The long noncoding RNA HOTAIR has tissue and cell type dependent effects on HOX gene expression and phenotype of cancer cells

HOTAIR was found to be overepressed in a subset of urothelial cancer tissues and cell lines compared to normal controls. Ectopic HOTAIR expression in urothelial cancer cells in vitro demonstrated cell type dependent changes in phenotype. While some cell lines showed increased proloferation activity and induction of an aggressive phenotypes (e.g. stable transfected VM-CUB1 cells), others displayed rather a reduction of proliferation and migration. Stable transfection of 5637 cells resulted in induction of an immune response. Results of microarray analysis of stable transfected VM-CUB1 and 5637 cells concurred well with observed phenotypical cell type-specific changes. For differential gene expression analyses three independent high quality RNA preparations from VM-CUB1 cells, stably transfected with HOTAIR (clone 20), and 5637 cells, stably transfected with HOTAIR (clone 4), were compared to the respective vector control cells.