Papillary Thyroid Cancer Cell Growth Research Articles

Clinical significance of eukaryotic translation initiation factor 5A2 in papillary thyroid cancer

ABSTRACT Eukaryotic translation initiation factor 5A2 (eIF5A2) plays an important role in tumor progression and prognosis evaluation. However, the potential role of eIF5A2 in human papillary thyroid cancer (PTC) is unknown. In this study, we aim to investigate the association between eIF5A2 expression and PTC clinical outcomes and underlying its Biological function in PTC cells in vitro and in vivo. The expression of eIF5A2 was examined by immunohistochemistry in PTC tissues and its adjacent tissue (n = 39) from 207 PTC patients. Functional analysis of eIF5A2 was performed in PTC cell lines in vitro and in vivo. The results showed that eIF5A2 was overexpressed in PTC tissues compared with the adjacent tissues. Enhanced eIF5A2 expression was significantly correlated with extrathyroidal extension (p = 0.012), lymph node metastasis (p = 0.002), TNM stage (p = 0.006), T classification (p = 0.047) and BRAF V600E mutation (p = 0.036). EIF5A2 inhibition prevented PTC cell growth, invasiveness and migration and induced cell apoptosis in vitro. Furthermore, eIF5A2 depletion inhibited tumor growth and metastasis in vivo. The data indicated that eIF5A2 could be employed as a novel prognostic marker and effective therapeutic target for PTC.

Alpinumisoflavone Inhibits Tumor Growth and Metastasis in Papillary Thyroid Cancer via Upregulating miR-141-3p.

Alpinumisoflavone (AIF) as a principal active ingredient of traditional Chinese herb Derris eriocarpa exerts a broad spectrum of anticancer activities against solid tumors. However, little is known about the effect of AIF on papillary thyroid cancer (PTC). Objectives of this study are to investigate the effect of AIF on cell growth, apoptosis, and metastasis of PTC cells and uncover its underlying mechanisms. Results showed that AIF treatment notably suppressed cell viability, migration, invasion, and epithelial-mesenchymal transition (EMT) process, as well as induced apoptotic cell death. In addition, microarray analysis results revealed that miR-141-3p level was dramatically elevated upon AIF insulation, suggesting that miR-141-3p may mediate the suppressive role of AIF against PTC. Moreover, miR-141-3p knockdown effectively reversed the effects of AIF on cell growth, migration, invasion, and EMT, while promoted PTC cell apoptosis escape. Furthermore, in vivo findings also confirmed that the antigrowth and antimetastasis activities of AIF were, at least partly, mediated by upregulation of miR-141-3p. Overall, AIF could serve as a potential anticancer compound for PTC treatment. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1842-1850, 2020. © 2019 American Association for Anatomy.

MicroRNA-675 directly targets MAPK1 to suppress the oncogenicity of papillary thyroid cancer and is sponged by long non-coding RNA RMRP.

BackgroundMicroRNA-675-5p (miR-675-5p) is dysregulated in multiple human cancers, but its involvement in papillary thyroid cancer (PTC) remains to be investigated. This study aimed to examine the expression pattern of miR-675 in PTC, determine the effects of miR-675 on regulating the progression of PTC, and to explore the underlying molecular mechanisms.MethodsThe expression profile of miR-675 in PTC tissues and cell lines was determined using RT-qPCR. CCK-8, transwell migration and invasion assays, and xenograft tumors in nude mice were employed to analyze proliferation, in vitro migration and invasion, and in vivo tumor growth of PTC cells, respectively. The putative target of miR-675 was predicted using bioinformatic algorithms and was confirmed using luciferase reporter assays, RT-qPCR, and Western blotting.ResultsmiR-675 expression was decreased in PTC tissues and cell lines. A low level of miR-675 expression was significantly correlated with lymphatic metastasis and TNM stage in PTC patients. Ectopic miR-675 expression suppressed PTC cell proliferation, migration, and invasion in vitro and hindered tumor growth in vivo. Mitogen-activated protein kinase 1 (MAPK1) was found to be the direct target gene of miR-675 in PTC cells. MAPK1 reintroduction negated the tumor-suppressing effect of miR-675 overexpression in PTC cells. Furthermore, the lncRNA mitochondrial RNA processing endoribonuclease (RMRP) functioned as a ceRNA of miR-675 in PTC cells. Silencing RMRP expression inhibited the growth and metastasis of PTC cells by sponging miR-675 and regulating MAPK1.ConclusionThese findings revealed that miR-675 directly targets MAPK1 and is sponged by lncRNA RMRP to inhibit the oncogenicity of PTC, suggesting the RMRP-miR-675-MAPK1 pathway is an effective target for the treatment of PTC patients.

