Grupp SA, Kalos M, Barrett D, et al.
Chimeric antigen receptor-modified T cells for acute lymphoid leukemia.
N Engl J Med. 2013; 368(16):1509-18 [PubMed]

Chimeric antigen receptor-modified T cells with specificity for CD19 have shown promise in the treatment of chronic lymphocytic leukemia (CLL). It remains to be established whether chimeric antigen receptor T cells have clinical activity in acute lymphoblastic leukemia (ALL). Two children with relapsed and refractory pre-B-cell ALL received infusions of T cells transduced with anti-CD19 antibody and a T-cell signaling molecule (CTL019 chimeric antigen receptor T cells), at a dose of 1.4×10(6) to 1.2×10(7) CTL019 cells per kilogram of body weight. In both patients, CTL019 T cells expanded to a level that was more than 1000 times as high as the initial engraftment level, and the cells were identified in bone marrow. In addition, the chimeric antigen receptor T cells were observed in the cerebrospinal fluid (CSF), where they persisted at high levels for at least 6 months. Eight grade 3 or 4 adverse events were noted. The cytokine-release syndrome and B-cell aplasia developed in both patients. In one child, the cytokine-release syndrome was severe; cytokine blockade with etanercept and tocilizumab was effective in reversing the syndrome and did not prevent expansion of chimeric antigen receptor T cells or reduce antileukemic efficacy. Complete remission was observed in both patients and is ongoing in one patient at 11 months after treatment. The other patient had a relapse, with blast cells that no longer expressed CD19, approximately 2 months after treatment. Chimeric antigen receptor-modified T cells are capable of killing even aggressive, treatment-refractory acute leukemia cells in vivo. The emergence of tumor cells that no longer express the target indicates a need to target other molecules in addition to CD19 in some patients with ALL.

Chaber R, Fiszer-Maliszewska L, Noworolska-Sauren D, et al.
The BCL-2 protein in precursor B acute lymphoblastic leukemia in children.
J Pediatr Hematol Oncol. 2013; 35(3):180-7 [PubMed]

The BCL-2 protein plays an important role in controlling apoptosis. Disorders of this process can lead to the emergence and development of acute lymphoblastic leukemia (ALL) and can determine the resistance of leukemic cells to chemotherapy. The levels of BCL-2 mRNA were determined in 20 children with pre-B ALL using RT-polymerase chain reaction and the percentage of BCL-2+ cells in 51 patients using flow cytofluorometry. Similar levels of BCL-2 mRNA (P=0.18) with a higher percentage of cells BCL-2+ (P=0.04) were shown in the bone marrow of patients with pre-B ALL compared to normal peripheral blood mononuclear cells. We could not find any connection between the level of BCL-2 mRNA or the percentage of BCL-2+ cells and selected clinical features. A high percentage of BCL-2+ cells and high levels of BCL-2 mRNA did not affect the 5-year overall survival probability nor the 5-year relapse-free survival probability. These results may indicate a high activity of mechanisms promoting the development of the final form of the BCL-2 protein from mRNA in leukemic cells. A high BCL-2 level does not affect the clinical course or worsen the prognosis in children with ALL.

Martinez-Mancilla M, Rodriguez-Aguirre I, Tejocote-Romero I, et al.
Clinical relevance of the fusion transcripts distribution pattern in mexican children with acute lymphoblastic leukemia.
J Pediatr Hematol Oncol. 2013; 35(3):170-3 [PubMed]

Chromosomal translocation-generated fusion genes in childhood acute lymphoblastic leukemia (ALL) are well-known indicators of prognostic outcome. This study was conducted to establish the clinical relevance of the fusion genes distribution pattern in Mexican children with newly diagnosed ALL. Multiplex RT-PCR assays were used to detect 4 commonest fusion transcripts in 261 Mexican children with B-cell precursor ALL aged 1 to 14 years old, comparing differences in the distribution of the patients between molecular subgroups to a common collection of clinical parameters. We documented a 13% significant proportion of all patients who are more than 10 years of age, harboring fusion transcripts associated with leukocytosis and poor response to remission-induction chemotherapy, than those negative children for chimeric transcripts (P<0.001). Most notable observation was identified a significant number of e2a-pbx1-positive patients who showed a more aggressive disease at diagnosis. As presented here, this report gives an overview of the clinical implications of the fusion gene positivity in Mexican children with ALL in the context of traditional risk stratification variables. Our data support the existence of important ethnic and geographic differences in Mexican population.

Shimizu H, Handa H, Hatsumi N, et al.
Distinctive disease subgroups according to differentiation stages in adult patients with T-cell acute lymphoblastic leukemia.
Eur J Haematol. 2013; 90(4):301-7 [PubMed]

