Apoptosis In Thyroid Cancer Research Articles

MiR-1284 suppresses the proliferation and migration of thyroid cancer.

To elucidate the role of microRNA-1284 (miR-1284) in the onset of thyroid cancer (TC) and its underlying mechanism. Differential expressions of miR-1284 in TC and thyroid tissues were detected. Regulatory effects of miR-1284 on proliferative, migratory, apoptotic potentials and cell cycle progression were assessed. In addition, miR-1284 levels in TC tissues and peripheral blood of TC patients were determined as well. Through collecting culture medium and exosomes of PTC cells, changes in miR-1284 levels were examined. MiR-1284 was downregulated in TC than normal thyroid tissues. Overexpression of miR-1284 attenuated proliferative and migratory potentials, but induced apoptosis in TPC-1 and FTC-133 cells. Moreover, overexpression of miR-1284 upregulated E-cadherin and downregulated N-cadherin in papillary TC (PTC) cells. MiR-1284 was downregulated in TC tissues, while its level in the peripheral blood of TC patients was upregulated. Besides, miR-1284 was upregulated in the culture medium and exosomes of PTC cells, which was reversed by Brefeldin A treatment. Overexpression of miR-1284 suppresses proliferative and migratory potentials and induces apoptosis in TC. Upregulated miR-1284 in the peripheral blood of TC patients may be derived from exosomes secreted by PTC cells.

MiR-524 inhibits cell proliferation and induces cell apoptosis in thyroid cancer via targeting SPAG9.

The article "MiR-524 inhibits cell proliferation and induces cell apoptosis in thyroid cancer via targeting SPAG9", by Z. Zhen, F. Dong, H. Shen, Q.-G. Wang, L. Yang, J. Hu, published in Eur Rev Med Pharmacol Sci 2018; 22 (12): 3812-3818-DOI: 10.26355/eurrev_201806_15265-PMID: 29949157, has been retracted by the authors due to some unrepeated data in their current research. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/15265.

Promoter Methylation of Tumor Suppressors in Thyroid Carcinoma: A Systematic Review.

Background:The tumor suppressor genes play a critical role in cellular and molecular mechanisms such as cell cycle processes, cell differentiation and apoptosis. Aberrant DNA methylation of tumor suppressor genes and subsequent gene expression changes have shown to be involved in the initiation and progression of various malignancies including thyroid malignancies. In this review, we investigated what is known about the impact of promoter hypermethylation on the key tumor suppressor genes known to be involved in cell growth and/or apoptosis of thyroid cancer.Methods:The most important databases were searched for research articles until June 2020 to identify reported tumor suppressor genes that are modulated by methylation modulation changes in thyroid carcinoma. Following the inclusion and exclusion criteria, 26 studies were reviewed using the full text to meet the inclusion and exclusion criteria.Results:The tumor suppressor genes reviewed here are suggestive biomarkers and potential targetable drugs. Inactivation of RASSF1A, DAPK1, SLCFA8, and TSHR through aberrant epigenetic methylation could activate BRAF/MEK/ERK kinase pathways with potential clinical implications in thyroid cancer patients. RARβ2 and RUNX3 could suppress cell cycle and induce apoptosis in malignant cells. TIMP3 and PTEN could prevent angiogenesis and invasion through PIP3 pathway and arrest VEFG activity.Conclusion:The methylation status of key genes in various types of thyroid malignancies could be used in early diagnosis as well as differentiation of malignant and benign thyroid. This is valuable in drug repurposing and discovering alternative treatments or preventions in thyroid cancer.

Inhibition of circular RNA_0000285 prevents cell proliferation and induces apoptosis in thyroid cancer by sponging microRNA-654-3p.

