The effect of docosahexaenoic acid and 5-fluorouracil on human gastric cancer cell lines and the expression of bcl-2, bcl 2l12 and bax / 中华普通外科杂志

ABSTRACT

Objective To evaluate the growth inhibition of human gastric carcinoma cell lines SGC 7901 in vitro and the expression of bcl-2, bcl 2l12 and bax with docosahexaenoic acid (DHA) and 5-fluorouracil (5-FU). Methods The effect of DHA and 5-FU was measured by trypan blue, and the interaction between two agents was judged by combination index (CI). Cells were observed by inverted microscope. Flow cytometry was used for analysis of apoptosis by PI staining and Annexin-V/PI. RT-PCR was used to analyze the levels of bcl-2, bcl 2l12 and bax mRNA. Results DHA significantly inhibited the growth of SGC 7901 cells in a dose- and time-dependent way ( P < 0. 05 ), the IC50 of 24 h and 48 h was 67. 81 μg/ml and 45.76 μg/ml, and a strong synergism was found in the combination of DHA and 5-FU (CI < 1 ,P <0. 01 ). Treated by DHA and 5-FU for 48 h, cells became sparse under inverted microscope. DHA or 5-FU was able to induce apoptosis and the effect became even more significant by the combination of DHA and 5-FU. Cells were holted in phase of G01/G1 and S. RT-PCR showed that DHA or 5-FU down-regulated the expression of bcl-2 and bcl 2l12 mRNA, while bax mRNA expression was not downregnlated. Conclusions DHA could inhibit the growth of gastric carcinoma cells, DHA and 5-FU had synergetic effect in the inhibition of the cells growth and blockage of the cell cycles possibly by down-regulating the expression of bcl-2 and bcl 2l12.