Acute Lymphoblastic Leukemia Cell Lines Research Articles

Abstract 3964: Co-targeting MDM2-p53 and BCL-2 apoptosis pathways overcomes resistance conferred by acquired BCL-2 gene mutations in preclinical models

Abstract The BCL-2 inhibitor venetoclax has shown impressive efficacy in patients with chronic lymphocytic leukemia, but its clinical benefits are limited by acquired BCL-2 gene mutations that confer drug resistance. Among acquired mutations, those proximal to BH3 binding motifs (e.g., G101V, D103E, and V156D) have the most significant impact on BCL-2 binding to BH3-only prodeath proteins and BH3 mimetics (e.g., venetoclax). Hence, it is important to identify novel therapeutics that address this emerging unmet need. To this end, we investigated the effect of co-targeting BCL-2 and MDM2-p53 apoptosis pathways in preclinical models of acute lymphoblastic leukemia (ALL) with BCL-2 mutations. We first genetically engineered cell lines that express clinically relevant BCL-2 gene mutations in ALL cell line RS4;11, which shows greater expression of mutants, compared to endogenous wild-type BCL-2 protein. Relative to parental cells, sensitivity to venetoclax and investigational, clinical-stage BCL-2 inhibitor lisaftoclax (APG-2575) in mutant cell lines was reduced 160-fold. Using these BCL-2-inhibitor-resistant cell lines, we assessed the effect of combining lisaftoclax with investigational, clinical-stage MDM2-p53 inhibitor alrizomadlin (APG-115). Alrizomadlin inhibits the MDM2-p53 interaction and activates the prodeath p53 tumor suppressor signaling pathways (Aguilar A et al. J Med Chem 2017). Also potentially consequential was the observation that combining alrizomadlin with lisaftoclax synergistically inhibited proliferation and induced apoptosis in RS4:11 cells carrying G101V, V156D, or D103E mutations. Treatment with this combination also synergistically enhanced antitumor activity in mouse xenograft tumor models derived from RS4:11 cells carrying G101V or V156D mutations. In these animal models, lisaftoclax alone exhibited no or limited activity, with T/C (%; i.e., relative tumor volume of treatment group vs. control) values ranging from 86.40% to 99.15%. In contrast, single-agent alrizomadlin exerted slightly more potent activity, with T/C values ranging from 57.25% to 62.35%. Importantly, the combination of lisaftoclax and alrizomadlin demonstrated synergy, with T/C values ranging from 12.30% to 32.16%. Mechanistically, alrizomadlin likely induced expression of prodeath BCL-2 family proteins BAX, PUMA, and Noxa, which are p53 target genes. Further, lisaftoclax plus alrizomadlin more effectively blocked cell cycle entry into the G2/M phase, resulting in accumulation of sub-G1 apoptotic cells. In summary, our study demonstrates, for the first time, that co-targeting BCL-2 and MDM2-p53 apoptosis pathways overcame resistance to BCL-2 inhibitors conferred by acquired BCL-2 gene mutations, potentially offering a viable strategy to overcome drug resistance and thus providing a rationale for clinical investigation. Citation Format: Jing Deng, Kaixiang Zhang, Qiuqiong Tang, Xiaojing Huang, Qixin Wang, Na Li, Douglas D. Fang, Dajun Yang, Yifan Zhai. Co-targeting MDM2-p53 and BCL-2 apoptosis pathways overcomes resistance conferred by acquired BCL-2 gene mutations in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3964.

