Genomic Profiling of Childhood Tumor Patient-Derived Xenograft Models to Enable Rational Clinical Trial Design

Accelerating cures for children with cancer remains an immediate challenge as a result of extensive oncogenic heterogeneity between and within histologies, distinct molecular mechanisms evolving between diagnosis and relapsed disease, and limited therapeutic options. To systematically prioritize and rationally test novel agents in preclinical murine models, researchers within the Pediatric Preclinical Testing Consortium are continuously developing patient-derived xenografts (PDXs)-many of which are refractory to current standard-of-care treatments-from high-risk childhood cancers. Here, we genomically characterize 261 PDX models from 37 unique pediatric cancers; demonstrate faithful recapitulation of histologies and subtypes; and refine our understanding of relapsed disease. In addition, we use expression signatures to classify tumors for TP53 and NF1 pathway inactivation. We anticipate that these data will serve as a resource for pediatric oncology drug development and will guide rational clinical trial design for children with cancer.

Activated stromal cells transfer mitochondria to rescue acute lymphoblastic leukemia cells from oxidative stress

We investigated and modeled the mesenchymal stromal cell (MSC) niche in adult acute lymphoblastic leukemia (ALL). We used gene expression profiling, cytokine/chemokine quantification, flow cytometry, and a variety of imaging techniques to show that MSCs, directly isolated from the primary bone marrow specimens of patients with ALL, frequently adopted an activated, cancer-associated fibroblast phenotype. Normal, primary human MSCs and the MSC cell line HS27a both were activated de novo, when exposed to the reactive oxygen species (ROS)-inducing chemotherapy agents cytarabine (AraC) and daunorubicin (DNR), a phenomenon blocked by the antioxidant N-acetyl cysteine. Chemotherapy-activated HS27a cells were functionally evaluated in a coculture model with ALL targets. Activated MSCs prevented therapy-induced apoptosis and death in ALL targets, via mitochondrial transfer through tunneling nanotubes (TNTs). Reduction of mitochondrial transfer by selective mitochondrial depletion or interference with TNT formation by microtubule inhibitors, such as vincristine (VCR), prevented the "rescue" function of activated MSCs. Corticosteroids, also a mainstay of ALL therapy, prevented the activation of MSCs. We also demonstrated that AraC (but not VCR) induced activation of MSCs, mitochondrial transfer, and mitochondrial mass increase in a murine NSG model of disseminated SEM cell-derived ALL, wherein CD19+ cells closely associated with nestin+ MSCs after AraC, but not in the other conditions. Our data propose a readily clinically exploitable mechanism for improving treatment of ALL, in which traditional ROS-inducing chemotherapies are often ineffective at eradicating residual disease, despite efficiently killing the bulk population.

Cannabidiol directly targets mitochondria and disturbs calcium homeostasis in acute lymphoblastic leukemia

Anticancer properties of non-psychoactive cannabinoid cannabidiol (CBD) have been demonstrated on tumors of different histogenesis. Different molecular targets for CBD were proposed, including cannabinoid receptors and some plasma membrane ion channels. Here we have shown that cell lines derived from acute lymphoblastic leukemia of T lineage (T-ALL), but not resting healthy T cells, are highly sensitive to CBD treatment. CBD effect does not depend on cannabinoid receptors or plasma membrane Ca2+-permeable channels. Instead, CBD directly targets mitochondria and alters their capacity to handle Ca2+. At lethal concentrations, CBD causes mitochondrial Ca2+ overload, stable mitochondrial transition pore formation and cell death. Our results suggest that CBD is an attractive candidate to be included into chemotherapeutic protocols for T-ALL treatment.

