title: Development of Genetically Modified Chinese Hamster Ovary Host Cells for the Enhancement of Recombinant Tissue Plasminogen Activator Expression.
abstract: BACKGROUND
  Chinese hamster ovary (CHO) cells are the most commonly used host system for the expression of high quality recombinant proteins. However, the development of stable, high-yielding CHO cell lines is a major bottleneck in the industrial manufacturing of therapeutic proteins. Therefore, different strategies such as the generation of more efficient expression vectors and establishment of genetically engineered host cells have been employed to increase the efficiency of cell line development. In order to examine the possibility of generating improved CHO host cells, cell line engineering approaches were developed based on ceramide transfer protein (CERT), and X-box binding protein 1s (XBP1s).
  
  
  METHODS
  CHO cells were transfected with CERT S132A, a mutant variant of CERT which is resistant to phosphorylation, or XBP1s expression plasmids, and then stable cell pools were generated. Transient expression of t-PA was examined in engineered cell pools in comparison to un-modified CHO host cells.
  
  
  RESULTS
  Overexpression of CERT S132A led to the enhancement of recombinant tissue plasminogen activator (t-PA) expression in transient expression by 50%. On the other hand, it was observed that the ectopic expression of the XBP1s, did not improve the t-PA expression level.
  
  
  CONCLUSIONS
  The results obtained in this study indicate successful development of the improved CHO host cells through CERT S132A overexpression.
authors.affiliation: Department of Tissue engineering, Faculty of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, 1985717443, Iran.
authors.forename: Azam
authors.initials: A
authors.lastname: Rahimpour
authors.affiliation: Department of Virology, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Roshanak
authors.initials: R
authors.lastname: Ahani
authors.affiliation: Department of Biochemistry, Payame Noor University, Tehran, 1659639884, Iran.
authors.forename: Azita
authors.initials: A
authors.lastname: Najaei
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Adeli
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Barkhordari
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Mahboudi
keywords: CHO cells; cell engineering; tissue plasminogen activator