Objective To investigate the expression profiles and their clinical significance of TRAIL receptors (TRAILR) in human hepatocellular carcinoma (HCC). Methods The expression profiles of TRAILR were determined in 60 s...Objective To investigate the expression profiles and their clinical significance of TRAIL receptors (TRAILR) in human hepatocellular carcinoma (HCC). Methods The expression profiles of TRAILR were determined in 60 samples from hepatocellular carcinoma, 20 from normal liver tissue and two HCC cell lines HepG2, SMMC-7721 by in situ hybridization. Results Both DR4 and DR5 were present in all HCC tissues as well as normal hepatic tissues. In contrast, 54 HCC tissues did not express DcR1 and 25 did not express DcR2. But both DcR were detectable in all of the normal liver tissues. The expression patterns of DR and DcR in HCC samples (higher DR expression level and lower DcR expression level) were quite different from those in normal tissue. DR5, DR4, and DcR2 expressed in both cell lines, while no DcR1 expression was detected. The expression level of DR was correlated with HCC differentiation and stage. The weaker expression was more commonly found in HCC with poor differentiation and late stage, while the stronger expression was more common in HCC with middle to high-differentiation and early stage. No relationship was found between DR and gender, age, negative or positive HBsAg, tumor size, grade or metastasis. Multidrug resistance cell lines expressed lower level DR. Conclusion TRAILR expression was prevalent and discrepancy of receptor types was exited in HCC. Loss of DcR1 may contribute for TRAIL therapy for HCC. Key words TRAILR - apoptosis - hepatocellular carcinoma Supported by the Major Fundation of Ministry of Health, NO. 2001–2003展开更多
Bleeding from the gastrointestinal tract and its management are associated with significant morbidity and mortality.The predisposing factors that led to the occurrence of these hemorrhagic instances are largely linked...Bleeding from the gastrointestinal tract and its management are associated with significant morbidity and mortality.The predisposing factors that led to the occurrence of these hemorrhagic instances are largely linked to the life style of the affected persons.Designing a new strategy aimed at educating the publics and improving their awareness of the problem could effectively help in eradicating this problem with no associated risks and in bringing the mortality rates down to almost zero.展开更多
It has been almost three decades since the term ＂apoptosis＂ was first coined to describe a unique form of cell death that involves orderly, gene-dependent cell disintegration. It is now well accepted that apoptosis ...It has been almost three decades since the term ＂apoptosis＂ was first coined to describe a unique form of cell death that involves orderly, gene-dependent cell disintegration. It is now well accepted that apoptosis is an essential life process for metazoan animals and is critical for the formation and function of tissues and organs. In the adult mammalian body, apoptosis is especially important for proper functioning of the immune system. In recent years, along with the rapid advancement of molecular and cellular biology, great progress has been made in understanding the mechanisms leading to apoptosis. It is generally accepted that there are two major pathways ofapoptotic cell death induction： extrin- sic signaling through death receptors that leads to the formation of the death-inducing signaling complex （DISC）, and intrinsic signaling mainly through mitochondria which leads to the formation of the apoptosome. Formation of the DISC or apoptosome, respectively, activates initiator and common effector caspases that execute the apoptosis process. In the immune system, both pathways operate; however, it is not known whether they are sufficient to maintain lymphocyte homeostasis. Recently, new apoptotic mechanisms including caspase-independent pathways and granzyme-initiated pathways have been shown to exist in lymphocytes. This review will summarize our understanding of the mechanisms that control the homeostasis of various lymphocyte populations.展开更多