Suppression of HSP70 inhibits the development of acute lymphoblastic leukemia via TAK1/Egr-1

Acute lymphoblastic leukemia (ALL), usually treated with chemotherapy, has limited therapeutic effects and high toxicity. Upregulation of HSP70 induces tumor development, however, the molecular mechanism of HSP70 in ALL remains unclear. In our research, we aimed to investigate the role of HSP70 in ALL, specifically the molecular mechanisms underlying cell apoptosis and proliferation. We found that HSP70 expression in leukomonocytes from ALL patients was increased compared with the control group. HSP70 expression in NALM-6 and BE-13 was also up-regulated contrast with AHH-1. Inhibition of HSP70 significantly promoted cell apoptosis and suppressed cell proliferation in ALL cell lines. Suppression of HSP70 decreased TAK1 and increased Egr-1 protein expression. Further experiments indicated that overexpression of TAK1 ameliorated the effect of HSP70 inhibition on Egr-1 protein expression, cell apoptosis and proliferation. In order to determine whether the effect of HSP70 inhibition on apoptosis and proliferation of ALL cell lines could be achieved via regulation of Egr-1, we performed a loss-of-function experiment for Egr-1. Egr-1 suppression was found to reverse the effect of HSP70 inhibition on cell apoptosis and proliferation in ALL. Taken together, our results suggest that HSP70 inhibition upregulates Egr-1 via TAK1, inducing apoptosis and restricting proliferation in ALL cells.

Differential network analysis and protein-protein interaction study reveals active protein modules in glucocorticoid resistance for infant acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common type of cancer diagnosed in children and Glucocorticoids (GCs) form an essential component of the standard chemotherapy in most treatment regimens. The category of infant ALL patients carrying a translocation involving the mixed lineage leukemia (MLL) gene (gene KMT2A) is characterized by resistance to GCs and poor clinical outcome. Although some studies examined GC-resistance in infant ALL patients, the understanding of this phenomenon remains limited and impede the efforts to improve prognosis.

METHODS

This study integrates differential co-expression (DC) and protein-protein interaction (PPI) networks to find active protein modules associated with GC-resistance in MLL-rearranged infant ALL patients. A network was constructed by linking differentially co-expressed gene pairs between GC-resistance and GC-sensitive samples and later integrated with PPI networks by keeping the links that are also present in the PPI network. The resulting network was decomposed into two sub-networks, specific to each phenotype. Finally, both sub-networks were clustered into modules using weighted gene co-expression network analysis (WGCNA) and further analyzed with functional enrichment analysis.

RESULTS

Through the integration of DC analysis and PPI network, four protein modules were found active under the GC-resistance phenotype but not under the GC-sensitive. Functional enrichment analysis revealed that these modules are related to proteasome, electron transport chain, tRNA-aminoacyl biosynthesis, and peroxisome signaling pathways. These findings are in accordance with previous findings related to GC-resistance in other hematological malignancies such as pediatric ALL.

CONCLUSIONS

Differential co-expression analysis is a promising approach to incorporate the dynamic context of gene expression profiles into the well-documented protein interaction networks. The approach allows the detection of relevant protein modules that are highly enriched with DC gene pairs. Functional enrichment analysis of detected protein modules generates new biological hypotheses and may help in explaining the GC-resistance in MLL-rearranged infant ALL patients.

CRLF2 rearrangement in Ph-like acute lymphoblastic leukemia predicts relative glucocorticoid resistance that is overcome with MEK or Akt inhibition

Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a genetically heterogeneous subtype of B-cell ALL characterized by chromosomal rearrangements and mutations that result in aberrant cytokine receptor and kinase signaling. In particular, chromosomal rearrangements resulting in the overexpression of cytokine receptor-like factor 2 (CRLF2) occur in 50% of Ph-like ALL cases. CRLF2 overexpression is associated with particularly poor clinical outcomes, though the molecular basis for this is currently unknown. Glucocorticoids (GCs) are integral to the treatment of ALL and GC resistance at diagnosis is an important negative prognostic factor. Given the importance of GCs in ALL therapy and the poor outcomes for patients with CRLF2 overexpression, we hypothesized that the aberrant signal transduction associated with CRLF2 overexpression might mediate intrinsic GC insensitivity. To test this hypothesis, we exposed Ph-like ALL cells from patient-derived xenografts to GCs and found that CRLF2 rearranged (CRLF2_R) leukemias uniformly demonstrated reduced GC sensitivity in vitro. Furthermore, targeted inhibition of signal transduction with the MEK inhibitor trametinib and the Akt inhibitor MK2206, but not the JAK inhibitor ruxolitinib, was sufficient to augment GC sensitivity. These data suggest that suboptimal GC responses may in part underlie the poor clinical outcomes for patients with CRLF2 overexpression and provide rationale for combination therapy involving GCs and signal transduction inhibitors as a means of enhancing GC efficacy.

The Population Pharmacokinetics of High-Dose Methotrexate in Infants with Acute Lymphoblastic Leukemia Highlight the Need for Bedside Individualized Dose Adjustment: A Report from the Children's Oncology Group

BACKGROUND

Infants with acute lymphoblastic leukemia (ALL) treated with high-dose methotrexate may have reduced methotrexate clearance (CL) due to renal immaturity, which may predispose them to toxicity.

OBJECTIVE

The aim of this study was to develop a population pharmacokinetic (PK) model of methotrexate in infants with ALL.

METHODS

A total of 672 methotrexate plasma concentrations were obtained from 71 infants enrolled in the Children's Oncology Group (COG) Clinical Trial P9407. Infants received methotrexate 4 g/m2 intravenously for four cycles during weeks 4-12 of intensification. A population PK analysis was performed using NONMEM® version 7.4. The final model was evaluated using a non-parametric bootstrap and a visual predictive check. Simulations were performed to evaluate methotrexate dose and the utility of a bedside algorithm for dose individualization.

RESULTS

Methotrexate was best characterized by a two-compartment model with allometric scaling. Weight was the only covariate included in the final model. The coefficient of variation for interoccasion variability (IOV) on CL was relatively high at 25.4%, compared with the interindividual variability for CL and central volume of distribution (10.7% and 13.2%, respectively). Simulations identified that 21.1% of simulated infants benefitted from bedside dose adjustment, and adjustment of methotrexate doses during infusions can avoid supratherapeutic concentrations.

CONCLUSION

Infants treated with high-dose methotrexate demonstrated a relatively high degree of IOV in methotrexate CL. The magnitude of IOV in the CL of methotrexate suggests that use of a bedside algorithm may avoid supratherapeutic methotrexate concentrations resulting from high IOV in methotrexate CL.

Novel ETV6-RUNX1 Mouse Model to Study the Role of ELF-MF in Childhood B-Acute Lymphoblastic Leukemia: a Pilot Study

Exposure to extremely low-frequency magnetic fields (ELF-MFs) has been classified by the International Agency for Research on Cancer (IARC) as "possibly carcinogenic to humans," based on limited scientific evidence concerning childhood leukemia. This assessment emphasized the lack of appropriate animal models recapitulating the natural history of this disease. Childhood B-cell acute lymphoblastic leukemia (B-ALL) is the result of complex interactions between genetic susceptibility and exposure to exogenous agents. The most common chromosomal alteration is the ETV6-RUNX1 fusion gene, which confers a low risk of developing the malignancy by originating a preleukemic clone requiring secondary hits for full-blown disease to appear. To develop potential prophylactic interventions, we need to identify the environmental triggers of the second hit. Recently, we generated a B-ALL mouse model of the human ETV6-RUNX1+ preleukemic state. Here, we present the results from the ARIMMORA pilot study, obtained by exposing 34 Sca1-ETV6-RUNX1 mice (vs. 27 unexposed) to a 50 Hz magnetic field of 1.5 mT with both fundamental and harmonic content, with an on/off cycle of 10 min/5 min, for 20 h/day, from conception until 3 months of age. Mice were monitored until 2 years of age and peripheral blood was periodically analyzed by flow cytometry. One of the exposed mice developed B-ALL while none of the non-exposed did. Although the results are statistically non-significant due to the limited number of mice used in this pilot experiment, overall, the results show that the newly developed Sca1-ETV6-RUNX1 mouse can be successfully used for ELF-MF exposure studies about the etiology of childhood B-ALL. Bioelectromagnetics. 2019;40:343-353. © 2019 Bioelectromagnetics Society.

