Advances of circular RNAs in thyroid cancer: An overview

Unveiling the prominent roles of circular RNAs ubiquitin binding associated protein 2 in cancers

Circular RNAs (circRNAs), a novel type of covalently closed non-coding RNAs, are widely expressed in eukaryotes and viruses. Accumulating evidence has shown that circRNAs play key roles in the pathophysiological changes process of human diseases and can affect cancer development and progression through regulating target genes expression, linear RNA transcription and protein generation. Recent studies had found that circRNA-UBAP2 (ubiquitin binding associated protein 2) was aberrantly expressed in various human tumors and could affect tumor cells proliferation, migration, invasion, cell cycle, anti-apoptosis, radioresistance, chemoresistance and other malignant biological behavioral progress. Mechanistic studies further revealed that circUBAP2 could affect the occurrence and development of human tumors through multiple different molecular regulatory pathways in vivo and in vitro. In addition, the abnormal expression of circUBAP2 was significantly correlated with the clinicopathological characteristics of malignant tumors and had potential value as biomarkers for the diagnosis and prognosis evaluation of cancer patients, which deserved further study. This review had summarized and discussed the oncogenic roles and clinical performances of circUBAP2 in various human malignancies with a focus on biological functions and molecular mechanisms, which could help to elevate the understanding to the roles of circRNAs and continue subsequent studies on circUBAP2.

Preparation and MRI Study of HER2-Targeted Bimodal Molecular Probe Gd-Cy5.5-Pertuzumab for Thyroid Cancer

Purpose. A bimodal nanoprobe for thyroid cancer targeting human epidermal growth factor receptor 2 (HER2) was synthesized by coupling the magnetic resonance contrast agent Gd3+ with the fluorescent dyes Cy5.5 and pertuzumab as a preliminary study of Gd-Cy5.5-pertuzumab in magnetic resonance and fluorescence imaging. Methods. The bifunctional chelate p-SCN-Bn-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid (DOTA) was dissolved in deionized water, added to pertuzumab solution, and stirred overnight at room temperature to obtain the product DOTA pertuzumab. 1,2-dichloroethane and N-hydroxysuccinimide were added to activate the carboxyl group on DOTA. After 0.5 hr of activation, the amino fluorescent dye Cy5.5 was further added to react with it to synthesize the intermediate product Cy5.5-DOTA-pertuzumab. Finally, we added GdCl3-6H2O and placed it in a magnetic stirrer for 6 hr before the unreacted substance was removed by dialysis to obtain Gd-Cy5.5-pertuzumab. Following that, the hydrated particle size and zeta potential of the nanoprobe were measured by particle size analyzer, the fluorescence spectrum by a fluorescence detector, the infrared spectrum by the infrared analyzer, the cytotoxicity by CCK-8 method, the relaxation rate by Niumai small nuclear magnetic field, and the binding ability of HER2 to thyroid cancer 8505C by laser confocal microscope. Nanoprobes were injected into a subcutaneous thyroid cancer nude mouse model through the tail vein, and in vivo MRI and near-infrared (NIR) fluorescence imaging were performed. Finally, the nude mice were dissected and hematoxylin and eosin (HE) staining of pathological tissues was performed to evaluate the imaging performance of the prepared bimodal probes. Results. The synthesized bimodal probe Gd-Cy5.5-pertuzumab had a hydrodynamic size of 131.34 ± 9.43 nm and zeta potential of −31.73 ± 6.24 mV with a significant absorption peak at 685 nm. The relaxation rate of the probe was 46.53 mM−1 s−1, which was determined by Niumai small nuclear magnetism, and the T1 signal intensity increased gradually with the concentration of the probe. Laser confocal microscopy showed that HER2 was mainly expressed in cell membranes. In vitro and in vivo experiments indicated that the probe had low cytotoxicity. MRI and small animal fluorescence imaging of tumor-bearing nude mice showed that the probe could clearly image tumor tissue. Conclusion. The bimodal probe Gd-Cy5.5-pertuzumab was successfully synthesized with good stability, which can specifically bind to target cells in vivo and has good magnetic resonance/fluorescence imaging performance.

Noncoding RNAs in Thyroid-Follicular-Cell-Derived Carcinomas

Simple Summary

Thyroid tumors represent the most common neoplastic pathology of the endocrine system. Mutations occurring in oncogenes and tumor suppressor genes are responsible for thyroid carcinogenesis; however, the complete mutational landscape characterizing these neoplasias has not been completely unveiled. It has been established that only the 2% of the human genome codes for proteins, suggesting that the vast majority of the genome has regulatory capabilities, which, if altered, could account for the onset of cancer. Hence, many scientific efforts are currently focused on the characterization of the heterogeneous class of noncoding RNAs, which represent an abundant part of the transcribed noncoding genome. In this review, we mainly focus on the involvement of microRNAs, long noncoding RNAs, and pseudogenes in thyroid cancer. The determination of the diagnosis, prognosis, and treatment of thyroid cancers based on the evaluation of the noncoding RNA network could allow the implementation of a more personalized approach to fighting these pathologies.

Abstract

Among the thyroid neoplasias originating from follicular cells, we can include well-differentiated carcinomas, papillary (PTC) and follicular (FTC) thyroid carcinomas, and the undifferentiated anaplastic (ATC) carcinomas. Several mutations in oncogenes and tumor suppressor genes have already been observed in these malignancies; however, we are still far from the comprehension of their full regulation-altered landscape. Even if only 2% of the human genome has the ability to code for proteins, most of the noncoding genome is transcribed, constituting the heterogeneous class of noncoding RNAs (ncRNAs), whose alterations are associated with the development of several human diseases, including cancer. Hence, many scientific efforts are currently focused on the elucidation of their biological role. In this review, we analyze the scientific literature regarding the involvement of microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and pseudogenes in FTC, PTC, and ATC. Recent findings emphasized the role of lncRNAs in all steps of cancer progression. In particular, lncRNAs may control progression steps by regulating the expression of genes and miRNAs involved in cell proliferation, apoptosis, epithelial–mesenchymal transition, and metastatization. In conclusion, the determination of the diagnosis, prognosis, and treatment of cancer based on the evaluation of the ncRNA network could allow the implementation of a more personalized approach to fighting thyroid tumors.