Differential Expression of lincRNA-ROR Spliced Transcript Variants in Breast Cancer

We investigated the expression pattern of a human stem cell-specific, large intergenic noncoding RNA (lincRNA) regulator of reprogramming (lincRNA-ROR) and its spliced transcript variants in breast tumors. Breast cancer is the leading cause of cancer mortality in women; therefore, finding a reliable diagnostic tumor marker, based on the molecular profile of tumor cells, is warranted.

qRT-PCR was used to investigate the expression alteration of a specific stem cell-related lincRNA and its spliced transcript variants in breast tumors which provided by the Iran National Tumor Bank (2014-2016). Suitability of lincRNA-ROR and expression alterations of its spliced transcript variants as breast tumor biomarkers were examined by ROC curve analysis.

Expression was significantly upregulated in lincRNA-ROR variants 1 (NR-048536) and 4 (AB844432) and downregulated in variant 3 (AB844431), with expression levels failing to distinguish between breast tumor types, grades, and malignancy stages. Whereas ROC curve analysis gave good scores to the expressions of variants 1 (AUC=0.7675, P=0.003) and 3 (AUC=0.9383, P=0.00173), suggesting their suitability as potential breast tumor biomarkers, it gave an AUC score of 0.6033 for lincRNA-ROR spliced variant 4 (P=0.4118), denoting its unsuitability as a breast cancer biomarker.

Aberrant expressions of lincRNA-ROR spliced transcript variants could serve as reliable biomarkers with potential usefulness in breast cancer diagnosis. However, further research should elucidate the role and tissue expression of lincRNA-ROR spliced transcript variants in various cancers.