Role of ILK siRNA on expression of GSK-3β and β-catenin in human tubular epithelial cells stimulated by high glucose

AIM：To investigate the effects of siRNA targeting integrin-linked kinase (ILK) on the expression of glycogen synthase kinase 3β (GSK-3β) and β-catenin during epithelial-mesenchymal transition (EMT) in human kidney proximal tubular epithelial cell line HKC induced by high glucose. METHODS：HKC cells were divided into 4 groups:normal glucose (NG) group, high glucose (HG) group, HG+HK (a vector containing the non-specific siRNA designed as negative control) group and HG＋ILK siRNA group. The inverted fluorescence microscope was used to examine the expression of green fluorescent protein (GFP). The expression of ILK at mRNA and protein levels was detected by RT-PCR and Western blotting. The expression of p-GSK-3β and β-catenin was observed by immunocytochemical staining. The protein expression of total GSK-3β, p-GSK-3β, nuclear β-catenin, total β-catenin, E-cadherin and α-smooth muscle actin (α-SMA) was measured by Western blotting. RESULTS：GFP was observed in HKC cells, indicating that the transfection was successful. Both the protein and mRNA of ILK were down-regulated in HG＋ILK siRNA group compared with HG group and HG+HK group, but still higher than those in NG group. Silencing of ILK down-regulated the expression of p-GSK-3β and nuclear β-catenin. No difference of total GSK-3β or total β-catenin was observed among the 4 groups. CONCLUSION:These data support a functional role of ILK, GSK-3β and β-catenin in tubular EMT induced by high glucose. ILK may promote tubular EMT by regulating the activity of GSK-3β and β-catenin, the downstream effectors of the Wnt/β-catenin pathway.     

Effects of GSK-3β inhibitor on proliferation and apoptosis of SW480 cells

AIM: To investigate the mechanism and the effect of glycogen synthase kinase 3β (GSK-3β) inhibitor (2’Z,3'E)-6-bromoindirubin-3'-oxime (BIO) on the protein expression of β-catenin and Bcl-2, and proliferation and apoptosis in colon carcinoma SW480 cells.METHODS: The immunohistochemical staining and Western blotting were performed to detect the protein expression of β-catenin, cyclin D1 and Bcl-2. The cell cycle distribution and apoptotic rate were detected by flow cytometry. The morphologic features of SW480 cells before and 24 h after BIO exposure at different concentrations were observed under microscope with HE staining.RESULTS: Compared with the untreated SW480 cells, the protein expression of β-catenin significantly increased and some β-catenin positive nuclear staining positive cells appeared in BIO treated cells. and The cells exposed to BIO showed that the cyclin D1 protein and the cells in S stage and G₂/M stage moderately increased, the protein level of Bcl-2 moderately decreased, and the cell apoptosis rate was significantly lower than those in control cells. Furthermore, the morphological changes of the SW480 cells were observed 24 h after BIO treatment. CONCLUSION: Our results indicate that GSK-3β inhibitor BIO participates in the cellular processes of promoting proliferation and inhibiting apoptosis in colon carcinoma cells. The mechanisms are mainly associated with activating the β-catenin pathway and regulating the balance of Bcl-2 pathway, and the up-regulation of β-catenin is most likely the possible factor for SW480 cell regression.     

Overexpression of HBXIP in HepG2 cells induces cell migration and regulates expression of β-catenin

AIM: To investigate the effects of hepatitis B virus X-interacting protein(HBXIP) in hepatic cancer cells on the cell migration and expression of β-catenin. METHODS: Transwell assay was used to assess the cell migration. Gelatin zymography was used to observe the activity of matrix metalloproteinase 9 (MMP-9). The expression of MMP-9, glycogen synthase kinase 3β(GSK-3β), p-GSK3β, β-catenin and p-β-catenin in HepG2 cells was determined by Western blotting. RESULTS: HepG2 cells which stably overexpressed HBXIP (HepG2-HBXIP) exhibited higher migration ability than the control cells. The results of the gelatin zymography assay showed that HBXIP overexpression increased the activity of MMP-9 in HepG2 cells. The results of Western blotting indicated that HBXIP increased the expression of MMP-9 and β-catenin, inhibited the phosphorylation of β-catenin and promoted the phosphorylation of GSK-3β (Ser9). CONCLUSION: HBXIP regulates the GSK-3β/β-catenin signaling pathway, resulting in a significant improvement of hepatocellular carcinoma cell migration.     

