According to GLOBOCAN 2012, the worldwide burden of cancer increased and is expected to worsen within the next decades. Therefore, universal combat against cancer will not succeed with treatment solely; effective prevention and early detection are urgently needed to tackle the cancer crisis. Emerging data demonstrate that long non-coding RNAs are involved in numerous biological and pathological processes like development and differentiation and in a variety of human diseases including cancer. Located at 18q21, LINC-ROR (regulator of reprogramming) is a modulator of ESCs maintenance and hypoxia-signaling pathways in hepatocellular cancer cells. The aim of this study was to examine the expression of LINC-ROR in various cell lines and representative samples of human cancers by quantitative real-time RT-PCR to provide a snapshot on how LINC-ROR expression may be deregulated in cancer. More than 30 cell lines and 112 patient specimens from various tissues were assessed for relative expression of LINC-ROR. Our results revealed that the expression of LINC-ROR was lower in all somatic cancer cell lines compared to stem cells or cells with stem cell-like capabilities, like the embryonic carcinoma cell line, NTERA-2. In tissues, expression patterns vary, but some cancerous tissues displayed increased LINC-ROR expression compared to corresponding normal tissues. Thus, we hypothesize that LINC-ROR may have a key function in a subpopulation of cells from the tumor bulk, i.e., the cancer stem cells associated with specific properties including resistance to adverse environmental conditions.
Keywords: Cancer; Gene expression; LINC-ROR; Long non-coding RNAs.