The Macrophage Inhibitor CNI-1493 Blocks Metastasis in a Mouse Model of Ewing Sarcoma through Inhibition of Extravasation

Metastatic Ewing Sarcoma carries a poor prognosis, and novel therapeutics to prevent and treat metastatic disease are greatly needed. Recent evidence demonstrates that tumor-associated macrophages in Ewing Sarcoma are associated with more advanced disease. While some macrophage phenotypes (M1) exhibit anti-tumor activity, distinct phenotypes (M2) may contribute to malignant progression and metastasis. In this study, we show that M2 macrophages promote Ewing Sarcoma invasion and extravasation, pointing to a potential target of anti-metastatic therapy. CNI-1493 is a selective inhibitor of macrophage function and has shown to be safe in clinical trials as an anti-inflammatory agent. In a xenograft mouse model of metastatic Ewing Sarcoma, CNI-1493 treatment dramatically reduces metastatic tumor burden. Furthermore, metastases in treated animals have a less invasive morphology. We show in vitro that CNI-1493 decreases M2-stimulated Ewing Sarcoma tumor cell invasion and extravasation, offering a functional mechanism through which CNI-1493 attenuates metastasis. These data indicate that CNI-1493 may be a safe and effective adjuvant agent for the prevention and treatment of metastatic Ewing Sarcoma.     

Regulation of TNF-α release from bone marrow–derived macrophages by vitamin D

The calcium-regulating hormone 1,25-dihydroxyvitamin D₃[1,25(OH)₂D₃] is recognized as an immuno-modulator affecting the activities of macrophages and lymphocytes. We have shown that macrophages harvested from vitamin D–deficient mice (–D MPs) exhibit impaired phagocytic and tumoricidal activities as compared with control cells (+D MPs), and that bone marrow–derived macrophage (BMDM) differentiation is modulated by 1,25(OH)₂D₃. The release of tumor necrosis factor–α (TNF-α) by macrophages is considered a major mechanism by which these cells exert their tumoricidal function. This cytokine was also implicated in modulation of bone resorption. In the present study we examine the role of 1,25(OH)₂D₃ in TNF-α synthesis and release. BMDMs were harvested from +D and ?D mice, cultured in vitro, and their conditioned media were analyzed for the presence of TNF-α. BMDMs did not release measurable amounts of TNF-α without stimulation. Addition of endotoxin (LPS) to the cultures resulted in a marked stimulation of TNF-α release. 1,25(OH)₂D₃ increased the stimulatory action of LPS, but failed to elicit a stimulatory effect in the absence of LPS. The use of another macrophage activator, interferon-γ (IFN-γ), yielded essentially similar results. +D and ?D mice were injected with LPS and TNF-α levels in the serum were measured. A marked reduction (～ fourfold) in the TNF-α levels was observed in the serum of ?D mice as compared with +D mice. Western blot and immunoprecipitation analyses suggested that the main effect of 1,25(OH)₂D₃ is on TNF-α synthesis. Our findings suggest that 1,25(OH)₂D₃ plays a role in the regulation of TNF-α secretion by mononuclear phagocytes. © 1994 Wiley-Liss, Inc.     

Detection of plasmid-mediated quinolone resistance in clinical isolates of Enterobacteriaceae strains in Hamadan,West of Iran

Plasmid mediated quinolone resistance (PMQR) determinants have arisen as a significant concern in recent years. The aim of this study was screening of resistant-clinical isolates to fluoroquinolone antibiotics and detection of qnr and aac(6′)-Ib-cr genes.For this purpose we collected 100 fluoroquinolone-resistant Enterobacteriaceae which were from 3 hospitals in Hamadan, west provinces of Iran, between October 2012 and June 2013. The all samples were identified by biochemical tests and confirmed by PCR method. Antimicrobial susceptibility to 14 antimicrobial agents including levofloxacin and ciprofloxacin were determined by disk diffusion methods and ciprofloxacin MIC was obtained by broth microdilution method as Clinical Laboratory Standards Institute (CLSI) recommendations. The isolates were screened for the presence of qnrA, qnrB, qnrS and aac(6′)-Ib-cr genes using PCR assay. Among the screened isolates, 64 strains (64%) of Escherichia coli, 23 strains (23%) of Klebsiella pneumoniae, 13 strains (13%) of Proteus mirabilis were collected as quinolone-resistant isolates. out of 100 isolates, two (2%) were positive for qnrS, seventeen (17%) isolates were positive for qnrB and we did not find qnrA gene in any of the isolates. There were also 32 positive isolates for aac(6′)-Ib-cr determinant. We described the prevalence of qnr and aac(6′)-Ib-cr genes in fluoroquinolone-resistant Enterobacteriaceae in Hamadan city. The carriage rate of multidrug-resistant Enterobacteriaceae in healthy people in Hamadan City is extremely high. Moreover, genes encoding transferable quinolones, in particular aac(6′)-Ib-cr, are highly prevalent in these strains.