OBJECTIVE: To investigate the effects of DNA hypomethylation on mRNA and protein expression of perforin promotor in T cells. METHODS: T cells were isolated from the peripheral venous blood of healthy donors by density gradient centrifugation. CD4(+) and CD8(+) subsets were isolated using Miltenyi beads and protocols provided by the manufacturer. Where indicated the T cells were stimulated with PHA for 24 h, then treated with 5-azaC for an additional 72 h. Genomic DNA, mRNA, and protein were isolated from untreated and 5-azaC-treated T cells. Purified DNA was treated with sodium bisulfite, the desired sequences were amplified in sequential fragments using nested PCR. The amplified fragments were cloned into bacteria DH5 alpha and 5 independent clones for each of the amplified fragments were sequenced. The expression of perforin was determined using real time RT-PCR and Western blot. RESULTS: The perforin mRNA and protein in the CD4(+) and CD8(+) subsets treated with 5-azaC were significantly higher than those in the untreated subsets (P<0.05). The results of bisulfite genomic sequencing showed that the methylation of perforin promotor was significantly reduced in the treated cells compared with the untreated cells (P<0.05). CONCLUSION The mRNA and protein expression of perforin significantly increases in the CD4(+) and CD8(+) T cells treated with 5-azaC,which is associated with DNA hypomethylation of perforin promoter in T cells.
Adult ; Azacitidine ; pharmacology ; Cells, Cultured ; DNA Methylation ; drug effects ; Humans ; Perforin ; genetics ; Promoter Regions, Genetic ; genetics ; T-Lymphocyte Subsets ; metabolism

This study was aimed to investigate the effects of bortezomib combined with 5-azacytidine on the apoptosis of K562 cells and expressiom of SHIP mRNA. The K562 cells were cultured and treated with different concentrations of bortezomib, 5-azacytidine or their combination for 24 hours. Then, the expression of SHIP mRNA was detected by RT-PCR,the cell proliferation was analyzed by using MTT assay and flow cytometry. The results showed that 5-20 nmol/L bortezomib could effectively inhibit the proliferation of K562 and this inhibitory effect gradually enhanced along with the increase of bortezomib concentration, the group of bortezomib combined with 5-azacytidine showed more inhibitory effect on K562 cells than that of bortezomib or 5-azacytidine alone.The bortezomib could promote the apoptosis of K562 cells in a dose-dependent manner,and this apoptotic effect was higher in group of bortezomib combined with 5-azacytidine than that in group of bortezomib or 5-azacytidine alone.Bortezomib could down-regulated the expression of SHIP mRNA in a dose-dependent manner,and this down-requlated effect was higher in group of bortezomib combined with 5-azacytidine than that in group of bortezomib or 5-azacytidine alone.It is concluded that bortezomib and 5-azacytidine can induce apoptosis by inhibiting the expression of SHIP mRNA in K562 cells.The combination of bortezomib with 5-azacytidine displays a synergetic effect.
Apoptosis ; drug effects ; Azacitidine ; pharmacology ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Proliferation ; Humans ; Inositol Polyphosphate 5-Phosphatases ; K562 Cells ; Phosphoric Monoester Hydrolases ; genetics ; Pyrazines ; pharmacology ; RNA, Messenger ; biosynthesis

OBJECTIVEThe loss of caspase-8 expression correlates with unfavorable survival outcomes in neuroblastoma (NB). Caspase-8 gene inactivation is caused by methylation. This study aimed to explore the effect of the demethylation agent 5-azacytidine on caspase-8 expression and whether 5-azacytidine can increase the sensitivity of chemotherapy drug doxorubicin to NB cells.

METHODSCaspase-8 mRNA expression in NB cell lines (SH-SY5Y cells) was examined by RT-PCR before and after 5-azacytidine treatment. Survival rates of SH-SY5Y cells were detected using MTT analysis and compared among the doxorubicin alone treatment, 5-azacytidine along with doxorubicin treatment, and caspase-8 inhibitor+5-azacytidine+doxorubicin treatment groups.

