LncRNA GAS8-AS1 inhibits cell proliferation through ATG5-mediated autophagy in papillary thyroid cancer

LncRNA GAS8-AS1 dinucleotide genetic variantn.713A>G, n.714T>C is associated with early-stage disease, lymph node, and distant metastasis in differentiated thyroid cancer

PURPOSE

Long noncoding RNAs (lncRNAs) play an essential role in the epigenetic regulation of various key genes involved in vital cellular functions. A somatic dinucleotide mutation in the lncRNA GAS8-AS1 was reported in Chinese papillary thyroid cancer. However, GAS8-AS1 dinucleotide alteration and its impact have never been explored in differentiated thyroid cancers and other populations.

METHODS

We extracted genomic DNA from 265 DTCs and 97 normal healthy subjects, PCR amplified and Sanger sequenced to examine the GAS8-AS1 dinucleotide alteration. Calculated genotype/allele frequency to test Hardy-Weinberg Equilibrium (HWE) and performed a genetic model of inheritance to determine its association with DTC risk. Correlated the GAS8-AS1 dinucleotide variant distribution with clinical characteristics to find the association. Predicted GAS8-AS1 RNA secondary structure for wild type and variant using RemuRNA and RNAfold to assess the conformational changes.

RESULTS

GAS8-AS1 dinucleotide alteration (n.713A > G, rs55742939; n.714T > C, rs61118444) identified in DTCs is a germline variant not somatic. The GAS8-AS1 genotype and allele frequency significantly deviated for HWE in DTCs (χ2 = 37.954; p = 0.0001) though not associated with its risk. Dinucleotide variant distribution was remarkably associated with early-stage disease (p = 0.002), lymph node (p = 0.01), and distant metastasis (p = 0.01) in DTCs. The GAS8-AS1 bearing dinucleotide variant markedly showed conformational change compared to that of its wild type.

CONCLUSIONS

These findings indicate that GAS8-AS1 is genetically deregulated and implicated in several stages of DTC tumorigenesis suggesting it could be a promising prognostic biomarker in DTCs.

Subverting the Canon: Novel Cancer-Promoting Functions and Mechanisms for snoRNAs

Small nucleolar RNAs (snoRNAs) constitute a class of intron-derived non-coding RNAs ranging from 60 to 300 nucleotides. Canonically localized in the nucleolus, snoRNAs play a pivotal role in RNA modifications and pre-ribosomal RNA processing. Based on the types of modifications they involve, such as methylation and pseudouridylation, they are classified into two main families-box C/D and H/ACA snoRNAs. Recent investigations have revealed the unconventional synthesis and biogenesis strategies of snoRNAs, indicating their more profound roles in pathogenesis than previously envisioned. This review consolidates recent discoveries surrounding snoRNAs and provides insights into their mechanistic roles in cancer. It explores the intricate interactions of snoRNAs within signaling pathways and speculates on potential therapeutic solutions emerging from snoRNA research. In addition, it presents recent findings on the long non-coding small nucleolar RNA host gene (lncSNHG), a subset of long non-coding RNAs (lncRNAs), which are the transcripts of parental SNHGs that generate snoRNA. The nucleolus, the functional epicenter of snoRNAs, is also discussed. Through a deconstruction of the pathways driving snoRNA-induced oncogenesis, this review aims to serve as a roadmap to guide future research in the nuanced field of snoRNA-cancer interactions and inspire potential snoRNA-related cancer therapies.

Autophagy-related lncRNAs in tumor progression and drug resistance: A double-edged sword

The incidence and mortality rates of cancer are increasing every year worldwide but the survival rate of cancer patients is still unsatisfactory. Therefore, it is necessary to further elucidate the molecular mechanisms involved in tumor development and drug resistance to improve cancer cure or survival rates. In recent years, autophagy has become a hot topic in the field of oncology research, which plays a double-edged role in tumorigenesis, progression, and drug resistance. Meanwhile, long non-coding RNA (lncRNA) has also been shown to regulate autophagy, and the two-sided nature of autophagy determines the dual regulatory role of autophagy-related lncRNAs (ARlncRNAs). Therefore, ARlncRNAs can be effective therapeutic targets for various cancers. Furthermore, the high abundance and stability of ARlncRNAs in tumor tissues make them promising biomarkers. In this review, we summarized the roles and mechanisms of ARlncRNAs in tumor cell proliferation, apoptosis, migration, invasion, drug resistance, angiogenesis, radiation resistance, and immune regulation. In addition, we described the clinical significance of these ARlncRNAs, including as biomarkers/therapeutic targets and their association with clinical drugs.

Aberrantly Expressed lncRNA LINC00847 May Serve as a Promising Prognostic Factor for Thyroid Cancer

Thyroid cancer is a tumor that occurs in the head and neck, which originates from the thyroid follicular epithelial cells. The current research is discussed and elaborated from the perspective of molecular prognostic biomarkers to gain a deeper understanding of the molecular mechanism of thyroid cancer and to provide more effective treatment and prognostic methods for patients. Thyroid cancer patients were explored from histological, cellular and clinical levels. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of LINC00847 and miR-146b-5p in the tissues and cells of the subjects. Cell growth and thyroid cancer progression were determined by the cell counting kit-8 (CCK-8) and transwell assays. The LINC00847 sponge miR-146b-5p was assessed by bioinformatics tools and luciferase reporter assay, and the Kaplan-Meier method and multivariate Cox regression analysis suggested the prognostic value of high expression of LINC00847. In thyroid cancer tissues and cells, the expression of LINC00847 was decreased. Overexpression of LINC00847 remarkably inhibited the proliferation level, migration ability and invasion ability of thyroid cancer cells. Besides, miR-146b-5p was upregulated in thyroid cancer tissues and cells. It was confirmed that LINC00847 targeting miR-146b-5p had a regulatory effect on the progression of thyroid cancer, and LINC00847 was negatively correlated with miR-146b-5p. LINC00847 may be considered a meaningful prognostic marker to influence tumor growth through sponge miR-146b-5p, which provides a new basis for the prognosis and treatment of thyroid cancer.

Long-chain noncoding RNA sequencing analysis reveals the molecular profiles of chemically induced mammary epithelial cells

Long noncoding RNAs (lncRNAs) were important regulators affecting the cellular reprogramming process. Previous studies from our group have demonstrated that small molecule compounds can induce goat ear fibroblasts to reprogram into mammary epithelial cells with lactation function. In this study, we used lncRNA-Sequencing (lncRNA-seq) to analyze the lncRNA expression profile of cells before and after reprogramming (CK vs. 5i8 d). The results showed that a total of 3,970 candidate differential lncRNAs were detected, 1,170 annotated and 2,800 new lncRNAs. Compared to 0 d cells, 738 lncRNAs were significantly upregulated and 550 were significantly downregulated in 8 d cells. Heat maps of lncrnas and target genes with significant differences showed that the fate of cell lineages changed. Functional enrichment analysis revealed that these differently expressed (DE) lncRNAs target genes were mainly involved in signaling pathways related to reprogramming and mammary gland development, such as the Wnt signaling pathway, PI3K-Akt signaling pathway, arginine and proline metabolism, ECM-receptor interaction, and MAPK signaling pathway. The accuracy of sequencing was verified by real-time fluorescence quantification (RT-qPCR) of lncRNAs and key candidate genes, and it was also demonstrated that the phenotype and genes of the cells were changed. Therefore, this study offers a foundation for explaining the molecular mechanisms of lncRNAs in chemically induced mammary epithelial cells.

Unravelling the complexity of lncRNAs in autophagy to improve potential cancer therapy

Autophagy is well-known as an internal catabolic process that is evolutionarily conserved and performs the key biological function in maintaining cellular homeostasis. It is tightly controlled by several autophagy-related (ATG) proteins, which are closely associated with many types of human cancers. However, what has remained controversial is the janus roles of autophagy in cancer progression. Interestingly, the biological function of long non-coding RNAs (lncRNAs) in autophagy has been gradually understood in different types of human cancers. More recently, numerous studies have demonstrated that several lncRNAs may regulate some ATG proteins and autophagy-related signaling pathways to either activate or inhibit the autophagic process in cancer. Thus, in this review, we summarize the latest advance in the knowledge of the complicated relationships between lncRNAs and autophagy in cancer. Also, the in-depth dissection of the lncRNAs-autophagy-cancers axis involved in this review would shed new light on discovery of more potential cancer biomarkers and therapeutic targets in the future.