OBJECTIVES: The categorization of T-cell acute lymphoblastic leukemia (T-ALL) into four subgroups according to the degree of thymic differentiation was proposed in 1995, and this categorization scheme has been described in the World Health Organization classification 4th edition with minor changes. The aim of this study is to explore the clinical significance of leukemia cell differentiation stages in patients with T-ALL.
METHODS: We analyzed 36 adult T-ALL patients, including six patients (17%) in pro-T stage, 16 (44%) in pre-T stage, three (8%) in cortical-T stage, and 11 (31%) in medullary-T stage. Pro-T and pre-T stages were arbitrarily clustered as the immature group, and cortical-T and medullary-T stages as the mature group.
RESULTS: Patients in the immature group had unique presentations, including lower lactate dehydrogenase levels, lower frequency of mediastinal tumor, and higher expression of myeloid antigens than the mature group. There was no difference in the treatment strategies between both groups. Although patients in the immature group had a lower complete remission (CR) rate when compared with the mature group (45% vs. 79%, respectively; P = 0.04), the 3-yr overall survival (OS) for both groups was comparable (27% vs. 38%, respectively; P = 0.66). Such discrepancy between the CR rates and the OS could be partially explained by survival benefit of allogeneic transplantation observed in the immature group but not in the mature group.
CONCLUSIONS: These findings indicate that T-ALL patients can be categorized into two biologically distinctive subgroups according to the differentiation stages, and this stratification might enable prospective identification of patients with poor chemotherapy response.

Khandanpour C, Phelan JD, Vassen L, et al.
Growth factor independence 1 antagonizes a p53-induced DNA damage response pathway in lymphoblastic leukemia.
Cancer Cell. 2013; 23(2):200-14 [PubMed] Article available free on PMC after 11/02/2014

Most patients with acute lymphoblastic leukemia (ALL) fail current treatments highlighting the need for better therapies. Because oncogenic signaling activates a p53-dependent DNA damage response and apoptosis, leukemic cells must devise appropriate countermeasures. We show here that growth factor independence 1 (Gfi1) can serve such a function because Gfi1 ablation exacerbates p53 responses and lowers the threshold for p53-induced cell death. Specifically, Gfi1 restricts p53 activity and expression of proapoptotic p53 targets such as Bax, Noxa (Pmaip1), and Puma (Bbc3). Subsequently, Gfi1 ablation cures mice from leukemia and limits the expansion of primary human T-ALL xenografts in mice. This suggests that targeting Gfi1 could improve the prognosis of patients with T-ALL or other lymphoid leukemias.

Tzoneva G, Perez-Garcia A, Carpenter Z, et al.
Activating mutations in the NT5C2 nucleotidase gene drive chemotherapy resistance in relapsed ALL.
Nat Med. 2013; 19(3):368-71 [PubMed] Article available free on PMC after 03/08/2013

Acute lymphoblastic leukemia (ALL) is an aggressive hematological tumor resulting from the malignant transformation of lymphoid progenitors. Despite intensive chemotherapy, 20% of pediatric patients and over 50% of adult patients with ALL do not achieve a complete remission or relapse after intensified chemotherapy, making disease relapse and resistance to therapy the most substantial challenge in the treatment of this disease. Using whole-exome sequencing, we identify mutations in the cytosolic 5'-nucleotidase II gene (NT5C2), which encodes a 5'-nucleotidase enzyme that is responsible for the inactivation of nucleoside-analog chemotherapy drugs, in 20/103 (19%) relapse T cell ALLs and 1/35 (3%) relapse B-precursor ALLs. NT5C2 mutant proteins show increased nucleotidase activity in vitro and conferred resistance to chemotherapy with 6-mercaptopurine and 6-thioguanine when expressed in ALL lymphoblasts. These results support a prominent role for activating mutations in NT5C2 and increased nucleoside-analog metabolism in disease progression and chemotherapy resistance in ALL.

Tanir MK, Kuguoglu S
Impact of exercise on lower activity levels in children with acute lymphoblastic leukemia: a randomized controlled trial from Turkey.
Rehabil Nurs. 2013 Jan-Feb; 38(1):48-59 [PubMed]

This randomized, controlled experimental study was carried out to determine the effects of an exercise program on both physical parameters and the quality of life of children with acute lymphoblastic leukemia (ALL). A total of 41 children with ALL (20 trial and 21 control cases) at two university hospitals were accepted into the study. Due to the demise of one of the children in the trial group, the study was completed with 19 trial and 21 control patients, a total of 40 children and their parents. Regular and systematic exercise regimens implemented by children with ALL have resulted in improved testing results, enhanced physical performance, and better laboratory results compared with a control group and to children's scores before the initiation of such a program.

Vrooman LM, Stevenson KE, Supko JG, et al.
Postinduction dexamethasone and individualized dosing of Escherichia Coli L-asparaginase each improve outcome of children and adolescents with newly diagnosed acute lymphoblastic leukemia: results from a randomized study--Dana-Farber Cancer Institute ALL Consortium Protocol 00-01.
J Clin Oncol. 2013; 31(9):1202-10 [PubMed] Article available free on PMC after 20/03/2014

