Objective: To investigate the effect of X-ray radiation at the median lethal dose (LD50) on the outcome of a cluster of differentiation 133 (CD133)- cells in nasopharyngeal carcinoma.
Materials and methods: CD133- cells were obtained from human nasopharyngeal carcinoma cells (CNE-1 and CNE-2) based on CD133-labeled fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS), respectively. Changes in invasion ability and in-vivo tumorigenicity of CD133- cells before and after X-ray radiation at LD50 were observed. Moreover, CD133, SRY-related HMG-box 2 (SOX2), and organic carnitine transporter 4 (OCT4) expression changes were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.
Results: The invasion ability and in-vivo tumorigenicity of CD133+ cell subsets were significantly stronger than those of CD133- cell subsets. After X-ray radiation at LD50, the invasion ability of CD133- cell subsets and in-vivo tumorigenicity were significantly increased. RT-PCR and Western blotting results manifested that the expression levels of CD133, SOX2, and OCT4 were remarkably up-regulated after radiation.
Conclusions: X-ray radiation at LD50 can enhance the stemness potential by up-regulating the expression of stemness-related genes in nasopharyngeal carcinoma CD133- cells.