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Phage-mediated Delivery of Targeted sRNA Constructs to Knock Down Gene Expression in E. coli
Published on: March 20, 2016
Selective cyclooxygenase-2 silencing mediated by engineered E. coli and RNA interference induces anti-tumour effects
A Strillacci1, C Griffoni, G Lazzarini
1Department of Experimental Biology, University of Bologna, via Selmi 3, Bologna 40126, Italy. antonio.strillacci@unibo.it
Background:
Cyclooxygenase-2 (COX-2) overexpression is strongly associated with colorectal tumourigenesis. It has been demonstrated that the chronic use of non-steroidal anti-inflammatory drugs (COX inhibitors) partially protects patients from colorectal cancer (CRC) development and progression but induces severe cardiovascular side effects. New strategies for selective COX-2 blockade are required.
Methods:
We developed an improved technique, based on RNA interference (RNAi), to gain a selective COX-2 silencing in CRC cells by a tumour-dependent expression of anti-COX-2 short-hairpin RNA (shCOX-2). Anti-COX-2 shRNA-expressing vectors were delivered in CRC cells (in vitro) and in colon tissues (ex vivo) using engineered Escherichia coli strains, capable of invading tumour cells (InvColi).
Results:
A highly tumour-dependent shCOX-2 expression and a significant COX-2 silencing were observed in CRC cells following InvColi strain infection. Cyclooxygenase-2 silencing was associated with a strong reduction in both proliferative and invasive behaviour of tumour cells. We also demonstrated a pivotal role of COX-2 overexpression for the survival of CRC cells after bacterial infection. Moreover, COX-2 silencing was achieved ex vivo by infecting colon tissue samples with InvColi strains, leading to anti-inflammatory and anti-tumour effects.
Conclusion:
Our RNAi/InvColi-mediated approach offers a promising tool for a highly selective COX-2 blockade in vitro and in vivo.
Insights
This study introduces a novel RNA interference (RNAi) method using engineered bacteria to selectively silence cyclooxygenase-2 (COX-2) in colorectal cancer cells, reducing tumor growth and invasion.
Area of Science:
- Molecular biology
- Cancer research
- Microbial therapeutics
Background:
- Cyclooxygenase-2 (COX-2) overexpression is linked to colorectal cancer development.
- Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit COX-2 but cause cardiovascular side effects.
- Selective COX-2 inhibition strategies are needed for colorectal cancer (CRC) treatment.
Purpose of the Study:
- To develop a selective COX-2 blockade method using RNA interference (RNAi) and engineered bacteria.
- To investigate tumor-dependent expression of anti-COX-2 short-hairpin RNA (shCOX-2) in CRC cells.
- To evaluate the therapeutic potential of this approach in vitro and ex vivo.
Main Methods:
- Engineered Escherichia coli (InvColi) strains delivered anti-COX-2 shRNA (shCOX-2) into CRC cells and colon tissues.
- Utilized RNA interference (RNAi) for targeted gene silencing.
- Assessed COX-2 silencing, cell proliferation, invasion, and survival post-infection.
Main Results:
- Achieved tumor-dependent shCOX-2 expression and significant COX-2 silencing in CRC cells.
- Demonstrated reduced tumor cell proliferation and invasion.
- Confirmed COX-2's role in CRC cell survival and showed ex vivo anti-inflammatory and anti-tumor effects.
Conclusions:
- The RNAi/InvColi approach provides a promising method for selective COX-2 blockade.
- This strategy offers potential for targeted colorectal cancer therapy with reduced side effects.
- Further research is warranted to explore in vivo applications.
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