Acute lymphoblastic leukemia: introduction

TP53 lacks tetramerization and N-terminal domains due to novel inactivating mutations detected in leukemia patients

Background

TP53 is a highly conserved tumor suppressor gene present on chromosome 17 and comprised 11 exons and 12 introns. The TP53 protein maintained the genomic integrity of the cell by regulating different pathways. The association of TP53 with leukemia and the increasing prevalence of leukemia in Pakistan instigated us to initiate the current study.

Materials and Methods

The TP53 gene of acute myeloid leukemia patients (n = 23) and normal individuals (n = 30) was amplified through polymerase chain reaction (PCR). The PCR amplified products of 3 samples 1 normal (NC-30) and 2 cancerous (LK-6 and LK-19) were subjected to deoxyribonucleic acid (DNA) sequence analysis. Bioinformatics analysis of the obtained DNA sequences helped to identify nature, type, and functional impact of mutations, if any.

Results

Results revealed 2 novel mutations in Case No. 1 (c. G >A10987 and c. InsA13298_13299) and Case No. 2 (c. InsC13284_13285, c. T >A13365) which generate a premature codon (ocher) at position 239 and lead to truncated TP53 protein. In Case No. 3, 16 novel mutations were identified and c. delC11093 mutation created a premature codon (opal) at 59^th position. Hence, the resultant protein will lack its tetramerization and N-terminal domain required for its normal functioning. Moreover, some intronic mutations were noticed and found to have a negative impact on splicing related regulatory sequences.

Conclusion

Results suggest the role of TP53 inactivating mutations in pathogenesis of leukemia.

BRD4 PROTAC degrader ARV-825 inhibits T-cell acute lymphoblastic leukemia by targeting 'Undruggable' Myc-pathway genes

Background

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL.

Methods

Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP).

Results

BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo.

Conclusions

BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01908-w.

FoxO3a Gene Down-regulation in Pathogenesis of Pediatric Acute Lymphoblastic Leukemia

Introduction: Acute lymphoblastic leukemia (ALL) is the most common malignancy found in the pediatrics with the peak prevalence between the ages of 2 and 5 years. The constitutive activation of PI3K/AKT pathway inhibits the tumor-suppressor role of FoxO3a (a member of the forkhead class O [FoxO] transcription factor family) in a variety of cancers and leads to tumorigenesis. This study aims to investigate the expression of FoxO3a in three different stages of pediatric ALL in mRNA level. Subjects and Methods: In this case-control study, 70 patients with childhood ALL and 70 healthy age- and gender-matched as the control group were enrolled. Real-time quantitative RT-polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression level of FoxO3a in children with different stages of ALL and healthy children as a control group. Results: Data showed that the expression of FoxO3a mRNA was lower in newly diagnosed ALL patients compared to controls (P < 0.0001), maintenance (P = 0.0342), and relapse (P = 0.0006) groups, while no difference was observed between other groups. In addition, T-ALL patients showed decreased expression of FoxO3a compared to Pre-B ALL ones (P < 0.0001). Conclusion: The study results suggest that FoxO3a plays a tumor-suppressor role in ALL. Thus, its up-regulation seems to be a plausible therapeutic strategy for this type of tumor.

Acute lymphoblastic leukemia presenting with mesenteric ischemia

Malignancy can induce a hypercoagulable state and lead to an increased risk of thromboembolic events. The pathogenesis of the prothrombotic state in cancer is complicated but is thought to involve several mechanisms. Thrombosis predominantly affects the venous circulation and infrequently the arteries. Arterial occlusion as an initial manifestation of acute leukemia is unusual. This is a case of a 44-year-old male admitted with complete thrombotic occlusion of the superior mesenteric artery and treated with emergent thrombectomy. Hematologic work-up was consistent with a diagnosis of T-cell acute lymphoblastic leukemia. To our knowledge, this is the first case of complete occlusion of the superior mesenteric artery presenting as the initial manifestation of T-cell acute lymphoblastic leukemia.

MIF-173G/C (rs755622) polymorphism as a risk factor for acute lymphoblastic leukemia development in children

BACKGROUND

Macrophage inhibitory factor (MIF) is a pro-inflammatory cytokine modulating monocyte motility and a pleiotropic regulator of different biological and cellular processes. The MIF-173G/C (rs755622) polymorphism is found in the promoter region and affects its activity. The present study investigated the MIF polymorphism as a risk factor for the development of acute lymphoblastic leukemia (ALL) in Egyptian children.

