IL-8 is a novel prometastatic chemokine in intrahepatic cholangiocarcinoma that induces CXCR2-PI3K/AKT signaling upon CD97 activation.

Intrahepatic cholangiocarcinoma (ICC) is a rare but highly aggressive malignant tumor arising within the liver, with a 5-year survival rate of only 20-40% after surgery. The role of interleukin-8 (IL-8) in ICC progression remains elusive. A transcriptomic approach based on IL-8 stimulation first revealed significant upregulation of the prometastatic gene CD97 and key epithelial-mesenchymal transition (EMT) factors E-cadherin and vimentin. Immunohistochemistry of 125 ICC tissues confirmed the positive correlation between IL-8 and CD97. Multivariable Cox regression indicated that they are both independent predictors of ICC prognosis. Mechanistically, IL-8 treatment induced CD97 expression at 50 and 100 ng/ml in QBC-939 and QBE cells, respectively. Moreover, the induction of cell migration and invasion upon IL-8 treatment was attenuated by CD97 RNA interference, and the expression of EMT-associated genes was dramatically inhibited. To determine whether CXCR1 or CXCR2 are downstream effectors of IL-8, siCXCR2 was applied and shown to significantly attenuate the oncogenic effects of IL-8 by inhibiting the phosphorylation of PI3K/AKT. Finally, the induction of CD97 expression by the PI3K pathway was verified by treatment with the inhibitor LY294002. In vivo, the significant tumor growth and lung metastasis effects induced by intraperitoneal injection of IL-8 were greatly inhibited by silencing CD97 in nude mice. Collectively, the study presents a novel mechanism of the IL-8-CXCR2-PI3K/AKT axis in regulating CD97 expression, which leads to ICC metastasis mainly through EMT. The study may provide alternatives for targeting the tumor microenvironment in metastatic ICC.

RIP1 regulates TNF-α-mediated lymphangiogenesis and lymphatic metastasis in gallbladder cancer by modulating the NF-κB-VEGF-C pathway.

BACKGROUND: Tumor necrosis factor alpha (TNF-α) enhances lymphangiogenesis in gallbladder carcinoma (GBC) via activation of nuclear factor (NF-κB)-dependent vascular endothelial growth factor-C (VEGF-C). Receptor-interacting protein 1 (RIP1) is a multifunctional protein in the TNF-α signaling pathway and is highly expressed in GBC. However, whether RIP1 participates in the signaling pathway of TNF-α-mediated VEGF-C expression that enhances lymphangiogenesis in GBC remains unclear. METHODS: The RIP1 protein levels in the GBC-SD and NOZ cells upon stimulation with increasing concentrations of TNF-α as indicated was examined using Western blot. Lentiviral RIP1 shRNA and siIκBα were constructed and transduced respectively them into NOZ and GBC-SD cells, and then PcDNA3.1-RIP1 vectors was transduced into siRIP1 cell lines to reverse RIP1 expression. The protein expression of RIP1, inhibitor of NF-κB alpha (IκBα), p-IκBα, TAK1, NF-κB essential modulator were examined through immunoblotting or immunoprecipitation. Moreover, VEGF-C mRNA levels were measured by quantitative real-time polymerase chain reaction, VEGF-C protein levels were measured by immunoblotting and enzyme-linked immunosorbent assay, and VEGF-C promoter and NF-κB activities were quantified using a dual luciferase reporter assay. The association of NF-κB with the VEGF-C promoter was analysed by chromatin immunoprecipitation assay. A three-dimensional coculture method and orthotopic transplantation nude mice model were used to evaluate lymphatic tube-forming and metastasis ability in GBC cells. The expression of RIP1 protein, TNF-α protein and lymphatic vessels in human GBC tissues was examined by immunohistochemistry, and the dependence between RIP1 protein with TNF-α protein and lymphatic vessel density was analysed. RESULTS: TNF-α dose- and time-dependently increased RIP1 protein expression in the GBC-SD and NOZ cells of GBC, and the strongest effect was observed with a concentration of 50 ng/ml. RIP1 is fundamental for TNF-α-mediated NF-κB activation in GBC cells and can regulate TNF-α-mediated VEGF-C expression at the protein and transcriptional levels through the NF-κB pathway. RIP1 can regulate TNF-α-mediated lymphatic tube formation and metastasis in GBC cells both in vitro and vivo. The average optical density of RIP1 was linearly related to that of TNF-α protein and the lymphatic vessel density in GBC tissues. CONCLUSION: We conclude that RIP1 regulates TNF-α-mediated lymphangiogenesis and lymph node metastasis in GBC by modulating the NF-κB-VEGF-C pathway.

Serum vascular endothelial growth factors C and D as forecast tools for patients with gallbladder carcinoma.

