Treatment of Childhood Acute Lymphoblastic Leukemia

Time--and Concentration--Dependent Effects of Resveratrol on miR 15a and miR16-1 Expression and Apoptosis in the CCRF-CEM Acute Lymphoblastic Leukemia Cell Line

BACKGROUND

Chemotherapy is one of the common approaches in treatment of cancers, especially leukemia. However, drug resistance phenomena reduce the likelihood of treatment success. Resveratrol is a herbal compound which through complicated processes makes some selected cells sensitive to treatment and induction of apoptosis. In the present study, the effects of resveratrol on the expression of miR 15a and miR16-1 and apoptosis in the CCRF-CEM cell line were investigated.

MATERIALS AND METHODS

The CCRF-CEM cell line was cultured under standard conditions and changes in miR 15a and miR 16-1 expression were analyzed by real time-PCR technique, with attention to reveratrol dose and time dependence. Also, apoptosis is evaluated by flow cytometry using annexin V and PI.

RESULTS

CCRF-CEM cells underwent dose-dependent apoptotic cell death in response to resveratrol. MiR 15a and miR 16-1 expression was up-regulated after 24 and 48 hours resveratrol treatment (p<0.05).

CONCLUSIONS

The results of our study indicate that resveratrol induces apoptosis in a time and dose- dependent manner in CCRF-CEM cells. Also, increased expression level of miR 16-1 and miR 15a by means of resveratrol in CCRF-CEM cells might have a role in apoptosis induction and predisposition. According to our results resveratrol can be regarded as a dietary supplement to improve efficacy of anti-leukemia therapies.

Some GCR Polymorphisms (N363S, ER22/23EK, and Bcl-1) May Influence Steroid-induced Toxicities and Survival Rates in Children With ALL

We investigated whether an altered individual glucocorticoid sensitivity due to particular glucocorticoid receptor single-nucleotide polymorphisms (SNPs) (N363S, ER22/23EK, and Bcl-1) influences the susceptibility to steroid-related toxicities, prognostic factors, and survival rates in children with acute lymphoblastic leukemia. In total, 346 pediatric patients with acute lymphoblastic leukemia were enrolled in our study. Their carrier status was investigated by allele-specific polymerase chain reaction analysis. Clinical and laboratory signs of glucocorticoid-related toxicities, day-8 prednisone response, 5-year event-free survival, and 5-year overall survival rates were analyzed and compared retrospectively. Hepatotoxicity occurred significantly more often in 363S carriers (P=0.004), and glucose metabolism abnormalities were more common in 363S carriers (P=0.001), but did not occur in patients with the ER22/23EK SNP. Hypertension and central nervous system/behavioral changes did not occur in patients with the ER22/23EK SNP. None of the patients with the N363S SNP, the ER22/23EK polymorphism, or the GG genotype for the Bcl-1 polymorphism had a poor prednisone response. The 363S carriers had significantly better 5-year event-free survival (P=0.012) and 5-year overall survival (P=0.013) rates compared with noncarriers. The Bcl-1 SNP was not associated with any of the toxicities investigated or survival. Children with the N363S polymorphism in the glucocorticoid receptor gene were more prone to steroid-related toxicities, whereas those with the ER22/23EK polymorphism were less susceptible. Children with the N363S polymorphism may have more favorable survival rates.

Feasibility Study of a Novel Experimental Induction Protocol Combining B43-PAP (Anti-CD19) Immunotoxin With Standard Induction Chemotherapy in Children and Adolescents With Relapsed B-Lineage ALL: A Report From the Children's Oncology Group

BACKGROUND

B43-pokeweed antiviral protein (B43-PAP) is a high-affinity anti-CD19 immunotoxin that is capable of causing apoptotic death in B-lineage leukemic cells with a drug-resistant phenotype. B43-PAP exhibited in vivo antileukemic activity in preclinical studies as well as on a single-agent phase I clinical trial. This pediatric phase I/II study evaluated the toxicity profile and efficacy of B43-PAP immunotoxin in combination with standard induction chemotherapy in children and adolescents with relapsed CD19-positive B-lineage acute lymphoblastic leukemia (B-ALL). Pharmacokinetic profile and immunogenicity of B43-PAP were assessed.

EXPERIMENTAL DESIGN

B43-PAP in combination with standard 3 and 4-drug induction chemotherapy was administered on days 9-13 and 21-25 of a 28-day treatment course with vincristine, prednisone, L-asparaginase, daunomycin, and intrathecal methotrexate. Thirty patients with relapsed B-ALL were enrolled on study CCG-0957.

RESULTS

Grade III/IV nonhematologic dose-limiting toxicities were encountered in 4 patients evaluable for toxicity and included myalgias, motor dysfunction, pulmonary toxicity, and elevated liver transaminase. Dose-limiting toxicities occurred only with the 4-drug regimen. Fourteen patients achieved a complete remission at the end of induction among the 20 patients evaluable for response.

CONCLUSIONS

B43-PAP in combination with standard induction chemotherapy can be safely administered and exhibits clinical antileukemic activity against relapsed B-ALL.

Outcome of Childhood Acute Lymphoblastic Leukemia Treated Using the Thai National Protocols

BACKGROUND

In recent decades, the prognosis for childhood leukemia has improved, especially for acute lymphoblastic leukemia (ALL). In Thailand, though, the survival rate for ALL is unimpressive. In 2006, standard national protocols for childhood leukemia treatment were implemented. We herein report the outcome of the ALL national protocols and explanations behind discrepancies in outcomes between institutions.

MATERIALS AND METHODS

Between March 2006 and February 2008, 486 children with ALL from 12 institutions were enrolled in the Thai national protocols. There were 3 different protocols based on specific criteria: one each for standard risk, high risk and Burkitt's ALL. We classified participating centers into 4 groups of institutions, namely: medical schools in Bangkok, provincial medical schools, hospitals in Bangkok and provincial hospitals. We also evaluated supportive care, laboratory facilities in participating centers, socioeconomics, and patient compliance. Overall and event-free survival were determined for each group using the Kaplan Meier method. Statistical differences were determined using the log-rank test. Previous outcomes of Thai childhood ALL treatment between 2003 and 2005 served as the historic control.

RESULTS

Five-year overall survival of ALL treated using the Thai national protocol was 67.2%; an improvement from the 63.7% of the 12-institute historical control (p-value=0.06). There were discrepancies in event-free survival of ALL between centers in Bangkok and up-country provinces (69.9% vs 51.2%, p-value <0.01). Socioeconomics and patient compliance were key elements in determining the outcome (65.5% vs 47.5%, 59.4% vs 42.9%) (p-value < 0.02).

CONCLUSIONS

Implementation of standard national protocols for childhood leukemia in Thailand did not significantly improve the outcome of ALL. Factors leading to better outcomes included (a) improvement of treatment compliance (b) prevention of treatment abandonment and

Dietary intake and childhood leukemia: The Diet and Acute Lymphoblastic Leukemia Treatment (DALLT) cohort study

OBJECTIVE

Children with acute lymphoblastic leukemia (ALL) are at elevated risk for nutrition-related morbidity both during and after therapy. We present the demographic characteristics and nutrient intake at study entry of a prospective cohort in which evaluating dietary intake in children diagnosed with ALL was investigated.

METHODS

Dietary intake data were collected for participants enrolled on the Dana-Farber Cancer Institute ALL Consortium Protocol. Dietary intake was assessed with a food frequency questionnaire and was compared with the dietary reference intake by ALL risk group (standard and high risk).

RESULTS

Dietary intake data were collected from 81% of participants (n = 640). We found that 27% of participants were overweight/obese. Intake of total calories and other nutrients exceeded the dietary reference intake in up to 79% of children. This was evident in both risk groups and was pronounced among younger children. For micronutrients, dietary intake of calcium, vitamin D (females only), and zinc differed significantly between patients with standard-risk and those with high-risk ALL.