In the present article, we report that DR4 or DR5 overexpression dramatically activates the release of the inflammatory cytokines IL-8, TNF-α, CCL20, MIP-2 and MIP-1β in an NF-κB-dependent manner in 293T, MDA-MB-23...In the present article, we report that DR4 or DR5 overexpression dramatically activates the release of the inflammatory cytokines IL-8, TNF-α, CCL20, MIP-2 and MIP-1β in an NF-κB-dependent manner in 293T, MDA-MB-231 and HCT-116 cells. We showed that death receptor-mediated signals were extracellular domain-independent, whereas the effect of overexpression of the DR4 intracellular domain was much less potent. The TRADD-TRAF2-NIK- IKKα/β signaling cascade, which plays an essential role in TNF-induced NF-κB activation, was found to be involved in tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） receptor-mediated signal transduction. The FADD-caspase signaling pathway, which has been reported to be mostly related to apoptosis, was identified as being essential for DR4 or DR5 overexpression-mediated NF-κB activation and cytokine secretion and crosstalks with the TRADD-TRAF2-NIK-IKKα/β signaling cascade. Furthermore, a DR5 agonistic antibody （AD5-10） triggered the inflammatory cytokine release. These data, together with previous reports, provide strong evidence that TRAIL and TRAIL receptors play an important role in inflammation.展开更多
Identification of tumour necrosis factor apoptosis inducing ligand (TRAIL), a TNF family ligand, sparked a torrent of research, following an initial observation that it could kill tumour cells, but spare normal cells....Identification of tumour necrosis factor apoptosis inducing ligand (TRAIL), a TNF family ligand, sparked a torrent of research, following an initial observation that it could kill tumour cells, but spare normal cells. Almost a decade after its discovery, and with five known receptors, the true physiological role of TRAIL is still debated and its anti-tumorigenic properties limited by potential toxicity. This review takes a comprehensive look at the story of this enigmatic ligand, addressing its remaining potential as a therapeutic and providing an overview of the TRAIL receptors themselves.展开更多
AIM:To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors,in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand(TRAIL),on overcoming TRAIL resis...AIM:To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors,in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand(TRAIL),on overcoming TRAIL resistance in hepatocellular carcinoma(HCC)and to study the efficacy of agonistic TRAIL antibodies,as well as the commitment of antiapoptotic BCL-2 proteins, in TRAIL-induced apoptosis. METHODS:Surface expression of TRAIL receptors (TRAIL-R1-4)and expression levels of the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL were analyzed by flow cytometry and Western blotting,respectively. Knock-down of MCL-1 and BCL-xL was performed by transfecting specific small interfering RNAs.HCC cellswere treated with kinase inhibitors and chemotherapeutic drugs.Apoptosis induction and cell viability were analyzed via flow cytometry and 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. RESULTS:TRAIL-R1 and-R2 were profoundly expressed on the HCC cell lines Huh7 and Hep-G2. However,treatment of Huh7 and Hep-G2 with TRAIL and agonistic antibodies only induced minor apoptosis rates.Apoptosis resistance towards TRAIL could be considerably reduced by adding the chemotherapeutic drugs 5-fluorouracil and doxorubicin as well as the kinase inhibitors LY294002[inhibition of phosphoinositol- 3-kinase(PI3K)],AG1478(epidermal growth factor receptor kinase),PD98059(MEK1),rapamycin(mam- malian target of rapamycin)and the multi-kinase inhibitor Sorafenib.Furthermore,the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL play a major role in TRAIL resistance:knock-down by RNA interference increased TRAIL-induced apoptosis of HCC cells.Additionally, knock-down of MCL-1 and BCL-xL led to a significant sensitization of HCC cells towards inhibition of both c-Jun N-terminal kinase and PI3K.CONCLUSION:Our data identify the blockage of survival kinases,combination with chemotherapeutic drugs and targeting of antiapoptotic BCL-2 proteins as promising ways to overcome TRAIL resistance in HCC.展开更多