METHODS

We analyzed the MIF-173G/C (rs755622) polymorphism in 180 ALL cases and 150 healthy control children by amplification of the gene using a polymerase chain reaction followed by restriction endonuclease digestion and running on an agarose gel for visualization of the product.

RESULTS

We found a significant incidence of the homozygous polymorphic (CC) genotype and the combined polymorphic genotypes (GC + CC) in ALL patients compared to healthy controls (p = 0.001 and p = 0.007, respectively), whereas the wild-type genotype (GG) was more common in healthy controls (p = 0.006). Multivariate logistic regression analysis adjustment for MIF different genotypes and other potential risk factors such as age, sex and parental smoking indicated that the CC genotype is the only significant risk factor for the test (p = 0.02). We also noted that, by increasing the C-allele representation within the gene [GC, CC], there was an increase in total leukocytic count (p = 0.09 and p = 0.001, respectively) that may reflect the bad prognostic impact of the polymorphic allele, although further studies are needed.

CONCLUSIONS

The results of the present study indicate that the MIF-173G/C (rs755622) polymorphism is a risk factor for childhood ALL development with respect to both homozygous and combined polymorphic genotypes. In addition, the increased leukocytic count in synchronization with the increased representation of the polymorphic C-allele may reflect its bad prognostic impact.

"Exposure to the insecticides permethrin and malathion induces leukemia and lymphoma-associated gene aberrations in vitro"

Epidemiological studies have associated the exposure to permethrin and malathion with increased risk of leukemia and lymphoma. The aim of this study was to evaluate whether in vitro exposure to permethrin and malathion induces aberrations in genes involved in the etiology of these hematological malignancies. Genetic abnormalities in the IGH, KMT2A (MLL), ETV6 and RUNX1 genes, and aneuploidy induced by the in vitro exposure to permethrin and malathion (200μM, 24h), were analyzed by FISH in peripheral blood mononuclear cells (PBMCs). The gene fusions IGH-BCL2, KMT2A-AFF1 and ETV6-RUNX1 were further analyzed with nested RT-PCR in PBMCs, and in K562 cells exposed to acute and chronic treatments (0.1μM, 24h or every third day for two weeks) of insecticides. FISH analysis revealed that permethrin induces aneuploidy and structural alterations in IGH and KMT2A genes, and malathion induces breaks in KMT2A. RT-PCR detected ETV6-RUNX1 fusion in PBMCs acutely exposed to permethrin. Permethrin also induced ETV6-RUNX1 and IGH-BCL2 fusions in K562 cells, and malathion induced KMT2A-AFF1 and ETV6-RUNX1 fusions. Overall, we identified that both insecticides induce breaks and fusions in the studied genes, and permethrin induces aneuploidy. This study presents evidence of damage in cancer genes caused by these insecticides.

Pediatric haematopoiesis and related malignancies

Survival after acute paediatric (0–14 years), adolescent (15–19 years) and young adult (20–39 years) leukaemia has improved substantially over the last five decades, particularly for acute lymphoblastic leukaemia (ALL) and acute promyelocytic leukaemia. This progress represents one of the most successful achievements in the history of medicine and has been attributed to the development of effective chemotherapy regimens, improvement in supportive care, better risk stratification, use of targeted therapies, and advances in haematopoietic stem cell transplantation. Recent studies have revealed improvement in survival over time for all age groups and subtypes of leukaemia. However, these outcomes varied widely by age and are associated with sociodemographic and clinical factors. The present review concludes that survival and early death after acute leukaemia has greatly improved among young patients. However, inequalities in outcomes remain and are likely a result of multiple factors.

