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Background Highly efficient capture and detection of circulating tumor cells (CTCs) remain elusive mainly because of their extremely low concentration in patients’ peripheral blood. Methods We present an approach for the simultaneous capturing, isolation, and detection of CTCs using an immuno-fluorescent magnetic nanobead system (iFMNS) coated with a monoclonal anti-EpCAM antibody. Results The developed antibody nanobead system allows magnetic isolation and fluorescent-based quantification of CTCs. The expression of EpCAM on the surface of captured CTCs could be directly visualized without additional immune-fluorescent labeling. Our approach is shown to result in a 70–95% capture efficiency of CTCs, and 95% of the captured cells remain viable. Using our approach, the isolated cells could be directly used for culture, reverse transcription-polymerase chain reaction (RT-PCR), and immunocytochemistry (ICC) identification. We applied iFMNS for testing CTCs in peripheral blood samples from a lung cancer patient. Conclusions It is suggested that our iFMNS approach would be a promising tool for CTCs enrichment and detection in one step. Graphic abstract

Highly efficient capture and detection of circulating tumor cells (CTCs) remain elusive mainly because of their extremely low concentration in the peripheral blood of patients. Herein, we present an approach for the simultaneous capturing, isolation, and detection of CTCs using an immuno-fluorescent magnetic nanobead system (iFMNS) coated with a monoclonal anti-EpCAM antibody. The developed antibody nanobead system allows magnetic isolation and fluorescent-based quantification of CTCs. The expression of EpCAM on the surface of captured CTCs could be directly visualized without additional immune-fluorescent labeling. Our approach is shown to result in a 70 - 95% capture efficiency of CTCs, and 95% of the captured cells remain viable. Using our approach, the isolated cells could be directly used for culture, reverse transcription-polymerase chain reaction (RT-PCR), and immunocytochemistry (ICC) identification. We applied iFMNS for testing CTCs in peripheral blood samples from a lung cancer patient, which suggested that this approach would be a promising tool for CTCs enrichment and detection in one step.

The incidence of aggressive neuroendocrine prostate cancers (NEPC) related to androgen-deprivation therapy (ADT) is rising. NEPC is still poorly understood, such as its neuroendocrine differentiation (NED) and angiogenic phenotypes. Here we reveal that NED and angiogenesis are molecularly connected through EZH2 (enhancer of zeste homolog 2). NED and angiogenesis are both regulated by ADT-activated CREB (cAMP response element-binding protein) that in turn enhances EZH2 activity. We also uncover anti-angiogenic factor TSP1 (thrombospondin-1, THBS1) as a direct target of EZH2 epigenetic repression. TSP1 is downregulated in advanced prostate cancer patient samples and negatively correlates with NE markers and EZH2. Furthermore, castration activates the CREB/EZH2 axis, concordantly affecting TSP1, angiogenesis and NE phenotypes in tumor xenografts. Notably, repressing CREB inhibits the CREB/EZH2 axis, tumor growth, NED, and angiogenesis in vivo. Taken together, we elucidate a new critical pathway, consisting of CREB/EZH2/TSP1, underlying ADT-enhanced NED and angiogenesis during prostate cancer progression., Neuroendocrine prostate cancers are very difficult to treat and often arise after androgen-deprivation therapy. Here the authors show that ADT activates CREB that acts by increasing EZH2 activity to promote neuroendocrine differentiation in prostate cancer, providing alternative avenues for therapy.

A fluorometric and magnetic resonance (MR) dual-modal detection scheme is presented for determination of ascorbic acid (AA). It is based on the use of a blended Au/MnO2@BSA mixture that was prepared via a biomimetic strategy, using bovine serum albumin (BSA) as the template at physiological temperature. The MnO2@BSA fraction (one part of the composite) is not susceptible to MR but can be degraded to MR-active compounds upon a redox reaction with even ultralow concentrations of AA. In parallel, the blended Au/MnO2@BSA recovers its fluorescence because MnO2@BSA acts as a quencher of the fluorescence of circumjacent Au@BSA (the other part of the composite). Fluorescence typically is measured at excitation/emission wavelengths of 470/625 nm. Leveraging on this redox reaction between MnO2 and AA, a dual-mode detection scheme for AA was developed. Both the fluorescence and the MR signal increase with the concentration of AA. The lowest limit for the detection of AA is 0.6 μM in the fluorometric mode and 0.4 μM in the MR mode. Analysis of AA-spiked serum samples showed that the recoveries obtained by either the fluorometric and MR mode can reach 94%. This is the first report of the use of blended nanoparticles with their inherent cross-validation regularity.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) have been used to treat non-small cell lung carcinoma (NSCLC) patients that have EGFR-activating mutations. EGFR-TKI monotherapy in most NSCLC patients with EGFR mutations who initially respond to EGFR-TKIs results in the development of acquired resistance. We investigated the role of fibroblasts in stromal cell-mediated resistance to gefitinib-induced apoptosis in EGFR-mutant NSCLC cells. While gefitinib induced apoptosis in EGFR-mutant NSCLC cells, apoptosis induction was diminished under stromal co-culture conditions. Protection appeared to be mediated in part by Aurora-A kinase (AURKA) upregulation. The protective effect of stromal cells was significantly reduced by pre-exposure to AURKA-shRNA. We suggest that combinations of AURKA antagonists and EGFR inhibitors may be effective in clinical trials targeting mutant EGFR NSCLCs.

