Supplementary Figure S2 from Functional Analyses of Mutations in Receptor Tyrosine Kinase Genes in Non–Small Cell Lung Cancer: Double-Edged Sword of <i>DDR2</i>

Abstract

<p>(A) Protein expression of DDR2 in transfectant PC-9 and H3122 cell lines. The DDR2 mRNA expression level was evaluated using real-time RT-PCR; GAPDH was used as an internal control. The DDR2 protein expression level was evaluated using western blotting. The DDR2 E655K-overexpressed cell lines had particularly low DDR2 protein expressions, compared with the levels in DDR2 WT-overexpressed cell lines, despite having an equal expression of DDR2 mRNA. The DDR2 protein produced a fragmented ladder in the DDR2 E655K-overexpressed cell lines. β-actin was used as an internal control. Columns, mean of independent triplicate experiments; Bars, SD. (B) Cellular proliferation of transfectant PC-9 and H3122 cell lines. Cellular growth was examined using an MTT assay with or without stimulation with collagen I (10 µg/mL). Without collagen I, no significant difference in proliferation was observed among the transfectant cell lines. In contrast, under exposure to collagen I, the cellular proliferations of the DDR2 WT-overexpressed cell lines were significantly reduced, compared with those of the EGFP-overexpressed cell lines, whereas a reduction was not observed in the DDR2 E655K-overexpressed cell lines. Columns, mean of independent triplicate experiments; Bars, SD; *, P < 0.05; n.s., not significant.</p>