Retracted: Long non-coding RNA LINC00152 promotes cell growth and invasion of papillary thyroid carcinoma by regulating the miR-497/BDNF axis

Long intergenic non-coding RNA 152 (LINC00152) was reported to be tightly linked to tumorigenesis and progression in multiple cancers. However, its biological role and modulatory mechanism in papillary thyroid carcinoma (PTC) has not been elucidated. In this study, we determined the expression levels of LINC00152 in PTC tissues and cell lines by quantitative real time polymerase chain reaction (qRT-PCR). Cell proliferation, colony formation, migration, and invasion were measured by a Cell Counting Kit-8 assay, colony formation analysis, wound healing, and transwell invasion assay, respectively. A luciferase reporter assay and qRT-PCR were used to determine whether LINC00152 interacts with miR-497 directly. We established a xenograft mouse model to examine the underlying molecular mechanism and effect of LINC00152 on tumor growth in vivo. We found that LINC00152 expression was significantly increased in PTC tissues and derived cell lines. LINC00152 knockdown significantly inhibited proliferation, colony formation, migration, and invasion in vitro, and impaired tumor growth in vivo. We revealed that LINC00152 functioned as a competing endogenous RNA to the miR-497 sponge, downregulating its downstream target brain-derived neurotrophic factor (BDNF), which is an oncogene in thyroid cancer. These findings suggest that LINC00152 is responsible for PTC cell proliferation and invasion and exerts its function by regulating the miR-497/BDNF axis.     

Mutual regulation of TGF-β1, TβRII and ErbB receptors expression in human thyroid carcinomas

The role of EGF and TGF-β1 in thyroid cancer is still not clearly defined. TGF-β1 inhibited the cellular growth and migration of follicular (FTC-133) and papillary (B-CPAP) thyroid carcinoma cell lines. Co-treatments of TGF-β1 and EGF inhibited proliferation in both cell lines, but displayed opposite effect on their migratory capability, leading to inhibition in B-CPAP and promotion in FTC-133 cells, by a MAPK-dependent mechanism. TGF-β1, TβRII and EGFR expressions were evaluated in benign and malignant thyroid tumors. Both positivity (51.7% and 60.0% and 80.0% in FA and PTC and FTC) and overexpression (60.0%, 77.7% and 75.0% in FA, PTC and FTC) of EGFR mRNA correlates with the aggressive tumor behavior. The moderate overexpression of TGF-β1 and TβRII mRNA in PTC tissues (61.5% and 62.5%, respectively), counteracted their high overexpression in FTC tissues (100% and 100%, respectively), while EGFR overexpression was similar in both carcinomas. Papillary carcinomas were positive to E-cadherin expression, while the follicular carcinomas lose E-cadherin staining. Our findings of TGF-β1/TβRII and EGFR overexpressions together with a loss of E-cadherin observed in human follicular thyroid carcinomas, and of increased migration ability MAPK-dependent after EGF/TGF-β1 treatments in the follicular thyroid carcinoma cell line, reinforced the hypothesis of a cross-talk between EGF and TGF-β1 systems in follicular thyroid carcinomas phenotype.     

Silencing of lncRNA LINC00514 inhibits the malignant behaviors of papillary thyroid cancer through miR-204–3p/CDC23 axis

Numerous studies have provided that long noncoding RNAs (lncRNAs) possess important roles in regulating tumorigenesis. However, up to data, the role of LINC00514 in cancer, including thyroid cancer, remains unknown. In the present study, we found that LINC00514 expression was significantly upregulated in papillary thyroid cancer (PTC) tissues by bioinformatics analysis. Loss-of-function studies revealed that LINC00514 silencing inhibited the proliferation, migration and invasion of PTC cells while promoting apoptosis in vitro. Moreover, LINC00514 knockdown suppressed PTC growth in vivo. RNA-FISH showed that LINC00514 mainly locates in the nucleus of PTC cells. Through bioinformatics prediction, we identified that LINC00514 served as the sponge for miR-204–3p, and miR-204–3p directly targeted CDC23. Thus, LINC00514 promoted CDC23 expression via restraining miR-204–3p activity, leading to PTC progression. In sum, our findings demonstrated that LINC00514 contributes to PTC progression and might be a potential target for PTC therapy.     

