Inhibition of cervical cancer cell growth in vitro and in vivo with dual shRNAs

Abstract

RNA interference (RNAi)-based gene silencing is widely used in laboratories for gene function studies and also holds a great promise for developing treatments for diseases. However, in vivo delivery of RNAi therapy remains a key issue. Lentiviral vectors have been employed for stable gene transfer and gene therapy and therefore are expected to deliver a stable and durable RNAi therapy. But this does not seem to be true in some disease models. Here, we showed that lentivirus delivered short-hairpin RNA (shRNA) against human papillomavirus (HPV) E6/E7 oncogenes were effective for only 2 weeks in a cervical cancer model. However, using this vector to carry two copies of the same shRNA or two shRNAs targeting at two different but closely related genes (HPV E6 and vascular endothelial growth factor) was more effective at silencing the gene targets and inhibiting cell or even tumor growth than their single shRNA counterparts. The cancer cells treated with dual shRNA were also more sensitive to chemotherapeutic drugs than single shRNA-treated cells. These results suggest that a multi-shRNA strategy may be a more attractive approach for developing an RNAi therapy for this cancer.

Oligonucleotide Applications for the Therapy and Diagnosis of Human Papillomavirus Infection

“…Although many reports have established the feasibility of this approach (Bai et al, 2006;Bousarghin et al, 2009;Gu et al, 2011), it is clear that prolonged siRNA expression may lead to dysfunction of the RNAi pathway (Tang et al, 2006) or other intracellular effects (Koivusalo et al, 2006) due to the sudden rise in p53 and pRB proteins after siRNA treatment (Sima et al, 2008). Thus, siRNA treatment has been used to enhance already established therapies for cervical cancer such as paclitaxel (Liu et al, 2009), cisplatin (Wu et al, 2011) and TRAIL (Eaton et al, 2011) with sometimes mixed results depending on the condition of p53 expression (Koivusalo et al, 2005).…”

Dendritic Cells and Lentiviral Vectors: Mapping the Way to Successful Immuno Gene Therapy

“…To improve safety, the incorporation of a suicide-gene has been proposed to eliminate cells that are transformed as a consequence of LV integration (Tseng et al 2009). Finally the discovery of RNA interference opens novel possibilities for LVs in terms of stable gene silencing (Gu et al ;Arrighi et al 2004), as well as for LV de-targeting strategies (Brown et al 2006b). Last but not least also the envelope plasmid is variable.…”

Targeted Silencing of MLL5β Inhibits Tumor Growth and Promotes Gamma-Irradiation Sensitization in HPV16/18-Associated Cervical Cancers

“…With its precise targeting of specific oncogenes, RNAi stands out as one of the most favorable cancer therapeutics in the near future. In the development of RNAi-based therapeutic strategies for HPV-related cervical cancers, efforts have been focused on the potential of direct suppression of E6 and E7 expression through their siRNAs (26,27,(29)(30)(31)(32).…”