scholarly journals Inhibition of GCN2 sensitizes ASNS-low cancer cells to asparaginase by disrupting the amino acid response

2018 ◽  
Vol 115 (33) ◽  
pp. E7776-E7785 ◽  
Author(s):  
Akito Nakamura ◽  
Tadahiro Nambu ◽  
Shunsuke Ebara ◽  
Yuka Hasegawa ◽  
Kosei Toyoshima ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cancer Cells ◽  
Cellular Response ◽  
De Novo ◽  
Mapk Pathway ◽  
Lymphoblastic Leukemia ◽  
Combined Treatment ◽  
Myelogenous Leukemia ◽  
Pancreatic Cancer Cells ◽  
Amino Acid Response

General control nonderepressible 2 (GCN2) plays a major role in the cellular response to amino acid limitation. Although maintenance of amino acid homeostasis is critical for tumor growth, the contribution of GCN2 to cancer cell survival and proliferation is poorly understood. In this study, we generated GCN2 inhibitors and demonstrated that inhibition of GCN2 sensitizes cancer cells with low basal-level expression of asparagine synthetase (ASNS) to the antileukemic agent l-asparaginase (ASNase) in vitro and in vivo. We first tested acute lymphoblastic leukemia (ALL) cells and showed that treatment with GCN2 inhibitors rendered ALL cells sensitive to ASNase by preventing the induction of ASNS, resulting in reduced levels of de novo protein synthesis. Comprehensive gene-expression profiling revealed that combined treatment with ASNase and GCN2 inhibitors induced the stress-activated MAPK pathway, thereby triggering apoptosis. By using cell-panel analyses, we also showed that acute myelogenous leukemia and pancreatic cancer cells were highly sensitive to the combined treatment. Notably, basal ASNS expression at protein levels was significantly correlated with sensitivity to combined treatment. These results provide mechanistic insights into the role of GCN2 in the amino acid response and a rationale for further investigation of GCN2 inhibitors for the treatment of cancer.

scholarly journals BTK inhibition sensitizes Acute Lymphoblastic Leukemia to asparaginase by suppressing the Amino Acid Response pathway

Blood ◽  
2021 ◽  
Author(s):  
Miriam Butler ◽  
Dorette S van Ingen Schenau ◽  
Jiangyan Yu ◽  
Silvia Jenni ◽  
Maria Pamela Dobay ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Amino Acid ◽  
Tyrosine Kinase ◽  
Lymphoblastic Leukemia ◽  
Synthetic Lethal Interaction ◽  
Synthetic Lethal ◽  
Genetic Inactivation ◽  
Pdx Model ◽  
Btk Inhibitor ◽  
Amino Acid Response

Asparaginase (ASNase) therapy has been a mainstay of Acute Lymphoblastic Leukemia (ALL) protocols for decades and shows promise in the treatment of a variety of other cancers. To improve the efficacy of ASNase treatment, we employed a CRISPR/Cas9-based screen to identify actionable signaling intermediates that improve the response to ASNase. Both genetic inactivation of Bruton's Tyrosine Kinase (BTK) and pharmacological inhibition by the BTK inhibitor ibrutinib strongly synergize with ASNase by inhibiting the amino acid response pathway, a mechanism involving c-Myc mediated suppression of GCN2 activity. This synthetic lethal interaction was observed in 90% of patient derived xenografts, irrespective of the genomic subtype. Moreover, ibrutinib substantially improved ASNase treatment response in a murine PDX model. Hence, ibrutinib may be used to enhance the clinical efficacy of ASNase in ALL.

scholarly journals HRX involvement in de novo and secondary leukemias with diverse chromosome 11q23 abnormalities [see comments]

Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3197-3203 ◽  
Author(s):  
SP Hunger ◽  
DC Tkachuk ◽  
MD Amylon ◽  
MP Link ◽  
AJ Carroll ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Topoisomerase Ii ◽  
De Novo ◽  
Lymphoblastic Leukemia ◽  
Myelogenous Leukemia ◽  
Chromosome Band ◽  
11Q23 Abnormalities ◽  
Acute Myeloid ◽  
Secondary Leukemias