RESULTSCaspase-8 mRNA was not expressed in untreated SH-SY5Y cell lines. Caspase-8 mRNA expression in SH-SY5Y cells was detectable 3 days after 5-azacytidine treatment, and increased significantly 5 days after 5-azacytidine treatment (P < 0.05). Survival rates of SH-SY5Y cells treated with 5-azacytidine along with different concentrations of doxorubicin (0.05, 0.1,0.25, 0.5 microg/mL) were (77.61 +/- 7.30)%, (57.35 +/- 6.64)%, (46.25 +/- 4.46)% and (35.59 +/- 5.12)%, respectively, which were significantly lower than those treated with doxorubicin alone (94.89 +/- 4.15%, 80.60 +/- 8.50%, 64.48 +/- 4.92% and 52.32 +/- 6.71%) (P < 0.01). Caspase-8 inhibitor pretreatment resulted in an increased survival rate of SH-SY5Y cells (92.95 +/- 3.48%, 78.39 +/- 4.28 %, 62.31 +/- 6.50% and 49.92 +/- 5.77%) compared with the 5-azacytidine+doxorubicin treatment group.

CONCLUSIONS5-azacytidine may enhance anti-tumor efficacy of doxorubicin to NB cell lines, possibly through an up-regulation of caspase-8 mRNA expression.

Antineoplastic Agents ; pharmacology ; Azacitidine ; pharmacology ; Caspase 8 ; genetics ; Caspase Inhibitors ; Cell Line, Tumor ; Doxorubicin ; pharmacology ; Drug Synergism ; Humans ; RNA, Messenger ; analysis

Azacitidine ; administration & dosage ; analogs & derivatives ; pharmacology ; Cell Proliferation ; drug effects ; Daunorubicin ; administration & dosage ; pharmacology ; HL-60 Cells ; Humans ; PTEN Phosphohydrolase ; metabolism

OBJECTIVETo investigate the reversal effects of different concentrations of DNA methylation inhibitor, 5-aza-2-deoxycytidine, on the hypermethylation of maternally expressed gene 3 (MEG3) gene promoter, and then the inhibitory effect of restoration of MEG3 expression on the proliferation of ovarian cancer cells.

METHODSHuman ovarian cancer OVCAR3 cells were treated with various concentration of 5-aza-2-deoxycytidine (0, 1, 5, 10, 20 µmol/L, respectively) for 6 days. Then the methylation status of MEG3 promoter was detected by methylation specific PCR (MSP). The alteration of MEG3 gene expression was detected by RT-PCR. Cell proliferation was determined by MTT assay and EdU incorporation assay.

RESULTSAfter treated with 5-aza-2-deoxycytidine, the methylation status of MEG3 in the 0, 1, 5, 10, 20 µmol/L 5-aza-2-deoxycytidine groups were 1.00 ± 0.00, 0.79 ± 0.00, 0.67 ± 0.00, 0.65 ± 0.03 and 0.61 ± 0.01 folds, respectively (P < 0.05 for all). The relative expressions of MEG3 mRNA in the 0, 1, 5, 10, 20 µmol/L 5-aza-2-deoxycytidine groups were 1.00 ± 0.00, 2.04 ± 0.16, 2.44 ± 0.17, 3.19 ± 0.34 and 5.34 ± 0.39, respectively (P < 0.05 for all). In contrast to the negative control, the inhibition rates of the OVCAR3 cell growth were increased significantly when treated with 1, 5, 10, 20 µmol/L 5-aza-2-deoxycytidine in 2, 4 and 6 days. There were (40.78 ± 0.80)%, (35.65 ± 0.33)%, (31.81 ± 0.66)%, (27.33 ± 1.27)% and (17.75 ± 1.85)% of EdU-positive cells in the 0, 1, 5, 10 and 20 µmol/L 5-aza-2-deoxycytidine groups (P < 0.01 for all).

CONCLUSIONSMaternally expressed gene 3 promoter hypermethylation is reversed by 5-aza-2-deoxycytidine in ovarian cancer cells. The downregulation of MEG3 gene might be resulted from the methylation, and the re-expression of MEG3 partly contribute to the growth inhibition of epithelial ovarian cancer cells.

