Upregulated NNT-AS1, a long noncoding RNA, contributes to proliferation and migration of colorectal cancer cells in vitro and in vivo

Unveiling the Genetic Complexity of Teratozoospermia: Integrated Genomic Analysis Reveals Novel Insights into lncRNAs' Role in Male Infertility

Male infertility is a global health issue, affecting over 20 million men worldwide. Genetic factors are crucial in various male infertility forms, including teratozoospermia. Nonetheless, the genetic causes of male infertility remain largely unexplored. In this study, we employed whole-genome sequencing and RNA expression analysis to detect differentially expressed (DE) long-noncoding RNAs (lncRNAs) in teratozoospermia, along with mutations that are exclusive to teratozoospermic individuals within these DE lncRNAs regions. Bioinformatic tools were used to assess variants' impact on lncRNA structure, function, and lncRNA-miRNA interactions. Our analysis identified 1166 unique mutations in teratozoospermic men within DE lncRNAs, distinguishing them from normozoospermic men. Among these, 64 variants in 23 lncRNAs showed potential regulatory roles, 7 variants affected 4 lncRNA structures, while 37 variants in 17 lncRNAs caused miRNA target loss or gain. Pathway Enrichment and Gene Ontology analyses of the genes targeted by the affected miRNAs revealed dysregulated pathways in teratozoospermia and a link between male infertility and cancer. This study lists novel variants and lncRNAs associated for the first time with teratozoospermia. These findings pave the way for future studies aiming to enhance diagnosis and therapy in the field of male infertility.

LncRNA NNT-AS1/hsa-miR-485-5p/HSP90 axis in-silico and clinical prospect correlated-to histologic grades-based CRC stratification: A step toward ncRNA Precision

The oncogenic effects of long non-coding RNA (lncRNA) Nicotinamide Nucleotide Transhydrogenase-antisense RNA1 (NNT-AS1) role in colorectal cancer (CRC) hasn't been sufficiently inspected in relation to the Homo sapiens (hsa)-microRNA (miR)- 485-5p/ heat shock protein 90 (HSP90) axis, clinically. qRT-PCR was performed to detect lncRNA NNT-AS1 and hsa-miR-485-5p expression levels in 60 Egyptian patients' sera. HSP90 serum level was quantified using Enzyme-linked immunosorbent assay (ELISA). The relative expression level of the studied non-coding RNAs as well as the HSP90 ELISA concentration were correlated with patients clinicopathological characteristics and correlated to each other. The axis diagnostic utility in comparison with carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) tumor markers (TMs) was studied by receiver operating characteristic (ROC) curve analysis. The relative lncRNA NNT-AS1 expression level fold change 56.7 (13.5-112) and HSP90 protein ELISA level 6.68 (5.14-8.77) (ng/mL) were elevated, while, for hsa-miR-485-5p 0.0474 (0.0236-0.135) expression fold change was repressed in CRC Egyptian patients' cohort sera, being compared to 28 apparently healthy control subjects. LncRNA NNT-AS1 specificity is 96.4% and a sensitivity of 91.7%, hsa-miR-485-5p showed 96.4% specificity, 90% sensitivity, and for HSP90 89.3%, 70% specificity and sensitivity, respectively. Those specificities and sensitivities were superior to the classical CRC TMs. A significant negative correlation was found between hsa-miR-485-5p with lncRNA NNT-AS1 (r = -0.933) expression fold change or with HSP90 protein blood level (r = -0.997), but, significant positive correlation was there between lncRNA NNT-AS1 and HSP90 (r = 0.927). LncRNA NNT-AS1/hsa-miR-485-5p/HSP90 axis could be a prospect for CRC development as well as diagnosis. Being correlated and related to CRC histologic grades 1-3, therefore, lncRNA NNT-AS1/hsa-miR-485-5p/HSP90 axis (not individually) expression approved clinically and in silico, could aid treatment precision.

Insights on the potential oncogenic impact of long non-coding RNA nicotinamide nucleotide transhydrogenase antisense RNA 1 in different cancer types; integrating pathway(s) and clinical outcome(s) association

Long non-coding RNAs (lncRNAs) are becoming more prevalent in the cancer field arena, with functional roles in both oncogenic and onco-suppressive pathways. Despite their widespread aberrant expression in a range of human malignancies, the biological activities of the ncRNAs majority are unknown. All showed the involvement of the lncRNA nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1). Since NNT-AS1 influences cellular proliferation, invasion, migration, apoptosis, and metastasis, this lncRNA appears to be linked to deregulating the normal cellular processes driving malignancy. This was observed in breast cancer (BC), gastric cancer (GC), colorectal cancer (CRC), epithelial ovarian cancer (EOC), and hepatocellular carcinoma (HCC). The current narrative non-systematic review will discuss "the significance of lncRNAs in cancer", as well as "lncRNAs future potential application(s) as diagnostic or predictive biomarkers", therefore, comprising an opportunity as treatment target(s). The review will have a special emphasis on lncRNA NNT-AS1.

Cross-Talk Between m6A- and m5C-Related lncRNAs to Construct a Novel Signature and Predict the Immune Landscape of Colorectal Cancer Patients

Background

N6-methyladenosine (m⁶A) and 5-methylcytosine (m⁵C) can modify long non-coding RNAs (lncRNAs), thereby affecting tumorigenesis and tumor progression. However, there is a lack of knowledge regarding the potential roles and cross-talk of m⁶A- and m⁵C-related lncRNAs in the tumor microenvironment (TME) and their effect on prognosis.

Methods

We systematically evaluated the expression patterns of m⁶A- and m⁵C-related lncRNAs in 1358 colorectal cancer (CRC) samples from four datasets. Consensus clustering was conducted to identify molecular subtypes of CRC, and the clinical significance, TME, tumor-infiltrating immune cells (TIICs), and immune checkpoints in the different molecular subtypes were analyzed. Finally, we established a m⁶A- and m⁵C-related lncRNA signature and a prognostic nomogram.

Results

We identified 141 m⁶A- and m⁵C-related lncRNAs by co-expression analysis, among which 23 lncRNAs were significantly associated with the overall survival (OS) of CRC patients. Two distinct molecular subtypes (cluster A and cluster B) were identified, and these two distinct molecular subtypes could predict clinicopathological features, prognosis, TME stromal activity, TIICs, immune checkpoints. Next, a m⁶A- and m⁵C-related lncRNA signature for predicting OS was constructed, and its predictive capability in CRC patients was validated. We then constructed a highly accurate nomogram for improving the clinical applicability of the signature. Analyses of clinicopathological features, prognosis, TIICs, cancer stem cell (CSC), and drug response revealed significant differences between two risk groups. In addition, we found that patients with a low-risk score exhibited enhanced response to anti-PD-1/L1 immunotherapy. Functional enrichment analysis showed that these lncRNAs related to the high-risk group were involved in the development and progression of CRC.

Conclusions

We conducted a comprehensive analysis of m⁶A- and m⁵C-related lncRNAs in CRC and revealed their potential functions in predicting tumor-immune-stromal microenvironment, clinicopathological features, and prognosis, and determined their role in immunotherapy. These findings may improve our understanding of the cross-talk between m⁶A- and m⁵C-related lncRNAs in CRC and pave a new road for prognosis assessment and more effective immunotherapy strategies.

Long non-coding RNAs as the critical regulators of epithelial mesenchymal transition in colorectal tumor cells: an overview

Colorectal cancer (CRC) is the second most common cause of cancer mortality and a major health challenge worldwide. Despite advances in therapeutic and diagnostic methods, there is still a poor prognosis in CRC patients. Tumor recurrence and metastasis are the main causes of high mortality rate in these patients, which are due to late diagnosis in advanced tumor stages. Epithelial-mesenchymal transition (EMT) is known to be the most important cause of CRC metastasis, during which tumor cells obtain metastasis ability by losing epithelial features and gaining mesenchymal features. Long non-coding RNAs (lncRNAs) are pivotal regulators of EMT process. Regarding the higher stability of lncRNAs compared with coding RNAs in body fluids, they can be used as non-invasive diagnostic markers for EMT process. In the present review, we summarized all of the lncRNAs involved in regulation of EMT process during CRC progression and metastasis. It was observed that lncRNAs mainly induced the EMT process in CRC cells by regulation of EMT-related transcription factors, Poly comb repressive complex (PRC), and also signaling pathways such as WNT, NOTCH, MAPK, and Hippo.

Clinicopathological implications of lncRNAs, immunotherapy and DNA methylation in lung squamous cell carcinoma: a narrative review

Objective

To explore the clinicopathological impact of lncRNAs, immunotherapy, and DNA methylation in lung squamous cell carcinoma (LUSC), emphasizing their exact roles in carcinogenesis and modes of action.

