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Epigenetic dysregulation of the erythropoietic transcription factor KLF1 and the ?-like globin locus in juvenile myelomonocytic leukemia.

ABSTRACT: Increased levels of fetal hemoglobin (HbF) are a hallmark of more than half of the children diagnosed with juvenile myelomonocytic leukemia (JMML). Elevated HbF levels in JMML are associated with DNA hypermethylation of distinct gene promoter regions in leukemic cells. Since the regulation of globin gene transcription is known to be under epigenetic control, we set out to study the relation of DNA methylation patterns at ?-/?-globin promoters, mRNA and protein expression of globins, and epigenetic modifications of genes encoding the globin-regulatory transcription factors BCL11A and KLF1 in nucleated erythropoietic precursor cells of patients with JMML. We describe several altered epigenetic components resulting in disordered globin synthesis in JMML. We identify a cis-regulatory upstream KLF1 enhancer sequence as highly sensitive to DNA methylation and frequently hypermethylated in JMML. The data indicate that the dysregulation of ?-like globin genes is a genuine attribute of the leukemic cell clone in JMML and involves mechanisms not taking part in the normal fetal-to-adult hemoglobin switch.

SUBMITTER: Fluhr S

PROVIDER: S-EPMC5687323 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

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Epigenetic dysregulation of the erythropoietic transcription factor KLF1 and the β-like globin locus in juvenile myelomonocytic leukemia.

Fluhr Silvia S Krombholz Christopher Felix CF Meier Angelina A Epting Thomas T Mücke Oliver O Plass Christoph C Niemeyer Charlotte M CM Flotho Christian C

Epigenetics 20170727 8

Increased levels of fetal hemoglobin (HbF) are a hallmark of more than half of the children diagnosed with juvenile myelomonocytic leukemia (JMML). Elevated HbF levels in JMML are associated with DNA hypermethylation of distinct gene promoter regions in leukemic cells. Since the regulation of globin gene transcription is known to be under epigenetic control, we set out to study the relation of DNA methylation patterns at β-/γ-globin promoters, mRNA and protein expression of globins, and epigenet ...[more]

PMID: 28749240

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Project description:Background: Juvenile myelomonocytic leukemia (JMML) is a rare myelodysplastic/myeloproliferative neoplasm diagnosed in young children, characterized by somatic or germline mutations that lead to hyperactive RAS signaling. The only curative option is hematopoietic stem cell transplantation (HSCT). Recent data showing that aberrant DNA methylation plays a significant role in pathogenesis and correlates with clinical risk suggest a possible benefit of hypomethylating agents (HMA) in JMML treatment. Aim: The aim is to report the results of HMA-based therapy with 5-azacytidine (AZA) in three JMML patients treated in a single center, non-participating in EWOG-MDS study. Methods: The diagnosis and treatment response were evaluated according to international consensus criteria. AZA 75 mg/m2 intravenous (i.v.) was administered once daily on days 1-7 of each 28-day cycle. All patients were monitored for hematologic response, spleen size, and evolution of extramedullary disease. Targeted next generation sequencing (NGS) were performed after the 3rd AZA cycle and before SCT to evaluate the molecular alterations and genetic response. Results: Three patients diagnosed with JMML were treated with AZA (off-label indication) in Pediatric Department of Fundeni Clinical Institute, Bucharest, Romania between 2017 and 2019. There were two females and one male with median age 11 months, range 2-16 months. The cytogenetic analysis showed normal karyotype in all patients. Molecular analysis confirmed KRAS G13D mutation in two patients and NRAS G12D mutation in one patient. The clinical evaluation showed important splenomegaly and hepatomegaly in all 3 pts. One patient received AZA for early relapse after haploidentical HSCT and the other two patients received upfront AZA, as bridging therapy before HSCT. After HMA therapy, 2/3 patients achieved clinical partial response (cPR), 1/3 had clinical stable disease (cSD) and all had genetic stable disease (gSD) after 3 cycles and were able to receive the planned HSTC. One patient achieved clinical and genetic complete response before HSCT. During 22 cycles of AZA there were only four adverse events but only one determined dose reduction and treatment delay. Conclusion: Our data show that AZA monotherapy is safe and effective in controlling disease both in upfront and relapsed patients in order to proceed to HSCT.

Dataset Information

Epigenetic dysregulation of the erythropoietic transcription factor KLF1 and the ?-like globin locus in juvenile myelomonocytic leukemia.

Publications

Epigenetic dysregulation of the erythropoietic transcription factor KLF1 and the β-like globin locus in juvenile myelomonocytic leukemia.

Similar Datasets

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