Epidermal Growth Factor potentiates EGFR(Y992/1173)-mediated therapeutic response of triple negative breast cancer cells to cold atmospheric plasma-activated medium

Abstract

Cold atmospheric plasma (CAP) holds promise as a cancer-specific treatment that selectively kills basal-like breast cancer cells. We used CAP-activated media (PAM) to capture the multi-modal chemical species of CAP. Specific antibodies, small molecule inhibitors and CRISPR/Cas9 gene-editing approaches showed an essential role for receptor tyrosine kinases, especially epidermal growth factor (EGF) receptor, in mediating triple negative breast cancer (TNBC) cell responses to PAM. EGF also dramatically enhanced the sensitivity and specificity of PAM against TNBC cells. Site-specific phospho-EGFR analysis, signal transduction inhibitors and reconstitution of EGFR-depleted cells with EGFR-mutants confirmed the role of phospho-tyrosines 992/1173 and phospholipase C gamma signaling in upregulating levels of reactive oxygen species above the apoptotic threshold. EGF-triggered EGFR activation enhanced the sensitivity and selectivity of PAM effects on TNBC cells, such that a strategy based on the synergism of CAP and EGF therapy may provide new opportunities to improve the clinical management of TNBC.

Effects of N361 Glycosylation on Epidermal Growth Factor Receptor Biological Function

“…3C-E). 43 In normal media, cells with double mutant EGFR N361A/L858R proliferated less than L858R alone in both MCF10A and 293T cells (Supplementary Fig. 4).…”

“…MCF10A cells were selected because they are grown in EGF-enriched media and have an inherent dependency on EGFR signaling. 43 In contrast, 293T cells have low expression of EGFR and are not naturally dependent on the EGFR pathway. Our results are consistent with this functional difference, in that MCF10A cells were highly sensitive to osimertinib in an EGFR dependent manner, while 293T cells were only impacted at the highest doses (Fig.…”