Thyroid cancer is derived from follicular or thyroid cells and has become the most prevalent malignant tumor of endocrine organs, with increased morbidity and mortality. Circular RNAs (circRNAs) are used as prognostic and predictive markers for different types of cancer. However, the role of circRNA_0000285 in thyroid cancer and its potential molecular mechanism remain unclear. The present study aimed to investigate the roles and underlying molecular mechanism of circRNA_0000285 in thyroid cancer to identify novel treatments for this disease. The target binding site of circRNA_0000285 and microRNA-654-3p (miR-654-3p) were predicted and confirmed via the dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Thyroid cancer cell viability and apoptosis were determined via the MTT assay and flow cytometric analysis, respectively, whereas the expression levels of circRNA_0000285 and miR-654-3p were determined via reverse transcription-quantitative PCR analysis. In addition, the protein expression levels of the apoptosis-associated proteins, Bax and B-cell lymphoma 2 (Bcl-2), were detected via western blotting. The results of the dual-luciferase reporter and RIP assays demonstrated that miR-654-3p directly targeted circRNA_0000285. The expression levels of circRNA_0000285 and miR-654-3p in thyroid cancer cells (TPC-1 and FTC133) were upregulated and downregulated, respectively. Knockdown of circRNA_0000285 via small interfering (si)RNA inhibited circRNA_0000285 levels and increased miR-654-3p levels. In addition, miR-654-3p expression decreased following transfection with miR-654-3p inhibitor. Functional experiments demonstrated that circRNA_0000285-siRNA decreased thyroid cancer cell proliferation, promoted cell apoptosis, enhanced Bax expression and suppressed Bcl-2 expression. All these effects were reversed following transfection with miR-654-3p inhibitor. Taken together, the results of the present study suggest that circRNA_0000285 plays a vital role in thyroid cancer progression by regulating miR-654-3p, which provides a potential therapeutic target for this disease.

NCOA3 is a critical oncogene in thyroid cancer via the modulation of major signaling pathways.

The Nuclear Receptor Coactivator (NCOA3, also known as SRC-3, AIB1, p/CIP, RAC3, ACTR, and TRAM1), acts as an oncogene in multiple tumors, but its biological function in thyroid cancer remains unclear. This study was designed to explore the role of NCOA3 in thyroid cancer. The study assessed NCOA3 expression in thyroid cancer and their matched non-cancerous thyroid tissues at mRNA and protein levels. Then we evaluated the effect of NCOA3 on malignant activities of thyroid cancer cells. To better understand the oncogenic role of NCOA3 in thyroid tumorigenesis, we tested the effect of NCOA3 on major proteins related to thyroid cancer. Our data demonstrated that protein expression of NCOA3 was significantly upregulated in thyroid cancer tissues. NCOA3 knockdown inhibited cell proliferation and invasion, and induced cell cycle arrest and apoptosis in thyroid cancer. Conversely, ectopic expression of NCOA3 promoted cell proliferation and invasiveness in thyroid cancer. Mechanistically, NCOA3 could improve the survival and invasiveness of thyroid cancer cells through the modulation of the ErbB, AKT, ERK, and β-catenin pathways. Collectively, these findings suggest that NCOA3 is critical in the initiation and development of thyroid cancer, and might be a possible marker for prognosis and therapy.

Long non-coding RNA LINC00607 silencing exerts antioncogenic effects on thyroid cancer through the CASP9 Promoter methylation.

Thyroid cancer (TC) was the most frequent thyroid malignant tumour, accounting for about 1% of all malignant tumours. Some long non‐coding RNAs (lncRNAs) have been reported to exert essential tumour promotion effects, while caspase‐9 (CASP9) gene could play a promotive role in the cell apoptosis in TC. However, whether they have a specific effect on TC remains unclear. Hence, this study aims to explore the relationship between LINC00607 and CASP9, and its effect in TC. LINC00607 expression in the TC tissues and cell lines was determined. Then, we explored the combination effect between a LINC00607 and a methylation inhibitor 5‐Aza‐dc in doxorubicin‐resistant ARO cells using colony formation assay, flow cytometry, WST‐1 and EdU assay, as well as in vivo tumour growth assay. Besides, the dual‐luciferase reporter gene assay, RIP, ChIP, methylation‐specific PCR and BSP method were employed to detect the relationship between LINC00607 and CASP9 and its methylation. LINC00607 expression was up‐regulated in the doxorubicin‐resistant TC cell lines and tissues and negatively correlated to the poor prognosis of TC patients. Knockdown of LINC00607 suppressed doxorubicin resistance, proliferation and colony formation, and promoted cell apoptosis of TC cells in vitro, as well as suppressed tumour growth in vivo, whereas LINC00607 overexpression was observed to exercise the opposite effects. Notably, it was also revealed that LINC00607 down‐regulated the CASP9 expression by promoting CASP9 promoter methylation. In conclusion, LINC00607 could inhibit the apoptosis and augment the doxorubicin resistance of TC cells by decreasing CASP9 expression, which might provide a novel therapeutic target for TC treatment.

