Zhou Ren, Zhang Long-Zhou, Wang Rui-Zhi
Department of Neurosurgery, The Second Affiliated Hospital, Medical College of Xi'an Jiao Tong University, Xi'an, Shaanxi 710004, P.R. China.
Chin J Cancer. 2010 Mar;29(3):294-9. doi: 10.5732/cjc.009.10290.
Celecoxib, one of the new generation of non-steroidal anti-inflammatory drugs (NSAIDs), has a specific inhibitory effect on COX-2. Studies have shown that celecoxib can inhibit the proliferation of tumor cells and induce cell apoptosis, which has been confirmed in colorectal tumors and familial adenomatous polyposis. This study explored the effect of celecoxib on the proliferation and apoptosis of human glioma cell line U251 and elucidated the correlation between the effect of celecoxib and the expression of survivin.
U251 cells were treated with different concentrations of celecoxib. Cell morphologic changes were observed by optical microscopy. MTT assay was used to detect the absorbance value and to calculate inhibition and survival rates. The rates of apoptosis of U251 cells after 48 h of treatment with celecoxib were assessed by flow cytometry. The expression of survivin was analyzed by immunocytochemistry (ICC) and Western blot analysis. The expression of survivin mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR).
Significant morphologic changes were shown in U251 cells after treatment with celecoxib. The MTT assay results revealed that celecoxib inhibited the proliferation of U251 cells and the inhibitory rates significantly increased in a dose-and time-dependent manner. After 48 h of treatment with celecoxib, the apoptotic cells could be obviously observed, and the apoptosis rate significantly increased with increases in concentrations of celecoxib. The expression of survivin was observed in the control group, however, the expression of survivin was significantly down-regulated as the concentration of celecoxib increased. The level of survivin mRNA expression in U251 cells was significantly down-regulated after treatment with different concentrations of celecoxib (P < 0.05).
The inhibition of proliferation and apoptosis in U251 cells could be induced by celecoxib in a dose-and time-dependent manner, and its mechanism might be the downregulation of the expression of survivin.
塞来昔布是新一代非甾体抗炎药（NSAIDs）之一，对COX-2具有特异性抑制作用。研究表明，塞来昔布可抑制肿瘤细胞增殖并诱导细胞凋亡，这在结直肠癌和家族性腺瘤性息肉病中已得到证实。本研究探讨塞来昔布对人胶质瘤细胞系U251增殖和凋亡的影响，并阐明塞来昔布作用与生存素表达之间的相关性。
用不同浓度的塞来昔布处理U251细胞。通过光学显微镜观察细胞形态变化。采用MTT法检测吸光度值并计算抑制率和生存率。用流式细胞术评估塞来昔布处理48小时后U251细胞的凋亡率。通过免疫细胞化学（ICC）和蛋白质印迹分析检测生存素的表达。用逆转录-聚合酶链反应（RT-PCR）测定生存素mRNA的表达。
塞来昔布处理后U251细胞出现明显的形态学变化。MTT法结果显示，塞来昔布抑制U251细胞增殖，抑制率呈剂量和时间依赖性显著增加。塞来昔布处理48小时后，可明显观察到凋亡细胞，且凋亡率随塞来昔布浓度增加而显著升高。对照组观察到生存素的表达，然而，随着塞来昔布浓度增加，生存素的表达显著下调。用不同浓度的塞来昔布处理后，U251细胞中生存素mRNA表达水平显著下调（P<0.05）。
塞来昔布可剂量和时间依赖性地诱导U251细胞增殖抑制和凋亡，其机制可能是生存素表达下调。
