Tumor suppressor function of ezrin-radixin-moesin-binding phosphoprotein-50 through β-catenin/E-cadher in pathway in human hepatocellular cancer

AIM:To determine the effect and molecular mechanism of ezrin-radixin-moesin-binding phosphoprotein-50(EBP50) in hepatocellular carcinoma(HCC).METHODS:Three human HCC cell lines,i.e.,SMMC7721,HepG2 and Hep3B,were used.We transfected the Pbk-CMV-HA-EBP50 plasmid into SMMC7721 cells with Lipofectamine 2000 to overexpress EBP50.Western blotting were performed to determine the effects of the plasmid on EBP50 expression and to detect the expression of β-catenin and E-cadherin before and after the transfection of the plasmid into SMMC7721 cells.In vitro cell proliferation was assessed with a Cell Counting Kit-8(CCK-8) assay.Cell cycle distribution was assessed with flow cytometry.Invasion and migration ability of before and after the transfection were determined with a transwell assay.Cell apoptosis was demonstrated with Annexin V-FITC.The effect of EBP50 overexpressing on tumor growth in vivo was performed with a xenograft tumor model in nude mice.RESULTS:The transfection efficiency was confirmed with Western blotting(1.36 ± 0.07 vs 0.81 ± 0.09,P < 0.01).The CCK8 assay demonstrated that the growth of cells overexpressing EBP50 was significantly lower than control cells(P < 0.01).Cell cycle distribution showed there was a G0/G1 cell cycle arrest in cells overexpressing EBP50(61.3% ± 3.1% vs 54.0% ± 2.4%,P < 0.05).The transwell assay showed that cell invasion and migration were significantly inhibited in cells overexpressing EBP50 compared with control cells(5.8 ± 0.8 vs 21.6 ± 1.3,P < 0.01).Annexin V-FITC revealed that apoptosis was significantly increased in cells overexpressing EBP50 compared with control cells(14.8% ± 2.7% vs 3.4% ± 1.3%,P < 0.05).The expression of β-catenin was downregulated and E-cadherin was upregulated in cells overexpressing EBP50 compared with control cells(0.28 ± 0.07 vs 0.56 ± 0.12,P < 0.05;0.55 ± 0.08 vs 0.39 ± 0.07,P < 0.05).In vivo tumor growth assay confirmed that up-regulation of EBP50 could obviously slow the growth of HCC derived from SMMC7721 cells(     

High dose glargine alters the expression profiles of microRNAs in pancreatic cancer cells

AIM: To investigate the effect of high dose glargine on the expression profiles of microRNAs in human pancreatic cancer cells.METHODS: Real-time polymerase chain reaction array (RT-PCR) was applied to investigate miRNAs differentially expressed in Sw1990 cells treated with or without 100 IU/L glargine. Stem-loop RT-PCR was used to confirm the results of the array assay in Sw1990 and Panc-1 cells. The effects of miR-95 on cell growth, apoptosis, invasion and migration abilities were respectively examined by CCK8 assay, apoptosis assay, Matrigel invasion and migration assay in Sw1990 and Panc-1 cells. Nude mice xenograft models with Sw1990 cells were built to investigate pancreatic cancer growth in vivo after transfection by the lentivirus pGLV3-GFP- miR-95.RESULTS: Ten miRNAs were significantly up-regulated and 2 miRNAs down-regulated in glargine treated Sw1990 cells when compared with non-treated cells (2.48-fold changes on average, P < 0.01). miR-95, miR-134 and miR-34c-3p are the top three miRNAs regulated by glargine (3.65-fold, 2.67-fold and 2.60-fold changes respectively, P < 0.01) in Sw1990 cells. Stem-loop RT-PCR confirmed that high dose glargine up-regulated the expression of miR-95 and miR-134 in both Sw1990 and Panc-1 cells. The most obvious change is the apparent increase of miR-95. Forced expression of miR-95 significantly increased cell proliferation (Sw1990: 2.510 ± 0.129 vs 2.305 ± 0.187, P < 0.05; Panc-1: 2.439 ± 0.211 vs 2.264 ± 0.117, P < 0.05), invasion (Sw1990: 67.90 ± 12.33 vs 47.30 ± 5.89, P < 0.01; Panc-1: 37.80 ± 8.93 vs 30.20 ± 5.14, P < 0.01), migration (Sw1990: 101 ± 6.00 vs 51.20 ± 8.34, P < 0.01; Panc-1: 91.80 ± 9.22 vs 81.50 ± 7.47, P < 0.01) and inhibited cell apoptosis (Sw1990: 22.05% ± 1.92% vs 40.32% ± 1.93%, P < 0.05; Panc-1: 20.17% ± 0.85% vs 45.60% ± 1.43%, P < 0.05) when compared with paired negative controls, whereas knockdown of miR-95 obtained the opposite effect. Nude mice xenograft models confirmed that miR-95 promoted the growth of pancreatic cancer in vivo when compared with negative control (tumor volume: 373.82 ± 23.67 mL vs 219.69 ± 17.82 mL, P < 0.05).CONCLUSION: These observations suggested that modulation of miRNA expression may be an important mechanism underlying the biological effects of glargine.     