Abstract 3934: KT-253, a highly potent and selective heterobifunctional MDM2 degrader for the treatment of wildtype p53 tumors with superior potency and differentiated biological activity compared to small molecule inhibitors (SMI)

Abstract Background: The murine double minute 2 (MDM2) oncoprotein is a key E3 ubiquitin ligase that degrades the tumor-suppressor p53. Reversible SMIs of the MDM2/p53 interaction have been developed to stabilize p53 and to induce apoptosis in wildtype p53 tumors. However, MDM2 SMIs induce a p53/MDM2 feedback loop, resulting in upregulation of MDM2 protein levels and p53 pathway inhibition, thus drastically limiting their biological activity and clinical application. MDM2 targeted protein degradation suppresses p53-dependent MDM2 protein feedback upregulation and is therefore expected to lead to a superior response compared to SMIs. Objectives: We discovered KT-253, a novel, highly potent heterobifunctional MDM2 degrader. We characterized the activity and molecular mechanism of KT-253 in wildtype p53 cell lines and xenograft models and demonstrated that KT-253 has superior activity compared to SMIs in these models. Methods: We characterized KT-253 in MDM2-dependent cell lines in vitro, as well as in in vivo mouse AML and ALL xenograft models. Methods included in vitro cell proliferation and apoptosis assays, gene expression profiling, and in vivo pharmacological studies. Results: KT-253 selectively depletes MDM2 protein levels with sub-nanomolar cellular potency. We demonstrated in the Acute Lymphoblastic Leukemia (ALL) cell line RS4;11 that KT-253 can overcome the p53-dependent upregulation of MDM2 protein levels as seen for reversible SMIs. In addition, even brief exposures to KT-253 in these cells could more potently stabilize p53 compared to SMIs, leading to apoptosis mediated through p53 target genes. The superior MDM2/p53 pathway inhibition and induction of apoptosis by KT-253 translates into a >200-fold stronger cell growth inhibition, compared to SMIs, across a panel of solid and hematological tumor cell lines. Using mouse xenograft models, we established an intermittent dosing schedule that drives anti-tumor efficacy. Importantly, a single dose of KT-253 at 1 mg/kg resulted in sustained tumor regression in the RS4;11 mouse xenograft model. In this model, KT-253 exposures correlated with induction of apoptotic p53 target genes and tumor growth inhibition. In addition, weekly administration of KT-253 significantly prolonged the survival in a disseminated Acute Myeloid Leukemia (AML) model when compared to vehicle treated animals. Conclusions: In summary, KT-253, our development candidate, has significantly improved potency relative to reversible SMIs leading to potent in vitro and in vivo efficacy that is superior to all clinically active agents. In addition, an intermittent dosing schedule of the highly potent KT-253 degrader can induce rapid apoptosis in MDM2-dependent cancer cells potentially leading to improved efficacy and safety profile. Citation Format: Yogesh Chutake, Michele Mayo, Dapeng Chen, Bradley Enerson, Patricia Cho, Jessica Filiatrault, Crystal Brown, Michael Placke, Madison Adams, Rahul Karnik, James Shaw, Yatao Shi, Dirk Walther, Alice McDonald, Frank Qi, Phillip Liu, Joseph D. Growney, Kirti Sharma, Duncan Walker, Stefanie Schalm, Juliet Williams, Matthew Weiss. KT-253, a highly potent and selective heterobifunctional MDM2 degrader for the treatment of wildtype p53 tumors with superior potency and differentiated biological activity compared to small molecule inhibitors (SMI) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3934.

In Silico Analysis of L-Asparaginase Exposure on Acute Lymphoblastic Leukemia Cell Line RS 4: 11

Background The antineoplastic action of Asparaginase (ASNase) was connected to the inability of certain cancer cells to synthesise appropriate level of asparagine (asn). Due to the high affinity of clinically applicable ASNase for asn, asn is rapidly decreased in serum and extracellular fluids following intravenous or intramuscular injection. Tumor cells dependent on external Asn supply and unable of mitigating asn deficiency on their own may starve to death if exogenous asn depletion persists. Methods The current study focused on identifying Differentially Expressed Genes (DEGs) in Acute Lymphoblastic Leukemia (ALL) cell line RS 4;11. A complex biomolecular network for the DEGs was built and various tools were used to compute network parameters and identify drug targets. Results The biomolecular network comprised 109 DEGs. NOTCH1 and PIK3CA may be hub genes and require further research. Conclusion DEGs found could be employed as therapeutic targets for ALL tests or as leads for novel ALL treatments. The current study clarifies the L-ASNase’s exposure on sensitive ALL cell line; resistant cell lines may be investigated further in the future to obtain a greater understanding of ALL.