Abstract Chromosome band 11q23 is a site of recurrent translocations and interstitial deletions in human leukemias. Recent studies have shown that the 11q23 gene HRX is fused to heterologous genes from chromosomes 4 or 19 after t(4;11)(q21;q23) and t(11;19)(q23;p13) translocations to create fusion genes encoding proteins with structural features of chimeric transcription factors. In this report, we show structural alterations of HRX by conventional Southern blot analyses in 26 of 27 de novo leukemias with cytogenetically diverse 11q23 abnormalities. The sole case that lacked HRX rearrangements was a t(11;17)-acute myeloid leukemia with French-American-British M3-like morphology. We also analyzed 10 secondary leukemias that arose after therapy with topoisomerase II inhibitors and found HRX rearrangements in 7 of 7 with 11q23 translocations, and in 2 of 2 with unsuccessful karyotypes. In total, we observed HRX rearrangements in 35 leukemias involving at least nine distinct donor loci (1q32, 4q21, 6q27, 7p15, 9p21–24, 15q15, 16p13, and two 19p13 sites). All breakpoints localized to an 8-kb region that encompassed exons 5–11 of HRX, suggesting that fusion proteins containing similar portions of HRX may be consistently created in leukemias with 11q23 abnormalities. We conclude that alteration of HRX is a recurrent pathogenetic event in leukemias with 11q23 aberrations involving many potential partners in a variety of settings including acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia in blast crisis, and topoisomerase II inhibitor- induced secondary leukemias of both the myeloid and lymphoid lineages.

HOXA10 Promotes Cell Invasion and MMP-3 Expression Via TGFβ2-Mediated Activation of the p38 MAPK Pathway in Pancreatic Cancer Cells

2014 ◽  
Vol 59 (7) ◽  
pp. 1442-1451 ◽  
Author(s):  
Xian-Ping Cui ◽  
Cheng-Kun Qin ◽  
Zhen-Hai Zhang ◽  
Zhong-Xue Su ◽  
Xin Liu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
P38 Mapk ◽  
Cell Invasion ◽  
Mapk Pathway ◽  
Pancreatic Cancer Cells ◽  
P38 Mapk Pathway

Abstract 2154: ERK/MAPK pathway inhibits tumorigenesis and cellular reprogramming of pancreatic cancer cells

2015 ◽  
Author(s):  
Benjamin le Calvé ◽  
Xavier Deschenes-Ximard ◽  
Filippos Kottakis ◽  
Véronique Bourdeau ◽  
Frédéric Lessard ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Mapk Pathway ◽  
Cellular Reprogramming ◽  
Erk Mapk ◽  
Pancreatic Cancer Cells

Abstract 462: Hyperactivation of ERK/MAPK pathway reduces pancreatic cancer cells' proliferation and tumor progression through phosphoproteome reprogramming

2018 ◽  
Author(s):  
Marie-Camille Rowell ◽  
Xavier Deschênes-Simard ◽  
Benjamin Le Calvé ◽  
Stéphane Lopes-Paciência ◽  
Ana Fernandez Ruiz ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Mapk Pathway ◽  
Erk Mapk ◽  
Pancreatic Cancer Cells

scholarly journals Branched-chain amino acid aminotransferase 2 regulates ferroptotic cell death in cancer cells

2020 ◽  
Author(s):  
Kang Wang ◽  
Zhengyang Zhang ◽  
Hsiang-i Tsai ◽  
Yanfang Liu ◽  
Jie Gao ◽  
...  
Keyword(s):  
Cell Death ◽  
Amino Acid ◽  
Cancer Cells ◽  
Ectopic Expression ◽  
Branched Chain Amino Acid ◽  
Pancreatic Cancer Cells ◽  
Key Enzyme ◽  
Branched Chain

Abstract Ferroptosis, a form of iron-dependent cell death driven by cellular metabolism and iron-dependent lipid peroxidation, has been implicated as a tumor-suppressor function for cancer therapy. Recent advance revealed that the sensitivity to ferroptosis is tightly linked to numerous biological processes, including metabolism of amino acid and the biosynthesis of glutathione. Here, by using a high-throughput CRISPR/Cas9-based genetic screen in HepG2 hepatocellular carcinoma cells to search for metabolic proteins inhibiting ferroptosis, we identified a branched-chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib, and sulfasalazine) activated AMPK/SREBP1 signaling pathway through iron-dependent ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 as the key enzyme mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc– inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. On the contrary, direct inhibition of BCAT2 by RNA interference, or indirect inhibition by blocking system Xc– activity, triggers ferroptosis. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies. Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance.

