Influencing factors of iron metabolism assessment in patients with myelodysplastic syndrome: A retrospective study / 中华血液学杂志

Objective: To analyze the influencing factors of iron metabolism assessment in patients with myelodysplastic syndrome. Methods: MRI and/or DECT were used to detect liver and cardiac iron content in 181 patients with MDS, among whom, 41 received regular iron chelation therapy during two examinations. The adjusted ferritin (ASF) , erythropoietin (EPO) , cardiac function, liver transaminase, hepatitis antibody, and peripheral blood T cell polarization were detected and the results of myelofibrosis, splenomegaly, and cyclosporine were collected and comparative analyzed in patients. Results: We observed a positive correlation between liver iron concentration and ASF both in the MRI group and DECT groups (r=0.512 and 0.606, respectively, P<0.001) , only a weak correlation between the heart iron concentration and ASF in the MRI group (r=0.303, P<0.001) , and no significant correlation between cardiac iron concentration and ASF in the DECT group (r=0.231, P=0.053) . Moreover, transfusion dependence in liver and cardiac [MRI group was significantly associated with the concentration of iron in: LIC: (28.370±10.706) mg/g vs (7.593±3.508) mg/g, t=24.30, P<0.001; MIC: 1.81 vs 0.95, z=2.625, P<0.05; DECT group: liver VIC: (4.269±1.258) g/L vs (1.078±0.383) g/L, t=23.14, P<0.001: cardiac VIC: 1.69 vs 0.68, z=3.142, P<0.05]. The concentration of EPO in the severe iron overload group was significantly higher than that in the mild to moderate iron overload group and normal group (P<0.001) . Compared to the low-risk MDS group, the liver iron concentration in patients with MDS with cyclic sideroblasts (MDS-RS) was significantly elevated [DECT group: 3.80 (1.97, 5.51) g/L vs 1.66 (0.67, 2.94) g/L, P=0.004; MRI group: 13.7 (8.1,29.1) mg/g vs 11.6 (7.1,21.1) mg/g, P=0.032]. Factors including age, bone marrow fibrosis, splenomegaly, T cell polarization, use of cyclosporine A, liver aminotransferase, and hepatitis antibody positive had no obvious effect on iron metabolism. Conclusion: There was a positive correlation between liver iron concentration and ASF in patients with MDS, whereas there was no significant correlation between cardiac iron concentration and ASF. Iron metabolism was affected by transfusion dependence, EPO concentration, and RS.

Inhibitory Effect of Decitabine on Proliferation of MDS-L Cells and Its Mechanism / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of decitabine (DAC) in various dosages on the proliferention of MDS-RAEB cell line MDS-L and its mechanism.</p><p><b>METHODS</b>LC-MS/MS method was used to test the blood DAC concentration of 2 groups of MDS patients being treated with DAC 20 and 15 mg/m×5 d. In according to the various blood DAC concentration levels, the MDS-L cells were treated with different DAC dosages for 24, 48, 72 and 96 h, respectively. The CCK-8 method was applied to determine the cell proliferation, the flow cytometry was used to analyze the cell cycle and cell apoptosis changes, the P15DNA methylation status was measured by methylation specific PCR using EZ DNA Methylation-Gold Kit.</p><p><b>RESULTS</b>The blood DAC concentration of MDS patients treated with DAC 20 mg/m×5 d was 174.08±80.15(84.7-311) ng/ml, which was significantly higher than 89.87±32.94(43.2-165)ng/ml for the group treated with 15 mg/m×5 d (P=0.014). DAC could notably inhibit the proliferation of MDS-L cells, and the effect was in dose- and- time-dependent manner(r=0.786). However, when DAC concentration was ≥0.1 µg/ml, the proliferation inhibition rates were not significantly different between various dosages. After DAC treatment, MDS-L cells in Gphase increased notably, while cells in S phase decreased significantly. Also, the P15DNA methylation status of MDS-L cells decreased after being treated with DAC for 96 h, but the difference was not significant between various dosages.</p><p><b>CONCLUSION</b>DAC can significantly suppress MDS-L cell proliferation, block MDS-L cells in Gphase and induce the apoptosis at low concentration (0.1-0.2 µg/ml).</p>

