Analysis of Clinical Features and Risk Factors for Oral Ulcers and Bloodstream Infection in Patients with Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

OBJECTIVE@#To investigate the risk factors of oral ulcers and bloodstream infection in patients with hematopoietic stem cell transplantation.@*METHODS@#The clinical data of 401 hematopoietic stem cell transplant patients in the First Affiliated Hospital of Zhengzhou University from January 2020 to December 2021 were retrospective analyzed, and the risk factors of oral ulcers and bloodstream infection statistical and analyzed.@*RESULTS@#Among the 401 patients, the incidence of oral ulcers was 61.3% (246/401), and the incidence of bloodstream infection was 9.0% (36/401). A total of 40 strains of pathogenic bacteria were isolated from 36 patients, including 26 strains of Gram negative strains (65%), 13 strains of Gram positive strains (32.5%), and 1 strain of fungi (2.5%). Single-factor analysis showed that oral hygiene was associated with the occurrence of bloodstream infection, and the Multi-factor analysis showed that age ≥14 years old, disease diagnosis of leukemia, and allogeneic hematopoietic stem cell transplantation were risk factors for oral ulcers.@*CONCLUSION@#The incidence of oral ulcers in patients with hematopoietic stem cell transplantation is high. The age ≥14 years, disease diagnosis of leukemia, and allogeneic hematopoietic stem cell transplantation were risk factors for oral ulcers in patients, and oral hygiene was associated with the occurrence of bloodstream infection.

Clinical and Pathological Characteristics of Related-Renal Damage in Patients with POEMS Syndrome / 中国实验血液学杂志

OBJECTIVE@#To investigated the clinical and pathological characteristics of related-renal damage in patients with POEMS syndrome.@*METHODS@#Five patients diagnosed as POEMS syndrome in our hospital were selected. Their clinical manifestation, pathological characteristics of kidney and laboratory examination were analyzed retrospectively. Among the 5 patients, three males and two females with a median age of 50 years old. The mean interval before diagnosis was 13.0±7.2 months.@*RESULTS@#All the patients showed neuropathy, endocrinopathy, monoclonal plasma cell-proliferative disorder, skin changes and extravascular volume overload, in which 4 patients showed organomegaly. Proteinuria was found in 5 patients, and microhematuria was found in 4 patients. Moreover, 4 patients showed an elevated blood urea, while 2 patients showed creatinine elevation. 1 patient at chronic kidney disease (CKD)-G1 stage, 2 patients at CKD-G2 stage, and 1 patient at CKD-G3b stage, moreover, 1 patient at CKD-G5 stage. Endothelial injury and mesangial lesion were the main characteristics of renal pathology. 3 patients were pathologically diagnosed as thrombotic microangiopathy kidney damage, while 2 patients as light chain amyloidosis.@*CONCLUSION@#POEMS syndrome is a multi-systemic disease with complex clinical manifestations. 5 patients had different degrees of renal insufficiency. Endothelial injury and mesangial lesion are the main features of renal pathology.

MiR-124-3p Enhances the Sansitivity of Chronic Myelogenous Leukemia Cell K562-R to Imatinib by Targeting ABCA2 / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect and mechanism of miR-124-3p-targeing regulating ABCA2 on chronic myelogenous leukemia cell K562-R.@*METHODS@#CML cells with miR-124-3p-overexpression and ABCA2-over-expression as well as subcutaneoustrans planted tumor nude mice were used as study objects. And the CML cells were divided into four groups: K562-R blank control, miR-124-3p mimic control, ABCA2-overexpression and mimic+PC ABCA2. The effects of miR-124-3p and ABCA2 on CML cells were analyzed. The levels of proliferation-, apoptosis- and autophagy- related protein were determined by Western blot. qRT-PCR was employed to detect the levels of miR-124-3p and ABCA2 in K562-R cells. The relationship between miR-124-3p and ABCA2 was validated by luciferase reporter system assays and bioinformatics. Hoechst/immunohistochemical staining and CCK-8 assay were performed to investigate the function involved.@*RESULTS@#miR-124-3p highly expressed in K562-S cells and lowly expressed in K562-R cells, however, ABCA2 lowly expressed in K562-S cells and highly expressed in K562-R cells. Over-expression of miR-124-3p significantly decreased ABCA2 level and cell growth, but increased autophagy and apoptosis in K562-R cells (P＜0.01). When ABCA2 was over-expressed, the K562-R cell growth was promoted and autophagy and apoptosis were inhibited (P＜0.01). The miR-124-3p promoted cell autophagy and apoptosis but inhibited cell growth in nude mice transplant tumor model (P＜0.01).@*CONCLUSION@#miR-124-3p can target ABCA2 to inhibit the growth of CML cells and promote the cell autophagy and apoptosis of CML cells.

