Fig. 1

Expression of miR-7-5p in SCLC cell lines. a Cell viability of four SCLC cell lines (H69, H69AR, H446, and H446AR) in the presence of Dox. b Hierarchical clustering of differentially expressed miRNAs in H69 and H69AR cells, black: increased expression, white: decreased expression. c The expression of miR-7-5p in four SCLC cell lines was quantified by qRT-PCR. d MiR-7-5p expression in SCLC cells was determined after transfection with miR-7-5p mimic, inhibitor or negative control. e-f Effect of miR-7-5p expression on survival in four SCLC cell lines treated with Dox. Each cell line was treated with Dox for 24 h after transfection with miR-7-5p mimic or inhibitor, and the IC50 was calculated. Dox: Doxorubicin, Con: nontransfected, miR-mimic: miR-7-5p mimic, NC-mimic: negative control for miR-mimic, miR-inhibitor: miR-7-5p inhibitor, NC-inhibitor: negative control for miR-inhibitor. Error bars represent the mean ± SD based on three independent experiments. *P < 0.05, **P < 0.01 and ***P < 0.001