Axl glycosylation mediates tumor cell proliferation, invasion and lymphatic metastasis in murine hepatocellular carcinoma

AIM: To investigate the effects of Axl deglycosylation on tumor lymphatic metastases in mouse hepatocellular carcinoma cell lines. METHODS: Western blotting was used to analyze the expression profile of Axl glycoprotein in mouse hepa-tocellular carcinoma cell line Hca-F treated with tunicamycin and PNGase F 3-(4,5)-dimethylthiazol(-zyl)-3,5- diphenyltetrazolium bromide (MTT) assay, extracellular matrix (ECM) invasion assay (in vitro ) and tumor metastasis assay (in vivo ) were utilized to evaluate the effect of Axl deglycosylation on the Hca-F cell proliferation, invasion and lymphatic metastasis. RESULTS: Tunicamycin and PNGase F treatment markedly inhibited Axl glycoprotein synthesis and expression, proliferation, invasion, and lymphatic metastasis both in vitro and in vivo . In the MTT assay, proliferation was apparent in untreated Hca-F cells compared with treated Hca-F cells. In the ECM invasion assay (in vitro ), treated cells passed through the ECMatrix gel in significantly smaller numbers than untreated cells (tunicamycin 5 μg/mL: 68 ± 8 vs 80 ± 9, P=0.0222; 10 μg/mL: 50 ± 6vs 80 ± 9,P=0.0003; 20 μg/mL: 41 ± 4 vs 80 ± 9, P=0.0001); (PNGase F 8 h: 66 ± 7 vs 82 ± 8, P=0.0098; 16 h: 49 ± 4 vs 82 ± 8, P=0.0001; 24 h: 34 ± 3 vs 82 ± 8, P=0.0001). In the tumor metastasis assay (in vivo ), average lymph node weights of the untreated Hca-F group compared with treated Hca-F groups (tunicamycin 5 μg/mL: 0.84 ± 0.21 g vs 0.72 ± 0.19 g, P=0.3237; 10 μg/mL: 0.84 ± 0.21 g vs 0.54 ± 0.11 g, P=0.0113; 20 μg/mL: 0.84 ± 0.21 g vs 0.42 ± 0.06 g, P=0.0008); (PNGase F 8 h: 0.79 ± 0.15 g vs 0.63 ± 0.13 g, P=0.0766; 16 h: 0.79 ± 0.15 g vs 0.49 ± 0.10 g, P=0.0022; 24 h: 0.79 ± 0.15 g vs 0.39 ± 0.05 g, P=0.0001). Also, average lymph node volumes of the untreated Hca-F group compared with treated Hca-F groups (tunicamycin 5 μg/mL: 815 ± 61 mm 3 vs 680 ± 59 mm 3 , P=0.0613; 10 μg/mL: 815 ± 61 mm 3 vs 580 ± 29 mm 3 , P=0.0001; 20 μg/mL: 815 ± 61 mm 3 vs 395 ± 12 mm 3 , P=0.0001); (PNGase F 8 h: 670 ± 56 mm 3 vs 581 ± 48 mm 3 , P=0.0532; 16 h: 670 ± 56 mm 3 vs 412 ± 22 mm 3 , P=0.0001; 24 h: 670 ± 56 mm 3 vs 323 ± 11 mm 3 , P=0.0001). CONCLUSION: Alteration of Axl glycosylation can at-tenuate neoplastic lymphatic metastasis. Axl N-glycans may be a universal target for chemotherapy.     