CONCLUSIONS

This study was successful in collecting dietary intake data at the time of cancer diagnosis in a multicenter setting in a pediatric population at high-risk for nutrition-related morbidity. We identified "at-risk" dietary intakes, which vary by sex and ALL risk group; such patients may benefit from future dietary interventions.

Sensitization of acute lymphoblastic leukemia cells for LCL161-induced cell death by targeting redox homeostasis

Disturbed redox homeostasis with both elevated reactive oxygen species (ROS) levels and antioxidant defense mechanisms has been reported in acute lymphoblastic leukemia (ALL). We therefore hypothesized that inhibition of pathways responsible for ROS detoxification renders ALL cells more susceptible for cell death. Here, we report that pharmacological inhibitors of key pathways for the elimination of ROS, i.e. Erastin, buthionine sulfoximine (BSO) and Auranofin, sensitize ALL cells for cell death upon treatment with the Smac mimetic LCL161 that antagonizes Inhibitor of Apoptosis (IAP) proteins. Erastin, BSO or Auranofin significantly increase LCL161-induced cell death and also act in concert with LCL161 to profoundly suppress long-term clonogenic survival in several ALL cell lines. Erastin or BSO cooperates with LCL161 to stimulate ROS production and lipid peroxidation prior to cell death. ROS production and lipid peroxidation are required for this cotreatment-induced cell death, since ROS scavengers or pharmacological inhibition of lipid peroxidation provides significant protection against cell death. These results emphasize that inhibition of antioxidant defense mechanisms can serve as a potent approach to prime ALL cells for LCL161-induced cell death.

Shorter Maintenance Therapy in Childhood Acute Lymphoblastic Leukemia: The Experience of the Prospective, Randomized Brazilian GBTLI ALL-93 Protocol

AIM

Maintenance therapy is an important phase of the childhood ALL treatment, requiring 2-year long therapy adherence of the patients and families. Weekly methotrexate with daily 6-mercaptopurine (6MP) constitutes the backbone of maintenance therapy. Reduction in the maintenance therapy could overweight problems related with poverty of children with ALL living in limited-income countries (LIC).

OBJECTIVE

To compare, prospectively, the EFS rates of children with ALL treated according to two maintenance regimens: 18 vs. 24 months duration.

MATERIALS AND METHODS

From October 1993 to September 1999, 867 consecutive untreated ALL patients <18 years of age were treated according to the Brazilian Cooperative Group for Childhood ALL Treatment (GBTLI) ALL-93 protocol. Risk classification was based exclusively on patient's age and leukocyte count (NCI risk group) and clinical extra medullary involvement of the disease. Data were analyzed by the intention-to-treat approach.

RESULTS

Fourteen patients (1.6%) were excluded: wrong diagnosis (n = 7) and previous corticosteroid (n = 7). Of the 853 eligible patients, 421 were randomly allocated, at study enrollment, to receive 18-month (group 1) and 432 to receive 24-month (group 2) maintenance therapy. Complete remission rate was achieved in 96% of the patients (817/853). Twenty-eight patients (3.4%) died during the induction phase. Thirty-four patients (4.0%) were lost to follow-up. The overall EFS was 66.1 ± 1.7% at 15 years. No difference was seen according to maintenance: EFS_15y was 65.8 ± 2.3% (group 1) and 66.3 ± 2.3% (group 2; p = 0.79). No difference between regimens was detected after stratifying the analyses according to factors associated with adverse prognosis in this study (age group <1 year or >10 years and high WBC at diagnosis). Overall death in remission rate was 6.85% (56 patients). Deaths during maintenance were 13 in group 1 and 12 in group 2, all due to infection. Over 15 years of follow-up, two patients both from group 2 presented a second malignancy (Hodgkin's disease and thyroid carcinoma) after 8.3 and 11 years off therapy, respectively.

CONCLUSION

Six-month reduction of maintenance therapy in ALL children treated according to the GBTLI ALL-93 protocol provided the same overall outcome as 2-year duration regimen.

Germline genetic variation in ETV6 and risk of childhood acute lymphoblastic leukaemia: a systematic genetic study

BACKGROUND

Hereditary predisposition is rarely suspected for childhood acute lymphoblastic leukaemia (ALL). Recent reports of germline ETV6 variations associated with substantial familial clustering of haematological malignancies indicated that this gene is a potentially important genetic determinant for ALL susceptibility. Our aims in this study were to comprehensively identify ALL predisposition variants in ETV6 and to determine the extent to which they contributed to the overall risk of childhood ALL.

METHODS

Whole-exome sequencing of an index family with several cases of ALL was done to identify causal variants for ALL predisposition. Targeted sequencing of ETV6 was done in children from the Children's Oncology Group and St Jude Children's Research Hospital front-line ALL trials. Patients were included in this study on the basis of their enrolment in these clinical trials and the availability of germline DNA. ETV6 variant genotypes were compared with non-ALL controls to define ALL-related germline risk variants. ETV6 variant function was characterised bioinformatically and correlated with clinical and demographic features in children with ALL.

FINDINGS

We identified a novel non-sense ETV6 variant (p.Arg359X) with a high penetrance in an index family. Subsequent targeted sequencing of ETV6 in 4405 childhood ALL cases identified 31 exonic variants (four non-sense, 21 missense, one splice site, and five frameshift variants) that were potentially related to ALL risk in 35 cases (1%). 15 (48%) of 31 ALL-related ETV6 variants clustered in the erythroblast transformation specific domain and were predicted to be highly deleterious. Children with ALL-related ETV6 variants were significantly older at leukaemia diagnosis than those without (10·2 years [IQR 5·3-13·8] vs 4·7 years [3·0-8·7]; p=0·017). The hyperdiploid leukaemia karyotype was highly over-represented in ALL cases harbouring germline ETV6 risk variants compared with the wild-type group (nine [64%] of 14 cases vs 538 [27%] of 2007 cases; p=0·0050).

INTERPRETATION

Our findings indicated germline ETV6 variations as the basis of a novel genetic syndrome associated with predisposition to childhood ALL. The development of recommendations for clinical interventions and surveillance for individuals harbouring ALL-related ETV6 variants are needed.

FUNDING

US National Institutes of Health and American Lebanese Syrian Associated Charities.

High expression of Midkine (MK) indicates poor prognosis in childhood acute lymphoblastic leukemia

OBJECTIVES

Midkine (MK) expression has been reported to be correlated with the poor prognosis of patients with various tumors. However, there are no data available about the prognostic value of MK expression in childhood acute lymphoblastic leukemia (ALL).

METHODS

In this study, MK mRNA expression was determined by real-time polymerase chain reaction in 120 childhood ALL and 30 healthy volunteers. Patients were dichotomized at the median value and divided into two groups: MK(low) group and MK(high) group.

RESULTS

MK(high) patients had higher white blood cell counts, higher peripheral blood blasts percentages, and higher minimal residual disease levels than MK(low) patients. Moreover, the MK gene was expressed significantly higher in patients with relapsed ALL than in patients who maintained complete remission or at diagnosis. MK(high) patients harbored inferior relapse-free survival (RFS, P = 0.047) and overall survival (OS, P = 0.022) than MK(low) patients, and high expression of MK was found to be independently predictive of inferior OS (P = 0.032) but not RFS (P = 0.077) in the overall cohort.

CONCLUSION AND DISCUSSION

MK high expression is an independent adverse prognostic factor in childhood ALL. Its level may be incorporated into an improved risk classification system for ALL and suggest the need of alternative regimens.