Glutaminase Activity of L-Asparaginase Contributes to Durable Preclinical Activity against Acute Lymphoblastic Leukemia

We and others have reported that the anticancer activity of L-asparaginase (ASNase) against asparagine synthetase (ASNS)-positive cell types requires ASNase glutaminase activity, whereas anticancer activity against ASNS-negative cell types does not. Here, we attempted to disentangle the relationship between asparagine metabolism, glutamine metabolism, and downstream pathways that modulate cell viability by testing the hypothesis that ASNase anticancer activity is based on asparagine depletion rather than glutamine depletion per se. We tested ASNase wild-type (ASNase^WT) and its glutaminase-deficient Q59L mutant (ASNase^Q59L) and found that ASNase glutaminase activity contributed to durable anticancer activity against xenografts of the ASNS-negative Sup-B15 leukemia cell line in NOD/SCID gamma mice, whereas asparaginase activity alone yielded a mere growth delay. Our findings suggest that ASNase glutaminase activity is necessary for durable, single-agent anticancer activity in vivo, even against ASNS-negative cancer types.

High cortactin expression in B-cell acute lymphoblastic leukemia is associated with increased transendothelial migration and bone marrow relapse

Cancer is a major cause of death in children worldwide, with B-lineage cell acute lymphoblastic leukemia (B-ALL) being the most frequent childhood malignancy. Relapse, treatment failure and organ infiltration worsen the prognosis, warranting a better understanding of the implicated mechanisms. Cortactin is an actin-binding protein involved in cell adhesion and migration that is overexpressed in many solid tumors and in adult B-cell chronic lymphocytic leukemia. Here, we investigated cortactin expression and potential impact on infiltration and disease prognosis in childhood B-ALL. B-ALL cell lines and precursor cells from bone marrow (BM) and cerebrospinal fluid (CSF) of B-ALL patients indeed overexpressed cortactin. In CXCL12-induced transendothelial migration assays, transmigrated B-ALL cells had highest cortactin expression. In xenotransplantation models, only cortactinhigh-leukemic cells infiltrated lungs, brain, and testis; and they colonized more easily hypoxic BM organoids. Importantly, cortactin-depleted B-ALL cells were significantly less efficient in transendothelial migration, organ infiltration and BM colonization. Clinical data highlighted a significant correlation between high cortactin levels and BM relapse in drug-resistant high-risk B-ALL patients. Our results emphasize the importance of cortactin in B-ALL organ infiltration and BM relapse and its potential as diagnostic tool to identify high-risk patients and optimize their treatments.

Time-Delayed Integration-Spectral Flow Cytometer (TDI-SFC) for Low-Abundance-Cell Immunophenotyping