MiR-196a-2 Promotes Malignant Progression of Thyroid Carcinoma by Targeting NRXN1.

Thyroid cancer (TC) is the most common endocrine malignant disease with a rising morbidity year by year. Accumulating studies have shown that microRNAs (miRNAs) play a regulatory role in the progression of various tumors, but the molecular regulatory mechanism of miR-196a-2 in TC is still unknown. qRT-PCR was employed to measure the expression of miR-196a-2 and NRXN1 mRNA in TC cells, while western blot was used to detect the protein expression of NRXN1. CCK-8, colony formation and flow cytometry assays were used to measure cell proliferation and apoptosis of TC cells. Dual-luciferase reporter gene assay was used to predict and verify the targeted binding relationship between miR-196a-2 and NRXN1. Our study results manifested that miR-196a-2 was dramatically overexpressed in cells of TC, while NRXN1 was lowly expressed. miR-196a-2 could promote cell proliferation and inhibit cell apoptosis of TC. Additionally, miR-196a-2 could also target and inhibit the expression of NRXN1. Silencing NRXN1 could reverse the inhibitory effect of miR-196a-2 downregulation on cell proliferation of TC, as well as the promoting effect on cell apoptosis. In a conclusion, we found that miR-196a-2 could promote cell proliferation and inhibit cell apoptosis of TC by targeting NRXN1. Therefore, miR-196a-2/NRXN1 is potential to be a molecular therapeutic target for TC.

Loss of primary cilia promotes mitochondria-dependent apoptosis in thyroid cancer

The primary cilium is well-preserved in human differentiated thyroid cancers such as papillary and follicular carcinoma. Specific thyroid cancers such as Hürthle cell carcinoma, oncocytic variant of papillary thyroid carcinoma (PTC), and PTC with Hashimoto’s thyroiditis show reduced biogenesis of primary cilia; these cancers are often associated the abnormalities in mitochondrial function. Here, we examined the association between primary cilia and the mitochondria-dependent apoptosis pathway. Tg-Cre;Ift88flox/flox mice (in which thyroid follicles lacked primary cilia) showed irregularly dilated follicles and increased apoptosis of thyrocytes. Defective ciliogenesis caused by deleting the IFT88 and KIF3A genes from thyroid cancer cell lines increased VDAC1 oligomerization following VDAC1 overexpression, thereby facilitating upregulation of mitochondria-dependent apoptosis. Furthermore, VDAC1 localized with the basal bodies of primary cilia in thyroid cancer cells. These results demonstrate that loss-of-function of primary cilia results in apoptogenic stimuli, which are responsible for mitochondrial-dependent apoptotic cell death in differentiated thyroid cancers. Therefore, regulating primary ciliogenesis might be a therapeutic approach to targeting differentiated thyroid cancers.

Interference with the Expression of miR-93 Inhibits the Proliferation and Migration and Promotes Apoptosis of Thyroid Tumor Cells Through Targeting Large Tumor Suppressor Molecule 2

Thyroid cancer (TC) is a common malignant tumor of the endocrine system. Currently, it is an urgent problem to be solved to explore the relevant molecular targets and molecular mechanisms for the occurrence and development of TC. miR-93 plays a role in regulating tumors in multiple cancers, but its expression in TC and its effect on proliferation,migration and apoptosis of TC cells have not been reported so far. In this paper, RT-qPCR was used to detect the expression of miR-93 and LATS2. Cell transfection techniques was used to interfere with or overexpress miR-93 and interfere with the expression of LATS2, and RT-qPCR was used to detect transfection efficiency. CCK-8 technique and clone formation assay were used to detect cell survival. Transwell and wound healing assay was used to detect cell migration and invasion, and western blot was used to detect the expression of invasion and migration related proteins MMP2 and MMP9. The apoptosis rate was detected by flow cytometry, and the expression of apoptotic proteins bcl-2, Bax, caspase3/9 and pro-caspase-3/9 was detected by western blot. The results showed that miR-93 was significantly increased in TC cell lines, especially in TPC1 cells. Interference with the expression of miR-93 inhibited proliferation, invasion, and migration, and promoted the apoptosis of TPC1 cells. In addition, we also found that interfering with the expression of miR-93 can promote the expression level of LATS2 in TPC1 cells. Interference with the expression of LATS2 can inhibit the effect on the proliferation, invasion, migration and apoptosis of TPC1 cells after miR-93 interference. In conclusion, interference with the expression of miR-93 inhibits the proliferation and migration and promotes apoptosis of TC cells through targeting LATS2.

