Effective Gene Silencing Mediated by Polypeptide Nanoparticles LAH4-L1-siMDR1 in Multi-Drug Resistant Human Breast...

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cancer Therapeutics

Background:

• Multi-drug resistance (MDR) significantly hinders effective cancer treatment.
• RNA interference (RNAi) offers a strategy to reverse MDR, but effective in vivo delivery of small interfering RNA (siRNA) remains a challenge.
• Cationic peptides are promising for gene delivery due to their biocompatibility and safety.

Purpose of the Study:

• To develop self-assembled polypeptide nanoparticles (PNLS) loaded with siMDR1 for overcoming multi-drug resistance in human breast cancer.
• To investigate the cellular uptake pathways and internalization mechanisms of PNLS.
• To evaluate the in vitro and in vivo efficacy of PNLS in combination with Paclitaxel (PTX) for breast cancer treatment.

Main Methods:

• Preparation and characterization of LAH4-L1-siRNA (PNLS) nanoparticles.
• In vitro studies using human breast cancer MCF-7/ADR cells to assess gene silencing efficiency and cellular uptake.
• In vivo studies in tumor-bearing nude mice to evaluate biodistribution, tumor targeting, and therapeutic efficacy in combination with PTX.

Main Results:

• PNLS demonstrated enhanced cellular uptake of siRNA and high gene silencing efficiency due to the peptide's cationic charges and alpha-helical conformation.
• In vivo biodistribution studies showed higher tumor-targeted delivery of PNLS.
• Combined PNLS and PTX treatment exhibited significant antitumor effects and effective MDR1 gene silencing in vivo.

Conclusions:

• PNLS nanoparticles are effective for targeted gene knockdown in vivo.
• This PNLS system holds significant potential as a novel therapeutic strategy for overcoming multi-drug resistance in breast cancer treatment.