The lncRNA H19 Promotes Cell Proliferation by Competitively Binding to miR-200a and Derepressing β-Catenin Expression in Colorectal Cancer

Exosomal lncRNAs as regulators of breast cancer chemoresistance and metastasis and their potential use as biomarkers

Breast cancer is the most common cancer in women and the leading cause of female deaths by cancer in the world worldwide. Hence, understanding the molecular mechanisms associated with breast cancer development and progression, including drug resistance and breast cancer metastasis, is essential for achieving the best management of breast cancer patients. Cancer-related long noncoding RNAs have been shown to be involved in the regulation of each stage of breast cancer progression. Additionally, exosomes are extracellular microvesicles that are central to intercellular communication and play an important role in tumorigenesis. Exosomes can be released from primary tumor cells into the bloodstream and transmit cellular signals to distant body sites. In this work, we review the findings regarding the cellular mechanisms regulated by exosomal lncRNAs that are essentials to chemoresistance development and metastasis of breast cancer. Likewise, we evaluate the outcomes of the potential clinical use of exosomal lncRNAs as breast cancer biomarkers to achieve personalized management of the patients. This finding highlights the importance of transcriptomic analysis of exosomal lncRNAs to understand the breast cancer tumorigenesis as well as to improve the clinical tests available for this disease.

The long noncoding RNA SUMO1P3 as urinary biomarker for monitoring bladder cancer progression

Introduction

Urothelial Bladder Cancer (BC) is the ninth most common cancer worldwide. It is classified into Non Muscle Invasive (NMIBC) and Muscle Invasive Bladder Cancer (MIBC), which are characterized by frequent recurrences and progression rate, respectively. The diagnosis and monitoring are obtained through invasive methods as cystoscopy and post-surgery biopsies. Thus, a panel of biomarkers able to discriminate BC based on grading or staging represents a significant step forward in the patients' workup. In this perspective, long non-coding RNAs (lncRNAs) are emerged as reliable candidates as potential biomarker given their specific and regulated expression. In the present work we propose two lncRNAs, the Small Ubiquitin Modifier 1 pseudogene 3 (SUMO1P3), a poorly characterized pseudogene, and the Urothelial Carcinoma Associated 1 (UCA1) as candidates to monitor the BC progression.

Methods

This study was a retrospective trial enrolling NMIBC and MIBC patients undergoing surgical intervention: the expression of the lncRNA SUMO1P3 and UCA1 was evaluated in urine from 113 subjects (cases and controls). The receiver operating characteristic curve analysis was used to evaluate the performance of single or combined biomarkers in discriminating cases from controls.

Results

SUMO1P3 and UCA1 expression in urine was able to significantly discriminate low grade NMIBC, healthy control and benign prostatic hyperplasia subjects versus high grade NMIBC and MIBC patients. We also demonstrated that miR-320a, which binds SUMO1P3, was reduced in high grade NMIBC and MIBC patients and the SUMO1P3/miR-320a ratio was used to differentiate cases versus controls, showing a statistically significant power. Finally, we provided an automated method of RNA extraction coupled to ddPCR analysis in a perspective of clinical application.

Discussion

We have shown that the lncRNA SUMO1P3 is increased in urine from patients with high grade NMIBC and MIBC and that it is likely to be good candidate to predict bladder cancer progression if used alone or in combination with UCA1 or with miRNA320a.

H19: An Oncogenic Long Non-coding RNA in Colorectal Cancer

Colorectal cancer (CRC) has been recorded amongst the most common cancers in the world, with high morbidity and mortality rates, and relatively low survival rates. With risk factors such as chronic illness, age, and lifestyle associated with the development of CRC, the incidence of CRC is increasing each year. Thus, the discovery of novel biomarkers to improve the diagnosis and prognosis of CRC has become beneficial. Long non-coding RNAs (lncRNAs) have been emerging as potential players in several tumor types, one among them is the lncRNA H19. The paternally imprinted oncofetal gene is expressed in the embryo, downregulated at birth, and reappears in tumors. H19 aids in CRC cell growth, proliferation, invasion, and metastasis via various mechanisms of action, significantly through the lncRNA-microRNA (miRNA)-messenger RNA (mRNA)-competitive endogenous RNA (ceRNA) network, where H19 behaves as a miRNA sponge. The RNA transcript of H19 obtained from the first exon of the H19 gene, miRNA-675 also promotes CRC carcinogenesis. Overexpression of H19 in malignant tissues compared to adjacent non-malignant tissues marks H19 as an independent prognostic marker in CRC. Besides its prognostic value, H19 serves as a promising target for therapy in CRC treatment.

