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.

Key words: 
Fanconi anemia, head and neck squamous carcinoma, nutrient mixture, tumor growth, MMPs, Matrigel invasion, cell migration

Access: 
http://www.spandidos-publications.com/10.3892/ijo.2012.1639