SP1-induced lncRNA TINCR overexpression contributes to colorectal cancer progression by sponging miR-7-5p

Plasma Circulating Terminal Differentiation-Induced Non-Coding RNA Serves as a Biomarker in Breast Cancer

Background: Breast cancer is identified as the most common malignancy and cause of cancer-related death worldwide. Compared with healthy controls, this study evaluated the expression level and diagnostic power of lncRNA plasma TINCR in breast cancer patients. Materials and Methods: Fifty-eight women diagnosed with invasive ductal carcinoma and fifty healthy age- matched controls were included in the study. TRIzol® LS regent was used to isolate the total RNA from the whole plasma. Total RNA was converted to cDNA using Prime ScriptTM RT reagent kit and the expression levels of TINCR were quantified by qRT-PCR. Results: Low levels of TINCR lncRNA were observed in the plasma of breast cancer patients compared with control subjects. Plasma TINCR level was also positively correlated with the diagnostic age of breast cancer patients. Conclusion: A low level of plasma TINCR could discriminate breast cancer patients from healthy control subjects.

Prognostic value of circulating long non-coding RNAs in colorectal cancer patients: a meta-analysis

OBJECTIVES

This meta-analysis aimed to evaluate the prognostic significance of circulating long non-coding RNAs (lncRNAs) in colorectal cancer (CRC).

METHODS

A comprehensive literature search was conducted in databases (Embase, Web of Science, PubMed, and Cochrane Library) up to July 2022. The quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS). Statistical analysis was performed with Review Manager 5.4 and Stata 17.0. Publication bias was assessed using Begg's test, and sensitivity analysis was conducted to validate the meta-analysis results.

RESULTS

Ten articles, comprising 1,473 CRC patients and 18 different circulating lncRNAs, were included. Thirteen circulating lncRNAs were found to be up-regulated in CRC patients, while five were down-regulated. High expression of circulating lncRNAs up-regulated in CRC patients was associated with shorter CRC OS (HR = 2.91, 95% CI: 1.17, 7.22; P = 0.02, I2 = 86%). Conversely, high expression of circulating lncRNAs down-regulated in CRC patients was linked to longer CRC OS (HR = 0.16, 95% CI: 0.07, 0.40; P < 0.0001, I2 = 0%) and improved DFS (HR = 0.52, 95% CI: 0.37, 0.74; P = 0.0002, I2 = 0%). Additionally, circulating lncRNA levels correlated with TNM staging, tumor location, and lymph node metastasis.

CONCLUSION

Circulating lncRNAs show promise as prognostic markers for CRC patients, but further studies are warranted to validate these findings.

LncRNA PTTG3P promotes tumorigenesis and metastasis of NSCLC by binding with ILF3 to maintain mRNA stability and form a positive feedback loop with E2F1

Non-small cell lung cancer (NSCLC) is a highly lethal disease worldwide. We found the pseudogene-derived lncRNA PTTG3P is upregulated in NSCLC and associated with larger tumor size, advanced staging, and poor prognosis. This study investigated the oncogenic roles and mechanisms of PTTG3P in NSCLC. We demonstrate that PTTG3P promoted NSCLC cell proliferation, migration, tumorigenesis, and metastasis while inhibiting apoptosis in vitro and in vivo. Mechanistically, PTTG3P formed an RNA-protein complex with ILF3 to maintain MAP2K6 and E2F1 mRNA stability, two oncogenic factors involved in NSCLC progression. RNA-seq revealed MAP2K6 and E2F1 were downregulated upon PTTG3P knockdown. RIP and RNA stability assays showed PTTG3P/ILF3 interaction stabilized MAP2K6 and E2F1 transcripts. Interestingly, E2F1 transcriptionally upregulated PTTG3P by binding its promoter, forming a positive feedback loop. Knockdown of E2F1 or PTTG3P attenuated their mutual regulatory effects on cell growth and migration. Thus, a PTTG3P/ILF3/E2F1 axis enhances oncogene expression to promote NSCLC pathogenesis. Our study reveals PTTG3P exerts oncogenic functions in NSCLC via mRNA stabilization and a feedback loop, highlighting its potential as a prognostic biomarker and therapeutic target.

Interaction of lncRNAs with mTOR in colorectal cancer: a systematic review

Colorectal cancer (CRC) is the third most widespread cancer and the fourth leading lethal disease among different societies. It is thought that CRC accounts for about 10% of all newly diagnosed cancer cases with high-rate mortality. lncRNAs, belonging to non-coding RNAs, are involved in varied cell bioactivities. Emerging data have confirmed a significant alteration in lncRNA transcription under anaplastic conditions. This systematic review aimed to assess the possible influence of abnormal mTOR-associated lncRNAs in the tumorigenesis of colorectal tissue. In this study, the PRISMA guideline was utilized based on the systematic investigation of published articles from seven databases. Of the 200 entries, 24 articles met inclusion criteria and were used for subsequent analyses. Of note, 23 lncRNAs were prioritized in association with the mTOR signaling pathway with up-regulation (79.16%) and down-regulation (20.84%) trends. Based on the obtained data, mTOR can be stimulated or inhibited during CRC by the alteration of several lncRNAs. Determining the dynamic activity of mTOR and relevant signaling pathways via lncRNAs can help us progress novel molecular therapeutics and medications.

Specificity Proteins (Sp) and Cancer

The specificity protein (Sp) transcription factors (TFs) Sp1, Sp2, Sp3 and Sp4 exhibit structural and functional similarities in cancer cells and extensive studies of Sp1 show that it is a negative prognostic factor for patients with multiple tumor types. In this review, the role of Sp1, Sp3 and Sp4 in the development of cancer and their regulation of pro-oncogenic factors and pathways is reviewed. In addition, interactions with non-coding RNAs and the development of agents that target Sp transcription factors are also discussed. Studies on normal cell transformation into cancer cell lines show that this transformation process is accompanied by increased levels of Sp1 in most cell models, and in the transformation of muscle cells into rhabdomyosarcoma, both Sp1 and Sp3, but not Sp4, are increased. The pro-oncogenic functions of Sp1, Sp3 and Sp4 in cancer cell lines were studied in knockdown studies where silencing of each individual Sp TF decreased cancer growth, invasion and induced apoptosis. Silencing of an individual Sp TF was not compensated for by the other two and it was concluded that Sp1, Sp3 and Sp4 are examples of non-oncogene addicted genes. This conclusion was strengthened by the results of Sp TF interactions with non-coding microRNAs and long non-coding RNAs where Sp1 contributed to pro-oncogenic functions of Sp/non-coding RNAs. There are now many examples of anticancer agents and pharmaceuticals that induce downregulation/degradation of Sp1, Sp3 and Sp4, yet clinical applications of drugs specifically targeting Sp TFs are not being used. The application of agents targeting Sp TFs in combination therapies should be considered for their potential to enhance treatment efficacy and decrease toxic side effects.

LncRNAs in colorectal cancer: Biomarkers to therapeutic targets

Colorectal cancer (CRC) is the third leading cause of cancer-related death in men and women worldwide. As early detection is associated with lower mortality, novel biomarkers are urgently needed for timely diagnosis and appropriate management of patients to achieve the best therapeutic response. Long noncoding RNAs (lncRNAs) have been reported to play essential roles in CRC progression. Accordingly, the regulatory roles of lncRNAs should be better understood in general and for identifying diagnostic, prognostic and predictive biomarkers in CRC specifically. In this review, the latest advances on the potential diagnostic and prognostic lncRNAs as biomarkers in CRC samples were highlighted, Current knowledge on dysregulated lncRNAs and their potential molecular mechanisms were summarized. The potential therapeutic implications and challenges for future and ongoing research in the field were also discussed. Finally, novel insights on the underlying mechanisms of lncRNAs were examined as to their potential role as biomarkers and therapeutic targets in CRC. This review may be used to design future studies and advanced investigations on lncRNAs as biomarkers for the diagnosis, prognosis and therapy in CRC.

The role and application of transcriptional repressors in cancer treatment

Gene expression is modulated through the integration of many regulatory elements and their associated transcription factors (TFs). TFs bind to specific DNA sequences and either activate or repress transcriptional activity. Through decades of research, it has been established that aberrant expression or functional abnormalities of TFs can lead to uncontrolled cell division and the development of cancer. Initial studies on transcriptional regulation in cancer have focused on TFs as transcriptional activators. However, recent studies have demonstrated several different mechanisms of transcriptional repression in cancer, which could be potential therapeutic targets for the development of specific anti-cancer agents. In the first section of this review, "Emerging roles of transcriptional repressors in cancer development," we summarize the current understanding of transcriptional repressors and their involvement in the molecular processes of cancer progression. In the subsequent section, "Therapeutic applications," we provide an updated overview of the available therapeutic targets for drug discovery and discuss the new frontier of such applications.

