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

• Published in: Clinical & experimental metastasis Vol. 17; no. 10; pp. 857 - 863
• Main Authors: Kido, A, Krueger, S, Haeckel, C, Roessner, A
• Format: Journal Article
• Language: English
• Published: Netherlands Springer Nature B.V 01.01.1999
• Subjects: 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
• ISSN: 0262-0898; 1573-7276
• 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.