[Efficacy and Safety of Cladribine-based Intensified Conditioning Regimen in Hematopoietic Stem Cell Transplantation in Patients with High-Risk Acute Myeloid Leukemia].

OBJECTIVE: To investigate the efficacy, safety and the risk factors affecting prognosis of high-risk acute myeloid leukemia (AML) patients treated by cladribine-based intensified conditioning regimen. METHODS: The clinical data of 28 patients with high-risk AML treated by cladribine in combination with busulfan plus cyclophosphamide (BuCy) intensified conditioning regimen before allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Zhujiang Hospital, Southern Medical University from October 2016 to June 2020 were analyzed retrospectively. The overall survival (OS) rate, cumulative progression-free survival (PFS) rate, relapse rate, non-relapse mortality (NRM), regimen related toxicity (RRT) and risk factors affecting prognosis of the patients were analyzed. RESULTS: The 1-year OS and PFS of the patients after implantation was (78.8±8.6)% and (79.8±8.1)%, while the 1-year cumulative relapse rate and NRM of the patients was 9.3% and 22.0%, respectively. The 1-year expected OS of MRD- high-risk patients before HSCT was 100%. The 1-year expected OS and PFS of the patients in pre-transplant relapse group was (46.9±18.7)% and (50.0±17.7)%, respectively. The incidence of I/II grade RRT was 39.3%. NO III/IV grade RRT were found in 28 patients. Multivariate analysis showed that pre-transplant relapse was the independent risk factor affecting OS and PFS of the patients. CONCLUSION: The intensified conditioning regimen of cladribine in combination with BuCy can reduce the relapse rate of high-risk AML transplantation, and its RRT is mild, exhibiting good safety. MRD- high-risk patients before HSCT can achieve better transplant benefits, but the prognosis of patients with relapse before transplantation is not significantly improved. Therefore, for non-relapsed high-risk AML patients, this intensified conditioning regimen deserves to be considered.

[Efficacy and Prognosis of Allogeneic Hematopoietic Stem Cell Transplantation for Acute Monocytic Leukemia Patients].

OBJECTIVE: To investigate the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of acute monocytic leukemia (AML-M5) and the related factors that affecting the prognosis of the patients. METHODS: The clinical data of 71 patients with AML-M5 treated with allo-HSCT in Zhujiang Hospital Affiliated to Southern Medical University from April 2009 to October 2019 were collected and retrospectively analyzed. The incidence of graft-versus-host disease (GVHD), cumulative overall survival (OS) rate, cumulative progression-free survival (PFS) rate, transplantation-related mortality (TRM), relapse rate and the risk factors affecting prognosis in the patients were analyzed. RESULTS: 66 patients obtained hematopoietic reconstruction after transplantation, the median time of granulocyte implantation was 12 (9-26) d, and the median time of megakaryocytic implantation was 13 (8-72) d. The incidence of acute GVHD and chronic GVHD was 33.8% (24/71) and 36.6% (26/71), respectively. The median follow-up time was 13.81 (0.16 to 112.54) months; the median OS and PFS was 31.27 and 26.07 months, respectively. The cumulative OS of the patients in 1 and 3 years after transplantation was 64.9% and 48.6%, respectively, and the cumulative PFS of the patients in 1 and 3 years was 55.0% and 39.5%, respectively. The cumulative relapse rate of the patients in 1 and 3 years was 24% and 40%, respectively. Multivariate analysis showed that pre-transplantation relapse was the independent risk factor affecting OS (HR=2.32, 95%CI:1.17-4.62, P=0.02) and PFS (HR=3.08, 95%CI:1.61-5.90, P=0.001) of the patients; invasive fungal disease after transplantation was the independent risk factor affecting OS (HR=2.71, 95% CI:1.32-5.56, P=0.007) and PFS (HR=2.87, 95%CI=1.40-5.86, P=0.004) of the patients; FLT3 mutation was the independent risk factor affecting PFS (HR=2.13, 95%CI=1.07-4.24, P=0.03) of the patients. CONCLUSION: AML-M5 is the intermediate or high-risk leukemia, and allo-HSCT can improve the survival prognosis of the patients. Pre-transplantation relapse and invasive fungal disease after transplantation are the important factors affecting the efficacy of allo-HSCT in patients with AML-M5.

