Background: Natural killer (NK) cells are crucial innate components in anti-tumor immunity. However, the clinical impacts and their phenotypes in bladder cancer (BC) remain unclear.
Objective: To assess the clinical significance of NK cell subsets in tumor-draining lymph nodes of patients with BC.
Methods: In a cross-sectional study, pelvic lymph nodes were obtained from 49 untreated patients with BC. Mononuclear cells were isolated and immunophenotyped using CD3, CD56, CD16, CD27, and CD11b markers. NK cells were then classified based on their expression patterns of CD56/CD16 (conventional) and CD27/CD11b (new).
Results: On average, NK cells constituted 2.99±1.44% of the total lymphocytes in the draining lymph node of patients with BC. The CD56^dim and regulatory NK subsets (CD27⁺CD11b^+/-) were the predominant old and new NK, respectively. The NK cells significantly increased in patients with at least one involved node (LN⁺) compared with those with free nodes (LN^-; p=0.022). Conversely, CD56^dimCD16^- subset significantly decreased in higher stages (p=0.032) and in tumors with muscle invasion (p=0.038). Significant variations were also observed in different T-stages (p<0.05). Regarding new classification, the frequency of CD11b⁺ regulatory NK cells was significantly lower in node-positive patients (p=0.025).
Conclusion: These findings emphasize the dynamic nature of NK cell subsets in bladder cancer and their potential relevance in disease progression and management, suggesting potential implications for therapeutic strategies targeting these specific subsets.