M. Zahn-zabal et al., Development of stable cell lines for production or regulated expression using matrix attachment regions, J BIOTECH, 87(1), 2001, pp. 29-42
One of the major hurdles of isolating stable, inducible or constitutive hig
h-level producer cell lines is the time-consuming selection procedure. Give
n the variation in the expression levels of the same construct in individua
l clones, hundreds of clones must be isolated and tested to identify one or
more with the desired characteristics. Various boundary elements (BEs), ma
trix attachment regions, and locus control regions (LCRs) were screened for
their ability to augment the expression of heterologous genes in Chinese h
amster ovary (CHO) cells. Of the chromatin elements assayed, the chicken ly
sozyme matrix-attachment region (MAR) was the only element to significantly
increase stable reporter expression. We found that the use of the MAR incr
eases the proportion of high-producing clones. thus reducing the number of
clones that need to be screened. These benefits are observed both for const
ructs with MARs flanking the transgene expression cassette, as well as when
constructs are co-transfected with the MAR on a separate plasmid. Moreover
, the MAR was co-transfected with a multicomponent regulatable beta -galact
osidase expression system in C2C12 cells and several clones exhibiting regu
lated expression were identified. Hence, MARs are useful in the development
of stable cell lines for production or regulated expression. (C) 2001 Else
vier Science B.V. All rights reserved.