Death receptors induce apoptosis by intracellular signaling transmission and relate to body growth, development, disease and death. This paper reviews the structural character of death receptors, and the mechanisms by which apoptosis is induced. The biology and pathobiology of these death receptors in liver are discussed as well.
Apoptosis ; physiology ; GPI-Linked Proteins ; Humans ; Liver ; pathology ; physiology ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; Receptors, Tumor Necrosis Factor ; physiology ; Receptors, Tumor Necrosis Factor, Member 10c ; Tumor Necrosis Factor Decoy Receptors ; fas Receptor ; physiology

There exist two major apoptotic signaling pathways: the intrinsic mitochondria-mediated pathway, and the extrinsic death receptor-induced pathway. TNF-related apoptosis-inducing ligand (TRAIL), which is the ligand for death receptor 4 (DR4) and death receptor 5 (DR5) and induces apoptosis by ligation with DR4 or DR5. We review the characteristic of TRAIL and its receptors, the mechanism of apoptosis induced by TRAIL, the distribution of death receptors in cancer, and applications and prospects of TRAIL signaling pathway in the treatment of cancer.
Animals ; Antineoplastic Agents ; pharmacology ; therapeutic use ; Apoptosis ; drug effects ; Drug Delivery Systems ; GPI-Linked Proteins ; genetics ; metabolism ; Genetic Therapy ; Humans ; Neoplasms ; metabolism ; pathology ; therapy ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; classification ; genetics ; metabolism ; Receptors, Tumor Necrosis Factor, Member 10c ; Signal Transduction ; TNF-Related Apoptosis-Inducing Ligand ; genetics ; metabolism ; pharmacology ; Tumor Necrosis Factor Decoy Receptors ; genetics ; metabolism

OBJECTIVETo evaluate the differentially expressed genes between the Stress fracture (SF) cases and controls.

METHODSTotal RNA was extracted and purified from peripheral blood sample of 3 SF cases and 3 controls who conducted a 1:1 matched case-control study, then used for Human Genome Array analysis. The hybridization data were analyzed using SAM software. Parts of these genes were analyzed and identified by real-time PCR.

RESULTSUpregulated and downregulated genes were 22 and 1, respectively. Thus the highest ratio and most significant cytokine was tumor necrosis factor receptor superfamily, member 10c (TNFRSF10C). The result of real-time PCR shows that TNFRSF10C was over-expressed in 3 cases and low-expressed in 1 case.

CONCLUSIONObvious difference exists in gene expression between SF cases and controls, showing there may be a lot of genes involving in the occurrence and development of SF. Meanwhile, the identification of the specific genes is helpful for biomechanics study, early diagnosis and screening of SF.

Case-Control Studies ; DNA, Complementary ; genetics ; Fractures, Stress ; blood ; metabolism ; GPI-Linked Proteins ; genetics ; metabolism ; Gene Expression ; Gene Expression Profiling ; Humans ; Male ; Military Personnel ; Oligonucleotide Array Sequence Analysis ; Receptors, Tumor Necrosis Factor, Member 10c ; Tumor Necrosis Factor Decoy Receptors ; genetics ; metabolism ; Young Adult

OBJECTIVETo investigate the effects of X ray on human colorectal cancer cells for their tumor necrosis factor receptor-p55 (TNFR-p55) expression and release of soluble soluble TNFR-p55 (sTNFR-p55) in vitro.

METHODSThe protein expression of TNFR-p55 in Lovo cells exposed to X-ray was detected using immunohistochemistry, and enzyme-linked immunosorbent assay was used to examine the levels of sTNFR-p55 in the supernatants of the cell culture. The cell apoptosis of the exposed cells was analyzed with flow cytometry, and the changes in cell morphology were observed microscopically.

RESULTSX-ray exposure of cells resulted in a strong increase in TNFR-p55 expression of (P<0.01) and LoVo cell apoptosis (P<0.05). The levels of sTNFR-p55 in the supernatant of cells with X-ray exposure was significantly lowered in comparison with the levels before exposure (P<0.01). Optical microscopy showed that the exposed LoVo cells shrank and became spherical with cytoplasmic condensation and nuclear pyknosis.

