Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, China; Department of Medical Biochemistry and Microbiology, University of Uppsala, Uppsala, Sweden.
Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, China.
Biochem Biophys Res Commun. 2020 Jan 1;521(1):232-237. doi: 10.1016/j.bbrc.2019.10.114. Epub 2019 Oct 22.
The use of highly efficient high-throughput screening (HTS) platform has recently gained more attention as a plausible approach to identify de novo therapeutic application potential of conventional anti-tumor drugs for cancer treatments. In this study, we used hepatocellular carcinoma (HCC) cells as models to identify cytotoxic compounds by HTS. To identify cytotoxic compounds for potential HCC treatments, 3271 compounds from three well established small molecule libraries were screened against HCC cell lines. Thirty-two small molecules were identified from the primary screen to induce cell death. Particularly, mitoxantrone (MTX), which is an established antineoplastic drug, significantly and specifically inhibited the growth and proliferation of HCC cells in vitro. Mechanistic studies of LC3-II, p62 and phosphorylation of p70S6K in HepG2 cells revealed that MTX treatment induced mTOR-dependent autophagy activation, which was further confirmed by the autophagic flux assay using lysosomal inhibitor chloroquine (CQ). In the combined treatment of MTX and CQ, where autophagy was inhibited by CQ, the elevations of cleaved Caspase-3 and PARP were observed, indicating the enhanced apoptosis in HepG2 cells. Taken together, we hypothesize that MTX-induced autophagy plays an pro-survival role in HCC treatment. Combined treatment with autophagy inhibitor may combat the chemo-resistance of HCC to MTX treatment and therefore deserves future clinical investment.
最近，高效高通量筛选（HTS）平台作为一种可行的方法，用于发现传统抗肿瘤药物在癌症治疗中的新的治疗应用潜力，引起了更多的关注。在这项研究中，我们使用肝癌（HCC）细胞作为模型，通过 HTS 来鉴定细胞毒性化合物。为了鉴定潜在的 HCC 治疗用细胞毒性化合物，我们对 3271 种来自三种成熟的小分子文库的化合物进行了 HCC 细胞系的筛选。从初次筛选中鉴定出 32 种小分子化合物诱导细胞死亡。特别是米托蒽醌（MTX），作为一种已确立的抗肿瘤药物，显著且特异性地抑制 HCC 细胞在体外的生长和增殖。在 HepG2 细胞中对 LC3-II、p62 和 p70S6K 磷酸化的机制研究表明，MTX 处理诱导了 mTOR 依赖性自噬激活，这通过使用溶酶体抑制剂氯喹（CQ）的自噬流测定进一步得到证实。在 MTX 和 CQ 的联合治疗中，CQ 抑制自噬，观察到 cleaved Caspase-3 和 PARP 的升高，表明 HepG2 细胞中的凋亡增强。总之，我们假设 MTX 诱导的自噬在 HCC 治疗中发挥了一种促进生存的作用。联合使用自噬抑制剂可能会对抗 HCC 对 MTX 治疗的耐药性，因此值得未来进行临床投资。
