Telomere-Mitochondrion Links Contribute to Radiation-Induced Senescence in MCF-7 Cells

Heavy-ion radiotherapy has demonstrated the advantages over conventional radiotherapy , taking advantage of its improved dose conformation and higher relative biological effectiveness (Jakel et al., 2008). Telomerase is active in about 90% cancer cells which is important for cancer cells to maintain their immortalization. But the effects of heavy-ion radiation on telomere are largely unknown. Understanding how telomere influences sensitivity to carbon-ion is highly relevant given the emergence of telomerase inhibition as a potential cancer therapeutic modality. Currently few reports have investigated the effects of heavy-ion on telomere function. Durante et al. (2006) reported loss of telomere in the progeny of human lymphocytes after exposure to heavy-ion. Our previous findings showed that telomere function is closely related to carbon-ion radiation-induced cancer cell inactivation (Zhou et al., 2013), but the missing link between telomere dysfunction and cancer cell death remain elusive. Our previous paper found that carbon-ion radiation induced extensive senescence in breast cancer cells MCF-7 (Zhou et al., 2013). MCF-7 senescence has been reported