The Changes in Myeloid Derived Suppressor Cells in Mice with Hepatic Transplanted Tumor and the Regulatory Effects of Arsenious Acid / 中国肿瘤临床

ABSTRACT

Objective: To discuss the correlation between myeloid derived suppressor cells (MDSCs) and hepatic trans-planted tumor and to explore new ways to inhibit the development of hepatic cancer. Methods: We established the animal models with H_(22) hepatic carcinoma cells transplanted to the anterior right limb. Then the MDSCs morphology was observed with confocal microscopy and the proportion of MDSCs in blood and spleen was measured with flow cytometry. The 36 mice were divided into three groups the control group, the low-dose group (2mg/kg) and the high-dose group (4mg/kg). Then As_2O_3 was injected twice a week to the mice before repeating the aforementioned measures. The direct effects of As_2O_3 on MDSCs cultured with H_(22)-ascites supernatant was observed. Results: At 25 days after transplantion, the tumor weight was increased to 5.67g, and the proportion of MDSCs in blood and spleen was increased to 20.46% and 9.50%, re-spectively. There was a positive correlation between hepatic transplanted tumor and MDSCs in blood and spleen and the relative factors were 0.95 and 0.96, respectively (t=-5.270 and 5.939, P<0.05). With the effect of As_2O_3, the proportion of MD-SCs in blood in low-dose group and high-dose group was 11.31% and 10.00% at 28 days after treatment, lower than that in the control group (t=3.193 and 5.486, P<0.05), and there was also a statistical difference between the high-dose group and low-dose group (t=3.066, P<0.05). The proportion of MDSCs in the spleen in low-dose group and high-dose group was 10.90% and 9.04% at 28 days, lower than that in the control group (t=3.586.and 5.279, P<0.05), but there was no statistical difference between the high-dose group and low-dose group (1=1.298, P>0.05). In vitro, the proportion of MDSCs in nutrient fluid was increased to 12.67% at 12 days after treatment with H_(22)-ascites supematant, and was decreased to 7.44% at 18 days after treatment with As_2O_3. Conclusion: The proportion of MDSCs in H_(22) tumor-bearing mice is increased because of tu-mor development. There is a positive correlation between MDSCs and hepatic transplanted tumor. As_2O_3 can decrease MD-SCs and inhibit tumor growth.