Background

LUSC is the second most prevalent form, accounting for around 30% of non-small cell lung cancer (NSCLC). To date, molecular-targeted treatments have significantly improved overall survival in lung adenocarcinoma patients but have had little effect on LUSC therapy. As a result, there is an urgent need to discover new treatments for LUSC that are based on existing genomic methods.

Methods

In this review, we summarized and analyzed recent research on the biological activities and processes of lncRNA, immunotherapy, and DNA methylation in the formation of LUSC. The relevant studies were retrieved using a thorough search of Pubmed, Web of Science, Science Direct, Google Scholar, and the university's online library, among other sources.

Conclusions

LncRNAs are the primary components of the mammalian transcriptome and are emerging as master regulators of a number of cellular processes, including the cell cycle, differentiation, apoptosis, and growth, and are implicated in the pathogenesis of a variety of cancers, including LUSC. Understanding their role in LUSC in detail may help develop innovative treatment methods and tactics for LUSC. Meanwhile, immunotherapy has transformed the LUSC treatment and is now considered the new standard of care. To get a better knowledge of LUSC biology, it is critical to develop superior modeling systems. Preclinical models, particularly those that resemble human illness by preserving the tumor immune environment, are essential for studying cancer progression and evaluating novel treatment targets. DNA methylation, similarly, is a component of epigenetic alterations that regulate cellular function and contribute to cancer development. By methylating the promoter regions of tumor suppressor genes, abnormal DNA methylation silences their expression. DNA methylation indicators are critical in the early detection of lung cancer, predicting therapy efficacy, and tracking treatment resistance. As such, this review seeks to explore the clinicopathological impact of lncRNAs, immunotherapy, and DNA methylation in LUSC, emphasizing their exact roles in carcinogenesis and modes of action.

Long non-coding RNA NNT-AS1 positively regulates NPM1 expression to affect the proliferation of estrogen-mediated endometrial carcinoma by interacting

Objective: This study aims to investigate the mechanism of long non-coding RNA NNT-AS1 in the proliferation of estrogen-mediated endometrial carcinoma (EC).

Materials and methods: NNT-AS1, miR-30c, and Nucleophosmin 1 (NPM1) expressions were measured by quantitative real-time PCR and Western blotting. Cell Counting Kit-8 assay and 5-Ethynyl-2'-deoxyuridine (EdU) assay were used to detect the viability and proliferation of Ishikawa and HEC-1-A cells, respectively. RNA immunoprecipitation assay was used to confirm the interaction between NNT-AS1 and miR-30c. Luciferase reporter assay was performed to confirm the interaction between miR-30c and NPM1.

Results: NNT-AS1 and NPM1 expressions in EC tissues and cell lines were higher than in benign endometrium and normal endometrial epithelial cells (EECs). miR-30c expression in EC tissues and cell lines was lower than in benign endometrium and normal EECs. NNT-AS1 interacted with miR-30c, and miR-30c negatively regulated NPM1 expression. Overexpression of NNT-AS1 increased NPM1 expression in EC cells, while overexpression of miR-30c reversed the effect. NNT-AS1 interference inhibited the mRNA level of NPM1, while the miR-30c inhibitor reversed the result. Estradiol (E₂) promoted the proliferation of EC cells, small interfering RNA (siRNA) against NNT-AS1 inhibited EC cell proliferation, miR-30c inhibitor promoted cell proliferation, and NPM1 siRNA inhibited cell proliferation. E₂ increased tumor volume, and NNT-AS1 interference reduced tumor volume in vivo.

Conclusion: NNT-AS1 promoted the proliferation of estrogen-mediated EC by regulating miR-30c/NPM1.

Serum long non‑coding RNA NNT‑AS1 protected by exosome is a potential biomarker and functions as an oncogene via the miR‑496/RAP2C axis in colorectal cancer

Increasing evidence has indicated that long non-coding RNAs (lncRNAs) serve an essential role in carcinogenesis and cancer development. It has been reported that lncRNA nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) serves a crucial role in several types of cancer. However, the clinical significance of circulating NNT-AS1 expression in colorectal cancer (CRC) remains to be elucidated. The current study aimed to investigate the potential role of NNT-AS1 and the clinical significance of its serum expression levels in patients with CRC. The expression of NNT-AS1 was measured in 40 pairs of tumor and adjacent normal tissues from patients with CRC via reverse transcription-quantitative PCR. The serum expression levels of NNT-AS1 were assayed in an independent cohort of healthy controls and patients with CRC. The levels of NNT-AS1 were also compared between paired preoperative and postoperative serum samples. In addition, the presence of exosomal NNT-AS1 in serum was explored. Furthermore, the biological roles of NNT-AS1 were investigated in CRC cells in vitro. The expression of NNT-AS1 was significantly upregulated in tumor tissues compared with adjacent normal tissues (P<0.05). A higher level of NNT-AS1 was associated with an advanced CRC stage. The serum levels of NNT-AS1 were significantly upregulated in patients with CRC compared with healthy subjects (P<0.05). Furthermore, the NNT-AS1 levels were significantly decreased in postoperative samples compared with preoperative samples (P<0.01). In addition, it was also identified that NNT-AS1 was upregulated in CRC exosomes (P<0.01), whereas no significant difference was observed in NNT-AS1 levels between serum and exosomes. Silencing of NNT-AS1 inhibited the proliferation, migration and invasion of CRC cells. It was also identified that NNT-AS1 exerted its effects via regulation of the microRNA-496/Ras-related protein Rap-2c axis. The present study demonstrated that circulating NNT-AS1, which may be protected by exosomes, could be a novel potential biomarker and therapeutic target in CRC.

Silencing long non-coding RNAs nicotinamide nucleotide transhydrogenase antisense RNA 1 inhibited papillary thyroid cancer cell proliferation, migration and invasion and promoted apoptosis via targeting miR-199a-5p

The increasing incidence of papillary thyroid cancer (PTC) has attracted many researchers to investigate the mechanism underlying PTC progression. This study explored the growth and apoptosis of PTC cells based on an lncRNA regulatory mechanism. The expression of nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) in PTC cell lines and PTC tissues was analyzed by qRT-PCR. The mutual binding site between NNT-AS1 and miR-199a-5p was predicted by starBase and confirmed by dual-luciferase reporter assay. The correlation between NNT-AS1 and miR-199a-5p was shown by Pearson correlation test. The viability, clone formation, migration, invasion and apoptosis of TPC-1 and IHH-4 cells were examined by CCK-8, colony formation, wound-healing, transwell, and flow cytometry assays, respectively. The expressions of Bax, cleaved Caspase-3, Bcl-2, E-Cadherin, N-Cadherin and SNAIL in TPC-1 and IHH-4 cells were determined by Western blot or qRT-PCR. NNT-AS1 expression was upregulated in PTC cells and tissues. In TPC-1 cells, silencing NNT-AS1 inhibited viability, clone formation, migration, and invasion as well as the expressions of N-Cadherin, SNAIL and Bcl-2, but promoted the expressions of E-Cadherin, Bax, and cleaved caspase-3. The effects of NNT-AS1 overexpression on IHH-4 cells were opposite to those of silencing NNT-AS1. In PTC tissues, miR-199a-5p was low-expressed and targeted by NNT-AS1, and it was negatively correlated with NNT-AS1. MiR-199a-5p inhibitor promoted TPC-1 cell progression, but miR-199a-5p mimic inhibited IHH-4 cell progression. NNT-AS1 and miR-199a-5p exerted opposite effects on PTC cells. Silencing NNT-AS1 inhibited PTC cell proliferation, migration and invasion, but promoted apoptosis via upregulation of miR-199a-5p.

Long noncoding RNA network: Novel insight into hepatocellular carcinoma metastasis (Review)

Hepatocellular carcinoma (HCC) is one of the most common, aggressive malignancies with poor prognosis and high mortality. Although great progress has been made in recent decades, overall survival of HCC patients remains unsatisfactory due to high recurrence and metastasis. Accordingly, understanding and clarifying the underlying molecular mechanisms of metastasis has become increasingly important. Recently, accumulated reports have supported that long noncoding RNAs (lncRNAs) are dysregulated in HCC and are involved in various pivotal biological processes, including metastasis. The aim of this review was to investigate the dysregulation of lncRNAs in HCC and their function as oncogenes or tumour suppressors. Furthermore, reciprocal regulatory networks between lncRNAs and various molecules that were identified in HCC metastasis, including regulating epithelial-mesenchymal transition (EMT), controlling metastasis-associated genes, and regulating tumour angiogenesis were examined. Numerous reports and information on lncRNAs may help identify lncRNAs that are potential novel diagnostic markers, prognostic markers and therapeutic targets.

