Fig. 4: Inhibition of PTPN2 is associated with copper stimulated activation of EGFR.

a Evaluation of the effects on EGR1 expression levels of 200 μM CuCl₂ (60 min treatment) following siRNA knockdown of various PTPs in A549 cells. Depicted are two interpretations of the results. (top) All fold-changes are reported relative to the negative control siRNA transfect (Neg.) without CuCl₂ supplementation. (bottom) Each result is reported as the fold-change between the denoted siRNA knockdown after 60 min 200 μM CuCl₂ supplementation and the siRNA knockdown by itself. (n = 3 replicates per condition). Same box plot definitions as in Fig. 1. * denotes p < 0.05, ** denotes p < 0.01, and *** denotes p < 0.001 for two-sided t-test comparison between conditions. b pNPP (p-nitrophenyl phosphate) assay of ΔPTPN1 PTP activity following addition of various amounts of Cu¹⁺ (n = 12 replicates per condition). c Proteome profiler antibody array volcano plot depicting statistically significant increases in phosphorylation levels following HEK 293 T supplementation with 20 μM ZnCl₂. (n = 2 replicates for each condition). d Changes in A549 EGR1 expression levels 60 min after ZnCl₂ supplementation. The fold-changes are overlayed on the fold-changes induced by CuCl₂ supplementation for reference. (n = 2 replicates per condition). Same box plot definitions as in Fig. 1. e RNA-qPCR fold-changes of select transcripts 4 h post-supplementation of 500 nM CuGTSM or 5 µM CS1 relative to DMSO treated A549 cells. (n = 3 replicates per condition). Data points correspond to biological replicates, p-values calculated as paired two-tailed t-test. Same box plot definitions as in Fig. 1. Figure 4a, b, d, and e source data are provided as a Source Data file, as are exact p-values for Fig. 4a, e. * denotes p < 0.05, ** denotes p < 0.01, and *** denotes p < 0.001 for two-sided t-test comparison between conditions.