Regulation of the eicosanoid pathway by tumour necrosis factor alpha and leukotriene D4 in intestinal epithelial cells.
In this study the mRNA and protein levels of the key enzymes involved in eicosanoid biosynthesis and the cysteinyl leukotriene receptors (CysLT1R and CysLT2R) have been analysed in non-transformed intestinal epithelial and colon cancer cell lines. Our results revealed that tumour necrosis factor alpha (TNF-alpha), and leukotriene D4 (LTD4), which are inflammatory mediators implicated in carcinogenesis, stimulated an increase of cyclooxygenase-2 (COX-2), in non-transformed epithelial cells, and 5-lipoxygenase (5-LO) in both non-transformed and cancer cell lines. Furthermore, these mediators also stimulated an up-regulation of LTC4 synthase in cancer cells as well as non-transformed cells. We also observed an endogenous production of CysLTs in these cells. TNF-alpha and LTD4, to a lesser extent, up-regulate the CysLT1R levels. Interestingly, TNF-alpha also reduced CysLT2R expression in cancer cells. Our results demonstrate that inflammatory mediators can cause intestinal epithelial cells to up-regulate the expression of enzymes needed for the biosynthesis of eicosanoids, including the cysteinyl leukotrienes, as well as the signal transducing proteins, the CysLT receptors, thus providing important mechanisms for both maintaining inflammation and for tumour progression.
Yudina
Yulyana
Y
Cell and Experimental Pathology, Department of Laboratory Medicine, Lund University, Malmö University Hospital, CRC, Entrance 72, Building 91, Floor 11, SE-205 02 Malmö, Sweden.
Parhamifar
Ladan
L
Bengtsson
Astrid M-L
AM
Juhas
Maria
M
Sjölander
Anita
A
D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015777:Eicosanoids / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007422:Intestines / Q000166:cytology; D017998:Leukotriene D4 / Q000494:pharmacology*; D018077:Receptors, Leukotriene / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D015777:Eicosanoids; D018077:Receptors, Leukotriene; D014409:Tumor Necrosis Factor-alpha; D017998:Leukotriene D4; C412375:cysteinyl leukotriene receptor 2; D001094:Arachidonate 5-Lipoxygenase; D051546:Cyclooxygenase 2; C083169:leukotriene D4 receptor