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 relationships between LncRNA NNT-AS1, CRP, PCT and their interactions and the refractory mycoplasma pneumoniae pneumonia in children

To investigate the relationships between LncRNA NNT-AS1, CRP, PCT and their interactions and the refractory mycoplasma pneumoniae pneumonia (RMPP) in children. Serum levels of LncRNA NNT-AS1 of RMPP and non-RMPP (NRMPP) patients were detected by real-time PCR, and were analyzed together with serum c-reactive protein (CRP) and procalcitonin (PCT). Correlations between LncRNA NNT-AS1 and CRP and PCT were analyzed by Pearson correlation test. The ROC curve was used to analyze the potential of LncRNA NNT-AS1, CRP and PCT as biomarkers for predicting RMPP. Logistic regression crossover model and the Excel compiled by Andersson et al. were used to analyze the interactions among the biomarkers. We found that LncRNA NNT-AS1, CRP and PCT were all highly expressed in patients with RMPP. LncRNA NNT-AS1 could positively correlate with the expressions of CRP and PCT, and jointly promote the occurrence of RMPP. The combined diagnosis of LncRNA NNT-AS1, CRP and PCT could predict the occurrence of RMPP.

Prognostic Factors Involved in the Epithelial-Mesenchymal Transition Process in Colorectal Cancer Have a Preponderant Role in Oxidative Stress: A Systematic Review and Meta-Analysis

Epithelial-to-mesenchymal transition (EMT) is one of the most accepted mechanisms leading to metastasis, which is responsible for most of the cancer-related deaths. In order to identify EMT-related biomarkers able to predict clinical outcomes in colorectal cancer (CRC), a systematic review and meta-analysis of prognostic factors associated to overall survival (OS) and progression free survival (PFS) was conducted. The systematic literature search included studies from June 2014 to June 2019 available at PubMed and Scopus databases. Meta-analysis was performed for those markers appearing in minimum three works with a total number of 8656 participants. The rest were enlisted and subjected to functional enrichment. We identified nine clinical biomarkers and 73 EMT-related molecular biomarkers associated to OS and/or PFS in CRC. The significant enrichment of biomarkers found involved in cellular oxidoreductase activity suggests that ROS generation plays an active role in the EMT process. Clinical practice needs new biomarkers with a reliable prognostic value able to predict clinical outcomes in CRC. Our integrative work supports the role of oxidative stress in tumorigenesis and EMT progress highlighting the importance of deciphering this specific mechanism to get a better understanding of metastasis.

The Role of Long Non-Coding RNA NNT-AS1 in Neoplastic Disease

Simple Summary

Nicotinamide nucleotide transhydrogenase-antisense 1 (NNT-AS1), which is a newly-discovered long non-coding RNA (lncRNA), has been found to be dysregulated in a variety of neoplastic diseases. With the accumulation of studies on NNT-AS1 in recent years, the mechanism of NNT-AS1 and its significance for tumor occurrence and progression are constantly being updated and improved. Thus, this paper aims to summarize the abnormal expression of NNT-AS1 and its prognostic values in different neoplastic diseases. In addition, the detailed competing endogenous RNA networks and subsequent biology behaviors, as well as the role of NNT-AS1 in mediating cisplatin resistance are revealed in this paper. This review not only summarizes the past research of NNT-AS1, but also provides some ideas for future research in this field.

Abstract

Studies have shown that non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), play an important regulatory role in the occurrence and development of human cancer. Nicotinamide nucleotide transhydrogenase-antisense 1 (NNT-AS1) is a newly-discovered cytoplasmic lncRNA. Many studies have shown that it has abnormally-high expression levels in malignant tumors, but there are also a few studies that have reported low expression levels of NNT-AS1 in gastric cancer, breast cancer, and ovarian cancer. At present, the regulatory mechanism of NNT-AS1 as a miRNA sponge, which may be an important reason affecting tumor cell proliferation, invasion, metastasis, and apoptosis is being studied in-depth. In addition, NNT-AS1 has been found to be related to cisplatin resistance. In this review, we summarize the abnormal expression of NNT-AS1 in a variety of neoplastic diseases and its diagnostic and prognostic value, and we explain the mechanism by which NNT-AS1 regulates cancer progression by competing with miRNAs. In addition, we also reveal the correlation between NNT-AS1 and cisplatin resistance and the potential clinical applications of NNT-AS1.

NNT-AS1 modulates prostate cancer cell proliferation, apoptosis and migration through miR-496/DDIT4 axis

Background

Emerging studies have disclosed long non-coding RNAs (lncRNAs) as pivotal modulators in the progression of prostate cancer (PCa). Current research planned to figure out the involvement of lncRNA nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) in PCa.

Methods

RNA expression was examined using RT-qPCR in PCa cells. Functional assays assessed the viability, proliferation, apoptosis and migration of PCa cells. RNA pull down and luciferase reporter experiments detected the interplay between miRNA and lncRNA or mRNA.

Results

NNT-AS1 was apparently upregulated in PCa cells. NNT-AS1 deficiency abrogated PCa cell viability, proliferation and migration but promoted apoptosis. Besides, miR-496 could be sequestered by NNT-AS1 to elevate the expression of DNA damage inducible transcript 4 (DDIT4) in PCa. Rescue assays indicated that overexpressed DDIT4 or restrained miR-496 could reverse the influence of NNT-AS1 depletion on malignant processes in PCa cells.

Conclusion

NNT-AS1 contributes to the malignant phenotypes of PCa cells through targeting miR-496 to boost DDIT4 expression.

Upregulated expression of LncRNA nicotinamide nucleotide transhydrogenase antisense RNA 1 is correlated with unfavorable clinical outcomes in cancers

Background

The nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) is a long non-coding RNA aberrantly expressed in human malignancies. We aimed to analyze available data to evaluate the correlation between NNT-AS1 expression and cancer prognosis.

Methods

Literature retrieval was performed by systematic searching related databases from inception to April 2, 2020. Studies regarding correlation between NNT-AS1 expression, survival outcomes and clinical characteristics of cancer patients were collected and pooled to calculate the the hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (95% CIs).

Results

Ten studies comprising 699 patients were included, all of which were conducted in China according to literature selection criteria. Overexpression of NNT-AS1 had a significant association with unfavorable overall survival (OS) (HR = 2.08, 95% CI: 1.84–2.36, P < 0.001). Stratified analysis showed that tumor type, sample size, follow-up months, and survival analysis approach did not change the predictive value of NNT-AS1 on OS. Furthermore, elevated NNT-AS1 level had significant association with distant metastasis (DM) (OR = 2.45, 95% CI: 1.39–4.30), lymph node metastasis (LNM) (OR = 3.92, 95% CI: 1.35–11.41), TNM stage (OR = 4.25, 95% CI: 1.71–10.56), and vascular invasion (OR = 3.98, 95% CI: 2.06–7.71), but was not associated with age and gender. The TCGA dataset further consistently showed that the NNT-AS1 expression was associated with poor OS and disease-free survival.

Conclusions

High expression of NNT-AS1 is associated with unfavorable survival outcomes and poor clinicopathologic characteristics. However, large-cohort data and geographical studies are still needed to further validate the prognostic value of NNT-AS1 in cancers.

Long non-coding RNA (lncRNA) and epithelial-mesenchymal transition (EMT) in colorectal cancer: a systematic review

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related death. Epithelial-mesenchymal transition (EMT) is a major process in tumor metastasis development. This systematic review aims to describe the role of long non-coding RNA (lncRNA) in EMT in CRC.

METHODS

The electronic databases, PubMed, Cochrane, and EMBASE, were searched from January1990 to June 2019 to identify studies examining lncRNA and their role in mediating EMT in CRC. Studies examining clinical specimens and/or in vitro experiments were included.

RESULTS

In 61 identified studies, 54 lncRNAs were increased in CRC compared to normal colorectal epithelium. Increased lncRNA expression was frequently associated with worse survival. Many lncRNAs mediate their effect through competitive endogenous RNA or transcription factor regulation. The ZEB1, 2/E-cadherin, Wnt/β-catenin signaling, and chromatin remodeling pathways are discussed in particular.

CONCLUSIONS

lncRNAs are major regulators of EMT and predictor adverse outcome in CRC patients. Future research must focus on delineating lncRNA function prior to potential clinical use.