Antimetabolites, Antineoplastic ; pharmacology ; Azacitidine ; analogs & derivatives ; pharmacology ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; DNA Methylation ; Female ; Humans ; Neoplasms, Glandular and Epithelial ; Ovarian Neoplasms ; Promoter Regions, Genetic ; RNA, Messenger

OBJECTIVETo study the effect on promoter de-methylation, expression of ALDH1a2 gene and cell apoptosis by treated with 5-Aza-dC and TSA in five human bladder cancer cell lines.

METHODSHuman bladder cancer cell lines RT-4, 253J, 5637, BIU-87 and T24 were cultured and treated with 5-Aza-dC and(or) TSA. The expression of the ALDH1a2 gene was detected by RT-PCR and Western blot. The methylation status of gene promoter was determined by MSP, and the cell cycle profile was established by flow cytometry.

RESULTSALDH1a2 was silenced in five human bladder cancer cell lines. Re-expression of ALDH1a2 was detected after treated with 5-Aza-dC alone or TSA in combination. ALDH1a2 transcript was marked in each cell lines combined with 5-Aza-dC and TSA treatment which showed a synergistic effect on expression of ALDH1a2 transcript. Early apoptotic was the main mode of apoptosis and death of human bladder cancer cell lines induced by 5-Aza-dC and TSA. The percentage of early apoptotic cells was 1.4% in control group and 2.8% in TSA group, however, 20.2% in 5-Aza-dC group and 33.8% in 5-Aza-dC + TSA group, respectively. The groups of TSA, 5-Aza-dC and 5-Aza-dC + TSA were significantly different from control group (P < 0.05).

CONCLUSIONSAberrant methylation of ALDH1a2 gene is the main cause for gene transcriptional inactivation. Re-expression of ALDH1a2 gene and cell apoptosis are detected after either treatment with 5-Aza-dC alone or in combination with TSA.

Apoptosis ; drug effects ; Azacitidine ; pharmacology ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Humans ; Hydroxamic Acids ; pharmacology ; Retinal Dehydrogenase ; metabolism ; Urinary Bladder Neoplasms ; metabolism ; pathology

This study was aimed to investigate the methylation status of WT1 gene in leukemia cell lines and its relation with expression of WT1 gene. The WT1 gene was silenced by DNA methylation or histone deacetylation, and the expression of WT1 gene was induced by using HDAC inhibitor and/or demethylation agent of DNA. Some leukemia cell lines (U937, HL-60, K562, KG1) were detected by RT-PCR, MS-PCR, restriction analysis, and DNA sequencing. U937 leukemic cells without WT1 mRNA expression were incubated with HDAC inhibitor Trichostatin A (TSA) and/or demethylation agent decitabine. The results showed that the U937 cells did not express WT1 gene, but HL-60, K562 and KG1 cells highly expressed WT1 gene; WT1 gene was unmethylated in HL-60 cells, but methylated in K562 and U937 cells. WT1 expression could be reactivated by co-incubation with TSA and decitabine, but not was observed by using single drug. It is concluded that WT1 promoter is methylated in some leukemia cells, however, the methylation can not affect its expression. DNA methylation and deacetylation of histones are synergistic to inhibit the expression of WT1 in leukemic U937 cells, the combination of TSA with decitabine can induce expression of WT1 gene.
Azacitidine ; analogs & derivatives ; pharmacology ; DNA Methylation ; Gene Silencing ; HL-60 Cells ; Histones ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; K562 Cells ; Promoter Regions, Genetic ; U937 Cells ; WT1 Proteins ; genetics

