The CSN5/HSF/SPI1/PU.1 Axis Regulates Cell Proliferation in Hypocellular Myelodysplastic Syndrome Patients.

OBJECTIVE: This study explored the relationship between the activation of the jak/stat3 signaling pathway and the CSN5 gene transcript and protein expression levels in the hematopoietic stem cells of patients with myelodysplastic syndromes (MDSs). This study also aimed to investigate the correlation between the expression level of CSN5 and the deubiquitination of HSF1, as well as the transcript level of the spi1/pu.1 genes to explore the pathogenesis of MDS. MATERIALS AND METHODS: We isolated cells from normal individuals and MDS patients, and the mRNA and protein expression levels of spi1/pu.1 in cd34+ cells (hematopoietic stem cells) were measured by PCR and western blotting, respectively. A ChIP assay was used to detect the binding of HSF1 to the spi1/pu.1 promoter in cd34+ cells. The ubiquitination of HSF1 in cd34+ cells was detected by CO-IP. The binding of HSF1 and Fbxw7α was detected in in cd34+ cells by CO-IP. The binding of HSF1 and CSN5 was evaluated. A luciferase reporter assay was used to detect the effect of STAT3 on CSN5 promoter activation in cd34+ cells. Western blotting was used to detect the phosphorylation of STAT3 in cd34+ cells of MDS patients. The binding of STAT3 and C/EBP beta in cd34+ cells was detected by CO-IP. RESULTS: Inhibition of SPI1/PU.1 expression was observed in MDS samples with low proliferation ability. Further experiments proved that phosphorylation of STAT3 affected CSN5 function and mediated the ubiquitination of HSF, the upstream regulator of SPI1/PU.1 transcription, which led to the inhibition of SPI1/PU.1 expression. Restoration of CSN5 rescued the inhibition of HSF1 ubiquitination, causing SPI1/PU.1 transcription to resume and increasing SPI1/PU.1 expression, promoting the recovery of cell proliferation in hypocellular MDS. CONCLUSIONS: Our research revealed the regulatory role of the CSN5/HSF/SPI1/PU.1 axis in hypocellular MDS, providing a probable target for clinical intervention.

Combination of venetoclax with BCR-ABL tyrosine kinase inhibitor as a therapeutic strategy for Philadelphia chromosome-positive leukemias.

OBJECTIVES: Venetoclax has shown synergism with BCR-ABL1 tyrosine kinase inhibitors (TKIs) in preclinical studies for patients with Philadelphia chromosome-positive (Ph+) leukemias. This combination may suggest a novel treatment strategy for Ph + leukemias. METHODS: We conducted a retrospective study to summarize the activity of combining venetoclax and BCR-ABL1 TKI-based therapies in Ph + leukemias. RESULT: A total of 18 patients with Ph + leukemias were enrolled in this study. At the time of venetoclax and TKI-based therapy, 5 patients were initially diagnosed, with Ph + acute myeloid leukemia (AML) (n = 1) and mixed phenotype acute leukemia (MPAL) (n = 4), 7 patients had chronic myeloid leukemia at blastic phase (CML-BP), and the remaining 6 patients had relapsed or refractory to prior therapy. The overall response rate (ORR) was 88.9% (9 CR, 2 CRi, 4 MLFS, 1 PR), and a major molecular response (MMR) (or better) was achieved in 7 (38.8%) of all patients. With a median follow-up of 7.0 months (range, 2.3-15.6), 15 (83.3%) were in continuous CR at the time of this analysis, with a 1-year OS of 85.6%, 1-year LFS of 76.7%, and 1-year CIR of 22.4%. Moreover, 10 of 18 patients were treated with venetoclax, TKI and hypomethylating agent (HMA) regimens, which also associated with a high ORR rate (6 CR, 1 CRi, 3 MLFS), and can be used for induction or salvage therapy. CONCLUSION: Venetoclax and TKI-based combination regimens may be a feasible approach for Ph + leukemias, and prospective studies are needed to properly assess the safety, tolerability and efficacy of this regimen.