Identification of PTK7 as a promising therapeutic target for thyroid cancer.

To evaluate the possible involvement of PTK7 in the progression of human thyroid cancer and assess its potential effects on the proliferation and apoptosis of thyroid cancer. Immunohistochemical (IHC) assays and clinical significance analysis were performed to explore the correlations between PTK7 expression and clinical characteristics of patients with thyroid cancer. Quantitative PCR assays and Immunoblot assays were performed to detect the expression of PTK7 in control or PTK7 shRNA plasmids transfected thyroid cancer cells. MTT assays were performed to detect the effects on the proliferation of thyroid cancer cells. Flow cytometry (FCM) assays were performed to assess the changes in cell apoptosis of thyroid cancer. Additionally, the effects of PTK7 on tumor growth were detected through in vivo tumor growth assays. PTK7 is highly expressed in human thyroid cancer tissues, and its expression levels are associated with the clinical characteristics, including TNM stage (p=0.015*), and intraglandular dissemination (p=0.024*) of patients with thyroid cancer. PTK7 ablation inhibits cell proliferation and stimulates cell apoptosis of thyroid cancer in vitro. Additionally, PTK7 contributes to tumor growth of thyroid cancer cells in mice. We demonstrated the involvement of PTK7in the progression of thyroid cancer, and therefore provided a novel and promising therapeutic target for thyroid cancer treatment.

Hsa_circ_0102272 serves as a prognostic biomarker and regulates proliferation, migration and apoptosis in thyroid cancer.

Accumulating evidence shows that circRNAs comprise a class of non-coding RNA exhibiting tremendous potential for cancer diagnosis and prognosis and they are also implicated in the pathogenesis of carcinogenesis. The present study aimed to investigate abnormally expressed circRNAs in thyroid cancer (TC). Five pairs of TC tissues and adjacent nornal specimens were used to analyze abnormal circRNA expression using high-throughput sequencing. MTT and Annexin V-fluorescein isothiocyanate/propidium iodide assays were performed to evaluate cell proliferation and apoptosis in vitro. Cell migration and invasion were detected by a Transwell assay conducted in vitro. Fifty-four circRNAs, including 19 down-regulated and 35 up-regulated, were significantly aberrantly expressed in TC tissues compared to para-carcinoma tissues. Both sequencing and quantitative reverse transcriptse-polymersase chain reaction analysis corroborated that hsa_circ_0102272 was dramatically elevated in TC tissues and cell lines compared to the control group. Patients with high expression of hsa_circ_0102272 showed significantly short overall survival and progression-free survival compared to those patients with hsa_circ_0102272 low expression. In vitro experiments confirmed that knockdown of hsa_circ_0102272 could restrain cell proliferation, migration and invasion, as well as facilitate apoptosis of TC cells in vitro. Hsa_circ_0102272 displays oncogenic function via repressing malignant biological properties and serves as a prognostic biomarker in TC patients.

Hsa_circ_0124055 and hsa_circ_0101622 regulate proliferation and apoptosis in thyroid cancer and serve as prognostic and diagnostic indicators.

