scholarly journals Benserazide As a Novel Fetal Hemoglobin Inducer: An Observational Study in Non-Carriers of Hemoglobin Disorders

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2345-2345 ◽  
Author(s):  
Marina Erê A. H. P. Santos ◽  
Felipe Vendrame ◽  
Alvaro Henrique Junqueira Tavares ◽  
Leticia Marani ◽  
Paula C. de Azevedo ◽  
...  
Keyword(s):  
Globin Gene ◽  
Dose Range ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Clinical Use ◽  
Gamma Globin ◽  
Significant Difference ◽  
F Cells ◽  
Chronic Use

Abstract Induction of fetal hemoglobin (HbF) production is an effective therapeutic strategy in the management of patients with beta hemoglobinopathies. Hydroxyurea is the only drug with this mechanism approved for clinical use, and 20% or more of patients do not respond or tolerate it, which has led to the search for new HbF inducers. Benserazide (BEN) is a DOPA decarboxylase inhibitor used in combination with levodopa in the treatment of parkinsonism, but it was also noticed to induce increased gamma globin production in preclinical models. The mechanisms by which BEN acts include downregulation of BCL11A, LSD1 and HDAC3 on the promoter region of the gamma globin gene, making it an interesting candidate for clinical studies in hemoglobinopathies. We hypothesized that patients undergoing treatment for parkinsonism with chronic use of BEN-containing medication may develop increase in HbF production and in circulating F-cells. Material and Methods: Peripheral blood samples were collected from patients with parkinsonism during their follow-up at the Neurology Clinic, who had been using BEN for at least 30 days (BEN group), from healthy controls (group AA), and from patients known to have increased of HbF due to sickle cell anemia (group SS), for comparison purposes. Exclusion criteria for BEN and AA groups were: any hemoglobinopathy, transfusion in the last 90 days, and use of HU or any chemotherapeutic agent. Automated complete blood counts with reticulocyte count were performed on a XN-3000 equipment (Sysmex, Japan), HbF levels were determined by HPLC (BioRad, USA), and F-cell percentage was determined by flow cytometry (BD FACSCalibur, USA). Results: Thirty-five patients on BEN, 10 negative controls (AA group) and five positive controls (SS group) were included. One patient taking BEN was excluded due to HPLC compatible with beta thalassemia trait. Patients taking BEN had blood counts within the normal range. There was no statistically significant difference between BEN and AA groups, and the SS group was significantly anemic as expected. We found a strongly positive correlation between HbF and circulating F-cells (p <0.0001, r = 0.946) when analyzing the entire population, but within the subgroup of patients using BEN, this correlation was much weaker (p = 0.0032, r = 0.492). Dose range of BEN used by the patients was 100-700mg daily, at 1.21 to 11.1mg/kg/day, but we found no correlation between dose and HbF levels. Discussion: We found no differences in blood counts, and extensive use of this regimen support that chronic use of BEN is safe in doses up to 11.1mg/kg/day. In vitro studies suggest that BEN is 30 times more potent than HU. Therefore, considering the minimum dose of HU used in clinical practice of 15mg/kg/day, we had expected that some increase in HbF could be observed at 0.5mg/kg/day of BEN. However, our data show that, even with chronic use of doses 20 times higher, there was no increase in HbF or F-cell levels. The lack of effectiveness of BEN in this population may be explained by its hydrolysis in the intestinal mucosa, and by its reported short half-life (48min), which could account for reduced bioavailability. In addition, patients not bearing beta globin mutations may be less likely to respond to gamma globin induction. Conclusion: Although BEN is already in clinical use and is a strong candidate as a new HbF inducer, we did not detect this effect in humans without hemoglobinopathies. Our data impact the experimental design of future clinical trials with BEN, and suggests the need for more studies on its pharmacokinetics and pharmacodynamics to improve the chances of achieving the desired clinical effect. Disclosures Fertrin: Alexion Pharmaceutical Brasil: Speakers Bureau; Apopharma Inc.: Honoraria.

scholarly journals The beta-globin gene on the Chinese delta beta-thalassemia chromosome carries a promoter mutation

Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1470-1474 ◽  
Author(s):  
GF Atweh ◽  
XX Zhu ◽  
HE Brickner ◽  
CH Dowling ◽  
HH Jr Kazazian ◽  
...  
Keyword(s):  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Promoter Mutation ◽  
Beta Globin Gene ◽  
Gamma Globin ◽  
New Type

