ISO-1 Binding to the Tautomerase Active Site of MIF Inhibits Its Pro-inflammatory Activity and Increases Survival in Severe Sepsis

MIF is a proinflammatory cytokine that has been implicated in the pathogenesis of sepsis, arthritis, and other inflammatory diseases. Antibodies against MIF are effective in experimental models of inflammation, and there is interest in strategies to inhibit its deleterious cytokine activities. Here we identify a mechanism of inhibiting MIF pro-inflammatory activities by targeting MIF tautomerase activity. We designed small molecules to inhibit this tautomerase activity; a lead molecule, "ISO-1 ((S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester)," significantly inhibits the cytokine activity in vitro. Moreover, ISO-1 inhibits tumor necrosis factor release from macrophages isolated from LPStreated wild type mice but has no effect on cytokine release from MIFdeficient macrophages. The therapeutic importance of the MIF inhibition by ISO-1 is demonstrated by the significant protection from sepsis, induced by cecal ligation and puncture in a clinically relevant time frame. These results identify ISO-1 as the first small molecule inhibitor of MIF proinflammatory activities with therapeutic implications and indicate the potential of the MIF active site as a novel target for therapeutic interventions in human sepsis

Olefin metathesis-iodoetherification-dehydroiodination strategy for spiroketal subunits of polyether antibiotics.

2 fig.- 7 esqu.The convergent synthesis of two pentacyclic analogues of the polyether monensin A is described. Although different with respect to the configuration of the alcohol at the 3 position of the six-membered ring of the spiroketal subunit, the configuration at the acetal center in both structures is unchanged and is consistent with the anomeric effect. The key synthetic steps are the coupling of two complex segments via an olefin metathesis, and the subsequent conversion of a dihydroxyalkene to the spiroketal through an iodoetherification−dehydroiodination sequence. The compatibility of these transformations with a variety of functional groups makes the overall strategy appropriate for highly substituted frameworksThis investigation was supported by grant R01 GM57865 from the National Institute of General Medical Sciences of the National Institutes of Health (NIH). “Research Centers in Minority Institutions” award RR-03037 from the National Center for Research Resources of the NIH, which supports the infrastructure and instrumentation of the Chemistry Department at Hunter College, is also acknowledgedPeer reviewe

Anticancer properties of the novel nitric oxide-donating compound (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid-nitric oxide in vitro and in vivo

Preclinical studies have shown that nitric oxide (NO)donating nonsteroidal anti-inflammatory drugs possess anticancer activities. Here, we report in vitro and in vivo studies showing the antitumor effect of the NO-donating isoxazole derivative (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid (GIT-27NO). GIT-27NO, but not the NO-deprived parental compound VGX-1027, significantly affected viability of both rodent (L929, B16, and C6) and human (U1251, BT20, HeLa, and LS174) tumor cell lines. GIT-27NO triggered either apoptotic cell death (e.g., L929 cells) or autophagic cell death (C6 and B16 cells). Moreover, GIT-27NO hampered the viability of cisplatin-resistant B16 cells. NO scavenger hemoglobin completely prevented GIT-27NO-induced death, indicating that NO release mediated the tumoricidal effect of the compound. Increase in intracellular NO upon on the treatment was associated with intensified production of reactive oxygen species, whereas their neutralization by antioxidant N-acetylcysteine resulted in partial recovery of cell viability. The antitumor activity of the drug was mediated by the selective activation of mitogen-activated protein kinases in a cell-specific manner and was neutralized by their specific inhibitors. In vivo treatment with GIT-27NO significantly reduced the B16 melanoma growth in syngeneic C57BL/6 mice. The therapeutic effect occurred at dose (0.5 mg/mouse) up to 160 times lower than those needed to induce acute lethality (80 mg/mouse). In addition, a dose of GIT-27NO five times higher than that found effective in the melanoma model was well tolerated by the mice when administered for 4 consecutive weeks. These data warrant additional studies to evaluate the possible translation of these findings to the clinical setting.nul

