Bioinformatics Analysis and Verification of Aging-Related Genes of Bone Marrow Mesenchymal Stem Cells in Patients with Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To screen and verify the differentially expressed genes related with aging of bone marrow mesenchymal stem cells (BM-MSCs) in acute myeloid leukemia (AML) patients by bioinformatics, so as to provide new molecular markers for the research and clinical treatment of AML.@*METHODS@#The gene expression profiling chip related with BM-MSCs in AML patients in our hospital and the gene chip GSE84881 selected from NCBI database GEO were used for data analysis and exploration. The DAVID analysis software was used to perform gene ontology (GO) enrichment analysis and KEGG pathway enrichment analysis. Furthermore, the differentially expressed genes related with aging of BM-MSCs in AML patients were identified. Bone marrow samples were collected and MSCs were amplified in vitro, and RT-PCR was used to verify the differentially expressed genes, which should be further identified with senescence-associated β-galactosidase staining and MTT cell proliferation assays.@*RESULTS@#A total of 247 differentially expressed genes were screened out by bioinformatics methods, including genes of 132 up-regulated expression and 115 down-regulated expression. Six differentially expressed genes related with aging of BM-MSCs in AML patients were screened out, including the genes of up-regulated expression, COL3A1 (P<0.05), CRYAB (P<0.01), DCN (P<0.05), and the genes of down-regulated expression, including CCL2 (P<0.05), CTSC (P<0.01) and IL6 (P<0.05). These 6 differentially expressed genes were consistent with data from chip assays, and which was significantly correlated with aging of BM-MSCs in AML patients. Meanwhile, the positive rate of senescence-associated β-galactosidase staining in BM-MSCs of AML patients was significantly different from that of healthy donors (P<0.01). MTT cell proliferation assay showed that BM-MSCs in AML patients had proliferative ability lower than the healthy donors' BM-MSCs.@*CONCLUSION@#The data here suggest novel clues for the clinical research and treatment of BM-MSCs aging in AML patients.

Effect of CIAPIN1 gene on proliferation of K562 cells / 中国实验血液学杂志

The study was aimed to investigate the effect of CIAPIN1 gene on the proliferation of chronic myeloid leukemia (CML) cell line K562. The shRNA eukaryotic expression vector targeting CIAPIN1 gene was constructed and transfected into K562 cells. The inhibitory efficiency on K562 cells was detected by real-time PCR and Western blot; the proliferative activity of K562 cells was detected by MTT assay; the number and size of colonies were assessed by using colony-forming test; the tumorigenic potential was tested in vivo by using nude mice. The results indicated that as compared with control group, the CIAPIN1 gene expression statistically decreased; the proliferative activity of K562 cells in interference group was distinctly weakened; the number and size of colonies were significantly reduced; the tumorigenic potential was also lowered in vivo. It is concluded that inhibition of CIAPIN1 expression can inhibit K562 cell proliferation in vitro and in vivo.

Effects of Sam68 gene silence on proliferation of acute T lymphoblastic leukemia cell line Jurkat / 中国实验血液学杂志

This study was purpose to investigate the effect of Sam68 gene silence on proliferation of human acute T lymphoblastic leukemia cell line Jurkat. The sequence of shRNA targeting the site 531-552 of Sam68 mRNA was designed and chemically synthesized, then a single-vector lentiviral, Tet-inducible shRNA-Sam68 system (pLKO-Tet-On) was constructed; next the Jurkat cells were infected with lentivirus to create stable cell clones with regulatable Sam68 gene expression. The inhibitory efficiency of Sam68 gene was assayed by Real-time PCR and Western blot; the cell activity of Jurkat cells was detected with MTT assay; the change of colony forming potential of Jurkat cells was analyzed by colony forming test; the cell cycle distribution was tested by flow cytometry. The results indicated that the expression of Sam68 in experimental cells was statistically decreased as compared with that of the control cells; the cells activity and colony forming capacity of the Jurkat cells with Sam68 gene silence were significantly inhibited; with Sam68 gene silencing, the percentage of S phase cells was significantly increased, while the percentage of G2 phase cells was significantly decreased. It is concluded that the silencing Sam68 gene using shRNA interference can effectively inhibit the proliferation of human acute T lymphoblastic leukemia cell line Jurkat.

