J Cancer 2024; 15(3):623-631. doi:10.7150/jca.90085 This issue Cite
Research Paper
1. Department of Urology, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
2. Emergency and Disaster Medical Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
3. Edmond H. Fischer Translational Medical Research Laboratory, Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
4. Clinical laboratory, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
*These authors have contributed equally to this work and share first authorship
Bladder instillation therapy is a common treatment for superficial or nonmuscle invasive bladder cancer. After surgery or reresection, chemotherapy drugs (epirubicin) or medications such as Bacillus Calmette-Guérin (BCG) are used for bladder instillation therapy, which can reduce the risk of bladder cancer recurrence and progression. However, the specific mechanism by which BCG stimulates the antitumor response has not been thoroughly elucidated. Additionally, although BCG immunotherapy is effective, it is difficult to predict which patients will have a positive response. In this study, we explored the BCG-induced immune response and found that high levels of Fms-related receptor tyrosine kinase 3 ligand (FLT3LG) were expressed after BCG treatment. This FLT3LG can directly act on CD8+ T cells and promote their proliferation and activation. The use of FLT3 inhibitors can neutralize the antitumor effects of BCG. In vitro experiments showed that FLT3LG can synergize with T-cell receptor activators to promote the activation of tumor-derived T cells. This study partially elucidates the mechanism of CD8+ T-cell activation in BCG immunotherapy and provides a theoretical basis for optimizing BCG instillation therapy in bladder cancer
Keywords: Bacillus Calmette-Guérin (BCG), FLT3, FLT3LG, T-cell activation