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The receptor tyrosine kinase Met is crucial for the genetic program causing cancer progression and metastasis. Its nodal function during aggressiveness and resistance acquisition poses Met inhibition as an obligatory step in anti-cancer targeted therapy. Here, we applied a "Met-focussed" forward chemical biological screen to discover new agents antagonizing Met-triggered biological functions. The identified new scaffold, JLK1360, has a dual mechanism of action towards Met: it impairs Met signalling and also prevents its restoration after degradation. Docking and molecular dynamics provide evidences on the interacting mode of JLK1360 within the Met ATP-binding pocket. Moreover, computational and biochemical studies also highlighted that JLK1360 has a good degree of selectivity towards Met than other RTKs tested. Altogether, these findings demonstrate that the approach we have applied is a powerful strategy to identify compounds with combined properties towards a chosen target. Our studies show how integration of chemistry, biology and computational analysis can provide robust strategies to identify new inhibitory scaffolds suitable for further development of anti-cancer targeted therapies.

Alcohols act as anaesthetics only up to a certain chain length, beyond which their biological activity disappears. Although the molecular nature of general target sites remains unknown, presently available data support the hypothesis that this 'cut-off' in anaesthetic activity could be due to a corresponding cut-off in the absorption of long-chain alcohols into lipid-bilayer portions of nerve membranes. To test this hypothesis, we developed a method based on leakage of Ru(bpy)3(2+) ions across the membrane of dihexadecylphosphate (DHP) vesicles induced by aliphatic alcohols (C1 to C18) and some of their omega-diol. The permeant effects of aliphatic linear alcohols expressed as PD50 values rise to a maximum for n-dodecanol (PD50 = 2 x 10(-3) M 1(-1]. Dodecanol was found to be the alcohol which presents the greatest anaesthetic potency among the series of linear aliphatic alcohols (cut-off anaesthetic effect). The results are discussed in terms of the structural physicochemical and geometrical characteristics of the permeating alcohols.

Analogues of N-formyl methionyl leucyl phenylalanine possessing three and four peptide units grafted onto an inert carbon skeleton were tested as activators of human polymorphonuclear leukocytes. For the two responses studied, degranulation and respiratory burst, the polymeric analogues showed two maxima of activity, one at the same concentration as the monomer, the other one at a concentration 100- to 1000-fold lower. The potency of the polymers with respect to the monomer is discussed in terms of receptor clustering. The similarity of the dose-response curves for superoxide production and lysozyme secretion indicates that the early transmembrane signalling events are identical for the two responses studied.

The preparation of cyclic tetramers of formyl-methionyl-leucylphenylalanine (FMLP) amides from tetraazacycloalkanes incorporating different spacers is described. The corresponding monomeric analogs are also reported. The ability of these FMLP analogs to release lysozyme from human neutrophils was evaluated. The cyclic clusters proved to be superactive and in a manner suggestive of a cooperative response of the membrane receptors. The spasmogenicity of two prototype compounds on the guinea-pig ileum was also measured and the results briefly discussed.