Migration Of Thyroid Cancer Cells Research Articles

The function of SNHG7/miR-449a/ACSL1 axis in thyroid cancer.

Thyroid cancer (TC) has been characterized as the most common malignant malady of the endocrine system. Small nucleolar RNA host gene 7 (SNHG7) has been reported to serve as a key regulator in a large number of human cancer types, but its role in TC and the underlying regulatory mechanism have never been evaluated yet. The present study indicated that the expression of SNHG7 was markedly higher in TC cell lines. Knockdown of SNHG7 led to a suppression of TC cell progression and migration. Acyl-CoA synthetase long-chain family member 1 (ACSL1) has also been demonstrated as an oncogene in many cancers. Herein an inhibition of ACSL1 after SNHG7 knockdown was captured. Further, the suppressing effects of SNHG7 knockdown on TC cell processes were counteracted by ACSL1 overexpression. Data from online bioinformatics analysis, RNA immunoprecipitation, and luciferase reporter assays validated the interaction between microRNA-449a (miR-449a) and SNHG7 or ACSL1. It was also verified that SNHG7 sequestered miR-449a and therefore elevated ACSL1 expression levels. To conclude, the current study indicated that SNHG7 promoted proliferation and migration of TC cells by sponging miR-449a and therefore upregulating ACSL1. The present study may provide more explorations about the molecular regulation mechanism of long noncoding RNAs in TC progression.

The TUSC2 Tumour Suppressor Inhibits the Malignant Phenotype of Human Thyroid Cancer Cells via SMAC/DIABLO Protein.

Thyroid carcinoma is the most common endocrine cancer and includes different forms. Among these, anaplastic thyroid carcinoma (ATC) is the rarest but the most lethal subtype, compared to papillary thyroid carcinoma (PTC) which shows an overall good prognosis. We have previously showed that Tumor Suppressor Candidate 2 (TUSC2), a known tumour suppressor gene, is downregulated in human PTC and ATC compared to normal thyroid samples. The aim of this study was to gain insight into the molecular mechanisms induced by TUSC2 in thyroid cancer cells. Here, we stably transfected TUSC2 in papillary (TPC-1) and in anaplastic (8505C) thyroid cancer cell lines and studied its effects on several biological processes, demonstrating that TUSC2 overexpression decreased thyroid cancer cell proliferation, migration and invasion. Through the proteome profiler apoptosis array, we observed that TUSC2 increased sensitivity to apoptosis by increasing the SMAC/DIABLO and CYTOCHROME C proteins. On the other hand, transient silencing of TUSC2, by siRNA, in an immortalized thyroid follicular epithelial cell line (Nthy-ori 3-1) showed the opposite effect. Finally modulation of SMAC/DIABLO partially rescued the biological effects of TUSC2. Thus, our data highlight a tumour suppressor role of TUSC2 in thyroid carcinogenesis, suggesting that it could be a promising target and biomarker for thyroid carcinoma.

RETRACTED: Upregulation of OIP5-AS1 Predicts Poor Prognosis and Contributes to Thyroid Cancer Cell Proliferation and Migration

As a common malignancy, thyroid cancer mainly occurs in the endocrine system. There have been accumulating studies on therapeutic methods of thyroid cancer, but its internal molecular mechanism is still not fully understood. Long noncoding RNA (lncRNA) OIP5-AS1 was confirmed as an oncogene and related to poor prognosis in various cancers. Nevertheless, its role and underlying mechanism remain unclear in thyroid cancer. Here, we observed a significant upregulation of OIP5-AS1 in thyroid cancer tissues and cells, and upregulated OIP5-AS1 was correlated with poor prognosis in thyroid cancer. Moreover, OIP5-AS1 knockdown resulted in the inhibited cell proliferation and migration, while overexpressed OIP5-AS1 exhibited the reverse function in thyroid cancer. Besides, OIP5-AS1 was found to positively regulate Wnt/β-catenin signaling pathway. Through mechanism exploration, OIP5-AS1 was discovered to activate Wnt/β-catenin signaling pathway via FXR1/YY1/CTNNB1 axis. Finally, rescue assays indicated that the inhibitive role of silenced OIP5-AS1 in thyroid cancer cell growth and Wnt/β-catenin signaling pathway could be rescued by overexpression of CTNNB1 or addition of lithium chloride (LiCl). In conclusion, upregulation of OIP5-AS1 predicted unfavorable prognosis and enhanced thyroid cancer cell growth by activating Wnt/β-catenin signaling pathway.

