ABSTRACT
Objective To investigate the expression of transcription factor Oct 4 in gastric carcinoma and its effects on gastric cancer cell proliferation and apoptosis after Oct 4 gene interfered by lentivirus vector.Methods Real time PCR and Western blot were used to observe the expression of Oct 4 in different differentiated gastric cancer cell lines.Gastric cancer cell lines with high expression of Oct 4 was cultured and infected by siRNA-Oct 4-lentivirus vector.Cell proliferation and apoptosis were observed after Oct 4 gene was interfered.Results Oct 4 was highly expressed in poorly and moderately differentiated gastric cancer cells.Gene interfered with siRNA inhibits the expression of Oct 4 in gastric cancer cells and show significant effects on cell proliferation and mobility as well as apoptosis after down-regulation of Oct 4.Condusions Oct 4 expression is in close relationship with gastric cancer cell proliferation and invasive ability.
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.