Studies On Ad5E1A Protein Expression, Anticancer Function And Screening Related New Gene Fragments As Well As Overcoming DXR

It has been demonstrated that adenovirus 5 type E1A as a tumor suppressor gene can inhibit tumor growth and enhance the sensitivity of chemotherapy and radiotherapy. Despite the progress in the studies of E1A gene therapy research, there are still many aspects for further studies including enhancing vector targeting and specificity, regulating gene expression and so on. This prompted us to select the E1A protein for treatment of cancer in order to overcome the limitations of E1A gene therapy. Thus, we firstly constructed E1A eucaryotic expression vector (pPlC9/ElA), transformated the pichia pastoris yeast cells (GS115) and screened the high-expressing recombinant strains. The positive yeast strains were cultured in the shake flask, and induced for 3 days. The crude E1A protein was purified using two steps of column chromatography on HiTrap Q and HiTrap SP. The purified E1A protein was identified by SDS-PAGE and Western blot. E1A protein was mostly located at cellular nuclear when Chariot delivered E1A protein into cells. The analysis in vitro indicated that the E1A protein/Chariot arrested LN686 cell cycle at G2/M phase, and significantly inhibited the growth of LN686 tumor cells. The E1A protein/chariot sensitized LN686 tumor cells to apoptosis induced by various...