Enhanced Cancer Theranostics with Self-Assembled, Multilabeled siRNAs

Area of Science:

• Bioconjugation Chemistry
• Molecular Biology
• Nanotechnology

Background:

• Theranostics integrates therapy and diagnostics for improved disease treatment, particularly in oncology.
• RNA interference (RNAi) using small interfering RNA (siRNA) is a key strategy for gene silencing therapies.

Purpose of the Study:

• To develop and characterize fluorescently labeled siRNA nanostructures for theranostic applications.
• To evaluate the efficacy of these constructs in monitoring cellular processes and inducing cancer cell death.

Main Methods:

• Covalent attachment of fluorescein isothiocyanate (FITC) labels to linear, V- and Y-shaped siRNA nanostructures via solid-phase bioconjugation.
• Assessment of siRNA structural integrity, hybrid stability, and RNAi activity post-labeling.
• Evaluation of mRNA knockdown, cell death induction, and fluorescent signaling in a prostate cancer cell line.

Main Results:

• FITC-labeled siRNAs, including higher-order V- and Y-shapes, retained structural integrity and RNAi activity.
• siRNA constructs achieved efficient mRNA knockdown (50-90%) and significant cancer cell death (20-95%).
• Y-shaped siRNA with three FITC probes showed enhanced fluorescence signaling while maintaining therapeutic efficacy.

Conclusions:

• Multilabeled FITC-siRNA constructs exhibit theranostic potential for cancer gene therapy.
• These labeled nanostructures enable effective monitoring of cellular uptake and biological activity.
• The study demonstrates the feasibility of using advanced siRNA designs for targeted cancer treatment.