This prompted us to investigate the effect of a nutrient mixture containing lysine, proline, ascorbic acid, and green tea extract (NM) on the growth of human synovial sarcoma cell Hs 701.T xenografts in athymic nude mice, and on the invasive potential of human synovial sarcoma cells SW 982, in vitro.
Male nude mice, 5-6 weeks of age, were inoculated with 3x106 synovial sarcoma Hs 701.T cells, divided into two groups, and fed either a regular diet or a diet supplemented with 0.5% NM. After four weeks, tumors were excised, weighed, and processed for histology. In addition, the in vitro effect of NM on human synovial sarcoma cells SW 982 was evaluated: cell proliferation by MTT assay, MMP secretion by gelatinase zymography, and invasion through Matrigel.
NM reduced the size of synovial sarcoma tumors in nude mice by 44%. In vitro, NM inhibited the secretion of both MMPs in a dose-dependent fashion with virtual total inhibition of MMP-2 at 500 μg/ml and MMP-9 at 50 μg/ml concentration and blocked the invasion of human synovial sarcoma cells through Matrigel at 1000 μg/ml NM (p<0.0001).
Our results suggest NM is potentially an excellent candidate for therapeutic use in the treatment of synovial sarcoma, by inhibiting tumor growth and critical steps in cancer development, such as inhibiting MMP secretion and invasion.