Long noncoding RNA H19 competitively binds miR-17-5p to regulate YES1 expression in thyroid cancer

CircCTDP1 promotes nasopharyngeal carcinoma progression via a microRNA‑320b/HOXA10/TGFβ2 pathway

Circular RNAs have been reported to play a vital role in the development and progression of various types of cancer. However, the underlying molecular role of circular RNA CTDP1 (circCTDP1) in the tumorigenesis of nasopharyngeal carcinoma (NPC) remains unknown. In the present study, circCTDP1 expression was found to be markedly upregulated in NPC tissues and cell lines (SUNE1, SUNE2 and 6-10B cell lines). Knockdown of circCTDP1 resulted in inhibition of proliferation, migration and invasion, and promoted apoptosis of NPC cells. Moreover, circCTDP1 directly interacted with microRNA (miR)-320b based on bioinformatics prediction and dual luciferase assay, and transfection with an miR-320b inhibitor reversed the effects of circCTDP1 knockdown on NPC cells. Furthermore, circCTDP1/miR-320b promoted NPC progression by regulating the expression of homeobox A10 (HOXA10). In addition, it was demonstrated that HOXA10 may exert its oncogenic role in NPC by regulating the expression of transforming growth factor β2 (TGFβ2). Taken together, these results revealed a novel regulatory mechanism, which may provide an improved understanding of NPC tumorigenesis and be useful in the development of potential targets for NPC therapy.

LINC00511 influences cellular proliferation through cyclin-dependent kinases in papillary thyroid carcinoma

Background: Proverbially, the incidence rate of papillary thyroid carcinoma (PTC) has increased year by year. Many long noncoding RNAs (lncRNAs) have been discovered having a relationship with tumor genesis tightly recently. Thanks to the previous researches, we found long intergenic noncoding RNA 00511 (LINC00511) is overexpressed and acts as an oncogene in non-small-cell lung cancer and breast cancer. However, the biological role and function of LINC00511 are still unclear in PTC. Methods: We got the expression of LINC00511 in PTC tissues and matched adjacent tissues, as well the cell lines (B-CPAP, KTC-1, and KTC-1) by way of quantitative real-time polymerase chain reaction (qRT-PCR). In vitro, we knocked down the LINC00511 with small interfering RNA in PTC cell lines and demonstrated the function of LINC00511 by Cell Counting Kit-8, cell colony formation, Transwell migration, Transwell invasion, apoptosis assays, and cell cycle assays. Then, we discovered several downstream proteins of LINC00511 using Western blotting. Results: We proved that LINC00511's expression in PTC tissues and cell lines is higher than the control. LINC00511 promoted cellular proliferation, migration, invasion, G1/S transition and reduced apoptosis in vitro experiment. Knocked-down of LINC00511 resulted in the reduction of histone methyltransferase enhancer of zeste homolog 2 (EZH2), cyclin-dependent kinase 2 (CDK2) and cyclin-dependent kinase 4 (CDK4). Conclusions: Our results certified the role and function of LINC00511 in PTC, and it could become a novel tumor therapeutic target.

H19 lncRNA: Roles in tumorigenesis

H19 is a long non-coding RNA [lncRNA] which was firstly described as an oncofetal transcript. The imprinted gene is normally expressed from the maternal allele. However, this pattern of imprinting is dysregulated in several cancers leading to aberrant up-regulation of H19 in malignant tissues. Several studies have utilized this aberrant expression pattern to find specific biomarkers for detection of cancer in tumoral tissues or peripheral blood. Moreover, single nucleotide polymorphisms within H19 have been associated with risk of oral squamous cell carcinoma, hepatocellular carcinoma, breast cancer, bladder cancer, gastric cancer and colorectal cancer. Taken together, H19 is regarded as a biomarker for cancer and a putative therapeutic target in these human disorders.

LncRNA H19 induced by helicobacter pylori infection promotes gastric cancer cell growth via enhancing NF-κB-induced inflammation

Background

The aim of this study was to investigate the role of long non-coding RNA (lncRNA) H19 in gastric cancer (GC) with Helicobacter pylori (H. pylori).

Methods

H19 expression in peripheral blood from H. pylori+/- GC patients and healthy donors (control) as well as in GC tissues and cells were detected by qRT-PCR. Cell proliferation was evaluated by CCK-8 assay. Cell migration and invasion were evaluated by Transwell assay. The levels of pro-inflammatory cytokines were determined by ELISA. The protein levels of IκBα, p-IκBα and p65 were determined by western blotting.

Results

H19 expression was upregulated in H. pylori-infected GC tissues and cells. Furthermore, H. pylori promoted GC cell viability, migration, invasion and inflammatory response. Moreover, H19 overexpression promoted the proliferation, migration and invasion of H. pylori-infected GC cells via enhancing NF-κB-induced inflammation.

Conclusions

LncRNA H19 promotes H. pylori-induced GC cell growth via enhancing NF-κB-induced inflammation.

H19 promote calcium oxalate nephrocalcinosis-induced renal tubular epithelial cell injury via a ceRNA pathway

Background

Intrarenal calcium oxalate (CaOx) crystals induce inflammation and kidney tubular cell injury, which are processes that involve TLR4/NF-κB signalling. A recent genome-wide gene expression profile analysis of Randall's plaques in CaOx stone patients revealed that the expression of the long noncoding RNA H19 was significantly upregulated. However, to date, its role in kidney CaOx stones has not been reported.

Method

A Gene Expression Omnibus (GEO) dataset was utilized to analyse gene expression profiles. Luciferase reporter, Western blotting, qRT-PCR, immunofluorescence staining and reactive oxygen species (ROS) assays were employed to study the molecular mechanism of HMGB1/TLR4/NF-κB regulation by H19 and miR-216b. In vitro and in vivo assays were performed to further confirm the proinflammatory and prooxidative stress effects.

Finding

H19 expression was significantly increased and positively correlated with the expression levels of HMGB1, TLR4 and NF-κB in Randall's plaques and glyoxylate-induced CaOx nephrocalcinosis mouse models. H19 interacted with miR-216b and suppressed its expression. Additionally, miR-216b inhibited HMGB1 expression by directly binding its 3′-untranslated region. Moreover, H19 downregulation inhibited HMGB1, TLR4 and NF-κB expression and suppressed CaOx nephrocalcinosis-induced renal tubular epithelial cell injury, NADPH oxidase, and oxidative stress in vivo and in vitro. Interestingly, miR-216b inhibition partially reversed the inhibitory effect of H19 knockdown on HMGB1 expression.

Interpretation

We determined that H19 might serve as a facilitator in the process of CaOx nephrocalcinosis-induced oxidative stress and renal tubular epithelial cell injury, and we revealed that the interaction between H19 and miR-216b could exert its effect via the HMGB1/TLR4/NF-κB pathway.

Funding

This work was supported by the National Nature Science Foundation of China (Nos. 8196030190, 8190033175, 81370805, 81470935, 81900645, 81500534, and 81602236).

Influencers on Thyroid Cancer Onset: Molecular Genetic Basis

Thyroid cancer, a cancerous tumor or growth located within the thyroid gland, is the most common endocrine cancer. It is one of the few cancers whereby incidence rates have increased in recent years. It occurs in all age groups, from children through to seniors. Most studies are focused on dissecting its genetic basis, since our current knowledge of the genetic background of the different forms of thyroid cancer is far from complete, which poses a challenge for diagnosis and prognosis of the disease. In this review, we describe prevailing advances and update our understanding of the molecular genetics of thyroid cancer, focusing on the main genes related with the pathology, including the different noncoding RNAs associated with the disease.