Improved survival in adult patients with acute lymphoblastic leukemia in the Netherlands: a population-based study on treatment, trial participation and survival

This nationwide population-based study assessed trends in treatment, trial participation and survival among 1833 adult patients diagnosed with acute lymphoblastic leukemia (ALL) in the Netherlands between 1989 and 2012 reported to the Netherlands Cancer Registry. Patients were categorized into four periods and five age groups (18-24, 25-39, 40-59, 60-69 and ⩾70 years). The application of allogeneic stem cell transplantation (alloSCT), particularly reduced-intensity conditioning (RIC) alloSCT, increased over time up to age 70 years. The inclusion rate in the trials was 67, 66, 55, 58 and 0% for the five age groups. Survival improved over time for patients below 70 years. Five-year relative survival in the period 2007-2012 was 75, 57, 37, 22 and 5% for the five age groups. In that same period, 5-year overall survival among patients aged 18-39 years was 68% for the chemotherapy-alone group and 66% for the alloSCT group. For patients aged 40-69 years, the corresponding estimates were 24 and 41%. Pronounced survival improvement observed among patients aged 18-39 years might mainly be explained by implementation of pediatric-based regimens since 2005, whereas among patients aged 40-69 years, increased application of RIC-alloSCT has contributed significantly to the observed improvement. Outcome of patients aged ⩾70 remains unsatisfactory, indicating a need for specific trials for the elderly.

Rational combination therapies targeting survival signaling in aggressive B-cell leukemia/lymphoma

PURPOSE OF REVIEW

The identification of oncogenic 'driver' mutations and activated survival pathways in selected aggressive B-cell malignancies directs the development of novel adjunctive therapies using targeted small molecule inhibitors. With a focus on diffuse large B-cell lymphoma 'not otherwise specified', Hodgkin lymphoma and childhood B-cell precursor acute lymphoblastic leukemia, this review will provide an up-to-date account of the current literature on the development of new molecularly targeted treatment modalities for aggressive B-cell malignancies.

RECENT FINDINGS

Subclassification of B-cell malignancies depending on their particular genetic 'driver' lesions and transcriptional and/or signaling signatures has led to the development of targeted therapeutic approaches using small molecule inhibitors to amend current combination chemotherapy.

SUMMARY

Treatment outcome with current combination chemotherapy is still poor for subsets of aggressive B-cell malignancies, and demands development of targeted therapeutic approaches. Advanced gene expression profiling and genomic sequencing have revealed a more detailed landscape of recurrent alterations, allowing a better subclassification of B-cell lymphomas and leukemias. Many alterations directly or indirectly lead to activation of survival signaling pathways and expression of key oncoproteins and prosurvival molecules, including Janus kinase-signal transducer and activator of transcription (JAK-STAT), phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR), avian myelocytomatosis viral oncogene homolog (MYC) and B-cell lymphoma 2 (BCLl-2). Small molecule inhibitors targeting these proteins and pathways are currently being tested in clinical trials and preclinically to improve chemotherapeutic regimes and treatment outcomes.

Outcome of B-Cell Acute Lymphoblastic Leukemia in Brazilian Children: Immunophenotypical, Hematological, and Clinical Evaluation

The aim of this study is to investigate the clinical, hematological, and immunophenotypic characteristics of Brazilian children with B-cell acute lymphoblastic leukemia (B-ALL) to identify prognostic biomarkers of the disease. Thirty-three children newly diagnosed with B-ALL were followed between March 2004 and December 2009. Information about the demographic profile, diagnosis, immunophenotype, clinical manifestations, and disease outcome were gathered from the patients' medical records. Of the 33 patients with B-ALL, 18 were male and 15 female. Eighteen patients were classified as high risk; 13 as low risk, and 2 as true low risk. The frequencies of cluster of differentiation (CD)10, CD19, and CD20 antigens were 69.7%, 81.8%, and 18.2%, respectively. Six patients (18.2%) had aberrant expression of myeloid antigens. At diagnosis, patients immunopositive for CD20 had elevated white blood cell counts (P = 0.018) and lower platelet counts (P = 0.017). The 6-year overall survival was 67.5%± 3.47%. Our results demonstrate the distinct immunophenotypic and prognostic characteristics of patients with B-ALL, which can be related to the Brazilian racial admixture. Consequently, these results will most likely aid in the selection of additional prognostic markers and their use in monitoring the clinical manifestations and treatment response among B-ALL patients.

Clinical characteristics of acute lymphoblastic leukemia in male and female patients: A retrospective analysis of 705 patients

The aim of the present study was to compare the clinical characteristics of acute lymphoblastic leukemia (ALL) that occurred in male and female patients at one institution in Southern China. The medical electronic records of Nanfang Hospital, affiliated to Southern Medical University, were searched for patients with a definite diagnosis of ALL that were diagnosed between January 1, 2001 and December 31, 2012. The clinical data of the patients were collected and analyzed. A total of 705 eligible patients were identified. The gender ratio of male to female patients was 1.84:1. The average ages at the time of diagnosis were 16.43 and 19.54 years for male and female patients, respectively (P=0.007). No significant differences were identified in the seasonal occurrence distribution, blood group distribution or ratio for the presence of the Ph chromosome between males and females. However, a higher incidence of T-cell type ALL was identified in males (P=0.023). The present study reveals that ALL demonstrates a male predominance, but similar clinical characteristics of ALL are present in males and females in Southern China.

CD19-antigen specific nanoscale liposomal formulation of a SYK P-site inhibitor causes apoptotic destruction of human B-precursor leukemia cells

We report the anti-leukemic potency of a unique biotargeted nanoscale liposomal nanoparticle (LNP) formulation of the spleen tyrosine kinase (SYK) P-site inhibitor C61. C61-loaded LNP were decorated with a murine CD19-specific monoclonal antibody directed against radiation-resistant CD19-receptor positive aggressive B-precursor acute lymphoblastic leukemia (ALL) cells. The biotargeted C61-LNP were more potent than untargeted C61-LNP and consistently caused apoptosis in B-precursor ALL cells. The CD19-directed C61-LNP also destroyed B-precursor ALL xenograft cells and their leukemia-initiating in vivo clonogenic fraction. This unique nanostructural therapeutic modality targeting the SYK-dependent anti-apoptotic blast cell survival machinery shows promise for overcoming the clinical radiochemotherapy resistance of B-precursor ALL cells.

Emerging technologies in paediatric leukaemia

Genetic changes, in particular chromosomal aberrations, are a hallmark of acute lymphoblastic lymphoma (ALL) and accurate detection of them is important in ensuring assignment to the appropriate drug protocol. Our ability to detect these genetic changes has been somewhat limited in the past due to the necessity to analyse mitotically active cells by conventional G-banded metaphase analysis and by mutational analysis of individual genes. Advances in technology include high resolution, microarray-based techniques that permit examination of the whole genome. Here we will review the current available methodology and discuss how the technology is being integrated into the diagnostic setting.

Comprehensive craniospinal radiation for controlling central nervous system leukemia

PURPOSE

To determine the benefit of radiation therapy (RT) in resolution of neurologic symptoms and deficits and whether the type of RT fields influences central nervous system (CNS) control in adults with CNS leukemia.

METHODS AND MATERIALS

A total of 163 adults from 1996 to 2012 were retrospectively analyzed. Potential associations between use of radiation and outcome were investigated by univariate and multivariate analysis.

RESULTS

The median survival time was 3.8 months after RT. Common presenting symptoms were headache in 79 patients (49%), cranial nerve VII deficit in 46 (28%), and cranial nerve II deficit in 44 (27%). RT was delivered to the base of skull in 48 patients (29%), to the whole brain (WB) in 67 (41%), and to the craniospinal axis (CS) in 48 (29%). Among 149 patients with a total of 233 deficits, resolution was observed in 34 deficits (15%), improvement in 126 deficits (54%), stability in 34 deficits (15%), and progression in 39 deficits (17%). The 12-month CNS progression-free survival was 77% among those receiving CS/WB and 51% among those receiving base of skull RT (P=.02). On multivariate analysis, patients who did not undergo stem cell transplantation after RT and base of skull RT were associated with worse CNS progression-free survival.

