1-1 Namiki, Tsukuba, Ibaraki
305-0044, Japan/Cell-Materials Interaction Group, Biomaterials Unit, International
Center for Materials Nanoarchitectonics, National Institute for
Materials Science, Tsukuba, Ibaraki 305-8572, Japan/Biomaterials and
Tissue Engineering, Graduate School of Comprehensive Human Science,
University of Tsukuba.
Recently, many biopharmaceuticals have been developed such as cytokines, growth factors, and antibodies.
These recombinant proteins are mostly expressed by CHO cells. However, the culture medium of CHO cells requires the
addition of serum, which can contain unknown biological substances such as viruses, or requires the addition of expensive
growth factors. To avoid the risks of biological ingredients and to decrease the cost of biopharmaceutical production, we
developed a non-protein and lipid medium adopted (NPLAd) CHO cell line using the adapted culture method. Our results
indicated that autocrine EGF production and insulin addition are essential for NPLAd CHO cell growth. However, the rate
of cell proliferation of NPLAd CHO cells was decreased compared with original CHO-K1 cells. The proliferation of
NPLAd CHO cells was improved by GM3 addition, suggesting increased signaling efficiency of autocrine factors. No difference
was found in the growth rate between original CHO-K1 and NPLAd CHO cells supplemented with insulin and
GM3. The productivity of recombinant protein in NPLAd CHO cells was verified using secreting luciferase reporter system.
As a result, luciferase activity in NPLAd CHO cells showed more than three times higher than in the original CHOK1
cells. The results suggested that this cell line could be useful for biopharmaceutical recombinant protein.