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

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

Long noncoding RNAs in thyroid cancer

PURPOSE OF REVIEW

Our understanding of the molecular pathology events involved in thyroid cancer initiation and progression and its subtypes has markedly improved as a result of multiomic studies. Recently, long noncoding RNA (lncRNA) have been shown to have a role in cancer initiation and progression and have also been studied in thyroid cancer.

RECENT FINDINGS

lncRNA are dysregulated in thyroid cancer. lncRNA have tumor suppressive and oncogenic function in thyroid cancer cells and play a role in some of the established genetic drivers of thyroid cancer initiation and progression. Lastly, some lncRNA are associated with clinicopathologic features of thyroid cancer and circulating blood lncRNA could potentially detect the presence of thyroid cancer.

SUMMARY

We highlight the possible clinical utility of analyzing lncRNAs as biomarkers for thyroid cancer diagnosis and prognosis and their association with common genetic changes associated with thyroid cancer.

Long non-coding RNA small nucleolar RNA host gene 7 is upregulated and promotes cell proliferation in thyroid cancer

Thyroid cancer (THCA) is one of the most common types of endocrine cancer worldwide. However, the mechanisms underlying THCA progression have not been fully elucidated. Recent studies have demonstrated that long non-coding RNAs (lncRNAs) are dysregulated in human diseases, and are involved in regulating various biological processes. Furthermore, several reports have indicated that lncRNAs serve important roles in THCA. In the present study, a dataset from The Cancer Genome Atlas was used to analyze the expression levels and the clinical information of small nucleolar RNA host gene 7 (SNHG7) in THCA. Starbase was used to construct the competing endogenous RNA network. The Molecule Annotation System was used to analyze the data from Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. Furthermore, cell proliferation and cell cycle assays were used to detect the functions of SNHG7 in THCA. The present study revealed for the first time, to the best of our knowledge, that SNHG7 is markedly upregulated in THCA samples following analysis of The Cancer Genome Atlas datasets. SNHG7 expression was higher in advanced stage compared with early stage THCA samples. In addition, high expression levels of SNHG7 were associated with shorter survival times in THCA patients compared with low expression levels. Bioinformatics analysis revealed that SNHG7 was associated with the processes of ‘protein translation’, ‘viral life cycle’, ‘RNA processing’, ‘mRNA splicing’, ‘histone ubiquitination’, ‘endoplasmic reticulum-to-Golgi vesicle-mediated transport’, ‘sister chromatid cohesion’, ‘DNA damage checkpoint regulation’, ‘translation’ and ‘the spliceosome’. Additionally, knockdown of SNHG7 significantly inhibited thyroid cancer cell proliferation and cell cycle progression in vitro. Taken together, the results obtained in the present study suggested that SNHG7 may serve as a novel therapeutic and prognostic target for THCA.

Novel interactions between ERα-36 and STAT3 mediate breast cancer cell migration

Background

Breast cancer is the leading cause of cancer death in women worldwide which is closely related to metastasis. But the exact molecular mechanism of ERα-36 and STAT3 on metastasis is still not fully understood.

Methods

MCF-7 and MDA-MB-231 human breast cancer cell lines and MCF-10A were overexpressioned or knockdown ERα-36 and STAT3 and tested for migration, invasion and proliferation assays. Direct interaction of STAT3 and ERα-36 were analyzed by coimmunoprecipitation assays. The effect of STAT3 and ERα-36 on MMP2/9 expression was analyzed by qPCR and western blotting. STAT3 phospholyation and acetylation by ERα-36 and p300 were observed and quantified by coimmunoprecipitation assays and western blotting.

Results

Cross-talk between ERα-36 and STAT3 was demonstrated to mediate through a direct physical association between the two proteins. Furthermore, the interaction between ERα-36 and STAT3 was demonstrated to give rise to functional changes in their signaling events. Both MMP2 and MMP9 expression require the binding of the newly identified protein complex, ERα-36-STAT3, to its promoter, the second phase, which is more robust, depends on ERα-mediated recruitment of p300 onto the complex and the subsequent acetylation of STAT3. In addition, STAT3 is tyrosine-phosphorylated in a biphasic manner, and the late phase requires ERα-36-mediated p300-dependent acetylation. Furthermore, interference with acetylation of STAT3 by overexpression of acetylation null STAT3 mutant led to the loss of MMP2 and MMP9 expression. ChIP analysis and reporter gene assays revealed that ERα-36-STAT3 complex binding to the MMP2 and MMP9 promoter led to an enhanceosome formation and facilitated MMP2 and MMP9 expression.

Conclusions

Our studies demonstrate for the first time that the function of MMP2 and MMP9 in breast cancer cell migration, which is mediated by interactions between ERα-36 and STAT3.

lncRNA NR_038323 Suppresses Renal Fibrosis in Diabetic Nephropathy by Targeting the miR-324-3p/DUSP1 Axis

Several studies have suggested that long intergenic noncoding RNAs are involved in the progression of diabetic nephropathy (DN). However, the exact role and regulatory mechanism of long noncoding RNA (lncRNA) NR_038323 in diabetic nephropathy (DN) remain largely unclear. In the present study, we found that lncRNA NR_038323 overexpression ameliorated the high glucose (HG)-induced expression levels of collagen I, collagen IV, and fibronectin, whereas lncRNA NR_038323 knockdown exerted the opposite effects. Moreover, the results of bioinformatic prediction, luciferase assay, and fluorescence in situ hybridization (FISH) demonstrated that lncRNA NR_038323 directly interacted with miR-324-3p. Additionally, miR-324-3p mimic aggravated the HG-induced expression levels of collagen I, collagen IV, and fibronectin by dual-specificity protein phosphatase-1 (DUSP1) expression to activate p38 mitogen-activated protein kinase (MAPK) and ERK1/2 pathways. In contrast, overexpression of DUSP1 attenuated the HG-induced expression levels of collagen I, collagen IV, and fibronectin via inactivation of p38 MAPK and ERK1/2 pathways. In addition, lncRNA NR_038323 knockdown increased the expression levels of collagen I, collagen IV, and fibronectin by upregulating DUSP1 expression during HG treatment, which were markedly reversed by miR-324-3p inhibitor. Furthermore, these molecular changes were verified in the human kidney samples of DN patients. Finally, overexpression of lncRNA NR_038323 ameliorated the interstitial fibrosis in STZ-induced diabetic nephrology (DN) rat via miR-324-3p/DUSP1/p38MAPK and ERK1/2 axis. In conclusion, our data indicate that overexpression of lncRNA NR_038323 may suppress HG-induced renal fibrosis via the miR-324-3p/DUSP1/p38MAPK and ERK1/2 axis, which provides new insights into the pathogenesis of DN.

Identification of prognostic signatures associated with long-term overall survival of thyroid cancer patients based on a competing endogenous RNA network

Competing endogenous RNAs (ceRNAs) are considered as transcripts that can regulate each other at post-transcription level by competing for shared miRNAs. Considering the key roles of lncRNAs acting as ceRNAs in progression of solid tumors, to develop prognostic signatures in thyroid cancer (THCA), patients with corresponding clinical data were selected and two ceRNA networks were constructed using online databases. Two prognostic signatures (Lnc5m4 and Lnc2mi1m2) were found to be more efficient in predicting long-term survival of THCA patients. However, the high-risk score of Lnc2mi1m2 was not an independent factor.The risk score of Lnc5m4 was able to effectively stratify patients in stage III-IV into low- and high-risk groups, and also could predict poor prognosis of patients in stage III-IV. In conclusion, these findings indicate that Lnc5m4 is a novel prognostic signature for predicting long-term overall survival of THCA patients, which could provide a new approach to lncRNA research in THCA progression.

