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Updated: Mar 25, 2026
An Orthotopic Bladder Tumor Model and the Evaluation of Intravesical saRNA Treatment
Published on: July 28, 2012
PLK-1 Silencing in Bladder Cancer by siRNA Delivered With Exosomes
Kristin A Greco1, Carrie A Franzen1, Kimberly E Foreman2
1Department of Urology, Loyola University Chicago, Maywood, IL.
Objective:
To use exosomes as a vector to deliver small interfering ribonucleic acid (siRNA) to silence the polo-like kinase 1 (PLK-1) gene in bladder cancer cells.
Materials And Methods:
Exosomes were isolated from both human embryonic kidney 293 (HEK293) cell and mesenchymal stem cell (MSC) conditioned media. Fluorescently labeled exosomes were co-cultured with bladder cancer and normal epithelial cells and uptake was quantified by image cytometry. PLK-1 siRNA and negative control siRNA were loaded into HEK293 and MSC exosomes using electroporation. An invasive bladder cancer cell line (UMUC3) was co-cultured with the electroporated exosomes. Quantitative reverse transcriptase polymerase chain reaction was performed. Protein analysis was performed by Western blot. Annexin V staining and MTT assays were used to investigate effects on apoptosis and viability.
Results:
Bladder cancer cell lines internalize an increased percentage of HEK293 exosomes when compared to normal bladder epithelial cells. Treatment of UMUC3 cells with exosomes electroporated with PLK-1 siRNA achieved successful knockdown of PLK-1 mRNA and protein when compared to cells treated with negative control exosomes.
Conclusion:
HEK293 and MSC exosomes were effectively used as a delivery vector to transport PLK-1 siRNA to bladder cancer cells in vitro, resulting in selective gene silencing of PLK-1. The use of exosomes as a delivery vector for potential intravesical therapy is attractive.
Insights
Exosomes effectively delivered small interfering ribonucleic acid (siRNA) to bladder cancer cells, silencing the polo-like kinase 1 (PLK-1) gene. This demonstrates exosomes as a promising vector for potential intravesical therapy.
Area of Science:
- Biotechnology
- Molecular Biology
- Cancer Research
Background:
- Exosomes are nanoscale vesicles involved in intercellular communication.
- Targeted delivery of therapeutic agents to cancer cells remains a challenge.
- Polo-like kinase 1 (PLK-1) is a key regulator of cell division, often overexpressed in cancers.
Purpose of the Study:
- To investigate the potential of exosomes as a delivery vector for small interfering ribonucleic acid (siRNA) targeting the PLK-1 gene in bladder cancer.
- To evaluate the efficiency and specificity of exosome-mediated gene silencing in bladder cancer cells.
Main Methods:
- Exosomes were isolated from human embryonic kidney 293 (HEK293) cells and mesenchymal stem cells (MSCs).
- PLK-1 siRNA was loaded into exosomes via electroporation.
- Uptake by bladder cancer cells and gene silencing effects were assessed using quantitative reverse transcriptase polymerase chain reaction and Western blot.
Main Results:
- Bladder cancer cells showed increased uptake of exosomes compared to normal cells.
- Exosomes loaded with PLK-1 siRNA successfully reduced PLK-1 mRNA and protein levels in bladder cancer cells.
- No significant impact on apoptosis or viability was observed with control exosomes.
Conclusions:
- HEK293 and MSC exosomes serve as effective vectors for delivering PLK-1 siRNA to bladder cancer cells.
- Exosome-mediated delivery resulted in selective gene silencing of PLK-1 in vitro.
- Exosomes represent a promising platform for developing intravesical therapies for bladder cancer.