Although B cells play important roles in the humoral immune response and the regulation of adaptive immunity, B cell subpopulations with unique phenotypes, particularly those with non-classical immune functions, should be further investigated. By challenging mice with Listeria monocytogenes, Escherichia coli, vesicular stomatitis virus and Toll-like receptor ligands, we identified an inducible CD11ahiFcγRIIIhi B cell subpopulation that is significantly expanded and produces high levels of IFN-γ during the early stage of the immune response. This subpopulation of B cells can promote macrophage activation via generating IFN-γ, thereby facilitating the innate immune response against intracellular bacterial infection. As this new subpopulation is of B cell origin and exhibits the phenotypic characteristics of B cells, we designated these cells as IFN-γ-producing innate B cells. Dendritic cells were essential for the inducible generation of these innate B cells from the follicular B cells via CD40L-CD40 ligation. Increased Bruton's tyrosine kinase activation was found to be responsible for the increased activation of non-canonical NF-κB pathway in these innate B cells after CD40 ligation, with the consequent induction of additional IFN-γ production. The identification of this new population of innate B cells may contribute to a better understanding of B cell functions in anti-infection immune responses and immune regulation.

Hepatic ischemia-reperfusion (I/R) injury contributes to hepatic dysfunction and failure after liver transplantation, major hepatic resection, trauma, and hypovolemic shock. Therefore, reducing I/R injury is an important goal to improve the outcome of these procedures. Recently, high-mobility group box 1 protein (HMGB1) has been identified as a pathogenic mediator in several inflammatory diseases, including hepatic I/R. PNU-282987, a selective α7 nicotinic acetylcholine receptor agonist, prevents nuclear factor κB (NF-κB) activation and thereby inhibits cytokine secretion through a specific cholinergic anti-inflammatory pathway. Our study was designed to evaluate whether PNU-282987 would inhibit HMGB1 expression and prevent I/R-induced liver damage. C57BL/6 mice were randomly divided into 3 groups as follows: sham group, vehicle plus I/R group, and PNU-282987 plus I/R group. Mice were subjected to 70% partial hepatic I/R for 60 min and pretreated with either vehicle or with PNU-282987, and blood and hepatic tissue samples were collected at 3, 6, and 12 h following reperfusion. The results showed that pretreatment with PNU-282987 decreased serum transaminase levels and ameliorated liver injury after hepatic I/R. Moreover, pretreatment with PNU-282987 suppressed NF-κB activation, cytokine production (tumor necrosis factor α, interleukin 1β), and HMGB1 expression in liver after hepatic I/R. These observations suggest that PNU-282987 protects the liver from I/R injury possibly by inhibiting HMGB1 expression, suppressing cytokine production, and preventing NF-κB activation in mice.

Bruton tyrosine kinase (Btk) is not only critical for B cell development and differentiation but is also involved in the regulation of Toll-like receptor-triggered innate response of macrophages. However, whether Btk is involved in the regulation of natural killer (NK) cell innate function remains unknown. Here, we show that Btk expression is up-regulated during maturation and activation of mouse NK cells. Murine Btk -/-NKcells have decreased innate immune responses to the TLR3 ligand, with reduced expressions of IFN-γ, perforin, and granzyme-B and decreased cytotoxic activity. Furthermore, Btk is found to promote TLR3-triggered NK cell activation mainly by activating the NF-κB pathway. Poly(I:C)-induced NK cell-mediated acute hepatitis was observed to be attenuated in Btk -/- mice or the mice with in vivo administration of the Btk inhibitor. Correspondingly, liver damage was aggravated in Btk -/- mice after the adoptive transfer of Btk +/+ NK cells, further indicating that Btk-mediated NK cell activation contributes to TLR3-triggered acute liver injury. Importantly, reduced TLR3-triggered activation of human NK cells was observed in Btk-deficient patients with X-linked agammaglobulinemia, as evidenced by the reduced IFN-γ, CD69, and CD107a expression and cytotoxic activity. These results indicate that Btk is required for activation of NK cells, thus providing insight into the physiological significance of Btk in the regulation of immune cell functions and innate inflammatory response. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc., link_to_subscribed_fulltext