RADIORESISTANCE ASSOCIATED MARKERS IN LUNG CANCER AND DESIGN OF THERAPEUTIC STRATEGIES BASED ON SIRNA

GIANNONI F; CERDA M; LLOYD R; GIANNONI A; IEZZI ME; PODHAJCER O; POLICASTRO LL

Congreso; LXI Reunion de la Sociedad Argentina de Investigación Clinica; 2016

Tumor radioresistance is one of themain causes that lead to the failure of radiation treatments. Silencing theexpression of radioresistant-associated genes by small interference RNA (siRNA)is a promising strategy to optimize radiotherapy. On the other hand, for anoptimal delivery of therapeutics siRNAs it is important to design effectivenanovehicles. The aims of this work were to characterize the intrinsicradiosensitivity (IR) of human lung cancer cell lines to identify potentialresistant-associated genes to be silencing by siRNAs molecules in a lung cancermodel and also evaluate efficient strategies to delivery siRNA molecules. Wehave evaluated the expression of Ku80, a gene associated to DNA repair and theperoxirredoxin2 (Prx2) a critical enzyme of cellular antioxidant systems inA549, H292 and H1975 human lung cell lines. We have evaluated cellularradiosensitivity by survival curves. A549 was the most radioresistant cell lineand H292 and H1975 have shown similar radiosensibility and significantly lower respectto A549. The expression of Ku80 was inducted by IR in all human lung celllines, but Prx2 was not modulated after IR exposition. Silencing of Ku80 andalso Prx2 in A549 by siRNAs have induced a significantly radiosensitization inA549 cells. We also have explored the encapsulation of plasmid containing ashRNA against the firefly luciferase reporter gene complexes with the cationic polymerpoly(ethylene imine) (PEI) in liposomes. We encapsulated the complexes by thethin film hydration method. Nanovectors have shown a hydrodynamic diameter of140-170nm and polydispersity index of 0.2. The stability of complexes wasvisualized in agarose gel. In future experiment we will evaluate the silencingpotential of nanovehicles using a constitutive luciferase cell line, in order toobtain an optimized non-viral nanovehicle to delivery siRNAs againstradioresitant-associated gene in lung cancer.