Integrin β4 (ITGB4) has been reported to be involved in carcinomas. Currently, ITGB4 has been characterized in colon cancer, however, its clinical significance is not very clear. In the present study, we utilized the large public datasets from NCBI Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases and collected clinical samples in our center to investigate the transcriptional expressions of ITGB4 in colon cancer, and then explored the associations of ITGB4 with clinicopathological features and overall survival. The statistical analyses suggested that ITGB4 mRNA expressions were up-regulated significantly in colon cancer. High ITGB4 expression was observed to be associated with elder onset age, proximal tumor location, and high microsatellite instability (MSH) status. Further, Kaplan-Meier curves and univariate analysis demonstrated high ITGB4 expression was significantly associated with unfavorable overall survival in colon cancer (HR=1.292, 95%CI=1.084-1.540, P=0.004). And significant association was also found after adjusting the confounding factors including age, gender, and stage (adjusted HR=1.254, 95%CI=1.050-1.497, P=0.012). The annotation of ITGB4 co-expressed genes suggested the pathways including cell growth, positive regulation of cell migration, and apoptotic signaling might be involved in the potential mechanisms of ITGB4 in colon cancer development. The molecular regulation mechanism of ITGB4 ectopic expression in colon cancer was also explored and the results indicated that ITGB4 might be up-regulated by the transcription factor FOSL1 (FOS like 1, AP-1 Transcription Factor Subunit) and its promoter hypomethylation. Our results revealed that ITGB4 might be a therapeutic target and prognosis marker for individual therapy of colon cancer.
Objective
Intima formation involves smooth muscle cell (SMC) proliferation and migration that ultimately drives arterial stenosis, thrombosis, and ischemia in atherosclerosis, hypertension, and arterial revascularization. Receptor for advanced glycation endproducts (RAGE) is a transmembrane signaling receptor implicated in diabetic renal and vascular complications, and post-injury intima formation, partly via Signal transducer and activator of transcription 3 (STAT3) activation. The metabolic super-regulator Adenosine monophosphate kinase (AMPK) inhibits SMC proliferation and intima formation. AMPK activation is promoted by liver kinase B1 (LKB1), and LKB1 inhibits STAT3 activation. Here, we tested the hypothesis that RAGE promotes arterial intima formation by modulating both LKB1 and AMPK.
Methods and Results
RAGE ligands (the calgranulin S100A11, and glycated albumin) suppressed AMPK activation in conjunction with increased proliferation and migration of cultured SMCs. These effects were inhibited both by RAGE deficiency and by prior AMPK activation. In SMCs, RAGE ligands decreased LKB1 activity. Moreover, knockdown of both LKB1 and AMPK were associated with increased STAT3 phosphorylation levels. In response to murine carotid artery ligation, expression of RAGE and S100A11 increased, whereas AMPK and LKB1 activity decreased in situ. Conversely, LKB1 and AMPK activity increased in situ, and neointima formation was attenuated in Rage−/− mice.
Conclusion
The linkage of decreased LKB1 and AMPK activity with increased STAT3 in SMCs mediates the capacity of RAGE ligand-induced signaling to promote neointima formation in response to arterial injury.
Polymorphisms in cytokine genes may contribute to increased susceptibility to different cancers. The aim of this paper is to investigate the association of IL-8-251A/T polymorphism and Helicobacter pylori (H. pylori) infection with the risk of developing gastric cardiac adenocarcinoma (GCA) in the south of Taihang Mountain, a high-incidence area of esophageal cancer in China. The IL-8-251 A/T polymorphism was genotyped in 519 cases of GCA and 504 healthy controls. The H. pylori infection in GCA patients and controls was detected by rapid urease test (RUT), histopathology or (14)C-urea breath test ((14)C-UBT). The results showed that family history of upper gastrointestinal cancer (UGIC) and H. pylori infection significantly increased the risk of developing GCA. The overall genotype and allelotype distributions of IL-8 promoter SNPs in GCA patients were significantly different from those in healthy controls. Compared with TT genotype, AA genotype significantly elevated the risk of developing GCA. The stratification analysis revealed that, compared with the TT genotype, the AA genotype significantly elevated the risk of developing GCA in both positive family history of UGIC and H. pylori infection subgroups. This study provides evidence to support a relationship of increased susceptibility to GCA in individuals of the south Taihang Mountain region with IL-8 251 AA genotype, especially for those individuals who have family history of UGIC or H. pylori infection.
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