乳腺癌中FBX022基因通过HIF-1α对血管形成的影响

Effects of FBXO22 gene on angiogenesis via HIF- 1α pathway in breast cancer

目的探讨FBXO22基因在乳腺癌血管形成中的作用及分子生物学机制。方法使用FBXO22-siRNA转染人乳腺癌MDA—MB-231和BT-549细胞，体外血管形成实验观察2种乳腺癌细胞中干扰FBXO22后使人脐静脉内皮细胞（human umbilical vein endothelial cells, HUVECs）血管形成数量的变化；Western blot检测FBXO22-siRNA对2种乳腺癌细胞中FBX022、缺氧诱导因子-1α（hypoxia inducible factor-1，HIF—1α）、血管内皮生长因子（vascular endothelial growth factor，VEGF）蛋白表达的影响；Real time—PCR检测干扰FBXO22对2种乳腺癌细胞中HIF-1α和VEGF的mRNA水平的影响。结果在MDA—MB-231和BT-549细胞中干扰FBXO22后分为FBXO22-Ctrl组和FBXO22-si组。与FBX022-Ctrl组相比，MDA—MB-231和BT-549细胞FBX022-si组血管形成数目分别增加了107．1％和181．8％；FBXO22蛋白表达量分别减少了55．5％和51．9％；HIF-1α蛋白表达量分别上升了39．3％和68．4％；VEGF蛋白表达量分别上升了40．7％和21．7％；HIF-1α和VEGF的mRNA水平无明显变化。结论在乳腺癌中FBX022作为抑癌基因对血管形成发挥着重要作用，干扰FBX022后能够通过HIF-1α通路导致VEGF蛋白表达量提高并促进血管形成。

Objective To investigate the role effects of FBXO22 gene in the angiogenesis of breast cancer and its molecular biological mechanism. Methods FBXO22 - siRNA was transfected into human breast cancer MDA - MB - 231 and BT - 549 cells. Then, the number of vessels developed by human umbilical vein endothelial cells （HUVECs） that were affected by the two types of cancer cells under the interference of FBXO22 - siRNA was observed by in vitro angio- genesis experiment. The effects of FBXO22- siRNA in MDA -MB -231 and BT- 549 cells on FBXO22, hypoxia inducible factor- 1α （HIF-1α） and vascular endothelial growth factor （VEGF） were detected by Western blotting. The levels of HIF -1α and VEGF mRNA after FBXO22 interference were examined by real time - PCR. Results After transfection with FBXO22 -Ctrl RNA and FBXO22 -siRNA into MDA -MB -231 and BT -549 cells, the ceils were divided into a FBXO22 - Ctrl group and an FBXO22 - si group. Compared with the FBXO22 - Ctrl group, the FBXO22 - si group showed increases in the number of vessels newly formed in MDA -MB -231 and BT -549 cells by 107.1% and 181.8% respectively, decreases in the levels of FBXO22 by 55.5% and 51.9%, increases in the levels of both HIF - 1 protein by 39.3% and 68.4% and VEGF protein by 40.7% and 21.7%. There were no significant differences in mRNA level of HIF -1α and VEGF between the two groups. Conclusions FBXO22 plays an important role in angiogenesis as a tumor suppressor gene in breast cancer. After FBXO22 interference, it can increase the expression of VEGF at the protein level and promote angiogenesis through the HIF-1α pathway.