SP1-induced PROX1-AS1 contributes to tumor progression by regulating miR-326/FBXL20 axis in colorectal cancer

Long noncoding RNAs (lncRNAs) play pivotal roles in cancers by regulating tumorigenesis and metastasis. LncRNA PROX1-AS1 has been reported to be involved in tumor progression, however, its role in colorectal cancer (CRC) remains ambiguous. Based on TCGA and GTEx databases, we found that the expression of PROX1-AS1 was upregulated in CRC tissues and cells. Bioinformatics analysis revealed that high PROX1-AS1 expression was associated with poor overall survival. Functionally, PROX1-AS1 knockdown suppressed CRC cell proliferation, migration, and invasion in vitro, as well as inhibiting tumor growth in vivo. Mechanistically, PROX1-AS1 was identified to act as a miR-326 sponge by luciferase reporter and RIP assay. Meanwhile, we found that the transcription factor SP1 activated PROX1-AS1/miR-32/FBXL20 axis, thereby promoting CRC progression. Our data demonstrated that PROX1-AS1 served as a promising prognostic biomarker for CRC, and the potential mechanism was unraveled.

Comprehensive analysis to identify pseudogenes/lncRNAs-hsa-miR-200b-3p-COL5A2 network as a prognostic biomarker in gastric cancer

OBJECTIVE

Gastric cancer is one of the most common and deadly types of cancer. The molecular mechanism of gastric cancer progression remains unclear.

MATERIALS AND METHODS

Four hub genes were identified through GEO and TCGA database screening and analysis. Prognostic analysis revealed that COL5A2 was the most likely to affect the prognosis of gastric cancer among the four hub genes. The relationships between COL5A2 and clinical variables and immune cell infiltration were analyzed. Then, COL5A2 was analyzed for single-gene differences and related functional enrichment. Using the starBase database for prediction and analysis, miRNAs and pseudogenes/lncRNAs that might combine with COL5A2 were identified; thus, the ceRNA network was constructed. Finally, the network was verified by Cox analysis and qPCR, and a nomogram was constructed.

RESULTS

First, we found that COL5A2, COL12A1, BGN and THBS2 were highly expressed in gastric cancer. COL5A2 had statistical significance in overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) analysis. Immune infiltration analysis suggested that COL5A2 might influence the changes in the tumor immune microenvironment. The StarBase database was used to predict that 3 pseudogenes and 7 lncRNAs might inhibit the hsa-miR-200b-3p-COL5A2 axis in gastric cancer. The pseudogenes/lncRNA-hsa-miR-200b-3p-COL5A2 ceRNA network was identified and verified using Cox regression analysis and PCR. Finally, we constructed a nomogram.

CONCLUSIONS

We elucidated the regulatory role of the pseudogenes/lncRNA-hsa-miR-200b-3p-COL5A2 network in gastric cancer progression and constructed a nomogram. These studies may provide effective treatments and potential prognostic biomarkers for gastric cancer.

Genetic predisposition to papillary thyroid carcinoma is mediated by a long non-coding RNA TINCR enhancer polymorphism

Single nucleotide polymorphisms (SNPs) in the enhancer region have been demonstrated to confer to altered enhancer activities, aberrant gene expression, and cancer susceptibility. In this study, we aimed to examine the association between an SNP, rs8101923, within terminal differentiation-induced non-coding RNA (TINCR) and the risk of papillary thyroid carcinoma (PTC). Blood samples from 559 patients with PTC and 445 healthy individuals were collected. The rs8101923 was genotyped by using polymerase chain reaction-restriction fragment length polymorphism assay. The impact of the rs8101923 on TINCR expression and enhancer activity was evaluated by quantitative real-time PCR and dual-luciferase reporter assay. The binding of AP-2α to TINCR enhancer was determined by chromatin immunoprecipitation. The rs8101923 G allele was significantly associated with a higher risk of PTC (adjusted OR = 1.37; 95% CI: 1.15-1.64). Mechanistically, the rs8101923 was related to increased transcriptional levels and enhancer activities (P < 0.05). Transcription factor AP-2α binds to the enhancer region of TINCR containing the rs8101923 locus, and promotes cell proliferation in PTC. These findings suggest the rs8101923 as a risk factor in the pathogenesis of PTC, which provides evidence for explaining the mechanism of the rs8101923 risk allele predisposing to PTC.

Multi-Omics Prognostic Signatures Based on Lipid Metabolism for Colorectal Cancer

Background: The potential biological processes and laws of the biological components in malignant tumors can be understood more systematically and comprehensively through multi-omics analysis. This study elaborately explored the role of lipid metabolism in the prognosis of colorectal cancer (CRC) from the metabonomics and transcriptomics.

Methods: We performed K-means unsupervised clustering algorithm and t test to identify the differential lipid metabolites determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) in the serum of 236 CRC patients of the First Hospital of Jilin University (JLUFH). Cox regression analysis was used to identify prognosis-associated lipid metabolites and to construct multi-lipid-metabolite prognostic signature. The composite nomogram composed of independent prognostic factors was utilized to individually predict the outcome of CRC patients. Glycerophospholipid metabolism was the most significant enrichment pathway for lipid metabolites in CRC, whose related hub genes (GMRHGs) were distinguished by gene set variation analysis (GSVA) and weighted gene co-expression network analysis (WGCNA). Cox regression and least absolute shrinkage and selection operator (LASSO) regression analysis were utilized to develop the prognostic signature.

Results: Six-lipid-metabolite and five-GMRHG prognostic signatures were developed, indicating favorable survival stratification effects on CRC patients. Using the independent prognostic factors as variables, we established a composite nomogram to individually evaluate the prognosis of CRC patients. The AUCs of one-, three-, and five-year ROC curves were 0.815, 0.815, and 0.805, respectively, showing auspicious prognostic accuracy. Furthermore, we explored the potential relationship between tumor microenvironment (TME) and immune infiltration. Moreover, the mutational frequency of TP53 in the high-risk group was significantly higher than that in the low-risk group (p < 0.001), while in the coordinate mutational status of TP53, the overall survival of CRC patients in the high-risk group was significantly lower than that in low-risk group with statistical differences.

Conclusion: We identified the significance of lipid metabolism for the prognosis of CRC from the aspects of metabonomics and transcriptomics, which can provide a novel perspective for promoting individualized treatment and revealing the potential molecular biological characteristics of CRC. The composite nomogram including a six-lipid-metabolite prognostic signature is a promising predictor of the prognosis of CRC patients.

A Novel Defined Necroptosis-Related miRNAs Signature for Predicting the Prognosis of Colon Cancer

Objective

This study aims at exploring the relationship between necroptosis-related miRNAs and colon cancer prognosis.

Methods

We downloaded the miRNA sequencing data from the TCGA, and eight differentially expressed necroptosis-related miRNAs were screened. Then, we used Cox regression analysis to establish a prediction model of necroptosis-related miRNA. Finally, the prognosis related miRNAs were used to predict the target genes, and functional analysis was used to explore the potential mechanism of these target genes.

Results

The miRNA-seq data of 444 COAD cases were downloaded from TCGA. We identified 8 differentially expressed miRNAs (has-miR-16-5p, has-miR-141-3p, has-miR-148a-3p, has-miR-425-5p, has-miR-7-5p, has-miR-223-3p, has-miR-200a-5p, and has-miR-500a-3p), then Cox analysis was performed for determining eight-miRNA signature prognostic biomarkers with obviously different OS. The area under the curve (AUC) of receiver operating characteristic (ROC) curve for predicting 1-, 3-, and 5-year survival were 0.663, 0.653 and 0.639, respectively. The multivariate analysis also implied that the risk score was an independent prognostic factor considering other confounding factors (HR = 1.847, 95% CI = 1.197–2.848, P = 0.006). According to the Kaplan–Meier analysis, the expression of hsa-miR-500a-3p (P = 0.003), hsa-miR-16-5p (P = 0.004) and hsa-miR-148a-3p (P = 0.035) significantly affected OS outcomes. We predicted the target genes of these three miRNAs and then screened 10 hub genes (CCND1, SMAD3, SMAD2, CDK1, TGFB2, CDC25A, CHEK1, VEGFA, CCNE1, WEE1). In addition, CHEK1 was associated with the survival prognosis.

