低氘水对肺癌细胞增殖的抑制作用及其可能的机制

目的：初步探讨低氘水（deuteriumdepleted water，DDW）在体内外对人肺癌细胞增殖的抑制作用及其可能机制。方法：MTT法检测DDW对肺癌A549细胞和正常人胚肺成纤维细胞HLF1增殖的抑制作用，TUNEL法检测A549细胞凋亡情况，流式细胞仪检测细胞周期的变化。建立BALB/c裸鼠人肺癌H460细胞移植瘤模型，低氘水饮用60 d后观察裸鼠移植瘤的生长情况。结果：与对照组比较，培养10 h时体积分数为0.0025％、0.0050％和0.0105％的DDW对A549 细胞增殖具有显著抑制作用（P<0.05），随后抑制作用消失，48 h后又逐渐出现抑制现象，72 h抑制作用显著（P<0.05）；相同条件下不同体积分数的DDW对正常人胚肺成纤维细胞HLF1无显著抑制作用。TUNEL染色显示，0.005%DDW作用后A549细胞出现凋亡，凋亡率显著高于对照组细胞\（25.38±3.90）% vs (10.87±1.11)%), P<0.05\]。流式细胞仪检测显示，DDW作用后A549细胞S期细胞显著增加（P<0.05）。人肺癌细胞H460移植瘤裸鼠饮用DDW后，能够明显提高裸鼠的生活质量，抑瘤率达30.08%。结论：DDW对肺癌细胞增殖的抑制作用仅限于一定的剂量范围，且具有波动性和时段性的特点；其机制可能与诱导肺癌细胞S期阻滞和细胞凋亡有关。

Inhibitory effect of deuterium depleted water on proliferation of lung carcinoma cells and the possible mechanism

Objective:To explore the in vitro and in vivo inhibitory effects of deuterium-depleted water (DDW) on the proliferation of human lung carcinoma cells, and to explore the possible mechanism. Methods: The inhibitory effect of DDW on the proliferation of human lung carcinoma A549 cells and human embryonic lung fibroblast HLF-1 cells was examined by MTT assay; apoptosis of A549 cells was examined by TUNEL; and cell cycle was analyzed by flow cytometry. Mouse model of lung carcinoma was established by inoculating human lung carcinoma H460 cells into BALB/c nude mice, and the growth of implanted tumors was observed after DDW treatment for 60 d. Results: Compared with control group, A549 cells treated with 0.0025％, 0.0050％ or 0.0105％ DDW showed significantly decreased proliferation 10 h after treatment (P<0.01). Then the inhibitory effects of DDW gradually disappeared, but appeared 48 h later again, with the inhibitory effects at 72 h being significant (P<0.05). DDW at the same dosages showed no inhibition on the proliferation of HLF-1 cells (P>0.05). TUNEL assay verified the apoptosis of DDW-treated A549 cells, and the apoptosis rate of DDW-treated A549 cells was significantly higher than that of control group（45.30±4.21]% vs 22.25±030]%, P<0.01). Cells in S phase were significantly increased in DDW-treated A549 cells compared with those in the control group (P<0.05). The life quality of H460 cell-inoculated nude mice treated with DDW was greatly improved, with the tumor inhibition rate being 30.08%. Conclusion: DDW can inhibit the proliferation of lung cancer cells within a certain range of dosage and in a fluctuating pattern; its mechanism might be associated with induction of apoptosis and cell cycle arrest in S phase of tumor cells.