Effects of lentivirus-mediated shRNA targeting integrin-linked kinase on oral squamous cell carcinoma in vitro and in vivo

New Perspectives on the Role of Integrin-Linked Kinase (ILK) Signaling in Cancer Metastasis

Simple Summary

Today, the vast majority of deaths from cancer are due to cancer metastasis. Metastasis requires that cancer cells escape from the initial tumor, travel through blood vessels, and form new tumors in distant host tissues. Integrin-linked kinase (ILK) is overexpressed by many types of cancer cells and provides both structural and signaling functions that are important for successful metastasis. Here, we discuss recent findings that show how ILK is involved in promoting physical changes important for cell motility and invasion, and how ILK relays signals to other machinery components during metastasis, including interactions with components of the immune system and communication between cancer cells and normal cells, to affect the process of metastasis. We also discuss the contribution of ILK to therapeutic resistance and examine efforts to target ILK for the treatment of metastatic disease.

Abstract

Cancer metastasis is a major barrier to the long-term survival of cancer patients. In cancer cells, integrin engagement downstream of cell-extracellular matrix (ECM) interactions results in the recruitment of cytoskeletal and signaling molecules to form multi-protein complexes to promote processes critical for metastasis. One of the major functional components of these complexes is Integrin Linked Kinase (ILK). Here, we discuss recent advances in our understanding of the importance of ILK as a signaling effector in processes linked to tumor progression and metastasis. New mechanistic insights as to the role of ILK in cellular plasticity, epithelial mesenchymal transition (EMT), migration, and invasion, including the impact of ILK on the formation of invadopodia, filopodia-like protrusions (FLPs), and Neutrophil Extracellular Trap (NET)-induced motility are highlighted. Recent findings detailing the contribution of ILK to therapeutic resistance and the importance of ILK as a potentially therapeutically tractable vulnerability in both solid tumors and hematologic malignancies are discussed. Indeed, pharmacologic inhibition of ILK activity using specific small molecule inhibitors is effective in curtailing the contribution of ILK to these processes, potentially offering a novel therapeutic avenue for inhibiting critical steps in the metastatic cascade leading to reduced drug resistance and increased therapeutic efficacy.

GTW inhibits the Epithelial to Mesenchymal Transition of Epithelial Ovarian Cancer via ILK/AKT/GSK3β/Slug Signalling Pathway

Background: Epithelial ovarian cancer (EOC) accounts for the most lethal of all gynaecological cancers which is attributed to metastasis, invasiveness and drug resistance. A crucial link has been found between epithelial-mesenchymal transition (EMT) and cancer metastasis and chemo-resistance. Previous studies have confirmed that one of the main components of tripterygium glycosides (GTW)-triptolide (TPL) has anticancer effects. Methods: The purpose of this study is to determine whether GTW could inhibit EMT in A2780/DPP cells in vitro and in vivo, and explore the underlying mechanism. Results: In vitro results showed that GTW inhibited cell proliferation, invasion and migration, and intensified the sensitivity of A2780/DDP cells to cisplatin (DDP). GTW, especially GTW+DDP, significantly inhibited the expression of N-cadherin, integrin-linked kinase (ILK), phospho-protein kinase B/AKT (PKB/p-AKT), phospho-glycogen synthase kinase (p-GSK3β) and Slug, while it increased E-cadherin levels by inhibiting EMT via the ILK/AKT/GSK3β/Slug signalling pathway. Animal results indicated that GTW, especially GTW+DDP, significantly reduced tumour burden, prolonged the life span of mice, and down-regulated the levels of tumour markers CA125 and HE4 by regulating EMT through the ILK/AKT/GSK3β/Slug signalling pathway. Conclusion: Our results highlighted the significance of EMT in EOC metastasis, invasiveness and resistance to DDP and investigated the potential role of GTW as an adjuvant therapeutic agent in chemo-resistant EOC.

