Department of Pathology, Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, China.
Cancer Gene Ther. 2013 Sep;20(9):487-92. doi: 10.1038/cgt.2013.44. Epub 2013 Aug 16.
Poly (ADP-ribose) glycohydrolase (PARG), which was discovered during studies on DNA damage study and in inflammation research, is an attractive target protein in current cancer research. The enzymatic hydrolysis of poly (ADP-ribose) (PAR) has not been clarified in the regulation of cancer. The purpose of this study was to understand the relationship between PARG and the adhesion of colorectal carcinoma CT26 cells to platelets. PARG was silenced by short hairpin RNA (shRNA) transfection in CT26 cells. A fluorescence method was used to identify adhesion of CT26 cells to platelets and the expression of poly (ADP-ribose) polymerase (PARP)-1, p-Akt, nuclear factor kappa-B (NF-κB), P-selectin and intercellular adhesion molecule-1 (ICAM-1) was analyzed by western blot in various treated groups and control groups. The results were as follows: (a) PARG silencing led to inhibition of adhesion of CT26 cells to platelets, whereas an inhibitor of p-Akt boosted adhesion of PARG-short hairpin RNA interference (shRNAi) CT26 cells to platelets; (b) a PARP-1 inhibitor depressed the expression of P-selectin and ICAM-1 in CT26 cells; (c) PARG silencing increased phosphorylation of Akt and decreased expression of PARP-1, NF-κB, ICAM-1 and P-selectin in CT26 cells; and (d) a p-Akt inhibitor intensified expression of NF-κB, ICAM-1 and P-selectin in PARG-shRNAi CT26 cells accordingly. These results showed the effectiveness of knockout of PARG in inhibiting adhesion of CT26 cells to platelets and its connection with the phosphatidylinositol 3 kinase/Akt pathway.
多聚（ADP-核糖）水解酶（PARG）在 DNA 损伤研究和炎症研究中被发现，是当前癌症研究中具有吸引力的靶蛋白。多聚（ADP-核糖）（PAR）的酶水解在癌症调控中尚未阐明。本研究旨在了解 PARG 与结直肠癌细胞 CT26 与血小板黏附之间的关系。通过短发夹 RNA（shRNA）转染沉默 CT26 细胞中的 PARG。荧光法用于鉴定 CT26 细胞与血小板的黏附，并用 Western blot 分析各组和对照组中多聚（ADP-核糖）聚合酶（PARP）-1、磷酸化 Akt（p-Akt）、核因子 kappa-B（NF-κB）、P-选择素和细胞间黏附分子-1（ICAM-1）的表达。结果如下：（a）PARG 沉默导致 CT26 细胞与血小板的黏附受到抑制，而 p-Akt 的抑制剂则促进 PARG-shRNAi CT26 细胞与血小板的黏附；（b）PARP-1 抑制剂降低 CT26 细胞中 P-选择素和 ICAM-1 的表达；（c）PARG 沉默增加 Akt 的磷酸化，降低 CT26 细胞中 PARP-1、NF-κB、ICAM-1 和 P-选择素的表达；（d）p-Akt 抑制剂则相应地增强 PARG-shRNAi CT26 细胞中 NF-κB、ICAM-1 和 P-选择素的表达。这些结果表明 PARG 敲除在抑制 CT26 细胞与血小板黏附中的有效性及其与磷脂酰肌醇 3 激酶/Akt 通路的关系。
