Figure 1.

MALAT1 Expression Was Upregulated in Docetaxel-Resistant LUAD Cells and Modulated miR-200b at the Post-transcriptional Level

(A) An RT² lncRNA PCR array system was applied to measure the expression levels of lncRNAs that were potentially involved in the modulation of miR-200b expression in DTX-resistant LUAD cells. The results were compared with those from parental SPC-A1 and H1299 cells. (B) The effect of the three lncRNAs on the miR-200b expression level was detected by qRT-PCR in both SPC-A1/DTX and H1299/DTX cells. (C) Subcellular fractionation of SPC-A1 cell to determine the cellular location of MALAT1. (D) RNA FISH was used to identify the MALAT1 location. (E) RIP experiments revealed the enrichment of MALAT1 and miR-200b in the Ago2 immunoprecipitation compared with the control IgG precipitation. (F) Two binding sites of MALAT1 to miR-200b were predicted. (G) Two binding sites were separately mutated (Mut1 and Mut2) or simultaneously mutated (Mut1/2) and were constructed into different vectors. The wild-type (WT) vector and three mutant-type vectors were cotransfected into SPC-A1/DTX and HEK293T cells, together with miR-200b mimics or miR-NC. The reporter vectors were normalized to Renilla luciferase vector. *p < 0.05, **p < 0.01; n.s., no significance.