miRNA-15a regulates the proliferation and apoptosis of papillary thyroid carcinoma via regulating AKT pathway

LncRNA PFAR facilitates the proliferation and migration of papillary thyroid carcinoma by competitively binding to miR-15a

Papillary thyroid carcinoma (PTC) is type of aggressive tumor, with a markedly declined survival rate when distant metastasis occurs. It is of great significance to develop potential biomarkers to evaluate the progression of PTC. LncRNAs are recently widely claimed with biomarker value in malignant tumors. Herein, the role of LncRNA PFAR in PTC was investigated to explore potential prognostic marker for PTC. Compared to NTHY-ORI 3-1 cells, LncRNA PFAR was found markedly upregulated in PTC cell lines. In LncRNA PFAR knockdown TPC-1 cells, markedly declined cell viability, increased apoptotic rate, enhancive number of migrated cells, and elevated migration distance were observed, accompanied by a suppressed activity of the RET/AKT/mTOR signaling. In LncRNA PFAR overexpressed BCPAP cells, signally increased cell viability, declined apoptotic rate, reduced number of migrated cells, decreased migration distance, and increased tumor volume and tumor weight in nude mice xenograft model were observed, accompanied by an activation of the RET/AKT/mTOR signaling. The binding site between LncRNA PFAR and miR-15a, as well as miR-15a and RET, was confirmed by the dual luciferase reporter assay. The FISH study revealed that LncRNA PFAR was mainly located in the cytoplasm. Furthermore, the impact of the siRNA targeting LncRNA PFAR against the growth and migration of PTC cells was abolished by the inhibitor of miR-15a or SC79, an activator of AKT/mTOR signaling. Collectively, LncRNA PFAR facilitated the proliferation and migration of PTC cells by mediating the miR-15a/RET axis.

Potential Role of Selected miRNAs in the Pathogenesis of Autoimmune Thyroid Diseases in Children and Adolescents

BACKGROUND

Many epigenetic factors, including microRNAs, are involved in the process of changing gene expressions. Small non-coding RNA molecules, called miRNAs, are responsible for regulating gene translation by silencing or degrading target mRNAs. It is acknowledged that for many diseases, they may be novel diagnostic and prognostic biomarkers. Patients with autoimmune thyroid diseases are more likely to develop nodules in the thyroid tissue, and Hashimoto's thyroiditis and Graves' disease predispose patients to thyroid cancer. We evaluated the concentrations of microRNA molecules (miR-15a-5p, miR-126-3p, miR-142-5p, miR-21-5p, miR-150-5p) in the blood of children with thyroid disorders. In addition, we wished to identify molecules whose change in concentration predisposes to the development of thyroid cancer.

AIM

The aim of this study is to evaluate selected epigenetic elements by analyzing the levels of miR-15a-5p, miR-126-3p, miR-142-5p, miR-150-5p and miR-21-5p in the blood of pediatric patients with Graves' disease (n = 25), Hashimoto's thyroiditis (n = 26) and thyroid nodular disease (n = 20) compared to a control group of healthy children (n = 17).

MATERIALS AND METHODS

The study consists of groups of children and adolescents aged 10-18 years with autoimmune thyroid disease, with thyroid nodular disease compared to a control group. The miR-15a-5p, miR-126-3p, miR-142-5p, miR-21-5p and miR-150-5p molecules were determined through an immunoenzymatic assay using BioVendor reagents.

RESULTS

There is a statistically significant decrease in the expression of the miR-15a-5p in children with Graves' disease (21.61 vs. 50.22 amol/μL, p = 0.03) and in patients with thyroid nodular disease compared to controls (20.23 vs. 50.22 amol/μL, p = 0.04). Higher levels of the miR-142-5p molecule are found in patients with thyroid disease (with GD-3.8 vs. 3.14 amol/μL, p = 0.01; with HT-3.7 vs. 3.14 amol/μL, p = NS, with thyroid nodular disease-4.16 vs. 3.14 amol/μL, p = 0.04). Lower levels of miR-126-3p were noted in the GD group compared to the control group (7.09 vs. 7.24 amol/μL, p = 0.02). No statistically significant changes in the expressions of miR-150-5p and miR-21-5p molecules were observed in the study groups.