The estrogen-regulated lncRNA H19/miR-216a-5p axis alters stromal cell invasion and migration via ACTA2 in endometriosis

Fibrotic tissue may contribute to the origin of some endometriosis-related symptoms, such as chronic pelvic pain and infertility. Alterations in the H19/miR-216a-5p/ACTA2 pathway may mediate the regulation of eutopic endometrial stromal cell (euESC) invasion and migration and may represent a potential mechanism underlying fibrous tissue formation or fibrosis in women with endometriosis. In this study, we aimed to determine the expression of H19 and ACTA2 in endometrial tissues of women with endometriosis. Two groups of 23 infertile women with endometriosis and 23 matched infertile women without endometriosis were investigated. Primary cultured cells of endometrial tissues were analyzed using RT-PCR and western blotting (WB) to determine expression of H19 and ACTA2. 5-Ethyl-2'-deoxyuridine, CCK8 and Transwell assays were used to study the functions of H19 and ACTA2. Human embryonic kidney 293 cells were used for luciferase assays to study miR-216a-5p binding sites with H19 and ACTA2. We found that H19 and ACTA2 levels were significantly higher in endometriosis euESCs than in control euESCs (P < 0.05) and were positively correlated in endometriosis euESCs. Luciferase assays indicated that H19 regulates ACTA2 expression via competition for inhibitory miR-216a-5p binding sites. Our results indicate that alterations in the estrogen/H19/miR-216a-5p/ACTA2 pathway regulated endometriosis euESC invasion and migration. Downregulation of H19 or ACTA2 inhibited endometriosis euESC invasion and migration; however, estrogen promoted endometriosis euESC invasion and migration via H19. The main limitation of our study was that experiments were conducted in vitro and further in vivo studies are required in the future. However, our study showed that primary cultured cells represented endometriosis cells more clearly than cell lines.

Overexpression of Long Non-Coding RNA FGF14-AS2 Inhibits Colorectal Cancer Proliferation Via the RERG/Ras/ERK Signaling by Sponging microRNA-1288-3p

Colorectal cancer remains one of most common cancer types with poor prognosis globally. Recent years, numerous studies depicted pivotal roles of lncRNAs in colorectal cancer progression. This study aimed to investigate the role of FGF14-AS2 in colorectal cancer development. FGF14-AS2 was found as a significantly downregulated lncRNA in TCGA dataset. Via RT-qPCR, we confirmed the downregulation of FGF14-AS2 in collected colorectal carcinoma samples. Transfection of plasmid containing full length of FGF14-AS2 repressed cell proliferation and induced elevation of cell apoptosis in colorectal cancer cells. In addition, FGF14-AS2 overexpression inactivated MAPK/ERK signaling in cells. Bioinformatic analysis and subsequent cell-based assays showed that FGF14-AS2 sponging miR-1288-3p, an oncogenic miRNA in colorectal cancer. RERG, the regulator of Ras/ERK pathway, was predicted and verified as target gene of miR-1288. Via downregulation of miR-1288, FGF14-AS2 elevated RERG expression in colorectal cancer cells. Rescue assays indicated that FGF14-AS2 relied on regulation of RERG to control cell proliferation and apoptosis in colorectal cancer. Taken together, the current study demonstrated FGF14-AS2 as a regulator of colorectal cancer development via downregulation of miR-1288-3p and inactivation of Ras/ERK signaling.

Long non-coding RNA NNT-AS1 regulates proliferation, apoptosis, inflammation and airway remodeling of chronic obstructive pulmonary disease via targeting miR-582-5p/FBXO11 axis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a kind of chronic lung disease that mainly induced by smoking-caused inflammation. Long non-coding RNAs (lncRNAs) have been reported to play a part in the course of pulmonary diseases. Here, we studied the role of lncRNA NNT-AS1 in the development of COPD.

MATERIALS

qRT-PCR analysis and ELISA assay were applied to evaluate the expression of genes and inflammatory cytokines, respectively. CCK8 and EdU assays were utilized to assess proliferation, while flow cytometry assay was conducted to evaluate apoptosis. Luciferase reporter, RNA pull down and RIP assays were combined to explore relationships between genes.

RESULTS

NNT-AS1 was observed to be up-regulated in cigarette smoke extract (CSE)-treated 16HBE cells. Knockdown of NNT-AS1 abolished CSE-caused suppressive effects on cell proliferation, apoptosis, inflammation and airway remodeling. Mechanistically, NNT-AS1 up-regulated FBXO11 expression via sponging miR-582-5p. Moreover, miR-582-5p inhibitor or FBXO11 overexpression counteracted NNT-AS1 silence-elicited effects on proliferation, apoptosis, inflammation and airway remodeling.

CONCLUSION

Our data revealed that NNT-AS1 played a promoting role in smoking-induced COPD via modulating miR-582-5p/FBXO11 signaling, suggesting a novel potential target for COPD treatment.

[Serum level of lncRNA TUSC7 in patients with esophageal squamous cell carcinoma and its role in promoting tumor cell migration and invasion]

OBJECTIVE

To investigate serum levels of long non-coding RNA (lncRNA) TUSC7 in patients with esophageal squamous cell carcinoma (ESCC), its association with clinicopathological parameters and its role in promoting tumor metastasis and invasion.

METHODS

Serum samples were collected from 60 patients with ESCC admitted between January, 2017 and May, 2019, with 60 age- and gender-matched healthy subjects as the control group. Serum level of TUSC7 in ESCC patients and its expression in 4 ESCC cell lines was detected with RT-qPCR. The association of serum TUSC7 level with the clinicopathological features of the patients was analyzed. KYSE-30 cell models with TUSC7 overexpression or knockdown were established, and the proliferation of the cells was examined with MTT assay and their migration and invasion were assessed using wound healing and Transwell assays. Western blotting was used to detect the cellular expressions of the proteins associated with epithelial-mesenchymal transition (EMT).

RESULTS

The patients with ESCC had significantly lower serum TUSC7 level than the healthy control subjects (P &lt; 0.05). The ESCC cell lines also expressed lower levels of TUSC7 than normal cells (P &lt; 0.05). Serum TUSC7 level was negatively correlated with tumor staging, lymph node metastasis and infiltration (P &lt; 0.05) but was not significantly correlated with other clinicopathological parameters in ESCC patients. In the invitro cell experiment, overexpression of TUSC7 in KYSE-30 cells significantly inhibited cell migration and invasion (P &lt; 0.05), enhanced the expression of the EMT marker protein E-cadherin and lowered the expressions of N-cadherin, Vimentin and MMP9 (P &lt; 0.05); knocking down TUSC7 in the cells produced the opposite effects.

CONCLUSIONS

The down-regulation of TUSC7 expression in the serum of ESCC patients and in ESCC cell lines is associated with the metastasis of ESCC and promotes tumor cell migration and invasion by promoting EMT, indicating the potential of serum TUSC7 level as a molecular marker for diagnosis, treatment and metastasis monitoring of ESCC.

LncRNA NNT-AS1 promotes lung squamous cell carcinoma progression by regulating the miR-22/FOXM1 axis

Background

Recent studies have revealed that dysregulated expression of long non-coding RNA nicotinamide nucleotide transhydrogenase antisense RNA 1 (lncRNA NNT-AS1) is associated with cell tumorigenicity in non-small cell lung cancer. However, the exact molecular mechanisms of NNT-AS1 in lung squamous cell carcinoma (LUSC) remain largely unknown.

Methods

The expression of NNT-AS1, microRNA (miR)-22 and Forkhead box protein M1 (FOXM1) was measured using quantitative real-time polymerase chain reaction or western blot, respectively. The interaction between miR-22 and NNT-AS1 or FOXM1 was confirmed using a dual-luciferase reporter assay and RNA immunoprecipitation assay. Cell migration and invasion abilities were measured by Transwell assay. Flow cytometry was used to detect apoptotic cells.

Results

NNT-AS1 and FOXM1 were up-regulated but miR-22 was down-regulated in LUSC tissues and cell lines. NNT-AS1 was a sponge of miR-22, and NNT-AS1 deletion suppressed the migration and invasion but induced apoptosis in LUSC cells. FOXM1 was a target of miR-22, and overexpression of miR-22 inhibited cell carcinogenesis in LUSC by targeting FOXM1. Additionally, NNT-AS1 could directly regulate FOXM1 expression by binding to miR-22 in LUSC cells.

Conclusion

LncRNA NNT-AS1 contributes to cell carcinogenesis in LUSC by regulating the miR-22/FOXM1 axis, providing a novel insight into the pathogenesis of LUSC and a new potential therapeutic target for LUSC treatment.

LncRNA NNT-AS1 promote glioma cell proliferation and metastases through miR-494-3p/PRMT1 axis

Long noncoding RNAs (lncRNAs) are key players in cancer progression. However, the function of lncRNA NNT-AS1 on glioma is unclear. In the present study, a total of 73 tumor tissues and matched adjacent non-tumor tissues were collected, and glioma cell lines were cultured in vitro. mRNA expression was tested using RT-qPCR. The protein expression level was determined using the western blot assay, cell proliferation was measured using the CCK-8 and BrdU proliferation assay, and the cell cycle, cell migration and invasion were determined using flow cytometry analysis, the wound healing assay and transwell, respectively. The results showed that lncNNT-AS1 is significantly up-regulated during the early stages of glioma. In particular, high levels of NNT-AS1 are observed in glioma cell lines compared to human astrocyte (HA) cells. Furthermore, the inhibition of lnc-NNT-AS1 by siRNA interfere attenuates the cell viability, proliferation, migration and invasion of glioma cell lines. Mechanistically, the inhibition of NNT-AS1 directly interacted with miRNA-494-3p, and positively regulated the downstream target PRMT1 in vitro. Further study proved that the overexpression of miRNA-494-3p and the inhibition of PRMT1 could attenuate both glioma cell proliferation and metastases. Collectively, our results indicated that the miR-494-3p-PRMT1 axis is involved the tumor-suppressive effects of NNT-AS1 inhibition, which sheds new light on lncRNA-directed diagnostics and the therapeutics of glioma.

