Tumor promoter TPA stimulates MMP-9 secretion from human keratinocytes by activation of superoxide-producing NADPH oxidase

Abstract

Matrix metalloproteinase-9 (MMP-9) is involved in physiological tissue remodelling processes as well as in tumor invasion and metastasis. The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) increases MMP-9 secretion from normal human epidermal keratinocytes (NHEK) in vivo and in vitro. Here we show that the flavoprotein inhibitor diphenyleneiodinium (DPI) and the NADPH oxidase inhibitor apocynin block TPA-induced MMP-9 secretion of NHEK in vitro. Furthermore, N-acetyl-L-cysteine and L-cysteine lowered TPA-induced MMP-9 secretion, suggesting an involvement of reactive oxygen species(ROS). TPA exerts its effect on MMP-9 gene expression and secretion via the superoxide-producing enzyme NADPH oxidase: TPA rapidly stimulates generation of superoxide anion as well as gene expression of two cytosolic NADPH oxidase subunits (p47-phox and p67-phox) after 2 h, which is followed by induction of MMP-9 gene expression after 4 h. Taken together, the novel finding herein is the TPA-induced MMP-9 secretion from normal human epidermal keratinocytes through a NADPH oxidase dependent pathway.

Heme oxygenase-1 inhibits breast cancer invasion via suppressing the expression of matrix metalloproteinase-9

“…In epidermal keratinocytes, TPA induces MMP-9 secretion through activation of NADPH oxidase (45), and in hepatoma cells, TPA increases tumor migration via ROS production (19). These data suggest that ROS elevation may contribute to tumor progression.…”

The NOX Family of ROS-Generating NADPH Oxidases: Physiology and Pathophysiology

“…There is ample evidence that NOX-derived ROS are involved in the regulation of expression and/or activation of matrix metalloproteinases (130,199,329,412,540,561,763,831,906,978). However, while most studies report a stimulatory role of NOX enzymes on matrix metalloproteinase expression, recent in vivo data from NOX2-deficient mice appear to suggest that the absence of NOX2 might also lead to elevated matrix metalloproteinase levels (440,578,902).…”

“…violet light (69,934) and to phorbol esters (831). Interestingly, these ROS responses can be blocked by NADPH oxidase inhibitors, raising the possibility that ROS generation even in response to ultraviolet light is not simply a physicochemical process, but might involve NOX enzymes.…”

Delaying of insulin signal transduction in skeletal muscle cells by selenium compounds

“…Presence of intracellular ROS was determined using 2′,7′-dichlorodihydrofluorescein diacetate (H 2 DCFDA) (Merck) as described [25] with slight modifications: L6 myotubes were cultured for 24 h in serum-free DMEM with or without Se compounds in 96-well black microplates (Greiner Bio-One, Frickenhausen, Germany), and loaded for 30 min with 30 μM H 2 DCFDA in Hank's buffered saline (HBSS). To assure linearity of the measurement, DCF fluorescence was monitored for 30 min with a Fluostar Optima plate reader (BMG Labtech; Offenburg, Germany) at 485 nm (excitation wavelength) and 520 nm (emission wavelength).…”