CONCLUSIONS

1. The overexpression of the miR-142-5p molecule occurs in children and adolescents with thyroid diseases. 2. Decreased blood levels of miR-15a-5p predispose patients to the formation of focal lesions in the thyroid gland. 3. Identifying a lower expression of the miR-126-3p molecule in the blood of children with GD requires careful follow-up for the development of focal lesions in the thyroid gland and evaluation for their potential malignancy.

Cyto-Histological Profile of MicroRNAs as Diagnostic Biomarkers in Differentiated Thyroid Carcinomas

INTRODUCTION

The repertoire of microRNAs (miRNAs) in thyroid carcinomas starts to be elucidated. Among differentiated thyroid carcinomas (DTCs), papillary thyroid carcinoma (PTC) is the most frequent. The assessment of miRNAs expression may contribute to refine the pre-surgical diagnosis in order to obtain a personalized and more effective treatment for patients.

AIMS

This study aims to evaluate (1) the miRNAs in a series of DTCs, and their association with the presence of selected genetic mutations in order to improve diagnosis and predict the biologic behavior of DTC/PTC. (2) The reliability of molecular tests in Ultrasound-guided Fine Needle Aspiration Cytology (US-FNAC) for a more precise preoperative diagnosis.

MATERIAL AND METHODS

This series includes 176 samples (98 cytology and 78 histology samples) obtained from 106 patients submitted to surgery, including 13 benign lesions (controls) and 93 DTCs (cases). The microRNA expression was assessed for miR-146b, miR-221, miR-222, and miR-15a through quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The results were analyzed by the 2-ΔΔCT method, using miR16 as an endogenous control. Regarding PTC diagnosis, the discriminative ability of miRNAs expression was assessed by the area under the Receiver Operating Characteristic Curve (AUC). In PTCs, the association of miRNAs expression, clinicopathological features, and genetic mutations (BRAF, RAS, and TERTp) was evaluated.

RESULTS/DISCUSSION

All the analyzed miRNAs presented a tendency to be overexpressed in DTCs/PTCs when compared with benign lesions, both in cytology and histology samples. In cytology, miRNAs expression levels were higher in malignant tumors than in benign tumors. In histology, the discriminative abilities regarding PTC diagnosis were as follows: miR-146b (AUC 0.94, 95% CI 0.87-1), miR-221 (AUC 0.79, 95% CI 0.68-0.9), miR-222 (AUC 0.76, 95% CI 0.63-0.89), and miR-15a (AUC 0.85, 95% CI 0.74-0.97). miR-146b showed 89% sensitivity (se) and 87% specificity (sp); miR-221 se = 68.4, sp = 90; miR-222 se = 73, sp = 70; and mi-R15a se = 72, sp = 80. MicroRNAs were associated with worst-prognosis clinicopathological characteristics in PTCs (p < 0.05), particularly for miR-222. Our data reveal a significant association between higher expression levels of miR-146b, miR-221, and miR-222 in the presence of the BRAF mutation (p < 0.001) and miR-146b (p = 0.016) and miR-221 (p = 0.010) with the RAS mutation, suggesting an interplay of these mutations with miRNAs expression. Despite this study having a relatively small sample size, overexpression of miRNAs in cytology may contribute to a more precise preoperative diagnosis. The miRNAs presented a good discriminative ability in PTC diagnosis. The association between the miRNAs expression profile and genetic alterations can be advantageous for an accurate diagnosis of DTCs/PTCs in FNAC.

Circular RNA hsa_circ_0003892 promotes the development of papillary thyroid carcinoma by regulating the miR-326/LASP1 axis

BACKGROUND

Thyroid cancer is the most common malignancy of the endocrine system. Circular RNA (circRNA) is recognized as a key regulator of tumorigenesis in papillary thyroid carcinoma (PTC). Here this work focused on the mechanism of circRNA_0003892 (circ_0003892) in PTC progression.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine circ_0003892, microRNA-326 (miR-326) and LIM and SH3 protein 1 (LASP1) mRNA expression levels in PTC tissues and cell lines. Besides, cell counting kit-8 (CCK-8), EdU and transwell assays were conducted to detect the proliferative, migrative and invasive abilities of PTC cells, respectively. B The targeting relationships between miR-326 and circ_0003892 or LASP1 3'-UTR were verified by dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay.

