scholarly journals Reducing FASN expression sensitizes acute myeloid leukemia cells to differentiation therapy

2021 ◽  
Author(s):  
Magali Humbert ◽  
Kristina Seiler ◽  
Severin Mosimann ◽  
Vreni Rentsch ◽  
Katyayani Sharma ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Fatty Acid ◽  
Myeloid Leukemia ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Acid Synthesis ◽  
Mrna Levels ◽  
Differentiation Therapy ◽  
Granulocytic Differentiation ◽  
Acute Myeloid

AbstractFatty acid synthase (FASN) is the only human lipogenic enzyme available for de novo fatty acid synthesis and is often highly expressed in cancer cells. We found that FASN mRNA levels were significantly higher in acute myeloid leukemia (AML) patients than in healthy granulocytes or CD34+ hematopoietic progenitors. Accordingly, FASN levels decreased during all-trans retinoic acid (ATRA)-mediated granulocytic differentiation of acute promyelocytic leukemia (APL) cells, partially via autophagic degradation. Furthermore, our data suggest that inhibition of FASN expression levels using RNAi or (-)-epigallocatechin-3-gallate (EGCG) accelerated the differentiation of APL cell lines and significantly re-sensitized ATRA refractory non-APL AML cells. FASN reduction promoted translocation of transcription factor EB (TFEB) to the nucleus, paralleled by activation of CLEAR network genes and lysosomal biogenesis. Together, our data demonstrate that inhibition of FASN expression in combination with ATRA treatment facilitates granulocytic differentiation of APL cells and may extend differentiation therapy to non-APL AML cells.

scholarly journals Reducing FASN expression sensitizes acute myeloid leukemia cells to differentiation therapy

2020 ◽  
Author(s):  
Magali Humbert ◽  
Kristina Seiler ◽  
Severin Mosimann ◽  
Vreni Rentsch ◽  
Sharon L. McKenna ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Fatty Acid ◽  
Transcriptional Activation ◽  
Myeloid Leukemia ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Mrna Levels ◽  
Differentiation Therapy ◽  
Granulocytic Differentiation ◽  
Acute Myeloid

AbstractFatty acid synthase (FASN) is the only human lipogenic enzyme available for de novo fatty acid synthesis and is often highly expressed in cancer cells. We found that FASN mRNA levels were significantly higher in acute myeloid leukemia (AML) patients than in healthy granulocytes or CD34+ hematopoietic progenitors. Accordingly, FASN levels decreased during all-trans retinoic acid (ATRA)-mediated granulocytic differentiation of acute promyelocytic leukemia (APL) cells, partially via autophagic degradation. Furthermore, our data suggests that inhibition of FASN expression levels using RNAi or (-)-epigallocatechin-3-gallate (EGCG), accelerates the differentiation of APL cell lines and significantly re-sensitized ATRA refractory non-APL AML cells. FASN reduction promoted translocation of transcription factor EB (TFEB) to the nucleus, paralleled by activation of CLEAR network genes and lysosomal biogenesis. Lysosomal biogenesis was activated, consistent with TFEB transcriptional activation of CLEAR network genes.Together, our data demonstrate that inhibition of FASN expression in combination with ATRA treatment facilitates granulocytic differentiation of APL cells and may extend differentiation therapy to non-APL AML cells.

Rig-I Activates Expression of Interferon-Stimulated Genes (ISGs) and Inhibits the Proliferation of Acute Myeloid Leukemia Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2846-2846 ◽  
Author(s):  
Nan-Nan Zhang ◽  
Lei Chen ◽  
Wu Zhang ◽  
Xian-Yang Li ◽  
Lin-Jia Jiang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Leukemia Cells ◽  
Mrna Levels ◽  
Terminal Part ◽  
Granulocytic Differentiation ◽  
Acute Myeloid Leukemia Cells ◽  
Acute Myeloid