We describe a unique flow cytometer (TDI-SFC) for the immunophenotyping of low-abundance cells, particularly when cell counts are sample-limited and operationally difficult for analysis by fluorescence microscopy (>100 cells) or multiparameter flow cytometry (MFC, <10 000 cells). TDI-SFC combines the high spectral resolution of spectral flow cytometry (SFC) with a CCD operated in time-delayed integration (TDI) for improved duty cycle and sensitivity. Cells were focused with a 1D-sheathing microfluidic device, and fluorescence emission generated from a 488 nm laser was collected by epi-illumination and dispersed along one axis of a CCD by a spectrograph. Along the other axis, the CCD's shift rate was clocked at a rate that closely matched the cells' velocity through the field of view. This TDI-SFC format allowed the CCD shutter to remain open during signal acquisition, providing a duty cycle ∼100% and assurance that ∼95% cells were interrogated. We used fluorescent beads to optimize synchronization of TDI clocking with the sheathed-cell velocity and to improve sensitivity via the excitation intensity, epi-illumination numerical aperture, and integration time. TDI achieved integrated signals of 106 counts at a signal-to-noise ratio (SNR) of 610 for beads corresponding to a load of 4 × 105 antibodies. We also evaluated multiplexing capabilities by spectral deconvolution and undertook a proof-of-concept application to immunophenotype low-abundance cells; the demonstration consisted of immunophenotyping a model cell line, in this case SUP-B15 cells representing B-cell acute lymphoblastic leukemia (B-ALL). The B-ALL cell line was stained against a leukemic marker (terminal deoxynucleotidyl transferase, TdT), and we successfully used spectral unmixing to discriminate TdT(+) cells from TdT(-) cells even at low cell counts (∼100 cells). The TDI-SFC could potentially be used in any application requiring the immunophenotyping of low-abundance cells, such as in monitoring measurable residual disease in acute leukemias following affinity enrichment of circulating leukemia cells from peripheral blood.

DNA damage signalling from the placenta to foetal blood as a potential mechanism for childhood leukaemia initiation

For many diseases with a foetal origin, the cause for the disease initiation remains unknown. Common childhood acute leukaemia is thought to be caused by two hits, the first in utero and the second in childhood in response to infection. The mechanism for the initial DNA damaging event are unknown. Here we have used in vitro, ex vivo and in vivo models to show that a placental barrier will respond to agents that are suspected of initiating childhood leukaemia by releasing factors that cause DNA damage in cord blood and bone marrow cells, including stem cells. We show that DNA damage caused by in utero exposure can reappear postnatally after an immune challenge. Furthermore, both foetal and postnatal DNA damage are prevented by prenatal exposure of the placenta to a mitochondrially-targeted antioxidant. We conclude that the placenta might contribute to the first hit towards leukaemia initiation by bystander-like signalling to foetal haematopoietic cells.

Expression of Leukocytic Syncytin-1 in B-Cell Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia Patients

BACKGROUND

Syncytin-1 is improperly expressed in several cancers. However, its expression profile across leukocytes in leukemia patients has not yet been analyzed.

METHODS

A total of 50 AML cases and 14 B-cell ALL patients were consecutively recruited. Bone marrow samples were subjected to flow cytometry. Statistical analysis was applied to compare syncytin-1 expression between B-cell ALL and AML across granulocytes, leukemia cells, and T-lymphocytes (including CD3+, CD4+, and CD8+ subsets thereof) and to correlate syncytin-1 expression to leukemia cells and lymphocytes with the T-cell subset percentages.

RESULTS

The syncytin-1-expressing leukemia cell% in AML patients was significantly higher than that in B-cell ALL patients (p < 0.05). The CD8+ T-cell% in AML patients was significantly higher than that in B-cell ALL patients (p < 0.05). The syncytin-1 expression rate on leukemia cells was positively correlated with the CD8+ T-cell percentage (r = 0.289, p < 0.05), while the syncytin-1 expression rate on lymphocytes was negatively correlated with the CD3+, CD4+, and CD8+ T-cell percentages (r = -0.273, -0.450, and -0.307, respectively; p < 0.05).

CONCLUSIONS

The percentage of syncytin-1-expressing leukemia cells in AML - due to its positive correlation with the CD8+ suppressor T-cell percentage - shows potential as an indicator of poorer long-term immunity in AML patients.

Long-term effects on growth, development, and metabolism of ALL treatment in childhood

INTRODUCTION

One aim of the long-term care in survivors from acute lymphoblastic leukemia (ALL) during childhood is to avoid or limit complications caused by aggressive therapeutic strategies.