The Cooperative Anti-Neoplastic Activity of Polyphenolic Phytochemicals on Human T-Cell Acute Lymphoblastic Leukemia Cell Line MOLT-4 In Vitro.

Acute lymphoblastic leukemia (ALL) is the most common hematological malignancy affecting pediatric patients. ALL treatment regimens with cytostatics manifest substantial toxicity and have reached the maximum of well-tolerated doses. One potential approach for improving treatment efficiency could be supplementation of the current regimen with naturally occurring phytochemicals with anti-cancer properties. Nutraceuticals such as quercetin, curcumin, resveratrol, and genistein have been studied in anti-cancer therapy, but their application is limited by their low bioavailability. However, their cooperative activity could potentially increase their efficiency at low, bioavailable doses. We studied their cooperative effect on the viability of a human ALL MOLT-4 cell line in vitro at the concentration considered to be in the bioavailable range in vivo. To analyze their potential side effect on the viability of non-tumor cells, we evaluated their toxicity on a normal human foreskin fibroblast cell line (BJ). In both cell lines, we also measured specific indicators of cell death, changes in cell membrane permeability (CMP), and mitochondrial membrane potential (MMP). Even at a low bioavailable concentration, genistein and curcumin decreased MOLT-4 viability, and their combination had a significant interactive effect. While resveratrol and quercetin did not affect MOLT-4 viability, together they enhanced the effect of the genistein/curcumin mix, significantly inhibiting MOLT-4 population growth in vitro. Moreover, the analyzed phytochemicals and their combinations did not affect the BJ cell line. In both cell lines, they induced a decrease in MMP and correlating CMP changes, but in non-tumor cells, both metabolic activity and cell membrane continuity were restored in time. (4) Conclusions: The results indicate that the interactive activity of analyzed phytochemicals can induce an anti-cancer effect on ALL cells without a significant effect on non-tumor cells. It implies that the application of the combinations of phytochemicals an anti-cancer treatment supplement could be worth further investigation regardless of their low bioavailability.

Astaxanthin decreases the growth-inhibitory dose of cytarabine and inflammatory response in the acute lymphoblastic leukemia cell line NALM-6.

In spite of the great progress in acute lymphoblastic leukemia (ALL) treatment, a large number of patients still suffer from chemotherapy drug toxicity. As a routine medication for ALL treatment, cytarabine (Ara-C) has many side effects on the patients. Astaxanthin (ASX), on the other hand, is a carotenoid with antioxidant, anti-inflammatory and anti-cancer properties. The present study investigated the effects of ASX in combination with Ara-C on cell proliferation, apoptosis induction, and cell cycle arrest in NALM-6 cell line. NALM6 cells were treated with different concentrations of ASX, Ara-C, and their co-treatment. Cytotoxic effects were evaluated using MTT assay. After treating the cells with the IC50 dose of ASX, Ara-C and their co-treatment, we studied apoptosis induction, cell cycle arrest, and expression of apoptotic, anti-apoptotic, and inflammatory genes. MTT assay demonstrated that co-treatment of cytarabine and ASX had greater cytotoxicity effects compared with the IC50 dose of Ara-C alone. After 48h of treatment of NALM-6 cells with the combination dose, expression levels of apoptotic genes (P53, caspase-8, 3), the anti-apoptotic gene (Bcl-xL) and inflammatory genes (IL-6, TNF-α) changed significantly compared to the untreated group (p < 0.05). Co-treatment of ASX and Ara-C has synergism effects on apoptosis pathways, cell proliferation inhibition, and decreased inflammation.

