scholarly journals PIC-1/SUMO-1-Modified PML-Retinoic Acid Receptor α Mediates Arsenic Trioxide-Induced Apoptosis in Acute Promyelocytic Leukemia

1999 ◽  
Vol 19 (7) ◽  
pp. 5170-5178 ◽  
Author(s):  
Thomas Sternsdorf ◽  
Elena Puccetti ◽  
Kirsten Jensen ◽  
Dieter Hoelzer ◽  
Hans Will ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Fusion Protein ◽  
Arsenic Trioxide ◽  
Acute Promyelocytic Leukemia ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Nuclear Bodies ◽  
Acid Receptor ◽  
Retinoic Acid Receptor Α ◽  
Induced Apoptosis

ABSTRACT Fusion proteins involving the retinoic acid receptor α (RARα) and PML or PLZF nuclear protein are the genetic markers of acute promyelocytic leukemia (APL). APLs with PML-RARα or PLZF-RARα fusion protein differ only in their response to retinoic acid (RA) treatment: the t(15;17) (PML-RARα-positive) APL blasts are sensitive to RA in vitro, and patients enter disease remission after RA treatment, while those with t(11;17) (PLZF-RARα-positive) APLs do not. Recently it has been shown that complete remission can be achieved upon treatment with arsenic trioxide (As2O3) in PML-RARα-positive APL, even when the patient has relapsed and the disease is RA resistant. This appears to be due to apoptosis induced by As2O3 in the APL blasts by poorly defined mechanisms. Here we report that (i) As2O3induces apoptosis only in cells expressing the PML-RARα, not the PLZF-RARα, fusion protein; (ii) PML-RARα is partially modified by covalent linkage with a PIC-1/SUMO-1-like protein prior to As2O3 treatment, whereas PLZF-RARα is not; (iii) As2O3 treatment induces a change in the modification pattern of PML-RARα toward highly modified forms; (iv) redistribution of PML nuclear bodies (PML-NBs) upon As2O3 treatment is accompanied by recruitment of PIC-1/SUMO-1 into PML-NBs, probably due to hypermodification of both PML and PML-RARα; (v) As2O3-induced apoptosis is independent of the DNA binding activity located in the RARα portion of the PML-RARα fusion protein; and (vi) the apoptotic process is bcl-2 and caspase 3 independent and is blocked only partially by a global caspase inhibitor. Taken together, these data provide novel insights into the mechanisms involved in As2O3-induced apoptosis in APL and predict that treatment of t(11;17) (PLZF-RARα-positive) APLs with As2O3 will not be successful.

scholarly journals Role of Promyelocytic Leukemia (Pml) Sumolation in Nuclear Body Formation, 11s Proteasome Recruitment, and as2O3-Induced Pml or Pml/Retinoic Acid Receptor α Degradation

2001 ◽  
Vol 193 (12) ◽  
pp. 1361-1372 ◽  
Author(s):  
Valérie Lallemand-Breitenbach ◽  
Jun Zhu ◽  
Francine Puvion ◽  
Marcel Koken ◽  
Nicole Honoré ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Nuclear Matrix ◽  
Viral Infections ◽  
Retinoic Acid Receptor ◽  
Nuclear Body ◽  
Promyelocytic Leukemia ◽  
Nuclear Bodies ◽  
Acid Receptor ◽  
Pml Nuclear Bodies ◽  
Retinoic Acid Receptor Α

Promyelocytic leukemia (PML) is the organizer of nuclear matrix domains, PML nuclear bodies (NBs), with a proposed role in apoptosis control. In acute promyelocytic leukemia, PML/retinoic acid receptor (RAR) α expression disrupts NBs, but therapies such as retinoic acid or arsenic trioxide (As2O3) restore them. PML is conjugated by the ubiquitin-related peptide SUMO-1, a process enhanced by As2O3 and proposed to target PML to the nuclear matrix. We demonstrate that As2O3 triggers the proteasome-dependent degradation of PML and PML/RARα and that this process requires a specific sumolation site in PML, K160. PML sumolation is dispensable for its As2O3-induced matrix targeting and formation of primary nuclear aggregates, but is required for the formation of secondary shell-like NBs. Interestingly, only these mature NBs harbor 11S proteasome components, which are further recruited upon As2O3 exposure. Proteasome recruitment by sumolated PML only likely accounts for the failure of PML-K160R to be degraded. Therefore, studying the basis of As2O3-induced PML/RARα degradation we show that PML sumolation directly or indirectly promotes its catabolism, suggesting that mature NBs could be sites of intranuclear proteolysis and opening new insights into NB alterations found in viral infections or transformation.

