Figure 3
From: Tumor hypoxia as a driving force in genetic instability
Hypoxia induces chromosomal aberrations following exogenous damage. A, Chromatin bridges or anaphase bridges in fibroblasts maintained under continual hypoxic (0.2% O2) conditions following 2 Gy of irradiation. These bridges can break into fragments and give rise to micronuclei [121]. The type, the number, and the fate of chromosome bridges under hypoxia is not known and requires further investigation. Representative DAPI stained and M-FISH images of fibroblasts are shown. Scale bar = 10 μm. B, M-FISH karyotype of fibroblasts maintained under oxic (21% O2) conditions following 2 Gy of irradiation or hypoxic (0.2% O2) conditions following 2 Gy of irradiation. Shown are reciprocal translocation between chromosomes 2 and 17, loss of chromosome 20 and two extra copies of chromosome Y in hypoxic cells following 2 Gy of irradiation. C, Percentages of chromosomal aberrations in oxic and hypoxic fibroblasts as measured by Giemsa staining analysis. NIR = non-irradiated; white columns = oxia (21% O2); black columns = hypoxia (0.2% O2). D, Percentages of chromosomal aberrations in oxic and hypoxic fibroblasts as measured by M-FISH analysis. NIR = non-irradiated; white columns = oxia (21% O2); black columns = hypoxia (0.2% O2). Plots are based on quantitative assessment of data published in Kumareswaran et al. [82].