Molecular regulatory mechanism of key LncRNAs in subclinical mastitic cows with folic acid supplementation

BACKGROUND

Folic acid is a water-soluble B vitamin (B9), which is closely related to the body's immune and other metabolic pathways. The folic acid synthesized by rumen microbes has been unable to meet the needs of high-yielding dairy cows. The incidence rate of subclinical mastitis in dairy herds worldwide ranged between 25%~65% with no obvious symptoms, but it significantly causes a decrease in lactation and milk quality. Therefore, this study aims at exploring the effects of folic acid supplementation on the expression profile of lncRNAs, exploring the molecular mechanism by which lncRNAs regulate immunity in subclinical mastitic dairy cows.

RESULTS

The analysis identified a total of 4384 lncRNA transcripts. Subsequently, differentially expressed lncRNAs in the comparison of two groups (SF vs. SC, HF vs. HC) were identified to be 84 and 55 respectively. Furthermore, the weighted gene co-expression network analysis (WGCNA) and the KEGG enrichment analysis result showed that folic acid supplementation affects inflammation and immune response-related pathways. The two groups have few pathways in common. One important lncRNA MSTRG.11108.1 and its target genes (ICAM1, CCL3, CCL4, etc.) were involved in immune-related pathways. Finally, through integrated analysis of lncRNAs with GWAS data and animal QTL database, we found that differential lncRNA and its target genes could be significantly enriched in SNPs and QTLs related to somatic cell count (SCC) and mastitis, such as MSTRG.11108.1 and its target gene ICAM1, CXCL3, GRO1.

CONCLUSIONS

For subclinical mastitic cows, folic acid supplementation can significantly affect the expression of immune-related pathway genes such as ICAM1 by regulating lncRNAs MSTRG.11108.1, thereby affecting related immune phenotypes. Our findings laid a ground foundation for theoretical and practical application for feeding folic acid supplementation in subclinical mastitic cows.

LncRNA LINC01871 sponging miR-142-3p to modulate ZYG11B promotes the chemoresistance of colorectal cancer cells by inducing autophagy

BACKGROUND

Colorectal cancer (CRC) is a malignant tumor in the digestive tract. Increasing evidence indicated that chemoresistance leads to a poor prognosis of CRC. Herein, we aimed to uncover the potential mechanism by which long intergenic noncoding RNA-1871 (LINC01871) affects the chemoresistance of CRC cells.

METHODS

Relative level of LINC01871 in CRC tissues was assessed by reverse transcription quantitative PCR (RT-qPCR). Kaplan-Meier analysis was conducted to determine the relevance of LINC01871 and the prognosis of CRC patients. Cell Counting Kit-8 (CCK-8) and colony formation assay were used to evaluate the proliferation of SW480 cells. Expression levels of proteins and their genes were assessed by western blot, immunofluorescence staining and RT-qPCR. In addition, the interaction of LINC01871, miR-142-3p and protein zyg-11 homolog B (ZYG11B) were analyzed via dual-luciferase reporter assays.

RESULTS

LINC01871 was low-expressed in CRC tissues and cell lines. Patients with a low level of LINC01871 showed significantly lower survival rate. pcDNA-LINC01871 significantly reduced the viability of SW480 cells ( P  < 0.01), elevated SW480 cells sensitivity to 5-FU ( P  < 0.01), reduced LC3 punctate aggregates ( P  < 0.01) and downregulated the relative mRNA expression level of autophagy related protein 9A, autophagy related protein 4B and high mobility group box 1 ( P  < 0.01) in SW480 cells. Moreover, LINC01871 was found to sponge miR-142-3p, and ZYG11B was the target of miR-142-3p. MiR-142-3p mimic significantly recovered the effect of pcDNA-LINC001871, whereas pcDNA-ZYG11B reversed the recovery effect of the miR-142-3p mimic.

CONCLUSION

LINC01871/miR-142-3p/ ZYG11B axis regulates the chemoresistance of CRCs by inducing autophagy.

SnoRNA and lncSNHG: Advances of nucleolar small RNA host gene transcripts in anti-tumor immunity

The small nucleolar RNA host genes (SNHGs) are a group of genes that can be transcript into long non-coding RNA SNHG (lncSNHG) and further processed into small nucleolar RNAs (snoRNAs). Although lncSNHGs and snoRNAs are well established to play pivotal roles in tumorigenesis, how lncSNHGs and snoRNAs regulate the immune cell behavior and function to mediate anti-tumor immunity remains further illustrated. Certain immune cell types carry out distinct roles to participate in each step of tumorigenesis. It is particularly important to understand how lncSNHGs and snoRNAs regulate the immune cell function to manipulate anti-tumor immunity. Here, we discuss the expression, mechanism of action, and potential clinical relevance of lncSNHGs and snoRNAs in regulating different types of immune cells that are closely related to anti-tumor immunity. By uncovering the changes and roles of lncSNHGs and snoRNAs in different immune cells, we aim to provide a better understanding of how the transcripts of SNHGs participate in tumorigenesis from an immune perspective.

Non-coding RNAs associated with autophagy and their regulatory role in cancer therapeutics

Cancer widely affects the world's health population and ranks second leading cause of death globally. Because of poor prognosis of various types of cancer such as sarcoma, lymphoma, adenomas etc., their high recurrence and metastasis rate and low early diagnosis rate have become concern lately. Role of autophagy in cancer progression is being studied since long. Autophagy is cell's self-degradative mechanism towards stress and has role in degradation of the cytoplasmic macromolecules which has potential to damage other cytosolic molecules. Autophagy can promote as well as inhibit tumorigenesis depending upon the associated protein combinations in cancer cells. Recent studies have shown that non-coding RNAs (ncRNAs) do not code for protein but play essential role in modulation of gene expression. At transcriptional level, different ncRNAs like lncRNAs, miRNAs and circRNAs directly or indirectly affect different stages of autophagy like autophagy-dependent and non-apoptotic cell death in cancer cells. This review focuses on the involvement of ncRNAs in autophagy and the modulation of several cancer signal transduction pathways in cancers such as lung, breast, prostate, pancreatic, thyroid, and kidney cancer.

Exploring the role of non-coding RNAs in autophagy

As a self-degradative mechanism, macroautophagy/autophagy has a role in the maintenance of energy homeostasis during critical periods in the development of cells. It also controls cellular damage through the eradication of damaged proteins and organelles. This process is accomplished by tens of ATG (autophagy-related) proteins. Recent studies have shown the involvement of non-coding RNAs in the regulation of autophagy. These transcripts mostly modulate the expression of ATG genes. Both long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been shown to modulate the autophagy mechanism. Levels of several lncRNAs and miRNAs are altered in this process. In the present review, we discuss the role of lncRNAs and miRNAs in the regulation of autophagy in diverse contexts such as cancer, deep vein thrombosis, spinal cord injury, diabetes and its complications, acute myocardial infarction, osteoarthritis, pre-eclampsia and epilepsy.Abbreviations: AMI: acute myocardial infarction; ATG: autophagy-related; lncRNA: long non-coding RNA; miRNA: microRNA.

RBM47/SNHG5/FOXO3 axis activates autophagy and inhibits cell proliferation in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the main type of thyroid carcinoma. Despite the good prognosis, some PTC patients may deteriorate into more aggressive diseases, leading to poor survival. Molecular technology has been increasingly used in the diagnosis and treatment of thyroid carcinoma. In this study, we identified that RNA Binding Motif Protein 47 (RBM47) was downregulated in PTC tissues and cells, and overexpression of RBM47 could activate autophagy and inhibit proliferation in PTC cells. RBM47 promotes but can not bind directly to Forkhead Box O3 (FOXO3). FOXO3 activates Autophagy Related Gene 3 (ATG3), ATG5, and RBM47 to form a loop and promote autophagy. RBM47 can bind directly to and stabilized lncRNA Small Nucleolar RNA Host Gene 5 (SNHG5) to inhibit PTC cells proliferation and activate autophagy in vitro and in vivo. SNHG5 inhibits ubiquitination and degradation of FOXO3 by recruiting Ubiquitin Specific Peptidase 21 (USP21), then promotes the translocation of FOXO3 from cytoplasm to nucleus. Our study revealed the regulatory mechanism of RBM47/SNHG5/FOXO3 axis on cell proliferation and autophagy in PTC, which may provide valuable insight for the treatment of PTC.