A new type of delta beta-thalassemia characterized by decreased expression of the beta-globin gene and increased expression of both G gamma and A gamma globin gene in the absence of a detectable deletion has recently been described in the Chinese population. In this study we characterize the mutant beta-globin gene from this delta beta- thalassemia chromosome. An A to G transversion is identified in the “ATA” sequence of the promoter region that leads to decreased expression of the beta-globin gene in vivo and in vitro. We also demonstrate the presence of this mutation in every individual with a high fetal hemoglobin phenotype in this family and its absence in every individual with a normal hemoglobin phenotype. This same promoter mutation has recently been detected in Chinese beta-thalassemia genes where it is present on chromosomes of the same haplotype as that of the delta beta-thalassemia chromosome we are studying. These data support the hypothesis that an as yet unidentified mutation occurred on the ancestral chromosome carrying the promoter mutation and subsequently gave rise to the delta beta-thalassemia phenotype.

scholarly journals The beta-globin gene on the Chinese delta beta-thalassemia chromosome carries a promoter mutation

Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1470-1474 ◽  
Author(s):  
GF Atweh ◽  
XX Zhu ◽  
HE Brickner ◽  
CH Dowling ◽  
HH Jr Kazazian ◽  
...  
Keyword(s):  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Promoter Mutation ◽  
Beta Globin Gene ◽  
Gamma Globin ◽  
New Type

Abstract A new type of delta beta-thalassemia characterized by decreased expression of the beta-globin gene and increased expression of both G gamma and A gamma globin gene in the absence of a detectable deletion has recently been described in the Chinese population. In this study we characterize the mutant beta-globin gene from this delta beta- thalassemia chromosome. An A to G transversion is identified in the “ATA” sequence of the promoter region that leads to decreased expression of the beta-globin gene in vivo and in vitro. We also demonstrate the presence of this mutation in every individual with a high fetal hemoglobin phenotype in this family and its absence in every individual with a normal hemoglobin phenotype. This same promoter mutation has recently been detected in Chinese beta-thalassemia genes where it is present on chromosomes of the same haplotype as that of the delta beta-thalassemia chromosome we are studying. These data support the hypothesis that an as yet unidentified mutation occurred on the ancestral chromosome carrying the promoter mutation and subsequently gave rise to the delta beta-thalassemia phenotype.

scholarly journals Molecular analysis of Japanese delta beta-thalassemia

Blood ◽  
1988 ◽  
Vol 72 (5) ◽  
pp. 1771-1776
Author(s):  
S Shiokawa ◽  
H Yamada ◽  
Y Takihara ◽  
E Matsunaga ◽  
Y Ohba ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Globin Genes ◽  
Beta Globin ◽  
Beta Globin Gene ◽  
Gamma Globin ◽  
Large Deletions ◽  
Deletion Junction

A DNA fragment containing the deletion junction region from a Japanese individual with homozygous delta beta-thalassemia has been cloned. A clone containing the normal DNA surrounding the 3′ breakpoint of this deletion and a clone carrying the G gamma- and A gamma-globin genes of this patient were also isolated. Sequences of the deletion junction and both gamma-globin genes were determined. A comparison of these sequences with previously determined sequences of the normal counterparts revealed that the 5′ breakpoint is located between 2,134 and 2,137 base pairs (bp) 3′ to the polyA site of the A gamma-globin gene, the 5′ breakpoint is located just downstream of the 3′ border of the fetal gamma-globin duplication unit, and no molecular defects are evident within the gamma-globin gene region. A comparison between the sequences of the normal DNA surrounding the 3′ breakpoint and the normal DNA surrounding the 5′ breakpoint shows that deletion is the result of a nonhomologous recombination event. There are A+T-rich stretches near the 5′ and 3′ breakpoints in the normal DNA, and a portion of an Aly repeat is located in the region 3′ to the 3′ breakpoint. Southern blot analysis using probes 3′ to the beta-globin gene showed that the deletion extends in the 3′ direction further than any other deletions associated with delta beta-thalassemia and hereditary persistence of fetal hemoglobin (HPFH) heretofore reported. These results are discussed in terms of the mechanism generating large deletions in mammalian cells and three models for the regulation of gamma-globin and beta-globin gene expression in humans.