[Clinical Summarization of Allogeneic Hematopoietic Stem Cell Transplantation for Leukemia: A Report of 100 Cases].

OBJECTIVE: To analyze the treatment outcome of a consecutive series of 100 leukemia patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The clinical data of leukemia patients received allo-HSCT were analyzed retrospectively, the therapeutic efficacy was summarized. 100 evaluable cases of leukemia included 47 cases of AML, 33 cases of ALL, 2 cases of AL (biphenotypic), 16 CML and 2 CMML. Before transplantation, 76 cases were in first complete remission, 9 cases in second or greater complete remission and 15 cases in non-remission or relapse. All the patients received peripheral blood hematopoietic stem cell transplantation (PBHSCT). The conditioning regimen of human leukocyte antigen (HLA)-matched allo-HSCT group was modified BuCy, but in HLA-mismatched group Fludarabine and anti-human thymocyte globulin (ATG) was added. CsA+MTX regimen was used for prophylaxis of graft-versus-host disease (GVHD) in HLA-identical allo-HSCT, while additional MMF was added in HLA-mismatched group. The average time of follow-up was 13 months. RESULTS: At the last follow-up, 66.0% (66/100) patients survived, 53.0% (53/100) patients survived without leukemia, 28.0% (28/100) patients relapsed and 34.0% (34/100) patients died, 44.1% patients of them died from infectious pulmonary complications. During transplantation, 65.0% of the patients were suffered from lung infection. The overall survival (OS) and disease-free survival (DFS) of all cases was 60.9% and 48.8%, respectively. The recurrence rate was significantly higher in non-remission (66.7%) than in CR (21.2%) patients (P < 0.05). The cumulative incidence of GVHD in HLA-mismatched transplantation was 60.8%, which was significantly higher than that of HLA-matched transplantation (38.8%) (P < 0.05). CONCLUSION: Allo-HSCT can cure a significant proportion of leukemia patients, especially for those in CR status. Since the incidence of infectious pulmonary complications after allo-HSCT is still high, much more attention should be paid to it. The comprehensive prognosis of HLA-matched transplantation is better than the HLA-mis-matched transplantation.

[Research Progres on Relationship between the Graft-Versus-Host Disease and Cytomegalovirus Infection--Review].

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of leukemia patients can improve overall survival and disease-free survival, and reduce relapse. Although the allo-HSCT is more widely used in the treatment of leukemia, but the graft-versus-host disease (GVHD) and cytomegalovirus (CMV) infections are the common complications, and are the major cause of mortality for patients following allo-HSCT. Previous studies showed that there might be a mutual promotive relationship between GVHD and CMV infection, but the clear relationship remained to be elucidated. The relationship of GVHD and CMV has been the focus of clinical research. Recently, a great progress has been made on researches of the relationship and its mechanism between GVHD and CMV infection. In this article, the relationship and its mechanism between GVHD and CMV infection after allo-HSCT are reviewed.

[Progress of Clinical Trials on Bone Marrow Mesenchymal Stem Cells for Prevention and Therapy of Graft-Versus-Host Disease].

Graft-versus-host disease (GVHD) is a major complication following allogenetic hematopoietic stem cell transplantation, which shows a great threat to patients' survival and life quality. Along with multiple differentiation potential to various types of progenitor cells, bone marrow mesenchymal stem cells (BMMSC) have been confirmed to possess low immunogenicity and exert favorable immunomodulation. The recent studies show that the safety and high efficiency of BMMSC to prevent and cure GVHD greatly improved survival rate of the hosts. The most recent progress on prevention and therapy of GVHD is summarized in this review based on biology of BMMSC and pathogenesis of GVHD, so as to provide the effective evidence for further research.

