ABSTRACT
BACKGROUND: We used the CellScan, a novel static cytometer, to monitor changes induced by anti-neoplastic drugs in the fluorescence intensity and polarization of fluorescently-labeled tumor cells. MATERIALS AND METHODS: T47D and T80 human breast cancer cell lines were exposed to navelbine and to 5-fluorouracil and the fluorescence properties of the treated cells, stained with fluorescein diacetate and rhodamine 123, were measured by the CellScan. RESULTS: A strong correlation was found between the inhibition of cell growth induced by the two drugs, as estimated from cell counts, and the resulting changes in fluorescence intensity and polarization, as monitored by the CellScan. Fluorescence hyperpolarization of the labeled cells occurred in conjunction with AnnexinV binding and propidium iodide exclusion, indicating that such hyperpolarization, resulting from drug action, reflects an early stage of apoptosis, as previously proposed. CONCLUSION: The system presented here could serve as the basis for assessing drug sensitivity or resistance of cancer cells derived from small biopsies of solid human tumors, thus eliminating prior tumor culturing and time-consuming assays.