The aim of this study was to investigate the proliferation-inhibitory and inducing apoptotic effects of decitabine (DAC) on acute promyelocytic leukemia NB4-R2 cells. Cell inhibitory rate was determined by cell proliferation and cytotoxicity assay (WST-1 assay) after NB4-R2 cells were treated with 0.01 - 0.5 µmol/L DAC for 24, 48 and 72 h. Apoptosis of NB4-R2 cells treated with 0.05 - 5 µmol/L DAC for 48 h was detected by flow cytometry with PI staining and AnnexinV/PI staining. Reverse transcription-PCR (RT-PCR) was used to determine the mRNA expression level of MDR1 gene encoding P-glycoprotein (P-gp). The results indicated that DAC (0.01 - 0.5 µmol/L) inhibited the proliferation of NB4-R2 cells in both time- and concentration-dependent manners. The IC(50) of DAC on the viability of NB4-R2 cells after treatment for 48 and 72 h were 0.089 and 0.064 µmol/L respectively. DAC (0.05 - 5 µmol/L) induced NB4-R2 cell apoptosis in dose-dependent manner with down-regulation of MDR 1 gene expression. It is concluded that a low concentration of DAC (< 0.5 µmol/L) inhibits cell proliferation, while higher concentration of DAC (1 or 5 µmol/L) induces apoptosis on NB4-R2 cells, accompanied with reduction of MDR1 levels.
Apoptosis ; drug effects ; Azacitidine ; analogs & derivatives ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Drug Resistance, Neoplasm ; Humans ; Leukemia, Promyelocytic, Acute ; metabolism ; pathology ; Tretinoin ; pharmacology

The aim of the research was to ascertain different expression levels of miRNA-17-19b in different cell lines and to observe the changes of miR-17-19b expression in the cell line K562 with high expression level of miR-17-19b after 5-azacytidine (5-aza) treatment. Total RNA was extracted from K562, HL-60, NB-4 and HeLa cell lines, white blood cells of peripheral blood from patient with chronic myeloid leukemia (CML) and mobilized white blood cells of peripheral blood from normal persons, respectively. Total RNA was polyadenylated by poly (A) polymerases and the expressions of miR-17-19b in the cell lines and the above mentioned cells were detected by SYBR-green real-time PCR. The K562 cell line was treated with 2.5 µmol/L 5-aza for 24, 48 and 72 hours, then were collected at 96 hours. The changes of miR-17-19b expression were determined by real-time PCR after 5-aza treatment. K562 cell line proliferation was observed after inhibition of miR-19a function. The results showed that the expression levels of miRNA-17-19b in K562 cells and white blood cells of peripheral blood from CML patients were higher than those in mobilized white blood cells of peripheral blood from normal person. The expression level of miR-17-19b in K562 cells with high expression of miR-17-19b was down-regulated after 5-aza treatment. The proliferation of K562 cells was inhibited through suppression of miR-19a function. It is concluded that expression level of miR-17-19b is higher in K562 cell line and white blood cells of peripheral blood from CML patients than that in white blood cells of peripheral blood from normal person. Expression of miR-17-19b is inhibited in K562 cell line after 5-aza treatment. Inhibition of miR-19a in vitro can suppress the proliferation of K562 cell line.
Antimetabolites, Antineoplastic ; pharmacology ; Apoptosis ; Azacitidine ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Down-Regulation ; HL-60 Cells ; Humans ; K562 Cells ; MicroRNAs ; genetics

The aim of this research is to find an effective cardiomyocyte-induced method derived from porcine amniotic fluid stem cells (pAFS). For cardiac differentiation, the cells were formed embryoid bodies (EBs) firstly, then cultured in induced-medium including 5-azacytidine (5-aza) and vitamin C (Vc). We detected the specific markers of cardiomyocyte by immunocytochemistry, RT-PCR and transmission electron microscope. The results showed that some embryoid bodies beat rhythmically after 10 days of induction. Furthermore, analysis of t test revealed that the percentage of beating cardiomyocyte-like cell clusters was highest (33%) when induction using 0.1 mmol/L Vc and 5 micromol/L 5-aza. Immunocytochemistry analysis demonstrated that cardiomyocyte-like cell clusters expressed alpha-actin, Tnni3. RT-PCR analysis also illustrated that TbX5, Gata4, alpha-MHC and Tnni3 were expressed positive in cardiomyocyte-like cell clusters. Especially, we observed basic structures of myocardium, such as myofilament, glycogen granule and so on by transmission electron microscope. In conclusion, 5-azacytidine and vitamin C could promote differentiation of pAFS into myocardium.
Amniotic Fluid ; cytology ; Animals ; Ascorbic Acid ; pharmacology ; Azacitidine ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Embryoid Bodies ; Embryonic Stem Cells ; cytology ; Female ; Myocytes, Cardiac ; cytology ; Swine