Osteogenic Differentiation Potential of Bone Marrow Mesenchymal Stem Cells in Patients with Myelodysplastic Syndromes / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the osteogenic differentiation potential of bone marrow mesenchymal stem cells (BMMSC) in patients with myelodysplastic syndromes (MDS) and to explore the role of BMMSC osteogenic differentiation in the pathogenesis of MDS.</p><p><b>METHODS</b>BMMSC were isolated from bone marrow of patients with MDS and healthy donors, then expanded in vitro. The expression of transcription factor gene RUNX2, Osterix and osteogenic differentiation markers (ALP, BSP, OPN, OCN) were measured by real-time PCR, the alkaline phosphatase(ALP) activity was assessed at 3, 7, 10 days after osteogenic differentiation. Mineralization analysis was performed at day 21 of osteogenic induction.</p><p><b>RESULTS</b>The expression level of RUNX2 and Osterix were significantly decreased in BMMSC from lower-risk MDS patients compared with normal controls (P<0.05). After osteogenic induction, low-risk MDS showed lower alkaline phosphatase activity at day 3 (P<0.05), less intense alizarin red S staining at day 21 (P<0.05), and lower gene expression of osteogenic differentiation markers (P<0.05), however, these expressions in higher-risk MDS were normal.</p><p><b>CONCLUTION</b>BMMSC from low-risk MDS have abnormalities in osteogenic differentiation, it may contribute to the ineffective hamatopoiesis of MDS.</p>

mRNA expression of notch ligand-delta-like-1 and jagged-1 in mesenchymal stem cells of MDS patients / 中国实验血液学杂志

This study was aimed to investigated the mRNA expression levels of Notch ligands- Delta-like-1 and Jagged-1 in bone marrow mesenchymal stem cells of patients with myelodysplastic syndrome (MDS), and to explore their relation with onset of MDS. Bone marrow mesenchymal stem cells of 38 patients with MDS and 16 normal subjects as control were collected to detect mRNA expression of Delta-like-1 and Jagged-1 by using real-time quantitative polymerase chain reaction. The results showed that the expression levels of Delta-like-1 and Jagged-1 in mesenchymal stem cells of MDS patients were significantly higher than that in normal controls (P < 0.05). According to WHO criteria, the mRNA expression of Delta-like-1 in RA/RAS, RCMD and RAEB groups were significantly higher than that in normal controls (P < 0.05), the mRNA expression of Jagged-1 in RAEB group was also significantly higher than that in normal controls (P < 0.05). The mRNA expression of Delta-like-1 was significantly correlated with the proportion of blasts in the bone marrow of MDS patients (r = 0.502, P < 0.05). The expression levels of Delta-like-1 and Jagged-1 in MDS patients with abnormal karyotypes were significantly higher than those in MDS patients with normal karyotypes (P < 0.05). The mRNA expression of Delta-like-1 in higher risk group according to International Prognostic Scoring System was significantly higher than that in lower risk group (P < 0.05), there was no significant difference in Jagged-1 expression levels between higher risk group and lower risk group (P > 0.05). It is concluded that the changes of Delta-like-1 and Jagged-1 expression level in MSC may play a role in the pathogenesis of myelodysplastic syndrome.

Expression of p57kip2 in patients with de novo myelodysplastic syndrome and its relationship with SDF-1/CXCR4 axis / 中国实验血液学杂志