Expression of RHBDD1 gene in patients with chronic myeloid leukemia and its clinical significance / 中国实验血液学杂志

This study was aimed to investigate the expression of RHBDD1 gene in patients with chronic myeloid leukemia (CML) and explore its clinical significance. The relative expression levels of RHBDD1 in bone marrow mononuclear cells of healthy controls and CML patients were detected by using real time PCR. The results showed that the expression level of RHBDD1 in CML patients was significantly higher than that in healthy controls. The expression level of RHBDD1 in CML patients with negative BCR/ABL p210 was remarkably higher than that in patients with positive BCR/ABL p210. In patients ≥ 50 years old RHBDD1 expression was lower than the patients < 50 years old. There were no significant relation of RHBDD1 expression with sex of patients. It is concluded that RHBDD1 gene may be involved in the pathogenesis and progression of CML, particularly reflects in the pathogenesis of the patients with negative BCR/ABL p210.

Inhibition of NHE1 down-regulates IL-8 expression and enhances p38 phosphorylation / 中国实验血液学杂志

This study was purposed to explore the changes of possible angiogenetic factors other than VEGF after inhibition of NHE1 and their related mechanisms. The K562 cells were treated by NHE1 specific inhibitor cariporide, the angiogenesis factors after inhibition of NHE1 were screened by using protein chip, the IL-8 expression level after cariporide treatment was detected by real-time quantitative PCR; the K562 cells with stable interference of NHE1 were constructed, the IL-8 expression level after interference of NHE1 was detected by real-time quantitative PCR; the p38 phosphorylation level in K562 cells treated with cariporide was detected by Western blot. After treatment of K562 cells with p38 inhibitor SB203580, the IL-8 expression level was decreased by real-time quantitative PCR. The results of protein chip showed that IL-8 expression decreased after cariporide treatment. Real-time quantitative PCR confirmed this inhibitory effect. The p38 phosphorylation level increased after cariporide treatment. The down-regulation of IL-8 expression induced by cariporide treatment was partially restored after K562 cells were treated with p38 inhibitor SB203580. It is concluded that the inhibition of NHE1 can inhibit IL-8 expression through up-regulation of p38 phosphorylation.

Effect of DOT1L gene silence on proliferation of acute monocytic leukemia cell line THP-1 / 中国实验血液学杂志

This study was aimed to investigate the influence of short hairpin RNA (shRNA) on proliferation of human leukemia cell line THP-1. The shRNA targeting the site 732-752 of DOT1L mRNA was designed and chemically synthesized, then a single-vector lentiviral, tet-inducible shRNA-DOT1L system (Plko-Tet-On) was generated. Thereafter, the THP-1 cells with lentivirus were infected to create stable cell line with regulatable shRNA expression. The expression of DOT1L in the THP-1 cell line was assayed by RT-PCR. Effect of shRNA-DOT1L on the proliferation of THP-1 cells was detected with MTT method,and the change of colony forming potential of THP-1 cells was analyzed by colony forming unit test. Cell cycle distribution was tested by flow cytometry. The results indicated that the expression of DOT1L was statistically lower than that in the control groups. The proliferation and colony forming capacity of THP-1 cells were significantly inhibited. The percentage of cells at G0/G1 phase increased in THP-1/shRNA cells treated with Dox while the percentage of cells at S phase significantly decreased as compared with that in the control group. It is concluded that the shRNA targeting DOT1L can effectively inhibit the proliferation of acute monocytic leukemia cell line THP-1.

Dexamethasone impairs immunosuppressive ability of mesenchymal stem cells / 中国实验血液学杂志

This study was aimed to investigate the effect of dexamethasone (Dex) on immunosuppressive ability of mesenchymal stem cells (MSC) during expansion and differentiation of MSC. MSC were cultured in 96-well flat-bottom plates. Proliferation assays were performed by using the BrdU colorimetric ELISA Kit. To explore the effect of Dex on MSC immunosuppressive ability, MSC were firstly cultured in complete culture medium for 14 d with Dex (10 nmol/L), and then, peripheral blood mononuclear cells (PBMNC) were co-cultured with MSC in 96-well flat-bottom plates for 3 d. Phytohemagglutinin A (PHA, 10 µg/ml) was used to stimulate activation of PBMNC. The concentrations of IFN-γ in culture supernatants was detected by ELISA. The results indicated that there was no obvious difference in representative phenotypes of MSC between experimental and control groups after MSC were treated with low concentration of Dex (10 nmol/L) for 14 d, but the suppression of Dex-treated MSC on lymphocyte activation in same concentration of cells was significantly reduced as compared with control group. After the Dex-treated MSC were co-cultured with IFN-γ for 12 h, the immunoregulatory ability of MSC was recovered in a certain degree. It is concluded that the Dex impairs the immunosuppressive ability of MSC, the IFN-γ can protect and reverse the immunosuppressive ability of MSC impaired by Dex, so that, when the immunoregulatory activity of MSC is investigated, it is necessary to avoid adding Dex in the culture medium.

