Fig. 6: Cyclin B1 fluorescence intensity serves as a presage protein signals for S-phase arrest induced by nucleoside analog anticancer drugs.

HeLa cells were treated with water (a), cytarabine (b), gemcitabine (c), nelarabine (d), and clofarabine (e) for 24 h followed by staining with DAPI. The sum fluorescence intensity of nuclear DAPI was measured and is shown as a histogram. The G1 phase peak in water condition is indicated by the red vertical line. Sample sizes were as follows: water (4444), cytarabine (1403 cells), gemcitabine (1662 cells), nelarabine (1979 cells), and clofarabine (1522 cells). For all conditions, the number of biological replicates was N = 1. f The ratio of cells in the G1 (blue), S (orange), and G2/M (green) phases following treatment with water, cytarabine, gemcitabine, nelarabine, and clofarabine for 24 h. Sample sizes were as follows: water (4444 cells), cytarabine (1403 cells), gemcitabine (1662 cells), nelarabine (1979 cells), and clofarabine (1522 cells). For all conditions, the number of biological replicates was N = 1. g HeLa cells were treated with water and anticancer drugs for 4 h and immunostained for cyclin B1. Segmentation of cell nuclei, mitochondria, and cytoplasmic regions was performed, and the mean fluorescence intensity of cyclin B1 in the nucleus, mitochondria, and cytoplasmic regions was quantified. The MAD ratios compared with the water condition for each drug and cell cycle are shown as a heatmap. Sample sizes were as follows: water (2149 cells), cytarabine (1849 cells), gemcitabine (2273 cells), nelarabine (2039 cells), and clofarabine (1523 cells). For all conditions, the number of biological replicates was N = 1. h–j HeLa cells were treated with cytarabine (h), gemcitabine (i), and clofarabine (j) for 4 h, and the mean MAD, mean correlation, and DNB index of cyclin B1 in the G1, S, and G2 phases of the cell cycle are shown. Sample sizes were as follows: water (2149 cells), cytarabine (1849 cells), gemcitabine (2273 cells), and clofarabine (1523 cells). For all conditions, the number of biological replicates was N = 1.