Atractylodes macrocephala polysaccharides regulate the innate immunity of colorectal cancer cells by modulating the TLR4 signaling pathway.

BACKGROUND: It has been well-recognized that the polysaccharides from Atractylodes macrocephala (PAM) are immune system enhancers, which can facilitate the proliferation of lymphocytes and stimulate immune cells. Nevertheless, the antitumor effects of PAM and their molecular mechanisms remain unclear. AIM: Our research aimed to evaluate the anti-cancer effects of PAM on colorectal cancer (CRC). METHODS: We tested the effects of PAM on the growth and proliferation of CRC cells and macrophages by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The pro-inflammatory cytokines expression and secretion was analyzed by real-time RT-PCR and ELISA assay. We also used MC38 cells xenograft model to test the anti-cancer effects of PAM in vivo. RESULTS: We found that although PAM treatment did not significantly affect the growth of CRC cells or enhance the proliferation of bone marrow-derived macrophages (BMDMs), it could enhance the phagocytosis of BMDMs by CRC cells. Biochemical tests and immunoblotting assays revealed that exposing BMDMs to PAM promoted the production of interleukin-6 (IL-6), interferon λ (IFN λ), tumor necrosis factor α (TNF-α), and nitric oxide (NO) through the MyD88/TLR4-dependent signaling pathway. One noteworthy observation is that PAM treatment could significantly prevent tumorigenesis of MC38 cells in C57BL/6J mice and increase the survival duration of mice with tumors, without influence on the weight of those mice. However, the anti-cancer effects of PAM were compromised in TLR4 KO mice, further suggesting that TLR4 signaling plays a vital role in the anti-cancer effects of PAM. CONCLUSION: Therefore, PAM may prove to be a potential candidate in cancer immunotherapy.

Polysaccharide of atractylodes macrocephala inhibits the growth of mice in-situ colon cancer HT-29 cell xenograft via activating immune cells / 中国肿瘤生物治疗杂志

@# 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.

Dissociated roles of the parietal and frontal cortices in the scope and control of attention during visual working memory.

Mounting evidence suggests that multiple mechanisms underlie working memory capacity. Using transcranial direct current stimulation (tDCS), the current study aimed to provide causal evidence for the neural dissociation of two mechanisms underlying visual working memory (WM) capacity, namely, the scope and control of attention. A change detection task with distractors was used, where a number of colored bars (i.e., two red bars, four red bars, or two red plus two blue bars) were presented on both sides (Experiment 1) or the center (Experiment 2) of the screen for 100ms, and participants were instructed to remember the red bars and to ignore the blue bars (in both Experiments), as well as to ignore the stimuli on the un-cued side (Experiment 1 only). In both experiments, participants finished three sessions of the task after 15min of 1.5mA anodal tDCS administered on the right prefrontal cortex (PFC), the right posterior parietal cortex (PPC), and the primary visual cortex (VC), respectively. The VC stimulation served as an active control condition. We found that compared to stimulation on the VC, stimulation on the right PPC specifically increased the visual WM capacity under the no-distractor condition (i.e., 4 red bars), whereas stimulation on the right PFC specifically increased the visual WM capacity under the distractor condition (i.e., 2 red bars plus 2 blue bars). These results suggest that the PPC and PFC are involved in the scope and control of attention, respectively. We further showed that compared to central presentation of the stimuli (Experiment 2), bilateral presentation of the stimuli (on both sides of the fixation in Experiment 1) led to an additional demand for attention control. Our results emphasize the dissociated roles of the frontal and parietal lobes in visual WM capacity, and provide a deeper understanding of the neural mechanisms of WM.

The Role of the Frontal and Parietal Cortex in Proactive and Reactive Inhibitory Control: A Transcranial Direct Current Stimulation Study.

Mounting evidence suggests that response inhibition involves both proactive and reactive inhibitory control, yet its underlying neural mechanisms remain elusive. In particular, the roles of the right inferior frontal gyrus (IFG) and inferior parietal lobe (IPL) in proactive and reactive inhibitory control are still under debate. This study aimed at examining the causal role of the right IFG and IPL in proactive and reactive inhibitory control, using transcranial direct current stimulation (tDCS) and the stop signal task. Twenty-two participants completed three sessions of the stop signal task, under anodal tDCS in the right IFG, the right IPL, or the primary visual cortex (VC; 1.5 mA for 15 min), respectively. The VC stimulation served as the active control condition. The tDCS effect for each condition was calculated as the difference between pre- and post-tDCS performance. Proactive control was indexed by the RT increase for go trials (or preparatory cost), and reactive control by the stop signal RT. Compared to the VC stimulation, anodal stimulation of the right IFG, but not that of the IPL, facilitated both proactive and reactive control. However, the facilitation of reactive control was not mediated by the facilitation of proactive control. Furthermore, tDCS did not affect the intraindividual variability in go RT. These results suggest a causal role of the right IFG, but not the right IPL, in both reactive and proactive inhibitory control.

Polysaccharopeptide exerts immunoregulatory effects via MyD88-dependent signaling pathway.