Genetic Engineering and Enrichment of Human NK Cells for CAR-Enhanced Immunotherapy of Hematological Malignancies.

The great clinical success of chimeric antigen receptor (CAR) T cells has unlocked new levels of immunotherapy for hematological malignancies. Genetically modifying natural killer (NK) cells as alternative CAR immune effector cells is also highly promising, as NK cells can be transplanted across HLA barriers without causing graft-versus-host disease. Therefore, off-the-shelf usage of CAR NK cell products might allow to widely expand the clinical indications and to limit the costs of treatment per patient. However, in contrast to T cells, manufacturing suitable CAR NK cell products is challenging, as standard techniques for genetically engineering NK cells are still being defined. In this study, we have established optimal lentiviral transduction of primary human NK cells by systematically testing different internal promoters for lentiviral CAR vectors and comparing lentiviral pseudotypes and viral entry enhancers. We have additionally modified CAR constructs recognizing standard target antigens for acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) therapy—CD19, CD33, and CD123—to harbor a CD34-derived hinge region that allows efficient detection of transduced NK cells in vitro and in vivo and also facilitates CD34 microbead-assisted selection of CAR NK cell products to >95% purity for potential clinical usage. Importantly, as most leukemic blasts are a priori immunogenic for activated primary human NK cells, we developed an in vitro system that blocks the activating receptors NKG2D, DNAM-1, NKp30, NKp44, NKp46, and NKp80 on these cells and therefore allows systematic testing of the specific killing of CAR NK cells against ALL and AML cell lines and primary AML blasts. Finally, we evaluated in an ALL xenotransplantation model in NOD/SCID-gamma (NSG) mice whether human CD19 CAR NK cells directed against the CD19+ blasts are relying on soluble or membrane-bound IL15 production for NK cell persistence and also in vivo leukemia control. Hence, our study provides important insights into the generation of pure and highly active allogeneic CAR NK cells, thereby advancing adoptive cellular immunotherapy with CAR NK cells for human malignancies further.

Lactobacillus acidophilus’ post biotic extracts combined with methotrexate regulated the levels of the apoptotic genes’ expressions in the acute lymphoblastic leukemia cell line

Lactobacillus acidophilus’ post biotic extracts combined with methotrexate regulated the levels of the apoptotic genes’ expressions in the acute lymphoblastic leukemia cell line

Validation of a small molecule inhibitor of PDE6D-RAS interaction with favorable anti-leukemic effects

RAS mutations prevalent in high-risk leukemia have been linked to relapse and chemotherapy resistance. Efforts to directly target RAS proteins have been largely unsuccessful. However, since RAS-mediated transformation is dependent on signaling through the RAS-related C3 botulinum toxin substrate (RAC) small GTPase, we hypothesized that targeting RAC may be an effective therapeutic approach in RAS mutated tumors. Here we describe multiple small molecules capable of inhibiting RAC activation in acute lymphoblastic leukemia cell lines. One of these, DW0254, also demonstrates promising anti-leukemic activity in RAS-mutated cells. Using chemical proteomics and biophysical methods, we identified the hydrophobic pocket of phosphodiester 6 subunit delta (PDE6D), a known RAS chaperone, as a target for this compound. Inhibition of RAS localization to the plasma membrane upon DW0254 treatment is associated with RAC inhibition through a phosphatidylinositol-3-kinase/AKT-dependent mechanism. Our findings provide new insights into the importance of PDE6D-mediated transport for RAS-dependent RAC activation and leukemic cell survival.

Integrative multi-omics and drug response profiling of childhood acute lymphoblastic leukemia cell lines.