Conclusion

Our study demonstrated that necroptosis is closely associated with colon cancer, and the model of eight necroptosis-related miRNAs are potentially useful prognostic biomarkers and therapeutic targets for colon cancer.

SP1-induced lncRNA ZFPM2 antisense RNA 1 (ZFPM2-AS1) aggravates glioma progression via the miR-515-5p/Superoxide dismutase 2 (SOD2) axis

Glioma is a common life-threatening tumor with high malignancy and high invasiveness. LncRNA ZFPM2 antisense RNA 1 (ZFPM2-AS1) was confirmed to be implicated in numerous tumors, while its biological function and mechanism have not been thoroughly understood in glioma. The gene expression was measured by RT-qPCR. Cell proliferation, cell cycle, and cell apoptosis of glioma cells were validated by CCK-8, colony formation, flow cytometry and TUNEL assays. The effect of ZFPM2-AS1 on tumor growth was verified by in vivo assay. The exploration on ZFPM2-AS1-mediated mechanism was carried out via ChIP, luciferase reporter, and RIP assays. In the present study, ZFPM2-AS1 was demonstrated as a highly-expressed lncRNA in glioma tissues and cells. ZFPM2-AS1 silencing suppressed cell proliferation and cell cycle, but facilitated cell apoptosis. In addition, the inhibitive effect of silenced ZFPM2-AS1 was also observed in tumor growth. Furthermore, we found that SP1 interacted with ZFPM2-AS1 promoter to transcriptionally activate ZFPM2-AS1 expression. Moreover, ZFPM2-AS1 was identified as a competing endogenous RNA (ceRNA) for miR-515-5p to target SOD2. Rescue assays verified that SOD2 overexpression partially abolished the suppressive impact of ZFPM2-AS1 silencing on glioma cell growth. In conclusion, this study corroborated the regulatory mechanism of SP1/ZFPM2-AS1/miR-515-5p/SOD2 axis in glioma, indicating that targeting ZFPM2-AS1 might be an effective way to treat glioma.

lncRNA TINCR attenuates the proliferation and invasion, and enhances the apoptosis of cutaneous malignant melanoma cells by regulating the miR‑424‑5p/LATS1 axis

Cutaneous malignant melanoma (CMM) is responsible for ≥1/2 of skin cancer‑related mortalities. The aberrant expression of long non‑coding RNAs (lncRNAs) has been associated with the development of CMM. However, to the best of our knowledge, the role of the lncRNA TINCR ubiquitin domain containing (TINCR) in CMM has not been previously investigated, and thus, the current study aimed to evaluate this in vitro and in vivo. Reverse transcription‑quantitative PCR (RT‑qPCR) was used to analyze microRNA (miR)‑424‑5p expression, and RT‑qPCR and western blotting were used to measure TINCR, large tumor suppressor kinase 1 (LATS1), cellular communication network factor 2 (CTGF), cellular communication network factor 1 (CCN1) and AXL receptor tyrosine kinase (AXL) mRNA and protein expression levels, respectively. Cell Counting Kit‑8, flow cytometry and Transwell assays were used to detect the proliferation, apoptosis and invasion of CMM cell lines, respectively. The binding sites between TINCR and miR‑424‑5p were predicted using the miRDB database. A dual luciferase reporter assay and RT‑qPCR were used to identify the relationship between TINCR and miR‑424‑5p in CMM cell lines. The bioinformatics analysis revealed that TINCR was one of the most significantly downregulated lncRNAs in CMM, and advanced stage CMM tissues showed the greatest decrease in TINCR expression. Moreover, in the collected CMM tissues and tested cell lines of the current study, TINCR expression was found to be downregulated compared with the respective controls. Notably, TINCR overexpression inhibited the expression levels of CTGF, CCN1 and AXL, decreased the proliferation and invasion, and induced the apoptosis of CMM cell lines. In addition, a mutual binding association was identified between miR‑424‑5p and TINCR in CMM cells. LATS1, a target of miR‑424‑5p, was found to be positively regulated by TINCR. TINCR activated Hippo signaling and repressed the activity of Yes 1 associated transcriptional regulator by regulating LATS1 expression, while LATS1 knockdown reversed the effect of TINCR overexpression on CMM cells. Collectively, the findings of the present study suggested that TINCR may attenuate the progression of CMM by regulating the miR‑424‑5p/LATS1 signaling axis. These results indicated that TINCR may play a tumor suppressive role in CMM.

Metastatic colorectal cancer: Perspectives on long non-coding RNAs and promising therapeutics

Metastatic colorectal cancer (mCRC) has long been lethal despite the continuous efforts of researchers worldwide to discover and improve therapeutic regimens. Thanks to the emergence of long non-coding RNAs (lncRNAs), which has strongly reshaped our inherent perspectives on the pathophysiological patterns of disease, research in the field has been reinvigorated. Here, we focus on current understanding of the modes of action of lncRNAs, and review their regulatory roles in metastatic colorectal cancer, and discuss correlated potential lncRNA-based therapeutics. All of the discussed studies share clear and promising perspectives on future diagnostic and therapeutic remedies for metastatic colorectal cancer.

LncRNA CASC21 induces HGH1 to mediate colorectal cancer cell proliferation, migration, EMT and stemness

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Long non-coding RNAs (lncRNAs) have been increasingly reported to serve vital parts in malignancies including CRC. Although cancer susceptibility 21 (CASC21) has been uncovered to play a part in CRC, its mechanism still needs further explanation. Thus, our study aimed to further explore the influence and mechanism of CASC21 in CRC progression. Quantitative real-time RT-PCR and western blot were performed to detect gene expression; a series of functional assays were performed to investigate the effect of CASC21 on CRC cells; in vivo tumour growth was evaluated via the nude mice xenograft model. The results revealed that CASC21 facilitated CRC cell proliferation, migration, epithelial-mesenchymal transition (EMT) and stemness. In addition, CASC21 was co-expressed with and bound to transcription factor POU5F1B (POU class 5 homeobox 1B). CASC21 recruited POU5F1B to HGH1 promoter to activate the transcription of HGH1 homolog. Also, CASC21 served as a competitive endogenous RNA (ceRNA) to up-regulate HGH1 via endogenously sponging miR-485-5p. Moreover, HGH1 overexpression counteracted the suppression of CASC21 deficiency on CRC tumour growth. In summary, our study indicated that CASC21 enhanced the expression of HGH1 to promote the malignancy of CRC by recruiting POU5F1B and sponging miR-485-5p, suggesting a key role of CASC21 in CRC progression.

Long noncoding RNAs as diagnostic biomarkers for the early detection of digestive tract cancers: a systematic review and meta-analysis

BACKGROUND

long noncoding RNAs (lncRNAs) have attracted attention recently. However, many inconsistencies frequently appeared for the early diagnosis of digestive tract cancers (DTCs). We performed this meta-analysis to describe the diagnostic performance of lncRNAs in the discrimination of DTCs.

METHODS

data were extracted from PubMed, Web of Science, Embase, and Cochrane Library. Their quality was evaluated using the revised Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Such parameters as sensitivity and specificity were included for pooled analyses. The STATA 12.0 and Meta-Disc 1.4 software packages were used to perform the statistical analysis.

RESULTS

sixty-nine papers were included in this meta-analysis. The pooled analysis of DTCs showed that lncRNAs had a sensitivity of 0.78 and a specificity of 0.80. The area under the summary ROC curve (AUC) was 0.86. For gastric cancer (GC), the pooled sensitivity and specificity were 0.77 (95 % CI: 0.72-0.81) and 0.75 (95 % CI: 0.71-0.79), respectively, and the AUC was 0.83. For colorectal cancer (CRC), these three parameters were 0.82 (95 % CI: 0.76-0.86), 0.84 (95 % CI: 0.79-0.88), and 0.90, respectively. For esophageal cancer (EC) sensitivity was 0.74 (95 % CI: 0.67-0.80) and specificity reached 0.86 (95 % CI: 0.72-0.93), with an AUC of 0.82.

CONCLUSIONS

LncRNAs show potential diagnostic value for discrimination between DTCs.

