Lie Wang

IL-1β-induced activation of p38 promotes metastasis in gastric adenocarcinoma via upregulation of AP-1/c-fos, MMP2 and MMP9.

BackgroundInterleukin-1β (IL-1β) has been implicated in the progression of gastric adenocarcinoma (GA); however, the molecular mechanisms of action of IL-1β in GA are poorly characterized. P38 and JNK are the major MAPK family members that regulate IL-1β signaling pathways. Here, we investigated the role of both p38 and JNK in IL-1β-induced GA cell migration, invasion and metastatic potential.MethodsThe effects of IL-1β-induced p38 and JNK activation in GA cells were determined using in vitro Transwell migration and invasion assays of MKN-45 and AGS cells, or an in vivo metastasis assay in nude mice. The IL-1β-induced p38 signaling pathway was further characterized in GA cells. Activation of the IL-1β/p38 signaling pathway was also assessed in human primary GA tissues by immunohistochemistry.ResultsIL-1β-induced activation of p38 increased GA cell migration and invasion in vitro and promoted the metastatic potential of GA cells in vivo; these effects were attenuated by p38 siRNA or the p38 inhibitor SB202190. MMP2 or MMP9 siRNAs and the MMP2/9 inhibitor BiPS also inhibited IL-1β-induced GA cell migration and invasion in vitro. IL-1β-induced p38 activation significantly increased MMP2 and MMP9 mRNA and protein expression and activity. Luciferase reporter assays demonstrated that the activator protein-1 (AP-1) and the AP-1 binding sites of the MMP9 promoter (−670/MMP9) were activated by IL-1β-induced p38 activation. Phospho-p38 was significantly upregulated in human GA tissues (compared to matched non-neoplastic tissues), and significantly associated with lymph node metastasis, and invasion beyond the serosa. Expression of phospho-p38 significantly correlated with IL-1β, MMP2, MMP9, and c-fos expression in both human GA tissues and GA cell metastases in the lungs of nude mice. IL-1β was also capable of activating JNK in GA cells, but activation of JNK was not associated with GA cell migration and invasion. Therefore, IL-1β-induced the migration and invasion in GA cells were regulated by p38, but not by JNK.ConclusionsIL-1β-induced p38 activation and the IL-1β/p38/AP-1(c-fos)/MMP2 & MMP9 pathway play an important role in metastasis in GA; this pathway may provide a novel therapeutic target for GA.

PSYCHOLOGICAL STRESS INDUCES DYSREGULATION OF IRON METABOLISM IN RAT BRAIN

Oxidative damage induced by abnormal iron accumulation in the brain is a primary cause of many neurodegenerative diseases, while the reason for iron deposition remains unclear. A previous study reported that various kinds of stress could cause a change in iron level and psychological stress (PS) was a risk factor for neuron death. In the present study we investigated the influence of PS on iron metabolism in rat brain. The results showed that both total iron and non-protein-bound-iron (NPBI) levels were higher in the cerebral cortex, hippocampus and striatum of PS rats. The levels of iron regulatory factors, including transferrin receptor 1 (TfR1), ferritin (Fn), and iron regulatory protein1 (IRP1), were all changed in the iron deposition regions of the PS-exposed rat brain, accompanied by intensified oxidative stress. It is concluded that PS can increase the intake of iron in some regions of brain and subsequently causes regional iron accumulation, indicating PS might be an important reason for iron deposition-caused neurodegenerative diseases.

Epidermal growth factor (EGF) and interleukin (IL)-1β synergistically promote ERK1/2-mediated invasive breast ductal cancer cell migration and invasion.

BackgroundPatients with invasive breast ductal carcinoma (IBDC) with metastasis have a very poor prognosis. Little is known about the synergistic action of growth and inflammatory factors in IBDC metastases.MethodsThe expression of activated extracellular signal-regulated kinase1/2 (phosphorylated or p-ERK1/2) was analyzed by immunohistochemistry in IBDC tissue samples from 80 cases. BT474 IBDC cell migration and invasion were quantified using the Transwell assay. Matrix metalloproteinase (MMP)-9 expression and activity were analyzed by RT-PCR, Western blotting and zymography. Activator protein (AP)-1 activity was measured with a luciferase reporter gene assay. The Wilcoxon signed-rank test, Chi-square test, the partition of Chi-square test, independent t-test, and Spearman’s method were used for the statistical analysis.ResultsPhosphorylated ERK1/2 was detected in 58/80 (72.5%) IBDC tissues, and was associated with higher TNM stage and lymph node metastasis, but not patient age or tumor size. Individually, epidermal growth factor (EGF), and interleukin (IL)-1β activated ERK1/2, increased cell migration and invasion, MMP-9 expression and activity, AP-1 activation in vitro and the expression of p-ERK1/2 was positively correlated with EGF expression levels, as well as IL-1β, MMP-9 and c-fos in IBDC tissue samples. Co-stimulation with EGF and IL-1β synergistically increased ERK1/2 and AP-1 activation, cell migration and invasion, and MMP-9 expression and activity. Inhibition of ERK1/2 using U0126 or siRNA abolished EGF and/or IL-1β-induced cell migration and invasion in a dose-dependent manner.ConclusionActivated ERK1/2 was associated with higher TNM stage and lymph node metastasis in IBDC. Both in vitro and in vivo studies indicated that ERK-1/2 activation may increase the metastatic ability of IBDC cells. Growth and inflammatory factors synergistically induced IBDC cell migration and invasion via ERK1/2 signaling, AP-1 activation and MMP-9 upregulation.