AREAS COVERED

ALL survivors are a heterogeneous group according to therapeutic protocols. In the last decades, cranial radiotherapy (cRT) has been largely replaced by intrathecal chemotherapy (CT) with a reduction of endocrine sequelae. Published studies are generally difficult to be interpreted because patients were treated according to different risk-adapted protocols and results are conflicting. We perform this review on endocrine long-term effects in childhood ALL survivors focusing on studies published in the last decades. Articles were selected using the following terms (Mesh terms): 'acute lymphoblastic leukemia' AND 'survivors' AND 'childhood' AND 'growth/puberty/fertility/obesity/metabolic syndrome/bone'.

EXPERT COMMENTARY

Most childhood ALL survivors treated with CT alone attain normal height and have adequate pubertal development. Despite recent protocols improvements, ALL survivors still develop long-term metabolic complications (overweight, obesity, and cardiovascular disease) especially the female gender and patients with an increased body mass index (BMI) at diagnosis. The aim of this review is to describe the state of the art on these topics. We should be able to anticipate, prevent, and treat endocrine long-term morbidities through a well-established follow-up strategy.

Lymphocyte-Specific Chromatin Accessibility Pre-determines Glucocorticoid Resistance in Acute Lymphoblastic Leukemia

Glucocorticoids play a critical role in the treatment of lymphoid malignancies. While glucocorticoid efficacy can be largely attributed to lymphocyte-specific apoptosis, its molecular basis remains elusive. Here, we studied genome-wide lymphocyte-specific open chromatin domains (LSOs), and integrated LSOs with glucocorticoid-induced RNA transcription and chromatin modulation using an in vivo patient-derived xenograft model of acute lymphoblastic leukemia (ALL). This led to the identification of LSOs critical for glucocorticoid-induced apoptosis. Glucocorticoid receptor cooperated with CTCF at these LSOs to mediate DNA looping, which was inhibited by increased DNA methylation in glucocorticoid-resistant ALL and non-lymphoid cell types. Our study demonstrates that lymphocyte-specific epigenetic modifications pre-determine glucocorticoid resistance in ALL and may account for the lack of glucocorticoid sensitivity in other cell types.

New therapeutic opportunities from dissecting the pre-B leukemia bone marrow microenvironment

The microenvironments of leukemia and cancer are critical for multiple stages of malignancies, and they are an attractive therapeutic target. While skeletal abnormalities are commonly seen in children with acute lymphoblastic leukemia (ALL) prior to initiating osteotoxic therapy, little is known about the alterations to the bone marrow microenvironment during leukemogenesis. Therefore, in this study, we focused on the development of precursor-B cell ALL (pre-B ALL) in an immunocompetent BCR-ABL1+ model. Here we show that hematopoiesis was perturbed, B lymphopoiesis was impaired, collagen production was reduced, and the number of osteoblastic cells was decreased in the bone marrow microenvironment. As previously found in children with ALL, the leukemia-bearing mice exhibited severe bone loss during leukemogenesis. Leukemia cells produced high levels of receptor activator of nuclear factor κB ligand (RANKL), sufficient to cause osteoclast-mediated bone resorption. In vivo administration of zoledronic acid rescued leukemia-induced bone loss, reduced disease burden and prolonged survival in leukemia-bearing mice. Taken together, we provide evidence that targeting leukemia-induced bone loss is a therapeutic strategy for pre-B ALL.

Capturing B type acute lymphoblastic leukemia cells using two types of antibodies

One way to monitor minimal residual disease (MRD) is to screen cells for multiple surface markers using flow cytometry. In order to develop an alternative microfluidic based method, isolation of B type acute lymphoblastic cells using two types of antibodies should be investigated. The immunomagnetic beads coated with various antibodies are used to capture the B type acute lymphoblastic cells. Single beads, two types of beads and surface immobilized antibody were used to measure the capture efficiency. Both micro and nanosize immunomagnetic beads can be used to capture B type acute lymphoblastic cells with a minimum efficiency of 94% and maximum efficiency of 98%. Development of a microfluidic based biochip incorporating immunomagnetic beads and surface immobilized antibodies for monitoring MRD can be an alternative to current cost and time inefficient laboratory methods. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2737, 2019.

