Research Progress of Expression and Clinical Significant of EZH2 in Hematological Malignancies--Review / 中国实验血液学杂志

Enhancer of zeste homolog 2(EZH2) is a histone methyltransferase which regulate gene expression through epigenetic machinery. The abnormal expression of EZH2 has been described in many cancer types. With in-depth study, it was found that EZH2 is involved in the occurrence and development in many kinds of malignant hematologic disease which may play a dual role of oncogenes and tumor suppressor genes. In recent years, the emergence of EZH2 inhibitors provide a new option for the future treatment of hematological malignancies. In this review, the expression and clinical significance of EZH2 in various of hematological tumors were summarized briefly.

Clinical Efficacy of Decitabine-Based Chemotherapy Regimens in the Treatment of Newly Diagnosed Elderly Patients with Acute Myeloid Leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the safety and efficacy of decitabine combined with CAG regimen in the treat-ment of newly diagnosed elderly patients with acute myeloid leukemia(AML).</p><p><b>METHODS</b>Fourty-nine patients with newly diagnosed acute myeloid leukemia (except M3) who were admitted to our hospital were selected. All the patients were older than 50 years old, and allogeneic hematopoietic stem cell transplantation could not be performed for various reasons. Decitabine-based chemotherapy regimens were used during induction therapy including single decitabine therapy(DAC), decitabine combined with CAG regimen(DAC-CAG) and decitabine combined with HAAG regimen(DAC-HAAG). Most of patients continued to use the original treatment after complete remission, while others were given the standard "3+7" regimen chemotherapy. A total of 2-4 courses of treatment was conducted in the majority of patients.</p><p><b>RESULTS</b>All of the 49 patients completed the induction therapy, in which 26 cases achieved complete remission(CR), 7 cases achieved partial remission(PR) and no response(NR) existed in 16 cases. The complete remission and the overall response rate(ORR) were 53% and 67% respectively. The overall response rate of DAC group, DAC-CAG group and DAC-HAAG group were 17%, 77% and 63% respectively. 14 patients were infected and 1 patients died of pulmonary infection during the induction therapy. The median number of suspended red blood cells and platelet infused were 9 units and 69 units respectively. Neutrophil recovery time was 15.1 days while the platelet recovery time was 20.1 days during the induction therapy. The mean follow-up time was 21 months. Overall survival(OS) was 75% at 6 months, 30% at 1 year, and 26% at 2 year, while disease-free survival(DFS) was 83% at 3 months, 54% at 1 year, and 47% at 2 year. The induction therapy could reach CR that was an independent prognostic factor, however, the initial white blood cell count, platelet count, age, chemotherapy regimen, prognostic stratification and whether complical by pnenmonia during chemotherapy were not independent prognostic factors.</p><p><b>CONCLUSION</b>The induction efficacy of decitabine combined with chemotherapy is superior to that of decitabine alone. The outcome of induction chemotherapy is an independent prognostic factor, however, the high white blood cell count, poor karyotype, complications and AML with myelodysplasia-related changes do not affect long-term survival. DAC-CAG regimen is effective and have relatively few adverse reactions in AML. It is suitable for the patients who are ineligible for conventional chemotherapy.</p>

Long term in-vitro expansion reduces immune modulation function of placental chorionic villi mesenchymal stem cells / 中国实验血液学杂志

The main aim of this study was to investigate the biological activities and immune modulation changes of chorionic villi mesenchymal stem cells (CV-MSC) after long term culture. The morphology of the CV-MSC of passage 3 and passage 9 were observed by microscopy, and their phenotypes were detected by flow cytometry. CV-MSC of passage 3 and 9 were co-cultured with PHA-stimulated PBMNC, and IFN-γ concentration in culture medium was detected by ELISA. The mRNA expression of COX-2, HGF and HLA-G in CV-MSC were detected by real-time PCR. The results showed that after long term culture, the CV-MSC kept the MSC morphology and most of the phenotypes including CD31, CD34, CD44, CD45, CD62L, CD73, CD90, CD105, CD117, CD151, CD235a, CD271 and HLA-DR, while the CD49d was significantly up-regulated. Immune modulation ability of CV-MSC was reduced and the mRNA expression of COX-2 and HGF was down regulated after long term culture, but the expression of HLA-G did not found to be obvious change. It is concluded that the long term in vitro expansion changes the expression of CD49d and reduces immune modulation of CV-MSC.

IL-1β promotes the hematopoietic support of human umbilical cord mesenchymal stem cells / 中国实验血液学杂志

This study was aimed to investigate the effect of IL-1β on hematopoietic support of human umbilical cord mesenchymal stem cells (hUC-MSC). 2×10(6) hUC-MSC were seeded in 75 cm(2) flasks, after adherence to wall for 2 h, 10 ng/ml IL-1β was added in hUC-MSC supernatant and cultured for 36 h, then the culture supernatants and cells were harvested. The effect of conditioned medium with/without IL-1β on CD34(+) cell hematopoietic support was observed, mRNA expression changes of hUC-MSC cultured in medium with/without IL-1β were monitored by real time PCR, the differences in hematopoiesis-related factors were detected by ELISA. The results showed that the conditioned culture medium of hUC-MSC with IL-1β enhanced the ability to form colony of CD34(+) cells, especially CFU-G and CFU-GM in vitro; IL-1β promoted the mRNA expression of GM-CSF, G-CSF, IL-6 on MSC; IL-1β also promoted the secretion of GM-CSF, G-CSF, and IL-6 protein from hUC-MSC. It is concluded that IL-1β enhances hematopoietic support capacity especially, capability of MSC to myeloid differentiation.

