Du Xue-lian, Jiang Tao, Sheng Xiu-gui, Gao Rong, Li Qing-shui
Department of Gynecologic Oncology, Shandong Cancer Hospital & Institute, Jinan 250117, PR China.
Gynecol Oncol. 2009 Dec;115(3):371-6. doi: 10.1016/j.ygyno.2009.08.029. Epub 2009 Sep 23.
Osteopontin (OPN) has been found to play an important role in tumor angiogenesis in recent years. Our previous studies have shown that OPN is overexpressed in tumor-associated human endometrial endothelial cells (HEECs) isolated from tissue samples of patients with endometrial cancer. In the present study, we aimed to further determine the role of OPN in endometrial cancer-associated angiogenesis.
We knock down OPN expression in HEECs and human endometrial cancer Ishikawa (ISK) cells using the small interference RNA method, and then evaluate the effects of OPN on endometrial cancer-associated angiogenesis by in vivo mouse studies and in vitro assays.
Our results revealed that proliferative activity of HEECs and ISK cells in vitro was not affected by transfection with the siOPN-RNA (P>0.05). Inhibition of OPN expression in HEECs reduced the cell migration, with the percentage of repaired area of 36.32+/-2.88 vs. 8.54+/-1.13 (P=0.007). HEEC/siOPN and ISK/siOPN demonstrated 67.4% and 51.2% decreased invasiveness compared with controls, respectively (P<0.05). The number of branched points per well was obviously lower in HEEC/siOPN than that in HEEC/Control (32.46+/-17.10 vs. 53.15+/-15.44, P=0.021). Furthermore, ISK cells transfected with OPN siRNA formed smaller tumor in mice and led to a lower microvessel density, i.e., angiogenesis, in transplanted tumors of mice than scrambled siRNA controls (12.88+/-7.14 vs. 28.42+/-9.69 vessels per HPF, P=0.019).
These data confirm the positive role of OPN in endometrial cancer-associated angiogenesis and might be of great benefit for finding rational approach in endometrial cancer therapy.
近年来发现骨桥蛋白（OPN）在肿瘤血管生成中发挥重要作用。我们之前的研究表明，OPN在从子宫内膜癌患者组织样本中分离出的肿瘤相关人子宫内膜内皮细胞（HEECs）中过度表达。在本研究中，我们旨在进一步确定OPN在子宫内膜癌相关血管生成中的作用。
我们使用小干扰RNA方法敲低HEECs和人子宫内膜癌Ishikawa（ISK）细胞中OPN的表达，然后通过体内小鼠研究和体外试验评估OPN对子宫内膜癌相关血管生成的影响。
我们的结果显示，体外HEECs和ISK细胞的增殖活性不受siOPN-RNA转染的影响（P>0.05）。抑制HEECs中OPN的表达可降低细胞迁移，修复面积百分比为36.32±2.88，而对照组为8.54±1.13（P=0.007）。与对照组相比，HEEC/siOPN和ISK/siOPN的侵袭性分别降低了67.4%和51.2%（P<0.05）。HEEC/siOPN每孔分支点的数量明显低于HEEC/对照（32.46±17.10对53.15±15.44，P=0.021）。此外，与乱序siRNA对照组相比，用OPN siRNA转染的ISK细胞在小鼠体内形成的肿瘤较小，并且在小鼠移植瘤中的微血管密度较低，即血管生成较少（每高倍视野12.88±7.14对28.42±9.69个血管，P=0.019）。
这些数据证实了OPN在子宫内膜癌相关血管生成中的积极作用，可能对寻找子宫内膜癌治疗的合理方法有很大帮助。