PURPOSE: We assessed the toxicity and efficacy of dexamethasone and a novel dosing method of Escherichia coli L-asparaginase (EC-Asnase) in children and adolescents with newly diagnosed acute lymphoblastic leukemia (ALL).
PATIENTS AND METHODS: Patients achieving complete remission (CR) on Dana-Farber Cancer Institute ALL Consortium Protocol 00-01 were eligible for random assignment to 1) dexamethasone or prednisone, administered as 5-day pulses, every 3 weeks, and 2) weekly EC-Asnase, administered as a 25,000 IU/m(2) fixed dose (FD) or individualized dose (ID) starting at 12,500-IU/m(2), adjusted every 3 weeks based on nadir serum asparaginase activity (NSAA) determinations.
RESULTS: Between 2000 and 2004, 492 evaluable patients (ages 1 to 18 years) enrolled; 473 patients (96%) achieved CR. Four hundred eight patients (86%) participated in the corticosteroid randomization and 384 patients (81%) in the EC-Asnase randomization. With 4.9 years of median follow-up, dexamethasone was associated with superior 5-year event-free survival (EFS; 90% v 81% for prednisone; P = .01) but higher rates of infection (P = .03) and, in older children, higher cumulative incidence of osteonecrosis (P = .02) and fracture (P = .06). ID EC-Asnase had superior 5-year EFS (90% v 82% for FD; P = .04), but did not reduce the frequency of asparaginase-related toxicity. Multivariable analysis identified both dexamethasone and ID EC-Asnase as independent predictors of favorable EFS.
CONCLUSION: There was no overall difference in skeletal toxicity by corticosteroid type; dexamethasone was associated with more infections and, in older children, increased incidence of osteonecrosis and fracture. There was no difference in asparaginase-related toxicity by EC-Asnase dosing method. Dexamethasone and ID EC-Asnase were each associated with superior EFS. Monitoring NSAA during treatment with EC-Asnase may be an effective strategy to improve outcome in pediatric ALL.

Sharma A, Gupta R, Rizvi Y, et al.
Acute renal failure in a patient with acute lymphoblastic leukemia: a rare cause.
Saudi J Kidney Dis Transpl. 2013; 24(1):93-6 [PubMed]

A young adult was diagnosed to have acute lymphoblastic leukemia, T-cell immunophenotype and was initiated on chemotherapy. He presented with acute renal failure two days after the completion of his induction regimen. A renal biopsy showed features of necrotizing crescentic glomerulonephritis (GN). Serology for c-anti-neutrophil cytoplasmic antibody (ANCA) was positive and a final diagnosis of ANCA-associated necrotizing crescentic GN was made. Aggressive immunosuppression could not be used due to the presence of nosocomial pneumonia and the patient expired 26 days after the renal biopsy diagnosis. We report for the first time the association of acute lymphoblastic leukemia with crescentic GN and, hence, expand the list of malignancy-related ANCA-positive GN.

Mendivil-Perez M, Velez-Pardo C, Jimenez-Del-Rio M
TPEN induces apoptosis independently of zinc chelator activity in a model of acute lymphoblastic leukemia and ex vivo acute leukemia cells through oxidative stress and mitochondria caspase-3- and AIF-dependent pathways.
Oxid Med Cell Longev. 2012; 2012:313275 [PubMed] Article available free on PMC after 20/03/2014

Acute lymphoblastic leukemia is still an incurable disease with resistance to therapy developing in the majority of patients. We investigated the effect of TPEN, an intracellular zinc chelator, in Jurkat and in ex vivo acute lymphoblastic leukemia (ALL) cells resistant to chemotherapy. Changes of nuclei morphology, reactive oxygen species generation, presence of hypodiploid cells, phosphatidylserine translocation, mitochondrial membrane depolarization, immunohistochemical identification of cell death signalling molecules, and pharmacological inhibition were assayed to detect the apoptotic cell death pathways. We found that TPEN induces apoptosis in both types of cells by a molecular oxidative stress pathway involving O(2)(•-) > H(2)O(2) > NF-κB (JNK/c-Jun) >p53> loss ΔΨ(m)> caspase-3, AIF > chromatin condensation/DNA fragmentation. Interestingly, TPEN induced apoptosis independently of glucose; leukemic cells are therefore devoid of survival capacity by metabolic resistance to treatment. Most importantly, TPEN cytotoxic effect can eventually be regulated by the antioxidant N-acetyl-cysteine and zinc ions. Our data suggest that TPEN can be used as a potential therapeutic prooxidant agent against refractory leukemia. These data contribute to understanding the importance of oxidative stress in the treatment of ALL.

Hsieh YT, Gang EJ, Geng H, et al.
Integrin alpha4 blockade sensitizes drug resistant pre-B acute lymphoblastic leukemia to chemotherapy.
Blood. 2013; 121(10):1814-8 [PubMed] Article available free on PMC after 07/03/2014

Bone marrow (BM) provides chemoprotection for acute lymphoblastic leukemia (ALL) cells, contributing to lack of efficacy of current therapies. Integrin alpha4 (alpha4) mediates stromal adhesion of normal and malignant B-cell precursors, and according to gene expression analyses from 207 children with minimal residual disease, is highly associated with poorest outcome. We tested whether interference with alpha4-mediated stromal adhesion might be a new ALL treatment. Two models of leukemia were used, one genetic (conditional alpha4 ablation of BCR-ABL1 [p210(+)] leukemia) and one pharmacological (anti-functional alpha4 antibody treatment of primary ALL). Conditional deletion of alpha4 sensitized leukemia cell to nilotinib. Adhesion of primary pre-B ALL cells was alpha4-dependent; alpha4 blockade sensitized primary ALL cells toward chemotherapy. Chemotherapy combined with Natalizumab prolonged survival of NOD/SCID recipients of primary ALL, suggesting adjuvant alpha4 inhibition as a novel strategy for pre-B ALL.