Long non-coding RNA TINCR promotes hepatocellular carcinoma proliferation and invasion via STAT3 signaling by direct interacting with T-cell protein tyrosine phosphatase (TCPTP)

The long non-coding RNAs (lncRNAs) participate in modulating numerous important cancer phenotypes via formation of RNA-protein complex. TINCR (terminal differentiation-induced lncRNA) modulates cancer cell behavior in many human malignancies, such as hepatocellular carcinoma (HCC). Herein, we proposed to investigate the underlying mechanism by which TINCR regulates HCC progression via formation of RNA-protein. RNA pulldown, LC-MS/MS, bioinformatics analysis, and RNA immunoprecipitation (RIP) assays were employed to identify TINCR-interacting protein TCPTP in HCC cells. The siRNAs for TINCR and TCPTP were transfected into HCC cells. The plasmids encoding full length or the 1–360 nt deletion of TINCR were generated and applied to cell transfection. The CCK-8, colony formation, EdU, wound healing along with transwell assays were employed to examine cell proliferation, apoptosis, migration, and infiltration. Real-time PCR, as well as western blot assays were employed to assess the levels of STAT3 phosphorylation and its target genes. We identified 1–360 nt region of TINCR, which directly bound with the phosphatase domain of TCPTP to inhibit its tyrosine phosphatase activity. Then, the results showed that the increasing of cell growth, migration, infiltration, and the reducing of apoptosis in TINCR-knockdown HCC cells was remarkably reversed with TCPTP silence. Additionally, Δ1-360 TINCR overexpression did not affect HCC cell growth, apoptosis, migration, infiltration, and STAT3 target genes expression. Our data revealed that TINCR directly bound TCPTP and suppressed the dephosphorylation of STAT3, thus promoting STAT3 activation and its downstream target genes in HCC progression and tumorigenicity.

Highlights

LncRNA TINCR interacted with protein TCPTP

LncRNA TINCR maintained STAT3 phosphorylation

LncRNA TINCR affected STAT3 signaling in HCC

Abbreviations:

lncRNAs: long non-coding RNAs; TINCR: terminal differentiation-induced lncRNA; TCPTP: T cell protein tyrosine phosphatase; siRNA: small-interfering RNA; HCC: hepatocellular carcinoma; nt: nucleotide; LC-MS/MS: Liquid Chromatography - Tandem Mass Spectrometry; RIP: RNA immunoprecipitation; ANOVA: analysis of variance; EdU: 5-ethynyl-2’-deoxyuridine; real-time PCR: real-time polymerase chain reaction; CCK-8: cell counting kit-8; aa: amino acids; STAT3: signal transducer and activator of transcription 3

The Staufen1-dependent cell cycle regulon or how a misregulated RNA-binding protein leads to cancer

In recent years, an increasing number of reports have linked the RNA-binding protein Staufen1 (STAU1) to the control of cell decision making. In non-transformed cells, STAU1 balances the expression of messenger RNA (mRNA) regulons that regulate differentiation and well-ordered cell division. Misregulation of STAU1 expression and/or functions changes the fragile balance in the expression of pro- and anti-proliferative and apoptotic genes and favours a novel equilibrium that supports cell proliferation and cancer development. The misregulation of STAU1 functions causes multiple coordinated modest effects in the post-transcriptional regulation of many RNA targets that code for cell cycle regulators, leading to dramatic consequences at the cellular level. The new tumorigenic equilibrium in STAU1-mediated gene regulation observed in cancer cells can be further altered by a slight increase in STAU1 expression that favours expression of pro-apoptotic genes and cell death. The STAU1-dependent cell cycle regulon is a good model to study how abnormal expression of an RNA-binding protein promotes cell growth and provides an advantageous selection of malignant cells in the first step of cancer development.

MiR-7 in Cancer Development

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.

Down-Regulation of Long Non-Coding RNA TINCR Induces Cell Dedifferentiation and Predicts Progression in Oral Squamous Cell Carcinoma

Objectives

Recently long non-coding RNAs (lncRNAs) have emerged as novel gene regulators involved in tumorigenic processes, including oral squamous cell carcinoma (OSCC). Here, we identified a differentiation-related lncRNA, terminal differentiation-induced non-coding RNA (TINCR). However, its biological function and clinicopathological significance in OSCC still remain unclear.

Methods

The lncRNA expression profiles in OSCC tissues and paired adjacent non-tumor tissues (NATs) from 10 patients were detected by lncRNA microarrays. Weighted gene co-expression network analysis (WGCNA) and gene ontology (GO) enrichment were performed to identify the most significant module and module functional annotation, respectively. Potential differentiation-related lncRNAs were screened by differential expression analysis. TINCR was further confirmed in OSCC cell lines and tissues of another patient cohort by using qRT-PCR. The correlation between the TINCR expression level and clinicopathological characteristics was analyzed. The effects of TINCR on cell differentiation, migration and invasion were assessed by knockdown or knock-in in vitro and in vivo.

Results

WGCNA and GO enrichment analysis showed that one co-expression network was significantly enriched for epithelial cell differentiation, among which, TINCR was significantly downregulated. qRT-PCR analyses validated down-regulation of TINCR in tumor tissues compared with paired NATs, and its expression was closely correlated with pathological differentiation and lymph node metastasis in patients with OSCC. Patients with lower TINCR expression levels had worse survival. Cell function experiments showed that TINCR played a crucial role in epithelial differentiation. Both TINCR and epithelial differentiation-associated genes, including IVL and KRT4, were significantly upregulated during OSCC cell calcium-induced differentiation but were reduced when cell dedifferentiation occurred in tumor spheres. Overexpression of TINCR dramatically suppressed cell dedifferentiation, migration and invasion in vitro, while knockdown of TINCR had the opposite effects. Upregulation of TINCR significantly elevated the expression of terminal differentiation genes and repressed tumor growth in vivo. Moreover, TINCR significantly suppressed the activation of JAK2/STAT3 signaling in OSCC cells.

Conclusion

Our study suggests that TINCR functions as a tumor suppressor by inducing cell differentiation through modulating JAK2/STAT3 signaling in OSCC. TINCR may serve as a prognostic biomarker and therapeutic target for OSCC.

The Emerging Landscape of Long Non-Coding RNAs in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers, with extremely high rates of morbidity and mortality. The main cause of death in CRC is distant metastasis; it affects patient prognosis and survival and is one of the key challenges in the treatment of CRC. Long non-coding RNAs (lncRNAs) are a group of non-coding RNA molecules with more than 200 nucleotides. Abnormal lncRNA expression is closely related to the occurrence and progression of several diseases, including cancer. Recent studies have shown that numerous lncRNAs play pivotal roles in the CRC metastasis, and reversing the expression of these lncRNAs through artificial means can reduce the malignant phenotype of metastatic CRC to some extent. This review summarizes the major mechanisms of lncRNAs in CRC metastasis and proposes lncRNAs as potential therapeutic targets for CRC and molecular markers for early diagnosis.

The emerging role of non-coding RNAs in the regulation of PI3K/AKT pathway in the carcinogenesis process

The PI3K/AKT pathway is an intracellular signaling pathway with an indispensable impact on cell cycle control. This pathway is functionally related with cell proliferation, cell survival, metabolism, and quiescence. The crucial role of this pathway in the development of cancer has offered this pathway as a target of novel anti-cancer treatments. Recent researches have demonstrated the role of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in controlling the PI3K/AKT pathway. Some miRNAs such as miR-155-5p, miR-328-3p, miR-125b-5p, miR-126, miR-331-3p and miR-16 inactivate this pathway, while miR-182, miR-106a, miR-193, miR-214, miR-106b, miR-93, miR-21 and miR-103/107 enhance activity of this pathway. Expression levels of PI3K/AKT-associated miRNAs could be used to envisage the survival of cancer patients. Numerous lncRNAs such as GAS5, FER1L4, LINC00628, PICART1, LOC101928316, ADAMTS9-AS2, SLC25A5-AS1, MEG3, AB073614 and SNHG6 interplay with this pathway. Identification of the impact of miRNAs and lncRNAs in the control of the activity of PI3K/AKT pathway would enhance the efficacy of targeted therapies against this pathway. Moreover, each of the mentioned miRNAs and lncRNAs could be used as a putative therapeutic candidate for the interfering with the carcinogenesis. In the current study, we review the role of miRNAs and lncRNAs in controlling the PI3K/AKT pathway and their contribution to carcinogenesis.

