MicroRNA in Papillary Thyroid Carcinoma: A Systematic Review from 2018 to June 2020

Abstract

The involvement of micro-ribonucleic acid (microRNAs) in metabolic pathways such as regulation, signal transduction, cell maintenance, and differentiation make them possible biomarkers and therapeutic targets. The purpose of this review is to summarize the information published in the last two and a half years about the involvement of microRNAs in papillary thyroid carcinoma (PTC). Another goal is to understand the perspective offered by the new findings. Main microRNA features such as origin, regulation, targeted genes, and metabolic pathways will be presented in this paper. We interrogated the PubMed database using several keywords: “microRNA” + “thyroid” + “papillary” + “carcinoma”. After applying search filters and inclusion criteria, a selection of 137 articles published between January 2018–June 2020 was made. Data regarding microRNA, metabolic pathways, gene/protein, and study utility were selected and included in the table and later discussed regarding the matter at hand. We found that most microRNAs regularly expressed in the normal thyroid gland are downregulated in PTC, indicating an important tumor-suppressor action by those microRNAs. Moreover, we showed that one gene can be targeted by several microRNAs and have nominally described these interactions. We have revealed which microRNAs can target several genes at once.

MicroRNA Profile for Diagnostic and Prognostic Biomarkers in Thyroid Cancer

“…Deregulation of miRNA expression plays a role in the development, progression, and cell death of thyroid tumors [13][14][15][16]. From previous studies performed on PTC [15,16], the most consistently upregulated miRNAs were miR-146b, miR-181b, miR-221, and miR-222 [13]. Tumor suppressor miRNAs in PTC include miR-137 and miR-451 [13].…”

“…MicroRNAs (miRNAs) are the major post-transcriptional regulators of messenger RNA (mRNA) expression, leading to downregulation or upregulation of protein synthesis [12]. Deregulation of miRNA expression plays a role in the development, progression, and cell death of thyroid tumors [13][14][15][16]. From previous studies performed on PTC [15,16], the most consistently upregulated miRNAs were miR-146b, miR-181b, miR-221, and miR-222 [13].…”

Biomarker Value of miR-221 and miR-222 as Potential Substrates in the Differential Diagnosis of Papillary Thyroid Cancer Based on Data Synthesis and Bioinformatics Approach

“…Besides, miRNAs can be stably measured in various types of sample sources, making them possess promising biomarker characteristics (6). Moreover, recent evidence has revealed that the expression of miRNA is highly associated with the occurrence and development of PTC and can be employed as a molecular biomarker for its diagnosis, treatment and prognosis (7). Therefore, identifying miRNAs that may serve as potential markers of PTC after an initial screening or diagnostic test has a significant clinical value.…”

Epigenetic Silencing of SOX15 Is Controlled by miRNAs rather than Methylation in Papillary Thyroid Cancer

“…Accumulating data show that various miRNAs are dysregulated in thyroid carcinoma and most of these miRNAs are involved in the regulation of malignancy and metastasis [21-23, 26, 37, 38]. Hitu et al [22] have reported that 106 of 139 miRNAs which have been investigated were upregulated in PTC while 33 were downregulated. In a previous report, Zhu et al [23] revealed that overexpression of miR-182 regulates PTC proliferation and invasion through downregulating CHL1 expression.…”

“…MicroRNAs (miR-NAs) are endogenous noncoding RNA molecules, about 18-26 nucleotides in length, which bind to target mRNAs and posttranscriptionally regulate their expression [20]. Recent reports have indicated that deregulation of miRNAs is associated with the development and progression of various cancers including thyroid carcinoma [21,22]. A significant number of studies have shown that miRNAs have important functions in thyroid cancer.…”