Inhibition of
Proliferation and Expression of N-ras in Hepatoma
Cells by Antioxidation Treatment
LIU Shan Lin*, SHI Dong-Yun, PAN Xi-Hua, SHEN
Zong-Hou
( Department of Biochemistry, Medical Center of Fudan University, Shanghai 200032,
China )
Abstract Kunming
mice inoculated with hepatoma cell (H22) suspension subcutaneously at their
right axilla were administered orally with antioxidants such as vitamine
E,β-carotene, glutamine, kappa-selenocarrageenan and polysaccharide-peptide of coriolus
(PSP) solution. It was found that the inoculated hepatoma growth was suppressed
to various extents. The two kinds of polysaccharide antioxidants improved
non-specific immunity, enhanced the nitrogen monoxide (NO) content in plasma
and strengthened the inhibition of hepatoma. Above antioxidants added in the
culture of 7721 human hepatoma cells inhibited the cell proliferation and
inducedits apoptosis. Meanwhile, the activity of glutathione peroxidase
(GSH-Px) in the plasma of mice increased and the content of malondialdehyde
(MDA) decreased. H2O2 in low concentration improved the
cancer cell proliferation and inhanced the expression of Mn-SOD、c-fos and c-jun, but led
to cells apoptosis or necrosis in high concentration. The mechanism of
antioxidants inhibiting tumor growth and improving cancer cells apoptosis might
be that, on the one hand, the antioxidants blocked the free radicals signal
transduction on cancer cells proliferation, and on the other hand, they
improved the release of NO through enhancing the non specific immunity, so
inhibiting the cancer cells proliferation directly.
Key words antioxidant；apoptosis；NO；human hepatoma cell strain；N-ras
*Corresponding author：Tel,86-21-64041900-2698；e-mail,[email protected]