Objective:To detect the effects of polysaccharopeptide(PSP) on MyD88-dependent signaling pathway in EAC tumor-bearing mice,and explore the immunomodulatory mechanism of PSP.Methods: Ehrlich′s ascites carcinoma(EAC) C57BL/6 mice were used to establish the animal model for solid tumor.Mice were divided into two groups:WT group and MyD88-/-group.After 22 days of treatment,quantitative real-time PCR( Q-PCR) ,Western blot and were used to detect the related gene and protein expression of TLR4 pathway in spleens,ELISA were used to detect the terminal effect factors secretion eyeball blood from each group.Results:Related genes and proteins of TLR4 pathway in spleen were up-regulated significantly from two groups.Compared with WT group, related genes and proteins in MyD88-dependent pathway(MyD88,TRAF6,NF-κB,AP-1)was down-regulated in MyD88-/-group(P<0.05).Meanwhile,There was no significant change of the related genes and proteins of MyD88-independent pathway(TRAM,TRIF)in MyD88-/-group( P>0.05 ) .The terminal effect factors secretion of IL-2, IL-6, IL-10, TNF-αand IFN-γin MyD88-/-group were decreased significantly compared with WT group(P<0.05).Conclusion:The immunoregulatory effect of PSP on EAC tumor-bearing mice may be implement through the regulation of MyD88-dependent signaling pathway.

Objective: To investigate the effect and mechanism of polysaccharide of atractylodes macrocephala (PAM) on the growth of colon cancer cells in mice bearing in-situ colon cancer transplantation tumor. Methods: 1×107 colon cancer HT-29 cells labeled with luciferase were injected into colon serosa of the mice to establish the in-situ colon cancer transplantation tumor model. When the tumor volume reached 230 mm3, the mice were given 30 mg/kg PAM (PAM group) or equal volume of normal saline (Control group) by gavage for 10 consecutive days. The effect of PAM on the growth of colon cancer cells in mice was tested by in vivo tumor imaging technology. The expressions of MHCII and IL-12 in granulocytes, dendritic cells and macrophages, the activation of lymphocytes, and IFN-γ expression in CD4+ and CD8+ cells of tumor tissues were detected by Flow cytometry. Results: PAM significantly inhibited the growth of colon cancer cells in mice bearing in-situ colon cancer transplantation tumor (P<0.01). PAM activated immune cells though increasing the expression levels of MHCII and IL-12 in dendritic cells and macrophages (both P<0.01). PAM significantly increased the frequency of CD8+ cells, NK cells, CD44+/NK cells and CD44+/CD4+ cells in tumor tissues and the number of CD8+ cells and NK cells per unit volume (all P<0.01). PAM significantly increased the IFN-γ secretion of CD4+ and CD8+ cells (both P<0.01), too. Conclusion: PAM inhibits the growth of colon cancer by activating immune cells in tumor tissues of mice bearing in-situ colon cancer transplantation tumor.