LncRNA Gas5 acts as a ceRNA to regulate PTEN expression by sponging miR-222-3p in papillary thyroid carcinoma

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.

[Research Progress of LncRNA SNHGs in Regulating the Biological Behavior of Non-small Cell Lung Cancer]

Lung cancer is one of the malignant tumors with the highest incidence and mortality rate in China, and its occurrence and development mechanism and treatment methods are the current research focuses. In recent years, the emergence of drugs targeting various tumor driver genes has significantly improved patients' survival and quality of life, setting off a wave of research on new therapeutic targets. Among them, long non-coding RNA (lncRNA) plays a crucial role in the malignant behavior of tumors, which has attracted widespread attention. Shown by a large number of studies, partial members of lncRNA small nucleolar RNA host gene (SNHG) family are aberrantly expressed in many maliglant tumors including non-small cell lung cancer (NSCLC) and participate in cell proliferation, invasion and migration, which may act as a new diagnostic and prognostic biomarker and can be a therapeutic target of NSCLC. In this review, we comprehensively summarize and explore the recent investigation of SNHGs in NSCLC in order to provide new ideas for the diagnosis and treatment of NSCLC.
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An Association Between GAS5 rs145204276, NEAT1 rs512715, and MEG3 rs4081134 Gene Polymorphisms and Papillary Thyroid Carcinoma

Background

This study explores the association between growth arrest-specific 5 (GAS5) rs145204276, nuclear paraspeckle assembly transcript 1 (NEAT1) rs512715, and Maternally Expressed 3 (MEG3) rs4081134 polymorphisms and their impact on susceptibility to papillary thyroid carcinoma (PTC), considering differential expression of long noncoding RNAs (lncRNAs) in PTC.

Methods

A case-control study involving 125 papillary thyroid carcinoma (PTC) patients and 125 controls was conducted. Genotyping of polymorphisms was performed using tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) methods.

Results

No significant association was found between the two groups regarding genotypes and allelic frequencies of GAS-5 145204276 and MEG3 rs4081134 polymorphisms. Genetic models also showed the same results. Regarding NEAT1 rs512715, The PTC group had more GC genotypes and over-dominant models of NEAT1 rs512715 than controls, while controls showed a higher frequency of recessive models.

Conclusion

GAS5 rs145204276 and MEG3 rs4081134 polymorphisms showed no significant association with papillary thyroid carcinoma (PTC) risk. In contrast, NEAT1 rs512715 exhibited a significant impact on PTC development.

MiR-20b Tissue Expression Level Displays the Diagnostic Value in Papillary Thyroid Carcinoma

Background

Detection of cancer in patients with thyroid nodules requires sensitive and specific diagnostic modalities that are accurate and inexpensive. This study aimed to identify a potential microRNA(miRNA) panel to detect papillary thyroid carcinoma (PTC).

Methods

Following a comprehensive literature review as well as miRNA target predictor databases, Real-time PCR was used to quantify the expression of candidate miRNAs in 59 tissue specimens from 30 patients with PTC and 29 patients with benign nodules. A receiver operating characteristic (ROC) curve analysis was used to assess the accuracy of miRNA expression levels compared to the pathology report as the gold standard. Based on prediction results, four miRNAs, including miR-9, miR-20b, miR-221, and miR-222, were selected to evaluate their expression level in Iranian thyroid samples.

Results

A significant difference between the tissue expression level of miR-20b, miR-9, miR-222, and miR-221 was detected in the PTC group compared with non-PTC (P < 0.05). The area under the curves for the included miRs were 1, 0.98, 0.99, 0.98, and 1, respectively.

Conclusion

Our results confirmed deregulations of miR-20b as well as miR-222, miR-221, and miR-9 in PTC and, therefore, could be used as a helpful miRNA panel to differentiate PTC from benign nodules, which results in the more efficient clinical management of PTC patients.

Identification of non-coding RNA related prognosis biomarkers based on ceRNA network in thyroid cancer

Introduction: Thyroid cancer (THCA) has become a serious malignant tumor worldwide. Identification of non-coding RNA related regulators is very necessary to improve the knowledge of THCA treatment. The aim of this study was to identify novel therapeutic targets and prognosis biomarkers for predicting pathological characteristics and subsequently treating THCA. Methods: We investigated the alterations of miRNAs, mRNAs and lncRNAs in THCA. Functional enrichment and clustering analysis were conducted for these aberrantly expressed RNAs. Multiple interaction networks among miRNAs, mRNAs and lncRNAs were constructed and the functional modules associated with THCA patients' prognosis were identified. Furthermore, we evaluated the prognostic roles of the important miRNAs, mRNAs and lncRNAs in THCA and investigated the regulatory potential of non-coding RNAs on immune cell infiltration. Results: We firstly identified that miR-4709-3p and miR-146b-3p could significantly classify patients into high/low risk groups, which may be potential prognosis biomarkers of THCA. Secondly, we constructed a THCA-related miRNA-mRNA network, which displayed small world network topological characters. Two THCA-related functional modules were identified from the miRNA-mRNA network by MCODE. Results showed that two modules could implicate in known cancer pathways, such as apoptosis and focal adhesion. Thirdly, a THCA-related miRNA-lncRNA network was constructed. A subnetwork of miRNA-lncRNA network showed strong prognosis effect in THCA. Fourthly, we constructed a THCA-related mRNA-lncRNA network and detected several typical lncRNA-miRNA-mRNA crosstalk, such as AC068138, BCL2, miR-21 and miR-146b, which had good prognosis effect in THCA. Immune infiltration results showed that lncRNAs LA16c-329F2, RP11-395N3, RP11-423H2, RP11-399B17 and RP11-1036E20 were high related to neutrophil and dendritic cell infiltration. Discussion: Non-coding RNA-mediated gene regulatory network has the strong regulatory potential in pathological processes of THCA. All these results could help us uncover the non-coding RNA-mediated regulatory mechanism in THCA.

Genomic and epigenomic profile of thyroid cancer

Thyroid cancer is the most common malignancy of the endocrine system, and its incidence has been steadily increasing. Advances in sequencing have allowed analysis of the entire cancer genome, and has provided new information on the genetic lesions and modifications responsible for the onset, progression, dedifferentiation and metastasis of thyroid carcinomas. Moreover, integrated genomics has advanced our understanding of the development of cancer and its behavior, and has facilitated the identification of new genetic mutations and molecular pathways. The functional analysis of epigenetic modifications, such as DNA methylation, histone acetylation and non-coding RNAs, have contributed to define new regulatory mechanisms that control cell malignancy in thyroid cancer, especially aggressive forms. Here we review the most recent advances in genomics and epigenomics of thyroid cancer, which have resulted in a new classification and interpretation of the initiation and progression of thyroid tumors, providing new tools and opportunities for further investigation and for the clinical development of new treatment strategies.

Long Non-Coding RNA GAS5 Promotes BAX Expression by Competing with microRNA-128-3p in Response to 5-Fluorouracil

The acquisition of drug resistance is a major hurdle for effective cancer treatment. Although several efforts have been made to overcome drug resistance, the underlying mechanisms have not been fully elucidated. This study investigated the role of long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5) in drug resistance. GAS5 was found to be downregulated in colon cancer cell lines that are resistant to 5-fluorouracil (5-FU). Downregulation of GAS5 decreased the viability of HCT116 cells and the level of the pro-apoptotic BAX protein, while GAS5 overexpression promoted cell death in response to 5-FU. The interaction between GAS5 and BAX mRNA was investigated using MS2-tagged RNA affinity purification (MS2-trap) followed by RT-qPCR, and the results showed that GAS5 bound to the 3'-untranslated region of BAX mRNA and enhanced its expression by interfering with the inhibitory effect of microRNA-128-3p, a negative regulator of BAX. In addition, ectopic expression of GAS5 increased the sensitivity of resistant cells in response to anti-cancer drugs. These results suggest that GAS5 promoted cell death by interfering with miR-128-3p-mediated BAX downregulation. Therefore, GAS5 overexpression in chemo-resistant cancer cells may be a potential strategy to improve the anti-cancer efficacy of drugs.

