Investigation of Long Non-Coding Rna Linc00961 Expression in Luminal Subtype of Breast Cancer

Background and aim: breast cancer (bc), the most common cancer among females worldwide, is the second leading cause of cancer deaths in women. moreover, it is the most common neoplasm among iranian women, with an average age of 46 to 49 years. luminal subtype of bc, including luminal a and b, accounts for nearly two-thirds of this cancer. long non-coding rnas (lncrnas) are a class of rnas with more than 200 nucleotides. they play significant roles in the regulation of diverse molecular and cellular processes. they are also associated with the development of various cancers, including bc. this study aims to determine the possible role of lncrna linc00961 in bc.methods: linc00961 expression was evaluated in 79 luminal a and b bc tissues and adjacent non-tumoral tissues, as well as bc cell lines (mcf7 and t47d) and a non-tumorigenic cell line (mcf10a), by qrt-pcr. then, the correlation of linc00961 expression with clinicopathological features was evaluated by χ2 test and independent t-test. moreover, various databases, such as, gepia web server, genevestigator, david and revigo, were used to investigate the possible role of linc00961 in bc.results: linc00961 was significantly downregulated in luminal bc tissues and luminal a cell lines, compared to adjacent non-tumoral tissues and a normal cell line, respectively (p-value<0.001). also, low expression of linc00961 was significantly associated with smoking status and age of menarche. according to co-expression analysis, linc00961 was significantly co-expressed with 417 genes across various bc datasets (r>0.5). gene ontology terms enrichment analysis of the co-expressed genes suggested that linc00961 might be involved in several biological processes, including, g-proteincoupled receptor signaling pathway, neurological system process and regulation of jak-stat cascade. it also might be involved in various molecular functions, like, transmembrane signaling receptor activity, and structural molecule activity. according to cellular component terms, it is possibly located in the neuron part, and extracellular matrix.conclusion: we found that the expression of linc00961 was significantly decreased in luminal bc. also, exploration of the association of linc00961 with its co-expressed genes and the analysis of their potential roles in bc datasets may help to better understand the function of linc00961 in this cancer.