Cells were also treated with PMA to induce MMP-9 activity. Cell proliferation was detected by MTT assay, secretion of MMPs by gelatinase zymography, invasion through Matrigel, migration by scratch test and morphology by H&E staining. In vivo, athymic male nude mice (n=12) were inoculated with 3x106 OHSU-974 cells subcutaneously and randomly divided into two groups: group A was fed a regular diet and group B a regular diet supplemented with 1% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. NM inhibited the growth of OHSU-974 tumor by 47% and tumor burden by 50%. At lower concentrations, NM demonstrated no effect on proliferation, but at 1000 µg/ml showed 40% toxicity. Zymography revealed MMP-2 and PMA-induced MMP-9 secretion. NM suppressed secretion of both MMPs in a dose-dependent manner; with virtual inhibition at 500 µg/ml. NM inhibited OHSU-974 invasion through Matrigel in a dose-dependent fashion with total block at 1000 µg/ml. H&E staining showed no morphological changes below 500 µg/ml. The results suggest that NM has potential therapeutic use in the treatment of human FA HNSCC.
Fanconi anemia, head and neck squamous carcinoma, nutrient mixture, tumor growth, MMPs, Matrigel invasion, cell migration