A Comprehensive Risk Assessment and Stratification Model of Papillary Thyroid Carcinoma Based on the Autophagy-Related LncRNAs

Background

Papillary thyroid carcinoma (PTC) is one of the most common malignant carcinomas in the endocrine system, and it has a growing incidence worldwide. Despite the development of diagnosis and treatment modalities for thyroid carcinoma, the outcome remains uncertain. Autophagy participates in the process of cancer invasion, malignancy, metastasis, and drug resistance. Emerging research has shown that long noncoding RNAs (lncRNAs) play an important role in the process of different types of cancers. However, the interaction between the process of autophagy and lncRNA and the value of autophagy-related lncRNA for risk assessment, prediction of drug sensitivity, and prognosis prediction in PTC patients remains unknown.

Materials and Methods

We screened 1,283 autophagy-related lncRNAs and identified 144 lncRNAs with prognostic value in The Cancer Genome Atlas (TCGA) cohorts. Univariate and multivariate Cox regression analyses were used to establish the prognosis-related autophagy-related lncRNA risk classification consisting of 10 lncRNAs to indicate the level of risk, according to which the patients were grouped into high-risk group and low risk-group.

Results

The high-risk group had dramatically worse overall survival compared with the low-risk group. Cox regression analysis was performed to confirm the independent prognostic value of the autophagy-related lncRNA risk stratification, and the time-dependent receiver operating characteristic curves of the risk stratification were 0.981 (1 year), 0.906 (3 years), and 0.963 (5 years). LncRNA CRNDE (LINC00180) is overexpressed in the tumor, and its high expression matched with poorer survival state. So, we chose it for further experiment. Finally, knockdown of the CRNDE in PTC increased the sensitivity to sorafenib.

Conclusion

Collectively, we successfully established a novel risk stratification for PTC based on the expression profiles of autophagy-related lncRNAs.

Overexpression of lncRNA SLC26A4-AS1 inhibits papillary thyroid carcinoma progression through recruiting ETS1 to promote ITPR1-mediated autophagy

Papillary thyroid carcinoma (PTC), accounting for approximately 85% cases of thyroid cancer, is a common endocrine tumour with a relatively low mortality but an alarmingly high rate of recurrence or persistence. Long non‐coding RNAs (lncRNAs) is emerging as a critical player modulating diverse cellular mechanisms correlated with the progression of various cancers, including PTC. Herein, we aimed to investigate the role of lncRNA SLC26A4‐AS1 in regulating autophagy and tumour growth during PTC progression. Initially, ITPR1 was identified by bioinformatics analysis as a differentially expressed gene. Then, Western blot and RT‐qPCR were conducted to determine the expression of ITPR1 and SLC26A4‐AS1 in PTC tissues and cells, both of which were found to be poorly expressed in PTC tissues and cells. Then, we constructed ITPR1‐overexpressing cells and revealed that ITPR1 overexpression could trigger the autophagy of PTC cells. Further, we performed a series of gain‐ and loss‐of function experiments. The results suggested that silencing of SLC26A4‐AS1 led to declined ITPR1 level, up‐regulation of ETS1 promoted ITPR1 expression, and either ETS1 knockdown or autophagy inhibitor Bafilomycin A1 could mitigate the promoting effects of SLC26A4‐AS1 overexpression on PTC cell autophagy. In vivo experiments also revealed that SLC26A4‐AS1 overexpression suppressed PTC tumour growth. In conclusion, our study elucidated that SLC26A4‐AS1 overexpression promoted ITPR1 expression through recruiting ETS1 and thereby promotes autophagy, alleviating PTC progression. These finding provides insight into novel target therapy for the clinical treatment of PTC.

lncRNA GAS8-AS1 genetic alterations in papillary thyroid carcinoma and their clinical significance

The long non-coding RNA (lncRNA) GAS8-AS1 is the second-most frequently altered gene, following the BRAF gene, in papillary thyroid carcinoma (PTC). We aimed to study the specificity and significance of genetic alterations in GAS8-AS1 in PTC. In this study, we reported the prevalence of genetic alterations of GAS8-AS1 in tissues of 48 nodular goiter, 573 papillary thyroid cancer, 95 colorectal cancer, 101 non-small cell lung cancer, 92 glioma, and 69 gastrointestinal stromal tumor patients, and in peripheral white blood cells of 286 healthy volunteers. We observed that the genomic sequence of GAS8-AS1 had a high frequency of genetic alterations in addition to the previously reported c.713A>G/714T>C substitution. Substitution of c.713A>G was completely linked with four other loci at c.714T>C, c.728A>G, c.737G>A, and c.752G>A. Two novel substitutions at c.749G>A and c.826A>G were also found. Interestingly, evidence from different samples indicated that these variations were not unique variants for PTC; they were also found in other malignant tissues and white blood cells of healthy volunteers. The c.713A>G substitution was associated with the T stage of PTC, while c.749G>A was more likely to occur in younger patients with PTC. PTC patients carrying heterozygous variants at the c.749 and c.826 loci had a higher risk of developing multiple lesions. These associations were also observed in patients with PTC and concomitant benign thyroid disease. Notably, the rare homozygous GG at the c.826 site conferred a higher risk of developing T2 PTC without benign thyroid disease, and a lower risk of developing T2 PTC with benign thyroid disease. Alterations of c.749G>A and c.826A>G had higher levels of serum TSH (thyroid stimulating hormone) in PTC subjects. Our study provides evidence that the detection of GAS8-AS1 genetic alterations would be useful in diagnostic screening and prognostic assessment of PTC.

Long noncoding RNA LINC01296 plays an oncogenic role in colorectal cancer by suppressing p15 expression

OBJECTIVE

To examine the role of the long noncoding RNA LINC01296 in colorectal carcinoma (CRC) and to explore the underlying mechanism.

METHODS

We detected LINC01296 expression levels in a cohort of 51 paired CRC and normal tissues. We also assessed the effects of LINC01296 on cell proliferation and apoptosis in CRC cells in vitro, and measured its effect on tumor growth in an in vivo mouse model. We identified the potential downstream targets of LINC01296 and assessed its regulatory effects.

RESULTS

Expression levels of LINC01296 were elevated in 37/51 CRC tissues compared with the corresponding normal tissues and were significantly associated with tumor stage, lymph node metastasis, and distant metastasis. Knockdown of LINC01296 using antisense oligonucleotides inhibited cell proliferation and promoted apoptosis of colon cancer cells in vitro and inhibited tumor growth in vivo. Knockdown of LINC01296 also significantly increased the gene expression of p15 in colon cancer cells. LINC01296-specific suppression of p15 was validated by the interaction between enhancer of zeste homolog 2 and LINC01296.

CONCLUSION

Overexpression of LINC01296 suppressed the expression of p15 leading to CRC carcinogenesis. These findings may provide the basis for novel future CRC-targeted therapies.

An aqueous extract of Prunella vulgaris L. inhibits the growth of papillary thyroid carcinoma by inducing autophagy in vivo and in vitro

The continued global rise in papillary thyroid carcinoma (PTC) combined with potential adverse effects of regular treatments calls for an alternative therapy. Prunella vulgaris L. (PV) is commonly used as a herbal remedy for thyroid diseases in China, but its influence on PTC is unclear. This study investigated the effect of PV aqueous extract on PTC and its underlying mechanism using a mouse xenograft model and the human PTC cell line K1. PV suppressed tumor growth in PTC-bearing mice at 0.05 and 0.1 g/kg bw, accompanied by improvements in autophagy-related protein expressions in xenografts. In K1 cells, PV inhibited cell growth and induced autophagic flux, manifesting as changes in autophagy-related proteins, the presence of autophagosomes, and a further increase in LC3-II by co-incubation with bafilomycin A1. Autophagy inhibitor 3-methyladenine ameliorated the autophagic cell death caused by PV. The mammalian target of rapamycin (mTOR) activator MHY1485 blocked the antiproliferative activity of PV by regulating mTOR, unc-51-like autophagy activating kinase 1 (ULK1), autophagosomes formation, and autophagy-related proteins. The adenosine monophosphate-activated protein kinase (AMPK) inhibitor compound C attenuated PV-induced inhibition of mTOR. Our results suggest that PV inhibits the growth of PTC in vivo and in vitro via autophagy, which is associated with the AMPK/mTOR/ULK1 pathway. Thus, PV has the potential to function as a therapeutic agent against PTC.