Long non-coding RNA H19 knockdown inhibits the cell viability and promotes apoptosis of thyroid cancer cells through regulating the PI3K/AKT pathway

Certain long non-coding (lnc)RNAs have been reported to serve important roles in the genesis and progression of thyroid cancer (TC). Recent studies have demonstrated that the expression of lncRNA H19 is upregulated in TC tissues; however, knowledge of the associated molecular mechanisms is limited. Therefore, the present study aimed to clarify the roles of H19 in TC. The mRNA expression of lncRNA H19 in TC tissues was determined using reverse transcription-quantitative polymerase chain reaction analysis, and the effects of H19 knockdown on cell viability and apoptosis in vitro were assessed using MTT and flow cytometric assays, respectively. Finally, the signaling pathways involved in the effects of H19 were examined. The results indicated that H19 was upregulated in TC tissues. Silencing of H19 inhibited the cell viability and promoted apoptosis of FTC-133 and TPC-1 TC cells, accompanied by an increased expression of B-cell lymphoma 2 (Bcl-2)-associated X protein and caspase 3, and repressed expression of Bcl-2. The results of western blot analysis suggested that the levels of phosphorylated phosphoinositide-3 kinase (PI3K) and phosphorylated AKT were attenuated by H19 silencing. These results suggest that lncRNA H19 exerts an oncogenic function in TC, in part through the PI3K/AKT pathway.

Effect of miR-140-5p on the regulation of proliferation and apoptosis in NSCLC and its underlying mechanism

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer accounting for ~80% of lung cancer cases. According to novel research, numerous microRNAs (miRs) have been suggested to function as important regulators of cancer. In addition, the expression of miR-140-5p is decreased in patients with NSCLC. Therefore, it is important to further elucidate the role of miR-140-5p in NSCLC. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used in order to investigate the expression of miR-140-5p in NSCLC tissues and matched normal tissues and to determine miR-140-5p levels following transfection with mimics into A549 lung cancer cells. Targetscan software was used to predict the oncogene target of miR-140-5p. This analysis revealed that YES proto-oncogene 1 (YES1) includes a target site for miR-140-5p binding. The results revealed that YES1 is a potential target gene of miR-140-5p, and this was further confirmed by the results of luciferase reporter assays, which demonstrated that miR-140-5p directly targeted the predicted binding site in the 3'-untranslated region of YES1. Cell Counting Kit-8 (CCK-8) and flow cytometry assays were performed to determine the levels of cell viability and apoptosis. Western blot assays was performed to investigate the expression levels of YES1 and proteins associated with apoptosis in A549 cells following transfection. The results revealed that miR-140-5p expression was significantly downregulated in NSCLC tissues compared with matched normal tissues. The expression of miR-140-5p was significantly increased following transfection with miR-140-5p mimics. The results of CCK-8 and flow cytometry assays indicated that miR-140-5p inhibited proliferation and induced apoptosis of tumor cells. Western blot analysis and RT-qPCR revealed that YES1 and B-cell lymphoma 2 (Bcl-2) mRNA and protein expression levels were markedly decreased in A549 cells, while Bcl-2 associated X (Bax) and caspase-3 expression levels increased significantly following transfection with miR-140-5p mimics compared with the negative control group. In conclusion, miR-140-5p may induce apoptosis in A549 cells by targeting YES1 and regulating the expression of apoptosis-associated proteins Bcl-2, Bax and caspase-3.

Long noncoding RNA LINC00052 inhibits colorectal cancer metastasis by sponging microRNA-574-5p to modulate CALCOCO1 expression

The dysregulation of long-chain noncoding ribonucleic acid (lncRNA) is a common phenomenon in many human cancers. Some studies on the biological function of long intergenic non-protein-coding RNA 52 (LINC00052) in cancer indicate that this gene can act as either oncogene or tumor suppressor in some kinds of cancers, such as breast cancer, gastric cancer, liver cancer, and lung cancer. However, the biological function of LINC00052 in colorectal cancer (CRC) has not been studied. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blot (WB) techniques were applied to detect the expression levels of LINC00052, miR-574-5p, and calcium-binding and coiled-coil domain 1 (CALCOCO1) in CRC cells and tissues. We authenticated the biological function of LINC00052 and miR-574-5p in CRC, and find some target genes for LINC00052 and miR-574-5p via bioinformatics methods. Dual-luciferase reporter gene assay was performed to identify the interaction between LINC00052 and miR-574-5p or CALCOCO1 and miR-574-5p. The results demonstrated that LINC00052 was downregulated in CRC tissues compared with their adjacent tissues. And LINC00052 could suppress CRC cells metastasis both in vivo and in vitro. Beyond that, miR-574-5p was upregulated in CRC tissues, and as an oncogene, it accelerated CRC cell migration and invasion. More importantly, the results of our research demonstrated that LINC00052 could regulate the expression of CALCOCO1 via sponging miR-574-5p in CRC. Overall, our study illuminated the lncRNA-miRNA functional networks in CRC, and these results might provide a new research direction for the diagnosis and treatment of CRC.

TSP-1 is downregulated and inversely correlates with miR-449c expression in Cushing's disease

The pathogenesis of Cushing's disease, which is caused by pituitary corticotroph adenoma, remains to be studied. Secreted angioinhibitory factor thrombospondin-1 (TSP-1) is an adhesive glycoprotein that mediates cell-to-cell and cell-to-matrix interactions and is associated with platelet aggregation, angiogenesis and tumorigenesis. We have found that the expression of TSP-1 is significantly lower in human pituitary corticotroph tumours compared with normal adenohypophysis. This study aims to elucidate the role of TSP-1 in regulating the tumour function of pituitary adenomas. Forced overexpression of TSP-1 in a murine AtT20 pituitary corticotroph tumour cell line decreased corticotroph precursor hormone proopiomelanocortin (POMC) transcription and adrenocorticotropic hormone (ACTH) secretion. Functional studies showed that TSP-1 overexpression in pituitary adenoma cells suppressed proliferation, migration and invasion. We have demonstrated that TSP-1 is a direct target of miR-449c. Further study showed that miR-449c activity enhanced tumorigenesis by directly inhibiting TSP-1 expression. Low expression of lncTHBS1, along with low expression of TSP-1, was associated with the high expression of miR-449c in Cushing's disease patients. Furthermore, RNA-immunoprecipitation associates miR-449c with lncTHBS1 suggesting that lncTHBS1 might be a negative regulator of miR-449c. Taken together, this study has demonstrated that lncTHBS1 might function as competing endogenous RNA for miR-449c, which could suppress the development of Cushing's disease.

Long Non-Coding RNA ZFAS1 as a Novel Potential Biomarker for Predicting the Prognosis of Thyroid Cancer

Background

Thyroid cancer is a type of endocrine cancers with rapidly increased incidence. Recent studies have indicated long non-coding RNAs (lncRNAs) played crucial roles in thyroid cancer tumorigenesis and progression. However, the roles of most lncRNAs in thyroid cancer were still unclear.

