scholarly journals Amino-terminal protein-protein interaction motif (POZ-domain) is responsible for activities of the promyelocytic leukemia zinc finger-retinoic acid receptor-alpha fusion protein.

1996 ◽  
Vol 93 (8) ◽  
pp. 3624-3629 ◽  
Author(s):  
S. Dong ◽  
J. Zhu ◽  
A. Reid ◽  
P. Strutt ◽  
F. Guidez ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Fusion Protein ◽  
Protein Interaction ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Retinoic Acid Receptor Alpha ◽  
Terminal Protein ◽  
Promyelocytic Leukemia Zinc Finger ◽  
Protein Protein Interaction ◽  
Amino Terminal

scholarly journals PML protein expression in hematopoietic and acute promyelocytic leukemia cells

Blood ◽  
1993 ◽  
Vol 82 (6) ◽  
pp. 1858-1867 ◽  
Author(s):  
MT Daniel ◽  
M Koken ◽  
O Romagne ◽  
S Barbey ◽  
A Bazarbachi ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Fusion Protein ◽  
Acute Promyelocytic Leukemia ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Leukemia Cells ◽  
Cytoplasmic Localization ◽  
Wild Type ◽  
Retinoic Acid Receptor Alpha ◽  
Dominant Effect

Abstract Acute promyelocytic leukemia (APL) is thought to be caused by the t(15,17) translocation that fuses the PML gene to that of the retinoic acid receptor alpha (RAR alpha) and generates a PML/RAR alpha fusion protein. Yet, paradoxically, APL cells are exquisitely sensitive to retinoic acid (RA), as they terminally differentiate upon RA exposure. In this report, we have examined the expression of PML and PML/RAR alpha in normal and APL cells. By immunofluorescence or immunocytochemistry, we show that PML has a speckled nuclear pattern of expression that contrasts with that of PML/RAR alpha (mostly a micropunctuated nuclear pattern or a cytoplasmic localization). The APL- derived cell line NB4 that expresses both the PML and PML/RAR alpha genes also shows the fine micropunctuated nuclear pattern, suggesting a dominant effect of the fusion protein over the localization of wild- type PML. RA treatment of NB4 cells or clones expressing PML/RAR alpha gradually leads to a PML pattern before apparent morphologic maturation. In 14 untreated APL patients, the PML-reactive proteins were cytoplasmic (by immunocytochemistry) or both cytoplasmic and nuclear with a micropunctuated pattern (by immunofluorescence). Strikingly, in 4 patients, after 1 to 2 weeks of RA therapy, the speckled nuclear PML pattern reappeared concomitant with the onset of differentiation. These results establish that fusion of PML to RAR alpha results in an altered localization of PML that is reverted upon RA treatment. This observation, which highlights the importance of PML, is likely to be a key to unravelling the molecular mechanism of both leukemogenesis and RA-induced differentiation of APL.

scholarly journals PML protein expression in hematopoietic and acute promyelocytic leukemia cells

Blood ◽  
1993 ◽  
Vol 82 (6) ◽  
pp. 1858-1867 ◽  
Author(s):  
MT Daniel ◽  
M Koken ◽  
O Romagne ◽  
S Barbey ◽  
A Bazarbachi ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Fusion Protein ◽  
Acute Promyelocytic Leukemia ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Leukemia Cells ◽  
Cytoplasmic Localization ◽  
Wild Type ◽  
Retinoic Acid Receptor Alpha ◽  
Dominant Effect

Acute promyelocytic leukemia (APL) is thought to be caused by the t(15,17) translocation that fuses the PML gene to that of the retinoic acid receptor alpha (RAR alpha) and generates a PML/RAR alpha fusion protein. Yet, paradoxically, APL cells are exquisitely sensitive to retinoic acid (RA), as they terminally differentiate upon RA exposure. In this report, we have examined the expression of PML and PML/RAR alpha in normal and APL cells. By immunofluorescence or immunocytochemistry, we show that PML has a speckled nuclear pattern of expression that contrasts with that of PML/RAR alpha (mostly a micropunctuated nuclear pattern or a cytoplasmic localization). The APL- derived cell line NB4 that expresses both the PML and PML/RAR alpha genes also shows the fine micropunctuated nuclear pattern, suggesting a dominant effect of the fusion protein over the localization of wild- type PML. RA treatment of NB4 cells or clones expressing PML/RAR alpha gradually leads to a PML pattern before apparent morphologic maturation. In 14 untreated APL patients, the PML-reactive proteins were cytoplasmic (by immunocytochemistry) or both cytoplasmic and nuclear with a micropunctuated pattern (by immunofluorescence). Strikingly, in 4 patients, after 1 to 2 weeks of RA therapy, the speckled nuclear PML pattern reappeared concomitant with the onset of differentiation. These results establish that fusion of PML to RAR alpha results in an altered localization of PML that is reverted upon RA treatment. This observation, which highlights the importance of PML, is likely to be a key to unravelling the molecular mechanism of both leukemogenesis and RA-induced differentiation of APL.

scholarly journals A PML/retinoic acid receptor alpha fusion transcript is constantly detected by RNA-based polymerase chain reaction in acute promyelocytic leukemia