Anti-CD19 CAR T-cell consolidation therapy combined with CD19+ feeding T cells and TKI for Ph+ acute lymphoblastic leukemia.

We conducted a single-arm, open-label, single-center phase 1 study to assess the safety and efficacy of multicycle-sequential anti-CD19 chimeric antigen receptor (CAR) T-cell therapy in combination with autologous CD19+ feeding T cells (FTCs) and tyrosine kinase inhibitor (TKI) as consolidation therapy in patients under the age of 65 years with de novo Ph-positive CD19+ B-cell acute lymphoblastic leukemia. Participants were given induction chemotherapy as well as systemic chemotherapy with TKI. Afterward, they received a single cycle of CD19 CAR T-cell infusion and another 3 cycles of CD19 CAR T-cell and CD19+ FTC infusions, followed by TKI as consolidation therapy. CD19+ FTCs were given at 3 different doses. The phase 1 results of the first 15 patients, including 2 withdrawals, are presented. The most common adverse events were cytopenia (13/13) and hypogammaglobinemia (12/13). There was no incidence of cytokine release syndrome above grade 2 or immune effector cell-associated neurotoxicity syndrome or grade 4 nonhematological toxicities. All 13 patients achieved complete remission, including 12 patients with a complete molecular response (CMR) at the data cutoff. The relapse-free survival was 84%, and the overall survival was 83% with a median follow-up of 27 months. The total number of CD19-expressing cells decreased with an increasing CMR rate. CD19 CAR T cells survived for up to 40 months, whereas CD19+ FTCs vanished in 8 patients 3 months after the last infusion. These findings could form the basis for the development of an allo-HSCT-free consolidation paradigm. This trial was registered at www.clinicaltrials.gov as #NCT03984968.

Integrative genomic and transcriptomic profiling reveals distinct molecular subsets in adult mixed phenotype acute leukemia.

Mixed phenotype acute leukemia (MPAL) is a subtype of leukemia in which lymphoid and myeloid markers are co-expressed. Knowledge regarding the genetic features of MPAL is lacking due to its rarity and heterogeneity. Here, we applied an integrated genomic and transcriptomic approach to explore the molecular characteristics of 176 adult patients with MPAL, including 86 patients with T-lymphoid/myeloid MPAL (T/My MPAL-NOS), 42 with Ph+ MPAL, 36 with B-lymphoid/myeloid MPAL (B/My MPAL-NOS), 4 with t(v;11q23), and 8 with MPAL, NOS, rare types. Genetically, T/My MPAL-NOS was similar to B/T MPAL-NOS but differed from Ph+ MPAL and B/My MPAL-NOS. T/My MPAL-NOS exhibited higher CEBPA, DNMT3A, and NOTCH1 mutations. Ph+ MPAL demonstrated higher RUNX1 mutations. B/T MPAL-NOS showed higher NOTCH1 mutations. By integrating next-generation sequencing and RNA sequencing data of 89 MPAL patients, we defined eight molecular subgroups (G1-G8) with distinct mutational and gene expression characteristics. G1 was associated with CEBPA mutations, G2 and G3 with NOTCH1 mutations, G4 with BCL11B rearrangement and FLT3 mutations, G5 and G8 with BCR::ABL1 fusion, G6 with KMT2A rearrangement/KMT2A rearrangement-like features, and G7 with ZNF384 rearrangement/ZNF384 rearrangement-like characteristics. Subsequently, we analyzed single-cell RNA sequencing data from five patients. Groups G1, G2, G3, and G4 exhibited overexpression of hematopoietic stem cell disease-like and common myeloid progenitor disease-like signatures, G5 and G6 had high expression of granulocyte-monocyte progenitor disease-like and monocyte disease-like signatures, and G7 and G8 had common lymphoid progenitor disease-like signatures. Collectively, our findings indicate that integrative genomic and transcriptomic profiling may facilitate more precise diagnosis and develop better treatment options for MPAL.

