Cancer fluorescence activated cell

Buchegger, F. Dupertuis, Y. M. Perillo-Adamer, F. A pitfall of propidium iodide staining in fluorescence-activated cell sorting cell cycle analysis Cancer Res. 2007, 67, 5576-5577. 

Much less inhibition was found in the MCF7/MDR1 drug-resistant human breast cancer cell line in the presence of same carotenoids as were investigated earlier on the human MDR1 gene-transfected mouse lymphoma cells. As Table 5 shows the, rhodamine accumulation was enhanced only moderately from 1.1 to 2.2 fluorescence activity ratio, which means that the rhodamine uptake was enhanced from 10% to 120% in the human breast cancer cells. On the other hand, some carotenoids such as Zl-neoxanthin, mono-epoxy-a-carotene and 15,15-dehydro-diepoxy-/J-carotene were inactive (Table 5). 

The majority of carotenoids tested in this study increased the rhodamine accumulation of the Colo 320 MDR/MRP human colon cancer cells by the inhibition of the MDR1-mediated efflux pump activity. The cell size and the intracellular or sub cellular structures of carotenoid-treated cells were not modified during the short period of the flow cytometric experiments. The mean fluorescence and the shift of the fluorescence peak increased to various extents in the presence of carotenoids. The most active compounds were antheraxanthin, violeoxanthin, apple peel phytox-anthin, lutein and violaxanthin, while the luteoxanthin, neoxanthin and /f-cryploxanlhin were only moderate in their inhibition of the efflux pump (Tables 7, 8). 

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