Andrographolide inhibits growth of human T-cell acute lymphoblastic leukemia Jurkat cells by downregulation of PI3K/AKT and upregulation of p38 MAPK pathways

T-cell acute lymphoblastic leukemia (T-ALL) as a prevalent hematologic malignancy is one of the most common malignant tumors worldwide in children. Andrographolide (Andro), the major active component from Andrographis paniculata, has been shown to possess antitumor activities in several types of cancer cells. However, whether Andro would inhibit T-ALL cell growth remains unclear. In this study, we investigated the cytotoxic effect of Andro on human T-ALL Jurkat cells and explored the mechanisms of cell death. Cell apoptosis was assayed by flow cytometry, and the signaling transduction for Andro was analyzed by Western blotting. The results indicated 10 μg/mL Andro could significantly induce Jurkat cells’ apoptosis, depending on the inhibition of PI3K/AKT pathway. Moreover, Andro-induced apoptosis is enhanced by AKT-selective inhibitor LY294002. ERK- or JNK-selective inhibitors PD98059 and SP600125 had no effect on Andro-induced apoptosis. In addition, p38 inhibitor SB203580 could reverse Andro-induced apoptosis in Jurkat cells. We also found that the protein expression of p-p53 and p-p38 were increased after Andro treatments. The result of an in vivo study also demonstrated Andro’s dose-dependent inhibition in subcutaneous Jurkat xenografts. In conclusion, our findings explained a novel mechanism of drug action by Andro in Jurkat cells and suggested that Andro might be developed into a new candidate therapy for T-ALL patients in the coming days.

Molecular Cytotoxic Mechanisms of 1-(3,4,5-Trihydroxyphenyl)-dodecylbenzoate in Human Leukemia Cell Lines

Recent studies have shown that gallic acid and its alkylesters induce apoptosis in different cell lines. Since new compounds with biological activity and less cytotoxicity to normal cells are necessary for cancer therapy, the aim of this study was to evaluate the cytotoxic effect of 1-(3,4,5-trihydroxyphenyl)-dodecylbenzoate on human acute myeloid leukemia K562 cells and on human acute lymphoblastic leukemia Jurkat cells. The cell viability was determined by MTT method. The apoptosis induction was assessed by bromide and acridine orange staining and by Annexin V-FITC Apoptosis Detection kit. The cell cycle analysis was carried out by flow cytometry using propidium iodide. Cytometric analysis was also performed to evaluate the expression of the following proteins: AIF, p53, Bcl-2 and Bax. The mitochondrial potential was also assessed by flow cytometry using MitoView633 kit. The results showed that the compound significantly reduced the cell viability of K562 and Jurkat cells in a concentration and time dependent manner (IC50 of 30 μM). The compound induced cell cycle arrest in G0/G1phase and significantly increased the proportion of cells in the sub-G0/G1phase. Apoptosis was confirmed by the sight of morphological characteristics of apoptosis and by phosphatidylserine externalization (73.47±5.71% of cells expressing annexin). The results also showed that the compound promotes a modification in Bax:Bcl-2 ratio and increases p53 expression. Thus, it is possible to conclude that 1-(3,4,5-trihydroxyphenyl)-dodecylbenzoate induces apoptosis by inhibiting the antiapoptotic protein Bcl-2 and by increasing the release of AIF, Bax and p53. In addition, it blocks the cell cycle at G0/G1, stopping cell proliferation. So far, the results suggest that this compound may have a potential therapeutic effect against leukemia cells.

Cytotoxicity of cardiotonic steroids in sensitive and multidrug-resistant leukemia cells and the link with Na(+)/K(+)-ATPase

Cardiotonic steroids have long been in clinical use for treatment of heart failure and are now emerging as promising agents in various diseases, especially cancer. Their main target is Na(+)/K(+)-ATPase, a membrane protein involved in cellular ion homeostasis. Na(+)/K(+)-ATPase has been implicated in cancer biology by affecting several cellular events and signaling pathways in both sensitive and drug-resistant cancer cells. Hence, we investigated the cytotoxic activities of 66 cardiotonic steroids and cardiotonic steroid derivatives in sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells. Data were then subjected to quantitative structure-activity relationship analysis (QSAR) and molecular docking into Na(+)/K(+)-ATPase, which both indicated a possible differential expression of the pump in the mentioned cell lines. This finding was confirmed by western blotting, intracellular potassium labeling and next generation sequencing which showed that Na(+)/K(+)-ATPase was less expressed in multidrug-resistant than in sensitive cells.