Long non‑coding RNA NNT‑AS1 knockdown represses the progression of gastric cancer via modulating the miR‑142‑5p/SOX4/Wnt/β‑catenin signaling pathway

Patients with advanced gastric cancer (GC) have a poor prognosis with a median overall survival of 10–12 months. Long non-coding RNA nicotinamide nucleotide transhydrogenase-antisense RNA1 (NNT-AS1) and sex-determining region Y-related high mobility group box 4 (SOX4) have been reported to be associated with the progression of various types of cancer; however, the regulatory mechanism between NNT-AS1 and SOX4 in GC is not completely understood. Reverse transcription-quantitative PCR was used to detect the expression levels of NNT-AS1, microRNA (miR)-142-5p and SOX4. Western blotting was performed to assess the protein expression levels of SOX4, β-catenin, c-Myc, Bcl-2 and E-cadherin. The proliferation, apoptosis, migration and invasion of GC cells were determined using MTT, flow cytometry and Transwell assays. The relationship between miR-142-5p and NNT-AS1 or SOX4 was investigated using a dual-luciferase reporter assay. NNT-AS1 and SOX4 were upregulated, whereas miR-142-5p was downregulated in GC tissues and cells compared with normal tissues and cells. Both NNT-AS1 and SOX4 knockdown inhibited GC cell proliferation, migration and invasion, and enhanced GC cell apoptosis. Moreover, the results indicated that NNT-AS1 modulated SOX4 expression by sponging miR-142-5p. In addition, SOX4 overexpression reversed NNT-AS1 knockdown-mediated effects on GC cell proliferation, apoptosis, migration and invasion. NNT-AS1 knockdown blocked the Wnt/β-catenin signaling pathway via the miR-142-5p/SOX4 axis. Collectively, the present study indicated that NNT-AS1 knockdown decreased GC cell proliferation, migration and invasion, and induced GC cell apoptosis by regulating the miR-142-5p/SOX4/Wnt/β-catenin signaling pathway axis.

Long Non-Coding RNA NNT-AS1 Contributes to Cisplatin Resistance via miR-1236-3p/ATG7 Axis in Lung Cancer Cells

Purpose

Lung cancer is one of the most prevailing human cancers worldwide. Emerging evidence implies that long non-coding RNA nicotinamide nucleotide transhydrogenase-antisense RNA1 (NNT-AS1) is implicated in the tumorigenesis of lung cancer. Herein, we aimed to expose the impact of NNT-AS1 on the drug resistance of lung cancer.

Methods

Levels of NNT-AS1, microRNA (miR)-1236-3p and autophagy-related gene 7 (ATG7) were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was implemented to detect cell proliferation and the half maximal inhibitory concentration (IC₅₀) of cisplatin (DDP) in vitro. Moreover, flow cytometry was performed to assess cell apoptosis. Cell migration and invasion were examined utilizing transwell assay in lung cancer cells. Besides, levels of ATG7 and cell behavior-related proteins were determined via Western blot. Dual-luciferase reporter assay was administrated to identify the interaction between miR-1236-3p and NNT-AS1 or ATG7. The biological role of NNT-AS1 in DDP resistance of lung cancer was examined by xenograft tumor model in vivo.

Results

NNT-AS1 and ATG7 were upregulated, whereas miR-1236-3p was curbed in lung cancer tissues and in with or without DDP-resistant cell lines. NNT-AS1 detection significantly constrained cell growth, metastasis, and the IC₅₀ of DDP in A549/DDP and H522/DDP cells. Interestingly, the influence of miR-1236-3p mimic on DDP resistance was overturned via NNT-AS1 upregulation in vitro. Reintroduction of miR-1236-3p inhibitor relieved the effect of ATG7 silencing on DDP sensitivity in A549/DDP and H522/DDP cells. Importantly, NNT-AS1 was a sponge of miR-1236-3p to separate ATG7. Besides, NNT-AS1 silencing enhanced DDP sensitivity of lung cancer in vivo.

Conclusion

NNT-AS1/miR-1236-3p/ATG7 axis regulated DDP resistance in lung cancer cells and might supply a probable target and prognostic marker in lung cancer treatment.

LncRNAs as Regulators of Autophagy and Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is a common malignancy with 1. 8 million cases in 2018. Autophagy helps to maintain an adequate cancer microenvironment in order to provide nutritional supplement under adverse conditions such as starvation and hypoxia. Additionally, most of the cases of CRC are unresponsive to chemotherapy, representing a significant challenge for cancer therapy. Recently, autophagy induced by therapy has been shown as a unique mechanism of resistance to anticancer drugs. In this regard, long non-coding RNAs (lncRNAs) analysis are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. With increasing development of quantitative detection techniques, lncRNAs derived from patients' non-invasive samples (i.e., blood, stools, and urine) has become into a novel approach in precision oncology. Tumorspecific GAS5, HOTAIR, H19, and MALAT are novels CRC related lncRNAs detected in patients. Nonetheless, the effect and mechanism of lncRNAs in cancer autophagy and chemoresistance have not been extensively characterized. Chemoresistance and autophagy are relevant for cancer treatment and lncRNAs play a pivotal role in resistance acquisition for several drugs. LncRNAs such as HAGLROS, KCNQ1OT1, and H19 are examples of lncRNAs related to chemoresistance leaded by autophagy. Finally, clinical implications of lncRNAs in CRC are relevant, since they have been associated with tumor differentiation, tumor size, histological grade, histological types, Dukes staging, degree of differentiation, lymph node metastasis, distant metastasis, recurrent free survival, and overall survival (OS).

High expression of long non-coding RNA NNT-AS1 facilitates progression of cholangiocarcinoma through promoting epithelial-mesenchymal transition

BACKGROUND

Cholangiocarcinoma (CCA) is a biliary malignancy, which is notoriously difficult to diagnose and associated with poor survival. Accumulating evidence indicates that long non-coding RNA Nicotinamide Nucleotide Transhydrogenase-antisense RNA1 (NNT-AS1) is overexpressed in several tumors and plays a crucial role in the development of neoplasm. However, the expression pattern and functional role of NNT-AS1 in CCA remain largely unknown.

METHODS

NNT-AS1 expression was assessed by RT-qPCR and In Situ Hybridization (ISH) assay. The clinical relevance of NNT-AS1 was analyzed using a CCA tissue microarray with follow-up data. The function role of NNT-AS1 and its underlying molecular mechanisms were evaluated using both in vitro/in vivo experiments and bioinformatics analysis. Luciferase reporter assay, western blot and RT-qPCR were conducted to identify the miRNA/target gene involved in the regulation of CCA progression.

RESULTS

LncRNA NNT-AS1 was found highly expressed in CCA. Upregulated NNT-AS1 expression was tightly associated with clinical malignancies and predicted poor prognosis of CCA patients. Functional studies showed that NNT-AS1 knockdown inhibited cell proliferation, migration and invasion of CCA cells in vitro. Conversely, NNT-AS1 overexpression showed the opposite biological effects. In a tumor xenograft model, we confirmed that NNT-AS1 knockdown could significantly inhibit the growth of CCA, while NNT-AS1 overexpression promoted CCA development. Mechanistically, we demonstrated that NNT-AS1 might function as a ceRNA in regulating HMGA2 (high mobility group AT-hook 2) through competitively binding to miR-142-5p in CCA. Moreover, we showed that NNT-AS1 regulated epithelial-mesenchymal transition in CCA.

CONCLUSION

In summary, these findings suggest the potential prognostic and therapeutic value of NNT-AS1/miR-142-5p/HMGA2 axis in CCA patients.

Transcription Levels of nicotinamide nucleotide transhydrogenase and Its Antisense in Breast Cancer Samples

Objective

To evaluate association of patients’ clinicopathological data with expression of nicotinamide nucleotide transhydrogenase (NNT) and naturally occurring antisense RNA of the same gene locus (NNT-AS1) in breast cancer samples.

Materials and Methods

In the current case-control study, mean expressions of NNT and NNT-AS1 were assessed in 108 breast tissue samples including 54 invasive ductal carcinoma samples and 54 adjacent non-cancerous tissues (ANCTs) by quantitative reverse transcription-polymerase chain reaction (qRT-PCR).

Results

NNT expression was not significantly different between tumor tissues and ANCTs. However, NNT-AS1 expression was significantly down-regulated in tumor tissues compared to ANCTs (expression ratio=0.51, P=0.01). NNT-AS1 expression was significantly higher in estrogen receptor (ER) negative samples, in comparison with ER positives (P=0.01). No considerable difference was found in the gene expressions between other subcategories of patients. Considerable correlations were detected between expression levels of these two genetic loci in both tumor tissues and ANCTs.