Long non-coding RNA H19 enhances the pro-apoptotic activity of ITF2357 (a histone deacetylase inhibitor) in colorectal cancer cells

Introduction: Long non-coding RNA H19 (lncH19) is highly expressed in colorectal cancer (CRC) and plays critical roles in tumor development, proliferation, metastasis, and drug resistance. Indeed, the expression of lncH19 usually affects the outcomes of chemo-, endocrine, and targeted therapies. ITF2357 (givinostat) is a histone deacetylase inhibitor (HDACi) that revealed a significant anti-tumor action by inducing apoptosis in different tumor models, including leukemia, melanoma, and glioblastoma. However, no data are present in the literature regarding the use of this compound for CRC treatment. Here, we investigate the role of lncH19 in ITF2357-induced apoptosis in CRC cells. Methods: The HCT-116 CRC cell line was stably silenced for H19 to investigate the role of this lncRNA in ITF2357-induced cell death. Cell viability assays and flow cytometric analyses were performed to assess the anti-proliferative and pro-apoptotic effects of ITF2357 in CRC cell lines that are silenced or not for lncH19. RT-PCR and Western blot were used to study the effects of ITF2357 on autophagy and apoptosis markers. Finally, bioinformatics analyses were used to identify miRNAs targeting pro-apoptotic factors that can be sponged by lncH19. Results: ITF2357 increased the expression levels of H19 and reduced HCT-116 cell viability, inducing apoptosis, as demonstrated by the increase in annexin-V positivity, caspase 3 cleavage, and poly (ADP-ribose) polymerase (PARP-1) degradation. Interestingly, the apoptotic effect of ITF2357 was much less evident in lncH19-silenced cells. We showed that lncH19 plays a functional role in the pro-apoptotic activity of the drug by stabilizing TP53 and its transcriptional targets, NOXA and PUMA. ITF2357 also induced autophagy in CRC cells, which was interpreted as a pro-survival response not correlated with lncH19 expression. Furthermore, ITF2357 induced apoptosis in 5-fluorouracil-resistant HCT-116 cells that express high levels of lncH19. Conclusion: This study shows that lncH19 expression contributes to ITF2357-induced apoptosis by stabilizing TP53. Overall, we suggest that lncH19 expression may be exploited to favor HDACi-induced cell death and overcome 5-fluorouracil chemoresistance.

In silico analysis to identify novel ceRNA regulatory axes associated with gallbladder cancer

Competitive endogenous RNA (ceRNA) networks are reported to play a crucial role in regulating cancer-associated genes. Identification of novel ceRNA networks in gallbladder cancer (GBC) may improve the understanding of its pathogenesis and might yield useful leads on potential therapeutic targets for GBC. For this, a literature survey was done to identify differentially expressed lncRNAs (DELs), miRNAs (DEMs), mRNAs (DEGs) and proteins (DEPs) in GBC. Ingenuity pathway analysis (IPA) using DEMs, DEGs and DEPs in GBC identified 242 experimentally observed miRNA-mRNA interactions with 183 miRNA targets, of these 9 (CDX2, MTDH, TAGLN, TOP2A, TSPAN8, EZH2, TAGLN2, LMNB1, and PTMA) were reported at both mRNA and protein levels. Pathway analysis of 183 targets revealed p53 signaling among the top pathway. Protein-protein interaction (PPI) analysis of 183 targets using the STRING database and cytoHubba plug-in of Cytoscape software revealed 5 hub molecules, of which 3 of them (TP53, CCND1 and CTNNB1) were associated with the p53 signaling pathway. Further, using Diana tools and Cytoscape software, novel lncRNA-miRNA-mRNA networks regulating the expression of TP53, CCND1, CTNNB1, CDX2, MTDH, TOP2A, TSPAN8, EZH2, TAGLN2, LMNB1, and PTMA were constructed. These regulatory networks may be experimentally validated in GBC and explored for therapeutic applications.