Effect of BMP9 over-expression on migration and invasion of human lung squamous-cell carcinoma NCI-H520 cells

AIM: To investigate the effect of bone morphogenetic proteins 9(BMP9) on the migration and invasion abilities of human lung squamous-cell carcinoma NCI-H520 cells and its mechanism. METHODS: The expression of BMP9 at mRNA and protein levels in the NCI-H520 cells and human bronchial epithelial (HBE) cells was detected by RT-PCR and Western blot. The NCI-H520 cells were transfected with the recombinant adenovirus AdBMP9 and the expression of BMP9 at mRNA and protein levels was validated by RT-PCR and Western blot. The migration and invasion abilities of the NCI-H520 cells were determined by wound-healing and Transwell assays. The mRNA and protein levels of the migration-related factor matrix metalloproteinase 2(MMP2) were detected by RT-PCR and Western blot. The level of phosphorylated Smad1/5(p-Smad1/5) was detected by Western blot. Meanwhile, NCI-H520 cells were treated with BMP specific antagonist AdNoggin and AdBMP9. The level of p-Smad1/5 and the cell migration ability were measured by Western blot, wound-healing and Transwell assays. RESULTS: The expression of BMP9 at mRNA and protein levels was lower in NCI-H520 cells than that in HBE cells. After AdBMP9 was stably transfected into the NCI-H520 cells, the expression of BMP9 at mRNA and protein levels was significantly up-regulated, cell migration and invasion abilities were significantly decreased, and the mRNA and protein levels of MMP2 were decreased. Meanwhile, the level of p-Smad1/5 was increased. Noggin reversed BMP9-caused the increase in p-Smad1/5 and the decrease in cell migration ability. CONCLUSION: Over-expression of BMP9 inhibits the migration and invasion abilities of lung squamous-cell carcinoma NCI-H520 cells. The activation of BMP-Smad signaling pathway may be involved in this inhibitory process.     

Effect of andrographolide on osteosarcoma 143B cells and its mechanism

AIM To investigate the inhibitory effect of andrographolide （AG） on human osteosarcoma 143B cells and its underlying molecular mechanism. METHODS Osteosarcoma 143B cells were cultured in vitro and treated with AG at different concentrations (0~20 μmol/L), and the effect of AG on the proliferation of 143B cells was determined by crystal violet staining, MTT assay and colony formation assay. The wound-healing assay was performed to detect the migration ability of osteosarcoma 143B cells. Transwell assay was performed to analyze the invasive capacity of osteosarcoma 143B cells. The effect of AG on the apoptosis of osteosarcoma 143B cells was detected by Hoechst 33258 staining and flow cytometry. After treatment with of AG at different concentrations, the protein levels of the molecules related to proliferation, migration, invasion and apoptosis of osteosarcoma 143B cells were determined by Western blot. The expression of β-catenin and its related molecule c-Myc in the Wnt signaling pathway was analyzed by Western blot. RESULTS Compared with blank group, the proliferation, migration and invasion of osteosarcoma 143B cells in AG treatment group were significantly inhibited (P<0.05) in a concentration-dependent manner. The expression levels of invasion- and migration-related proteins matrix metalloproteinase-9 (MMP-9), vimentin and Snail were all down-regulated (P<0.05). AG also increased the expression of antiapoptotic protein Bcl-2, and the levels of apoptosis-related protein caspase-3 was decreased but cleaved caspase-3 was increased. At the same time, the expression levels of Wnt/β-catenin signaling pathway related proteins β-catenin and c-Myc were significantly decreased (P<0.05). CONCLUSION Andrographolide may inhibit the proliferation, migration, and invasion of osteosarcoma 143B cells and promote their apoptosis by inhibiting the activity of Wnt signaling pathway.     

