Supplementary Figure S2 from Autocrine 17-β-estradiol/estrogen receptor-α loop determines the response to immune-checkpoint inhibitors in non-small cell lung cancer

Immunohistochemical characterization of PD-L1 and ERα in non-small cell lung cancer samples. a. Representative immunohistochemical images of one NSCLC patient classified as PD-L1low (tumor proportion score, TPS: 60%) and one NSCLC patient classified as PD-L1high (TPS: 90%), according to the internal scale used in our prospective study (see Results section for details). Bar: 20 µm. b. Representative immunohistochemical images of ERα and phospho(Ser118)ERα from one NSCLC patient classified as ERαlow (Histo-score, Hscore: 30 for cytosolic ERα, 90 for nuclear ERα) and one NSCLC patient classified as ERαhigh (Hscore: 270 for cytosolic ERα, 240 for nuclear ERα) in our prospective study. One ER+ (score:3+) and one ER- (0+) breast cancer are included as positive and negative control, respectively. Arrow: normal breast tissue as internal control. Bar: 20 µm. c. Expression of ERα-target genes CXCL12, IGFBP4 and ABCA3, measured by RT-PCR (technical triplicates), in samples from 6 NSCLC classified as ERαlow and in 6 NSCLC classified as ERαhigh according to ERα mRNA and protein levels. The same genes were assessed in an ER+ and in an ER-breast cancer, chosen as positive or negative controls, respectively. The mean relative expression of each gene in ERαlow tumors was considered 1. Data are means+SD (n=6). ***p<0.001: ERα high NSCLC tumors versus ERα low NSCLC tumors; °°°p<0.001: ER+breast cancer versus ERα low NSCLC tumors.