Possible contribution of aminopeptidase N (APN/CD13) to invasive potential enhanced by interleukin-6 and soluble interleukin-6 receptor in human osteosarcoma cell lines

Clin Exp Metastasis. 1999;17(10):857-63. doi: 10.1023/a:1006794617406.


This study aimed at clarifying the role of Aminopeptidase N (APN), a Zn2+-dependent ectopeptidase localized on the cell surface of human osteosarcoma cell lines treated with proinflammatory cytokines. We investigated the proinflammatory cytokines interleukin-1 beta (IL-1beta), IL-6 and tumor necrosis factor alpha (TNF-alpha) as well as the anti-inflammatory cytokine transforming growth factor beta (TGF-beta) for their influence on APN regulation. Soluble IL-6 receptor (sIL-6R) was always used together with IL-6 to achieve a stable effect. In addition, the invasive potential of the osteosarcoma cell lines MG63 and HOS was examined. Competitive RT-PCR and Ala-pNA activity assays revealed that IL-6 and sIL-6R significantly increased the mRNA expression and activity of APN in both osteosarcoma cell lines. Although IL-1beta significantly stimulated APN mRNA expression in both cell lines, it influenced the enzyme activity only in MG63. TNF-alpha and TGF-beta, however, had an effect neither on mRNA expression nor on the enzyme activity of APN in both cell lines. In the Matrigel invasion assay, IL-6 and sIL-6R significantly up-regulated the transmigration of these cell lines, whereas other cytokines did not. The up-regulated invasion was inhibited by bestatin, a specific inhibitor of APN. Cellular migration correlated highly with APN activity (r = 0.79, P < 0.002). These findings suggest that APN contributes to the invasive potential of human osteosarcomas enhanced by IL-6 and SIL-6R.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Neoplasms / drug therapy
  • Bone Neoplasms / metabolism
  • Bone Neoplasms / pathology*
  • CD13 Antigens / drug effects
  • CD13 Antigens / genetics
  • CD13 Antigens / metabolism*
  • Humans
  • Interleukin-1 / pharmacology
  • Interleukin-6 / chemistry
  • Interleukin-6 / pharmacology
  • Neoplasm Invasiveness
  • Osteosarcoma / drug therapy
  • Osteosarcoma / metabolism
  • Osteosarcoma / pathology*
  • Receptors, Interleukin / chemistry
  • Receptors, Interleukin-6
  • Recombinant Fusion Proteins / chemistry
  • Transforming Growth Factor beta / pharmacology
  • Tumor Cells, Cultured
  • Tumor Necrosis Factor-alpha / pharmacology


  • Interleukin-1
  • Interleukin-6
  • Receptors, Interleukin
  • Receptors, Interleukin-6
  • Recombinant Fusion Proteins
  • Transforming Growth Factor beta
  • Tumor Necrosis Factor-alpha
  • interleukin 6-interleukin 6 receptor fusion protein, recombinant
  • CD13 Antigens