Cancer stem cells play an important role in resistance of laryngeal squamous cancer to irradiation mediated by hypoxia
10.3760/cma.j.issn.1673-0860.2011.12.011
- VernacularTitle:喉癌干细胞在低氧介导的喉癌放疗抵抗中的作用机制
- Author:
Mao-Xin WANG
1
;
Xiao-Ming LI
;
Yong ZHAO
;
Xiu-Ying LU
;
Yong-Tao QU
;
Ou XU
;
Qing-Jia SUN
Author Information
1. 解放军总医院耳鼻咽喉头颈外科医院
- Keywords:
Neoplastic stem cells;
Laryngeal neoplasms;
Hypoxia;
Radiotherapy;
Hypoxiainducible factor 1,alpha subunit
- From:
Chinese Journal of Otorhinolaryngology Head and Neck Surgery
2011;46(12):1024-1029
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study whether laryngeal cancer stem cells in hypoxia have the characteristic of resistance to irradiation and underlying mechanism.Methods CD133 + cells were separated from Hep-2 cells with flow cytometry(FCM)and the purity was 92.8％.The separated CD133 + cells were cultured in serum-free medium in hypoxia in normoxia enviroment respetively,and hypoxiainducible factor 1 alpha(HIF-1α)expression was detected by FCM.The cells were exposed respectively to X-rays emitted by linear accelerator with a dose of 0,5,10,15 or 20 Gy for 24 hours,with additional time points of 12,36,and 48 hours for the cells exposed to 10 Gy.Then the growth inhibition ratios of ceils in hypoxia and normoxia groups were detected with MTT assay at different time points.Soft agar colony formation assay was used to dectect colony formation ratios of cells in hypoxia and normoxia groups.DNA dependent protein kinase catalytic subunit(DNA-PKcs),ataxiatelangiectasia mutate(ATM),Survivin and P53 were detected by FCM.Results Growth inhibition ratio of CD133 + cells in hypoxia group was lower than that in normoxia group(P ＜0.05).Colony formation ratio of CD133 + cells was higher than that of CD133-cells(P ＜ 0.01)and the ratio of CDi33 + cells in hypoxia group was higher than that in nonnoxia group(P ＜0.05).The ratio of hypoxia group was not affected by irradiation,while the ratio of normoxia group decreased significantly after irradiation(P ＜ 0.05).The expressions of DNA-PKcs,ATM,Survivin and P53 in CD133+ cells were higher than those in CD133-cells respectively(P ＜0.01).In CD133 + cells with radiation,the expressions of DNA-PKcs and Survivin of hypoxia group were higher those of normoxia group(P ＜ 0.05),but no difference in the expression of ATM or P53 between the two groups.Conclusions Laryngeal cancer stem cells play an important role in radioresistance mediated by hypoxia.
