塞来昔布和埃罗替尼对结肠癌细胞HT-29的协同抑制作用

Synergistic inhibitory effect of celecoxib and erlotinib on the proliferation of colorectal cancer cells

目的探讨表皮生长因子受体(EGFR)抑制剂及环氧化酶-2(COX-2)抑制剂埃罗替尼、塞来昔布及二者联合用药对结肠癌细胞HT-29增殖的抑制作用及其机制。方法将HT-29细胞分为对照组(完全培养基)、塞来昔布组(220μmol/L)、埃罗替尼组(50μmol/L)及联合用药组(塞来昔布220μmol/L、埃罗替尼50μmol/L)四组,作相应处理后均在适宜条件下培养;48 h后采用MTT法观察细胞抑制率,Real-time PCR法及Western blotting法检测EGFR、COX-2 m RNA及蛋白表达情况,ELISA法检测前列腺素E2(PGE2)含量。结果 48 h后塞来昔布组和埃罗替尼组对HT-29细胞抑制率分别为(56.6±4.3)%和(56.9±3.9)%,联合用药组抑制率为(86.1±7.1)%,与单独用药组比较,联合用药组对HT-29细胞增殖的抑制作用更明显,差异有统计学意义(P<0.05或0.01);与对照组比较,埃罗替尼组、塞来昔布组均能降低HT-29细胞中COX-2及EGFR的m RNA及蛋白表达水平,也可降低HT-29细胞PGE2的分泌,且联合用药组效果较单一用药组更显著,差异均有统计学意义(P<0.01)。结论塞来昔布和埃罗替尼均能抑制结肠肿瘤的细胞生长,可同时阻断EGFR、COX-2信号通路,二者联合应用具有协同作用,其机制可能是抑制EGFR、COX-2的表达及PGE2的分泌。

Objective To investigate the synergistic inhibitory effect of EGFR and COX-2 inhibitors named celecoxib and erlotinib or its combinations on the proliferation of colorectal cancer cell lines HT-29 and its possible mechanism. Methods The HT-29 cells were divided into four groups such as the control group （complete medium）,the celecoxib group （220μmol/L）, the erlotinib group（50μmol/L） and the combination group（220μmol/L celecoxib,50μmol/L erlotinib） according to different medications,all of which were cultivated under appropriate environments. It adopted MTT assay to observe the cell inhibitory rate,Real-time PCR and Western blotting assays to detect the expressions of EGFR,COX-2mRNA and proteinand ELISA assay to measure the content of PGE2 after 48 hours. Results The inhibition rates on HT-29 cells in the celecoxib group and the erlotinib group after 48 hours were（56.6±4.3）%and（56.9±3.9）%respectively while the combination group being（86.1±7.1）%,the prolifer-ation of HT-29 cell was inhibited in the combination group more apparently than in the celecoxib group and erlotinib group ,which had statistically significant difference（P〈0.05 or 0.01）;compared with the control group,both the celecoxib group and the erlotinib group were reduced COX-2 in the HT-29,mRNA of EGFR and expression level of protein,as well as PGE2 secretion of HT-29 cells. The combination group was more significant than the single group in effect , all of which had statistical significance in dif ference（P〈0.01）. Conclusions Celecoxib and erlotinib may depress the growth of colorectal cancer cell lines,block the communi-cation paths of EGFR and COX-2 simultaneously,both of which have a synergistic inhibitory effect,whose possible mechanism may be inhibit expression of EGFR,COX-2 and secretion of PGE2.