胃泌素受体拮抗剂丙谷胺和选择性COX2抑制剂塞来昔布对人胃癌细胞株BGC-823增殖和PGE2分泌的影响

Impact of combined proglumide and celecoxib on cell proliferation and PGE2 secretion in human gastric cancer cell line BGC-823

目的:探讨胃泌素受体拮抗剂丙谷胺和选择性环氧合酶-2(cyclooxygenase-2,COX-2)抑制剂塞来昔布对人胃癌细胞株BGC-823增殖的抑制作用及其对COX-2、15-羟基前列腺素脱氢酶(15-hydroxyprostaglandin dehydrogenase,15-PGDH)和前列腺素E2(prostaglandin E2,PGE2)的影响.方法:采用M T T法分别检测丙谷胺和塞来昔布单独及联合应用对人胃癌细胞株BGC-823增殖的影响;RT-PCR法检测COX-2和15-PGDH m RNA的表达;Western blot检测COX-2和15-PGDH蛋白质的表达;ELISA检测细胞培养液中PGE2含量变化.结果:丙谷胺和塞来昔布呈剂量和时间依赖性地抑制胃癌BGC-823细胞的增殖.采用低于细胞增殖半数抑制浓度(the half maximal inhibitory concentration,IC50)的丙谷胺(6mmol/L)和塞来昔布(50μm o l/L)联合应用,48 h时对胃癌细胞B G C-823的增殖抑制率为65.1%±7.7%,显著高于单独应用丙谷胺(6 mmol/L,38.1%±7.1%)和塞来昔布(50μmol/L,32.6%±3.3%)时的抑制率(P值均<0.05).丙谷胺和塞来昔布两药均能下调胃癌BGC-823细胞中COX-2及上调15-PGDH m RNA和蛋白的表达,联合应用比单独用药更为显著(P值分别<0.05,<0.01).同时,两药也能降低BGC-823细胞分泌PGE2,联合用药作用更加明显(P值分别<0.05,<0.01).结论:丙谷胺、塞来昔布均呈时间和剂量依赖性抑制胃癌细胞株BGC-823的增殖,其可能机制之一为通过下调COX-2 m RNA和蛋白的表达,同时上调15-PGDH mRNA和蛋白的表达,进而减少PGE2合成与分泌而实现.两药联合应用可能具有协同抗癌作用.

AIM：To investigate the effect of proglumide（a gastrin receptor antagonist） and celecoxib[a selective cyclooxygenase-2（COX-2）inhibitor]on cell proliferation and COX-2,15-hydroxyprostaglandin dehydrogenase（15-PGDH） and prostaglandin E2（PGE2）expression in human gastric cancer cell line BGC-823.METHODS：BGC-823 cells were treated with proglumide and celecoxib,alone or in combination.MTT assay was used to detect the proliferation of BGC-823 cells.Real-time PCR was used to detect COX-2 and 15-PGDH mRNA expression.Western blot was used to detect COX-2 and 15-PGDH protein expression,and ELISA was used to determine the content of PGE2 in culture medium.RESULTS：Proglumide and celecoxib inhibited the growth of BGC-823 cells in a dose- and time-dependent manner.Treatment with combined proglumide（6 mmol/L,less than IC50） and celecoxib（50 μmol/L,less than IC50） for 48 h was associated with a significantly higher inhibition rate than either of the agents alone（65.1%± 7.7%vs 38.1%±7.1%,32.6%± 3.3%,P 〈 0.05）.Proglumide and celecoxib down-regulated the expression of COX-2 mRNA and protein,and up-regulated the expression of 15-PGDH mRNA and protein in BGC-823 cells,and the effects of combined treatment were more significant than treatment with either of the agents alone（P 〈 0.05 vs proglumide;P 〈 0.01 vs celecoxib）.Proglumide and celecoxib reduced the secretion of PGE2,and the effects of combined treatment were more significant than either of the agents alone（P 〈 0.05 vs proglumide;P 〈0.01 vs celecoxib）.CONCLUSION：Proglumide and celecoxib inhibit the growth of cultured BGC-823 cells time- and dose-dependently,possibly by down-regulating the expression of COX-2mRNA and protein,up-regulating the expression of 15-PGDH mRNA and protein,and reducing PGE2 synthesis or secretion.Combined use of proglumide and celecoxib has a synergistic effect.