Interleukin-1alpha enhances IL-8 secretion through p38 mitogen-activated protein kinase and reactive oxygen species signaling in human pancreatic cancer cells

Med Sci Monit. 2005 Oct;11(10):BR343-50. Epub 2005 Sep 26.


Background: Interleukin (IL)-1alpha plays an important role in modulating the expression of various growth factors and angiogenic factors in tumor cells. In here, we investigated effect of IL-1alpha on IL-8 secretion in human pancreatic cancer cells and underlying signal transduction pathways.

Material/methods: IL-8 expression and secretion by pancreatic cancer cells was measured by Western blot and enzyme-linked immunosorbent assay (ELISA), respectively. Activation of extracellular signal regulated kinases-1/2 (ERK-1/2), p38 mitogen-activated protein kinase (MAPK), c-jun aminoterminal kinase, Akt, and nuclear factor-kappaB (NF-kappaB) was determined by Western blot. Involvement of reactive oxygen species (ROS) were examined by measuring the H2O2. Activity of activator factor-1 (AP-1) and NF-kappaB was examined by electrophoretic mobility sift assay (EMSA). Proliferation of human umbilical vein endothelial cells (HUVECs) was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye reduction method and cell count.

Results: IL-1alpha modulated IL-8 secretion and induced activation of ERK-1/2 and p38 MAPK. Specific inhibitors for MEK-1 and p38 MAPK suppressed IL-8 secretion. IL-1alpha also induced production of ROS. Exogenous H2O2 enhanced IL-8 secretion and N-acetyl cysteine (NAC) prevented IL-1alpha-induced ROS production and IL-8 secretion. EMSA confirmed that IL-1alpha increased DNA-binding activity of AP-1 and NF-kappaB. Inhibitors and ROS scavenger studies revealed that upstream signalings for AP-1 and NF-kappaB were MAPK and ROS, respectively. Conditioned media from pancreatic cancer cells pretreated with IL-1alpha remarkably stimulated in vitro HUVECs growth.

Conclusions: These results suggest that MAPK/AP-1 and ROS/NF-kappaB signaling pathways are involved in IL-1alpha-induced IL-8 secretion and that these paracrine signaling pathways enhance endothelial cell proliferation.

MeSH terms

  • Blotting, Western
  • Culture Media, Conditioned
  • Electrophoretic Mobility Shift Assay
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Interleukin-1 / physiology*
  • Interleukin-8 / metabolism*
  • NF-kappa B / metabolism
  • Pancreatic Neoplasms / enzymology
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Reactive Oxygen Species*
  • Signal Transduction / physiology*
  • Transcription Factor AP-1 / metabolism
  • Tumor Cells, Cultured
  • p38 Mitogen-Activated Protein Kinases / metabolism*


  • Culture Media, Conditioned
  • Interleukin-1
  • Interleukin-8
  • NF-kappa B
  • Reactive Oxygen Species
  • Transcription Factor AP-1
  • p38 Mitogen-Activated Protein Kinases