Isolation and biological characteristics of mesenchymal stem cells derived from human placenta decidua basalis / 中国实验血液学杂志

Comparing to bone marrow mesenchymal stem cells (MSCs), placenta-derived MSCs have the advantages of adequate sources, low immunogenicity, little risk of viral contamination, and no ethical controversy, and thus possess a better prospect for clinical application. Placental tissue not only includes chorionic and amniotic, but also contains decidua basalis which locate in the maternal placenta surface. The biological characteristics of MSCs isolated from decidua basalis have not been well studied. This study was aimed to investigate the biologic characteristics of placenta decidua basalis-derived MSC from placenta decidua basalis (DB) by enzymatic digestion. Short tandem repeats (STR) test was used to identify the cells derived from the maternal placenta surface. Growth rate of decidua basalis mesenchymal stem cells (DB-MSC) was measured by MTT. Cell cycle and cell phenotype were detected by flow cytometry. Inducing differentiation was used to evaluate multipotency of DB-MSC. For testing the immunosuppression of DB-MSC, they were co-cultured with peripheral blood mononuclear cells (PBMNC) stimulated by phytohemagglutinin (PHA) and then IFN-γ in the co-cultured media was quantified by ELISA. The results showed that the cells were derived from the maternal placenta by STR analysis. DB-MSC showed typical fibroblast morphology in the culture and were positive for the MSC surface markers: CD90, CD73, CD105, CD44 and negative for CD45, CD11b, and CD34. DB-MSC underwent osteogenic, adipogenic and chondrogenic differentiation in inducing medium. DB-MSC could inhibit the secretion of IFN-γ by PBMNC. It is concluded that the cells are isolated from placenta decidua basalis and possess the basic characteristics of MSC. DB-MSC can be an important maternal autologous MSC and may be a safe and effective treatment for immune system diseases, which makes the DB-MSC as an important source of autologous MSC from mother. DB-MSC can be safely for the treatment of the mother's immune system diseases.

Comparative study of biological characteristics of human umbilical cord and placental chorionic villous mesenchymal stem cells / 中国实验血液学杂志

Because advantage of tissue origin and proliferation potential, the umbilical cord-derived mesenchymal stem cells (UC-MSC) and placental chorionic villous-derived mesenchymal stem cells (CV-MSC) have clinical application potential, as compared with bone marrow MSC. But whether the differences of biological characteristics exist between UC-MSC and CV-MSC, which deserve to be further explored. This study was purposed to compare the biological characteristics of UC-MSC and CV-MSC. The placental and umbilical cord were cleaned by using the sterile physiological salt, the UC-MSC and CV-MSC were separated by enzyme digestion. Short tandem repeat (STR) analysis was used to detect whether the MSC obtained from fetal tissue. MTT method was used to detect proliferation of MSC. Flow cytometry was applied to analyze cell phenotype. The different differential medium was used to detect their multi-directional differentiation capacity. After the MSC and PHA-stimulated peripheral blood mononuclear cells were co-cultured, the γ-interferon (IFN-γ) levels of the co-culture supernatant were detected using the ELISA. The results showed that these MSC were derived from fetal tissue by STR analysis. They were adherent cells with typical fibroblast morphology. Cells expressed the MSC surface markers CD90, CD73 and CD105 and CD44, not expressed CD45 and of CD11b and CD34.These cells could differentiate into osteoblasts and adipoblasts under culture with different conditioned medium, but in the adipogenic differentiation of CV-MSC, the larger lipid droplets appeared. It is concluded that these cells are obtained MSC. These MSC can inhibit peripheral blood mononuclear cells stimulated by PHA to secrete IFN-γ, and the the CV-MSC have a stronger suppression capacity, which makes the CV-MSC to have a greater advantage in the treatment of autoimmune diseases.

Supportive effects of conditioned culture media of human umbilical cord mesenchymal stem cells on hematopoiesis in vitro / 中国实验血液学杂志

This study was aimed to explore whether the conditioned culture medium of human umbilical cord-derived mesenchymal stem cells (hUC-MSC) has supportive effects on hematopoiesis in vitro. hUC-MSC were cultured in 75 cm(2) culture flasks at a concentration of 2×10(6) cells per flask. After 48 h, the conditioned culture medium was harvested. CD34(+) cells were isolated with the human cord blood CD34 positive selection kit. The CD34(+) cells were plated in three different culture systems: the culture supernatant from hUC-MSC added into incomplete methylcellulose without recombinant human cytokines as conditioned culture medium; the complete methylcellulose medium with recombinant human cytokines as positive control medium; incomplete methylcellulose adding DMEM/F12 with 10% FBS instead of conditioned culture medium as the negative control medium. After 14 days of culture, colonies containing ≥ 50 cells were scored and types of colonies were classified under inverted microscope. The immunophenotypes of cells which were collected from the colonies were detected by flow cytometry. The results showed that conditioned culture medium of hUC-MSC supported the differentiation of CD34(+) cells into CFU-G (47.67 ± 0.58), CFU-GM (48.67 ± 4.73) and CFU-M (3.00 ± 2.00) in vitro, while the CFU-E, BFU-E or CFU-GEMM were absent. Comparatively, in the positive control medium all kinds of CFU were observed. Interestingly, the percentage of CD45(+)cells of CFU in conditioned culture medium (97.43 ± 2.15)% was more than CD45(+)cells in positive control medium (39.69 ± 0.96)% (P < 0.05). It is concluded that the conditioned culture medium of hUC-MSC has been confirmed to have ability to support hematopoiesis separately in vitro. Besides, it enhances the differentiation of CD34(+) cells into myeloid cells except cells of erythroid lineage.