Effect of miR-205 on proliferation and migration of thyroid cancer cells by targeting CCNB2 and the mechanism.

This study explored the target of miR-205 and the effect of miR-205 on the proliferation and migration regulating its target in thyroid cancer cells (TC). Twenty-five pairs of TC and adjacent tissues were collected after surgical resection. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of miR-205 in TC tissues and cells (SW579, B-CPAP, TPC-1, WRO). SW579 cells were transfected with miR-205 mimic, and SW579 cells with overexpression of miR-205 were constructed. The effects of miR-205 overexpression on the proliferation and migration of SW579 cells were observed by cell counting kit-8 (CCK-8) and Transwell assays, respectively. Luciferase reporter assay was further used to look for the target of miR-205 and to study the mechanism of miR-205 in the proliferation and migration of TC cells. Compared with normal tissues and cells, the expression of miR-205 was significantly reduced in TC tissues (t=3.47, P=0.031) and cells (t=5.41, P=0.016). Overexpression of miR-205 inhibited the proliferation (t=4.12, P=0.035) and migration (t=4.47, P=0.027) of SW579 cells. Luciferase reporter assays found that CCNB2 was a target gene of miR-205 (t=4.63, P=0.024), qRT-PCR and western blot assays confirmed there was negatively correlation between CCNB2 and miR-205 (t=3.55, P=0.029; t=2.86, P=0.043). CCNB2 overexpression reversed the inhibition of miR-205 on the proliferation (t=3.70, P=0.031) and migration (t=4.12, P=0.022) of SW579 cells. In conclusion, miR-205 inhibits the proliferation and migration of TC cells by targeting CCNB2, which may be a potential target of TC therapy.

VCAM-1 Upregulation Contributes to Insensitivity of Vemurafenib in BRAF-Mutant Thyroid Cancer

Vemurafenib, an inhibitor of mutant BRAF activity, is a promising anticancer agent for patients with BRAF-mutant metastatic melanoma. However, it is less effective in BRAF-mutant thyroid cancer, and the reason for this discrepancy is not yet fully elucidated. By RNA sequencing analysis, we identified vascular cell adhesion molecular-1 (VCAM-1) to be highly upregulated in both time- and dose-dependent manners during BRAF inhibition (BRAFi) in a BRAF-mutant papillary thyroid cancer cell line (BCPAP). Cell cytotoxicity and apoptosis assays showed that knockdown of the induced VCAM-1 in BCPAP cells augmented the antitumor effects of vemurafenib, with decreased IC50 values of 1.4 to 0.8 μM. Meanwhile, overexpression of VCAM-1 in a BRAF-mutant anaplastic thyroid cancer cell line (FRO) reduced the sensitivity to vemurafenib, with increased IC50 values of 1.9 to 5.8 μM. Further investigation showed that PI3K-Akt-mTOR pathway was activated during BRAFi. Co-treatment with Akt signaling inhibitor MK2206 decreased the induced expression of VCAM-1 during BRAFi. This combination further improved the efficacy of vemurafenib. Moreover, VCAM-1 promoted migration and invasion in thyroid cancer cells in vitro, which was also indicated in thyroid cancer patients. The present study is the first to demonstrate that VCAM-1 is upregulated in thyroid cancer cells treated with vemurafenib and contributes to vemurafenib resistance in BRAF-mutant thyroid cancer cells. Targeting the PI3K-Akt-mTOR pathway–mediated VCAM-1 response may be an alternative strategy to sensitize BRAF-mutant thyroid cancers to vemurafenib.

CDK12 promotes papillary thyroid cancer progression through regulating the c-myc/β-catenin pathway.