Abstract Acute promyelocytic leukemia (APL) is initiated by the formation of PML/RARα oncogenic fusion protein, a potent transcriptional repressor. Retinoid acid (RA) at pharmacological dosage can physically bind to the PML/RARα protein, ushering in the unfolding of downstream programs normally regulated by the wild type RARα. However, through what particular regulatory pathways RA inhibits APL malignant hematopoiesis has remained largely obscured. Rig-I is one of the genes whose mRNA levels were highly up-regulated, along with all-trans-RA (ATRA)-induced terminal granulocytic differentiation of APL cell line NB4 cells in vitro. Based on the analysis of a Rig-I−/− mouse model, recently we have reported a critical regulatory role of Rig-I in normal granulopoiesis. To understand the functional contribution of Rig-I induction in RA-mediated leukemia cell differentiation, we converted a pair of previously reported Rig-I RNAi-duplex sequences into a miR30a-based small hairpin-encoding sequence, which was expressed under the CMV enhancer/promoter within a lentiviral vector. As expected, Rig-I shRNAmir30 infection induced a significant knockdown of Rig-I protein level, and accordingly its delivery into HL-60 cells partially inhibited ATRA-induced granulocytic differentiation, growth inhibition/cell cycle arrest and apoptosis induction, suggesting that Rig-I upregulation participates in RA-induced granulocytic differentiation of acute myeloid leukemia cells. In order to investigate the effect of Rig-I induction on the proliferation of APL cells in vivo, we transduced PML/RARα-harboring leukemic cells with vector or Rig-I-expressing retrovirus, and then transplanted these cells into the syngeneic mice. The vector-transduced APL cells readily expanded in vivo, but the proliferation of Rig-I-transduced cells was apparently prohibited. Moreover, we found that the forced expression of Rig-I induced the expression of numerous ISGs in APL cells, which was recapitulated by the transduction of the C terminal part of Rig-I, but not by the N terminal part. In line with this, during the in vitro short-term culture post-IFNγ or IFNα stimulation, Stat1 phosphorylation at p701 in Rig-I−/− granulocytes was significantly inhibited. In parallel, the induction of multiple ISGs by IFNs was also significantly impaired. In conclusion, our findings indicate that the Rig-I induction inhibited APL reconstitution potentially through up-regulating a number of ISGs via regulating Stat1Tyr701 phosphorylation.

CBFβ-SMMHC, Expressed in M4eo Acute Myeloid Leukemia, Reduces p53 Induction and Slows Apoptosis in Hematopoietic Cells Exposed to DNA-Damaging Agents

Blood ◽  
1998 ◽  
Vol 92 (11) ◽  
pp. 4344-4352 ◽  
Author(s):  
Martin Britos-Bray ◽  
Manuel Ramirez ◽  
Wangsen Cao ◽  
Xinping Wang ◽  
P. Paul Liu ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Ionizing Radiation ◽  
Myeloid Leukemia ◽  
De Novo ◽  
P53 Gene ◽  
Mrna Levels ◽  
Dna Damaging Agents ◽  
Independent Mechanism ◽  
De Novo Aml ◽  
Acute Myeloid

CBFβ-SMMHC is expressed in M4Eo acute myeloid leukemia (AML) as a result of inv(16), but how it contributes to leukemogenesis is unknown. p53 mutations are rare in de novo AML, but they are common in many malignancies. Expression of CBFβ-SMMHC in Ba/F3 cells reduced p53 induction in response to ionizing radiation or etoposide 3- to 4-fold. However, p53 induction was normal in Ba/F3 cells expressing a CBFβ-SMMHC variant that does not interfere with DNA binding by CBF, indicating that a CBF genetic target regulates p53 induction. The p53 gene may be regulated by CBF, because p53 mRNA levels were reduced by CBFβ-SMMHC. Reduced p53 induction was not caused by slowed cell proliferation, a consequence of CBFβ-SMMHC expression, because p53 was induced similarly in control cultures and in cultures propagated in 10-fold less interleukin-3 (IL-3). CBFβ-SMMHC did not slow apoptosis resulting from IL-3 withdrawal, where p53 induction is minimal, but slowed apoptosis in Ba/F3 cells exposed to 10 Gy of ionizing radiation or 3 to 8 μg/mL etoposide, providing 2-fold protection at 6 or 18 hours. Inhibition of apoptosis was temporary, because all the cells exposed to these doses ultimately died, and clonal survival assays performed using 0.04 μg/mL etoposide did not show protection by CBFβ-SMMHC. p21 levels were increased in cells subjected to DNA damage, regardless of CBFβ-SMMHC expression and attenuated p53 induction. Bcl-2, bcl-xL, bcl-xS, and bax levels were unaffected by CBFβ-SMMHC. Attenuated p53 induction may contribute to leukemogenesis by CBFβ-SMMHC by slowing apoptosis via a p21-independent mechanism.

scholarly journals Sox4 cooperates with PU.1 haploinsufficiency in murine myeloid leukemia

