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The increased expression of cluster of differentiation (CD)47 has been identified in a number of different tumor types and is recognized as an adverse prognostic factor that indicates an increased risk of mortality in patients. The binding of CD47 to signal regulatory protein α (SIRPα) inhibits the macrophage phagocytosis of tumor cells by triggering an inhibitory 'do not eat me' signal. This is one of the mechanisms used by tumor cells to evade immune surveillance. In the present study, CD47 levels and macrophage infiltration were assessed in patients with esophageal squamous cell cancer (ESCC). CD47-overexpressing ESCC cell lines were selected and human M2 macrophage phagocytic activity was measured. The results revealed that CD47 is highly expressed and macrophages are markedly infiltrated in cancerous tissue compared with non-cancerous tissue. High CD47 expression was detected in ESCC cell lines and the results of a phagocytosis assay indicated that human M2 macrophages phagocytized tumor cells in a dose-dependent manner following the blocking of CD47-SIRPα signaling by anti-CD47 antibodies. The results of the present study therefore support the use of anti-CD47 immunotherapy to treat patients with ESCC. [ABSTRACT FROM AUTHOR]

Objective: To study the effect of simultaneously increasing PTEN gene expression and inhibiting Livin gene expression on the gastric carcinoma cell line (BGC823) and construct a recombinant vector expressing PTEN while simultaneously silencing Livin., Methods: The siRNA expression unit against Livin gene (siLivin) was cleaved from pRNAT-U6.1-Livin vector and then inserted into pCL-neo-PTE to construct the recombinant vector pCL-neo-PTEN-siLivin. Then pCL-neo-PTEN-siLivinp, pCL-neo-PTEN, pRNAT-U6.1-Livin, pCL-neo and pRNAT-U6.1 were respectively transfected into the gastric carcinoma cell line (BGC823) with LipofectAMINE(TM) 2000. The mRNA and protein expression level of PTEN and Livin genes in each cell group was detected by fluorescent quantitative RT-PCR and Western blot., Results: Recombinant vectors of pCL-neo-PTEN, pRNAT-U6.1-Livin and pCL-neo-PTEN-siLivin were constructed successfully. After transfection with pCL-neo-PTEN-siLivin, the mRNA and protein expression level of PTEN (0.897±0.112) rose in BGC823 cells while Livin gene became silenced. And the characterization of regulated cell bioactivity improved. There were significant differences between transfected and control groups (P<0.05). And the inhibiting effect on the proliferation and metastasis of BGC823 cell by increasing PTEN expression and silencing Livin simultaneously was better than that only by regulating PTEN genes or Livin genes alternatively., Conclusion: The recombinant vector of expressing PTEN and silencing Livin gene simultaneously is successfully constructed.

Objective: To investigate the apoptosis effect of isothiocyanates (ITCS) on human liver cancer cells HepG-2, and its mechanism., Method: HepG-2 cells were treated with different concentrations of ITCS. MTT assay was used to evaluate the influence of ITCS on cell proliferation. Flow cytometry was used to test ROS levels, intracellular mitochondrial transmembrane potential (deltapsim) , and hypodiploid apoptosis peak in HepG-2 cells., Result: ITCS obviously inhibited proliferation of HepG-2 cells. When treated with 15, 30, 60, 120, 240 microg x mL(-1) of ITCS for 24 h, ROS levels were (23.1+/-1. 8)%, (53.3+/-3.3)%, (57.9+/-2.0)%, (79.9+/-3.4)%, (93.4+/-2. 6)% respectively; and deltapsim were (94.8+/-5.5)%, (91.8+/-5.4)%, (66.0+/-5.6)%, (65. 5+/-6.6)% and (44.3+/-2.7)% respectively; when treated with 60, 120, 240 microg x mL(-1) of ITCS for 48 h, cell apoptotic rates were (16.6+/-2.8)%, (21.9+/-4.4) % and (70.2+/-5.3) % respectively., Conclusion: ITCS generates ROS in gastric cancer HepG-2 cells, which causes mitochondrial membrane permeabilization and deltapsim decrease, therefore, leads to apoptosis of HepG-2 cells.