Involvement of DNMT 3B promotes epithelial-mesenchymal transition and gene expression profile of invasive head and neck squamous cell carcinomas cell lines

Abstract

BackgroundThe 5-year overall survival rates for head and neck cancer (HNC) relies on distant metastasis. Importantly, the epithelial-mesenchymal transition (EMT) is believed to be an initial step of metastasis. However, the relationship of epigenetic with EMT formation is still unexplored in HNC. This study focuses on invasive subclones of HNC cell lines through the simulation of invasion in vitro; and underlying mechanisms were analyzed including DNA methylation and gene expression profile.MethodsInvasive subclones of NHC cell lines were successfully obtained using transwell coated with Matrixgel. Cells invaded through 8 μm pore several times were subcultured and examined with EMT features including morphology, EMT marker genes expression, and invasive ability. Moreover, compared the profile of genes expression in parental and invasive cells was analyzed using mRNA expression array.ResultsDNA methyltransferase 3B (DNMT 3B) was upregulated in invasive subclones and might control the 5′ region of E-cadherin (E-cad) methylation and further inhibited E-cad protein expression. Interference of DNMT 3B by siRNA or miRNA 29b could reduce EMT and cell invasion. Expression array analysis revealed the most possible involved pathways in cell invasion including arginine and proline metabolism, TGF-beta, and focal adhesion.ConclusionsDNMT 3B might control EMT by DNA methylation manner in invasive HNC cell lines. Moreover, miR-29b mimic downregulated DNMT 3B and inhibited EMT and cell invasion indicated the role of therapeutic agent for invasive HNC. Genes identified from array data and new molecules are involved in metastasis of HNC need further validation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2468-x) contains supplementary material, which is available to authorized users.

E-cadherin, Snail, ZEB-1, DNMT1, DNMT3A and DNMT3B expression in normal and breast cancer tissues*

“…Nevertheless, Tang and others (Tang et al, 2014) had shown that the mechanism which contributes to breast cancer may be the effect of miR-185 on E2F6, DNMT1 and BRCA1. Moreover, DNMT3B and DNMT3B can reduce the level of E-cadherin expression (Chen et al, 2016).…”

Epigenetic Modification of CFTR in Head and Neck Cancer

“…These previous studies on CFTR in other cancers, lead to a hypothesis that CFTR might be deeply related to metastasis, poor prognosis, or even poor survival rates. Five-year survival rates for HNC patients with metastasis are extremely low, at about 10%, while rates for other HNC patients are about 50% [62]. The addressing of these challenges by early diagnosis of HNC and the definition of HNC metastasis indicators is urgently required.…”

Epithelial‐mesenchymal transition and microRNAs: Challenges and future perspectives in oral cancer

“…The miRNA‐29b may also controls tumor microenvironment by targeting prometastatic regulators, which are involved in angiogenesis, collagen remodeling, and proteolysis. Moreover, it is also recently reported that the use of miRNA‐29b mimic in HNSCC/OSCC cell lines downregulates DNA methyltransferase 3 beta and inhibits epithelial‐mesenchymal transition and cell invasion …”

“…Accumulating evidence suggests a critical role of miRNAs in the regulation of epithelial‐mesenchymal transition and epithelial‐mesenchymal transition‐related malignant phenotypes in OSCC . The most relevant altered miRNAs in OSCC that are related to epithelial‐mesenchymal transition are summarized in Table …”

“…In general, cells proceeding epithelial‐mesenchymal transition exhibit downregulation of many epithelial markers including E‐cadherin, occludin, claudin, cytokeratin, and catenin proteins and upregulation of mesenchymal markers including N‐cadherin, vimentin, laminin‐β1 and collagen type VI‐α, as well as matrix metalloproteinases (MMPs) …”