Long noncoding RNA GAS8-AS1: A novel biomarker in human diseases

Long non-coding RNAs (lncRNAs) represent a group of ncRNAs with more than 200 nucleotides. These RNAs can specifically regulate gene expression at both the transcriptional and the post-transcriptional levels, and increasing evidence indicates that they play vital roles in a variety of disease-related cellular processes. The lncRNA GAS8 antisense RNA 1 (GAS8-AS1, also known as C16orf3) is located in the second intron of GAS8 and has been reported to be both abnormally expressed in several diseases and closely correlated with many clinical characteristics. GAS8-AS1 has been shown to affect many biological functions, including cell proliferation, migration, invasiveness, and autophagy using several signaling pathways. In this review, we have summarized current studies on GAS8-AS1 roles in disease and discuss its potential clinical utility. GAS8-AS1 may be a promising biomarker for both diagnoses and prognoses, and a novel target for many disease therapies.

Epigenetic regulation of papillary thyroid carcinoma by long non-coding RNAs

Thyroid cancer is the most common primary endocrine malignancy with papillary thyroid carcinoma (PTC) its most common subtype. The jump in diagnoses over last many years has prompted re-assessment of molecularly targeted therapies and the discovery of novel targets. Long non-coding RNAs (lncRNAs) are increasingly being assessed for their expression in various PTC models. Interestingly, in addition to cell line models, a large proportion of the reported studies have evaluated lncRNA levels in PTC patient samples providing an immediate clinical relevance of their findings. While most lncRNAs either promote or suppress PTC pathogenesis, data on individual lncRNAs is not very clear. As expected, lncRNAs function in PTC through sponging of microRNAs as well as modulation of several signaling pathways. The process of epithelial-mesenchymal transition and the PI3K/Akt and wnt signaling pathways have emerged as the primary targets of lncRNAs in PTC. This comprehensive review discusses all the information that is available on lncRNAs in PTC, ranging from in vitro and in vivo findings to the possible role of lncRNAs as diagnostic and/or prognostic biomarkers.

LncRNA PROX1-AS1 Facilitates Gastric Cancer Progression via miR-877-5p/PD-L1 Axis

Introduction

Growing evidences imply that multiple long non-coding RNAs (lncRNAs) play a significant role in the treatment of cancer. Therefore, it is of great significance to discover new biomarkers or therapeutic targets of gastric cancer (GC). However, the potential molecular mechanism of lncPROX1-AS1 in GC remains unknown. The objective of current study is to investigate the effect of PROX1-AS1 in GC.

Methods

Thus, we detect that PROX1-AS1 is over-expressed in tissues and cell lines of GC using qRT-PCR analysis. CCK-8, colony formation, flow cytometry, wounding healing and transwell analyses were performed to explore the effect of PROX1-AS1 on GC malignant behaviors.

Results

It is further disclosed that silencing of PROX1-AS1 represses cell proliferation, migration, and invasion, whereas promotes cell apoptosis in GC. Bioinformatics analysis suggests that miR-877-5p is negatively regulated by PROX1-AS1 and ectopic of miR-877-5p alleviates the malignant behaviors of GC. Subsequently, miR-877-5p suppresses the activity of PD-L1-3ʹ UTR. At last, rescue assays demonstrated that the GC progression is suppressed by sh-PROX1-AS1 and facilitated on account of miR-877-5p inhibitors and then is retrieved by sh-PD-L1.

Discussion

Our findings reveal that PROX1-AS1 exerts its role via miR-877-5p/PD-L1 axis in the GC progression, suggesting that PROX1-AS1 may represent a new therapeutic target for the diagnosis and treatment of GC patients.

Antiangiogenic effect of arsenic trioxide in HUVECs by FoxO3a-regulated autophagy

Arsenic trioxide (ATO) has been shown to have antitumor effect in different tumors, although the underlying mechanisms are not fully understood. Autophagy plays a critical role in tumorigenesis and cancer therapy and has been found to be activated by ATO in different cells. However, the role of autophagy in the antitumor effect of ATO has not yet been elucidated. In this study, we investigated the role of autophagy in the antiangiogenic effect of ATO in human umbilical vein endothelial cells (HUVECs) in vitro and its underlying mechanism. Our data showed that ATO suppresses angiogenesis and induces autophagy in HUVECs through upregulation of forkhead box protein O3 (FoxO3a). Co-incubated with autophagy inhibitor or knockdown of FoxO3a effectively inhibited ATO-induced autophagy and reversed the antiangiogenic effect of ATO, indicating that ATO-induced autophagy plays an antiangiogenic role in HUVECs. Our results highlight the importance of autophagy in the antiangiogenic effect of ATO and provide an improved understanding of the function of ATO.

Long non-coding RNA signatures as predictors of prognosis in thyroid cancer: a narrative review

Thyroid cancer (TC) is the most common endocrine malignancy, with high incidence rates in recent decades. Most TC cases have good prognoses, but a high risk of recurrence and metastases poses challenges, especially for patients with high-risk factors. Currently used prognostic markers for TC involve a combination of genetic factors and overexpressed proteins. Long non-coding RNAs (lncRNAs) regulate several integral biologic processes by playing key roles in the transcription of several downstream targets maintaining cellular behavior. Prior studies have revealed that lncRNAs promote tumor cell proliferation, invasion, metastasis, and angiogenesis, making them important targets for therapeutic intervention in cancer. While the exact molecular mechanisms underlying the role of lncRNAs in modulating TC progression and recurrence is still unclear, it is important to note that some lncRNAs are upregulated in certain cancers, while others are downregulated. In the present study, we review several key lncRNAs, their association with cancer progression, and the important roles they may play as tumor suppressors or tumor promoters in tumorigenesis. We discuss the potential mechanisms of lncRNA-mediated pathogenesis that can be targeted for the treatment of TC, the existing and potential benefits of using lncRNAs as diagnostic and prognostic measures for cancer detection, and tumor burden in patients.

Identification of Potential lncRNAs and miRNAs as Diagnostic Biomarkers for Papillary Thyroid Carcinoma Based on Machine Learning

BACKGROUND

Papillary thyroid carcinoma (PTC) accounts for most of the proportion of thyroid cancer (TC). The objective of this study was to identify diagnostic, differentially expressed long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), contributing to understanding the epigenetics mechanism of PTC.

METHODS

The data of lncRNA, miRNA, and mRNA were downloaded from the Cancer Genome Atlas (TCGA) dataset, followed by functional analysis of differentially expressed mRNAs. Optimal diagnostic lncRNA and miRNA biomarkers were identified via random forest. The regulatory network between optimal diagnostic lncRNA and mRNAs and optimal diagnostic miRNA and mRNAs was identified, followed by the construction of ceRNA network of lncRNA-mRNA-miRNA. Expression validation and diagnostic analysis of lncRNAs, miRNAs, and mRNAs were performed. Overexpression of ADD3-AS1 was performed in PTC-UC3 cell lines, and cell proliferation and invasion assay were used for investigating the role of ADD3-AS1 in PTC.

RESULTS

A total of 107 differentially expressed lncRNAs, 81 differentially expressed miRNAs, and 515 differentially expressed mRNAs were identified. 11 lncRNAs and 6 miRNAs were regarded as the optimal diagnostic biomarkers for PTC. The epigenetic modifications via the above diagnostic lncRNAs and miRNAs were identified, including MIR181A2HG-FOXP2-hsa-miR-146b-3p, BLACAT1/ST7-AS1-RPS6KA5-hsa-miR-34a-5p, LBX2-AS1/MIR100HG-CDHR3-hsa-miR-34a-5p, ADD3-AS1-PTPRE-hsa-miR-9-5p, ADD3-AS1-TGFBR1-hsa-miR-214-3p, LINC00506-MMRN1-hsa-miR-4709-3p, and LOC339059-STK32A-hsa-miR-199b-5p. In the functional analysis, MMRN1 and TGFBR1 were involved in cell adhesion and endothelial cell migration, respectively. Overexpression of ADD3-AS1 inhibited cell growth and invasion in PTC cell lines.

CONCLUSION

The identified lncRNAs/miRNAs/mRNA were differentially expressed between normal and cancerous tissues. In addition, identified altered lncRNAs and miRNAs may be potential diagnostic biomarkers for PTC. Additionally, epigenetic modifications via the above lncRNAs and miRNAs may be involved in tumorigenesis of PTC.

