Evaluation of changes in the lncRNA HCG11 expression levels in tissue samples of thyroid cancer patients for use as the diagnostic biomarker

Abstract

Papillary thyroid cancer (PTC) which accounts for more than 80% of all thyroid cancers, is known as the most common endocrine malignancy and its global incidence is continuing to increase rapidly. Surgery is considered the primary treatment for this disease. It has been shown that inappropriate gene expression which could possibly be due to genomic instability or changes in epigenetic markers, is considered one of important players in PTC regulation. LncRNAs are part of gene expression products that are not being translated to proteins and regarding their unique molecular structure, play major role in modulating different oncogenes and tumor suppressors and also in proliferation, migration, and EMT (Epithelial to Mesenchial Transition) of cancer cells. In various cancers, many lncRNAs, such as HCG11 became out of regulation. Therefore, in this study, we investigated the expression of HCG11 in tissue samples of thyroid cancer and also samples from bioinformatic datasets in order to determine its role in onset and progression of thyroid cancer and also evaluating its potential for being a biomarker. Materials and methods: First, 20 samples of thyroid cancer tissue and 20 samples of paired adjacent healthy tissue were taken from patients and after RNA extraction and cDNA synthesis, the HCG11 gene expression level was measured by qRT-PCR technique and then the association of HCG11 gene expression with clinical and pathological features of patient’s tissue samples was investigated. Besides, to confirm the results, HCG11 gene expression was evaluated using TCGA bioinformatic database in thyroid cancer samples compared to healthy samples. ROC curve analysis and Kaplan-Meier method were used for evaluating the diagnostic power of this gene and also its relationship with survival of patients with different stages of cancer, respectively. Findings: The results showed that the expression level of HCG11 was significantly lower in cancer samples compared to healthy samples and these results were confirmed using TCGA database samples. Furthermore, it has been shown that expression pattern of this gene could be considered a potential diagnostic biomarker for thyroid cancer. Additionally results indicated negative association between HCG11 expression and survival rate of patients with different stages of cancer.