title: Effects of carbon-ion beam or X-ray irradiation on anti-apoptosis ΔNp73 expression in HeLa cells.
abstract: ΔNp73 has emerged as an interesting novel factor in cancer research. Here, we report the effect of carbon-ion beams on ΔNp73 expression in human cervix carcinoma HeLa cells in contrast to the effect of X-rays. Cellular sensitivities were determined by colony formation. Radiation-induced cell cycle arrest was investigated with flow cytometry. Additionally, radiation-induced apoptosis was analyzed with flow cytometry and Hoechst staining. Furthermore, ΔNp73 expression was examined by semi-quantitative reverse transcription-PCR (semi-quantitative RT-PCR) as well as by Western blot analysis. Following irradiation, stronger G2/M phase arrest, more significant increase in apoptosis and more pronounced ΔNp73 degradation were observed after exposure to high-LET carbon beams in comparison with X-rays at 4 Gy doses. These observations indicate that there is a differential ΔNp73 expression in response to different LET radiations, and down-regulated ΔNp73 expression might play a critical role in promoting cycle arrest and apoptosis in cancer cells. This study highlights the potential of ΔNp73 in radiotherapy.
authors.affiliation: Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Cui-Xia
authors.initials: CX
authors.lastname: Di
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Yang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Li-Zhe
authors.initials: LZ
authors.lastname: An
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Ma
authors.forename: Chao
authors.initials: C
authors.lastname: Sun
authors.forename: Xiao-Hu
authors.initials: XH
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Yang
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Si
mesh_terms: D017209:Apoptosis / Q000235:genetics / Q000528:radiation effects*; D059447:Cell Cycle Checkpoints / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects*; D006367:HeLa Cells; D006801:Humans; D018499:Linear Energy Transfer; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism; D014965:X-Rays / Q000009:adverse effects
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins; C000606369:delta Np73 protein, human