Small nucleolar RNAs and SNHGs in the intestinal mucosal barrier: Emerging insights and current roles

BACKGROUND

Previous studies have focused on the involvement of small nucleolar RNAs (snoRNAs) and SNHGs in tumor cell proliferation, apoptosis, invasion, and metastasis via multiple pathways, including phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT), Wnt/β catenin, and mitogen-activated protein kinase (MAPK). These molecular mechanisms affect the integrity of the intestinal mucosal barrier.

AIM OF REVIEW

Current evidence regarding snoRNAs and SNHGs in the context of the mucosal barrier and modulation of homeostasis is fragmented. In this review, we collate the established information on snoRNAs and SNHGs as well as discuss the major pathways affecting the mucosal barrier.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Intestinal mucosal immunity, microflora, and the physical barrier are altered in non-neoplastic diseases such as inflammatory bowel diseases. Dysregulated snoRNAs and SNHGs may impact the intestinal mucosal barrier to promote the pathogenesis and progression of multiple diseases. SnoRNAs or SNHGs has been shown to be associated with poor disease behaviors, indicating that they may be exploited as prognostic biomarkers. Additionally, clarifying the complicated interactions between snoRNAs or SNHGs and the mucosal barrier may provide novel insights for the therapeutic treatment targeting strengthen the intestinal mucosal barrier.

Tumor Suppressive Effects of GAS5 in Cancer Cells

In recent years, long non-coding RNAs (lncRNAs) have been shown to play important regulatory roles in cellular processes. Growth arrests specific transcript 5 (GAS5) is a lncRNA that is highly expressed during the cell cycle arrest phase but is downregulated in actively growing cells. Growth arrests specific transcript 5 was discovered to be downregulated in several cancers, primarily solid tumors, and it is known as a tumor suppressor gene that regulates cell proliferation, invasion, migration, and apoptosis via multiple molecular mechanisms. Furthermore, GAS5 polymorphism was found to affect GAS5 expression and functionality in a cell-specific manner. This review article focuses on GAS5’s tumor-suppressive effects in regulating oncogenic signaling pathways, cell cycle, apoptosis, tumor-associated genes, and treatment-resistant cells. We also discussed genetic polymorphisms of GAS5 and their association with cancer susceptibility.

Identification of Exosomal microRNAs and Their Targets in Papillary Thyroid Cancer Cells

The release of molecules in exosomal cargoes is involved in tumor development and progression. We compared the profiles of exosomal microRNAs released by two thyroid cancer cell lines (TPC-1 and K1) with that of non-tumorigenic thyroid cells (Nthy-ori-3-1), and we explored the network of miRNA–target interaction. After extraction and characterization of exosomes, expression levels of microRNAs were investigated using custom TaqMan Advanced array cards, and compared with those expressed in the total cell extracts. The functional enrichment and network-based analysis of the miRNAs’ targets was also performed. Five microRNAs (miR-21-5p, miR-31-5p, miR-221-3p, miR-222-3p, and let-7i-3p) were significantly deregulated in the exosomes of tumor cells vs. non-tumorigenic cells, and three of them (miR-31-5p, miR-222-3p, and let-7i-3p) in the more aggressive K1 compared to TPC-1 cells. The network analysis of the five miRNAs identified some genes as targets of more than one miRNAs. These findings permitted the identification of exosomal microRNAs secreted by aggressive PTC cells, and indicated that their main targets are regulators of the tumor microenvironment. A deeper analysis of the functional role of the targets of exosomal miRNAs will provide further information on novel targets of molecular treatments for these neoplasms.

LncRNA CALML3-AS1 suppresses papillary thyroid cancer progression via sponging miR-20a-5p/RBM38 axis

Background

The incidence and mortality of thyroid cancer (TC) has been steadily rising in the past decades. It is imperative to have a better understanding of the molecular mechanisms underlying TC development and identify novel therapeutic targets. This study characterized the role of lncRNA CALML3-AS1 (CALML3-AS1) in the development of papillary thyroid cancer (PTC).

Method

Related mRNAs expression were validated in the tumor and adjacent normal tissues from 52 PTC patients and PTC cell lines by qRT-PCR. Expression of RBM38 was detected by Western blot. We have also conducted CCK-8 and colony formation assays were used to detect the effect of CALML3-AS1 on cell proliferation, Transwell assay was utilized to evaluate cell migration and invasion, apoptosis detected by flow cytometry assay, RNA pull-down and luciferase assays were performed to validate gene predictions.

Results

The results indicated that the expression of both CALML3A-S1 and RBM38 were significantly downregulated in PTC tissues (p < 0.01), while the expression of miR-20a-5p was increased in PTC (p < 0.01). Functionally, CALML3-AS1 overexpression inhibited PTC cell proliferation in vitro and in vivo. Mechanistically, CALML 3-AS1 sponged miR-20a-5p, which in turn leads to the suppression of RBM38 expression and PTC progression.

Conclusions

CALML3-AS1 functions as a ceRNA for miR-20a-5p in the regulation of the expression of RBM38 in PTC. Higher level of CALML3-AS1 serves as a good prognostic indicator of survival in PTC patients. Targeting CALML3-AS1/ miR-20a-5p/RBM38 axis may represent a novel therapeutic strategy in the treatment of PTC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09360-3.

lnc‑MICAL2‑1 sponges miR‑25 to regulate DKK3 expression and inhibits activation of the Wnt/β‑catenin signaling pathway in breast cancer

The Dickkopf 3 (DKK3) protein antagonizes the Wnt receptor complex in the Wnt signaling pathway; however, to date, there have been no relevant studies investigating its upstream regulatory mechanism in breast cancer (BC), to the best of our knowledge. The present study aimed to explore whether long non‑coding RNA MICAL2‑1 (lnc‑MICAL2‑1) sponged microRNA (miR)‑25 to regulate DKK3 and inhibit activation of the Wnt/β‑catenin signaling pathway. The Atlas of non‑coding RNA in Cancer database was used to measure the expression levels of lnc‑MICAL2‑1 and their correlation with DKK3 expression levels. In addition, cell proliferation, invasion and migration were determined following the silencing or overexpression of lnc‑MICAL2‑1. The binding between lnc‑MICAL2‑1 and miR‑25, or miR‑25 and DKK3 was verified using RNA pull‑down and dual‑luciferase reporter assays. The effects of overexpression or knockdown of lnc‑MICAL2‑1 on DKK3 expression and the Wnt signaling pathway were further evaluated in a nude mouse xenograft model. The results revealed that, compared with in adjacent normal tissue, the expression levels of lnc‑MICAL2‑1 were downregulated in BC tissues, and the expression levels of lnc‑MICAL2‑1 were found to be positively correlated with DKK3 expression. The overexpression of lnc‑MICAL2‑1 in BC cells upregulated the mRNA expression levels of DKK3 and inhibited their proliferation. Results from the RNA pull‑down and dual luciferase reporter assays validated that lnc‑MICAL2‑1 could bind to miR‑25, which targets DKK3. The in vivo experimental data demonstrated that lnc‑MICAL2‑1 inhibited tumor growth via regulating the Wnt signaling pathway. In conclusion, the findings of the present study highlighted a novel molecular mechanism through which lnc‑MICAL2‑1 may regulate the DKK3‑mediated Wnt signaling pathway in BC, highlighting potential targets for the treatment of the disease.

