Epigenetic regulation of proMMP-1 expression in the HT1080 human fibrosarcoma cell line

Abstract

Abstract. The matrix metalloproteinase (MMP) family members play an important role in various physiological and pathological processes. Although MMP-1 (collagenase-1) has been shown to be involved in tumor invasiveness, the regulation of its expression is still not fully elucidated and could implicate epigenetic mechanisms. The aim of this study was to analyze the effects of the Histone Deacetylase Inhibitor (HDI) trichostatin A (TSA) and the inhibitor of DNA methylation 5-aza-2'-deoxycytidine (5-azadC) on the proMMP-1 expression in the human HT1080 fibrosarcoma cell line. Real-time RT-PCR revealed that 5-azadC or 5-azadC + TSA but not TSA alone, despite global histone H4 hyperacetylation, increased proMMP-1 mRNA levels. This transcription activation was correlated with chromatin decondensation determined by nuclear texture image analysis technique. Western blot analysis of cell culture conditioned media revealed a significant increase in proMMP-1 secretion after 5-azadC or 5-azadC + TSA treatment compared to untreated cells. These results suggested that epigenetic mechanisms could be involved in proMMP-1 gene expression including chromatin supra-organization changes. Indeed, although the proMMP-1 gene promoter does not appear to contain CpG islands, its expression can be induced by the demethylating agent 5-azadC. Further experiments revealed that inhibition of protein neosynthesis by cycloheximide decreased 5-azadC-induced proMMP-1 mRNA, suggesting that epigenetically regulated intermediate molecules could be involved in proMMP-1 expression regulation in these cells.

Matrix metalloproteinase‑1 expression is regulated by HIF‑1‑dependent and epigenetic mechanisms and serves a tumor‑suppressive role in gastric cancer progression

“…Previously, the upregulation of MMP-1 by HIF-1α has been reported in metastatic bladder cancer cells ( 59 ). Epigenetic regulation of MMP-1 expression is also reported in a previous study, in which 5-aza-dC plus TSA treatments increases MMP-1 mRNA expression in a human fibrosarcoma cell line ( 58 ). The present study demonstrated that both HIF-1α-dependent and epigenomic mechanisms are involved in regulating MMP-1 expression in GC cell lines.…”

“…These results clearly demonstrated that MMP-1 expression was directly upregulated by HIF-1α in hypoxic 58As9 cells. In addition, combination treatment with 5-aza-dC and TSA significantly increased MMP-1 expression in MMP-1-deficient MKN45 and MKN74 cells, which suggested that epigenetic mechanisms, including chromatin supraorganization, may play an important role in silencing MMP-1 expression ( 57 , 58 ). Previously, the upregulation of MMP-1 by HIF-1α has been reported in metastatic bladder cancer cells ( 59 ).…”

Regulation and involvement of matrix metalloproteinases in vascular diseases

“…Another study suggested that proMMP-1 expression is influenced by epigenetics in human fibrosarcoma cells even though its promoter is not believed to possess CpG islands, yet proMMP-1 expression increased under 5-aza-dC treatment which was mitigated with cycloheximide suggesting epigenetic regulation through some other intermediate product (153). Enzymes involved in the pathology, mainly MMP-9 and superoxide dismutase 2, of diabetic retinopathy have been reported to be under the epigenetic regulation of histone lysine demethylase 1, (LSD1) and DNMT (154).…”