DNA copy number gain-mediated lncRNA LINC01061 upregulation predicts poor prognosis and promotes papillary thyroid cancer progression

Progress in long non-coding RNAs as prognostic factors of papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is generally recognized as a slow-growing tumor. However, a small subset of patients may still experience relapse or metastasis shortly after therapy, leading to a poor prognosis and raising concerns about excessive medical treatment. One major challenge lies in the inadequacy of effective biomarkers for accurate risk stratification. Long non-coding RNAs (lncRNAs), which are closely related to malignant characteristics and poor prognosis, play a significant role in the genesis and development of PTC through various pathways. The objective of this review is to provide a comprehensive summary of the biological functions of lncRNAs in PTC, identify prognosis-relevant lncRNAs, and explore their potential mechanisms in drug resistance to BRAF kinase inhibitors, tumor dedifferentiation, and lymph node metastasis. By doing so, this review aims to offer valuable references for both basic research and the prediction of PTC prognosis.

LINC01061 triggers inflammation and inflammasome activation in autoimmune thyroiditis via microRNA-612/BRD4 axis

Considering the significance of LINC01061 in papillary thyroid cancer, here, we commenced to study the role of LINC01061 in autoimmune thyroid disease (AITD) and the potential mechanism. Thyroid tissues were attained from patients with AITD, and Nthy-ori 3-1 cells were induced with lipopolysaccharide (LPS), followed by measurement of LINC01061, microRNA (miR)-612, and BRD4 expression as well as their binding relation. The ectopic expression and silencing experimentations were carried out in LPS-induced Nthy-ori 3-1 cells to detect cell viability and apoptosis as well as inflammation and inflammasome. BRD4 and LINC01061 upregulation and miR-612 downregulation were observed in thyroid tissues of AITD patients and LPS-induced Nthy-ori 3-1 cells. Mechanistic analysis manifested that LINC01061 bound to miR-612 that negatively targeted BRD4. LINC01061 upregulated BRD4 to enhance cell viability, trigger inflammation and inflammasome activation but reduce apoptosis of LPS-induced Nthy-ori 3-1 cells by sponging miR-612. In conclusion, LINC01061 induced the occurrence of AITD by upregulation of miR-612-mediated BRD4 expression.

Long non-coding RNA KIKAT/LINC01061 as a novel epigenetic regulator that relocates KDM4A on chromatin and modulates viral reactivation

KDM4A is a histone lysine demethylase that has been described as an oncogene in various types of cancer. The importance of KDM4A-mediated epigenetic regulation in tumorigenesis is just emerging. Here, by using Kaposi’s sarcoma associated herpesvirus (KSHV) as a screening model, we identified 6 oncogenic virus-induced long non-coding RNAs (lncRNAs) with the potential to open chromatin. RNA immunoprecipitation revealed KSHV-induced KDM4A-associated transcript (KIKAT)/LINC01061 as a binding partner of KDM4A. Integrated ChIP-seq and RNA-seq analysis showed that the KIKAT/LINC01061 interaction may mediate relocalization of KDM4A from the transcription start site (TSS) of the AMOT promoter region and transactivation of AMOT, an angiostatin binding protein that regulates endothelial cell migration. Knockdown of AMOT diminished the migration ability of uninfected SLK and iSLK-BAC16 cells in response to KIKAT/LINC01061 overexpression. Thus, we conclude that KIKAT/LINC01061 triggered shifting of KDM4A as a potential epigenetic mechanism regulating gene transactivation. Dysregulation of KIKAT/LINC01061 expression may represent a novel pathological mechanism contributing to KDM4A oncogenicity.