Blood ◽  
2011 ◽  
Vol 118 (17) ◽  
pp. 4674-4681 ◽  
Author(s):  
Georg Aue ◽  
Yang Du ◽  
Susan M. Cleveland ◽  
Stephen B. Smith ◽  
Utpal P. Davé ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Bone Marrow Cells ◽  
Regulatory Element ◽  
Mrna Levels ◽  
Wild Type ◽  
Myeloid Leukemias ◽  
Acute Myeloid

Abstract Cooperation of multiple mutations is thought to be required for cancer development. In previous studies, murine myeloid leukemias induced by transducing wild-type bone marrow progenitors with a SRY sex determining region Y-box 4 (Sox4)–expressing retrovirus frequently carried proviral insertions at Sfpi1, decreasing its mRNA levels, suggesting that reduced Sfpi1 expression cooperates with Sox4 in myeloid leukemia induction. In support of this hypothesis, we show here that mice receiving Sox4 virus-infected Sfpi1ko/+ bone marrow progenitors developed myeloid leukemia with increased penetrance and shortened latency. Interestingly, Sox4 expression further decreased Sfpi1 transcription. Ectopic SOX4 expression reduced endogenous PU.1 mRNA levels in HL60 promyelocytes, and decreased Sfpi1 mRNA levels were also observed in the spleens of leukemic and preleukemic mice receiving Sox4 virus-infected wild-type bone marrow cells. In addition, Sox4 protein bound to a critical upstream regulatory element of Sfpi1 in ChIP assays. Such cooperation probably occurs in de novo human acute myeloid leukemias, as an analysis of 285 acute myeloid leukemia patient samples found a significant negative correlation between SOX4 and PU.1 expression. Our results establish a novel cooperation between Sox4 and reduced Sfpi1 expression in myeloid leukemia development and suggest that SOX4 could be an important new therapeutic target in human acute myeloid leukemia.

CBFβ-SMMHC, Expressed in M4eo Acute Myeloid Leukemia, Reduces p53 Induction and Slows Apoptosis in Hematopoietic Cells Exposed to DNA-Damaging Agents

Blood ◽  
1998 ◽  
Vol 92 (11) ◽  
pp. 4344-4352 ◽  
Author(s):  
Martin Britos-Bray ◽  
Manuel Ramirez ◽  
Wangsen Cao ◽  
Xinping Wang ◽  
P. Paul Liu ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Ionizing Radiation ◽  
Myeloid Leukemia ◽  
De Novo ◽  
P53 Gene ◽  
Mrna Levels ◽  
Dna Damaging Agents ◽  
Independent Mechanism ◽  
De Novo Aml ◽  
Acute Myeloid

Abstract CBFβ-SMMHC is expressed in M4Eo acute myeloid leukemia (AML) as a result of inv(16), but how it contributes to leukemogenesis is unknown. p53 mutations are rare in de novo AML, but they are common in many malignancies. Expression of CBFβ-SMMHC in Ba/F3 cells reduced p53 induction in response to ionizing radiation or etoposide 3- to 4-fold. However, p53 induction was normal in Ba/F3 cells expressing a CBFβ-SMMHC variant that does not interfere with DNA binding by CBF, indicating that a CBF genetic target regulates p53 induction. The p53 gene may be regulated by CBF, because p53 mRNA levels were reduced by CBFβ-SMMHC. Reduced p53 induction was not caused by slowed cell proliferation, a consequence of CBFβ-SMMHC expression, because p53 was induced similarly in control cultures and in cultures propagated in 10-fold less interleukin-3 (IL-3). CBFβ-SMMHC did not slow apoptosis resulting from IL-3 withdrawal, where p53 induction is minimal, but slowed apoptosis in Ba/F3 cells exposed to 10 Gy of ionizing radiation or 3 to 8 μg/mL etoposide, providing 2-fold protection at 6 or 18 hours. Inhibition of apoptosis was temporary, because all the cells exposed to these doses ultimately died, and clonal survival assays performed using 0.04 μg/mL etoposide did not show protection by CBFβ-SMMHC. p21 levels were increased in cells subjected to DNA damage, regardless of CBFβ-SMMHC expression and attenuated p53 induction. Bcl-2, bcl-xL, bcl-xS, and bax levels were unaffected by CBFβ-SMMHC. Attenuated p53 induction may contribute to leukemogenesis by CBFβ-SMMHC by slowing apoptosis via a p21-independent mechanism.

scholarly journals CDDO induces granulocytic differentiation of myeloid leukemic blasts through translational up-regulation of p42 CCAAT enhancer–binding protein alpha

