Mdig suppresses epithelial-mesenchymal transition and inhibits the invasion and metastasis of non-small cell lung cancer via regulating GSK-3β/β-catenin signaling

Abstract

Mineral dust-induced gene (mdig) can inhibit the invasion and metastasis of A549 cells. The main purpose of this study was to explore the molecular mechanism underlying the inhibitory effect of mdig on cell invasion and metastasis. Mdig-knockdown and mdig-overexpressing A549 cells and an mdig-overexpressing human umbilical vein endothelial cell (HUVEC) line were constructed using lentiviral vectors, and western blot analysis was performed to verify the silencing and overexpression of the mdig protein. A Transwell invasion assay was used to detect the invasive abilities of each experimental group, and Transwell migration and scratch assays were used to detect cell migration ability. Western blotting was subsequently conducted to detect the major biochemical indices of the GSK-3β/β-catenin pathway and the protein expression levels and modifications of epithelial‑mesenchymal transition (EMT) transcription factors, as well as changes in the expression levels of EMT molecular markers and intercellular adhesion proteins. The results indicated that overexpression of mdig in A549 cells inhibited cell invasion and metastasis, while silencing of mdig increased the invasive and metastatic properties of cells. The molecular mechanism underlying the effects of mdig downregulation on A549 cell invasion and metastasis was found to involve the inhibition of GSK-3β phosphorylation, which in turn promoted the phosphorylation and destabilization of β-catenin. This was associated with downregulation of the downstream transcription factors slug, snail and ZEB1, thus leading to increased expression levels of epithelial cell markers and upregulation of the intercellular adhesion molecules E-cadherin, claudin‑1, ZO‑1, integrin β1 and integrin β4, which was accompanied by downregulation of the mesenchymal cell markers vimentin and N-cadherin. The HUVECs were used to validate the aforementioned molecular mechanisms and the same conclusions were obtained. The present results indicate that mdig can inhibit the phosphorylation of GSK-3β and promote the phosphorylation and destabilization of β-catenin, in order to suppress the expression of slug, snail, and ZEB1 and the occurrence of EMT, and thereby inhibit the invasion and metastasis of non-small cell lung cancer (NSCLC).

The CNPY2 enhances epithelial‐mesenchymal transition via activating the AKT/GSK3β pathway in non‐small cell lung cancer

“…Much effort has been made to investigate the mechanism of EMT. Downregulation of mimeral dust‐induced gene (mdig) in NSCLC cells inhibits the phosphorylation of GSK‐3β, thus enhances level of β‐catenin phosphorylation and degradation, which inhibits EMT and cancer metastasis (Geng et al, ). Deregulation of TRIM22 can activate the PI3K/AKT/GSK3β/β‐catenin pathway and further to change the molecules expression involved in EMT in NSCLC (Liu et al, ).…”

The emerging roles of ribosomal histidyl hydroxylases in cell biology, physiology and disease

“…Perhaps consistent with the latter, overexpression of MINA suppressed the migration and invasion of A549 and H226B lung cancer cells in vitro [ 31 , 69 ]. Conversely, MINA knockdown enhanced their invasion and migration [ 31 , 69 ], and in a manner that was associated with changes in markers of epithelial–mesenchymal transition [ 70 ].…”

Fibrillin 2 gene knockdown inhibits invasion and migration of lung cancer cells

“…Epithelial-mesenchymal transformation (EMT) refers to the biological process in which epithelial cells are transformed into cells with mesenchymal phenotypes through specific procedures (12). To elucidate the molecular mechanism involved in the EMT process in malignant tumor cells, to understand its pathological significance in the occurrence and metastasis of malignant tumors, it is important to focus on key proteins of EMT and therapeutic methods targeting these key proteins (13). In this study, FBN2 knockdown with shRNA significantly downregulated the expression levels of Ncadherin and vimentin and significantly upregulated the transcription of E-cadherin.…”