不同负载的DC-CIK联合5-FU治疗方案对结肠癌HT-29细胞移植瘤裸鼠的疗效观察

Treatment efficacy of DC-CIK with different loading combined with 5-FU on nude mice bearing colon cancer HT-29 cell transplanted tumor

目的:探讨树突状细胞诱导的杀伤细胞(DC-CIK)联合5-氟尿嘧啶(5-FU))并加载CD133^+HT-29细胞的裂解液或RNA,对裸鼠结肠癌细胞HT-29移植瘤治疗的有效性及其作用机制。方法:取对数生长期的人结肠癌HT-29细胞系,建立BALB/c裸鼠结肠癌移植瘤模型,分别注射无抗原加载的DC-CIK、5-FU+DC-CIK、R+DC-CIK(加载CD133^+细胞总RNA)、L+DCCIK(加载CD133^+细胞裂解液)、5-FU及生理盐水,观察不同治疗方案治疗3个周期对移植瘤生长的影响,并绘制裸鼠生长曲线;治疗结束2 d后采用颈髓离断法处死裸鼠并测定瘤体积和体质量。qPCR法检测移植瘤组织中AKT mRNA的表达水平、WB法检测磷酸化AKT蛋白的表达水平。结果:治疗结束后R+DC-CIK组、L+DC-CIK组、5-FU+DC-CIK组裸鼠体质量呈现总体平稳上升,而DC-CIK组与5-Fu组体质量逐渐下降;R+DC-CIK组、5-FU+DC-CIK组、L+DC-CIK组裸鼠肿瘤生长速度明显慢于对照组(P<0.05)。加载裂解液和RNA联合化疗比单独给予5-Fu化疗和DC-CIK治疗对移植瘤组织AKT mRNA和蛋白表达水平影响更加明显(均P<0.05)。结论:不同负载的DC-CIK或其与5-FU联合治疗的疗效优于单独化疗,其机制之一与下调AKT水平有关。

Objective:To investigate the therapeutic effect of dendritic cell-induced killer cells(DC-CIK) combined with 5-fluorouracil(5-FU) and loaded with CD133^+HT-29 cell lysate or RNA on mice bearing colon cancer HT-29 cell transplanted tumor,and to explore the underlying mechanism.Methods:Colon cancer xenograft model was established in BALB/c nude mice by using human colon cancer HT-29 cells at logarithmic growth phase;Antigen-free DC-CIK,5-FU+DC-CIK,R+DC-CIK(loaded with total RNA of CD133^+cells),L+DC-CIK(loaded with CD133^+cell lysate),5-FU and normal saline were respectively injected into transplanted mice,and the treatment efficacies on the growth of transplanted tumor in each group after three treatment cycles were observed,and the tumor growth curve was drawn.The nude mice were sacrificed by cervical dislocation and the tumor volume and body weight were measured.qPCR was used to detect the expression of AKT mRNA in transplanted tumor tissue,and WB was used to detect the expression of phosphorylated AKT protein.Results:After treatment,the body mass of nude mice in R+DC-CIK group,L+DC-CIK group and5-FU+DC-CIK group increased steadily,while the body mass of nude mice in DC-CIK group and 5-FU group decreased gradually;the tumor growth speed of nude mice in R+DC-CIK group,5-FU+DC-CIK group and L+DC-CIK group was significantly slower than that of the control group(P<0.05).Compared with 5-FU and DC-CIK alone,the combined treatment with loaded lysate/RNA had more significant effect on mRNA and protein expressions of AKT(P<0.05).Conclusion:The effect of DC-CIK with different loading or its combination with 5-FU is better than that of chemotherapy alone.One of the mechanisms is related to the down-regulation of AKT level.