CONCLUSIONS

Improvement or resolution of symptoms occurred in two thirds of deficits after RT. Comprehensive radiation to the WB or CS seems to offer a better outcome, especially in isolated CNS involvement.

TGFβ and IL10 have an impact on risk group and prognosis in childhood ALL

BACKGROUND

Cytokines and their genes have been described to have an influence on incidence and prognosis in malignant, infectious and autoimmune disease. We previously described the impact of cytokine production on prognosis in paediatric standard-risk acute lymphoblastic leukaemia (ALL).

PROCEDURE

In this study, we investigated the influence of cytokine gene polymorphisms (TNFα, TGFβ, IL10 and IFNγ) on frequency, risk group and prognosis in 95 paediatric ALL-patients. We further report on intracellular production of these cytokines in T-cells.

RESULTS

IL10 high-producer-haplotypes were reduced in ALL-patients compared with healthy controls and resulted in a reduced relapse rate compared with low-producer haplotypes. TGFβ high-producer-haplotypes were correlated with a high initial blast-count (codon 25: G/G) and were elevated in high-risk ALL-patients (codon 10: T/T). IL10 was positively and IFNγ-production was negatively correlated with initial blast-count. At diagnosis the expression of TNFα and IFNγ was reduced in patients compared with healthy controls. This was more pronounced in high-risk and in T-ALL-patients.

CONCLUSION

We conclude that gene-polymorphisms of the regulatory/anti-inflammatory cytokines, TGFβ and IL10, but not of the pro-inflammatory cytokines, IFNγ and TNFα, have an impact on prognosis and risk-group of ALL. However, the reduced capacity to produce pro-inflammatory cytokines at diagnosis may serve as another important, functional risk factor. These data may help in further risk stratification and adaptation of therapy-intensity in paediatric patients with ALL.

Impairment of antioxidant defense via glutathione depletion sensitizes acute lymphoblastic leukemia cells for Smac mimetic-induced cell death

Evasion of apoptosis in pediatric acute lymphoblastic leukemia (ALL) is linked to aberrant expression of inhibitor of apoptosis (IAP) proteins and dysregulated redox homeostasis, rendering leukemic cells vulnerable to redox-targeting therapies. Here we discover that inhibition of antioxidant defenses via glutathione (GSH) depletion by buthionine sulfoximine (BSO) primes ALL cells for apoptosis induced by the Smac mimetic BV6 that antagonizes IAP proteins. Similarly, BSO cooperates with BV6 to induce cell death in patient-derived primary leukemic samples, underscoring the clinical relevance. In contrast, BSO does not sensitize non-malignant lymphohematopoietic cells from healthy donors toward BV6, pointing to some tumor selectivity. Mechanistically, both agents cooperate to stimulate reactive oxygen species (ROS) production, which is required for BSO/BV6-induced cell death, as ROS inhibitors (that is, N-acetylcysteine, MnTBAP, Trolox) significantly rescue cell death. Further, BSO and BV6 cooperate to trigger lipid peroxidation, which is necessary for cell death, as genetic or pharmacological blockage of lipid peroxidation by GSH peroxidase 4 (GPX4) overexpression or α-tocopherol significantly inhibits BSO/BV6-mediated cell death. Consistently, GPX4 knockdown or GPX4 inhibitor RSL3 enhances lipid peroxidation and cell death by BSO/BV6 cotreatment. The discovery of redox regulation of Smac mimetic-induced cell death has important implications for developing rational Smac mimetic-based combination therapies.

Childhood leukaemia risks: from unexplained findings near nuclear installations to recommendations for future research

Recent findings related to childhood leukaemia incidence near nuclear installations have raised questions which can be answered neither by current knowledge on radiation risk nor by other established risk factors. In 2012, a workshop was organised on this topic with two objectives: (a) review of results and discussion of methodological limitations of studies near nuclear installations; (b) identification of directions for future research into the causes and pathogenesis of childhood leukaemia. The workshop gathered 42 participants from different disciplines, extending widely outside of the radiation protection field. Regarding the proximity of nuclear installations, the need for continuous surveillance of childhood leukaemia incidence was highlighted, including a better characterisation of the local population. The creation of collaborative working groups was recommended for consistency in methodologies and the possibility of combining data for future analyses. Regarding the causes of childhood leukaemia, major fields of research were discussed (environmental risk factors, genetics, infections, immunity, stem cells, experimental research). The need for multidisciplinary collaboration in developing research activities was underlined, including the prevalence of potential predisposition markers and investigating further the infectious aetiology hypothesis. Animal studies and genetic/epigenetic approaches appear of great interest. Routes for future research were pointed out.

The synthetic glucocorticoids prednisolone and dexamethasone regulate the same genes in acute lymphoblastic leukemia cells

Background

Glucocorticoids (GCs) cause apoptosis in malignant cells of lymphoid lineage by transcriptionally regulating a plethora of genes. As a result, GCs are included in almost all treatment protocols for lymphoid malignancies, particularly childhood acute lymphoblastic leukemia (chALL). The most commonly used synthetic GCs in the clinical setting are prednisolone and dexamethasone. While the latter has a higher activity and more effectively reduces the tumor load in patients, it is also accompanied by more serious adverse effects than the former. Whether this difference might be explained by regulation of different genes by the two GCs has never been addressed.

Results

Using a recently developed GC bioassay based on a GC-responsive reporter construct in human Jurkat T-ALL cells, we found ~7-fold higher biological activity with dexamethasone than prednisolone. Similarly, 1.0e-7 M dexamethasone and 7.0e-7 M prednisolone triggered similar cell death rates in CCRF-CEM-C7H2 T-chALL cells after 72 hours of treatment. Using microarray-based whole genome expression profiling and a variety of statistical and other approaches, we compared the transcriptional response of chALL cells to 6 hour exposure to both synthetic GCs at the above concentrations. Our experiments did not detect any gene whose regulation by dexamethasone differed significantly from that by prednisolone.

Conclusions

Our findings suggest that the reported differences in treatment efficacy and cytotoxicity of dexamethasone and prednisolone are not caused by inherent differences of the 2 drugs to regulate the expression of certain genes, but rather result either from applying them in biologically in-equivalent concentrations and/or from differences in their pharmacokinetics and - dynamics resulting in different bioactivities in tumor cells and normal tissues.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-662) contains supplementary material, which is available to authorized users.

Influence of genetic polymorphisms of FPGS, GGH, and MTHFR on serum methotrexate levels in Chinese children with acute lymphoblastic leukemia

PURPOSE

To investigate the correlation between common genetic polymorphisms of folylpolyglutamate synthase (FPGS), gamma-glutamyl hydrolase (GGH), and methylenetetrahydrofolate reductase (MTHFR) and serum levels of methotrexate (MTX) in Chinese children with acute lymphoblastic leukemia (ALL).

METHODS

Ninety-one children with ALL who received high-dose MTX were recruited. The polymorphisms FPGS (rs1544105 G>A), GGH (rs3758149 C>T), and MTHFR (rs1801133 C>T) were genotyped through polymerase chain reaction-restriction fragment length polymorphism analysis. Serum MTX was measured by fluorescence polarization immunoassay. The association between targeted polymorphisms and MTX concentration-to-dose (C/D) ratios was assessed, and between targeted polymorphisms and the percent of MTX above the therapeutic threshold (40 µmol/L).