Circular RNAs expression profiles in human gastric cancer

Circular RNAs (circRNAs) are implicated in a variety of cancers. However, the roles of circRNAs in gastric cancer (GC) remain largely unknown. In the current study, circRNAs expression profiles were screened in GC, using 5 pairs of GC and matched non-GC tissues with circRNA chip. Preliminary results were verified with quantitative PCR (qRT-PCR). Briefly, total of 713 circRNAs were differentially expressed in GC tissues vs. non-GC tissues (fold change ≥ 2.0, p < 0.05): 191 were upregulated, whereas 522 were downregulated in GC tissues. qRT-PCR analysis of randomly selected 7 circRNAs from the 713 circRNAs in 50 paired of GC vs. non-GC control tissues confirmed the microarray data. Gene ontology (GO) and KEGG pathway analyses showed that many circRNAs are implicated in carcinogenesis. Among differentially expressed circRNAs, hsa_circ_0076304, hsa_circ_0035431, and hsa_circ_0076305 had the highest magnitude of change. These results provided a preliminary landscape of circRNAs expression profile in GC.

Additive effects of EGF and IL-1β regulate tumor cell migration and invasion in gastric adenocarcinoma via activation of ERK1/2

Growth and inflammatory factors are associated with poor prognosis in gastric adenocarcinoma (GA); however, the additive effects of growth and inflammatory factors in GA remain unclear. In this study, we investigated the ability of epidermal growth factor (EGF) and interleukin (IL-1β) to activate extracellular signal-regulated kinase (ERK)1/2 in GA cells, and correlated the relationships between their roles with the metastatic potential both in GA cells and GA tissues. The effects of EGF, IL-1β and EGF plus IL-1β in AGS and MKN-45 GA cells were examined using western blotting, Transwell migration and invasion assays, immunocytochemical staining and an activator protein (AP)-1 luciferase reporter gene assay, and was further characterized in GA tissues by immunohistochemistry. The results exhibited that EGF and IL-1β additively activated ERK1/2, increased migration and invasion than either EGF or IL-1β alone in AGS and MKN-45 cells. The mechanisms were involved in upregulating MMP-9 expression through increasing AP-1 transcriptional activity via ERK1/2 pathway; these effects were dose-dependently inhibited by silencing ERK1/2 or using U0126. In vivo data also confirmed that the overexpression of p-ERK1/2 in GA tissues correlated well with the EGF, IL-1β, EGF plus IL-1β, and was associated with metastasis, which was well correlation with the expression of MMP-9 and c-fos (AP-1). The results demonstrate that growth and inflammatory factors play an important role in metastasis of GA by additively activating ERK-1/2 and AP-1, and upregulating MMP-9. As both cytokines contribute to the migration and invasion of GA cells, EGF/IL-1β/ERK1/2 pathways may be key pathways closely associated with GA progression.

Evaluation of the expression and clinical value of lncRNA AC010761.9 in human gastric adenocarcinoma

BackgroundThe current study determined the expression and clinical value of lncRNA AC010761.9 in human gastric adenocarcinoma (GA).MethodsReal-time quantitative reverse transcription (qRT)-PCR was used to detect the level of lncRNA expression in 145 GA tissues and three GA cell lines, and the correlation between its level and clinicopathologic characteristics and potential corresponding mRNA of TNF receptor-associated factor 4 gene (TRAF4) was then evaluated.ResultsElevated lncRNA AC010761.9 was detected in all 6 GA tissues by previous lncRNA expression profile microarray assay. LncRNA AC010761.9 was over-expressed in 99 of 145 GA tissues (68.3%) with an elevated fold change of up to 35.14 compared to matched paracancerous tissues (p < 0.05), and was also over-expressed in the 3 GA cell lines (MGC803, BGC823, and SGC7901) compared to the normal gastric mucosal epithelial cell line (GES-1 cells; p < 0.05) by qRT-PCR. The elevated expression of this lncRNA was related to tumor size (p = 0.028), degree of differentiation (p = 0.047), and serum carbohydrate antigen (CA19-9) and carcinoembryonic antigen (CEA) concentrations (p = 0.026 and p = 0.037, respectively). Multivariate analysis further confirmed that the expression of lncRNA AC010761.9 was related to the degree of tumor differentiation (p = 0.015). Additionally, the expression of lncRNA AC010761.9 had a positive correlation with the mRNA expression of the potentially associated gene (TRAF4) in GA tissues (r = 0.385, p < 0.01).ConclusionsLncRNA AC010761.9 may be linked to GA progression and is a potential new biomarker for GA.