Damage Mechanism of CK2 and IKAROS in Philadelphia Like Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is characterized by immature and poorly differentiated B lymphocytes in large numbers in the blood. B cells are distinct from the cell types involved in their development (common lymphoid progenitor cells, pro-B cells, pre-B cells, and mature cells). The process of B cell maturation depends on precise communication within the cell: signals activate specific genes that are essential for proper development. Errors in this intricate signaling network can lead to issues with B cell function and contribute to disease. B-lineage acute lymphoid leukemias, malignancies of precursor-stage B lymphoid cells inhibit lymphoid differentiation, leading to abnormal cell proliferation and survival. The process of developing leukemia (leukemogenesis) can be triggered by an overproduction of both hematopoietic stem cells (the cells that form all blood cells) and the immature versions of white blood cells called lymphoblasts. Acute lymphoblastic leukemia (ALL) with the presence of the Philadelphia chromosome (ALL Ph) is classified as a high-risk manifestation of the disease, this chromosome is the product of the reciprocal translocation, whose product is a BCR-ABL fusion protein. It is a highly active tyrosine kinase that can transform hematopoietic cells into cytokine-independent. Hyperphosphorylation cascades inhibit the differentiating function of IKZF1 as a tumor suppressor gene which leads to an abnormal proliferation of B cells due to the presence of the Philadelphia chromosome;it inhibits the differentiating process, leukemogenesis involving immature B cells in the bloodstream can result from the uncontrolled growth and division of hematopoietic stem cells and immature lymphoblasts (the precursors to B cells).

Philadelphia chromosome-positive leukemia stem cells in acute lymphoblastic leukemia and tyrosine kinase inhibitor therapy

Leukemia stem cells(LSCs),which constitute a minority of the tumor bulk,are functionally defined on the basis of their ability to transfer leukemia into an immunodeficient recipient animal.The presence of LSCs has been demonstrated in acute lymphoblastic leukemia(ALL),of which ALL with Philadelphia chromosome-positive(Ph+).The use of imatinib,a tyrosine kinase inhibitor(TKI),as part of front-line treatment and in combination with cytotoxic agents,has greatly improved the proportions of complete response and molecular remission and the overall outcome in adults with newly diagnosed Ph+ ALL.New challenges have emerged with respect to induction of resistance to imatinib via Abelson tyrosine kinase mutations.An important recent addition to the arsenal against Ph+ leukemias in general was the development of novel TKIs,such as nilotinib and dasatinib.However,in vitro experiments have suggested that TKIs have an antiproliferative but not an antiapoptotic or cytotoxic effect on the most primitive ALL stem cells.None of the TKIs in clinical use target the LSC.Second generation TKI dasatinib has been shown to have a more profound effect on the stem cell compartment but the drug was still unable to kill the most primitive LSCs.Allogeneic stem cell transplantation(SCT) remains the only curative treatment available for these patients.Several mechanisms were proposed to explain the resistance of LSCs to TKIs in addition to mutations.Hence,TKIs may be used as a bridge to SCT rather than monotherapy or combination with standard chemotherapy.Better understanding the biology of Ph+ ALL will open new avenues for effective management.In this review,we highlight recent findings relating to the question of LSCs in Ph+ ALL.

The Role of Mitochondrial VDAC2 in the Survival and Proliferation of T-Cell Acute Lymphoblastic Leukemia Cells

Background: T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with aberrant T-cell developmental arrest. Individuals with relapsed T-ALL have limited therapeutic alternatives and poor prognosis. The mitochondrial function is critical for the T-cell viability. The voltage-dependent anion channel 2 (VDAC2) in the mitochondrial outer membrane, interacts with pro-apoptotic BCL-2 proteins and mediates the apoptosis of several cancer cell lines. Objective: The aim of the current study is to explore the role of VDAC2 in T-ALL cell survival and proliferation. Methods: Publicly available datasets of RNA-seq results were analyzed for expression of VDAC isoforms and T-ALL cell lines were treated with a VDAC2 small molecular inhibitor erastin. A VDAC2 RNA interference (siRNA) was delivered to T-ALL cell lines using a retroviral vector. Functional assays were performed to investigate the VDAC2 siRNA impacts on cell proliferation, apoptosis and survival of T-ALL cells. Results: Our analysis found a high expression of VDAC2 mRNA in various T-ALL cell lines. Public datasets of T-ALL RNA-seq also showed that VDAC2 is highly expressed in T-ALL (116.2 ± 36.7), compared to control groups. Only two T-ALL cell lines showed sensitivity to erastin (20 μM) after 48 hours of incubation, including Jurkat (IC50 = 3.943 μM) and Molt4 (IC50 = 3.286 μM), while another two T-ALL cells (CUTLL1 and RPMI 8402) had unstable IC50. However, five T-ALL cell lines (LOUCY, CCRF-CEM, P12-ICHI, HPB-ALL, and PEER cells) showed resistance to erastin. On the contrary, all T-ALL cell lines genetically inhibited with VDAC2 siRNA led to more than 80% decrease in VDAC2 mRNA levels, and a Conclusion: VDAC2 is highly expressed in T-ALL cells. The inhibition of VDAC2 significantly decreased cell viability, increased apoptosis, reduced cell proliferation and caused cell cycle sub-G1 arrest of T-ALL cells.