Hsa_circ_0039411 promotes tumorigenesis and progression of papillary thyroid cancer by miR-1179/ABCA9 and miR-1205/MTA1 signaling pathways.

Papillary thyroid cancer (PTC) is a common malignancy in endocrine system worldwide. Increasing evidence has shown that dysregulation of circular RNAs (circRNAs) could contribute to PTC tumorigenesis. The aims of this project are to investigate the potential role and molecular mechanism of hsa_circ_0039411 in PTC. In the project, RT-qPCR was performed to measure the expression profile of hsa_circ_0039411 in PTC tissues and cells. Cell counting kit-8, clonogenic, flow cytometric, and transwell experiments were used to identify the biological role of hsa_circ_0039411 on PTC cell progression. Bioinformatics methods, along with the dual-luciferase reporter test, was used to identify the potential mechanism of hsa_circ_0039411. Hsa_circ_0039411 was identified as enhanced in PTC tissues/cells. Gain-of-function experiments indicated that hsa_circ_0039411 facilitated PTC cell growth, migration, and invasion and inhibited cell apoptosis. Knockdown of hsa_circ_0039411 caused the opposite effects mentioned above. The mechanism exploration showed that hsa_circ_0039411 functioned as a sponge for miR-1179 and miR-1205 to elevate ATP-binding cassette transporter A9 (ABCA9) and metastasis-associated 1 (MTA1) expression at the post-transcriptional level, respectively. Further investigation confirmed that the functions of hsa_circ_0039411 are dependent on its modulation of ABCA9 and MTA1 in PTC cells. This study uncovered a mechanism of hsa_circ_0039411 in PTC, which might act as a novel therapeutic target for PTC.

MiR-128 suppresses the growth of thyroid carcinoma by negatively regulating SPHK1

Accumulating evidences have emphasized the essential roles of differentially expressed miRNAs in papillary thyroid cancer (PTC) and follicular thyroid carcinoma (FTC) progression. MiR-128 has been reported to be down-regulated in multiple cancers to restrain tumor growth. However, the role of miR-128 in the development of PTC and FTC and the underlying mechanism remain to be unclear. In this present study, the results indicated that miR-128 expression was markedly down-regulated in PTC and FTC tissues and various thyroid carcinoma cell lines. Functional analysis indicated that over-expression of miR-128 suppressed PTC and FTC cancer cell growth, induced apoptosis and cell cycle arrest in G0/G1 phase. In addition, miR-128 over-expression markedly inhibited cancer cell migration and invasion. However, the processes above were reversed by silencing miR-128 expressions in thyroid tumor cells. Following, we characterized sphingosine kinase-1 (SPHK1) as a direct target of miR-128 that interacted with the 3′-untranslated region (UTR) of SPHK1, and the results were confirmed by using luciferase-reporter assay. We also observed that SPHK1 expression was decreased and negatively correlated with miR-128 expression in PTC and FTC tissues clinically. Importantly, ectopic expression of SPHK1 significantly abrogated the tumor-suppressive effect induced by miR-128, as supported by the reduced apoptosis, while the enhanced proliferation and metastasis. Finally, over-expressing miR-128 apparently reduced the tumor growth rate and tumor weight in vivo using xenograft tumor model, accompanied with a remarkable decrease of SPHK1. Thus, our study illustrated that miR-128 might be a tumor suppressor microRNA that played an essential role in thyroid carcinoma progression.

