Expression, Purification Of Recombinant Human Interferonβ In Escherichia Coli And Its Induction Of Autophagy In Malignant Gliomas

Interferon beta is a type-I interferon exhibiting multiple activities in anti-virus, anti-tumor and immunomodulatory effects. Currently, interferon beta is mainly applied to the clinical treatment of multiple sclerosis (MS), which is the only biological medicine authorized by FDA in MS and has the best curative effect. In addition, because of its anti-tumor’s activities, interferon beta is also frequently used in the treatment of malignant tumors like glioma and pancreatic cancer.Interferon beta has a short half-life period (only4to6hours), in order to sustain the effective blood concentration in vivo, it needs to be administered for multiple times or utilizing the protein long-acting modified technology to elongate its half-life period.We constructed the expression vector of interferon beta by molecular cloning; transformed this expression vector into E.coli and induced the expression of the protein by IPTG; purified the protein through molecular sieve. Meanwhile, we used activated PSA to modifying interferon beta, but the modified products are not stable and easily precipitate. So we constructed the expression vector of interferon beta-XTEN via molecular cloning, transformed into E.Coli and induced the expression of the protein by IPTG, but we should still do some research in purification of recombined protein.Interferon beta could induce autophagy in U251MG and U87MG human glioma cells; Suppression of autophagy by3-MA, chloroquine and RNA interference could enhance the interferon beta-induced growth inhibition and cell apoptosis; inhibition of cell apoptosis could impair the interferon beta-induced autophagy in human glioma cells; In addition, interferon beta induced autophagy is related with the inhibition of Akt/mTOR signaling pathway and activation of Erk signaling pathway.On one hand, the study first expressed and purified interferon beta, trying to preliminarily investigate the long term modification of polysialic acid and new polypeptides, providing study foundation for elongating half life period of interferon beta in vivo; on the other hand, based on interferon beta inhibiting malignant glioma, this study explored the function and molecular mechanisms of autophagy in the process of interferon beta treating glioma, providing theoretical basis for enhancing the therapeutic effect of interferon beta.