[The effect of DNA hydroxymethylase Tet2 on γ globin activation in the treatment of ß-thalassemia].
Zhonghua Nei Ke Za Zhi
; 57(3): 206-211, 2018 Mar 01.
Article
in Zh
| MEDLINE
| ID: mdl-29518866
ABSTRACT
Objective:
To study the function of ten-eleven translocation 2 (Tet2) in γ globin gene expression in patients with ß- thalassemia.Methods:
Gamma globin expression was induced by 5-azacytidine and Tet2 gene expression was knocked down by short hairpin RNA (shRNA) in a human immortalized myelogenous leukemia K562 cell line. The global 5-hydroxymethylcytosine (5hmC) level was measured by an ELISA kit. 5hmC level of γ globin gene was quantified by sulfite sequencing. The mRNA level of Tet2, γ globin, and related transcription factors Nfe4 and Klf1 were quantified by real-time PCR.Results:
Tet2 knockdown resulted in a decreased global 5hmC level from 0.14% to 0.03% as of the control group in K562 cells. The expression of γ globin was enhanced after 5-azacytidine treatment in vitro. However, γ globin mRNA level in Tet2 knockdown cells was only 55% as that in control group. The CG sites on γ globin gene were unmethylated. As Tet2 was down-regulated, the expression levels of Nfe4 and Klf1 decreased by about 80% and increased to 3.5 folds, respectively.Conclusions:
Tet2 appears to maintain 5hmC level and facilitates γ globin gene activation. Moreover, Tet2 more likely regulates γ globin expression via affecting transcription factors rather than the gene itself. Thus, Tet2 could be a potential therapeutic target for ß thalassemias.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Gene Expression Regulation
/
Proto-Oncogene Proteins
/
Beta-Thalassemia
/
K562 Cells
/
DNA-Binding Proteins
/
Gamma-Globins
Limits:
Humans
Language:
Zh
Journal:
Zhonghua Nei Ke Za Zhi
Year:
2018
Document type:
Article