interleukin-8 and antileukinate

The experiments aimed to determine if alpha-chemokine inhibitors are effective suppressors of the growth of adenocarcinomas, a neoplasm with a high mortality rate.. Expression of growth-related oncogene (GROalpha) and interleukin-8 (IL-8) was determined by enzyme-linked immunosorbent assay. Inhibition of alpha-chemokine binding to tumor cells was assessed in the presence and absence of the hexapeptide, antileukinate. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were performed to determine the effect of alpha-chemokines, monoclonal antibodies (mAb), and antileukinate on cell proliferation. Finally, antileukinate inhibition of human, lung adenocarcinoma tumor growth, was determined in BALB/c nude mice.. All of the adenocarcinomas tested produced either GROalpha or IL-8 or both. Proliferation of lung, stomach and colon adenocarcinoma cells was inhibited by anti-GROalpha mAb and/or anti-IL-8 mAb while recombinant human GROalpha stimulated the proliferation of lung and stomach adenocarcinomas. Antileukinate inhibited GROalpha binding to specific receptors on adenocarcinoma cells and inhibited the proliferation of all adenocarcinomas tested. Colon-derived adenocarcinomas specifically bound IL-8 and this binding was also inhibited by antileukinate. Administration of antileukinate in vivo inhibited the tumor growth of adenocarcinoma A549.. GROalpha and IL-8 are necessary for the growth of lung, stomach and colon adenocarcinomas, and can be inhibited by the hexapeptide, antileukinate. The findings suggest the possibility of using alpha-chemokine receptor inhibitors in the treatment of adenocarcinoma.

Topics: Adenocarcinoma; Animals; Chemokine CXCL1; Chemokines, CXC; Chemotactic Factors; Enzyme-Linked Immunosorbent Assay; Growth Inhibitors; Growth Substances; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Mice; Mice, Inbred BALB C; Neoplasm Proteins; Oligopeptides; Proto-Oncogenes; Tumor Cells, Cultured

GROalpha, an autocrine mitogenic factor for melanoma cell lines, belongs to the superfamily of alpha-chemokines. Here, we report that GROalpha stimulates the growth of human umbilical vein endothelial cells (HUVEC) in vitro, with proliferation being significantly stimulated by 100 nM recombinant human (rh) GROalpha. Proliferation was significantly inhibited by 100 microg/ml anti- human GROalpha monoclonal antibody (mAb), while excess GROalpha restored the growth. The addition of rhIL-8, rhIP-10, anti-human IL-8 or anti-human ENA-78 mAbs did not alter HUVEC proliferation. [125I]IL-8 binding to HUVEC was saturable and inhibited by non-radioactively iodinated IL-8, but not non-iodinated IL-8. [125I]GROalpha binding was also inhibited by iodinated IL-8. Since these data suggested specific binding sites for alpha-chemokines on HUVEC, we tested the effect of antileukinate, a potent alpha-chemokine receptor inhibitor, on [125I]GROalpha binding. Antileukinate inhibited GROalpha binding and suppressed HUVEC proliferation in a dose-dependent manner. Antileukinate was not cytotoxic, with no decrease in cell viability in the presence of 100 microM antileukinate. These findings suggest that GROalpha is essential for HUVEC growth factor and that antileukinate inhibits growth by preventing autocrine GROalpha receptor binding. This raises the interesting possibility of alpha-chemokine receptor inhibitors, such as antileukinate, in the treatment of cancer where angiogenesis is an important factor for tumour growth.

Topics: Antibodies, Monoclonal; Cell Division; Cells, Cultured; Chemokine CXCL1; Chemokine CXCL10; Chemokines, CXC; Chemotactic Factors; Endothelium, Vascular; Growth Substances; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Neutralization Tests; Oligopeptides; Receptors, Chemokine; Recombinant Proteins