An Autophagy-Related Long Noncoding RNA Signature Contributes to Poor Prognosis in Colorectal Cancer

Purpose

Colorectal cancer is one of the most common malignant primary tumors, prone to metastasis, and associated with a poor prognosis. As autophagy is closely related to the development and treatment of colorectal cancer, we investigated the potential prognostic value of long noncoding RNA (lncRNA) associated with autophagy in colorectal cancer.

Methods

In this study, we acquired information on the expression of lncRNAs in colorectal cancer from the Cancer Genome Atlas (TCGA) database and found that 860 lncRNAs were associated with autophagy-related genes. Subsequently, univariate Cox regression analysis was used to investigate 32 autophagy-related lncRNAs linked to colon cancer prognosis. Subsequently, eight of the 32 autophagy-related lncRNAs (i.e., long intergenic nonprotein coding RNA 1503 [LINC01503], ZEB1 antisense RNA 1 [ZEB1-AS1], AC087481.3, AC008760.1, AC073896.3, AL138756.1, AL022323.1, and TNFRSF10A-AS1) were selected through multivariate Cox regression analysis. Based on these autophagy-related lncRNAs, a risk signature was constructed, and the patients were divided into high- and low-risk groups.

Results

The high-risk group's overall survival time was significantly shorter than that of the low-risk group (p < 0.0001). Receiver operating characteristic curve analysis was performed to further confirm the validity of the model (area under the curve: 0.689). Moreover, multivariate regression suggested that the risk score was a significant prognostic risk factor in colorectal cancer. Gene set enrichment analysis showed that these gene sets are significantly enriched in cancer-related pathways, such as Kirsten rat sarcoma viral oncogene homolog (KRAS) signaling.

Conclusion

The risk signature of eight autophagy-related lncRNAs has prognostic potential for colorectal cancer. These autophagy-related lncRNAs may play a vital role in the biology of colorectal cancer.

LncRNA GAS8-AS1 Inhibits Ovarian Cancer Progression Through Activating Beclin1-Mediated Autophagy

Background

Early detection and diagnosis of ovarian cancer (OC) is complicated due to the concealment of the ovarian anatomical position and the lack of clinical manifestations and specific indicators of early OC. Therefore, it is urgent to study the pathogenesis of OC, especially the molecular mechanism.

Results

LncRNA GAS8-AS1 was decreased in OC tissues and cell lines, and high expression of GAS8-AS1 indicated a higher 5-year survival rate of OC patients. Overexpression of GAS8-AS1 suppressed growth of OC cells, while deletion of GAS8-AS1 promoted the progression of OC cells. Further data indicated GAS8-AS1 activated autophagy in OC cells. Functional experiments showed that 3-MA removed the inhibitory effect of GAS8-AS1 in OC cells. On the contrary, Rapamycin reversed the promoting effect of GAS8-AS1 in OC cells. Furthermore, GAS8-AS1 bound with Beclin1 and promoted its expression, and silencing of Beclin1 reversed the inhibitory role of GAS8-AS1 in OC progression. In vivo tumorigenesis assay showed GAS8-AS1 suppressed OC progression and activated Beclin1 mediated autophagy.

Conclusion

Our study suggested GAS8-AS1 inhibited OC progression by activating autophagy via binding with Beclin1, and GAS8-AS1 might be a potential therapeutic target for OC clinical treatment.

ATF2-Induced lncRNA GAS8-AS1 Promotes Autophagy of Thyroid Cancer Cells by Targeting the miR-187-3p/ATG5 and miR-1343-3p/ATG7 Axes

Long non-coding RNAs (lncRNAs) play an essential regulatory role in multiple cancers. However, the role of lncRNAs in papillary thyroid carcinoma (PTC) is still unknown. Here, GAS8-AS1, a novel lncRNA that is significantly downregulated in PTC, was selected for further investigation. The roles of GAS8-AS1 in PTC cells were verified by gain- and loss-of-function experiments. The functional mechanism of GAS8-AS1 on the microRNA (miR)-187-3p/ATG5 axis and miR-1343-3p/ATG7 axis in PTC cells was evaluated using bioinformatics analysis, luciferase reporter assay, Cell Counting Kit-8 (CCK-8) assay, immunohistochemistry analysis, transmission electron microscopy, and immunofluorescence. We found that GAS8-AS1 was downregulated in PTC tissues and cell lines. In patients with PTC, low GAS8-AS1 expression was associated with higher tumor-node-metastasis (TNM) stage and lymph node metastasis (LNM). Functionally, GAS8-AS1 significantly promoted autophagy and inhibited PTC cell proliferation in vitro and promoted tumorigenesis in vivo. Mechanistically, GAS8-AS1 acted as a sponge of miR-187-3p and miR-1343-3p and upregulated ATG5 and ATG7 expression, respectively. The transcription factor ATF2 regulated GAS8-AS1 by binding to the GAS8-AS1 promoter. In conclusion, upregulation of ATF2 activated GAS8-AS1-promoted autophagy of PTC cells by sponging oncogenic miR-187-3p and miR-1343-3p and upregulating the expression of ATG5 and ATG7, respectively, making GAS8-AS1 a potential prognostic biomarker and therapeutic target for PTC.

CDKL3 Targets ATG5 to Promote Carcinogenesis of Esophageal Squamous Cell Carcinoma

Objective

Our previous study suggested cyclin-dependent kinase-like 3 (CDKL3) acts as a new oncogene in esophageal squamous cell carcinoma (ESCC) cell line TE-1. However, the molecular mechanisms and biological effects of CDKL3 in ESCC remain unknown. In the present study, we aimed to explore the clinical significance of CDKL3 in ESCC and how CDKL3 regulates the malignant behavior of ESCC.

Methods

ESCC samples were stained by immunohistochemical staining (IHC) and analyzed for the expression of CDKL3. The functions of CDKL3 on proliferation, apoptosis, migration, invasion, and colony formation were investigated by celigo assay, MTT assay, colony formation, caspase 3/7 activity analysis, transwell migration and invasion assay, respectively. A transplanted tumor model was established to study the functions of CDKL3 on the tumorigenesis of ESCC cells. Microarray analysis was utilized to identify the CDKL3-regulated genes in ESCC cells.

Results

ESCC tumor tissues possessed a significantly higher expression of CDKL3 and autophagy-related gene 5 (ATG5) than matched adjacent normal tissues. The high expressions of CDKL3 were positively associated with the tumor-node-metastasis (TNM) stage and Ki67. Upregulated ATG5 expression was positively correlated with male, advanced tumor (T) stage, and TNM stage. Kaplan-Meier analysis showed that ESCC patients with higher expression of CDKL3 or ATG5 had a shorter overall survival. The worst prognosis was recognized in patients with both high manifestations of CDKL3 and ATG5. Time-dependent receiver operating characteristic (ROC) curve was established to reveal that the combination of CDKL3, ATG5, and TNM stage–based model had better prognostic accuracy than TNM stage. Moreover, CDKL3 knockdown markedly repressed cell growth and aggressivity in vitro and in vivo. Mechanistically, ATG5 was confirmed as a downstream gene involved in the pro-oncogenic function of CDKL3.

Conclusion

CDKL3 can be utilized as an independent poor prognostic marker in ESCC patients. Furthermore, CDKL3 may promote tumor profession, invasion, metastasis, and prohibit tumor apoptosis partly by ATG5 activation.

Long Non-Coding Small Nucleolar RNA Host Genes (SNHGs) in Endocrine-Related Cancers

Long non-coding RNAs (lncRNAs) are emerging regulators of a diverse range of biological processes through various mechanisms. Genome-wide association studies of tumor samples have identified several lncRNAs, which act as either oncogenes or tumor suppressors in various types of cancers. Small nucleolar RNAs (snoRNAs) are predominantly found in the nucleolus and function as guide RNAs for the processing of transcription. As the host genes of snoRNAs, lncRNA small nucleolar RNA host genes (SNHGs) have been shown to be abnormally expressed in multiple cancers and can participate in cell proliferation, tumor progression, metastasis, and chemoresistance. Here, we review the biological functions and emerging mechanisms of SNHGs involved in the development and progression of endocrine-related cancers including thyroid cancer, breast cancer, pancreatic cancer, ovarian cancer and prostate cancer.

