Open AccessHORMAD 2 methylation‐mediated epigenetic regulation of gene expression in thyroid cancer
Author(s) -
Lin Qiuyu,
Hou Sen,
Guan Feng,
Lin Chenghe
Publication year - 2018
Publication title -
journal of cellular and molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.44
H-Index - 130
eISSN - 1582-4934
pISSN - 1582-1838
DOI - 10.1111/jcmm.13680
Subject(s) - dna methylation , methylation , viability assay , cancer research , biology , epigenetics , cell growth , microbiology and biotechnology , cell cycle , thyroid cancer , cpg site , flow cytometry , apoptosis , gene expression , cancer , gene , genetics
This study is aimed to investigate the methylation level of candidate genes and its impact on thyroid carcinoma ( THCA ) development. Infinium Human Methylation 450 BeadChip Arrays by Illumina (Illumina HM 450K) was the most popular CpG microarray platform widely used in biological and medical research. The methylation level of differentially expressed genes and their corresponding CpG sites were analysed by R programme. The expression of HORMAD 2 was evaluated by qRT ‐ PCR and Western blot, while the methylation level was examined via methylation‐specific PCR . Cell viability, metastasis, cell cycle and apoptosis were detected by MTT assay, transwell and wound healing assay and flow cytometry, respectively, after treatment with 5‐aza‐2′‐deoxycytidine (5‐Aza). Tumour formation assay was used to analyse thyroid tumour growth in nude mice in vivo. The methylation levels of all 116 differentially expressed genes were analysed. HORMAD 2 was significantly hypermethylated and its mRNA expression was inhibited in THCA cells. After treatment with 5‐Aza, HORMAD 2 expression was up‐regulated in THCA cells and its overexpression can suppress thyroid cancer cell viability, mobility and invasiveness remarkably. Up‐regulation of HORMAD 2 in THCA cells could prolong G0/G1 phase and shorten S phase to impede cell mitosis as well as promote thyroid cancer cells apoptosis. Furthermore, tumour formation assay showed that increased HORMAD 2 level impeded tumour growth in vivo. Hypermethylation of HORMAD 2 could induce THCA progression, while hypomethylation of HORMAD 2 retard cell growth and mobility and facilitate apoptosis through increasing its mRNA expression.