Material/Methods

We used TCGA (The Cancer Genome Atlas), GSE50901, GSE29265, and GSE33630 datasets to analyze the expression pattern of ZFAS1 (ZNFX1 antisense RNA 1). The correlation between ZFAS1 and clinicopathological features in thyroid cancer was analyzed. Cell proliferation and cell cycle assays were used to validate the roles of ZFAS1 in thyroid cancer cell lines. DAVID (the database for annotation, visualization and integrated discover) system was used to perform GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis. The starBase datasets and Cytoscape was used to perform ceRNA (competitive endogenous RNA) network.

Results

We demonstrated ZFAS1 was highly expressed in thyroid cancer compared to normal samples. Moreover, upregulation of ZFAS1 was positively correlated with clinicopathological features and poor prognosis in thyroid cancer. Functional validation showed knockdown of ZFAS1 suppressed cell proliferation and cell cycle in thyroid cancer cells. Bioinformatics analysis showed ZFAS1 was associated with translation, rRNA processing, intra-Golgi vesicle-mediated transport, ribosome, and ubiquitin-mediated proteolysis.

Conclusions

Our study suggested ZFAS1 could serve as a biomarker for thyroid cancer.

LncRNA ENST00000539653 acts as an oncogenic factor via MAPK signalling in papillary thyroid cancer

Background

Papillary thyroid cancer (PTC) is the most frequent type of thyroid malignancy. In this study, we investigated the mechanisms whereby long non-coding RNAs (lncRNAs) are associated with PTC pathogenesis.

Methods

Microarray analysis was used to determine differentially expressed lncRNAs between paired PTC tissues and normal adjacent thyroid tissues. Quantitative RT-PCR was used for validation in 86 PTC cases. Small interfering RNA (siRNA) transfection assays were then performed to assess how a novel lncRNA affected key proliferation and cell death pathways in IHH4 PTC cells.

Results

We identified 1878 differentially expressed lncRNAs versus matched control samples (fold change ≥2.0, P < 0.05), of which 429 were upregulated and 1449 were downregulated. ENST00000539653.1 (ENS-653), one of the top hits in this microarray, was selected for further study. Higher ENS-653 expression was observed in PTC tissue samples versus adjacent normal tissues, and was associated with a larger tumor size and a more advanced clinical stage. In the Cancer Genome Atlas (TCGA) PTC cohort, higher ENS-653 expression was correlated with more frequent BRAF (V600E) mutation and poorer disease-free survival. Furthermore, ENS-653 downregulation reduced the proliferation of PTC cells and led to G1-S arrest, but had no impact on apoptosis. ENS-653 downregulation also inactivated ERK1/2 and ERK5, causing partial MAPK cascade suppression.

Conclusion

ENS-653 exhibits oncogenic properties in PTC, and could be a diagnostic and/or prognostic PTC biomarker, in addition to possibly being a future target for therapy.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5533-4) contains supplementary material, which is available to authorized users.

Regulatory roles of long noncoding RNAs implicated in cancer hallmarks

Cancer cells acquire numerous biological properties (designated "cancer hallmarks"), such as cell survival and energy metabolism, that facilitate tumor growth and metastatic dissemination during development. To date, eight hallmarks of cancer have been identified that provide a logical framework for understanding the remarkable diversity of neoplastic diseases, as proposed by Douglas Hanahan and Robert A. Weinberg. Long noncoding RNAs (lncRNAs), a category of transcripts widely demonstrated to exert significant regulatory effects on biological processes, have attracted considerable research attention due to their association with the occurrence and development of cancer. The mechanisms by which lncRNAs exert their functions require elucidation to optimize their potential utility as alternative biomarkers and therapeutic targets during tumor occurrence and progression. In this review, we have discussed recent research progress on lncRNAs involved in various cancer hallmarks and their related mechanisms of action, with a view to providing an updated picture of their immense therapeutic potential in the fight against cancer.

The role of long non-coding RNAs in the pathogenesis of hereditary diseases

Background

Thousands of long non-coding RNA (lncRNA) genes are annotated in the human genome. Recent studies showed the key role of lncRNAs in a variety of fundamental cellular processes. Dysregulation of lncRNAs can drive tumorigenesis and they are now considered to be a promising therapeutic target in cancer. However, how lncRNAs contribute to the development of hereditary diseases in human is still mostly unknown.

Results

This review is focused on hereditary diseases in the pathogenesis of which long non-coding RNAs play an important role.

Conclusions

Fundamental research in the field of molecular genetics of lncRNA is necessary for a more complete understanding of their significance. Future research will help translate this knowledge into clinical practice which will not only lead to an increase in the diagnostic rate but also in the future can help with the development of etiotropic treatments for hereditary diseases.

LncRNA H19 interacted with miR-130a-3p and miR-17-5p to modify radio-resistance and chemo-sensitivity of cardiac carcinoma cells

The current investigation explored the synthetic contribution of lncRNA H19, miR-130a-3p, and miR-17-5p to radio-resistance and chemo-sensitivity of cardiac cancer cells. Totally 284 human cardiac cancer tissues were gathered, and they have been pathologically diagnosed. The cardiac cancer cells were isolated with utilization of the mechanic method. Moreover, cisplatin, adriamycin, mitomycin, and 5-fluorouracil were designated as the chemotherapies, and single-dose X-rays were managed as the radiotherapy for cardiac cancer cells. We also performed luciferase reporter gene assay to verify the targeted relationship between H19 and miR-130a-3p, as well as between H19 and miR-17-5p. Finally, mice models were established to examine the functions of H19, miR-130a-3p, and miR-17-5p on the development of cardiac cancer. The study results indicated that H19, miR-130a-3p, and miR-17-5p expressions within cardiac cancer tissues were significantly beyond those within adjacent nontumor tissues (P < 0.05), and H19 expression was positively correlated with both miR-130a-3p (r_s  = 0.43) and miR-17-5p (r_s  = 0.49) expressions. The half maximal inhibitory concentrations (IC50) of cisplatin, adriamycin, mitomycin, and 5-fluorouracil for cardiac cancer cells were, respectively, determined as 2.01 μg/mL, 8.35 μg/mL, 24.44 μg/mL, and 166.42 μg/mL. The overexpressed H19, miR-130a-3p, and miR-17-5p appeared to improve the survival rate and viability of cardiac cancer cells that were exposed to chemotherapies and X-rays (all P < 0.05). It was also drawn from luciferase reporter gene assay that H19 could directly target miR-130a-3p and miR-17-5p, thereby modifying the sensitivity of cardiac cancer cells to drugs and X-rays (P < 0.05). Finally, the mice models also produced larger tumor size and higher tumor weight, when H19, miR-130a-3p, or miR-17-5p expressions were up-regulated within them (P < 0.05). In conclusion, H19 could act on miR-130a-3p or miR-17-5p to alter the radio- and chemo-sensitivities of cardiac cancer cells, helping to improve the radio-/chemotherapies for cardiac cancer.

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.

Long noncoding RNA H19 is a critical oncogenic driver and contributes to epithelial-mesenchymal transition in papillary thyroid carcinoma

BACKGROUND

Growing evidence has indicated that the long noncoding RNA H19 (lncRNA H19), frequently deregulated in almost all tumor types tested, acted as a pivotal contributor to both cancer initiation and progression. However, the role of lncRNA H19 in human papillary thyroid carcinoma (PTC) remains controversial. The aim of the study was to investigate the expression and potential function of lncRNA H19 in human PTC.