Monocyte Chemoattractant Protein 1 Promotes VEGF-A Expression in OSCC by Activating ILK and MEK1/2 Signaling and Downregulating miR-29c

Oral squamous cell carcinoma (OSCC) is an aggressive tumor that has a poor prognosis, with high levels of local invasion and lymph node metastasis. Vascular endothelial growth factor A (VEGF-A) plays essential roles in OSCC tumor angiogenesis and metastasis. Monocyte chemoattractant protein-1 (MCP-1, CCL2) is implicated in various inflammatory conditions and pathological processes, including oral cancer. The existing evidence has failed to confirm any correlation between MCP-1 or VEGF-A expression and OSCC angiogenesis. In this study, high expression levels of MCP-1 and VEGF-A were positively correlated with disease stage in patients with OSCC. In oral cancer cells, MCP-1 increased VEGF-A expression and subsequently promoted angiogenesis; miR-29c mimic reversed MCP-1 activity. We also found that MCP-1 modulated VEGF-A expression and angiogenesis through CCR2/ILK/MEK1/2 signaling. Ex vivo results of the chick embryo chorioallantoic membrane (CAM) assay revealed the angiogenic qualities of MCP-1, with increased numbers of visible blood vessel branches. Our data suggest that MCP-1 is a new molecular therapeutic target for the inhibition of angiogenesis and metastasis in OSCC.

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

Purpose

To explore the exact mechanism through which emodin down-regulates the migration and invasion abilities of endometrial stromal cells. Moreover, to explore the theoretical basis of emodin in the treatment of endometriosis.

Patients and Methods

Endometriosis endometrial stromal cells (EESs) were cultured from 15 women with endometriosis and control endometrial stromal cells (CESs) were cultured from 12 women without endometriosis. The levels of proteins were evaluated by Western blot. The migration and invasion abilities of cells were detected by transwell assays.

Results

The abilities of migration and invasion of EESs were much stronger than those of CESs. After treated with emodin, the migration and invasion abilities of EESs and CESs were significantly down-regulated, and the levels of integrin-linked kinase (ILK) and p-GSK-3β were statistically down-regulated in EESs. Besides that, the expression of keratin was up-regulated while the expression of vimentin, β-catenin and slug were all down-regulated by emodin in a dose- and time-dependent manner. Silencing of ILK gene in EESs also achieved the above effects, which were strengthened by emodin. Conversely, exogenous expression of ILK in CESs increased the expression of p-GSK-3β, which were abrogated by emodin. Furthermore, SB216763 increased migration and invasion abilities of CESs by facilitating the epithelial-mesenchymal transition (EMT) through up-regulating levels of p-GSK-3β, β-catenin and slug, which were also abrogated by emodin.

Conclusion

Emodin inhibits the migration and invasion abilities of human endometrial stromal cells by reversing the EMT via ILK/GSK-3β pathway. So, emodin may be considered as a promising targeted therapy for endometriosis.

Integrin-Linked Kinase Is Involved In the Proliferation and Invasion of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive type of cancer with high mortality rate in China, largely due to its high invasive and metastatic potential. The purposes of this study are to investigate the potential molecular mechanisms behind the aggressive nature of ESCC and search for new prognostic biomarkers. By employing the quantitative proteomic based strategy, we compared the proteomic profile between three ESCC samples and paired adjacent tissues. After bioinformatics analysis, four candidate proteins were validated in thirteen paired patient samples. Further validation of the key candidate, integrin-linked kinase (ILK), was carried out in one hundred patient samples. The specific inhibitor compound 22 (cpd22) was used to assess the influence of ILK to ESCC cell motility and invasiveness by applying wound-healing and transwell assay. Western blot analysis was performed to elucidate the signaling pathways involved in ILK-mediated ESCC invasion. Total 236 proteins were identified by proteomic analysis. Bioinformatics analysis suggested a key role of the collagen/integrin/ILK signaling pathway during ESCC progression. Further validation indicated that ILK is overexpressed in ESCC tissues and is correlated with poor patient prognosis. Inhibition of ILK kinase activity suppresses proliferation and blocks invasion and migration of ESCC cells. Signaling pathway analysis revealed that ILK regulates AKT phosphorylation on Ser473 but not GSK-3β on Ser9 to promote proliferation and motility of ESCC cells. In conclusion, our results indicated that ILK may play a crucial role in ESCC invasion and metastasis and may serve as a prognostic biomarker and therapeutic target for ESCC.