RESULTS

The minor allele frequencies of rs1544105 G (34.1%), rs3758149 T (19.2%), and rs1801133 C (48.4%) observed in our population were significantly lower than those reported for European populations (64.2, 30.8, and 69.0%, respectively). The association between the GGH rs3758149 polymorphism and MTX C/D was gender-specific; in girls, the MTX C/D at 24 h of GGH rs3758149 CC carriers (12.09 μmol/L per g/m(2)) was significantly lower than that of CT or TT carriers (16.80 μmol/L per g/m(2)). The percent of serum MTX above the therapeutic threshold in GGH rs3758149 CC carriers (18.3%) was significantly lower than that of CT and TT carriers (38.7%). The MTX C/D ratios at 24 h and the percent of MTX >40 µmol/L for the A-T-T (three variant alleles) haplotype were significantly higher than those for other haplotypes combined (P < 0.05).

CONCLUSIONS

These data indicate that FPGS rs1544105, GGH rs3758149, and MTHFR rs1801133 polymorphisms contribute to the variability of MTX pharmacokinetics, and their genotyping may be useful to reduce toxicities associated with MTX therapy.

Raised expression of APRIL in Chinese children with acute lymphoblastic leukemia and its clinical implications

This study was to determine the expression of a proliferation-inducing ligand (APRIL) and its receptors, B-cell maturation antigen (BCMA) and transmembrane activator and calcium-modulating cyclophilin ligand interactor in childhood acute lymphoblastic leukemia (ALL). The correlation between the plasma APRIL levels and clinical status was also evaluated. Plasma samples from 20 untreated children with ALL, 23 children with ALL in remission, and 15 normal controls were assayed for APRIL plasma concentration by enzyme-linked immunosorbent assay. Real-time quantitative polymerase chain reaction was performed to determine the mRNA expression of APRIL and its receptors in blood mononuclear cells in 20 untreated ALL children and 15 normal controls. The untreated ALL patients had higher plasma APRIL levels than the remission group and the normal controls (P<0.001, respectively). No significant difference was found between the remission group and the normal controls in the plasma APRIL levels (P=0.339). The plasma APRIL levels in the untreated patients correlated with white blood cell count at diagnosis (P=0.002) and risk category (P=0.013). The mRNA expression of both APRIL and BCMA in blood mononuclear cells of the ALL patients were higher than those of the normal controls (both P<0.001). No significant difference was found between the patients and the normal controls in the transmembrane activator and calcium-modulating cyclophilin ligand interactor expression (P>0.05). These findings indicate that APRIL and BCMA are over expressed in untreated ALL children. The levels of APRIL correlate with the progression of childhood ALL, which may provide certain clues for monitoring ALL clinically.

Survival from childhood acute lymphoblastic leukaemia in West Germany: does socio-demographic background matter?

BACKGROUND

Sex, age, immunophenotype and white blood cell count at diagnosis are well accepted predictors of survival from acute lymphoblastic leukaemia (ALL) in children. Less is known about the relationship between socio-economic determinants and survival from paediatric ALL, studied here for the first time in German children.

METHODS

ALL cases were diagnosed between 1992 and 1994 and their parents interviewed during a previous nationwide case-control study. Children were followed-up for 10 years after diagnosis by the German Childhood Cancer Registry. Cox proportional hazards models estimating hazard ratios (HRs) were calculated to assess the impact of selected socio-demographic characteristics on overall and event-free survival.

RESULTS

Overall survival was 82.5%, with a higher proportion of girls than boys surviving (85% versus 81%). We found a non-linear relationship between age at diagnosis and survival, with poorer survival in infants and children aged >5 years. There was no association between socio-economic factors and survival or risk of relapse. For five levels of increasing family income, all HRs were close to one. No relationship was seen with parental educational level.

CONCLUSION

Socio-economic determinants did not affect ALL survival in West German children, in contrast to studies from some other countries. Dissimilarities in social welfare systems, including access to health care, lifestyle and differences in treatment may contribute to these differences in findings. Our observation of no social inequalities in paediatric ALL survival is reassuring, but needs continued monitoring to assess the potential impact of evolvement of treatment options and changes in paediatric health service.

Association of -24CT, 1249GA, and 3972CT ABCC2 gene polymorphisms with methotrexate serum levels and toxic side effects in children with acute lymphoblastic leukemia

Acute lymphoblastic leukemia patients after being treated with methotrexate, have differences in methotrexate serum levels and toxic side effects. One of the main determinants of these toxic side effects is the host pharmacogenetics. The aim of this study was to evaluate the association of -24CT, 1249GA, and 3972CT ABCC2 gene polymorphisms with serum levels, and toxic side effects of methotrexate in childhood acute lymphoblastic leukemia. Applying polymerase chain reaction and restriction fragment length polymorphism techniques, the prevalence of -24CT, 1249GA, and 3972CT ABCC2 gene polymorphisms was evaluated in 65 acute lymphoblastic leukemia patients. The relationship between polymorphisms and methotrexate serum levels and toxicities was studied. A reverse significant relationship was detected between 3972T allele carriers and hepatotoxicity (P = 0.01, OR = 0.25, 95% CI = 0.09-0.72). Also, 1249A allele carriers had increased rate of gastrointestinal toxicity (P = 0.05, OR = 3.47, 95% CI = 1.04-11.57). No significant relationship was detected between -24CT polymorphism and methotrexate toxic side effects. There was no significant relationship between these three polymorphisms and methotrexate serum levels. Genotyping for 3972CT and 1249GA ABCC2 gene variants maybe useful in acute lymphoblastic leukemia to optimize methotrexate therapy and reducing the associated toxicity.

SMYD2 is highly expressed in pediatric acute lymphoblastic leukemia and constitutes a bad prognostic factor

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Although several clinical characteristics can be associated with worse prognosis, more robust biological markers still remains uncovered. SMYD2, a member of SMYD protein family, regulates the activity of several proteins through methylation. In this study, we performed quantitative real time PCR to compare the expression of SMYD2 in 83 pediatric ALL patients and non-neoplastic bone marrow samples (BMS). The study revealed that SMYD2 expression is altered in ALL BMS and its high expression was correlated with a bad prognosis. Moreover, we also revealed that SMYD2 expression level significantly decreases in patients that respond to chemotherapy treatment.

Asparaginase-associated pancreatitis in children with acute lymphoblastic leukaemia in the NOPHO ALL2008 protocol

L-asparaginase is an important drug in the treatment of childhood acute lymphoblastic leukaemia (ALL). Treatment is associated with several toxicities, including acute pancreatitis. Clinical course, presentation, re-exposure to L-asparginase after pancreatitis and risk of recurrent pancreatitis within an asparaginase-intensive protocol has been poorly reported. Children (1-17 years) on the ongoing Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL2008 protocol with asparaginase-associated pancreatitis (AAP) diagnosed between 2008 and 2012 were identified through the online NOPHO ALL toxicity registry. NOPHO ALL2008 includes eight or 15 doses of intramuscular pegylated L-asparginase (PEG-asparaginase) 1000 iu/m(2) /dose at 2-6 weeks intervals, with a total of 30 weeks of exposure to PEG-asparaginase (clinicaltrials.gov no: NCT00819351). Of 786 children, 45 were diagnosed with AAP with a cumulative risk of AAP of 5·9%. AAP occurred after a median of five doses (range 1-13), and 11 d (median) from the latest administration of PEG-Asparaginase. Thirteen patients developed pseudocysts (30%) and 11 patients developed necrosis (25%). One patient died from pancreatitis. Twelve AAP patients were re-exposed to L-asparginase, two of whom developed mild AAP once more, after four and six doses respectively. In conclusion, re-exposure to PEG-asparaginase in ALL patients with mild AAP seems safe.

Clinical characteristics and treatment outcome of childhood acute lymphoblastic leukemia in Saudi Arabia: a multi-institutional retrospective national collaborative study

BACKGROUND

Treatment of childhood acute lymphoblastic leukemia (ALL) has been available in Saudi Arabia (SA) for over 30 years; however, only limited data have been published from there. This study was conducted to establish processes for collaborative data collection and provide clinical characteristics and outcome of children with ALL in SA.

