Cytokine release syndrome and relevant factors of CD19 targeted chimeric antigen receptor T cell therapy in relapsed/refractory B cell hematological malignancies.

OBJECTIVES AND METHODS: We reviewed the outcomes of 77 episodes of CD19 CAR-T therapy in 67 patients with B cell hematological malignancies from October 2016 to January 2020. Factors related to the grade of cytokine release syndrome (CRS) were explored by multivariate analysis, nonparametric test was conducted to explore the correlation between CRS and response. Kaplan-Meier curves were used to indicate survival profiles, and the correlation between CRS and survival was determined by the log-rank test. RESULTS: The rate of complete remission (CR) was 74.0% (57/77). CRS of any grade occurred in 68 of 77 episodes (grade 1: 32.5%, grade 2: 24.7%, grade 3: 22.1%, grade 4: 6.5%, grade 5: 2.6%). Patients with a history of transplantation had less severe CRS, and dose escalation-based infusion reduced the severity of CRS. Severe CRS was related to a higher CR rate but had no significant impact on event-free survival (EFS), relapse-free survival (RFS), or overall survival (OS). CONCLUSION: As a common adverse reaction of CAR-T therapy, the severity of CRS can be alleviated by dose escalation infusion, a history of transplantation was correlated with less severe CRS. Severe CRS was related to better response but was unrelated to long-term survival.

LukS-PV Induces Apoptosis via the SET8-H4K20me1-PIK3CB Axis in Human Acute Myeloid Leukemia Cells.

Evidence suggests that histone modification disorders are involved in leukemia pathogenesis. We previously reported that LukS-PV, a component of Panton-Valentine leukocidin (PVL), has antileukemia activities that can induce differentiation, increase apoptosis, and inhibit proliferation of acute myeloid leukemia (AML) cells. Furthermore, LukS-PV inhibited hepatoma progression by regulating histone deacetylation, speculating that LukS-PV may exert antileukemia activity by targeting histone modification regulators. In this study, the results showed that LukS-PV induced apoptosis by downregulating the methyltransferase SET8 and its target histone H4 monomethylated at Lys 20 (H4K20me1). Furthermore, chromatin immunoprecipitation sequencing and polymerase chain reaction identified the kinase PIK3CB as a downstream target gene for apoptosis mediated by SET8/H4K20me1. Finally, our results indicated that LukS-PV induced apoptosis via the PIK3CB-AKT-FOXO1 signaling pathway by targeting SET8. This study indicates that SET8 downregulation is one of the mechanisms by which LukS-PV induces apoptosis in AML cells, suggesting that SET8 may be a potential therapeutic target for AML. Furthermore, LukS-PV may be a drug candidate for the treatment of AML that targets epigenetic modifications.

CaMKIIγ regulates the viability and self-renewal of acute myeloid leukaemia stem-like cells by the Alox5/NF-κB pathway.

Acute myeloid leukaemia (AML) is a frequently fatal malignant disease of haematopoietic stem and progenitor cells. The molecular and phenotypic characteristics of AML are highly heterogeneous. Our previous study concluded that CaMKIIγ was the trigger of chronic myeloid leukaemia progression from the chronic phase to blast crisis, but how CaMKIIγ influences AML stem-like cells remains elusive. In this study, we found that CaMKIIγ was overexpressed in AML patients and AML cell lines, as measured by qRT-PCR and Western blot assays. Moreover, CaMKIIγ decreased when the disease was in remission. Using an shRNA lentivirus expression system, we established CaMKIIγ stable-knockdown AML cell lines and found that knockdown of CaMKIIγ inhibited the viability and self-renewal of AML stem-like cell lines. Additionally, the ratio of CD34 + AML cell lines decreased, and CaMKIIγ knockdown induced the downregulation of Alox5 levels. We further detected downstream molecules of the Alox5/NF-κB pathway and found that c-myc and p-IκBα decreased while total IκBα remained normal. In conclusion, our study describes a new role for CaMKIIγ as a stem-like cell marker that is highly regulated by the Alox5/NF-κB pathway in AML stem-like cells. CaMKIIγ can participate in the viability and self-renewal of AML stem-like cells by regulating the Alox5/NF-κB pathway.

[Efficacy Analysis of Unrelated Cord Blood Transplantation for High-Risk Refractory AML1-ETO Positive Myeloid Leukemia].