[Comparison of Therapeutic Efficacy between Hypomenthylating Agents Combined with Venetoclax and Half Dose Priming Regimen in Elderly Patients with Newly Diagnosed Acute Myeloid Leukemia].

OBJECTIVE: To compare the clinical efficacy and safety of hypomenthylating agents (HMA) combined with Venetoclax (VEN) and half dose priming regimen (CAG-like) in the treatment of elderly patients with newly diagnosed acute myeloid leukemia (AML) who were not suitable for intensive chemotherapy. METHODS: The clinical data of 43 newly diagnosed elderly patients with AML who were not suitable for intensive chemotherapy in our hospital from April 2019 to October 2020 were retrospectively analyzed. Among them, 16 cases received HMA-VEN regimen and 27 cases received HMA-CAG-like regimen. The remission rate, early mortality and survival were compared between the two groups. And, the patients were grouped according to HCT-CI score. The effects of two different regimens in different groups on the efficacy and survival of patients were compared, and the prognosis of patients was further analyzed. RESULTS: After one course of treatment, the total remission rate of HMA-VEN group and HMA-CAG-like group was 81.3% (13/16) and 51.9% (14/27), respectively, and the difference between the two groups was statistically significant (χ2=4.650, P=0.045). The median overall survival (OS) time of HMA-VEN group had not yet reached, while that of HMA-CAG-like group was 11.2 months, and the HMA-VEN group had a longer OS (P=0.055). There was no tumor lysis syndrome occurred in both groups. The main adverse reactions were digestive tract reaction, bone marrow suppression and infection. The amount of agranulocytosis infection, pulmonary infection and platelet infusion in HMA-VEN group were significantly lower than those in HMA-CAG-like group (P<0.05), while the time of agranulocytosis and amount of erythrocyte infusion were similar (P>0.05). In HMA-Ven group 1 case died early, while in HMA-CAG-like group 8 cases died early due to pulmonary infection, respiratory failure, cerebral hemorrhage, and alveolar hemorrhage, the mortality in HMA-CAG-like group was significantly higher than that in HMA-VEN group (P=0.043). Among 43 patients, there was a significant difference in OS between HCT score 0-2 group and ≥3 group (P=0.033). In HMA-CAG-like group, patients with HCT score ≥3 had a worse prognosis (P=0.01), while in HMA-VEN group patients showed no statistically significant difference in prognosis (P=0.681). In HCT score 0-2 group, 9 cases receiving HMA-VEN regimen and 22 cases receiving HMA-CAG-like regimen showed no statistical difference in OS (P=0.281). In HCT score ≥3 group, 7 cases receiving HMA-VEN regimen had a longer OS than 5 cases receiving HMA-CAG-like regimen (P=0.015). CONCLUSION: Venetoclax combined with HMA can achieve higher response rate, lower early mortality, and longer OS, especially in those with more comorbidities and poor tolerability.

Investigation of the risk factors to predict cytokine release syndrome in relapsed or refractory B-cell acute lymphoblastic leukemia patients receiving IL-6 knocking down anti-CD19 chimeric antigen receptor T-cell therapy.

CD19 chimeric antigen receptor-T (CAR-T) cell therapy has achieved remarkable results in patients with relapsed or refractory B-cell acute lymphoblastic leukemia (r/r B-ALL). However, the cytokine release syndrome (CRS) was presented in most patients as common toxicity and severe CRS (sCRS) characterized by the sharp increase in interleukin-6 (IL-6) could be life-threatening. We conducted a phase II clinical trial of ssCAR-T-19 cells, anti-CD19 CAR-T cells with shRNA targeting IL-6, in 61 patients with r/r B-ALL. This trial was registered at www.clinicaltrials.gov as #NCT03275493. Fifty-two patients achieved CR while nine patients were considered NR. The median duration of response (DOR) and overall survival (OS) were not reached (>50 months). CRS developed in 81.97% of patients, including 54.10% with grades 1 to 2 (grade 1, 31.15%; grade 2, 22.95%) and 27.87% with grades 3 to 4 (grade 3, 26.23%; grade 4, 1.64%). sCRS occurs earlier than mild CRS (mCRS). A multivariable analysis of baseline characteristics identified high bone marrow disease burden and poor genetic risk before infusion as independent risk factors for sCRS. After infusion, patients with sCRS exhibited larger expansion of ssCAR-T-19 cells, higher peak levels of IL-6, IL-10, and IFN-γ, and suffered more severe hematological and non-hematological toxicities compared with those with mCRS.