Comparision of Mutational Spectrum between Elderly and Young Adults with Acute Myeloid Leukemia Based on Next Generation Sequencing / 中国实验血液学杂志

OBJECTIVE@#To compare the gene mutational spectrum between elderly and young adults with acute myeloid leukemia(AML) based on next generation sequencing(NGS).@*METHODS@#The specimens of 250 AML patients in first affiliated hospital of Zhengzhou University from January 2018 to November 2018 were collected and analyzed retrospectively. The mutation of 22 related genes were detected by using AML NGS chips. Then, the differences between elderly (≥60 years old) and young adults (＜60 years old) were compared.@*RESULTS@#The most frequent mutations of 250 patients were as follows: NPM1(22.4%), FLT3-ITD(18.8%), NRAS(17.2%), DNMT3A(14.4%), TET2(11.6%), IDH2(9.6%), Biallelic CEBPA(8.8%), Moallelic CEBPA(8.4%), KIT(8.4%), RUNX1(7.6%), IDH1(7.6%), ASXL1(6.0%), U2AF1(5.2%), SRSF2 (3.2%), SF3B1(3.2%), TP53(2.4%), KRAS(2.0%). The NPM1, CEBPA, DNMT3A mutation significantly increased in intermediate prognosis group while KIT significantly increased in favourable prognosis group. The TET2 and IDH2 mutation rate in elderly patients were significantly higher than that in young patients (21.8% vs 8.7%) (χ=7.180, P=0.007) and (20.0% vs 6.7%) ( χ=8.788, P=0.003) respectively. Compared with young patients, the frequencies of DNA methylation and demethylation mutations (including DNMT3A, TET2, IDH1, IDH2) and RNA splicing enzyme mutations (inc-luding SRSF2, SF3B1, U2AF1, ZRSR2) in elderly patients significantly increased(67.3% vs 36.4%) (χ=16.653, P=0.000) and (23.6% vs 8.7%)(χ=9.041, P=0.003) respectively.@*CONCLUSION@#The gene mutational spectrum in elderly and young adult AML shows heterogeneity. Compared with young adults, the frequencies of DNA methylation and demethylation mutations and RNA splicing enzyme mutations in elderly patients significantly increase.

Change of Autophagic Activity of U266 Cells after Bortezomib -Resistance and Its Mechanisms / 中国实验血液学杂志

OBJECTIVE@#To explore the changes of autophagic activity after resistance of U266 cells to bortezomib (Bor) and its mechanisms.@*METHODS@#The proliferation inhibition rate, 50% inhibitory concentration (IC), drug-resistance coefficient, drug-resistance reversed multiple by 3-methyladenine (3-MA) in U266 and U266/Bor cells treated with Bor were detected and calculated by using MTT method, then the proliferation inhibition curve was drawed. The Western blot was used to detect the expression of LC3-I, IC3-II, p-mTOR, Beclin-1, ATG5 and ATG7 proteins.@*RESULTS@#The Bor showed the its proliferation inhibition effect on U266 cells and U266/Bor cells, IC of Bor on U266 and U266/Bor cells on 24 hours were 35.7 nmol/L and 526.5 nmol/L respectively; the drug-resistance coefficient was 14.7; the drug-resistance reversed multiple by 3-MA was 2.7. The expression of LC3-II, Beclin11, ATG5 and ATG7 in U266/Bor cells was higher than that in U266 cells; after the treatment with Bor for 24 h, the expression levels of LC3-II, Beclin-1, ATG5 and ATG7 in U266 cells all decreased, as compared with levels before treatment; while the expression levels of LC3-II, Beclin-1, ATG5 and ATG7 in U266/Bor cells were higher than those before treatment. There were no significant difference of p-mTOR expression among U266, U266+Bor, U266/Bor, U266/Bor+Bor cells.@*CONCLUSION@#The increase of autophagy closely relates with resistance of U266 cells to bortezomib, moreover with up-regulation of Beclin-1, ATG5 and ATG7 expression.