Methylation of DACT2 Promotes Papillary Thyroid Cancer Metastasis by Activating Wnt Signaling

Thyroid cancer is the most common endocrine malignant disease and the incidence is increasing. DACT2 was found frequently methylated in human lung cancer and hepatocellular carcinoma. To explore the epigenetic change and the role of DACT2 in thyroid cancer, 7 thyroid cancer cell lines, 10 cases of non-cancerous thyroid tissue samples and 99 cases of primary thyroid cancer samples were involved in this study. DACT2 was expressed and unmethylated in K1, SW579, FTC-133, TT, W3 and 8505C cell lines. Loss of expression and complete methylation was found in TPC-1 cells. Restoration of DACT2 expression was induced by 5-aza-2′deoxycytidine treatment. It demonstrates that the expression of DACT2 was regulated by promoter region methylation. In human primary papillary thyroid cancer, 64.6% (64/99) was methylated and methylation of DACT2 was related to lymph node metastasis (p<0.01). Re-expression of DACT2 suppresses cell proliferation, invasion and migration in TPC-1 cells. The activity of TCF/LEF was inhibited by DACT2 in wild-type or mutant β-catenin cells. The activity of TCF/LEF was increased by co-transfecting DACT2 and Dvl2 in wild-type or mutant β-catenin cells. Overexpression of wild-type β-catenin promotes cell migration and invasion in DACT2 stably expressed cells. The expression of β-catenin, c-myc, cyclinD1 and MMP-9 were decreased and the level of phosphorylated β-catenin (p-β-catenin) was increased after restoration of DACT2 expression in TPC-1 cells. The expression of β-catenin, c-myc, cyclinD1 and MMP-9 were increased and the level of p-β-catenin was reduced after knockdown of DACT2 in W3 and SW579 cells. These results suggest that DACT2 suppresses human papillary thyroid cancer growth and metastasis by inhibiting Wnt signaling. In conclusion, DACT2 is frequently methylated in papillary thyroid cancer. DACT2 expression was regulated by promoter region methylation. DACT2 suppresses papillary thyroid cancer proliferation and metastasis by inhibiting Wnt signaling.     

Growth‐associated protein 43 promotes thyroid cancer cell lines progression via epithelial‐mesenchymal transition

Thyroid cancer is maintaining at a high incidence level and its carcinogenesis is mainly affected by a complex gene interaction. By analysis of the next‐generation resequencing of paired papillary thyroid cancer (PTC) and adjacent thyroid tissues, we found that Growth Associated Protein 43 (GAP43), a phosphoprotein activated by protein kinase C, might be novel markers associated with PTC. However, its function in thyroid carcinoma has been poorly understood. We discovered that GAP43 was significantly overexpressed in thyroid carcinoma and these results were consistent with that in The Cancer Genome Atlas (TCGA) cohort. In addition, some clinicopathological features of GAP43 in TCGA database showed that up‐regulated GAP43 is significantly connected to lymph node metastasis (P < 0.001) and tumour size (P = 0.038). In vitro experiments, loss of function experiments was performed to investigate GAP43 in PTC cell lines (TPC‐1 and BCPAP). The results proved that GAP43 knockdown in PTC cell significantly decreased the function of cell proliferation, colony formation, migration, and invasion and induced cell apoptosis. Furthermore, we also indicated that GAP43 could modulate the expression of epithelial‐mesenchymal transition‐related proteins, which could influence invasion and migration. Put those results together, GAP43 is a gene which was associated with PTC and might be a potential therapeutic target.     

Downregulation of uPAR inhibits migration,invasion, proliferation,FAK/PI3K/Akt signaling and induces senescence in papillary thyroid carcinoma cells

Papillary thyroid carcinoma (PTC) is the most common endocrine and thyroid malignancy. The urokinase plasminogen activator receptor (uPAR) plays an important role in cancer pathogenesis, including breakdown of the extracellular matrix, invasion and metastasis. Additionally, there is increasing evidence that uPAR also promotes tumorigenesis via the modulation of multiple signaling pathways. BRAF^V600E, the most common initial genetic mutation in PTC, leads to ERK1/2 hyperphosphorylation, which has been shown in numerous cancers to induce uPAR. Treatment of the BRAF^V600E-positive PTC cell line, BCPAP, with the MEK/ERK inhibitor U0126 reduced uPAR RNA levels by 90%. siRNA-mediated downregulation of uPAR in BCPAP cells resulted in greatly decreased activity in the focal adhesion kinase (FAK)/phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. This phenomenon was concurrent with drastically reduced proliferation rates and decreased clonigenic survival, as well as demonstrated senescence-associated nuclear morphology and induction of β-galactosidase activity. uPAR-knockdown BCPAP cells also displayed greatly reduced migration and invasion rates, as well as a complete loss of the cells'' ability to augment their invasiveness following plasminogen supplementation. Taken together, these data provide new evidence of a novel role for uPAR induction (as a consequence of constitutive ERK1/2 activation) as a central component in PTC pathogenesis, and highlight the potential of uPAR as a therapeutic target.Key words: urokinase plasminogen activator receptor (uPAR), papillary thyroid carcinoma, invasion, migration, proliferation, senescence, FAK, PI3K, Akt     

