Small interfering RNA targeting ILK inhibits EMT in human peritoneal mesothelial cells through phosphorylation of GSK-3β

Abstract

Emerging evidence has suggested that human peritoneal mesothelial cells (HPMCs) undergo epithelial‑mesenchymal transition (EMT) in peritoneal fibrosis. The molecular mechanisms underlying peritoneal fibrosis and the key molecules involved are not yet fully elucidated. In order to enhance the understanding of peritoneal fibrosis, the present study investigated the roles of integrin‑linked kinase (ILK) and glycogen synthase kinase 3β (GSK‑3β) in high glucose‑induced phenotypic alterations of HPMCs. It was observed that HPMCs exhibited a cobblestone morphology under normal glucose conditions, whereas under high glucose conditions they had a spindle morphology. Additionally, under high glucose conditions it was found that E‑cadherin expression was decreased and vimentin expression was increased in HPMCs, suggesting HPMCs underwent EMT. ILK expression in high glucose conditions was also increased in a dose‑ and time‑dependent manner. The role of ILK in the induction of EMT in HPMCs was further investigated using small interfering RNA (siRNA). Following knockdown of ILK gene expression by siRNA, low vimentin expression as well as high E‑cadherin expression were observed, suggesting that EMT was inhibited. ILK‑knockdown also inhibited phosphorylation of GSK‑3β. These results indicate that ILK‑knockdown inhibits EMT of HPMCs through inhibition of GSK‑3β phosphorylation. These findings suggest that ILK may be used as a novel diagnostic and therapeutic target for HPMC fibrosis in the future.

<p>Emodin Reverses the Epithelial–Mesenchymal Transition of Human Endometrial Stromal Cells by Inhibiting ILK/GSK-3β Pathway</p>

“…30 Additionally, knockout of ILK decreased the invasion and metastasis abilities of cells through inhibiting the EMT process. 31 , 32 Considering the crucial roles of EMT in modulating cell migration and invasion, ILK may be a promising treatment target for various diseases. Tang et al discovered that emodin inhibited the expression of ILK through the crosstalk of AMPKα and ERK1/2 signaling.…”

“… 37 Knockout of the ILK gene inhibited the EMT program in human peritoneal mesothelial cells through phosphorylation of GSK-3β. 32 Moreover, inhibition of GSK-3β is crucial for EGF-induced EMT in human prostate and lung cancer. 38 Previous studies indicated that GSK-3β played a crucial role in controlling the expression of β-catenin in the cytoplasm.…”

Integrin-linked kinase regulates cadherin switch in bladder cancer

“…Akt phosphorylates GSK-3β at Ser 9, leading to inactivation of its kinase activity, and ILK can phosphorylate GSK-3β at Ser 9 in Akt-independent way [23]. Luo et al [24] demonstrated that ILK knockdown inhibits EMT through inhibition of GSK-3β phosphorylation at Ser 9. On the other hand, actions which promote cell death, such as growth factor removal, stimulate kinase activity by increasign phosphorylation within the catalytic domain at Tyr 216.…”

Knockdown of ILK inhibits glioma development via upregulation of E-cadherin and downregulation of cyclin D1

“…ILK is widely expressed in several types of human cancers including glioma and has been positively correlated with tumor growth and closely related to tumor apoptosis, proliferation, invasion and migration (13,14). ILK is a ubiquitously expressed serine/threonine protein kinase that binds directly to the cytoplasmic domains of β1 and β3 integrins and has been shown to have clinical/prognostic and functional significance in various human cancers.…”