[Molecular mechanism of hydroxyurea enhances K562 cell apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand].

Objective: To explore the molecular mechanism via which the chemotherapeutic drug hydroxyurea (HU) enhances K562 cell apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL).

Methods: Chronic myelogenous leukemia-derived K562 and SVT-35 cells were treated with recombinant soluble TRAIL (rsTRAIL) alone or combined with HU for a time course, and the cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-4-sulfophenyl-2H-tetrazolium-phenazine methosulphate assay. Western blot was performed to analyze the activation of apoptosis-related protein kinases and the expression of apoptosis inhibitor molecules.

[Construction and stable expression of anti-human tumor necrosis factor-related apoptosis-inducing ligand receptor 2 chimeric antibody in CHO cells].

Aim: To establish an human-mouse chimeric antibody against tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 2 (death receptor 5, DR5) in an eukaryotic cell line and analyse its tumoricidal activity.

Methods: The cDNAs encoding for the variable regions of heavy chain (V(H);) and light chain (V(L);) of AD5-10 were amplified by PCR and inserted into the human IgG heavy and light chain containing expression vector RpCI-neo, respectively. The recombinant plasmids were co-transfected into HEK293 and/or CHO cells.

Structural and functional analysis of the N-terminal region of death receptor 5.

Objective: To investigate the structure and function of the N-terminal region (NTR) of death receptor 5 (DR5).

Methods: A series of deletions of the DR5 extracellular domain (DR5-ECD) proteins were expressed in E.coli.

[Construction and expression of anti-tumor necrosis factor related apoptosis-inducing ligand receptor death receptor 5 chimeric antibody in eukaryotic cells].

Objective: To construct the human/mouse chimeric antibody of a functional anti-death receptor 5 (DR5) antibody. Methods The viable region of light chain (VL) and viable region of heavy chain (VH) genes of anti-DR5 antibody were amplified and cloned into the light- and heavy-chain expression vectors respectively, then the recombinant plasmids were co-transfected into dihydrofolate reductase(-) Chinese hamster ovary cell (CHO-dhfr(-)) for expression. The positive clone was screened by the two selective genes (neo and dhfr).

[Effects of human telomerase reverse transcriptase promoter and survivin promoter in targeted tumor gene therapy].

Objective: To investigate the effects of human telomerase reverse transcriptase (hTERT) promoter and survivin promoter in tumor-specific gene therapy.

Methods: hTERT promoter and survivin promoter were obtained by PCR using Jurkat genomic DNA. Recombinant adeno-associated virus (AAV) vectors containing exogenous TRAIL gene and hTERT promoter or survivin promoter were constructed and designated as rAAV-hTERT-TRAIL (h/TRAIL) or rAAV-survivin-TRAIL (s/TRAIL).

Comparative proteomics analysis of cerebrospinal fluid of patients with Guillain-Barré syndrome.

To better understand the pathophysiologic mechanisms underlying Guillain-Barré syndrome (GBS), Comparative proteomic analysis of cerebrospinal fluid (CSF) between patients with GBS (the experiment group) and control subjects suffering from other neurological disorders (the control group) was carried out using two-dimensional gel electrophoresis (2-DE) technique, in combination with matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and database searching to determine abnormal CSF proteins in GBS patients. Image analysis of 2-DE gels silver stained revealed that 10 protein spots showed significant differential expression between the two groups of CSF samples. The expression of cystatin C, transthyretin, apolipoprotein E and heat shock protein 70 were decreased.

[Mechanisms of sensitization by 8-chloro-adenosine of human tumor cells to TRAIL-induced apoptosis].

Objective: To study the effect of 8-chloro-adenosine (8-Cl-Ado) on the sensitivity of human hepatoma and breast cancer cell lines to TRAIL-induced apoptosis in vitro and its mechanisms.

Methods: Recombinant soluble TRAIL (rsTRAIL) or 8-Cl-Ado was used to treat hepatoma cell line BEL-7402 and breast cancer cell line MCF-7 in vitro. MTT assay was used to evaluate cell viability.

Ornithine decarboxylase gene is overexpressed in colorectal carcinoma.

Aim: To investigate the ornithine decarboxylase (ODC) gene expression in colorectal carcinoma, ODC mRNA was assayed by RT-PCR and ODC protein was detected by a monoclonal antibody against fusion of human colon ODC prepared by hybridoma technology.

Methods: Total RNA was extracted from human colorectal cancer tissues and their normal counterpart tissues. ODC mRNA levels were examined by RT-PCR.

[Expression of TRAIL(114-281) mediated by adeno-associated virus and its tumoricidal activity].

Objective: To investigate the expression of the soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediated by adeno-associated virus (AAV) and its tumoricidal activity in vitro and vivo.

Methods: The recombinant AAV expression vector encoding the extracellular domain (114-281aa peptide, TRAIL(114-281)) of TRAIL was constructed and transfected into human embryotic kidney cells HEK293 for virus package. The human tumor cell lines of T lymphocyte leukemia Jurkat, liver cancer HepG2 and SMMC-7721, and cervical cancer HeLa were transduced by using the recombinant virus particles respectively.

[Chemotherapeutic drugs enhanced rsTRAIL tumoricidal activity].

Objective: To explore the role and mechanisms of chemotherapeutic drugs in TRAIL induced cell death.

Methods: Tumoricidal activities of the chemotherapeutic drugs and/or rsTRAIL in 13 strains of tumor cell lines were evaluated by MTS-PMS assay and flow cytometry. DR5 expression in the cells was observed by Western blot.

[Synergetic role of CD3epsilon and 5-fluorouracil in T Lymphocyte apoptosis and P53 expression].

Objective: To investigate the relationship between apoptosis induced by CD3epsilon and 5-fluorouracil (5-FU), and study the P53 expression in the apoptosis process provide a novel insight and useful information of the apoptosis signaling pathway induced by CD3epsilon and/or 5-FU, and an important implication for the treatment of T-lymphocyte leukemia.

Methods: The viabilities of Jurkat T lymphocytes (JK), TJK [JK with over-expression of the CD8epsilon chimeria molecule] and T3JK [JK with over-expression of the CD8epsilon (Y170F/Y181F) mutation molecule] cells were cultured and treated with pre-coated anti-CD8 mAb (200 micro g/ml) and/or 5-FU (2.5 micro g/ml) were detected with MTS assay and the apoptosis percentages were calculated.

[The primary study on a novel protein binding to the death domain of the death receptor 4].

Objective: To clone and identify novel proteins binding to the death domain of the death receptor 4 (DR4).

Methods: The yeast two-hybrid system was used for this study. Automatic sequencing was carried out for DNA sequencing.

Cloning and expression of ornithine decarboxylase gene from human colorectal carcinoma.

Aim: To construct and express ODC recombinant gene for further exploring its potential use in early diagnosis of colorectal carcinoma.

Methods: Total RNA was extracted from colon cancer tissues and amplified by reverse-transcription PCR with two primers, which span the whole coding region of ODC. The synthesized ODC cDNA was cloned into vector pQE-30 at restriction sites BamH I and Sal I which constituted recombinant expression plasmid pQE30-ODC.