School of Life Sciences, Lanzhou University, PR China.
Cancer Biother Radiopharm. 2012 Mar;27(2):113-8. doi: 10.1089/cbr.2011.1037. Epub 2012 Jan 13.
We aimed to investigate the effects of (12)C(6+) irradiation on the cell cycle and apoptosis as well as the associated mechanisms in the human lung cancer cell line H1299.
After irradiation with different doses of (12)C(6+) for varying lengths of incubation, the changes in H1299 cells were assayed by flow cytometry and the microculture tetrazolium test. The expression of caspase-3 was detected by immunocytochemistry, western blot, and reverse transcription-polymerase chain reaction (RT-PCR).
The G(2)/M phase was blocked after treatment with 1 and 2 Gy at the 12-hour time point, and the most obvious block of G(2)/M occurred after treatment with 2 and 4 Gy at the 24-hour time point in a dose-dependent manner. The apoptosis rate increased with increasing radiation dose and reached a peak after the cells were irradiated with 2 Gy and incubated for 48 hours. In addition, the RT-PCR, western blot, and ICC results showed that irradiation with (12)C(6+) significantly increased the expression of caspase-3 compared with the control group (p<0.05).
Irradiation of H1299 cells with (12)C(6+) induced apoptosis and significantly inhibited their growth through heavy ion irradiation-mediated activation of the caspase-3 pathway. Our results show that caspase-3 may play an important role in radiation-induced apoptosis through a p53-independent pathway.
本研究旨在探讨（12）C（6+）辐照对人肺癌细胞系 H1299 细胞周期和凋亡的影响及其相关机制。
用不同剂量的（12）C（6+）辐照不同孵育时间后，采用流式细胞术和微量细胞培养四唑盐试验检测 H1299 细胞的变化。用免疫细胞化学、western blot 和逆转录-聚合酶链反应（RT-PCR）检测 caspase-3 的表达。
1 和 2 Gy 处理 12 小时后，G2/M 期被阻断，2 和 4 Gy 处理 24 小时后，G2/M 期被剂量依赖性阻断最为明显。细胞凋亡率随辐射剂量的增加而增加，在细胞接受 2 Gy 照射并孵育 48 小时后达到峰值。此外，RT-PCR、western blot 和 ICC 结果表明，与对照组相比，（12）C（6+）辐照显著增加了 caspase-3 的表达（p<0.05）。
（12）C（6+）辐照 H1299 细胞诱导细胞凋亡，并通过重离子辐照介导的 caspase-3 途径显著抑制其生长。我们的结果表明，caspase-3 可能通过一种不依赖 p53 的途径在辐射诱导的凋亡中发挥重要作用。