PROCEDURE

Clinical data for patients diagnosed from 2004 to 2008 were retrospectively collected at eight institutions and entered remotely into a custom-built database. Statistics regarding clinical and genetic characteristics and treatment outcome were calculated.

RESULTS

The 594 evaluable patients had a median age of 4.37 years and 56.4% were boys. Majority of patients had B-precursor ALL while 10.7% had T-ALL. CNS leukemia was present in 5.2% of patients. The distribution of common genetic abnormalities was similar to that reported from western populations, with 24.6% hyperdiploidy, 21% RUNX1-ETV6 positivity, 4.2% BCR-ABL1 positivity, and 2.5% with MLL gene rearrangement. Patients received risk-adapted therapy according to various protocols, although treatment strategies for the majority were similar. Five-year OS, RFS and EFS were 86.9%, 79.1%, and 73.3%, respectively. The OS for patients with pre-B ALL was significantly higher than for T-ALL (88.0% vs. 71.8%; P = 0.019, Log-Rank test). Patients with pre-B ALL categorized as low-risk by NCI/Rome criteria and those with hyperdiploidy had OS of 93.4% and 95.8%, respectively.

CONCLUSIONS

The characteristics of childhood ALL in SA are similar to those observed in developed countries. Future prospective studies utilizing unified national protocols are needed to further improve the outcome of our patients.

Acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia occurs in both children and adults but its incidence peaks between 2 and 5 years of age. Causation is multifactorial and exogenous or endogenous exposures, genetic susceptibility, and chance have roles. Survival in paediatric acute lymphoblastic leukaemia has improved to roughly 90% in trials with risk stratification by biological features of leukaemic cells and response to treatment, treatment modification based on patients' pharmacodynamics and pharmacogenomics, and improved supportive care. However, innovative approaches are needed to further improve survival while reducing adverse effects. Prognosis remains poor in infants and adults. Genome-wide profiling of germline and leukaemic cell DNA has identified novel submicroscopic structural genetic changes and sequence mutations that contribute to leukaemogenesis, define new disease subtypes, affect responsiveness to treatment, and might provide novel prognostic markers and therapeutic targets for personalised medicine.

Engraftment of low numbers of pediatric acute lymphoid and myeloid leukemias into NOD/SCID/IL2Rcγnull mice reflects individual leukemogenecity and highly correlates with clinical outcome

Although immortalized cell lines have been extensively used to optimize treatment strategies in cancer, the usefulness of such in vitro systems to recapitulate primary disease is limited. Therefore, the design of in vivo models ideally utilizing patient-derived material is of critical importance. In this regard, NOD.Cg-Prkdc(scid) IL2rg(tmWjl) /Sz (NSG) mice have been reported to provide superior engraftment rates. However, limited data exist on the validity of such a model to constitute a surrogate marker for clinical parameters. We studied primary and serial engraftment on more than 200 NSG mice with 54 primary pediatric B cell precursor acute lymphatic leukemia (B-ALL), myeloid leukemia (AML) and T cell leukemia (T-ALL) samples, characterized the leukemogenic profile and correlated engraftment kinetics with clinical outcome. Median time to engraftment was 7-10 weeks and 90% of the mice engrafted. Male recipients conferred significantly higher engraftment levels than female recipients (p ≤ 0.004). PCR-based minimal residual disease marker expression and fluorescence in situ hybridization confirmed the presence of patient-specific genetic aberrations in mice. Transcriptome cluster analysis of genes known to be important in the leukemogenesis of all three diseases revealed that well-known tumor-regulating genes were expressed to a comparable extent in mice and men. The extent of engraftment and overall survival of NSG mice highly correlated with the individual prognosis of B-ALL, AML and T-ALL patients. Thus, we propose an in vivo model that provides a valuable preclinical tool to explore the heterogeneity of leukemic disease and exploit patient-tailored leukemia-targeting strategies within multivariate analyses.

Occurrence and modulation of therapeutic targets of Aurora kinase inhibition in pediatric acute leukemia cells

Acute lymphoblastic leukemia (ALL) is one of the most prevelant pediatric malignancies. Although cure rates have improved in recent decades, approximately one in five children relapse, and survival rates post-relapse remain low. Therefore, more effective and innovative therapeutic strategies are needed in order to improve the outcome in these children. Aurora kinases, a family of serine/threonine kinases essential for regulated mitosis, are overexpressed in many forms of cancer, and have been identified as potential targets for cancer therapeutics. Based on this premise, we evaluated the activity of the Aurora-A/B inhibitor AT9283 against pediatric leukemia cells. It was found that AT9283 significantly inhibited the growth and survival of cell lines derived from patients with pediatric leukemia. Specifically, AT9283 promoted Flt-3 dephosphorylation, inhibiting the activity of downstream effectors such as Erk and Mek. In addition, apoptotic markers were also identified, providing a panel of markers for biological correlative analysis for drug activity. Lastly, drug combination studies demonstrated the potential of several novel and conventional agents to synergize with AT9283, including apicidin, 17-allylamino-17-demethoxygeldanamycin (17-AAG) and doxorubicin. These data provide a rationale for further studies and the formulation of a clinical trial of AT9283 for the treatment of refractory pediatric ALL.

In search of Pinkel's children: unravelling the biological heterogeneity of childhood acute lymphoblastic leukaemia by genotype and treatment molecular response

BACKGROUND

Acute lymphoblastic leukaemia (ALL), the commonest childhood malignancy has seen remarkable progress since the 1960s with cure rates now approaching 85%. To achieve this patients undergo intensive treatment that usually takes 2.5-3.5 years involving on average 15 different chemotherapeutic drugs. In 1971, Donald Pinkel reported Total Therapy-Protocol V that used 5 drugs and cranial radiation therapy over a similar time period. Today, one half of these patients (Pinkel's children) remain alive and free of leukaemia.

AIM

The aim of this study was to evaluate the impact post-induction minimal residual disease (MRD) levels had on survival and its relationship with the more established clinical and biological prognostic predictors of outcome in the hope of identifying a subgroup of patients that are at very low risk of failure.

METHODS

A retrospective review of 250 Irish children with ALL was carried out. MRD status after 28 days of induction chemotherapy and other known predictors of outcome were correlated with 5 year event-free survival (EFS).

RESULTS

MRD status was the strongest predictor of outcome with 5 year EFS rates greater that 90% seen in those patients with low-risk MRD and this was associated with TEL/AML1 rearrangement, high hyperdiploidy (HH) karyotype and female gender.

CONCLUSION

Both MRD and karyotype are powerful determinants of outcome in childhood ALL. Therefore, it is reasonable to conclude that the majority of children cured by Pinkel et al. in the late 1960s were most likely composed of low-risk MRD, TEL/AML1 and HH patients.

Genome-wide association study identifies germline polymorphisms associated with relapse of childhood acute lymphoblastic leukemia

With the use of risk-directed therapy for childhood acute lymphoblastic leukemia (ALL), outcome has improved dramatically in the past 40 years. However, a substantial portion of patients, many of whom have no known risk factors, experience relapse. Taking a genome-wide approach, in the present study, we evaluated the relationships between genotypes at 444 044 single nucleotide polymorphisms (SNPs) with the risk of relapse in 2535 children with newly diagnosed ALL after adjusting for genetic ancestry and treatment regimen. We identified 134 SNPs that were reproducibly associated with ALL relapse. Of 134 relapse SNPs, 133 remained prognostic after adjusting for all known relapse risk factors, including minimal residual disease, and 111 were significant even among patients who were negative for minimal residual disease after remission induction therapy. The C allele at rs7142143 in the PYGL gene was associated with 3.6-fold higher risk of relapse than the T allele (P = 6.7 × 10(-9)). Fourteen of the 134 relapse SNPs, including variants in PDE4B and ABCB1, were also associated with antileukemic drug pharmacokinetics and/or pharmacodynamics. In the present study, we systematically identified host genetic variations related to treatment outcome of childhood ALL, most of which were prognostic independent of known risk factors for relapse, and some of which also influenced outcome by affecting host dis-position of antileukemic drugs. All trials are registered at www.clinicaltrials.gov or www.cancer.gov (COG P9904: NCT00005585; COG P9905: NCT00005596; COG P9906: NCT00005603; St Jude Total XIIIB: NCI-T93-0101D; and St Jude Total XV: NCT00137111).

