Promoter methylation and expression levels of selected hematopoietic genes in pediatric B-cell acute lymphoblastic leukemia

Ewa Musialik; Mateusz Bujko; Paulina Kober; Agnieszka Wypych; Karolina Gawle-Krawczyk; Michal Matysiak; Janusz Aleksander Siedlecki

doi:10.5045/br.2015.50.1.26

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Original Article

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Blood Res 2015; 50(1):

Published online March 31, 2015

https://doi.org/10.5045/br.2015.50.1.26

Promoter methylation and expression levels of selected hematopoietic genes in pediatric B-cell acute lymphoblastic leukemia

Ewa Musialik^1,#*, Mateusz Bujko^1,#, Paulina Kober¹, Agnieszka Wypych², Karolina Gawle-Krawczyk², Michal Matysiak², and Janusz Aleksander Siedlecki¹

Author Info. +

¹Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Medical University of Warsaw, Warsaw, Poland.

²Department of Pediatric Haematology & Oncology, Medical University of Warsaw, Warsaw, Poland.

Correspondence to : Correspondence to Ewa Musialik, M.S. Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, W.K. Roentgena 5, 02-781 Warsaw, Poland. Tel: +48-22-546-28-98, Fax: +48-22-546-31-91, musialik.ewa@gmail.com

Received: June 13, 2014; Revised: September 28, 2014; Accepted: January 9, 2015

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

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Abstract

Background

Precursor B-cell acute lymphoblastic leukemia (B-cell ALL) is the most common neoplasm in children and is characterized by genetic and epigenetic aberrations in hematopoietic transcription factor (TF) genes. This study evaluated promoter DNA methylation and aberrant expression levels of early- and late-acting hematopoietic TF genes homeobox A4 and A5 (HOXA4 and HOXA5), Meis homeobox 1 (MEIS1), T-cell acute lymphocytic leukemia 1 (TAL1), and interferon regulatory factors 4 and 8 (IRF4 and IRF8) in pediatric B-cell ALL.

Methods

Blood samples of 38 ALL patients and 20 controls were obtained. DNA was treated with sodium bisulfite and DNA methylation level of HOXA4, HOXA5, MEIS1, TAL1, IRF4, and IRF8 was assessed using quantitative methylation-specific polymerase chain reaction (PCR). Relative gene expression was measured using quantitative reverse transcription-PCR.

Results

Aberrant methylation of TAL1, IRF8, MEIS1, and IRF4 was observed in 26.3%, 7.9%, 5.3%, and 2.6% patients, respectively, but not in controls. HOXA4 and HOXA5 were methylated in some controls and hypermethylated in 16% and 5% patients, respectively. IRF8, MEIS1, and TAL1 expression was lower in patients than in controls. MEIS1 expression was inversely correlated with white blood cell (WBC) count. HOXA4 expression was down-regulated in patients with high risk according to the National Cancer Institute (NCI) classification. TAL1 methylation was slightly elevated in patients aged >9 years and in patients showing relapse, suggesting its potential prognostic value.

Conclusion

Aberrant methylation and expression of the selected hematopoietic genes were correlated with demographic/clinical prognostic factors of pediatric ALL, such as age, WBC count, and NCI risk classification.

Keywords DNA methylation, Acute lymphoblastic leukemia, Gene expression, Transcription factors

Article

Original Article

Blood Res 2015; 50(1): 26-32

Published online March 31, 2015 https://doi.org/10.5045/br.2015.50.1.26

Promoter methylation and expression levels of selected hematopoietic genes in pediatric B-cell acute lymphoblastic leukemia

Ewa Musialik^1,#*, Mateusz Bujko^1,#, Paulina Kober¹, Agnieszka Wypych², Karolina Gawle-Krawczyk², Michal Matysiak², and Janusz Aleksander Siedlecki¹

¹Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Medical University of Warsaw, Warsaw, Poland.

²Department of Pediatric Haematology & Oncology, Medical University of Warsaw, Warsaw, Poland.

Correspondence to: Correspondence to Ewa Musialik, M.S. Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, W.K. Roentgena 5, 02-781 Warsaw, Poland. Tel: +48-22-546-28-98, Fax: +48-22-546-31-91, musialik.ewa@gmail.com

Received: June 13, 2014; Revised: September 28, 2014; Accepted: January 9, 2015

Abstract

Background

Methods

Results

Conclusion

Keywords: DNA methylation, Acute lymphoblastic leukemia, Gene expression, Transcription factors

Abstract

Fig 1.

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Figure 1.

Analysis of promoter methylation and expression of genes encoding hematopoietic TFs in pediatric patients with B-cell ALL. (A) Comparison of promoter methylation levels of HOXA4, HOXA5, MEIS1, IRF4, IRF8, and TAL1 in samples from patients with ALL and controls. (B) Comparison of expression levels of HOXA4, HOXA5, MEIS1, IRF4, IRF8, and TAL1 in samples from patients with ALL and control. (C) Comparison of TAL1 methylation level in patients aged 1-9 years and those aged >10 years. (D) Comparison of TAL1 methylation level in patients who experienced and did not experience relapse. (E) Comparison of HOXA4 expression level in patients with ALL showing intermediate and high risk according to NCI risk classification. (F) Correlation between MEIS1 expression level and WBC count in patients with ALL. Horizontal lines indicate median value.