MiR-192-5p inhibits proliferation,migration, and invasion in papillary thyroid carcinoma cells by regulation of SH3RF3

Background: The decreased level of miR-192-5p has been reported in several kinds of cancers, including bladder, colon, ovarian, and non-small cell lung cancer. However, the expression and function of miR-192-5p in papillary thyroid carcinoma/cancer (PTC) remains unknown.Objective: The present study aimed to explore the function and underlying mechanism of miR-192-5p in PTC development.Methods: PTC tissues and relative normal controls from PTC patients were collected. qRT-PCR analysis was performed to measure miR-192-5p and SH3RF3 mRNA level in PTC tissues and cell lines. CCK-8 method and FCM assay were used to test cell proliferation and apoptosis in TPC-1 cells, respectively. The abilities of cell migration and invasion were detected by wound healing and transwell assays, respectively. The protein expression was evaluated by Western blot. The interaction between miR-192-5p and Src homology 3 (SH3) domain containing ring finger 3 (SH3RF3) were confirmed by dual-luciferase reporter assay.Results: MiR-192-5p level was obviously decreased in PTC tissues and cell lines. Overexpression of miR-192-5p suppressed proliferation, migration, invasion, and EMT process, while induced apoptosis in TPC-1 cells. In addition, miR-192-5p negatively modulated SH3RF3 expression by binding to its 3′-untranslated region (3′UTR). Silencing SH3RF3 inhibited the migration, invasion, and EMT of TPC-1 cells. In the meantime, matrine, an alkaloid extracted from herb, exerted its anti-cancer effects in PTC cells dependent on increase in miR-192-5p expression and decrease in SH3RF3 expression.Conclusion: We firstly declared that miR-192-5p played a tumor suppressive role in PTC via targeting SH3RF3. Moreover, matrine exerted its anti-cancer effects in PTC via regulating miR-192-5p/SH3RF3 pathway.     

MiR-886-3p regulates cell proliferation and migration, and is dysregulated in familial non-medullary thyroid cancer

Background

The molecular basis and characteristics of familial non-medullary thyroid cancer are poorly understood. In this study, we performed microRNA (miRNA) profiling of familial and sporadic papillary thyroid cancer tumor samples.

Methodology/Principal Findings

Genome wide miRNA profiling of sporadic and familial papillary thyroid cancer was performed. Differentially expressed miRNAs were validated by quantitative RT-PCR. Ectopic expression of miR-886-3p in thyroid cancer lines was performed to identify pathways targeted by the miRNA, as well as, to determine its effect on tumor cell biology. We found four differentially expressed miRNAs between familial and sporadic papillary thyroid cancer tumor samples. MiR-886-3p and miR-20a were validated to be differentially expressed by 3- and 4-fold, respectively. Pathway analysis of genome-wide expression data on cells overexpressing miR-886-3p and target prediction analysis showed genes involved in DNA replication and focal adhesion pathways were regulated by miR-886-3p. Overexpression of miR-886-3p in thyroid cancer cell lines significantly inhibited cellular proliferation, the number and size of spheroids and cellular migration. Additionally, overexpression of miR-886-3p increased the number of cells in S phase.

Conclusions/Significance

Our findings for the first time suggest that miR-886-3p plays an important role in thyroid cancer tumor cell biology and regulates genes involved in DNA replication and focal adhesion. Thus, miR-886-3p may play a role in the initiation and or progression of papillary thyroid cancer.     