Effect of Metformin on Proliferation Capacity, Apoptosis and Glycolysis in K562 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of metformin on the proliferation, apoptosis and energy metabolism of acute myeloid leukemia (AML) K562 cells and the possible mechanism.@*METHODS@#Different doses (0, 5, 10, 20 and 30 mmol/L) of metformin was added into the K562 cells, which were cultivated for 24 h, 48 h and 72 h. The inverted optical microscope was used to observe the cell growth, CCK 8 was used to detect the cell vitality. The appropriate metformin doses (0, 10, 20 and 30 mmol/L) and the best time (48 h) were selected for subsequent experiments. The flow cytometer with Annexin V-FITC /PI doulde staining was used to detect apoptosis; the glucose detection kit and lactate detection kit were used to detect glucose consumption and lactate production; fluorescence quantitative PCR was used to detect glycolysis-related gene expression, and Western blot was used to detect protein expression.@*RESULTS@#Metformin inhibited the proliferation of K562 cells in a dose-dependent manner (r=0.92), and the relative survival in the 30 mmol/L group was as low as 19.84% at 72 h. When treated with metformin for 48 h, the apoptosis rates of 0, 10, 20 and 30 mmol/L groups were 5.14%, 12.19%, 26.29% and 35.5%, respectively. Compared with the control group, the glucose consumption and lactate secretion of K562 cells treated with metformin were significantly reduced (P<0.05), and showed a dose-dependent effect(r=0.94,r=0.93,respectively). Metformin inhibited the expression of GLUT1, LDHA, ALDOA, PDK1, and PGK1 genes of K562 cells (P<0.05) showing a dose-dependent manner(r=0.83，r=0.80，r=0.72，r=0.76，r=0.73,respectively). Metformin inhibited the expression of P-Akt, P-S6, GLUT1, LDHA proteins of K562 cells(P<0.05), showing a dose-dependent relationship(r=0.80，r=0.92，r=0.83，r=0.92,respectively).@*CONCLUSION@#Metformin can inhibit the growth and proliferation of K562 cells and promote the apoptosis of K562 cells by inhibiting glycolysis energy metabolism. PI3K/Akt/mTOR signaling pathway may be one of the molecular mechanisms of metformin on k562 cells.

Reversal Effect of Pioglitazone on Multidrug Resistance in K562/ADR Cells and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To explore the reversal effect of pioglitazone (PIO) on multidrug resistance in K562/ADR cells and its mechanism.@*METHODS@#The proliferation inhibition rate, half inhibition concentration (IC) and drug-resistance reversal multipe were detected and the curve of proliferation inhibition rate was drawn by MTT assay, the transcription of PPARγ, CYP2C8 and CYP2J2 genes was detected by RT-PCR; the expression of PPARγ, CYP2C8 and CYP2J2 proteins was detected by Western blot.@*RESULTS@#The IC of PIO on K562 and K562/ADR cells for 60 h was 326.7 μmol/L and 349.1 μmol/L respectively. The reversal multiple of 30 μmol/L PIO on ADR-resistance of K562/ADR cells was 6.4. After treatment of K562/ADR cells with PIO, the transcription of CYP2C8 and CYP2J2 and the protein expression of CYP2C8 and CYP2J2 significantly decreased, the transcription of PPARγ gene and the expression of PPARγ protein were not changed.@*CONCLUSIONS@#Pioglitazone can reverse the adriamycin-resistance in K562/ADR cells that is closely related to the decrease of protein expression of CYP2C8 and CYP2J2. Pioglitazone is an effective multidrug resistance reversal agent for tumors.

Genetic haploidentical peripheral blood stem cell transplantation for treatment of myelodysplastic syndrome:a 2-year follow-up visit of 21 cases / 中国组织工程研究

