CDH17 alters MMP-2 expression via canonical NF-κB signalling in human gastric cancer

Identifying natural products for gastric cancer treatment through pharmacophore creation, 3D QSAR, virtual screening, and molecular dynamics studies

BACKGROUND

Gastric cancer (GC) is known as the fourth leading cause of cancer-related death and the fifth major cancer in the world, and this is a serious threat to general health all over the world. The lack of early detection markers results in a belated diagnosis, i.e. the final stages, which could be associated with the ineffectiveness of the treatment strategies, and naturally, it leads to poor prognosis. Even though a variety of treatments have been developed, there is a trend of studying traditional medicinal plants, due to the worrying side effect of drugs available in the market.

METHODS

In this study, pharmacophore generation and 3D-QSAR model were created using 50 compounds with anti-gastric cancer activity (with IC50 had been reported in the previous studies).

RESULTS

Based on three of the best pharmacophoric hypotheses, virtual screening was performed to discover the top anti-gastric cancer compounds from a database of 183,885 compounds. The selected compounds were used for molecular docking with three protein receptors 7BKG, 4F5B, and 4ZT1 to investigate the intermolecular interactions between these ligands and receptors. Finally, 21 lead compounds with the highest amount of docking score ranging from - 13.366 to -6.404 kcal/mol were selected, and then the ADME/Tox properties of these compounds were calculated. All these compounds have a fitness score above 1.8, a molecular weight of less than 500 g/mol, hydrogen bond donors up to 3, hydrogen bond acceptors up to 8.50, and logP of 1.013 to 4.174. Finally, molecular dynamic simulations for top-scoring ligand-receptor complexes were investigated.

CONCLUSION

These selected lead compounds have the most anti-gastric cancer effects among the 183,885 compounds in the database. Therefore, lead compounds might be considered for gastric cancer therapy in future studies.

Integrated transcriptomics and proteomics data analysis identifies CDH17 as a key cell surface target in colorectal cancer

Immunotherapy development against colorectal cancer (CRC) is hindered by the lack of cell surface target highly expressed in cancer cells but with restricted presence in normal tissues to minimize off-tumor toxicities. In this in silico analysis, a longlist of genes (n = 13,488) expressed in CRCs according to the Human Protein Atlas (HPA) database were evaluated to shortlist for potential surface targets based on the following prerequisites: (i) Absent from the brain and lung tissues to minimize the likelihood of neurologic and pulmonary toxicities; (ii) Restricted expression profile in other normal human tissues; (iii) Genes that potentially encode cell surface proteins and; (iv) At least moderately expressed in CRC cases. Fifteen potential targets were shortlisted and subsequently ranked according to the combination of their transcript and protein expression levels in CRCs derived from multiple datasets (i.e. DepMap, TCGA, CPTAC-2, and HPA CRCs). The top-ranked target with the highest and homogenous expression in CRCs was cadherin 17 (CDH17). Downstream analysis of CRC transcriptomics and proteomics datasets showed that CDH17 was significantly correlated with carcinoembryonic antigen expression. Moreover, CDH17 expression was significantly lower in CRC cases with high microsatellite instability, as well as negatively associated with immune response gene sets and the expression of MHC class I and II molecules. CDH17 represents an optimal target for therapeutic development against CRCs, and this study provides a novel framework to identify key cell surface targets for therapeutic development against other malignancies.

IQGAP1 enhances cell invasion and matrix metalloproteinase-2 expression through upregulating NF-κB activity in esophageal squamous cell carcinoma cells

Esophageal squamous cell carcinoma (ESCC) is one type of the most common malignancies, yet the overall survival rate is still not ideal. IQ motif containing GTPase activating protein 1 (IQGAP1) participates in cell biological functions of various tumors as an oncogene. However, the mechanisms of IQGAP1 affecting malignant development of ESCC are still unclear. In this study, the expression and correlation of IQGAP1 and MMP2 in esophageal cancer tissues were evaluated by online databases and immunohistochemistry. Stably transfected cell lines with IQGAP1 overexpression and knockdown were constructed. Cell growth, migration and invasion ability, the expression of MMP2 and NF-κB expression were examined in ESCC cells. Furthermore, the cellular malignant phenotypes of ESCC and MMP2 expression in IQGAP1 overexpressing cells after treatment with the NF-κB inhibitor pyrrolidinecarbodithioic acid (PDTC) or JSH-23 were detected. We found that the expression of IQGAP1 and MMP2 were up-regulated and positively correlated in ESCC tissues. IQGAP1 overexpression promoted the growth, migration and invasion of ESCC cells, and up-regulated the expression of MMP2, and increased the expression and the nuclear localization level of NF-κB. Treating with PDTC or JSH-23 reversed IQGAP1-mediated cell migration and invasion ability, as well as the expression of MMP2. In summary, IQGAP1 plays a tumor promotion role to regulate the migration and invasion of ESCC cells and the expression of MMP2 through upregulating NF-κB activity, supporting a promising therapeutic target against ESCC.