Sodium Selenite Regulates the Proliferation and Apoptosis of Gastric Cancer Cells by Suppressing the Expression of LncRNA HOXB-AS1

Gastric carcinoma has a high incidence, accounting for approximately 6% of all cancers worldwide. The in vivo antitumor effect of sodium selenite on gastric carcinoma has been demonstrated. This study therefore aimed to further explore its targets in gastric cancer in vitro and elucidate its mechanism of action. The effects of inorganic sodium selenite (Na2SeO3) on apoptosis, proliferation, and invasion of gastric cancer cells were investigated, and the interaction between Na2SeO3 and expression of long noncoding RNA homeobox B cluster antisense RNA 1 (HOXB-AS1) was investigated to elucidate the specific mechanism of action of selenium on gastric cancer cell proliferation through regulation of HOXB-AS1. Na2SeO3 downregulated the expression of HOXB-AS1 in the human gastric cancer (HGC) cell lines, HGC-27, NCI-N87, and KATO III cells, while inhibiting their proliferation and invasion and inducing apoptosis. The upregulation of HOXB-AS1 produced the opposite results. Na2SeO3 was used to stimulate HGC-27 cells, which caused HOXB-AS1 overexpression. The cell counting kit-8 (CCK-8) assay revealed a decrease in cell proliferation, while western blotting, flow cytometry, and transwell migration assays showed the expression of apoptosis-related (Bad, Bcl-2, and cleaved-caspase-3) and invasion-related (MMP2, E-cadherin, and N-cadherin) proteins, indicating increased apoptosis and decreased invasion. We therefore conclude that Na2SeO3 inhibits the malignant progression of gastric cancer by downregulating the expression of HOXB-AS1 and thus could be used as a potential drug for its treatment.

Comprehensive landscape and future perspectives of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC): Based on a bibliometric analysis

This review aimed to use bibliometric analysis to sort out, analyze and summarize the knowledge foundation and hot topics in the field of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC), and point out future trends to inspire related research and innovation. We used CiteSpace to analyze publication outputs, countries, institutions, authors, journals, references, and keywords. Knowledge foundations, hotspots, and future trends were then depicted. The overall research showed the trend of biomedical-oriented multidisciplinary. Much evidence indicates that lncRNA plays the role of oncogene or tumor suppressor in the occurrence and development of CRC. Besides, many lncRNAs have multiple mechanisms. lncRNAs and metastasis of CRC, lncRNAs and drug resistance of CRC, and the clinical application of lncRNAs in CRC are current research hotspots. Through insight into the development trend of lncRNAs in CRC, this study will help researchers extract hidden valuable information for further research.

Identification and Validation of an m6A-Related LncRNA Signature to Predict Progression-Free Survival in Colorectal Cancer

The RNA methylation of N6 adenosine (m6A) plays a crucial role in various biological processes. Strong evidence reveals that the dysregulation of long non-coding RNAs (lncRNA) brings about the abnormality of downstream signaling in multiple ways, thus influencing tumor initiation and progression. Currently, it is essential to discover effective and succinct molecular biomarkers for predicting colorectal cancer (CRC) prognosis. However, the prognostic value of m6A-related lncRNAs for CRC remains unclear, especially for progression-free survival (PFS). Here, we screened 24 m6A-related lncRNAs in 622 CRC patients and identified five lncRNAs (SLCO4A1-AS1, MELTF-AS1, SH3PXD2A-AS1, H19 and PCAT6) associated with patient PFS. Compared to normal samples, their expression was up-regulated in CRC tumors from TCGA dataset, which was validated in 55 CRC patients from our in-house cohort. We established an m6A-Lnc signature for predicting patient PFS, which was an independent prognostic factor by classification analysis of clinicopathologic features. Moreover, the signature was validated in 1,077 patients from six independent datasets (GSE17538, GSE39582, GSE33113, GSE31595, GSE29621, and GSE17536), and it showed better performance than three known lncRNA signatures for predicting PFS. In summary, our study demonstrates that the m6A-Lnc signature is a promising biomarker for forecasting patient PFS in CRC.