Increasing sensitivity of leukemia cells to imatinib by inhibiting NHE1 and p38MAPK signaling pathway / 中国实验血液学杂志

This study was aimed to investigate whether the inhibition of NHE1 activity and intracellular acidification can reverse resistance of leukemia cells to the imatinib and to explore downstream signal molecule networks of BCR/ABL in the cells of chronic myelocytic leukemia (CML) patients. The mRNA and protein expression of P-glycoprotein (Pgp) and the drug accumulation were assayed after acidifying the primary leukemia cells of patients or K562/DOX and K562/G01 cells. The effects of intracellular acidification of primary leukemia cells on the phosphorylation level changes of ERK1/2 and p38 MAPK were analyzed by Western blot. The results showed that the intracellular concentration of drugs in the advanced patients increased and the sensitivity of K562/DOX and K562/G01 cells to imatinib was enhanced after intracellular acidification or treatment with NHE1 inhibitor cariporide. With downregulation of intracellular pH, the phosphorylation of p38 MAPK decreased in advanced patients and the phosphorylation of ERK1/2 increased within 3 min and then decreased after 30 min. SB203580, the specific inhibitor of p38 MAPK, displayed a synergistic effect with the inhibitor of NHE1 to downregulate the mRNA and protein expression of Pgp. It is concluded that the inhibiton of NHE1 can significantly decrease the protein expression of Pgp in K562/DOX and K562/G01 cells, increase the accumulation of Rhodamine123 and doxorubicin in the cells of advanced patients and enhance the sensitivity of cells to imatinib in which the p38 MAPK signal transduction pathways involves.

Expression of CIAPIN1 gene in BMMNC of patients with leukemia / 中国实验血液学杂志

This study was aimed to investigate the expression level of CIAPIN1 mRNA in leukemia patients and explore its significance in leukemias. The fresh bone marrow was collected from 112 newly diagnosed leukemia patients, the total RNA was extracted by means of TRIzoL, the cDNA was synthesized, the expression of CIAPIN1 mRNA was detected by real-time quantitative PCR using β-actin as internal reference; 10 normal healthy persons were selected as controls. The results showed that the expression of CIAPIN1 mRNA was statistically higher in acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL) and chronic phase chronic myeloid leukemia (CML) patients than that in normal persons (p < 0.05); but there was no statistical difference between chronic lymphocytic leukemia (CLL) and normal persons (p > 0.05). It is concluded that the CIAPIN1 gene higher expresses in MNC of newly diagnosed leukemia patients, up-regulation of CIAPIN1 expression may play an important role in pathogenesis of leukemia.

Early apoptosis of HL-60 cells induced by anti-CD44 McAb A3D8 inhibiting ERK1/2-upregulated Bim expression / 中国实验血液学杂志

This study was aimed to investigate the effects of anti-CD44 mAb A3D8 on proliferation and apoptosis of AML cells, to explore the mechanism of ERK1/2 and Bim in this process. Effect of the anti-CD44 mAb A3D8 on the HL-60 cell proliferation was assayed with MTT method, the change of mitochondrial transmembrane potential of HL-60 cells was analyzed by flow cytometry. The mRNA expression of Bim was determined by real-time quantitative RT-PCR. Western blot was used to detect the protein expression of p-ERK1/2. The results showed that mAb A3D8 could remarkably inhibit the proliferation capacity of the HL-60 cells in a dosage- and time-dependent ways. The mitochondrial transmembrane potential in HL-60 cells treated with A3D8 (3.0 µg/ml) was significantly decreased as compared with the control cells. Furthermore, the mRNA expression of Bim was much higher than that in controls. Expression of the p-ERK was much lower than that of the controls. It is concluded that anti-CD44 mAb A3D8 can inhibit the proliferation and induce the apoptosis of HL-60 cells, mechanism of which is enhancing the expression of Bim via inhibiting p-ERK1/2.