Background: CDK12 is a potential therapeutic target in papillary thyroid cancer that regulates the c-myc/β-catenin pathway.Objective: We aimed to explore the specific mechanism of CDK12 in papillary thyroid cancer and provide a new target of cancer therapy.Methods: RT-qPCR was used to determine the CDK12 mRNA expression level. An IHC assay was performed to detect the tissue expression of CDK12. Then, we downregulated CDK12 expression in the thyroid cancer cell lines TPC-1-shCDK12 and KAT-5-shCDK12. CCK8 assays, colony formation assays, and animal xenograft models were used to evaluate the effect of CDK12 on tumorigenesis. Transwell assays and in vivo metastasis models were used to observe whether CDK12 can promote cancer metastasis. Western blotting further confirmed the mechanism of CDK12 in papillary thyroid cancer through the c-myc/β-catenin pathway.Results: Upregulated CDK12 expression in papillary thyroid cancer promoted papillary thyroid cancer carcinogenesis in vivo, and in vitro CDK12 strengthened papillary thyroid cancer (PTC) cell migration and tumor metastasis. CDK12 promoted tumor progression by regulating c-myc/β-catenin pathway activation.Conclusions: CDK12 affects the c-myc/β-catenin pathway to stimulate papillary thyroid cancer proliferation and metastasis. Inhibiting CDK12 might be a new method in papillary thyroid cancer therapy.

FOXE1 regulates migration and invasion in thyroid cancer cells and targets ZEB1.

FOXE1 is a thyroid-specific transcription factor essential for thyroid gland development and maintenance of the differentiated state. Interestingly, a strong association has been recently described between FOXE1 expression and susceptibility to thyroid cancer, but little is known about the mechanisms underlying FOXE1-induced thyroid tumorigenesis. Here, we used a panel of human thyroid cancer-derived cell lines covering the spectrum of thyroid cancer phenotypes to examine FOXE1 expression and to test for correlations between FOXE1 expression, the allele frequency of two SNPs and a length polymorphism in or near the FOXE1 locus associated with cancer susceptibility, and the migration ability of thyroid cancer cell lines. Results showed that FOXE1 expression correlated with differentiation status according to histological sub-type, but not with SNP genotype or cell migration ability. However, loss-and-gain-of-function experiments revealed that FOXE1 modulates cell migration, suggesting a role in epithelial-to-mesenchymal transition (EMT). Our previous genome-wide expression analysis identified Zeb1, a major EMT inducer, as a putative Foxe1 target gene. Indeed, gene silencing of FOXE1 decreased ZEB1 expression, whereas its overexpression increased ZEB1 transcriptional activity. FOXE1 was found to directly interact with the ZEB1 promoter. Lastly, ZEB1 silencing decreased the ability of thyroid tumoral cells to migrate and invade, pointing to its importance in thyroid tumor mestastases. In conclusion, we have identified ZEB1 as a bona fide target of FOXE1 in thyroid cancer cells, which provides new insights into the role of FOXE1 in regulating cell migration and invasion in thyroid cancer.

Knockdown of long noncoding RNA DLX6-AS1 inhibits migration and invasion of thyroid cancer cells by upregulating UPF1.

Recently, long non- coding RNAs (lncRNAs) have attracted much attention for their roles in tumor progression. The aim of this study was to investigate the exact role of lncRNA DLX6 antisense RNA 1 (DLX6-AS1) in the development of thyroid cancer (TC), and to explore the underlying mechanism. DLX6-AS1 expression in both TC cells and tissue samples was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Moreover, transwell assay and wound healing assay were conducted. QRT-PCR and Western blot assay were used to explore the underlying mechanism. Furthermore, the function of DLX6-AS1 was identified in vivo. DLX6-AS1 expression level in TC tissues was significantly higher than that of the corresponding normal tissues. Moreover, TC cell migration and invasion were markedly inhibited after DLX6-AS1 was knocked down in vitro. The mRNA and protein expressions of UPF1 were both remarkably up-regulated after knockdown of DLX6-AS1. Meanwhile, the expression level of UPF1 was negatively correlated with the expression of DLX6-AS1 in TC tissues. Furthermore, knockdown of DLX6-AS1 significantly inhibited tumor metastasis in vivo. Knockdown of DLX6-AS1 could inhibit TC cell migration and invasion via upregulating UPF1, which might be a potential therapeutic target in TC.

