Zhou Baosheng, Bu Guoyun, Zhou Yipin, Zhao Yue, Li Wei, Li Mu
Department of Neurosurgery, The First Central Hospital of Tianjin, 56 Fukang Road, Tianjin, 300192, China.
Med Oncol. 2015 Jan;32(1):378. doi: 10.1007/s12032-014-0378-9. Epub 2014 Nov 30.
Cell division cycle 2 (CDC2) is always overexpressed in malignant tumor cells and is correlated with chemosensitivity, but it is unclear whether CDC2 overexpression contributes to the chemoresistance potential of glioma cells. The aim of study was to determine the relationship of CDC2 expression with the prognosis and chemoresistance of glioblastoma. In this study, the glioblastoma U87 and U251 cell lines were steadily transfected with a lentivirus vector expressing a short hairpin RNA-targeting CDC2. Expression of CDC2 was evaluated in glioblastoma and cell lines by immunohistochemistry and Western blot analysis. The relationship between CDC2 expression and clinicopathological characteristics was analyzed. Using RNA interference, the effects of CDC2 on chemosensitivity to temozolomide (TMZ) were investigated in U87 and U251 cell lines in vitro. Combined CDC2 knockdown and TMZ treatment inhibited cell proliferation and induced apoptosis in vitro more effectively than either treatment alone. qRT-PCR and Western blot analysis showed that cells underexpressing CDC2 revealed lower expression of the anti-apoptotic protein B cell lymphoma-2 and increased expression of the apoptosis effector caspase-3 compared to U87 and U251 cells transfected with a control vector. Furthermore, expression levels of CDC2 in U87 and U251 cells were related to the IC50 of the antitumor drug TMZ. Knockdown of CDC2 expression was associated with decreased expression of Ral-binding protein 1, a classical chemotherapy drugs transporter. These results indicate that the ability to suppress the malignant phenotype by down-regulating CDC2 expression may provide a new gene therapy approach for overcoming CDC2-associated chemoresistance in patients with malignant glioma.
细胞分裂周期2（CDC2）在恶性肿瘤细胞中总是过度表达，且与化疗敏感性相关，但尚不清楚CDC2的过度表达是否有助于胶质瘤细胞的化疗耐药潜能。本研究的目的是确定CDC2表达与胶质母细胞瘤预后和化疗耐药性之间的关系。在本研究中，用表达靶向CDC2的短发夹RNA的慢病毒载体稳定转染胶质母细胞瘤U87和U251细胞系。通过免疫组织化学和蛋白质印迹分析评估胶质母细胞瘤和细胞系中CDC2的表达。分析CDC2表达与临床病理特征之间的关系。利用RNA干扰，在体外U87和U251细胞系中研究CDC2对替莫唑胺（TMZ）化疗敏感性的影响。与单独的任何一种处理相比，联合敲低CDC2和TMZ处理在体外更有效地抑制细胞增殖并诱导细胞凋亡。定量逆转录聚合酶链反应（qRT-PCR）和蛋白质印迹分析表明，与用对照载体转染的U87和U251细胞相比，低表达CDC2的细胞显示抗凋亡蛋白B细胞淋巴瘤-2的表达降低，凋亡效应因子半胱天冬酶-3的表达增加。此外，U87和U251细胞中CDC2的表达水平与抗肿瘤药物TMZ的半数抑制浓度（IC50）相关。敲低CDC2表达与经典化疗药物转运体Ral结合蛋白1的表达降低有关。这些结果表明，通过下调CDC2表达来抑制恶性表型的能力可能为克服恶性胶质瘤患者中与CDC2相关的化疗耐药性提供一种新的基因治疗方法。