Gallbladder carcinoma (GBC) is the most common cancer of the biliary tract. Lymph node metastasis (LNM) is the major diffusion route of GBC and is a prognosis factor. The aim of study was to assess the potential of the serum VEGF-C and VEGF-D (sVEGF-C/D) levels to predict the presence of LNM and the survival of GBC patients. The preoperative sVEGF-C/D levels of 31 patients with GBC, 10 patients with cholesterol polyps, and 10 healthy volunteers were measured by enzyme-linked immunoadsorbent assay (ELISA). The sVEGF-C/D levels of patients with GBC were significantly higher than those of people with healthy gallbladders (p < 0.001 and p = 0.001, respectively) and cholesterol polyp (p = 0.032 and p = 0.004, respectively). In GBC, the sVEGF-C levels were associated with LNM (p = 0.011), distant metastasis (p = 0.018), and stage (p = 0.045), but the sVEGF-D levels had a significant association with the tumor depth (p = 0.001), LNM (p = 0.001), distant metastasis (p = 0.047), and stage (p = 0.002). The sVEGF-C/D diagnostic values for the presence of GBC were sensitivity of 71.0 and 74.2 % and specificity of 80.0 and 85.0 %, respectively. With respect to the diagnosis of LNM, the diagnostic values of sVEGF-C/D were as follows: sensitivity 81.2 and 87.5 % and specificity 73.3 and 80.0 %, respectively. The mean survival time with high sVEGF-C was significantly shorter than that with low sVEGF-C (p < 0.001), which was also true for low sVEGF-D (p = 0.032). The preoperative sVEGF-C/D levels might be reliable biomarkers for the presence of disease and LNM in patients with GBC. The sVEGF-C/D levels may be prognosis factors that can predict a poor outcome for GBC patients.

Establishment of and comparison between orthotopic xenograft and subcutaneous xenograft models of gallbladder carcinoma.

BACKGROUND: Gallbladder carcinoma (GBC) is the most common carcinoma of the biliary system. Among its research models, orthotopic xenograft models, important research tools, have been rarely reported in the literature however. AIM: To explore establishment of an orthotopic xenograft model and to evaluate the advantage and disadvantage as compared with other models. MATERIALS AND METHODS: Subcutaneous xenograft and orthotopic xenograft models of gallbladder carcinoma in nude mice were established and compared with human gallbladder carcinomas. RESULTS: For the orthotopic xenograft model and clinical gallbladder carcinomas, the lymph node metastatic rates were 69.2% and 53.3% (p>0.05); ascites generation rates, 38.5% and 11.7%(p<0.05); liver invasive rates, 100% and 61.7%(p<0.05); and lymphatic vessel densities (LVD), 10.4 ± 3.02 and 8.77 ± 2.92 (p>0.05), respectively. In the subcutaneous xenograft model, no evidence of ascites generation, lymph node metastasis and liver metastasis were found, and its LVD was lower (4.56 ± 1.53, p<0.05). CONCLUSIONS: Compared with the subcutaneous xenograft model, the orthotopic xenograft model better simulates clinical gallbladder carcinoma in terms of metastasis and invasion, which may be attributed to the difference in microenvironment and LVD.

Hepatitis B virus X protein enhances activation of nuclear factor κB through interaction with valosin-containing protein.

Hepatitis B virus X protein (HBx protein) is a multifunctional regulatory protein. The transactivation of nuclear factor kappa B (NF-κB) by HBx protein has been shown to be of importance in the pathogenesis of HBV-related diseases. However, the mechanism involved remains largely unclear. In this study, a CytoTrap yeast two-hybrid system was employed to screen binding partners of the HBx protein; 29 cellular proteins, including valosin-containing protein (VCP), were identified. The interaction between HBx protein and VCP was further confirmed in vitro and in vivo using a glutathione S-transferase pull-down assay and co-immunoprecipitation, respectively. It was also shown that this interaction is mediated by amino acid residues 51-120 of the HBx protein. In Huh-7 hepatoma cells, HBx protein enhanced the VCP-mediated activation of NF-κB. Our findings provide new insights into the molecular mechanisms that lead to the activation of NF-κB by HBx protein.

[Expressions of VEGF-C and VEGF-D and their correlation with lymphangiogenesis and angiogenesis in gallbladder carcinoma].

OBJECTIVE: To investigate the expression of VEGF-C and VEGF-D and their correlations with lymphangiogenesis and angiogenesis in gallbladder carcinoma. METHODS: Fifty cases of gallbladder carcinoma with complete clinical and pathological data were analyzed. The expression of VEGF-C and -D, D2-40, CD31 was assayed by immunohistochemical staining, with 10 samples of normal gallbladder tissues away from cancer and 19 samples of chronic cholecystitis as controls, and their correlation with clinicopathological findings were analyzed retrospectively. RESULTS: Thirty-two (64.0%) of the 50 gallbladder cancers were positive for VEGF-C protein expression by immunohistochemistry and the positive rate of VEGF-D protein expression was 62.0% (31/50). The protein expression of VEGF-C and VEGF-D in tumor tissues was significantly higher than that in normal gallbladder tissues away from the tumor (P < 0.05), but no correlation with that in chronic cholecystitis (P < 0.05). The VEGF-C expression correlated with the patient age and lymph node metastasis (both P < 0.05). The VEGF-D expression only correlated with lymph node metastasis (P < 0.05). In the 50 gallbladder cancers, the MLVD was 6.9 + or - 3.6 and the MVD was 36.1 + or - 12.8. The MLVD in both VEGF-C and -D positive groups was significantly higher than that in the negative groups (P = 0.000), and the lymph node metastasis also increased. MVD in both VEGF-C and -D positive groups was higher than that in the negative groups (P < 0.05), and it was also correlated with tumor differentiation (P < 0.05). A significant positive correlation was also found between VEGF-C and VEGF-D expression (r = 0.498, P < 0.01). CONCLUSION: VEGF-C and VEGF-D are involved in the lymphangiogenesis and angiogenesis in gallbladder carcinoma, promote lymph node metastasis of the tumor, and both are important in the regulation of lymphangiogenesis and angiogenesis in this cancer. VEGF-C and VEGF-D are of clinical significance in evaluating lymph node metastatic potency and estimation of prognosis in gallbladder carcinoma.

