乳香胶联合吉西他滨对人胰腺癌BxPc-3细胞的作用及机制初探

The preliminary research of the effect of Gum mastic combined with gemcitabine in human pancreaticcarcinoma BxPc-3 cells and its mechanism

目的研究乳香胶联合吉西他滨对体内、外培养的人胰腺癌BxPc-3细胞的作用及相关机制。方法四唑氮蓝还原法检测BxPc-3细胞增殖，流式细胞仪检测细胞凋亡（PI单染色法）。Westernblot检测不同浓度的乳香胶联合吉西他滨（两药联合组）用药后BxPc-3细胞内测核转录因子-κB（NF-KB）p65亚基以及NF-κB抑制蛋白IκB、凋亡调节蛋白Bel-2和Bax的表达水平的变化。建立人胰腺癌裸鼠皮下移植瘤模型，监测移植瘤体积变化。结果两药联合组选择乳香胶（40mg／L）和吉西他滨（10mg／L）处理72h后，抑制人胰腺癌细胞株BxPc-3细胞的作用显著优于单独使用（P〈0．01）；凋亡比例（45．13±4．01）明显高于乳香胶组或吉西他滨组（P〈0．01）和对照组（5．07±1．37，P〈0．01）；乳香胶或两药联合可抑制NF-κB的活性；对人胰腺癌BxPc-3细胞作用48h后，Bcl-2的蛋白表达明显低于吉西他滨组和对照组（P〈0．01）。而IkB和Bax蛋白的表达显著高于吉西他滨组和对照组（P〈0．01）。与对照组比较，乳香胶或两药联合组可显著抑制裸鼠胰腺癌皮下移植瘤生长（P〈0．05）。结论乳香胶可通过抑制NF-κB的活性，增加IκB和Bax蛋白表达、抑制Bcl-2的蛋白表达，发挥抗肿瘤作用，并增强吉西他滨的药效。

Objective To investigate the effect of Gum mastic combined with gemcitabine on human pancreatic carcinoma BxPc-3 cells and its mechanism. Methods Cell proliferation and apopto- sis were examined using the methyl thiazolyl tetrazolium assay and propidium iodine staining, respec- tively. After BxPc-3 cells were treated with different concentrations of Gum mastic and gemcitabine, the expression of NF-κB p65 subunit, IkB, Bcl-2 and Bax proteins was detected by Western blot. BxPc 3 cells were injected subcytaneously into nude mice to establish pancreatic xenograft tumors, and the changes of tumor volume were monitored. Results Compared to either single agent, treatment with Gum mastic （40 ng/L） combined with gemcitabine （10 mg/L） for 72 h signi cantly inhibited the proliferation of BxPc-3 cells （P〈0.01）. Its rate of apoptosis（45.13±4.01）was more than Gum mas- tic,gemcitabine（P〈0.01）and control group （5. 07± 1.37, P〈0.01）. When cells were treated with gemcitabine in combination with gum mastic in human pancreatic carcinoma BxPc-3 cells for 48 h, the IκB level was increased, whereas NF-κB activation was blocked; the expression of Bax protein was substantially increased, but Bcl-2 protein was down-regulated; gum mastic or combined with gemcit- ahine could significantly inhibit the growth of pancreatic xenograft tumors （P〈 0.05）. Conclusions Gum mastic could effectively strengthen the sensitivity of human pancreatic carcinoma BxPe 3 cells to gemcitabine. It may inhibit the expression of NFκB p65 subunit and Bcl-2 proteins and increase the expression of IκB and Bax proteins.