Epigenetic regulation of chromatin structure and gene function connects genotype to phenotype and diseases. Long non-coding RNA (lncRNA) is emerging as a novel type of epigenetic regulator exhibiting diverse biological functions. Aberrant lncRNA expression is associated with various diseases, including cancer. The widespread epigenetic changes that occur during the latent-to-lytic switch of herpes virus life cycle make it an attractive model to study epigenetic regulation. Using Kaposi’s sarcoma associated herpesvirus (KSHV) as a model, we screened the epigenetic function of lncRNAs whose expression was induced by reactivation of this oncogenic virus. KIKAT/LINC01061 was identified as a novel histone lysine-specific demethylase 4A (KDM4A) interacting lncRNA. KDM4A is the first identified histone trimethyl demethylase that has been demonstrated as an oncogene in various cancers. Our data reveal a novel lncRNA-mediated regulation of the epigenetic function of KDM4A and demonstrate this lncRNA-chromatin modifier interaction may serve as a potential target in cancer therapy.

Enhanced LINC01061 Levels as a Serum Biomarker in Gastric Cancer and Promotion of Malignant Transformation

BACKGROUND

The genomic copy number of LINC01061 is amplified in papillary thyroid cancer. However, its role in gastric cancer is not clear.

MATERIALS AND METHODS

Tissues and serum of GC patients were collected to detect the expression of LINC01061 by quantitative real-time polymerase chain reaction (qRT-PCR). ShRNA were applied to knock down the expression of LINC01061. Growth curves and colony formation experiments were applied to evaluate cell growth. Cell migration was assessed by transwell migration experiments. Cell cycle and apoptosis were analyzed by flow cytometry. Epithelial-mesenchymal transition (EMT) was examined by qRT-PCR and Western blot.

RESULTS

The expression of LINC01061 was upregulated in tissues and serum of GC patients and it was associated with the clinicopathological features and survival time. Functional study indicated that cell growth and migration were suppressed after LINC01061 knockdown. Cell cycle arrest and increased apoptosis occurred when LINC01061 expression was inhibited. EMT was also impaired combined with a decrease in β-catenin expression after LINC01061 knockdown.

CONCLUSIONS

Our data indicate that LINC01061 is a novel biomarker for diagnosis and prognosis of GC. LINC01061 promoted progression of GC through cell cycle regulation and EMT.

Integrated Dissection of lncRNA-Perturbated Triplets Reveals Novel Prognostic Signatures Across Cancer Types

Long noncoding RNA (lncRNA)/microRNA(miRNA)/mRNA triplets contribute to cancer biology. However, identifying significative triplets remains a major challenge for cancer research. The dynamic changes among factors of the triplets have been less understood. Here, by integrating target information and expression datasets, we proposed a novel computational framework to identify the triplets termed as “lncRNA-perturbated triplets”. We applied the framework to five cancer datasets in The Cancer Genome Atlas (TCGA) project and identified 109 triplets. We showed that the paired miRNAs and mRNAs were widely perturbated by lncRNAs in different cancer types. LncRNA perturbators and lncRNA-perturbated mRNAs showed significantly higher evolutionary conservation than other lncRNAs and mRNAs. Importantly, the lncRNA-perturbated triplets exhibited high cancer specificity. The pan-cancer perturbator OIP5-AS1 had higher expression level than that of the cancer-specific perturbators. These lncRNA perturbators were significantly enriched in known cancer-related pathways. Furthermore, among the 25 lncRNA in the 109 triplets, lncRNA SNHG7 was identified as a stable potential biomarker in lung adenocarcinoma (LUAD) by combining the TCGA dataset and two independent GEO datasets. Results from cell transfection also indicated that overexpression of lncRNA SNHG7 and TUG1 enhanced the expression of the corresponding mRNA PNMA2 and CDC7 in LUAD. Our study provides a systematic dissection of lncRNA-perturbated triplets and facilitates our understanding of the molecular roles of lncRNAs in cancers.

The Changing Face of in vitro Culture Models for Thyroid Cancer Research: A Systematic Literature Review

Background: Thyroid cancer is the most common endocrine malignancy worldwide. Primary treatment with surgery and radioactive iodine is usually successful, however, there remains a small proportion of thyroid cancers that are resistant to these treatments, and often represent aggressive forms of the disease. Since the 1950s, in vitro thyroid culture systems have been used in thyroid cancer research. In vitro culture models have evolved from 2-dimensional thyrocyte monolayers into physiologically functional 3-dimensional organoids. Recently, research groups have utilized in vitro thyroid cancer models to identify numerous genetic and epigenetic factors that are involved with tumorigenesis as well as test the efficacy of cytotoxic drugs on thyroid cancer cells and identify cancer stem cells within thyroid tumors.

