Background. Vitamin D3 is a potent regulator of cell growth, differentiation and death, tumour invasion, and angiogenesis. Production of matrix metalloproteinase (MMP)-9 and MMP-13 by tumour cells may promote tumour growth, invasion and metastasis.
Aim. To investigate whether calcipotriol could suppress the expression of MMP-9 and MMP-13 in a human squamous cell carcinoma (SCC) cell line (DJM cells), and to examine the mechanism of modulation of MMP-9 and MMP-13 by calcipotriol in DJM cells treated with tumour necrosis factor (TNF)-α.
Methods. Protein and mRNA levels of MMP-9 and MMP-13 were examined by ELISA and real-time PCR, respectively. Activation of signalling cascades was assessed using several inhibitors of signalling molecules and western blot analysis.
Results. Production of MMP-9 and MMP-13 markedly increased when the cells were treated with TNF-α. Calcipotriol suppressed the production of MMP-9 and MMP-13 mRNA and proteins significantly, in a dose-dependent manner. Induction of MMP-9 by TNF-α was suppressed by an extracellular signal-regulated kinase (ERK) inhibitor but not by a p38 inhibitor, whereas induction of MMP-13 was inhibited by a p38 inhibitor but not by an ERK inhibitor. Calcipotriol inhibited the phosphorylation of both ERK and p38, as shown by western blotting.
Conclusion. Calcipotriol reduces MMP-9 and MMP-13 production through inhibiting the phosphorylation of ERK and p38, respectively.