Fig. 4: Blocking nEGFR enhances NK cell recruitment and cytotoxicity.

a Tumors from WAP-TGFα female mice treated with cSNX1.3 (n = 9) or cPTD4 (n = 9) were fixed in 10% buffered formalin and paraffin embedded (tumors from both ≥100 mm³ and ≥250 mm³ groups were used for IHC). Slides were incubated with NKp46 primary antibody for NK cell detection, an anti-EGFR antibody, and counterstained with methyl green (nuclei). Black arrow heads indicate examples of positive staining for each. ×40 magnification for all images. b Quantification; identification of methyl green and positive NKp46 stain. Bar graph showing NK cells/(NK cells + nuclei) for each experimental group. c Table including the mice used for IHC, alongside their average tumor growth rate and the number of cells positive for NKp46 stain and methyl green (nuclei). d MDA-MB-468 cells were labeled with DiO, stimulated with EGF (10 ng/ml), treated with cSNX1.3 (10 μM) or cPTD4 (10 μM), and co-cultured with NK-92 cells labeled with DiD. Cells were tracked for 24 h and total intensity of both DiO and DiD staining is shown. e Target cell count after drug treatment and primary NK cell co-culture. MDA-MB-468 target cells were seeded at a density of 50,000 cells/well (Donors 1–3) or 400,000 cells/well (Donor 4). Target cells were stimulated with EGF (10 ng/ml) and treated with either cSNX1.3 (10 μM), erlotinib (15 μM), or cPTD4 (10 μM) for 24 h, and pre-activated primary NK cells were co-cultured with the target cells at an E:T ratio of 4:1 for 4 h.