Sun Siwen, Jing Xiaomeng, Tong Guangquan, Chen Chaoqun, Xie Shuaijun, Wang Chong, Chen Dan, Zhao Jinyao, Qi Yangfan, Zhang Wenjing, Liu Congcong, Zhang Ge, Zhang Jinrui, Sun Bing, Wang Yang, Lv Yuesheng
Department of Oncology & Sino-US Research Center for Cancer Translational Medicine, the Second Affiliated Hospital of Dalian Medical University, Dalian Medical University, Dalian 116023, China.
Sino-US Research Center for Cancer Translational Medicine of the Second Affiliated Hospital of Dalian Medical University & Institute of Cancer Stem Cell, Dalian Medical University, Dalian 116023, China.
Theranostics. 2025 Jan 2;15(5):1879-1895. doi: 10.7150/thno.102425. eCollection 2025.
Lung cancer remains a major global health burden with limited therapeutic options. Alternative splicing, a critical post-transcriptional process, contributes to lung cancer progression through autophagy, although the underlying mechanisms remain largely unexplored. This study aims to elucidate the role of DDX24 as a splicing factor that contributes to lung cancer progression via autophagy. To establish the link between DDX24 and lung cancer progression, we performed colony formation assays, growth curve analyses, and xenograft tumor models in nude mice. Mass spectrometry and RNA sequencing were employed to investigate the involvement of DDX24 in alternative splicing, with a specific focus on the splicing of IKBKG. The mechanisms by which DDX24 regulates autophagy were further explored using co-immunoprecipitation and luciferase reporter assays. The splicing factor DDX24 is significantly elevated in lung cancer tissues. Loss of DDX24 suppresses lung cancer growth by promoting autophagy. We identified DDX24 as a splicing factor that plays critical roles in the regulation of alternative splicing. Mechanistically, DDX24 regulates the alternative splicing of autophagy-related genes, including IKBKG. We demonstrate that DDX24 directly binds to IKBKG pre-mRNA, whereas DDX24 ablation stimulates the generation of the long splicing isoform of IKBKG, thereby promoting autophagy through activating of the NF-kB signaling pathway and the transcription of the BECN1 gene. Functional rescue experiments confirm that the long IKBKG isoform-mediated autophagy confers the anti-tumor effects of DDX24 depletion. In addition, IKBKG-L is positively associated with improved survival in lung cancer patients. This study uncovers a novel regulatory axis involving DDX24, IKBKG splicing, and autophagy in lung cancer. Our findings suggest that targeting DDX24 may represent a promising therapeutic strategy for lung cancer treatment, offering new insights into the molecular underpinnings of this disease.
肺癌仍然是一个重大的全球健康负担,治疗选择有限。可变剪接是一种关键的转录后过程,它通过自噬促进肺癌进展,尽管其潜在机制在很大程度上仍未得到探索。本研究旨在阐明DDX24作为一种剪接因子通过自噬促进肺癌进展的作用。为了建立DDX24与肺癌进展之间的联系,我们进行了集落形成试验、生长曲线分析以及裸鼠异种移植肿瘤模型实验。采用质谱和RNA测序来研究DDX24在可变剪接中的作用,特别关注IKBKG的剪接。使用免疫共沉淀和荧光素酶报告基因检测进一步探索DDX24调节自噬的机制。剪接因子DDX24在肺癌组织中显著升高。DDX24的缺失通过促进自噬抑制肺癌生长。我们确定DDX24是一种在可变剪接调控中起关键作用的剪接因子。从机制上讲,DDX24调节自噬相关基因的可变剪接,包括IKBKG。我们证明DDX24直接结合IKBKG前体mRNA,而DDX24的缺失刺激IKBKG长剪接异构体的产生,从而通过激活NF-κB信号通路和BECN1基因的转录来促进自噬。功能挽救实验证实,长IKBKG异构体介导的自噬赋予了DDX24缺失的抗肿瘤作用。此外,IKBKG-L与肺癌患者生存率的提高呈正相关。本研究揭示了肺癌中一个涉及DDX24、IKBKG剪接和自噬的新型调控轴。我们的研究结果表明,靶向DDX24可能是一种有前景的肺癌治疗策略,为该疾病的分子基础提供了新的见解。