lncRNA GAS5 Sensitizes Breast Cancer Cells to Ionizing Radiation by Inhibiting DNA Repair

Radioresistance of breast cancer is a major reason for therapeutic failure and limits further increases in the dose of radiation due to severe adverse effects. Recently, long noncoding RNAs (lncRNAs) have been shown to regulate cancer proliferation, chemoresistance, and radioresistance. Among these lncRNAs, lncRNA GAS5 expression was shown to be downregulated in breast cancer and related to trastuzumab resistance. However, its role in the radiation response is unclear. In this study, we demonstrated that lncRNA GAS5 expression was reduced in irradiated cells and that overexpression of GAS5 reduced cell viability and promoted cell apoptosis after irradiation. Moreover, overexpression of GAS5 resulted in increased G2/M arrest and unrepaired DNA damage, indicating a radiosensitizing role of GAS5 in breast cancer cells. Finally, we found that a GAS5-interacting miRNA, miR-21, reversed the radiosensitizing effects of GAS5 by inhibiting the apoptotic pathway. In conclusion, we found that lncRNA GAS5 sensitized breast cancer cells to ionizing radiation by inhibiting DNA repair and suppressing miR-21, identifying novel targets for breast cancer radiosensitization.

Expression Profiles of Long Non-Coding RNA GAS5 and MicroRNA-222 in Younger AML Patients

Acute myeloid leukemia (AML) is a heterogeneous malignant disease both on clinical and genetic levels. AML has poor prognosis and, therefore, there is a constant need to find new prognostic markers, as well as markers that can be used as targets for innovative therapeutics. Recently, the search for new biomarkers has turned researchers’ attention towards non-coding RNAs, especially long non-coding RNAs (lncRNAs) and micro RNAs (miRNAs). We investigated the expression level of growth arrest-specific transcript 5 (GAS5) lncRNA in 94 younger AML patients, and also the expression level of miR-222 in a cohort of 39 AML patients with normal karyotype (AML-NK), in order to examine their prognostic potential. Our results showed that GAS5 expression level in AML patients was lower compared to healthy controls. Lower GAS5 expression on diagnosis was related to an adverse prognosis. In the AML-NK group patients had higher expression of miR-222 compared to healthy controls. A synergistic effect of GAS5^low/miR-222^high status on disease prognosis was not established. This is the first study focused on examining the GAS5 and miR-222 expression pattern in AML patients. Its initial findings indicate the need for further investigation of these two non-coding RNAs, their potential roles in leukemogenesis, and the prognosis of AML patients.

RHO GTPase-Related Long Noncoding RNAs in Human Cancers

RHO GTPases are critical signal transducers that regulate cell adhesion, polarity, and migration through multiple signaling pathways. While all these cellular processes are crucial for the maintenance of normal cell homeostasis, disturbances in RHO GTPase-associated signaling pathways contribute to different human diseases, including many malignancies. Several members of the RHO GTPase family are frequently upregulated in human tumors. Abnormal gene regulation confirms the pivotal role of lncRNAs as critical gene regulators, and thus, they could potentially act as oncogenes or tumor suppressors. lncRNAs most likely act as sponges for miRNAs, which are known to be dysregulated in various cancers. In this regard, the significant role of miRNAs targeting RHO GTPases supports the view that the aberrant expression of lncRNAs may reciprocally change the intensity of RHO GTPase-associated signaling pathways. In this review article, we summarize recent advances in lncRNA research, with a specific focus on their sponge effects on RHO GTPase-targeting miRNAs to crucially mediate gene expression in different cancer cell types and tissues. We will focus in particular on five members of the RHO GTPase family, including RHOA, RHOB, RHOC, RAC1, and CDC42, to illustrate the role of lncRNAs in cancer progression. A deeper understanding of the widespread dysregulation of lncRNAs is of fundamental importance for confirmation of their contribution to RHO GTPase-dependent carcinogenesis.

Long noncoding RNA GAS5 in age-related diseases

Aging refers to a natural process and a universal phenomenon in all cells, tissues, organs and the whole organism. Long non-coding RNAs (lncRNAs) are non-coding RNAs with the length of 200 nucleotides. LncRNA growth arrest-specific 5 (lncRNA GAS5) is often down-regulated in cancer. The accumulation of lncRNA GAS5 has been found to be able to inhibit cancer growth, invasion and metastasis, while enhancing the sensitivity of cells to chemotherapy drugs. LncRNA GAS5 can be a signaling protein, which is specifically transcribed under different triggering conditions. Subsequently, it is involved in signal transmission in numerous pathways as a signal node. LncRNA GAS5, with a close relationship to multiple miRNAs, was suggested to be involved in the signaling pathway under three action modes (i.e., signal, bait and guidance). LncRNA GAS5 was found to be involved in different age-related diseases (e.g., rheumatoid arthritis, type 2 diabetes, atherosclerosis, osteoarthritis, osteoporosis, multiple sclerosis, cancer etc.). This study mainly summarized the regulatory effect exerted by lncRNA GAS5 on age-related diseases.

A novel lncRNA-protein interaction prediction method based on deep forest with cascade forest structure

Long noncoding RNAs (lncRNAs) regulate many biological processes by interacting with corresponding RNA-binding proteins. The identification of lncRNA-protein Interactions (LPIs) is significantly important to well characterize the biological functions and mechanisms of lncRNAs. Existing computational methods have been effectively applied to LPI prediction. However, the majority of them were evaluated only on one LPI dataset, thereby resulting in prediction bias. More importantly, part of models did not discover possible LPIs for new lncRNAs (or proteins). In addition, the prediction performance remains limited. To solve with the above problems, in this study, we develop a Deep Forest-based LPI prediction method (LPIDF). First, five LPI datasets are obtained and the corresponding sequence information of lncRNAs and proteins are collected. Second, features of lncRNAs and proteins are constructed based on four-nucleotide composition and BioSeq2vec with encoder-decoder structure, respectively. Finally, a deep forest model with cascade forest structure is developed to find new LPIs. We compare LPIDF with four classical association prediction models based on three fivefold cross validations on lncRNAs, proteins, and LPIs. LPIDF obtains better average AUCs of 0.9012, 0.6937 and 0.9457, and the best average AUPRs of 0.9022, 0.6860, and 0.9382, respectively, for the three CVs, significantly outperforming other methods. The results show that the lncRNA FTX may interact with the protein P35637 and needs further validation.

SNHG9 promotes Hepatoblastoma Tumorigenesis via miR-23a-5p/Wnt3a Axis

Background: Hepatoblastoma is a common hepatic tumor occurring in children between 0-5 years. Accumulating studies have shown lncRNA's potential role in distinct cancer progression and development, including hepatoblastoma. SnoRNA host gene 9 (SNHG9) is associated with the progression of distinct human cancers, but, its specific molecular mechanisms in hepatoblastoma is not unknown.

Methods: In this study, we estimated SNHG9 expression in hepatoblastoma tissue and cell lines by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Next, we downregulated and upregulated SNHG9 expression in hepatoblastoma cell lines and then determined cell proliferation (CCK-8), colony formation, and cellular apoptosis activity. The dual luciferase reporter activity, RNA immunoprecipitation (RIP), biotin RNA pull down and Spemann's Pearson correlation coefficient assay were performed to establish the interaction between SNHG9, WNt3a and miR- 23a-5p. A xenograft in-vivo tumorgenicity test was performed to elucidate the role of SNHG9 hepatoblastoma in tumorigenesis. SNHG9 role in Cisplatin drug resistance in hepatoblastoma was also determined.