Rapid and Efficient Response to Gilteritinib and Venetoclax-Based Therapy in Two AML Patients with FLT3-ITD Mutation Unresponsive to Venetoclax Plus Azacitidine.

The presence of FLT3-ITD mutation is associated with relapse and poor survival in AML patients. Venetoclax combined with hypomethylating agents (VEN+HMA) was approved for the frontline treatment of elderly or unfit AML patients, which leads to noteworthy impacts on AML management. The combination therapy is associated with encouraging efficacy in FLT3-mutated AML among both newly diagnosed unfit and relapsed/refractory patients. However, we found that two AML patients with FLT3-ITD mutation did not respond to venetoclax plus azacitidine (VEN+AZA). Given that the combined efficacy of venetoclax and the FLT3 inhibitor has been proved in pre-clinical models of FLT3+ AML, it is a scientific rationale to investigate venetoclax combined with the FLT3 inhibitor in AML patients with FLT3-ITD mutation. This is the first report of assessing the safety and response of gilteritinib (the first and only targeted second-generation FLT3 tyrosine kinase inhibitor approved by the US FDA) and venetoclax-based therapy in two AML patients with FLT3-ITD mutation unresponsive to VEN+AZA, which may bring new hope to FLT3 mutated patients who are unresponsive to VEN+HMA.

A Phase II Trial of the Double Epigenetic Priming Regimen Including Chidamide and Decitabine for Relapsed/Refractory Acute Myeloid Leukemia.

OBJECTIVE: To explore the role of chidamide, decitabine plus priming regimen in the salvage treatment of relapsed/refractory acute myeloid leukemia. METHODS: A clinical trial was conducted in relapsed/refractory acute myeloid leukemia patients using chidamide, decitabine, cytarabine, idarubicin, and granulocyte-colony stimulating factor, termed CDIAG, a double epigenetic priming regimen. RESULTS: Thirty-five patients were recruited. Three patients received 2 treatment cycles. In 32 evaluable patients and 35 treatment courses, the completed remission rate (CRR) was 42.9%. The median OS time was 11.7 months. The median OS times of responders were 18.4 months, while those of nonresponders were 7.4 months (P = 0.015). The presence of RUNX1 mutations was associated with a high CRR but a short 2-year OS (P = 0.023) and PFS (P = 0.018) due to relapse after treatment. The presence of IDH mutations had no effect on the remission rate (80.0% vs. 73.3%), but showed a better OS (2-year OS rate: 100.0% vs. 28.9%). Grade 3/4 nonhematological adverse events included pneumonia, hematosepsis, febrile neutropenia, skin and soft tissue infection and others. CONCLUSION: The double epigenetic priming regimen (CDIAG regimen) showed considerably good antileukemia activity in these patients. Adverse events were acceptable according to previous experience. The study was registered as a clinical trial. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/, identifier:NCT03985007.

Successful application of anti-CD19 CAR-T therapy with IL-6 knocking down to patients with central nervous system B-cell acute lymphocytic leukemia.

