Liu Maoxi, Du Kunli, Jiang Bo, Wu Xingye
Department of Anorectal Surgery, Shanxi Cancer Hospital, Taiyuan, 030013, People's Republic of China.
Department of Anorectal Surgery, Xijing Hospital, Xian, 710032, People's Republic of China.
Pathol Oncol Res. 2020 Jan;26(1):281-290. doi: 10.1007/s12253-018-0429-1. Epub 2018 Aug 8.
Hypoxia is a typical feature of colon cancer occurrence and progression. We have reported that high expression and activity of PhospholipaseD2 (PLD2) induced by hypoxia in colon cancer cells. In order to further investigate the role of PLD2 in colon cancer under hypoxic conditions. MTT assay was used to detect the proliferation of human colon cancer cells (SW480 and SW620) under hypoxic conditions by decrease the PLD2 gene expression or inhibit the activity of PLD2. Expression level of p-P65/T-P65 and Cyclin D1 were detected in those cells treated as above through using western blot and RT-PCR analysis. Effect of NF-Bp65 inhibitor (BAY-117082) on the proliferation and expression level of Cyclin D1 and PLD2 of colon cancer cells under hypoxic conditions were further analysised. As a result, decreased the expression of PLD2 or inhibited the activity of PLD2 leaded to the proliferation of hypoxia colon cancer cells reduced, and along with the expression level of p-P65/T-P65 and Cyclin D1 reduced. However, inhibition the expression level of p-P65/T-P65 lead to the proliferation and expression of Cyclin D1 in those hypoxia colon cancer cells also reduced. In vivo growth decreased in response to PLD2 and NF-Bp65 inhibition. Our study indicates that high expression of PLD2 induced by hypoxia promotes the proliferation of colon cancer cells, and it may elevate the expression level of Cyclin D1 through activating NF-Bp65 signaling pathway. Inhibition of the PLD2 expression may provide a new clue for treatment for colon cancer.
缺氧是结肠癌发生和发展的典型特征。我们曾报道过，缺氧可诱导结肠癌细胞中磷脂酶D2（PLD2）的高表达和高活性。为了进一步研究PLD2在缺氧条件下对结肠癌的作用，采用MTT法通过降低PLD2基因表达或抑制PLD2活性来检测缺氧条件下人结肠癌细胞（SW480和SW620）的增殖情况。通过蛋白质免疫印迹法和逆转录-聚合酶链反应分析，检测上述处理细胞中p-P65/T-P65和细胞周期蛋白D1的表达水平。进一步分析了NF-κBp65抑制剂（BAY-117082）对缺氧条件下结肠癌细胞增殖以及细胞周期蛋白D1和PLD2表达水平的影响。结果显示，降低PLD2表达或抑制PLD2活性会导致缺氧结肠癌细胞的增殖减少，同时p-P65/T-P65和细胞周期蛋白D1的表达水平也降低。然而，抑制p-P65/T-P65的表达水平也会导致那些缺氧结肠癌细胞中细胞周期蛋白D1的增殖和表达减少。在体内，抑制PLD2和NF-κBp65会导致肿瘤生长减缓。我们的研究表明，缺氧诱导的PLD2高表达促进结肠癌细胞增殖，并且它可能通过激活NF-κBp65信号通路来提高细胞周期蛋白D1的表达水平。抑制PLD2表达可能为结肠癌治疗提供新的线索。
