PARG基因沉默对肿瘤局部B220+ DEC205+ DC的影响

Effect of silencing PARG on proliferation and differentiation of local B220+ DEC205+ DC

摘要:

目的： 探讨聚（腺苷二磷酸核糖）水解酶［Poly(ADP-ribose)glycohydrolase,PARG］基因沉默对肿瘤局部B220+ DEC205+ DC增殖分化的影响及其在大肠癌转移中的作用。方法：以PARG-shRNA慢病毒载体转染CT26细胞为实验组，未转染CT26细胞和空载体CT26细胞为对照组，分别在小鼠脾包膜下接种形成肝转移模型；Western blot法检测脾脏移植瘤中PARG、PARP、NF-κB蛋白的表达；免疫荧光双标法检测脾脏中B220+DEC205+DC的表达；ELISA法检测各组小鼠血清中IL-10、TGF-β的表达。结果：PARG基因沉默后，脾脏移植瘤体积缩小，肝脏转移癌结节数目减少，差异有统计学意义(P<0.05)；脾脏移植瘤中PARG、PARP、NF-κB蛋白的表达量明显较对照组降低，差异有统计学意义(P<0.05)；脾脏组织中的B220+ DEC205+ DC较对照组明显降低，差异有统计学意义（P<0.05）；血清中IL-10、TGF-β的表达较对照组显著降低，差异有统计学意义（P<0.05）。结论： PARG基因沉默可抑制小鼠结肠癌CT26细胞肝转移，可能与PARG沉默后下调PARP，并下调NF-κB的活性，从而影响NF-κB依赖性因子IL-10、TGF-β的表达，进而影响B220+DEC205+DC的增殖分化有关。

Abstract:

Objective: To investigate the effect of silencing PARG on the proliferation and differentiation of tumor local B220+DEC205+DC and its role in colon carcinoma metastasis. Methods：Experiment group was established by transfecting lentivirus Poly (ADP-ribose) glycohydrolase short hairpin RNA (PARG-shRNA) into mouse colon carcinoma CT26 cells and control group by enrolling CT26 cells without any treatment and CT26 cells with empty vector.Liver metastasis model of colon carcinoma was established by splenic subcapsular inoculation.The expressions of PARG,PARP and NF-κB proteins in splenic carcinoma were detected by Western blot and those of B220+DEC205+DC in the spleen by immunofluorescence double labeling assay.The levels of IL-10 and TGF-β in the serum were measured by enzyme-linked immunosorbent assay(ELISA). Results：The size of splenic carcinoma and the number of metastatic liver nodules in experiment group were smaller and lower than those in control group (P<0.05).The expressions of PARG,PARP and NF-κB in splenic carcinoma were reduced obviously in experiment group compared with those in control group (P<0.05).The number of B220+DEC205+DC in the spleen was significantly fewer in experiment group than those in control group (P<0.05) and the levels of IL-10 and TGF-β in the serum were significantly decreased in experiment group than those in control group (P<0.05). Conclusion：These studies demonstrate that silencing PARG could suppress the metastasis of CT26 cells to the liver,which is possibly related with the processes of down regulating of both PARP and NF-κB as well as decreasing IL-10 and TGF-β and finally affecting the proliferation and differentiation of local B220+DEC205+DC.