The Effect of Soy Nut Compared to Cowpea Nut on Body Weight, Blood Cells, Inflammatory Markers and Chemotherapy Complications in Children with Acute Lymphoblastic Leukemia: A Randomized Controlled Clinical Trial

No previous studies were found to examine the effect of soy as a whole food on patients with leukemia. The present randomized controlled clinical trial studied the effect of soy nut on children with B-cell acute lymphoblastic leukemia (ALL) who were in the maintenance phase of chemotherapy. The eligible patients were randomized to receive 30 g/day soy or cowpea nut powder for 12 weeks. Dietary intake, physical activity, anthropometric measurements, complete blood count, serum albumin, serum highly sensitive C-reactive protein (hs-CRP), and Tumor necrosis factor alpha (TNF-α) as well as chemotherapy side effects were assessed at the start and the end of the study. In total 29 and 27 children completed the study (aged 6.34 ± 2.44 and 5.85 ± 2.35 years) in soy and cowpea nut groups, respectively. The total energy and protein intake, and physical activity as well as body weight, body mass index, number of red blood cells, hemoglobin and hematocrit levels, and fatigue were significantly improved in the soy nut group compared to patients who consumed cowpea nut (P < 0.05). Soy nut intake might improve the nutritional status, anemia, and fatigue in children with ALL. Studies targeting blood cell fractions and disease recurrence are highly recommended.

Why and how to treat Ph-like ALL?

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL), or BCR-ABL1-like ALL, is a high-risk subtype of B-cell precursor ALL characterized by a gene expression profile similar to Ph-positive ALL, a high frequency of IKZF1 alterations, and poor outcome. The prevalence of Ph-like ALL is common among all ages, ranging from 10% to 15% in children to over 25% in young adults. Patients with Ph-like ALL harbor a diverse range of genetic alterations that activate cytokine receptor and kinase signaling and can be targeted with tyrosine kinase inhibitors. The majority of Ph-like ALL alterations are divided into two main groups based on activation of ABL-class or JAK-STAT alterations. Accordingly, preclinical studies and anecdotal reports suggest patients harboring ABL-class fusions are candidates for ABL1-inhibitors, whilst alterations activating the JAK-STAT pathway may be amenable to treatment with JAK inhibitors. Diagnostic screening approaches and precision medicine trials are now being developed and implemented to test the efficacy of targeted therapy with a backbone of chemotherapy, similar to the treatment of Ph-positive ALL.

Selective Cytotoxicity of α-Santonin from the Persian Gulf Sponge Dysidea Avara on Pediatric ALL B-lymphocytes via Mitochondrial Targeting

Background: Acute lymphoblastic leukemia (ALL) is one of the most dominant malignancies among children, characterized by production of immature and dysfunctional blasts which are resistant to cytotoxic chemotherapeutic agents. Therefore, research protocols are currently focusing on discovery of novel anti-cancer agents to enhance survival rates and decrease unwanted side effects. Approximately two-thirds of the planet is covered by oceans with a massive range of marine organisms of interest to scientists in pharmaceutical fields. Methods: Among marine resources, sponges are known to have beneficial effects in the treatment of numerous malignancies. One fraction of crude extracts containing α-Santonin was made from the Persian Gulf marine sponge, Dysidea avara, and investigated for anticancer effects. Results: Treatment of ALL B-lymphocytes with the Dysidea avara extract caused augmentation in ROS generation, decline in mitochondrial membrane potential, mitochondrial swelling, release of cytochrome c from mitochondria and activation of caspase-3 only in mitochondria isolated from B-ALL lymphocytes. Conclusion: In brief, our results suggest that Dysidea avara extracts may selectively induce apoptosis in malignant pediatric lymphocytes.