Adrenocortical tumors have a distinct long non-coding RNA expression profile and LINC00271 is downregulated in malignancy

Background: Adrenocortical carcinoma (ACC) is an aggressive
malignancy with a low but variable overall survival rate. The role of
long noncoding RNAs (lncRNAs) in ACC is poorly understood. Thus, in this
study we performed lncRNA expression profiling in ACC, adrenocortical
adenoma (ACA) and normal adrenal cortex (NAC).
Methods: LncRNA expression profile, using ArrayStar Human LncRNA/mRNA
Expression Microarray V3.0, was analyzed in 11 ACA, 9 ACC and 5 NAC
samples. Differentially expressed lncRNAs were validated using TaqMan
real-time quantitative PCR with additional samples. The ACC Cancer Genome
Atlas (TCGA) project dataset was used to evaluate the prognostic utility
of lncRNAs.
Results: Unsupervised hierarchical clustering showed distinct clustering
of ACC samples compared with NAC and ACA samples by lncRNA expression
profiles. A total of 874 lncRNAs were differentially expressed between
ACC and NAC. LINC00271 expression level was associated with prognosis,
patients with low LINC00271 expression survived shorter than patients
with high LINC00271 expression. Low LINC00271 expression was positively
associated with WNT signaling, cell cycle, and chromosome segregation
pathways.
Conclusions: ACC has a distinct lncRNA expression profile. LINC00271 is
downregulated in ACC and is involved in biological pathways commonly
dysregulated in ACC.