Comprehensive Analysis of Pyroptosis-Related Long Noncoding RNA Immune Infiltration and Prediction of Prognosis in Patients with Colon Cancer

Colon cancer (CC) is one of the most prevalent malignant tumours of the alimentary canal. It is unclear whether pyroptosis-related lncRNA expression is correlated with CC prognosis. We discovered 20 pyroptosis-related lncRNAs that were expressed differently in CC and normal colon tissues in our investigation. Based on differentially expressed genes (DEGs), we grouped all CC patients into two categories (Clusters 1 and 2). Cluster 1 was shown to be connected with a higher overall survival rate, upregulated expression of immune checkpoints, higher immunoscores, higher estimated scores, and immune cell infiltration. Using data from the Cancer Genome Atlas (TCGA), to create a multigene signature, the predictive significance of each lncRNA linked with pyroptosis for survival was assessed. A 9-lncRNA signature was established using the least absolute shrinkage and selection operator (LASSO) Cox regression method, and all CC patients in the TCGA cohort were classified into low-risk or high-risk groups. The low-risk CC patients had a much greater chance of survival than those in the high-risk group. The risk score is an independent prognostic indicator for predicting survival. In addition, risk characteristics are linked to immune characteristics. In summary, pyroptosis-related lncRNAs can be used to predict CC prognosis and participate in tumour immunity.

The association of long non-coding RNA in the prognosis of oral squamous cell carcinoma

BACKGROUND

Oral cancer is considered one of the most prevalent cancers in India. This is mainly because India suffers from high usage of tobacco, which is one of the main causative agents of oral cancer, and lacks proper health and sexual hygiene in rural areas.

DISCUSSION

Non-coding RNAs are reported to be involved in the various mechanism and causality of cancer. Numerous reports have identified viable prospects connecting non-coding RNA (ncRNA) with cancer. Specific ncRNAs like long non-coding RNA or lncRNAs are recently being prioritized as potential associations in the cause of cancer.

CONCLUSION

This review aims at presenting a concise perspective on the basics and the recent advancements of the lncRNA research pertaining specifically to oral cancer, its recurrence, and the future possibilities of knowledge it might possess.

RPARP-AS1/miR125a-5p Axis Promotes Cell Proliferation, Migration and Invasion in Colon Cancer

Background

It was reported that long-noncoding RNAs (lncRNAs) had been identified as a novel class of regulators related to various cancers. RPARP-AS1, a differentially-expressed gene, was found in analysis of the gene expression profile of CRC from GEO database. However, its function has not been clear.

Methods

RPARP-AS1 expression was determined by qPCR and Startbase3 analysis. Knockdown of RPARP-AS1 in CRC cell lines was performed by RNAi technology, named si-RPARP-AS1 HCT116 and si-RPARP-AS1 LoVo. Cell proliferation was examined by CCK8 and colony formation assay. RNA pull-down and Luciferase reporter assay were performed to confirm the interaction between RPARP-AS1 and miR-125a-5p.

Results

In the study, we found that the expression of RPARP-AS1 was significantly up-regulated in CRC tissues and multiple CRC cell lines, which was closely related to poor prognosis of CRC patients. Loss-of-function studies indicated that knockdown of RPARP-AS1 inhibited CRC cell proliferation, migration and invasion in HCT116 and LoVo cell lines. Results of research on the mechanisms showed that RPARP-AS1 functioned as a competitive endogenous RNA (ceRNA) to sponge miR-125a-5p, therefore promoting CRC procession.

Conclusion

In summary, these results indicated that RPARP-AS1/miR-125a-5p axis played a positive role in promoting cell proliferation, migration and invasion in CC. It may be as a biomarker used to evaluate CRC prognosis.

LncRNA-H19 gene plays a significant role in regulating glioma cell function

Background

Glioma is an aggressive adult primary cancer, and is characterized by low cure rate, poor prognosis, and high recurrence. The present study aimed to investigate the effect of lncRNA‐H19 gene silencing on glioma cell function.

