Comparison of TFs versus RNAi technologies to modulate gene expression
| TFs | RNAi & Antisense | |
|---|---|---|
| Vector-based delivery | Transient | Transient |
| Retroviral | Retroviral | |
| Adenoviral | Adenoviral | |
| Lentiviral | Lentiviral | |
| Direct delivery | Protein transduction | Lipids or electroporation |
| Optimal expression levels | Low, pol II promoters | High, pol III or pol II promoters |
| Chemical synthesis | Yes but not practical | Yes |
| Regulation of expression | Yes, by inducible promoters and post-transcriptional activation of TFs | Yes, by inducible promoters |
| Specificity | Limited by number and quality of ZF-DNA contacts | Limited by base pairing and biochemistry |
| Limited by accessibility due to endogenous proteins | Limited by accessibility due to endogenous proteins and RNA structure | |
| Gene regulation | ||
| Gain of function | Yes, with activator domains | No |
| Loss of function | Yes, with repressor domains | Yes |