Therapeutic targeting of c-Myc in T-cell acute lymphoblastic leukemia, T-ALL

T-ALL patients treated with intensive chemotherapy achieve high rates of remission. However, frequent long-term toxicities and relapses into chemotherapy-refractory tumors constitute major clinical challenges which could be met by targeted therapies. c-MYC is a central oncogene in T-ALL, prompting the exploration of the efficacy of MYC inhibitors such as JQ1 (BET-bromodomain inhibitor), and SAHA (HDAC inhibitor). Using a standardized ex vivo drug screening assay, we show here that JQ1 and SAHA show competitive efficiency compared to inhibitors of proteasome, PI3K/AKT/mTOR and NOTCH pathways, and synergize in combination with Vincristine. We also compared for the first time the in vivo relevance of such associations in mice xenografted with human primary T-ALLs. Our data indicate that although treatments combining JQ1 or SAHA with chemotherapeutic regimens might represent promising developments in T-ALL, combinations will need to be tailored to specific subgroups of responsive patients, the profiles of which still remain to be precisely defined.

Association between the polymorphism rs3217927 of CCND2 and the risk of childhood acute lymphoblastic leukemia in a Chinese population

CyclinD proteins, the ultimate recipients of mitogenic and oncogenic signals, play a crucial role in cell-cycle regulation. CyclinD2, one of the cyclinD family, is overexpressed in T-acute lymphoblastic leukemia (ALL) and B-cell chronic lymphocytic leukemia and involved in the pathogenesis of leukemias. Recent reports indicated that CCND2 polymorphisms are associated with human cancer risk, thusly we hypothesized that CCND2 gene polymorphisms may contribute to childhood ALL susceptibility. We selected the polymorphism rs3217927 located in the 3'UTR region of CCND2 to assess its associations with childhood ALL risk in a case-control study. A significant difference was found in the genotype distributions of rs3217927 polymorphism between cases and controls (P = 0.019) and homozygous GG genotype may be an increased risk factor for childhood ALL (adjusted OR  =  1.84, 95% CI  =  1.14 -2.99). Furthermore, this increased risk was more pronounced with GG genotype among high-risk ALL (adjusted OR  = 1.95, 95% CI  =  1.04-3.67), low-risk ALL (adjusted OR  =  2.09, 95% CI  =  1.13-3.87), B-phenotype ALL patients (adjusted OR  =  1.78, 95% CI  =  1.08-2.95) and T-phenotype ALL patients (adjusted OR  =  2.87, 95% CI  =  1.16-7.13). Our results provide evidence that CCND2 polymorphism rs3217927 may be involved in the etiology of childhood ALL, and the GG genotype of rs3217927 may modulate the genetic susceptibility to childhood ALL in the Chinese population. Further functional studies and investigations in larger populations should be conducted to validate our findings.

Increased Th22 cells as well as Th17 cells in patients with adult T-cell acute lymphoblastic leukemia

BACKGROUND

Immune regulation is important for the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL). Th22 cells are recently-identified CD4(+) T cells that implicated in the pathogenesis of many hematological diseases, such as AML. However, the role of Th22 cells in the pathophysiology of T-ALL remains unclear. We examined the Th22, Th17 and Th1 cell frequencies in peripheral blood of T-ALL patients.

METHODS

We studied 24 newly-diagnosed (ND), 17 morphologic complete remission (CR) T-ALL patients and 30 healthy controls. Th subsets were examined by flow cytometry. Plasma IL-22 and IL-17 concentrations were measured by ELISA. Transcription factor RORC, T-bet and AHR mRNA expressions were examined by RT-PCR.

RESULTS

Th22, Th17 frequencies, plasma IL-22 concentration and AHR expression were significantly increased in ND or CR T-ALL patients compared with controls. Moreover, Th22 showed positive correlation with Th17 or Th1 cells in T-ALL patients. However, a significant decrease of IL-17 concentration, Th1 frequency and T-bet expression was found in ND or CR ALL patients compared with controls. Furthermore, Th17 cells showed positive correlation but Th1 cells showed negative correlation with white blood cell counts.

CONCLUSION

The profile of Th subsets was distinct for T-ALL patients and showed some correlations with clinical index, which suggest that these Th subsets may be implicated in the pathogenesis of T-ALL and be reasonable targets for therapeutic intervention.