Blood ◽  
2007 ◽  
Vol 110 (10) ◽  
pp. 3695-3705 ◽  
Author(s):  
Steffen Koschmieder ◽  
Francesco D'Alò ◽  
Hanna Radomska ◽  
Christine Schöneich ◽  
Ji Suk Chang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Binding Protein ◽  
Upstream Open Reading Frame ◽  
Dependent Manner ◽  
Granulocytic Differentiation ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Acute Myeloid

Abstract 2-Cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) induces differentiation and apoptosis of tumor cells in vitro and in vivo. Here we assessed the effects of CDDO on CCAAT enhancer–binding protein alpha (CEBPA), a transcription factor critical for granulocytic differentiation. In HL60 acute myeloid leukemia (AML) cells, CDDO (0.01 to 2 μM) induces apoptosis in a dose-dependent manner. Conversely, subapoptotic doses of CDDO promote phagocytic activity and granulocytic-monocytic differentiation of HL60 cells through increased de novo synthesis of p42 CEBPA protein. CEBPA translational up-regulation is required for CDDO-induced granulocytic differentiation and depends on the integrity of the CEBPA upstream open reading frame (uORF). Moreover, CDDO increases the ratio of transcriptionally active p42 and the inactive p30 CEBPA isoform, which, in turn, leads to transcriptional activation of CEBPA-regulated genes (eg, GSCFR) and is associated with dephosphorylation of eIF2α and phosphorylation of eIF4E. In concordance with these results, CDDO induces a CEBPA ratio change and differentiation of primary blasts from patients with acute myeloid leukemia (AML). Because AML is characterized by arrested differentiation, our data suggest the inclusion of CDDO in the therapy of AML characterized by dysfunctional CEBPA expression.

Upregulation of adipocyte metabolism by agouti protein: possible paracrine actions in yellow mouse obesity

1996 ◽  
Vol 270 (1) ◽  
pp. E192-E196 ◽  
Author(s):  
B. H. Jones ◽  
J. H. Kim ◽  
M. B. Zemel ◽  
R. P. Woychik ◽  
E. J. Michaud ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Ectopic Expression ◽  
Acid Synthesis ◽  
Mrna Levels ◽  
Simultaneous Treatment ◽  
Agouti Protein ◽  
Agouti Gene

Mutations leading to ectopic expression of the murine agouti gene (a) result in progressive obesity. To further characterize this model, we analyzed adipose and hepatic mRNA levels for fatty acid synthase (FAS) and stearoyl-CoA desaturase (SCD), two key enzymes in de novo fatty acid synthesis and desaturation, respectively. FAS and SCD mRNA in both tissues of obese (Avy) mice were dramatically increased relative to lean (ala) controls. Excessive expression of these genes in this model could be due to direct effects of the agouti gene product; to test this possibility we treated 3T3-L1 adipocytes in vitro with recombinant agouti protein. Agouti treatment increased FAS and SCD mRNA levels by 1.5- and 4-fold, respectively. In addition, FAS activity and triglyceride content were 3-fold higher in agoutitreated 3T3-L1 cells relative to controls; these effects were attenuated by simultaneous treatment with a calcium channel blocker (nitrendipine). These data demonstrate that the agouti protein can directly increase lipogenesis in adipocytes and suggest that these effects are mediated through an intracellular calcium-dependent mechanism.

C/Ebpa Gene Mutation and C/Ebpa Promoter Hypermethylation in Acute Myeloid Leukemia with Normal Cytogenetics.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1570-1570
Author(s):  
Ying Lu ◽  
Wengang Chen ◽  
Wei Chen ◽  
Anthony Stein ◽  
Lawrence M. Weiss ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Gene Mutation ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Gene Mutations ◽  
Promoter Hypermethylation ◽  
Granulocytic Differentiation ◽  
Npm1 Mutation ◽  
Normal Cytogenetics ◽  
Acute Myeloid