Naderi EH, Ugland HK, Diep PP, et al.
Selective inhibition of cell death in malignant vs normal B-cell precursors: implications for cAMP in development and treatment of BCP-ALL.
Blood. 2013; 121(10):1805-13 [PubMed]

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is the most commonly occurring pediatric cancer. Despite its relatively good prognosis, there is a steady search for strategies to improve treatment effects and prevent the undesired side effects on normal cells. In the present paper, we demonstrate a differential effect of cyclic adenosine monophosphate (cAMP) signaling between normal BCPs and BCP-ALL blasts, pointing to a potential therapeutic window allowing for manipulation of cAMP signaling in the treatment of BCP-ALL. By studying primary cells collected from pediatric BCP-ALL patients and healthy controls, we found that cAMP profoundly decreased basal and DNA damage-induced p53 levels and cell death in malignant cells, whereas normal BCP counterparts displayed slightly augmented cell death when exposed to cAMP-increasing agents. We did not find evidence for a selection process involving generation of increased basal cAMP levels in BCP-ALL cells, but we demonstrate that paracrine signaling involving prostaglandin E2-induced cAMP generation has the potential to suppress p53 activation and cell death induction. The selective inhibitory effect of cAMP signaling on DNA damage-induced cell death in BCP-ALL cells appears to be an acquired trait associated with malignant transformation, potentially allowing the use of inhibitors of this pathway for directed killing of the malignant blasts.

Köchling J, Schmidt M, Rott Y, et al.
Can anthocyanins improve maintenance therapy of Ph(+) acute lymphoblastic leukaemia?
Eur J Haematol. 2013; 90(4):291-300 [PubMed]

Chemotherapy and tyrosine kinase inhibitors provide high remission rates. However, prognosis of adult patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph(+) ALL) still remains poor. Because most adults eventually relapse without allogeneic stem cell transplantation, which is not available for all patients, novel strategies are required for relapse prevention. As the integrity of the immune system is essential for the control of remaining leukaemia cells, we compared the efficacy of anthocyanins, imatinib and a DNA-based vaccine as non-immunosuppressant components with 6-mercaptopurine (6-MP) to control minimal residual disease in vitro and in vivo using different leukaemia cell lines and syngeneic mice. Proliferation of Ph(+) ALL was significantly better inhibited by anthocyanin-rich berry extract or imatinib compared with 6-MP. Although anthocyanins induced apoptosis in some leukaemia cell lines, the level of caspase-3, caspase-8 and caspase-9 was significantly lower compared with imatinib and 6-MP. When used as single components, anthocyanins and imatinib mesylate failed to eradicate pre-existing Ph(+) ALL in syngeneic mice, while 6-MP led to 10% and DNA vaccination to 56% survival. Intriguingly, only the combination of DNA vaccination with berry extract but not with the isolated anthocyanin, cyanidin-3-rutinoside or imatinib further increased leukaemia-free and overall survival, and 90% of lethally challenged mice survived. We suggest that induction and enhancement of a leukaemia-specific immunity by DNA vaccination and anthocyanin-rich berry extract can also decrease the relapse rate in patients with Ph(+) ALL. Furthermore, this approach may serve as strategy for maintenance therapy of other malignancies.

Zou J, Li P, Lu F, et al.
Notch1 is required for hypoxia-induced proliferation, invasion and chemoresistance of T-cell acute lymphoblastic leukemia cells.
J Hematol Oncol. 2013; 6:3 [PubMed] Article available free on PMC after 07/03/2014

BACKGROUND: Notch1 is a potent regulator known to play an oncogenic role in many malignancies including T-cell acute lymphoblastic leukemia (T-ALL). Tumor hypoxia and increased hypoxia-inducible factor-1α (HIF-1α) activity can act as major stimuli for tumor aggressiveness and progression. Although hypoxia-mediated activation of the Notch1 pathway plays an important role in tumor cell survival and invasiveness, the interaction between HIF-1α and Notch1 has not yet been identified in T-ALL. This study was designed to investigate whether hypoxia activates Notch1 signalling through HIF-1α stabilization and to determine the contribution of hypoxia and HIF-1α to proliferation, invasion and chemoresistance in T-ALL.
METHODS: T-ALL cell lines (Jurkat, Sup-T1) transfected with HIF-1α or Notch1 small interference RNA (siRNA) were incubated in normoxic or hypoxic conditions. Their potential for proliferation and invasion was measured by WST-8 and transwell assays. Flow cytometry was used to detect apoptosis and assess cell cycle regulation. Expression and regulation of components of the HIF-1α and Notch1 pathways and of genes related to proliferation, invasion and apoptosis were assessed by quantitative real-time PCR or Western blot.
RESULTS: Hypoxia potentiated Notch1 signalling via stabilization and activation of the transcription factor HIF-1α. Hypoxia/HIF-1α-activated Notch1 signalling altered expression of cell cycle regulatory proteins and accelerated cell proliferation. Hypoxia-induced Notch1 activation increased the expression of matrix metalloproteinase-2 (MMP2) and MMP9, which increased invasiveness. Of greater clinical significance, knockdown of Notch1 prevented the protective effect of hypoxia/HIF-1α against dexamethasone-induced apoptosis. This sensitization correlated with losing the effect of hypoxia/HIF-1α on Bcl-2 and Bcl-xL expression.
CONCLUSIONS: Notch1 signalling is required for hypoxia/HIF-1α-induced proliferation, invasion and chemoresistance in T-ALL. Pharmacological inhibitors of HIF-1α or Notch1 signalling may be attractive interventions for T-ALL treatment.