Expression changes of Wnt/β-catenin signaling pathway in diabetic ulcer

AIM: To observe the effect of Wnt/β-catenin signaling pathway on diabetic ulcer. METHODS: Diabetic animal model was established in the female Wistar rats by intraperitoneal injection of low-dose streptozotocin following high-fat diet feeding. A circular wound was made on the dorsum of the rats in both control group and diabetic group. The condition of wound healing was recorded and the structures of the wound tissues were observed by HE staining in the 2 groups at 3, 7 and 14 d after wounding. The expression of β-catenin, GSK-3β and Rspo-3 at mRNA and protein levels in the wound tissues was detected by RT-PCR and ELISA. RESULTS: In diabetic group, the wound healing rate was lower (P<0.05), and the inflammatory cells, fibroblast cells and new capillaries in the wound tissues were fewer than those in control group. The expression of β-catenin and Rspo-3 at mRNA and protein levels in the wound tissues in control group was significantly higher than those in diabetic group, and the expression of GSK-3β was exactly the opposite (P<0.05). CONCLUSION: The down-regulation of Wnt/β-catenin probably resultes from the decreased level of Rspo-3, which may be one of the reasons for delaying the diabetic ulcer healing.     

Pim-1 kinase inhibitor SMI-4a inhibits proliferation and induces apoptosis in U937 cells

AIM: To study the growth-inhibiting and proapoptotic effects of Pim-1 kinase inhibitor SMI-4a on human acute myeloid leukemia cell line U937.METHODS: The effect of SMI-4a on U937 cell viability was measured by CCK-8 assay. The apoptotic rate was assessed by flow cytometry with Annexin V-PI staining and by fluorescence microscopy with Hoechst 33342 staining. Methylcellulose was used to assess colony formation ability of the cells. The expression of β-catenin in the cell cytosol and nucleus was detected by Western blot, and the expression of apoptosis-related proteins in the U937 cells was also examined. Intracellular distribution of β-catenin was detected by the method of immunofluorescence.RESULTS: SMI-4a inhibited the viability of U937 cells. Annexin V-PI staining showed that SMI-4a induced apoptosis in dose-and time-dependent manners. Hoechst 33342 staining also verified the apoptosis. SMI-4a significantly inhibited the colony formation capacity of the U937 cells. The results of Western blot demonstrated that SMI-4a upregulated the expression of PARP and Bax, downregulated the expression of Bcl-2 and change the distribution of β-catenin in intracellular compartment. Immunofluorescence observation found that SMI-4a decreased the expression level of β-catenin in the U937 cells.CONCLUSION: SMI-4a induces U937 cell apoptosis through regulating the expression of apoptosis-related genes.     

Indomethacin induces gastric cancer cell apoptosis through Akt/GSK3β/NAG-1 pathway

AIM: To investigate whether indomethacin induces gastric cancer cell apoptosis through Akt/GSK3β/NAG-1 pathway.METHODS: Gastric cancer cell line MGC-803 was used in the study. Cell viability was measured by MTT method. Hoechst 33258 nuclear staining and flow cytometry analysis were used to determine apoptosis. The protein expression level was examined by Western blotting. RESULTS: Indomethacin induced MGC-803 cell apoptosis via caspase-dependent pathway. Indomethacin inhibited Ser473-Akt and Ser9-GSK3β phosphorylation and up-regulated the expression of non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1). Inhibition of PI3K or Akt alone also increased NAG-1 expression. Moreover, the effect of indomethacin on NAG-1 expression was abolished by pretreatment of the cells with GSK3β inhibitor SB216763. CONCLUSION: Indomethacin induces gastric cancer cell apoptosis through Akt/GSK3β/NAG-1 pathway.     

