LncRNA Expression Discriminates Karyotype and Predicts Survival in B-lymphoblastic Leukemia (Affymetrix)

Long non-coding RNAs (lncRNAs) have been found to play a role in gene regulation with dysregulated expression in various cancers. The precise role that lncRNA expression plays in the pathogenesis of B-acute lymphoblastic leukemia (B-ALL) is unknown. Therefore, unbiased microarray profiling was performed on human B-ALL specimens and it was determined that lncRNA expression correlates with cytogenetic abnormalities, which was confirmed by RT-qPCR in a large set of B-ALL cases. Importantly, high expression of BALR-2 correlated with poor overall survival and diminished response to prednisone treatment. In line with a function for this lncRNA in regulating cell survival, BALR-2 knockdown led to reduced proliferation, increased apoptosis, and increased sensitivity to prednisolone treatment. Conversely, overexpression of BALR-2 led to increased cell growth and resistance to prednisone treatment. Interestingly, BALR-2 expression was repressed by prednisolone treatment and its knockdown led to upregulation of the glucocorticoid response pathway in both human and mouse B-cells. Together, these findings indicate that BALR-2 plays a functional role in the pathogenesis and/or clinical responsiveness of B-ALL and that altering the levels of particular lncRNAs may provide a future direction for therapeutic development. To define gene expression changes attributable to expression of lncRNAs, we transduced RS4;11 cells with a siRNA against BALR-2 or control vector. These cells were left untreated or treated with prednisolone.