OBJECTIVEThis study was designed to clarify the significance of DNA methylation in the expression of runt-related transcription factor 3 (Runx3) gene.

METHODSReverse transcription-PCR (RT-PCR) was used to measure the expression level of Runx3 mRNA in paired samples of primary gastric cancer and corresponding non-cancerous gastric mucosa, taken from surgical specimens of 70 gastric cancer patients. Western blot was used to detect the protein expression level of Runx3 gene. The promoter methylation status of Runx3 gene was detected by methylation specific PCR (MSP). Furthermore, RT-PCR was used to mesure the expression of DNA methyltransferase 1 (Dnmtl) mRNA . The correlation of Runx3 expression and methylation with Dnmt1 mRNA expression was analyzed.

RESULTSThe mRNA expression level of Runx3 gene was significantly lower in gastric cancer than that in the matched normal gastric mucosa (0.5740 +/- 0.3580 vs. 1.7250 +/- 0.4080, P < 0.05), and the Runx3 protein expression level in gastric cancer was also significantly lower than that in the matched normal gastric mucosa (P < 0.05). Promoter hypermethylation of Runx3 gene was detected in 50.0% (28/56) of the gastric cancer samples, which resulted in a reduced expression of Runx3 mRNA. It was found that the mRNA expression level of Dnmt1 gene was significantly higher in the gastric cancer tissues with methylated Runx3 gene than that in the ones without. There was a significant correlation of Runx3 gene methylation with increased expression of Dnmtl mRNA (r = 0.64, P < 0.05).

CONCLUSIONThe promoter hypermethylation may be one of the predominant inactivation mechanisms of the runt-related transcription factor 3 gene, and may be associated with carcinogenesis of human gastric cancer. Reduced Runx3 expression in gastric cancer may be partially correlated with a high level of DNA methyltransferase 1.

Adenocarcinoma ; genetics ; metabolism ; Adult ; Aged ; Core Binding Factor Alpha 3 Subunit ; genetics ; metabolism ; DNA (Cytosine-5-)-Methyltransferase 1 ; DNA (Cytosine-5-)-Methyltransferases ; biosynthesis ; genetics ; DNA Methylation ; Down-Regulation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Male ; Middle Aged ; Promoter Regions, Genetic ; RNA, Messenger ; metabolism ; Stomach Neoplasms ; genetics ; metabolism ; Young Adult

OBJECTIVETo investigate the effects of tributyrin (TB), a histone deacetylase inhibitor, on the growth, differentiation and apoptosis of SHI-1 leukemia cells and explore its possible mechanism.

METHODCell proliferation and viability were determined by cell counting, trypan blue dye exclusion. Cell morphological analysis, Annexin binding, DNA electrophoresis, expression of CD11b and CD14, NBT reduction were performed to evaluate differentiation and apoptosis of SHI-1 cells. The level of acetylated histone H3 was detected by Western blot and p21(WAF1/CIP1) expression by semi-quantitative RT-PCR.

RESULTSTB inhibited the proliferation and viability of SHI-1 cells in a time-dose dependent manner. The morphology of SHI-1 cells cultured in the presence of 0.1 mmol/L TB for 72 hs was more mature with higher NBT positivity and up-regulated expressions of CD11b and CD14 than that of control group. Exposed to 0.5 - 1.0 mmol/L TB for 48 hs, SHI-1 cells exhibited the morphological hallmarks of apoptosis, the increasing of Annexin binding and the DNA ladder on gel electrophoresis. The level of acetylated histone H3 and p21(WAF1) mRNA extracted from SHI-1 cells were increased by the treatment of TB.

CONCLUSIONTB can inhibit proliferation, induce differentiation and apoptosis of SHI-1 cells. The mechanism may associate with its up-regulation of acetylated histone and the expression of p21(WAF1).