PI3K/Akt/GSK-3β pathway mediates ABC transporter regulating multidrug resistance in human colon cancer HCT-15 cells

AIM: To investigate whether the PI3K/Akt signaling pathway regulates the expression of ABC transporter through the downstream glycogen synthase kinase-3β (GSK-3β) pathway and participates in the multidurg resistance of colorectal cancer (CRC) HCT-15 cells. METHODS: Colorectal cancer HCT-15 cells were cultured and then treated with GSK-3β inhibitor (HY-19807) and PI3K/Akt pathway inhibitor (HY-13898), respectively. The median inhibitory concentration (IC₅₀) of oxaliplatin for HCT-15 cells in each group was detected by CCK-8 assay, the inhibition rate and resistance index were also calculated. The protein levels of Akt, p-Akt, GSK-3β, p-GSK3β-Ser9 and ABC transporters P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP-2) in the HCT-15 cells were determined by Western blot. The mRNA expression of ABC transporter in the HCT-15 cells was detected by RT-qPCR. The cell cycle distributions were analyzed by flow cytometry assasy. RESULTS: After GSK-3β inhibitor HY-19807 was used in the HCT-15 cells, the median inhibitory concentration of oxaliplatin was significantly increased, the protein levels of p-GSK3β-Ser9, P-gp and MRP-2 were up-regulated compared with control group (P<0.05), the changes of Akt and p-Akt were not obvious compared with control group (P>0.05). The results of RT-qPCR also showed that the mRNA levels of ABCB1 and ABCC2 were increased (P<0.01). Meanwhile, analysis of the cell cycle distribution showed that GSK-3β inhibitor HY-19807 promoted HCT-15 cell transition from G₁ phase to S phase, and cell proliferation was vigorous. After the PI3K/Akt pathway inhibitor HY-13898 was applied to HCT-15 cells, the IC₅₀ of oxaliplatin was decreased compared with control group (P<0.05). Moreover, the protein levels of p-Akt, p-GSK3β-Ser9, P-gp and MRP-2 were down-regulated (P<0.01). RT-qPCR results also showed that the mRNA expression of ABCB1 and ABCC2 was decreased (P<0.01). At the same time, G₁ phase was prolonged, which inhibited cell transition from G₁ phase to S phase, and inhibited cell proliferation. The protein expression of total GSK-3β was consistent in each group. CONCLUSION: The PI3K/Akt signaling pathway is involved in the proliferation and multidrug resistance of colorectal cancer HCT-15 cells by regulating the phosphorylation of GSK-3β and changing the expression of ABC transporter.     

Mechanism of AKT1 negatively regulating breast cancer cell migration

AIM: To investigate the molecular mechanism and downstream signaling pathway by which AKT1 inhibition regulates breast cancer cell migration. METHODS: RNA interference was used to knockdown the expression of AKT1. Western blot assay was performed to examine the expression of AKT1 total protein, β-catenin total protein and β-catenin nuclear protein. Immunofluorescence was used to examine the cellular localization of β-catenin. Transwell assay was used to investigate whether β-catenin nuclear accumulation as an alternative pathway was responsible for breast cancer metastasis induced by AKT1 inhibition. RESULTS: The total protein expression of AKT1 was decreased in MCF-7 and MDA-MB-231 cells treated with AKT1 siRNA. A significant increase in the protein expression of β-catenin was observed in MCF-7 cells and MDA-MB-231 cells treated with AKT1 siRNA. Immunofluorescence staining showed that MCF-7 cells and MDA-MB-231 cells displayed strong β-catenin staining in the cytoplasm and nucleus after knockdown of AKT1 expression. The ability of tumor cell migration increased dramatically after treated with AKT1 specific siRNA in the breast cancer MCF-7 cells and MDA-MB-231 cells in Transwell assay. XAV-939 reversed breast cancer cell migration induced by knockdown of AKT1 expression. CONCLUSION: β-catenin nuclear accumulation contributes to AKT1 inhibition-mediated breast cancer cell migration.     

