Evaluating the expression levels of LINC00472 lncRNA in thyroid cancer tissues as a diagnostic biomarker

Abstract

Thyroid cancer is a rare tumor with a range of 2-20 cases per 100,000 people per year. This cancer is the most common endocrine malignancy and the main cause of death of all endocrine tumors. Papillary Thyroid Cancer (PTC) is considered the most common type of cancer among all thyroid cancers. There have been many advances in the treatment of PTC, but the prognosis is very poor. Therefore, identifying the molecular mechanisms that trigger PTC is necessary to improve the prognosis and treatments of this tumor. New diagnostic and treatment options, including molecular methods, have been suggested. Long noncoding RNAs (lncRNAs) refer to a class of endogenous ncRNA transcripts that are 200 nucleotides or more in length and do not appear to contain protein-coding sequences. However, it is now known that some lncRNAs are translated into functional micropeptides. These molecules participate in positive or negative transcriptional, epigenetic or post-transcriptional regulation of gene expression. A significant volume of studies is emerging from the role of lncRNAs in cancer, as they can act as oncogenes or tumor suppressor genes. Many lncRNAs have been reported to be associated with PTC. In this study, after previously screening several lncRNAs in PTC tissues, we focused on LINC00472. LINC00472 has been shown to inhibit cell migration and invasion and increase cell adhesion in various types of cancer, including lung cancer. However, its role in thyroid cancer is unclear. in this study, the level of expression of LINC00472 in thyroid cancer samples was investigated in comparison with adjacent healthy tissues. Materials and methods: In this study, 25 thyroid cancer tissues and 25 adjacent healthy tissue samples were selected from thyroid cancer patients and their clinical and pathological characteristics were investigated. Then, RNA was extracted from the samples and cDNA was synthesized and using real-time PCR, LINC00472 expression was measured in the samples and its relationship with clinical and pathological characteristics was investigated. Also, its expression was evaluated in a bioinformatic way using TCGA database in thyroid cancer samples relative to healthy samples to confirm the obtained results. Also, using ROC analysis, specificity and sensitivity of LINC00472 as a biomarker were investigated. Results: The obtained results showed that the expression levels of LINC00472 in tumor samples was significantly downregulated compared to normal samples in our experimental cohort and TCGA cohort and can be considered as a biomarker for the diagnosis of this malignancy. Besides, despite no significant correlation between the expression of this gene and clinical features in our samples, the results obtained from TCGA evidence it is downregulated by the progression of disease and in higher tumor stages.