Concurrent pancreatic and renal leukemic cell infiltration

Pancreatic involvement in acute lymphoblastic leukemia (ALL) is uncommon more so in adults. It can present as obstructive jaundice, pancreatitis or can be asymptomatic. We report here the clinical and imaging features in a 28 years old man with B cell ALL with simultaneous involvement of pancreas and bilateral kidneys. Computed tomography of abdomen showed diffuse infiltration of pancreas by multiple tiny hypodense lesions and multiple hypodense lesions in both kidneys. Although leukemic involvement of pancreas is unusual and our patient was asymptomatic, one should consider the possibility of pancreatic infiltration in a leukemic patient presenting with pancreatic enlargement, cholestatic jaundice or pancreatitis.

Differential mRNA expression levels of human histone-modifying enzymes in normal karyotype B cell pediatric acute lymphoblastic leukemia

Histone modification enzymes regulate gene expression by altering the accessibility of promoters to transcription factors. We sought to determine whether the genes encoding histone modification enzymes are dysregulated in pediatric acute lymphoblastic leukemia (ALL). A real-time PCR array was designed, tested and used to profile the expression of 85 genes encoding histone modification enzymes in bone marrow mononuclear cells from 30 pediatric ALL patients and 20 normal controls. The expression profile of histone-modifying genes was significantly different between normal karyotype B cell pediatric ALL and normal controls. Eleven genes were upregulated in pediatric ALL, including the histone deacetylases HDAC2 and PAK1, and seven genes were downregulated, including PRMT2 and the putative tumor suppressor EP300. Future studies will seek to determine whether these genes serve as biomarkers of pediatric ALL. Ingenuity Pathway Analysis revealed that Gene Expression and Organ Morphology was the highest rated network, with 13 focus molecules (significance score = 35). Ingenuity Pathway Analysis also indicated that curcumin and miR-34 are upstream regulators of histone-modifying enzymes; future studies will seek to validate these results and examine the role of curcumin and miR-34 in leukemia. This study provides new clues into the molecular mechanisms of pediatric ALL.

Chronic stress enhances progression of acute lymphoblastic leukemia via β-adrenergic signaling

Clinical studies suggest that stress-related biobehavioral factors can accelerate the progression of hematopoietic cancers such as acute lymphoblastic leukemia (ALL), but it is unclear whether such effects are causal or what biological pathways mediate such effects. Given the network of sympathetic nervous system (SNS) fibers that innervates the bone marrow to regulate normal (non-leukemic) hematopoietic progenitor cells, we tested the possibility that stress-induced SNS signaling might also affect ALL progression. In an orthotopic mouse model, Nalm-6 human pre-B ALL cells were transduced with the luciferase gene for longitudinal bioluminescent imaging and injected i.v. into male SCID mice for bone marrow engraftment. Two weeks of daily restraint stress significantly enhanced ALL tumor burden and dissemination in comparison to controls, and this effect was blocked by the β-adrenergic antagonist, propranolol. Although Nalm-6 ALL cells expressed mRNA for β1- and β3-adrenergic receptors, they showed no evidence of cAMP signaling in response to norepinephrine, and norepinephrine failed to enhance Nalm-6 proliferation in vitro. These results show that chronic stress can accelerate the progression of human pre-B ALL tumor load via a β-adrenergic signaling pathway that likely involves indirect regulation of ALL biology via alterations in the function of other host cell types such as immune cells or the bone marrow microenvironment.

Asymptomatic leukemic-cell infiltration of the pancreas: US findings

Pancreatic infiltration of leukemic cells is a very rare manifestation at the onset of acute lymphoblastic leukemia (ALL) in childhood. Pancreatic enlargement in this situation is unusual and pancreatic involvement is often associated with biliary obstruction, cholestasis and pancreatitis. We report a 3-month-old girl who presented with asymptomatic leukemic infiltration of the pancreas, demonstrated by US with heterogeneous pancreatic enlargement associated with multiple hypoechogenic lesions, without cholestasis. Although these manifestations are rare, ALL should be considered a cause of pancreatic enlargement.