Vasekar M, Allen JE, Joudeh J, Claxton D
Emerging molecular therapies for the treatment of acute lymphoblastic leukemia.
Adv Exp Med Biol. 2013; 779:341-58 [PubMed]

The improved molecular understanding of cancer initiation, progression, and therapeutic resistance has yielded several novel molecular events that are being targeted by emerging therapies. While the treatment of ALL is a success story in the pediatric population, achieving a sustained remission in the adult population remains an area of investigation. Nevertheless, certain therapies have significantly improved the overall survival for adult ALL patients that should continue to improve with the discovery of better molecular targets and targeted agents. Here, we discuss novel therapeutic options under clinical investigation for the treatment of Philadephia chromosome negative ALL including immunotherapy, monoclonal antibodies, and small molecules that may be used as single agent or adjuvant therapy in the management of adult ALL.

Gowda C, Dovat S
Genetic targets in pediatric acute lymphoblastic leukemia.
Adv Exp Med Biol. 2013; 779:327-40 [PubMed]

Acute leukemia represents 31% of all cancers diagnosed in children and 80% of it is of Lymphoblastic type. Multiple genetic lesions in the hematopoietic progenitor cells prior to or during differentiation to B and T cell lead to development of leukemia. There are several subtypes of Acute Leukemia based on chromosome number changes, the presence of certain translocations and gene mutations, each of which has different clinical, biological and prognostic features. High throughput genomic technologies like array-based comparative genomic hybridization (array-CGH) and single nucleotide polymorphism microarrays (SNP arrays), have given us insight through a very detailed look at the genetic changes of leukemia, specifically, ALL. Here, we discuss various genetic mutations identified in Acute Lymphoblastic Leukemia. We also explore various genetic targets and currently available as well as upcoming targeted therapies for ALL.

Lamanna N, Heffner LT, Kalaycio M, et al.
Treatment of adults with acute lymphoblastic leukemia: do the specifics of the regimen matter?: Results from a prospective randomized trial.
Cancer. 2013; 119(6):1186-94 [PubMed]

BACKGROUND: Induction therapy for adults with acute lymphoblastic leukemia (ALL) is similar across essentially all regimens, comprised of vincristine, corticosteroids, and anthracyclines intensified with cyclophosphamide, asparaginase, or both. Given the lack of randomized data, to date, no regimen has emerged as standard. The authors previously evaluated cytarabine 3 g/m(2) daily for 5 days with mitoxantrone 80 mg/m(2) (the ALL-2 regimen) as a novel induction regimen. Compared with historic controls, the ALL-2 regimen was superior in terms of incidence of complete remission, failure with resistant disease, and activity in patients with Philadelphia chromosome (Ph)-positive ALL.
METHODS: The authors conducted a multicenter, prospective, randomized trial of the ALL-2 regimen compared with a standard 4-drug induction (the L-20 regimen). Patients also received consolidation, maintenance therapy, and central nervous system prophylaxis. The trial accrued patients from August 1996 to October 2004.
RESULTS: The median follow-up for survivors was 7 years, and the median patient age was 43 years. Responses were evaluated in 164 patients. The treatment arms were balanced in terms of pretreatment characteristics. The frequency of complete remission for the ALL-2 regimen versus the L-20 regimen was 83% versus 71% (P = .06). More patients on the L-20 arm failed with resistant disease (21% vs 8%; P = .02). Induction deaths were comparable at 9% (ALL-2) versus 7% (L-20). The median survival was similar; and, at 5 years, the survival rate was 33% alive on the ALL-2 arm versus 27% on the L-20.
CONCLUSIONS: Despite superior results of induction therapy with the ALL-2 regimen, this treatment did not improve long-term outcomes. When coupled to the reported experience of other studies in adults with ALL, the results of this randomized trial raise the possibility that ultimate outcomes in adult ALL may be independent of the specific regimen chosen. Cancer 2013. © 2012 American Cancer Society.

Diamanti P, Cox CV, Moppett JP, Blair A
Parthenolide eliminates leukemia-initiating cell populations and improves survival in xenografts of childhood acute lymphoblastic leukemia.
Blood. 2013; 121(8):1384-93 [PubMed]

Approximately 20% of children with acute lymphoblastic leukemia (ALL) relapse because of failure to eradicate the disease. Current drug efficacy studies focus on reducing leukemia cell burden. However, if drugs have limited effects on leukemia-initiating cells (LICs), then these cells may expand and eventually cause relapse. Parthenolide (PTL) has been shown to cause apoptosis of LIC in acute myeloid leukemia. In the present study, we assessed the effects of PTL on LIC populations in childhood ALL. Apoptosis assays demonstrated that PTL was effective against bulk B- and T-ALL cells, whereas the CD34(+)/CD19(-), CD34(+)/CD7(-), and CD34(-) subpopulations were more resistant. However, functional analyses revealed that PTL treatment prevented engraftment of multiple LIC populations in NOD/LtSz-scid IL-2Rγ(c)-null mice. PTL treatment of mice with established leukemias from low- and high-risk patients resulted in survival and restoration of normal murine hemopoiesis. In only 3 cases, disease progression was significantly slowed in mice engrafted with CD34(+)/CD19(-) or CD34(+)/CD7(-) and CD34(-) cells, but was not prevented, demonstrating that individual LIC populations within patients have different responses to therapy. These observations indicate that PTL may have therapeutic potential in childhood ALL and provide a basis for developing effective therapies that eradicate all LIC populations to prevent disease progression and reduce relapse.