PATIENTS AND METHODS

The lncRNA H19 level was determined by quantitative real-time (RT)-PCR analyses in 58 PTC tissue samples and their paired paracancerous tissue samples. RNA interference, RT-PCR analysis, and Western blot assay were used to determine the impact of lncRNA H19 on epithelial-mesenchymal transition (EMT) markers in human PTC cells. The migratory and invasive capacities of PTC cells were determined by wound-healing and transwell migration and invasion assays.

RESULTS

lncRNA H19 expression was 2.417-fold higher in PTC tissues than their paired paracancerous tissue (95% CI: 1.898-2.935, P<0.0001). Higher level of lncRNA H19 was correlated to elevated expression of Vimentin, ZEB2, Twist, and Snail2. Inhibition of lncRNA H19 resulted in upregulation of E-cadherin and downregulation of Vimentin both at mRNA and protein levels. Conversely, enforced expression of the exogenous lncRNA H19 led to E-cadherin mRNA and protein downregulation and relative upregulation of Vimentin. Moreover, wound-healing and transwell migration and invasion assays showed that lncRNA H19 could promote the migratory and invasive abilities of PTC cells.

CONCLUSION

The level of lncRNA H19 was significantly higher in PTC tissues than paired paracancerous tissue or normal tissues. Overexpression of lncRNA H19 was correlated with higher tumor burden of PTC. It also contributes to EMT process, as well as promotes migration and invasion of PTC cells.

Contribution of the Long Noncoding RNA H19 to β-Cell Mass Expansion in Neonatal and Adult Rodents

Pancreatic β-cell expansion throughout the neonatal period is essential to generate the appropriate mass of insulin-secreting cells required to maintain blood glucose homeostasis later in life. Hence, defects in this process can predispose to diabetes development during adulthood. Global profiling of transcripts in pancreatic islets of newborn and adult rats revealed that the transcription factor E2F1 controls expression of the long noncoding RNA H19, which is profoundly downregulated during the postnatal period. H19 silencing decreased β-cell expansion in newborns, whereas its re-expression promoted proliferation of β-cells in adults via a mechanism involving the microRNA let-7 and the activation of Akt. The offspring of rats fed a low-protein diet during gestation and lactation display a small β-cell mass and an increased risk of developing diabetes during adulthood. We found that the islets of newborn rats born to dams fed a low-protein diet express lower levels of H19 than those born to dams that did not eat a low-protein diet. Moreover, we observed that H19 expression increases in islets of obese mice under conditions of increased insulin demand. Our data suggest that the long noncoding RNA H19 plays an important role in postnatal β-cell mass expansion in rats and contributes to the mechanisms compensating for insulin resistance in obesity.

Involvement of H19/miR-326 axis in hepatocellular carcinoma development through modulating TWIST1

Overexpression of long noncoding RNA (lncRNA) H19 has been observed in various cancers, which indicates that H19 exert important roles in the progression of carcinogenesis. MiR-326 has been reported to play tumor suppressive roles in multiple tumors. Recently, the competing endogenous RNA (ceRNA) hypothesis has implied that lncRNAs might function as molecular sponges for microRNAs in various cancers. However, the roles of H19/miR-326 in human hepatocellular carcinoma (HCC) still remain unclear. The aim of our study was to determine H19/miR-326 expression in HCC cells and investigate their roles in HCC development. We found that H19 was significantly elevated and miR-326 was decreased in HCC cells including Hep3B, HepG2, MHCC-97L, SK-hep1, Hun7, SMCC-7721 compared with LO2 cells, respectively. In the subsequent experiments, we observed that inhibition of H19 can repress HCC cell growth, migration, and invasion in vitro. H19 downregulation can increase miR-326 expression in HCC cells. Meanwhile, miR-326 mimics can also inhibit HCC progression, whereas miR-326 inhibitors exhibited a reverse phenomenon by modulating H19 expression. In addition, a negative association between H19 and miR-326 was predicted and confirmed. Furthermore, the transcription factor TWIST1 has been recognized as a significant regulator in tumor progression. Here, by performing bioinformatics analysis, TWIST1 was identified as a downstream target of miR-326. The findings of our study implied that lncRNA H19 can serve as a ceRNA to sponge miR-326 and modulate TWIST1 levels in HCC pathogenesis. Taken these together, these findings indicated that H19/miR-326/TWIST1 axis was involved in HCC development and can indicate a novel HCC target.

Identification of differential expressed lncRNAs in human thyroid cancer by a genome-wide analyses

Recently, a growing number of evidence has revealed that long noncoding RNAs (lncRNAs) act as key regulators in various cellular biologic processes, and dysregulation of lncRNAs involves in tumorigenesis and cancer progression. However, the expression pattern, clinical relevance, and biologic function of most lncRNAs in human thyroid cancer remain unclear. To identify more thyroid-cancer-associated lncRNAs, we analyzed the expression profile of lncRNAs in thyroid cancer tissues and adjacent normal or non-tumor tissues using RNA sequencing data and gene microarray data from The Cancer Genome Atlas and Gene Expression Omnibus. Annotation and analyses of these data revealed that hundreds of lncRNAs are differentially expressed in thyroid cancer tissues when compared with normal tissues. By copy number variation analyses, we identified that some of those dysregulated lncRNAs genome locus are accompanied with the copy number amplification or deletion. Moreover, some lncRNAs expression levels are significantly associated with thyroid cancer patients overall or recurrence-free survival time, such as RUNDC3A-AS1, FOXD2-AS1, PAX8-AS1, and CRYM-AS1. Furthermore, we validated an lncRNA termed LINC00704 in thyroid cancer cells by performing loss of function assays. Downregulation of LINC00704 could significantly impair thyroid cancer cells proliferation, colony formation, inhibit cell-cycle progression and cell invasion, and induce cell apoptosis. Taken together, our findings reveal that lots of lncRNAs are dysregulated and may play critical roles in thyroid cancer, and this study could provide useful resource for identification and investigation of novel lncRNA candidates for thyroid cancer.

Long noncoding RNA LINC00152 promotes cell proliferation through competitively binding endogenous miR-125b with MCL-1 by regulating mitochondrial apoptosis pathways in ovarian cancer

Recently, an increasing number of studies have focused on the key function of long noncoding RNAs (lncRNAs) in biological activity. Abnormal lncRNA expression was found to relate to the development and pathogenesis of multiple cancers. LncRNA LINC00152 served as an oncogene in multiple cancers; however, its role in ovarian cancer remains unknown. In our research study, LINC00152 was upregulated in ovarian cancer tissues and cell lines. An increasing LINC00152 level was positively correlated with the histological grade, clinical stage, and poor prognosis of ovarian cancer patients. In addition, knockdown of LINC00152 reduced cell growth, induced cell apoptosis, and suppressed tumor growth. Moreover, we revealed that LINC00152 and Myeloid cell leukemia‐1 (MCL‐1) were targeted by miR‐125b and had the same miR‐125b combining site. The miR‐125b level was negatively correlated with the expression of LINC00152, while MCL‐1 was positively related to the LINC00152 level. MiR‐125b could affect LINC00152 levels as evaluated by qRT‐PCR. Finally, we affirmed that LINC00152 mediated cell proliferation by affecting MCL‐1 expression and MCL‐1‐mediated mitochondrial apoptosis pathways and by working as a competitive endogenous RNA (ceRNA) of miR‐125b. In summary, based on ceRNA theory, the combined research on miR‐125b and MCL‐1, and taking LINC00152 as a new study point, we provide new insight into the molecular mechanism of reversing cell proliferation in ovarian cancer.