RESULTS

Circ_0003892 expression was raised in PTC tissues and cells, which was significantly interrelated with larger tumor size and extrathyroidal extension in PTC sufferers. Overexpression of circ_0003892 significantly promoted the malignant biological behaviors of PTC cells. Additionally, miR-326 was a downstream target of circ_0003892, and miR-326 overexpression weakened the promoting effect of circ_0003892 overexpression on the malignant progression of PTC. MiR-326 specifically inhibited LASP1. Circ_0003892 positively regulated LASP1 expression by targeting miR-326.

CONCLUSION

Circ_0003892 up-regulates LASP1 expression and facilitates PTC progression via competitively binding to miR-326.

Differential microRNA expression for diagnosis and prognosis of papillary thyroid cancer

Papillary thyroid cancer accounts for 85% of thyroid cancer. The diagnosis is based on ultrasound methods and tumor biopsies (FNA). In recent years, research has revealed the importance of miRNAs, non-coding RNA molecules that regulate gene expression and are involved in many diseases. The present mini review describes upregulated and downregulated miRNAs expression in papillary thyroid cancer patient samples (tissue, serum, plasma) and the genes regulated by these non-coding molecules. In addition, a bibliographic search was performed to identify the expression of miRNAs that are common in tumor tissue and blood. The miRNAs miR-146b, miR-221-3p, miRNA 222, miR-21, miR-296-5p, and miR-145 are common in both tissue and bloodstream of PTC patient samples. Furthermore, these miRNAs regulate genes involved in biological processes such as cell differentiation, proliferation, migration, invasion, and apoptosis. In conclusion, miRNAs could potentially become valuable biomarkers, which could help in the early diagnosis and prognosis of papillary thyroid cancer.

miR-576-5p Promotes the Proliferation of Papillary Thyroid Carcinoma through the MAPK4-AKT Pathway

Background

MicroRNA-576-5p (miR-576-5p) plays an important role in different human cancers. However, the biological function of miR-576-5p in papillary thyroid carcinoma (PTC) is still unclear. In this study, we explored the function and specific role of miR-576-5p in PTC.

Methods

Expression levels of miR-576-5p in PTC patient tissues and cell lines were determined by reverse transcription-quantitative polymerase chain reaction (qRT‒PCR). Cell counting using cell counting kit-8 (CCK-8), wound healing, and Transwell assays were performed to evaluate the effect of miR-576-5p on the proliferation, migration, and invasion of TPC-1 cells. Expression levels of mitogen-activated protein kinase 4 (MAPK4) and phosphorylation levels of protein kinase B (AKT), extracellular regulated protein kinase (ERK), and P38 mitogen-activated protein kinase (P38) were detected by western blotting or immunohistochemistry (IHC).

Results

The expression level of miR-576-5p in PTC tissues and TPC-1 cells was significantly increased. In vitro, overexpression of miR-576-5p promoted the proliferation, migration, and invasion of TPC-1 cells. In addition, MAPK4 was highly expressed in PTC tissues, and miR-576-5p could upregulate the expression of MAPK4. Interestingly, MAPK4 knockdown reversed cell proliferation but not migration and invasion in TPC-1 cells after miR-576-5p was overexpressed. Moreover, overexpression of miR-576-5p induced activation of the AKT pathway in TPC-1 cells, and MAPK4 gene knockout reversed this AKT pathway activation.

