Abstract:
Objective This study aims to investigate spontaneous cell apoptosis in the prediction of the radio-sensitivity of nasopharyngeal carcinoma(NPC) cells and the molecular foundation of differential spontaneous apoptosis rate.
Methods The surviving fractions and radiation biological parameters of well and poorly differentiated NPC cell lines(CNE-1/CNE-2) were determined through colony-forming assay and radiation dose-survival curve using a single-hit multi-target model and a linear quadratic model.Early-and late-stage apoptotic events were detected by flow cytometry on days 2, 4, 6, and 8.The mRNA and protein expression levels of apoptosis-correlated genes(Bcl-2, Bcl-xl, Bcl-w, Bax, Bad, Bid, and Bak) were detected using RT-PCR and western blot.
Results CNE-2 was more radio-sensitive than CNE-1, and CNE-2 exhibited higher rates of early-and late-stage apoptotic events than CNE-1 on the same culture days(P < 0.05).The mRNA and protein expression levels of Bcl-2, Bcl-xl, Bcl-w, Bax, Bad, Bid, and Bak were significantly higher in CNE-2 than in CNE-1(P < 0.05).
Conclusion The radio-sensitivity of NPC cells can be detected based on their spontaneous apoptosis rate, which is related to the different expression levels of apoptosis-correlated genes.