The utility of tumor-specifically internalizing peptides for targeted siRNA delivery into human solid tumors

Area of Science:

• Oncology
• Molecular Biology
• Drug Delivery

Background:

• Ribonucleotide reductase (hRRM1/hRRM2) is crucial for DNA replication and tumorigenesis.
• Anti-hRRM2 small interfering RNA (siRNA) targets hRRM2 mRNA, showing therapeutic potential in early trials.
• HN-1 is a peptide that specifically targets and internalizes into human head and neck squamous cell carcinoma.

Purpose of the Study:

• To develop a targeted delivery system for anti-hRRM2 siRNA using the HN-1 peptide.
• To evaluate the efficacy of the peptide-siRNA conjugate in suppressing hRRM2 expression in cancer cells.

Main Methods:

• Synthesis of a peptide-siRNA conjugate using HN-1 and RNase-resistant anti-hRRM2 siRNA.
• Monitoring peptide internalization via fluorescence microscopy.
• Assessing hRRM2 expression levels using western blot analysis.

Main Results:

• The modified HN-1 peptide (HN-1(TYR)) was successfully internalized by human head and neck and breast cancer cells.
• The HN-1(TYR)-anti-hRRM2 siRNA(R) conjugate maintained the properties of both components.
• Treatment with the conjugate led to partial suppression of endogenous hRRM2 in human breast cancer cells.

Conclusions:

• Tumor-specifically internalizing peptides are effective for targeted delivery of siRNA into human cancer cells.
• This strategy holds promise for developing novel cancer therapeutics targeting specific gene expression.