Diagnostic efficacy of long non-coding RNA in lung cancer: a systematic review and meta-analysis

LncRNA GAS5 Modulates the Progression of Glioma Through Repressing miR-135b-5p and Upregulating APC

Purpose

The main purpose of this paper is to explore the interaction between GAS5 and miR-135b-5p to understand their function in the metastasis, invasion, and proliferation of glioma. This may provide new ideas for the pathogenesis and treatment of glioma.

Patients and Methods

Western blotting assays and RT‑qPCR were employed to investigate the expression of related genes in glioma tissues or cell lines. CCK-8 was used to examine the impact of GAS5 on cell viability. Motile activities were adopted by the transwell and wound healing experiments. A double luciferase experiment was performed to elucidate transcriptional regulation.

Results

GAS5 showed low expression in glioma cells and tissues, and up-regulation of GAS5 could depress the invasion, proliferation, and metastasis of glioma. GAS5 negatively regulates miR-135b-5p, which can counteract the cellular effects caused by GAS5. APC was the target of miR-135b-5p, and GAS5 can regulate the expression of APC by sponging miR-135b-5p. APC overexpression reversed the effects of miR-135b-5p promotion on glioma cells, while miR-135b-5p has the opposite function. As a downstream target gene of GAS5, miR-135b-5p was negatively regulated by GAS5. The restoration of miR-135b-5p can remarkably reverse the impact of GAS5 on glioma cells. In addition, GAS5 increased the expression of APC in glioma cells by inhibiting miR-135b-5p.

Conclusion

GAS5 increased APC expression by restraining miR-135b-5p and partially blocked the progression of glioma, suggesting that it could be an advantageous therapeutic target for glioma intervention.

Glycation-Associated Diabetic Nephropathy and the Role of Long Noncoding RNAs

The glycation of various biomolecules is the root cause of many pathological conditions associated with diabetic nephropathy and end-stage kidney disease. Glycation imbalances metabolism and increases renal cell injury. Numerous therapeutic measures have narrowed down the adverse effects of endogenous glycation, but efficient and potent measures are miles away. Recent advances in the identification and characterization of noncoding RNAs, especially the long noncoding RNAs (lncRNAs), have opened a mammon of new biology to explore the mitigations for glycation-associated diabetic nephropathy. Furthermore, tissue-specific distribution and condition-specific expression make lncRNA a promising key for second-generation therapeutic interventions. Though the techniques to identify and exemplify noncoding RNAs are rapidly evolving, the lncRNA study encounters multiple methodological constraints. This review will discuss lncRNAs and their possible involvement in glycation and advanced glycation end products (AGEs) signaling pathways. We further highlight the possible approaches for lncRNA-based therapeutics and their working mechanism for perturbing glycation and conclude our review with lncRNAs biology-related future opportunities.

Dysregulated LINC00961 Contributes to the Vitality and Migration of NSCLC Via miR-19a-3p/miR-19b-3p/miR-125b-5p

Accumulating evidence implies that long noncoding RNAs participate in non-small cell lung cancer (NSCLC) tumorigenesis. Our current study synthetically analyzed RNA sequencing data downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We identified LINC00961 significantly downregulated in NSCLC tissues. We explored the LINC00961 expression in NSCLC tumor tissues and cell lines with reverse transcription-quantitative polymerase chain reaction analysis. Lentivirus-mediated infection upregulated the expression of LINC00961 in A549 cells. The proliferation and migration capability were also measured in A549 cells. In addition, we performed luciferase reporter gene assay to investigate whether LINC00961 directly interacts with miR-19a-3p/miR-19b-3p/miR-125b-5p. A nude mice model was used to detect the potential biological process of LINC00961 on tumor growth in vivo. The results showed that LINC00961 was significantly down-egulated in NSCLC tissues and cell lines. LV-LINC00961 effectively increased the expression of LINC00961 and decreased the expression of miR-19a-3p/miR-19b-3p/miR-125b-5p. LINC00961 upregulation remarkably inhibited cell proliferation, migration, and invasion while promoting cell apoptosis in A549 cells. Luciferase reporter gene assay revealed that LINC00961 could directly sponge miR-19a-3p/miR-19b-3p/miR-125b-5p. Moreover, overexpressed miR-19a-3p/miR-19b-3p/miR-125b-5p reversed the effect of LINC00961 on cell function of A549 cells. Western blot assays revealed that LINC00961 could partially act as a tumor suppressor via affecting PI3K-AKT/MAPK/mTOR signaling pathway. In addition, overexpressed LINC00961-inhibited tumor growth was demonstrated in vivo. Overexpression of LINC00961 inhibited cell viability, invasion, and induced apoptosis in NSCLC, potentially via suppressing the expression of miR-19a-3p/miR-19b-3p/miR-125b-5p by targeting PI3K-AKT/MAPK/mTOR signaling pathways, which might provide the potential biomarker for NSCLC diagnosis and therapies.