This study was purposed to explore the expression of p57kip2 in the bone marrow of patients with de novo myelodysplastic syndrome (MDS) and its role in MDS pathogenesis, as well as the relationship between the expression of p57kip2 and SDF-1/CXCR4 signal. The expression of p57kip2 and CXCR4 in 67 de novo MDS patients was measured by real-time quantitative PCR. The percentage of CD34(+) cells in the bone marrow from MDS patients was measured by flow cytometry. 18 healthy volunteers were recruited for control. The effect of SDF-1 on p57kip2 expression in bone marrow mononuclear cell (BMMNC) from MDS or normal controls was investigated in vitro, and difference between them was compared. The results showed that low-risk MDS and high-risk MDS displayed a significant reduction of p57kip2 mRNA expression in BMMNC compared with that in control group (P < 0.001) and there was a negative correlation between p57kip2 expression and percentage of CD34(+) (r = -0.458, P < 0.001); the patients with abnormal karyotype showed lower expression of p57kip2 gene, compared to patients with normal karyotype (P = 0.045). Although the expression of CXCR4 had no difference between MDS patients and normal controls, a positive correlation between p57kip2 and CXCR4 in MDS patients was still found (r = 0.609, P < 0.001). Moreover, SDF-1 increased p57kip2 expression in normal BMMNC in dose-dependent manner, but BMMNC from MDS patients showed no response to SDF-1. SDF-1-induced p57 expression was blocked by AMD3100. It is concluded that the low expression of p57 gene in MDS may play a role in the pathogenesis of MDS. Furthermore, SDF-1-induced p57kip2 expression in BMMNC, and the decreasing response of BMMNC to SDF-1 may contribute to the low expression of p57kip2 in MDS patients.

Study of aberrant p73 promoter methylation in patients with myelodysplastic syndrome / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the methylation status of p73 gene promoter in patients with myelodysplastic syndrome (MDS) and explore its significance with clinical prognosis.</p><p><b>METHODS</b>Methylation of p73 promoter was detected in bone marrow cells from 135 MDS patients and 13 healthy controls by methylation-specific PCR (MSP). The results of MSP were confirmed by bisulfite sequencing. The expression of p73 mRNA was detected by real-time quantitative PCR. Primary bone marrow cells from MDS patients were treated with decitabine, the changes of p73 methylation status and p73 mRNA expression were measured. The role of p73 methylation in the prognosis of MDS and the correlated clinical data were explored.</p><p><b>RESULTS</b>p73 hypermethylation was present in 37.04% of MDS cases and patients with high risk MDS (RAEB-1 and RAEB-2) exhibited a significantly higher frequency of p73 methylation than that of low risk MDS (58.8% vs 29.7%, P = 0.002). The expression of p73 mRNA in the methylated group was decreased compared to that of the unmethylated group (P = 0.032). Decitabine treatment decreased the level of p73 methylation and increased the level of p73 transcripts. Patients with p73 methylation progressed rapidly to AML (P < 0.001) and had shorter survival (P = 0.002) than those who did not have p73 methylation. In the multivariate Cox regression model, BM blast and p73 methylation status emerged as independent prognostic factor for overall survival and leukemia free survival.</p><p><b>CONCLUSION</b>p73 gene methylation is common in patients with MDS and may indicate poor prognosis. p73 may be a therapeutic target in MDS.</p>

Influence of bisphosphonate combined with chemotherapy on bone mineral density of patients with multiple myeloma / 中国实验血液学杂志

The purpose of this study was to investigate the effect of bisphosphonate combined with chemotherapy on bone mineral density (BMD) of patients with multiple myeloma (MM) and analyse its value of BMD detection in clinic of these patients. 53 MM cases were enrolled in this study, including 33 newly diagnosed, 10 refractory/relapsed and 10 stable cases. They were divided randomly into two groups, 33 MM cases were treated with bisphosphonates combined with chemotherapy and 20 MM cases were treated with chemotherapy alone. The chemotherapy schedules for all patients were same. BMD was tested using the dual energy X-ray absorptiometry at 2 time points, i.e. pretreatment (basal level) and 12 months after treatment with chemotherapy and bisphosphonates. Comparisons was performed with t tests using SPSS 11.0 software. The results indicated that there was minor difference between 2 groups for BMD scores of whole body and lumbar vertebra (L1-L4), but no difference for scores of the near-end of left femur. After treatment for 12 months, all BMD scores (whole body, lumbar vertebra and the near-end of left femur) increased significantly in the bisphosphonate combined with chemotherapy group (P < 0.05). In contrast, only minor changes were seen in chemotherapy alone group. It is concluded that the bisphosphonate combined with chemotherapy has displayed promotive effect on BMD of MM patients, the detection of BMD is sensitive and special method for monitoring therapeutic effect of bisphosphonate in MM patients, thus has useful value in clinic of these patients.

