WSS25, a sulfated polysaccharide, inhibits RANKL-induced mouse osteoclast formation by blocking SMAD/ID1 signaling.

AIM: WSS25 is a sulfated polysaccharide extracted from the rhizome of Gastrodia elata BI, which has been found to bind to bone morphogenetic protein 2 (BMP-2) in hepatocellular cancer cells. Since BMP-2 may regulate both osteoclasts and osteoblasts, here we investigated the effects of WSS25 on osteoclastogenesis in vitro and bone loss in ovariectomized mice. METHODS: RAW264.7 cells or mouse bone marrow macrophages (BMMs) were treated with RANKL to induce osteoclastogenesis, which was assessed using TRAP staining, actin ring formation and pit formation assays, as well as bone resorption assay. Cell viability was detected with MTT assay. The mRNA levels of osteoclastogenesis-related genetic markers (TRAP, NFATc1, MMP-9 and cathepsin K) were detected using RT-PCR, while the protein levels of p-Smad1/5/8 and Id1 were measure with Western blotting. WSS25 was administered to ovariectomized mice (100 mg·kg(-1)·d(-1), po) for 3 months. After the mice were euthanized, total bone mineral density and cortical bone density were measured. RESULTS: In RAW264.7 cells and BMMs, WSS25 (2.5, 5, 10 µg/mL) did not affect the cell viability, but dose-dependently inhibited RANKL-induced osteoclastogenesis. Furthermore, WSS25 potently suppressed RANKL-induced expression of TRAP, NFATc1, MMP-9 and cathepsin K in RAW264.7 cells. Treatment of RAW264.7 cells with RANKL increased BMP-2 expression, Smad1/5/8 phosphorylation and Id1 expression, which triggered osteoclast differentiation, whereas co-treatment with WSS25 or the endogenous BMP-2 antagonist noggin suppressed the BMP-2/Smad/Id1 signaling pathway. In RAW264.7 cells, knockdown of Id1 attenuated RANKL-induced osteoclast differentiation, which was partially rescued by Id1 overexpression. In conformity to the in vitro experiments, chronic administration of WSS25 significantly reduced the bone loss in ovariectomized mice. CONCLUSION: WSS25 inhibits RANKL-induced osteoclast formation in RAW264.7 cells and BMMs by blocking the BMP-2/Smad/Id1 signaling pathway. WSS25 administration reduces bone loss in ovariectomized mice, suggesting that it may be a promising therapeutic agent for osteoporosis.

Lobolide, a diterpene, blockades the NF-κB pathway and p38 and ERK MAPK activity in macrophages in vitro.

AIM: Recent studies have shown that constitutive activation of the nuclear factor κB (NF-κB) plays a key role in chronic inflammation and cancers. The aim of this study was to characterize lobolide, a cembrane diterpene, as a drug candidate targeting the NF-κB signaling pathway. METHODS: A HEK 293/NF-κB-Luc stable cell line was constructed to evaluate the effect of lobolide on NF-κB activation. THP-1 human monocytes and peripheral blood mononuclear cells (PBMCs) from healthy volunteers were tested. Lipopolysaccharide (LPS)-induced TNFα and IL-1ß production and activation of the TAK1-IKK-NF-κB pathway were studied using ELISA and Western blot analysis. RESULTS: In HEK 293/NF-κB-Luc stable cells, lobolide (0.19-50 µmol/L) inhibited NF-κB activation in a concentration-dependent manner with an IC(50) value of 4.2 ± 0.3 µmol/L. Treatment with lobolide (2.5-10 µmol/L) significantly suppressed LPS-induced production of TNFα and IL-1ß in both THP-1 cells and PBMCs. In THP-1 cells, the suppression was partially caused by blockade of the translocation of NF-κB from the cytoplasm to the nucleus via affecting the TAK1-IKK-NF-κB pathway and p38 and ERK MAPK activity. CONCLUSION: Lobolide is a potential inhibitor of the NF-κB pathway, which blocks the translocation of NF-κB from the cytoplasm to the nucleus. Lobolide inhibits LPS-stimulated TNFα and IL-1ß release, suggesting that the compound might be an anti-inflammatory compound.

A novel small molecule, HK-156, inhibits lipopolysaccharide-induced activation of NF-κB signaling and improves survival in mouse models of sepsis.