Association between long non-coding RNA (lncRNA) GAS5 polymorphism rs145204276 and cancer risk

OBJECTIVE

The long non-coding RNA (lncRNA) growth arrest‑specific transcript 5 (GAS5) plays an important role in various tumors, and an increasing number of studies have explored the association of the GAS5 rs145204276 polymorphism with cancer risk with inconclusive results.

METHODS

PubMed, Medline, EMBASE, Cochrane databases, and Web of Science were searched, and nine studies involving 6107 cases and 7909 controls were deemed eligible. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the relationship between rs145204276 and cancer risk in six genetic models.

RESULTS

The pooled results suggest that the variant allele del was not associated with overall cancer risk. However, the subgroup analysis showed that allele del was significantly associated with a 22% decreased risk of gastrointestinal cancer (OR = 0.78, 95% CI: 0.72-0.85). Both sensitivity analyses and trial sequential analyses (TSA) demonstrated that the subgroup results were reliable and robust. Moreover, False-Positive Report Probability (FPRP) analysis indicated that the results had true significant correlations.

CONCLUSION

These findings provide evidence that the GAS5 rs145204276 polymorphism is associated with the susceptibility to gastrointestinal cancer. Further studies with different ethnicities and larger sample sizes are warranted to confirm these results.

Prognostic and immunological significance of metastasis associated lung adenocarcinoma transcript 1 among different kinds of cancers

LncRNAs belong to the type of noncoding RNA transcripts, which exceed 200 nucleotides in size. MALAT1 as one of the earlier identified lncRNAs in cancer is investigated by more and more scientific researchers. Expression, clinical significance and function of MALAT1 in pan-cancer exist as big difference. To detect the expression and clinical significance of MALAT1 gene precisely and comprehensively among different kinds of cancers, some classical databases such as GEPIA, TIMER, KM Plotter, and PrognoScan were fully applied. An immunological role of MALAT1 among different kinds of cancers was also determined in TIMER database. Our results showed that MALAT1 was differently expressed in different kinds of cancers using GEPIA, Oncomine, and TIMER databases to analyze. Especially, MALAT1 high RNA level was related to the early stage in lung and gastric cancer patients. MALAT1 expression was closely related to prognosis among different cancer patients. Furthermore, expression of MALAT1 was related to tumor immune cell infiltrating. Expression level of MALAT1 was also related to immune makers such as macrophage, T cell, NK cells, and so on. These findings indicate that MALAT1 could be a potential prognostic biomarker of some kinds of cancer and was significantly correlated with tumor-infiltrating immune cells in a wide variety of cancers.

Progress in understanding the role of lncRNA in programmed cell death

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides but not translated into proteins. LncRNAs regulate gene expressions at multiple levels, such as chromatin, transcription, and post-transcription. Further, lncRNAs participate in various biological processes such as cell differentiation, cell cycle regulation, and maintenance of stem cell pluripotency. We have previously reported that lncRNAs are closely related to programmed cell death (PCD), which includes apoptosis, autophagy, necroptosis, and ferroptosis. Overexpression of lncRNA can suppress the extrinsic apoptosis pathway by downregulating of membrane receptors and protect tumor cells by inhibiting the expression of necroptosis-related proteins. Some lncRNAs can also act as competitive endogenous RNA to prevent oxidation, thereby inhibiting ferroptosis, while some are known to activate autophagy. The relationship between lncRNA and PCD has promising implications in clinical research, and reports have highlighted this relationship in various cancers such as non-small cell lung cancer and gastric cancer. This review systematically summarizes the advances in the understanding of the molecular mechanisms through which lncRNAs impact PCD.