Blood ◽  
1992 ◽  
Vol 79 (12) ◽  
pp. 3110-3115 ◽  
Author(s):  
S Castaigne ◽  
N Balitrand ◽  
H de The ◽  
A Dejean ◽  
L Degos ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Retinoic Acid Receptor Alpha ◽  
Rt Pcr ◽  
Amplification Product ◽  
Chain Reaction ◽  
Acid Receptor ◽  
Polymerase Chain

Abstract The t(15;17) translocation is specifically observed in patients with promyelocytic leukemia (AML3). The chromosomal rearrangement juxtaposes the retinoic acid receptor alpha (RAR alpha) and PML genes, resulting in PML/RAR alpha fusion transcripts. Our previous studies have shown that a polymerase chain reaction (PCR) amplification product could be obtained from the cDNA of the NB4 promyelocytic cell line from which the chimaeric PML/RAR alpha was cloned. We report here that in all 14 AML3 patients tested, reverse transcriptase-PCR (RT-PCR) allows the detection of three specific fusion products. In eight patients, one amplification product was detected corresponding to the previously described abnormal fusion. Five patients displayed a different amplified fragment corresponding to a different fusion point. One other patient always showed a third different-sized product. The different types of fusion transcripts amplified were correlated to the size of the abnormal RAR alpha transcripts detected in these patients by Northern analysis, but did not prove determinant for either the phenotypic features or the retinoic acid responsiveness in AML3 cells in this group of patients. The consistent identification by RT-PCR of the fusion of the PML and RAR alpha genes in AML3 patients suggest that this method will provide a useful tool for the diagnosis and detection of minimal residual disease in these patients.

scholarly journals Molecular monitoring of the myl/retinoic acid receptor-alpha fusion gene in acute promyelocytic leukemia by polymerase chain reaction

Blood ◽  
1992 ◽  
Vol 80 (2) ◽  
pp. 492-497 ◽  
Author(s):  
A Biondi ◽  
A Rambaldi ◽  
PP Pandolfi ◽  
V Rossi ◽  
G Giudici ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Polymerase Chain Reaction ◽  
Retinoic Acid ◽  
Acute Promyelocytic Leukemia ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Pcr Analysis ◽  
Retinoic Acid Receptor Alpha ◽  
Chain Reaction ◽  
Polymerase Chain

Abstract The acute promyelocytic leukemia (APL) t(15;17) translocation generates a myl/retinoic acid receptor-alpha (RAR-alpha) chimeric gene that is transcribed as a fusion myl/RAR-alpha messenger RNA. Using primer sets derived from RAR-alpha and myl cDNAs, we were able to amplify the breakpoint sites of the fusion transcripts of all 35 APL RNA samples by reverse polymerase chain reaction (PCR) and nested primer approach of two rounds of amplification. DNA fragments of different size were obtained according to the chromosome 15 breakpoints (intron 3-bcr 3; exon 6-bcr 2; and intron 6-bcr 1). bcr 1 and bcr 3 represent the regions of the myl locus most frequently involved among APL (48.5 and 34.2 of cases, respectively); bcr 3 constitutes 62.5% of cases among M3V as compared with 25.9% of M3 cases. The feasibility of monitoring the APL clone by PCR analysis in five APL patients who received different treatment (chemotherapy, all-trans-retinoic acid or bone marrow transplantation) was evaluated. In five of nine bone marrow samples of patients in complete remission, t(15;17)-positive cells could be detected by PCR analysis. We conclude that PCR amplification of the myl/RAR-alpha junctions represents the easiest and rapid method for diagnosis and monitoring of the APL clone.

scholarly journals In vivo analysis of the role of aberrant histone deacetylase recruitment and RARα blockade in the pathogenesis of acute promyelocytic leukemia

2006 ◽  
Vol 203 (4) ◽  
pp. 821-828 ◽  
Author(s):  
Hiromichi Matsushita ◽  
Pier Paolo Scaglioni ◽  
Mantu Bhaumik ◽  
Eduardo M. Rego ◽  
Lu Fan Cai ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Fusion Protein ◽  
Acute Promyelocytic Leukemia ◽  
Histone Deacetylases ◽  
Retinoic Acid Receptor ◽  
Promyelocytic Leukemia ◽  
Dominant Negative

The promyelocytic leukemia–retinoic acid receptor α (PML-RARα) protein of acute promyelocytic leukemia (APL) is oncogenic in vivo. It has been hypothesized that the ability of PML-RARα to inhibit RARα function through PML-dependent aberrant recruitment of histone deacetylases (HDACs) and chromatin remodeling is the key initiating event for leukemogenesis. To elucidate the role of HDAC in this process, we have generated HDAC1–RARα fusion proteins and tested their activity and oncogenicity in vitro and in vivo in transgenic mice (TM). In parallel, we studied the in vivo leukemogenic potential of dominant negative (DN) and truncated RARα mutants, as well as that of PML-RARα mutants that are insensitive to retinoic acid. Surprisingly, although HDAC1-RARα did act as a bona fide DN RARα mutant in cellular in vitro and in cell culture, this fusion protein, as well as other DN RARα mutants, did not cause a block in myeloid differentiation in vivo in TM and were not leukemogenic. Comparative analysis of these TM and of TM/PML−/− and p53−/− compound mutants lends support to a model by which the RARα and PML blockade is necessary, but not sufficient, for leukemogenesis and the PML domain of the fusion protein provides unique functions that are required for leukemia initiation.

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