De Keersmaecker K, Atak ZK, Li N, et al.
Exome sequencing identifies mutation in CNOT3 and ribosomal genes RPL5 and RPL10 in T-cell acute lymphoblastic leukemia.
Nat Genet. 2013; 45(2):186-90 [PubMed]

T-cell acute lymphoblastic leukemia (T-ALL) is caused by the cooperation of multiple oncogenic lesions. We used exome sequencing on 67 T-ALLs to gain insight into the mutational spectrum in these leukemias. We detected protein-altering mutations in 508 genes, with an average of 8.2 mutations in pediatric and 21.0 mutations in adult T-ALL. Using stringent filtering, we predict seven new oncogenic driver genes in T-ALL. We identify CNOT3 as a tumor suppressor mutated in 7 of 89 (7.9%) adult T-ALLs, and its knockdown causes tumors in a sensitized Drosophila melanogaster model. In addition, we identify mutations affecting the ribosomal proteins RPL5 and RPL10 in 12 of 122 (9.8%) pediatric T-ALLs, with recurrent alterations of Arg98 in RPL10. Yeast and lymphoid cells expressing the RPL10 Arg98Ser mutant showed a ribosome biogenesis defect. Our data provide insights into the mutational landscape of pediatric versus adult T-ALL and identify the ribosome as a potential oncogenic factor.

Forman SJ, Rowe JM
The myth of the second remission of acute leukemia in the adult.
Blood. 2013; 121(7):1077-82 [PubMed] Article available free on PMC after 14/02/2014

Although the majority of adult patients with both acute lymphoblastic leukemia and acute myelogenous leukemia achieve remission with upfront chemotherapy, many patients still suffer relapse. Often, the strategy is proposed of treating patients with relapsed leukemia into a second remission (CR2) and then proceeding to allogeneic transplantation as the definitive curative approach. However, the long-term outcomes of such a strategy are poor: the 5-year overall survival from first relapse for patients with acute leukemia is only approximately 10%. This Perspective highlights the fact that most patients do not achieve CR2 and therefore never really have an opportunity for a potential curative therapy. Although patients who undergo transplantation after relapse may be cured, those who do not achieve CR2 are rarely candidates for transplantation; therefore, the overall outcome for patients who relapse is dismal. There is therefore an urgent need not only for more effective upfront therapy to prevent relapse, but also for the development of therapies that can serve as effective bridging treatments between relapse and transplantation. We suggest that more optimal use of minimal residual disease detection during first remission may also improve the chances for successful transplantation therapy via earlier reinduction therapy, allowing transplantation before overt relapse.

Haso W, Lee DW, Shah NN, et al.
Anti-CD22-chimeric antigen receptors targeting B-cell precursor acute lymphoblastic leukemia.
Blood. 2013; 121(7):1165-74 [PubMed] Article available free on PMC after 14/02/2014

Immune targeting of B-cell malignancies using chimeric antigen receptors (CARs) is a promising new approach, but critical factors impacting CAR efficacy remain unclear. To test the suitability of targeting CD22 on precursor B-cell acute lymphoblastic leukemia (BCP-ALL), lymphoblasts from 111 patients with BCP-ALL were assayed for CD22 expression and all were found to be CD22-positive, with median CD22 expression levels of 3500 sites/cell. Three distinct binding domains targeting CD22 were fused to various TCR signaling domains ± an IgG heavy chain constant domain (CH2CH3) to create a series of vector constructs suitable to delineate optimal CAR configuration. CARs derived from the m971 anti-CD22 mAb, which targets a proximal CD22 epitope demonstrated superior antileukemic activity compared with those incorporating other binding domains, and addition of a 4-1BB signaling domain to CD28.CD3 constructs diminished potency, whereas increasing affinity of the anti-CD22 binding motif, and extending the CD22 binding domain away from the membrane via CH2CH3 had no effect. We conclude that second-generation m971 mAb-derived anti-CD22 CARs are promising novel therapeutics that should be tested in BCP-ALL.

Rayar M, Webber CE, Nayiager T, et al.
Sarcopenia in children with acute lymphoblastic leukemia.
J Pediatr Hematol Oncol. 2013; 35(2):98-102 [PubMed]

Children with acute lymphoblastic leukemia experience musculoskeletal morbidity during therapy. We examined the patterns of change in skeletal muscle mass (SMM) and the relationship between change in SMM and the burden of illness as reflected in days of hospitalization. Ninety-one children had dual energy x-ray absorptiometry (DXA scans) during treatment, yielding the sum of lean tissue mass in all 4 limbs; the appendicular lean mass. SMM was derived from appendicular lean mass. The number of inpatient days was recorded. DXA scans at 5 time points showed a profile of change in SMM characterized by a drop in the mean Z score from -0.18 at diagnosis to -1.08 after 6 months of therapy, with a partial recovery 12 to 24 months after diagnosis. Levels of serum creatinine, a surrogate measure of SMM, were mainly unchanged. The extent of the drop in SMM during early therapy was associated with the duration of hospitalization (r=0.31, P<0.05). Children with acute lymphoblastic leukemia experience a notable reduction in SMM early in treatment, with incomplete recovery. The degree of loss is associated with the burden of illness. These findings provide a target for a therapeutic intervention and a measure to determine its efficacy.

