LncRNA landscape analysis identified LncRNA LEF-AS1 as an oncogene that upregulates LEF1 and promotes survival in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a malignant disorder of mature B lymphocytes, and the precise pathogenesis is largely unknown at present. This study set out to screen the differential expression profile of long non-coding RNA (lncRNA) by microarray and explore the underlying mechanism, biological function, and clinical significance of lncRNA in CLL cells. Compared to the lncRNA expression profiles of the control group, we picked lncRNA LEF1-AS1 for further exploration. By quantitative real-time polymerase chain reaction (qRT-PCR), we validated that primary CLL cells harbor higher lncRNA LEF1-AS1 levels than normal B cells. In the two cell lines with stable overexpression of LEF1-AS1, expression of LEF1 elevated on RNA and protein level, proliferation rates increased, and apoptosis rates decreased. In primary CLL cells, mRNA expression of LEF1 decreased by qRT-PCR after negatively regulating the expression of LEF1-AS1. RNA Binding Protein Immunoprecipitation and RNA pull-down demonstrated that LncRNA LEF1-AS1 and LEF1 protein could combine especially. This thesis concludes LEF1-AS1 may be an oncogenic lncRNA that regulates the target gene LEF1 by interacting with protein LEF1. However, the prognostic significance of lncRNA LEF1-AS1 in CLL patients is still unclear.