Synthesis of folate-labeled siRNAs from a folate derivative phosphoramidite
Lidya Salim1, Jean-Paul Desaulniers1
1Ontario Tech University, Faculty of Science, 2000 Simcoe Street North, Oshawa, ON L1G 0C5, Canada. Jean-Paul.Desaulniers@ontariotechu.ca.
Abstract:
With the recent success of GalNAc and the need for extra-hepatic RNAi delivery systems, other receptor-targeting ligands, like folate, have gained increased attention. The folate receptor is an important molecular target in cancer research, as it is overexpressed on numerous tumours while having limited expression in non-malignant tissues. Despite the promise of folate conjugation as a delivery platform in cancer therapeutics, its application in RNAi has been limited by sophisticated, and often expensive, chemistry. Here, we report a straightforward and cost-effective strategy to synthesize a novel folate derivative phosphoramidite for siRNA incorporation. In the absence of a transfection carrier, these siRNAs were selectively taken up by folate receptor-expressing cancer cell lines and displayed potent gene-silencing activity.
Insights
Researchers developed a new, cost-effective method to create folate-conjugated small interfering RNAs (siRNAs) for cancer therapy. These siRNAs target folate receptors on cancer cells, showing potent gene silencing without needing transfection carriers.
Area of Science:
- Biochemistry
- Molecular Biology
- Cancer Therapeutics
Background:
- RNA interference (RNAi) requires effective delivery systems for therapeutic applications.
- N-acetylgalactosamine (GalNAc) has shown success in liver-targeted RNAi delivery.
- Extra-hepatic delivery systems are needed, with folate receptor (FR) emerging as a promising target.
Purpose of the Study:
- To develop a straightforward and cost-effective strategy for synthesizing folate-conjugated small interfering RNAs (siRNAs).
- To evaluate the targeted delivery and gene-silencing efficacy of these novel siRNAs in cancer cells.
- To overcome limitations in current folate-based RNAi delivery chemistry.
Main Methods:
- Synthesis of a novel folate derivative phosphoramidite for siRNA incorporation.
- Incorporation of the folate derivative into siRNA sequences.
- In vitro assessment of cellular uptake and gene silencing in folate receptor-expressing cancer cell lines.
- Evaluation of delivery efficacy in the absence of transfection carriers.
Main Results:
- A facile and economical method for creating folate-conjugated siRNAs was established.
- The synthesized siRNAs demonstrated selective uptake by cancer cells overexpressing folate receptors.
- Potent gene-silencing activity was observed in target cancer cells without the need for transfection agents.
- This approach bypasses complex and expensive chemical synthesis methods.
Conclusions:
- The developed folate-phosphoramidite strategy offers a practical and affordable platform for RNAi delivery.
- Targeted delivery to FR-positive cancer cells is achievable, enabling potent gene silencing.
- This advancement holds potential for developing novel, carrier-free RNAi-based cancer therapeutics.
Related Concept Videos
02:30siRNA - Small Interfering RNAs
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
01:23RNA Interference
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
02:30Small interfering RNAs (siRNA)