Fig. 4
From: TRIM28 inhibits alternative lengthening of telomere phenotypes by protecting SETDB1 from degradation
TRIM28 deletion promotes APB formation and telomere extension. A IF-FISH of TRIM28 KD U2OS cells was performed using a telomere probe (green) and antibodies against PML (red). DAPI was used to stain nuclei. Arrows indicate colocalization signals. B Results from (A) were quantified. About 200 cells were observed and those with ≥ 5 APBs were counted as positive. Error bars indicate standard error (n = 3). ***P < 0.001, Student’s t-test. C Telomere length of U2OS cells was measured by telomere DNA-FISH after TRIM28 knockout. DAPI was used to stain chromosomes. D Data from (C) were quantified to assess relative telomere length, more than 150 cells were observed for each cell line. **P < 0.01, Student’s t-test. E T-SCEs in TRIM28-depleted U2OS cells were shown. Briefly, after the chromosome was fixed and digested by exonuclease III, Cy3-labeled (TTAGGG)3 (red signal) and FITC-labeled (CCCTAA)3 (green signal) fluorescent probes were used for in situ hybridization, the single strand region showed a single fluorescent signal, and the recombination region showed yellow signal due to the existence of double strands. The enlarged image shown the typical T-SCEs. F Quantification of (E). More than 200 chromosomes were examined. **P < 0.01, Student’s t-test