AIM: To characterize a small molecule compound HK-156 as a novel inhibitor of the nuclear factor κB (NF-κB) signaling pathway. METHODS: THP-1 monocytes and HEK293/hTLR4A-MD2-CD14 cells were tested. HK-156 and compound 809, an HK-156 analogue, were synthesized. A luciferase assay was used to evaluate the transcriptional activity of NF-κB. The levels of cytokines were measured with cytokine arrays, ELISA and quantitative PCR. An electrophoretic mobility shift assay (EMSA), immunofluorescence, Western blot and mass spectrometry were used to investigate the molecular mechanisms underlying the actions of the agent. BALB/c mice challenged with lipopolysaccharide (LPS, 15 mg/kg, ip) were used as a mouse experimental endotoxemia model. RESULTS: In HEK293hTLR4/NF-κB-luc cells treated with LPS (1000 ng/mL), HK-156 inhibited the transcriptional activity of NF-κB in a concentration-dependent manner (IC50=6.54 ± 0.37 µmol/L). Pretreatment of THP-1 monocytes with HK-156 (5, 10 and 20 µmol/L) significantly inhibited LPS-induced release and production of TNF-α and IL-1ß, attenuated LPS-induced translocation of NF-κB into the nucleus and its binding to DNA, and suppressed LPS-induced phosphorylation and degradation of IκBα, and phosphorylation of IKKß and TGFß-activated kinase (TAK1). Meanwhile, HK-156 (5, 10 and 20 µmol/L) slightly suppressed LPS-induced activation of p38. The effect of HK-156 on LPS-induced activation of NF-κB signaling was dependent on thiol groups of cysteines in upstream proteins. In mouse models of sepsis, pre-injection of HK-156 (50 mg/kg, iv) significantly inhibited TNFα production and reduced the mortality caused by the lethal dose of LPS. CONCLUSION: HK-156 inhibits LPS-induced activation of NF-κB signaling by suppressing the phosphorylation of TAK1 in vitro, and exerts beneficial effects in a mouse sepsis model. HK-156 may therefore be a useful therapeutic agent for treating sepsis.

Lentivirus-mediated RNA silencing of c-Met markedly suppresses peritoneal dissemination of gastric cancer in vitro and in vivo.

AIM: To investigate the expression of c-Met in peritoneal free cancer cells isolated from human gastric cancer ascites, and its relationship to peritoneal dissemination of gastric cancer. METHODS: Peritoneal free cancer cells (PFCCs) were isolated from ascites specimens of gastric cancer patients. c-Met expression in PFCCs was detected with immunocytochemistry. In human gastric cancer cell line SGC7901, c-Met expression was detected using RT-PCR and Western blot, and was suppressed with lentivirus-mediated RNAi. The proliferation of SGC7901 cells was measured using MTT assay, and the invasion ability was detected with invasion assay. The adhesion of SGC7901 cells to peritoneum was observed in human peritoneal mesothelial cells (HPMCs) monolayer in vitro and in mice in vivo. RESULTS: PFCCs were isolated from ascites of 6 out of 10 gastric cancer patients. c-Met expression in PFCCs was detected in 5 of the 6 gastric cancer patients. In SGC7901 cells, Lentivirus-mediated RNAi significantly reduced both c-Met mRNA and protein expression, which resulted in suppressing the cell proliferation, invasion and adhesion to peritoneum. The expression of α3ß1 integrin and E-cadherin was significantly inhibited in SGC7901 cells transfected with Lenti-miRNAc-Met. In the peritoneal dissemination model of gastric cancer, intraperitoneal injection of Lenti-miRNAc-Met markedly suppressed the tumor Progression of SGC7901 cells. CONCLUSION: c-Met is expressed in PFCCs from the ascites of gastric cancer patients. Down-regulation of c-Met expression markedly suppresses the multistep process of peritoneal dissemination, thus may be a potential target for the treatment of gastric cancer.

Different significance between intratumoral and peritumoral lymphatic vessel density in gastric cancer: a retrospective study of 123 cases.

BACKGROUND: Patients with gastric cancer in China have worse outcome and poorer prognosis. Tumor-induced lymphangiogenesis plays a crucial role in metastasis and tumor progression. The intratumoral and peritumoral lymphatics were supposed to have different biological effects. Three major growth factors, vascular endothelial growth factor- (VEGF)-A, VEGF-C and VEGF-D, are involved in the activation process via their receptors (VEGFRs). The purpose of current study is to investigate the significant difference between intratumoral and peritumoral lymphatic vessel density (LVD) in gastric cancer and their correlations with lymphangiogenetic growth factors. METHODS: Intratumoral LVD (I-LVD) and peritumoral LVD (P-LVD) of 123 patients with primary gastric cancer were assessed after staining with D2-40, and confirmed by double staining with D2-40/CD34. Proliferative activity of lymphatics endothelium was evaluated by double staining with D2-40/Ki-67. The associations were analyzed between I-LVD/P-LVD and the expression level of VEGF-A, VEGF-C, VEGF-D and the receptor VEGFR-3, which was measured by immunohistochemistry (IHC). The correlations of I-LVD and P-LVD with patient prognosis were also valued. RESULTS: (1) The peritumoral lymphatics (PTLs) were relatively enlarged with dilated lumen compared with the intratumoral lymphatics (ITLs). Increased P-LVD was significantly higher than I-LVD (P < 0.05). (2) P-LVD was found significantly associated with lymph node metastasis (LNM) (P < 0.001), lymphatic vessel invasion (LVI) (P < 0.001), VEGF-C (P = 0.003), VEGF-D expression level (P = 0.005) and VEGFR-3 expression level (P < 0.001) in peritumoral tissues, despite no significant association was found between above variants with I-LVD. However, increased I-LVD was demonstrated to be associated with decreased tumor volume (P < 0.001). Neither I-LVD nor P-LVD was correlated with VEGF-A expression (P > 0.05). (3) Proliferative activity of lymphatics endothelium was observed in PTLs, in spite of ITLs. (4) Increased P-LVD, but not I-LVD, was indicated to be an independent risk factor for lymph node metastasis by multivariate logistic regression analysis, and was related to worse disease-free survival and overall survival. CONCLUSIONS: PTLs play roles in gastric cancer progression. Increased P-LVD, but not I-LVD, was significantly associated with VEGF-C/-D/VEGFR-3 system, and could be an independent risk factor for lymph node metastasis and a prognostic factor in gastric cancer.