Objective of Review: The objective of this literature review is to summarize how thyroid in vitro culture models have evolved and highlight how in vitro models have been fundamental to thyroid cancer research.

Type of Review: Systematic literature review.

Search Strategy: The National Institute for Health and Care Excellence (NICE) Healthcare and Databases Advanced Search (HDAS) tool was used to search EMBASE, Medline and PubMed databases. The following terms were included in the search: “in vitro” AND “thyroid cancer”. The search period was confined from January 2008 until June 2019. A manual search of the references of review articles and other key articles was also performed using Google Scholar.

Evaluation Method: All experimental studies and review articles that explicitly mentioned the use of in vitro models for thyroid cancer research in the title and/or abstract were considered. Full-text versions of all selected articles were evaluated. Experimental studies were reviewed and grouped according to topic: genetics/epigenetics, drug testing/cancer treatment, and side populations (SP)/tumor microenvironment (TME).

Results: Three thousand three hundred and seventy three articles were identified through database and manual searches. One thousand two hundred and sixteen articles remained after duplicates were removed. Five hundred and eighty nine articles were excluded based on title and/or abstract. Of the remaining 627 full-text articles: 24 were review articles, 332 related to genetic/epigenetics, 240 related to drug testing/treatments, and 31 related to SP/TME.

Conclusion:In vitro cell culture models have been fundamental in thyroid cancer research. There have been many advances in culture techniques- developing complex cellular architecture that more closely resemble tumors in vivo. Genetic and epigenetic factors that have been identified using in vitro culture models can be used as targets for novel drug therapies. In the future, in vitro systems will facilitate personalized medicine, offering bespoke treatments to patients.

Machine Learning and Feature Selection Applied to SEER Data to Reliably Assess Thyroid Cancer Prognosis

Utilizing historical clinical datasets to guide future treatment choices is beneficial for patients and physicians. Machine learning and feature selection algorithms (namely, Fisher’s discriminant ratio, Kruskal-Wallis’ analysis, and Relief-F) have been combined in this research to analyse a SEER database containing clinical features from de-identified thyroid cancer patients. The data covered 34 unique clinical variables such as patients’ age at diagnosis or information regarding lymph nodes, which were employed to build various novel classifiers to distinguish patients that lived for over 10 years since diagnosis, from those who did not survive at least five years. By properly optimizing supervised neural networks, specifically multilayer perceptrons, using data from large groups of thyroid cancer patients (between 6,756 and 20,344 for different models), we demonstrate that unspecialized and existing medical recording can be reliably turned into power of prediction to help doctors make informed and optimized treatment decisions, as distinguishing patients in terms of prognosis has been achieved with 94.5% accuracy. We also envisage the potential of applying our machine learning strategy to other diseases and purposes such as in designing clinical trials for unmasking the maximum benefits and minimizing risks associated with new drug candidates on given populations.

MicroRNA-4316 inhibits gastric cancer proliferation and migration via directly targeting VEGF-A

Background and aims

microRNAs (miRNAs) have been reported to regulate proliferation and migration by down-regulating the expression of target genes. The aims of this study were to investigate whether miR-4316 inhibited proliferation and migration by downregulating vascular endothelial growth factor A (VEGF-A) and its clinical significance in gastric cancer (GC).

Methods

The clinical tissues of the GC patients for miR-4316 and VEGF-A were detected by qRT-PCR. The protein levels of VEGF-A and c-Met were determined by western blotting. Cell Proliferation, migration, and colony forming assays were conducted to show whether miR-4316 affects proliferation by CCK-8, migration by transwell, wound healing and colony formation assays. The bioinformatic methods and luciferase reporter assay were applied to detect the relationship between miRNA and VEGF-A on its targeting 3-untranslated regions (3-UTRs). CCK-8, colony formation, wound healing, and transwell assay were performed to explore the function of miR-4316.