Downregulation of long non‑coding RNA GACAT1 suppresses proliferation and induces apoptosis of NSCLC cells by sponging microRNA‑422a

Increasing evidence has demonstrated the important roles of long non‑coding (lnc) RNA in non‑small cell lung cancer (NSCLC). lncRNA gastric cancer‑associated transcript 1 (GACAT1) has been reported to play an oncogenic role in different types of cancer; however, the function of GACAT1 in NSCLC remains unclear. The present study found that GACAT1 was overexpressed in NSCLC tissues and was associated with poor outcomes in patients with NSCLC. Functional experiments revealed that GACAT1 downregulation inhibited proliferation, induced apoptosis and cell cycle arrest of 2 NSCLC cell lines. GACAT1 was found to target microRNA(miR)‑422a mechanically and negatively regulated miR‑422a expression. Reduced expression of miR‑422a in NSCLC tissues was inversely correlated with that of GACAT1. Furthermore, YY1 transcription factor (YY1) was identified as a downstream miR‑422a target. Reduced expression of GACAT1 inactivated YY1 by sponging miR‑422a in NSCLC cells. YY1 reintroduction reversed the reduced proliferation of NSCLC cells via GACAT1 knockdown. Taken together, these results revealed the novel role of the GACAT1/miR‑422a pathway in the progression of NSCLC cell lines, providing a possible therapeutic strategy for NSCLC treatment.

LncRNA MALAT1 accelerates non-small cell lung cancer progression via regulating miR-185-5p/MDM4 axis

Non-small cell lung cancer (NSCLC) is the commonest malignancy with high death rate around the world. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is greatly overexpressed in multifarious cancers, including NSCLC. However, the precise mechanism of MALAT1 in NSCLC tumorigenesis is blurry. This paper aims to investigate the theory of MALAT1 action in NSCLC progression. The levels of MALAT1, microRNA (miR)-185-5p, and mouse double minute 4 protein (MDM4) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell proliferation and apoptosis were, respectively, determined by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and flow cytometry. Cell migratory and invasive abilities were inspected by transwell assay. The binding relationship between miR-185-5p and MALAT1 or MDM4 was confirmed by dual-luciferase reporter assay. The impacts of MALAT1 on tumor growth in vivo were measured by a xenograft experiment. We found MALAT1 and MDM4 were upregulated and MALAT1 positively regulated the MDM4 expression. MALAT1 and MDM4 deletion significantly hindered the proliferation, metastasis, and expedited the apoptosis of NSCLC cells. MDM4 overexpression partly overturned the influence of MALAT1 downregulation on cell development. Moreover, miR-185-5p, as a target of MALAT1, could directly target MDM4, and miR-185-5p upregulation exerted inhibitory effects on NSCLC cells. Besides, knockdown of MALAT1 inhibited tumor growth in vivo through miR-185-5p/MDM4 axis in NSCLC. Collectively, MALAT1 contributed to proliferation, migration, invasion, and impeded apoptosis by regulating the MDM4 expression mediated by miR-185-5p in NSCLC cells.

m6 A transferase METTL3-induced lncRNA ABHD11-AS1 promotes the Warburg effect of non-small-cell lung cancer

N⁶ -methyladenosine (m⁶ A) and long noncoding RNAs (lncRNAs) are both crucial regulators in non-small-cell lung cancer (NSCLC) tumorigenesis. However, the pathological roles of m⁶ A and lncRNAs in NSCLC progression are still limited and undefined. Here, lncRNA ABHD11-AS1 was upregulated in NSCLC tissue specimens and cells and the ectopic overexpression was closely correlated with unfavorable prognosis of NSCLC patients. Functionally, ABHD11-AS1 promoted the proliferation and Warburg effect of NSCLC. Mechanistically, m⁶ A profile was analyzed by methylated RNA immunoprecipitation sequencing (MeRIP-Seq). MeRIP-Seq presented that there was m⁶ A modification site in ABHD11-AS1. m⁶ A methyltransferase-like 3 (METTL3) installed the m⁶ A modification and enhanced ABHD11-AS1 transcript stability to increase its expression. In conclusion, our findings highlight the function and mechanism of METTL3-induced ABHD11-AS1 in NSCLC and inspire the understanding of m⁶ A and lncRNA in cancer biology.

A five-long non-coding RNA signature with the ability to predict overall survival of patients with lung adenocarcinoma

An increasing number of studies have indicated that the abnormal expression of certain long non-coding RNAs (lncRNAs) is linked to the overall survival (OS) of patients with lung adenocarcinoma (LUAD). The aim of the present study was to establish an lncRNA signature to predict the survival of patients with LUAD. The gene expression profiles and associated clinical information of patients with LUAD were downloaded from The Cancer Genome Atlas database. The cohort was randomly sub-divided into training and verification cohorts. Univariate Cox regression analysis was performed on differentially expressed lncRNAs in the training cohort to select candidate lncRNAs closely associated with survival. Next, a risk score (RS) model consisting of 5 lncRNAs was established by multivariate Cox regression analysis on candidate lncRNAs. Using the median RS obtained from the training cohort as a cut-off point, patients were classified into high- and low-risk groups. Kaplan-Meier survival analysis revealed a significant difference in OS between high- and low-risk groups. The survival prediction ability of the 5-lncRNA signature was further tested in the verification and total cohorts. The results proved that the 5-lncRNA signature had good reliability and stability in survival prediction for patients with LUAD. The univariate Cox regression analysis for the 5-lncRNA signature in each cohort indicated that the 5-lncRNA signature was closely associated with survival. Multivariate Cox regression analysis and stratification analysis proved that the prognostic signature was an independent predictor of survival for patients with LUAD. In addition, functional enrichment analysis indicated that the 5 prognostic lncRNAs may be involved in the tumorigenesis of LUAD through cancer-associated pathways and biological processes. Taken together, the present study provided a 5-lncRNA signature that may serve as an independent survival predictor for patients with LUAD.

