Characterization of merocyanine photooxidated products (pMC540) and cytotoxicity in human carcinoma cell lines

CALZETTA N.L.; ALONSO, S. DEL V.; MARANZANA, E.S.B.

Santiago del Estero

Congreso; SAB XLIV, XLIV Reunión anual de la Sociedad Argentina de Biofisica; 2015

SAB, Sociedad Argentina de Biofisica

Merocyanine 540 (MC540) is a non-cytotoxic photosensitizer fluorescent dye that after direct light irradiation produces a mixture of non-fluorescent photoproducts (pMC540) that showed antitumor activity against leukemia cell lines [1].The aim of this study is to characterize MC540 photoproducts (pMC540) and evaluate their cytotoxicity in vitro in human carcinoma cell lines.MC540 and pMC540 were characterized by UV-visible, fluorescence, FT-IR and mass spectrometry.Human breast MCF-7, prostate PC-3 and colorectal Caco-2 carcinoma cells were treated with different doses of pMC540 or MC540 and cell viability was determined by crystal violet, MTT and LDH assays.Our results show that light irradiation of MC540 produces a mixture of at least two major pMC540 that resulted to be dose- and time-dependent cytotoxic for PC-3 cells and MCF-7 cells whereas Caco-2 cells was not susceptible to pMC540. No any cell line was susceptible to MC540.We conclude that photooxidation breaks down MC540 generating at least two biologically active pMC540 which cytotoxicity is dependent on the cell line type.Our hypothesis is that pMC540 interacts differentially depending on specific cell lipid membrane constituents. Further assays and analysis are ongoing to strengthen this hypothesis.