Effects of sulindac on oxidative stress in an autistic model induced by prenatal exposure to valproic acid

AIM: To investigate the effects of sulindac on oxidative stress in autism. METHODS: With an autistic model induced by prenatal exposure to valproic acid (VPA), we detected the expression of the signaling molecules of canonical Wnt pathway in the prefrontal cortex (PFC) and hippocampus (HC) of autistic rats treated with sulindac. The protein expression levels of glycogen synthase kinase 3β (GSK-3β), β-catenin and 4-hydroxynonenal (4-HNE) were observed by Western blotting. The mRNA expression of thioredoxin(Trx)1 and Trx2 was assessed by semi-quantitative RT-PCR.RESULTS: The protein level of GSK-3β and mRNA levels of Trx1 and Trx2 were lower, whereas the protein expression levels of β-catenin and 4-HNE were higher in VPA group than those in control group. In contrast, the protein levels of GSK-3β were significantly higher in the animals treated with both VPA and sulindac than those in VPA group, while the levels of β-catenin and 4-HNE were decreased.CONCLUSION: Sulindac attenuates oxidative stress in the pathogenesis of autism, suggesting the up-regulation of the Wnt/β-catenin signaling pathway disrupts oxidative homeostasis and further facilitates susceptibility to autism.     

Kaempferol inhibits cell proliferation,invasion and migration via Wnt/β-catenin signaling in HBx-HepG2 cells

AIM: To explore the effects of kaempferol on the proliferation, invasion and migration abilities of HBx-HepG2 cells and to examine the underlying molecular mechanisms. METHODS: The expression levels of related genes at mRNA and protein levels were determined by RT-qPCR and Western blot. The cell apoptotic rate was analyzed by flow cytometry. The cell proliferation, growth, invasion and migration abilities were measured by MTT assay, colony formation assay, Transwell invasion assay and wound healing assay, respectively. RESULTS: Kaemferol inhibited HBx-HepG2 cell proliferation in a concentration-and time-dependent manner. Kaempferol at 100 μmol/L significantly inhibited the colony formation, invasion and migration abilities of the HBx-HepG2 cells. Kaemferol at 100 μmol/L also increased cell apoptotic rate, increased the protein levels of cleaved caspase-3, cleaved caspase-9 and Bax, and decreased the expression level of Bcl-2. In addition, kaemferol at 100 μmol/L suppressed the mRNA and protein expression levels of β-catenin, c-Myc and cyclin D1 in the HBx-HepG2 cells. Kaemferol at 100 μmol/L also suppressed the protein level of p-GSK-3β and the β-catenin protein levels in both cytoplasm and nucleus. LiCl treatment reversed the inhibitory effect of kaempferol on the growth, invasion and migration of the HBx-HepG2 cells. CONCLUSION: Kaempferol inhibits cell proliferation, invasion and migration via activating Wnt/β-catenin signaling in HBx-HepG2 cells.     

Effects of shRNA targeting COL1A1 gene on proliferation and apoptosis of human breast cancer cell line MDA-MB-231

AIM: To investigate the effects of shRNA-mediated collagen type I alpha 1 (COL1A1) gene silencing on the proliferation and apoptosis of human breast cancer cell line MDA-MB-231. METHODS: The specific recombinant vector pSilencer2.1-U6-COL1A1 was transiently transfected into human breast cancer cell line MDA-MB-231 with lipofectamine. RT-PCR and Western blotting were performed to detect the expression levels of COL1A1. MTT assay was employed to evaluate the effect of COL1A1 gene silencing on the cell proliferation. Flow cytometry was used to determine the apoptosis and cell cycle of transfected cells. The morphological characteristics of apoptosis were observed by Hoechst 33258 staining. RESULTS: Compared with mock group and scrambled group, the mRNA and protein levels of COL1A1 were reduced by pshRNA-COL1A1 transfection (P<0.05). The proliferation of MDA-MB-231 cells treated in shRNA-COL1A1 was significantly inhibited in a time-dependent way. The percentages of G₀/G₁ phase cells and early apoptotic rate were significantly higher in pshRNA-COL1A1 group than those in mock and scrambled group (P<0.05). The changes of apoptotic morphology such as cell shrinkage and nuclear condensation were also observed by staining with Hoechst 33258 under fluorescence microscope. CONCLUSION: Transfection of eukaryotic expression vector pshRNA-COL1A1 effectively inhibits the proliferation, induces apoptosis and arrests MDA-MB-231 cells in G0/G1 phase.     