Signaling proteins and transcription factors in normal and malignant early B cell development

B cell development starts in bone marrow with the commitment of hematopoietic progenitors to the B cell lineage. In murine models, the IL-7 and preBCR receptors, and the signaling pathways and transcription factors that they regulate, control commitment and maintenance along the B cell pathway. E2A, EBF1, PAX5, and Ikaros are among the most important transcription factors controlling early development and thereby conditioning mice homeostatic B cell lymphopoiesis. Importantly, their gain or loss of function often results in malignant development in humans, supporting conserved roles for these transcription factors. B cell acute lymphoblastic leukemia is the most common cause of pediatric cancer, and it is characterized by unpaired early B cell development resulting from genetic lesions in these critical signaling pathways and transcription factors. Fine mapping of these genetic abnormalities is allowing more specific treatments, more accurately predicting risk profiles for this disease, and improving survival rates.

A new, lineage specific, autoup-regulation mechanism for human glucocorticoid receptor gene expression in 697 pre-B-acute lymphoblastic leukemia cells

Glucocorticoid (GC) steroid hormones induce apoptosis in acute lymphoblastic leukemia (ALL). Autoup-regulation of human GC receptor (hGR) levels is associated with sensitivity to GC-mediated apoptosis. Among the major hGR promoters expressed in 697 pre-B-ALL cells (1A, 1B, 1C, and 1D), only promoters 1C and 1D are selectively activated by the hormone. Promoter 1B is unresponsive, and promoter 1A is down-regulated by dexamethasone (Dex) in 697 cells, whereas they are both up-regulated in CEM-C7 T-ALL cells. Autoup-regulation of promoter 1C and 1D in 697 cells requires sequences containing GC response units (GRUs) (1C GRU, -2915/-2956; 1D GRU, -4525/-4559) that were identified previously in CEM-C7 cells. These GRUs potentially bind GR, c-myeloblastosis (c-Myb), and E-twenty six (Ets) proteins; 697 cells express high levels of c-Myb protein, as well as the E-twenty six family protein members, PU.1 and Spi-B. Dex treatment in 697 cells elevates the expression of c-Myb and decreases levels of both Spi-B and PU.1. Chromatin immunoprecipitation assays revealed the specific recruitment of GR, c-Myb, and cAMP response element-binding protein binding protein to the 1C and 1D GRUs upon Dex treatment, correlating to observed autoup-regulated activity in these two promoters. These data suggest a hormone activated, lineage-specific mechanism to control the autoup-regulation of hGR gene expression in 697 pre-B-ALL cells via steroid-mediated changes in GR coregulator expression. These findings may be helpful in understanding the mechanism that determines the sensitivity of B-ALL leukemia cells to hormone-induced apoptosis.

Comparison of neurocognitive functioning in children previously randomly assigned to intrathecal methotrexate compared with triple intrathecal therapy for the treatment of childhood acute lymphoblastic leukemia

PURPOSE

For the majority of children with acute lymphoblastic leukemia (ALL), CNS prophylaxis consists of either intrathecal (IT) methotrexate or triple IT therapy (ie, methotrexate with both cytarabine and hydrocortisone). The long-term neurotoxicities of these two IT strategies have not yet been directly compared.

PATIENTS AND METHODS

In this multisite study, 171 children with standard-risk ALL, age 1 to 9.99 years at diagnosis, previously randomly assigned to IT methotrexate (n = 82) or to triple IT therapy (n = 89) on CCG 1952, underwent neurocognitive evaluation by a licensed psychologist at a mean of 5.9 years after random assignment.

RESULTS

Patients who received IT methotrexate had a mean Processing Speed Index that was 3.6 points lower, about one fourth of a standard deviation, than those who received triple IT therapy (P = .04) after analysis was adjusted for age, sex, and time since diagnosis. Likewise, 19.5% of children in the IT methotrexate group had a Processing Speed Index score in the below-average range compared with 6.9% in the triple IT therapy group (P = .02). Otherwise, the groups performed similarly on tests of full-scale intelligence quotient, academic achievement, attention/concentration, memory, and visual motor integration. The association of treatment with measures of cognitive functioning was not modified by sex or age at diagnosis. In the post-therapy period, there were no group differences in special education services, neurologic events, or use of psychotropic medications.

CONCLUSION

This study did not show any clinically meaningful differences in neurocognitive functioning between patients previously randomly assigned to IT methotrexate or triple IT therapy except for a small difference in processing speed in the IT methotrexate group.