Exosomal long non-coding RNA DLX6-AS1 as a potential diagnostic biomarker for non-small cell lung cancer

Distal-less homeobox 6 antisense RNA 1 (DLX6-AS1) is upregulated in various solid tumors and serves a critical role in the tumorigenesis of cancer. However, to the best of our knowledge, the expression of circulating DLX6-AS1 and its role in the diagnosis of non-small cell lung cancer (NSCLC) have not been previously clarified. The aim of the present study was to investigate the expression and clinical significance of circulating DLX6-AS1 using reverse transcription-quantitative PCR in serum and exosomes derived from patients with NSCLC and healthy donors. The diagnostic value of circulating DLX6-AS1 was identified by receiver operating characteristic curve (ROC) analysis. First, it was revealed that the expression levels of DLX6-AS1 were significantly increased in tumor tissues compared with in adjacent normal tissues. In addition, DLX6-AS1 was highly expressed in NSCLC cell lines compared with in BEAS-2B cells. DLX6-AS1-knockdown inhibited cell proliferation and migration in vitro. It was subsequently demonstrated that the serum DLX6-AS1 level was significantly higher in patients with NSCLC compared with in healthy controls. Additionally, the higher DLX6-AS1 expression was associated with advanced disease stage, positive lymph node metastasis and poor tumor differentiation of NSCLC. ROC analysis demonstrated that the sensitivity and specificity of DLX6-AS1 were higher than those of CYFRA21-1, which is a serum marker for NSCLC. Finally, exosomal DLX6-AS1 expression was increased in patients with NSCLC compared with in healthy controls. The present data implied that circulating DLX6-AS1 was mainly incorporated into exosomes, providing a novel potential diagnostic marker for NSCLC.

Prognostic value of long non-coding RNA 01296 expression in human solid malignant tumours: a meta-analysis

Long intergenic non-coding RNA 01296 (LINC01296) has been reported to play an important role in many human malignancies, but a consistent perspective has not been established now. To explore the prognostic value of LINC01296 in different types of human solid malignant tumours, we performed this meta-analysis.An electronic search of PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure, Cochrane Library, Chinese Biological Medical Literature database and WanFang database was applied to select eligible literatures. Pooled ORs or HRs with their 95% CIs were calculated to estimate the effects.A total of 559 patients from nine eligible studies were enrolled in this meta-analysis. The results revealed that high LINC01296 expression was significantly related to larger tumour size (OR 3.42, 95% CI 2.08 to 5.63), lymph node metastasis (OR 3.03, 95% CI 2.01 to 4.57) and advanced tumor-node-metastasis (TNM) stage (OR 4.41, 95% CI 2.65 to 7.34). Moreover, we found that elevated LINC01296 expression predicted a poor outcome for overall survival (HR 1.78, 95% CI 1.48 to 2.14) and recurrence-free survival (HR 4.00, 95% CI 1.04 to 15.67).High expression levels of LINC01296 were associated with unfavourable clinical outcomes of patients with cancer. Our results indicated that LINC01296 could serve as a prognostic predictor in human solid malignant tumours.

Noncoding RNAs in Extracellular Fluids as Cancer Biomarkers: The New Frontier of Liquid Biopsies