Changes of canonical Wnt signaling pathway in brains of rats with autism induced by prenatal exposure to valproic acid

AIM：To investigate the roles of the canonical Wnt pathway in autism. METHODS：Using an autistic model induced by prenatal exposure to valproic acid (VPA), we detected the expression of the signaling molecules of the canonical Wnt pathway in the prefrontal cortex (PFC) and hippocampus formation (HF) of autistic rats. The expression levels of glycogen synthase kinase 3β (GSK-3β), phosphorylated GSK-3β, β-catenin and phosphorylated β-catenin were observed by Western blotting. The mRNA expression of GSK-3β, β-catenin, c-Myc and cyclin D1 was assessed by semi-quantitative RT-PCR. RESULTS：The results of Western blotting showed that inactivated GSK-3β (Ser9) phosphorylation was significantly increased, and inhibitory β-catenin (Ser33/37/Thr41) phosphorylation was obviously decreased compared with control group. The results of RT-PCR showed that the mRNA levels of β-catenin, c-Myc and cyclin D1 increased, and GSK-3β was significantly enhanced in VPA-exposed rats compared with the controls. CONCLUSION：Increased activity of canonical Wnt pathway in the PFC and HF of autistic rats may contribute to the susceptibility to autism.     

Role of HMGA2 in epithelial-mesenchymal transition of gastric cancer cells

AIM:To investigate the role of HMGA2 in the epithelial-mesenchymal transition (EMT) in gastric cancer cells. METHODS:The expression of HMGA2 in human gastric cancer cell lines with different degrees of differen-tiation (MKN45, MKN28 and SGC7901) and immortalized human gastric epithelial cell line GES-1 was determined by Western blot and RT-qPCR. pcDNA3.0-HMGA2 plasmid was transfected into the MKN28 cells by liposome method. Transfection of si-HMGA2 interference fragments into MKN45 cells was also performed. The transfection efficiency was evaluated by Western blot and RT-qPCR. The effects of HMGA2 over-expression in the MKN28 cells and knock-down in the MKN45 cells on the cell viability were measured by CCK-8 assay. The effects of HMGA2 over-expression in the MKN28 cells on the cell migration and invasion abilities were detected by wound healing and Transwell invasion assays. The effects of HMGA2 over-expression in the MKN28 cells and knock-down in the MKN45 cells on the expression of EMT-related markers E-cadherin, N-cadherin, vimentin at mRNA and protein levels were determined by RT-qPCR and Western blot. The changes of Wnt/β-catenin signaling pathway-related molecules in the MKN28 cells with HMGA2 over-expression were also determined by RT-qPCR. RESULTS:The expression levels of HMGA2 were quite different in different differentiation levels of gastric cancer cells (P<0.05). The increased expression level of HMGA2 in MKN28 cells inhibited the cell viability (P<0.05), while the decreased expression level of HMGA2 in MKN45 cells promoted the cell viability (P<0.05). The increased expression level of HMGA2 in MKN28 cells promoted cell migration and invasion (P<0.05), changed the expression of EMT-related markers (P<0.05), while the decreased expression level of HMGA2 in the MKN45 cells changed the expression of EMT-related markers (P<0.05). The increased expression level of HMGA2 in the MKN28 cells significantly increased the mRNA levels of β-catenin in the Wnt/β-catenin pathway and the downstream molecules c-Myc and cyclin D1 (P<0.05). CONCLUSION:HMGA2 is closely related to the migration and invasion abilities of gastric cancer cells. Moreover, it promotes the EMT process of gastric cancer cells by activating Wnt/β-catenin pathway.     