Acetylation ; drug effects ; Apoptosis ; drug effects ; Blotting, Western ; Cell Differentiation ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; Enzyme Inhibitors ; pharmacology ; Gene Expression ; drug effects ; Histone Deacetylase Inhibitors ; Histone Deacetylases ; metabolism ; Histones ; metabolism ; Humans ; Leukemia, Monocytic, Acute ; genetics ; metabolism ; pathology ; Reverse Transcriptase Polymerase Chain Reaction ; Triglycerides ; pharmacology

Vascular endothelial growth factor (VEGF), a central mediator of angiogenesis, not only plays an important role in the pathogenesis of leukemia, but also is an independent prognostic factor in patients with hematologic malignancies, like those in solid tumors. However, the importance of VEGF during differentiation or apoptosis of leukemia cells remains to be elucidated. In order to assess the alternation of VEGF gene expression in the process of all-trans retinoic acid (ATRA)-induced differentiation of NB4 acute promyelocytic leukemia cell line, and a competitor DNA fragment, VEGF gene competative template (T-VEGFDelta) was constructed by using gene recombinant technologies, and a competitive quantitative reverse transcriptase-polymerase chain reaction (cQRT-PCR) method was developed. A standard curve was obtained by co-amplification of serial dilutions of the target nulecules with constant amount of competitive template and this curve was used to detect molecular number of target gene in measuring sample. The surface expression of CD11b antigen and nitroblue tetrazolium (NBT) reduction rate of NB4 cells were also assayed at different time points. The results showed that cQRT-PCR was a sensitive, reliable tool for analysis of VEGF gene expression with a detectable range from 1 x 10(4) to 2 x 10(5) molecules. The number of VEGF gene transcripts detected by means of cQRT-PCR assay was 42.3 x 10(5), 12.6 x 10(5), 3.6 x 10(5), and less than 1.0 x 10(5)/microg total RNA at 0, 12, 24 and 48 hours after ATRA treatment, respectively. This rapid down-regulation of VEGF gene expression, during ATRA-induced NB4 cell differentiation, was accompanied by the up-regulation of CD11b expression and an increased NBT reduction rate. In conclusion, cQRT-PCR method was successtully constructed, confirming that ATRA efficiently repressed VEGF, at the same time, the ATRA might exert an antileukemic effect, other than induction of differentiation via inhibition of angiogenesis.
Antineoplastic Agents ; pharmacology ; CD11b Antigen ; genetics ; Cell Differentiation ; drug effects ; genetics ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Leukemia, Promyelocytic, Acute ; genetics ; pathology ; Molecular Sequence Data ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Tretinoin ; pharmacology ; Vascular Endothelial Growth Factor A ; genetics

To elucidate the effect of established primary bone marrow stromal layers on the gene transduction of human hematopoietic stem/progenitor cells (HSC/HPC), mononuclear cells (MNC) from adult bone marrow were isolated by centrifugation on Ficoll-Hypaque gradients and plated in stromal culture medium. The cells were incubated until passage 4 to establish primary stromal layers. The HSC/HPC prestimulated by cytokines were transduced by retroviral supernatant containing mdr1 gene in presence of irradiated stroma-contact support. Transduced cells were plated in a colony-forming unit assay with and without vincristine (VCR) to assess the efficiency of transduction. Individual colonies were also analyzed by polymerase chain reaction (PCR) for the presence of provirus. The results showed that the mixed adherent cell layers were formed when adult bone marrow stromal cells were incubated for four to six weeks, mainly being composed of fibroblasts. In the presence of stroma-contact support, the average of gene transduction efficiency in marrow-derived progenitors increased 2.1 to 3.3 folds measured by colony-forming assay and/or PCR, significantly higher than those without support of stroma. It is concluded that the presence of bone marrow stroma support in combination with cytokine facilitates augmenting the extent of retroviral-mediated gene transduction.
Bone Marrow Cells ; physiology ; Genes, MDR ; Hematopoietic Stem Cells ; metabolism ; Humans ; Retroviridae ; genetics ; Stromal Cells ; physiology ; Transduction, Genetic

To elucidate the possible mechanism of differentiation and/or apoptosis in NB4, K562 cells induced by tributyrin (TB), a histone deacetylase inhibitor (HDACi), the level of acetylated histone H3 was detected by Western blot, p21(WAF1) expression was detected by semi-quantitative RT-PCR. The results showed that histone H3 hyperacetylation was detected in NB4 (or K562) cells after treatment with TB 0.1 mmol/L (or TB 0.5 mmol/L) for 16 hours in a dose-dependent manner. p21(WAF1) dose-dependently increased at RNA level in these two cell lines treated by TB 0.1 mmol/L. The level of p21(WAF1) mRNA increased at 2 hours after TB treatment, reaching peak at 16 hours, and maintaining for 48 hours. In conclusion, the mechanism of differentiation and apoptosis in NB4, K562 cells induced by tributyrin may associate with its up-regulation of acetylated histone and p21(WAF1) mRNA level.
Acetylation ; drug effects ; Apoptosis ; drug effects ; Blotting, Western ; Cell Differentiation ; drug effects ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; Dose-Response Relationship, Drug ; Enzyme Inhibitors ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Histone Deacetylase Inhibitors ; Histone Deacetylases ; metabolism ; Histones ; metabolism ; Humans ; K562 Cells ; Leukemia ; genetics ; metabolism ; pathology ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Triglycerides ; pharmacology