The need for worldwide policy and action plans for rare diseases

There are more than 6000 rare diseases (defined as affecting <5/10 000 individuals in Europe, <200 000 people in the United States). The rarity can create problems including: difficulties in obtaining timely, accurate diagnoses; lack of experienced healthcare providers; useful, reliable and timely information may be hard to find; research activities are less common; developing new medicines may not be economically feasible; treatments are sometimes very expensive; and in developing countries, the problems are compounded by other resource limitations. Emphasis is required to support appropriate research and development leading to better prevention, diagnosis and treatments of rare diseases. Notably, clinical trials using already existing drugs may result in new, affordable, treatment strategies. Moreover, rare diseases may teach us about common disorders.

HLA-DPβ1 Asp84-Lys69 antigen-binding signature predicts event-free survival in childhood B-cell precursor acute lymphoblastic leukaemia: results from the MRC UKALL XI childhood ALL trial

We previously reported that children in the UKALL XI ALL trial with HLA-DP 1 and -DP 3 supertypes had significantly worse event-free survival (EFS) than children with other DP supertypes. As DP 1 and DP 3 share two of four key antigen-binding amino-acid polymorphisms (aspartic acid84–lysine69), we asked whether Asp84-Lys69 or Asp84 alone were independent prognostic indicators in childhood acute lymphoblastic leukemia (ALL). We analysed EFS in 798 UKALL XI patients, stratified by Asp84-Lys69 vs non-Asp84-Lys69, for a median follow-up of 12.5 years. Asp84-Lys69 was associated with a significantly worse EFS than non-Asp84-Lys69 (5-year EFS: Asp84-Lys69: 58.8% (95% CI (confidence of interval): 52.7–64.9%); non-Asp84-Lys69: 67.3% (63.4–71.2%); 2P=0.007). Post-relapse EFS was 10% less in Asp84-Lys69 than non-Asp84-Lys69 patients. EFS was significantly worse (P=0.03) and post-relapse EFS marginally worse (P=0.06) in patients with Asp84 compared with Gly84. These results suggest that Asp84-Lys69 predicted adverse EFS in the context of UKALL XI because of Asp84, and may have influenced post-relapse EFS. We speculate that this may be due to the recruitment of Asp84-Lys69-restricted regulatory T cells in the context of this regimen, leading to the re-emergence of residual disease. However, functional and molecular studies of the prognostic value of this and other HLA molecular signatures in other childhood ALL trials are needed.

Implementation of an intensive risk-stratified treatment protocol for children and adolescents with acute lymphoblastic leukemia in Lebanon

With modern risk-adapted therapy, over 80% of children with acute lymphoblastic leukemia (ALL) in high-income countries (HICs) are cured. In countries with limited resources, however, therapy results for pediatric ALL are still not encouraging. We describe our experience in treating children with ALL using a risk-adapted protocol at a tertiary referral center in Lebanon. From May 2002 to August 2009, 111 consecutive patients 1-21 years of age with newly diagnosed ALL received the CCCL ALL protocol which was based on the St. Jude Children's Research Hospital Total XV Study. The median age at diagnosis was 5 years 5 months. The male to female ratio was 1.5. Forty-six patients received the intermediate-/high-risk arm and 65 received the low-risk arm. Only one patient (0.9%) died during induction therapy. Relapse occurred in 8 (7.2%) patients. Eight (7.2%) patients died, 4 of whom were in remission. The median follow-up of the patients was 38 months. The 5-year overall survival and event-free survival were and 88.5% (95% CI: 77.1-94.4) and 78.7% (95% CI: 69.8-88.4), respectively. Our results are comparable to those in HICs in spite of the limited resources and the relatively low socioeconomic status of the Lebanese population. Children treated on this protocol experienced significant toxicity necessitating expert supportive care, but benefited from improved cure rates and prolonged survival.

Identification of germline susceptibility loci in ETV6-RUNX1-rearranged childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a malignant disease of the white blood cells. The etiology of ALL is believed to be multifactorial and likely to involve an interplay of environmental and genetic variables. We performed a genome-wide association study of 355 750 single-nucleotide polymorphisms (SNPs) in 474 controls and 419 childhood ALL cases characterized by a t(12;21)(p13;q22) - the most common chromosomal translocation observed in childhood ALL - which leads to an ETV6-RUNX1 gene fusion. The eight most strongly associated SNPs were followed-up in 951 ETV6-RUNX1-positive cases and 3061 controls from Germany/Austria and Italy, respectively. We identified a novel, genome-wide significant risk locus at 3q28 (TP63, rs17505102, P(CMH)=8.94 × 10(-9), OR=0.65). The separate analysis of the combined German/Austrian sample only, revealed additional genome-wide significant associations at 11q11 (OR8U8, rs1945213, P=9.14 × 10(-11), OR=0.69) and 8p21.3 (near INTS10, rs920590, P=6.12 × 10(-9), OR=1.36). These associations and another association at 11p11.2 (PTPRJ, rs3942852, P=4.95 × 10(-7), OR=0.72) remained significant in the German/Austrian replication panel after correction for multiple testing. Our findings demonstrate that germline genetic variation can specifically contribute to the risk of ETV6-RUNX1-positive childhood ALL. The identification of TP63 and PTPRJ as susceptibility genes emphasize the role of the TP53 gene family and the importance of proteins regulating cellular processes in connection with tumorigenesis.

The AKT/NF-κB inhibitor xanthohumol is a potent anti-lymphocytic leukemia drug overcoming chemoresistance and cell infiltration

Although the vast majority of patients with acute lymphocytic leukemia (ALL) attain remission with modern therapies, relapsed leukemia will continue to be a common malignancy both in childhood and in adults, until new treatments are available. Therapeutic options for advanced B-cell acute lymphocytic leukemia are still limited and acquired drug resistance and extramedullary tissue infiltration are two major obstacles during treatment. The prenylflavonoid xanthohumol (XN) has shown in vitro and in vivo therapeutic potential against a range of tumors. In the present study we investigated the effects of XN on B-ALL cells in vitro and in an ALL-like xenograft mouse model. Treatment of ALL cell lines with XN resulted in growth arrest and apoptosis induction. XN retained its cytotoxicity when adriamycin resistant cells were examined while ALL cell clones adapted to long-term exposure to XN resulted highly responsive to cytotoxic drugs. Administration of 50μg XN/mouse (5 days/week) significantly increased animal life span by delaying the insurgence of neurological disorders due to leukemic cells dissemination. In agreement with a less invasive phenotype, cell migration and invasion were impaired by XN and basal levels of FAK, AKT and NF-κB signaling pathways were down-regulated in ALL cells upon XN exposure. Our data indicate that XN has significant antileukemic activity both in vitro and in vivo, which associates with impaired cell migration and invasion. Interestingly, this activity overcomes mechanisms leading to drug-resistance. XN represents a promising agent perspective for ALL therapy and recurrence prevention and would deserve clinical testing in the near future.

