Introduction. Mangosteen xantones exert anti-tumorigenic effects, however their toxicity was never investi-gated in a 3D model mimicking the hypoxic regions far from the vasculature that cannot be easily reached by drugs. Here we tested a-mangostin toxicity against breast cancer spheroids at doses useful to kill cancer cells under 2D conditions. Methods. Cancer spheroids of radius > 250 um were produced by seeding MCF7 breast cancer cells at the density of 1.5x103 cells per well onto 96-well round-bottomed plates and culturing them for 3 days. a-Man-gostin (5, 10, 20 ug/ml) was then added for 4 days and the spheroid radius measured by Image-J. Resazurin reduction assay allowed the evaluation of redox metabolism while accutase-induced cell dissociation was performed to count living cells that resisted to drug toxicity. Results. Spheroid cells became dishomogeneous and showed irregular frayed edges after drug treatment. These looser contacts were presumably responsible of the increased radius observed with the lowest dose of a-mangostin vs. control (507 vs. 415 um, respectively). By contrast, the radius decreased at higher doses (384 and 307 um for 10 and 20 ug/ml, respectively). The effects of 10 and 20 ug/ml a-mangostin also correlated with a 75% and 90% reduction in cell number, respectively. Redox metabolism was 90% reduced after admi-nistration of the lowest dose and decrease by 99% with 10 or 20 ug/ml a-mangostin vs. control.Conclusions. Although the most relevant effects of a-mangostin on MCF7-derived spheroids was related to the decrease of the redox status, a few viable cells were dissociated indicating that they were not affected by drug toxicity suggesting that a very low cell component inside big-sized spheroids can resist to a-mangostin and that might generate cancer stem cells.Research support: Fondazione del Monte di Bologna e Ravenna. Project: “Distruzione selettiva di cellule sta-minali tumorali ipossiche mediante uso di nanoparticelle bifunzionali”.
Effects od alpha-mangostin on cell growth, viability and metabolic activity evaluated in a hypoxic model of breast cancer spheroids
PAZZINI, CLAUDIA;BONAFÈ, FRANCESCA;GIORDANO, EMANUELE DOMENICO;MUSCARI, CLAUDIO;GUARNIERI, CARLO
2015
Abstract
Introduction. Mangosteen xantones exert anti-tumorigenic effects, however their toxicity was never investi-gated in a 3D model mimicking the hypoxic regions far from the vasculature that cannot be easily reached by drugs. Here we tested a-mangostin toxicity against breast cancer spheroids at doses useful to kill cancer cells under 2D conditions. Methods. Cancer spheroids of radius > 250 um were produced by seeding MCF7 breast cancer cells at the density of 1.5x103 cells per well onto 96-well round-bottomed plates and culturing them for 3 days. a-Man-gostin (5, 10, 20 ug/ml) was then added for 4 days and the spheroid radius measured by Image-J. Resazurin reduction assay allowed the evaluation of redox metabolism while accutase-induced cell dissociation was performed to count living cells that resisted to drug toxicity. Results. Spheroid cells became dishomogeneous and showed irregular frayed edges after drug treatment. These looser contacts were presumably responsible of the increased radius observed with the lowest dose of a-mangostin vs. control (507 vs. 415 um, respectively). By contrast, the radius decreased at higher doses (384 and 307 um for 10 and 20 ug/ml, respectively). The effects of 10 and 20 ug/ml a-mangostin also correlated with a 75% and 90% reduction in cell number, respectively. Redox metabolism was 90% reduced after admi-nistration of the lowest dose and decrease by 99% with 10 or 20 ug/ml a-mangostin vs. control.Conclusions. Although the most relevant effects of a-mangostin on MCF7-derived spheroids was related to the decrease of the redox status, a few viable cells were dissociated indicating that they were not affected by drug toxicity suggesting that a very low cell component inside big-sized spheroids can resist to a-mangostin and that might generate cancer stem cells.Research support: Fondazione del Monte di Bologna e Ravenna. Project: “Distruzione selettiva di cellule sta-minali tumorali ipossiche mediante uso di nanoparticelle bifunzionali”.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