[Expression of nm23 and KAI1 and their clinical significance in gallbladder adenocarcinoma].

OBJECTIVE: To investigate the expression of two tumor metastasis suppressor genes nm23 and KAI1 in gallbladder adenocarcinoma, and their clinicopathological significance. METHODS: Specimens and clinical data from 31 gallbladder adenocarcinoma patients were collected. Histopathological grading and the expression of nm23 and KAI1 were detected by HE and immunohistochemical staining, respectively. All cases were followed up for at least three years. RESULTS: Immunohistochemical staining showed that the positive rate of nm23 and KAI1 proteins was 71.0% (22/31) and 61.3% (19/31), respectively. The positive expression rates of nm23 and KAI1 proteins in the early stage carcinomas were significantly higher than those in the moderate and advanced stage ones (P exact = 0.0051 and P exact = 0.0084), and both had an negative correlation with clinicopathologic stage (P trend = 0.0047 and P trend = 0.0058). There was a significant difference in the expression of nm23 and KAI1 proteins among well, moderately and poorly differentiated carcinomas (P exact = 0.0328 and P exact = 0.0020). The expression of nm23 and KAI1 was positively correlated with histopathological grade (P trend = 0.0086 and P trend = 0.0006). There was also a significant difference in the expression of nm23 and KAI1 proteins between 17 survival and 14 dead patients (P exact = 0.0038 and P exact = 0.0001 ). A synergistic effect of nm23 and KAI1 protein on the survival was observed , and seemed to be more important than any individual gene alone (P exact = 0.0005). CONCLUSION: The expressions of nm23 and KAI1 proteins are negatively correlated with clinical stage, but positively with histopathological grade in gallbladder adenocarcinoma. These two tumor metastasis suppressor genes may act synergistically to inhibit the tumor metastasis.

[Expression of vascular endothelial growth factors (VEGF)-A, -C and -D and their prognostic significance and relationship with angio- and lymphangiogenesis in gastric cancer].

OBJECTIVE: To investigate the expressions of vascular endothelial growth factors (VEGF)-A, -C and -D and their prognostic significance and relation to angio- and lymphangiogenesis in gastric cancer. METHODS: The expression of VEGF-A, -C and -D in 123 primary gastric cancers was detected by immunohistochemical staining. The lymphatic vessel density (LVD) and microvessel density (MVD) were assessed after immunohistochemical double-staining with D2-40 and CD34, respectively. The correlation between the expression of those VEGF factors and clinicopathological parameters were analyzed by univariate method. The overall survival was evaluated by Kaplan-Meier method and log-rank test. Multivariate analysis was carried out using Cox proportion hazard model. RESULTS: The positive expression rate of VEGF-A, -C and -D in primary gastric cancer samples were 64.2%, 65.9% and 41.5%, respectively. High expression of VEGF-A, or -C or -D, or any two of them was correlated with high LVD (P < 0.05). High expression of both VEGF-A and -C was associated with high MVD, lymph node metastasis, LVI and MVI (P < 0.05). Both VEGF-C and -D high expression was correlated with LVI and lymph node metastasis (P < 0.05). The patients with high expression of these factors had a statistically shorter overall survival (P < 0.05). The patients with both VEGF-A and -C expression had the shortest survival (56 months). Multivariate analysis showed that VEGF-A high expression, MVD, lymph node metastasis and depth of tumor invasion were independent survival predictors (P = 0.033, 0.002, 0.019 and P < 0.001, respectively). CONCLUSION: High expression of both VEGF-A and -C imply high potential of lymphangiogenesis, metastasis and poorer survival in gastric cancer patients. High expression of VEGF-C and -D may induce lymphangiogenesis and promote lymph node metastasis, but only VEGF-A is an independent predictor of survival.