Chen Yi, Yu Dongke, Zhang Caixia, Shang Boyang, He Hongwei, Chen Jinjing, Zhang Hao, Zhao Wuli, Wang Zhen, Xu Xiaoyu, Zhen Yongsu, Shao Rong-guang
College of Pharmaceutical Sciences, Southwest University, Chongqing, China; Laboratory of Oncology, MOH Key Laboratory of Antibiotic Bioengineering, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Mol Carcinog. 2015 Jan;54(1):1-8. doi: 10.1002/mc.22069. Epub 2013 Jul 16.
Recently, tumor initiating cells are considered as the central role of tumorigenicity in hepatocellular carcinoma. Enediyne anticancer antibiotic lidamycin with great potential antitumor activity is currently evaluated in Phase II clinical trials. In this study, we evaluated the effect of lidamycin on tumor initiating cells of hepatocellular carcinoma Huh7 and identified the potential mechanism. Flow cytometry analysis and sorting assay, surface marker assay, sphere formation assay, and aldefluor assay were used to evaluate the effect of lidamycin on Huh7 tumor initiating cells in vitro. To investigate the potential mechanism, the activity of GSK3β/β-catenin pathway was detected by Western blot and T cell factors transcriptional activity assay. Subcutaneous tumor model in nude mice was used to observe in vivo effect of lidamycin on Huh7 cells. Lidamycin decreased the proportion of EpCAM+ cells and the expression of EpCAM protein. Lidamycin inhibited sphere formation of sorted EpCAM+ cells in 7 d, and of parental cells in three serial passages. The population of aldehyde dehydrogenase-positive cells was reduced by lidamycin. In addition, lidamycin restrained tumor volume and incidence in vivo. Lidamycin activated GSK3β, and degraded the activity of β-catenin. Consequently, transcriptional activity of β-catenin/T cell factors was decreased. In brief, these results suggest that lidamycin suppressed Huh7 tumor initiating cells via GSK3β/β-catenin pathway. These findings reveal the potential mechanism of lidamycin on tumor initiating cells and the benefit for further clinical evaluation.
最近，肿瘤起始细胞被认为在肝细胞癌的肿瘤发生过程中起核心作用。具有巨大潜在抗肿瘤活性的烯二炔类抗癌抗生素力达霉素目前正在进行II期临床试验评估。在本研究中，我们评估了力达霉素对肝癌Huh7肿瘤起始细胞的作用，并确定了潜在机制。采用流式细胞术分析和分选测定、表面标志物测定、成球测定和醛荧光测定来评估力达霉素在体外对Huh7肿瘤起始细胞的作用。为了研究潜在机制，通过蛋白质免疫印迹法和T细胞因子转录活性测定来检测GSK3β/β-连环蛋白信号通路的活性。利用裸鼠皮下肿瘤模型观察力达霉素对Huh7细胞的体内作用。力达霉素降低了EpCAM+细胞的比例和EpCAM蛋白的表达。力达霉素在7天内抑制了分选的EpCAM+细胞的成球能力，并且在连续三代传代中抑制了亲代细胞的成球能力。力达霉素使醛脱氢酶阳性细胞群体减少。此外，力达霉素在体内抑制肿瘤体积和发病率。力达霉素激活GSK3β，并降低β-连环蛋白的活性。因此，β-连环蛋白/T细胞因子的转录活性降低。简而言之，这些结果表明力达霉素通过GSK3β/β-连环蛋白信号通路抑制Huh7肿瘤起始细胞。这些发现揭示了力达霉素对肿瘤起始细胞的潜在作用机制，有利于进一步的临床评估。