Recent studies have corroborated that circular RNAs (circRNAs) as endogenous noncoding RNAs gain research interest in carcinogenesis, functioning as prognostic and diagnostic biomarkers and therapeutic targets. The present study is aimed to determine whether circRNAs could serve as prognostic and diagnostic biomarkers to predict thyroid carcinoma. High-throughput sequencing analysis was conducted to detect circRNAs expression profile in thyroid cancer. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) measurement was utilized to validate circRNAs expression in blood and tissue specimens. Kaplan-Meier method and receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to assess whether circRNAs could function as prognostic and diagnostic biomarkers of thyroid cancer, respectively. Hsa_circ_0124055 and hsa_circ_0101622 as the most conspicuous biomarkers were significantly increased in tumor tissues and plasma of thyroid cancer patients. High hsa_circ_0124055 or hsa_circ_0101622 expression exhibited shorter overall survival. Our findings also provided strong evidence that plasma hsa_circ_0124055 (AUC = 0.836, 95% CI: 0.763-0.908, p<0.001) and hsa_circ_0101622 (AUC = 0.805, 95% CI: 0.727-0.883, p<0.001) could be used as diagnostic markers for thyroid cancer, and hsa_circ_0124055 combined with hsa_circ_0101622 could provide a more powerful diagnostic value (AUC = 0.911, 95% CI: 0.859-0.962, p<0.001) than the use of hsa_circ_0124055 or hsa_circ_0101622 alone. Furthermore, the knockdown of hsa_circ_0124055 or hsa_circ_0101622 exhibited a significant anti-proliferative and pro-apoptotic activity of thyroid cancer cells in vivo and in vitro. Both hsa_circ_0124055 and hsa_circ_0101622 could facilitate the prognosis and diagnosis of thyroid cancer, and function as the therapeutic targets for clinical practice.

MiR-17-5p knockdown inhibits proliferation, autophagy and promotes apoptosis in thyroid cancer via targeting PTEN.

Thyroid cancer is one common endocrine malignancy with various pathological types. MicroRNAs (miRNAs) play essential roles in development, prognosis and treatment of thyroid cancer. However, the role of miR-17-5p in thyroid cancer progression and its mechanism remain poorly understood. The expressions of miR-17-5p and phosphatase and tensin homolog (PTEN) were measured in thyroid cancer tissues and cells by quantitative real-time polymerase chain reaction or western blot. Cell proliferation and apoptosis were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and flow cytometry, respectively. The protein levels of biomarkers in autophagy or protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) pathway were analyzed by western blot. The interaction between miR-17-5p and PTEN was probed by luciferase activity assay. We found that miR-17-5p expression was elevated and PTEN level was reduced in thyroid cancer tissues and cells compared with their corresponding controls. Knockdown of miR-17-5p or overexpression of PTEN suppressed cell proliferation and autophagy but promoted apoptosis in thyroid cancer cells. PTEN was indicated as a target of miR-17-5p and its interference reversed abrogation of miR-17-5p-mediated inhibition of proliferation and autophagy and increase of apoptosis. Moreover, downregulation of miR-17-5p impeded the activation of AKT/mTOR pathway in thyroid cancer cells, which was attenuated by silencing PTEN. Our data supported that knockdown of miR-17-5p upregulated PTEN expression, therefore leading to suppression of the malignancy of thyroid cancer and inactivation of AKT/mTOR pathway, providing a novel avenue for treatment of thyroid cancer.

LINC01410/miR-3619-5p/FOXM1 Feedback Loop Regulates Papillary Thyroid Carcinoma Cell Proliferation and Apoptosis.

Backgrounds: Thyroid cancer (TC) is a prevalent type of cancer in endocrine system. Past decades have seen the rising mortality and morbidity of TC. Long noncoding RNAs are renowned modulators of cancer onset and progression as validated by mounting studies. Long intergenic non-protein coding RNA 1410 (LINC01410) has been suggested as tumor-promoting gene in colon cancer and gastric cancer, but its role in TC is elusive. This study investigated the impact and mechanism of LINC01410 in TC. Materials and Methods: RT-qPCR and western blot were used to detect gene expression levels. Cell counting kit-8 (CCK-8) and ethynyl-2'-deoxyuridine (EdU) assays were used to determine proliferation. Caspase-3 activity assay was used to examine apoptosis. Intermolecular interaction was investigated by luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay. Results: We confirmed the elevation of LINC01410 expression in TC cells. Loss-of-function experiments indicated that LINC01410 knockdown suppressed proliferation and facilitated apoptosis in TC. Mechanism research illustrated that LINC01410 positively regulated forkhead box M1 (FOXM1) expression through targeting miR-3619-5p, and that FOXM1 in turn transcriptionally activated LINC01410. Rescue experiments validated that LINC01410 regulated TC proliferation and apoptosis through miR-3619-5p/FOXM1. Conclusions: This study demonstrated that LINC01410/miR-3619-5p/FOXM1 positive feedback loop regulated cell proliferation and apoptosis in TC, shedding a light on the molecular target identification and promising treatment improvement in TC.

