[EGF/PI3K signaling pathway regulates the expression of osteopontin in liver cancer HepG2 cells].
OBJECTIVE
To investigate the effect of epidermal growth factor (EGF) on the expression of osteopontin (OPN) in liver cancer HepG2 cells.


METHODS
Human liver caner cells of HepG2 line were cultured in medium without bovine serum. EGF was added. Another cells were pretreated with specific phosphatidylinositol 3 (PI3) inhibitor Wortmannin and then added with EGF. HepG2 cell were collected. RNase prote4ction assay and Western blotting were used to examine the expression of OPN in the HepG2 cells.


RESULTS
HepG2 cells cultured in the bovine serum free medium expressed very low level of OPN. EGF increased the expression of OPN mRNA and protein in a dose- and time-dependent manners. Pretreatment of Wortmannin significantly reduced the EGF-induced OPN expression.


CONCLUSIONS
EGF increases the OPN expression, possibly through PI3 signaling pathway. It is possible to block the synthesis of OPN through manipulating several target genes, thus inhibiting the metastasis of liver cancer.
Zhang
Guo-xin
GX
Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Zhao
Zhi-quan
ZQ
Lin
Xiu-wen
XW
D000730:Androstadienes / Q000494:pharmacology; D045744:Cell Line, Tumor; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism*; D053495:Osteopontin; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D012795:Sialoglycoproteins / Q000235:genetics*; D015398:Signal Transduction / Q000502:physiology*; D000077191:Wortmannin
D000730:Androstadienes; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin; D004815:Epidermal Growth Factor; D019869:Phosphatidylinositol 3-Kinases; D000077191:Wortmannin