Resveratrol Induces Apoptosis and Autophagy in T-cell Acute Lymphoblastic Leukemia Cells by Inhibiting Akt/mTOR and Activating p38-MAPK

Objective To explore the effects of resveratrol-induced apoptosis and autophagy in T-cell acute lymphoblastic leukemia （T-ALL） cells and potential molecular mechanisms. Methods The anti-proliferation effect of resveratrol-induced, apoptosis and autophagy on T-ALL cells were detected by using MTI- test, immunofluorescence, electronic microscope, and flow cytometry, respectively. Western blotting was performed for detecting changes of apoptosis-associated proteins, cell cycle regulatory proteins and state of activation of Akt, mTOR, p70S6K, 4E-BP1, and p38-MAPK. Results Resveratrol inhibited the proliferation and dose and time-dependent manner. It also induced cyclin-dependent kinase （CDK） inhibitors p21 and induced apoptosis and autophagy in T-ALL cells in a cell cycle arrest at G0/G1 phase via up regulating p27 and down regulating cyclin A and cyclin D1. Western blotting revealed that resveratrol significantly decreased the expression of antiapoptotic proteins （Mcl-1 and Bcl-2） and increased the expression of proapoptotic proteins （Bax, Bim, and Bad）, and induced cleaved-caspase-3 in a time-dependent manner. Significant increase in ratio of LC3-11/LC3-1 and Beclin 1 was also detected. Furthermore, resveratrol induced significant dephosphorylation of Akt, mTOR, p70S6K, and 4E-BP1, but enhanced specific phosphorylation of p38-MAPK which could be blocked by SB203580. When autophagy was suppressed by 3-MA, apoptosis in T-ALL cells induced by resveratrol was enhanced. Conclusion Our findings have suggested that resveratrol induces cell cycle arrest, apoptosis, and autophagy in T-ALL cells through inhibiting Akt/mTOR/p7OS6K/4E-BP1 and activating p38-MAPK signaling pathways. Autophagy might play a role as a self-defense mechanism in T-ALL cells treated by resveratrol. Therefore, the reasonable inhibition of autophagy in T-ALL cells may serve as a promising strategy for resveratrol induced apoptosis and can be used as adjuvant chemotherapy for T-ALL.

Predictive Value of Dynamic Peri-Transplantation MRD Assessed By MFC Either Alone or in Combination with Other Variables for Outcomes of Patients with T-Cell Acute Lymphoblastic Leukemia

We performed a retrospective analysis to investigate dynamic peri-hematopoieticstem cell transplantation(HSCT)minimal/measurable residual disease(MRD)on outcomes inpatients with T-cell acute lymphoblastic leukemia(T-ALL).A total of 271 patients were enrolledand classified into three groups:unchanged ncgative MRD pre-and post-HSCT group(group A),post-MRD non-increase group(group B),and post-MRD increase group(group C).The patientsin group B and group C experienced a higher cumulative incidence of relapse(CIR)(42%vs.71%vs.16%,P<0.001)and lower leukemia-free survival(LFS)(46%vs.21%vs.70%,P<0.001)andoverall survival(OS)(50%vs.28%vs.72%,P<0.001)than in group A,but there was no significantdifference in non-relapse mortality(NRM)among three groups(14%vs.12%vs.8%,P=0.752).Multivariate analysis showed that dynamic peri-HSCT MRD was associated with CIR(HR=2.392,95%CI,1.816-3.151,P<0.001),LFS(HR=1.964,95%CI,1.546-2.496,P<0.001)and os(HR=1.731,95%CI,1.348-2.222,P<0.001).We also established a risk scoring system based ondynamic peri-HSCT MRD combined with remission status pre-HSCT and onsct of chronic graft-versus-host disease(GVHD).This risk scoring system could better distinguish ClR(c=0.730)thanthat for pre-HSCT MRD(c=0.562),post-HSCT MRD(c=0.616)and pre-and post-MRD dynamics(c=0.648).Our results confirm the outcome predictive value of dynamic peri-HSCT MRD eitheralone or in combination with other variables for patients with T-ALL.