Knockdown of liver-intestine cadherin decreases BGC823 cell invasiveness and metastasis in vivo

AIM: To assess BGC823 gastric cancer (GC) cell metastasis after knockdown of liver-intestine cadherin (CDH17) and the therapeutic value of CDH17-RNAi-lentivirus in vivo.METHODS: We evaluated primary tumor growth and assessed local infiltration and systemic tumor dissemination using an orthotopic implantation technique. The therapeutic value of CDH17 knockdown was examined by intratumoral administration of CDH17-RNA interference (RNAi)-lentivirus in an established GC tumor xenograft mouse model. Furthermore, a comparative proteomic approach was utilized to identify differentially expressed proteins in BGC823 and lenti-CDH17-miR-neg cells following CDH17 knockdown.RESULTS: Metastases in the liver and lung appeared earlier and more frequently in animals with tumors derived from BGC823 or lenti-CDH17-miR-neg cells than in tumors derived from lenti-CDH17-miR-B cells. Average tumor weight and volume in the CDH17-RNAi-lentivirus-treated group were significantly lower than those in the control group (tumor volume: 0.89 ± 0.04 cm³ vs 1.16 ± 0.06 cm³, P < 0.05; tumor weight: 1.15 ± 0.58 g vs 2.09 ± 0.08 g, P < 0.05). Fifteen differentially expressed proteins were identified after CDH17 silencing in BGC823 cells, including a variety of cytoskeletal and chaperone proteins as well as proteins involved in metabolism, immunity/defense, cell proliferation and differentiation, cell cycle, and signal transduction.CONCLUSION: Our data establish a foundation for future studies of the comprehensive protein expression patterns and effects of CDH17 in GC.     

HIF-1α induces VE-cadherin expression and modulates vasculogenic mimicry in esophageal carcinoma cells

AIM: To investigate whether hypoxia inducible factor (HIF)-1α modulates vasculogenic mimicry (VM) by upregulating VE-cadherin expression in esophageal squamous cell carcinoma (ESCC).METHODS: Esophageal squamous cancer cell lines Eca109 and TE13 were transfected with plasmids harboring small interfering RNAs targeting HIF-1α or VE-cadherin. The proliferation and invasion of esophageal carcinoma cells were detected by MTT and Transwell migration assays. The formation of tubular networks of cells was analyzed by 3D culture in vitro. BALB/c nude mice were used to observe xenograft tumor formation. The relationship between the expression of HIF-1α and VE-cadherin, ephrinA2 (EphA2) and laminin5γ2 (LN5γ2) was measured by Western blot and real-time polymerase chain reaction.RESULTS: Knockdown of HIF-1α inhibited cell proliferation (32.3% ± 6.1% for Eca109 cells and 38.6% ± 6.8% for TE13 cells, P < 0.05). Both Eca109 and TE13 cells formed typical tubular networks. The number of tubular networks markedly decreased when HIF-1α or VE-cadherin was knocked down. Expression of VE-cadherin, EphA2 and LN5γ2 was dramatically inhibited, but the expression of matrix metalloproteinase 2 had no obvious change in HIF-1α-silenced cells. Knockdown of VE-cadherin significantly decreased expression of both EphA2 and LN5γ2 (P < 0.05), while HIF-1α expression was unchanged. The time for xenograft tumor formation was 6 ± 1.2 d for Eca109 cells and Eca109 cells transfected with HIF-1α Neo control short hairpin RNA (shRNA) vector, and 8.4 ± 2.1 d for Eca109 cells transfected with an shRNA against HIF-1α. Knockdown of HIF-1α inhibited vasculogenic mimicry (VM) and tumorigenicity in vivo.CONCLUSION: HIF-1α may modulate VM in ESCC by regulating VE-cadherin expression, which affects VM formation through EphA2 and LN5γ2.     

Cortactin expression confers a more malignant phenotype to gastric cancer SGC-7901 cells

