Effect of Iron on MMP-9 Expression in HNSCC Cell Lines

MMP-9 is a zinc-dependent endopeptidase which implicated in cancer invasion and metastasis. The regulation of MMP-9 is depended upon a large number of cytokines, growth factors and other stimuli, including iron. Iron is a crucial element for life but overload iron has been shown to positively associate with risk of various types of cancer.

Objectives: To investigate whether iron is able to modulate MMP-9 expression in head and neck squamous carcinoma (HNSCC) cell lines.

Methods: Cultures of HNSCC (HN-22 and OM-2) and normal keratinocyte (RT-7) cell lines were tested for iron toxicity in the form of ferric ammonium citrate (FAC) at 5, 15, 25 and 50 µg/ml for 24 hours by MTT analysis. After stimulation with FAC for 48 hours, conditioned media were analysed for MMP-9 expression by gelatin zymography. The results were analysed by statistical analysis of Paired T-test.

Results: FAC at non-toxic dose of 5 µg/ml increased the expression of MMP-9 in HN-22 and OM-2, whereas no effect on the expression of MMP-9 in RT-7.

Conclusion: Iron had the efficiency to increase the expression of MMP-9 in HNSCC cell lines more than that in normal keratinocyte cell line.