The stress-activated protein kinase pathway and the expression of stanniocalcin-1 are regulated by miR-146b-5p in papillary thyroid carcinogenesis

Abstract

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Deciphering the pathophysiological mechanisms that contribute to PTC development is essential to the discovery of optimal diagnostic and therapeutic approaches. MiR-146b-5p has been identified as a cancer-associated microRNA highly up-regulated in PTC. This study explores the hypothesis that miR-146b-5p contributes to papillary thyroid carcinogenesis through regulation of cell signaling pathways in a manner that overcomes the cellular growth suppressive events and provides survival advantage. The effect of miR-146b-5p inhibition on major cancer related signaling pathways and expression of Stanniocalcin-1 (STC1), an emerging molecule associated with stress response and carcinogenesis, was tested in cultured primary thyroid cells using luciferase reporter assays, quantitative real-time PCR, immunofluorescence staining, and flow cytometry. Our results demonstrated that miR-146b-5p inhibits the JNK/AP1 pathway activity and down-regulates the expression of STC-1 in thyroid-cultured cells and in thyroid tissue samples. In the presence of miR-146b-5p, PTC cells were resistant to cell death in response to oxidative stress. This is a novel report that miR-146b-5p directly targets STC1 and regulates the activity of JNK/AP1 pathway. Considering the importance of the JNK/AP1 pathway and STC1 in mediating many physiological and pathological processes like apoptosis, stress response and cellular metabolism, a biological regulator of these pathways would have a great scientific and clinical significance. ARTICLE HISTORY

A new paradigm for epidermal growth factor receptor expression exists in PTC and NIFTP regulated by microRNAs

“…Primary thyroid cell culture was done as described in our previous work ( 55 ). Cultured cells, at a density of 1 × 10 6 cells, were transfected using 15 μL of HiPerFect Transfection Reagent (QIAGEN) and 150 ng of Anti has- miR-146b-5p miScript miRNA Inhibitor (QIAGEN) or Syn-hsa-miR-7-5p miScript miRNA Mimic (QIAGEN), or negative control siRNA (QIAGEN).…”

“…Oxidative stress was induced by treating the cancer cells with Paraquat (3 μM) for 24 h before analysis. This concentration of paraquat was optimized previously and proved to be the highest concentration that cause less than 10% cell death in thyroid cells culture ( 55 ).…”

“…Cultured and transfected thyroid cells was tested for change of expression of EGFR protein by Western immunoblot technique as described previously ( 55 ). 20 μg of protein was electrophoresed on SDS-PAGE gel and transferred to PVDF membranes at a stable current of 300 mA overnight at 4°C.…”

“…miR-146b-5p was suggested as a useful tool for overcoming EGFR resistance through regulation of miR-146b-5p/IRAK1/NF-kB signaling (53). miR-146b-5p overexpression was suggested as a new tool to improve the clinical benefit of EGFR-targeted treatments in ovarian cancer patients (54). There are no reports on the interaction of miR-7-5p and miR-146b-5p with EGFR in PTC or on the expression of EGFR in the newly classified tumors such as NIFTP.…”

PSG7 indicates that age at diagnosis is associated with papillary thyroid carcinoma: A study based on the cancer genome atlas data

“…Additionally, rearrangements, including rearranged during transfection (RET) and neurotrophic tyrosine kinase receptor type 1 (NTRK1), can accelerate the progression of the malignancy by activating mitogen-activated protein kinase signaling ( Pekova et al, 2020 ; Salvatore et al, 2021 ). Moreover, non-coding RNA regions can also be implicated in the tumorigenesis of PTC in various forms, including microRNAs, lncRNAs, and circRNA ( Gou et al, 2018 ; Al-Abdallah et al, 2020 ; Wu et al, 2020 ). Most intriguingly, the risk of PTC in carriers of the rs944289 single nucleotide polymorphism (SNP) was increased per year of age ( Kula et al, 2017 ); there were significantly more TERT mutations in PTC patients ≥ 55-years-old ( Park et al, 2021 ), which portended a poor prognosis likely by promoting immortalization and genomic instability in two phases ( Chiba et al, 2017 ).…”