The MALAT-1 noncoding RNA Regulates Cell Mobility by Modulating Gene Expressions

MALAT-1, originally identified as a metastasis associated long noncoding transcript in lung adenocarcinoma, is localized to nuclear speckles. However, functional role of MALAT-1 in metastatic characters in cancer cells has not been elucidated. Our current research has revealed that suppression of MALAT-1 expression in lung adenocarcinoma cell line by RNA interference significantly inhibited cellular mobility both in wound healing assay and in migration assay using Boyden's chamber. Moreover, we have identified metastasis/mobility-associated genes among down-regulated genes in the MALAT-1 knockdown cells by DNA microarray analysis. Quantitative analysis of pre-mRNAs has shown that the pre-mRNAs of some genes were suppressed in MALAT-1 knockdown cells but the others were not suppressed even though their matured mRNAs were found to be down-regulated. Our results suggest that MALAT-1 facilitates cell mobility by modulating the expression of metastasis/mobility-associated genes at the transcriptional and post-transcriptional stages. Comparison between control (A549) and knockdown (MALAT-1) cells was performed. Two biological replicates were used, and each replicate was dye-swaped.