Background and Aim: Breast Cancer (BC) is the most common cancer in women worldwide. Luminal A breast cancer is the most frequent molecular subtype among five intrinsic breast cancer subtypes. Long noncoding RNAs are a class of regulatory non-coding RNAs that they have ۲۰۰nt or more in length. Noncoding RNAs have different expression profiles in tumor tissues compared with normal tissues. Study of different roles of lncRNAs in cancers may help to define novel biomarkers and new targets for cancer therapies. Our work in this study was the evaluation of
LINC۰۰۹۶۸ lncRNA expression level in luminal A and B tumor tissues and performing some bioinformatic analysis to elucidate the probable functions of
LINC۰۰۹۶۸ lncRNA in breast cancer.Methods: The expression level of
LINC۰۰۹۶۸ was evaluated in seventy-one pairs of luminal A and B breast cancer tissues and adjacent non-tumor tissues and luminal A breast cancer cell lines (T۴۷D and MCF۷) and control MCF۱۰A cell line using qRT-PCR technique. Co-expression analysis was performed using GENEVESTIGATOR software and GEPIA web server and gene ontology (GO) terms enrichment analysis was done using DAVID and REVIGO database and Cytoscape software.Results:
LINC۰۰۹۶۸ lncRNA was significantly downregulated in luminal A and B tumor tissues and breast cancer cell lines (T۴۷D and MCF۷) (P-value<۰.۰۰۱). Also, low expression level of
LINC۰۰۹۶۸ gene was significantly related to lymph node metastasis and tumor stage.
LINC۰۰۹۶۸ is significantlyco-expressed with ۴۲۰ genes (R>۰.۴) in breast cancer datasets that most of them are expressed in low levels in BRCA dataset similar to the expression of
LINC۰۰۹۶۸ gene according to GEPIA web server. Genes co-expressed with
LINC۰۰۹۶۸ gene are involved in some biological processes (like cell-cell signaling, chemical synaptic transmission, cell proliferation and development) and some molecular function (like receptor binding, growth factor activity) and are enriched in some cellular component (like integral component of plasma membrane, ion channel complex, extracellular matrix).
LINC۰۰۹۶۸ may function in the same process and in the same way of the co-expressed genes.Conclusion: According to this study, downregulation of
LINC۰۰۹۶۸ and its significant association with higher stage and lymph node metastasis suggested that
LINC۰۰۹۶۸ may function as tumor suppressor gene and maybe dysregulation of this lncRNA can lead to the invasion and metastasis of breast tumors but further experimental tests are needed to confirm the validity of our conclusion. Also, enrichment analysis indicated that
LINC۰۰۹۶۸ may paly role in some processes that involve in the progression of breast cancer.