Over-expression of SCUBE2 suppresses epithelial-mesenchymal transition through Wnt/β-catenin signaling pathway in colorectal cancer cells

AIM: To study the effect of SCUBE2 on epithelial-mesenchymal transition (EMT) in colorectal cancer cells and its mechanism. METHODS: The expression of SCUBE2 in human colorectal cancer cell line HCT116 and normal colonic cell line FHC was detected by real-time PCR and Western blot. HCT116 cells were transfected with GV144-SCUBE2 to over-express SCUBE2, and then the cell viability, migration, and apoptosis were determined by MTT assay, Transwell assay and flow cytometry, respectively. The expression of EMT markers (E-cadherin, vimentin, and Snail), β-catenin, c-Myc and cyclin D1 in the HCT116 cells was analyzed by real-time PCR or Western blot after transfection with GV144-SCUBE2 for 6 h, followed by the stimulation of 10 μg/L recombinant TGF-β1 protein for 48 h. Additionally, the EMT process of HCT116 cells, which were stimulated by TGF-β1, over-expressed SCUBE2, and treated with Wnt/β-catenin pathway activator lithium chloride (LiCl) or inhibitor XAV93920, was analyzed by Western blot. RESULTS: Compared with FHC cells, the expression of SCUBE2 in the HCT116 cells was significantly decreased. The viability and migration ability of the HCT116 cells were suppressed by SCUBE2 over-expression, but the apoptosis was not markedly changed. Elevated expression of SCUBE2 increased E-cadherin expression, and decreased the expression of vimentin, Snail, β-catenin, c-Myc and cyclin D1 induced by TGF-β1. Treatment with LiCl blocked but treatment with XAV93920 enhanced the effects of SCUBE2 on EMT. CONCLUSION: Over-expression of SCUBE2 may inhibit the cell growth and migration, and suppress EMT through Wnt/β-catenin signaling pathway.     

Ginsenoside Rh4 induces apoptosis of human hepatocellular carcinoma HepG2 cells

AIM: To investigate the apoptosis and molecular mechanism of human hepatocellular carcinoma HepG2 cells induced by ginsenoside Rh4. METHODS: Human hepatocellular carcinoma HepG2 cells were treated with ginsenoside Rh4 at doses of 10, 20 and 40 μmol/L, and the inhibitory effect of ginsenoside Rh4 on HepG2 cell viability was measured by MTT assay. The apoptotic rate of HepG2 cells was analyzed by flow cytometry. The morphological changes of the HepG2 cells were observed by Hoechst 33258 and TUNEL staining. The expression of apoptosis-related proteins Bax, Bcl-2, caspase-3 and caspase-9 was determined by Western blot. RESULTS: Ginsenoside Rh4 promoted apoptosis of HepG2 cells in a dose-dependent manner. TUNEL and Hoechst 33258 staining showed that the cells appeared obvious shrinking, swelling and rupture after treated with ginsenoside Rh4 for 24 h. The results of Western blot showed that with the increasing concentrations of ginsenoside Rh4, the expression of pro-apoptotic proteins Bax, cleaved caspase-3 and caspase-9 increased, while anti-apoptotic protein Bcl-2 decreased gradually. CONCLUSION: Ginsenoside Rh4 induces apoptosis of human hepatocellular carcinoma HepG2 cells, and the main mechanism may be related to down-regulation of Bcl-2 and up-regulation of Bax, cleaved caspase-3, and caspase-9.     

Inhibition of miR-9 expression suppresses proliferation,invasion and migration of nasopharyngeal carcinoma cells

