The significant increase and dynamic changes of the myeloid-derived suppressor cells percentage with chemotherapy in advanced NSCLC patients.

PURPOSE

To investigate the correlations between myeloid-derived suppressor cells (MDSCs) in the peripheral blood and cancer stage, immune function, and chemotherapy.

METHODS

Percentages of MDSCs (CD11b(+)CD14(-)CD33(+) cells) and lymphocyte subsets in peripheral blood mononuclear cells (PBMCs) of 94 patients with Non-small cell lung cancer (NSCLC) who were treated naïve and 30 healthy individuals were measured. Changes of the MDSCs percentage were further detected in patients with advanced NSCLC treated with systemic chemotherapy. Finally, coculture with CD8(+) cells was developed to determine effect of MDSCs on IFN-γ secretion of T lymphocytes.

RESULTS

MDSCs percentage of 94 patients with NSCLC was significantly higher than that of 30 healthy subjects (P < 0.05), the percentages were increased with tumor progression, in patients with stage III and IV percentages were significantly higher than those in stage I and II patients (P = 0.013). The MDSCs percentage was negatively related to percentage of CD8(+) cells in the peripheral blood (r = -0.354, n = 38, P = 0.029), and when they were cocultured, IFN-γ secretion of CD8(+) cells was significantly decreased (P < 0.05). In 20 patients with advanced NSCLC who received systemic chemotherapy, nine partial remission (PR) cases got MDSCs percentage significantly decreased (P < 0.001), three stable disease (SD) cases remained invariable (P = 0.307) and eight progressive disease (PD) cases got significantly increased (P = 0.024).

CONCLUSION

The percentage of MDSCs in the patients was significantly higher than that of the healthy control subjects and it increased with tumor progression partially by inhibiting the CD8(+) cell function. The dynamic changes of MDSCs percentage reflected the efficacy of systemic chemotherapy.