The Transcription Factor ETV5 Mediates BRAFV600E-Induced Proliferation and TWIST1 Expression in Papillary Thyroid Cancer Cells

The ETS family of transcription factors is involved in several normal remodeling events and pathological processes including tumor progression. ETS transcription factors are divided into subfamilies based on the sequence and location of the ETS domain. ETV5 (Ets variant gene 5; also known as ERM) is a member of the PEA3 subfamily. Our meta-analysis of normal, benign, and malignant thyroid samples demonstrated that ETV5 expression is upregulated in papillary thyroid cancer and was predominantly associated with BRAF V600E or RAS mutations. However, the precise role of ETV5 in these lesions is unknown. In this study, we used the KTC1 cell line as a model for human advanced papillary thyroid cancer (PTC) because the cells harbor the heterozygous BRAF (V600E) mutation together with the C250T TERT promoter mutation. The role of ETV5 in PTC proliferation was tested using RNAi followed by high-throughput screening. Signaling pathways driving ETV5 expression were identified using specific pharmacological inhibitors. To determine if ETV5 influences the expression of epithelial-to-mesenchymal (EMT) markers in these cells, an EMT PCR array was used, and data were confirmed by qPCR and ChIP-qPCR. We found that ETV5 is critical for PTC cell growth, is expressed downstream of the MAPK pathway, and directly upregulates the transcription factor TWIST1, a known marker of intravasation and metastasis. Increased ETV5 expression could therefore be considered as a marker for advanced PTCs and a possible future therapeutic target.

LncRNA CRNDE promotes cell proliferation, invasion and migration by competitively binding miR-384 in papillary thyroid cancer.

Thyroid cancer is one of the most prevalent endocrine neoplasm. The present study examined the effects of Colorectal Neoplasia Differentially Expressed (CRNDE) on the progression of papillary thyroid cancer (PTC), and explored the underlying molecular mechanisms. Quantitative real-time PCR was used to detect CRNDE, miR-384 and pleiotrophin (PTN) mRNA expression. Western blot was used to measure PTN protein levels. Cell proliferation, cell growth, cell invasion and migration of PTC cells were determined by CCK-8, colony formation, transwell invasion and migration assays, respectively. CRNDE was up-regulated in PTC tissues and cell lines. Overexpression of CRNDE promoted BCPAP cell proliferation, invasion and migration, while knock-down of CRNDE suppressed K1 cell proliferation, invasion and migration. CRNDE negatively regulated the expression of miR-384 in PTC cells, which was further confirmed by luciferase reporter assay. MiR-384 was down-regulated and inversely correlated with CRNDE expression in PTC tissues. MiR-384 suppressed cell proliferation, invasion and migration in PTC cells, and enforced expression of miR-384 attenuated the oncogenic effects of CRNDE in PTC cells. PTN was predicted as a downstream target of miR-384, which was confirmed by luciferase reporter assay, and PTN was up-regulated in PTC tissues, and was negatively correlated with miR-384 expression and positively correlated with CRNDE expression in PTC tissues. In summary, our results suggested that the CRNDE/miR-384/PTN axis may play an important role in the regulation of PTC progression, which provides us with new insights into understanding the PTC.

MicroRNA-335 is downregulated in papillary thyroid cancer and suppresses cancer cell growth, migration and invasion by directly targeting ZEB2.

