Radiotherapy is a critical modality in cancer treatment, not only to eradicate cancer cells but also to trigger antitumor immunity. IL-21, an immunomodulatory cytokine with potential in cancer therapy, has unexplored synergy with radiotherapy. Our study, leveraging human cancer databases and tissue microarrays, identified a positive correlation between IL-21 and radiotherapy outcomes, particularly in tumor microenvironment (TME) activation. In mouse tumor models, IL-21 combined with radiation significantly enhanced the TME, boosting CD8+ T cell activation and function, reducing tumor burden, and extending survival. Single-cell transcriptome sequencing revealed that the combination of IL-21 and radiation increased the cytotoxicity of effector and memory CD8+ T cells and prevented their exhaustion. These effects were further validated in humanized mice, where IL-21 combined with radiation reduced A549 tumor growth and enhanced CD8+ T cell function. Post-neoadjuvant radiotherapy samples from patients with esophageal cancer showed a positive correlation between IL-21 levels and CD8+ T cell infiltration. Our findings suggest that IL-21 is a promising adjuvant to radiotherapy, potentially improving treatment efficacy through TME enhancement. This study provides a foundation for future clinical exploration of IL-21 for enhancing radiotherapy.
Xin-yang Li, Xue-qi Xie, Bao-chao Wei, Xiao-zheng Sun, Min-xin Chen, Ru-fei Liu, Qing-xu Tao, Yi-heng Huang, Qian Wang, Shuang-shuang Ma, Ling Wei, Rong Xiao, Zhao-yun Liu, Jin-ming Yu, Meng Wu, Dawei Chen
Usage data is cumulative from January 2026 through June 2026.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 2,120 | 0 |
| 705 | 0 | |
| Figure | 499 | 0 |
| Supplemental data | 256 | 0 |
| Citation downloads | 240 | 0 |
| Totals | 3,820 | 0 |
| Total Views | 3,820 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.