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Although standard-of-care chemotherapeutics are sufficient for most ALL cases, there are subsets of patients with poor response who relapse in disease. The biology underlying differences between subtypes and their response to therapy has only partially been explained by genetic and transcriptomic profiling. Here, we perform comprehensive multi-omic analyses of 49 readily available childhood ALL cell lines, using proteomics, transcriptomics, and pharmacoproteomic characterization. We connect the molecular phenotypes with drug responses to 528 oncology drugs, identifying drug correlations as well as lineage-dependent correlations. We also identify the diacylglycerol-analog bryostatin-1 as a therapeutic candidate in the MEF2D-HNRNPUL1 fusion high-risk subtype, for which this drug activates pro-apoptotic ERK signaling associated with molecular mediators of pre-B cell negative selection. Our data is the foundation for the interactive online Functional Omics Resource of ALL (FORALL) with navigable proteomics, transcriptomics, and drug sensitivity profiles at https://proteomics.se/forall.

Amino acid stress response genes promote L-asparaginase resistance in pediatric acute lymphoblastic leukemia

AbstractUnderstanding the genomic and epigenetic mechanisms of drug resistance in pediatric acute lymphoblastic leukemia (ALL) is critical for further improvements in treatment outcomes. The role of transcriptomic response in conferring resistance to l-asparaginase (LASP) is poorly understood beyond asparagine synthetase (ASNS). We defined reproducible LASP response genes in LASP-resistant and LASP-sensitive ALL cell lines as well as primary leukemia samples from newly diagnosed patients. Defining target genes of the amino acid stress response-related transcription factor activating transcription factor 4 (ATF4) in ALL cell lines using chromatin immunoprecipitation sequencing (ChIP-seq) revealed 45% of genes that changed expression after LASP treatment were direct targets of the ATF4 transcription factor, and 34% of these genes harbored LASP-responsive ATF4 promoter binding events. SLC7A11 was found to be a response gene in cell lines and patient samples as well as a direct target of ATF4. SLC7A11 was also one of only 2.4% of LASP response genes with basal level gene expression that also correlated with LASP ex vivo resistance in primary leukemia cells. Experiments using chemical inhibition of SLC7A11 with sulfasalazine, gene overexpression, and partial gene knockout recapitulated LASP resistance or sensitivity in ALL cell lines. These findings show the importance of assessing changes in gene expression following treatment with an antileukemic agent for its association with drug resistance and highlight that many response genes may not differ in their basal expression in drug-resistant leukemia cells.

Phosphorylation of SHP2 at Tyr62 Enables Acquired Resistance to SHP2 Allosteric Inhibitors in FLT3-ITD-Driven AML.

These findings suggest that combined inhibition of SHP2 and FLT3 effectively treat FLT3-ITD-positive AML, highlighting the need for development of more potent SHP2 inhibitors and combination therapies for clinical applications.

High-Throughput Drug Library Screening in Primary KMT2A-Rearranged Infant ALL Cells Favors the Identification of Drug Candidates That Activate P53 Signaling.

KMT2A-rearranged acute lymphoblastic leukemia (ALL) in infants (<1 year of age) represents an aggressive type of childhood leukemia characterized by a poor clinical outcome with a survival chance of <50%. Implementing novel therapeutic approaches for these patients is a slow-paced and costly process. Here, we utilized a drug-repurposing strategy to identify potent drugs that could expeditiously be translated into clinical applications. We performed high-throughput screens of various drug libraries, comprising 4191 different (mostly FDA-approved) compounds in primary KMT2A-rearranged infant ALL patient samples (n = 2). The most effective drugs were then tested on non-leukemic whole bone marrow samples (n = 2) to select drugs with a favorable therapeutic index for bone marrow toxicity. The identified agents frequently belonged to several recurrent drug classes, including BCL-2, histone deacetylase, topoisomerase, microtubule, and MDM2/p53 inhibitors, as well as cardiac glycosides and corticosteroids. The in vitro efficacy of these drug classes was successfully validated in additional primary KMT2A-rearranged infant ALL samples (n = 7) and KMT2A-rearranged ALL cell line models (n = 5). Based on literature studies, most of the identified drugs remarkably appeared to lead to activation of p53 signaling. In line with this notion, subsequent experiments showed that forced expression of wild-type p53 in KMT2A-rearranged ALL cells rapidly led to apoptosis induction. We conclude that KMT2A-rearranged infant ALL cells are vulnerable to p53 activation, and that drug-induced p53 activation may represent an essential condition for successful treatment results. Moreover, the present study provides an attractive collection of approved drugs that are highly effective against KMT2A-rearranged infant ALL cells while showing far less toxicity towards non-leukemic bone marrow, urging further (pre)clinical testing.