scholarly journals The importance of serine metabolism in cancer

2016 ◽  
Vol 214 (3) ◽  
pp. 249-257 ◽  
Author(s):  
Katherine R. Mattaini ◽  
Mark R. Sullivan ◽  
Matthew G. Vander Heiden
Keyword(s):  
Cell Proliferation ◽  
Amino Acid ◽  
Cancer Cells ◽  
De Novo ◽  
Redox Homeostasis ◽  
Cancer Cell Proliferation ◽  
Acid Transport ◽  
Nucleotide Synthesis ◽  
Serine Metabolism

Serine metabolism is frequently dysregulated in cancers; however, the benefit that this confers to tumors remains controversial. In many cases, extracellular serine alone is sufficient to support cancer cell proliferation, whereas some cancer cells increase serine synthesis from glucose and require de novo serine synthesis even in the presence of abundant extracellular serine. Recent studies cast new light on the role of serine metabolism in cancer, suggesting that active serine synthesis might be required to facilitate amino acid transport, nucleotide synthesis, folate metabolism, and redox homeostasis in a manner that impacts cancer.

scholarly journals Unusual T-Lymphoblastic Blast Phase of Chronic Myelogenous Leukemia

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Jie Xu ◽  
Shaoying Li
Keyword(s):  
Lymph Node ◽  
Chronic Myelogenous Leukemia ◽  
De Novo ◽  
Lymphoblastic Leukemia ◽  
Chronic Phase ◽  
Myelogenous Leukemia ◽  
Imatinib Treatment ◽  
Cell Transplant ◽  
Blast Phase ◽  
History Of

T-lymphoblastic leukemia/lymphoma (T-ALL) presenting as blast phase of chronic myelogenous leukemia (CML-BP) is rare. In patients without history of CML, it is difficult to differentiate between CML-BP or de novo T-ALL. Here we reported 2 unusual cases of T-ALL presenting as CML-BP. Case 1 was a 24-year-old female with leukocytosis. Besides T-lymphoblasts (32%), her marrow exhibited some morphologic features of CML. Multiple remission or relapsing marrow had never demonstrated morphologic features of CML. Despite of imatinib treatment and stem cell transplant, she died 2.5 years later. Case 2, a 66-year-old male with diffuse lymphadenopathy, showed T-ALL in a lymph node and concurrent CML chronic phase (CML-CP) in his marrow. Same BCR-ABL1 fusion transcript with minor breakpoint was present in both the lymph node and marrow specimens. Although both cases did not have a history of CML, both cases represented T-lymphoblastic CML-BP with unusual features: Case 1 is unusual in that it presented as T-ALL with some CML morphologic feature but never showed CML-CP in her subsequent marrows biopsies; Case 2 is the first reported case of T-lymphoblastic CML-BP harboring BCR-ABL1 transcript with a minor breakpoint.

scholarly journals Branched chain amino acid aminotransferase 2 Regulates Ferroptotic Cell Death in Cancer Cells

2020 ◽  
Author(s):  
Kang Wang ◽  
Zhengyang Zhang ◽  
Tsai Hsiang-i ◽  
Yanfang Liu ◽  
Ming Wang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cancer Cells ◽  
Therapeutic Strategy ◽  
Ectopic Expression ◽  
Branched Chain Amino Acid ◽  
Pancreatic Cancer Cells ◽  
Branched Chain

AbstractFerroptosis has been implicated as a tumor-suppressor function for cancer therapy. Recently the sensitivity to ferroptosis was tightly linked to numerous biological processes, including metabolism of amino acid. Here, using a high-throughput CRISPR/Cas9 based genetic screen in HepG2 cells to search for metabolic proteins inhibiting ferroptosis, we identified branched chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib and sulfasalazine) activated AMPK/SREBP1 signaling pathway through ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc– inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies. Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance.

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