Non-Small Cell Lung Cancer Cells Induce Monocytes to Increase Expression of Angiogenic Activity

Abstract

Tumors are dependent on angiogenesis for survival and propagation. Accumulated evidence suggests that macrophages are a potentially important source of angiogenic factors in many disease states. However, the role(s) of macrophages in non-small cell lung cancer (NSCLC) have not been determined. We hypothesized that monocyte-derived macrophages are induced by NSCLC to increase expression of angiogenic factors. To define the role of macrophage-tumor cell interaction with respect to angiogenesis, human peripheral blood monocytes (PBM) were cocultured with A549 (human bronchoalveolar cell carcinoma) or Calu 6 (human anaplastic carcinoma) NSCLC cells. The resultant conditioned medium (CM) was evaluated for angiogenic potential and for expression of angiogenic factors. We found that endothelial cell chemotactic activity (as a measure of angiogenic potential) was significantly increased in response to CM from cocultures of PBM/NSCLC compared with PBM alone, NSCLC alone, or a combination of NSCLC and PBM CM generated separately. Subsequent analysis by ELISA reveals markedly increased CXC chemokine expression, with a lesser increase in vascular endothelial growth factor, in CM from PBM/NSCLC coculture. Neutralizing Ab to angiogenic CXC chemokines blocked the increase in endothelial cell chemotaxis. Furthermore, with separately generated CM as a stimulus, we found that macrophages are the predominant source of increased CXC chemokine expression. Finally, we found that NSCLC-derived macrophage migration-inhibitory factor is responsible for the increased expression of macrophage-derived angiogenic activity. These data suggest that the interaction between host macrophages and NSCLC cells synergistically increases angiogenic potential, and that this is due to an increased elaboration of angiogenic CXC chemokines.

Thymidine phosphorylase expression in normal, hyperplastic and neoplastic prostates: correlation with tumour associated macrophages, infiltrating lymphocytes, and angiogenesis

“…This finding, which is in accordance with a previous report of ours on non-small cell lung carcinomas , reinforces the view for a chemotactic activity of TP on mononuclear cells (Miyazono and Takaku, 1991). TP-mediated macrophage chemotaxia may, therefore, contribute to the angiogenic process, as activated macrophages, apart from producing TP, usually secrete a variety of pro-angiogenic and angiogenic cytokines (Sunderkotter et al, 1994;Ono et al, 1999;White et al, 2001). The angiogenic relevance of an intense macrophage infiltration of the tumour stroma has been shown in a variety of other human tumours including breast (Leek et al, 2000), endometrial (Hashimoto et al, 2000) and lung carcinomas (Takanami et al, 1999), gliomas and malignant melanomas (Torisu et al, 2000).…”

A Novel Pathway for Nickel-induced Interleukin-8 Expression

“…The CXC chemokine interleukin 8 (IL-8) is markedly upregulated in pulmonary fibrosis (6 -8) and has been implicated in promoting the growth of lung tumors (9,10). IL-8 attracts and activates neutrophils, induces transendothelial migration of neutrophils, modulates chemotaxis for T-lymphocytes, promotes angiogenesis, and induces contraction of airway smooth muscle cells (10,11).…”

Monocyte-Fibronectin Interactions, Via α5β1 Integrin, Induce Expression of CXC Chemokine-Dependent Angiogenic Activity

“…After informed consent was obtained, whole blood (anticoagulated with 1000 U of heparin per 60 ml) was obtained by venipuncture from healthy, nonsmoking donors, and monocytes were obtained by Ficoll-Paque (Amersham Pharmacia Biotech, Uppsala, Sweden) density centrifugation and adherence purification as previously described (15). For some conditions, monocytes were cultured in 2% autologous serum (saved at the time of initial phlebotomy).…”

“…ECC assays were performed in 12-well, blind-well chemotaxis chambers (NeuroProbe, Gaithersburg, MD) as previously described (15). After the appropriate time for chemotaxis had elapsed, membranes were removed and nonadherent cells were removed by scraping with a rubber policeman.…”

“…We and others have demonstrated that tumors are infiltrated with monocyte-derived macrophages, and that this infiltration is mediated by members of the CC chemokine family (13,14). Moreover, we have recently demonstrated that soluble factors derived from non-small cell lung cancer (NSCLC) 3 cell lines induce angiogenic activity from monocytes (15).…”