MicroRNA-145-3p suppresses the malignant behaviors of T-cell acute lymphoblastic leukemia Jurkat cells via inhibiting the NF-kappaB signaling pathway

T-cell acute lymphoblastic leukemia(T-ALL)is a hematological tumor caused by the malignant transformation of immature T-cell progenitor cells.Emerging studies have stated that microRNAs(miRNAs)may play key roles in T-ALL progression.This study aimed to investigate the roles of miR-145-3p in T-ALL cell proliferation,invasion,and apoptosis with the involvement of the nuclear factor-kappaB(NF-κB)signaling pathway.T-ALL Jurkat cells were harvested,and the expression of miR-145-3p and NF-κB-p65 was measured.Gain-and loss-of-functions of miR-145-3p and NF-κB-p65 were performed to identify their roles in the biological behaviors of Jurkat cells,including proliferation,apoptosis,and invasion.Consequently,the current study demonstrated that miR-145-3p was down-regulated while NF-κB-p65 was up-regulated in Jurkat cells.miR-145-3p directly bound to the 3’untranslated region of NF-κB-p65.Over-expression of miR-145-3p inhibited Jurkat cell proliferation,invasion,and resistance to apoptosis,while over-expression of NF-κB-p65 presented opposite trends.Co-transfection of miR-145-3p and NF-κB-p65 promoted the malignant behaviors of Jurkat cells compared to miR-145-3p transfection alone,while it reduced these behaviors of Jurkat cells compared to NF-κB-p65 transfection alone.Taken together,this study provided evidence that miR-145-3p could suppress proliferation,invasion,and resistance to the death of T-ALL cells via inactivating the NF-κB signaling pathway.

Prognostic Features of BCR-ABL Genetic Variations in Acute Lymphoblastic Leukemia

Background: Acute lymphoblastic leukemia (ALL) is a hematologic malignancy which results from accumulation of lymphoid progenitor cells in the bone marrow and/or extramedullary sites. Philadelphia chromosome (Ph1) positive ALL, a high-risk cytogenetic subset, accounts for 25% - 30% of adult ALL cases but occurs in less than 5% of children. We aimed with this study to detect BCR-ABL genes fusion, amplification and deletion in ALL patients, using extrasignal-fluorescence in situ hybridization (ES-FISH), and to assess their relation with other standard prognostic factors and therapeutic response. Patients and Methods: This study was carried out on 39 newly diagnosed ALL patients. All patients were subjected to: history, clinical examination and laboratory investigations, which included complete blood count (CBC), peripheral blood (PB), bone marrow (BM) examination, immunophenotyping and fluorescence in situ hybridization using extra-signal probe to detect BCR-ABL genes fusion. Results: This study showed statistical analysis of patients’ t(9;22) with other factors revealed, significant association (p 35 years, hepatosplenomegaly, absence of lymphadenopathy, TLC ≥ 50 × 109/L, absolute PB blasts ≥ 4.4 × 109/L, immunophenotyping and other aberrations. Conclusion: BCR/ABL fusion gene analysis by ES-FISH may serve as a prognostic marker in adulthood ALL. The age, TLC and t(9;22) represent the significant standard prognostic factors in relation to patients’ outcome.

