JLK1486, a Bis 8-Hydroxyquinoline-Substituted Benzylamine, Displays Cytostatic Effects in Experimental Gliomas through MyT1 and STAT1 Activation and, to a Lesser Extent, PPARγ Activation.

Gliomas account for 5% to 7% of all solid cancers in adults and up to 30% of solid cancers in children; glioblastomas are the most malignant type of glioma and often have dismal prognoses. The alkylating agent temozolomide provides the greatest chemotherapeutic benefits currently available; however, glioblastoma patients cannot be cured. Novel drugs that efficiently combat glioblastomas are therefore of great interest. We report here that JLK1486, an 8-hydroxyquinoline-substituted benzylamine, could represent a novel chemical scaffold to reach this goal. Indeed, JLK1486 mediated anticancer activity in vivo (through intravenous as well as oral routes of administrations) in an orthotopic xenograft model and displayed efficiency similar to that of temozolomide. The therapeutic benefits of JLK1486 seem to relate to its ability to activate various transcription factors (including Myt1, STAT1, and peroxisome proliferator-activated receptor γ) in glioma cells. These transcription factors are implicated in the control of glioma cell proliferation, and the resultant global effect of their activation by JLK1486 was cytostatic, not cytotoxic. Thus, the current study opens the door for the development of novel compounds to combat glioblastoma using 8-hydroxyquinoline benzylamine analogs.

Alternative responses of primary tumor cells and glioblastoma cell lines to N,N-bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines: cell death versus P53-independent senescence.

N,N-bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines (HQNBA) represent a new class of compounds showing anti-cancer activity. At the chemical level the compounds were shown to react preferentially with thiol radicals which may lead to unfolded cysteine containing proteins and subsequent ER-stress. At the molecular level, treatment of U87 cells with this class of derivatives induced an over-expression of stress genes, including P53 and numerous P53 target genes. By generating shRNA U87 cell clones impaired in P53 expression we found that P53 mediates neither proliferation arrest of treated U87 cells nor over-expression of potential P53 targets. Moreover, we discovered that a representative HQNBA derivative (JLK1486) induces strong but transient senescence in U87 cells in a P53-independent manner. We demonstrate that, in contrast to its effect on established glioblastoma cell lines, JLK1486 induces extensive death of primary glioblastoma cells. We provide evidence that both caspase 3, and 7 activation, and cathepsin B and D activities account for at least part of this cell death.

N,N-Bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines (HQNBA): peroxisome proliferator-activated receptor (PPAR-γ) agonists with neuroprotective properties.

We report on the neuroprotective effects of N,N-bis-(8-hydroxyquinoline-5-yl methyl)-benzyl substituted amines (HQNBA) in a model of oxidative stress-induced nerve cell death using mouse hippocampal-derived HT22 cells. The four derivatives (JLK1472, JLK1486, JLK1522 and JLK1535) protected the HT22 cells from death at concentrations ranging from 0.1 to 1 µM. Their action is partially dependent on their ability to act as PPARγ agonists. These analogues also maintain GSH levels suggesting that they have indirect anti-oxidant effects.

Neuroprotective effects of N-alkyl-1,2,4-oxadiazolidine-3,5-diones and their corresponding synthetic intermediates N-alkylhydroxylamines and N-1-alkyl-3-carbonyl-1-hydroxyureas against in vitro cerebral ischemia.

Herein we report the synthesis and neuroprotective effects of new N-alkyl-1,2,4-oxadiazolidine-3,5-diones and their corresponding synthetic intermediates, N-alkylhydroxylamines and N-1-alkyl-3-carbonyl-1-hydroxyureas, in an in vitro model of ischemia. We found five analogues that protect HT22 cells from death in the concentration range of 1-5 muM. Because members of the MAP kinase family are known to be key players in nerve cell survival and death, we characterized the role of these kinases in the neuroprotective mechanisms of the newly synthesized analogues. The results indicate that these compounds provide neuroprotection through distinct mechanisms of action.

Structure-activity relationships and mechanism of action of antitumor bis 8-hydroxyquinoline substituted benzylamines.

A series of twenty six 8-hydroxyquinoline substituted amines, structurally related to compounds 2 and 3, were synthesized to evaluate the effects of structural changes on antitumor activity and understand their mechanism of action. The studies were performed on a wide variety of cancer cell lines within glioma and carcinoma models. The results obtained from chemical models and biological techniques such as microarrays suggest the following hypothesis that a quinone methide intermediate which does not react with DNA but which gives covalent protein thiol adducts. Micro-array analysis showed that the drugs induce the expression of a variety of stress related genes responsible for the cytotoxic and cytostatic effects in carcinoma and glioblastoma cells respectively. The described analogues could represent new promising anti-cancer candidates with specific action mechanisms, targeting accessible thiols from specific proteins and inducing potent anti-cancer effects.

Potential neuroprotective drugs in cerebral ischemia: new saturated and polyunsaturated lipids coupled to hydrophilic moieties: synthesis and biological activity.

The ganglioside GM1 has neuroprotective effects but is not of therapeutic value because of its lack of bioavailability. Thus, molecules that mimic GM1 represent a novel approach to neuroprotection. We have synthesized 19 small GM1-like analogues whose simplified structure includes a hydrophobic saturated or unsaturated moiety linked to a hydrophilic moiety. We report their neuroprotective effects in two distinct models of nerve cell death using hippocampus-derived HT22 cells. We found that several analogues protected the HT22 cells from death at concentrations ranging from 2 to 5 microM. Additional neuroprotective assays using cortical slices injured by glutamate confirmed these results. Since members of the MAP kinase family are known to be key players in nerve cell survival and death, we characterized the role of these kinases in the neuroprotective mechanisms of the GM1-like analogues. Interestingly, the results indicate that the compounds provide neuroprotection through distinct mechanisms of action.