Circular RNA circ_0067934 exhaustion expedites cell apoptosis and represses cell proliferation, migration and invasion in thyroid cancer via sponging miR-1304 and regulating CXCR1 expression.

Distant metastasis or local recurrence is the leading cause of death in some patients with thyroid cancer (TC), a malignant tumor of the endocrine system. Circular RNA circ_0067934 (circ_0067934) has been reported to be connected with the tumorigenesis of multiple tumors. However, there are few reports on the role and regulatory mechanisms of circ_0067934 in TC. The expression levels of circ_0067934, protein kinase C iota (PRKCI), microRNA-1304 (miR-1304), and C-X-C chemokine receptor types 1 (CXCR1) were detected with quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The proliferation, apoptosis, migration, and invasion of TC cells were evaluated by Cell Counting Kit-8 (CCK8) assay, flow cytometry assay, and transwell assay, respectively. The relationship between circ_0067934 or CXCR1 and miR-1304 was confirmed with Dual-Luciferase reporter assay or RNA immunoprecipitation (RIP) assay. Protein level of CXCR1 was analyzed via Western blot analysis. Xenograft assay was executed to verify the role of circ_0067934 in vivo. Circ_0067934 and CXCR1 were enhanced and miR-1304 decreased in TC tissues and cells. Circ_0067934 downregulation triggered apoptosis and curbed proliferation, migration, and invasion of TC cells in vitro, as well as repressed tumor growth in vivo. Notably, circ_0067934 regulated CXCR1 expression via sponging miR-1304 in TC cells. Both miR-1304 silencing and CXCR1 elevation reversed the facilitation of apoptosis and the retardation of proliferation, migration, and invasion induced by circ_0067934 reduction in TC cells. Circ_0067934 downregulation expedited apoptosis and retarded proliferation, migration, and invasion of TC cells through miR-1304/CXCR1 axis.

TRIM30 modulates Interleukin-22-regulated papillary thyroid Cancer cell migration and invasion by targeting Sox17 for K48-linked Polyubiquitination

BackgroundInterleukin-22 (IL-22) belongs to the IL-10 cytokine family and is mainly produced by activated Th1 cells. Although IL-22 expression is reported to be elevated in many cancers, and increased IL-22 expression correlates with tumor progression and poor prognosis, little is known about the role of IL-22 in papillary thyroid cancer (PTC). We previously demonstrated that IL-22 promotes PTC cell migration and invasion through the microRNA-595/Sox17 axis.MethodsWe used qRT-PCR and western blot to determine TRIM30, Sox17 and β-catenin expression in PTC cells. Knockdown and overexpression were performed to detect the role of TRIM30/Sox17/β-catenin axis on the migration and invasion PTC cells. Co-IP were used to determine the interaction between TRIM30 and Sox17.FindingsIn this study, we demonstrated that IL-22 triggered tripartite-motif protein 30 (TRIM30) association with Sox17, thereby mediating K48-linked polyubiquitination of Sox17. We then demonstrated that TRIM30 was a positive regulator of IL-22-regulated migration and invasion of PTC cells. We also found that IL-22 induced the transcriptional activity of β-catenin and translocation of β-catenin from cytosol to the nucleus. Upon investigating the mechanisms behind this event, we found that IL-22 disrupted Sox17/β-catenin interactions by inducing TRIM30/Sox17 interactions, leading to promotion of β-catenin-dependent signaling. The analysis of hundreds of clinical specimens revealed that IL-22, TRIM30 and β-catenin levels were upregulated in PTC tissues compared with normal thyroid, and that their expression levels were closely correlated. Taken together, under the influence of IL-22, by sequestration of Sox17, TRIM30 promotes β-catenin-dependent signaling that promotes PTC cell proliferation.