The Role of Long Non-Coding RNAs in Thyroid Cancer

Thyroid cancer, the most common endocrine malignancy, has become the most commonly diagnosed malignant solid tumor. Moreover, some cases have poor prognosis, and the survival period is only 3-5 months. Long noncoding RNAs (lncRNAs) are a group of functional RNA molecules more than 200 nucleotides in length that lack the ability to encode protein but participate in all aspects of gene regulation. Functionally, many lncRNAs play essential roles in epigenetic regulation at transcriptional and post-transcriptional levels via various molecular mechanisms. Recent studies have discovered important roles for lncRNAs during the complex process of carcinogenesis in thyroid cancer. In this review, we focus on lncRNAs dysregulated in thyroid cancer and summarize recently reported associations between lncRNAs and thyroid cancer in order to demonstrate the significant value of lncRNAs in diagnosis and treatment.

Metformin Affects Paclitaxel Sensitivity of Ovarian Cancer Cells Through Autophagy Mediated by Long Noncoding RNASNHG7/miR-3127-5p Axis

Background: Ovarian cancer is the public health issue worldwide. Paclitaxel is a first-line chemotherapy drug for ovarian cancer, but the paclitaxel resistance weakens the therapeutic effect. Metformin (Met) improved the paclitaxel sensitivity in a mouse model of ovarian cancer. However, the mechanism of Met on paclitaxel sensitivity is still unclear in ovarian cancer. Methods: Cell viability, apoptosis, migration, and invasion were measured by Cell Counting Kit-8 (CCK8), flow cytometry, and transwell assays severally. The expression of long noncoding RNA (lncRNA) small nucleolar RNA host gene 7 (SNHG7) and microRNA-3127-5p (miR-3127-5p) were detected by real-time quantitative polymerase chain reaction. The protein levels of poly (ADP-ribose) polymerase, microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, and Beclin 1 were examined by western blot assay. RNA immunoprecipitation assay detected the relationship between SNHG7 and miR-3127-5p. Then, the binding correlation between SNHG7 and miR-3127-5p was predicted by starBase and verified by the dual-luciferase reporter. The effects of Met and SNHG7 on tumor growth were tested in ovarian cancer mice model. Results: Met inhibited cell viability, migration, invasion, SNHG7 level, and autophagy and promoted apoptosis in paclitaxel-resistant ovarian cancer cells. Moreover, Met partly reversed SNHG7-mediated paclitaxel sensitivity and autophagy in ovarian cancer cells. SNHG7 directly bound to miR-3127-5p. Met abolished the promoting effect of SNHG7 overexpression on tumor growth and autophagy in vivo. Conclusion: The authors' findings indicated that Met expedited paclitaxel sensitivity by regulating SNHG7/miR-3127-5p-mediated autophagy in ovarian cancer cells.

Expression analysis of growth arrest specific 8 and its anti-sense in breast cancer tissues

The Growth arrest specific 8 (GAS8) and its anti-sense transcript (GAS8-AS1) are located in a genomic region that is frequently mutated in breast cancer. These transcripts have established tumor suppressor effects in some human malignancies. In the current investigation, we aimed at identification of the role of GAS8 and GAS8-AS1 in breast cancer. We measured gene expression of GAS8 and GAS8-AS1 in paired tumoral and non-tumoral tissues obtained from 88 breast cancer patients by means of real time PCR. No significant differences were identified in expressions of GAS8 and GAS8-AS1 in tumoral samples compared with non-tumoral tissues (Fold changes = 1.53 and 1.71; P values = .28 and 0.14 respectively). Transcript levels of GAS8-AS1 was significantly correlated with estrogen receptor (ER) status (P = .01). Expression of GAS8 gene was associated with history of oral contraceptive use (P = .04). The similar expressions of GAS8 and GAS8-AS1 genes in tumoral and non-tumoral tissues of breast in spite of previous reports regarding their fundamental tumor suppressor roles in other tissues show that these genes are not involved in the pathogenesis of breast cancer. So, these genes have distinct roles in diverse tissues.

Long Non Coding RNA SNHG16 Facilitates Proliferation, Migration, Invasion and Autophagy of Neuroblastoma Cells via Sponging miR-542-3p and Upregulating ATG5 Expression

Background

Neuroblastoma (NB) is a heterogeneous pediatric malignant tumor with many biological and clinical characteristics. Long non-coding RNA small nucleolar RNA host gene 16 (SNHG16) plays vital role in the development of NB. However, the potential mechanism of SNHG16 in the progression of NB is rarely reported.

Methods

The expression levels of SNHG16, miR-542-3p and autophagy-related gene 5 (ATG5) were measured with quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration and invasion of NB cells were determined using 3-(4, 5-dimethylthiazol-2-YI)-2, 5-diphenyltetrazolium bromide (MTT) or transwell assay. Protein levels of ATG5, microtubule-associated protein A1/1B-light chain3 (LC3-I/II) and p62 were detected by Western blot analysis. The interaction between miR-542-3p and SNHG16 or ATG5 was predicted by starBase and confirmed by dual luciferase reporter assay. Xenograft mice models were constructed to confirm the role of SNHG16 in vivo.

Results

SNHG16 was upregulated in NB tissues and cells and associated with clinical stage and poor prognosis of NB. Knockdown of SNHG16 impeded proliferation, migration, invasion and autophagy of NB cells in vitro, and suppressed tumor growth in vivo. Interestingly, SNHG16 mediated ATG5 expression through sponging miR-542-3p in NB cells. Moreover, miR-542-3p downregulation reversed the inhibitory effects of SNHG16 silencing on proliferation, migration, invasion and autophagy of NB cells. Besides, ATG5 overturned the regulatory effects on proliferation, migration, invasion and autophagy of NB cells induced by SNHG16 or miR-542-3p knockdown.

Conclusion

SNHG16 facilitated proliferation, migration, invasion and autophagy of NB cells via sponging miR-542-3p and upregulating ATG5 expression in NB.

Long noncoding RNA ZFAS1 promotes progression of papillary thyroid carcinoma by sponging miR-590-3p and upregulating HMGA2 expression

Background

Thyroid cancer is the most common endocrine malignancy, papillary thyroid carcinoma (PTC) is the main form of thyroid cancer. The long non-coding RNA (lncRNA) zinc finger antisense 1 (ZFAS1) is highly expressed in various cancer tissues and it has been shown to function as a tumor promoter in various cellular processes. However, the role of ZFAS1 in PTC is not well understood currently. Thus, this study aimed to explore the potential roles of ZFAS1 in the development and progression of PTC.

Material and methods

PTC tissues (n=80) and noncancerous tissues were collected. Gain- and loss-of-function assays were performed to determine the effect of ZFAS1 on proliferation in K-1 and TPC-1 cells. The ZFAS1/mir-590-3P/HMGA2 aixs were analysed in PTC cell lines.

Results

We found that the expression of ZFAS1 was increased in PTC tissues and four PTC cell lines (B-CPAP, IHH-4, TPC-1, and K-1). The gain- and loss-of-function assays showed that overexpressing ZFAS1 promoted cell proliferation and inhibited cell apoptosis in PTC cells in vitro. We demonstrated that knockdown of ZFAS1 inhibits tumor growth and upregulation of ZFAS1 promotes tumor growth in vivo. Bioinformatics analysis revealed that miR-590-3p targeted the 3ʹ-UTR of ZFAS1. The double luciferase reporter and RNA-binding protein immunoprecipitation assay demonstrated that miR-590-3p is a target of ZFAS1. Rescue experiments confirmed that miR-590-3p could reverse the effect of ZFAS1 on PTC cells. Moreover, we identified high mobility group AT-hook 2 (HMGA2) to be a downstream target of miR-590-3p and ZFAS1 which activates HMGA2 expression by sponging to miR-590-3p.

Conclusion

High ZFAS1 expression level was associated with the progression of PTC, and ZFAS1 contributed to PTC progression via miR-590-3p/HMGA2 regulatory aixs. Therefore, ZFAS1 might be a potential therapeutic target for PTC intervention.

