J Cancer Prev.  2019 Sep;24(3):183-191. 10.15430/JCP.2019.24.3.183.

15-Deoxy-Δ(12,14)-prostaglandin J₂ Upregulates the Expression of 15-Hydroxyprostaglandin Dehydrogenase by Inducing AP-1 Activation and Heme Oxygenase-1 Expression in Human Colon Cancer Cells

• Park JM
• Na HK

• KMID: 2468800
• DOI: http://doi.org/10.15430/JCP.2019.24.3.183

Abstract

BACKGROUND
Abnormal upregulation of prostaglandin E₂ (PGE₂) is considered to be a key oncogenic event in the development and progression of inflammation-associated human colon cancer. It has been reported that 15-hydroxyprostaglandin dehydrogenase (15-PGDH), an enzyme catabolizing PGE₂, is ubiquitously downregulated in human colon cancer. 15-Deoxy-Δ(12,14)-prostaglandin J₂ (15d-PGJ₂), a peroxisome proliferator-activated receptor γ ligand, has been shown to have anticarcinogenic activities. In this study, we investigate the effect of 15d-PGJ₂ on expression of 15-PGDH in human colon cancer HCT116 cells.
METHODS
HCT116 cells were treated with 15d-PGJâ‚‚ analysis. The expression of 15-PGDH in the treated cells was measured by Western blot analysis and RT-PCR. In addition, the cells were subjected to a 15-PGDH activity assay. To determine which transcription factor(s) and signaling pathway(s) are involved in 15d-PGJâ‚‚-induced 15-PGDH expression, we performed a cDNA microarray analysis of 15d-PGJâ‚‚-treated cells. The DNA binding activity of AP-1 was measured by an electrophoretic mobility shift assay. To determine whether the AP-1 plays an important role in the 15d-PGJâ‚‚-induced 15-PGDH expression, the cells were transfected with siRNA of c-Jun, a major subunit of AP-1. To elucidate the upstream signaling pathways involved in AP-1 activation by 15d-PGJâ‚‚, we examined its effect on phosphorylation of Akt by Western blot analysis in the presence or absence of kinase inhibitor.
RESULTS
15d-PGJ₂ (10 μM) significantly upregulated 15-PGDH expression at the mRNA and protein levels in HCT-116 cells. 15-PGDH activity was also elevated by 15d-PGJ₂. We observed that genes encoding C/EBP delta, FOS-like antigen 1, c-Jun, and heme oxygenase-1 (HO-1) were most highly induced in the HCT116 cells following 15d-PGJ₂ treatment. 15d-PGJ₂ increased the DNA binding activity of AP-1. Moreover, transfection with specific siRNA against c-Jun significantly reduced 15-PGDH expression induced by 15d-PGJ₂. 15d-PGJ₂ activates Akt and a pharmacological inhibitor of Akt, LY294002, abrogated 15d-PGJ₂-induced 15-PGDH expression. We also observed that an inhibitor of HO-1, zinc protoporphyrin IX, also abrogated upregulation of 15-PGDH and down-regulation of cyclooxygenase-2 expression induced by 15d-PGJ₂.
CONCLUSIONS
These finding suggest that 15d-PGJâ‚‚ upregulates the expression of 15-PGDH through AP-1 activation in colon cancer HCT116 cells.

Keyword

15-deoxy-Δ(12,14)-prostaglandin J₂; 15-PGDH; AP-1; HO-1; Colon cancer

MeSH Terms

Blotting, Western
Colon*
Colonic Neoplasms*
Cyclooxygenase 2
DNA
Down-Regulation
Electrophoretic Mobility Shift Assay
HCT116 Cells
Heme Oxygenase-1*
Heme*
Humans*
Oligonucleotide Array Sequence Analysis
Oxidoreductases*
Peroxisomes
Phosphorylation
Phosphotransferases
RNA, Messenger
RNA, Small Interfering
Transcription Factor AP-1*
Transfection
Up-Regulation
Zinc
Cyclooxygenase 2
DNA
Heme
Heme Oxygenase-1
Oxidoreductases
Phosphotransferases
RNA, Messenger
RNA, Small Interfering
Transcription Factor AP-1
Zinc