Emerging Role and Therapeutic Potential of lncRNAs in Colorectal Cancer

Maintenance of the intestinal epithelium is dependent on the control of stem cell (SC) proliferation and differentiation. The fine regulation of these cellular processes requires a complex dynamic interplay between several signaling pathways, including Wnt, Notch, Hippo, EGF, Ephrin, and BMP/TGF-β. During the initiation and progression of colorectal cancer (CRC), key events, such as oncogenic mutations, influence these signaling pathways, and tilt the homeostatic balance towards proliferation and dedifferentiation. Therapeutic strategies to specifically target these deregulated signaling pathways are of particular interest. However, systemic blocking or activation of these pathways poses major risks for normal stem cell function and tissue homeostasis. Interestingly, long non-coding RNAs (lncRNAs) have recently emerged as potent regulators of key cellular processes often deregulated in cancer. Because of their exceptional tissue and tumor specificity, these regulatory RNAs represent attractive targets for cancer therapy. Here, we discuss how lncRNAs participate in the maintenance of intestinal homeostasis and how they can contribute to the deregulation of each signaling pathway in CRC. Finally, we describe currently available molecular tools to develop lncRNA-targeted cancer therapies.

The SP1-Induced Long Noncoding RNA, LINC00339, Promotes Tumorigenesis in Colorectal Cancer via the miR-378a-3p/MED19 Axis

Introduction

Accumulating evidence has indicated that long noncoding RNAs (lncRNAs) are pivotal regulators involved in the pathogenesis of cancer; however, the molecular mechanism of LINC00339 in colorectal cancer (CRC) remains unclear.

Methods

The quantitative real-time polymerase chain reaction for the expression of LINC00339 and miR-378a-3p and Western blots for MED19 were performed. A dual-luciferase assay was used to investigate the interaction between LIN00339 and miR-378a-3p, as well as between miR-378a-3p and MED19. Cell proliferation was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and 5-ethynyl-2ʹ-deoxyuridine (EdU) assay. The cell cycle was analyzed by propidium iodide staining followed by flow cytometry analysis. The wound-healing and transwell invasion assays were used to evaluate cell migration and invasion.

Results

The expression of LINC00339 was significantly upregulated in CRC cells and tissues, and high LINC00339 expression indicated an advanced tumor stage. Further experiments demonstrated that SP1 activated LINC00339 expression by binding to its promoter region. Luciferase activity and RNA pull-down assays demonstrated a direct interaction between LINC00339 and miR-378a-3p. miR-378a-3p expression was decreased in CRC samples and negatively correlated with LINC00339 expression in tumors. Gain- and loss-of-function assays indicated that LINC00339 contributed to cell proliferation, cell cycle progression, migration, and invasion, while miR-378a-3p reversed these effects. Furthermore, cotransfection of wild-type MED19 3ʹ-UTR reporters and miR-378a-3p significantly reduced luciferase activity. MED19 mRNA and protein expression was inhibited and enhanced by miR-378a-3p and LINC00339, respectively. MED19 overexpression reversed the effect of miR-378a-3p on cellular processes. Moreover, LINC00339 promoted tumor growth in vivo and induced epithelial–mesenchymal transition (EMT) and activated the Wnt/β-catenin signaling pathway in cells.

Conclusion

Our findings demonstrate the regulatory role of the SP1/LINC00339/miR-378a-3p/MED19 axis in CRC tumorigenesis and provide novel insight into the molecular mechanism underlying CRC.

Diagnostic value of circulating lncRNAs as biomarkers of digestive system cancers: A systematic review and meta-analysis

OBJECTIVE

This meta-analysis aims to explore the diagnostic value and accuracy of circulating lncRNAs as biomarkers of digestive system tumors.

METHODS

PubMed, Embase, Cochrane Library, and Web of science were searched for relevant articles that were published before April 2019, and a meta-analysis was conducted.

RESULTS

52 studies with 63 lncRNAs were discussed in the meta-analysis. The pooled sensitivity and specificity of diagnosis were 0.80 (95% CI: 0.79-0.81) and 0.76 (95% CI: 0.75-0.77), respectively. The pooled DOR (the diagnostic odds ratio) was 15.63 (95% CI: 12.77-19.12), and the overall AUC (the area under the curve) was 0.87. Besides, subgroup analyzes showed that the DOR and AUC of large sample sizes (>80), multiple lncRNAs, serum-based lncRNAs, and downregulation group were superior to those of small sample sizes (≤80), single lncRNA, plasma-based lncRNAs, and upregulation group, respectively. The current data also highlight that the diagnostic accuracy of circulating lncRNAs in the case of colorectal cancer was higher than gastric cancer, hepatocellular carcinoma, esophageal carcinoma, and pancreatic cancer. And there is no difference in the perspective of geographical regions.

CONCLUSION

The circulating lncRNAs have high diagnostic value and accuracy in digestive system cancers and may serve as potential biomarkers.

Long non-coding RNA LPP-AS2 promotes glioma tumorigenesis via miR-7-5p/EGFR/PI3K/AKT/c-MYC feedback loop

Background

Glioblastoma is the most common primary malignant intracranial tumor with poor clinical prognosis in adults. Accumulating evidence indicates that long non-coding RNAs (lncRNAs) function as important regulators in cancer progression, including glioblastoma. Here, we identified a new lncRNA LPP antisense RNA-2 (LPP-AS2) and investigated its function and mechanism in the development of glioma.

Methods

High-throughput RNA sequencing was performed to discriminate differentially expressed lncRNAs and mRNAs between glioma tissues and normal brain tissues. Expression of LPP-AS2, epidermal growth factor receptor (EGFR) and miR-7-5p in glioma tissues and cell lines was detected by real-time quantitative PCR (RT-qPCR), and the functions of lncRNA LPP-AS2 in glioma were assessed by in vivo and in vitro assays. Insight into the underlying mechanism of competitive endogenous RNAs (ceRNAs) was obtained via bioinformatic analysis, dual luciferase reporter assays, RNA pulldown assays, RNA immunoprecipitation (RIP) and rescue experiments.

Results

The results of high-throughput RNA-seq indicated lncRNA LPP-AS2 was upregulated in glioma tissues and further confirmed by RT-qPCR. Higher LPP-AS2 expression was related to a poor prognosis in glioma patients. Based on functional studies, LPP-AS2 depletion inhibited glioma cell proliferation, invasion and promoted apoptosis in vitro and restrained tumor growth in vivo, overexpression of LPP-AS2 resulted in the opposite effects. In addition, LPP-AS2 and EGFR were observed in co-expression networks. LPP-AS2 was found to function as a ceRNA to regulate EGFR expression by sponging miR-7-5p in glioma cells. The result of chromatin immunoprecipitation (ChIP) assays validated that c-MYC binds directly to the promoter region of LPP-AS2. As a downstream protein of EGFR, c-MYC was modulated by LPP-AS2 and in turn enhanced LPP-AS2 expression. Thus, lncRNA LPP-AS2 promoted glioma tumorigenesis via a miR-7-5p/EGFR/PI3K/AKT/c-MYC feedback loop.

Conclusions

Our study elucidated that LPP-AS2 acted as an oncogene through a novel molecular pathway in glioma and might be a potential therapeutic approach for glioma diagnosis, therapy and prognosis.

MicroRNA-7 regulates the proliferation and metastasis of human papillary carcinoma cells by targeting Bcl-2

Papillary carcinoma is the most common type of thyroid cancer responsible for significant number of mortalities across the globe. This study was conducted to investigate the role and therapeutic implications of microRNA-7 in human papillary carcinoma. Gene expression analysis was carried out through quantitative real time PCR method. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was performed to determine the cell proliferation. Clonogenic assay was used to assess the colony forming ability of cancer cells. Cell apoptosis was analyzed by 4',6-diamidino-2-phenylindole (DAPI), acridine orange/ethidium bromide (AO/EB) and annexin V/PI staining assays. Migration of cancer cells was estimated through scratch heal assay and cell invasion was determined by transwell assay method. Western blotting was done to examine the protein expression. Xenografted mice models were employed to examine the effects of miR-7 overexpression in vivo. Results showed miR-7 to be significantly (P < 0.05) repressed in papillary carcinoma. Cancer cell proliferation was inhibited by miR-7 through induction of apoptotic cell death as revealed by DAPI, AO/EB and annexin V/PI staining assays. The colony forming potential of cancer cells also decreased under miR-7 overexpression. miR-7 overexpression also inhibited the migration and invasion of cancer cells. Bcl-2 was identified as the intracellular target of miR-7 and regulatory effects of miR-7 were seen to be exerted through translation repression of Bcl-2. The results of xenograft study revealed miR-7 overexpression significantly (P < 0.05) suppressed the growth of the tumor in vivo. The results point towards the therapeutic implications of miR-7 in the management of papillary carcinoma.