OBJECTIVETo investigate DNA-dependent protein kinase catalytic subunit (DNA-PKcs) content and activity in lung adenocarcinoma cell lines and its correlation with radiosensitivity.

METHODSThe content and activity of DNA-PKcs were analyzed in two lung adenocarcinoma cell lines A549 and H1299 by Western blotting and the Signa TECT DNA-PK assay kit. The dose-survival relationship for two cell lines was analyzed using clonogenic formation assay.

RESULTSA549 was more radiosensitive than H1299. The survival fractions at 2 Gy (SF2) were 0.7412 in A549 cell line and 0.2473 in H1299 cell line. The content of DNA-PKcs was significantly higher in A549 cells than in H1299 cells (t=10.37, P<0.001). The integrated optical densities were 3.29-/+0.44 in A549 cells and 0.50-/+0.17 in H1299 cells. DNA-PKcs activities in A549 and H1299 cells were 8.29-/+1.37 and 2.47-/+1.09, respectively, showing a significant difference between them (t=5.76, P=0.005).

CONCLUSIONDNA-PKcs is an important factor to affect the radiosensitivity of lung adenocarcinoma cell lines.

Adenocarcinoma ; enzymology ; pathology ; Calcium-Binding Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Humans ; Lung Neoplasms ; enzymology ; pathology ; Radiation Tolerance

cDNA microarray, recently applied to analyze gene expression profile of cancers, was difficult to be utilized in myelodysplastic syndrome (MDS) for a special need of excessive mRNA hardly provided by ordinary bone marrow aspiration in MDS patients. The aim of this study was to investigate the feasibility of exploring the molecular events underlying MDS by using cDNA microarray and mixing mRNA from multiple patients. A commercially purchased BioStar H141 cDNA microarray containing 14,110 clones of cDNA or EST was employed to analyze the gene expression profile of bone marrow mononuclear cells from two cases of MDS. Equal amount of total RNA from each patient was mixed, reversely transcribed to cDNA and labeled with Cy5. Mixture of Cy5-labeled cDNA and Cy3-labeled cDNA from normal bone marrow cells was concomitantly hybridized to H141 microarray in duplicate. In H141 chips, 1,064 cDNAs were spotted at least twice targeting different fragments of a single gene cDNA. The results showed that among these 1,064 cDNA clones, the expression level of 625 (58.7%) and 630 (59.2%) ones was consistent within these two chips, respectively, 297 (27.9%) and 191 (18.0%) inconsistent, 21 (2.0%) and 11 (1.0%) in opposite. Among 411 duplicately spotted cDNAs with complete data, expression levels of 400 (97.3%) was consistent between two chips. 488 genes with known function were identified as differentially expressed in MDS, among which 101 genes were involved in hematopoiesis regulation, including those encoding transcription factors, cell cycle-regulating proteins, metabolism-relating enzymes, and adhesive molecules. It is concluded that cDNA microarray can be used for profiling gene expression of mixed MDS samples and replication shall be necessary for reducing the data bias caused by experimental operation.
Bone Marrow Cells ; metabolism ; Gene Expression Profiling ; Humans ; Leukocytes, Mononuclear ; metabolism ; Male ; Middle Aged ; Myelodysplastic Syndromes ; metabolism ; Oligonucleotide Array Sequence Analysis ; Reproducibility of Results

OBJECTIVETo investigate the level and significance of interleukin-8 (IL-8), soluble intercellular adhesion molecule (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in patients peripheral blood (PB) during mobilization for peripheral blood stem cells harvesting.

METHODSThe levels of IL-8, sICAM-1 and sVCAM-1 in patients were dynamically assayed by ELISA during the mobilization procedure and the number of CD(34)(+) cell, white blood cell (WBC) and platelet (BPC) by flow cytometric analysis and hematometry respectively. Colony formation was assayed by using semisolid methycellulose culture.