T cell receptor engineering of primary NK cells to therapeutically target tumors and tumor immune evasion

BackgroundT cell receptor (TCR)-engineered cells can be powerful tools in the treatment of malignancies. However, tumor resistance by Human Leukocyte antigen (HLA) class I downregulation can negatively impact the success...

Phosphoproteomic profiling of T cell acute lymphoblastic leukemia reveals targetable kinases and combination treatment strategies

Protein kinase inhibitors are amongst the most successful cancer treatments, but targetable kinases activated by genomic abnormalities are rare in T cell acute lymphoblastic leukemia. Nevertheless, kinases can be activated in the absence of genetic defects. Thus, phosphoproteomics can provide information on pathway activation and signaling networks that offer opportunities for targeted therapy. Here, we describe a mass spectrometry-based global phosphoproteomic profiling of 11 T cell acute lymphoblastic leukemia cell lines to identify targetable kinases. We report a comprehensive dataset consisting of 21,000 phosphosites on 4,896 phosphoproteins, including 217 kinases. We identify active Src-family kinases signaling as well as active cyclin-dependent kinases. We validate putative targets for therapy ex vivo and identify potential combination treatments, such as the inhibition of the INSR/IGF-1R axis to increase the sensitivity to dasatinib treatment. Ex vivo validation of selected drug combinations using patient-derived xenografts provides a proof-of-concept for phosphoproteomics-guided design of personalized treatments.

Integrin α6-Targeted Molecular Imaging of Central Nervous System Leukemia in Mice.

Central nervous system leukemia (CNS-L) is caused by leukemic cells infiltrating into the meninges or brain parenchyma and remains the main reason for disease relapse. Currently, it is hard to detect CNS-L accurately by clinically available imaging models due to the relatively low amount of tumor cells, confined blood supply, and the inferior glucose metabolism intensity. Recently, integrin α6-laminin interactions have been identified to mediate CNS-L, which suggests that integrin α6 may be a promising molecular imaging target for the detection of CNS-L. The acute lymphoblastic leukemia (ALL) cell line NALM6 stabled and transfected with luciferase was used to establish the CNS-L mouse model. CNS-L-bearing mice were monitored and confirmed by bioluminescence imaging. Three of our previously developed integrin α6-targeted peptide-based molecular imaging agents, Cy5-S5 for near-infrared fluorescence (NIRF), Gd-S5 for magnetic resonance (MR), and 18F-S5 for positron emission tomography (PET) imaging, were employed for the molecular imaging of these CNS-L-bearing mice. Bioluminescence imaging showed a local intensive signal in the heads among CNS-L-bearing mice; meanwhile, Cy5-S5/NIRF imaging produced intensive fluorescence intensity in the same head regions. Moreover, Gd-S5/MR imaging generated superior MR signal enhancement at the site of meninges, which were located between the skull bone and brain parenchyma. Comparatively, MR imaging with the clinically available MR enhancer Gd-DTPA did not produce the distinguishable MR signal in the same head regions. Additionally, 18F-S5/PET imaging also generated focal radio-concentration at the same head regions, which generated nearly 5-times tumor-to-background ratio compared to the clinically available PET radiotracer 18F-FDG. Finally, pathological examination identified layer-displayed leukemic cells in the superficial part of the brain parenchyma tissue, and immunohistochemical staining confirmed the overexpression of the integrin α6 within the lesion. These findings suggest the potential application of these integrin α6-targeted molecular imaging agents for the accurate detection of CNS-L.