Conclusion

In this study, we found that miR-576-5p was significantly overexpressed in PTC tissues and TPC-1 cells. In addition, miR-576-5p promoted the proliferation of TPC-1 cells by enhancing expression of MAPK4 and activating the AKT pathway.

miR-15a and miR-20b sensitize hepatocellular carcinoma cells to sorafenib through repressing CDC37L1 and consequent PPIA downregulation

Sorafenib is a classical targeted drug for the treatment of advanced hepatocellular carcinoma (HCC), but intrinsic resistance severely limited its therapeutic effects. In the present study, we aimed to identify crucial genes in HCC cells that affect sorafenib resistance by a CRISPR/Cas9 genome-scale screening. The results indicated that the deficiency of miR-15a and miR-20b contributed to sorafenib resistance, whereas exogenous expression of miR-15a and miR-20b enhanced sorafenib sensitivity of HCC cells by cell viability, colony formation, and flow cytometry analyses. Further analyses revealed that cell division cycle 37 like 1 (CDC37L1) as a common target of miR-15a and 20b, was negatively regulated by the two miRNAs and could enhance sorafenib resistance of HCC cells in vitro and in vivo. Mechanistically, CDC37L1, as a cochaperone, effectively increased the expression of peptidylprolyl isomerase A (PPIA) through strengthening the binding between heat shock protein 90 (HSP90) and PPIA. The results from immunohistochemical staining of a HCC tissue microarray revealed a positive association between CDC37L1 and PPIA expression, and high expression of CDC37L1 and PPIA predicted worse prognosis of HCC patients after sorafenib therapy. Taken together, our findings reveal crucial roles of miR-15a, miR-20b, CDC37L1, and PPIA in sorafenib response of HCC cells. These factors may serve as therapeutic targets and predict prognosis for HCC treated with sorafenib.

MicroRNA-203a-3p may prevent the development of thyroid papillary carcinoma via repressing MAP3K1 and activating autophagy

Background

Papillary thyroid carcinoma (PTC) grows slowly but has a great risk of metastasis. MicroRNAs are well known as vital tumor‐related gene regulators. In PTC, the role of miR‐203a‐3p and the underlying mechanisms remain not completely understood.

Methods

We conducted CCK8 assay, wound healing assay, transwell experiment and flow cytometry analyses to investigate the function of miRNA‐203a‐3p. The interaction of miRNA‐203a‐3p with its gene MAP3K1 was characterized by quantitative real‐time polymerase chain reaction, western blotting and luciferase assay.

Results

We found that the levels of miRNA‐203a‐3p were statistically decreased in PTC tissues. When mimics were delivered to TPC‐1 and KTC‐1 cells to upregulate miR‐203a‐3p, it was observed that cell proliferation, metastatic abilities and cell cycle process were prevented but cell apoptosis was enhanced. Furthermore, we proved the interaction between MAP3K1 and miR‐203a‐3p. Intriguingly, similar to miR‐203a‐3p mimics, siMAP3K1 showed a tumor‐suppressive effect, and this effect could be reversed when miR‐203a‐3p was simultaneously inhibited. Finally, selected autophagy‐linked proteins such as LC3 Beclin‐1 were detected and found to be increased when miR‐203a‐3p was upregulated or MAP3K1 was inhibited.

Conclusion

Overall, miR‐203a‐3p inhibits the oncogenic characteristics of TPC‐1 and KTC‐1 cells via suppressing MAP3K1 and activating autophagy. Our findings might enrich the understanding and the therapeutic strategies of PTC.

MicroRNAs in Papillary Thyroid Cancer: What Is New in Diagnosis and Treatment

Introduction

Papillary thyroid cancer (PTC) accounts for up to 80% of thyroid malignancies. New diagnostic and therapeutic options are suggested including innovative molecular methods. MicroRNAs (miRNAs) are nonprotein coding single-stranded RNAs that regulate many cell processes. The aim of the present study is to review the deregulated miRNAs associated with PTCs.

Methods

A bibliographic research was conducted, resulting in 272 articles referred to miRNAs and PTC. Regarding our exclusion criteria, 183 articles were finally included in our review.

