心肌细胞裂解液对鼻咽癌CNE-2细胞株的放射增敏作用及其机制的研究

In vitro study of radiation sensitizing effect of cardiac muscle cell lysate on human nasopharyngeal carcinoma cell line and its mechanism in cell level

目的探讨心肌细胞裂解液对鼻咽癌CNE-2细胞的放射增敏作用和机制。方法采用超滤离心法获得分子量>10kD、<5kD及5～10kD的乳Wistar大鼠心肌细胞裂解液超滤液(CMCLnr)、成年Wistar大鼠心肌细胞裂解液超滤液(CMCLar)、乳Wistar大鼠心肌细胞培养液超滤液(CMCMnr)和20日龄乳Wistar大鼠心肌细胞培养液超滤液(CMCM20dr)。用抑瘤活性实验检测上述滤液(0.3mg/ml)和顺铂(1.26μg/ml DDP)作用鼻咽癌CNE-2细胞株的细胞存活率。用放射增敏实验检测CMCLnr(5～10kD)和拓扑替康(TPT)的放射(RT)增敏效果,单击多靶数学模型进行曲线拟合作图。流式细胞术检测TPT、CMCLnr(5～10kD)、RT单独或联合作用CNE-2细胞后细胞周期分布及凋亡率情况。结果分子量为5～10kD CMCLnr、CMCLar、CMCMnr和CMCM20dr均较对照组能够显著降低CNE-2细胞的存活率(P<0.05),且与DDP组差异无统计学意义。CNE-2细胞RT组的D0值为1.185Gy,Dq值为0.676Gy,N值为3.729,SF2为69%;CMCLnr+RT组的D0值为0.762Gy,Dq值为0.600Gy,N值为6.147,SF2为25%,放射增敏比指标SERD0为1.555,SERDq为1.127,SERSF2为2.760。CMCLnr+RT组的细胞凋亡率为(19.34±0.23)%,均高于TPT+RT组和RT组,差异有统计学意义(P<0.05)。结论心肌细胞裂解液可抑制鼻咽癌CNE-2细胞的增殖,并对CNE-2细胞具有较强的放射增敏作用,细胞水平的研究表明其放射增敏的机制可能与诱导S期阻滞及促进凋亡有关。

Objective To study the effect of proliferation and radiation sensitivity of cardiac muscle cell lysate on human nasopharyngeal carcinoma CNE-2 cells.Methods Lysates of rat cardiac muscle tissue of10kD,5kD and 5-10kD were obtained by ultrafiltration centrifugation method,including CMCLnr from neonatal Wistar rat and CMCLar from adult Wistar rat;culture solutions of rat cardiac muscle tissue of10kD,5kD and 5-10kD were obtained too,CMCMnr from neonatal Wistar rat and CMCM20dr from 20-day old neonatal Wistar rat.Survival rate of CNE-2 cells was detected when it was treated with 0.3mg/ml different molecular weights of CMCLnr,CMCLar,CMCMnr,CMCM20dr and 1.26μg/ml DDP for 48h.The radiosensibility of CMCLnr（5-10kD） and topotecan（TPT） was detected and single-hit multitarget model was used to plot survival curve.CNE-2 cell cycle and apoptosis were measured by flow cytometer.Results Compared with control group,5-10kD CMCLnr,CMCLar,CMCMnr,CMCM20dr could significantly inhibit the survival rate of CNE-2 cells（P〈0.05）.They had the same anticancer activity as platinum（P〈0.05）.The values of D0,Dq,N and SF2 of CNE-2 cells received radiation treatment alone were 1.185Gy,0.676Gy,3.729 and 69%.Those of CNE-2 cells received radiation plus CMCLnr（5-10kD） were 0.762Gy,0.600Gy,6.147 and 25%.SERD0,SERDqand SERSF2were 1.555,1.127 and 2.760.The apoptotic rate of CMCLnr＋radiation group was（19.34±0.23）%,which was higher than that in topotecan＋radiation group and single radiation group（P〈0.05）.Conclusion The cardiac muscle cell lysate can inhibit the proliferation of CNE-2 cells and has shown radiosensitizing effect in vitro on CNE-2 cells.The radiosensitizing mechanism may be related to the induction of S phase arrest and apoptosis-promoting effects.