Fig. 3: ALT-positive cancer cells are particularly prone to form heritable telomere lesions.
From: RPA shields inherited DNA lesions for post-mitotic DNA synthesis
a ALT-positive GM847 cells were treated as indicated and stained for EdU, RPA and TRF2. Cell cycle staging to identify G1 cells was performed by QIBC from at least 1000 cells per condition. Cell cycle-resolved scatter plots are depicted with RPA foci on the y-axis and DNA content on the x-axis. A rescaled version is shown on the right with a focus on cells in G1. Representative images of G1 cells are shown below. b Quantification of the percentage of ALT-positive U-2 OS cells with RPA-marked lesions in G1 in different treatment conditions from n = 3 independent samples with n1 = 499, n2 = 495, n3 = 476 (Control), n1 = 367, n2 = 345, n3 = 278 (APH), n1 = 944, n2 = 1046, n3 = 968 (ATRi), n1 = 959, n2 = 1042, n3 = 1044 (APH + ATRi) cells in G1 per sample. Individual values and means ± SD are shown. P-values were determined by two-tailed unpaired t-test; *p < 0.05 (exact p-value is p = 0.0462), **p < 0.01 (exact p-value is p = 0.0023). c Quantification of the percentage of ALT-positive GM847 cells with RPA-marked lesions in G1 in different treatment conditions from n = 3 independent samples with n1 = 323, n2 = 221, n3 = 306 (Control), n1 = 235, n2 = 221, n3 = 206 (APH), n1 = 407, n2 = 442, n3 = 437 (ATRi), n1 = 247, n2 = 287, n3 = 241 (APH + ATRi) cells in G1 per sample. Individual values and means ± SD are shown. P-values were determined by two-tailed unpaired t-test; *p < 0.05 (exact p-value is p = 0.0186), ***p ≤ 0.001 (exact p-value is p = 0.0002), ****p ≤ 0.0001. d Quantification of the percentage of ALT-negative HeLa cells with RPA-marked lesions in G1 in different treatment conditions from n = 3 independent samples with n1 = 1079, n2 = 1090, n3 = 1208 (Control), n1 = 789, n2 = 775, n3 = 882 (APH), n1 = 1192, n2 = 1232, n3 = 1242 (ATRi), n1 = 260, n2 = 313, n3 = 225 (APH + ATRi) cells in G1 per sample. Individual values and means ± SD are shown. P-values were determined by two-tailed unpaired t-test; **p < 0.01 (the exact p-values are p = 0.0067, p = 0.0011, and p = 0.0045, respectively). e Quantification of the percentage of ALT-negative RPE-1 cells with RPA-marked lesions in G1 in different treatment conditions from n = 3 independent samples with n1 = 1984, n2 = 1761, n3 = 2281 (Control), n1 = 588, n2 = 563, n3 = 641 (APH 0,4 μM), n1 = 2668, n2 = 2434, n3 = 2586 (ATRi), n1 = 785, n2 = 746, n3 = 860 (APH + ATRi) cells in G1 per sample. Individual values and means ± SD are shown. P-values were determined by two-tailed unpaired t-test; **p < 0.01 (the exact p-value is p = 0.0021). f Quantification of the percentage of ALT-positive SW26 cells with RPA-marked lesions in G1 in different treatment conditions from n = 3 independent samples with n1 = 1091, n2 = 781, n3 = 929 (Control), n1 = 737, n2 = 594, n3 = 642 (APH), n1 = 806, n2 = 770, n3 = 706 (ATRi), n1 = 501, n2 = 355, n3 = 396 (APH + ATRi) cells in G1 per sample. Individual values and means ± SD are shown. P-values were determined by two-tailed unpaired t-test; *p < 0.05 (exact p-value is p = 0.0209), **p < 0.01 (exact p-value is p = 0.0039). g Quantification of the percentage of ALT-negative SW39 cells with RPA-marked lesions in G1 in different treatment conditions from n = 3 independent samples with n1 = 552, n2 = 565, n3 = 468 (Control), n1 = 366, n2 = 279, n3 = 312 (APH), n1 = 582, n2 = 578, n3 = 597 (ATRi), n1 = 351, n2 = 385, n3 = 396 (APH + ATRi) cells in G1 per sample. Individual values and means ± SD are shown. P-values were determined by two-tailed unpaired t-test; *p < 0.05 (exact p-value is p = 0.0265). Scale bar: 10 μm. A. U., arbitrary units. Source data are provided as a Source Data file.