Methods

lncRNA‐H19 interference vector (LV3‐si‐H19) and negative control vector (LV3‐NC) were stably transfected into U251 and U87‐MG cells, respectively. Quantitative real‐time PCR (qRT‐PCR) was performed to investigate the expression of lncRNA‐H19. Cell proliferation capacity was tested by adopting cell counting kit (CCK8), and propidium iodide (PI) was used for cell cycle analysis. Meanwhile, flow cytometry (FCM) method was used to investigate cell apoptosis, cell migration capacity was detected via wound healing and transwell experiments, and sphere‐forming ability was examined in serum‐free suspension culture. Additionally, glioma animal models were conducted through injecting U251 cells to estimate the effects of lncRNA‐H19 on glioma growth in vivo.

Results

Knocking down lncRNA‐H19 gene could effectively suppress the proliferation of U251 and U87‐MG cells. The knockdown of lncRNA‐H19 remarkably inhibited the migration and blocked cycle progressions of U251 and U87‐MG cells, yet, no obvious changes were observed in cell apoptosis. Besides, inhibiting lncRNA‐H19 expression could attenuate sphere‐forming function of U251 and U87‐MG cells. Additionally, tumor volume and weight were significantly reduced in rats injected with U251 LV‐si‐H19 cell line compared to untransfected and negative controls, when survival time was obviously prolonged in U251 LV‐si‐H19 injection groups.

Conclusion

LncRNA‐H19 gene plays a carcinogenic role in glioma progression via enhancing aggressive behavior of glioma cells.

LncRNA H19: A novel oncogene in multiple cancers

Long non-coding RNAs (lncRNAs) are a series of non-coding RNAs that lack open reading frameworks. Accumulating evidence suggests important roles for lncRNAs in various diseases, including cancers. Recently, lncRNA H19 (H19) became a research focus due to its ectopic expression in human malignant tumors, where it functioned as an oncogene. Subsequently, H19 was confirmed to be involved in tumorigenesis and malignant progression in many tumors and had been implicated in promoting cell growth, invasion, migration, epithelial-mesenchymal transition, metastasis, and apoptosis. H19 also sequesters some microRNAs, facilitating a multilayer molecular regulatory mechanism. In this review, we summarize the abnormal overexpression of H19 in human cancers, which suggests wide prospects for further research into the diagnosis and treatment of cancers.

Long non-coding RNAs regulating multiple proliferative pathways in cancer cell

Long non-coding RNAs (lncRNAs) belong to an extremely heterogeneous class of non-coding RNAs with a length ranging from 200 to 100,000 bp. They modulate a series of cellular pathways in both physiological and pathological context. It is no coincidence that they are expressed in an aberrant way in pathologies such as cancer, so as to deserve to be subclassified as oncogenes or tumor suppressors. These molecules are also involved in the regulation of cancer cell proliferation. Several lncRNAs are able to modulate cell growth both positively and negatively, and in this review we have focused on a small group of them, characterized by the simultaneous action on different pathways regulating cell proliferation. They have been considered in the light of their behavior in three different subtypes of proliferative pathways that we can define as (I) tumor suppressor, (II) oncogenic and (III) transcriptionally-driven. More specifically, we have characterized some lncRNAs considered oncogenes (such as H19, linc-ROR, MALAT1, HULC, HOTAIR and ANRIL), tumor suppressors (such as MEG3 and lincRNA-p21), and both oncogenes/tumor suppressors (UCA1 and TUG1) in a little more detail. As can be understood from the review, the interactions between lncRNAs and their molecular targets, only in the context of controlling cell proliferation, give rise to an intricate molecular network, the understanding of which, in the future, will certainly be of help for the treatment of molecular diseases such as cancer.