The Long Non-Coding RNA ENST00000489676 Influences Papillary Thyroid Cancer Cell Proliferation and Invasion through Regulating MiR-922

Purpose: Long noncoding RNAs (lncRNAs) have been reported to be associated with the growth and progression of numerous cancers. The aim of this study was to explore the potential function and molecular mechanism of lncRNA ENST00000489676 in the proliferation and invasion of papillary thyroid cancer (PTC). Methods: QRT-PCR (quantitative reverse transcriptase-polymerase chain reaction) was used to determine the levels of ENST00000489676. CCK-8 (Cell Counting Kit-8) assay and colony formation assay were performed to detect the cell proliferation. Flow cytometry was used to analyze the cell cycle. Transwell and scratch assay were performed to detect the migration and invasion ability. Results: The expression of ENST00000489676 was significantly overexpressed in TPC1 compared to KTC1 cell lines. When ENST00000489676 expression was knocked down, the proliferation, migration and invasion ability as well as cell cycle were all promoted in PTC cell lines, while those abilities were all suppressed when ENST00000489676 overexpressed. Overexpression of ENST00000489676 could inhibit cell proliferation, migration and invasion in vitro. Moreover, ENST00000489676 may mediate tumor suppression in PTC cells through suppressing miR-922. Conclusions: ENST00000489676 negatively regulated the proliferation, migration invasion and cell cycle of PTC. The overexpression of ENST00000489676 inhibited the progression of PTC through suppressing miR-922. ENST00000489676 could be act as a novel diagnosis marker and a potential therapeutic target for PTC.

Targeted next-generation sequencing in papillary thyroid carcinoma patients looking for germline variants predisposing to the disease

PURPOSESS

The purpose of this study was using next-generation sequencing technique to explore the potential association between germline variants of 14 targeted genes and papillary thyroid carcinoma (PTC) predisposition as well as disease progression.

METHODS

In all, 516 subjects were enrolled in this study including 416 PTC patients and 100 healthy controls. PTC patients were divided into distant metastasis group and non-distant metastasis group. Patients in distant metastasis group were further divided into radioiodine-refractory PTC (RR-PTC) and non-RR-PTC depending on their response to radioiodine therapy. Genomic DNA was extracted from peripheral blood sample and MiSeq Benchtop Sequencer was used for sequencing.

RESULTS

We found rs11246050 in NLRP6 (dominant model, OR/95% CI: 2.028/1.091-3.769, p = 0.025), rs2286742 and rs3740530 in HABP2 (recessive model, OR/95% CI: 9.644/1.307-71.16, p = 0.026 and 3.989/1.413-11.26, p = 0.009), rs2736098 in TERT (recessive model, OR/95% CI: 2.322/1.028-5.242. p = 0.042) and rs62054619 in GAS8-AS1 (recessive model, OR/95% CI: 2.219/1.067-4.617, p = 0.033) were associated with the risk of PTC. rs1137282 in KRAS (dominant model, OR/95% CI: 0.5430/0.3192-0.9236, p = 0.024), rs1347591 and rs4461062 in NUP93 (dominant model, OR/95% CI: 0.6121/0.4128-0.9076, p = 0.015 and 0.6156/0.4157-0.9117, p = 0.015) were associated with low risk of distant metastatic disease in PTC patients. rs33954691 in TERT was associated with the risk of RR-PTC under dominant model (OR/95% CI: 3.161/1.596-6.262).

CONCLUSIONS

Germline variants of related genes could be associated with the susceptibility of PTC as well as disease progression (distant metastasis and radioiodine-refractory status). However, these results must be further verified and the potential biological functions of these germline variants in the pathogenesis of PTC remain to be determined in future studies.

LncRNA FOXD2-AS1 accelerates the papillary thyroid cancer progression through regulating the miR-485-5p/KLK7 axis

It has been proved that long noncoding RNAs (lncRNAs) are important modulators in the tumorigenesis and progression of various malignant tumors. Recently, lncRNA FOXD2-AS1 has been reported to be an oncogene in several kinds of human cancers. However, the function of FOXD2-AS1 in papillary thyroid cancer (PTC) has not been well investigated. This study aims to explore the biological role and mechanism of FOXD2-AS1 in PTC. At first, the expression of FOXD2-AS1 was examined in PTC tissues and cell lines with quantitative reverse transcription-polymerase chain reaction (qRT-PCR). FOXD2-AS1 was found to observably upregulated in PTC tissues and cell lines. Kaplan-Meier survival analysis revealed that high expression of FOXD2-AS1 was closely correlated with the unfavorable prognosis of patients with PTC. Based on the TCGA data set, KLK7 was overexpressed in PTC tumor samples. Our experimental data further validated the upregulation of KLK7 in PTC tissues and cell lines. Similarly, high level of KLKF was associated with poor prognosis of patients with PTC. The positive expression association between FOXD2-AS1 and KLK7 was analyzed with Pearson correlation coefficient. Loss-of-function assays revealed that knockdown of FOXD2-AS1 or KLK7 greatly inhibited PTC cell proliferation and migration, while induced cell apoptosis. Results of mechanism experiments suggested that FOXD2-AS1 functioned as a competing endogenous RNA (ceRNA) to enhance the expression of KLK7 by sponging miR-485-5p in PTC. Rescue assays were conducted to verify the function of FOXD2-AS1/miR-485-5p/KLK7 axis in PTC progression.

Targeting autophagy in thyroid cancers

Thyroid cancer is one of the most common endocrine malignancies. Although the prognosis for the majority of thyroid cancers is relatively good, patients with metastatic, radioiodine-refractory or anaplastic thyroid cancers have an unfavorable outcome. With the gradual understanding of the oncogenic events in thyroid cancers, molecularly targeted therapy using tyrosine kinase inhibitors (TKIs) is greatly changing the therapeutic landscape of radioiodine-refractory differentiated thyroid cancers (RR-DTCs), but intrinsic and acquired drug resistance, as well as adverse effects, may limit their clinical efficacy and use. In this setting, development of synergistic treatment options is of clinical significance, which may enhance the therapeutic effect of current TKIs and further overcome the resultant drug resistance. Autophagy is a critical cellular process involved not only in protecting cells and organisms from stressors but also in the maintenance and development of various kinds of cancers. Substantial studies have explored the complex role of autophagy in thyroid cancers. Specifically, autophagy plays important roles in mediating the drug resistance of small-molecular therapeutics, in regulating the dedifferentiation process of thyroid cancers and also in affecting the treatment outcome of radioiodine therapy. Exploring how autophagy intertwines in the development and dedifferentiation process of thyroid cancers is essential, which will enable a more profound understanding of the physiopathology of thyroid cancers. More importantly, these advances may fuel future development of autophagy-targeted therapeutic strategies for patients with thyroid cancers. Herein, we summarize the most recent evidence uncovering the role of autophagy in thyroid cancers and highlight future research perspectives in this regard.

Long Non-Coding RNAs in Thyroid Cancer: Implications for Pathogenesis, Diagnosis, and Therapy

Thyroid cancer is a rare malignancy and accounts for less than 1% of malignant neoplasms in humans; however, it is the most common cancer of the endocrine system and responsible for most deaths from endocrine cancer. Long non-coding (Lnc)RNAs are defined as non-coding transcripts that are more than 200 nucleotides in length. Their expression deregulation plays an important role in the progress of cancer. These molecules are involved in physiologic cellular processes, genomic imprinting, inactivation of chromosome X, maintenance of pluripotency, and the formation of different organs via changes in chromatin, transcription, and translation. LncRNAs can act as a tumor suppressor genes or oncogenes. Several studies have shown that these molecules can interact with microRNAs and prevent their binding to messenger RNAs. Research has shown that these molecules play an important role in tumorigenicity, angiogenesis, proliferation, migration, apoptosis, and differentiation. In thyroid cancer, several lncRNAs (MALAT1, H19, BANCR, HOTAIR) have been identified as contributing factors to cancer development, and can be used as novel biomarkers for early diagnosis or even treatment. In this article, we study the newest lncRNAs and their role in thyroid cancer.

Oncogenicity of lncRNA FOXD2-AS1 and its molecular mechanisms in human cancers

OBJECTIVES

Long non-coding RNAs (lncRNAs) are a group of noncoding RNAs with length larger than 200 nucleotides. LncRNAs have limited or no protein-coding capacity because of lack of obvious open reading frame. An increasing number of researches have shown that lncRNAs participate in the complex regulation network of cancer and play an important role in tumourigenesis and progression such as proliferation, migration and invasion. LncRNA FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1), located on chromosome 1p33 and with a transcript length of 2527 nucleotides, is a novel cancer-related lncRNA. FOXD2-AS1 was recently found to exhibit aberrant expression in various malignancies, including gastric, lung, bladder, colorectal, nasopharyngeal, esophageal, hepatocellular, thyroid and skin cancer, and its deregulation might be related to survival and prognosis of cancer patients. Pertinent to clinical practice, FOXD2-AS1 might act as a feasible biomarker or therapeutic target in human cancers. In this paper, we made a summary on the current findings concerning the biological functions and molecular mechanisms of FOXD2-AS1 in tumor progression.