CONCLUSIONX-ray exposure can induce LoVo cell apoptosis by increasing TNFR-p55 expression on the cell membrane and inhibiting the release of sTNFR-p55 in the supernatants.

Apoptosis ; Cell Line, Tumor ; Colorectal Neoplasms ; genetics ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; Humans ; Immunohistochemistry ; Receptors, Tumor Necrosis Factor, Type I ; genetics ; metabolism ; Tumor Necrosis Factor Decoy Receptors ; genetics ; metabolism ; X-Rays

OBJECTIVETo investigate the effect of doxorubicin on TRAIL resistance and TRAIL receptor expression in lymphoma cell line SNK-6 cells.

METHODSSNK-6 cells treated with doxorubicin at different concentrations alone or in combination with tumor necrosis factor related apoptosis inducing ligand (TRAIL). Cell proliferation was evaluated by MTT assay. Apoptosis and the expression of TRAIL receptors were determined by flow cytometry.

RESULTSMTT assay showed that treatment with 100 and 1000 ng/ml doxorubicin for 24 h, the survival rates of SNK-6 cells were (80.9 ± 7.2)% and (53.7 ± 2.8)%, significantly higher than that by treatment combined with 500 ng/ml TRAIL (64.9 ± 1.1)% and (34.0 ± 3.9)%, respectively (P < 0.05). Flow cytometry showed that after treatment with 100 and 1000 ng/ml doxorubicin for 48 h, the survival rates of SNK-6 cells were (69.9 ± 6.1)% and (31.1 ± 1.9)%, while treated in combination with 500 ng/ml TRAIL, the cell survival rates were (37.5 ± 6.4)% and (15.0 ± 1.8)%, respectively. The early apoptosis rate was (14.8 ± 0.6)% and (30.8 ± 1.5)%, significantly lower than that [(28.7 ± 0.6)% and (46.6 ± 2.8)%] after treatment in combination with TRAIL (P < 0.05). The expressions of TRAIL receptors and decoy receptors were increased when SNK-6 cells were treated with 100 ng/ml doxorubicin for 24 hours.

CONCLUSIONSDoxorubicin can overcome to a certain extent the TRAIL resistance of SNK-6 cells and induce upregulation of TRAIL death receptors and decoy receptors on the surface of SNK-6 cells. However, a higher dose is needed.

Antibiotics, Antineoplastic ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Doxorubicin ; administration & dosage ; pharmacology ; Drug Resistance, Neoplasm ; Drug Synergism ; Humans ; Lymphoma, Extranodal NK-T-Cell ; metabolism ; pathology ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; metabolism ; TNF-Related Apoptosis-Inducing Ligand ; pharmacology ; Tumor Necrosis Factor Decoy Receptors ; metabolism

Promoter CpG island hypermethylation has become recognized as an important mechanism for inactivating tumor suppressor genes or tumor-related genes in human cancers of various tissues. Gene inactivation in association with promoter CpG island hypermethylation has been reported to be four times more frequent than genetic changes in human colorectal cancers. Hepatocellular carcinoma is also one of the human cancer types in which aberrant promoter CpG island hypermethylation is frequently found. However, the number of genes identified to date as hypermethylated for hepatocellular carcinoma (HCC) is fewer than that for colorectal cancer or gastric cancer, which can be attributed to fewer attempts to perform genome-wide methylation profiling for HCC. In the present study, we used bead-array technology and coupled methylation-specific PCR to identify new genes showing cancer-specific methylation in HCC. Twenty-four new genes have been identified as hypermethylated at their promoter CpG island loci in a cancer-specific manner. Of these, TNFRSF10C, HOXA9, NPY, and IRF5 were frequently hypermethylated in hepatocellular carcinoma tissue samples and their methylation was found to be closely associated with inactivation of gene expression. Further study will be required to elucidate the clinicopathological implications of these newly found DNA methylation markers in hepatocellular carcinoma.
Antimetabolites, Antineoplastic/therapeutic use ; Azacitidine/analogs & derivatives/therapeutic use ; Carcinoma, Hepatocellular/drug therapy/*genetics ; Cell Line, Tumor ; CpG Islands ; *DNA Methylation ; GPI-Linked Proteins/genetics ; Gene Expression Profiling ; Homeodomain Proteins/genetics ; Humans ; Interferon Regulatory Factors/genetics ; Liver Neoplasms/drug therapy/*genetics ; Neuropeptide Y/genetics ; Oligonucleotide Array Sequence Analysis ; Promoter Regions, Genetic ; Tumor Necrosis Factor Decoy Receptors/genetics

OBJECTIVETo analyze the phenotypic and functional characteristics of endothelial (T3A) cells derived from human hepatocellular cell carcinoma.