Multi-omics integration reveals potential stage-specific druggable targets in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia(T-ALL),a heterogeneous hematological malignancy,is caused by the developmental arrest of normal T-cell progenitors.The development of targeted therapeutic regimens is impeded by poor knowledge of the stage-specific aberrances in this disease.In this study,we performed multi-omics integration analysis,which included mRNA expression,chromatin accessibility,and gene-dependency database analyses,to identify potential stage-specific druggable targets and repositioned drugs for this disease.This multi-omics integration helped identify 29 potential pathological genes for T-ALL.These genes exhibited tissue-specific expression profiles and were enriched in the cell cycle,hematopoietic stem cell differentiation,and the AMPK signaling pathway.Of these,four known druggable targets(CDK6,TUBA1A,TUBB,and TYMS)showed dysregulated and stage-specific expression in malignant T cells and may serve as stage-specific targets in T-ALL.The TUBA1A expression level was higher in the early T cell precursor(ETP)-ALL cells,while TUBB and TYMS were mainly highly expressed in malignant T cells arrested at the CD4 and CD8 double-positive or single-positive stage.CDK6 exhibited a U-shaped expression pattern in malignant T cells along the naıve to maturation stages.Furthermore,mebendazole and gemcitabine,which target TUBA1A and TYMS,respectively,exerted stage-specific inhibitory effects on T-ALL cell lines,indicating their potential stage-specific antileukemic role in T-ALL.Collectively,our findings might aid in identifying potential stage-specific druggable targets and are promising for achieving more precise therapeutic strategies for T-ALL.

Current assessment and management of measurable residual disease in patients with acute lymphoblastic leukemia in the setting of CAR-T-cell therapy

Chimeric antigen receptor(CAR)-modified T-cell therapy has achieved remarkable success in the treatment of acute lymphoblastic leukemia(ALL).Measurable/minimal residual disease(MRD)monitoring plays a significant role in the prognostication and management of patients undergoing CAR-T-cell therapy.Common MRD detection methods include flow cytometry(FCM),polymerase chain reaction(PCR),and next-generation sequencing(NGS),and each method has advantages and limitations.It has been well documented that MRD positivity predicts a poor prognosis and even disease relapse.Thus,how to perform prognostic evaluations,stratify risk based on MRD status,and apply MRD monitoring to guide individual therapeutic decisions have important implications in clinical practice.This review assesses the common and novel MRD assessment methods.In addition,we emphasize the critical role of MRD as a prognostic biomarker and summarize the latest studies regarding MRD-directed combination therapy with CAR-T-cell therapy and allogeneic hematopoietic stem cell transplantation(allo-HSCT),as well as other therapeutic strategies to improve treatment effect.Furthermore,this review discusses current challenges and strategies for MRD detection in the setting of disease relapse after targeted therapy.

Administration of imatinib in the first 90 days after allogeneic hematopoietic cell transplantation in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

Background Relapse happens frequently after allogeneic hematopoietic cell transplantation （alIo-HCT） in the patients with Philadelphia chromosome-positive acute lymphoblastic leukemia （Ph^＋ ALL）. Detection of the minimal residual disease （MRD） before and after alIo-HCT is associated with higher relapse rate. Early administration of imatinib after alIo-HCT may prevent recurrent Ph^＋ ALL. The aim of this study was to evaluate the safety and efficacy of imatinib in preventing hematological relapse when imatinib was administrated in the first 90 days after alIo-HCT. Methods Patients with Ph^＋ ALL that underwent alIo-HCT were enrolled in a prospective study. A TaqMan-based real-time quantitative polymerase chain reaction （RQ-PCR） technique was used to detect the MRD （bcr-abl transcript levels）. Imatinib therapy was initiated prior to 90 days after alIo-HCT if the patient＇s absolute neutrophil count （ANC） was above 1.0×10^9/L （without granulocyte colony-stimulating factor （G-CSF） administration） and the platelet count was greater than 50.0×10^9/L, or if the bcr-abl transcript levels were elevated in two consecutive tests, or if the bcr-abl transcript levels were 〉10.2 after the initial engraftment. The initial daily dose of imatinib was 400 mg/d for adults and 260 mg/m^2 for children （younger than 17 years）. Imatinib was administered for at least I month and the bcr-abl TaqMan results were negative for 3 consecutive tests, or complete molecular remission （CR^mol） was sustained for at least 3 months. Results From May 2005 to October 2008, 29 patients were enrolled in this study, of whom, 19 patients were male and 10 were female. The median age of the enrolled patients was 33 years （range 6-50 years）. Imatinib therapy was started at a median time of 60 days （range 20-122 days） post HCT （only one patient started Imatinib therapy at 122nd day after HCT）. Twenty-five adult patients could tolerate a dose of 300-400 mg/d of imatinib, and three children tolerated a dose of 260 mg·m^2·d^-1. Sixty-eight percent of the patients experienced various adverse events during imatinib therapy, hematological toxicity being the most common adverse event. The median duration of imatinib treatment was 3 months （range 7 days-18 months）. During the median follow-up of 24 months （range 16.0-54.5 months）, 3 out of 27 patients that could be evaluated for efficacy died from relapse. The 3-year probability of relapse for the evaluated patients was （11.34-0.61）%. The relapse rates among the subgroup of positive and negative bcr-abl patients before allo-HCT were 13.6% and 0, respectively （P 〉0.05）. The relapse rates among the subgroups of bcr-abl positive and negative patients after alIo-HCT were 20.0% and 5.9%, respectively （P 〉0.05）. The relapse rates among the patients in first complete remission （CR1） and second complete remission/non-remission （CR2/NR） before transplantation were 0 and 31.4%, respectively （P 〈0.05）. The 3-year probability of overall survival （OS） and disease-free survival （DFS） for the all enrolled patients were （75.3±8.1）%. The 3-year probabilities for OS and DFS among the subgroup of patients in CR1 and CR2/NR before transplantation were （87.7±8.2）% and （54.6±15.0）%, respectively （P 〈0.05）. Conclusions Administration of irnatinib at a dose of 300-400 mg/d in the first 90 days after allo-HCT is feasible in Ph^＋ ALL patients. With this treatment, bcr-abl positive patients before or after transplantation do not have a higher relapse rate after allo-HCT compared with the bcr-abl negative patients. Because of lower relapse rate and better OS and DFS, we recommend that Ph^＋ ALL patients receive allo-HCT in CRI.

