[Influence of tumor-associated macrophages on progression and prognosis of nasopharyngeal carcinoma].

Background & Objective: Tumor-associated macrophages (TAMs) density is negatively correlated to prognosis of lung cancer, breast cancer, and so on, and positively correlated to prognosis of gastric cancer and some colorectal cancer. This study was to investigate the influence of TAMs on the progression and prognosis of nasopharyngeal carcinoma (NPC).

Methods: Immunohistochemistry was adopted to detect the expression of CD68, a marker of TAMs, in 60 specimens of NPC. Macrophages were cocultured respectively with supernatant liquid of NPC cell lines CNE-1 and CNE-2 and lung cancer cell line 95D for 1 day or 6 days, and then activated by LPS for 1 day. The expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10), secreted by TAMs after coculture of TAMs and supernatant liquid of NPC cell lines CNE-1 and CNE-2, was detected by ELISA. The macrophages co-cultured with supernatant of lung cancer cell line 95D was used as positive control; normal macrophages were used as negative control.

Results: The 3-year tumor-freely survival rate was significantly higher in high TAMs density group than in low TAMs density group (85.7% vs. 56.3%, P<0.05). After coculture, the expression levels of TNF-alpha and IL-10 in supernatant were lower in CNE-1 group and CNE-2 group than in 95D group (73 pg/ml, 64 pg/ml vs. 7,794 pg/ml, P=0.001; 1 pg/ml, 1 pg/ml vs. 94 pg/ml, P=0.002); after LPS activation, the expression levels of TNF-alpha and IL-10 were higher in CNE-1 group and CNE-2 group than in 95D group (6,905 pg/ml, 6,788 pg/ml vs. 137 pg/ml, P=0.001; 87 pg/ml, 99 pg/ml vs. 416 pg/ml, P=0.015). But the difference between NPC cell lines and normal macrophages was not significant.

Conclusions: TAMs density is positively correlated to the prognosis of NPC. The cytokines secreted by TAMs trend to kill tumor cells and promote antitumor immune response.