Objective: To investigate the effect of ubiquitous mitochondrial creatine kinase 1(CKMT1) on the sensitivity of human nasopharyngeal carcinoma cell line CNE-1 to DDP. Methods: CNE-1 cells were transiently transfected with CKMT1 overexpression (CKMT1) or empty vector (EV). The growth curve and DDP IC50 were developed by MTT assay, plate clone formation assay was performed by gradient concentration of DDP treatment, cell cycle and apoptosis were detected by flow cytometry, levels of apoptosis related protein Bax/Bcl-2/C-PARP and the transcription factor p-STAT3-Tyr705 were detected by Western Blot. Results: The transfection efficiencies of CKMT1 and EV were more than 90% with a higher proliferation rate in the CKMT1-transfected cells. However, the CKMT1-transfected cells had a DDP IC50 of 2.76 μmol/L, which was significantly lower than that of 4.60 μmol/L in the EV-transfected cells (P<0.01). With the treatment of certain concentration of DDP, the CKMT1-transfected cells had a lower clone formation rate, the cell cycle arrested more obviously in G2/M phase, and the apoptosis rate was higher (P<0.01), with higher levels of Bax/C-PARP (P<0.05 or P<0.01), but lower levels of Bcl-2 (P<0.01) and p-STAT3-Tyr705 (P<0.01), compare with the EV-transfected cells. Conclusions: CKMT1 may inhibit the activation of STAT3, increasing the sensitivity of CNE-1 to chemotherapeutic drug DDP.
目的： 探讨线粒体肌酸激酶1(ubiquitous mitochondrial creatine kinase，CKMT1)在人鼻咽癌细胞株CNE－1对顺铂(cisplatin，DDP)敏感性中的影响。 方法： 瞬转CNE－1得CKMT1过表达细胞或空载体细胞(EV)，MTT法绘制生长曲线、计算DDP IC(50)，不同浓度DDP处理下平板克隆形成实验，流式细胞术检测细胞周期与凋亡，Western Blot检测凋亡相关蛋白Bax/Bcl－2/C－PARP及转录因子p－STAT3－Tyr705水平。采用GraphpadPad Prism5软件进行统计学处理。 结果： CKMT1和空载体细胞的转染效率均达90%以上；前者的增殖速度高于后者；但前者DDP IC(50)为2.76 μmol/L，显著低于后者的4.60 μmol/L(t＝6.91，P<0.01)，且在一定浓度DDP作用下前者的克隆形成率较低；细胞周期在G2/M期阻滞更明显。DDP浓度为2 μmol/L时，CKMT1凋亡率(18.33±0.67)%显著高于EV(11.80±0.70)%(t＝6.75，P<0.01)；CKMT1的促凋亡蛋白C－PARP和Bax显著高于EV(t＝72.63，P<0.01；t＝4.22，P<0.05)，而凋亡抑制蛋白Bcl－2在CKMT1中的表达显著低于EV(t＝49.08，P<0.01)；且p－STAT3－Tyr705水平也更低(t＝221.60，P<0.01)。 结论： DDP作用下，CKMT1可能通过一定的机制抑制STAT3的活化，进而提高CNE－1对DDP的敏感性。.
Keywords: Cisplatin; Nasopharyngeal neoplasms; Ubiquitous mitochondrial creatine kinase.