Efficacy and prognostic factors of imatinib plus CALLG2008 protocol in adult patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia

A CALLG2008 protocol was developed by the Chinese Acute Lymphoblastic Leukemia Cooperative Group for adult acute lymphoblastic leukemia （ALL）. We retrospectively analyzed 153 newly diagnosed adult patients with Philadelphia chromosome （Ph）-positive ALL enrolled into imatinib （400 mg/d） plus CALLG2008 regimen between 2009 and 2015. The median age was 40 years （range, 18-68 years）, with 81 （52.3%） males. The overall hematologic complete remission （CR） rate was 96.7% after induction. With a median follow-up of 24.2 months, the estimated 3-year overall survival （OS） and event-free survival （EFS） rates were 49.5% （95% confidence interval （CI）： 38.5%-59.5%） and 49.2% （95% CI： 38.3%-59.2%）, respectively. Fifty-eight （36 with haploidentical donor） patients underwent allogeneic hematopoietic stem call transplantation （allo-HSCT） in first CR. Among the patients in CR1 after induction, both the 3-year OS and EFS were significantly better in the allo-HSCT group than in the without alIo-HSCT group （73.2%, 95% CI： 58.3%-83.5% vs. 22.2%, 95% CI： 8.7%-39.6% and 66.5%, 95% CI： 50.7%-78.2% vs. 16.1%, 95% CI： 5.1%-32.7%, respectively）. Multivariate analysis showed that alIo-HSCT and achievement of major molecular response were associated with favorable OS or EFS independently. Interestingly, in the alIo-HSCT cohort, the donor type （haploidentical versus matched donors） had no significant impact on EFS or OS. All these results suggested that imatinib plus CALLG2008 was an effective protocol for Ph-positive ALL. Haploidentical donors can also be a reasonable alternative expedient donor pool.

Advances in the development of chimeric antigen receptor-T-cell therapy in B-cell acute lymphoblastic leukemia

CD19-targeted chimeric antigen receptor T-cell(CAR-T)therapy is effective in refractory/relapsed(R/R)B-cell acute lymphoblastic leukemia(B-ALL).This review focuses on achievements,current obstacles,and future directions in CAR-T research.A high complete remission rate of 68%to 93%could be achieved after anti-CD19 CAR-T treatment for B-ALL.Cytokine release syndrome and CAR-T-related neurotoxicity could be managed.In view of difficulties collecting autologous lymphocytes,universal CAR-T is a direction to explore.Regarding the high relapse rate after anti-CD19 CAR-T therapy,the main solutions have been developing new targets including CD22 CAR-T,or CD19/CD22 dual CAR-T.Additionally,some studies showed that bridging into transplant post-CAR-T could improve leukemia-free survival.Some patients who did not respond to CAR-T therapy were found to have an abnormal conformation of the CD19 exon or trogocytosis.Anti-CD19 CAR-T therapy for R/R B-ALL is effective.From individual to universal CAR-T,from one target to multi-targets,CAR-T-cell has a chance to be off the shelf in the future.