Racke F, Cole C, Walker A, et al.
Therapy-related pro-B cell acute lymphoblastic leukemia: report of two patients with MLL amplification.
Cancer Genet. 2012; 205(12):653-6 [PubMed]

Improvements in chemotherapy and medical support of patients treated with chemotherapy and radiation have led to an ever-increasing number of cancer survivors. Unfortunately, a small fraction of these patients develop secondary hematologic malignancies as a consequence of their exposure to genotoxic anti-cancer regimens. Most of these are myeloid malignancies, therapy-related acute myeloid leukemia (t-AML) or myelodysplasia (t-MDS); however, a small but growing body of literature exists, which describes therapy-related acute lymphoblastic leukemias (t-ALL). Nearly all these cases are reportedly associated with translocations involving chromosome 11q23, the site of the MLL gene. We herein report two cases of ALL occurring after chemotherapy for other malignancies that showed complex karyotypic abnormalities and distinct MLL amplification by fluorescence in situ hybridization analysis. Immunophenotypic analysis showed that both cases expressed a pro-B cell (CD10-) phenotype with aberrant myeloid antigen expression. Although MLL amplification has been reported in therapy-related myeloid disease, to our knowledge this is the first report of MLL amplification occurring in therapy-related B cell ALL.

Lin TC, Liu RS, Chao YT, Chen SY
Classifying subtypes of acute lymphoblastic leukemia using silhouette statistics and genetic algorithms.
Gene. 2013; 518(1):159-63 [PubMed]

Correct classification and prediction of tumor cells is essential for a successful diagnosis and reliable future treatment. In this study, we aimed at using genetic algorithms for feature selection and proposed silhouette statistics as a discriminant function to distinguish between six subtypes of pediatric acute lymphoblastic leukemia by using microarray with thousands of gene expressions. Our methods have shown a better classification accuracy than previously published methods and obtained a set of genes effective to discriminate subtypes of pediatric acute lymphoblastic leukemia. Furthermore, the use of silhouette statistics, offering the advantages of measuring the classification quality by a graphical display and by an average silhouette width, has also demonstrated feasibility and novelty for more difficult multiclass tumor prediction problems.

Islam N, Rahman MM, Aziz MA, et al.
Outcome of adult acute lymphoblastic leukaemia following induction chemotherapy with modified MRC UKALL XII/ECOG E2993 protocol.
Bangladesh Med Res Counc Bull. 2012; 38(2):43-6 [PubMed]

Cure rates for adult acute lymphoblastic leukaemia (ALL) in developing countries are significantly lower because of problems unique to these countries. Recent studies have reported complete response rates for any induction regimen of more than 90% in adult ALL patients. This study was conducted to evaluate the response rate of induction chemotherapy in adult ALL patients in the Department of Haematology, Bangabandhu Sheikh Mujib Medical University, from January 2007 to December 2008. In this observational study, 35 newly diagnosed ALL patients classified either as L1/L2 according to French-American-British (FAB) classification, aged between 15 to 60 years were assigned for induction therapy with modified MRC UKALL XII/ECOG E2993 protocol. But ultimately 30 patients completed therapy and available for statistical analysis. Among the studied 30 cases 12(40%) patients after phase 1 and overall 24 (80%) patients after phase 2 induction therapy, achieved morphologic complete remission (CR). After phase 2 therapy 6 (20%) patients fell in the group of non responders (NR) as the blast percentage was > or = 5% at the time of bone marrow evaluation. This study shows the response rates in adult ALL with induction therapy slightly below the anticipated response rates of developed countries which may be due to little modification of the original protocol.

Miyawaki Y, Imoto I, Tokairin Y, et al.
Esophageal squamous cell carcinoma developed 11 years after allogeneic bone marrow transplantation for acute lymphatic leukemia.
Jpn J Clin Oncol. 2013; 43(1):69-73 [PubMed]

Younger patients (aged <30 years) presenting with esophageal cancer are rare. Bone marrow transplantation offers a curative therapy in patients with malignant and nonmalignant lymphohematopoietic diseases and other disorders. However, one important late complication in transplantation survivors is the development of secondary malignancies including solid tumors. Although some solid cancers have been demonstrated to occur after bone marrow transplantation, only a few cases of esophageal squamous cell carcinoma have thus far been reported. We herein describe the case of a 27-year-old male with esophageal squamous cell carcinoma, who was diagnosed with T-cell-type acute lymphatic leukemia at the age of 12 and relapsed 5 years later. He achieved a second complete remission and underwent bone marrow transplantation at the age of 17. A genetic analysis revealed germ-line lineage-derived chimeric cellular populations of the donor and patient on both the esophageal squamous cell carcinoma and non tumorous portions of the patient's esophageal mucosa with a preponderance of the patient's germ-line lineage-derived cells, suggesting that repopulated donor-derived hemopoietic stem cells in the esophageal epithelia only partially contributed to the carcinogenesis of esophageal squamous cell carcinoma several years after bone marrow transplantation. Multiple events occurring during the course of treatment for primary hematological disorder may play an important role in the development of esophageal squamous cell carcinoma.

