Long noncoding RNA profiles of adrenocortical cancer can be used to predict recurrence

    1. S B Sidhu1,6
    1. 1Cancer Genetics Laboratory, Kolling Institute of Medical Research
      2Departments of Endocrinology
      3Anatomical Pathology, Royal North Shore Hospital and University of Sydney, St Leonards, New South Wales 2065, Australia
      4Department of Surgery, Bankstown Hospital and University of New South Wales, Bankstown, New South Wales 2065, Australia
      5Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2200, Australia
      6University of Sydney Endocrine Surgical Unit, Royal North Shore Hospital, St Leonards, New South Wales 2065, Australia
    1. Correspondence should be addressed to S B Sidhu; Email: stanley.sidhu{at}sydney.edu.au


    Adrenocortical carcinoma (ACC) is an aggressive malignancy with high rates of recurrence following surgical resection. Long noncoding RNAs (lncRNAs) play an important role in cancer development. Pathogenesis of adrenal tumours have been characterised by mRNA, microRNA and methylation expression signatures, but it is unknown if this extends to lncRNAs. This study describes lncRNA expression signatures in ACC, adrenal cortical adenoma (ACA) and normal adrenal cortex (NAC) and presents lncRNAs associated with ACC recurrence to identify novel prognostic and therapeutic targets. RNA was extracted from freshly frozen tissue with confirmation of diagnosis by histopathology. Focused lncRNA and mRNA transcriptome analysis was performed using the ArrayStar Human LncRNA V3.0 microarray. Differentially expressed lncRNAs were validated using quantitative reverse transcriptase-PCR and correlated with clinical outcomes. Microarray of 21 samples (ten ACCs, five ACAs and six NACs) showed distinct patterns of lncRNA expression between each group. A total of 956 lncRNAs were differentially expressed between ACC and NAC, including known carcinogenesis-related lncRNAs such as H19, GAS5, MALAT1 and PRINS (P≤0.05); 85 lncRNAs were differentially expressed between ACC and ACA (P≤0.05). Hierarchical clustering and heat mapping showed ACC samples correctly grouped compared with NAC and ACA. Sixty-six differentially expressed lncRNAs were found to be associated with ACC recurrence (P≤0.05), one of which, PRINS, was validated in a group of 20 ACCs and also found to be associated with metastatic disease on presentation. The pathogenesis of adrenal tumours extends to lncRNA dysregulation and low expression of the lncRNA PRINS is associated with ACC recurrence.

    • Revision received 10 November 2014
    • Accepted 1 December 2014
    | Table of Contents