Anticancer properties of the novel nitric oxide-donating compound (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid-nitric oxide in vitro and in vivo

Preclinical studies have shown that nitric oxide (NO)donating nonsteroidal anti-inflammatory drugs possess anticancer activities. Here, we report in vitro and in vivo studies showing the antitumor effect of the NO-donating isoxazole derivative (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid (GIT-27NO). GIT-27NO, but not the NO-deprived parental compound VGX-1027, significantly affected viability of both rodent (L929, B16, and C6) and human (U1251, BT20, HeLa, and LS174) tumor cell lines. GIT-27NO triggered either apoptotic cell death (e.g., L929 cells) or autophagic cell death (C6 and B16 cells). Moreover, GIT-27NO hampered the viability of cisplatin-resistant B16 cells. NO scavenger hemoglobin completely prevented GIT-27NO-induced death, indicating that NO release mediated the tumoricidal effect of the compound. Increase in intracellular NO upon on the treatment was associated with intensified production of reactive oxygen species, whereas their neutralization by antioxidant N-acetylcysteine resulted in partial recovery of cell viability. The antitumor activity of the drug was mediated by the selective activation of mitogen-activated protein kinases in a cell-specific manner and was neutralized by their specific inhibitors. In vivo treatment with GIT-27NO significantly reduced the B16 melanoma growth in syngeneic C57BL/6 mice. The therapeutic effect occurred at dose (0.5 mg/mouse) up to 160 times lower than those needed to induce acute lethality (80 mg/mouse). In addition, a dose of GIT-27NO five times higher than that found effective in the melanoma model was well tolerated by the mice when administered for 4 consecutive weeks. These data warrant additional studies to evaluate the possible translation of these findings to the clinical setting.nul

The antitumor properties of a nontoxic, nitric oxide-modified version of saquinavir are independent of Akt

Application of the HIV protease inhibitor saquinavir (Saq) to cancer chemotherapy is limited by its numerous side effects. To overcome this toxicity, we modified the original compound by covalently attaching a nitric oxide (NO) group. We compared the efficacy of the parental and NO-modified drugs in vitro and in vivo. The novel compound saquinavir-NO (Saq-NO) significantly reduced the viability of a wide spectrum of human and rodent tumor cell lines at significantly lower concentration than the unmodified drug. In contrast to Saq, Saq-NO had no effect on the viability of primary cells and drastically reduced B16 melanoma growth in syngeneic C57BL/6 mice. In addition, at the equivalent of the 100% lethal dose of Saq, Saq-NO treatment caused no apparent signs of toxicity. Saq-NO blocked the proliferation of C6 and 1316 cells, up-regulated p53 expression, and promoted the differentiation of these two cell types into oligodendrocytes or Schwann-like cells, respectively. Although it has been well documented that Saq decreases tumor cell viability by inhibiting Akt, the anticancer properties of Saq-NO were completely independent of the phosphatidylinositol 3-kinase/Akt signaling pathway. Moreover, Saq-NO transiently up-regulated Akt phosphorylation, delivering a protective signal that could be relevant for primary cell protection and the absence of drug toxicity in vivo. It was unlikely that released NO was independently responsible for these drug effects because Saq-NO treatment increased intracellular and secreted NO levels only slightly. Rather, the chemical modification seems to have produced a qualitatively new chemical entity, which may have a unique mode of action against cancer cells. [Mol Cancer Ther 2009;8(5):1169-78]Serbian Ministry of Science [143029]; University of Catani

Novel nitric oxide-donating compound (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid-nitric oxide (GIT-27NO) induces p53 mediated apoptosis in human A375 melanoma cells

