Targeting Cancer Cells Using LNA-Modified Aptamer-siRNA Chimeras

Area of Science:

• Biotechnology and Nanomedicine
• Molecular Biology and Genetics
• Oncology Therapeutics

Background:

• Aptamers are utilized in targeted cancer therapeutics, often chimerized with drugs, nanoparticles, or small interfering RNA (siRNA).
• Aptamer-chimerized siRNA enhances cellular uptake and therapeutic availability by overcoming non-specific delivery challenges.
• EpCAM RNA aptamer (EpApt) possesses structural properties suitable for siRNA chimerization, targeting cancer cells.

Purpose of the Study:

• To develop and evaluate Locked Nucleic Acid (LNA)-modified chimeric aptamers for targeted delivery of siRNA against oncogenes.
• To investigate the efficacy of EpCAM aptamer-siRNA chimeras targeting stathmin and survivin in retinoblastoma (RB) and breast cancer models.

Main Methods:

• Chimerization of EpCAM aptamer with siRNA targeting stathmin and survivin, incorporating LNA modifications.
• Assessment of chimeric aptamer stability and cellular internalization in RB (WERI-Rb1) and breast cancer (MDAMB453) cell lines.
• Evaluation of siRNA generation using recombinant dicer enzyme, followed by quantitative PCR and immunofluorescence for gene silencing analysis.

Main Results:

• LNA-modified chimeric aptamers demonstrated stability up to 96 hours and efficient internalization into target cancer cells.
• In vitro studies confirmed the generation of siRNA from chimeric constructs and significant silencing of stathmin and survivin.
• Chimeric aptamer-siRNA constructs effectively inhibited the proliferation of breast cancer cells.

Conclusions:

• LNA-modified aptamer-based siRNA delivery systems facilitate targeted cancer cell uptake and gene silencing.
• These chimeric constructs show significant potential for developing targeted cancer therapeutics, warranting further investigation in preclinical animal models.