Interactions of STAT5b-RARα, a novel acute promyelocytic leukemia fusion protein, with retinoic acid receptor and STAT3 signaling pathways

Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2637-2646 ◽  
Author(s):  
Shuo Dong ◽  
David J. Tweardy
Keyword(s):  
Retinoic Acid ◽  
Fusion Protein ◽  
Acute Promyelocytic Leukemia ◽  
Nuclear Receptor ◽  
Fusion Proteins ◽  
Transcriptional Activity ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Maturation Arrest ◽  
Acid Receptor

Abstract Signal transducer and activator of transcription (STAT) 5b-retinoic acid receptor (RAR) α is the fifth fusion protein identified in acute promyelocytic leukemia (APL). Initially described in a patient with all-trans retinoic acid (ATRA)–unresponsive disease, STAT5b-RARα resulted from an interstitial deletion on chromosome 17. To determine the molecular mechanisms of myeloid leukemogenesis and maturation arrest in STAT5b-RARα+ APL and its unresponsiveness to ATRA, we examined the effect of STAT5b-RARα on the activity of myeloid transcription factors including RARα/retinoid X receptor (RXR) α, STAT3, and STAT5 as well as its molecular interactions with the nuclear receptor corepressor, SMRT, and nuclear receptor coactivator, TRAM-1. STAT5b-RARα bound to retinoic acid response elements (RAREs) both as a homodimer and as a heterodimer with RXRα and inhibited wild-type RARα/RXRα transactivation. Although STAT5b-RARα had no effect on ligand-induced STAT5b activation, it enhanced interleukin 6–induced STAT3-dependent reporter activity, an effect shared by other APL fusion proteins including promyelocytic leukemia-RARα and promyelocytic leukemia zinc finger (PLZF)–RARα. SMRT was released from STAT5b-RARα/SMRT complexes by ATRA at 10−6 M, whereas TRAM-1 became associated with STAT5b-RARα at 10−7 M. The coiled-coil domain of STAT5b was required for formation of STAT5b-RARα homodimers, for the inhibition of RARα/RXRα transcriptional activity, and for stability of the STAT5b-RARα/SMRT complex. Thus, STAT5b-RARα contributes to myeloid maturation arrest by binding to RARE as either a homodimer or as a heterodimer with RXRα resulting in the recruitment of SMRT and inhibition of RARα/RXRα transcriptional activity. In addition, STAT5b-RARα and other APL fusion proteins may contribute to leukemogenesis by interaction with the STAT3 oncogene pathway.

scholarly journals PML-Retinoic Acid Receptor α Inhibits PML IV Enhancement of PU.1-Induced C/EBPε Expression in Myeloid Differentiation

2007 ◽  
Vol 27 (16) ◽  
pp. 5819-5834 ◽  
Author(s):  
Hitoshi Yoshida ◽  
Hitoshi Ichikawa ◽  
Yusuke Tagata ◽  
Takuo Katsumoto ◽  
Kazunori Ohnishi ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Fusion Protein ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Myeloid Differentiation ◽  
Granulocytic Differentiation ◽  
Acid Receptor ◽  
Type Iv ◽  
Retinoic Acid Receptor Α ◽  
Deficient Mice

