IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Pilot screening of phototoxicity of dyes by means of an automated motility bioassay using Caenorhabditis elegans
Autor/es:
BIANCHI, JAVIER; STOCKERT, JUAN C.; BUZZI, LUCILA INES; BLAZQUEZ CASTRO, ALFONSO; SIMONETTA, SERGIO H
Lugar:
Los Angeles
Reunión:
Congreso; 19th International C elegans Meeting; 2013
Institución organizadora:
Genetic Society of America GSA
Resumen:
Phototoxicity consists in the capability of certain innocuous molecules to become toxic when subjected to strong illumination. This has been particularly useful to develop new cancer therapies where patients are treated with the innocuous version of the drug, and once absorbed, the tumor area is focally illuminated in order to activate the phototoxic molecules and destroy cancer cells. In order to discover new compounds or characterize already existing molecules, it would be advantageous to count with simple and cheap biological tests which allow finding, in a short time, the best candidates. In this work, we present a pilot screening of 37 dyes to test for phototoxic effects in C.elegans. Nematodes were cultured in liquid medium and treated with different concentration of chemical dyes, and subsequently exposed to a pulse of light. We quantified behavioural effects of compound treatment through quantitation of global locomotor activity using an infrared tracking system (wmicrotracker). Of the tested compounds, 18 molecules were classified as positive in C.elegans, being Primuline and Phloxine B the most representatives. In order to characterize endogenous effect and mechanism of action of these chemicals, we retested the compounds washing them out of the medium before the pulse and also registered the staining of the nematodes. Intriguingly, 100% of the positive tested drugs were capable of permeating the animals and produce their phototoxic effects after the washout. We also tested through reporter strains the stress response being triggered by the compounds, endoplasmic reticulum stress response (hsp4::gfp strain), was activated in 22% of phototoxic compounds, and mitochondrial oxidative stress response (hsp6::gfp strain), was positive in 16% of phototoxic compounds. These results indicate a physiological effect in protein folding mechanism and oxidative stress similar as reported in cell culture lines. Our work shows for the first time the utility of C.elegans for running a phototoxic molecule screening and its potential application in the drug discovery pipeline.