Fig. 3

Reduction of DDX56 inhibits SqCLC cell growth, migration and tumor progression in a xenograft mouse model of SqCLC. a and b Analysis of growth of H226 (a) and SK-MES-1 (b) cells transfected with DDX56-specific or control shRNAs using a crystal violet assay. Cell growth of H226 and SK-MES-1 was significantly inhibited in DDX56 shRNA-transfected cells compared to control shRNA (shNC)-transfected cells (n = 4). c and d Analysis of growth of H226 and SK-MES-1 cells transfected with pCMV-DDX56 or control pCMV vectors using a crystal violet assay. Cell growth of H226 and SK-MES-1 was significantly enhanced in pCMV-DDX56-transfected cells compared to pCMV vector-transfected cells (n = 4). e and f Analysis of migration ability of H226 cells transfected with DDX56 or control siRNAs using wound healing assay. (e) Wound healing assay of H226 cells transfected with DDX56-specific or control siRNAs. (f) Quantification of wound closure by measuring the wound width of the % of the closure of original wound in triplicate plates. g and h Analysis of migration ability of H226 (g) and SK-MES-1 (h) cells transfected with DDX56-specific or control siRNAs using a transwell assay. Representative images of crystal violet-stained migrated H226 (200X) and SK-MES-1 (400X) cells on the membrane (left panel). Quantification of cell migration expressed by cell counting. Columns represent mean (n = 4). i and j, NOG CIEA were injected subcutaneously with H226 cells transfected with shDDX56 (n = 10) or shNC (n = 10) and monitored for H226 tumor growth at day 10, 19, 29 and 33 after injection (i). The tumor-bearing mice were sacrificed on day 33 and their tumors dissected. Representative tumors from DDX56 shRNA (n = 5) and control shRNA (n = 4) xenografts (j). Data are presented as mean ± SD. Two-sided Student’s t-test was used to compare the data. (*p < 0.05; **p < 0.01, ***p < 0.001, ****p < 0.0001). All data are representative of three independent experiments