Few studies have described chimeric antigen receptor-modified T cell (CAR-T) therapy for central nervous system (CNS) B-cell acute lymphocytic leukemia (B-ALL) patients due to life-threatening CAR-T-related encephalopathy (CRES) safety issues. In this study, CAR-Ts targeting CD19 with short hairpin RNA (shRNA)-IL-6 gene silencing technology (ssCART-19s) were prepared. We conducted a phase 1 clinical trial (ClinicalTrials.gov number, NCT03064269). Three patients with relapsed CNS B-ALL were enrolled, conditioned with the fludarabine and cyclophosphamide for lymphocyte depletion and infused with ssCART-19s for three consecutive days. Clinical symptoms and laboratory examinations were monitored. After ssCART-19 treatment, three patients' symptoms resolved almost entirely. Brain leukemic infiltration reduced significantly based on magnetic resonance imaging (MRI), and there were no leukemic blasts in cerebrospinal fluid (CSF), which was confirmed by cytological and molecular examinations. Additionally, increases in the levels of cytokines and immune cells were observed in the CSF of all patients. Only grade 1 cytokine release syndrome (CRS) manifesting as fever was noted in patients. In conclusion, CAR-Ts with shRNA-IL-6 gene knockdown migrated into the CNS, eradicated leukemic cells and elevated cytokines in CSF with mild, acceptable side effects.

Successful treatment of acute B lymphoblastic leukemia relapse in the skin and testicle by anti-CD19 CAR-T with IL-6 knocking down: a case report.

BACKGROUND: Extramedullary relapse is an important cause of treatment failure among patients with acute lymphoblastic leukemia (ALL). This type of relapse is commonly observed in the central nervous system, while it is rare in the testicles and skin. Chimeric antigen receptor-modified T cell (CAR-T) therapy targeting CD19 has shown to be a beneficial treatment approach for relapsed/refractory B cell acute lymphoblasticleukemia (r/r B-ALL). Yet, few studies have reported data regarding the treatment of extramedullary B-ALL relapse, especially both in skin and testicle, with CAR-T therapy. CASE PRESENTATION: Here we reported a single case of a patient with relapsed B-ALL in skin and testicle who was successfully treated by the shRNA-IL6-modified anti-CD19 CAR-T(ssCAR-T-19) therapy. A 29-year-old man with relapsed B-ALL in skin and testicle was enrolled in clinal trial involving the shRNA-IL6-modified anti-CD19 CAR-T(ssCAR-T-19) therapy (ClinicalTrials.gov number, NCT03919240). The patient had toxicity consistent with the grade 1 cytokine release syndrome. CONCLUSIONS: ssCART-19 therapy may be used to effectively eliminate infiltrating leukemia cells in the skin and testicle with mild toxicity, which could be a much safer approach to bridge allo-HSCT, thus further improving the patient's outcome. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT03919240, Registered 18 April 2019, retrospectively registered.

[Diagnostic Value of G and GM Tests in Acute Leukemia Patients with Invasive Fungal Disease].

OBJECTIVE: To analyze the diagnostic value of (1, 3) -ß-D-glucan and galactomannan (GM) tests in the patients with acute leukemia complicated by invasive fungal disease, and explore the application of serological detection (G/GM) and lung CT for early diagnosis of invasive fungal disease (IFD). METHODS: A total of 493 patients with acute leukemia complicated by high risk invasive fungal infection, also receival G and GM tests, in Department of hematology of our hospital from June 2016 to December 2016 were selected and were divided into IFD-confirmed group (62 cases) including confirmed and clinical diagnesed IFD, and IFD-unconfirmed group (431 cases) including suspected IFD and non-IFD according to the diagnostic criteria of IFD. The results of G and GM tests in patients of 2 groups were analyzed, then the diagnostic efficacy of G and GM done and combination evaluated. In addition, 26 patients whose lung CT negative at hospitalization, moreover, presentation of changes in lung by CT during hospitalization and serological G and GM test positive were selected, and the difference of time between serological that postive and presentation of changes in lung by CT were compared for the estimation of early diagnotic value. RESULTS: The positive rate of (1, 3) -ß-D-glucan in IFD-confirmed group and IFD-unconfirmed group was 56.5% and 10.4%, respectively. Meanwhile, that of galactomannan test was 41.9% and 9.0%, respectively. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of (1, 3) -ß-D-glucan was 56%, 90%, 44% and 92%, and that of galactomannan was 42%、91%、40% and 93%, respectively. Moreover, the combination of (1, 3) -ß-D-glucan and galactomannan could raise the sensitivity to 69% and specificity to 98%. The positive results of serological detection (G/GM) come earlier about five days than CT changes. CONCLUSION: Both (1, 3) -ß-D-glucan and galactomannan test have high sensitivity and specificity, and the combination of them can improve the diagnostic efficacy, and make the clinical antifungal therapy more precisely. In the early clinical diagnosis of IFD, the positive results of serological detection coming earlier than lung CT.