Results

A remarkably large number of miRNAs have been found to be deregulated during PTC manifestation in the literature. The deregulated miRNAs are detected in tissue samples, serum/plasma, and FNA samples of patients with PTC. These miRNAs are related to several molecular pathways, involving genes and proteins responsible for important biological processes. MiRNA deregulation is associated with tumor aggressiveness, including larger tumor size, multifocality, extrathyroidal extension, lymphovascular invasion, lymph node and distant metastasis, and advanced tumor node metastasis stage.

Conclusion

MiRNAs are proposed as new diagnostic and therapeutic tools regarding PTC. They could be essential biomarkers for PTC diagnosis applied in serum and FNA samples, while their contribution to prognosis is of great importance.

Upregulation of microRNA miR-652-3p is a prognostic risk factor for hepatocellular carcinoma and regulates cell proliferation, migration, and invasion

As powerful regulatory factors, microRNAs (miRNAs) are involved in tumor progression. The current research aimed to excavate the prognostic significance and potential regulatory mechanisms of miR-652-3p in hepatocellular carcinoma (HCC). Expression of miR-652-3p in HCC tissues and cells was exposed by Quantitative real-time polymerase chain reaction (RT-qPCR) assay, and we found that miR-652-3p was elevated in HCC tissues and cells than in the control group (P < 0.05). Then, the relationship between miR-652-3p levels and clinical characteristics was obtained from the Chi-square test. Kaplan-Meier survival analysis and Cox regression model to explore the outcome of miR-652-3p on the prognosis of HCC. The results investigated that overexpression of miR-652-3p was related to clinical tumor-node-metastasis (TNM) stage (P = 0.020) and differentiation (P = 0.031). HCC patients with elevated miR-652-3p levels were correlated with poor overall survival (log-rank, P = 0.007), and maybe a possible prognostic marker for HCC. Finally, CCK-8, colony formation, wound healing and Transwell assay was detected after transfection of HCC cells with miR-652-3p mimic or inhibitor. And the results confirmed that elevation miR-652-3p promoted the proliferation, migration, and invasion of tumor cells (P < 0.05). All data indicated that elevated miR-652-3p is a prognostic marker and would be able to participate in tumor progression of HCC by regulating cell proliferation, migration, and invasion.

Effect of valproic acid on miRNAs affecting histone deacetylase in a model of anaplastic thyroid cancer

BACKGROUND

Thyroid cancer is the most common malignant tumor of the endocrine system seen in the thyroid gland. More than 90% of thyroid cancers comprise papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC). Although anaplastic thyroid carcinoma (ATC) accounts for less than 2% of thyroid cancer. But patients' lifespan after diagnosis is about 6 months. Surgical interventions, radioactive iodine use, and chemotherapy are not sufficient in the treatment of ATC, so alternative therapies are needed.

METHODS AND RESULTS

The WST-1 assay test was performed to evaluate the anti-proliferative effects of Valproic acid (VPA). Also, the effect of VPA on miRNAs affecting histone deacetylase was determined by Quantitative RT-PCR. In the SW1736 cell line, IC50 dose for VPA was found 1.6 mg/ml. In our study, the level of oncogenic genes expression in cells treated with VPA, including miR-184, miR-222-5p, miR-124-3p, and miR-328-3p, decreased. Also, the expression of tumor inhibitory genes including miR-323-5p, miR-182-5p, miR-138-5p, miR-217, miR-15a-5p, miR-29b-3p, miR-324-5p and miR-101-5p increased significantly.

CONCLUSIONS

VPA can ad-just countless gene expression patterns, including microRNAs (miRNAs), by targeting histone deacetylase (HDAC). However, further studies are required for more accurate results.

Hsa-miR-330-5p Aggravates Thyroid Carcinoma via Targeting FOXE1

Background

Thyroid carcinoma (TC) is one of the frequent endocrine malignancies, and growing evidence suggests that aberrant microRNA (miRNA) expression contributes to TC development and progression. Nevertheless, the function of miR-330-5p in the progression of TC remains unknown.

Methods

The expression levels of miR-330-5 in patients with thyroid carcinoma and healthy controls were detected, and their potential diagnostic and prognostic values were analyzed.