Styczynski J, Piatkowska M, Jaworska-Posadzy A, et al.
Comparison of prognostic value of in vitro drug resistance and bone marrow residual disease on day 15 of therapy in childhood acute lymphoblastic leukemia.
Anticancer Res. 2012; 32(12):5495-9 [PubMed]

AIM: The analysis of the prognostic impact of residual disease at day 15 of induction therapy, individual tumor response testing (ITRT) at diagnosis, initial factors and initial therapy response to the risk of relapse in children with precursor B-cell acute lymphoblastic leukemia (ALL).
PATIENTS AND METHODS: A total of 87 children were tested at diagnosis for ITRT and for persistence of blasts in bone marrow at day 15 (BML15>0.5%) and were followed-up in long-term analysis.
RESULTS: The probability of disease-free survival (pDFS) was significantly better for patients with an ITRT profile showing sensitivity to prednisolone, vincristine, daunorubicin, and L-asparaginase. Patients with BML15>0.5% had higher ITRT for prednisolone, daunorubicin, L-asparaginase, and etoposide. Three factors had predictive impact for relapse: BML15>0.5%, ITRT for prednisolone and high combined ITRT profile for prednisolone, vincristine and L-asparaginase (PVA score).
CONCLUSION: Persistence of blasts in bone marrow at day 15, ITRT showing resistance to prednisolone and high PVA score were the strongest and comparable prognostic factors predicting relapse in childhood ALL.

Stojak M, Mazur L, Opydo-Chanek M, et al.
Effects of structural modifications of daunorubicin on in vitro antileukemic activity.
Anticancer Res. 2012; 32(12):5271-7 [PubMed]

BACKGROUND/AIM: In the search for new derivatives of anthracycline antibiotics, formamidinodaunorubicins containing in the amidine group either a morpholine moiety (DAUFmor) or a hexamethyleneimine moiety (DAUFhex) were synthesized. The biological effects of daunorubicin (DAU), DAUFmor and DAUFhex were compared.
MATERIALS AND METHODS: The experiments were performed on human acute lymphoblastic leukemia MOLT-4 cells and human acute myeloblastic leukemia ML-1 cells. The research was conducted using the spectrophotometric 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay and the electronic Beckman-Coulter method.
RESULTS: Temporary changes in the leukemia cell viability, size and count were found. The antileukemic activities of the new DAU analogs were weaker than that of daunorubicin. MOLT-4 cells were more sensitive than ML-1 cells to the action of all agents. Among the formamidinodaunorubicins, DAUFmor appeared to be more active in ML-1 cells than DAUFhex, but there were not differences between the analyzed values in MOLT-4 cells.
CONCLUSION: The structural modifications of daunorubicin were responsible for the different antileukemic potentials of the two formamidinodaunorubicins.

Singla A, Brace O'Neill JE, Smith E, Scott RM
Cavernous malformations of the brain after treatment for acute lymphocytic leukemia: presentation and long-term follow-up.
J Neurosurg Pediatr. 2013; 11(2):127-32 [PubMed]

OBJECT: The authors undertook this study to determine the clinical course and long-term outcomes in pediatric patients who developed cavernous malformations of the brain following treatment for acute lymphocytic leukemia (ALL).
METHODS: They reviewed the senior author's database of surgically treated cavernous malformations of the brain to identify those patients whose cavernous malformations developed after cranial radiation during treatment for ALL. The medical records of these patients were reviewed to determine their clinical presentation, radiological findings, and outcome at long-term follow-up.
RESULTS: Five patients fulfilled the specified criteria over a 23-year period. At the time of ALL diagnosis, they were all 4-5 years old. The cerebral cavernous malformations developed 2-8 years after cranial radiation, and 4 of the 5 patients presented with neurological symptoms, which ranged from focal deficits to seizures. Two patients required a second craniotomy, one from lesion recurrence possibly due to incomplete resection, and another for a second cavernous malformation, which developed at another site 6 years after the initial malformation was excised. Long-term follow-up of 2, 10, 11, 11, and 17 years has revealed no additional lesion development or recurrence.
CONCLUSIONS: Symptomatic cavernous malformations of the brain may develop several years after chemotherapy and cranial radiation treatment for ALL, and the clinical course of these cavernous malformations may be more aggressive than that of the typical post-radiation lesions seen in other conditions. Long-term clinical and imaging monitoring is recommended for children who have undergone treatment for ALL. Craniotomy for excision of the malformations appears to convey long-term protection from repeat hemorrhage and accumulating neurological deficits.

Loh ML, Zhang J, Harvey RC, et al.
Tyrosine kinome sequencing of pediatric acute lymphoblastic leukemia: a report from the Children's Oncology Group TARGET Project.
Blood. 2013; 121(3):485-8 [PubMed] Article available free on PMC after 17/01/2014

One recently identified subtype of pediatric B-precursor acute lymphoblastic leukemia (ALL) has been termed BCR-ABL1-like or Ph-like because of similarity of the gene expression profile to BCR-ABL1 positive ALL suggesting the presence of lesions activating tyrosine kinases, frequent alteration of IKZF1, and poor outcome. Prior studies demonstrated that approximately half of these patients had genomic lesions leading to CRLF2 overexpression, with half of such cases harboring somatic mutations in the Janus kinases JAK1 and JAK2. To determine whether mutations in other tyrosine kinases might also occur in ALL, we sequenced the tyrosine kinome and downstream signaling genes in 45 high-risk pediatric ALL cases with either a Ph-like gene expression profile or other alterations suggestive of activated kinase signaling. Aside from JAK mutations and 1 FLT3 mutation, no somatic mutations were found in any other tyrosine kinases, suggesting that alternative mechanisms are responsible for activated kinase signaling in high-risk ALL.