BACKGROUND: In recent years, genetic haploidentical peripheral blood stem cell transplantation has been gradually improved, and haploid allogeneic hematopoietic stem cell transplantation has become an important treatment choice for malignant hematopoietic disease. OBJECTIVE: To observe the clinical efficacy of genetic haploidentical peripheral blood stem cell transplantation for myelodysplastic syndrome. METHODS: The clinical data of 21 myelodysplastic syndrome cases undergoing genetic haploidentical peripheral blood stem cell transplantation were retrospectively analyzed. Modified BU/CY+ATG administration was performed as a pretreatment strategy for haploidentical peripheral blood stem cell transplantation, and the combined use of cyclosporine A+mycophenolate mofetil+short-range methotrexate±basiliximab was adopted to prevent graft-versus-host disease (GVHD). RESULTS AND CONCLUSION: (1) The 21 cases were followed for an median of 333 days (22-1 222 days), with 76% (16/21) infection of granulocyte lack period, 100% (21/21) neutrophil reconstruction, the median implantation time of 12 days (7-17 days), 81% (17/21) platelet engraftment, and the median implantation time of 14 days (7-68 days). (2) The accumulative incidence of GVHD was 52.4% (11/21), including 29% (6/21) of acute GVHD and 24% (5/21) of chronic GVHD. The incidence of hemorrhagic cystitis was 38.1% (8/21). The recurrence rate after transplantation was 4.8% (1/21). (3) The 2-year non-relapse mortality was 48% (10/21), and the 2-year disease-free survival rate was 46.8%. These results show that in the absence of HLA-identical related donors and unrelated donor, genetic haploidentical peripheral blood stem cell transplantation is a safe, effective, feasible and alternative treatment option for myelodysplastic syndrome.

Peripheral blood haploidentical hematopoietic stem cell transplantation for treatment of acute lymphoblastic leukemia in adults: monitoring minimal residual diseases to intervene recurrence / 中国组织工程研究

BACKGROUND: Recurrence of acute leukemia after hematopoietic stem cell transplantation is one of the major problems affecting the long-term survival of patients. Early intervention to prevent ALL recurrence after transplantation can improve disease-free survival, overall survival and reduce post-transplant mortality. Monitoring of minimal residual disease (MRD) by flow cytometry and PCR-based molecular biology techniques is a widely reliable and practicable method. OBJECTIVE: To dynamically monitor the MRD level of acute lymphoblastic leukemia after peripheral blood haploidentical hematopoietic stem cell transplantation and to explore its implications for predicting early relapse. METHODS: A retrospective study was conducted in 53 patients with acute lymphoblastic leukemia who had underwgone peripheral blood haploidentical hematopoietic stem cell transplantation at the First Affiliated Hospital of Zhengzhou University from June 2011 to June 2017. The patients were followed up for postoperative 1, 3, 6, 12 months to observe the relation between MRD levels and relapse after transplantation. RESULTS AND CONCLUSION: (1) The disease-free survival rate of MRD positive group and MRD negative group were 20.0% and 65.8%, respectively; and the overall survival rates were 50.8% and 68.9% in the two groups, respectively. There were significant differences between two groups. (2) Among 16 MRD positive patients accepting clinical intervention after transplantation, 4 patients presented with MRD negative and had no recurrence. (3) Eleven hematologic recurrence patients were given tyrosine kinase inhibitor-targeted therapy, chemotherapy, donor lymphocytes Infusion and secondary transplantation, but they eventually died. The median time from the discovery of MRD positive to hematologic recurrence was 100 (7-190) days, and during this period. Clinical intervention was confirmed to extend the recurrence time. In this study, one case refused clinical intervention, and eventually died of recurrence. Our findings indicate that dynamic monitoring of the MRD level in acute lymphoblastic leukemia patients after peripheral blood haploidentical transplantation can predict recurrence, by which the patients can be given early intervention to reduce the risk of recurrence and improve disease-free survival and overall survival.

Association between IgG N-glycans and Nonalcoholic Fatty Liver Disease in Han Chinese / 生物医学与环境科学（英文）

Nonalcoholic fatty liver disease (NAFLD) is a major public health issue worldwide. Immunoglobulin G (IgG) N-glycans are associated with risk factors for NAFLD, such as obesity and diabetes. A cross-sectional study involving 500 Han Chinese adults recruited from a community in Beijing was carried out to explore the association between IgG N-glycans and NAFLD. IgG N-glycosylation was significantly associated with NAFLD, with the disease showing a negative correlation with galactosylation (GP14, GP14n, and G2n), positive correlation with fucosylation (FBG2n/G2n), and positive correlation with bisecting N-acetylglucosamine (GlcNAc) [FBG2n/FG2n and FBG2n/(FG2n+FBG2n)], after controlling age, gender, and prevalence of obesity, type 2 diabetes mellitus, hypertension, and hyperlipidemia. In other words, the present study showed a possible association between NAFLD and the loss of galactose and elevations of fucose and bisecting GlcNAc. Aberrant IgG glycosylation might therefore be a potential biomarker for the primary or secondary prevention of NAFLD.

