We have previously shown that the angiogenic growth factor pleiotrophin (PTN) induces migration of endothelial cells through binding to its receptor protein tyrosine phosphatase beta/zeta (RPTPbeta/zeta). In this study, we show that a monoclonal antibody against alpha(nu)beta(3) but not alpha(5)beta(1) integrin abolished PTN-induced human endothelial cell migration in a concentration-dependent manner. Integrin alpha(nu)beta(3) was found to directly interact with PTN in an RGD-independent manner, whereas a synthetic peptide corresponding to the specificity loop of the beta(3) integrin extracellular domain ((177)CYDMKTTC(184)) inhibited PTN-alpha(nu)beta(3) interaction and totally abolished PTN-induced endothelial cell migration. Interestingly, alpha(nu)beta(3) was also found to directly interact with RPTPbeta/zeta, and PTN-induced Y773 phosphorylation of beta(3) integrin was dependent on both RPTPbeta/zeta and the downstream c-src kinase activation. Midkine was found to interact with RPTPbeta/zeta, but not with alpha(nu)beta(3), and caused a small but statistically significant decrease in cell migration. In the same line, PTN decreased migration of different glioma cell lines that express RPTPbeta/zeta but do not express alpha(nu)beta(3), while it stimulated migration of U87MG cells that express alpha(nu)beta(3) on their cell membrane. Overexpression or down-regulation of beta(3) stimulated or abolished, respectively, the effect of PTN on cell migration. Collectively, these data suggest that alpha(nu)beta(3) is a key molecule that determines the stimulatory or inhibitory effect of PTN on cell migration.

Background & Aims Persistent activation of the inflammatory response contributes to development of inflammatory bowel diseases, which increase the risk of colorectal cancer. We aimed to identify microRNAs that regulate inflammation during development of ulcerative colitis (UC) and progression to colitis-associated colon cancer (CAC). Methods We performed quantititave PCR analysis to measure microRNAs in 401 colon specimens from patients with UC, Crohn's disease, irritable bowel syndrome, sporadic colorectal cancer, or CAC, as well as subjects without these disorders (controls); levels were correlated with clinical features and disease activity of patients. Colitis was induced in mice by administration of dextran sodium sulfate (DSS), and carcinogenesis was induced by addition of azoxymethane; some mice were also given inhibitor of microRNA214 (miR214). Results A high-throughput functional screen of the human microRNAome found that miR214 regulated the activity of nuclear factor κB (NFκB). Higher levels of miR214 were detected in colon tissues from patients with active UC or CAC than patients with other disorders or controls and correlated with disease progression. Bioinformatic and genome-wide profile analyses revealed that miR214 activates an inflammatory response and is amplified through a feedback loop circuit mediated by phosphatase and tensin homolog (PTEN) and PDZ and LIM domain 2 (PDLIM2). Interleukin-6 induced STAT3-mediated transcription of miR214. A miR214 chemical inhibitor blocked this circuit and reduced the severity of DSS-induced colitis in mice, as well as the number and size of tumors that formed in mice given azoxymethane and DSS. In fresh colonic biopsies from patients with active UC, the miR214 inhibitor reduced inflammation by increasing levels of PDLIM2 and PTEN. Conclusions Interleukin-6 upregulates STAT3-mediated transcription of miR214 in colon tissues, which reduces levels of PDLIM2 and PTEN, increases phosphorylation of AKT, and activates NFκB. The activity of this circuit correlates with disease activity in patients with UC and progression to colorectal cancer.

A large number of mostly recent reports show enhanced expression of the multi-functional protein nucleolin (NCL) on the surface of activated lymphocytes, angiogenic endothelial and many different types of cancer cells. Translocation of NCL at the external side of the plasma membrane occurs via a secretory pathway independent of the endoplasmic reticulum-Golgi complex, requires intracellular intact actin cytoskeleton, and seems to be mediated by a variety of factors. Cell surface NCL serves as a binding partner of several molecules implicated in cell differentiation, adhesion, and leukocyte trafficking, inflammation, angiogenesis and tumor development, mediating their biological activities and in some cases, leading to their internalization. Accumulating evidence validates cell surface NCL as a strategic target for treatment of cancer, while its property of tumor-specific uptake of targeted ligands seems to be useful for the development of non-invasive imaging tools for the diagnosis of cancer and for the targeted release of chemotherapeutic drugs. The observation that cell surface NCL exists in complexes with several other proteins implicated in tumorigenesis and angiogenesis suggests that targeting cell surface NCL might trigger multi-inhibitory effects, depending on the cell type. This review summarizes papers and patents related to the redistribution and the biological functions of cell surface NCL, with emphasis on the potential importance and advantages of developing efficient anti-cell surface NCL strategies.

Background: Cell surface nucleolin (NCL) is a promising target for development of anticancer agents. Results: A novel pathway that includes ␣ ␤ 3 integrin and leads to cell surface NCL localization and cell migration has been identified. Conclusion: ␣ ␤ 3 can be used as a biomarker for the use of NCL antagonists. Significance: This pathway is active in endothelial and glioma cells, as well as in human glioblastomas.

ObjectiveDespite advances in the identification of epigenetic alterations in pancreatic cancer, their biological roles in the pathobiology of this dismal neoplasm remain elusive. Here, we aimed to characterise the functional significance of histone lysine methyltransferases (KMTs) and demethylases (KDMs) in pancreatic tumourigenesis.DesignDNA methylation sequencing and gene expression microarrays were employed to investigate CpG methylation and expression patterns of KMTs and KDMs in pancreatic cancer tissues versus normal tissues. Gene expression was assessed in five cohorts of patients by reverse transcription quantitative-PCR. Molecular analysis and functional assays were conducted in genetically modified cell lines. Cellular metabolic rates were measured using an XF24-3 Analyzer, while quantitative evaluation of lipids was performed by liquid chromatography-mass spectrometry (LC-MS) analysis. Subcutaneous xenograft mouse models were used to evaluate pancreatic tumour growth in vivo.ResultsWe define a new antitumorous function of the histone lysine (K)-specific methyltransferase 2D (KMT2D) in pancreatic cancer. KMT2D is transcriptionally repressed in human pancreatic tumours through DNA methylation. Clinically, lower levels of this methyltransferase associate with poor prognosis and significant weight alterations. RNAi-based genetic inactivation of KMT2D promotes tumour growth and results in loss of H3K4me3 mark. In addition, KMT2D inhibition increases aerobic glycolysis and alters the lipidomic profiles of pancreatic cancer cells. Further analysis of this phenomenon identified the glucose transporter SLC2A3 as a mediator of KMT2D-induced changes in cellular, metabolic and proliferative rates.ConclusionTogether our findings define a new tumour suppressor function of KMT2D through the regulation of glucose/fatty acid metabolism in pancreatic cancer.