RESULTSThere was a significant increase in plasma levels of IL-8 and both adhesion molecules [IL-8 (247.4 +/- 84.2) microg/L (P < 0.01); sICAM-1 (530.3 +/- 286.1) microg/L (P = 0.002 7); sVCAM-1 (575.3 +/- 350.4) microg/L (P = 0.001 3)] during the mobilization process; furthermore, IL-8 and sVCAM-1 concentration in the patient's plasma was paralleled to the numbers of CD(34)(+) cell, CFU-GM, WBC and BPC (P < 0.001).

CONCLUSIONThe levels of IL-8, sICAM-1 and sVCAM-1 in the patient's plasma were correlated to the PB number of CD(34)(+) cells, CFU-GM, WBC and BPC during the mobilization process. It suggested that analysis of IL-8, and sVCAM-1 dynamic changes may serve as markers for CD(34)(+) cells.

Adolescent ; Adult ; Enzyme-Linked Immunosorbent Assay ; Female ; Granulocyte Colony-Stimulating Factor ; therapeutic use ; Hematopoietic Stem Cell Mobilization ; methods ; Humans ; Intercellular Adhesion Molecule-1 ; blood ; Interleukin-8 ; blood ; Male ; Middle Aged ; Treatment Outcome ; Vascular Cell Adhesion Molecule-1 ; blood

To explore the feasibility of real-time quantitative PCR (QRT-PCR) for selecting cell strains which overexpress a certain transgene, expression level of RbAp46 was detected in transfected cell strains by using optimal real-time PCR with SYBR Green I. Meanwhile, semi-quantitative RT-PCR and Western blot were performed to compare with the QRT-PCR. The results showed that values of RbAp46(N) were 2064.42 +/- 253.47, 860.94 +/- 291.07, 234.456 +/- 31.08, 18.17 +/- 5.14 and 1.46 +/- 0.54 in K562/RbAp46, K562/CMV, SHG44/RbAp46 monoclone, SHG44/RbAp46 multiclone and SHG44/CMV, respectively. The results were consistent with that determined by semi-quantitative RT-PCR and Western blot. It is concluded that QRT-PCR provides a highly efficient and reproducible method for selection of transfected cell subclones at different level of transgene expression.
Blotting, Western ; Carrier Proteins ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; K562 Cells ; Nuclear Proteins ; genetics ; metabolism ; Organic Chemicals ; chemistry ; RNA, Neoplasm ; metabolism ; Retinoblastoma-Binding Protein 7 ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Transfection ; Transgenes ; genetics

In order to study the potential effects of exogenous WT1 gene isoform on apoptosis in leukemia cell line NB4 and its possible molecular mechanisms, the eukaryotic expression recombinant vector (pCB6(+)/WTA) containing full-length human WT1 isoform (WTA: -17aa/-KTS) cDNA and the vacant vector-alone were introduced into the leukemia cell line NB4 respectively by electroporation. The WTA mRNA and protein in cells were detected by RT-PCR and Western blot. Binding of Annexin V were tested by flow cytometry and agarose gel electrophoresis to verify whether exogenous WTA could induce apoptosis of NB4 cells. Expressions of p21, p53, bcl-2, bcl-XL and c-myc genes were determined by semi-quantitative RT-PCR after introducing recombinant vectors into the NB4 cells. The results showed that in exposure to As(2)O(3) at 0.8 micromol/L for 48 hours, the NB4/WTA cells exhibited the morphological hallmarks of apoptosis, the marked DNA ladder shown by gel electrophoresis, and the enhanced apoptosis rate marked by Annexin V. RT-PCR showed an increase in p21 and c-myc genes expression, a decrease in bcl-2 and a relative constant expression of p53, bcl-XL in NB4/WTA cells. It is concluded that the introduction and expression of exogenous WTA gene can lead to apoptosis of NB4/WTA cells by down-regulating the Bcl-2 gene expression and up-regulating the p21 and c-myc genes expression.
Apoptosis ; genetics ; physiology ; Blotting, Western ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Leukemia ; genetics ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; Proto-Oncogene Proteins c-myc ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection ; Tumor Suppressor Protein p53 ; genetics ; WT1 Proteins ; genetics ; metabolism ; physiology ; bcl-X Protein ; genetics