Open AccessHeterogeneity of bromodeoxyuridine sensitivity of cultured cells from melanoma metastases
Author(s) -
Poot Martin,
Hiller KarlHeinz,
Heimpel Simone,
Schuster Armin,
Köhler Julia,
Hoehn Holger
Publication year - 1995
Publication title -
cytometry
Language(s) - English
Resource type - Journals
eISSN - 1097-0320
pISSN - 0196-4763
DOI - 10.1002/cyto.990210112
Subject(s) - bromodeoxyuridine , flow cytometry , ethidium bromide , biology , cell cycle , cell culture , melanoma , microbiology and biotechnology , cell growth , cell , cancer research , biochemistry , dna , genetics
Continuously growing cell cultures, testing positive for tyrosinase activity, were derived from two brain and three lymph‐node metastases of five patients with malignant melanoma. These cell cultures were analyzed regarding their proliferation rate with continuous bromodeoxyuridine (BrdUrd) labeling followed by bivariate Hoechst 33258/ethidium bromide flow cytometry. Melanoma cell cultures are more sensitive toward BrdUrd in comparison to human diploid fibroblast cultures: 50% growth inhibition at 360 ± 130 μM BrdUrd (range: 130–520; n = 11) vs. 650 ± 50 μM BrdUrd (n = 3) for fibroblasts. Moreover, BrdUrd sensitivity in melanoma cells is oxygen dependent: 50% growth inhibition at 200 ± 55 μM (range: 65–400 μM) for 20% oxygen vs. 360 ± 130 μM BrdUrd for 5% oxygen. The cell cycle kinetic mechanism of BrdUrd‐induced growth inhibition is accumulation of cells in the G2 phase. Cultures from a single metastasis showed up to a 3‐fold variation in BrdUrd sensitivity. In one of the brain metastases two populations of different ploidy level (pseudotriploid vs. pseudotetraploid) and BrdUrd sensitivity could be resolved. Thus, continuous BrdUrd labeling followed by bivariate Hoechst 33258/ethidium bromide flow cytometry is a powerful tool to detect heterogeneity in proliferative capacity and drug sensitivity of cell populations within one tumor biopsy. © 1995 Wiley‐Liss, Inc.