In this study we evaluated the effects of the new NO donating compound (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid-nitric oxide (GIT-27NO) on the A375 human melanoma cell line. Treatment with the drug led to concentration-dependent reduction of mitochondrial respiration and number of viable cells in cultures. Decreased cell viability correlated with release and internalization of NO and was neutralized by the extracellular scavenger hemoglobin. GIT-27NO neither influenced cell division nor induced accidental or autophagic cell death. Early signs of apoptosis were observed upon coculture with the drug, and resulting in marked accumulation of hypodiploid cells, suggesting that the induction of apoptosis is one primary mode of action of the compound in A375 cells. GIT-27NO significantly inhibited the expression of the transcription repressor and apoptotic resistant factor YY1 and, in parallel, augmented the presence of total p53. The capacity of GIT-27NO to induce p53-mediated apoptosis along with inhibition of YY1 repressor in A375 melanoma cells indicates that GIT-27NO possesses an important anti-cancer pharmacological profile. The findings suggest the potential therapeutic use of GIT-27NO in the clinical setting. (C) 2008 Elsevier Inc. All rights reserved.nul

Novel nitric oxide-donating compound (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid-nitric oxide (GIT-27NO) induces p53 mediated apoptosis in human A375 melanoma cells

In this study we evaluated the effects of the new NO donating compound (S,R)-3-phenyl-4,5-dihydro-5-isoxazole acetic acid-nitric oxide (GIT-27NO) on the A375 human melanoma cell line. Treatment with the drug led to concentration-dependent reduction of mitochondrial respiration and number of viable cells in cultures. Decreased cell viability correlated with release and internalization of NO and was neutralized by the extracellular scavenger hemoglobin. GIT-27NO neither influenced cell division nor induced accidental or autophagic cell death. Early signs of apoptosis were observed upon coculture with the drug, and resulting in marked accumulation of hypodiploid cells, suggesting that the induction of apoptosis is one primary mode of action of the compound in A375 cells. GIT-27NO significantly inhibited the expression of the transcription repressor and apoptotic resistant factor YY1 and, in parallel, augmented the presence of total p53. The capacity of GIT-27NO to induce p53-mediated apoptosis along with inhibition of YY1 repressor in A375 melanoma cells indicates that GIT-27NO possesses an important anti-cancer pharmacological profile. The findings suggest the potential therapeutic use of GIT-27NO in the clinical setting. (C) 2008 Elsevier Inc. All rights reserved.nul

The antitumor properties of a nontoxic, nitric oxide-modified version of saquinavir are independent of Akt

Application of the HIV protease inhibitor saquinavir (Saq) to cancer chemotherapy is limited by its numerous side effects. To overcome this toxicity, we modified the original compound by covalently attaching a nitric oxide (NO) group. We compared the efficacy of the parental and NO-modified drugs in vitro and in vivo. The novel compound saquinavir-NO (Saq-NO) significantly reduced the viability of a wide spectrum of human and rodent tumor cell lines at significantly lower concentration than the unmodified drug. In contrast to Saq, Saq-NO had no effect on the viability of primary cells and drastically reduced B16 melanoma growth in syngeneic C57BL/6 mice. In addition, at the equivalent of the 100% lethal dose of Saq, Saq-NO treatment caused no apparent signs of toxicity. Saq-NO blocked the proliferation of C6 and 1316 cells, up-regulated p53 expression, and promoted the differentiation of these two cell types into oligodendrocytes or Schwann-like cells, respectively. Although it has been well documented that Saq decreases tumor cell viability by inhibiting Akt, the anticancer properties of Saq-NO were completely independent of the phosphatidylinositol 3-kinase/Akt signaling pathway. Moreover, Saq-NO transiently up-regulated Akt phosphorylation, delivering a protective signal that could be relevant for primary cell protection and the absence of drug toxicity in vivo. It was unlikely that released NO was independently responsible for these drug effects because Saq-NO treatment increased intracellular and secreted NO levels only slightly. Rather, the chemical modification seems to have produced a qualitatively new chemical entity, which may have a unique mode of action against cancer cells. [Mol Cancer Ther 2009;8(5):1169-78]Serbian Ministry of Science [143029]; University of Catani