Conclusion

In the current study, for the first time we simultaneously assessed expression of NNT and NNT-AS1 in breast cancer tissues. This study highlights association of ER status with dysregulation of NNT-AS1 in breast cancer tissues. Future researches are necessary to explore the function of this long non-coding RNA (lncRNA) in the pathogenesis of breast cancer.

Microarray profiling and co-expression network analysis of lncRNAs and mRNAs in ovarian cancer

Dysregulated long noncoding RNAs (lncRNAs) are involved in the pathogenesis and development of human diseases, such as epithelial ovarian cancer (EOC). In this study, we identified EOC-related lncRNAs and performed lncRNA and mRNA microarray analyses using IOSE80, a normal ovary cell line, and two ovarian carcinoma cell lines (SKOV3 and SKOV3/DDP) to investigate the potential roles of lncRNAs in EOC. lncRNA-HEIH expression in EOC tissues and cell lines was measured by quantitative real-time polymerase chain reaction (qPCR). In addition, we generated a lncRNA–mRNA co-expression network in order to identify lncRNA-expression trends and potential lncRNA target genes. Cell viability, migration, and invasion were determined by Cell Counting Kit-8, transwell assay, and wound-healing assay, respectively, and apoptosis was analyzed by flow cytometry. We identified 3527 differentially expressed lncRNAs upon comparison of the lncRNA profiles from IOSE80 with those of SKOV3 cell lines, with 11 differentially expressed lncRNAs confirmed by qPCR. Both pathway and gene ontology analyses demonstrated the involvement of lncRNAs, especially HEIH and LINC-PINT, in multiple biological processes. Furthermore, in vitro knockdown experiments confirmed that suppression of HEIH expression inhibited EOC cell proliferation. Our findings provide a foundation for further research into the role of these lncRNAs in EOC carcinogenesis and progression.

Regulation Mechanism of Long Noncoding RNAs in Colon Cancer Development and Progression

Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide, and its high rates of relapse and metastasis are associated with a poor prognosis. Despite extensive research, the underlying regulatory mechanisms of CRC remain unclear. Long noncoding RNAs (lncRNAs) are a major type of noncoding RNAs that have received increasing attention in the past few years, and studies have shown that they play a role in many biological processes in CRC. Here, we summarize recent studies on lncRNAs associated with CRC and the signaling pathways and mechanisms underlying this association. We show that dysregulated lncRNAs may be new prognostic and diagnostic biomarkers or therapeutic targets for clinical application. This review contributes not only to our understanding of CRC, but also suggests novel signaling pathways associated with lncRNAs that can be targeted to block or eradicate CRC.

Competing endogenous RNA networks in cervical cancer: function, mechanism and perspective

In the past several years, competing endogenous RNAs (ceRNAs) have emerged as a potential class of post-transcriptional regulators that alter gene expression through a microRNA (miRNA)-mediated mechanism. An increasing number of studies have found that ceRNAs play important roles in tumorigenesis. Cervical cancer is one of the most common cancers in female malignancies. Despite advances in our understanding of this neoplasm, patients with advanced cervical cancer still have poor prognosis. There is an urgent need to provide a new insight on the mechanism of cervical cancer development and may be acted as new anticancer therapeutic strategies. Here, we review the ceRNA studies and coherent researches in cervical cancer, especially in long non-coding RNA (lncRNA) and miRNAs in order to broaden horizons into mechanisms, selection biomarkers for diagnosis as well as predicting prognosis, and targeting treatment for cervical cancer in the future.

Long non-coding RNA RUNX1-IT1 plays a tumour-suppressive role in colorectal cancer by inhibiting cell proliferation and migration

Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in the progression of various cancers. In this study, we aim to investigate the role of lncRNA RUNX1-IT1 in the development of colorectal cancer (CRC). The expression levels of lncRNA RUNX1-IT1 were measured using quantitative real-time Polymerase Chain Reaction(qRT-PCR). CCK8 proliferation assay, transwell assay, and flow cytometry were performed to evaluate the effect of lncRNA RUNX1-IT1 on CRC cell proliferation, migration, and apoptosis. The proliferation markers (PCNA, Ki67), apoptosis markers (cleaved-PARP, cleaved-caspase3), and MMP9 are detected by western blotting. Significant down regulation of lncRNA RUNX1-IT1 was measured in CRC tissues and three CRC cell lines (HCT116, HT29, and RKO) compared with paired nontumorous adjacent tissues (P < 0.01) or the normal colonic epithelial cell line FHC (P < 0.05), respectively. Moreover, the proliferative and migration potential of CRC cells were inhibited by overexpressing lncRNA RUNX1-IT1, which could be obviously improved by knocking down lncRNA RUNX1-IT1. The protein levels of PCNA, Ki67, and MMP9 were upregulated by overexpressing lncRNA RUNX1-IT1 and down regulated in si-RUNX1-IT1 cells. Besides, lncRNA RUNX1-IT1 could also promote the apoptosis of CRC cells. In conclusion, lncRNA RUNX1-IT1 is downregulated in CRC and plays a tumour-suppressive role due to the regulatory of cell proliferation, migration, and apoptosis. SIGNIFICANCE OF THE STUDY: We demonstrated that lncRNA RUNX1-IT1 was down regulated both in CRC tissues and cell lines. Besides, lncRNA RUNX1-IT1 could serve as a potential diagnostic biomarker and play a tumour-suppressive role owing to its good diagnostic efficacy and inhibition of CRC cell proliferation and migration.

CRlncRC: a machine learning-based method for cancer-related long noncoding RNA identification using integrated features

BACKGROUND

Long noncoding RNAs (lncRNAs) are widely involved in the initiation and development of cancer. Although some computational methods have been proposed to identify cancer-related lncRNAs, there is still a demanding to improve the prediction accuracy and efficiency. In addition, the quick-update data of cancer, as well as the discovery of new mechanism, also underlay the possibility of improvement of cancer-related lncRNA prediction algorithm. In this study, we introduced CRlncRC, a novel Cancer-Related lncRNA Classifier by integrating manifold features with five machine-learning techniques.

RESULTS

CRlncRC was built on the integration of genomic, expression, epigenetic and network, totally in four categories of features. Five learning techniques were exploited to develop the effective classification model including Random Forest (RF), Naïve bayes (NB), Support Vector Machine (SVM), Logistic Regression (LR) and K-Nearest Neighbors (KNN). Using ten-fold cross-validation, we showed that RF is the best model for classifying cancer-related lncRNAs (AUC = 0.82). The feature importance analysis indicated that epigenetic and network features play key roles in the classification. In addition, compared with other existing classifiers, CRlncRC exhibited a better performance both in sensitivity and specificity. We further applied CRlncRC to lncRNAs from the TANRIC (The Atlas of non-coding RNA in Cancer) dataset, and identified 121 cancer-related lncRNA candidates. These potential cancer-related lncRNAs showed a certain kind of cancer-related indications, and many of them could find convincing literature supports.

CONCLUSIONS

Our results indicate that CRlncRC is a powerful method for identifying cancer-related lncRNAs. Machine-learning-based integration of multiple features, especially epigenetic and network features, had a great contribution to the cancer-related lncRNA prediction. RF outperforms other learning techniques on measurement of model sensitivity and specificity. In addition, using CRlncRC method, we predicted a set of cancer-related lncRNAs, all of which displayed a strong relevance to cancer as a valuable conception for the further cancer-related lncRNA function studies.

Upregulation of long non-coding RNA NNT-AS1 promotes osteosarcoma progression by inhibiting the tumor suppressive miR-320a

OBJECTIVE

To investigate the role and mechanism of action of nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) in osteosarcoma (OS).

METHODS

Bioinformatic analysis suggested miR-320a as potential target of NNT-AS1. Influence of NNT-AS1 overexpression or knockdown on OS cell proliferation, colony-formation, apoptosis, migration and invasion capacity was first investigated. Expression levels of NNT-AS1, miR-320a, beta-catenin, RUNX2, IGF-1R, c-Myc, Cyclin D1 and MMP13 were also evaluated by RT-qPCR and western blotting accordingly. Xenograft models using U2OS and OS-732 cells with different NNT-AS1 gene modifications were constructed for tumor formation assay as well as evaluation of miR-320a, beta-catenin and RUNX2 expression in primary lesion. NNT-AS1-overexpressing U2OS cells and NNT-AS1-knockdown OS-732 cells were subject to miR-320a mimic and inhibitor transfection, respectively, to investigate the miR-320a dependency of the osteosarcoma-promoting role of NNT-AS1.