Activation of AMPK promotes thyroid cancer cell migration through its interaction with PKM2 and β-catenin

AMP-activated protein kinase (AMPK) is induced by the exhaustion of cellular energy and activates adaptive alterations in cellular metabolism, which is the basis for cell survival during different environmental stresses. We aimed to investigate the biological functions of AMPK and its molecular mechanism in regulating thyroid cancer (TC) progression. In current study, we found that activation of AMPK by multiple agonists suppresses TC cell proliferation. However, AMPK activation also led to TC cell migration at the same time. Depletion of AMPK abolished the effect of its agonist on cell multiplication and migration. Mechanistic investigations revealed that the impact of AMPK in terms of cell migration is dependent on its nuclear translocation, since site mutation of AMPK in its nuclear translocation domain (K244A) abolished TC cell migration but did not affect the inhibition of cell proliferation by AMPK agonist. Moreover, the nuclear AMPK recruits PKM2 and β-catenin by their interaction, which promotes the transcription of cell migration related genes, including MMP7 and c-Myc. Furthermore, depletion of PKM2/β-catenin abolished the migration effect of AMPK agonists, but did not affect their effects on suppression of cell proliferation. Our results provided a novel function of AMPK in cancer migration, and suggested that a combination of AMPK activation and PKM2 depletion or inhibition can be a new strategy to achieve better therapeutic effects for TC patients.

Long non-coding RNA HOTAIR promotes cell viability, migration and invasion in thyroid cancer cells by sponging miR-17-5p.

Thyroid cancer is a common endocrine malignancy. Long non-coding RNAs (lncRNAs) were reported to regulate cellular processes in tumorigenesis and development. In this study, we mainly investigated the role of Homeobox Transcript Antisense Intergenic RNA (HOTAIR) in thyroid cancer and its potential mechanism. RT-qPCR was conducted to evaluate the expression of HOTAIR and miR-17-5p in thyroid cancer tissues and 4 cell lines (TPC-1, FTC-133, B-CPAP and SW579). MTT assay was employed to analyze the cell viability of TPC-1 and FTC-133 cells. The migration and invasion of TPC-1 and FTC-133 cells were detected via Transwell assay. Luciferase reporter assay was used to validate the target of HOTAIR. In vivo tumor formation assay in nude mice was applied to investigate the impact of HOTAIR on thyroid cancer tumorigenesis. HOTAIR was significantly upregulated, while miR-17-5p was downregulated in thyroid cancer tissues and cells, and the miR-17-5p expression in thyroid cancer tissues was inversely correlated with HOTAIR expression. Silencing HOTAIR significantly inhibited the cell viability, migration and invasion of TPC-1 and FTC-133 cells. MiR-17-5p was a target of HOTAIR and counter-regulated by HOTAIR. Introduction of miR-17-5p also inhibited the cell viability, migration and invasion in TPC-1 and FTC-133 cells. Moreover, introduction of miR-17-5p reversed knockdown of HOTAIR-mediated the suppression effects on the cell viability, migration and invasion in thyroid cancer cells. Additionally, knockdown of HOTAIR inhibited thyroid cancer tumorigenesis in mice. Our results suggested HOTAIR promotes cell viability, migration and invasion in thyroid cancer cells by sponging miR-17-5p.

Long non-coding RNA-BANCR has an effect on the migration and invasion of thyroid cancer cells

Long non-coding RNA-BANCR has an effect on the migration and invasion of thyroid cancer cells

KLF4 overexpression decreases the viability, invasion and migration of papillary thyroid cancer cells.