Overexpression of EPS8 is associated with poor prognosis in patients with acute lymphoblastic leukemia.

Molecular markers have become an invaluable tool in monitoring disease status particularly of leukemias, as bone marrow samples can be easily collected for analysis during all stages of disease development including diagnosis, treatment, and follow-up. Two genes that have been used as prognostic markers in acute leukemia are Wilms' tumor (WT1) and multidrug resistance-1 (MDR1). A novel gene, epidermal growth factor receptor pathway substrate 8 (EPS8), is often over-expressed and associated with poor outcome in some solid tumor types. However, whether EPS8 is also associated with the development of acute lymphoblastic leukemia (ALL) is unclear. Here, quantitative real-time PCR was used to evaluate the expression of EPS8, MDR1, and WT1 in bone marrow samples of adult ALL patients (n=107) and non-leukemia controls (n=22). EPS8, MDR1, and WT1 were detected in ALL patients, and significant correlations were found between expression profiles for EPS8 and MDR1, EPS8 and WT1, and MDR1 and WT1. In general, high expression of EPS8, MDR1, or WT1 in patients was associated with a higher risk of relapse. Furthermore, when patients were stratified based on high or low expression of the genes, Kaplan-Meier survival analysis indicated that disease-free survival of patients with the high-EPS8/high-WT1/high-MDR1 profile was significantly shorter than in patients with the low-EPS8/low-WT1/low-MDR1 profile or those excluded from either of these groups (P<0.0001). Thus, EPS8, as MDR1 and WT1, may be a clinically valuable biomarker for assessing the outcome of ALL patients.

[Cytotoxicity of Naja Naja Actra Venom Component combined with activated immune cells on leukemia cell line KG1a].

This study was aimed to investigate the cytotoxic effect of the Naja Naja Actra Venom Component (NNAVC) combined with activated immune cells on human acute myeloblastic leukemia line KG1a cells. The cytotoxic effects of NNAVC at different concentrations on KG1a cells were measured by CCK-8 method. LDH releasing assay was used to detect the cytotoxic effects of activated immune cells, NNAVC combined with activated immune cells on KG1a cells and the sensitivity of KG1a treated with NNAVC to activated immune cells. The results showed that the inhibitory rate of NNAVC on KG1a cells increased with the concentration enhancement, the cytotoxicity of activated immune cells at the different effector to target (E:T) ratios(6.25:1, 12.5:1, 25:1) on KG1a cells were 12.30%, 24.85% and 52.26%. The cytotoxicity of NNAVC combined with activated immune cells at the different E:T cell ratios (10:1, 20: 1) on KG1a cells were 56.21% and 85.59%, which were higher than that of NNAVC or activated immune cells alone. The cytotoxicity of activated immune cells at the E: T cell ratio of 10:1 on KG1a cells treated with NNAVC at different concentrations were 25.65%, 31.33%, 28.63% and 16.78%, respectively, and that at the E:T cell ratio of 20: 1 were 40.62%, 44.70%, 44.62% and 40.72%. It is concluded that:both of NNAVC and activated immune cells have lethal effect on KG1a cells, and the combination of NNAVC and activated immune cells can strengthen their effect on KG1a.

Cultivation and identification of colon cancer stem cell-derived spheres from the Colo205 cell line

Our group established a method to culture spheres under serum-free culture condition. However, the biological characteristics and the tumorigenicity of spheres are unknown. Here, we demonstrate that sphere cells expressed high levels of the putative colorectal cancer stem cell markers CD133 and CD44. The CD133-positive rates were 13.27 ± 5.62, 52.71 ± 16.97 and 16.47 ± 2.45 percent in sphere cells, regular Colo205 cells and differentiated sphere cells, respectively, while the CD44-positive rates were 62.92 ± 8.38, 79.06 ± 12.10 and 47.80 ± 2.5 percent, respectively, and the CD133/CD44-double-positive rates were 10.77 ± 4.96, 46.89 ± 19.17 and 12.41 ± 2.27 percent, respectively (P < 0.05). Cancer sphere cells formed crypt-like structures in 3-D culture. Moreover, cells from cancer spheres exhibited more tumorigenicity than regular Colo205 cells in a xenograft assay. The cancer sphere cells displayed much higher oncogenicity than regular Colo205 cells to initiate neoplasms, as assayed by H&E staining, Musashi-1 staining and electron microscopy. Our findings indicated that the sphere cells were enriched with cancer stem cells (CSCs), and exhibited more proliferation capacity, more differentiation potential and especially more tumorigenicity than regular Colo205 cells in vitro and in vivo. Further isolation and characterization of these CSCs may provide new insights for novel therapeutic targets and prognostic markers.

