Title : Investigation of the HPV 53 E2 protein as a potential treatment for cervical cancer
Abstract:
Human papilloma virus (HPV) types 16 and 18 are the most common cause of cervical cancer where integration-associated loss-of-function of the viral E2 protein promotes malignant progression. HPV type 53 is a low-risk virus which does not promote malignant changes and the current study aims to test whether the HPV53 E2 protein can replace the lost function of high-risk E2 in the HPV18 positive cervical carcinoma HeLa cell line. HeLa cells were transiently transfected with either HPV18 or HPV 53 E2 open reading frames (ORF’s) cloned into the mammalian expression vector pcDNA in combination with the GFP normalisation vector pVITRO GFP. Transfection efficiency, cell viability, apoptosis and differences in cell cycle were determined by use of an image cytometer (NC3000, Chemometec) and expression of E2 mRNA was analysed by RT-PCR. Ectopic expression of E2 mRNA’s was confirmed and apoptosis was shown to be significantly higher in cells transfected with HPV53 E2 than with HPV18 E2. Furthermore the former also showed marked differences in the percentage of cells at different stages of the cell cycle. These data demonstrate that the HPV53 E2 protein has the ability to replace the lost function of the endogenous HPV18 E2 protein which is known to be disrupted by integration of the virus into the host genome in HeLa cells.
