An Ex Vivo Human Tumor Assay Shows Distinct Patterns of EGFR Trafficking in Squamous Cell Carcinoma Correlating to Therapeutic Outcomes

Abstract

EGFR overexpression is associated with squamous cell carcinoma development. Altered endocytosis and polarization of receptor tyrosine kinases, including EGFR, affect migration and invasion in three-dimensional culture. These studies have been completed via genetic sequencing, cell line, or three-dimensional in vitro and in vivo murine models. Here, we describe an imaging method that allows ex vivo examination of ligand-induced endocytosis of EGFR in non-dissociated human tumors. We analyzed sets of tumor samples from advanced cutaneous squamous cell carcinoma and head and neck squamous cell carcinoma, actinic keratosis, intraepidermal carcinoma, and cutaneous squamous cell carcinoma. We show that EGFR endocytosis is dysregulated in advanced SCC and correlates with anti-EGFR monoclonal antibody therapy outcomes. In actinic keratosis, intraepidermal carcinoma, and well-differentiated cutaneous squamous cell carcinoma, different patterns of epidermal growth factor ligand uptake and binding were observed at the leading edge of different dysplastic lesions, suggesting that these differences in EGFR endocytosis might influence the metastatic potential of dysplastic squamous epithelium. These studies in live ex vivo human tumors confirm that endocytosis dysregulation is a physiological event in human tumors and has therapeutic implications.

Investigating therapeutic possibilities for treatment of perineural invasion

“…This also eliminates the need for early animal sacrifice to assess outcomes, although the advantage of histopathological analysis remains accessible at the end of the experiment. although recent data has illustrated that receptor trafficking and polarisation can influence the metastatic potential (189,224). In combination with previous findings from our laboratory, our data supports EGFR as a driver of PNS in cSCCHN rather than the process of perineural invasion and spread engendering EGFR overexpression (66).…”

“…Currently, EGFR is not regarded as a prognostic indicator or biomarker in cSCC, and cSCCHN with or without PNI. Whilst associated with metastatic disease, in fully formed tumours there is no clinical correlation of EGFR with tumour growth or patient outcome, although recent data has illustrated that receptor trafficking and polarisation can influence the metastatic potential (189,224). However, in combination with previous findings from our laboratory, our data supports EGFR as a driver of PNS in cSCCHN rather than the process of perineural invasion and spread engendering EGFR overexpression (66).…”

“…The EGFR expression in the metastases were diffusely and strongly positive compared to weakly positive in the primary tumours with genomic hybridization leading to the hypothesis that EGFR is required to confer metastatic potential (204). Our own observations in actinic keratoses, Bowen's disease and cSCC highlight that EGFR can become polarised to the leading edge of the basal layer of tumours (189). Given that cellular cytokinetic response to EGFR signalling can lead to migration and metastasis, the potential for invasion in polarised cells is high and it will be of interest analysing the potential of an actinic keratosis with high polarisation to develop into an SCC.…”

Long-Chain Non-Coding RNA (lncRNA) MT1JP Suppresses Biological Activities of Lung Cancer by Regulating miRNA-423-3p/Bim Axis

“…EGFR is a member of the ErbB receptor family. Studies have shown that EGFR overexpression may be associated with tumor cell proliferation, invasion, metastasis, apoptosis, and angiogenesis in a variety of solid tumors and that EGFR mutations contribute to the malignant transformation of epithelial cells [30]. In this study, EGFR protein expression was significantly inhibited as Bim protein expression increased, which may be the mechanism by which MT1JP inhibits the invasion and migration of A549 cells.…”

Non-Small-Cell Lung Cancer Signaling Pathways, Metabolism, and PD-1/PD-L1 Antibodies

“…Based on these assumptions, endocytosis inhibitors can be used to move tumor cell antigens targeted by therapeutic monoclonal antibodies to the cell surface, in order to improve the ADCC and clinical responses to these agents. An ex vivo human tumor assay has shown distinct patterns of EGFR trafficking in SCC, correlating with therapeutic outcomes [ 21 ]. The study shows that tumors can be classified into those where EGF was, or was not, able to be endocytosed.…”