Cultivation and identification of colon cancer stem cell-derived spheres from the Colo205 cell line.

Our group established a method to culture spheres under serum-free culture condition. However, the biological characteristics and the tumorigenicity of spheres are unknown. Here, we demonstrate that sphere cells expressed high levels of the putative colorectal cancer stem cell markers CD133 and CD44. The CD133-positive rates were 13.27 ± 5.62, 52.71 ± 16.97 and 16.47 ± 2.45% in sphere cells, regular Colo205 cells and differentiated sphere cells, respectively, while the CD44-positive rates were 62.92 ± 8.38, 79.06 ± 12.10 and 47.80 ± 2.5%, respectively, and the CD133/CD44-double-positive rates were 10.77 ± 4.96, 46.89 ± 19.17 and 12.41 ± 2.27%, respectively (P < 0.05). Cancer sphere cells formed crypt-like structures in 3-D culture. Moreover, cells from cancer spheres exhibited more tumorigenicity than regular Colo205 cells in a xenograft assay. The cancer sphere cells displayed much higher oncogenicity than regular Colo205 cells to initiate neoplasms, as assayed by H&E staining, Musashi-1 staining and electron microscopy. Our findings indicated that the sphere cells were enriched with cancer stem cells (CSCs), and exhibited more proliferation capacity, more differentiation potential and especially more tumorigenicity than regular Colo205 cells in vitro and in vivo. Further isolation and characterization of these CSCs may provide new insights for novel therapeutic targets and prognostic markers.

[Research progress on cellular and molecular genetics of acute non-lymphocytic leukemia].

With the extensive application of cellular and molecular genetic techniques in the research of acute leukemia (AL), the diagnosis of AL type has been developed from FAB typing which was based on morphological classification in 1976 to MICM typing in 2001. This progress highlights the importance of cellular and molecular genetic changes in the diagnosis of leukemia. The cellular and molecular genetic abnormalities in acute leukemia can make the stratification of risk and give the guidance for prognosis and treatment, which is also critical for the development of new drugs. This article has focused on chromosomal abnormalities, fusion gene expression and their relationship with the leukemia diagnosis, prognosis and treatment. This article is also a concise review on several common gene mutations in cytogenetics of ANLL for the assessment of disease prognosis. In recent years, further exploration of molecular cytogenetic mechanisms of various types of leukemia in ANLL contributed to the development of new therapeutic strategy for leukemia.

[Expression of NKG2D ligands on dendritic cells at different development stages and its effect on cytotoxicity of NK cells].

