Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 52 2 2023 01 30 427 435 Mozhgan Sadat Akhtar Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran Akram Gholipour Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Mahrokh Bagheri Moghadam Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Maziar Oveisee 1. School of Medicine, Bam University of Medical Sciences, Bam, Iran 2. Clinical Research Center, Pastor Educational Hospital, Bam University of Medical Sciences, Bam, Iran Seyed Javad Mowla Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran Mahshid Malakootian Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran 2022 05 27 2022 11 19 Background: 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. Methods: 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. Results: 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. Conclusion: 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.   https://ijph.tums.ac.ir/index.php/ijph/article/view/28877 https://ijph.tums.ac.ir/index.php/ijph/article/download/28877/7868