Comprehensive analysis of T cell leukemia signals reveals heterogeneity in the PI3 kinase-Akt pathway and limitations of PI3 kinase inhibitors as monotherapy

Ksionda, Olga; Mues, Marsilius; Wandler, Anica M.; Donker, Lisa; Tenhagen, Milou; Jun, Jesse E.; Ducker, Gregory S.; Matławska-Wasowska, Ksenia; Shannon, Kevin; Shokat, Kevan M.; Roose, Jeroen P.

doi:10.1371/journal.pone.0193849

Cited by 15 publications

(12 citation statements)

References 42 publications

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“…To determine the low-level activity in resting primary cells in a robust and quantitative manner, we coupled fluorescent cellular barcoding to phospho-flow cytometry on freshly isolated cells from LNs so that staining with antibodies to phosphorylated proteins is internally controlled (Krutzik and Nolan, 2006; Ksionda et al, 2018) (Figure 2C). Using this platform, we observed a strikingly robust P-S6 signal in CD4 + T cells (roughly 12-fold over background) when LN cells were fixed immediately upon dissection (Figure 2D).…”

Section: Resultsmentioning

confidence: 99%

Active Tonic mTORC1 Signals Shape Baseline Translation in Naive T Cells

et al. 2019

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SUMMARY Naive CD4 + T cells are an example of dynamic cell homeostasis: T cells need to avoid autoreactivity while constantly seeing self-peptides, yet they must be primed to react to foreign antigens during infection. The instructive signals that balance this primed yet quiescent state are unknown. Interactions with self-peptides result in membrane-proximal, tonic signals in resting T cells. Here we reveal selective and robust tonic mTORC1 signals in CD4 + T cells that influence T cell fate decisions. We find that the Ras exchange factor Rasgrp1 is necessary to generate tonic mTORC1 signals. Genome-wide ribosome profiling of resting, primary CD4 + T cells uncovers a baseline translational landscape rich in mTOR targets linked to mitochondria, oxidative phosphorylation, and splicing. Aberrantly increased tonic mTORC1 signals from a Rasgrp1 Anaef allele result in immunopathology with spontaneous appearance of T peripheral helper cells, follicular helper T cells, and anti-nuclear antibodies that are preceded by subtle alterations in the translational landscape.

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Section: Resultsmentioning

confidence: 99%

Active Tonic mTORC1 Signals Shape Baseline Translation in Naive T Cells

et al. 2019

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“…The limited effectiveness of mTOR targeting was initially explained on the basis of the activation of compensatory signaling pathways unleashed by mTOR inhibitors in cancer cells [ 97 ]. However, more recently, it became apparent that the low efficacy of these drugs could also depend on other reasons; these include, but are not limited to, the emergence of inhibitor treatment-resistant mTOR mutations [ 159 ], intratumor signaling network heterogeneity [ 80 , 160 ] due to the uneven clonal evolution of cancer [ 137 , 161 ] or an acidic tumor microenvironment [ 162 ].…”

Section: Discussionmentioning

confidence: 99%

“…In murine T-ALL cells with increased RASGRP1 expression, RASGRP1 contributed to cytokine receptor-activated RAS pathway that stimulated the proliferation of T-ALL cells in vivo [ 75 ]. Remarkably, RASGRP1 overexpression in T-ALL cells seems to impinge primarily on PI3K/Akt rather than on MEK/ERK signaling [ 79 , 80 ].…”

Section: Activation Of Mtorc1 and Mtorc2 In T-all Cellsmentioning

confidence: 99%

Therapeutic Targeting of mTOR in T-Cell Acute Lymphoblastic Leukemia: An Update

Evangelisti

Chiarini

McCubrey

et al. 2018

IJMS

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T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive blood malignancy that arises from the clonal expansion of transformed T-cell precursors. Although T-ALL prognosis has significantly improved due to the development of intensive chemotherapeutic protocols, primary drug-resistant and relapsed patients still display a dismal outcome. In addition, lifelong irreversible late effects from conventional therapy are a growing problem for leukemia survivors. Therefore, novel targeted therapies are required to improve the prognosis of high-risk patients. The mechanistic target of rapamycin (mTOR) is the kinase subunit of two structurally and functionally distinct multiprotein complexes, which are referred to as mTOR complex 1 (mTORC1) and mTORC2. These two complexes regulate a variety of physiological cellular processes including protein, lipid, and nucleotide synthesis, as well as autophagy in response to external cues. However, mTOR activity is frequently deregulated in cancer, where it plays a key oncogenetic role driving tumor cell proliferation, survival, metabolic transformation, and metastatic potential. Promising preclinical studies using mTOR inhibitors have demonstrated efficacy in many human cancer types, including T-ALL. Here, we highlight our current knowledge of mTOR signaling and inhibitors in T-ALL, with an emphasis on emerging evidence of the superior efficacy of combinations consisting of mTOR inhibitors and either traditional or targeted therapeutics.