Inhibition of NHE1 promotes hypoxia-induced differentiation of K562 leukemic cells / 中国实验血液学杂志

This study was purposed to investigate the effect of hypoxia microenvironment on K562 leukemic cell differentiation, and characteristics of NHE1 involvement in this process. The K562 cells were treated with hypoxia-mimical agent CoCl₂ or under actual hypoxia culture, and the specific NHE1 inhibitor Cariporide was used to inhibit NHE1 activity. The fluorescent probe BCECF was used for pH(i) measurements. Gene expression was analyzed by RT-PCR. The morphological characteristics was determined by Wright's staining. Signaling pathways were detected by Western blot using phosphospecific antibodies. The results indicated that the hypoxia or mimetic hypoxia favored K562 cells differentiation with up-regulation of C/EBPα. Moreover, treatment with Cariporide under hypoxia synergistically enhanced leukemia cell differentiation. Treatment with Cariporide increased levels of phosphorylated ERK5 and P38 mitogen-activated protein kinase (MAPK). It is concluded that the hypoxia or mimetic hypoxia can induce the differentiation of K562 cells, the inhibition of NHE1 activity can promote the hypoxia-induced K562 cell differentiation. The enhancement of hypoxia-induced K562 differentiation by Cariporide via MAPK signal pathway suggests a possible therapeutic target of NHE1 under hypoxia microenvironment in the treatment of leukemias.

Reversal of multidrug resistance in HL-60, MSC and CD34(+) cells from umbilical cord blood by sustained intracellular acidification / 中国实验血液学杂志

The aim of this study was to investigate the effect of intracellular acidification on accumulation of rhodamine 123 (rh123) in non-mature cells with none or low expression of multidrug resistance MDR1. The expression of MDR1 mRNA was detected by real-time quantitative RT-PCR. Confocal laser microscopy was used to determine the calibration curve of intracellular acidification (pHi). MTT assay was used to detect the cytotoxicity of intracellular acidification on HL-60, MSC and CD34(+) cells from umbilical cord blood. Flow cytometry was applied to measure the influence of intracellular acidification. The results indicated that the intracellular acidification had no obvious cytotoxicity on HL-60, MSC and CD34(+) cells. The acidification resulted in the increased rhodamine 123 accumulation in HL-60, MSC and CD34(+) cells without P-gp activity. Moreover, the more primitive cells, the less accumulation of intracellular Rh123 were observed. It is concluded that the intracellular acidification can reverse the MDR of HL-60, MSC and CD34(+) cells.

Na(+)/H(+) exchanger 1 expression and its effect on apoptosis in K562 and HL-60 cells with DNA damage / 中国实验血液学杂志

This study was aimed to investigate the expression of Na(+)/H(+) exchanger 1 (NHE1) in K562 and HL-60 cells undergoing DNA damage induced by etoposide and to elucidate the regulating mechanism. Real-time quantitative PCR (RQ-PCR) and Western blot methods were used to determine the expression of NHE1 in K562 cells after the treating with etoposide. Meanwhile, the flow cytometry was used to detect the apoptosis of leukemic cells. The luciferase reporter vector containing NHE1 promoter was constructed to measure relative luciferase activity after treating with different etoposide concentrations. The results showed that the mRNA and protein of NHE1 increased in accordance with apoptosis ratio in HL-60 cells after treated with etoposide (p < 0.05), but no such obvious increase in K562 cells. Treatment with NHE1 specific inhibitor could block etoposide induced alkalization and reduce the apoptosis ratio of HL-60 cells. The expression pattern and apoptosis alteration was not similar in K562 cells. Relative luciferase activity of reporter vector containing NHE1 promoter however increased in K562 cells after treated with etoposide. It is concluded that the expression of NHE1 is up-regulated in the process of apoptosis of HL-60 cells induced by etoposide and depends on the pHi increasing caused by NHE1 up-regulation which is not found in K562 cells although the transcriptional activity increased.