Expression and Clinical Significance of N-cadherin in Bone Marrow Leukemic Cells Derived from Patients with Acute Leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of N-cadherin in bone marrow leukemic cells derived from acute leukemia patients and its clinical significances.</p><p><b>METHODS</b>A total of 113 patients with acute leukemia were enrolled in this study. Flow cytometry was employed to detect the expression of N-Cadherin in bone marrow leukemic cells from acute leukemia patients and the relationships between the N-cadherin expression and the clinical characteristics of patients with acute leukemia were analyzed.</p><p><b>RESULTS</b>The expression of N-Cadherin in bone marrow leukemic cells deriveted from patients with acute leukemia was variable with 0%-99.7%. For adult AML patients, the positive rate of CD34 in N-cadheringroup was significantly higher than that in N-cadheringroup(67.39% vs 33.33%)(P=0.013), while the differences of total CR rate and rate of CR after 1 cycle of induction treatment were not significant between these 2 groups(P>0.05). As to ALL patients, N-cadheringroup had significant lower WBC count (21.31±7.07 vs 51.10±23.69)(P=0.008) and lower percentage of peripheral blood blast (43.22±5.75% vs 66.45±5.65%)(P=0.015). The CR rate after 1 cycle of induction treatment and rate of overall CR were lower and the relapse rate was higher in N-cadherinALL group than those in N-cadherinALL group, but the differences were not significant (P>0.05). For childhood ALL, the positive rate of CD33 in N-cadheringroup was significantly higher than that in N-cadheringroup(47.62% vs 0%)(P=0.012). The relapse rate was higher in N-cadheringroup than that in N-cadheringroup (30.00% vs 0%)(P=0.115). The median survival time, 3-year overall OS rate and 3-year relapse-free survival rate in N-cadheringroups of adult AML, non-M3 AML, ALL and chidhood ALL paients were superior to N-cadheringroups, but the differences were not significant.</p><p><b>CONCLUSION</b>The expression of N-cadherin in bone marrow leukemic cells relates to some clinical features of patients with acute leukemia and to some extent has inferior effect on survival of patients with acute leukemia.</p>

Clinical Study of Cytomegalovirus Infection and Preemptive Therapy after Allogenic Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To analyze the clinical characteristics of cytomegalovirus(CMV) infection after allogenic hematopoietic stem cell transplantation(allo-HSCT) and the effect of preemptive therapy.</p><p><b>METHODS</b>A total of 134 patients who underwent allo-HSCT from March 2010 to March 2015 in the Department of Hematology of our hospital were enrolled in this study. The CMV infection rate, the median time of CMV infection occurence, and the risk factors for CMV infection after allo-HSCT, the response rate of preemptive treatment and the median time of CMV-DNA turning negative were analyzed. Five-year overall survival rate was compared between the patients with or without CMV infection.</p><p><b>RESULTS</b>The incidence of CMV viremia was 55.2％(74／134), and the median time for the CMV with CMV-DNA positive for the first time was 34 days(14-283) after allo-HSCT．Both univariate and multivariate analysis showed that the thymoglobulin(ATG) used in conditioning regimen and Ⅱ-Ⅳ grade of aGVHD were the risk factors for CMV viremia. After preemptive treatment the 85.1% of patient with CMV viremia turned negative, and the median time of CMV-DNA turning negative were 15 days(5-82), only 2 patients died of CMV pneumonia. Five-year overall survival rate of the patients with or wihout CMV viremia was 49% and 66.3% respectively, and the difference between the 2 groups was significant(P=0.041）.</p><p><b>CONCLUSION</b>The ATG used in conditioning regimen and Ⅱ-Ⅳ grade of aGVHD may increase the incidence of CMV infection after allo-HSCT, and the preemptive thrapy can effectively prevent the CMV viremia turning to CMV disease.</p>

Reversal effect of cinobufacini on multidrug resistance of Raji/ADR cells and its mechanisms / 中国实验血液学杂志