OBJECTIVE: To analyze the clinical outcomes of engraftment, graft-versus-host disease (GVHD) and survival in the patients with AML1-ETO positive acute myeloid leukemia (AML) treated with unrelated umbilical cord blood transplantation (UCBT). METHODS: Forty-Five patients with high-risk refractory AML1-ETO positive AML were treated with a single UCBT in a single center from July 2010 to April 2018. All the patients underwent a myeloablative preconditioning regimen，and cyclosporine A (CSA) combined with mycophenolate mofetil (MMF) was used to prevent GVHD. RESULTS: The median value of total nucleated cells (TNC) in cord blood was 5.21 (1.96-12.68)×107/kg recipient body weight, and that of CD34+ cells was 5.61 (0.56-15.4)×105/kg recipient weight. The implantation rate of neutrophil at 42 d and that of platelet at 120 d were 95.6% and 86.7%, respectively. The median time of absolute neutrophil count (ANC)＞0.5×109/L and platelet 20×109/L were 16 (12-18) d and 37 (17-140) d after transplantation, respectively. The cumulative incidence of Ⅰ -Ⅳ grade acute GVHD (aGVHD) at 100 d after transplantation was 48.9% (95% CI 33.5%-62.6%), Ⅱ-Ⅳ grade aGVHD occurred in 12 cases (33.3%) (95% CI 20%-47.2%) , and Ⅲ-Ⅳ grade a GVHD in 8 cases (20%) (95% CI 9.8% -32.8%). In 5 cases of 40 patients survived over 100 days, the chronic GVHD (cGVHD) occurred after transplantation, among which 4 were localized, and 1 was extensive. 3 patients relapsed, and the 2-year cumulative relapse rate was 9.5% (95% CI 2.4%-22.8%). The median follow-up time was 23.5 (0.9-89.67) months, 10 patients died, 2-year disease-free survival rate (DFS) was 72.7%, and overall survival rate (OS) was 75.5%. Multivariate analysis showed that Ⅲ-Ⅳ. acute GVHD (aGVHD) affected overall survival. CONCLUSION: UCBT is an effective rescue treatment for patients with high-risk refractory AML1-ETO positive AML.

[Effects of HMGB1 on human cord blood CD34(+) hematopoietic stem cells proliferation and differentiation in vitro.].

OBJECTIVE: To study both the release of HMGB1 from irradiation-treated mesenchymal stem cells (MSCs) and the effects of HMGB1 on human cord blood CD34(+) hematopoietic progenitor cell proliferation and differentiation. METHODS: MSCs were obtained from human bone marrow. HMGB1 released by the MSCs after treatment with 12 Gy gamma-ray irradiation was determined by enzyme linked immunosorbent assay (ELISA). CD34(+) cells were positively selected with a MACS CD34 isolation kit. The freshly isolated CD34(+) cells were cultured in the presence of HMGB1 for 6 days. Phenotype of cultured cells surface molecules (CD13, CD14, CD11c, CD41 and CD71) were analyzed by flow cytometry. The proliferation and differentiation capacities of cord blood HSCs were assayed by colony forming cell assay. The receptors of HMGB1 (RAGE, TLR2 and TLR4) on cord blood CD34(+) cells were detected by flow cytometry. RESULTS: HMGB1 level in the supernatant \[(4.3 +/- 0.9) ng/ml\] of the irradiated MSC was significantly higher than that in control \[(0.4 +/- 0.2) ng/ml\] (P < 0.01). Human cord blood CD34(+) cells expressed the HMGB1 receptors RAGE, TLR2 and TLR4. The HMGB1-treated CD34(+) cells contained higher proportions of CD13(+) \[(32.6 +/- 5.9)% vs (18.4 +/- 3.8)%\], CD14(+)\[(25.4 +/- 4.4)% vs (12.6 +/- 2.7)%\], CD11c(+) \[(20.3 +/- 3.9)% vs (9.8 +/- 2.1)%\], CD71(+) \[(47.1 +/- 7.4)% vs (26.6 +/- 4.6)%\] cells compared with control group did. But HMGB1 did not induce the generation of CD41(+) cells \[(1.3 +/- 0.5)% vs (1.1 +/- 0.4)%\]. Furthermore, HMGB1 profoundly induced the growth of BFU-E, CFU-GM and total CFU in a dose-dependent manner, and this effect was partially inhibited by TLR2 and TLR4 antibodies. CONCLUSION: Human MSC treated with gamma-ray irradiation can release HMGB1, which can induce the proliferation and differentiation of human cord CD34(+) cells.

[Influence of high mobility group box 1 on migration of human cord blood CD34(+) cells].

The objective of study was to explore the influence of high mobility group box 1 (HMGB1) on migration of cord blood CD34(+) cells and their mechanism of migration. The expressions of receptor for advanced glycation end products (RAGE), toll-like receptor-2 (TLR2) and TLR4 were detected by flow cytometry. The CD34(+) cells in umbilical cord blood (CB) were enriched by MiniMACS and were exposed to various concentration of HMGB1 (10, 50, 100, 1, 000 ng/ml), then the migration effect of HMGB1 on umbilical cord blood (UCB) CD34(+) cell count was determined by microscopy, the chemotactic index was calculated. The CD34(+) cells untreated with HMGB1 were used as control. The results indicated that the purity of the isolated CD34(+) cells was more than 98%. The HMGB1 could promote the migration of CD34(+) cells, and the migration effect of HMGB1 on CD34(+) cells in certain concentrations gradually increased along with raise of concentration, the strongest effect was observed in concentration of 100 ng/ml, there was significant difference as compared with control (p < 0.01). Anti-RAGE antibody partially inhibited the migration effect of HMGB1 on CD34(+) cells. It is concluded that the HMGB1 in certain concentration can enhance migration of CD34(+) cells, which may be mediated through RAGE.