RESULTS

NNT-AS1 overexpression significantly increased proliferation, survival and mobility of U2OS cells in vitro as well as its tumor formation ability in vivo, while NNT-AS1 knockdown showed opposite effect on OS-732 cells. In both in vitro and in vivo model, NNT-AS1 expression level significantly correlated with that of beta-catenin, RUNX2, IGF-1R, c-Myc, Cyclin D1 and MMP13 as well as Akt phosphorylation level, and inversely correlated with miR-320a expression. Transfection of miR-320a mimic significantly inhibiter the promoting effect of NNT-AS1 on cell proliferation, survival and mobility of U2OS cells, while miR-320 inhibitor partially rescued that of OS-732 cells.

CONCLUSION

NNT-As1 functions as a cancer-promoting lncRNA by downregulating miR-320a, thus increasing the protein expression level of beta-catenin, RUNX2 and IGF-1R as well as activation of Akt in osteosarcoma.

Long noncoding RNA NNT-AS1 promotes gastric cancer proliferation and invasion by regulating microRNA-363 expression

Increasing studies showed that long noncoding RNAs (lncRNAs) had crucial regulatory roles in various tumors, including gastric cancer (GC). Recent studies demonstrated that lncRNA nicotinamide nucleotide transhydrogenase-antisense RNA1 (NNT-AS1) played an important role in several tumors. However, the role and expression of NNT-AS1 in GC progression remain unknown. In our study, we indicated that NNT-AS1 expression was upregulated in GC samples compared with the nontumor tissues. We also showed that NNT-AS1 expression was upregulated in the GC cell lines. Ectopic expression of NNT-AS1 promoted GC cell line HGC-27 cell proliferation, cell cycle progression, and invasion. In addition, we showed that NNT-AS1 acted as a sponge competing endogenous RNA for microRNA-363 (miR-363), which was downregulated in the GC samples and cell lines. miR-363 expression was negatively related with NNT-AS1 expression in GC samples. Upregulated expression of miR-363 suppressed GC cell growth, cycle, and invasion. Furthermore, we reported that elevated expression of NNT-AS1 promoted GC cell proliferation, cycle, and invasion partly by suppressing miR-363 expression. These results indicated that lncRNA NNT-AS1 acted as an oncogene in the development of GC partly by inhibiting miR-363 expression.

Long non-coding RNA NNT-AS1 sponges miR-424/E2F1 to promote the tumorigenesis and cell cycle progression of gastric cancer

Long non‐coding RNAs (lncRNAs) have been illustrated to function as important regulators in carcinogenesis and cancer progression. However, the roles of lncRNA NNT‐AS1 in gastric cancer remain unclear. In the present study, we investigate the biological role of NNT‐AS1 in gastric cancer tumorigenesis. Results revealed that NNT‐AS1 expression level was significantly up‐regulated in GC tissue and cell lines compared with adjacent normal tissue and normal cell lines. The ectopic overexpression of NNT‐AS1 indicated the poor prognosis of GC patients. In vitro experiments validated that NNT‐AS1 knockdown suppressed the proliferation and invasion ability and induced the GC cell cycle progression arrest at G0/G1 phase. In vivo xenograft assay, NNT‐AS1 silencing decreased the tumour growth of GC cells. Bioinformatics online program predicted that miR‐424 targeted the 3′‐UTR of NNT‐AS1. Luciferase reporter assay, RNA‐immunoprecipitation (RIP) and RNA pull‐down assay validated the molecular binding within NNT‐AS1 and miR‐424, therefore jointly forming the RNA‐induced silencing complex (RISC). Moreover, E2F1 was verified to act as the target gene of NNT‐AS1/miR‐424, indicating the NNT‐AS1/miR‐424/E2F1 axis. In conclusion, our study indicates that NNT‐AS1 sponges miR‐424/E2F1 to facilitate GC tumorigenesis and cycle progress, revealing the oncogenic role of NNT‐AS1 for GC.

Long non-coding RNA NNT-AS1 affects progression of breast cancer through miR-142-3p/ZEB1 axis

Some evidences have been provided to verify the effects of lncRNA NNT-AS1 on cancer progression. However, the crucial impacts of NNT-AS1 on the malignancy of breast cancer have not been elaborated. This study aims to detect the expression pattern and functional effects of NNT-AS1 in breast cancer. qRT-PCR analysis was applied to detect the expression of NNT-AS1 in both BC tissues and matched normal tissues. Loss of function assay was carried out to detect the effects of silenced NNT-AS1 on proliferation, metastasis and EMT process of BC cells. To understand the functional mechanism of NNT-AS1, mechanism assays were designed and performed in BC cells. Subcellular fractionation assay demonstrated that NNT-AS1 was located in the cytoplasm of BC cells. Therefore, NNT-AS1 might exert ceRNA functions in BC cells. To validate this hypothesis, we found the combination between NNT-AS1 and miR-142-3p through conducting bioinformatics analysis, RIP and luciferase reporter assays. Similarly, the combination between miR-142-3p and ZEB1 was verified. Finally, the recue assays were carried out to demonstrate the effects of NNT-AS1/miR-142-3p/ZEB1 axis on the biological behaviors of BC cells. All the above findings revealed a fact that NNT-AS1 affects breast cancer progression through modulating miR-142-3p/ZEB1 axis.

MicroRNA-485-5p reduces O-GlcNAcylation of Bmi-1 and inhibits colorectal cancer proliferation

Emerging evidences showed that miRNAs are involved in the oncogenesis of many cancers. Here, miRNA microarray analysis was performed to screen the significant miRNAs involved in the progression of colorectal cancer (CRC), miR-485-5p was chosen for further study. We found that the expression of miR-485-5p was significantly lower in CRC specimens and cell lines. In addition, low expression level of miR-485-5p is correlated with tumor progression and poor survival in CRC patients. Based on in vitro and in vivo assays, we found that miR-485-5p significantly inhibits CRC proliferation. Moreover, our results showed that miR-485-5p inhibits cell proliferation by reducing Bmi-1 protein expression, which has been reported to control the proliferation of many cancers. Mechanistically, OGT is a direct target of miR-485-5p, and miR-485-5p could inhibit the O-GlcNAcylation level of Bmi-1 by OGT. Overall, these results suggested that as a tumor suppressor, miR-485-5p may regulate CRC cells proliferation, which could regulate the O-GlcNAcylation and the stability of Bmi-1 through targeting OGT. This may give insight into a novel mechanism and therapy of CRC growth.

Long non-coding RNA NNT-AS1 contributes to cell proliferation, metastasis and apoptosis in human ovarian cancer

Ovarian cancer is a markedly heterogeneous malignancy characterized by various histological subtypes. Molecular biomarkers have been indicated to serve significant functions in the early diagnosis and treatment of early-stage ovarian cancer. However, the detailed mechanism underlying the tumorigenesis of ovarian cancer remains unclear. The present study aimed to identify a novel long non-coding RNA in patients with ovarian cancer. Nicotinamide nucleotide transhydrogenase-antisense 1 (NNT-AS1) was markedly downregulated in patients with ovarian cancer and in cultured human ovarian cancer cells. Knockdown of NNT-AS1 in the human ovarian cancer cell lines HO-8910 and SK-OV-3 promoted colony formation and arrested the cell cycle at G₀/G₁ phase. Furthermore, Transwell demonstrated that the downregulation of NNT-AS1 increased cell migration and invasion by ~60 and 70%, respectively, in HO-8910 and SK-OV-3 cells. Furthermore, cell apoptosis was inhibited by the transfection of siNNT-AS1 in the two cell lines, whereas the relative activities of caspase-3 and caspase-9 were decreased. These results indicated a protective function of NNT-AS1 in human ovarian cancer, providing novel insights into the diagnosis and treatment of ovarian cancer in clinical settings.

Long Noncoding RNA GAPLINC Promotes Cells Migration and Invasion in Colorectal Cancer Cell by Regulating miR-34a/c-MET Signal Pathway

BACKGROUND

Gastric adenocarcinoma predictive long intergenic noncoding RNA (GAPLINC) has been detected in colorectal cancer (CRC) cells and reportedly performs many functions related to tumor proliferation and metastasis. Aim The present study aimed to comprehensively explore the biological functions of GAPLINC and their underlying mechanism in CRC cell.

METHODS

The human cancer LncRNA PCR array was used to detect the differentially expressed long noncoding RNAs in human CRC samples. Real-time PCR, dual-luciferase assay, RNA pull-down assay, Transwell assay, and western blot analysis were performed to explore the molecular mechanism underlying GAPLINC functions related to migration and invasion of a human CRC cell line (HCT116).

RESULTS

Compared to the non-cancerous tissues, GAPLINC expression was obviously increased in CRC tissues. In HCT116, silencing of GAPLINC weakened cell migration and invasion, while overexpression of GAPLINC significantly promoted cell migration and invasion. Through dual-luciferase, RNA pull-down, and Transwell assays, we verified that miR-34a was the downstream molecule of GAPLINC and that miR-34a negatively regulated the migration and invasion of HCT116 cell. Furthermore, we found that GAPLINC positively regulated the miR-34a target gene c-MET in CRC tissues.