A New Conditioning Regimen Can Significantly Promote Post-Transplant Immune Reconstitution and Improve the Outcome of Umbilical Cord Blood Transplantation for Patients.

This study included data from 81 consecutively enrolled patients with hematological diseases who had been treated with unrelated umbilical cord blood transplantation (UCBT) between September 2014 and April 2019. All patients received intense conditioning regimens with combined fludarabine and high-dose cyclophosphamide (FC) before undergoing UCBT. Sixty-seven patients received a single UCBT, and 14 patients received a double UCBT. Fifty patients were pretreated with the fludarabine, busulfan, and cyclophosphamide (FBC) protocol, while 31 patients were treated with FC before transplantation. Graft-versus-host disease (GVHD) was prevented with cyclosporine A and mycophenolate mofetil administration. According to low-resolution, human leukocyte antigen (HLA) donor-recipient matching at six sites, 53 patients had 5-6 matches, while 28 patients had 4 matches. Seventy-eight patients (96.3%) achieved complete engraftment in this study. Thirty-six patients developed acute GVHD (aGVHD). The cumulative incidence of grade I-II aGVHD at day 100 posthematopoietic stem cell transplantation was 29.6%, and the cumulative incidence of grade III-IV aGVHD was 14.8%. At the end of the follow-up, 12 patients died due to treatment-related complications, and 4 died of disease relapse after transplantation. The transplant-related deaths were due to transplant-related infection (8 of 81), GVHD (2 of 81), and organ toxicity (2 of 81). The probability of overall survival (OS) was 80.2%. A higher dose of cyclophosphamide combined with fludarabine conditioning in UCBT was an effective curative method for treatment of hematologic disorders and could enhance the engraftment of umbilical cord blood stem cells, promote post-transplant immune reconstitution, and improve OS.

[Efficacy and Safety of the Induction Therapy with Different Doses of Anthracyclines for Patients with Newly Diagnosed Acute Promyelocytic Leukemia].

]Objective:To investigate the efficacy and safety of induction regimens containing arsenite, allo-transretinoic acid (ATRA) and anthracyclines of different doses as induction chemotherapy for acute promyelocytic leukemia (APL). METHODS: The clinical data of 129 consecutive hospitalized newly diagnosed APL patients from January 2011 to December 2017 were collected and retrospectively analyzed. Sixty-six patients received arsenite, ATRA and anthracyclines of low doses (low dose group), while other 63 patients received arsenite, ATRA and anthracyclines of standard doses (standard dose group), the efficacy and safety were compared and analyzed in 2 groups. RESULTS: There were no statistically significant differences in terms of age, sex, routine blood indexes,LDH level, bone marrow promyelocyte count,prognostic stratification between patients in two groups (P>0.05). During the treatment, WBC count peak and its time point were not significantly different between two groups (P>0.05). Both induction regimens showed good efficacy, the PML-RARα gene conversion rate from positive into negative, the 2-year overall survival rate and disease-free survival rate in the low-dose group were similar to those in the standard dose group(P＞0.05). The recovery time of neutrophils and platelets in the low-dose group was 0 d and 11 d, respectively, which were statistically  significantly shorter than those in the standard dose group (3 d,15 d) (both P=0.000). The median value of platelet and erythrocyte transfusion in the low-dose group was 6.9 U and 4.2 U, respectively, which were statistically significantly lower than that in the standard dose group (8.4 U,6.8 U) (P=0.037，0.000). And the inpatient time in the low and the standard dose groups were 30.98 and 30.71 days, respectively (P=0.770). CONCLUSION: For newly diagnosed patients with APL, the efficacy was similar between induction therapy containing arsenite,ATRA and low dose anthracyclines and the induction therapy containing arsenite, ATRA and standard dose anthracyclines, however, the former appears even safer.

