Intercellular delivery of therapeutic oligonucleotides

Area of Science:

• Molecular Biology
• Cancer Therapeutics
• Cellular Biology

Background:

• Cancer treatment strategies aim to modify gene expression to inhibit proliferation or induce cell death.
• Oligonucleotides (siRNA/miRNA) offer therapeutic potential by targeting specific genes.
• Efficient delivery of these oligonucleotides to cancer cells remains a challenge.

Purpose of the Study:

• To investigate human mesenchymal stem cells (hMSCs) as a delivery vehicle for therapeutic oligonucleotides.
• To explore gap junction and vesicular/exosomal pathways for intercellular oligonucleotide transfer from hMSCs to cancer cells.
• To evaluate the efficacy of delivered oligonucleotides in reducing cancer cell proliferation and inducing cell death.

Main Methods:

• hMSCs were loaded with synthetic oligonucleotides (AllStars HS Cell Death siRNA and miR-16 mimic).
• Oligonucleotide delivery was assessed in prostate (PC3), pancreatic (PANC1), and cervical (HeLa) cancer cell lines.
• Gap junction-mediated delivery was investigated using connexin 43 (Cx43) expressing and deficient cancer cells, alongside CRISPR/Cas9 gene editing.

Main Results:

• Co-culture with oligonucleotide-loaded hMSCs induced significant cancer cell death or proliferation reduction in Cx43-expressing cancer cells.
• Inhibition of gap junction pathways led to reduced, but still significant, anti-cancer effects, indicating the role of both gap junction and vesicular transport.
• Delivered oligonucleotides effectively reduced cancer cell proliferation and/or induced cell death in target cancer cell lines.

Conclusions:

• hMSC-based cellular delivery is an effective method for transferring therapeutic oligonucleotides to cancer cells.
• Both gap junction and vesicular/exosomal pathways contribute to intercellular oligonucleotide delivery from hMSCs.
• This approach shows significant potential for reducing tumor cell growth and warrants further investigation as a cancer therapy.