Results: SNHG9 was significantly upregulated in hepatoblastoma tissue and cell lines. SNHG9 overexpression on HUH6 & HepG2 resulted in a significant increase in cell proliferation and clonogenic activity while SNHG9 knock down resulted in a sustained inhibition of cell proliferation and clonogenic activity. Dual luciferase activity, RNA immunoprecipitation and biotin pull down confirmed the direct interaction of miR-23a-5p with SNHG9. The xenograft tumorgenicity test showed SNHG9 downregulation significantly inhibited the tumor growth in BALB/c mice. ROC and Kaplan-Meier analysis showed potential prognostic and diagnostic importance of SNHG9 in hepatoblastoma.

Conclusion: We concluded that SNHG9/miR-23a-5p/Wnt3a axis promotes the progression hepatoblastoma tumor.

The Emerging Landscapes of Long Noncoding RNA in Thyroid Carcinoma: Biological Functions and Clinical Significance

Thyroid carcinoma (TC) is one of the most prevalent primary endocrine tumors, and its incidence is steadily and gradually increasing worldwide. Accumulating evidence has revealed the critical functions of long noncoding RNAs (lncRNAs) in the tumorigenesis and development of TC. Many TC-associated lncRNAs have been documented to be implicated in TC malignant behaviors, including abnormal cell proliferation, enhanced stem cell properties and aggressiveness, and resistance to therapeutics, through interaction with proteins, DNA, or RNA or encoding small peptides. Therefore, further elucidating the lncRNA dysregulation sheds additional insights into TC tumorigenesis and progression and opens new avenues for the early diagnosis and clinical therapy of TC. In this review, we summarize the abnormal expression of lncRNA in TC and the fundamental characteristics in TC tumorigenesis and development. Additionally, we introduce the potential prognostic and therapeutic significance of lncRNAs in TC.

ETS like-1 protein ELK1-induced lncRNA LINC01638 accelerates the progression of papillary thyroid cancer by regulating Axin2 through Wnt/β-catenin signaling pathway

Papillary thyroid carcinoma (PTC) characterized by distant metastasis is a major public health issue among women worldwide. LncRNA LINC01638 is reportedly a critical oncogene in the development of certain cancers. However, the biological function of LINC01638 in PTC is currently unclear. The goal of this study was to identify LINC01638 expression level and its role in PTC progression. The expression of LINC01638 was detected applying qRT-PCR. CCK-8 assay, colony formation assay, immunofluorescence staining and flow cytometric analysis were performed to assess cell proliferation and cell cycle. In addition, cell migration and invasion were examined via wound healing assay, transwell assay and western blot analysis. We found that LINC0163 was upregulated in PTC cells compared with normal thyroid gland epithelial cell line Nthy-ori3-1. ELK1 could act as a transcription factor of LINC01638 and induce LINC01638 expression. LINC01638 silencing inhibited cell proliferation, migration and invasion, and obstructed the progress of TPC-1 cell cycle. LINC0163 silencing activated Axin2 while suppressing the expressions of β-catenin, Cyclin-D1 and c-MYC. Rescue experiment utilizing the transfection of Axin2 overexpression plasmid weakened LINC01638 overexpression-enhanced TPC-1 cell proliferation, metastasis, cell cycle progress and Wnt/β-catenin pathway. These results indicate that LINC0163 regulates PTC progression via inhibition of Wnt/β-catenin and activation of Axin2, which may develop into a novel therapeutic strategy for PTC treatment.

Long noncoding RNA ILF3-AS1 aggravates papillary thyroid carcinoma progression via regulating the miR-4306/PLAGL2 axis

BACKGROUND

It have been proven that long non-coding RNAs (lncRNAs) serve as regulators in carcinogenesis. Interleukin enhancer binding factor 3 antisense RNA 1 (ILF3-AS1) has been illuminated as a prognostic factor in some cancers. Nevertheless, its expression pattern and possible functions in papillary thyroid carcinoma (PTC) have not been studied.

METHODS

The expression of ILF3-AS1 was measured by RT-qPCR and ISH. Colony formation assay and EdU assay were used to probe cell proliferation. TUNEL assay was used for analysis of cell apoptosis. Immunofluorescence and western blot were conducted to evaluate the expression change of E-cadherin and N-cadherin. The RNA interaction was demonstrated by mechanism experiments, including pull down assay and dual luciferase reporter assay.

RESULTS

ILF3-AS1 expression was evidently upregulated in PTC cell lines. ILF3-AS1 knockdown restrained the proliferation, migration and invasion of PTC cells. Mechanical investigation revealed that miR-4306 could interact with ILF3-AS1. PLAGL2 was a downstream target of miR-4306. The effects of ILF3-AS1 knockdown on the cellular processes were abrogated by miR-4306 downregulation or pleiomorphic adenoma gene-like 2 (PLAGL2) overexpression.

CONCLUSION

ILF3-AS1 plays tumor-promoting role in PTC via targeting miR-4306/PLAGL2 axis.

METTL14 promotes tumorigenesis by regulating lncRNA OIP5-AS1/miR-98/ADAMTS8 signaling in papillary thyroid cancer

Background

Papillary thyroid cancer (PTC) is the most common type of cancer of the endocrine system. Long noncoding RNAs (lncRNAs) are emerging as a novel class of gene expression regulators associated with tumorigenesis. Through preexisting databases available for differentially expressed lncRNAs in PTC, we uncovered that lncRNA OIP5-AS1 was significantly upregulated in PTC tissues. However, the function and the underlying mechanism of OIP5-AS1 in PTC are poorly understood.

Methods

Expression of lncRNA OIP5-AS1 and miR-98 in PTC tissue and cells were measured by quantitative real-time PCR (qRT-PCR). And expression of METTL14 and ADAMTS8 in PTC tissue and cells were measured by qRT-PCR and western blot. The biological functions of METTL14, OIP5-AS1, and ADAMTS8 were examined using MTT, colony formation, transwell, and wound healing assays in PTC cells. The relationship between METTL14 and OIP5-AS1 were evaluated using RNA immunoprecipitation (RIP) and RNA pull down assay. And the relationship between miR-98 and ADAMTS8 were examined by luciferase reporter assay. For in vivo experiments, a xenograft model was used to investigate the effects of OIP5-AS1 and ADAMTS8 in PTC.

Results

Functional validation revealed that OIP5-AS1 overexpression promotes PTC cell proliferation, migration/invasion in vitro and in vivo, while OIP5-AS1 knockdown shows an opposite effect. Mechanistically, OIP5-AS1 acts as a target of miR-98, which activates ADAMTS8. OIP5-AS1 promotes PTC cell progression through miR-98/ADAMTS8 and EGFR, MEK/ERK pathways. Furthermore, RIP and RNA pull down assays identified OIP5-AS1 as the downstream target of METTL14. Overexpression of METTL14 suppresses PTC cell proliferation and migration/invasion through inhibiting OIP5-AS1 expression and regulating EGFR, MEK/ERK pathways.

Conclusions

Collectively, our findings demonstrate that OIP5-AS1 is a METTL14-regulated lncRNA that plays an important role in PTC progression and offers new insights into the regulatory mechanisms underlying PTC development.

LncRNA ST8SIA6-AS1 Promotes Cholangiocarcinoma Progression by Suppressing the miR-145-5p/MAL2 Axis

BACKGROUND

The tumor-promoting roles of ST8SIA6-AS1 and miR-145-5p have been found in several cancers, but their function in cholangiocarcinoma (CHOL) remains speculative. The purpose of this study was to examine the regulatory functions of the ST8SIA6-AS1/MAL2/miR-145-5p pathway in CHOL progression.