CONCLUSIONS

Our findings revealed that GAPLINC was up-regulated in CRC tissues and was involved in the migration and invasion of CRC cells by regulating miR-34a/c-MET signaling pathway.

The long non-coding RNA AK001796 contributes to tumor growth via regulating expression of p53 in esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is one of the prevalent and deadly cancers worldwide, especially in China. Considering the poor prognosis of ESCC, the aim of this study is to dissect the effects of long non-coding RNA (lncRNA) AK001796 on cell proliferation and cell cycle in vitro and tumorigenicity in vivo, providing therapeutic targets for ESCC.

Methods

We conducted quantitative real time PCR to detect the expression level of lncRNA AK001796 in human ESCC tumor and adjacent non-tumor tissues, and analyzed the correlation between lncRNA AK001796 expression and clinicopathologic feature of ESCC patients. Then we knocked down the expression of lncRNA AK001796 in human ESCC cell lines Eca-109 and TE-1, and next inspected cell cycle and apoptosis condition in these cells using flow cytometry. Subsequently, we used CCK-8 assay to test proliferation ability of the lncRNA AK001796-silenced ESCC cells, and the MDM2/p53 signaling pathway in these cells was analyzed by western blot analysis. At last, the ESCC xenograft models were established to verify the role of lncRNA AK001796 on the occurrence and development of ESCC.

Results

In this study, we demonstrated that lncRNA AK001796 was significantly upregulated in ESCC tumor tissues compared to adjacent non-tumor tissues. Knockdown of lncRNA AK001796 inhibited ESCC cell growth, cell cycle, and tumor growth in a xenograft mouse model via regulating MDM2/p53 signal pathway. The expression of lncRNA AK001796 was positively correlated with MDM2 levels in human ESCC samples.

Conclusions

Overall, lncRNA AK001796 regulates cell proliferation and cell cycle via modulating MDM2/p53 signaling in ESCC, which provides a new insight into the treatment targets for ESCC.

Trial registration This study was registrated in the Ethics Committee of the First Affiliated Hospital of Nanjing Medical University (Trial registration: 2012-SR-127, Registered 20 January 2012)

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0537-8) contains supplementary material, which is available to authorized users.

Aberrant Expression of the Long Non-coding RNA GHRLOS and Its Prognostic Significance in Patients with Colorectal Cancer

Long non-coding RNAs (lncRNAs), which have emerged as important regulatory RNA molecules that have been implicated in carcinogenesis and cancer progression, may also serve as novel potential biomarkers for cancer diagnosis and prognosis. Our previous analysis has identified the lncRNA GHRLOS, the ghrelin antisense strand non-coding RNA gene, as one of the hub genes in the co-expression network of differentially expressed lncRNAs/mRNAs in colorectal cancer (CRC). Here, we further evaluate the expression of GHRLOS in CRC and explore its clinical significance. The expression of GHRLOS in 366 pairs of CRC and adjacent non-cancerous tissues was detected by quantitative RT-PCR assays. The results showed that the expression level of GHRLOS was significantly lower in CRC tissues than in matched non-cancerous tissues (P < 0.001). Decreased GHRLOS expression was observed in 54.4% (199/366) of cases, and was significantly correlated with the occurrence of lymph node metastasis (P = 0.033) and distant metastasis (P = 0.005). A Kaplan-Meier analysis demonstrated that decreased GHRLOS expression contributed to poor disease-free survival (log-rank test, P < 0.001) and overall survival (log-rank test, P < 0.001). Moreover, a multivariate Cox regression analysis revealed the decreased expression of GHRLOS as an independent prognostic marker of poor outcomes [disease-free survival: hazard ratio (HR) = 2.02, 95% confidence interval (CI) = 1.42-3.88; overall survival: HR = 1.96, 95% CI = 1.34-2.86] in CRC patients. In conclusion, our data suggest that the lncRNA GHRLOS might serve as a candidate biomarker of tumor metastasis and a prognostic indicator in CRC.

Long noncoding RNA NNT-AS1 promotes hepatocellular carcinoma progression and metastasis through miR-363/CDK6 axis

Long non-coding RNAs (lncRNAs) have been tested to act as important regulator in liver cancer genesis and progression. LncRNA Nicotinamide Nucleotide Transhydrogenase-antisense RNA1 (NNT-AS1) has been reported to participate in the tumorigenesis. However, the exact molecular mechanism of NNT-AS1 in hepatocellular carcinoma (HCC) is still unknown. In present study, our team identified the up-regulated expression of NNT-AS1 in HCC tissue and cell lines compared with adjacent noncancerous tissue and normal cells. Moreover, HCC patients with high NNT-AS1 levels had poor prognosis than that with low NNT-AS1 level (p=0.0089). In vitro, gain- and loss-of-function experiments revealed that enhanced NNT-AS1 expression promoted the proliferation ability and alleviated the cycle arrest and apoptosis, while NNT-AS1 knockdown suppressed the proliferation and induced G0/G1 phase arrest and apoptosis. In vivo, NNT-AS1 knockdown inhibited the HCC neoplastic tumor volume and weight. Bioinformatics analysis and luciferase reporter assay validated that miR-363 targeted NNT-AS1 and CDK6 3’-UTR. MiR-363 was down-regulated in HCC tissue and cells. NNT-AS1 competed with CDK6 for miR-363 binding and could increase CDK6 expression. In summary, our results suggest the oncogenic role of NNT-AS1 in HCC tumorigenesis through miR-363/CDK6 axis, providing a novel therapeutic target for human HCC.

Long non-coding RNA LINC00959 predicts colorectal cancer patient prognosis and inhibits tumor progression

Long non-coding RNAs (lncRNAs) are increasingly implicated in tumorigenesis and cancer progression. This study focused on the relationship between the lncRNA LINC00959 and colorectal cancer (CRC). We found that LINC00959 expression was lower in CRC tissues than normal colorectal mucosae. High LINC00959 expression was negatively associated with TNM stage, distant metastasis, and lymphatic metastasis, and correlated with a better prognosis in 87 CRC cases. In vitro, LINC00959 knockdown enhanced colon cancer cell proliferation, invasion, and migration; upregulated N-cadherin and vimentin; and downregulated E-cadherin and Caspase-3. LINC00959 overexpression produced the opposite effects. These data suggest that LINC00959 inhibits tumor cell invasion and migration by suppressing epithelial-mesenchymal transition and promotes apoptosis through Caspase-3. LINC00959 may be a tumor suppressor and useful prognostic biomarker in CRC.

LncRNAs: key players and novel insights into diabetes mellitus

Long non-coding RNAs (LncRNAs) are a class of endogenous RNA molecules, which have a transcribing length of over 200 nt, lack a complete functional open reading frame (ORF), and rarely encode a functional short peptide. Recent studies have revealed that disruption of LncRNAs levels correlates with several human diseases, including diabetes mellitus (DM), a complex multifactorial metabolic disorder affecting more than 400 million people worldwide. LncRNAs are emerging as pivotal regulators in various biological processes, in the progression of DM and its associated complications, involving pancreatic β-cell disorder, insulin resistance, and epigenetic regulation, etc. Further investigation into the mechanisms of action of LncRNAs in DM will be of great value in the thorough understanding of pathogenesis. However, prior to successful application of LncRNAs, further search for molecular biomarkers and drug targets to provide a new strategy for DM prevention, early diagnosis, and therapy is warranted.

Long Non-Coding RNAs: Key Regulators of Epithelial-Mesenchymal Transition, Tumour Drug Resistance and Cancer Stem Cells

Epithelial mesenchymal transition (EMT), the adoption by epithelial cells of a mesenchymal-like phenotype, is a process co-opted by carcinoma cells in order to initiate invasion and metastasis. In addition, it is becoming clear that is instrumental to both the development of drug resistance by tumour cells and in the generation and maintenance of cancer stem cells. EMT is thus a pivotal process during tumour progression and poses a major barrier to the successful treatment of cancer. Non-coding RNAs (ncRNA) often utilize epigenetic programs to regulate both gene expression and chromatin structure. One type of ncRNA, called long non-coding RNAs (lncRNAs), has become increasingly recognized as being both highly dysregulated in cancer and to play a variety of different roles in tumourigenesis. Indeed, over the last few years, lncRNAs have rapidly emerged as key regulators of EMT in cancer. In this review, we discuss the lncRNAs that have been associated with the EMT process in cancer and the variety of molecular mechanisms and signalling pathways through which they regulate EMT, and finally discuss how these EMT-regulating lncRNAs impact on both anti-cancer drug resistance and the cancer stem cell phenotype.

The characteristic landscape of lncRNAs classified by RBP–lncRNA interactions across 10 cancers

RNA-binding proteins (RBPs) are key regulators of gene expression.