Department of Molecular Medicine, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 42601, Korea.
Department of Surgery, Keimyung University Dongsan Hospital, 1035 Dalgubeol-daero, Dalseo-gu, Daegu 41931, Korea.
Int J Mol Sci. 2022 Jun 6;23(11):6353. doi: 10.3390/ijms23116353.
Overexpression of casein kinase 2 (CK2) has an oncogenic and pro-survival role in many cancers. CX-4945 (Silmitasertib) is a CK2 inhibitor with anti-cancerous and anti-angiogenic effects. Up to date, the anti-cancer effect and mechanism of CX-4945 on human cholangiocarcinoma (CCA) remain unclear. This study investigated whether CX-4945 inhibits growth and induces apoptosis of HuCCT-1 cells, a human CCA cell line. Of note, treatment with CX-4945 at 20 μM markedly reduced survival and induced apoptosis of HuCCT-1 cells, as evidenced by nuclear DNA fragmentation, PARP cleavage, activation of caspase-9/3, and up-regulation of DR-4. Although CX-4945 did not affect the phosphorylation and expression of CK2, it vastly inhibited the phosphorylation of CK2 substrates, supporting the drug's efficacy in inhibiting CK2 and its downstream pathway. Importantly, knockdown of CK2 that partially suppressed the phosphorylation of CK2 substrates resulted in a significant reduction of HuCCT-1 cell survival. In addition, CX-4945 reduced the phosphorylation and expression of STAT-3 and STAT-5 in HuCCT-1 cells, and pharmacological inhibition or respective knockdown of these proteins resulted in significant growth suppression of HuCCT-1 cells. CX-4945 also had abilities to decrease Mcl-1 expression while increasing eIF-2α phosphorylation in HuCCT-1 cells. Furthermore, there was a time-differential negative regulation of HIF-1α expression by CX-4945 in HuCCT-1 cells, and knockdown of HIF-1α caused a significant reduction of the cell survival. In summary, these results demonstrated that CX-4945 has anti-growth, anti-angiogenic, and pro-apoptotic effects on HuCCT-1 cells, which are mediated through control of CK2, caspase-9/3, DR-4, STAT-3/5, Mcl-1, eIF-2α, and HIF-1α.
CK2 的过表达在许多癌症中具有致癌和促进存活的作用。CX-4945（Silmitasertib）是一种 CK2 抑制剂，具有抗癌和抗血管生成作用。迄今为止，CX-4945 对人胆管癌（CCA）的抗癌作用和机制尚不清楚。本研究旨在探讨 CX-4945 是否抑制人胆管癌细胞系 HuCCT-1 的生长并诱导其凋亡。值得注意的是，20 μM 的 CX-4945 处理明显降低了 HuCCT-1 细胞的存活率并诱导其凋亡，这表现为核 DNA 片段化、PARP 切割、caspase-9/3 的激活以及 DR-4 的上调。尽管 CX-4945 不影响 CK2 的磷酸化和表达，但它极大地抑制了 CK2 底物的磷酸化，支持了该药物抑制 CK2 及其下游途径的功效。重要的是，CK2 的敲低部分抑制了 CK2 底物的磷酸化，导致 HuCCT-1 细胞存活率显著降低。此外，CX-4945 降低了 HuCCT-1 细胞中 STAT-3 和 STAT-5 的磷酸化和表达，而这些蛋白的药理学抑制或各自的敲低导致 HuCCT-1 细胞的生长受到显著抑制。CX-4945 还能够降低 HuCCT-1 细胞中 Mcl-1 的表达，同时增加 eIF-2α 的磷酸化。此外，CX-4945 对 HuCCT-1 细胞中 HIF-1α 的表达具有时间上的负调节作用，并且 HIF-1α 的敲低导致细胞存活率显著降低。总之，这些结果表明，CX-4945 对 HuCCT-1 细胞具有生长抑制、抗血管生成和促凋亡作用，这是通过控制 CK2、caspase-9/3、DR-4、STAT-3/5、Mcl-1、eIF-2α 和 HIF-1α 来实现的。
