Other tumor types
The antitumor effect of DDW has been verified in preclinical and clinical studies carried out with several tumorous cell lines and tumor types.
In the first in vitro studies DDW inhibited the growth of the L929 cell line in tissue culture. To get further evidence on the inhibitory effect of DDW on cell growth, the DNA synthesis was followed by measuring the incorporation of tritiated thymidine. After testing three different human tumorous cell lines (MCF-7, breast; PC-3, prostate; M14, melanoma) we could concluded, that the replacement of normal medium with D-depleted medium resulted in a delay of cell proliferation. The same effect was found in HT-29 colon tumor cell line.
In vitro stable isotope-based metabolic profiling studies were also performed to determine the metabolic flux-modifying effects of DDW compared to water with normal deuterium content on [1,2-13C2]-D-glucose metabolism in cultured pancreatic (MIA-PaCa), lung (H-441) and breast (MCF-7) ductal carcinoma cells. It became evident that decreased deuterium to hydrogen ratios regulate sterol and fatty acid precursor synthesis, which likely affects the rate of division and cellular proliferation via limited reductive synthesis and new membrane formation.
The effect of DDW was investigated in vivo in immunosuppressed mice transplanted with human breast tumor. Eighty days after transplantation in 10 (59%) out of 17 tumorous mice the tumor, which initially grew, regressed and then disappeared. DDW also slowed down the tumor growth in immunosuppressed CBA/Ca mice transplanted with PC-3 human prostatic cells.
All tumor types responded favourably to DDW within a couple of weeks or within a couple of months depending on the size and the type of the tumor, in animals suffering from different tumor types (lymphoid leucosis, breast tumor, rectum tumor, epithelioma, diffuse seminoma), in spite of the variance of tumors. The tumor type was histologically verified in each case and tumor size was followed. Less striking effect of deuterium depletion was found in sarcomatoid tumors and melanoma.
The above studies and further retrospective human observations show that DDW may have a beneficial effect in kidney, bladder, breast, lung, prostate, stomach, colon, rectum, brain, gynecological, head and neck as well as haematopoietic tumors ((AML, ALL, CML, CLL, MM) and in lymphomas.
It is evident from the results that DDW is not specific against a certain type of tumor, but can be effective in general, however the sensitivity of tumor types is very different. DDW exerts its antitumor effect through those genetic and biochemical processes which are common in the different tumor types.