METHODSEndothelial cells were isolated from human hepatocellular carcinoma specimens. The identification of T3A cells was performed by checking von Willebrand Factor (vWF), CD31, CD34 and Dil-Ac-LDL uptake. The cell surface fenestrations, a specific morphological feature of tumor derived EC, were investigated by scanning and transmission electron microscopy. The phenotypic characteristics of T3A cells were analyzed by fluorescence-activated cell sorter (FACS) and were further conformed by real-time PCR at transcription level. Furthermore, tumor necrosis factor alpha (TNFalpha)-induced cytotoxicity was evaluated by 3-(4, 5-dimethythiazolyl) -2, -diphenyl-2H-tetrazolium-bromide (MTT) assay; Matrix metalloproteinase secretion was detected by zymography; Angiogenic ability in vitro was analyzed by culturing T3A cells in three-dimensional Matrigel plug. Coagulant and fibrinolytic activities were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSThe isolated T3A cells exhibited classic "spindle-shape" morphology and monolayer growth and contact inhibition properties. Immunofluorescent staining showed that T3A cells expressed vWF, CD31, CD34, and uptake of Dil-Ac-LDL at a high level. The cell surface fenestrations were observed on T3A cells by scanning and transmission electron microscopy. By FACS and real-time PCR, T3A cells were found to express alphav3, alphavbeta5 and TNF receptor p75 at high levels, and TNF receptor p55 and ICAM-1 at low levels, as compared with those in human liver sinusoidal endothelial cells (LSEC). In response to TNFalpha, LSEC exhibited a dose-dependent cytotoxicity, while T3A cells were resistant. Gelatin zymography showed that MMP-2 activity was higher in T3A cells than that in LSEC. In a three-dimensional plug of Matrigel, T3A cells exhibited stronger angiogenic ability as compared with LSEC. In addition, T3A cells released more tissue factor (TF), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) and urine plasminogen activator (u-PA) than LSEC in response to TNFalpha.

CONCLUSIONTumor-derived endothelial cells are phenotypically and functionally different from those derived from normal liver tissue.

Antigens, CD34 ; metabolism ; Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Proliferation ; drug effects ; Cell Shape ; Cells, Cultured ; Endothelial Cells ; metabolism ; pathology ; ultrastructure ; Gene Expression ; Humans ; Integrin alphaVbeta3 ; metabolism ; Integrins ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Lipoproteins, LDL ; metabolism ; Liver Neoplasms ; genetics ; metabolism ; pathology ; Lung ; blood supply ; metabolism ; pathology ; Matrix Metalloproteinase 2 ; metabolism ; Microscopy, Electron, Scanning ; Neovascularization, Pathologic ; metabolism ; pathology ; Phenotype ; Plasminogen Activator Inhibitor 1 ; metabolism ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Receptors, Tumor Necrosis Factor, Type I ; metabolism ; Receptors, Vitronectin ; metabolism ; Tissue Plasminogen Activator ; metabolism ; Tumor Cells, Cultured ; Tumor Necrosis Factor Decoy Receptors ; metabolism ; Tumor Necrosis Factor-alpha ; pharmacology ; von Willebrand Factor ; metabolism

OBJECTIVETo explore the enhanced sensitivity of leukemia cell line KG-1a to activated immune cell-mediated cytolysis after treated with resveratrol.

