Cytokines, inducers and inhibitors modulate MMP-2 and MMP-9 secretion by human Fanconi anemia immortalized fibroblasts

Abstract

Acute myeloid leukemia and head and neck squamous cell carcinomas are the major causes of mortality and morbidity in Fanconi anemia (FA) patients. Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, have been implicated in tumor invasion and metastasis. Various cytokines, mitogens, growth factors, inducers and inhibitors control MMP activities. We investigated the roles of these in the regulation of MMP-2 and MMP-9 in human immortalized fibroblasts from FA. Human FA immortalized fibroblast cell lines FA-A:PD220 and FA-D2:PD20 were grown in minimum essential medium (MEM) supplemented with 15% fetal bovine serum (FBS) and antibiotics in 24-well tissue culture plates. At near confluence, the cells were washed with phosphate-buffered saline (PBS) and incubated in serum-free media with the following: phorbol 12-myristate 13-acetate (PMA) at 10-100 ng/ml; tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) at 0.1-25 ng/ml; lipopolysaccharide (LPS) at 10-100 μg/ml; epigallocatechin gallate (EGCG) and doxycycline (Dox) at 10-100 μM without and with PMA; a nutrient mixture (NM) without and with PMA at 10-1,000 μg/ml; actinomycin-D and cyclohexamide at 2 and 4 μM; retinoic acid and dexamethasone at 50 μM. After 24 h, media were removed and analyzed for MMP-2 and MMP-9 by zymography. Both FA cell lines expressed only MMP-2 and responded similarly to cytokines, mitogens, inducers and inhibitors. PMA potently stimulated MMP-9 and had a moderate effect on MMP-2. TNF-α showed variable effects on MMP-2 and significantly enhanced MMP-9. IL-1β enhanced MMP-2 slightly and MMP-9 significantly. LPS had a moderate stimulatory effect on MMP-2 and no effect on MMP-9. EGCG, Dox and NM, without and with PMA, downregulated MMP-2 and MMP-9 expression. Actinomycin-D, retinoic acid and dexamethasone also had inhibitory effects on MMP-2. Our results showed that cytokines, mitogens and inhibitors modulated FA fibroblast MMP-2 and MMP-9 expression, suggesting the clinical use of MMP inhibitors, particularly such potent and non-toxic ones as the NM and its component EGCG in the management of FA cancers.