Osteopontin regulation by protein kinase B in HepG2 cells / 中华消化杂志

ABSTRACT

Objective It has been unclear how osteopontin, one of metastasis-associated genes, could be regulated in HepG2 cells. The aim of this study was to investigate the effect of protein kinase B(Akt) on the expression of osteopontin in HepG2 cells, and to explore the relationship between Akt and osteopontin expression. Methods HepG2 cells were transfected with constitutively active Akt and dominant negative Akt by lipofectmine, and transfectants were confirmed using Western blot for Akt. Osteopontin expression was detected by Northern blot and Western blot. Results HepG2 cells were successfully transfected with Akt genes including constitutively active Akt and dominant negative Akt, and overexpression of exozegenes Akt could be detected in HepG2 cells by Western blot. Using Northern blot and Western blot, we found that Akt gene regulated osteopontin expression in RNA level and protein level. In serum-free condition, HepG2 cells constitutively expressed low levels of osteopontin. Transfection of constitutively active Akt increased osteopontin mRNA and protein expression. Transfection of dominant negative Akt decreased osteopontin expression.Conclusions The fact that osteopontin gene expression can be regulated by Akt indicates that osteopontin synthesis can be blocked by inactivation of Akt gene and that metastasis of liver cancer might be inhibited by this intervention.