Results

In this study, we firstly found that miR-330-5p expression was markedly upregulated in TC tissue and cell lines. Functionally, the downregulation of miR-330-5p suppressed TC cell proliferation, migration, and invasion. Further studies revealed that miR-330-5p negatively regulated the expression of forkhead box E1 (FOXE1). More importantly, the results of rescue experiments suggested that FOXE1 overexpression reduced the positive effects of miR-330-5p overexpression in TPC-1 and K-1 cells.

Conclusions

This work revealed that miR-330-5p facilitated the TC progression through targeting FOXE1, which may offer novel therapeutic options for TC.

Exosomal hsa-miR-129-2 and hsa-miR-889 from a 6-microRNA signature might be a potential biomarker for predicting prognosis of papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is a subtype of thyroid cancer with increasing incidence over time.

OBJECTIVE

This study aimed to build a risk score (RS) system for PTC patients.

METHODS

PTC microRNA (miRNA) and messenger RNA (mRNA) expression data were extracted from The Cancer Genome Atlas (TCGA) database. The 491 PTC samples were randomly divided into training and validation sets. Using the limma software package, differentially expressed mRNAs (DEGs) and miRNAs (DEMs) between the tumor and control groups were screened. In order to construct an RS system, a survival package was used to select independent miRNAs related to prognosis. Enrichment analysis was performed, and a miRNA-mRNA co-expression network was constructed. High-throughput sequencing was also used to verify the prognostic miRNAs in exosomes.

RESULTS

We found 1363 DEGs and 171 DEMs between the tumor and control groups. After identifying 26 DEMs that were significantly related to prognosis, 6 independent prognosis-associated miRNAs were selected to build an RS system. The areas under the curves of the overall survival rates of the training, validation, and entire sets were 0.847, 0.772, and 0.819, respectively. By conducting pathway analysis using the miRNA-mRNA co-expression network, one overlapping factor and five overlapping pathways were obtained. In addition, high-throughput sequencing revealed that the hsa-miR-129-2, hsa-miR-548j, hsa-miR-6734, and hsa-miR-889 expression levels in TCGA tumor tissues and exosomes were consistent, and those of hsa-miR-129-2 and hsa-miR-889 between patients and controls were significantly different in exosomes.

CONCLUSION

The six-miRNA RS system in exosomes may comprise independent signatures for predicting PTC patient prognosis.

MicroRNA in Papillary Thyroid Carcinoma: A Systematic Review from 2018 to June 2020

Simple Summary

The most common form of endocrine cancer - papillary thyroid carcinoma, has an increasing incidence. Although this disease usually has an indolent behavior, there are cases when it can evolve more aggressively. It has been known for some time that it is possible to use microRNAs for the diagnosis, prognosis and even treatment monitoring of papillary thyroid cancer. The purpose of this study is to summarize the latest information provided by publications regarding the involvement of microRNAs in papillary thyroid cancer, underling the new clinical perspectives offered by these publications.

Abstract

The involvement of micro-ribonucleic acid (microRNAs) in metabolic pathways such as regulation, signal transduction, cell maintenance, and differentiation make them possible biomarkers and therapeutic targets. The purpose of this review is to summarize the information published in the last two and a half years about the involvement of microRNAs in papillary thyroid carcinoma (PTC). Another goal is to understand the perspective offered by the new findings. Main microRNA features such as origin, regulation, targeted genes, and metabolic pathways will be presented in this paper. We interrogated the PubMed database using several keywords: “microRNA” + “thyroid” + “papillary” + “carcinoma”. After applying search filters and inclusion criteria, a selection of 137 articles published between January 2018–June 2020 was made. Data regarding microRNA, metabolic pathways, gene/protein, and study utility were selected and included in the table and later discussed regarding the matter at hand. We found that most microRNAs regularly expressed in the normal thyroid gland are downregulated in PTC, indicating an important tumor-suppressor action by those microRNAs. Moreover, we showed that one gene can be targeted by several microRNAs and have nominally described these interactions. We have revealed which microRNAs can target several genes at once.