Chidamide inhibits the NOTCH1-MYC signaling axis in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia(T-ALL)is one of the most dangerous hematological malignancies,with high tumor heterogeneity and poor prognosis.More than 60%of T-ALL patients carry NOTCH1 gene mutations,leading to abnormal expression of downstream target genes and aberrant activation of various signaling pathways.We found that chidamide,an HDAC inhibitor,exerts an antitumor effect on T-ALL cell lines and primary cells including an anti-NOTCH1 activity.In particular,chidamide inhibits the NOTCH1-MYC signaling axis by down-regulating the level of the intracellular form of NOTCH1(NICD1)as well as MYC,partly through their ubiquitination and degradation by the proteasome pathway.We also report here the preliminary results of our clinical trial supporting that a treatment by chidamide reduces minimal residual disease(MRD)in patients and is well tolerated.Our results highlight the effectiveness and safety of chidamide in the treatment of T-ALL patients,including those with NOTCH1 mutations and open the way to a new therapeutic strategy for these patients.

Philadelphia chromosome-positive acute myeloid leukemia with masses and osteolytic lesions： finding of 18F-FDG PET/CT

Philadelphia chromosome-positive acute myeloid leukemia is controversial and difficult to distinguish from the blast phase of chronic myeloid leukemia. As a myeloid neoplasm, rare cases of this leukemia manifest multiple soft-tissue tumors or bone lyric lesions. In this paper, we describe a 49-year-old male patient who had an abrupt onset with sharp chest pain, fever, fatigue, emaciation, and splenomegaly. 18F-fluoro-deoxy-glucose positron emission tomography/computed tomography （18F-FDG PET/CT） result showed diffuse and uneven hypermetabolic lesions in the bone marrow with peripheral bone marrow expansion, multiple soft tissue neoplasms with high 18F-FDG uptake, and lyric bone lesions. Bone marrow smear and biopsy detected aberrant blast cells expressing myeloid rather than lymphoid immunophenotype marker. For the existence of Philadelphia chromosome and BCR-ABL1 fusion gene together with complex chromosome abnormalities, a diagnosis of Philadelphia-positive acute myeloid leukemia was made, although the type （de novo or blast crisis） remained unclear.

Haploidentical hematopoietic stem cell transplantation may improve long-term survival for children with high-risk T-cell acute lymphoblastic leukemia in first complete remission

Background: The role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with high-risk (HR) T-cell acute lymphoblastic leukemia (T-ALL) in first complete remission (CR1) is still under evaluation. Moreover, relapse is the main factor affecting survival. This study aimed to explore the effect of allo-HSCT (especially haploidentical HSCT [haplo-HSCT]) on improving survival and reducing relapse for HR childhood T-ALL in CR1 and the prognostic factors of childhood T-ALL in order to identify who could benefit from HSCT.Methods: A total of 74 newly diagnosed pediatric T-ALL patients between January 1, 2012 and June 30, 2018 were enrolled in this retrospective study. Patients were stratified into the low-risk chemotherapy cohort (n = 16), HR chemotherapy cohort (n = 31), and HR transplant cohort (n = 27). Characteristics, survival outcomes, and prognostic factors of all patients were then analyzed.Results: Patient prognosis in the HR chemotherapy cohort was significantly worse than that in the low-risk chemotherapy cohort (5-year overall survival [OS]: 58.5%vs. 100%,P = 0.003;5-year event-free survival [EFS]: 54.1%vs. 83.4%,P = 0.010;5-year cumulative incidence of relapse [CIR]: 45.2%vs. 6.3%,P = 0.011). In HR patients, allo-HSCT improved the 5-year EFS and CIR compared to that of chemotherapy (5-year EFS: 80.1%vs. 54.1%,P = 0.041;5-year CIR: 11.6%vs. 45.2%,P = 0.006). The 5-year OS was higher in the HR transplant cohort than that in the HR chemotherapy cohort (81.0%vs. 58.5%,P = 0.084). Minimal residual disease re-emergence was an independent risk factor for 5-year OS, EFS, and CIR;age ≥10 years was an independent risk factor for OS and EFS;and high white blood cell count was an independent risk factor for EFS and CIR.Conclusion: Allo-HSCT, especially haplo-HSCT, could effectively reduce relapse of children with HR T-ALL in CR1.