Long non-coding RNAs in thyroid cancer: Biological functions and clinical significance

Thyroid cancer is the most common endocrine malignant tumor with rapidly increasing incidence in recent decades. Although the majority of thyroid cancers are relatively indolent, some cases still have a risk of developing into more aggressive and lethal forms of thyroid cancers. Similar to other malignancies, thyroid tumorigenesis is a multistep process involving the accumulation of a large number of genetic and epigenetic alterations. Thus, determination of the mechanisms of tumorigenesis is an urgent need for thyroid cancer treatment. Long noncoding RNAs (LncRNAs) have recently been demonstrated to participate in cancer progression. However, their role and molecular mechanism in thyroid cancer remain largely unclear. In this review, we focus on the dysregulation of lncRNAs in thyroid cancer, summarize the latest findings regarding the functions and mechanism of lncRNAs in thyroid cancer, and discuss their potential clinical significance in diagnosis and prognosis of thyroid cancer.

Long Noncoding RNA LINC003121 Inhibits Proliferation and Invasion of Thyroid Cancer Cells by Suppression of the Phosphatidylinositol-3-Kinase (PI3K)/Akt Signaling Pathway

BACKGROUND The aim of this study was to explore the potential effects of long noncoding RNA (lncRNA) LINC003121 on thyroid cancer (TC) cell proliferation and invasion and to explore their possible mechanisms with the involvement of the PI3K/Akt signaling pathway. MATERIAL AND METHODS We enrolled 211 thyroid cancer tissues and 70 adjacent normal tissues in this study. TC cell lines K1, SW579, and 8505C and the human thyroid follicular cell line Nthy-ori3-1 were selected and assigned into blank, control vectors, LINC00312 vectors, si-control, and si-LINC00312 groups. Quantitative real-time PCR was used to determine the levels of LINC003121 and Western blotting was used to detect the protein expression of MMP-9, PI3K, t-Akt, and p-Akt. Cell proliferation was assessed by CCK8 assay and EdU incorporation assay, and cell invasion was assessed by Transwell assay. RESULTS The expression of LINC00312 was significantly decreased in TC tissues and cell lines. In an in vitro experiment, si-LINC00312 significantly promoted the invasion and proliferation of TC cells. Conversely, overexpression of LINC00312 decreased cell proliferation and invasion in vitro, and decreased tumorigenicity in TC xenograft models in nude mice. LINC00312-mediated tumor suppression in TC cells may occur via suppression of activation of the PI3K/Akt signaling pathway and expression of MMP-9, and the role of MMP-9 expression induced by overexpressed LINC00312 or si-LINC00312 could be weakened by LY294002 (PI3K inhibitor). CONCLUSIONS LINC00312 can act as a tumor-suppressor in TC by attenuating the PI3K/Akt signaling pathway, and LINC00312 could be a novel diagnosis biomarker and a promising therapeutic target for TC patients.

LncRNA TNRC6C-AS1 regulates UNC5B in thyroid cancer to influence cell proliferation, migration, and invasion as a competing endogenous RNA of miR-129-5p

To investigate the biological functions and regulatory mechanism of lncRNA TNRC6C-AS1 in thyroid cancer (TC). TNRC6C-AS1, miR-129-5p, and UNC5B expression levels were investigated by qRT-PCR and Western blot. CCK-8 assay was conducted to determine cell proliferation, while transwell assay was for inspection of cell migration and invasion. Through bioinformatic analysis, the interactions among TNRC6C-AS1, miR-129-5p, and UNC5B were predicted. Dual luciferase reporter gene assay and RNA pull-down assay confirmed the predicted target relationships. Tumor xenograft assay was applied to inspect the effect of TNRC6C-AS1 downregulation on TC development in vivo. TNRC6C-AS1 and UNC5B were overexpressed, while miR-129-5p was underexpressed in TC tissues and cells. TNRC6C-AS1/UNC5B downregulation and miR-129-5p overexpression could suppress proliferation, migration, and invasion of TC cells as well as inhibit tumorigenesis in vivo. MiR-129-5p targeted TNRC6C-AS1 and UNC5B in TC cells; and UNC5B expression was downregulated by knocking down TNRC6C-AS1, which competitively bound with miR-129-5p. Downregulation of TNRC6C-AS1 restrained TC development by knocking down UNC5B through upregulating the expression of miR-129-5p.

Long noncoding RNA NEAT1 regulate papillary thyroid cancer progression by modulating miR-129-5p/KLK7 expression

Considering the dilemma in papillary thyroid cancer treatment, this study intended to find solution in molecular respect. By probing into lncRNA-NEAT1/miR-129-5p/KLK7 interaction, this study would provide new targets for future treatment. Microarray analysis and R language package were applied to select possible lncRNA and miRNA. Luciferase reporter assay and RNA pull-down test were employed in the detection of target relationship between lncRNA and miRNA. Clone formation assay, flow cytometry analysis, wound healing assay, and transwell assay were, respectively, used to observe effects of lncRNA NEAT1/miR-129-5p/KLK7 to papillary thyroid cancer cells. Western blot and qRT-PCR were used to validate protein expressions and mRNA expressions in PTC tissues and cells. LncRNA NEAT1 was highly expressed in PTC tissues and cell lines and could deteriorate PTC by promoting proliferation, invasion, and migration accompanied by less apoptosis. Besides, miR-129-5p/lncRNA NEAT1 were found to negatively correlate with each other by direct target relationship and their combination suppressed the progression of PTC. KLK7, a highly expressed downstream protein in PTC tissues, could be directly regulated by miR-129-5p in a negative way. KLK7 accelerated the deterioration of PTC in vitro experiments which could be reversed by sh-lnc RNA NEAT1 and miR-129-5p mimics. In vivo experiments, silence of lncRNA NEAT1 restrain tumor growth in weight and volume. In conclusion, lncRNA NEAT1 suppression could inhibit PTC progression by upregulating miR-129-5p, which suppressed KLK7 expression either in vitro or vivo experiments.

LincRNA 1700020I14Rik alleviates cell proliferation and fibrosis in diabetic nephropathy via miR-34a-5p/Sirt1/HIF-1α signaling

Long intergenic noncoding RNAs (lincRNAs) have been gradually identified to be functional in a variety of different mechanisms associating with development and epigenetic regulation of cellular homeostasis. However, the study of lincRNAs in diabetic nephropathy (DN) is still in its infancy. Here, we have found dysexpressed long noncoding RNAs (lncRNAs) in renal tissues of db/db DN mice compared with db/m mice by RNA sequencing. In this study, 5 lincRNAs were confirmed to express in a consistent trend among these DN-related lncRNAs both in vivo and in vitro. Particularly, 1700020I14Rik was the downregulated one. Moreover, our data showed overexpression or knockdown of 1700020I14Rik could regulate cell proliferation and fibrosis in mouse mesangial cells (MCs). Furthermore, 1700020I14Rik was found to interact with miR-34a-5p via both the directly targeting way by bioinformatic investigation and luciferase assay and the Ago2-dependent manner by RIP assay. Results also displayed that overexpression of 1700020I14Rik inhibited cell proliferation and expressions of renal fibrosis markers through miR-34a-5p/Sirt1/HIF-1α pathway in MCs under high glucose condition, while knockdown of 1700020I14Rik could increase cell proliferation and expressions of renal fibrosis markers. In conclusion, these results provide new insights into the regulation between 1700020I14Rik and miR-34a-5p/Sirt1/HIF-1α signaling pathway during the progression of DN.

