Expression of NOTCH3 in lung adenocarcinoma (LUAD) tissues and tyrosine kinase inhibitor (TKI)-resistant cell line. (A) Expression levels of NOTCH3 mRNA were significantly higher in LUAD tissues, compared to matched normal tissues, while NOTCH1,2,4 levels were significantly lower in LUAD tissues than normal tissues (20 pairs). (B) Immunohistochemical staining of NOTCH3 in LUAD and matched normal tissues. Scale bar: 50 μm. Positive staining is located in the cell membrane. (C) NOTCH3 mRNA was upregulated in gefitinib-resistant HCC827GR6 cells compared to parental HCC827 cells, while other NOTCH members showed no significant difference. (D) Meta-analysis of NOTCH3 gene expression from nine Oncomine databases. Colored squares indicate the median rank for NOTCH3 (lung adenocarcinoma vs. normal tissue) across nine analyses. Beer lung (1), Bhattacharjee lung (2), Garber lung (3), Hou lung (4), Landi lung (5), Okayama lung (6), Selamat lung (7), Stearman lung (8), Su lung (9). The p value is given for the median rank analysis. (E) NOTCH3 protein expression was upregulated in HCC827GR6 cells compared to parental HCC827 cells.