Transcriptional gene silencing of HPV16 E6/E7 induces growth inhibition via apoptosis in vitro and in vivo.

Transcriptional silencing of HPV oncogenes using short interfering RNA (siRNA) blocks E6/E7 expression. Our objective was to estimate the effective value of E6/E7 specific siRNA-induced transcriptional gene silencing as a potential therapeutic strategy for cervical cancer. In vitro studies were performed by employing two categories of siRNA targeting promoter of E6/E7 gene and E7 transcript, respectively, and inhibitory effect of both siRNAs was further observed in vitro and on xenograft in BALB/c mice that were inoculated with siRNA transfected SiHa cells and parental SiHa cells followed by siRNA intratumoral injection in vivo. Tumor volume and growth curves were assessed. Furthermore, cellular proliferation and apoptosis of inoculated tumors were determined by immunohistochemistry staining and TUNEL assay. The two most active siRNA sequences specifically knockdown E6/E7 expressions at mRNA level in HPV16 positive Siha cells, increased p53 and decreased p16 expressions at protein level, inhibited cell proliferation, and induced cell apoptosis in vitro. Furthermore, both siRNAs effectively inhibited tumor formation and growth no matter in mice with siRNA transfected cells in vitro or with siRNA intratumoral injection in vivo. TUNEL staining and FCM assay consistently showed that tumor retardation was through induction of cellular apoptosis. RNAi targeting the promoter of HPV16 E6/E7 acts effectively in vitro and in vivo, especially through intratumoral delivery, and may be a candidate therapeutic strategy for cervical cancer.

Zhou J ，Peng C ，Li B ，Wang F ，Zhou C ，Hong D ，Ye F ，Cheng X ，Lü W ，Xie X ... -  《-》

Inhibition of cervical cancer cell growth in vitro and in vivo by lentiviral-vector mediated shRNA targeting the common promoter of HPV16 E6 and E7 oncogenes.

Deregulated expression of high-risk human papillomavirus oncogenes (E6 and E7) is a pivotal event for pathogenesis and progression in cervical cancer. Both viral oncogenes are therefore regarded as ideal therapeutic targets. Small interfering RNAs (siRNA) or double-stranded RNAs can knock down target genes effectively through siRNA-induced transcriptional gene silencing (TGS). Here, we established lentiviral-vector mediated shRNA (LV-shRNA) targeting common promoter of HPV16 E6/E7 and targeting E6 transcript, transduced the lentiviral construct into cervical HPV16-positive cell lines Siha and Caski, then selected and established stably transduced monoclonal cell lines. The results showed that LV-shRNA targeting promoter, as well as targeting E6 transcript, effectively knocked down E6 and E7 expression, resulted in accumulation of p53 and pRB protein and decrease of MCM7 and p16 protein, and consequently remarkably reduced the abilities of proliferation and invasiveness of cervical cancers cells in vitro. Then we inoculated subcutaneously those monoclonal cells into nude mice to establish the transplanted tumor animal models, and found dramatically inhibited tumorigenesis and growth, as well as prolonged survival time of mice incubated by cells with LV-shRNA targeting promoter and E6 transcript. Our results may provide evidence for application of LV-shRNA targeting HR-HPV key oncogenes, as a new treatment strategy, in cervical and other HPV-associated cancer therapy.

Zhou J ，Li B ，Peng C ，Wang F ，Fu Z ，Zhou C ，Hong D ，Ye F ，Lü W ，Xie X ... -  《-》

Gene silencing of HPV16 E6/E7 induced by promoter-targeting siRNA in SiHa cells.

Hong D ，Lu W ，Ye F ，Hu Y ，Xie X ... -  《-》

Gene silencing with siRNA targeting E6/E7 as a therapeutic intervention against head and neck cancer-containing HPV16 cell lines.

Adhim Z ，Otsuki N ，Kitamoto J ，Morishita N ，Kawabata M ，Shirakawa T ，Nibu K ... -  《-》

HPV-16 E6/E7 promotes cell migration and invasion in cervical cancer via regulating cadherin switch in vitro and in vivo.

Hu D ，Zhou J ，Wang F ，Shi H ，Li Y ，Li B ... -  《-》