外源性神经节苷脂GM_3对人肝癌细胞生长的抑制作用

INHIBITION OF EXOGENOUS GANGLIOSIDE GM_3 ON THE CELL GROWTH OF HUMAN HEPATOCARCINOMA CELL LINE SMMC-7721

为了解神经节苷脂（ＧＭ_３）是通过何种途径来调节细胞生长的。运用ＲＮＡ和蛋白质含量的测定及免疫组化法，结果发现：ＧＭ_３（１０ｍｇ／Ｌ）可明显抑制人肝癌细胞株ＳＭＭＣ－７７２１细胞增殖，抑制率达到２８．８１％；同时能降低细胞内平均ＲＮＡ和蛋白质含量，以ＧＭ_３处理细胞３ｄ时最为明显。ＧＭ_３能使ｃ－ｆｏｓ蛋白量在短时间内剧增，ＧＭ_３处理３０ｍｉｎ时增加了２．８５倍；而ｃ－ｍｙｃ蛋白量在短时间内明显减少，ＧＭ_３处理４５ｍｉｎ时抑制率达到８１．３１％。以上结果提示ＣＭ_３抑制细胞增殖可能与抑制ＲＮＡ、蛋白质合成及影响某些癌蛋白的表达有关。

PURPOSE Speculating the possible mechanism of how exogenous GM_3 regulates cell growth of human hepatocarcinoma cell SMMC-7721.METHODS Numbering living cells by Trypan Blue staining,Measuring RNA and protein content in cell, ABC immunocytochemical method and Image cytometry analysis. RESULTS At the concentration of 10 mg/L, GM_3 could inhibit cell proliferation significantly. After treatment with GM_3 for 4 days, the inhibitory rate reached to 28.81%. Compared with the control,the average amount of total RNA and protein declined most obviously in GM_3-treated cell for 3 days.c-fos oncoprotein concent was increased to 2.85 folds than that of control when exposing cells with GM_3 for 30 min.c-myc oncoprotein, which was known to be related to cell proliferation, could be decreased by GM_3 in very short time.When cells were incubated with GM_3 for 45 min, the inhibitory rate was up to 81.31%.CONCLUSIONS The inhibition on cell growth by GM_3 may be related to its effect on some oncoproteins expression.