MMP-11 promotes papillary thyroid cell proliferation and invasion via the NF-κB pathway

Papillary thyroid carcinoma (PTC) is the most common form of thyroid cancer, and its incidence is on the rise. It has been reported that some matrix metalloproteinases (MMPs) are abnormally expressed in PTC and can be used as diagnostic markers. However, few studies have explored the underlying mechanisms by which MMPs promote tumor progression. In this study, we used microarray analysis to compare the variations of gene expression within the PTC cell populations and their adjacent normal tissues and found that MMP-11 was the most differentially expressed MMP. To investigate the role of MMP-11 in the mediation of thyroid cancer cell development, pEnter-MMP-11 plasmid, and MMP-11 small interfering RNA were applied to up- and downregulate MMP-11 expression of in cultured PTC cell lines K1 and BCPAP. The results suggested that the levels of proliferation and migration of cells transfected with MMP-11 siRNA were significantly reduced, while the levels in MMP-11-plasmid-transfected cells were increased. In terms of the mechanism, experimental data showed that the change in cyclin D1 is consistent with MMP-11 expression, which may explain the changes in proliferation. In addition, Western blot assay was conducted to analyze the p65 and activated (phospho-) p65 protein levels concomitant with MMP-11 adjustments. Variations in intracellular MMP-11 significantly altered the amount of phospho-p65 in thyroid cells, while p65 knockdown did not affect MMP-11 expression. These results suggest that MMP-11 is located upstream of p65 and regulates its activity. Interestingly, the data for the Transwell assay suggested that MMP-11 regulatory migration is also associated with the NF-κB p65 signaling pathway. In conclusion, this report describes the important role of MMP-11 in the regulation of thyroid cell proliferation and migration. Mechanistic studies have shown that cyclin D1 and p65 are important mediators in the processes, which provides a new way to study the mechanism of MMPs promoting the progression of thyroid cancer.     

Long noncoding RNA LINC00460 promotes carcinogenesis via sponging miR-613 in papillary thyroid carcinoma

Long intergenic noncoding RNA 460 (LINC00460) has been identified as a critical regulator for multiple types of cancers. However, the biological role and underlying mechanism in human papillary thyroid carcinoma (PTC) still remain unclear and need to be uncovered. This study was aimed to ascertain the biological role and molecular mechanism of LINC00460 in PTC progression. Our findings revealed that the level of LINC00460 was significantly upregulated in PTC tissues and cell lines, which was positively correlated with advanced tumor–node–metastasis (TNM) stage and lymph node metastasis. Cellular experiments exhibited that knockdown of LINC00460 decreased proliferative, migratory, and invasive abilities of PTC cells. Mechanism assays noted that knockdown of LINC00460 suppressed cell proliferation, migration, and invasion, and inhibited expression of sphingosine kinase 2 (SphK2, a target of miR-613) in PTC cells, at least in part, by regulating miR-613. These findings suggested that LINC00460 could function as a competing endogenous RNA to regulate SphK2 expression by sponging miR-613 in PTC. Targeting LINC00460 could be a promising therapeutic strategy for patients with PTC.     

MicroRNA-524-5p suppresses the progression of papillary thyroid carcinoma cells via targeting on FOXE1 and ITGA3 in cell autophagy and cycling pathways

MicroRNAs are beneficial for cancer therapy as they can simultaneously downregulate multiple targets involved in diverse biological pathways related to tumor development. In papillary thyroid cancer, many microRNAs were identified as differentially expressed factors in tumor tissues. In another way, recent studies revealed cell proliferation, cell cycling, apoptosis, and autophagy are critical pathways controlling papillary thyroid cancer development and progression. As miR-524-5p was approved as a cancer suppressor targeting multiple genes in several types of cancer cells, this study aims to characterize the role of miR-524-5p in the thyroid cancer cell. The expression of miR-524-5p was decreased in the papillary thyroid cancer tissues and cell lines, while forkhead box E1 (FOXE1) and ITGA3 were increased. In the clinical case, expression of miR-524-5p, FOXE1, and ITGA3 were significantly correlated with papillary thyroid cancer development and progression. FOXE1 and ITGA3 were approved as direct targets of miR-524-5p. miR-524-5p could inhibit papillary thyroid cancer cell viability, migration, invasion, and apoptosis through targeting FOXE1 and ITGA3. Cell cycling and autophagy pathways were disturbed by downregulation of FOXE1 and ITGA3, respectively. Collectively, miR-524-5p targeting on FOXE1 and ITGA3 prevents thyroid cancer progression through different pathways including cell cycling and autophagy.     