AIM:To study the effects of cortactin on the tumor biology of SGC-7901 cells and identify the mechanism involved in the process.METHODS:Cell lines in which cortactin was stably overexpressed or knocked down as well as the respective control cell lines were established by standard molecular methods.The effects of cortactin on the proliferation,migration and invasion capacity of SGC-7901cells were assessed by the MTT assay,colony formation,flow cytometry,transwell migration and matrigel invasion.Nude mouse models were also used to assess the role of cortactin in the growth and metastasis of SGC-7901 cells in vivo.Western blotting analysis was performed to detect the expression of epidermal growth factor receptor(EGFR)and downstream molecules.RESULTS:Cell lines in which cortactin was stably overexpressed or knocked down as well as control cell lines were successfully established and designated as LV5-cortactin-SGC,LV5-SGC,LV3-shRNA-SGC and LV3-SGC.Cortactin overexpression promoted SGC-7901 cell migration(340.7±12.6 vs 229.1±23.2,P<0.01)and invasion(71.6±5.2 vs 48.4±3.6,P<0.01).Cortactin downregulation impaired SGC-7901 cell migration(136.2±19.8 vs 225±17)and invasion(29.2±5.2vs 49.6±3.8,P<0.01).The results from the MTT and colony formation assays results indicated increased LV5-cortactin-SGC cell proliferation and decreased LV3-shRNA-SGC cell proliferation compared to the control cells.Flow cytometry analysis demonstrated that cortactin overexpression promoted the proliferation index of SGC-7901 cells,and the results were reversed when cortactin was downregulated.Mouse tumor models confirmed that cortactin expression increased SGC-7901cell proliferation and metastasis in vivo.Western blotting analysis revealed that cortactin elevated EGFR expression and activated the downstream molecules.CONCLUSION:Cortactin expression promoted the migration,invasion and proliferation of SGC-7901 cells both in vivo and in vitro.The EGFR signaling pathway is mechanistically involved.     

Anticancer effects of sweet potato protein on human colorectal cancer cells

AIM: To investigate the effects of proteins purified from sweet potato storage roots on human colorectal cancer cell lines. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst 33258 nuclear staining and Boyden transwell chamber methods were used to determine whether purified sweet potato protein (SPP) from fresh sweet potato roots affected proliferation, migration and invasion, respectively, of human colorectal cancer SW480 cells in vitro . The inhibitory effects of SPP on growth of human colorectal cancer HCT-8 cells intraperitoneally xenografted in nude mice and spontaneous lung metastasis of murine Lewis lung carcinoma 3LL cells subcutaneously transplanted in C57 BL/6 mice were also investigated in vivo . RESULTS: SPP inhibited the proliferation of SW480 cells in a dose-dependent manner, with an IC 50 value of 38.732 μmol/L (r2 = 0.980, P = 0.003) in the MTT assay. Hoechst 33258 nuclear staining further revealed inhibition of cell viability and induction of apoptosis by SPP. The transwell assay disclosed significant reduction in migrated cells/field by 8 μmol/L SPP (8.4 ± 2.6 vs 23.3 ± 5.4, P = 0.031) and invaded cells/field through the ECMatrix by 0.8 μmol/L SPP, compared with the control (25.2 ± 5.2 vs 34.8 ± 6.1, P = 0.038). Both intraperitoneal (ip) and intragastric (ig) administration of SPP led to significant suppression of growth of intraperitoneally inoculated HCT-8 cells in nude mice to 58.0% ± 5.9% (P = 0.037) and 43.5% ± 7.1% (P = 0.004) of the controls, respectively, after 9 d treatment. Bloody ascites additionally disappeared after ip injection of trypsin inhibitor. Notably, ig and ip administration of SPP induced a significant decrease in spontaneous pulmonary metastatic nodule formation in C57 BL/6 mice (21.0 ± 12.3 and 27.3 ± 12.7 nodules/lung vs 42.5 ± 4.5 nodules/lung in controls, respectively, P < 0.05) after 25 d treatment. Moreover, the average weight of primary tumor nodules in the hind leg of mice decreased from 8.2 ± 1.3 g/mice in     

Melittin induces human gastric cancer cell apoptosis via activation of mitochondrial pathway

