Objective To analyze the changes of myeloid-derived suppressor cells (MDSCs) in peripheral blood and serum nitric oxide in tumor-bearing mice, and to explore their correlation and functions in tumor progression. Methods Orthotopic transplantation tumor model of hepatocarcinoma in mice was established. At the 7th, 14th, 21st day after tumor implantation, the proportion of peripheral blood MDSCs was tested by flow cytometry, and serum nitric oxide was detected using the method of nitric acid reductase. Results The proportion of peripheral blood MDSCs at the 7th, 14th, 21st day after tumor implantation in tumor-bearing mice was significantly higher than that in normal mice [(8.65±1.01)%, (14.20±2.52)%, (27.51± 2.98) % vs. (2.51 ±0.44) %, P<0.05]. The level of nitric oxide at the 7th, 14th, 21st day after tumor implantation in tumor-bearing mice was significantly lower than that in normal mice [(72.02 ±5.05) μmol/L, (94.70 ±3.34) μmol/L, (78.90 ± 8.19) μmol/L vs. (57.03 ±16.94) μmol/L, P<0.05]. The level of serum nitric oxide was positively associated with the proportion of MDSCs (r=0.689, P<0.01). Conclusion The proportion of peripheral blood MDSCs and the level of serum nitric oxide in mice are increased with the tumor progression, and there is a positive correlation between them.

Objective To investigate the expression and correlation of P73 and PS3 proteins in esophagus squamous cell carcinoma. Methods The immunohistochemistry staining assay was conducted to detect the expression of PS3 and P73 proteins in 46 cases with squamous cell carcinoma of esophagus and 30 normal mucosa cases. The protein expressions and clinic pathological observation and the correlation between two proteins were statistically analyzed. Results The expression of P53 and P73 proteins showed differences between esophageal cancer tiksue and normal mucosa ( P = 0.007,0.008) . The expression of P53 appeared to be correlated with lymph node metastasis(P = 0.047) and gender(P =0.028),but not correlated with age, the depth of invasion , differentiation of cancer tissue, gross observation and position of the tumor( P > 0.05 ). The expression of P73 appeared to be correlated with differentiation of cancer tissue and lymph node metastasis ( P = 0. 023, 0.035), but not correlated with age, gender, the depth of invasion,gross observation and position of the tumor (P >0.05). P73 expression was positively corelated with P53 expression in squamous cell carcinoma of the esophagus ( r = 0.359 ,P = 0.014 ). Conclusion Both P73 and P53 proteins are associated with the occurrence of squamous cell carcinoma of the esophagus and participate in the development of esophagus squamous cell carcinoma.

Objective:The changes and distribution of myeloid-derived suppressor cells (MDSCs) in spleen of tumor-bearing mice was studied,and its function in tumor escape was investigated.Methods:Orthotopic transplantation tumor model of hepatocarcinoma in mice was established.At the 7th,14th,21st day after tumor implantation,the proportion of MDSCs in spleen was tested by flow cytometry.The localization of MDSCs and semi-quantitative analysis was conducted by immunohistochemistry.Results:The proportion of spleen MDSCs in tumor-bearing mice was significantly higher than in normal mice (P

The rat anti-HRP McAbs were prepared with rat-rat hybridoma and the rat McPAP complex was made by conjugating this McAb with HRP. The results of the present work indicated that the rat MePAP can be used for detection of antibodyantigen reaction by immunohistochemical techniques and ELISA. In both assay it gave strong staining reaction for positive antigen and with background staining appeared very pale. The sensitivity of rat McPAP and HRP labelling rabbit anti-rat IgG has been compared.

Objective To investigate the effects of 5-fluorouracil (5-FU) on the distribution, pro-portion and immunosuppressive activities of myeloid-derived suppressor cells (MDSCs) in a mouse model of liver cancer.Methods Orthotopic transplantation of H22 cell line was performed to establish the mouse model of orthotopic liver cancer.Forty mice were randomly divided into four groups (n=10) on the 7th day after transplantation.Three different doses of 5-FU (10 mg/kg, 30 mg/kg and 50mg /kg) and 0.4 ml of PBS were respectively given to the mice in each group for 10 consecutive days .A control group without canc-er cell transplantation was set up correspondingly .The distribution of MDSCs in mice liver tissues was detec-ted by immunohistochemistry .The proportions of MDSCs in spleen tissues were tested by flow cytometry . The levels of IFN-γand Arginase-I ( Arg-I) in serum samples were analyzed by enzyme-linked immunosor-bent assay.The activities of nitric oxide synthetase (NOS) in serum samples were tested by chemical colori-metry.The proliferation of T lymphocytes was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltet-razolium bromide (MTT) test.Results 5-FU reduced the tumor size and alleviated the adhesion between liver tissues and abdominal cavity in mice with liver cancer in a dose-dependent manner .The proportions of MDSCs in liver and spleen tissues from mice in four model groups were significantly higher than those in con - trol group (P<0.05).The highest proportions of MDSCs were observed in PBS treated group , followed by 10 mg/kg of 5-FU treated group , 30 mg/kg of 5-FU treated group and 50 mg/kg of 5-FU treated group .Ex-cept for comparing between PBS treated group and 10 mg/kg of 5-FU treated group, there were significant differences with the proportions of MDSCs in liver tissues among other groups (P<0.05).The levels of Arg-I and the activities of NOS in mice with liver cancer were higher than those in control group (P<0.05).The mice in PBS treated group showed the highest level of Arg-I and the strongest activities of NOS that were de-creased as concentrations of 5-FU increased( P<0.05).The levels of IFN-γin serum samples from mice with liver cancer were lower than those in control group , and the lowest level was detected in PBS treated group.IFN-γlevels were increased as concentrations of 5-FU elevated.Except for comparing between PBS treated group and 10 mg/kg of 5-FU treated group , significant differences with the levels of IFN-γin serum samples (P<0.05) were observed among other groups .No significant differences with the proliferation of T cells were observed among all groups after 24 hours of culture (P>0.05),but that were decreased in model groups than those in control group after 48 hours of culture (P<0.05).T cells from mice in PBS treated group showed the lowest level of proliferation .T cell proliferation was enhanced upon the treatment of 5-FU in a dose-dependent manner .Except for comparing between PBS treated group and 10 mg/kg of 5-FU treated group, significant differences with T cell proliferation were observed among other groups (P<0.05).The proportions of MDSCs in liver and spleen tissues were positively correlated with the levels of Arg -I and the activities of NOS, but negatively correlated with IFN-γlevel and T cell proliferation at the time point of 48 h.Conclusion To a certain extent , 5-FU could reduce the numbers of MDSCs in liver and spleen tis-sues from mice with liver cancer , inhibit immunosuppressive activities of MDSCs and restrain the growth of the tumor in a dose-dependent manner .