MicroRNAs (miRs) are a group of short, endogenous, non-protein-coding and single-stranded RNAs that regulate gene expression by binding to the 3'-untranslated region (3'UTR) of mRNAs, which results in their degradation or translational repression. The aim of the present study was to investigate the expression and function of miR-335 in human papillary thyroid cancer (PTC). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to quantify the relative miR-335 expression levels in PTC tissues and cell lines. The effect of miR-335 on the proliferation, migration and invasion of PTC cells was assessed by an MTT assay, and transwell migration and invasion assays, respectively. Dual-luciferase reporter assays were employed to explore whether miR-335 directly targeted the 3'UTR of the potential target gene zinc finger E-box binding homeobox 2 (ZEB2). RT-qPCR and western blotting were adopted to assess the effect of miR-335 on the mRNA and protein expression of ZEB2. RT-qPCR revealed that miR-335 was downregulated in PTC tissues and cell lines. The MTT assay and transwell migration and invasion assays demonstrated that the overexpression of miR-335 significantly inhibited the proliferation, migration and invasion of PTC cells. ZEB2 was identified as a direct target of miR-335 with computational analysis, which was confirmed with a dual-luciferase reporter assay, RT-qPCR and western blotting. The knockdown of ZEB2 significantly inhibited the proliferation, migration and invasion of PTC cells, indicating that ZEB2 may be a functional target of miR-335. Taken together, these findings suggested that miR-335 functioned as a tumor suppressor and suppressed the growth and metastatic behavior of PTC cells by targeting ZEB2.

MicroRNA-613 inhibits cell growth, migration and invasion of papillary thyroid carcinoma by regulating SphK2.

MicroRNAs (miRNAs) have emerged as important gene regulators and are recognized as key players in carcinogenesis. In this study, we investigated the biological function and mechanism of miR-613 in the regulation of papillary thyroid cancer (PTC) development. We found that miR-613 was downregulated in PTC cell lines and tissues, and overexpression of miR-613 significantly suppressed PTC cell growth, migration and invasion in vitro and inhibited tumor growth in vivo. We identified the gene for sphingosine kinase 2 (SphK2) as a direct target of miR-613. Overexpression of miR-613 significantly repressed SphK2 expression by directly targeting its 3′-untranslated regions (3′-UTR) and restoration of SphK2 reversed the inhibitory effects of miR-613 on PTC cell growth and invasion. Taken together, our results indicated that miR-613 functions as a tumor suppressor in PTC and its suppressive effect is mediated by repressing SphK2 expression.

Destabilizing RET in targeted treatment of thyroid cancers.

Metastatic differentiated thyroid cancers (DTC) are resistant to traditional chemotherapy. Kinase inhibitors have shown promise in patients with progressive DTC, but dose-limiting toxicity is commonplace. HSP90 regulates protein degradation of several growth-mediating kinases such as RET, and we hypothesized that HSP90 inhibitor (AUY922) could inhibit RET-mediated medullary thyroid cancer (MTC) as well as papillary thyroid cancer (PTC) cell growth and also radioactive iodine uptake by PTC cells. Studies utilized MTC cell lines TT (C634W) and MZ-CRC-1 (M918T) and the PTC cell line TPC-1 (RET/PTC1). Cell viability was assessed with MTS assays and apoptosis by flow cytometry. Signaling target expression was determined by western blot and radioiodine uptake measured with a gamma counter. Prolonged treatment of both MTC cell lines with AUY922 simultaneously inhibited both MAPK and mTOR pathways and significantly induced apoptosis (58.7 and 78.7% reduction in MZ-CRC-1 and TT live cells respectively, following 1 μM AUY922; P<0.02). Similarly in the PTC cell line, growth and signaling targets were inhibited, and also a 2.84-fold increase in radioiodine uptake was observed following AUY922 administration (P=0.015). AUY922 demonstrates in vitro activity against MTC and PTC cell lines. We observed a potent dose-dependent increase in apoptosis in MTC cell lines following drug administration confirming its anti-tumorigenic effects. Western blots confirm inhibition of pro-survival proteins including AKT suggesting this as the mechanism of cell death. In a functional study, we observed an increase in radioiodine uptake in the PTC cell line following AUY922 treatment. We believe HSP90 inhibition could be a viable alternative for treatment of RET-driven chemo-resistant thyroid cancers.