Role of Na(+)/H(+) exchanger 1 in apoptosis of HL-60 cells induced by etoposide and its mechanism / 中国实验血液学杂志

This study was aimed to investigate the role of Na(+)/H(+) exchanger 1 (NHE1) in apoptosis of HL-60 cells induced by etoposide. Real-time quantitative PCR (RQ-PCR) and Western blot methods were used to determine the expression of NHE1 in HL-60 cells after the treatment with etoposide. Meanwhile, laser scanning confocal microscopy was used to test the intracellular pH (pHi) of HL-60 cells. Cell apoptosis was measured by DNA fragmentation and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. The results showed that etoposide induced cell apoptosis after treatment for 24 hours. The expression level of NHE1 mRNA increased by 2.848 +/- 0.886 times after treatment with etoposide for 12 hours (p < 0.01), and the expression of NHE1 protein was also up-regulated (p < 0.01). The pHi of HL-60 cells increased from 7.11 to 7.46 after treatment with etoposide for 24 hours. Treatment with cariporide could block etoposide-induced alkalinisation and enhance the apoptosis HL-60 cells. It is concluded that the expression of NHE1 is up-regulated in process of apoptosis of HL-60 cells induced by etoposide and the apoptosis depends on the pH increase caused by NHE1 higher expression.

Comparison of effect between homologous recombinant gene knockout and siRNA gene silence in cell lines / 中国实验血液学杂志

The objective of this study was to compare the effects between knocking-out Sam68 gene by homologous recombination method and silencing the gene by siRNA silencing technique in DT40 cell line. Gene targeting technique was used to isolate Sam68 gene-deleted chicken DT40 cells. Meanwhile, Sam68 gene silencing cells was obtained by using stable expression of siRNA plasmid pSilencer-Sam68. Then, the function of these two cell lines were analyzed by comparing with wild-type DT40 cell line. The results showed that the growth retardation in Sam68 gene knocked-out cell line was observed due to elongation of the G2/M phase, but which could not be found in Sam68 gene silencing cell line. It is concluded that in accordance with study of protein function in living cells, use of gene knockout technique for cell line can provide the experimental results more real than those resulting from gene silence technique.

Effect of intracellular acidification on drug resistance of leukemia cells with high P-glycoprotein expression / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the impact of intracellular acidification (IA) on drug resistance of leukemia cells with high P-glycoprotein (P-gp) expression, and to provide a new method for the reversing of multidrug resistance (MDR).</p><p><b>METHODS</b>Real-time PCR was used to determine the expression level of mdr1 gene, and the leukemia cells with high P-gp expression were selected. The specific inhibitor of Na+/H+ exchanger 1 and the "high K+" buffer were used to acidify the cells, and the confocal laser microscopy was used to determine the intracellular pH (pHi) and effect of IA on the accumulation of doxorubicin. The MTT method was used to determine the effect of IA on the cell viability. The flow cytometry was used to detect the effect of IA on the P-gp function, and Western blotting was used to determine the effect of IA on the expression of P-gp.</p><p><b>RESULTS</b>The pHi was decreased to 7.0, and compared with that of control the mdr1 mRNA expression was decreased to (53.2+/-11.0)% after 1 h, and to (16.6+/-7.0)% after 3 h treatment. The P-gp expression was decreased to (56.0+/-9.0)% of the control after 3 h treatment. The accumulation of Rh123 was 71.03+/-0.47 at pHi 7.0, which was increased obviously as compared to the control group 20.07+/-0.39. The increased accumulation of doxorubicin was also observed by confocal laser microscopy.</p><p><b>CONCLUSION</b>The expression and function of P-gp on the patients cells are inhibited by IA.</p>

Relationship between midkine expression and drug efflux in childhood acute lymphoblastic leukemia cells / 中国实验血液学杂志

This study was aimed to investigate the expression of midkine gene in childhood acute lymphoblastic leukemia patients (ALL) and to explore the possible effects of midkine gene on the chemotherapeutic drug efflux. Real-time quantitative PCR (RQ-PCR) method was used to determine the expression of midkine at mRNA level in 153 ALL patients and 20 normal children. Meanwhile, laser scanning confocal microscope was used to observe the rhodamine 123 efflux from the mononuclear cells in 30 de novo B-ALL patients and 20 healthy individuals (as control). Flow cytometry was used to detect intracellular mean fluorescence intensity (MFI) which can reflect the degree of drug accumulation. The results showed that the significant statistical difference of midkine gene expression was found among the normal controls, the B-ALL patients in complete remission (CR) and progress with the expression level increasing in turns 0.795 (0.697 - 1.570), 3.012 (0.932 - 5.076) and 12.909 (2.385 - 26.347) respectively (p < 0.01). Expression level of midkine gene in progressing B-ALL group was higher than that in progressing T-ALL (p < 0.01). The rhodamine 123 efflux test revealed that MFI in the leukemia cells was obviously lower than that in normal cells (p < 0.01), furthermore, there was an evident negative correlation between the MFI and MK mRNA expression (r = -0.869, p < 0.001). It is concluded that there is powerful drug efflux ability in lymphoblastic leukemia cells with high midkine gene expression. The midkine may take part in multidrug resistance.