Role of microRNA-7 in liver diseases: a comprehensive review of the mechanisms and therapeutic applications

MicroRNA-7 (miR-7) is a small non-coding RNA, which plays critical roles in regulating gene expression of multiple key cellular processes. MiR-7 exhibits a tissue-specific pattern of expression, with abundant levels found in the brain, spleen, and pancreas. Although it is expressed at lower levels in other tissues, including the liver, miR-7 is involved in both the development of organs and biological functions of cells. In this review, we focus on the mechanisms by which miR-7 controls cell growth, proliferation, invasion, metastasis, metabolism, and inflammation. We also summarize the specific roles of miR-7 in liver diseases. MiR-7 is considered as a tumor suppressor miRNA in hepatocellular carcinoma and is involved in the pathogenesis of hepatic steatosis and hepatitis. Future studies to further define miR-7 functions and its mechanism in association with other types of liver diseases should be explored. An improved understanding from these studies will provide us a useful perspective leading to mechanism-based intervention by targeting miR-7 for the treatment of liver diseases.

Emerging role of non-coding RNAs in allergic disorders

RNA transcripts that not undergo translation into polypeptides recently came into focus of research. Long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) comprise the most important groups of these transcripts. LncRNAs have a length over 200 nucleotides and like mRNAs, have regulated transcription in a tissue specific manner. Biogenesis and function of lncRNAs is related to cell differentiation, response to stimuli and regulation of immune responses. LncRNAs can interact with both miRNAs and mRNAs. MiRNAs are characterized by a length of 22-24 nucleotides. MiRNAs regulate expression of genes at the post-transcriptional level. LncRNAs together with miRNAs are considered as regulators of the immune system. Alterations in their biogenesis is an important mechanism in the development immune related disorders. CircRNAs are products of aberrant maturation of protein-coding transcripts in a process of back-splicing, in which a single strand RNA molecule attains a closed circle shape. Despite a low expression, some circRNA were found to titrate miRNAs and interfere with maturation of legitimate protein-coding transcripts. We summarize the current knowledge on the role of non-coding transcripts in allergic disorders: asthma, atopic dermatitis, allergic rhinitis and urticaria. The reviewed data suggest lncRNA and miRNAs as therapeutic targets and biomarkers of allergic disorders.

LncRNA ANRIL/miR-7-5p/TCF4 axis contributes to the progression of T cell acute lymphoblastic leukemia

Background

Antisense non-coding RNA in the INK4 locus (ANRIL) is of great importance in cell biological behaviors, and ANRIL functions in many kinds of cancers including leukemia. However, the mechanism of ANRIL in the progression of T-cell acute lymphoblastic leukemia (T-ALL) has not been clarified clearly.

Methods

qRT-PCR was performed to detect ANRIL expression in T-ALL samples. T-ALL cell lines (MOLT4, CCRF-CEM and KOPT-K1) were used as the cell models. The function of ANRIL on T-ALL cells was investigated by CCK-8 assays, Transwell assays, and apoptosis experiments in vitro. qRT-PCR, Western blot, luciferase reporter assay and RIP assay were used to confirm the interactions between ANRIL and miR-7-5p, miR-7-5p and its target gene transcription factor 4 (TCF4).

Results

ANRIL was significantly up-regulated in T-ALL samples. Its knockdown markedly inhibited viability, migration and invasion of T-ALL cells, but its overexpression exerted the opposite effects. TCF4 was proved to be a target gene of miR-7-5p. ANRIL down-regulated miR-7-5p via sponging it and in turn up-regulated TCF4.

Conclusions

LncRNA ANRIL can modulate malignant phenotypes of T-ALL cells, possibly by regulating miR-7-5p/TCF4 axis, and it serves as a potential therapeutic target for T-ALL.

Decreased lncRNA, TINCR, promotes growth of colorectal carcinoma through upregulating microRNA-31

Abnormal expression in terminal differentiation-induced noncoding RNA (TINCR), a long non-coding RNA (lncRNA), has been reported in different human cancers, including colorectal carcinoma (CRC). Moreover, the molecular mechanisms that underlie the effects of TINCR on CRC remain unclear. Here, by a set of bioinformatics studies, we found that microRNA-31 (miR-31), the oncogenic miRNA that robustly upregulates in CRC, was a sponge miRNA for TINCR. TINCR and miR-31 levels were inversely correlated in both CRC tissues and CRC cell lines. Luciferase reporter assay revealed a specific binding site on TINCR for miR-31. Suppression of TINCR promoted CRC cell growth and migration in vitro, while overexpression of TINCR inhibited CRC cell growth and migration in vitro. TINCR depletion increased tumor xenograft growth in vivo, while TINCR overexpression inhibited it. Together, our study suggests that re-expressing TINCR may suppress invasive outgrowth of CRC through miR-31.

Long non-coding RNA TINCR as potential biomarker and therapeutic target for cancer

Despite the recent scientific advances made in cancer diagnostics and therapeutics, cancer still remains the second leading cause of death worldwide. Thus, there is a need to identify new potential biomarkers/molecular targets to improve the diagnosis and treatment of cancer patients. In this regard, long non-coding RNAs (lncRNAs), a type of non-coding RNA molecule, have been found to play important roles in diverse biological processes, including tumorigenesis, and may provide new biomarkers and/or molecular targets for the improved detection of treatment of cancer. For example, one lncRNA, tissue differentiation-inducing non-protein coding RNA (TINCR) has been found to be significantly dysregulated in many cancers, and has an impact on tumor development and progression through targeting pivotal molecules in cancer-associated signaling pathways. Hence, based on recent discoveries, herein, we discuss the regulatory functions and the underlying mechanisms of how TINCR regulates signaling pathways attributed to cancer hallmarks associated with the pathogenesis of various human cancers. We also highlight studies assessing its potential clinical utility as a biomarker/target for early detection, cancer risk stratification, and personalized cancer therapies.

Overexpression of lncRNA TINCR is associated with high-grade, invasive, and recurring tumors, and facilitates proliferation in vitro and in vivo of urothelial carcinoma of the bladder

OBJECTIVES

The aberrant expression of long noncoding RNAs (lncRNAs) plays roles in cancer development. In this work, we measured the expression of lncRNA terminal differentiation-induced non-coding RNA (TINCR) in urothelial carcinoma of the bladder (UCB), determined its impact on the proliferation of UCB in vitro and in vivo and identified its possible targets.

METHODS

The expression levels of genes were measured by Real-Time quantitative Polymerase Chain Reaction (qPCR). Cell proliferation, cell motility, and cell apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, wound healing assay, and ELISA, respectively. Tumor growth in vivo was determined by xenograft formation assay in nude mice. The predicted binding site between TINCR and hsa-miR-125b was confirmed by dual luciferase reporter assay.

RESULTS

The expression levels of TINCR were higher in cancerous tissues than that in paired noncancerous tissues of UCB. Higher expression levels of TINCR were positively associated with high-grade, invasive, and recurring tumors. Depletion of TINCR retarded proliferation, decreased motility, increased apoptosis in UCB cells, and markedly reduced tumor growth in xenograft nude mice. The predicted binding site between TINCR and hsa-miR-125b was functional. TINCR downregulated hsa-miR-125b in UCB cells. Hsa-miR-125b mimic reversed the proliferation caused by TINCR up-expression in UCB cells.

CONCLUSIONS

Up-regulation of TINCR may act as an unfavorable indicator for the diseasing status of UCB. TINCR facilitates bladder cancer proliferation in vitro and in vivo. Hsa-miR-125b is a target for TINCR in UCB.