Abstract Abstract 1570 Poster Board I-594 Acute myeloid leukemia with normal cytogenetics (CN-AML) represents approximately 40-50% of de novo AML cases and constitutes the single largest cytogenetic group of AML. CN-AML is composed of a heterogeneous group of AML considered to be more or less in the intermediate prognostic category. Stratified prognostic determinants are required to predict which patients in this heterogeneous category have an increased risk of relapse, resistance to therapy or long term disease outcomes. The CCAAT enhancer binding protein alpha (C/EBPA) is a key transcription factor involved in regulation of granulocytic differentiation and myelopoiesis. In the past few years, various studies have suggested that C/EBPA is negatively regulated in certain AML patients. Impairments in C/EBPA signaling such as gene mutation, transcriptional dysregulation, as well as epigenetic modification via promoter hypermethylation have been identified in CN-AML and these alterations may play an important role in pathogenesis and may predict prognosis in these patients. In the current study, we investigated C/EBPA gene mutations and promoter hypermethylation in a series of 53 patients with CN-AML. In addition, we also analyzed two other frequent mutations (FLT3/ITD and NPM1) in these patients and correlated them with C/EBPA gene alterations. Genomic DNA was isolated from diagnostic bone marrow and peripheral blood samples. The C/EBPA gene mutations were detected by PCR amplification followed by direct DNA sequencing while the promoter hypermethylation was characterized by methylation-specific PCR analysis. The FLT3/ITD mutation and NPM1 mutation were detected by using multiplex PCR followed by capillary electrophoresis. The study included 28 female patients and 25 male patients, all adults, with a median age of 49 years. 13/53 (24.5%) patients were FLT3/ITD+/NPM1-, 11/53 (20.8%) patients were FLT3/ITD+/NPM1+, 9/53 (17.0%) patients were FLT3/ITD-/NPM1+, and 20/53 (37.7%) patients were FLT3/ITD-/NPM1-. Four out of the 53 cases (7.5%) displayed C/EBPA mutations, whereas 49 (92.5%) cases had only C/EBPA wild-type alleles. Of the 4 positive cases, three patients had N-terminal mutations only, while one patient had mutations in both the N- and C-terminal region. Two of the 4 positive cases also harbored both FLT3/ITD and NPM1 mutation simultaneously, while the other two patients had neither FLT3/ITD nor NPM1 mutations. In addition, 7 (13.2%) of the 53 cases displayed C/EBPA promoter hypermethylation. Interestingly they were all in CN-AML cases without FLT3/ITD or NPM1 mutations. None of the 7 patients with C/EBPA promoter hypermethylation showed C/EBPA mutation. In conclusion, C/EBPA mutation and promoter hypermethylation can be detected at a relatively low frequency in de novo CN-AML patients, suggesting they may contribute to leukemogenesis. C/EBPA mutation appears to be frequently seen “high-risk” AML (FLT3/ITD+/NPM1+; FLT3/ITD+/NPM1- or FLT3/ITD-/NPM1-), while C/EBPA hypermethylation appears to be more common in AML with FLT3/ITD- /NPM1- and is not associated with C/EBPA mutation. The clear prognostic relationship of C/EBPA alteration and FLT3/ITD, NPM1 mutation needs to be further validated. Disclosures No relevant conflicts of interest to declare.

scholarly journals Omics Technologies to Decipher Regulatory Networks in Granulocytic Cell Differentiation

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 907
Author(s):  
Svetlana Novikova ◽  
Olga Tikhonova ◽  
Leonid Kurbatov ◽  
Tatiana Farafonova ◽  
Igor Vakhrushev ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Regulatory Networks ◽  
Differentially Expressed ◽  
Leukemic Cells ◽  
Selected Reaction Monitoring ◽  
Repair System ◽  
Differentiation Therapy ◽  
Granulocytic Differentiation ◽  
Acute Myeloid

Induced granulocytic differentiation of human leukemic cells under all-trans-retinoid acid (ATRA) treatment underlies differentiation therapy of acute myeloid leukemia. Knowing the regulation of this process it is possible to identify potential targets for antileukemic drugs and develop novel approaches to differentiation therapy. In this study, we have performed transcriptomic and proteomic profiling to reveal up- and down-regulated transcripts and proteins during time-course experiments. Using data on differentially expressed transcripts and proteins we have applied upstream regulator search and obtained transcriptome- and proteome-based regulatory networks of induced granulocytic differentiation that cover both up-regulated (HIC1, NFKBIA, and CASP9) and down-regulated (PARP1, VDR, and RXRA) elements. To verify the designed network we measured HIC1 and PARP1 protein abundance during granulocytic differentiation by selected reaction monitoring (SRM) using stable isotopically labeled peptide standards. We also revealed that transcription factor CEBPB and LYN kinase were involved in differentiation onset, and evaluated their protein levels by SRM technique. Obtained results indicate that the omics data reflect involvement of the DNA repair system and the MAPK kinase cascade as well as show the balance between the processes of the cell survival and apoptosis in a p53-independent manner. The differentially expressed transcripts and proteins, predicted transcriptional factors, and key molecules such as HIC1, CEBPB, LYN, and PARP1 may be considered as potential targets for differentiation therapy of acute myeloid leukemia.

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