Point mutation associated with hereditary persistence of fetal hemoglobin decreases RNA polymerase III transcription upstream of the affected gamma-globin gene

1986 ◽  
Vol 6 (9) ◽  
pp. 3278-3282
Author(s):  
D P Carlson ◽  
J Ross
Keyword(s):  
Rna Polymerase ◽  
Globin Gene ◽  
Rna Polymerase Iii ◽  
Fetal Hemoglobin ◽  
In Vitro Transcription ◽  
Base Substitution ◽  
Gamma Globin ◽  
Polymerase Iii ◽  
Hemoglobin Production

A base substitution in the 5'-flanking region of a human fetal globin gene is associated with abnormal fetal hemoglobin production. It also reduces by 5- to 10-fold in vitro transcription of the gene by RNA polymerase III. We discuss potential links between polymerase III transcription and abnormal hemoglobin production.

scholarly journals A novel deletion of approximately 27 kb including the beta-globin gene and the locus control region 3'HS-1 regulatory sequence: beta zero- thalassemia or hereditary persistence of fetal hemoglobin?

Blood ◽  
1994 ◽  
Vol 83 (3) ◽  
pp. 822-827 ◽  
Author(s):  
AJ Dimovski ◽  
V Divoky ◽  
AD Adekile ◽  
E Baysal ◽  
JB Wilson ◽  
...  
Keyword(s):  
Control Region ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Locus Control Region ◽  
Regulatory Sequence ◽  
Beta Globin ◽  
Gamma Chain ◽  
Beta Globin Gene ◽  
Gamma Globin

Abstract A novel deletion of approximately 27 kb with the 5′ breakpoint 1.5 to 2.2 kb upstream of the beta-globin gene, and the 3′ breakpoint approximately 24 kb downstream of the beta-globin gene, has been found in five members of two families from Southeast Asia (Vietnam and Cambodia). Six members of another family from China, previously reported from our laboratory, have also been shown to carry this deletion. The patients presented with mild hypochromia and microcytosis, a hemoglobin (Hb) A2 level of approximately 4.0%, and a markedly increased, heterocellularly distributed, Hb F level (14.0 to 26.0%). In vitro globin-chain synthesis showed a mild imbalance with appreciable gamma-chain compensation (alpha/beta + gamma ratio of 1.46). The 3′ end of this deletion includes the 3′HS-1, and we hypothesize that removal of this region results in the loss of its gamma-globin gene-silencing effect, which causes a markedly elevated Hb F level with a modest increase in Hb A2 levels, unlike the situation in other deletional beta zero-thalassemias. The possible influence of particular sequence variations in the locus control region 5′HS-2 and the G gamma promoter, present on the chromosome with this deletion, on the overall gamma-globin gene should also be considered.

scholarly journals Point mutation associated with hereditary persistence of fetal hemoglobin decreases RNA polymerase III transcription upstream of the affected gamma-globin gene.

1986 ◽  
Vol 6 (9) ◽  
pp. 3278-3282 ◽  
Author(s):  
D P Carlson ◽  
J Ross
Keyword(s):  
Rna Polymerase ◽  
Globin Gene ◽  
Rna Polymerase Iii ◽  
Fetal Hemoglobin ◽  
In Vitro Transcription ◽  
Base Substitution ◽  
Gamma Globin ◽  
Polymerase Iii ◽  
Hemoglobin Production

A base substitution in the 5'-flanking region of a human fetal globin gene is associated with abnormal fetal hemoglobin production. It also reduces by 5- to 10-fold in vitro transcription of the gene by RNA polymerase III. We discuss potential links between polymerase III transcription and abnormal hemoglobin production.

scholarly journals Molecular analysis of Japanese delta beta-thalassemia

Blood ◽  
1988 ◽  
Vol 72 (5) ◽  
pp. 1771-1776 ◽  
Author(s):  
S Shiokawa ◽  
H Yamada ◽  
Y Takihara ◽  
E Matsunaga ◽  
Y Ohba ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Globin Genes ◽  
Beta Globin ◽  
Beta Globin Gene ◽  
Gamma Globin ◽  
Large Deletions ◽  
Deletion Junction

Abstract A DNA fragment containing the deletion junction region from a Japanese individual with homozygous delta beta-thalassemia has been cloned. A clone containing the normal DNA surrounding the 3′ breakpoint of this deletion and a clone carrying the G gamma- and A gamma-globin genes of this patient were also isolated. Sequences of the deletion junction and both gamma-globin genes were determined. A comparison of these sequences with previously determined sequences of the normal counterparts revealed that the 5′ breakpoint is located between 2,134 and 2,137 base pairs (bp) 3′ to the polyA site of the A gamma-globin gene, the 5′ breakpoint is located just downstream of the 3′ border of the fetal gamma-globin duplication unit, and no molecular defects are evident within the gamma-globin gene region. A comparison between the sequences of the normal DNA surrounding the 3′ breakpoint and the normal DNA surrounding the 5′ breakpoint shows that deletion is the result of a nonhomologous recombination event. There are A+T-rich stretches near the 5′ and 3′ breakpoints in the normal DNA, and a portion of an Aly repeat is located in the region 3′ to the 3′ breakpoint. Southern blot analysis using probes 3′ to the beta-globin gene showed that the deletion extends in the 3′ direction further than any other deletions associated with delta beta-thalassemia and hereditary persistence of fetal hemoglobin (HPFH) heretofore reported. These results are discussed in terms of the mechanism generating large deletions in mammalian cells and three models for the regulation of gamma-globin and beta-globin gene expression in humans.

