A novel auto-fluorescent porphyrin-lipid nanoparticle strategy for CTNNB1 gene silencing in hepatocellular carcinoma.

BACKGROUND

Hepatocellular carcinoma (HCC) remains a high-fatality cancer with limited effective therapies. CTNNB1 mutations, frequently observed in HCC, are associated with poor prognosis and immune evasion. CTNNB1 has long been considered an undruggable target due to its structural characteristics and extensive protein interactions. Porphyrin lipid nanoparticles (porphyrin-LNPs) are capable of targeting liver tumor cells, and their inherent autofluorescence allows evaluation of nanoparticle biodistribution in the liver. Our goal was to formulate a porphyrin-LNP encapsulating CTNNB1-targeting siRNA, as a novel strategy to target β-catenin-driven HCCs.

METHODS

We developed porphyrin-LNPs for systemic delivery of CTNNB1-targeting siRNA. Porphyrin-LNPs were synthesized via microfluidic rapid mixing and characterized by cryo-TEM and dynamic light scattering. Their delivery efficacy was validated in HCC cell lines (Hep3B, HepG2), and their therapeutic potential was evaluated in a murine model of CTNNB1/KRAS-driven HCC.

RESULTS

Porphyrin-LNPs showed high encapsulation efficiency (97%) and effective siRNA delivery in vitro. Treatment with porphyrin-LNP-si-CTNNB1 resulted in approximately 90% downregulation of CTNNB1 expression (p < 0.0001 in Hep3B at 50nM; p < 0.0001 in HepG2 at 10nM) and significantly reduced clonogenic survival in both Hep3B (50% reduction at 50nM, p < 0.0001) and HepG2 (75% reduction at 10nM, p < 0.001) cell lines. In vivo, porphyrin-LNP-si-CTNNB1 significantly reduced tumor burden by approximately 67% (p < 0.0001), liver-to-body weight ratio by 50% (p < 0.0001), histological tumor grade, and β-catenin expression in CTNNB1/KRAS-driven HCC mice by approximately 58% (p < 0.0001).

CONCLUSIONS

This study demonstrated that porphyrin-LNPs can effectively deliver siRNA to silence CTNNB1, an oncogene that has so far been undruggable in HCC. Future studies should explore biodistribution, immune modulation, and combination strategies to enhance clinical translatability of CTNNB1-targeted RNA interference in HCC.