The last two decades of cancer research have been devoted in two directions: (1) understanding the mechanism of carcinogenesis for an effective treatment, and (2) improving cancer prevention and screening for early detection of the disease. This last aspect has been developed, especially for certain types of cancers, thanks also to the introduction of new concepts such as liquid biopsies and precision medicine. In this context, there is a growing interest in the application of alternative and noninvasive methodologies to search for cancer biomarkers. The new frontiers of the research lead to a search for RNA molecules circulating in body fluids. Searching for biomarkers in extracellular body fluids represents a better option for patients because they are easier to access, less painful, and potentially more economical. Moreover, the possibility for these types of samples to be taken repeatedly, allows a better monitoring of the disease progression or treatment efficacy for a better intervention and dynamic treatment of the patient, which is the fundamental basis of personalized medicine. RNA molecules, freely circulating in body fluids or packed in microvesicles, have all the characteristics of the ideal biomarkers owing to their high stability under storage and handling conditions and being able to be sampled several times for monitoring. Moreover, as demonstrated for many cancers, their plasma/serum levels mirror those in the primary tumor. There are a large variety of RNA species noncoding for proteins that could be used as cancer biomarkers in liquid biopsies. Among them, the most studied are microRNAs, but recently the attention of the researcher has been also directed towards Piwi-interacting RNAs, circular RNAs, and other small noncoding RNAs. Another class of RNA species, the long noncoding RNAs, is larger than microRNAs and represents a very versatile and promising group of molecules which, apart from their use as biomarkers, have also a possible therapeutic role. In this review, we will give an overview of the most common noncoding RNA species detectable in extracellular fluids and will provide an update concerning the situation of the research on these molecules as cancer biomarkers.

Long noncoding RNA HOXA-AS2 promotes non-small cell lung cancer progression by regulating miR-520a-3p

Background: The HOXA cluster antisense RNA 2 (HOXA-AS2) has recently been discovered to be involved in carcinogenesis in multiple cancers. However, the role and underlying mechanism of HOXA-AS2 in non-small cell lung cancer (NSCLC) yet need to be unraveled. Methods: HOXA-AS2 expression in NSCLC tissues and cell lines was detected using quantitative real-time PCR (qRT-PCR). Furthermore, the effects of HOXA-AS2 on NSCLC cell proliferation, apoptosis, migration, and invasion were assessed by MTS, flow cytometry, wound healing and transwell invasion assays, respectively. Starbase2.0 predicted and luciferase reporter and RNA immunoprecipitation (RIP) assays were used to validate the association of HOXA-AS2 and miR-520a-3p in NSCLC cells. Results: Our results revealed that HOXA-AS2 in NSCLC tissues were up-regulated and cell lines, and were associated with poor prognosis and overall survival. Further functional assays demonstrated that HOXA-AS2 knockdown significantly inhibited NSCLC cell proliferation, induced cell apoptosis and suppressed migration and invasion. Starbase2.0 predicted that HOXA-AS2 sponge miR-520a-3p at 3'-UTR, which was confirmed using luciferase reporter and RIP assays. miR-520a-3p expression was inversely correlated with HOXA-AS2 expression in NSCLC tissues. In addition, miR-520a-3p inhibitor attenuated the inhibitory effect of HOXD-AS2-depletion on cell proliferation, migration and invasion of NSCLC cells. Moreover, HOXA-AS2 could regulate HOXD8 and MAP3K2 expression, two known targets of miR-520a-3p in NSCLC. Conclusion: These findings implied that HOXA-AS2 promoted NSCLC progression by regulating miR-520a-3p, suggesting that HOXA-AS2 could serve as a therapeutic target for NSCLC.

Overexpression of lncRNA GAS5 suppresses prostatic epithelial cell proliferation by regulating COX-2 in chronic non-bacterial prostatitis

Chronic non-bacterial prostatitis (CNP) is a common urologic disease that is linked to the development of prostate cancer. Long non-coding RNA (lncRNA) GAS5 has been identified to mediate cell proliferation in prostate cancer, although its role in CNP is still unclear. Human prostate epithelial cell line RWPE-1 was induced by lipopolysaccharide (LPS) to mimic CNP model in vitro. Real-time PCR was performed to determine the expression of GAS5 and COX-2, while western blotting was used to evaluate the protein expression of COX-2. The interaction between GAS5 and COX-2 was determined using RNA pull-down and RNA immunoprecipitation (RIP). Cell proliferation was determined using MTT assay. The expression of GAS5 was decreased, while COX-2 was increased in prostatitis tissues and in LPS-induced RWPE-1 cells. The overexpression of GAS5 suppressed the protein level of COX-2, and inhibited cell proliferation of LPS-induced RWPE-1 cells and HPECs, which was rescued by the co-transfection with pcDNA-GAS5 and pcDNA-COX-2. GAS5 was confirmed to promote the ubiquitination of COX-2, and the in vivo GAS5-overexpressed CNP rat model decreased the motor scores, the volume of prostate tissues, the average number of inflammatory cells, prostatic proliferation, and COX-2 expression. Our findings revealed that overexpression of GAS5 inhibited cell proliferation via negatively regulating the expression of COX-2, thus alleviating the progression of CNP.