Figure 1: TRF2 overexpression in HT1080 cells led to stochastic shortening of telomeres.
From: Elevated levels of TRF2 induce telomeric ultrafine anaphase bridges and rapid telomere deletions
(a) Elevated levels of TRF2 protein in a number of breast cancer and melanoma cells. Immunoblotting was performed to detect TRF2 in whole-cell extracts of the following human cell lines: Primary fibroblasts: IMR90, BJ and WI38; Breast cancer cells: MDA-MB-231, MDA-MB-453, MDA-MB-468, ZR-75-1, MCF-7 and SK-BR-3; Melanoma cells: Lox, CaCL 73-36, WM115, WM278, WM983A, WM983B and WM1158. Fibrosarcoma cell: HT1080. Tubulin was used as a loading control. (b) Assessing TRF2 overexpression levels. Parallel cultures of HT1080 clone A6 (a subclone of HT1080 cells that maintain stable telomere length) cells infected with lentiviruses expressing GFP or TRF2 were examined by immunoblotting (top panel) or immunostaining (bottom panel). Fold of TRF2 expression was quantified by the ImageJ software and normalized to tubulin levels. (c) Terminal Restriction Fragment analysis of HT1080 A6 cells infected with lentiviruses expressing GFP or TRF2. Cells were continuously passaged and collected at the indicated population doublings (PD). (d) Schematic diagram of STELA analysis. (e) Individual telomere lengths measured by STELA analysis in HT1080 A6 cells overexpressing GFP or TRF2 at PD6. Each lane represents a single PCR reaction performed with 100 pg of genomic DNA, followed by Southern blotting detection of XpYp telomeres using an XpYp subtelomeric probe.
