Laboratory of Translational Cancer Stem Cell Research, Institute of Life Sciences, Chongqing Medical University, Chongqing, China; College of Biomedical Engineering, Chongqing Medical University, Chongqing, China.
Laboratory of Translational Cancer Stem Cell Research, Institute of Life Sciences, Chongqing Medical University, Chongqing, China.
Life Sci. 2018 Aug 1;206:70-76. doi: 10.1016/j.lfs.2018.05.033. Epub 2018 May 18.
Asymmetric division (ASD), the unique characteristic of normal stem cells, is regarded as a stemness marker when applied to the study of cancer stem cells (CSCs). However, the role of ASD in the self-renewal of CSCs and its regulation remain largely unknown. Here, we first established a mouse Lewis lung carcinoma CSC cell line that could undergo asymmetric division (LLC-ASD cells) derived from the parental mouse Lewis lung carcinoma cancer cells (LLC-Parental cells). In vitro assessment of stemness by RT-qPCR and western blot analysis of stem cell markers, clonogenic assay (p < 0.001), single cell spheroid formation assay (p < 0.05) and 96-well-plate single-cell cloning assay (p < 0.01) indicated that the LLC-ASD cells exhibited stronger stemness features in comparison to the LLC-Parental cells. In vivo, tumorigenicity of LLC-ASD cells, transplanted subcutaneously to the nude mice, was increased compared to that of LLC-parental cells (p < 0.05). Further, Neuralized1a, a regulator of ASD in normal stem cells, was highly expressed in the LLC-ASD cells. Silencing Neuralized1a expression in LLC-ASD cells by siRNA weakened the stemness features measured by the in vitro assays listed above (p < 0.05). The tumorigenic ability was also decreased in the nude mice upon Neuralized1a silencing (p < 0.05). Collectively, the present study suggests that Neuralized1a regulates the stemness of LLC-ASD cells which could be the new marker and therapeutic target of CSCs.
不对称分裂 (ASD) 是正常干细胞的独特特征，当其应用于癌症干细胞 (CSC) 的研究时，被视为干细胞标志物。然而，ASD 在 CSCs 自我更新中的作用及其调控机制在很大程度上尚不清楚。在这里，我们首先建立了一个能够进行不对称分裂的小鼠 Lewis 肺腺癌 CSC 细胞系（LLC-ASD 细胞），该细胞系源自亲本小鼠 Lewis 肺腺癌癌细胞（LLC-Parental 细胞）。通过 RT-qPCR 和干细胞标志物的 Western blot 分析、集落形成实验（p<0.001）、单细胞球体形成实验（p<0.05）和 96 孔板单细胞克隆实验（p<0.01）对其进行体外干性评估，结果表明与 LLC-Parental 细胞相比，LLC-ASD 细胞表现出更强的干性特征。在体内，与 LLC-Parental 细胞相比，皮下移植 LLC-ASD 细胞的致瘤性增加（p<0.05）。此外，神经调节蛋白 1a（Neuralized1a）是正常干细胞中 ASD 的调节因子，在 LLC-ASD 细胞中高表达。用 siRNA 沉默 LLC-ASD 细胞中的 Neuralized1a 表达，减弱了上述体外检测的干性特征（p<0.05）。在沉默 Neuralized1a 后，裸鼠的致瘤能力也降低（p<0.05）。综上所述，本研究表明 Neuralized1a 调节 LLC-ASD 细胞的干性，这可能是 CSCs 的新标志物和治疗靶点。
