Abstract. to investigate the in vivo and in vitro inhibitory effects of deuterium-depleted water (ddW) on human lung cancer and the possible mechanisms underlying these effects, we cultured and treated human lung carcinoma cell line A549 and human embryonic lung fibroblasts HLF-1 with various concentrations of ddW from 2 to 72 h. cellular growth inhibition rates were determined using the 3-(4, 5-dimethyldiazol-2-yl)-2, 5-diphenyltetrazolium-bromide) (mtt) proliferation assay. a549 cells were treated with 50±5 ppm ddW, and the morphology and structure of cells were observed by scanning electron microscopy (Sem). We observed alterations in the cellular skeleton by transmission electron microscopy (tem) and changes in cell cycle by flow cytometry. Our data showed that DDW significantly inhibited the proliferation of A549 cells at a specific time point, and cells demonstrated the characteristic morphological changes of apoptosis under Sem and tem. the length of the S phase increased significantly in cells treated with 50 ppm ddW, whereas the G0 to G1 phase and G2 to m phase were decreased. We observed ddW-induced cellular apoptosis using terminal deoxynucleotidyl transferase dutp nick end labeling (tunel) and dna fragment analyses. in addition, we established a tumor transplantion model by injecting h460 tumor cells into subcutaneous tissue of BalB/c mice treated with ddW for 60 days. We determined the tumor inhibition rate of treated and control groups and found that the tumor weight was significantly decreased and the tumor inhibition rate was approximately 30% in the ddW group. We conclude that ddW is a promising new anticancer agent with potential for future clinical application.
Introductionlung cancer is one of the leading causes of death by cancer worldwide; approximately 80% of lung cancers can be histologically classified as non-small cell lung cancers (nSclcs). most patients present with locally advanced (37%) or metastatic (38%) disease at the time of diagnosis (1). despite advances in chemotherapy, the average 5-year survival rate for patients with advanced nSclc remains extremely poor (2), thus new agents are needed to establish an effective therapeutic strategy against nSclc. there is great interest in developing new preventive and anti-tumor agents that are more effective and less toxic. it has recently been suggested that deuterium-depleted water (ddW) may play a potentially beneficial role in cancer prevention (3).in nature, the ratio between deuterium and hydrogen (d/h) in ordinary water is approximately 1:6600 (4). it has been known for decades that the mass difference between hydrogen and deuterium leads to differences in the physical and chemical behavior of the two stable isotopes (5,6). in biological systems, the effect of replacing hydrogen with deuterium has also been well documented (7,8). early studies revealed that the life span of mice with ascites tumors was prolonged by drinking 25-30% deuterium water (deuterated water) (9), and the mortality caused by 60 co irradiation in mice was sig...