TRPM7 is required for ovarian cancer cell growth,migration and invasion

Our previous study demonstrated that the melastatin-related transient receptor potential channel 7 (TRPM7) was highly expressed in ovarian carcinomas and its overexpression was significantly associated with poor prognosis in ovarian cancer patients. However, the function of TRPM7 in ovarian cancer is mostly unknown. In this study, we examined the roles of TRPM7 in ovarian cancer cell proliferation, migration and invasion. We found that short hairpin RNA interference-mediated silence of TRPM7 significantly inhibited cell proliferation, colony formation, migration and invasion in multiple ovarian cancer cell lines. Mechanistic investigation revealed that silence of TRPM7 decreased phosphorylation levels of Akt, Src and p38 and increased filamentous actin and focal adhesion number in ovarian cancer cells. Thus, our results suggest that TRPM7 is required for proliferation, migration and invasion of ovarian cancer cells through regulating multiple signaling transduction pathways and the formation of focal adhesions.     

AZD1480 Blocks Growth and Tumorigenesis of RET- Activated Thyroid Cancer Cell Lines

Persistent RET activation is a frequent event in papillary thyroid carcinoma (PTC) and medullary thyroid carcinoma (MTC). In these cancers, RET activates the ERK/MAPK, the PI3K/AKT/mTOR and the JAK/STAT3 pathways. Here, we tested the efficacy of a JAK1/2- inhibitor, AZD1480, in the in vitro and in vivo growth of thyroid cancer cell lines expressing oncogenic RET. Thyroid cancer cell lines harboring RET/PTC1 (TPC-1), RET M918T (MZ-CRC1) and RET C634W (TT) alterations, as well as TPC-1 xenografts, were treated with JAK inhibitor, AZD1480. This inhibitor led to growth inhibition and/or apoptosis of the thyroid cancer cell lines in vitro, as well as to tumor regression of TPC-1 xenografts, where it efficiently blocked STAT3 activation in tumor and stromal cells. This inhibition was associated with decreased proliferation, decreased blood vessel density, coupled with increased necrosis. However, AZD1480 repressed the growth of STAT3- deficient TPC-1 cells in vitro and in vivo, demonstrating that its effects in this cell line were independent of STAT3 in the tumor cells. In all cell lines, the JAK inhibitor reduced phospho-Y1062 RET levels, and mTOR effector phospho-S6, while JAK1/2 downregulation by siRNA did not affect cell growth nor RET and S6 activation. In conclusion, AZD1480 effectively blocks proliferation and tumor growth of activated RET- thyroid cancer cell lines, likely through direct RET inhibition in cancer cells as well as by modulation of the microenvironment (e.g. via JAK/phospho-STAT3 inhibition in endothelial cells). Thus, AZD1480 should be considered as a therapeutic agent for the treatment of RET- activated thyroid cancers.     

UHRF1通过miR-206调控ERα表达促进甲状腺乳头状癌细胞增殖、侵袭和迁移

该研究探讨了泛素样含PDH和环指域1(UHRF1)对甲状腺乳头状癌(papillary thyroid carcinoma,PTC)细胞增殖、侵袭和迁移的影响。应用Real-time PCR检测正常甲状腺细胞Nthyori3-1、甲状腺乳头状癌细胞BCPAP和K1中UHRF1 mRNA、miR-206和ERαmRNA的表达水平;Real-time PCR检测UHRF1过表达或干扰对miR-206和ERαmRNA的表达影响;MTT、Transwell检测UHRF1过表达或干扰对Nthy-ori3-1、BCPAP、K1细胞增殖、侵袭和迁移影响;Western blot和双荧光素酶报告实验分析miR-206与ERα的靶向关系。结果表明,与Nthy-ori3-1细胞相比,BCPAP和K1细胞中UHRF1 mRNA和ERαmRNA表达水平显著增高(P<0.05),而miR-206表达水平显著降低(P<0.05);UHRF1过表达或干扰处理细胞后,miR-206表达水平与之变化趋势相反,而ERα表达水平与之变化趋势相同;UHRF1促进Nthy-ori3-1、BCPAP和K1细胞增殖、侵袭和迁移;Western blot和双荧光素酶报告实验证实,miR-206靶向ERα基因并抑制其表达。以上结果说明,UHRF1可通过miR-206调控ERα表达,促进甲状腺乳头状癌细胞增殖、侵袭和迁移。