TINCR is not a non-coding RNA but encodes a protein component of cornified epidermal keratinocytes

Long non-coding RNAs have been implicated in the regulation of a plethora of biological processes, yet it has been challenging to verify that they are truly not coding for proteins. Terminal differentiation-induced non-coding RNA (TINCR) is a 3.7-kilobase mRNA that is highly abundant in epidermal keratinocytes prior to cornification. Here, we report the presence of an evolutionarily conserved open reading frame in TINCR and the identification of peptides derived from this open reading frame in the proteome of human stratum corneum. Our results demonstrate that TINCR is a protein-coding RNA and suggest that the TINCR-encoded protein is involved in keratinocyte cornification.

lncRNA-TINCR Functions as a Competitive Endogenous RNA to Regulate the Migration of Mesenchymal Stem Cells by Sponging miR-761

Mounting evidences have indicated that terminal differentiation-induced lncRNA (TINCR) contributes to various cellular processes, such as proliferation, apoptosis, autophagy, migration, invasion, and metastasis. However, the function of TINCR in regulating migration of MSCs is largely unknown. In this study, the effects of TINCR on the migration of rat MSCs from the bone marrow were studied by Transwell assays and wound healing assays. Our results suggested that TINCR positively regulated migration of rMSCs. miR-761 mimics suppressed rMSC migration, whereas miR-761 inhibitor promoted migration. Target prediction analysis tools and dual-luciferase reporter gene assay identified Wnt2 as a direct target of miR-761. miR-761 could inhibit the expression of Wnt2. Further, the investigation about the function of TINCR in miR-761-induced migration of rMSCs was completed. These results demonstrated that TINCR took part in the regulation of miR-761-induced migration in rMSCs through the regulation of Wnt2 and its Wnt2 signaling pathway. Taken together, our results demonstrate that lncRNA-TINCR functions as a competitive endogenous RNA (ceRNA) to regulate the migration of rMSCs by sponging miR-761 which modulates the role of Wnt2. These findings provide evidence that lncRNA-TINCR has a chance to serve as a potential target for enhancing MSC homing through the miR-761/Wnt2 signaling pathway.

Knockdown of terminal differentiation induced ncRNA (TINCR) suppresses proliferation and invasion in hepatocellular carcinoma by targeting the miR-218-5p/DEAD-box helicase 5 (DDX5) axis

Terminal differentiation induced ncRNA (TINCR), a newly identified lncRNA, has been found to be associated with different human cancers including hepatocellular carcinoma (HCC). However, little is known regarding the pathological mechanisms of TINCR in HCC progression. In this study, we confirmed that TINCR expression was upregulated in HCC tumors and cell lines, and high TINCR expression was associated with larger tumor size, advanced tumor node metastasis stage, and poor prognosis. Functionally, knockdown of TINCR facilitated apoptosis and suppressed viability, colony formation and invasion in Huh7 and Hep3B cells. Mechanically, TINCR functioned as competing endogenous RNA (ceRNA) to regulate DEAD-box helicase 5 (DDX5) expression through sponging miR-218-5p. Moreover, the miR-218-5p expression was downregulated and DDX5 expression was upregulated in HCC tumors. The silencing of miR-218-5p or ectopic expression of DDX5 abated the tumor-suppressive effect of TINCR knockdown in vitro. Furthermore, si-TINCR-induced inactivation of AKT signaling was rescued by suppression of miR-218-5p or overexpression of DDX5. Also, the silencing of TINCR resulted in tumor growth inhibition in vivo. In summary, knockdown of TINCR suppressed HCC progression presumably by inactivation of AKT signaling through targeting the miR-218-5p/DDX5 axis, suggesting a novel TINCR/miR-218-5p/DDX5 pathway and therapy target for HCC.

Retracted Article: lncRNA TINCR sponges miR-214-5p to upregulate ROCK1 in hepatocellular carcinoma

Background

Our preliminary bioinformatics analysis showed that lncRNA TINCR may absorb miR-214-5p by serving is sponge, while miR-214-5p targets ROCK1. This study aimed to investigate the interactions among these 3 factors in hepatocellular carcinoma (HCC).

Methods

Expression of TINCR, ROCK1 and miR-214-5p in HCC and non-tumor tissues was detected by performing qPCR. The correlations among TINCR, ROCK1 and miR-214-5p in HCC tissues were analyzed by performing linear regression. Overexpression experiments were performed to analyze gene interactions. Cell proliferation was analyzed by CCK-8 assay.

Results

We found that TINCR and ROCK1 were upregulated, while miR-214-5p was downregulated in HCC. TINCR and ROCK1 were positively correlated, while TINCR and miR-214-5p were not significantly correlated. In HCC cells, TINCR overexpression is followed by ROCK1 overexpression, while miR-214-5p overexpression induced the downregulation of ROCK1. In addition, TINCR and miR-214-5p did not affect the expression of each other. TINCR and ROCK1 overexpression led to increased rate of cancer cell proliferation, while miR-214-5p played an opposite role and reduced the effects of TINCR overexpression. Therefore, TINCR sponges miR-214-5p to upregulate ROCK1 in HCC, thereby promoting cancer cell invasion and migration.

The regulation and interaction of colon cancer-associated transcript-1 and miR7-5p contribute to the inhibition of SP1 expression by solamargine in human nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is a common head and neck malignancy with higher incidence in Southern China and Southeast Asia. Solamargine (SM), a steroidal alkaloid glycoside, has been shown to have anticancer properties. However, the underlying mechanism involved remains undetermined. In this study, we showed that SM inhibited the growth of NPC cells. Mechanistically, we found that solamargine decreased lncRNA colon cancer-associated transcript-1 (CCAT1) and increased miR7-5p expression. There was a reciprocal interaction of CCAT1 and miR7-5p. In addition, SM inhibited the expression of SP1 protein and promoter activity, which was strengthened by miR7-5p mimics and inhibited by overexpressed CCAT1. MiR7-5p could bind to 3'-UTR of SP1 and attenuated SP1 gene expression. Exogenously expressed SP1 feedback resisted SM-increased miR7-5p expression and more importantly reversed SM-inhibited growth of NPC cells. Finally, SM inhibited NPC tumor growth in vivo. Collectively, our results show that SM inhibits the growth of NPC cells through reciprocal regulation of CCAT1 and miR7-5p, followed by inhibition of SP1 gene expression in vitro and in vivo. The interregulation and correlation among CCAT1, miR7-5p and SP1, and the feedback regulatory loop unveil the novel molecular mechanism underlying the overall responses of SM in anti-NPC.

Noncoding RNAs in inflammation and colorectal cancer

Despite advanced clinical treatments, mortality in patients with metastatic colorectal cancer (CRC) remains high. Three critical determinants in CRC progression include the epithelial proliferation checkpoints, epithelial-to-mesenchymal transition (EMT) and inflammatory cytokines in the tumour microenvironment. Genes involved in these three processes are regulated at the transcriptional and post-transcriptional level. Recent studies revealed previously unappreciated roles of non-coding ribonucleic acids (ncRNAs) in modulating the proliferation checkpoints, EMT, and inflammatory gene expression in CRC. In this review, we will discuss the mechanisms underlying the roles of ncRNAs in CRC as well as examine future perspectives in this field. Better understanding of ncRNA biology will provide novel targets for future therapeutic development.

Dysregulation of pseudogene/lncRNA-hsa-miR-363-3p-SPOCK2 pathway fuels stage progression of ovarian cancer

Objective: Ovarian cancer is one of the most common and lethal cancer types in women. The molecular mechanism of ovarian cancer progression is still unclear.

Results: Here, we first reported that expression levels of three genes, GJB2, S100A2 and SPOCK2, were significantly higher in advanced stage than that in early stage of ovarian cancer, and upregulation of them indicated poor prognosis of patients with ovarian cancer. Subsequently, 8, 6 and 20 miRNAs were predicted to target GJB2, S100A2 and SPOCK2, respectively. Among these miRNA-mRNA pairs, hsa-miR-363-3p-SPOCK2 axis was the most potential in suppressing progression of ovarian cancer. Mechanistically, we found that hsa-miR-363-3p-SPOCK2 axis was involved in regulation of actin cytoskeleton. Moreover, 6 pseudogenes and 8 lncRNAs were identified to potentially inhibit hsa-miR-363-3p-SPOCK2 axis in ovarian cancer.

Conclusions: Collectively, we elucidate a regulatory role of pseudogene/lncRNA-hsa-miR-363-3p-SPOCK2 pathway in progression of ovarian cancer, which may provide effective therapeutic approaches and promising prognostic biomarkers for ovarian cancer.

Materials and methods: Differentially expressed genes (DEGs) in ovarian cancer were first screened using GSE12470, after which DEGs expression were validated using GEPIA. Kaplan-Meier analysis was employed to assess the prognostic values. Potential miRNAs were predicted by seven target prediction databases, and upstream lncRNAs and pseudogenes of hsa-miR-363-3p were forecasted through miRNet or starBase. UALCAN and starBase were used to obtain the co-expressed genes of SPOCK. Enrichment analysis for these co-expressed genes was performed by Enrichr.