AIM: To investigate the apoptotic effects of melittin on SGC-7901 cells via activation of the mitochondrial signaling pathway in vitro.METHODS: SGC-7901 cells were stimulated by melittin, and its effect on proliferation and apoptosis of was investigated by methyl thiazolyl tetrazolium assay, morphologic structure with transmission electron microscopy, annexin-V/propidium iodide double-staining assay, measuring mitochondrial membrane potential(MMP) levels, and analyzing reactive oxygen species(ROS) concentrations were analyzed by flow cytometry. Cytochrome C(Cyt C), apoptosis-inducing factor(AIF), endonuclease G(Endo G), second mitochondria-derived activator of caspases(Smac)/direct IAP binding protein with low isoelectric point(Diablo), and FAS were analyzed by western blot. The expression of caspase-3 and caspase-8 was measured using activity assay kits.RESULTS: Melittin was incubated at 1.0, 2.0, 4.0, or 6.0 μg/m L for 1, 2, 4, 6, or 8 h and showed a timeand concentration-dependent inhibition of SGC-7901 cell growth. Melittin induced SGC-7901 cell apoptosis, which was confirmed by typical morphological changes. Treatment with 4 μg/m L melittin induced early apoptosis of SGC-7901 cells, and the early apoptosis rates were 39.97% ± 3.19%, 59.27% ± 3.94%, and 71.50% ± 2.87% vs 32.63% ± 2.75% for 1, 2, and 4 h vs 0 h(n = 3, P 0.05); the ROS levels were 616.53% ± 79.78%, 974.81% ± 102.40%, and 1330.94% ± 93.09% vs 603.74% ± 71.99%(n = 3, P 0.05); the MMP values were 2.07 ± 0.05, 1.78 ± 0.29, and 1.16 ± 0.25 vs 2.55 ± 0.42(n = 3, P 0.05); caspase-3 activity was significantly higher compared to the control(5492.3 ± 321.1, 6562.0 ± 381.3, and 8695.7 ± 449.1 vs 2330.0 ± 121.9), but the caspase activity of the non-tumor cell line L-O2 was not different from that of the control. With the addition of the caspase-3 inhibitor(Ac-DEVD-CHO), caspase-3 activity was significantly decreased compared to the control group(1067.0 ± 132.5 U/g vs 8695.7 ± 449.1 U/g). The expression of the Cyt C, Endo G, and AIF proteins in SGC-7901 cells was significantly higher than those in the control(P 0.05), while the expression of the Smac/Diablo protein was significantly lower than the control group after melittin exposure(P 0.01). Ac-DEVD-CHO did not, however, have any effect on the expression of caspase-8 and FAS in the SGC-7901 cells.CONCLUSION: Melittin can induce apoptosis of human gastric cancer(GC) cells through the mitochondria pathways, and it may be a potent agent in the treatment of human GC.     

Roles of BN52021 in platelet-activating factor pathway in inflammatory MS1 cells

AIM: To determine the effects of BN52021 on platelet-activating factor receptor (PAFR) signaling molecules under lipopolysaccharide (LPS)-induced inflammatory conditions in MS1 cells. METHODS: MS1 cells (a mouse pancreatic islet endothelial cell line) were grown in Dulbecco’s modified Eagle’s medium supplemented with 10% fetal bovine serum, 2 mmol/L glutamine and 100 μg/mL penicillin/streptomycin in 5% CO 2 at 37 ℃. After growth to confluency in media, the cells were processed for subsequent studies. The MS1 cells received 0, 0.1, 1 and 10 μg/mL LPS in this experiment. The viability/prolifera-tion of the cells induced by LPS was observed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Apoptosis and necrosis of the cells under the inflammatory condition described previously were observed using Hoechst 33342-propidium iodide staining. Adenylate cyclase (AC), phospholipase A 2 (PLA 2 ), phospholipase Cβ (PLCβ), protein tyrosine kinase (PTK), G protein-coupled receptor kinases (GRK) and p38-mitogen-activated protein kinase (p38 MAPK) mRNA in the PAFR signaling pathway were measured by real-time polymerase chain reaction. The protein expression level of phosphorylated AC (p-AC), phosphorylated PLA 2 (p-PLA 2 ), phosphorylated PTK (p-PTK), phosphorylated p38 MAPK (p-p38 MAPK), PLCβ and GRK was measured using Western blotting analysis. RESULTS: The activity of MS1 cells incubated with dif- ferent concentrations of LPS for 6 h decreased significantly in the 1 μg/mL LPS group (0.49 ± 0.10 vs 0.67 ± 0.13, P < 0.05) and 10 μg/mL LPS group (0.44 ± 0.10 vs 0.67 ± 0.13, P < 0.001), but not in 0.1 μg/mL group. When the incubation time was extended to 12 h (0.33 ± 0.05, 0.32 ± 0.03 and 0.25 ± 0.03 vs 0.69 ± 0.01) and 24 h (0.31 ± 0.01, 0.29 ± 0.03 and 0.25 ± 0.01 vs 0.63 ± 0.01), MS1 cell activity decreased in all LPS concentration groups compared with the blank control (P < 0.001). BN52021 significantly improved the cell activity when its concentration