Results

The results of qRT-PCR indicated that miR-4316 expression level was significantly downregulated in human GC tissues and GC cell lines compared with their control. miR-4316 inhibited proliferation, migration and colony formation in GC cell lines by reducing VEGF-A. And western blot results indicated that miR-4316 significantly inhibited GC through repressing VEGF-A and c-Met. The investigation of Luciferase assay indicated that VEGF-A is a direct target gene of miR-4316.

Conclusions

miR-4316 suppressed proliferation and migration of GC through the VEGF-A gene. MiR-4316 acts as a tumor suppressor by targeting VEGF-A and this indicated that MiR-4316 might be a potential therapeutic target for GC.

Long non-coding RNA BRM promotes proliferation and invasion of papillary thyroid carcinoma by regulating the microRNA-331-3p/SLC25A1 axis

Long non-coding RNA BRM (lncBRM) was first identified in liver cancer stem cells and was reported to promote multiple cancer types. However, the function of lncBRM in papillary thyroid carcinoma (PTC) remains unclear. The primary focus of the present study was to determine the biological role of lncBRM in PTC. Reverse transcription-quantitative PCR assays revealed that lncBRM was upregulated in PTC tissues and cells. Cell Counting Kit-8, Transwell invasion and colony-formation assays were performed to assess cell proliferation, invasion and migration, respectively. Furthermore, high expression of lncBRM was associated with poor overall survival time in patients with PTC. lncBRM knockout significantly suppressed cell proliferation, migration and invasion. lncBRM was predicted to bind to microRNA (miR)-331-3p and targets SLC25A1. Overexpression of miR-331-3p or inhibition of SLC25A1 resulted in significantly suppressed proliferation, migration and invasion of PTC cells. Rescue assays demonstrated that inhibition of miR-331-3p significantly abrogated the effects of lncBRM knockout on PTC cell proliferation, migration and invasion. In conclusion, the present study suggests that lncBRM promotes PTC by regulating miR-331-3p and targeting SLC25A1.

LncRNA MCM3AP-AS1 promotes proliferation and invasion through regulating miR-211-5p/SPARC axis in papillary thyroid cancer

BACKGROUND

Long non-coding RNAs (lncRNAs) are an emerging class of regulators in cancer. A lncRNA, MCM3AP-AS1, has been demonstrated as a versatile mediator in many cancers, except papillary thyroid cancer. The aim of this study is to investigate the role and mechanism of MCM3AP-AS1 in papillary thyroid cancer.

METHODS

Quantitative real-time PCR was used to assess the level of MCM3AP-AS1 and miR-211-5p in papillary thyroid cancer tissues and cells. Western blot was used to detect E-cadherin and secreted protein acidic and cysteine rich (SPARC) protein levels. CCK-8, scratch wound assay, and transwell assay were used to evaluate papillary thyroid cancer cell proliferation, migration, and invasion, respectively. BLAST alignment and luciferase assay were used to explore the interaction among MCM3AP-AS1, mi/r-211, and SPARC.

RESULTS

In papillary thyroid cancer, MCM3AP-AS1 was upregulated, while miR-211 was downregulated. MCM3AP-AS1 overexpression promoted papillary thyroid cancer proliferation, migration, and invasion. Further, MCM3AP-AS1 was shown to be negatively correlated with miR-211-5p. We next validated that miR-211-5p overexpression could reverse the promoting role of MCM3AP-AS1 in papillary thyroid cancer, whereby SPARC plays an important regulating role. In vivo, we confirmed the anti-tumor role of MCM3AP-AS1 silencing and the close relation among MCM3AP-AS1, miR-211-5p, and SPARC.

CONCLUSIONS

MCM3AP-AS1 promotes papillary thyroid cancer by regulating the MCM3AP-AS1/miR-211-5p/SPARC axis, which could potentially be a therapeutic target in papillary thyroid cancer.