Objective: To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1, and the mech...Objective: To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1, and the mechanisms involved in this effect. Methods: TRAIL gene was transfected into pancreatic cancer cell line Panc-1 by an adenovirus vector (Ad-TRAIL). Level of TRAIL mRNA expression was determined using RT-PCR, and TRAIL protein synthesis was evaluated with Western blot. Cell-growth activities were determined by MTT assay. The bystander effect was observed by co-culturing the Panc-1 cells with the transfected TRAIL gene at different ratios. Apoptosis in pancreatic cancer cells was detected by flow cytometry. Procaspase-8 and procaspase-3 were determined by Western blot. Results: The stable overexpression of TRAIL was de-tected in Panc-1 cells transfected by Ad-TRAIL. Ad-TRAIL significantly inhibited of cell viability of Panc-1 cells. Furthermore, co-culture of cancer cells transfected with TRAIL with that nontransfected resulted in the cell death of both cells by bystander effect. Moreover, the percentage of apoptotic cells was significantly higher in the Ad-TRAIL-treatment group compared to the control groups (P < 0.01). And there was a diminished amount of procaspase-8 and procaspase-3 after infection with Ad-TRAIL. Conclusion: The overexpression of TRAIL gene in Panc-1 cells by Ad-TRAIL exerts its antitumor effects, and the mechanisms involved in this effect may be proapoptosis and bystander effect.展开更多
This study is conducted to clone the cDNA encoding human TNF-related apoptosis-inducing ligand (hTRAIL) extracellular region (amino acids 41-281, hTRAIL41-281) and to express it in E.coli. The hTRAIL41-281 cDNA is amp...This study is conducted to clone the cDNA encoding human TNF-related apoptosis-inducing ligand (hTRAIL) extracellular region (amino acids 41-281, hTRAIL41-281) and to express it in E.coli. The hTRAIL41-281 cDNA is amplified by reverse transcription (RT) PCR from total RNA derived from human acute promyelocytic leukemia cell line HL-60. After sequenced, the cDNA is cloned into the vector pQE-80L and transformed into E.coli DH5 to express the recombinant hTRAIL41-281 (rhTRAIL41-281) induced by IPTG. The recombinant protein is analyzed by SDS-PAGE. The cloned cDNA is consistent with the cDNA sequence encoding hTRAIL41-281 reported in GenBankTM. After inducing, the hTRAIL41-281 protein is expressed, and the mass of the recombinant protein is about 30 % of total bacteria protein, which demonstrates that the cDNA encoding hTRAIL41-281 is successfully cloned and expressed in E.coli.展开更多
文摘Objective To investigate the expression profiles and their clinical significance of TRAIL receptors (TRAILR) in human hepatocellular carcinoma (HCC). Methods The expression profiles of TRAILR were determined in 60 samples from hepatocellular carcinoma, 20 from normal liver tissue and two HCC cell lines HepG2, SMMC-7721 by in situ hybridization. Results Both DR4 and DR5 were present in all HCC tissues as well as normal hepatic tissues. In contrast, 54 HCC tissues did not express DcR1 and 25 did not express DcR2. But both DcR were detectable in all of the normal liver tissues. The expression patterns of DR and DcR in HCC samples (higher DR expression level and lower DcR expression level) were quite different from those in normal tissue. DR5, DR4, and DcR2 expressed in both cell lines, while no DcR1 expression was detected. The expression level of DR was correlated with HCC differentiation and stage. The weaker expression was more commonly found in HCC with poor differentiation and late stage, while the stronger expression was more common in HCC with middle to high-differentiation and early stage. No relationship was found between DR and gender, age, negative or positive HBsAg, tumor size, grade or metastasis. Multidrug resistance cell lines expressed lower level DR. Conclusion TRAILR expression was prevalent and discrepancy of receptor types was exited in HCC. Loss of DcR1 may contribute for TRAIL therapy for HCC. Key words TRAILR - apoptosis - hepatocellular carcinoma Supported by the Major Fundation of Ministry of Health, NO. 2001–2003
文摘Bleeding from the gastrointestinal tract and its management are associated with significant morbidity and mortality.The predisposing factors that led to the occurrence of these hemorrhagic instances are largely linked to the life style of the affected persons.Designing a new strategy aimed at educating the publics and improving their awareness of the problem could effectively help in eradicating this problem with no associated risks and in bringing the mortality rates down to almost zero.
