School of Traditional Chinese Medicine, Binzhou Medical University, Yantai 264003, China.
School of Traditional Chinese Medicine, Binzhou Medical University, Yantai 264003, China; Department of Oral and Maxillofacial Surgery, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264003, China.
Phytomedicine. 2024 May;127:155440. doi: 10.1016/j.phymed.2024.155440. Epub 2024 Feb 9.
The high metastasis and mortality rates of head and neck squamous cell carcinoma (HNSCC) urgently require new treatment targets and drugs. A steroidal component of ChanSu, telocinobufagin (TBG), was verified to have anti-cancer effects in various tumors, but its activity and mechanism in anti-HNSCC were still unknown.
This study tried to demonstrate the anti-tumor effect of TBG on HNSCC and verify its potential mechanism.
The effect of TBG on cell proliferation and metastasis were performed and the TBG changed genes were detected by RNA-seq analysis in HNSCC cells. The GSEA and PPI analysis were used to identify the pathways targeted for TBG-regulated genes. Meanwhile, the mechanism of TBG on anti-proliferative and anti-metastasis were investigated in vitro and in vivo.
The in vitro and in vivo experiments confirmed that TBG has favorable anti-tumor effects by induced G2/M phase arrest and suppressed metastasis in HNSCC cells. Further RNA-seq analysis demonstrated the genes regulated by TBG were enriched at the G2/M checkpoint and PLK1 signaling pathway. Then, the bioinformatic analysis of clinical data found that high expressed PLK1 were closely associated with poor overall survival in HNSCC patients. Furthermore, PLK1 directly and indirectly modulated G2/M phase and metastasis (by regulated CTCF) in HNSCC cells, simultaneously. TBG significantly inhibited the protein levels of PLK1 in both phosphorylated and non-phosphorylated forms and then, in one way, inactivated PLK1 failed to activate G2/M phase-related proteins (including CDK1, CDC25c, and cyclin B1). In another way, be inhibited PLK1 unable promote the nuclear translocation of CTCF and thus suppressed HNSC cell metastasis. In contrast, the anti-proliferative and anti-metastasis effects of TBG on HNSCC cell were vanished when cells high-expressed PLK1.
The present study verified that PLK1 mediated TBG induced anti-tumor effect by modulated G2/M phase and metastasis in HNSCC cells.
头颈部鳞状细胞癌（HNSCC）的高转移率和高死亡率迫切需要新的治疗靶点和药物。蟾酥的甾体成分华蟾酥毒基（TBG）已被证实对多种肿瘤具有抗癌作用，但在抗 HNSCC 中的活性和机制尚不清楚。
本研究旨在探讨 TBG 对 HNSCC 的抗肿瘤作用，并验证其潜在机制。
采用 RNA-seq 分析检测 TBG 对 HNSCC 细胞增殖和转移的影响，检测 TBG 改变的基因。采用 GSEA 和 PPI 分析鉴定 TBG 调控基因的靶向途径。同时，在体外和体内研究 TBG 对增殖和转移的抑制作用。
体外和体内实验证实，TBG 通过诱导 G2/M 期阻滞和抑制 HNSCC 细胞转移，具有良好的抗肿瘤作用。进一步的 RNA-seq 分析表明，TBG 调控的基因在 G2/M 检查点和 PLK1 信号通路中富集。然后，对临床数据的生物信息学分析发现，高表达的 PLK1 与 HNSCC 患者的总生存期不良密切相关。此外，PLK1 直接和间接调节 HNSCC 细胞的 G2/M 期和转移（通过调节 CTCF），同时，TBG 显著抑制了 PLK1 的磷酸化和非磷酸化形式的蛋白水平，从而使 PLK1 失活，无法激活 G2/M 期相关蛋白（包括 CDK1、CDC25c 和 cyclin B1）。另一方面，抑制 PLK1 不能促进 CTCF 的核转位，从而抑制 HNSC 细胞的转移。相比之下，当细胞高表达 PLK1 时，TBG 对 HNSCC 细胞的增殖和转移抑制作用消失。
本研究证实，PLK1 介导 TBG 诱导的 HNSCC 细胞抗肿瘤作用是通过调节 G2/M 期和转移实现的。