MicroRNA-542-3p inhibits oral squamous cell carcinoma progression by inhibiting ILK/TGF-β1/Smad2/3 signaling

In this study, we investigated the effects of microRNA-542-3p (miR-542-3p) on ILK/TGF-β1/Smad2/3 signaling and oral squamous cell carcinoma (OSCC) progression. Levels of miR-542-3p were lower in OSCC tissues (n=108) than adjacent normal tissues, whereas levels of ILK, TGF-β1 and Smad2/3 were higher. Patients with undifferentiated tumors, advanced TNM stage and lymph node metastasis showed low miR-542-3p levels. This was accompanied by high ILK expression and poor survival. Dual luciferase reporter assays of SCC-9 cells showed that miR-542-3p inhibited ILK gene expression by binding to its 3’UTR at 233-240 bp. SCC-9 cells transfected with miR-542-3p mimics exhibited elevated miR-542-3p and decreased ILK, TGF-β1 and Smad2/3 expression. They also showed reduced self-renewal (fewer CD44⁺ cells and tumor-spheres), invasiveness, migration, proliferation and survival. Conversely, miR-542-3p inhibitors promoted increased self-renewal (more CD44⁺ cells and tumor-spheres), invasiveness, migration, proliferation and survival. In xenograft experiments with nude mice, SCC-9 cells transfected with miR-542-3p mimics or siRNA-ILK yielded tumors with smaller volumes and weights than control tumors. These results demonstrate that miR-542-3p is a tumor suppressor that inhibits ILK/TGF-β1/Smad2/3 signaling, thereby inhibiting OSCC progression.

Emodin suppresses proliferation, migration and invasion in ovarian cancer cells by down regulating ILK in vitro and in vivo

OBJECTIVE

Although our previous studies have confirmed that 1, 3, 8-trihydroxy-6-methylant hraquinone (emodin) inhibits migration and invasion in epithelial ovarian cancer (EOC) cells, the underlying molecular mechanism remains unknown. Here, the aim was to investigate the effects of emodin on EOC cells and to study further the mechanism underlying this process, both in vitro and in vivo.

MATERIALS AND METHODS

Cell proliferation was evaluated by the methylthiazolyl tetrazolium assay. Cell migration and invasion abilities were tested using the transwell assay. The expression of integrin-linked kinase (ILK) and epithelial-mesenchymal transition (EMT)-associated factors were measured with western blotting.

RESULTS

Exogenous ILK enhanced the proliferation, migration and invasion properties of A2780 and SK-OV-3 cells. After treatment with emodin, the survival rate of cells was gradually reduced, including those of SK-OV-3/pLVX-ILK and A2780/pLVX-ILK cells, with increasing emodin concentrations. The migration and invasion abilities of A2780 and SK-OV-3 cells were effectively increased by the transfection of pLVX-ILK, which could be abrogated by following this with 48 hours of emodin treatment. Treatment with emodin significantly downregulated the expression of ILK and EMT-related proteins. So, emodin suppressed proliferation, migration and invasion in ovarian cancer cells by downregulating ILK in vitro. SK-OV-3/pLVX-Con and SK-OV-3/pLVX-ILK cells were used to generate xenografts in nude mice. Tumors grew more rapidly in the SK-OV-3/pLVX-ILK group compared with the control group, and this could be significantly inhibited by emodin. Also, the expression of E-cadherin was downregulated, while the expression of Slug, MMP-9 and Vimentin were upregulated in the SK-OV-3/pLVX-ILK group, and this could be reversed by following treatment with emodin. Emodin did not demonstrate target toxicity on hepatocytes, nephrocytes and cardiomyocytes.