Downregulated LRRK2 gene expression inhibits proliferation and migration while promoting the apoptosis of thyroid cancer cells by inhibiting activation of the JNK signaling pathway.

Emerging studies have indicated that leucine-rich repeat kinase 2 (LRRK2) is associated with thyroid cancer (TC). The present study investigated the effect of LRRK2 on the cell cycle and apoptosis in TC, and examined the underlying mechanisms in vitro. To screen TC-associated differentially expressed genes, gene expression microarray analysis was conducted. Retrieval of pathways associated with TC from the Kyoto Encyclopedia of Genes and Genomes database indicated that the c-Jun N-terminal kinase (JNK) signaling pathway serves an essential role in TC. SW579, IHH-4, TFC-133, TPC-1 and Nthy-ori3-1 cell lines were used to screen cell lines with the highest and lowest LRRK2 expression for subsequent experiments. The two selected cell lines were transfected with pcDNA-LRRK2, or small interfering RNA against LRRK2 or SP600125 (a JNK inhibitor). Subsequently, flow cytometry, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, a 5-ethynyl-2′-deoxyuridine assay and a scratch test was conducted to detect the cell cycle distribution, apoptosis, proliferation and migration, respectively, in each group. The LRRK2 gene was determined to be elevated in TC based on the microarray data of the GSE3678 dataset. The SW579 cell line was identified to exhibit the highest LRRK2 expression, while IHH-4 cells exhibited the lowest LRRK2 expression. LRRK2 silencing, through inhibiting the activation of the JNK signaling pathway, increased the expression levels of genes and proteins associated with cell cycle arrest and apoptosis in TC cells, promoted cell cycle arrest and apoptosis, and inhibited cell migration and proliferation in TC cells, indicating that LRRK2 repression could exert beneficial effects through the JNK signaling pathway on TC cells. These observations demonstrate that LRRK2 silencing promotes TC cell growth inhibition, and facilitates apoptosis and cell cycle arrest. The JNK signaling pathway may serve a crucial role in mediating the anti-carcinogenic activities of downregulated LRRK2 in TC.

Anticancer Effects of Cyclocarya paliurus Polysaccharide (CPP) on Thyroid Carcinoma In Vitro and In Vivo

In this study, we explored the role and mechanisms of Cyclocarya paliurus polysaccharide on cell apoptosis in thyroid cancer (TC) cells. The apoptosis of thyroid cancer cells in vitro and tumor tissues in vivo induced by Cyclocarya paliurus polysaccharide was determined by MTT assay and flow cytometric assay. The downstream molecules including phosphop-protein kinase B (p-Akt), Akt, B-cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) in tumor tissue were evaluated by western blotting. MTT and flow cytometry assay in vitro revealed Cyclocarya paliurus polysaccharide-induced apoptosis of thyroid cancer cell line in a manner of time-dependent and dose-dependent. In vivo assay showed 50 mg/kg and 100 mg/kg Cyclocarya paliurus polysaccharide significantly suppressed the proliferation of thyroid cancer in mice. Western blotting showed downregulation of p-Akt, Akt, and Bcl-2 and upregulation of Bax. These results suggest that Cyclocarya paliurus polysaccharide may enhance thyroid cancer cell apoptosis by suppressing the activation of p-Akt, Akt, and Bcl-2 and activating Bax, which provide a novel use of CPP as a thyroid cancer treatment.

GINS2 promotes cell proliferation and inhibits cell apoptosis in thyroid cancer by regulating CITED2 and LOXL2.

To explore the mechanisms of GINS2 on cell proliferation and apoptosis in thyroid cancer (TC) cells. Expressions of GINS2 were inhibited in K1 and SW579 cells using gene interference technology. The abilities of proliferation and apoptosis, and cell cycle were determined by MTT assay and flow cytometric assay. The downstream molecules of GINS2 were searched by microarray and bioinformatics and validated by qRT-PCR and western blotting. In the in vivo study, the tumor growth was compared and the whole-body fluorescent imaging was analyzed. After GINS2 was interfered, cell proliferation was significantly inhibited (P < 0.01) and apoptosis rate increased (P < 0.01) in both K1 and SW579 cells. Cell cycle changed significantly in K1 cells, but not in SW579 cells. With bioinformatics upstream analysis, TGF-β1 was found as the most significantly upstream regulator. Expressions of TGF-β1 and its downstream target molecules CITED2 and LOXL2 were validated and found downregulated significantly in mRNA and protein levels (P < 0.05). The results of the nude mouse xenograft assay suggested that the volume and weight of tumor in ones infected with shGINS2 were statistically smaller than controls (P < 0.05). GINS2 plays an important role in cell proliferation and apoptosis of thyroid cancer by regulating the expressions of CITED2 and LOXL2, which may be a potential biomarker for diagnosis or prognosis and a drug target for therapy.