文摘It has been almost three decades since the term ＂apoptosis＂ was first coined to describe a unique form of cell death that involves orderly, gene-dependent cell disintegration. It is now well accepted that apoptosis is an essential life process for metazoan animals and is critical for the formation and function of tissues and organs. In the adult mammalian body, apoptosis is especially important for proper functioning of the immune system. In recent years, along with the rapid advancement of molecular and cellular biology, great progress has been made in understanding the mechanisms leading to apoptosis. It is generally accepted that there are two major pathways ofapoptotic cell death induction： extrin- sic signaling through death receptors that leads to the formation of the death-inducing signaling complex （DISC）, and intrinsic signaling mainly through mitochondria which leads to the formation of the apoptosome. Formation of the DISC or apoptosome, respectively, activates initiator and common effector caspases that execute the apoptosis process. In the immune system, both pathways operate; however, it is not known whether they are sufficient to maintain lymphocyte homeostasis. Recently, new apoptotic mechanisms including caspase-independent pathways and granzyme-initiated pathways have been shown to exist in lymphocytes. This review will summarize our understanding of the mechanisms that control the homeostasis of various lymphocyte populations.
基金We thank Drs Hongbing Shu （Wuhan University, China）, Jiandong Li （University of Rochester Medical Center, USA）, Andrew Thorbum （University of Colorado Comprehensive Cancer Center, USA） and Andreas Strasser （The Walter and Eliza Hall Institute of Medical Research, Australia） for the generous gifts of the constructs. This work was partially supported by the National Natural Science Foundation of China （Grants 30571687 and 30721063） and the State Key Basic Research Program of China （Grant 2007CB507404）.
文摘In the present article, we report that DR4 or DR5 overexpression dramatically activates the release of the inflammatory cytokines IL-8, TNF-α, CCL20, MIP-2 and MIP-1β in an NF-κB-dependent manner in 293T, MDA-MB-231 and HCT-116 cells. We showed that death receptor-mediated signals were extracellular domain-independent, whereas the effect of overexpression of the DR4 intracellular domain was much less potent. The TRADD-TRAF2-NIK- IKKα/β signaling cascade, which plays an essential role in TNF-induced NF-κB activation, was found to be involved in tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） receptor-mediated signal transduction. The FADD-caspase signaling pathway, which has been reported to be mostly related to apoptosis, was identified as being essential for DR4 or DR5 overexpression-mediated NF-κB activation and cytokine secretion and crosstalks with the TRADD-TRAF2-NIK-IKKα/β signaling cascade. Furthermore, a DR5 agonistic antibody （AD5-10） triggered the inflammatory cytokine release. These data, together with previous reports, provide strong evidence that TRAIL and TRAIL receptors play an important role in inflammation.
文摘Identification of tumour necrosis factor apoptosis inducing ligand (TRAIL), a TNF family ligand, sparked a torrent of research, following an initial observation that it could kill tumour cells, but spare normal cells. Almost a decade after its discovery, and with five known receptors, the true physiological role of TRAIL is still debated and its anti-tumorigenic properties limited by potential toxicity. This review takes a comprehensive look at the story of this enigmatic ligand, addressing its remaining potential as a therapeutic and providing an overview of the TRAIL receptors themselves.
