Expression of Infiltrating NK Cell Surface Receptors in Peripheral Blood and Cancer Tissues of Patients with Esophageal Squamous Cell Carcinoma

Objective To analyze the ratio and the surface receptor expression of natural killer (NK) cells in peripheral blood and cancer tissues of esophageal squamous cell carcinoma (ESCC) patients.

Methods NK cell ratio and its surface receptor expression were detected by flow cytometry.

Results The ratio of NK cells in ESCC tissues was significantly higher than that in normal tissues. The expression of CD16 in peripheral blood of ESCC patients was not significantly different from that of healthy controls, however, that in cancer tissues was significantly lower than that in normal tissues. The expression of NKp30 and NKG2D in cancer tissues were significantly lower than those in normal tissues. The expression of NKp44 was significantly higher than that in normal tissues. In the same patient, the expression of CD16, NKp30 and NKG2D in cancer tissues were significantly lower while the expression of NKp44 and NKG2A were higher than those in peripheral blood. The number of infiltrating NK cells both in peripheral blood and cancer tissues were negatively correlated with the progression of tumor.

Conclusion The imbalance of NK cell surface receptor expression in ESCC tissues may mediate the immune escape of esophageal squamous cell carcinoma.