AIM: To investigate the expression of NKG2D ligands on dendritic cells(DC) at different development stages and its effect on cytotoxicity of natural killer(NK) cells. METHODS: The monocytes were cultured into immature dendritic cells(iDC) and mature dendritic cells(mDC) with cytokines. NK cells were obtained from normal peripheral blood by CD56 antibody magnetic isolation.The expression of NKG2D ligands (MICA/B, ULBP1-3) was detected by flow cytometry. Cytotoxicity of NK cells and the NK cells blocked with anti-NKG2D mAbs against iDC and mDC was tested using LDH-releasing method. RESULTS: IDC and mDC were of typical morphology and phenotypes. MICA, MICB, ULBP1, and ULBP3 were expressed on iDC and their expression rate was (32.39+/-8.30)%, (17.75+/-3.40)%, (26.71+/-6.48)%, (38.37+/-6.89)%, respectively. MICA and ULBP3 were expressed on mDC and their expression rate was (7.81+/-3.33)% and (8.36+/-2.42)%, respectively, which was lower than that on mDC (P<0.01). At the each E:T ratio cytotoxicity of NK cells against iDC was stronger than that against mDC (P<0.01). cytotoxicity of NK cells blocked with anti-NKG2D mAb against iDC was decreased compared with that of NK cells unblocked (P<0.05) while cytotoxicity of NK cells blocked with anti-NKG2D mAb against mDC showed no decrease compared with that of NK cells unblocked (P>0.05). CONCLUSION: The expression of NKG2D ligands on iDC is higher than that on mDC, which plays an important role in the cytotoxic effect of NK cells against iDC, but has no effect on that against mDC. NKG2D-NKG2D ligands shows one of the molecular mechanisms that NK cells kill iDC selectively.

[Cytotoxicity of allogenetic natural killer cells against CD34+ acute myelogenous leukemia cells].

OBJECTIVE: To study the cytotoxic effect of allogenetic natural killer (NK) cells in vitro on human CD34+ acute myelogenous leukemia cells. METHODS: CD34 expression on acute myelogenous leukemia KG1a cells was detected by flow cytometry. KG1a cells were co-cultured at different effector-to-target (E:T) ratios with NK cells isolated from 5 healthy individuals using magnetic cell sorting. Lactate dehydrogenase (LDH) release assay was employed to examine the cytolysis of KG1a cells in the co-culture, and the inhibition rate of the KG1a cell colony formation in methylcellulose was determined with K562 cells sensitive to NK cells as the control. RESULTS: A expression rate as much as (98.0-/+1.1)% was detected for CD34 antigen on KG1a cells, and the isolated NK cells (CD3(-)CD16+CD56+ cells) had a purity of (93.2-/+3.7)% after magnetic cell sorting. Allogenetic NK cells exhibited obvious cytotoxicity and colony inhibition in vitro against KG1a cells at different E:T ratios, and the effects were significantly enhanced as the E:T ratios increased (P<0.05). At the same E:T ratio, the cytotoxicity and colony inhibition rate of allogenetic NK cells against KG1a cells was lower than those against K562 cells (P<0.05). CONCLUSION: Allogenetic NK cells exhibit obvious cytotoxicity and colony formation against CD34+ acute myelogenous leukemia cells.

[Spheres isolated from Colo205 cell line possess cancer stem-like cells under serum-free culture condition].

OBJECTIVE: Isolation and expansion tumor spheres from colorectal cancer cell line Colo205 cultured in serum-free medium(SFM) supplemented with human recombinant EGF and bFGF. METHODS: Colo205 cells were cultivated in SFM,while cells cultivated in serum-supplemented medium(SSM) served as the control. Cells morphology were observed by optical microscope, and expression of intestinal stem cells marker Musashi-1 was detected by immunocytochemical. To induce cell differentiation, tumour spheres were cultivated without EGF and bFGF in the presence of 10% serum. Then we analysed expressions of stem cell surface markers CD133 and CD44 among undifferentiated cell, post-differentiated cells and routine Colo205 cells under serum-supplemented culture condition by flow cytometry. At last we compared cell cycle and spectral karyotype between two groups. RESULTS: In SFM consisting of EGF and bFGF, a minority of Colo205 cells could survive, proliferate and form the suspended tumor spheres. We detected high Musashi-1 expression in these cells. Compared with the SSM group and the post-differentiation SFM group, the expressions of CD133 and CD44 were significantly increased in the undifferentiated SFM group (P<0.05). There was no statistical difference in the expression of CD133 and CD44 between the post-differentiation SFM group and the SSM group (P>0.05). Cell cycle analysis indicated that tumor spheres were of a high proliferation state.We could not find any noticeable difference in the number of chromatosomes between the SFM group and the SSM group. CONCLUSION: Tumor spheres in which enriched cancer stem cells can be generated under serum-free culture condition with EGF and bFGF.