaluated through gene-silencing assays, proliferation and migration assays in Hep3B cells, and intratumoral administration in a xenograft mouse model. Histopathology and cytokine profiling were conducted to assess biosafety. <b>Results:</b> GT-multi-siRNA formed uniform nanoparticles (50-100 nm) with moderate physicochemical stability and minimal cytotoxicity at concentrations ≤ 200 ng/μL. The nanostructure was efficiently processed by Dicer into functional siRNAs and remained detectable intracellularly for at least 36 h. In Hep3B cells, GT-multi-siRNA reduced GP73 and hTERT mRNA and protein levels by approximately 50%, accompanied by significant inhibition of cell proliferation and migration. In vivo, a single intratumoral dose suppressed tumor growth, while a two-dose regimen markedly limited tumor progression. No liver toxicity was observed, and cytokine analysis showed selective IL-4 upregulation without influencing IL-6 levels. <b>Conclusions:</b> GT-multi-siRNA demonstrates potent dual-gene silencing activity and favorable biosafety, providing a promising RNAi-based therapeutic strategy for targeted HCC treatment.