Thieno [2, 3-d] pyrimidine inhibits gastric cancer cell proliferation via the down-regulation of bcl-2 and survivin expressions

Purpose: To investigate the effect of thieno [2, 3-d] pyrimidine on gastric cancer (GC) cell proliferation, and elucidate the mechanism of action involved. Methods: Human GC cells (MKN1, MKN28 and SGC 7901) were cultured in RPMI-1640 medium supplemented with 10 % fetal bovine serum (FBS) and 1 % penicillin/ streptomycin solution at 37 degrees C for 24 h in a humidified atmosphere of 5 % CO2 and 95 % air. After attaining 60 - 70 % confluency, the cells were treated with serum-free medium and graded concentrations of thieno [2, 3-d] pyrimidine (0 - 12 mu M) for 24 h. Normal cell culture without thieno [2, 3-d] pyrimidine served as control group. The cells were used in logarithmic growth phase. Cell viability and apoptosis were assessed using 3 (4,5 dimethyl thiazol 2 yl) 2,5 diphenyl 2H tetrazolium bromide (MTT), and flow cytometric assays, respectively. The levels of expression of ZNF139, B cell lymphoma 2 (bcl-2) and survivin in MKN1 cells and orthotopically transplanted mice were determined using Western blotting and real-time quantitative polymerase chain reaction (qRT-PCR). Results: Treatment of MKN1, MKN28 and SGC 7901 cells with thieno [2, 3-d] pyrimidine for 72 h led to significant and dose-dependent reductions in their viabilities, as well as significant and dose-dependent increases in the number of apoptotic cells (p < 0.05). The results of qRT-PCR and Western blotting showed that ZNF139 mRNA and protein expressions in MKN1 cells were significantly down-regulated by thieno [2, 3-d] pyrimidine treatment (p < 0.05). Thieno [2, 3-d] pyrimidine treatment significantly and dose-dependently down-regulated the expressions of bcl 2 and survivin proteins in MKN1 cells and orthotopically transplanted mice (p < 0.05). It also significantly and dose-dependently inhibited the proliferation of GC cells in orthotopic mouse model of GC after 31 days of treatment (p < 0.05). Conclusion: These results suggest that thieno [2, 3-d] pyrimidine suppresses the proliferation of GC cells via down-regulation of the expressions of ZNF139, bcl 2 and surnotsignvivin. Thus, it has potentials for development for the management of gastric cancer.