Inhibitory effect of deuterium-depleted water on proliferation of lung carcinoma cells and the possible mechanism
目的:初步探討低氘水(deuterium-depleted water,DDW)在體內外對人肺癌細胞增殖的抑制作用及其可能機制.方法:MTT法檢測DDW對肺癌A549細胞和正常人胚肺成纖維細胞HLF-1增殖的抑制作用,TUNEL法檢測A549細胞凋亡情況,流式細胞儀檢測細胞週期的變化.建立BALB/c裸鼠人肺癌H460細胞移植瘤模型,低氘水飲用60 d後觀察裸鼠移植瘤的生長情況.結果:與對照組比較,培養10 h時體積分數為0.0025%、0.0050%和0.0105%的DDW對A549 細胞增殖具有顯著抑制作用(P<0.05),隨後抑制作用消失,48 h後又逐漸出現抑制現象,72 h抑制作用顯著(P<0.05);相同條件下不同體積分數的DDW對正常人胚肺成纖維細胞HLF-1無顯著抑制作用.TUNEL染色顯示,0.005%DDW作用後A549細胞出現凋亡,凋亡率顯著高於對照組細胞[(25.38±3.90)% vs (10.87±1.11)%), P<0.05].流式細胞儀檢測顯示,DDW作用後A549細胞S期細胞顯著增加(P<0.05).人肺癌細胞H460移植瘤裸鼠飲用DDW後,能夠明顯提高裸鼠的生活質量,抑瘤率達30.08%.結論:DDW對肺癌細胞增殖的抑制作用僅限於一定的劑量範圍,且具有波動性和時段性的特點;其機制可能與誘導肺癌細胞S期阻滯和細胞凋亡有關.
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±030]%, 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.