AIM: To investigate the effects of down-regulated miR-9 expression on the proliferation, invasion and migration of nasopharyngeal carcinoma (NPC) cells. METHODS: Human NPC CNE1 and CNE2 cells were transfected with the inhibitor of miR-9 by Lipofectamine to down-regulate the expression of miR-9, and the cells transfected with an inhibitor control were also set up. The cell proliferation and cell cycle were evaluated by CCK-8 assay and flow cytometry. The cell invasion and migration abilities were detected by Transwell invasion and wound-healing assays. Immunoblotting was applied to analyze the levels of the proteins. RESULTS: Compared with control group, inhibition of miR-9 expression in the NPC cells by transfection of the miR-9 inhibitor significantly decreased the proliferation ability (P<0.05). The percentages of the cells in G0/G1 phase ［CNE2: (57.96±1.39)% vs (47.93±1.76)%, P<0.05; CNE1: (51.24±0.88)% vs (48.29±0.39)%, P<0.05］ were significantly increased. The migration distances ［CNE2: (186.50±7.94)μm vs (247.56±15.56)μm, P<0.05; CNE1: (139.06±16.73)μm vs (230.66±14.27)μm, P<0.01］ and the invasion ability of the CNE2 cells (43.00±3.17 vs 65.80±5.20, P<0.01) were also significantly inhibited. Moreover, the tumor cells transfected with the inhibitors produced lower β-catenin. CONCLUSION: Inhibition of miR-9 expression suppresses the proliferation, invasion and migration of nasopharyngeal carcinoma cells.     

Effect of EZH2 regulating Wnt/β-catenin signaling pathway on apoptosis of brain glioma cells

AIM: To investigate the effect of enhancer of zeste homolog 2 (EZH2) regulating Wnt/β-catenin signaling pathway on the apoptosis of brain glioma cell lines. METHODS: The expression level of EZH2 in glioma cell lines U87, H4 and U251 and normal human astrocytes (NHA) was detected by RT-qPCR and Western blot. The EZH2 siRNA and siRNA control were transfected into the H4 cells. The cell viability was measured by MTT assay. The apoptosis was analyzed by flow cytometry. Caspase-3 activity was detected by spectrophotometry. The expression levels of the key protein β-catenin of the Wnt/β-catenin signaling pathway and the downstream target molecule c-Myc were determined by Western blot. After the H4 cells transfected with EZH2 siRNA were treated with an activator of Wnt/β-catenin signaling pathway, the apoptosis rate was measured by flow cytometry, and the expression of β-catenin and c-Myc was determined by Western blot. RESULTS: The mRNA and protein expression levels of EZH2 in the glioma cell lines U87, H4 and U251 were significantly higher than those in NHA (P<0.05). The expression of EZH2 at mRNA and protein levels in the H4 cells was higher than that in U87 cells and U251 cells (P<0.05). EZH2 siRNA obviously inhibited the expression of EZH2 at mRNA and protein levels in the H4 cells. Knockdown of EZH2 expression decreased the viability of H4 cells, the apoptotic rate was significantly increased, and the activity of caspase-3 was significantly increased in the cells (P<0.05). Knockdown of EZH2 expression also inhibited the expression of β-catenin and c-Myc. The activator of Wnt/β-catenin signaling pathway reduced the apoptosis rate of H4 cells induced by down-regulation of EZH2, and reduced the activity of caspase-3 in the cells. CONCLUSION: EZH2 is over-expressed in glioma cells. Down-regulation of EZH2 expression induces apoptosis of glioma cells by inhibiting the activation of Wnt/β-catenin signaling pathway.     

Effects of siRNA-mediated nestin silencing on invasion and migration of human esophageal cancer ECA109 cells

AIM: To investigate the effect of small interference RNA(siRNA)-mediated silencing of nestin gene on the invasion and migration of human esophageal cancer ECA109 cells and the possible mechanism. METHODS: The esophageal cell line ECA109 was transfected with siRNA targeting nestin and the cell invasion and migration abilities were observed. The expression of nestin, MMP2, MMP9, VEGF, and total and nuclear β-catenin proteins in the transfec-ted cells were determined by real-time PCR and Western blot. RESULTS: Compared with control group, the expression of nestin at mRNA and protein levels was significantly down-regulated in the ECA109 cells transfected with nestin-siRNA, so was the expression of MMP2, MMP9, VEGF, and total and nuclear β-catenin proteins. The levels of invasion and migration capacities of ECA109 cells transfected with nestin-siRNA were lower than those in the cells transfected with control-siRNA. CONCLUSION: Knockdown of nestin expression significantly inhibits the invasion and migration of the esophageal cancer cells, which may act via suppressing β-catenin translocation to the nucleus and influencing the expression of MMP2, MMP9 and VEGF.