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2909 DNA Methylation-Mediated Silencing of Mir-204 Enhances the Occurrence of T-Cell Acute Lymphoblastic Leukemia By Upregulating MMP-2 and MMP-9 through the NF-Κb Signaling Pathway

Program: Oral and Poster Abstracts
Session: 618. Acute Lymphoblastic Leukemia: Biology, Cytogenetics, and Molecular Markers in Diagnosis and Prognosis: Poster III
Hematology Disease Topics & Pathways:
Leukemia, ALL, Diseases, Lymphoid Malignancies
Monday, December 7, 2020, 7:00 AM-3:30 PM

Dabing Chen1*, Tingting Xiao1*, Dandan Lin1*, Haojie Zhu1*, Jingjing Xu1*, Xiaofeng Luo1*, Jinhua Ren1*, Zhihong Zheng1*, Zhizhe Chen1*, Jianda Hu, MD, PhD1 and Ting Yang, MD, PhD2

1Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory of Hematology, Fujian Medical University Union Hospital, Fuzhou, China
2Department of Hematology, Fujian Medical University Union Hospital,Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fuzhou, China

Background: MicroRNAs (miR) are non-coding RNAs that play a role in regulation multiple functions in different cell types. Previous studies have shown that miR-204 is downregulated in T-ALL. We previously reported that matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) gene polymorphisms may be associated with the risk of T-cell acute lymphoblastic leukemia (T-ALL). The present study aims to decipher the role of miR-204 and MMP-2/MMP-9 in T-ALL occurrence to guide the diagnosis and treatment of T-ALL in the clinics.

Methods: Expression of miR-204 was determined in the bone marrow and peripheral blood samples from 70 T-ALL patients and 70 healthy volunteers by real-time quantitative PCR (RT-qPCR). Bisulfite sequencing PCR (BSP) was used to detect the DNA methylation levels of the miR-204 promoter region in T-ALL patients and T-ALL cell lines.The effect of miR-204 on cell proliferation was evaluated with the cell counting kit-8 solution (CCK-8) assay and by Hoechst and PI double staining. The binding site of miR-204 on IRAK1 was predicted by the Primer Premier 5.0 and the defined binding sequences were used to construct luciferase-tag plasmids. The regulation of IRAK1 expression by miR-204 was evaluated by RT-qPCR and Western blot analysis. With the purpose to confirm the role of MMP-2 and MMP-9 in the occurrence of T-ALL, we investigated the effect of related proteins on T-ALL cells using Western blot. To determine that miR-204 affects the occurrence of T-ALL disease by regulating the NF-KB signaling pathway, RT-qPCR and Western Blot were used for verification.

Results: DNA methylation directly affects the miR-204 expression in the promoter region when T-ALL developed. Moreover, overexpression of miR-204 inhibited the proliferation and enhanced the apoptosis of T-ALL cells. Notably, overexpression of miR-204 inhibited IRAK1, which in turn inhibited the proliferation and enhanced the apoptosis of T-ALL cells. Furthermore, IRAK1 enhanced the expression of MMP-2 and MMP-9 through phosphorylation of of p65 NF-κB, and miR-204 modulated MMP-2 and MMP-9 expression through the IRAK1/NF-κB signaling pathway.

Conclusions: Our results demonstrate that in T-ALL cells, DNA methylation-mediated silencing of miR-204 regulates the expression of MMP-2 and MMP-9 through increased transcription of IRAK1, and activation of the NF-κB signaling pathway. These data provide a potential mechanism for the role of MMP-2 and MMP-9 in the occurrence of T-ALL. Further studies will be needed to demonstrate whether demethylation of miR-204 may be a promising treatment for T-ALL.

Disclosures: No relevant conflicts of interest to declare.

*signifies non-member of ASH