Expression Profile and Prognostic Values of CDH Family Members in Lung Adenocarcinoma

Many studies have confirmed that the classical cadherin (CDH) gene family may be involved in the development and progression of various tumors. However, the comprehensive assays of CDH family members in lung adenocarcinoma (LUAD) were rarely reported. In this study, our group analyzed TCGA datasets and identified 18 dysregulated CDH members in LUAD specimens. Several CDH members exhibited an increased level in LUAD specimens, such as CDH1, CDH2, CDH3, CDH4, CDH5, CDH15, CDH16, CDH17, CDH18, CDH24, and CDH26. However, some others exhibited decreased levels in LUAD specimens. Correlation analysis revealed that most CDH members were negatively regulated by the methylation of CDH genes, leading to their low expression in LUAD tissues. Survival assays identified 16 survival-related CDH members in LUAD patients. More importantly, we further performed multivariate analysis to determine the prognostic value of the above CDH family members and found that the expression levels of CDH17, CDH19, and CDH24 were an independent prognostic biomarker of the LUAD outcome. Finally, the results of functional enrichments revealed that CDH members participated in several tumor-related pathways. Collectively, our findings suggest that CDH Family members functioned as oncogenes or antioncogenes in LUAD and may be a potential biomarker for this malignancy.

Dihydroartemisinin suppresses proliferation, migration, the Wnt/β-catenin pathway and EMT via TNKS in gastric cancer

Gastric cancer is a common malignancy worldwide. However, the molecular mechanisms underlying this malignancy remain unclear and there are a lack of effective drugs. The present study aimed to investigate the antitumor effect of Dihydroartemisinin (DHA) or inhibition of Tankyrases (TNKS), and determine the underlying molecular mechanisms of gastric cancer. Immunohistochemistry and immunofluorescence analyses were performed to detect the expression levels of TNKS, epithelial-to-mesenchymal transition (EMT) and Wnt/β-catenin pathway-related proteins in gastric cancer tissues and adjacent normal tissues. The Cell Counting Kit-8 assay was performed to assess the viability of HGC-27 and AGS cells following treatment with different concentrations of HLY78 (a Wnt activator) or DHA. Following treatment with HLY78, DHA or small interfering (si)-TNKS1/si-TNKS2, colony formation and migratory abilities were assessed via the colony formation, wound healing and Transwell assays. Furthermore, western blot and immunofluorescence analyses were performed to detect the expression levels of TNKS, EMT- and Wnt/β-catenin-related proteins. The results demonstrated that the expression levels of TNKS, AXI2, β-catenin, N-cadherin and Vimentin were upregulated, whereas E-cadherin expression was downregulated in gastric cancer tissues compared with normal tissues. Furthermore, HLY78 and DHA suppressed the viability of HGC-27 and AGS cells, in a concentration-independent manner. Notably, TNKS knockdown or treatment with DHA suppressed colony formation, migration, TNKS expression, EMT and the Wnt/β-catenin pathway. Opposing effects were observed following treatment with HLY78, which were ameliorated following co-treatment with DHA. Taken together, these results suggest that DHA or inhibition of TNKS can suppress the proliferation and migration of gastric cancer cells, which is partly associated with inactivation of the Wnt/β-catenin pathway and EMT process.

cIAP2 via NF-κB signalling affects cell proliferation and invasion in hepatocellular carcinoma

AIMS

To investigate the role of cIAP2 in the malignant biological behaviours of hepatocellular carcinoma (HCC) cells and determine its mechanism of action.

MAIN METHODS

cIAP2 protein expression was detected via immunohistochemistry (IHC) in 102 HCC specimens and 43 paracancerous liver tissues, and its relationship with clinicopathological features and patient prognosis was analysed. Then, short interfering RNA (siRNA) technology was used to knock down cIAP2 expression in BEL7402 and HepG2 cells. Cell Counting Kit-8 (CCK8) and Transwell assays were used to determine cell proliferation and invasion after knockdown of cIAP2 expression. The relationship between cIAP2 and the NF-κB pathway was explored via western blotting (WB) and a dual luciferase reporter system. Finally, nude mouse models of liver cancer were established to detect the effect of cIAP2 on tumourigenicity and the proliferation activity of orthotopic HCC cells.

KEY FINDINGS

cIAP2 expression was significantly increased in HCC tissues and was correlated with intravascular thrombosis in HCC. High cIAP2 expression was correlated with poor patient prognosis. cIAP2 knockdown significantly reduced the proliferation and invasion of BEL7402 and HepG2 cells and the activity of the NF-κB pathway. Animal experiments showed that cIAP2 knockdown reduced the tumourigenicity of HepG2 cells in the liver of nude mice and the proliferation activity of the orthotopic HCC cells.

