Stimulation of tumor-cell growth by alpha-fetoprotein

The intracellular mechanism of alpha-fetoprotein promoting the proliferation of NIH 3T3 cells

“…Although the biological regulation of AFP on the cell growth has been extensively evaluated [8], [12][13][14] and verified by our results of the cellular prolifera- [15].…”

“…Human AFP was prepared by the method as described elsewhere [8]. Briefly, human cord blood AFP was precipitated by ammonium sulphate and passed through an anti-AFP affinity chromatography column.…”

Alpha-fetoprotein stimulated the expression of some oncogenes in human hepatocellular carcinoma Bel 7402 cells

“…When treated with AFP, the two oncogenes in Bel 7402 cells express promptly, thereafter the expression of these oncogenes dramatically declines. Previous researches had showed that AFP promoted the proliferation [1][2][3][4][5][6] and some oncogene expression of many tumor cells [15,16] . Cell growth was regulated by various factors, in which, some oncogene coding proteins have an important function in modulating growth and differentiation of the cells.…”

“…However, some studies had shown that treatment of tumor cells in vitro with high dosage of AFP (1-10 µmol/L) significantly suppressed the growth of tumor cells, because AFP positively regulated cytochrome c-mediated caspase activation, apoptosome complex formation, and low-dose cytochrome c-mediated signals [33,34] . The mechanisms for how AFP regulates the expression of these genes and signal transduction, and why it is not essential for embryonic development [24] , although it promotes the growth of some tumor cells [1][2][3][4][5][6][7][8] remain to be studied. A previous study showed that AFP could coordinate other growth factors existed in HSA and serum to promote the growth of porcine granulosa cells, and AFP could function to modulate growth factor-mediated cell proliferation during development and neoplasia [4] .…”

“…AFP always accompanies with the growth of liver cells, and it is possible that AFP may be related to the proliferation of tumor or fetal cells. Some investigations had showed that AFP could be individually synergy with other growth factors to promote the growth of many tumor or normal cells [1][2][3][4][5][6] . Alpha-fetoprotein (MW 69 ku) is a kind of biomacromolecules, and it is impossible to directly permeate the cells to regulate cell proliferation.…”