RETRACTED: KDM5B-mediated microRNA-448 up-regulation restrains papillary thyroid cancer cell progression and slows down tumor growth via TGIF1 repression

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Transwell assay results shown in Figures 3G, 6F, and 7F, which appear to contain image similarities within some of the panels, as detailed here: https://pubpeer.com/publications/7680482DF471CF3FADB2D14154BCFF and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. In addition, several suspected image similarities were detected within the whole brain images in Figure 7I, and within the Transwell assays of Figure 7G. The journal requested the corresponding author comment on these concerns and provide the raw data. However, the authors were not able to satisfactorily fulfill this request and therefore the Editor-in-Chief decided to retract the article.

Effects of CDK6 regulated by miR-298 on proliferation and apoptosis of thyroid cancer cells

Effects of CDK6 regulated by miR-298 on proliferation and apoptosis of thyroid cancer cells were explored. Seventy-five cases of thyroid carcinoma and adjacent tissues were collected. The expression levels of miR-298 and CDK6 mRNA in tissues and cells were detected by RT-PCR. In addition, thyroid cancer cells and human normal thyroid cells Nthy-ori3-1 were purchased, with the former transfected with miR-298-mimics, miR-298-inhibitor, miR-NC, si-CDK6, si-NC, Sh-CDK6, Sh-NC to build cell models. Then the expression levels of miR-298 and CDK6 in thyroid cancer tissues and cells were detected by qRT-PCR, and the expression of CDK6, Bax, Bcl-2 and caspase-3 by WB. CCK-8 and flow cytometry were employed to detect cell proliferation and apoptosis, and dual luciferase report was adopted to determine the relationship between miR-298 and CDK6. miR-298 was underexpressed in thyroid cancer, and CDK6 was highly expressed in thyroid cancer. Cell experiments revealed that overexpression of miR-298 or inhibition of CDK6 expression could suppress cell proliferation, promote apoptosis, and significantly increase the expression levels of Bax and caspase-3 proteins, decrease Bcl-2 protein expression, which was contrary to the biological phenotype of cells after inhibition of miR-298 or further overexpression of CDK6. Dual luciferase report confirmed that miR-298 was a targeting site of CDK6. miR-298 can inhibit the proliferation of thyroid cells and promote apoptosis of thyroid cancer cells by regulating the expression of CDK6, which is expected to be a potential target for clinical application.

Inhibition mechanism of lung cancer cell metastasis through targeted regulation of Smad3 by miR-15a

Effect of targeted regulation of mothers against decapentaplegic homolog 3 (Smad3) by microRNA-15a (miR-15a) on the proliferation, invasion and metastasis of non-small cell lung cancer (NSCLC) cells and its related mechanisms were investigated. Fifty pairs of NSCLC and para-cancerous tissues were collected to identify the expression level of miR-15a in NSCLC, para-cancerous tissue, and cell lines A549, H1299, H1975 and BEAS-2B by real-time fluorescence quantitative PCR (RT-PCR); A549 cells were transfected with miR-15a mimic; the MTT assay was performed to detect the role of miR-15a transfection in proliferation of A549 cells, the wound healing assay was carried out to identify the role of miR-15a in migration of A549 cells; Transwell invasion assay was conducted to analyze the role of miR-15a in invasion of A549 cells; western blotting was carried out to find the effect of miR-15a on Smad3 expression, and Spearman's rank correlation was used to analyze the correlation between miR-15a and Smad3 expression. NSCLC tissues and cells showed significantly lower miR-15a expression, compared with para-cancerous tissues and normal cell lines (P=0.023). miR-15a was significantly more expressed in A549 cells transfected with miR-15a mimic (P=0.043). Overexpression of miR-15a can significantly inhibit A549 cell proliferation (P=0.038), migration (P=0.033) and invasion (P=0.025), and significantly reduced the expression level of Smad3 (P=0.031) in A549 cells. Spearman's rank correlation showed negative correlation of miR-15a expression with Smad3, which may indicate negative regulation (r=−0.34, P<0.0001). Inhibition of proliferation, migration and invasion of NSCLC cells can be achieved with targeted regulation of Smad3 by miR-15a.