MATERIALS AND METHODS

In this paper, we summarized and figured out recent studies about the expression and molecular biological mechanisms of FOXD2-AS1 in tumor progression. Existing relevant studies were obtained through a systematic search from PubMed, Embase, BioMedNet, GEO database and Cochrane Library.

RESULTS

FOXD2-AS1 was a valuable tumor-associated lncRNA. Its expression level was up-regulation in various malignancies, including gastric, lung, bladder, colorectal, nasopharyngeal, esophageal, hepatocellular, thyroid and skin cancer. In addition, the aberrant expressions of FOXD2-AS1 have shown to contribute to proliferation, migration and invasion of cancer cells, and its deregulation is related to carcinogensis, overall survival, disease free survival, prognosis and tumor progression.

CONCLUSIONS

LncRNA FOXD2-AS1 is an oncogene and probably represents a feasible biomarker or therapeutic target in human cancers.

Identification of Long Noncoding RNA MIR22HG as a Novel Biomarker in Thyroid Cancer

Thyroid cancer (TC) is the one of the most common endocrine malignancy. However, currently there are no specific and sensitive biomarkers for predicting the prognosis for TC. In this study, we for the first time showed MIR22HG was down-regulated in thyroid cancer by analyzing public datasets, including TCGA, GSE29265, GSE33630, and GSE55091. Furthermore, we observed the lower expression levels of MIR22HG were significantly related to higher age, lymph node metastasis status, residual tumor status, N stage, Grade, and T stage in TC. We also observed higher MIR22HG expression was associated with longer overall and disease-free survival time in TC. In order to explore the potential mechanisms of MIR22HG regulating TC progression, 4 hub gene networks regulated by MIR22HG were constructed in the present study. Bioinformatics analysis showed MIR22HG was associated with apoptotic process, regulation of transcription, mRNA splicing, regulation of cell cycle, and Hippo signaling pathway in TC. These results suggested MIR22HG could serve as a novel biomarker for thyroid cancer.

Down-Regulation of APTR and it's Diagnostic Value in Papillary and Anaplastic Thyroid Cancer

APTR has been employed as a potential biomarker attributing to it was involved in carcinogenesis and malignancy's progression. However, the roles of APTR in papillary thyroid cancer (PTC) and anaplastic thyroid cancer (ATC) are unclear. In the present study, we aimed to explore the relative expression of APTR in PTC and ATC tissues and the relation between APTR expression and PTC clinicopathological features. We analyzed APTR expression in PTC and ATC by investigating data obtained from the Gene Expression Omnibus (GEO) database. Then, we tested 76-pair PTC and adjacent normal samples by qRT-PCR, and the result was in accordance with the analysis in GEO datasets. Chi-square (χ2) analysis was employed to evaluate the association between APTR and PTC clinical features. These results showed that APTR was negatively related to TNM stages, distant metastasis. In addition, we further evaluated the feasibility of using APTR to detect PTC and ATC patients by the receiver operating characteristic (ROC) and the area under curve (AUC). These findings implied that down-regulation of APTR is correlated with tumorigenesis, also indicated that the potential diagnostic value of APTR for detecting PTC and ATC patients.

Whole transcriptome sequencing analyses of DHA treated glioblastoma cells

Glioblastoma (GBM) is a typical malignant tumor, and there are no effective drugs capable of improving patient survival. Docosahexaenoic acid (DHA), a nutrient essential to animal health and neurodevelopment, exerts an anticancer effect in several types of cancer. However, the function of DHA in GBM is still unclear. Here, we showed that DHA could repress the migration and invasion of GBM U251 cells and promote their apoptosis in a dose- and time-dependent manner, indicating that DHA has an anticancer effect on GBM cells. Whole-transcriptome analysis indicated that DHA treatment mainly regulates the genes associated with receptor binding, oxidoreductase activity, organic acid transmembrane transporter activity, and carboxylic acid transmembrane transporter activity. Long non-coding RNAs (LncRNAs) involved in the regulation network of DHA were also identified, and their targets were assigned to the Gene Ontology (GO) categories. In silico analysis was conducted to predict the pathways related to the differentially expressed genes by DHA treatment. Our findings suggest that DHA acts as an antitumor agent in GBM, which may provide a suitable means of improving the efficacy of GBM treatment in the future.

Regulatory effects of lncRNAs and miRNAs on autophagy in malignant tumorigenesis

Autophagy is an important process in endogenous substrate degradation by lysosomes within cells, with a degree of evolutionary conservation. Like apoptosis and cell senescence, cell autophagy is a very important biological phenomenon involving the development and growth of biological processes. Abnormal autophagy may lead to tumorigenesis. In recent years, increasing studies have demonstrated that long non-coding RNAs (lncRNAs) and miRNAs can regulate cell autophagy by modulating targetting gene expression. In this review, we will provide an overview of lncRNAs and miRNAs in autophagy modulation and new insights into the underlying mechanisms, as well as their potential utilization in disease diagnosis, prognosis, and therapy.

lncRNA LINC00673 induces proliferation, metastasis and epithelial-mesenchymal transition in thyroid carcinoma via Kruppel-like factor 2

The incidence of thyroid cancer has increased in the past decades; however, the underlying molecular mechanisms of thyroid cancer tumorigenesis remain unknown. Using sequencing technology, long intergenic non‑protein coding RNA 673 (LINC00673) was identified to be upregulated in several tumor tissues. However, the biological role of LINC00673 in thyroid carcinoma has yet to be determined. In this study, 60 matched pairs of thyroid tumor tissue and normal tissue were selected for study using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to validate previous findings; then, clinicopathologic features of the tissues were analyzed. Proliferation, colony formation, migration and invasion assays were performed, and epithelial-mesenchymal transition (EMT)-associated phenotypes were investigated following transfection with small interfering RNA to determine the specific role of LINC00673 in thyroid carcinoma cell lines (TPC1, KTC‑1 and BCPAP). The study revealed that long non‑coding RNA LINC00673 was significantly upregulated in thyroid cancer tissues compared with paired adjacent non‑tumor tissues using RT-qPCR and that high expression of LINC00673 is was associated with larger tumor size and lymph node metastasis in the validated cohort. Knockdown of LINC00673 inhibited cell proliferation and metastasis, whereas, LINC00673 overexpression had the opposite effect. The results showed that LINC00673 may influence EMT and the expression of Kruppel-like factor 2 (KLF2). Notably, KLF2 is considered a tumor suppressor gene in a variety of tumors. Finally, knock down of KLF2 enhanced thyroid carcinoma cell proliferation, and invasion and migration. In this study, the function of LINC00673 in promoting the proliferation and metastasis of thyroid carcinoma cell lines was identified, and LINC00673 may act as a novel therapeutic target for treating thyroid carcinoma.

Upregulation of lncRNA-ATB by Transforming Growth Factor β1 (TGF-β1) Promotes Migration and Invasion of Papillary Thyroid Carcinoma Cells

Background

lncRNA-ATB plays an oncogenic role in various types of malignancies, but its involvement in papillary thyroid carcinoma (PTC) cells, which is a main type of thyroid cancer, is unknown.

Material/Methods

A total of 76 patients with PTC and 28 people with normal physiological conditions were included in this study. Tumor tissues and adjacent healthy tissues were collected from PTC patients and blood was extracted from both patients and healthy controls. Expression of lncRNA-ATB in those tissues was detected by qRT-PCR. All patients were followed up for 5 years and diagnostic and prognostic values of serum lncRNA-ATB for PTC were investigated by ROC curve analysis and survival curve analysis, respectively. lncRNA-ATB overexpression PTC cell lines were established and effects of lncRNA-ATB overexpression on cell migration and invasion were investigated by Transwell cell migration and invasion assay, respectively. Effects of lncRNA-ATB overexpression on TGF-β1 expression were investigated by Western blot.

Results

lncRNA-ATB expression level was higher in tumor tissues than in adjacent healthy tissues in most PTC patients. Serum level of lncRNA-ATB was higher in cancer patients than in healthy control. Serum lncRNA-ATB can be used to accurately predict PTC and its prognosis. lncRNA-ATB overexpression promoted tumor cell migration and invasion, lncRNA-ATB overexpression showed no significant effects on TGF-β1 expression, and TGF-β1 treatment increased the expression level of lncRNA-ATB.

Conclusion

Upregulation of lncRNA-ATB by TGF-β1 promotes migration and invasion of PTC cells.