DRPPM-EASY: A Web-Based Framework for Integrative Analysis of Multi-Omics Cancer Datasets.

Simple SummaryWith the influx of multi-omics profiling, effective integration of these data remains the bottleneck for omics-driven discovery. Thus, we developed DRPPM-EASY, an R Shiny framework for integrative multi-omics analysis of cancer datasets. Our tool enables the exploration of multi-omics data by providing a simple user interface that minimizes the need for computational experience. Furthermore, the interface can be deployed locally or on a webserver to facilitate scientific collaboration and discovery.High-throughput transcriptomic and proteomic analyses are now routinely applied to study cancer biology. However, complex omics integration remains challenging and often time-consuming. Here, we developed DRPPM-EASY, an R Shiny framework for integrative multi-omics analysis. We applied our application to analyze RNA-seq data generated from a USP7 knockdown in T-cell acute lymphoblastic leukemia (T-ALL) cell line, which identified upregulated expression of a TAL1-associated proliferative signature in T-cell acute lymphoblastic leukemia cell lines. Next, we performed proteomic profiling of the USP7 knockdown samples. Through DRPPM-EASY-Integration, we performed a concurrent analysis of the transcriptome and proteome and identified consistent disruption of the protein degradation machinery and spliceosome in samples with USP7 silencing. To further illustrate the utility of the R Shiny framework, we developed DRPPM-EASY-CCLE, a Shiny extension preloaded with the Cancer Cell Line Encyclopedia (CCLE) data. The DRPPM-EASY-CCLE app facilitates the sample querying and phenotype assignment by incorporating meta information, such as genetic mutation, metastasis status, sex, and collection site. As proof of concept, we verified the expression of TP53 associated DNA damage signature in TP53 mutated ovary cancer cells. Altogether, our open-source application provides an easy-to-use framework for omics exploration and discovery.

The KRAS-G12D mutation induces metabolic vulnerability in B-cell acute lymphoblastic leukemia

SummaryMutations in RAS pathway genes are highly prevalent in acute lymphoblastic leukemia (ALL). However, the effects of RAS mutations on ALL cell growth have not been experimentally characterized, and effective RAS-targeting therapies are being sought after. Here, we found that Reh ALL cells bearing the KRAS-G12D mutation showed increased proliferation rates in vitro but displayed severely compromised growth in mice. Exploring this divergence, proliferation assays with multiple ALL cell lines revealed that the KRAS-G12D rewired methionine and arginine metabolism. Isotope tracing results showed that KRAS-G12D promotes catabolism of methionine and arginine to support anabolism of polyamines and proline, respectively. Chemical inhibition of polyamine biosynthesis selectively killed KRAS-G12D B-ALL cells. Finally, chemically inhibiting AKT/mTOR signaling abrogated the altered amino acid metabolism and strongly promoted the in vivo growth of KRAS-G12D cells in B-ALL xenograft. Our study thus illustrates how hyperactivated AKT/mTOR signaling exerts distinct impacts on hematological malignancies vs. solid tumors.

Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 gene (PVT1) modulates the proliferation and apoptosis of acute lymphoblastic leukemia cells by sponging miR-486-5p