SIGNIFICANCE

cIAP2 plays an important role in HCC proliferation and invasion and may exert its effects via the NF-κB signalling pathway.

Upregulation of miRNA‑301a‑3p promotes tumor progression in gastric cancer by suppressing NKRF and activating NF‑κB signaling

MicroRNA‑301a (miRNA/miR‑301a) and nuclear factor (NF)‑κB signaling play important roles in tumor invasion, migration and progression. However, the role of miRNA‑301a‑3p in human gastric cancer (GC), and specifically in the activation of NF‑κB signaling, remains unclear. The aim of the present study was to investigate miRNA‑301a‑3p expression in GC progression and the molecular mechanisms as regards the regulation of NF‑κB signaling. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect miRNA‑301a‑3p expression in GC and paired normal tissues. The association between the expression of miRNA‑301a‑3p and patient pathological parameters and the prognosis of GC was statistically analyzed using an in situ hybridization (ISH) assay. An MTS assay and a Transwell assay were performed to evaluate the effects of miRNA‑301a‑3p on the proliferation, invasion and migration of GC cells. RT‑qPCR and western blot analysis were used to analyze the association between miRNA‑301a‑3p and nuclear factor‑κB repressing factor (NKRF) expression and the corresponding downstream NF‑κB signaling molecules. A luciferase assay was used to verify the target effect of miRNA‑301a‑3p and NKRF. It was found that miRNA‑301a‑3p expression was significantly higher in 30 cases of primary GC compared with matched normal tissues. Additionally, the ISH assay indicated that the high expression of miRNA‑301a‑3p in GC was associated with tumor invasion depth, lymph node metastasis, lymph node invasion and tumor metastasis stage. Patients whose tumors had a higher miRNA‑301a‑3p expression level exhibited a poorer prognosis. The in vitro assay indicated that miRNA‑301a‑3p affected the proliferative and invasive ability of GC cells by targeting the expression of NKRF, which then affected NF‑κB signaling. Therefore, it was hypothesize that miRNA‑301a‑3p promotes GC progression and affects the prognosis of patients with GC by targeting NKRF, which in turn, directly influences NF‑κB activation.

Beyond N-Cadherin, Relevance of Cadherins 5, 6 and 17 in Cancer Progression and Metastasis

Cell-cell adhesion molecules (cadherins) and cell-extracellular matrix adhesion proteins (integrins) play a critical role in the regulation of cancer invasion and metastasis. Although significant progress has been made in the characterization of multiple members of the cadherin superfamily, most of the published work continues to focus in the switch E-/N-cadherin and its role in the epithelial-mesenchymal transition. Here, we will discuss the structural and functional properties of a subset of cadherins (cadherin 17, cadherin 5 and cadherin 6) that have an RGD motif in the extracellular domains. This RGD motif is critical for the interaction with α2β1 integrin and posterior integrin pathway activation in cancer metastatic cells. However, other signaling pathways seem to be affected by RGD cadherin interactions, as will be discussed. The range of solid tumors with overexpression or "de novo" expression of one or more of these three cadherins is very wide (gastrointestinal, gynaecological and melanoma, among others), underscoring the relevance of these cadherins in cancer metastasis. Finally, we will discuss different evidences that support the therapeutic use of these cadherins by blocking their capacity to work as integrin ligands in order to develop new cures for metastatic patients.

LncRNA MAFG-AS1 facilitates the migration and invasion of NSCLC cell via sponging miR-339-5p from MMP15

Non-small-cell carcinoma (NSCLC) is the most common cancer along with high mortality rate worldwide. In the present study, our data showed that lncRNA MAF BZIP Transcription Factor G Antisense RNA 1 (MAFG-AS1) was over-expressed in NSCLC tissues and cell lines. Overexpression of MAFG-AS1 promoted the migration, invasion and enhanced epithelial-mesenchymal transition (EMT) of NSCLC cell. In addition, miR-339-5p was predicted to be a target of MAFG-AS1 and the level of miR-339-5p was down-regulated in NSCLC. Over-expression of MAFG-AS1 significantly decreased the level of miR-339-5p in NSCLC cell. Moreover, the matrix metalloproteinase 15 (MMP15) was identified to be a target of miR-339-5p. The level of MMP15 was negatively regulated by miR-339-5p whereas positively controlled by MAFG-AS1. In addition, up-regulation of miR-339-5p neutralized the promoting impact of MAFG-AS1 on the migration, invasion and EMT of NSCLC cell. Finally, the xenograft model suggested that MAFG-AS1 promoted the metastasis of NSCLC cell in vivo. Altogether, we proved that MAFG-AS1-miR-339-5p-MMP15 axis might be a promising therapeutic target for the treatment of patients with NSCLC.