Effect of GDF15 on iron overloading and erythropoiesis / 中国实验血液学杂志

Ineffective erythropoiesis is recognized as the principal reason of non-transfusional iron overload. In the process of expanded erythropoiesis, the apoptosis of erythroblasts induces the up-regulation of GDF15. GDF15 suppresses hepcidin production by the hepatocytes. Subsequently, low hepcidin levels increase iron absorption from the intestine resulting in iron overload. Physiological dose of GDF15 can promote the growth and differentiation of erythroid progenitors, but the high dose of GDF15 can suppress the secretion of hepcidin. The regulation of GDF15 may also be related to iron levels, epigenetic regulation and hypoxia. In this article the GDF15 and its expression and distribution, roles of GDF15 in erythropoiesis and iron overload, as well as the regulation factors of GDF15 are reviewed.

Some research progress of CXCR4 antagonist AMD3100 / 中国实验血液学杂志

AMD3100 (Plerixafor) is an antagonist of CXCR4, receptor for stromal cell-derived factor-1 (SDF-1).It disrupts binding of SDF-1 to CXCR4 by competing binding site, thus blocking the physiological function of SDF-1/CXCR4 axis. SDF-1/CXCR4 axis has been shown to play critical roles in stem cell mobilization, migration and homing, and in immunoregulation, inflammatory disease, autoimmune disorder, embryonic development, and tumor cell proliferation, migration and location. AMD3100 has been confined effective for the mobilization of HSC and MSC, inhibition of carcinoma growth and metastasis, suppression of some inflammatory and autoimmune disorder. Therefore, further research on AMD3100 will be helpful to understand the effects of bone marrow microenvironment on the pathogenesis of neoplasm, and to restore the traumatic tissues by mobilizing HSC effectively, that might provide a new idea and measure for the treatment of certain neoplasms. Some research progress of basic research and application on AMD3100 are summarized in this review.

Biological behavior of SDF-1/CXCR4 in patients with myelodysplastic syndrome / 中国实验血液学杂志

The purpose of this study was to evaluate the biological behavior of stromal cell-derived factor-1 (SDF-1) in migration, adhesion and apoptosis as well as the related signaling transduction pathways in patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). 37 patients with MDS, 10 patients with de novo AML and 14 patients with non-clonal cytopenia diseases were chosen for this study. The expression level of CXCR4 on CD34(+) cells and apoptosis of CD34(+) cells in bone marrow were detected by flow cytometry; the chemotaxis of SDF-1 on bone marrow mononuclear cells in 4 patients with low risk MDS (IPSS score ≤ 1.0) and 5 patients with high risk MDS (IPSS score ≥ 1.5) was assayed by transwell migration test of cells. The effect of SDF-1 on cell adhesion capability was measured by using CCK-8 method. The results indicated that the apoptosis rate of CD34(+) cells was significantly higher in MDS patients with low risk (IPPS score < 1.0) than that in MDS patients with high risk (IPSS score ≥ 1.5) (21.55% vs 7.52%, p < 0.001); as well, the apoptosis rate of CD34(+) cells was significantly higher in MDS patients with low risk than that in de novo AML patients (21.55% vs 7.33%, p < 0.001), no relation of CD34(+) cell apoptosis with age and sex of patients was found. SDF-1 could promote the cells of patients with CXCR4 high expression to adhere to the stroma cells, and induce migration of these cells, as well as, SDF-1 could trigger the polarization of the cells which highly expressed CXCR4. After addition of pertussis toxin, wortmannin and AMD3100, the ability of adhersion and migration of the cells with highly expressed CXCR4 decreased, but there was no above-mentioned phenomenon in patients who lowly expressed CXCR4. It is concluded that the SDF-1/CXCR4 axis enhances the ability of cell adhesion and migration through PI3K signaling pathway, thereby plays antiapoptosis role, moreover the above-mentioned effects can be blocked by PI3K pathway inhibitor and G protein inhibitor.