LncRNA LOC105372579 promotes proliferation and epithelial-mesenchymal transition in hepatocellular carcinoma via activating miR-4316/FOXP4 signaling

Background: Recently, a growing number of long noncoding RNAs (lncRNAs) have been identified to be important for human cancer development. However, how lncRNA regulates hepatocellular carcinoma (HCC) progression still remains largely unclear. We aimed to investigate the function of LOC105372579 in HCC progression. Materials and methods: The expression levels of lncRNA LOC105372579 in HCC tissues and cell lines were analyzed by qRT-PCR. The effects of LOC105372579 silencing on proliferation, migration and invasion were determined by using cell counting kit-8, colony formation assay and Transwell assay. Moreover, the xenograft mouse model was used to detect how LOC105372579 regulates HCC growth in vivo. Results: LOC105372579 was highly expressed in HCC tissues and cell lines. Moreover, upregulated levels of LOC105372579 predicted poor prognosis. LOC105372579 silencing suppressed the proliferation of HCC cells in vitro. We also validated that LOC105372579 knockdown inhibited the migration, invasion, and epithelial-mesenchymal transition of HCC cells. Xenograft assay demonstrated that LOC105372579 promotes tumor growth in vivo. Mechanistically, we identified that LOC105372579 is a sponge for miR-4316 and that FOXP4 is a direct target of miR-4316. Conclusion: Thus, our findings supported that LOC105372579 contributes to HCC cell proliferation, migration, invasion, and EMT by activating miR-4316/FOXP4 signaling.

LncRNA LINC01061 sponges miR-612 to regulate the oncogenic role of SEMA4D in cholangiocarcinoma

Cholangiocarcinoma (CCA) is the most usual malignancy of biliary tract, possessing a relatively low overall survival rate due to limited treatment options. Recently, long non-coding RNAs (lncRNAs) have been testified to have marked regulatory impacts on human cancers. The purpose of this paper is to explore the potent regulation mechanism of LINC01061 involved in CCA. Firstly, it was observed that LINC01061 expression was heightened in CCA cell lines, whose knockdown suppressed cell proliferation, induced cell apoptosis and restrained cell migration. Besides, LINC01061 existing in the cytoplasm of CCA cells interacted with miR-612. Moreover, subsequent experiments affirmed that LINC01061 regulated SEMA4D expression by acting as a competing endogenous RNA (ceRNA) of miR-612. At last, rescue assays validated that SEMA4D overexpression restored the repression caused by LINC01061 silence on the biological activities of CCA containing cell proliferation, apoptosis and migration. To sum up, our present exploration demonstrated that LINC01061 sponges miR-612 so as to upregulate SEMA4D expression for the progression of CCA, suggesting an optional promising and effective target for the therapy of patients with CCA.

Active Surveillance for Papillary Thyroid Microcarcinoma: Challenges and Prospects

Active surveillance (AS) can be considered as an alternative to immediate surgery in low-risk papillary thyroid microcarcinoma (PTMC) without clinically apparent lymph nodes, gross extrathyroidal extension (ETE), and/or distant metastasis according to American Thyroid Association. However, in the past AS has been controversial, as evidence supporting AS in the management of PTMC was scarce. The most prominent of these controversies included, the limited accuracy and utility of ultrasound (US) in the detection of ETE, malignant lymph node involvement or the advent of novel lymph node malignancy during AS, and disease progression. We summarized publications and indicated: (1) US, performer-dependent, could not accurately diagnose gross ETE or malignant lymph node involvement in PTMC. However, the combination of computed tomography and US provided more accurate diagnostic performance, especially in terms of selection sensitivity. (2) Compared to immediate surgery patients, low-risk PTMC patients had a slightly higher rate of lymph node metastases (LNM), although the overall rate for both groups remained low. (3) Recent advances in the sensitivity and specificity of imaging and incorporation of diagnostic biomarkers have significantly improved confidence in the ability to differentiate indolent vs. aggressive PTMCs. Our paper reviewed current imagings and biomarkers with initial promise to help select AS candidates more safely and effectively. These challenges and prospects are important areas for future research to promote AS in PTMC.