An Integrated Three-Long Non-coding RNA Signature Predicts Prognosis in Colorectal Cancer Patients

Colorectal cancer (CRC) is one of the most common cancers worldwide, whose morbidity and mortality gradually increased. Here, we aimed to identify and access prognostic long non-coding RNAs (lncRNAs) associated with overall survival (OS) in CRC. Firstly, RNA expression profiles were obtained from The Cancer Genome Atlas (TCGA) database, and 439 CRC patients were enrolled as a training set. Univariate Cox analysis and the least absolute shrinkage and selection operator analysis (LASSO) were performed to identify the prognostic lncRNAs. Multivariable Cox regression analysis was used to establish a prognostic risk formula including three lncRNAs (AP003555.2, AP006284.1, and LINC01602). The low-risk group had a better OS than the high-risk group (P < 0.0001), and the areas under the receiver operating characteristic curve (AUCs) of 3- and 5-year OS were 0.712 and 0.674, respectively. Then, we evaluated the signature in a clinical validation set which were collected from the Affiliated Hospital of Jiangnan University. Compared with the low-risk group, patients' OS were found to be significantly worse in the high-risk group (P = 0.0057). The AUCs of 3- and 5-year OS were 0.701 and 0.694, respectively. Finally, we constructed an lncRNA–microRNA (miRNA)–messenger RNA (mRNA) competing endogenous RNA (ceRNA) network to explore the potential function of three differentially expressed lncRNAs (DElncRNAs). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these DElncRNAs were involved with several cancer-related pathways. In summary, our data provide evidence that the three-lncRNA signature could serve as an independent biomarker to predict prognosis in CRC. This study will also suggest that these three lncRNAs potentially participate in the progression of CRC.

SP1-mediated long noncoding RNA POU3F3 accelerates the cervical cancer through miR-127-5p/FOXD1

Emerging evidence supports the critical roles of long noncoding RNA (lncRNA) in cervical cancer. However, the pathological roles of lncRNA POU3 F3 in the cervical cancer tumorigenesis are still elusive. POU3 F3 was validated to be up-regulated in the cervical cancer tissue specimens and cells comparing with normal controls. Moreover, the ectopic overexpression of POU3 F3 was closely correlated with poor prognosis. In vitro, POU3 F3 promoted the proliferation, invasion of cervical cancer cells. In vivo, POU3 F3 knockdown repressed the tumor growth of cervical cancer cells. The transcriptional expression of POU3 F3 was activated by the transcription factor SP1. Mechanically, POU3 F3 acted as the sponge to target miR-127-5p, while miR-127-5p bind with the 3'-UTR of FOXD1 gene. In conclusion, our data verifies that lncRNA POU3 F3, induced by transcription factor SP1, acts as an oncogene in the cervical cancer tumorigenesis via regulating miR-127-5p/FOXD1 axis, providing a possible therapeutic target for cervical cancer.

Sp1-induced upregulation of the long noncoding RNA TINCR inhibits cell migration and invasion by regulating miR-107/miR-1286 in lung adenocarcinoma

Long non-coding RNA tissue differentiation-inducing non-protein coding (TINCR) is associated with the carcinogenesis of several cancers. However, little is known about the function and mechanism of TINCR in lung adenocarcinoma (LUAD). Here, we aimed to analyze expression of TINCR and elucidate its mechanistic involvement in the progression of LUAD. The expression of TINCR was investigated according to Gene Expression Profiling Interactive Analysis at first and then detected in 29 LUAD tissues and paired adjacent normal tissues using qRT-PCR. Results indicated that TINCR was evidently downregulated in LUAD. The association between TINCR and clinicopathological parameters was analyzed by Pearson's chi-square test, suggesting TINCR was closely correlated with TNM stage and lymph mode metastasis. Subsequently, the function role of TINCR was examined by gain- and loss-of-function studies in LUAD (A549 and NCI-H292) cells. As analyzed by the scratch wound-healing and transwell assays, results revealed that TINCR suppressed the migration and invasion of A549 and NCI-H292 cells. However, TINCR exerted no effects on the cell proliferation as determined by CCK8 assay. Furthermore, we reported that loss of Sp1 could inhibit TINCR expression. Expressions of miR-107/miR-1286 were detected by qRT-PCR assay in A549 and NCI-H292 cells after TINCR knockdown or overexpression. In addition, the direct binding ability of the predicted miR-107 or miR-1286 binding site on TINCR was validated by luciferase activity assay. Results indicated TINCR could constrain the expression of miR-107/miR-1286, and was a target of them in LUAD cells. Bioinformatics analyses showed that BTRC and RAB14 was the potential target gene of miR-107 and miR-1286, respectively. These data revealed a possible regulatory mechanism in which upregulation of TINCR induced by Sp1 could constrain the migration and invasion through regulating miR-107 or miR-1286 in LUAD cells. Conjointly, our findings provide a valuable insight into the regulatory mechanism of TINCR in LUAD, supportive to its potential of therapeutic target for LUAD patients.

Long Non-coding RNA Zinc Finger Antisense 1 (ZFAS1) Regulates Proliferation, Migration, Invasion, and Apoptosis by Targeting MiR-7-5p in Colorectal Cancer

Background

Colorectal cancer (CRC) is one of the most common tumors, the causes of which remain unclear. Recently, many kinds of long non-coding RNAs (lncRNAs) have been identified to have an important role in the biological function of CRC. However, the effect of lncRNA zinc finger antisense 1 (ZFAS1) on development of CRC is still incompletely clear.

Material/Methods

Firstly, the expression of ZFAS1 and microRNA (miR)-7-5p in 40 CRC tissues and adjacent tissues was measured by real-time polymerase chain reaction. Then, we detected the cell proliferation, migration, invasion, and apoptosis in CRC cell lines by using Cell Counting Kit-8 assay, colony formation assay, flow analysis, and Transwell assay, respectively. Then, the relationship between ZFAS1 and miR-7-5p was verified by luciferase reporter assay. Finally, rescue experiments were conducted to confirmed that interaction of ZFAS1 and miR-7-5p in vitro.

Results

Our results showed that ZFAS1 was upregulated in CRC tissues, correlated with overall survival rates, and negatively related to the expression of miR-7-5p. It was verified that miR-7-5p was a direct target of ZFAS1 by bioinformatics analysis and luciferase reporter assay. In addition, knockdown of miR-7-5p inhibited proliferation, migration, and invasion, and promoted apoptosis in CRC cell lines, which could be rescue by miR-7-5p inhibitor.

Conclusions

Our study indicated that ZFAS1 directly targeted miR-7-5p, and knockdown of it could inhibit tumor growth, migration, invasion, and induce apoptosis in CRC. These data might provide a potent treatment mechanism or promising biomarker for CRC.

p53-induced long non-coding RNA PGM5-AS1 inhibits the progression of esophageal squamous cell carcinoma through regulating miR-466/PTEN axis

A growing body of evidence suggests that long non-coding RNA (lncRNA) is aberrantly expressed in human cancer and linked to cancer initiation and development. We previously identified Homo sapiens PGM5 antisense RNA 1 (PGM5-AS1) as a novel esophageal squamous cell carcinoma (ESCC)-related lncRNA by performing high-throughput RNA sequencing. However, its clinical implication and biological function in ESCC are still uncharacterized. In the present study, we found that PGM5-AS1 was frequently downregulated in ESCC tissues, plasma, and cell lines, and low PGM5-AS1 expression was positively correlated with poor differentiation, advanced tumor node metastasis (TNM) stage, and lymph node metastasis. Importantly, PGM5-AS1 was identified to be an effective diagnostic and prognostic biomarker for ESCC patients. Functional experiments revealed that exogenous expression of PGM5-AS1 significantly suppressed the proliferation, migration, and invasion of ESCC cells in vitro as well as tumor growth in vivo. Mechanistically, PGM5-AS1 was transcriptionally activated by p53 and it could directly interact with and sequester miR-466 to elevate PTEN expression, thereby inhibiting ESCC progression. Overall, our data indicate that PGM5-AS1 is a novel tumor suppressor in ESCC and restoration of PGM5-AS1 may be a promising avenue for treatment of ESCC patient.