Figure 5.

HOTAIR-knockdown abrogates CCL5-induced cisplatin resistance via activation of caspase-3-dependent apoptosis. (A) HOTAIR expression in A549 cells transfected with either siNC or siHOTAIR was determined by quantitative PCR. (B) Cell viability and (C) apoptosis of DDP- and CAF-CM-treated A549 cells transfected with either siNC or siHOTAIR was determined by MTT and flow cytometric assays, respectively. *P<0.05, **P<0.01 and ****P<0.0001 vs. siNC. (D) Protein expression levels of PARP, cleaved-PARP, Bcl-2, cleaved caspase-3 and caspase-3 in siNC- or siHOTAIR-transfected A549 cell lines with or without treatment with exogenous CCL5 (100 ng/ml) were determined by western blotting. The intensity of each experimental band was normalized to that of the loading control (β-actin). Each bar represents the mean ± SD of three relative intensity arbitrary units. **P<0.01 vs. siNC; ^##P<0.01 vs. siNC+DDP; ^&&P<0.01 vs. siHOTAIR+DDP. CAF, cancer-associated fibroblast; NF, normal fibroblast; CM, conditioned medium; DDP, cisplatin; CCL5, C-C motif chemokine ligand 5; HOTAIR, HOX transcript antisense RNA; si, small interfering RNA; NC, negative control; PARP, poly (ADP-ribose) polymerase.