METHODS

RT-qPCR assay was used to detect ST8SIA6-AS1 expression in CHOL tissues and cell lines. Cell migration, apoptosis, invasion, and proliferation abilities were assessed by RIP, RNA pull-down, and luciferase assays. CCK-8, BrdU, transwell, and FITC assays to investigate the regulatory functions of ST8SIA6-AS1, miR-145-5p, and MAL2 function in CHOL cells.

RESULTS

Findings revealed the enrichment of ST8SIA6-AS1 in CHOL tissues and cell lines. It was also found that ST8SIA6-AS1 facilitated cell growth and migration, but it reduced the apoptosis level of the CHOL cells. The results of experiments showed that ST8SIA6-AS1 sponged miR-145-5p, thereby allowing MAL2 to exert its biological function on CHOL cells.

CONCLUSION

This research suggested that the ST8SIA6-AS1/miR-145-5p/MAL2 axis could enhance CHOL progression, which might be useful to improve the clinical outcomes of CHOL patients.

Emerging roles and mechanisms of microRNA‑222‑3p in human cancer (Review)

MicroRNAs (miRNAs/miRs) are a class of small non‑coding RNAs that maintain the precise balance of various physiological processes through regulating the function of target mRNAs. Dysregulation of miRNAs is closely associated with various types of human cancer. miR‑222‑3p is considered a canonical factor affecting the expression and signal transduction of multiple genes involved in tumor occurrence and progression. miR‑222‑3p in human biofluids, such as urine and plasma, may be a potential biomarker for the early diagnosis of tumors. In addition, miR‑222‑3p acts as a prognostic factor for the survival of patients with cancer. The present review first summarizes and discusses the role of miR‑222‑3p as a biomarker for diverse types of cancers, and then focuses on its essential roles in tumorigenesis, progression, metastasis and chemoresistance. Finally, the current understanding of the regulatory mechanisms of miR‑222‑3p at the molecular level are summarized. Overall, the current evidence highlights the crucial role of miR‑222‑3p in cancer diagnosis, prognosis and treatment.

LncRNA LINC01503 aggravates the progression of cervical cancer through sponging miR-342-3p to mediate FXYD3 expression

Cervical cancer (CC), an aggressive malignancy, has a high risk of relapse and death, mainly occurring in females. Accumulating investigations have confirmed the critical role of long noncoding RNAs (lncRNAs) in diverse cancers. LncRNA LINC01503 has been reported as an oncogene in several cancers. Nonetheless, its role and molecular mechanism in CC have not been explored. In the present study, we found that FXYD3 expression was considerably up-regulated in CC tissues and cells. Moreover, FXYD3 deficiency conspicuously hampered cell proliferation and migration while facilitated cell apoptosis in CC cells. Subsequently, molecular mechanism experiments implied that FXYD3 was a downstream target gene of miR-342-3p, and FXYD3 expression was reversely mediated by miR-342-3p. Moreover, we discovered that LINC01503 acted as the endogenous sponge for miR-342-3p. Besides, LINC01503 negatively regulated miR-342-3p expression and positively regulated FXYD3 expression in CC. Rescue assays revealed that LINC01503 depletion-induced repression on CC progression could be partly recovered by miR-342-3p inhibition, and then the co-transfection of sh-FXYD3#1 rescued this effect. Conclusively, LINC01503 aggravated CC progression through sponging miR-342-3p to mediate FXYD3 expression, providing promising therapeutic targets for CC patients.

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.

Long Non-coding RNA GAS5 Regulates T Cell Functions via miR21-Mediated Signaling in People Living With HIV

T cells are critical for the control of viral infections and T cell responses are regulated by a dynamic network of non-coding RNAs, including microRNAs (miR) and long non-coding RNAs (lncRNA). Here we show that an activation-induced decline of lncRNA growth arrest-specific transcript 5 (GAS5) activates DNA damage response (DDR), and regulates cellular functions and apoptosis in CD4 T cells derived from people living with HIV (PLHIV) via upregulation of miR-21. Notably, GAS5-miR21-mediated DDR and T cell dysfunction are observed in PLHIV on antiretroviral therapy (ART), who often exhibit immune activation due to low-grade inflammation despite robust virologic control. We found that GAS5 negatively regulates miR-21 expression, which in turn controls critical signaling pathways involved in DNA damage and cellular response. The sustained stimulation of T cells decreased GAS5, increased miR-21 and, as a result, caused dysfunction and apoptosis in CD4 T cells. Importantly, this inflammation-driven T cell over-activation and aberrant apoptosis in ART-controlled PLHIV and healthy subjects (HS) could be reversed by antagonizing the GAS5-miR-21 axis. Also, mutation of the miR-21 binding site on exon 4 of GAS5 gene to generate a GAS5 mutant abolished its ability to regulate miR-21 expression as well as T cell activation and apoptosis markers compared to the wild-type GAS5 transcript. Our data suggest that GAS5 regulates TCR-mediated activation and apoptosis in CD4 T cells during HIV infection through miR-21-mediated signaling. However, GAS5 effects on T cell exhaustion during HIV infection may be mediated by a mechanism beyond the GAS5-miR-21-mediated signaling. These results indicate that targeting the GAS5-miR-21 axis may improve activity and longevity of CD4 T cells in ART-treated PLHIV. This approach may also be useful for targeting other infectious or inflammatory diseases associated with T cell over-activation, exhaustion, and premature immune aging.

LINC00893 inhibits papillary thyroid cancer by suppressing AKT pathway via stabilizing PTEN

Long non-coding RNAs (lncRNAs) are important to the occurrence and advancement of human cancers. We found through GEPIA that LINC00893 was lowly expressed in thyroid carcinoma (THCA) tissues, whereas the specific functions of LINC00893 has never been reported in PTC. In the current study, we confirmed that LINC00893 was expressed at a low level in PTC cells. Through gain-of-function assays, we determined that LINC00893 overexpression abrogated proliferation and migration abilities of PTC cells. Through signal transduction reporter array we found that LINC00893 potentially modulated the signals of phosphatase and tensin homolog (PTEN)/AKT pathway. In addition, overexpression of LINC00893 increased the expression of PTEN but reduced the levels of phosphorylated AKT in PTC. Additionally, mechanism assays unveiled that LINC00893 stabilized PTEN mRNA via recruiting Fused in sarcoma (FUS) protein. Finally, rescue assays demonstrated that LINC00893 hampered the proliferation and migration of PTC cells via PTEN/AKT pathway. Together, our study first clarified that LINC00893 functions as a tumor suppressor in PTC by blocking AKT pathway through PTEN upregulation.

LncRNAs and their regulatory networks in breast muscle tissue of Chinese Gushi chickens during late postnatal development

BACKGROUND

Chicken skeletal muscle is an important economic product. The late stages of chicken development constitute the main period that affects meat production. LncRNAs play important roles in controlling the epigenetic process of growth and development. However, studies on the role of lncRNAs in the late stages of chicken breast muscle development are still lacking. In this study, to investigate the expression characteristics of lncRNAs during chicken muscle development, 12 cDNA libraries were constructed from Gushi chicken breast muscle samples from 6-, 14-, 22-, and 30-week-old chickens.