Chromosomal changes detected by fluorescence in situ hybridization in patients with acute lymphoblastic leukemia

Objectives To investigate patients with acute lymphoblastic leukemia (ALL) for TEL/AML1 fusion, BCR/ABL fusion, MLL gene rearrangements, and numerical changes of chromosomes 4, 10, 17 and 21 by fluorescence in situ hybridization (FISH) and to determine the relationship and the significance of those findings.Methods Fifty-one American patients (34 men and 17 women) were included in this study. Of them there were 41 patients with pro-B cell type ALL, 9 with B cell type ALL and 1 with T cell type ALL. Chromosome metaphases of each sample were prepared according to standard protocols. Fluorescence in situ hybridization was performed using commercially available DNA probes, including whole chromosome painting probes, locus specific probes, specific chromosome centromere probes and dual color/multiple color translocation fusion probes. The digital image analysis was carried out using Cytovision and Quips FISH programs.Results An overall incidence of chromosomal anomalies, including t (9; 22), MLL gene rearrangements, t (12;21), and numerical chromosomal anomalies of chromosomes 4, 10, 17 and 21 was found in 33 patients (65%). Thirty-one of them were pediatric patients and two adults. The t (12;21) was the commonest chromosomal anomaly detected in this population; 14 out of the 45 pediatric patients (31%) were positive for TEL/AML1 fusion, among which three had an additional derivative 21 [t (12;21) ], four had a deletion of 12p and two had an extra copy of chromosome 21. All 14 patients with positive TEL/AML1 fusion had ALL pre-B cell or B-cell lineage according to standard immunotyping. The percentage of cells with fusion signals ranged from 20% to 80%. All fourteen patients positive for TEL/AML1 gene fusion were mosaic. Three out of the 14 patients positive for the TEL/AML1 gene fusion were originally reported to be culture failures and none of the remaining eleven samples had been found to have chromosome 12 abnormalities by conventional cytogenetic techniques. All pediatric patients with pre-T or T cell lineage and the six adults were negative for TEL/AML1 fusion. One patient had double Philadelphia chromosomes, three had a rearrangement or a deletion of the MLL gene, one had t (4;11) and two had a deletion of the MLL. One of the patients with an MLL deletion also had a large ring of chromosome 21, and r (21) was caused by AML1 gene tandemly duplicated at least five times. The second case with the MLL deletion was also unique, the patient had at (12;21) as well. A total of 20 patients had numerical changes (gain or loss) of chromosomes 4,10,17 and 21. Eight patients were found to have trisomies of three or four different chromosomes. Interestingly, seven of these patients did not have TEL/AML1, BCR/ ABL or the MLL gene rearrangement; one did have the TEL/AML1 gene fusion. Eleven patients with pro-B cell or 8 cell type ALL (9 children with ALL, 2 adults with ALL) had numerical changes of chromosome 21 (gain 1 or 2 chromosome 21), among them, 10 patients had no structural alteration of chromosome 21, and one was combined by t (12; 21). Four patients had a monosomy of chromosome 17 and three out of these patients with monosomy 17 also had a fusion signal of TEL/AML1. Conclusions FISH plays an important role in detecting chromosome changes, especially in some cryptic chromosome translocations and patients with culture failures. This study found a trend towards a division between patients who had structural changes such as t (12;21) or a ring chromosome 21 and those who had numerical changes of chromosome 21 as well as the patients with TEL/AML1 fusion and patients with the coexistence of numerical chromosomal changes of chromosomes 4, 10 and 17. In our opinion there are two separate mechanisms which lead to the development or progression of leukemia.

Animal models of T-cell acute lymphoblastic leukemia: mimicking the human disease

T-cell acute lymphoblastic leukemia(T-ALL)is a heterogeneous group of hematological tumors composed of distinct subtypes that vary in their genetic abnormalities.In the past decade,large-scale genomic analysis has shed new light on providing potentially important oncogenic or tumor suppressive candidates involved in the disease progression.Following in silico analysis,functional studies are usually performed to vigorously investigate the biological roles of candidate genes.For this purpose,animal models faithfully recapitulating the human disease are widely applied to decipher the mechanism underlying T-cell transformation.Conversely,an increased understanding of T-ALL biology,including identification of oncogene NOTCH1,TAL1 and MYC as well as tumor suppressor phosphatase and tensin homolog(PTEN),has significantly improved the development of T-ALL animal models.These progresses have opened opportunities for development of new therapeutic strategy to benefit T-ALL patients.In this review,we particularly summarize the mouse and zebrafish models used in T-ALL research and also the most recent advances from these in vivo studies.