Effect of intracellular acidification on P-glycoprotein in drug-resistant K562/A02 cells / 中国实验血液学杂志

The aim of this study was to investigate the effect of intracellular acidification on the P-gp in K562/A02 cells. Confocal laser microscope was used to determine the intracellular acidification. MTT assay was used to detect the cytotoxicity of intracellular acidification on K562 and K562/A02 cells. Flow cytometry was applied to measure the influence of intracellular acidification on the activity of P-gp. The P-gp expression at protein and mRNA levels were determined by Western blot and real-time RT-PCR respectively. The results indicated that intracellular acidification had no obvious cytotoxicity on K562 and K562/A02 cells. The function of P-gp in K562/A02 cells weakened along with decrease of intracellular acidification, the intracellular acidification significantly increased the accumulation of Rhodamine 123 (Rh 123) and suppressed the efflux of Rh 123 mediated by P-gp. The intracellular acidification also inhibited the expression of P-gp in K562/A02 cells at protein and mRNA levels which showed intracellular acidification with time-dependence. It is concluded that the intracellular acidification can inhibit the expression and function of P-gp in K562/A02 cells.

Ultrastructural analysis of 5' nucleotides distribution in acute myeloid leukemia subtypes / 中国实验血液学杂志

5' nucleotides (5'NT), a purine degradative enzyme, is capable of hydrolyzing nucleotide and acting as a phosphotransferase simultaneously. It has critical role in maintaining nucleotide metabolism balance. The present study was aimed to investigate the expression of 5'NT in bone marrow granulocytes (BMGs) from patients with acute myeloid leukemia (AML) and healthy donors comparatively. The BMGs were isolated from bone marrow of 33 patients with AML and 6 healthy donors by using lymphocyte isolating solution. The reactivity of 5'NT was detected by electron microscope and cytochemistry of cytidine monophosphate (CMP). The positive BMG ratio and their index were calculated on the base of ultrastructural observation semiquantitatively. The results indicated that electron microscopy revealed plasma membrane reacting pattern of CMP. Most BMGs from normal donors were CMP negative or exhibited lower active degree. All cases of M(0), M(1), M(2) and t (8; 21) showed high positive percentages and high indexes of BMGs, but no statistic differences between them. APL of t (15; 17) shared lower percentages and indexes than other subtypes. There was no significant difference between APL and normal donors statistically. In conclusions, the results suggested the expression of 5'NT may be associated with BMG differentiation in AML, and APL of t (15; 17) may be a highly differentiated leukemia subtype.

Expression of a tumor related gene chp2 in leukemia cells / 中国实验血液学杂志

The purpose of this study was to investigate the expression feature of a human tumor related gene chp2 in leukemia primary cells and leukemia cell lines, real-time quantitative PCR (RQ-PCR) was performed to detect the expression level of chp2 gene in peripheral blood mononuclear cells from 10 healthy individuals (as control) and 24 cases of leukemia, and in 4 kinds of leukemia cell lines. The results showed that the detection rate of chp2 gene in 10 normal controls was 80%, positive expression was (0.744 +/- 0.682) x 10(5) cps/microl. The expression levels of chp2 mRNA leukemia primary cells and leukemia cell lines were significantly higher than that in the normal control (p < 0.05). The expression levels of chp2 mRNA were higher in AML cells (7 cases), CML cells (6 cases), ALL cells (7 cases) and CLL cells (4 cases), and their expression levels were (11.637 +/- 5.588), (6.122 +/- 3.785), (4.262 +/- 2.561) and (3.434 +/- 1.974) x 10(5) cps/microl respectively. Gene chp2 positively expressed in four kinds of leukemia cell lines, and the expression levels in K562 cells, Jurkat cells, HL-60 cells and M07e cells were (5.243 +/- 1.852), (4.463 +/- 1.621), (4.137 +/- 1.837) and (2.578 +/- 1.137) x 10(6) cps/microl respectively. The expression level in leukemia cell lines was higher than that in primary cells. It is concluded that the human tumor related gene chp2 expression in leukemia primary cells and leukemia cell lines significantly increase, which may play an important role in growth process of leukemia cells.