基金Supported by Research grants from Merck KGaA,Darmstadt,Germany,to Schulze-Bergkamen H
文摘AIM:To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors,in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand(TRAIL),on overcoming TRAIL resistance in hepatocellular carcinoma(HCC)and to study the efficacy of agonistic TRAIL antibodies,as well as the commitment of antiapoptotic BCL-2 proteins, in TRAIL-induced apoptosis. METHODS:Surface expression of TRAIL receptors (TRAIL-R1-4)and expression levels of the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL were analyzed by flow cytometry and Western blotting,respectively. Knock-down of MCL-1 and BCL-xL was performed by transfecting specific small interfering RNAs.HCC cellswere treated with kinase inhibitors and chemotherapeutic drugs.Apoptosis induction and cell viability were analyzed via flow cytometry and 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. RESULTS:TRAIL-R1 and-R2 were profoundly expressed on the HCC cell lines Huh7 and Hep-G2. However,treatment of Huh7 and Hep-G2 with TRAIL and agonistic antibodies only induced minor apoptosis rates.Apoptosis resistance towards TRAIL could be considerably reduced by adding the chemotherapeutic drugs 5-fluorouracil and doxorubicin as well as the kinase inhibitors LY294002[inhibition of phosphoinositol- 3-kinase(PI3K)],AG1478(epidermal growth factor receptor kinase),PD98059(MEK1),rapamycin(mam- malian target of rapamycin)and the multi-kinase inhibitor Sorafenib.Furthermore,the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL play a major role in TRAIL resistance:knock-down by RNA interference increased TRAIL-induced apoptosis of HCC cells.Additionally, knock-down of MCL-1 and BCL-xL led to a significant sensitization of HCC cells towards inhibition of both c-Jun N-terminal kinase and PI3K.CONCLUSION:Our data identify the blockage of survival kinases,combination with chemotherapeutic drugs and targeting of antiapoptotic BCL-2 proteins as promising ways to overcome TRAIL resistance in HCC.
基金Supported by a grant from the National Natural Science Foundation of China (No. 30471693).
文摘Objective: To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1, and the mechanisms involved in this effect. Methods: TRAIL gene was transfected into pancreatic cancer cell line Panc-1 by an adenovirus vector (Ad-TRAIL). Level of TRAIL mRNA expression was determined using RT-PCR, and TRAIL protein synthesis was evaluated with Western blot. Cell-growth activities were determined by MTT assay. The bystander effect was observed by co-culturing the Panc-1 cells with the transfected TRAIL gene at different ratios. Apoptosis in pancreatic cancer cells was detected by flow cytometry. Procaspase-8 and procaspase-3 were determined by Western blot. Results: The stable overexpression of TRAIL was de-tected in Panc-1 cells transfected by Ad-TRAIL. Ad-TRAIL significantly inhibited of cell viability of Panc-1 cells. Furthermore, co-culture of cancer cells transfected with TRAIL with that nontransfected resulted in the cell death of both cells by bystander effect. Moreover, the percentage of apoptotic cells was significantly higher in the Ad-TRAIL-treatment group compared to the control groups (P < 0.01). And there was a diminished amount of procaspase-8 and procaspase-3 after infection with Ad-TRAIL. Conclusion: The overexpression of TRAIL gene in Panc-1 cells by Ad-TRAIL exerts its antitumor effects, and the mechanisms involved in this effect may be proapoptosis and bystander effect.
基金Funded by the Scientific Research Foundation of the Third Military Medical University.
文摘This study is conducted to clone the cDNA encoding human TNF-related apoptosis-inducing ligand (hTRAIL) extracellular region (amino acids 41-281, hTRAIL41-281) and to express it in E.coli. The hTRAIL41-281 cDNA is amplified by reverse transcription (RT) PCR from total RNA derived from human acute promyelocytic leukemia cell line HL-60. After sequenced, the cDNA is cloned into the vector pQE-80L and transformed into E.coli DH5 to express the recombinant hTRAIL41-281 (rhTRAIL41-281) induced by IPTG. The recombinant protein is analyzed by SDS-PAGE. The cloned cDNA is consistent with the cDNA sequence encoding hTRAIL41-281 reported in GenBankTM. After inducing, the hTRAIL41-281 protein is expressed, and the mass of the recombinant protein is about 30 % of total bacteria protein, which demonstrates that the cDNA encoding hTRAIL41-281 is successfully cloned and expressed in E.coli.
