A novel mechanism for anti‐EGFR antibody action involves chemokine‐mediated leukocyte infiltration

Abstract

Overexpression of the epidermal growth factor receptor (EGFR) is a hallmark of squamous cell carcinoma of the head and neck (SCCHN). Monoclonal antibodies (mAbs) against EGFR are currently used for therapy of recurrent or metastatic disease; however, their mode of action is not completely understood. To investigate the immunological effects of anti-EGFR mAb, we generated a three-dimensional spheroid model of EGFR-expressing SCCHN and used this model to study the effect of anti-EGFR mAb on leukocyte migration toward tumors. Pretreatment with the blocking anti-EGFR mAb EMD 72000, its F(ab 0 )2 fragments or an EGFR tyrosine kinase inhibitor led to substantially increased leukocyte infiltration into EGFR overexpressing tumor spheroids, but not into those with low EGFR expression. Nonblocking anti-EGFR mAb or fibroblast-specific mAb did not affect leukocyte infiltration, suggesting that the observed increase in leukocyte infiltration depends on interference with EGFR activation. Using a human cytokine macroarray, we demonstrated that the blockade of EGFR by anti-EGFR mAb in EGFR-overexpressing SCCHN cells leads to differential expression of several cytokines and chemokines, including the chemokine MCP-1/CCL-2. The significant upregulation of MCP-1/CCL2 on exposure to anti-EGFR mAb was confirmed by quantitative PCR and enzyme-linked immunospot analyses. Moreover, blocking anti-MCP-1 antibody inhibited leukocyte migration toward tumor cells induced by anti-EGFR mAb, pointing to an important role of MCP-1/CCL2 in anti-EGFR mAb-induced leukocyte migration. Our findings demonstrate that anti-EGFR mAb induces leukocyte infiltration to tumor spheroids by upregulating chemokine expression. This novel mechanism for anti-EGFR mAb action may contribute to the antitumor effects of anti-EGFR mAb in vivo.

Matrigel: From discovery and ECM mimicry to assays and models for cancer research

“…Furthermore, stromal cells have been incorporated into MCTS models using different configurations. Tumor cells have been mixed with stromal fibroblasts prior to spheroid formation [131,132]; spheroids have been placed on fibroblast monolayers [133]; fibroblast spheroids have been added to MCTS [134,135]; MCTS have been added to a fibroblast suspension; and fibroblast spheroids have been added to MCTS [73]. Melanoma MCTS have also been combined with endothelial cells to evaluate the potential role of angiogenesis in cancer progression [136], and melanoma MCTS have been incorporated into engineered skin models to evaluate combinatorial treatment regimens [137].…”

Drug delivery to solid tumors: the predictive value of the multicellular tumor spheroid model for nanomedicine screening

“…It is important to note that immune response can be stimulated by promoting infiltration and cytotoxicity of leukocytes in MCTS. 51 For example, it was demonstrated that the blocking of lactic acid secreted by tumor cells increased the migration of monocytes into MCTS. …”

Search for Theragnostic Biomarkers in Colorectal Liver Metastases: Focus on the Host Immune Cells

“…Each of the cells represents a potential target for decoding the clinical heterogeneity of CLM patients, for developing new biomarkers, and consequently for developing new personalized immunotherapies. In line with this, some experimental data showed that the blocking of the EGFR pathway was associated with an increased immune infiltration in solid cancers (90,91). In this regard, several in vitro and in vivo models have shown that the masking of EGFR with a specific blocking monoclonal Ab (mAb) inhibits tumor proliferation, induces terminal cellular differentiation and modulates chemo-and radio-sensitivity (92).…”

“…In this regard, several in vitro and in vivo models have shown that the masking of EGFR with a specific blocking monoclonal Ab (mAb) inhibits tumor proliferation, induces terminal cellular differentiation and modulates chemo-and radio-sensitivity (92). Recently, it has been also reported that the inhibition of the EGFR signaling pathway facilitates the activation of immune cells and their recruitment to tumor sites via the production of several cytokines and chemokines (90). This is particularly relevant for NK cells, as studies have shown that the use of a blocking anti-EGFR mAb stimulates these innate immune effector lymphocytes and induces antibodydependent cell cytotoxicity (93,94).…”