AIMS: The present study is to investigate the immunomodulatory mechanism and related pathways of polysaccharopeptide (PSP) in mice bearing Ehrlich's ascites carcinoma (EAC). METHODS: Twelve female wild-type C57 mice were randomly divided into three groups. Another twelve female myeloid differentiation factor 88 (MyD88)-deficient mice were randomly assigned to three groups. Cell survival and peritoneal macrophage phagocytosis were measured using WST8 assay. Nitric oxide concentration was determined by Griess reaction. ELISA was used to measure tumor necrosis factor-α and interferon-γ levels. Quantitative real-time PCR was employed to measure mRNA levels. Western blotting was performed to determine protein expression. RESULTS: PSP significantly inhibited the proliferation of EAC cells via macrophage activation. PSP-primed macrophages exhibited a higher tumoricidal activity than untreated macrophages. PSP markedly inhibited the growth of the tumor and increased macrophage phagocytosis, nitric oxide release and cytokine secretion. Expression of MyD88 was markedly increased in PSP-treated groups, while ST2825 inhibited MyD88 signaling and interfered with nitric oxide release and the secretion of tumor necrosis factor-α and interferon-γ. Moreover, mRNA and protein levels associated with MyD88-dependent signaling pathway in MyD88-deficient mice group were significantly down-regulated compared with wild-type mice group. CONCLUSIONS: PSP plays an immunoregulatory effect through MyD88-dependent signaling pathway.

A study on immunomodulatory mechanism of Polysaccharopeptide mediated by TLR4 signaling pathway.

BACKGROUND: Polysaccharopeptide (PSP), isolated from Coriolus versicolor COV-1 strain, is a protein-bound polysaccharide widely used as immunoadjuvant for cancer immunotherapy. Although the immunomodulatory activity of PSP has been well established, the precise molecule mechanisms of its biological activity have yet to be fully elucidated. METHODS: In the present study, we first investigated the immunomodulatory activity of PSP in peritoneal macrophages from C57BL/10J (TLR4(+/+)) and C57BL/10ScCr (TLR4(-/-)) mice carrying a defective toll-like receptor-4 (TLR4) gene and then evaluated PSP for its effect on tumor inhibition rates and the immune organ index in above two different strains of mice. In addition, PSP were also evaluated for its activation of TLR4, TLR4-downstream molecules (TRAF6, NF-κB and AP-1) in spleens of tumor-bearing C57BL/10J (TLR4(+/+)) and C57BL/10ScCr (TLR4(-/-)) mice. RESULTS: The results showed that PSP had adjuvant activities in stimulating expressions of cytokines as well as TLR4, TRAF6, phosphorylation of NF-κB p65 transcription factors and phosphorylation of c-Jun (a component of the transcription factor AP-1) in peritoneal macrophages from C57BL/10J (TLR4(+/+)) mice but not from C57BL/10ScCr (TLR4(-/-)) mice. In vivo PSP as well as Adriamycin (ADM) decreased the mean weights of tumors compared with normal saline and PSP increased thymus index and spleen index relative to ADM in tumor-bearing C57BL/10J (TLR4(+/+)) mice but not in C57BL/10ScCr (TLR4(-/-)) mice. CONCLUSIONS: We demonstrated that PSP activates peritoneal macrophages in vitro via TLR4 signaling pathway and PSP functions its immunoregulatory effect in vivo also via TLR4 signaling pathway. These data strongly suggest TLR4 signaling pathway is involved in PSP-mediated immunomodulatory activities.

[Expression and significance of MMP-26, TIMP-4 and MMP-9 in diffuse large B-cell lymphoma cells].

The aim of this study was to investigate the expression of matrix metalloproteinase 26 (MMP-26), tissue inhibitor of metalloproteinase-4 (TIMP-4) and matrix metalloproteinase 9 (MMP-9) in patients with diffuse large B cell lymphoma (DLBCL) and their correlations with pathogenesis and development of DLBCL. A total of 95 specimens excised from DLBCL patients were prepared. Expression of MMP-26, TIMP-4 and MMP-9 were tested by SABC immunohistochemistry method and its correlation to clinicopathology indexes were analyzed. The results showed that as compared with reactive hyperplasia of lymph nodes, the high expression of MMP-26, TIMP-4 and MMP-9 were found in different types of DLBCL. The positive expression rate of MMP-26 was related to immune typing (P < 0.05). The expression level of MMP-26 in GCB was lower than that in non-GCB, and did not relate to clinical staging, age, sex, diseased region (P > 0.05). The positive expression rate of MMP-9 was related to clinical staging, the positive expression rate of MMP-9 proteins in patient at III and IV stage was obviously higher than that in patients at I and II stage, but did not relate to immune type, age, sex and diseased region of DLBCL (P > 0.05). The expression of TIMP-4 did not relate to immune type, clinical stage, age, sex, disease region (P > 0.05). The expression of MMP-26 in pathologic tissue of DLBCL did not relate to expression of TIMP-4, but positively related to expression of MMP-9 protein (r = 0.486, P < 0.05). It is concluded that MMP-26 and MMP-9 synergically express in DLBCL. MMP-26 may be involve in pathogenesis and invasiveness of DLBCL, the expression of MMP-26 relates to subtypes of DLBCL. The MMP-26 may serve as an indicator for typing of DLBCL and contributes to predict the invasion and metastasis of DLBCL and itself may become a potential target for therapy.