The present invention belongs to the field of
genetic engineering technology, and specifically relates to a method for improving the expression level of recombinant proteins in CHO cells. The method comprises the following steps: (1) combining a
target gene recombinant vector with a
gene containing
cell cycle regulation-related genes; p18 and / or genes that regulate
cell growth aFGF The co-transgenic recombinant vector is co-transfected into CHO cells; the
gene p18 The sequence of is shown in SEQ ID NO: 1; the
gene aFGF The sequence is shown in SEQ ID NO:2; (2) co-transfecting the co-transgenic recombinant vector and the
target gene recombinant vector into CHO cells, culturing and screening to obtain a CHO
cell expression
system; (3) culturing the transient and stable transfected CHO cell lines in suspension serum-free culture to obtain the
target protein. The method of the present invention can significantly improve the expression level of the
target gene in CHO cells and achieve transient and stable high-level expression of the
target protein in CHO cells.