Dendriplexes in alveolar rhabdomyosarcoma therapy

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Alveolar rhabdomyosarcoma (ARMS) is an aggressive pediatric cancer driven by the PAX3-FOXO1 fusion oncogene.
• Current treatments have limited efficacy, and targeted therapies are scarce.

Purpose of the Study:

• To evaluate poly(propylene imine) dendrimers (PPI-G4) as delivery systems for PAX3-FOXO1-specific siRNA.
• To assess the in vitro and in vivo efficacy of glycodendrimer-siRNA complexes against ARMS.

Main Methods:

• Partially glycosylated fourth-generation poly(propylene imine) dendrimers (PPI-G4) were synthesized and characterized.
• Dendriplexes of PPI-G4 and PAX3-FOXO1-specific siRNA were formed and tested for transfection efficiency and biological activity in RH30 ARMS cells.
• In vivo studies involved intratumoral administration of dendriplexes in ARMS tumor models.

Main Results:

• Glycodendrimers formed stable dendriplexes with siRNA, with PPI-M3-20 and PPI-Lac-27 showing highest transfection efficiency.
• In vitro, dendriplexes reduced RH30 cell viability and migration.
• In vivo, intratumoral administration significantly inhibited tumor growth with no short-term toxicity. siRNA_2-PPI-M3-20 demonstrated potent antitumor effects and suppressed PAX3-FOXO1 expression.
• The PPI-M3-20 carrier alone also exhibited antitumor activity.

Conclusions:

• Partially glycosylated PPI-G4 dendrimers are effective carriers for PAX3-FOXO1-specific siRNA in ARMS.
• Intratumoral administration of these glycodendrimer-siRNA complexes shows promise as a dual-action nanotherapeutic strategy for fusion-positive ARMS.
• Further research is needed to evaluate systemic delivery, metastatic models, and long-term safety.