Methylation of promoter of RBL1 enhances the radioresistance of three dimensional cultured carcinoma cells.
Methylation of promoter of RBL1 enhances the radioresistance of three dimensional cultured carcinoma cells.
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RBL1启动子甲基化增强三维培养癌细胞的放射抗性
DOI：
10.18632/oncotarget.12647
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发表时间：
2017-01-17
期刊：
影响因子：
--
通讯作者：
Hu B
中科院分区：
文献类型：
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作者：
Pan D;Chen Y;Du Y;Ren Z;Li X;Hu B
三维(3D)体外培养是一种新的细胞培养模型，它更接近于体内环境的生理特征，在医学和生物学研究领域得到了广泛的应用。已经证明，与单层(2D)细胞相比，培养在3D基质中的癌细胞具有更强的辐射抗性。然而，造成这种差异的机制在很大程度上仍不清楚。在此，我们发现3D A549细胞的细胞周期分布和细胞周期调控基因的表达与2D细胞不同。与2D细胞相比，3D A549细胞中的RBL1等细胞周期调控基因启动子甲基化水平较高。照射或5-氮杂-镉处理激活了RBL1启动子的去甲基化，并导致RBL1在3DA549细胞中的表达增加。抑制RBL1可增强辐射对A549和MCF7细胞的辐射抗性，减少辐射诱导的G2/M期停滞。RBL1过表达可使3D培养的A549和MCF7细胞对辐射增敏。综上所述，据我们所知，这是第一次揭示RBL1由于其自身启动子甲基化而在3D细胞中的低表达增强了辐射抗性。我们的发现为理解3D培养细胞模型的特点及其在癌症放射治疗和医学发展基础研究中的应用提供了新的曙光。
Three dimensional (3D) culture in vitro is a new cell culture model that more closely mimics the physiology features of the in vivo environment and is being used widely in the field of medical and biological research. It has been demonstrated that cancer cells cultured in 3D matrices are more radioresistant compared with cells in monolayer (2D). However, the mechanisms causing this difference remain largely unclear. Here we found that the cell cycle distribution and expression of cell cycle regulation genes in 3D A549 cells are different from the 2D. The higher levels of the promotor methylation of cell cycle regulation genes such as RBL1 were observed in 3D A549 cells compared with cells in 2D. The treatments of irradiation or 5-Aza-CdR activated the demethylation of RBL1 promotor and resulted in the increased expression of RBL1 only in 3D A549 cells. Inhibition of RBL1 enhanced the radioresistance and decreased the G2/M phase arrest induced by irradiation in 2D A549 and MCF7 cells. Overexpression of RBL1 sensitized 3D cultured A549 and MCF7 cells to irradiation. Taken together, to our knowledge, it is the first time to revealthat the low expression of RBL1 due to itself promotor methylation in 3D cells enhances the radioresistance. Our finding sheds a new light on understanding the features of the 3D cultured cell model and its application in basic research into cancer radiotherapy and medcine development.