Construction of Tip60-encoding plasmid and the effect of Tip60 on the expression of HPV18 genes in HeLa cells

Abstract

Tip60 is a cellular protein belonging to the MYST family of histone acetyl transferase (HAT). It functions in DNA damage repair and transcriptional regulation in eukaryotic cells. Human papillomavirus (HPV) is a causative factor of cervical cancer which threatens the health of females worldwide. In the present study, the encoding sequence of Tip60 was amplified with the RT-PCR method and cloned into expressing vector pcDNA-tag2B to generate a Tip60-expressing plasmid. Subsequently, the effect of Tip60 on HPV18 E6 E7 genes was investigated in HeLa cells which carrying the integrated HPV18 DNA fragments. Results of plasmid sequencing confirmed the correct cloning of Tip60 plasmid and then the efficient overexpression of Tip60 in HeLa cells was demonstrated with RT-qPCR and Western-blotting. With Tip60 overexpression, the expression of HPV18 E6 and E7 genes was repressed significantly. Furthermore, co-overexpression of Tip60 and EP400, a chromatin remodeling factor, in HeLa cells synergistically suppressed the expression of HPV18 E6-E7. Findings in this study would help to reveal the roles of Tip60 in the regulation of viral oncogenes and inspire targeted therapy of cervical cancer.