Precision medicine in acute lymphoblastic leukemia

The cure rate of childhood acute lymphoblastic leukemia(ALL)has exceeded 90%in some contemporary clinical trials.However,the dose intensity of conventional chemotherapy has been pushed to its limit.Further improvement in outcome will need to rely more heavily on molecular therapeutic as well as immuno-and cellular-therapy approaches together with precise risk stratification.Children with ETV6-RUNX1 or hyperdiploid>50 ALL who achieve negative minimal residual disease during early remission induction are suitable candidates for reduction in treatment.Patients with Philadelphia chromosome(Ph)-positive or Ph-like ALL with ABL-class fusion should be treated with dasatinib.BH3 profiling and other preclinical methods have identified several high-risk subtypes,such as hypodiplod,early T-cell precursor,immature T-cell,KMT2A-rearranged,Ph-positive and TCF-HLF-positive ALL,that may respond to BCL-2 inhibitor venetoclax.There are other fusions or mutations that may serve as putative targets,but effective targeted therapy has yet to be established.For other high-risk patients or poor early treatment responders who do not have targetable genetic lesions,current approaches that offer hope include blinatumomab,inotuzumab and CAR-T cell therapy for B-ALL,and daratumumab and nelarabine for T-ALL.With the expanding therapeutic armamentarium,we should start focus on rational combinations of targeted therapy with non-overlapping toxicities.

Is there a role for B lymphocyte chimerism in the monitoring of B-acute lymphoblastic leukemia patients receiving allogeneic stem cell transplantation?

Objective: To determine the sensitivity and significance of B-cell chimerism for the detection of early engraftment, transplant rejection, and disease relapse. Methods: The dynamic monitoring of lineage-specific cell subtypes (B, T, and NK cells) was made in 20 B-cell acute lympho-blastic leukemia (B-ALL) patients following allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the early period after allo-HSCT, the latest establishment of B-cell complete chimerism (CC) was observed in a majority of patients. Results: The percentage of donor cells of B-cell lineage was lower than the percent of T-cell lineage in most of the mixed chimerism (MC) patients. During graft rejection, the frequency of patients with decreasing MC of B-, T-and NK-cell lineage were 5/5, 2/5, and 2/5. When disease relapsed, five patients showed a faster decrease of the donor percent of B-cells than of T-or NK-cells. Only one patient displayed a more rapid decrease in NK-cells than in T-or B-cells. Conclusion: Monitoring of B-cell chimerism after HSCT seems to be valuable for insuring complete engraftment, anticipating graft rejection, and relapse in B-ALL patients. Copyright ? 2015, Chinese Medical Association Production. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

儿童费城染色体样急性淋巴细胞白血病的临床分析

目的:探讨具有治疗靶点的儿童费城染色体样急性淋巴细胞白血病(Ph-like ALL)的临床特点、分子学特征、治疗及预后。方法:2017年12月至2021年6月在苏州大学附属儿童医院初诊且具备靶向药物治疗靶点的儿童Ph-like ALL共27例,回顾性分析患儿年龄、性别、初诊时白细胞计数、遗传学特征、分子生物学改变、化疗方案、给予不同靶向药物、d 19微小残留病(MRD)、d 46 MRD、是否行造血干细胞移植(HSCT)等资料,归纳总结患儿的临床特征及治疗效果。采用Kaplan-Meier方法进行生存分析。结果:27例患儿均根据诱导缓解治疗过程中MRD水平调整化疗强度,10例在治疗过程中加用靶向药,3例患儿桥接HSCT,其中1例死亡,2例存活。24例未行HSCT患儿中,1例患儿出现复发,采用嵌合抗原受体T细胞(CAR-T)治疗后达完全缓解(CR)。27例患儿3年总生存率为(95.5±4.4)%,3年无复发生存率为(95.0±4.9)%,3年无事件生存率为(90.7±6.3)%。结论:基于MRD监测的危险度分层化疗可改善Ph-like ALL患儿预后,对化疗效果欠佳的患儿联合靶向药可尽快完全缓解,诱导缓解治疗过程中MRD持续阳性的Ph-like ALL患儿序贯CAR-T和HSCT能显著提高治疗效果。