Background: Gene therapy is a promising approach for the treatment of
various cancers. However, most viral vectors used for this purpose carry risks, including
potential integration into the host genome.
Objective: We addressed this issue in the present study by constructing an episomal
lentiviral vector using the -interferon matrix attachment region to express the microRNA
-145(miR-145), and examining the effect of miR-145 overexpression on human
esophageal carcinomas (EC) cells. Some recent relevant patents are also discussed.
Method: Expression levels of miR-145 and the marker protein enhanced green fluorescent
protein (EGFP) in infected ECA109 and EC9706 human esophageal carcinoma
cells were detected by quantitative PCR and flow cytometry, respectively. Cell
proliferation and apoptosis were assessed by Cell Counting Kit-8 and flow cytometry, respectively. Plasmid
rescue experiments and fluorescence in situ hybridization were used to determine the episomal status
of the transfected vector.
Results: We found that EGFP and miR-145 were highly expressed in EC cells, and miR-145 overexpression
inhibited cell proliferation and induced apoptosis. Moreover, the lentiviral vector did not integrate
into the host genome, but was maintained episomally at lower copy numbers.
Conclusion: Taken together, our results demonstrate that miR-145-expressing episomal lentiviral vectors
are a promising tool for gene therapy in the treatment of EC.