Textile industry manufacturing by-products induce human melanoma cell proliferation via ERK1/2 activation

Objectives: Textiles used to make clothing can represent a source, often ignored, of chemicals potentially noxious to both skin and the whole organism. Among the most frequently produced potentially noxious chemical manufacturing by-products are formaldehyde (FA), nickel (Ni) and hexavalent chromium (Cr); they are of potential clinical interest as all are known to be carcinogenic to humans and to be potent skin sensitizers. The aim of this study was to investigate, in vitro, effects of these potentially dangerous compounds on two different melanoma cell lines. In particular, attention was focused on A375P, a poorly metastatic and low invasive cell line and SK-MEL-28, a highly metastatic cell line. Materials and methods: Effects of these compounds was evaluated on A375P and SK-MEL-28 cells. FA (1-5 × 10^-5 m), NiSO₄ (10^-6-10^-3 m), K₂Cr₂O₇ (10^-7-10^-6 m) effects on cell proliferation were evaluated by cell counting, while ERK pathway involvement was evaluated by Western blot analysis. Results: Low concentrations of the chemicals, covering a range that corresponds to commonly accepted limits in textile production, induced a significant increase in cell proliferation concomitant with transient activation of phosphorylated ERK expression. Conclusions: Data obtained suggest that increasing attention must be focused on these by-products' potentially harmful effects in chemical manufacturing of clothes and accessories, that remain for long periods of time, in contact with human skin.