Kruppel-like factor 4 (KLF4) has been implicated in a number of different types of cancer; however, the role of KLF4 in papillary thyroid cancer remains elusive. The present study aimed to investigate the role of KLF4 in papillary thyroid cancer and its potential underlying molecular mechanisms. The expression of KLF4 in thyroid tumor tissue and adjacent non-cancerous tissues were detected via immunohistochemistry and western blotting. The papillary thyroid cancer cell line, KTC1, was transfected with viruses carrying KLF4 overexpression vectors. The relative expression of KLF4, E-cadherin, N-cadherin, Vimentin, matrix metalloproteinase (MMP)2, MMP9 and collagen was detected via quantitative-PCR. The viability of KTC1 cells was detected using a cell counting kit-8 assay at 24, 48 and 72 h. Cell invasion was examined via a transwell invasion assay. Cell migration was examined via a scratch migration assay at 0 and 24 h. Compared with adjacent non-cancerous tissues, the expression of KLF4 was significantly lower in thyroid tumor tissues. The expression of KLF4 in KTC1 cells were significantly increased compared with the blank or negative control groups. The expression of N-cadherin, MMP2, MMP9 and collagen was significantly decreased in the KLF4 overexpression group. The viability of KTC1 cells was markedly decreased in KLF4 overexpression group at 24, 48 and 72 h when compared with the blank or negative control groups. The invasion of KTC1 cells in the KLF4 overexpression group was markedly decreased. Compared with the negative control group, the KTC1 cell migration in the KLF4 overexpression group was markedly decreased at 24 h. The expression of KLF4 was also significantly lower in thyroid tumor tissues. The cell viability, tumor invasion and migration ability and expression levels of N-cadherin, MMP2, MMP9 and collagen in papillary thyroid cancer cells were markedly decreased with KLF4 overexpression.

Hsa-miR-139-5p is a prognostic thyroid cancer marker involved in HNRNPF-mediated alternative splicing.

It is critical to identify biomarkers and functional networks associated with aggressive thyroid cancer to anticipate disease progression and facilitate personalized patient management. We performed miRNome sequencing of 46 thyroid tumors enriched with advanced disease patients with a median follow-up of 96 months. MiRNome profiles correlated with tumor-specific histopathological and molecular features, such as stromal cell infiltration and tumor driver mutation. Differential expression analysis revealed a consistent hsa-miR-139-5p downexpression in primary carcinomas from patients with recurrent/metastatic disease compared to disease-free patients, sustained in paired local metastases and validated in publicly available thyroid cancer series. Exogenous expression of hsa-miR-139-5p significantly reduced migration and proliferation of anaplastic thyroid cancer cells. Proteomic analysis indicated RICTOR, SMAD2/3 and HNRNPF as putative hsa-miR-139-5p targets in our cell system. Abundance of HNRNPF mRNA, encoding an alternative splicing factor involved in cryptic exon inclusion/exclusion, inversely correlated with hsa-miR-139-5p expression in human tumors. RNA sequencing analysis revealed 174 splicing events differentially regulated upon HNRNPF repression in our cell system, affecting genes involved in RTK/RAS/MAPK and PI3K/AKT/MTOR signaling cascades among others. These results point at the hsa-miR-139-5p/HNRNPF axis as a novel regulatory mechanism associated with the modulation of major thyroid cancer signaling pathways and tumor virulence.

Effect of bone morphogenetic protein-4 on proliferation, apoptosis and migration of thyroid cancer cells and its mechanism

Objective To investigate the effects of bone morphogenetic protein-4 (BMP-4) on the proliferation, apoptosis and migration of thyroid cancer cells through extracellular signal-regulated kinase 1/2 (ERK1/2)/p38 mitogen-activated protein kinase (p38MAPK) signaling pathway. Methods Thyroid papillary carcinoma (TPC)-1 cells (thyroid papillary carcinoma cells) were randomly divided into blank control group (BC), negative control group (NC) and interference group (KD). Cells in BC group were not transfected. NC group cells were transfected with negative control plasmids. KD group cells were transfected with the silenced BMP-4 plasmid. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to determine the BMP-4 mRNA levels. Cell counting kit-8 (CCK-8) was used to measure cell proliferation. Flow cytometry was used to determine cell apoptosis. Transwell chamber and scratch assay was used to determine cell migration capacity. The levels of ERK1/2, phosphorylated ERK1/2 (p-ERK1/2), p38MAPK and p-p38MAPK protein were determined by Western blotting. Results The level of BMP-4 mRNA in TPC-1 cells (5.86±0.42) was higher than that in HT-ori3 cells (normal thyroid cells) (1.00±0.03, t=30.537, P 0.05). Conclusion Silencing BMP-4 can inhibit the proliferation and migration of thyroid cancer cells and promote apoptosis, which may be related to down-regulation of ERK1/2/p38MAPK signaling pathway. Key words: Bone morphogenetic protein-4; Extracellular regulated protein kinase; p38 mitogen-activated protein kinase; Thyroid cancer; Proliferation; Apoptosis; Migration

MAPK- and AKT-activated thyroid cancers are sensitive to group I PAK inhibition.