ABSTRACT PML and PU.1 play important roles in myeloid differentiation. PML-deficient mice have an impaired capacity for terminal maturation of their myeloid precursor cells. This finding has been explained, at least in part, by the lack of PML action to modulate retinoic acid-differentiating activities. In this study, we found that C/EBPε expression is reduced in PML-deficient mice. We showed that PU.1 directly activates the transcription of the C/EBPε gene that is essential for granulocytic differentiation. The type IV isoform of PML interacted with PU.1, promoted its association with p300, and then enhanced PU.1-induced transcription and granulocytic differentiation. In contrast to PML IV, the leukemia-associated PML-retinoic acid receptor α fusion protein dissociated the PU.1/PML IV/p300 complex and inhibited PU.1-induced transcription. These results suggest a novel pathogenic mechanism of the PML-retinoic acid receptor α fusion protein in acute promyelocytic leukemia.

scholarly journals Identification of a myeloid committed progenitor as the cancer-initiating cell in acute promyelocytic leukemia

Blood ◽  
2009 ◽  
Vol 114 (27) ◽  
pp. 5415-5425 ◽  
Author(s):  
Florence C. Guibal ◽  
Meritxell Alberich-Jorda ◽  
Hideyo Hirai ◽  
Alexander Ebralidze ◽  
Elena Levantini ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Retinoic Acid ◽  
Acute Promyelocytic Leukemia ◽  
Retinoic Acid Receptor ◽  
Myeloid Cells ◽  
Promyelocytic Leukemia ◽  
Leukemic Cells ◽  
Acid Receptor ◽  
Enhancer Binding Protein ◽  
Retinoic Acid Receptor Α

Abstract Acute promyelocytic leukemia (APL) is characterized by a block in differentiation and accumulation of promyelocytes in the bone marrow and blood. The majority of APL patients harbor the t(15:17) translocation leading to expression of the fusion protein promyelocytic-retinoic acid receptor α. Treatment with retinoic acid leads to degradation of promyelocytic-retinoic acid receptor α protein and disappearance of leukemic cells; however, 30% of APL patients relapse after treatment. One potential mechanism for relapse is the persistence of cancer “stem” cells in hematopoietic organs after treatment. Using a novel sorting strategy we developed to isolate murine myeloid cells at distinct stages of differentiation, we identified a population of committed myeloid cells (CD34+, c-kit+, FcγRIII/II+, Gr1int) that accumulates in the spleen and bone marrow in a murine model of APL. We observed that these cells are capable of efficiently generating leukemia in recipient mice, demonstrating that this population represents the APL cancer–initiating cell. These cells down-regulate the transcription factor CCAAT/enhancer binding protein α (C/EBPα) possibly through a methylation-dependent mechanism, indicating that C/EBPα deregulation contributes to transformation of APL cancer–initiating cells. Our findings provide further understanding of the biology of APL by demonstrating that a committed transformed progenitor can initiate and propagate the disease.

scholarly journals Acute myeloid leukemia with CPSF6–RARG fusion resembling acute promyelocytic leukemia with extramedullary infiltration

2021 ◽  
Vol 12 ◽  
pp. 204062072097698
Author(s):  
Xiaoyan Han ◽  
Chunxiang Jin ◽  
Gaofeng Zheng ◽  
Yi Li ◽  
Yungui Wang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Retinoic Acid ◽  
Acute Promyelocytic Leukemia ◽  
Myeloid Leukemia ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Specific Factor ◽  
Acid Receptor ◽  
Response To Chemotherapy ◽  
Acute Myeloid

Some subtypes of acute myeloid leukemia (AML) share morphologic, immunophenotypic, and clinical features of acute promyelocytic leukemia (APL), but lack a PML–RARA (promyelocytic leukemia–retinoic acid receptor alpha) fusion gene. Instead, they have the retinoic acid receptor beta (RARB) or retinoic acid receptor gamma (RARG) rearranged. Almost all of these AML subtypes exhibit resistance to all-trans retinoic acid (ATRA); undoubtedly, the prognosis is poor. Here, we present an AML patient resembling APL with a novel cleavage and polyadenylation specific factor 6 ( CPSF6) –RARG fusion, showing resistance to ATRA and poor response to chemotherapy with homoharringtonine and cytarabine. Simultaneously, the patient also had extramedullary infiltration.

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