Carcinogenesis Advance Access originally published online on January 9, 2009
Carcinogenesis 2009 30(4):645-654; doi:10.1093/carcin/bgp012
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15-Deoxy-
12,14-prostaglandin J2 upregulates the expression of heme oxygenase-1 and subsequently matrix metalloproteinase-1 in human breast cancer cells: possible roles of iron and ROS
1 National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Shinlim-dong, Kwanak-ku, Seoul 151-742, South Korea
2 Cancer Research Institute, Seoul National University, Seoul 110-799, South Korea
3 Department of Pharmacology and Toxicology, College of Medicine, Inha University, Incheon 382-751, South Korea
4 Department of Dermatology, Seoul National University College of Medicine, Seoul 110-799, South Korea
* To whom correspondence should be addressed. Tel: +82 2 880 7845; Fax: +82 2 874 9775; Email: surh{at}plaza.snu.ac.kr
Heme oxygenase-1 (HO-1) has recently been found to be involved in angiogenesis and metastasis. In this study, we investigated whether HO-1 could potentiate the metastatic potential of human breast cancer cells. Treatment of MCF-7 and MDA-MB-231 cells with 30 µM of 15-deoxy-
12,14-prostaglandin J2 (15d-PGJ2) increased the expression of HO-1, which preceded the induction of matrix metalloproteinases (MMPs). The 15d-PGJ2-induced upregulation of MMP-1 was abrogated by the HO-1 inhibitor zinc protoporphyrin IX (ZnPP) as well as introduction of HO-1 short interfering RNA. In addition, HO-1 inducers, such as cobalt protoporphyrin IX and hemin, upregulated the expression of MMP-1. Overexpression of HO-1 in the MCF-7 cells caused the induction of MMP-1 expression. Treatment with the HO-1 inhibitor ZnPP abolished the migrative phenotype of 15d-PGJ2-treated MCF-7 cells. MCF-7 cells treated with 15d-PGJ2 exhibited intracellular accumulation of reactive oxygen species (ROS) which was abolished by ZnPP. We hypothesize that excess iron, released as a consequence HO-1 activity induced by 15d-PGJ2, is transiently available for the stimulation of intracellular ROS generation and subsequently MMP-1 expression. 15d-PGJ2-mediated upregulation of MMP-1 expression was blocked by the iron chelator desferrioxamine and the Fe2+-specific chelator 1,10-phenanthroline. The iron chelators as well as the antioxidant N-acetyl-L-cysteine abrogated ROS formation by 15d-PGJ2. In conclusion, 15d-PGJ2 upregulates MMP-1 expression via induction of HO-1 and subsequent production of iron capable of generating ROS, which may contribute to increased metastasis and invasiveness of the human breast cancer cells.
Abbreviations: cDNA, complementary DNA; CO, carbon monoxide; CoPP, cobalt protoporphyrin IX; COX-2, cyclooxygenase-2; Cp, crossing point; DCF-DA, dichlorofluorescein diacetate; DFX, desferrioxamine; 15d-PGJ2, 15-deoxy-12,14-prostaglandin J2; ECM, extracellular matrix; ER, estrogen receptor; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; HO-1, heme oxygenase-1; MMP, matrix metalloproteinases; mRNA, messenger RNA; NAC, N-acetyl-L-cysteine; PBS, phosphate-buffered saline; PCR, polymerase chain reaction; Phen, phenanthroline; PPAR
, peroxisome proliferator-activated receptor gamma; ROS, reactive oxygen species; siRNA, short interfering RNA; VEGF, vascular endothelial growth factor; ZnPP, zinc protoporphyrin IX; UV, ultraviolet
These authors equally contributed to this work. Received August 15, 2008; revised December 16, 2008; accepted January 6, 2009.