The miR-106b/NR2F2-AS1/PLEKHO2 Axis Regulates Migration and Invasion of Colorectal Cancer through the MAPK Pathway

Increasing numbers of miRNAs have been observed as oncogenes or tumor suppressors in colorectal cancer (CRC). It was recently reported that hsa-miR-106b-5p (miR-106b) promoted CRC cell migration and invasion. However, there were also studies showing contradictory results. Therefore, in the present study, we further explore the role of miR-106b and its downstream networks in the carcinogenesis of CRC. We observed that the expression of miR-106b is significantly increased in Pan-Cancer and CRC tissues compared with normal tissues from The Cancer Genome Atlas (TCGA) database. Furthermore, we used Transwell, Cell Counting Kit-8, and colony formation assays to clarify that miR-106b promotes the migratory, invasive, and proliferative abilities of CRC cells. For the first time, we systematically screened the target mRNAs and lncRNAs of miR-106b using TCGA database and the bioinformatics algorithms. Dual-luciferase reporter assay confirmed that NR2F2-AS1 and PLEKHO2 are the direct targets of miR-106b. Furthermore, NR2F2-AS1 acts as a competing endogenous RNA (ceRNA) to regulate PLEKHO2 expression by sponging miR-106b. The results of Gene set enrichment analysis (GSEA) and Western blot indicated that they play important roles in CRC progression by regulating MAPK pathway. Thus, miR-106b/NR2F2-AS1/PLEKHO2/MAPK signaling axis may suggest the potential usage in CRC treatment.

Long non-coding RNA CASC7 is associated with the pathogenesis of heart failure via modulating the expression of miR-30c

MiRNAs can be used as promising diagnostic biomarkers of heart failure, while lncRNAs act as competing endogenous RNAs of miRNAs. In this study, we collected peripheral blood monocytes from subjects with or without HF to explore the association between certain lncRNAs, miRNAs and HF. Heart failure patients with preserved or reduced ejection fraction were recruited for investigation. ROC analysis was carried out to evaluate the diagnostic values of certain miRNAs and lncRNAs in HF. Luciferase assays were used to study the regulatory relationship between above miRNAs and lncRNAs. LncRNA overexpression was used to explore the effect of certain miRNAs in H9C2 cells. Expression of miR‐30c was significantly decreased in the plasma and peripheral blood monocytes of patients suffering from heart failure, especially in these with reduced ejection fraction. On the contrary, the expression of lncRNA‐CASC7 was remarkably increased in the plasma and peripheral blood monocytes of patients suffering from heart failure. Both miR‐30c and lncRNA‐CASC7 expression showed a promising efficiency as diagnostic biomarkers of heart failure. Luciferase assays indicated that miR‐30c played an inhibitory role in lncRNA‐CASC7 and IL‐11 mRNA expression. Moreover, the overexpression of lncRNA‐CASC7 suppressed the expression of miR‐30c while evidently increasing the expression of IL‐11 mRNA and protein in H9C2 cells. This study clarified the relationship among miR‐30c, lncRNA‐CASC7 and IL‐11 expression and the risk of heart failure and showed that lncRNA‐CASC7 is potentially involved in the pathogenesis of HF via modulating the expression of miR‐30c.

An updated review of the H19 lncRNA in human cancer: molecular mechanism and diagnostic and therapeutic importance

Accumulating evidence has reported that H19 long non-coding RNA (lncRNA) expression level is deregulated in human cancer. It has been also demonstrated that de-regulated levels of H19 could affect cancer biology by various mechanisms including microRNA (miRNA) production (like miR-675), miRNA sponging and epigenetic modifications. Furthermore, lncRNA could act as a potential diagnosis and prognosis biomarkers and also a candidate therapeutic approach for different human cancers. In this narrative review, we shed light on the molecular mechanism of H19 in cancer development and pathogenesis. Moreover, we discussed the expression pattern and diagnostic and therapeutic importance of H19 as a potential biomarker in a range of human malignancies from breast to osteosarcoma cancer.