Baicalein inhibits breast cancer growth via activating a novel isoform of the long noncoding RNA PAX8-AS1-N

Baicalein, a natural flavonoid, has fascinating anti-cancer properties in breast cancer. Long noncoding RNAs (lncRNAs), a class of transcripts with no protein-coding potential, also exhibit critical roles in breast cancer. However, the molecular mechanisms mediating the anti-cancer properties of baicalein and whether lncRNAs are involved in the anti-cancer effects are still unclear. In this study, we identified a novel isoform of lncRNA PAX8-AS1 (PAX8-AS1-N), which is activated by baicalein in a dose- and time-dependent manner. Functional assays showed that PAX8-AS1-N reduced cell viability, inhibited cell-cycle progression, and induced apoptosis of breast cancer cells in vitro. Depletion of PAX8-AS1-N promoted breast xenograft tumor growth in vivo. Furthermore, depletion of PAX8-AS1-N attenuated the suppressive roles of baicalein on cell viability, the apoptosis induced by baicalein, and also the suppressive roles of baicalein on tumor growth in vivo. Mechanistically, PAX8-AS1-N bound to miR-17-5p, and up-regulated miR-17-5p targets, such as PTEN, CDKN1A, and ZBTB4. In addition, PAX8-AS1-N was down-regulated in breast cancer and reduced expression of PAX8-AS1-N indicated poor survival of breast cancer patients. In conclusion, our results demonstrated that PAX8-AS1-N activation mediated the anti-cancer effects of baicalein via regulating miR-17-5p, and suggested that baicalein and enhancing PAX8-AS1-N would be potential therapeutic strategies against breast cancer.

Long noncoding RNA H19 upregulates vascular endothelial growth factor A to enhance mesenchymal stem cells survival and angiogenic capacity by inhibiting miR-199a-5p

Background

Currently, the overall therapeutic efficiency of mesenchymal stem cells (MSCs) transplantation for the treatment of cardiovascular disease is not satisfactory. The low viability and angiogenic capacity of the implanted cells in the local infarct tissues restrict their further application. Evidence shows that long noncoding RNA H19 (lncRNA-H19) mediates cell survival and angiogenesis. Additionally, it is also involved in MSCs biological activities. This study aimed to explore the functional role of lncRNA-H19 in MSCs survival and angiogenic capacity as well as the underlying mechanism.

Methods

MSCs were obtained from C57BL/6 mice and cultured in vitro. Cells at the third passage were divided into the following groups: MSCs+H19, MSCs+H19 NC, MSCs+si-H19, MSCs+si-H19 NC and MSCs. The MSCs+H19 and MSCs+H19 NC groups were transfected with lncRNA-H19 and lncRNA-H19 scramble RNA respectively. The MSCs+si-H19 and MSCs+si-H19 NC groups were transfected with lncRNA-H19 siRNA and lncRNA-H19 siRNA scramble respectively. MSCs were used as the blank control. All groups were exposed to normoxia (20% O₂) and hypoxia (1% O₂)/serum deprivation (H/SD) conditions for 24 h. Cell proliferation, apoptosis and vascular densities were assessed. Bioinformatics and dual luciferase reporter assay were performed. Relevant biomarkers were detected in different experimental groups.

Results

Overexpression of lncRNA-H19 improved survival and angiogenic capacity of MSCs under both normoxia and H/SD conditions, whereas its knockdown impaired cell viability and their angiogenic potential. MicroRNA-199a-5p (miR-199a-5p) targeted and downregulated vascular endothelial growth factor A (VEGFA). MiR-199a-5p was a target of lncRNA-H19. LncRNA-H19 transfection led to a decreased level of miR-199a-5p, accompanied with an elevated expression of VEGFA. However, both miR-199a-5p and VEGFA presented inverse alterations in the condition of lncRNA-H19 knockdown.

Conclusions

LncRNA-H19 enhanced MSCs survival and their angiogenic potential in vitro. It could directly upregulate VEGFA expression by inhibiting miR-199a-5p as a competing endogenous RNA. This mechanism contributes to a better understanding of MSCs biological activities and provides new insights for cell therapy based on MSCs transplantation.

Long Noncoding RNA FOXC2-AS1 Predicts Poor Survival in Breast Cancer Patients and Promotes Cell Proliferation

Breast cancer (BC) is the most common malignant tumor in women. Recently, long noncoding RNAs (lncRNAs) have been proposed as critical regulators in biological processes, including tumorigenesis. FOXC2-AS1, a single antisense oligonucleotide RNA transcribed from the negative strand of forkhead box protein C2 (FOXC2), has been identified as an oncogene in osteosarcoma. In the present study, we investigated the prognosis value and biological role of FOXC2-AS1 in BC. Our findings revealed that FOXC2-AS1 was significantly increased in BC tissues and cell lines, and Kaplan–Meier survival analysis indicated that a high level of FOXC2-AS1 was associated with poor prognosis of BC patients. Loss of function revealed that silenced FOXC2-AS1 significantly suppressed the proliferation ability, and flow cytometric analysis illustrated the influence of FOXC2-AS1 on cell cycle and apoptosis rate. Finally, we found that cyclin D1, cyclin D2, and cyclin D3 were all partly positively modulated by FOXC2-AS1 in BC. Collectively, FOXC2-AS1 may serve as a promising prognostic biomarker and therapeutic target for BC patients.

LncRNA HCP5 promotes follicular thyroid carcinoma progression via miRNAs sponge

Long non-coding RNAs (lncRNAs), which are important functional regulators in cancer, have received increased attention in recent years. In this study, next-generation sequencing technology was used to identify aberrantly expressed lncRNAs in follicular thyroid carcinoma (FTC). The long non-coding RNA–HLA complex P5 (HCP5) was found to be overexpressed in FTC. The results of the qPCR analysis were consistent with the sequencing results. In addition, functional experiments showed that overexpression of HCP5 can promote the proliferation, migration, invasiveness and angiogenic ability of FTC cells. Furthermore, according to the sequencing results, HCP5 and alpha-2, 6-sialyltransferase 2 (ST6GAL2) were co-expressed in FTC. We hypothesised that ST6GAL2 may be regulated by HCP5, which would in turn mediate the activity of FTC cells. Through qPCR, immunostaining analyses and functional experiments, we determined that the expression of HCP5 was elevated and was correlated with the levels of ST6GAL2 in FTC tissues and cells. Mechanistic experiments showed that HCP5 functions as a competing endogenous RNA (ceRNA) and acts as a sponge for miR-22-3p, miR-186-5p and miR-216a-5p, which activates ST6GAL2. In summary, our study revealed that HCP5 is a tumour regulator in the development of FTC and that it may contribute to improvement of FTC diagnosis and therapy.