ABSTRACT Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 gene (PVT1) is related to the progress of various cancers. Here, we illuminated the role of PVT1 in acute lymphoblastic leukemia (ALL) cell proliferation and apoptosis. PVT1 was upregulated in plasma samples from patients with ALL and ALL cell lines. PVT1 silencing repressed cell viability and enhanced cell apoptosis in Jurkat and SUP-B15 cells. PVT1 targeted microRNA-486-5p (miR-486-5p) and negatively modulated miR-486-5p expression. Upregulation of miR-486-5p decreased cell viability and increased ALL cell apoptosis. Mastermind Like Transcriptional Coactivator 3 (MAML3) was a downstream molecule of miR-486-5p and miR-486-5p mimic transfection weakened its expression in ALL cells. Rescue experiments proved that reintroduction of PVT1 counteracted the impacts of miR-486-5p in ALL cell proliferation and apoptosis. In vivo, PVT1 silencing repressed the tumor growth of SUP-B15 cells and reduced the expression of MAML3. Altogether, silencing of PVT1 inhibited ALL cell growth and induced cell apoptosis through sponging miR-486-5p.

Elevated Bax/Bcl-2 Ratio: A Cytotoxic Mode of Action of Kermanian Propolis Against an Acute Lymphoblastic Leukemia Cell Line, NALM-6.

Currently, alternative cancer remedies, especially herbal-derived medicines, have attracted great interest. Propolis, a honeybee-produced naturopathic formulation, is an available, affordable, and safe example of such remedies with different content according to its geographic location. Findings regarding the protective properties of this resinous substance across numerous pathological conditions are promising. Although the anti-tumor effects of propolis from different origins have been explored to some degree, yet there is no study on the effects of Kermanian propolis in the treatment of hematologic malignancies. Accordingly, the objective of the present experiment was to divulge the anti-tumor potential of this bioactive substance both as monotherapy and in combination with doxorubicin against an acute lymphoblastic leukemia cell line (NALM-6).The viability of cells treated with Kermanian propolis (5-500μg/mL) and doxorubicin (5-100μg/mL) was analyzed during 72h. Based on the MTT results, the best incubation time, IC50 concentrations, and finally the cytotoxicity of the combination therapy were ascertained. Next, the apoptotic rate and expression of apoptosis-related genes (Bcl-2 and Bax) were assessed in mono and combination therapies using flow cytometry and real-time PCR assays, respectively. Kermanian propolis and doxorubicin have impressive tumor-suppressing activity in a dose-dependent manner (IC50 concentrations: 100 and 40μg/mL respectively). The best incubation time was considered 48h. For the combination approach, 50 and 10μg/mL were determined as optimum concentrations of the compounds. The selected concentrations induced notable apoptosis in the studied cells through significant (P < 0.01) upregulation of Bax/Bcl-2 level. The present study clearly suggests that Kermanian propolis, as an adjunct treatment option, has a promising apoptosis-induced cell death potential in the NALM-6 cell line.

A Novel Compound Plumercine from Plumeria alba Exhibits Promising Anti-Leukemic Efficacies against B Cell Acute Lymphoblastic Leukemia

The current study was focused to evaluate the antioxidant and the anti-cancerous properties of Plumeria alba. Plumeria alba was chosen due to its existing medicinal values. Antioxidant assays like Superoxide radical scavenging assay, Nitrous Oxide radical scavenging assay, were performed, on the methanolic and ethyl acetate extracts of the plant, that depicts the pro-oxidant nature of the extract. Further, they were tested to check cell viability on B cell Acute Lymphoblastic Leukemia (ALL) Cell line (NALM 6), human lung cancer cell line (A549), T cell Acute Lymphoblastic Leukemia cell line (MOLT4), and PBMC isolated from normal donors utilizing MTT assay. Robust anti-proliferative activity was observed in the case of NALM 6 followed by A549, MOLT4, whereas negligible activity was observed in the case of PBMC. Intrigued by this finding, in silico docking was performed using three bioactive compounds namely Plumericine, Isoplumericine, and 13-O-p-Coumaroylplumieride, unique to Plumeria sp. They were docked against five different cyclins and Cdk proteins responsible for ALL. The compounds have shown satisfactory results and their druggability and ADMET properties were checked further. Plumercine turned out to be the most competent compound and hence can be considered as a potential leukemic drug candidate in the future.