scholarly journals Laotian (delta beta) degree-thalassemia: molecular characterization of a novel deletion associated with increased production of fetal hemoglobin

Blood ◽  
1988 ◽  
Vol 72 (3) ◽  
pp. 983-988 ◽  
Author(s):  
JW Zhang ◽  
G Stamatoyannopoulos ◽  
NP Anagnou
Keyword(s):  
Globin Gene ◽  
Repetitive Sequences ◽  
Adult Life ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Globin Genes ◽  
Beta Globin ◽  
Beta Globin Gene ◽  
Mild Anemia ◽  
F Cells

Abstract We have identified and molecularly characterized a novel deletion in the beta-globin gene cluster that increases fetal hemoglobin (HbF) synthesis in a 24-year-old Laotian man who is heterozygous for this mutation. The patient is asymptomatic with a mild anemia, hypochromia, and microcytosis (Ht = 39%, MCH = 22.8 pg, MCV = 71 fl), normal levels of HbA2 (3.0%) and 11.5% HbF (G gamma A gamma ratio 60 to 40), with heterocellular distribution (52% F cells). Extensive restriction endonuclease mapping defined the 5′ breakpoint within the IVS II of the delta-globin gene, between positions 775 to 781 very similar to the 5′ breakpoint of the Sicilian delta beta-thalassemia. However, the 3′ breakpoint was localized between two Pst I sites 4.7 kb 3′ of the beta- globin gene, thus ending about 0.7 kb upstream from the 3′ breakpoint of the Sicilian delta beta-thalassemia. This results in a 12.5 kb deletion of DNA. It is of interest that the 5′ breakpoint of the deletion residues within an AT-rich region which has been proposed as a specific recognition signal for recombination events, while the 3′ breakpoint lies within a cluster of L1 repetitive sequences (formerly known as Kpn I family repeats). The presence of the 3′ breakpoints of several other deletions within this region of L1 repeats also suggests that such sequences might serve as hot spots for recombination and eventually lead to thalassemia deletions. The similarity of the 5′ and 3′ breakpoints of these delta beta-thalassemias underscores the putative regulatory role of the deleted and juxtaposed sequences on the expression of the gamma-globin genes in adult life.

scholarly journals Fetal hemoglobin silencing in humans

Blood ◽  
2006 ◽  
Vol 108 (6) ◽  
pp. 2081-2086 ◽  
Author(s):  
Patricia A. Oneal ◽  
Nicole M. Gantt ◽  
Joseph D. Schwartz ◽  
Natarajan V. Bhanu ◽  
Y. Terry Lee ◽  
...  
Keyword(s):  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Postnatal Life ◽  
Globin Genes ◽  
Beta Globin ◽  
Globin Mrna ◽  
Beta Globin Gene ◽  
Gamma Globin ◽  
Age Related

Abstract Interruption of the normal fetal-to-adult transition of hemoglobin expression should largely ameliorate sickle cell and beta-thalassemia syndromes. Achievement of this clinical goal requires a robust understanding of gamma-globin gene and protein silencing during human development. For this purpose, age-related changes in globin phenotypes of circulating human erythroid cells were examined from 5 umbilical cords, 99 infants, and 5 adult donors. Unexpectedly, an average of 95% of the cord blood erythrocytes and reticulocytes expressed HbA and the adult beta-globin gene, as well as HbF and the gamma-globin genes. The distribution of hemoglobin and globin gene expression then changed abruptly due to the expansion of cells lacking HbF or gamma-globin mRNA (silenced cells). In adult reticulocytes, less than 5% expressed gamma-globin mRNA. These data are consistent with a “switching” model in humans that initially results largely from gamma- and beta-globin gene coexpression and competition during fetal development. In contrast, early postnatal life is marked by the rapid accumulation of cells that possess undetectable gamma-globin mRNA and HbF. The silencing phenomenon is mediated by a mechanism of cellular replacement. This novel silencing pattern may be important for the development of HbF-enhancing therapies.

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