The aim of this study was to explore the reversing effect of cinobufacini on multidrug resistance of Raji/ADR cells and its mechanisms. The growth inhibitory rate, half inhibitory concentration (IC50), reversing multiples to adriamycin- resistance were detected by MTT, and the curve of growth inhibitory rate was drawn; the MDR-1 and MRP-1 gene transcription was determined by RT-PCR; the expressions of P-gp and MRP-1 proteins were assayed by Western blot and flow cytometry. The results showed that the inhibitory rates of cinobufacini on Raji and Raji/ADR cells at 72 h were 75.6% and 69.3% respectively, the IC50 were 3.9 mmol/L and 4.6 mmol/L without significant difference (P > 0.05). The reversing multiples to adriamycin-resistance were 255.7 multiples, the transcription of mdr-1 and mrp-1 genes and the expression of P-gp and MRP-1 proteins significantly decreased (P < 0.05) in Raji/ADR cells after the treatment with cinobufotalin. It is concluded that cinobufotalin can reverse the adriamycin-resistance in Raji/ADR cells and the expression of P-gp and MRP-1 proteins were down-regulated through the transcriptional pathway. The cinobufotalin is an effective reversal agent for the multidrug resistance of tumors.

Synergistic cytotoxic effects of rapamycin and idarubicin on human acute T-cell lymphoblastic leukemia Jurkat cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the cytotoxic effects of mTOR inhibitor rapamycin (Rapa) and idarubicin (IDA) on human T-cell acute lymphoblastic leukemia Jurkat cell line.</p><p><b>METHODS</b>The proliferation of Jurkat cells was observed by CCK-8 assay. The combined index was analyzed by Isobologram method. Apoptosis was detected by electron microscopy and flow cytometry with Annexin V/PI staining. Protein expressions of Caspase 3, PARP, Caspase 8, Caspase 9, Akt, p-Akt, P85S6K, p-P85S6K, P70S6K, p-P70S6K, ERK1/2 and p-ERK1/2 were determined by Western blotting.</p><p><b>RESULTS</b>The IC(50) of IDA for Jurkat cells was significantly reduced when combined with 10 nmol/L rapamycin. The combined index was <1. Both electron microscopy and Annexin V/PI staining flow cytometry revealed that rapamycin significantly increased apoptotic sensitivity to IDA. The combination of IDA with rapamycin enhanced the expressions of Caspase 3, PARP, Caspase 8 and Caspase 9. Rapamycin significantly inhibited mTOR signaling upstream Akt and downstream S6K activation triggered by IDA, and the combination of the two agents led to synergistic inhibition of ERK phosphorylation.</p><p><b>CONCLUSION</b>Combination of IDA with rapamycin exerted a synergistic anti-proliferative effect and promoted apoptosis by both extrinsic and intrinsic apoptotic pathways in Jurkat cells. Inhibition of ERK phosphorylation and mTOR signaling by rapamycin may play a certain role in this synergistic effect.</p>

Effects of mycophenolic acid on human bone marrow-derived mesenchymal stem cells in vitro / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of mycophenolic acid (MPA) on the proliferation and differentiation of human bone marrow-derived mesenchymal stem cells (MSCs).</p><p><b>METHODS</b>MSCs were treated with MPA at the concentration of 1 μ mol/L, 10 μ mol/L, 50 μ mol/L, and 100 μ mol/L, respectively. Cell proliferation was analyzed using CCK-8 method. Apoptosis was detected by PI/Annexin V assay kit. The mRNA expression of inosine-5'-monophosphate dehydrogenase (IMPDH) in MSCs was analyzed by RT-PCR. Osteogenic differentiation was analyzed by Von Kossa staining, Ca(2+) quantification and real-time PCR.</p><p><b>RESULTS</b>In the range of 1 μ mol/L to 100 μ mol/L, MPA caused a significant subdued proliferation rate of MSCs in a concentration-and time-dependent manner by guanosine depletion, and PI/Annexin staining showed no apoptosis induced by MPA. RT-PCR results showed that MSCs expressed both IMPDH I and IMPDH II. von Kossa staining and Ca(2+) quantification indicated that MPA inhibited osteogenic differentiation of MSCs, and real-time PCR detected a dose-dependent decrease in expression of Osteopontin and BMP-2. Further investigation showed that MPA down-regulated the expression of Runx2 and Osterix.</p><p><b>CONCLUSION</b>MPA can inhibit the proliferation of MSCs by guanosine depletion in a concentration-and time-dependent manner and inhibit the osteogenic differentiation of MSCs by down-regulation of the expression of Runx2 and Osterix.</p>