RESULTS

A total of 1252 new lncRNAs and 1376 annotated lncRNAs were identified. Furthermore, 53, 61, 50, 153, 117, and 78 DE-lncRNAs were found in the W14 vs. W6, W22 vs. W14, W22 vs. W6, W30 vs. W6, W30 vs. W14, and W30 vs. W22 comparison groups, respectively. After GO enrichment analysis of the DE-lncRNAs, several muscle development-related GO terms were found in the W22 vs. W14 comparison group. Moreover, it was found that the MAPK signaling pathway was one of the most frequently enriched pathways in the different comparison groups. In addition, 12 common target DE-miRNAs of DE-lncRNAs were found in different comparison groups, some of which were muscle-specific miRNAs, such as gga-miR-206, gga-miR-1a-3p, and miR-133a-3p. Interestingly, the precursors of four newly identified miRNAs were found to be homologous to lncRNAs. Additionally, we found some ceRNA networks associated with muscle development-related GO terms. For example, the ceRNA networks contained the DYNLL2 gene with 12 lncRNAs that targeted 2 miRNAs. We also constructed PPI networks, such as IGF-I-EGF and FZD6-WNT11.

CONCLUSIONS

This study revealed, for the first time, the dynamic changes in lncRNA expression in Gushi chicken breast muscle at different periods and revealed that the MAPK signaling pathway plays a vital role in muscle development. Furthermore, MEF2C and its target lncRNA may be involved in muscle regulation through the MAPK signaling pathway. This research provided valuable resources for elucidating posttranscriptional regulatory mechanisms to promote the development of chicken breast muscles after hatching.

Long Non-Coding RNA GAS5 Targeting microRNA-21 to Suppress the Invasion and Epithelial-Mesenchymal Transition of Uveal Melanoma

Objective

Human uveal melanoma (UM) is a common ocular malignant tumor with a high risk of metastasis. Emerging evidence indicates that long non-coding RNAs (lncRNAs) are correlated with the development of UM. Here, we aimed to determine the biological significance of lncRNA growth arrest-specific transcript 5 (GAS5) in UM.

Methods

The expression levels of GAS5 and microRNA-21 (miR-21) in UM tissues and cells were detected by qRT-PCR analysis. CCK-8 assay was performed to investigate the viability of UM cells after cell transfections, and the migration and invasion of UM cells were determined by transwell assay. The protein expression levels were detected by Western blot assay. The relationship between miR-21 and GAS5 in UM cells was confirmed by bioinformatics prediction and luciferase report assay.

Results

Our experiments demonstrated that GAS5 was markedly downregulated in UM cells and clinical specimens. Overexpression of GAS5 inhibited, whereas knockdown of GAS5 promoted the viability, migration, and invasion of UM cells. The epithelial-to-mesenchymal transition (EMT) process of UM cells was also suppressed by upregulating of GAS5 and enhanced by downregulating of GAS5. Additionally, as a competitive endogenous RNA (ceRNA), GAS5 directly binded to the oncogenic miR-21 in UM cells, and overexpression of miR-21 attenuated the EMT-suppressing effect of GAS5.

Conclusion

Taken together, our findings suggest that GAS5/miR-21 axis is implicated in the pathogenesis of UM and might serve as a potential therapeutic target.

Long non-coding RNA GAS5 overexpression inhibits M2-like polarization of tumour-associated macrophages in SMCC-7721 cells by promoting PTEN expression

Tumour-associated macrophage (TAM) polarization is associated with hepatocellular carcinoma but the molecular mechanism of this polarization is still unknown. Peripheral blood mononuclear cells were induced to differentiate into M0, M1 and M2 macrophages and TAMs. TAMs were transfected with pcDNA3.1-GAS5, pcDNA3.1-NC, si-GAS5, si-PTEN or si-Ctrl. A human liver cancer cell line (SMCC-7721) was incubated with the modified TAM supernatant. Quantitative real-time PCR and Western blot were performed to detect gene and protein expression. The cell proliferation and invasion properties of the SMCC-7721 cells were detected by MTT and Transwell assays. GAS5 is up-regulated in M1 macrophages and down-regulated in M2 macrophages and TAMs. GAS5 overexpression promoted M1-like polarization of TAMs and inhibited M2-like polarization of TAMs. Moreover, GAS5 promoted the expression of PTEN in TAMs. PTEN-silenced TAM supernatant treatment promoted cell proliferative and invasive properties of the SMCC-7721 cells and diminished the effect of GAS5-overexpressed TAM supernatant on the cell proliferation and invasion by SMCC-7721 cells. Our results demostrared that GAS5 overexpression inhibited M2-like polarization of TAMs by enhancing PTEN expression, thereby inhibiting cell proliferation and invasion by SMCC-7721 cells. Thus, our results suggest that GAS5 may be a new therapeutic target for HCC treatment.

NORAD, a critical long non-coding RNA in human cancers

The ^incidence of cancer is growing worldwide, and it is becoming the most common cause of death. Long non-coding RNAs (lncRNAs) are a group of RNA transcripts with a length larger than 200 nucleotides that cannot encode proteins or peptides. LncRNAs regulate different biological functions by controlling gene expressions at transcriptional, translational, and post-translational levels. Non-coding RNA activated by DNA damage (NORAD) is a highly conserved lncRNA necessary for genome stability. LncRNA NORAD is dysregulated in various types of cancers. This biomarker has been involved in numerous processes associated with carcinogeneses, such as cell proliferation, apoptosis, invasion, and metastasis. In this paper, we reviewed the role of lncRNA NORAD and its biological functions in various human cancers to provide future research insights.

New Insights into Mechanisms of Endocrine-Disrupting Chemicals in Thyroid Diseases: The Epigenetic Way

In recent years, the presence in the environment of chemical compounds with thyroid-disrupting effects is progressively increased. This phenomenon has risen concern for human health as the preservation of thyroid system homeostasis is essential for fetal development and for maintaining psychological and physiological wellbeing. An increasing number of studies explored the role of different classes of toxicants in the occurrence and severity of thyroid diseases, but large epidemiological studies are limited and only a few animal or in vitro studies have attempted to identify the mechanisms of chemical action. Recently, epigenetic changes such as alteration of methylation status or modification of non-coding RNAs have been suggested as correlated to possible deleterious effects leading to different thyroid disorders in susceptible individuals. This review aims to analyze the epigenetic alterations putatively induced by chemical exposures and involved in the onset of frequent thyroid diseases such as thyroid cancer, autoimmune thyroiditis and disruption of fetal thyroid homeostasis.

LncRNA growth arrest-special 5 polymorphisms and predisposition to cancer: A meta-analysis

AIM

The lncRNA growth arrest-special 5 (GAS5) is a critical tumor suppressor lncRNA, and its expression level has been found to be decreased in many types of cancers. So GAS5 polymorphisms are also likely to influence predisposition to many types of malignant diseases. Nevertheless, the relationships between GAS5 polymorphisms and cancer are still controversial. Thus, the authors designed this meta-analysis to get a more statistically reliable conclusion.

METHODS

The authors searched PubMed, Embase, and Web of Science for eligible studies. A total of 12 eligible studies involving 8693 cancer cases and 10,805 controls were pooled and analyzed in this meta-analysis.

RESULTS

Among GAS5 polymorphisms, only GAS5 rs145204276 insertion/deletion polymorphism could be analyzed in a meta-analysis with regard to predisposition to cancer since no any other GAS5 polymorphisms were explored by at least two individual genetic association studies. All eligible studies were found to be of Asian origin. Although the overall pooled meta-analysis results did not show any significant associations between rs145204276 insertion/deletion polymorphism and a predisposition to cancer, rs145204276 insertion/deletion polymorphism was demonstrated to be significantly associated with a predisposition to gastric cancer (dominant comparison: P<0.0001; recessive comparison: P=0.005; over-dominant comparison: P=0.0003; over-dominant comparison: P<0.0001) in Asians in further subgroup analyses.