The number of individuals who succumb to thyroid cancer has been increasing and those who are refractory to standard care have limited therapeutic options, highlighting the importance of developing new treatments for patients with aggressive forms of the disease. Mutational activation of MAPK signaling, through BRAF and RAS mutations and/or gene rearrangements, and activation of PI3K signaling, through mutational activation of PIK3CA or loss of PTEN, are well described in aggressive thyroid cancer. We previously reported overactivation and overexpression of p21-activated kinases (PAKs) in aggressive human thyroid cancer invasive fronts and determined that PAK1 functionally regulated thyroid cancer cell migration. We reported mechanistic crosstalk between the MAPK and PAK pathways that are BRAF-dependent but MEK independent, suggesting that PAK and MEK inhibition might be synergistic. In the present study, we tested this hypothesis. Pharmacologic inhibition of group I PAKs using two PAK kinase inhibitors, G-5555 or FRAX1036, reduced thyroid cancer cell viability, cell cycle progression and migration and invasion, with greater potency for G-5555. Combination of G-5555 with vemurafenib was synergistic in BRAFV600E-mutated thyroid cancer cell lines. Finally, G-5555 restrained thyroid size of BRAFV600E-driven murine papillary thyroid cancer by >50% (P < 0.0001) and reduced carcinoma formation (P = 0.0167), despite maintenance of MAPK activity. Taken together, these findings suggest both that group I PAKs may be a new therapeutic target for thyroid cancer and that PAK activation is functionally important for BRAFV600E-mediated thyroid cancer development.

Expression of ANGPTL2 and its impact on papillary thyroid cancer

BackgroundAlthough the most thyroid carcinoma patients have good prognosis, around 20% of papillary thyroid carcinoma (PTC) patients have a high rate of metastasis and recurrence after routine treatment, which causes high lethality with these patients. Tumor proliferation, metastasis, and invasion are important predictors of PTC invasiveness and are key factors in cancer-related death. Angiopoietin-like 2 (ANGPTL2), a secreted protein which belongs to the angiopoietin (ANGPTL) family, was reported to be involved in the regulation of several different type of cancer cell proliferation and metastasis. However, whether ANGPTL2 plays a role in the progression of PTC, particularly in metastasis and recurrence of PTC, remains unclear. Hence, the purpose of this study was to evaluate the level of ANGPTL2 in PTC and normal thyroid, as well as para-cancerous tissue. Furthermore, the impact of ANGPTL2 on PTC cell proliferation, metastasis, recurrence and invasion was assessed to investigate the possibility whether ANGPTL2 may become a novel target for PTC therapy and cancer prognosis.Materials and methodsThe level of ANGPTL2 in PTC and para-cancerous tissue was assessed by immunohistochemistry. The biological effect of ANGPTL2 on thyroid cancer cell proliferation and metastasis was investigated by the Cell Counting Kit-8 (CCK8) assay, cell scratch test, and transwell assay. Correlations of ANGPTL2 expression levels with proliferation, migration, and metastasis of thyroid cancer were assessed with the TCGA data set and analyzed by gene set enrichment analysis. Receiver operating characteristic analysis was used to evaluate the utility of ANGPTL2 as a biomarker for prediction of thyroid cancer. Survival analysis was performed using the thyroid cancer database in K–M Plotter to detect correlations between survival time and ANGPTL2 levels.ResultsCurrent study revealed that: (1) ANGPTL2 was highly expressed in thyroid cancer in comparison with adjacent normal thyroid tissue; (2) ANGPTL2 expression was increased with thyroid tumor progression; (3) ANGPTL2 increased proliferation of thyroid cancer cells; (4) ANGPTL2 promoted migration and invasion of thyroid cancer cells; (5) high level of ANGPTL2 in thyroid cancer patients were significantly associated with a poor prognosis. The patients showed a higher metastasis and recurrence rate.ConclusionANGPTL2 promoted and enhanced proliferation, metastasis, and invasion of thyroid cancer cells. ANGPTL2 may be considered as a potential biomarker for diagnosis and prognosis of thyroid cancer patients. Further evaluation needs to be done to analyze the possibility of taking ANGPTL2 as a prognostic marker and therapeutic target for papillary thyroid cancer.