[Effect of recombinant plasmid of Helicobacter pylori ureB gene on gastric epithelial cell].

To investigate the effect of recombinant plasmid of Helicobacter pylori ureB gene on gastric epithelial cell. The full length sequence of ureB gene from NCTC11637 was amplified by PCR. The recombinant plasmid was constructed by cloning the open reading frame (ORF) of ureB into the eukaryotic expression vector pcDNA3.1, and was transfected SGC-7901 cells, then the clones resisting Hygromycin were screened. mRNA expression of ureB of transfected cells was detected by RT-PCR. The effect of recombinant plasmid of Hp ureB gene on cell phenotype was observed by fluorescence strain, on proliferation by MTT, on apoptosis and cell cycles by flow cytometry, respectively. The positive clones of ureB (SureB) appeared cell membrane budding and cell shrinkage. MTT assay showed there was no statistic significance between the SureB and SpcDNA3.1 which were transfected only by pcDNA3.1 (P > 0.05), suggesting that the growth of SureB were not inhibited. The apoptosis rate of SureB was higher than that of SpcDNA3.1 (P = 0.007). Analysis for cell cycle showed that in SureB cells the proportion of S phase increased, the proportion of both G2/M and G0/G1 phase decreased. Positive transfection of ureB gene into SGC-7901 can change cell phenotype and induce cell apoptosis.

Virulence of water-induced coccoid Helicobacter pylori and its experimental infection in mice.

AIM: To explore the virulence and the infectivity of coccoid Helicobacter pylori (H. pylori) transformed from spiral form by exposure to sterile tap water. METHODS: Three strains of H. pylori, isolated from gastric biopsy specimens of confirmed peptic ulcer, were converted from spiral into coccoid form by exposure to sterile tap water. Both spiral and coccoid forms of H. pylori were tested for the urease activity, and the adherence to Hep-2 cells. The presence of flagella was examined under electron microscopy. In the experimental animal infection, the spiral and coccoid forms of H. pylori originated from the same strain F49 were inoculated intragastrically into BALB/c mice respectively four times at a 3-day interval. Half of the mice from each group were sacrificed at Day 21 and Day 28 after the last inoculation. Histology and H. pylori colonization were detected by urease test of gastric mucosa, cultures of H. pylori, and electron microscopy and so on. RESULTS: The urease activity and the ability of adherence to Hep-2 cells were found to be lower in coccoid H. pylori than that in its spiral form. For example, the transformation in strain F(44) led to a significant decrease of the adherence rate and adherence index from 70.0+/-5.3 % to 30.2+/-3.5 % (P<0.01), and from 2.6+/-0.4 to 0.86+/-0.3 (P<0.01), respectively. The flagella of coccoid H. pylori were observed under electron microscope. In the experimental infection in mice, the positive rate of gastric mucosa urease test was 93.8 % (15/16) in the group infected by spiral H. pylori and 50 % (8/16) in the group infected by coccoid H. pylori, and the estimated coccoid H. pylori colony number was 1.75 vs 0.56. The positive rates of H. pylori culture were 87.5 % (14/16) in spiral H. pylori group and 68.8 % (11/16) in coccoid H. pylori group. There was no significant difference in either urease test or bacterial culture rate between the groups examined at Day 21 and Day 28 after inoculation. Electron microscopic examination of the samples taken from both groups showed the adherence of H. pylori in spiral, bacillary and coccoid shapes to the epithelial cells of gastric wall. Histological examination showed the occurrence of gastric mucosal injury as indicated by various degrees of erosion, ulcer, and inflammatory cell infiltration. Mucosal injury was slighter in the mice infected by coccoid H. pylori. No positive result was obtained in the control group that received intragastrical administration of sterile tap water. CONCLUSION: Although the virulence of coccoid H. pylori induced by water decrease, coccoid H. pylori still remains a considerable urease activity and the adhering ability to epithelial cells. Furthermore, the flagella, an important component responsible for bacterial movement and infection, were still observed as a cellular structure of coccoid H. pylori under electron microscope. The coccoid H. pylori induced by water is capable of colonizing in gastric mucosa and causing gastrititis in mice.