Development and refinement of augmented treatment regimens for pediatric high-risk acute lymphoblastic leukemia

The 5-year survival rate for children and adolescents with acute lymphoblastic leukemia (ALL) is now at least 90%. However, clinical features (age and initial white blood cell count [WBC]), early treatment response, and the presence/absence of specific sentinel genomic lesions can identify subsets of high-risk (HR) ALL patients with a much higher risk of treatment failure. Chemotherapy regimens used to treat HR ALL have been refined over the past 3 decades through randomized clinical trials conducted by the Children's Oncology Group (COG) in North America and the Berlin-Frankfurt-Muenster (BFM) group in Western Europe. Contemporary COG HR ALL treatment regimens were developed from the BFM-76 regimen, with subsequent changes that led to development and refinement of a so-called augmented BFM (ABFM) regimen used today. Although contemporary COG and BFM treatment regimens are not identical, there are many more similarities than differences. With improvements in survival, it has become clear that although the outcome of some patients with HR ALL can be improved by optimizing use of standard cytotoxic chemotherapy agents, this approach has had only limited success for other patient subsets. In contrast, introduction of the tyrosine kinase inhibitor imatinib has led to dramatic outcome improvements for children and adolescents with Philadelphia chromosome-positive ALL. Genomic studies are identifying new sentinel genomic lesions that can serve as potential therapeutic targets, which will likely lead to the testing of novel and/or targeted therapies in more children with HR ALL. Such studies will require increased collaboration between Western European and North American cooperative groups.

Low platelet counts after induction therapy for childhood acute lymphoblastic leukemia are strongly associated with poor early response to treatment as measured by minimal residual disease and are prognostic for treatment outcome

BACKGROUND

Numerous reports have been published on the association between kinetics of leukemic cells during early treatment of childhood acute lymphoblastic leukemia and therapeutic outcome. In contrast, little is known about the prognostic relevance of normal blood counts in this setting.

DESIGN AND METHODS

Normal hematopoiesis during and after induction treatment (days 8, 15 and 33) was correlated with therapeutic outcome in a cohort of 256 children with acute lymphoblastic leukemia treated in one of three consecutive ALL-BFM trials at a single institute. Replication analysis of positive findings was performed in an independent cohort of 475 patients from the ALL-BFM 2000 multicenter trial.

RESULTS

A platelet count in the first quartile on treatment day 33 and a neutrophil count above the median on day 8 were significantly associated with treatment outcome, conferring multivariate risk ratios for an event of 3.27 (95% confidence interval 1.60-6.69) and 2.26 (95% confidence interval 1.23-4.29), respectively. Replication analysis confirmed the prognostic effect of platelet count on treatment day 33 and demonstrated a strong association with minimal residual disease-based risk group distribution (P<0.00001).

CONCLUSIONS

Platelet counts after induction treatment may improve treatment stratification for patients with childhood acute lymphoblastic leukemia and be of particular interest in non-minimal residual disease-based trials. (ALL-BFM 2000 is registered at: ClinicalTrials.gov: NCT00430118. National Cancer Institute: Protocol ID 68529).

Allogeneic hematopoietic cell transplantation for adult acute lymphoblastic leukemia (ALL) in first complete remission

BACKGROUND

Consolidation chemotherapy, autologous hematopoietic cell transplantation (HCT) and allogeneic HCT represent potential treatment alternatives for post-remission therapy in adult acute lymphoblastic leukemia (ALL), but there is genuine uncertainty regarding the optimal approach.

OBJECTIVES

To assess the effect of matched sibling donor vs. no donor status for adults with ALL in first complete remission (CR1).

SEARCH STRATEGY

We performed a search of CENTRAL, MEDLINE and EMBASE electronic databases in September 2010 along with handsearching of literature cited in relevant primary articles, search of abstracts from American Society of Hematology and American Society of Clinical Oncology meetings, as well as consultation with content experts in the field.

SELECTION CRITERIA

Review was performed by two authors, and Inclusion criteria included the following: controlled trials with donor vs. no donor comparison with assignment by genetic randomizationin adults with ALL in CR1.

DATA COLLECTION AND ANALYSIS

We extracted data on benefits (overall survival, progression-free survival) and harms (treatment-related mortality, relapse) of compared treatments. Adverse events were considered, but analysis of individual adverse events was not possible from the reported literature. We pooled summary results from each study using a random-effects model. We assessed heterogeneity. We performed subgroup analyses for disease risk categories. We performed sensitivity analyses according to methodological quality.

MAIN RESULTS

A total of 14 relevant trials were identified, consisting of a total of 3157 patients. There was a statistically significant overall survival advantage in favor of the donor versus no donor group (HR 0.86; 95% CI 0.77 to 0.97; P = 0.01), as well as significant improvement in disease-free survival in the donor group(HR 0.82; 95% CI 0.72 to 0.94; P = 0.004). Those in the donor group had significant reduction in primary disease relapse(RR 0.53; 95% CI 0.37 to 0.76; P = 0.0004) and significant increase in non-relapse mortality(RR 2.8; 95% CI 1.66 to 4.73; P = 0.001). Significant heterogeneity was detected in analysis of relapse (Chi(2) 40.51, df = 6, P < 0.00001; I(2) = 85%). In regard to methodologic quality, the majority of included studies were free of selective reporting, and performed analyses according to intention to treat. Conversely, few reported sample size calculation that informed the study design. While blinding was considered as an important domain of methodological quality, none of the studies reported on whether any of the study personnel were blinded (e.g. subjects, personnel, outcome assessors, data analysts etc). Therefore, we did not consider blinding further in the analysis of methodological quality in this review.

AUTHORS' CONCLUSIONS

The results of this systematic review and meta-analysis support matched sibling donor allogeneic hematopoietic cell transplantation as the optimal post-remission therapy in ALL patients aged 15 years or over. This therapy offers superior overall survival and disease-free survival, and significantly reduces the risk of disease relapse, but does impose an increased risk of non-relapse mortality. Importantly these data are based on adult ALL treated with largely total body irradiation-based myeloablative conditioning and sibling donor transplantation and, therefore, cannot be generalized to pediatric ALL, alternative donors including HLA (human leukocyte antigen) mismatched or unrelated donors, or reduced toxicity or non-myeloablative conditioning regimens.

Adherence to oral chemotherapy in childhood acute lymphoblastic leukemia: an evolutionary concept analysis

PURPOSE/OBJECTIVES

To clarify the concept of adherence to daily oral chemotherapy in children with acute lymphoblastic leukemia (ALL), to examine its implications for clinical practice, and to provide a foundation for further research and knowledge development.

DATA SOURCES

Published literature identified through the MEDLINE®, CINAHL®, PsycINFO, and ERIC databases.

DATA SYNTHESIS

Identified attributes of adherence to oral chemotherapy in childhood ALL included motivation, persistence, collaboration, mindfulness, cognitive capacity, flexibility, active participation, and identification of key participants in the process. Identified antecedents included a diagnosis of leukemia, the perceived value of adherence, and patient, family, and healthcare system-related factors. Identified consequences included the potential for maintaining optimal drug levels and improving disease outcome, as well as increased patient and caregiver esteem through active participation in the process. Adherence in the context of childhood ALL is defined as the active self-care behavior of taking (or having the responsibility for administering) daily oral chemotherapy, in collaboration with and according to the instructions of the healthcare provider over a defined, prolonged treatment period.

CONCLUSIONS

Adherence to oral chemotherapy in childhood ALL is a complex, multidimensional behavior that involves not only a willingness to follow the prescribed regimen over a prolonged period, but also the cognitive capacity and psychomotor skills to carry out the process.

IMPLICATIONS FOR NURSING

Nurses should recognize the importance of clear communication of medication instructions, reinforcement of adherence-related behaviors, and assistance with common issues such as pill-swallowing skills and reminder systems in caring for children with ALL.