METHODSThe value of 50% inhibition concentration (IC₅₀) for KG-1a by resveratrol was analyzed using trypan blue staining. Peripheral blood mononuclear cells were separated, and then activated by interleukin (IL)-2 and IL-15. The sensitivity of KG-1a treated with and without resveratrol to activated immune cell-mediated cytolysis was assayed by lactate dehydrogenase (LDH) -releasing assay. The expression of tumor necrosis factor related apoptosis inducing ligand (TRAIL) on the surface of activated immune cells and its receptors (DR4/5 and DcR1/2) on the surface of KG-1a were detected by flow cytometry.

RESULTSResveratrol could inhibit the proliferation of KG-1a and IC50 at 24 h was 25 mmol/L. At a ratio of 10:1 or 20:1 between effect and target, the cytolytic rates of treated KG-1a by activated immune cells were (55.80 ± 10.88)% and (72.31 ± 13.06)%, significantly higher than (24.96 ± 9.25)% and (37.93 ± 5.21)% of untreated KG-1a (P<0.05). The expression of DR5 on the surface of KG-1a treated with resveratrol was (9.05 ± 3.57)%, significantly higher than (3.11 ± 0.54)% of untreated KG-1a (P<0.05). Conversely, the expression of DcR1 on the surface of treated KG-1a was (13.23 ± 3.56)%, lower than (53.75 ± 10.51)% of KG-1a (P<0.05). When TRAIL pathway on the surface of activated immune cells was blocked, the cytolytic rates of treated KG-1a were (35.97 ± 6.36)% and (49.80 ± 10.68)%, significantly lower than (52.92 ± 6.98)% and (70.73 ± 9.79)% of untreated KG-1a (P<0.05) at the same ratio of effector and target.

CONCLUSIONResveratrol could enhance cytolytic sensitivity of KG-1a by activated immune cells through TRAIL pathway.

Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Leukemia ; metabolism ; pathology ; Leukocytes, Mononuclear ; drug effects ; immunology ; metabolism ; Male ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; metabolism ; Receptors, Tumor Necrosis Factor, Member 10c ; metabolism ; Stilbenes ; pharmacology ; TNF-Related Apoptosis-Inducing Ligand ; metabolism

Antibodies, Neutralizing ; Apoptosis ; Hep G2 Cells ; Humans ; Receptors, Tumor Necrosis Factor, Member 6b ; immunology ; metabolism

Objective: To investigate the effect of microRNA (miR-148b) targeting decoy receptor 3 (DcR3) on macrophage polarization in sepsis. Methods: Experimental study. From December 2019 to December 2022, serum microRNA expression was detected in 3 patients with sepsis and 3 healthy controls in the clinical laboratory of Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. Phorbol 12-myristate 13-acetate (PMA) was used to induce the differentiation of human acute monocytic leukemia cells THP-1 into macrophages, and then lipopolysaccharide (LPS) was added to stimulate the establishment of a sepsis cell model, and the expression changes of miR-148b and DcR3 were detected by RT-PCR and Western blot. Overexpression of DcR3 was used to detect the expression levels of TNF-α, CD163 and IL-10 in macrophages stimulated by LPS (100 ng/ml). Overexpression of miR-148b was used to observe the changes of molecular markers of macrophage polarization. The targeting regulation effect of miR-148b on DcR3 was determined by dual-luciferase reporter assay. t test was used to analyze whether there were statistical differences among the groups. Results: The expression of miR-148b was down-regulated (P<0.05) and the expression of DcR3 was up-regulated (P<0.01) in THP-1 macrophages stimulated by LPS. Overexpression of DcR3 inhibited the expression of TNF-α (P<0.05) and promoted the expression of CD163 (P<0.01) and IL-10 (P<0.01). When miR-148b mimics was added, the opposite effect was observed. The dual-luciferase reporter assay confirmed that miR-148b targets and binds to DcR3, inhibiting its transcription and expression. The results of flow cytometry showed that DcR3 could reverse the promoting effect of miR-148b on the CD86/CD163 ratio of macrophages (P<0.05). Conclusion: miR-148b inhibits the expression of DcR3, thereby inhibiting M2 polarization in LPS-stimulated macrophage cells.
Humans ; Interleukin-10 ; Lipopolysaccharides/pharmacology* ; Macrophages ; MicroRNAs/genetics* ; Receptors, Tumor Necrosis Factor, Member 6b/metabolism* ; Tumor Necrosis Factor-alpha