MiR-524 inhibits cell proliferation and induces cell apoptosis in thyroid cancer via targeting SPAG9.

To investigate the effect of miR-524 on the proliferation of thyroid cancer and its underlying mechanism. MiR-524 expression levels in thyroid cancer samples and para-cancer tissues were tested by quantitative Real-time polymerase chain reaction (qRT-PCR). Cells proliferative ability and apoptosis were evaluated through methyl thiazolyl tetrazolium (MTT) and apoptosis assays, respectively. Luciferase reporter assay was used to confirm the regulatory mechanism. MiR-524 expression was reduced in thyroid cancer specimen (p<0.05). Up-regulated miR-524 expression inhibited the proliferative ability and enhanced cell apoptosis of thyroid cancer cells. SPAG9 was a target gene of miR-524, and was reversely regulated by miR-524. MiR-524 represses thyroid cancer cell proliferation and induces cell apoptosis via targeting SPAG9.

Down-regulation of long non-coding RNA AFAP1-AS1 inhibits tumor growth, promotes apoptosis and decreases metastasis in thyroid cancer

Long non-coding RNAs (lncRNAs), a new type of transcripts, play important roles in various cellular biological processes, involving tumorigenesis. Previous studies showed that lncRNA AFAP1-AS1 was aberrantly expressed in numerous cancers. Nevertheless, we know quite a little about the expression pattern and biological function of AFAP1-AS1 in thyroid cancer. In this study, we adopted the quantitative real-time PCR (qRT-PCR) to detect the expression of AFAP1-AS1 in thyroid cancer tissues. We discovered that expression of AFAP1-AS1 was increased in thyroid cancer tissues. MTT assays elucidated that down-regulation of AFAP1-AS1 could suppress growth of thyroid cancer cells. And the results of flow cytometry analysis indicated knockdown of AFAP1-AS1 induced apoptosis in thyroid cancer. Transwell assay was applied to show decreased cell migration in thyroid cancer as a result of down-regulation of AFAP1-AS1. Hence, our study provided evidence for our hypothesis that AFAP1-AS1 could be a therapeutic target for thyroid cancer.

LMTK3 knockdown retards cell growth and invasion and promotes apoptosis in thyroid cancer.

Lemur tyrosine kinase-3 (LMTK3) is a member of the serine/threonine tyrosine kinase family, which is thought to be involved in tumor progression and prognosis. The purpose of the present study was to determine the diagnostic significance and therapeutic targets in thyroid cancer. ELISA assay was used to detect the protein expression of serum LMTK3. Immunohistochemistry and reverse transcription-quantitative polymerase chain reaction were employed to measure the expression of LMTK3. Flow cytometry was used to determine the cell cycle. Transwell assay was used to measure the invasion and migration of SW579 cells and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay to detect cell apoptosis. The LMTK3 level was positively associated with disease stage and pathological type, whereas there was no correlation between LMTK3 level and gender, age, tumor size or lymph node metastasis. The serum LMTK3 level was significantly increased in 102 thyroid carcinoma patients compared with 52 benign thyroid tumor patients and 50 healthy volunteers (P=0.001). The protein and mRNA expression of LMTK3 was markedly higher in thyroid cancer patients compared with patients with benign thyroid tumors. Notably, LMTK3 knockdown retarded proliferation, invasion and migration in SW579 cells. In addition, downregulation of LMTK3 promoted apoptosis in SW579 cells. These findings indicated that LMTK3 knockdown retards the growth of thyroid cancer cells partly through inhibiting proliferation, invasion, migration and inducing apoptosis in SW579 cells. It may serve as a useful diagnostic biomarker and a novel therapeutic target for patients with thyroid cancer.