CONCLUSIONS

This meta-analysis demonstrated that GAS5 rs145204276 insertion/deletion polymorphism was associated with a predisposition to gastric cancer in Asians. Nevertheless, considering that this positive finding was only based on three eligible studies from the same area, future studies with larger sample sizes in other populations are still warranted to test the robustness of our findings.

The interaction mechanism between autophagy and apoptosis in colon cancer

Autophagy and apoptosis play crucial roles in tumorigenesis. Recent studies have shown that autophagy and apoptosis have a cross-talk relationship in anti-tumor therapy. It is well established that apoptosis is one of the main pathways of tumor cell death. While autophagy can occurs in tumors with opposite function: protective autophagy and lethal autophagy. Protective autophagy can inhibit tumor apoptosis induced by anticancer drugs, while lethal autophagy can induce tumor cell apoptosis in cooperation with anticancer drugs. Hence, autophagy and apoptosis have synergistic and antagonistic effects in tumor. Colorectal cancer is a common malignant tumor with high morbidity and mortality. In recent years, colorectal carcinoma has achieved improved clinical efficacy with drug treatment. Nonetheless, increasing drug-resistance limit the treatment efficacy, highlighting the urgency of exploring the molecular events that drive drug resistance. Researchers have found that autophagy is one of the major factors leading to drug resistance in colon cancer. Therefore, elucidating the interaction between autophagy and apoptosis is helpful to improve the efficacy of anticancer drugs in clinical treatment of colorectal cancer. This review attaches great importance to the relationship between autophagy and apoptosis and related factors in colorectal cancer.

Identification of 12 immune-related lncRNAs and molecular subtypes for the clear cell renal cell carcinoma based on RNA sequencing data

Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cell carcinoma (RCC). Despite the existing extensive research, the molecular and pathogenic mechanisms of ccRCC are elusive. We aimed to identify the immune-related lncRNA signature and molecular subtypes associated with ccRCC. By integrating 4 microarray datasets from Gene Expression Omnibus database, we identified 49 immune-related genes. The corresponding immune-related lncRNAs were further identified in the TCGA dataset. 12-lncRNAs prognostic and independent signature was identified through survival analysis and survival difference between risk groups was further identified based on the risk score. Besides, we identified 3 molecular subtypes and survival analysis result showed that cluster 2 has a better survival outcome. Further, ssGSEA enrichment analysis for the immune-associated gene sets revealed that cluster 1 corresponded to a high immune infiltration level. While cluster 2 and cluster 3 corresponded to low and medium immune infiltration level, respectively. In addition, we validated the 12-lncRNA prognostic signature and molecular subtypes in an external validation dataset from the ICGC database. In summary, we identified a 12-lncRNA prognostic signature which may provide new insights into the molecular mechanisms of ccRCC and the molecular subtypes provided a theoretical basis for personalized treatment by clinicians.

GAS5‑mediated regulation of cell signaling (Review)

In recent years, an increasing number of long non-coding RNAs (lncRNAs) have been discovered using microarrays and nucleic acid sequencing technology. LncRNAs exert crucial biological functions by regulating signaling pathways. In particular, the lncRNA growth arrest-specific transcript 5 (GAS5) has been documented to serve a crucial role in numerous signaling pathways. This article discusses the latest developments in the association between GAS5 and microRNA (miRNA), p53, mTOR, glucocorticoid response element (GRE) and AKT in order to investigate the roles served by GAS5. miRNAs can activate related signaling pathways and GAS5 can combine with miRNA to regulate related signaling pathways. GAS5 may regulate p53 expression via derivation of snoRNA, but the underlying mechanism requires further investigation. GAS5 overxpresion reduces the expression level of mTOR, which is induced by inhibiting miR-106a-5p expression. GAS5 is a sponge of GR, and serves a role in controlling and maintaining glucocorticoid sensitivity and drug resistance via competitive combination with GR. GAS5 can interact with miRNAs, such as miR-21 and miR-532-5p, to regulate the expression of AKT signaling pathway, affecting cell survival and apoptosis. Collectively, the data indicate that GAS5 serves a key role in the miRNA, p53, mTOR, GRE, and AKT signaling pathways. GAS5 regulates complex intracellular signaling pathways primarily through three modes of action, all of which are interrelated: Signal, decoy and guide. In the present article, latest developments in the association between GAS5 and a number of cellular signaling pathways are discussed to examine the tumor suppressive role of GAS5.

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.

Long non-coding RNA GAS5 in human cancer

Long non-coding RNAs (lncRNAs) constitute a group of >200-nucleotide ncRNA molecules. lncRNAs regulate several cell functions, such as proliferation, apoptosis, invasion and metastasis. Meanwhile, lncRNAs are abnormally expressed in human malignancies, where they suppress or promote tumor growth. The present study focused on growth arrest-specific transcript 5 (GAS5), a well-known lncRNA that acts as a tumor suppressor but is suppressed in multiple types of cancer, including mammary carcinoma, prostate cancer, colorectal cancer, gastric cancer, melanoma, esophageal squamous cell carcinoma, lung cancer, ovarian cancer, cervical cancer, gliomas, osteosarcoma, pancreatic cancer, bladder cancer, kidney cancer, papillary thyroid carcinoma, neuroblastoma, endometrial cancer and liver cancer. Notably, GAS5 is overexpressed in liver cancer, potentially functioning as an oncogene. In the present study, the diagnostic and therapeutic roles of GAS5 in different tumors were reviewed, with a summary of the potential clinical application of the lncRNA, which may help identify novel study directions for GAS5.

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.

The Complex Landscape of PTEN mRNA Regulation

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a key tumor suppressor in the development and progression of different tumor types. Emerging data indicate that small reductions in PTEN protein levels can promote cancer. PTEN protein levels are tightly controlled by a plethora of mechanisms beginning with epigenetic and transcriptional regulation and ending with control of protein synthesis and stability. PTEN messenger RNA (mRNA) is also subject to exquisite regulation by microRNAs, coding and long noncoding RNAs, and RNA-binding proteins. Additionally, PTEN mRNA is markedly influenced by alternative splicing and variable polyadenylation. Herein we provide a synoptic description of the current understanding of the complex regulatory landscape of PTEN mRNA regulation including several specific processes that modulate its stability and expression, in the context of PTEN loss-associated cancers.

Long non-coding RNA GAS5 regulates human B lymphocytic leukaemia tumourigenesis and metastasis by sponging miR-222

Accumulating evidence has shown that lncRNA GAS5 is a novel tumour-promoting RNA that contributes to tumour progression by sponging miRNAs. However, the detailed role of lncRNA GAS5 in B lymphocytic leukaemia is still unclear. A qRT-PCR assay was used to examine the levels of lncRNA GAS5 and miR-222 in leukomonocytes of patients with B lymphocytic leukaemia and in healthy donors. Raji cells were transfected with GAS5 overexpression or shRNA-GAS5 plasmids for 48⁢h, and cell proliferation was assessed by the CCK-8 assay, while apoptosis and cell cycle progression were assessed using flow cytometry. The Transwell assay was applied to detect the invasion of Raji cells with GAS5 overexpression or knockdown. The dual luciferase reporter assay and regression curve were conducted to evaluate the binding interaction between lncRNA GAS5 and miR-222. The results showed that the expression of lncRNA GAS5 was decreased in B lymphocytic leukaemia patients compared with the healthy group, and the levels of lncRNA GAS5 in B lymphocytic leukaemia cell lines were significantly higher than those in the normal B cell line, whereas the levels of miR-222 were increased in B lymphocytic leukaemia patients compared with the healthy group. Moreover, cell culture experiments indicated that lncRNA GAS5 overexpression decreased B lymphocytic leukaemia cell proliferation, promoted B lymphocytic leukaemia cell apoptosis, arrested B lymphocytic leukaemia cells in the G1 phase of the cell cycle, and inhibited B lymphocytic leukaemia cell invasion. Finally, the luciferase reporter assay showed a direct target interaction between lncRNA GAS5 and miR-222. The regression analysis showed a negative correlation between the levels of lncRNA GAS5 and miR-222. Thus, our data suggested that lncRNA GAS5 could effectively sponge miR-222 to modulate human B lymphocytic leukaemia cell tumourigenesis and metastasis. This work advances our understanding of the clinical significance of lncRNA GAS5 from the perspective of lncRNA-miRNA regulation.

