RNA-binding protein HuR inhibition induces multiple programmed cell death in breast and prostate cancer

作者：Lanjing Wei, Sung Hae Kim, Ahlam M. Armaly, Jeffrey Aubé, Liang Xu, Xiaoqing Wu · 发表于：Cell Communication and Signaling · 年份：2024 · DOI：10.1186/s12964-024-01916-z · 被引用次数：14 · 研究领域：RNA Research and Splicing、RNA modifications and cancer、Cancer-related molecular mechanisms research

The RNA-binding protein Hu antigen R (HuR) plays a pivotal role in cancer progression, and previous studies have demonstrated its involvement in suppressing cell death in cancer. However, the precise mechanisms underlying HuR inhibition-induced cell death remain elusive. Here, we investigated the impacts of HuR functional inhibition via the small molecule inhibitor KH-3 on cell proliferation, colony formation, and cell death across multiple cancer cell lines, with an emphasis on breast and prostate cancers. KH-3 treatment induced apoptotic cell death of various cancer cell lines, as well as autophagy-associated cell death and ferroptosis. Remarkably, KH-3-induced cell death was partially rescued by an autophagy inhibitor and a ferroptosis inhibitor. The anti-tumor effects of KH-3 were further validated in two mouse xenograft models of human prostate cancer. Mechanistically, KH-3 reduced the expression of HuR targets involved in apoptosis and ferroptosis suppression, including cFLIP and SLC7A11, respectively. Moreover, cFLIP silencing enhanced Caspase-8 activation as well as PARP cleavage in both breast cancer and prostate cancer cells. Both KH-3-induced pharmacological HuR inhibition and RNA interference-mediated HuR knockdown reduced the expression of SLC7A11. Additionally, KH-3 also reduced XIAP and Survivin, enhancing the activation of multiple caspases and leading to apoptosis. This study highlights the critical roles of HuR in programmed cell death regulation, advocating...