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“…We previously uncovered that overexpression of RASGRP1 synergizes with cytokine receptor signals to aberrantly induce downstream RAS- and effector kinase-signals in T-ALL cell line models 4,5,22,39 , but these RASGRP1 signals have never been investigated in primary BM cells. Searching for mechanistic insights into the consequences of RoLoRiG in hematopoietic cells, we employed colony formation assays to determine the clonogenic capacity of hematopoietic progenitors as well as signaling assays ( Figure 4A ).…”

Section: Resultsmentioning

confidence: 99%

“…Downstream of RAS, GM-CSF-triggered modest induction of pAKT, but much more robustly induced pERK- and pS6-levels ( Figure 4E and Supplemental Figure S5 ). In T-ALL cell lines, cytokines robustly trigger ERK and AKT pathways that are significantly reduced when RASGRP1-expression levels are decreased 4,39 . Surprisingly, hRASGRP1 expression did not impact the magnitude of the induction of these effector kinase pathways in sorted CD11b + cells stimulated with GM-CSF.…”

Section: Resultsmentioning

confidence: 99%

Increased baseline RASGRP1 signals Enhance Stem Cell Fitness during Native Hematopoiesis

Karra

Romero‐Moya

Ksionda

et al. 2020

Preprint

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24Oncogenic mutations in RAS genes, like KRAS G12D or NRAS G12D , trap Ras in the active 25 state and cause myeloproliferative disorder and T cell leukemia (T-ALL) when induced 26 4 Keywords 43 Leukemia, bone marrow, T-ALL, RAS signaling, RASGRP1, cytokines, progenitor, stem 44 cells, hematopoiesis 45 46 47 5 48 49 Acute lymphoblastic leukemia (ALL) is an aggressive bone marrow (BM) malignancy. 50Approximately 15% of pediatric and 25% of adult cases of ALL are diagnosed as T-cell 51 ALL (T-ALL) cog. In the clinic, T-ALL patients receive combination chemotherapy, 52 sometimes combined with BM transplantation 2 . Understanding the molecularly altered 53 biochemical pathways implicated in T-ALL is critical to developing effective molecular 54 therapy (precision medicine). One commonly affected pathway is the RAS pathway with 55 roughly 50% of all patient T-ALL cases demonstrating hyperactive RAS signals in the 56 BM 3 . There are two major mechanisms of leukemogenic RAS signals in T-ALL patients; 57 the first consists of somatic activating mutations of small RAS GTPases themselves and 58 a second mechanism is through deregulated overexpression of the RAS activator 59 RASGRP1 (RAS guanine nucleotide releasing protein 1) 4,5 . 60 61Oncogenic mutations in RAS are among the most common somatic mutations in 62 cancer. Mutations in glycine at codon 12 in KRAS (KRAS G12 ) are prevalent in cancer 63 and result in severely impaired GTPase activity and elevated levels of constitutively 64 active, GTP-bound KRAS 6 . In hematopoietic malignancies, mutations in NRAS are 2 to 65 3 times more frequent than those in KRAS 7,8 , including pediatric T-ALL 9 . Generation of 66 Kras G12D mice aided the field of cancer research and oncogenic RAS signaling; these 67 mice express a mutation of glycine to aspartic acid at codon 12 from the endogenous 68Kras locus in a controlled and inducible manner via a LoxP-STOP-LoxP cassette 6 . In 69 BM cells, oncogenic KRAS G12D can be inducibly expressed using Mx1CRE transgenic 70 6 mice; in this model CRE is expressed from the IFN-α/β-inducible Mx1 promoter by 71 administration of polyinosinic-polycytidylic acid (pIpC) 10 . Such KRAS G12D mice develop 72 a lethal myeloproliferative disease (MPD) resulting in death around 35 days 11,12 . In the 73 background a T-ALL exists, which is suppressed by the MPD, but can be revealed via 74 transplantation of KRAS G12D hematopoietic stem cells into irradiated recipient mice [12][13][14] . 75Mx1CRE-driven NRAS G12D mutation does not lead to acute MPD 15 . Instead mice 76 develop a chronic myeloproliferative disorder and succumb to hematological disease by 77 15 months on a C57Bl/6 x 129/Sv.jae background but displaying a median survival of 78 588 days on a C57Bl/6 background 16 . 79 80We reported deregulated overexpression of the RAS guanine nucleotide exchange 81 factor RASGRP1 in T-ALL patients 4,5 . RASGRP1 has a growth promoting role in T-cell 82 leukemia 4 and skin cancer 17 . RASGRP1 overexpression through retroviral transduction 83 or via transgenic e...

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Comprehensive analysis of T cell leukemia signals reveals heterogeneity in the PI3 kinase-Akt pathway and limitations of PI3 kinase inhibitors as monotherapy

Cited by 15 publications

References 42 publications

Active Tonic mTORC1 Signals Shape Baseline Translation in Naive T Cells

Active Tonic mTORC1 Signals Shape Baseline Translation in Naive T Cells

Therapeutic Targeting of mTOR in T-Cell Acute Lymphoblastic Leukemia: An Update

Increased baseline RASGRP1 signals Enhance Stem Cell Fitness during Native Hematopoiesis

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