CONCLUSION

Emodin suppresses proliferation, migration and invasion in ovarian cancer by targeting ILK.

Genome wide profiling in oral squamous cell carcinoma identifies a four genetic marker signature of prognostic significance

BACKGROUND

Cancers of the oral cavity are primarily oral squamous cell carcinomas (OSCCs). Many of the OSCCs present at late stages with an exceptionally poor prognosis. A probable limitation in management of patients with OSCC lies in the insufficient knowledge pertaining to the linkage between copy number alterations in OSCC and oral tumourigenesis thereby resulting in an inability to deliver targeted therapy.

OBJECTIVES

The current study aimed to identify copy number alterations (CNAs) in OSCC using array comparative genomic hybridization (array CGH) and to correlate the CNAs with clinico-pathologic parameters and clinical outcomes.

MATERIALS AND METHODS

Using array CGH, genome-wide profiling was performed on 75 OSCCs. Selected genes that were harboured in the frequently amplified and deleted regions were validated using quantitative polymerase chain reaction (qPCR). Thereafter, pathway and network functional analysis were carried out using Ingenuity Pathway Analysis (IPA) software.

RESULTS

Multiple chromosomal regions including 3q, 5p, 7p, 8q, 9p, 10p, 11q were frequently amplified, while 3p and 8p chromosomal regions were frequently deleted. These findings were in confirmation with our previous study using ultra-dense array CGH. In addition, amplification of 8q, 11q, 7p and 9p and deletion of 8p chromosomal regions showed a significant correlation with clinico-pathologic parameters such as the size of the tumour, metastatic lymph nodes and pathological staging. Co-amplification of 7p, 8q, 9p and 11q regions that harbored amplified genes namely CCND1, EGFR, TPM2 and LRP12 respectively, when combined, continues to be an independent prognostic factor in OSCC.

CONCLUSION

Amplification of 3q, 5p, 7p, 8q, 9p, 10p, 11q and deletion of 3p and 8p chromosomal regions were recurrent among OSCC patients. Co-alteration of 7p, 8q, 9p and 11q was found to be associated with clinico-pathologic parameters and poor survival. These regions contain genes that play critical roles in tumourigenesis pathways.

Emodin Inhibits the Epithelial to Mesenchymal Transition of Epithelial Ovarian Cancer Cells via ILK/GSK-3β/Slug Signaling Pathway

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. Despite the anticancer capabilities of emodin observed in many cancers, including EOC, the underlying molecular mechanism remains to be elucidated. A crucial link has been discovered between the acquisition of metastatic traits and the epithelial-mesenchymal transition (EMT). The present study aimed to determine whether emodin could inhibit the EMT of EOC cells and explore the underlying mechanism. The CCK-8 assay and transwell assay showed that emodin effectively repressed the abilities of proliferation, invasion, and migration in A2780 and SK-OV-3 cells. The Western blot showed that emodin upregulated epithelial markers (E-cadherin and Claudin) while it downregulated mesenchymal markers (N-cadherin and Vimentin) and transcription factor (Slug) in a dose-dependent fashion. After transfection of siRNA-Slug, both Slug and N-cadherin were downregulated in EOC cells while E-cadherin was upregulated, which was intensified by emodin. Besides, emodin decreased the expression of ILK, p-GSK-3β, β-catenin, and Slug. Transfection of siRNA-ILK also achieved the same effects, which was further strengthened by following emodin treatment. Nevertheless, SB216763, an inhibitor of GSK-3β, could reverse the effects of emodin except for ILK expression. These findings suggest that emodin inhibited the EMT of EOC cells via ILK/GSK-3β/Slug signaling pathway.