Long non-coding RNA expression profiling in normal B-cell subsets and Hodgkin lymphoma reveals Hodgkin and Reed-Sternberg cell specific long non-coding RNAs

Hodgkin lymphoma (HL) is a malignancy of germinal center (GC) B-cell origin. To explore the role of long non-coding RNAs (lncRNAs) in HL, we studied lncRNA expression patterns in normal B-cell subsets, HL cell lines and tissues. Naive and memory B-cells showed a highly similar lncRNA expression pattern, distinct from GC-B cells. Significant differential expression between HL and normal GC-B cells was observed for 475 lncRNA loci. For two validated lncRNAs an enhanced expression was observed in HL, diffuse large B cell lymphoma and lymphoblastoid cell lines. For a third lncRNA, increased expression levels were observed in HL and part of Burkitt lymphoma cell lines. RNA-FISH on primary HL tissues revealed a tumor cell-specific expression pattern for all three lncRNAs. A potential cis-regulatory role was observed for 107 differentially expressed lncRNA-mRNA pairs localizing within a 60kb region. In line with a cis-acting role, we showed a preferential nuclear localization for two selected candidates. Thus, we showed dynamic lncRNA expression changes during the transit of normal B-cells through the GC reaction and widely deregulated lncRNA expression patterns in HL. Three lncRNAs showed a tumor cell-specific expression pattern in HL tissues and might therefore be of value as a biomarker. Expression of all known mRNAs and >10 000 lncRNAs was assessed in normal B-cell subsets and HL cell lines.