Exploration of Anti-cancer Mechanism of Lycium bararum Polysaccharide Plus Interferon-inducible Protein 10 Through Observation of Inducing Maturation of Dendritic Cells / 广州中医药大学学报

ABSTRACT

Objective To investigate the potential role of Lycium bararum polysaccharide (LBP) with or without interferon -inducible protein 10 ( CXCL10) in inducing dendritic cells ( DC) functional maturation by monitoring the alteration of cytokines for inducing DC maturation in peripheral blood and by detecting the expression of S-100 protein in tumor tissue, thus to reveal its mechanism of inhibiting experimental liver cancer. Methods H22 bearing mice model was established. The mice were randomized into model group, LBP group (50 mg/kg, ig), CXCL10 (right axillary subcutaneous injection of 15 μg/kg), LBP + CXCL10 group (LBP 50 mg/kg, ig, and right axillary subcutaneous injection of CXCL10 15 μg/kg), 5- fluorouracil (5FU) group ( intraperitoneal injection of 12mg/kg) , 12 mice in each group. The mice were administered the corresponding medicine once a day. After treatment for 2 continuous weeks, blood was sampled from infraorbital vein, and the tumor mass, spleen, thymus were extracted for the calculation of anti-tumor rate, thymus index and spleen index separately . The mRNA expression levels of interleukin 12 (IL-12) and tumor necrosis factor-α (TNF-α) in peripheral blood were detected by fluorescence quantitative PCR, the expression of S-100 protein in tumor tissues was detected by immunohistochemical assay. Results Compared with the model group, tumor growth in LBP group and LBP+CXCL10 group was obviously inhibited, and tumor-inhibitory rate was 55.90%, 50.91%, respectively. Meanwhile, the mRNA expression level of IL-12 was 2.94 folds higher in LBP group and 3.39 folds higher in LBP + CXCL10 group, and TNF-α mRNA expression level was 1.55 folds higher in LBP group and 4.74 folds higher in LBP+CXCL10 group than the model group, the differences being statistical significant ( P<0.05 or P<0.01). Results of immunohistochemical assay showed that S-100+DC number in LBP group and LBP+CXCL10 group was larger than that in the model group (P<0.05 ). Conclusion LBP and LBP+CXCL10 exert significant effect on inhibiting experimental liver cancer. The mechanism may be related with inducing the secretion of IL-12 and TNF-α, which plays a key role in inducing DC maturation, and with the increase of the number of DC in tumor microenvironment.