Effects of preemptive interferon-α monotherapy in acute leukemia patients with relapse tendency after allogeneic hematopoietic stem cell transplantation: a case-control study.

Interferon-α (IFN-α) inhibits tumor growth and mimics graft-versus-leukemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the current case-control study, we compared treatment responses in acute leukemia patients with relapse tendency post-allo-HSCT receiving preemptive IFN-α after withdrawal of immunosuppressants (n = 31) vs. receiving no IFN-α (n = 67). In the IFN-α group, 25 patients responded to the treatment without progressing to hematological relapse. In the non-IFN-α group, only 22 patients responded to the treatment. The response rate differed significantly (80.6 vs. 32.8%, P < 0.001). The 2-year cumulative incidence of relapse was 31.6 and 61.2% in the IFN-α and the non-IFN groups, respectively (P = 0.006). The 2-year leukemia-free survival and overall survival rate was 57.4 vs. 28.4% (P < 0.001) and 67.6 vs. 32.9% (P = 0.001), respectively. Among the 31 patients in the IFN-α group, 18 patients (58.1%) developed graft-versus-host disease (GVHD): 6 acute and 12 limited chronic GVHD. Patients who developed GVHD had higher treatment response rate than patients without GVHD (88.9 vs. 53.8%, P = 0.022). In conclusion, preemptive IFN-α therapy is a safe and effective treatment to prevent disease progression in high-risk patients with relapse tendency post-allo-HSCT.

MiR-130a is aberrantly overexpressed in adult acute myeloid leukemia with t(8;21) and its suppression induces AML cell death.

BACKGROUND: Emerging evidence has revealed that miRNAs can function as oncogenes or tumor suppressor genes in leukemia. The ectopic expression of miR-130a has been reported in chronic leukemia, but our understanding of the biological implications of miR-130a expression remains incomplete. METHODS: We quantified a cohort of de novo acute myeloid leukemia (AML) by bead-based miRNA and real-time quantitative PCR (Rq-PCR). The luciferase reporter gene assay was analyzed after the plasmid constructs which contain 5'-UTR of miR-130a and a Renilla luciferase reporter plasmid were transfected simultaneously into 293T cells. MTT and caspase 3/7 apoptosis assays were used to test cell viability and apoptosis. RESULTS: We identified miR-130a as significantly overexpressed in t(8;21) AML. Expression of miR-130a decreased significantly once patients with t(8;21) achieved complete remission, but increased sharply at the time of relapse. In patients with t(8;21) AML, KIT mutational status was associated with miR-130a expression-with higher expression associated with KIT activating mutations. Increased miR-130a expression in t(8;21) AML was associated with slightly worse event-free survival; however, no impact on overall survival was observed. Knockdown of AML1/ETO protein in the SKNO-1 cell line resulted in decrease of expression of miR-130a. Direct binding of AML1/ETO fusion protein with the promoter sequence of miR-130a was detected with luciferase reporter gene assay. Following miR-130a knockdown, SKNO-1 demonstrated increased sensitivity to etoposide. CONCLUSIONS: Our data suggest that miR-130a is directly activated by AML1/ETO, and may act as a factor which is associated with leukemia burden, event-free survival, and chemotherapy sensitivity in t(8;21) AML.