MicroRNA-592 suppresses the malignant phenotypes of thyroid cancer by regulating lncRNA NEAT1 and downregulating NOVA1.

Numerous studies have demonstrated that various microRNAs (miRs) are aberrantly expressed in thyroid cancer and play critical roles in thyroid cancer malignancy. The aberrant expression of miR‑592 has frequently been reported in multiple human cancer types; however, its expression profile and functions in thyroid cancer remain poorly understood. Reverse transcription‑quantitative polymerase chain reaction was carried out to determine the expression profile of miR‑592 in thyroid cancer tissues and cell lines. The regulatory effects of miR‑592 upregulation on thyroid cancer cell proliferation, migration, and invasion invitro, and tumor growth invivo were investigated using a CCK‑8 assay, migration and invasion assays, and a xenograft tumor model, respectively. Furthermore, the mechanisms underlying miR‑592‑mediated suppression of the aggressive phenotypes of thyroid cancer cells were explored in detail. The results indicated that miR‑592 was significantly downregulated in thyroid cancer samples, and its downregulation was associated with lymph node metastasis and tumor‑node‑metastasis stage. Patients with thyroid cancer and low miR‑592 expression exhibited shorter overall survival than patients with high miR‑592 expression. Overexpression of miR‑592 resulted in decreased cell proliferation, migration, and invasion in thyroid cancer. In addition, neuro‑oncological ventral antigen1 (NOVA1) was identified as a novel target gene of miR‑592 in thyroid cancer cells. Furthermore, ectopic NOVA1 expression may effectively abolish the tumor‑suppressing effects of miR‑592 overexpression in thyroid cancer cells. Notably, the lncRNA NEAT1 was proposed to function as a sponge of miR‑592 in thyroid cancer cells, thereby regulating NOVA1 expression. Finally, resuming miR‑592 expression significantly impaired thyroid cancer tumor growth invivo. The results indicated that the NEAT1/miR‑592/NOVA1 pathway may play regulatory roles in thyroid cancer malignancy invitro and invivo. Our findings may provide novel insight into the pathogenesis of thyroid cancer. Therefore, this pathway may be an effective target for treating patients with this disease.

Long non-coding RNA NR2F1-AS1 promoted proliferation and migration yet suppressed apoptosis of thyroid cancer cells through regulating miRNA-338-3p/CCND1 axis.

Thyroid cancer (TC) is a prevalent endocrine malignant cancer whose pathogenic mechanism remains unclear. The aim of the study was to investigate the roles of long non‐coding RNA (lncRNA) NR2F1‐AS1/miRNA‐338‐3P/CCND1 axis in TC progression. Differentially expressed lncRNAs and mRNAs in TC tissues were screened out and visualized by R program. Relative expression of NR2F1‐AS1, miRNA‐338‐3p and cyclin D1 (CCND1) was determined by quantitative real time polymerase chain reaction. In addition, Western blot analysis was adopted for evaluation of protein expression of CCND1. Targeted relationships between NR2F1‐AS1 and miRNA‐338‐3p, as well as miRNA‐338‐3p and CCND1 were predicted using bioinformatics analysis and validated by dual‐luciferase reporter gene assay. Besides, tumour xenograft assay was adopted for verification of the role of NR2F1‐AS1 in TC in vivo. NR2F1‐AS1 and CCND1 were overexpressed, whereas miRNA‐338‐3p was down‐regulated in TC tissues and cell lines. Down‐regulation of NR2F1‐AS1 and CCND1 suppressed proliferation and migration of TC cells yet greatly enhanced cell apoptotic rate. Silence of NR2F1‐AS1 significantly suppressed TC tumorigenesis in vivo. NR2F1‐AS1 sponged miRNA‐338‐3p to up‐regulate CCND1 expression to promote TC progression. Our study demonstrated that up‐regulation of NR2F1‐AS1 accelerated TC progression through regulating miRNA‐338‐3P/CCND1 axis.