ObjectiveTo explore the effect of DDX46 silencing on growth and apoptosis in esophageal squamous cell carcinoma cell TE-1 by the shRNA. MethodsThe relative expression of DDX46 mRNA in TE-1 cells was detected by real-time quantitative polymerase chain reaction (qRT-PCR) and compared with immortalized human esophageal squamous cell Het-1A. DDX46 shRNA-expressing lentivirus was applied to silence DDX46 (experimental group), and non-silencing control lentivirus was added (control group) with a multiplicity of infection of 5 in TE-1 cells. In both groups, cell growth was monitored using high content screening, cell colony-forming capacity was measured by colony formation assay, cell apoptosis were determined by flow cytometry. Further, the Stress and Apoptosis Signaling Antibody Array Kit was used to detect the changes of signaling molecules in TE-1 cells after DDX46 knockdown. ResultsCompared with the control group, cell counting after DDX46 silencing showed that TE-1 cell growth was significantly inhibited (P<0.001). Colony formation assay showed that cell colony-forming capacity was significantly inhibited (P<0.01). Annexin V-APC flow cytometry showed a significant increase in apoptosis (P<0.001). In PathScan® Antibody Array, the expression levels of Akt (Ser473, phosphorylation) and IκBα (Total, N/A) significantly decreased (P<0.01), and the expression of Caspase-3 (Asp175, cleaved) increased (P<0.05). ConclusionDDX46 is overexpressed in TE-1 cells. Targeted gene silencing of DDX46 inhibits cell growth, and induces cell apoptosis. DDX46 silencing probably by negative regulation of Akt/NF-κB signaling pathway, to play a role in inhibiting TE-1 cells growth and inducing apoptosis.
Objective To observe the growth of xenografted tumor in nude mice after DDX46 expression decreased, and to further study the role of DDX46 in the development and progression of esophageal squamous cell carcinoma. Methods DDX46-shRNA mediated RNAi was applied to silencing DDX46 in Eca-109 cells. Twenty-five female BALB/c nude mice were divided into 3 groups: an experiment group (DDX46-shRNA-LV, n=10), a control group (Control-LV, n=10) and a blank control group (Het-1A, n=5). The prepared Eca-109 cells of DDX46-shRNA-LV and Control-LV were subcutaneously injected into the right armpit of mice (4×106 cells per mouse), while Het-1A cells were subcutaneously injected into the bilateral armpits of mice (4×106 cells per side). Tumor growth was monitored twice a week on the 14th day after injection. Tumor volume was measured with calipers, in vivo imager to observe the fluorescence of each group. Further, western blotting analysis was used to detect the changes of apoptosis signaling molecules in xenografted tumor after DDX46 silence. Results The growth of xenografted tumor in nude mice was significantly slower in the DDX46-shRNA-LV group than that in the Control-LV group throughout the study period (P<0.001). Western blotting analysis showed that silencing DDX46 effectively suppressed the expression of DDX46, and upregulated the expression of cleaved Caspase-3 and cleaved PARP-1 in xenografted tumor (P<0.01). Conclusion DDX46 is involved in the development and progression of esophageal squamous cell carcinoma, and the silence of DDX46 expression can inhibit the growth of esophageal squamous cell carcinoma, which probably by positive regulation of apoptosis signaling pathway.
ObjectiveTo explore the mechanism of DDX46 regulation of esophageal squamous cell carcinoma.MethodsPicture signals of fluorescence in gene array were scanned and differential expression of gene in two groups (a DDX46-shRNA-LV group and a control-LV group) were compared by GCOSvL.4 software. These differential expressed genes were analyzed by bioinformatics methods finally, and validated by quantitative real time polymerase chain reaction (qRT-PCR) analysis.ResultsAccording to the screening criteria of fold change ≥2 and P<0.05, 1 006 genes were differentially expressed after DDX46 knockdown, including 362 up-regulated and 644 down-regulated genes. Bioinformatics analysis and gene co-expression network building identified that these differentially expressed genes were mainly involved in cell cycle, proliferation, apoptosis, adhesion, energy metabolism, immune response, etc. Phosphatidylinositol 3-kinase (PI3K) was the key molecule in the network. The results of RT-qPCR were completely consistent with the results of gene microarra.ConclusionBioinformatics can effectively exploit the microarray data of esophageal squamous cell carcinoma after DDX46 knockdown, which provides a valuable clue for further exploration of DDX46 tumorigenesis mechanism and helps to find potential drug therapy.
ObjectiveTo investigate the relationship between DDX46 genes and invasion and migration of esophageal squamous cell carcinoma cells. MethodsHuman esophageal squamous cell carcinoma cells TE-1 were transfected by fluorescent marker shRNA lentivirus (shDDX46 group), and an empty vector was transfected as a control (shCtrl group). The expression rate of green fluorescent protein under the microscope was used to evaluate the cell transfection efficiency. Real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) and Western blotting (WB) detected the knockdown efficiency of the target gene at the mRNA and protein expression levels. Wound healing, invasion assay and migration assay detected the changes of invasion and metastasis ability. Classical pathway analysis was used to explore signaling pathway changes and the possible mechanism of DDX46 in the invasion and metastasis was explored by detecting fibronectin expression. ResultsDDX46 gene at mRNA and protein levels was significantly inhibited after lentiviral transfection. Wound healing showed that after 8 h the cell mobility of TE-1 cells decreased significantly (P=0.001). Invasion assay showed that after 24 h the average cell metastasis rate of TE-1 cells was lower in the shDDX46 group than that in the shCtrl group (P<0.001). The cell metastasis rate in the shDDX46 group corresponding to observation points in the transwell assay was lower than that in the shCtrl group (P<0.001) after 24 h culture. The results of the classical pathway analysis showed that the integrin signaling pathway activity was inhibited, further exploration of the mechanism of action found that the expression of fibronectin associated with cell adhesion was decreased. ConclusionDDX46 gene is related to the invasion and migration ability of esophageal squamous cell carcinoma cells. Knockdown of DDX46 genes may reduce cell adhesion by downregulating the integrin pathway signaling.