Effect of cis-9 trans-11-conjugated linoleic acid on cell cycle of gastric adenocarcinoma cell line (SGC-7901)

摘要

AIM: To determine the effect of cis-9, trans-11-conjugated linoleic acid (c9,t11-CLA) on the cell cycle of gastric cancer cells (SGC-7901) and its possible mechanism in inhibition cancer growth.METHODS: Using cell culture and immunocytochemical techniques, we examined the cell growth, DNA synthesis, expression of PCNA, cyclin A, B1, D1, P16^ink4a and P21^cip/waf1 of SGC-7901 cells which were treated with various c9,t11-CLA concentrations (25, 50, 100 and 200 μmol•L⁻¹)of c9,t11-CLA for 24 and 48 h, with a negative control (0.1% ethane).RESULTS: The cell growth and DNA synthesis of SGC-7901 cells were inhibited by c9,t11-CLA. SGC-7901 cells. Eight day after treatment with various concentrations of c9,t11-CLA mentioned above, the inhibition rates were 5.92%, 20.15%, 75.61% and 82.44%, respectively and inhibitory effect of c9,t11-CLA on DNA synthesis (except for 25 μmol/L, 24 h) showed significantly less ³H-TdR incorporation than that in the negative controls (P < 0.05 and P < 0.01). Immunocytochemical staining demonstrated that SGC-7901 cells preincubated in media supplemented with different c9,t11-CLA concentrations at various times significantly decreased the expressions of PCNA (the expression rates were 7.2%-3.0%, 24 h and 9.1%-0.9% at 48 h, respectively), Cyclin A (11.0%-2.3%, 24 h and 8.5%-0.5%, 48 h), B1 (4.8%-1.8% at 24 h and 5.5%-0.6% at 48 h)and D1 (3.6%-1.4% at 24 h and 3.7%-0% at 48 h) as compared with those in the negative controls (the expressions of PCNA, Cyclin A, B1 and D1 were 6.5% at 24 h and 9.0% at 48 h, 4.2% at 24 h and 5.1% at 48 h, 9.5% at 24 h and 6.0% at 48 h, respectively) (P < 0.01), whereas the expressions of P16^ink4a and P21^cip/waf1, cyclin-dependent kinases inhibitors (CDKI), were increased.CONCLUSION: The cell growth and proliferation of SGC-7901 cell is inhibited by c9,t11-CLA via blocking the cell cycle, with reduced expressions of cyclin A, B1 and D1 and enhanced expressions of CDKI (P16^ink4a and P21^cip/waf1).