High lncRNA H19 expression as prognostic indicator: data mining in female cancers and polling analysis in non-female cancers

Upregulation of lncRNA H19 expression is associated with an unfavorable prognosis in some cancers. However, the prognostic value of H19 in female-specific cancers has remained uncharacterized. In this study, the prognostic power of high H19 expression in female cancer patients from the TCGA datasets was analyzed using Kaplan-Meier survival curves and Cox's proportional hazard modeling. In addition, in a meta-analysis of non-female cancer patients from TCGA datasets and 12 independent studies, hazard ratios (HRs) with 95% confidence interval (CI) for overall survival (OS) and disease-free survival (DFS)/relapse-free survival (RFS)/metastasis-free survival (MFS)/progression-free survival (PFS) were pooled to assess the prognostic value of high H19 expression. Kaplan-Meier analysis revealed that patients with uterine corpus cancer and higher H19 expression had a shorter OS (HR=2.710, p<0.05), while females with cervical cancer and increased H19 expression had a shorter RFS (HR=2.261, p<0.05). Multivariate Cox regression analysis showed that high H19 expression could independently predict a poorer prognosis in cervical cancer patients (HR=4.099, p<0.05). In the meta-analysis, patients with high H19 expression showed a poorer outcome in non-female cancer (p<0.05). These results suggest that high lncRNA H19 expression is predictive of an unfavorable prognosis in two female cancers (uterine corpus endometrioid cancer and cervical cancer) as well as in non-female cancer patients.

Long non-coding RNA LOC100507600 functions as a competitive endogenous RNA to regulate BMI1 expression by sponging miR128-1-3p in Hirschsprung's disease

Recently studies reported that long non-coding RNAs (lncRNAs) may take part in a lot of congenital diseases, meanwhile, Hirschsprung's disease (HSCR) is a major congenital digestive tract malformation. Nevertheless whether lncRNAs participate in the occurrence of HSCR and how it contributes to this disease are still unknown. LOC100507600 was selected from our gene expression microarray data obtained from bowel tissues from HSCR patients and negative controls. Subsequently, we used qRT-PCR to prove the result in 64 pairs of HSCR disease bowel stenosis tissues and negative controls. Transwell assay, CCK-8 assay and flow cytometry were employed to explore whether cellular functions change after knocking down the LOC100507600 in SH-SY5Y cell and human 293T cell. Dual-luciferase reporter assay was used to confirm the competitive relationship between BMI1 and LOC100507600 through their association with hsa-miR128-1-3p. Protein extraction and Western blotting were used to further confirm the relationship between LOC100507600 and BMI1. We found that LOC100507600 was obvious reduced in tissues from HSCR patients with noteworthy correlation with BMI1. Furthermore, Downregulation of LOC100507600 repressed cell migration and proliferation and didn't affect cell apoptosis or cycle. Dual-luciferase reporter assay, qRT-PCR and Western blotting assay verified that LOC100507600 serves as a competitive endogenous RNA of miR128-1-3p and down-regulates BMI1 expression by sponging miR128-1-3p in HSCR. In sum, our study researches the potential diagnostic value of LOC100507600 in HSCR and deduces that LOC100507600 can contributes to HSCR as a competitive endogenous RNA to regulate BMI1 expression by sponging miR128-1-3p.

Association of lncRNA H19 rs217727 polymorphism and cancer risk in the Chinese population: a meta-analysis

Reports on the relationship between the lncRNA H19 rs217727 polymorphism and the risk of cancer in the Chinese population have been inconsistent. Therefore, we performed a meta-analysis to evaluate this association, by searching the Embase, PubMed, Web of Science, Wanfang, and CNKI databases. Four case-control studies with 3,157 cases and 3,564 controls were selected for this meta-analysis. The odds ratios with 95% confidence intervals were examined using the random effect model. Allelic (A vs. G), dominant (AA + GA vs. GG), recessive (AA vs. GA + GG), and additive (AA vs. GG) genetic models were used to determine the association. Overall, no significant association was observed between the rs217727 polymorphism and cancer susceptibility in any of the four genetic models. Sensitivity analysis revealed that the results were stable in the allelic and dominant genetic models, but those from the recessive and additive models were unstable, which should be treated with caution. Our meta-analysis suggests that the lncRNA H19 rs217727 polymorphism might not be associated with overall cancer risk. However, well-designed, large-scale studies with different ethnic populations need to be conducted in the future to elucidate the potential association.

Long noncoding RNAs: emerging players in thyroid cancer pathogenesis

Thyroid cancer continues to be the most common malignancy of endocrine glands. The incidence of thyroid cancer has risen significantly over the past 4 decades and has emerged as a major health issue. In recent years, significant progress has been achieved in our understanding of the molecular mechanisms of thyroid carcinogenesis, resulting in significant diagnostic, prognostic and therapeutic implications; yet, it has not reached a satisfactory level. Identifying novel molecular therapeutic targets and molecules for diagnosis and prognosis is expected to advance the overall management of this common malignancy. Long noncoding RNAs (lncRNAs) are implicated in the regulation of various key cellular genes involved in cell differentiation, proliferation, cell cycle, apoptosis, migration and invasion mainly through modulation of gene expression. Recent studies have established that lncRNAs are deregulated in thyroid cancer. In this review, we discuss extensively the tumor-suppressive (for example, LINC00271, MEG3, NAMA, PTCSC1/2/3, etc.) and oncogenic (for example, ANRIL, FAL1, H19, PVT1, etc.) roles of various lncRNAs and their possible disease associations implicated in thyroid carcinogenesis. We briefly summarize the strategies and mechanisms of lncRNA-targeting agents. We also describe the potential role of lncRNAs as prospective novel therapeutic targets, and diagnostic and prognostic markers in thyroid cancer.

Association between long non-coding RNAs expression and pathogenesis and progression of gliomas

The incidence rate of gliomas is the highest among primary brain tumors. Although the understanding of the molecular pathology of glioma has improved during the previous two decades, effective therapies are not yet available to treat these tumors. Previous studies have indicated that long non-coding RNAs (lncRNAs) have a close association with glioma, suggesting that lncRNAs may be potential targets for the development of novel treatments for glioma. The present review summarized the latest studies on the dysregulation of lncRNAs in glioma, and discussed their potential use in the diagnosis, prognosis and therapies of glioma. The emergence of lncRNAs has revealed an additional facet to glioma oncogenesis. An improved understanding of their functions is important to advance lncRNA-based diagnosis, prognosis and therapeutic interventions of glioma.

Long noncoding RNA H19 promotes transforming growth factor-β-induced epithelial-mesenchymal transition by acting as a competing endogenous RNA of miR-370-3p in ovarian cancer cells

Ovarian cancer is a gynecological malignant tumor with a high mortality rate among women, owing to metastatic progression and recurrence. Acquisition of invasiveness is accompanied by the loss of epithelial features and a gain of a mesenchymal phenotype, a process known as epithelial–mesenchymal transition (EMT). Transforming growth factor-β (TGF-β) has been implicated in the regulation of EMT. In the present study, we aimed to investigate the role of long noncoding RNA H19 and microRNA-370 (miR-370-3p) in TGF-β-induced EMT. Ovarian cancer cell lines SKOV-3 and OVCAR3 were incubated with different concentrations of TGF-β, and the results showed that TGF-β treatment upregulated H19 and downregulated miR-370-3p. In addition, an H19 knockdown or miR-370-3p overexpression suppressed TGF-β-induced EMT, while H19 overexpression or a miR-370-3p knockdown promoted TGF-β-induced EMT. Mechanistically, H19 could directly bind to miR-370-3p and effectively act as its competing endogenous RNA. Furthermore, we demonstrated that this activity of H19 was involved in its promotion of TGF-β-induced EMT. Thus, our results may provide novel insights into the process of TGF-β-induced EMT.