LncRNA GAS5 promotes apoptosis as a competing endogenous RNA for miR-21 via thrombospondin 1 in ischemic AKI

Mounting evidence has indicated that long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) played important roles in renal ischemia/reperfusion (I/R) injury. However, the involvement of lncRNA growth arrest specific 5 (GAS5) in acute kidney injury (AKI) remained largely unexplored. This study aimed to determine possible mechanisms of GAS5 in the renal I/R process. We found that GAS5, noticeably upregulated by renal I/R injury, was further suppressed by delayed IPC while knockdown of miR-21 in vivo before IPC could significantly increased the GAS5 levels. Concurrently, TSP-1 was negatively regulated by miR-21 in vivo and vitro. Additionally, Reciprocal repression of GAS5 and miR-21 was identified. Knockdown of miR-21 in H6R0.5 treated HK-2 cells promoted apoptosis. Co-transfection of miR-21 mimic and pcDNA-GAS5 or pcDNA-Vector were performed, results of which showed that inhibition of miR-21 on TSP-1 could be rescued by overexpression of GAS5. This study suggested that GAS5 facilitated apoptosis by competitively sponging miR-21, which negatively regulated TSP-1 in renal I/R injury. This novel regulatory axis could act as a therapeutic target for AKI in the future.

LNCRNA Gas5 suppression protected Hl-1 cells against hypoxia injury by sponging Mir-222-3p

Hypoxia may cause diseases in human beings. The up- or down- regulation of lncRNAs were identified to possess the ability to protect the myocardial cells from hypoxia injury. This study explored the role of lncRNA GAS5 in sodium Hydrosulfite Induced Hl-1 Cells in vitro. RT-qPCR was applied to measure the expressions of RNAs whereas the cell viability was detected with CCK-8. Luciferase report assay was performed to validate the binding between lncRNA GAS5 and miR-222-3p. The proteins regarding PI3K/AKT signaling were evaluated through western blot analysis. The results showed that the hypoxia could reduce cell viabilities and enhance the apoptosis. Meanwhile, the PI3K/AKT signaling pathway was suppressed as well. lncRNA GAS5 got expressed higher in hypoxic cells whereas the suppressed GAS5 was able to increase cell viabilities while inhibiting apoptosis. MiR-222-3p was the target gene of lncRNA as determined by the luciferase report assay and its expressions were low in hypoxic cells. The overexpressed miR-222-3p could promote proliferation and inhibit apoptosis. Then, the correlation of GAS5 and miR-222-3p was measured which showed that miR-222-3p could resume the functions of GAS5 in cell viabilities and apoptosis through protein regulation in PI3K and AKT signaling pathways.

A comprehensive review of the role of long non-coding RNAs in organs with an endocrine function

Long non-coding RNAs (lncRNAs) are transcripts with sizes larger than 200 nucleotides and no/ small open reading frame that cannot produce functional proteins. The number of these transcripts surpasses the number of coding genes. LncRNAs regulate many aspects of cell functions such as proliferation, cell cycle transition and differentiation; so their dysregulation has pervasive effects on cell phenotype. Increasing numbers of these transcripts have been shown to participate in the pathogenesis of cancer. In the current review, we summarize recent findings regarding the role of lncRNAs in tumors originated from organs which have an endocrine function. We mostly focused on adrenal, pancreas and pituitary gland as prototypes of these organs. Moreover, we presented the obtained data of the role of lncRNAs in prostate, ovarian and testicular cancers. Recent data highly supports the role of lncRNAs in the pathogenesis of cancers originated from these organs. Moreover, certain genomic loci within lncRNAs have been shown to be associated with risk of these cancers. Diagnostic and prognostic role of some lncRNAs in these cancers have been evaluated recently. Taken together, lncRNAs are putative biomarkers for cancers originated from organs which have an endocrine function.

MiR-222-3p Promotes Cell Proliferation and Inhibits Apoptosis by Targeting PUMA (BBC3) in Non-Small Cell Lung Cancer

MicroRNAs have been demonstrated to be critical regulators in tumor progression, including non-small cell lung cancer. MicroRNA-222-3p has been reported to function as a tumor suppressor or oncogene in several types of cancer, but its function role in non-small cell lung cancer has not been uncovered. In this study, we first found the expression of microRNA-222-3p was significantly increased in non-small cell lung cancer tissues and cell lines. MicroRNA-222-3p inhibitor decreased the activity of non-small cell lung cancer cells to proliferate and increased cell apoptosis using cell counting kit-8, flow cytometry, and caspase-3 activity analysis. Overexpressed microRNA-222-3p in non-small cell lung cancer cells promoted cell proliferation, but decreased cell apoptosis. Moreover, Bcl-2-binding component 3 was the target gene of microRNA-222-3p, and its knockdown weakened the regulatory effect of microRNA-222-3p inhibitor on cell proliferation and apoptosis in non-small cell lung cancer cells. In conclusion, microRNA-222-3p plays a significant role in the regulation of Bcl-2-binding component 3 expression and might be a promising target for clinical non-small cell lung cancer therapy.

Exosomes-Derived Long Non-Coding RNA HOTAIR Reduces Laryngeal Cancer Radiosensitivity by Regulating microRNA-454-3p/E2F2 Axis

Background

Studies have revealed exosomes are implicated in tumor microenvironment and tumorigenesis. Emerging evidence suggests long non-coding RNAs (lncRNAs) possess pivotal roles in laryngeal cancer progression. For this study, we aimed to find out the mechanism of exosomes and lncRNA HOTAIR in laryngeal cancer.

Methods

Laryngeal cancer cells-derived exosomes were initially extracted, separated and identified. Flow cytometry was applied to detect apoptosis to evaluate the effect of exosomes on cell radiosensitivity. Dual luciferase reporter gene assay, RNA pull-down and RNA immunoprecipitation assays were conducted to verify the interactions among HOTAIR, microRNA (miR)-454-3p and E2F2. The gain-and-loss functions of HOTAIR or miR-454-3p were carried out to explore their effects on TU212 and LLN cell viability, apoptosis and radiosensitivity. Levels of HOTAIR, miR-454-3p and E2F2 were detected after different treatments. An in vivo analysis was carried out in mice bearing laryngeal cancer xenografts.

Results

Laryngeal cancer-derived exosomes reduced laryngeal cancer cell radiosensitivity. HOTAIR expression was increased after cells were treated with exosome, and HOTAIR overexpression reduced laryngeal cancer cell radiosensitivity. Besides, HOTAIR worked as a competing endogenous RNA (ceRNA) of miR-454-3p to regulate E2F2 in laryngeal cancer cells. In vivo results were reproduced in in vivo studies, which demonstrated that HOTAIR knockdown reduced laryngeal cancer cell radiosensitivity by sponging miR-454-3p to silence E2F2.

Conclusion

Exosome-mediated HOTAIR acts as a ceRNA of miR-545-3p to regulate E2F2, thereby negatively regulating the radiosensitivity of laryngeal cancer cells. This study may offer novel insight into laryngeal cancer treatment.