Hypoxia-Induced miR-675-5p Supports β-Catenin Nuclear Localization by Regulating GSK3-β Activity in Colorectal Cancer Cell Lines

The reduction of oxygen partial pressure in growing tumors triggers numerous survival strategies driven by the transcription factor complex HIF1 (Hypoxia Inducible Factor-1). Recent evidence revealed that HIF1 promotes rapid and effective phenotypic changes through the induction of non-coding RNAs, whose contribution has not yet been fully described. Here we investigated the role of the hypoxia-induced, long non-coding RNA H19 (lncH19) and its intragenic miRNA (miR-675-5p) into HIF1-Wnt crosstalk. During hypoxic stimulation, colorectal cancer cell lines up-regulated the levels of both the lncH19 and its intragenic miR-675-5p. Loss of expression experiments revealed that miR-675-5p inhibition, in hypoxic cells, hampered β-catenin nuclear localization and its transcriptional activity, while lncH19 silencing did not induce the same effects. Interestingly, our data revealed that miRNA inhibition in hypoxic cells restored the activity of Glycogen Synthase Kinase 3β (GSK-3β) reducing the amount of P-Ser9 kinase, thus unveiling a role of the miR-675-5p in controlling GSK-3β activity. Bioinformatics analyses highlighted the serine/threonine-protein phosphatases PPP2CA, responsible for GSK-3β activation, among the miR-675-5p targets, thus indicating the molecular mediator through which miR-675-5p may control β-catenin nuclear localization. In conclusion, here we demonstrated that the inhibition of the hypoxia-induced non-coding RNA miR-675-5p hampered the nuclear localization of β-catenin by regulating GSK-3β activity, thus proposing the miR-675-5p as a new therapeutic target for the treatment of colorectal cancer.

Role of non-coding RNAs as novel biomarkers for detection of colorectal cancer progression through interaction with the cell signaling pathways

Colorectal cancer (CRC) is one of the most common types of cancer which affects the colon and the rectum. Approximately one third of annual CRC mortality occurs due to the late detection of this type of cancer. Therefore, there is an urgent need for more powerful diagnostic and prognostic tools for identification and treatment of colorectal tumorigenesis. Non-coding RNAs (ncRNAs) have been implicated in the pathology of CRC and also linked to metastasis, proliferation, differentiation, migration, angiogenesis and apoptosis in numerous cancers. Recently, attention has turned towards ncRNAs as specific targets for diagnosis, prognosis and treatment of various types of cancers, including CRC. In this review, we have tried to outline the roles of ncRNAs, and their involvement in signaling pathways responsible for the progression of CRC.

LncRNA H19 gene rs2839698 polymorphism is associated with a decreased risk of colorectal cancer in a Chinese Han population: A case-control study

Background

Long non‐coding RNA (lncRNA) H19 is involved in the carcinogenesis, progression, and metastasis of colorectal cancer (CRC). Recently, a few studies explored the relationship between lncRNA H19 gene rs2839698 polymorphism and CRC risk, but with conflicting findings.

Materials and methods

A case‐control study with 315 CRC cases and 441 controls was designed in a Chinese population. Genotyping was performed using PCR‐RFLP.

Results

It was found rs2839698 polymorphism was associated with a decreased risk of CRC (AA vs GG: OR, 0.73; 95% CI, 0.54‐0.98; P = .037; A vs G: OR, 0.78; 95% CI, 0.63‐0.96; P = .021). Stratified analyses indicated this positive association was also significant in the non‐smokers (AA vs GG: OR, 0.49; 95% CI, 0.25‐0.93; P = .029), non‐drinkers, those aged ≥ 60 years, and overweight individuals (BMI ≥ 24). In addition, rs2839698 polymorphism was also related to the lymph node metastasis (AA vs GG: OR, 0.43; 95% CI, 0.21‐0.88; P = .019) and tumor size (AA vs GG: OR, 0.42; 95% CI, 0.20‐0.88; P = .020) for patients with CRC.

Conclusion

To sum up, the lncRNA H19 gene rs2839698 polymorphism decreases the risk of CRC in Chinese individuals, especially among the non‐smokers, non‐drinkers, individuals aged ≥ 60 years, and overweight individuals (BMI ≥ 24). Thus, the lncRNA H19 gene rs2839698 polymorphism might be an important biomarker and diagnostic marker for predicting the susceptibility to CRC in Chinese Han population.

lncRNA-ATB promotes stemness maintenance in colorectal cancer by regulating transcriptional activity of the β-catenin pathway

Long non-coding RNA activated by transforming growth factor-β (ATB) was recently reported to be involved in a wide range of physiological and pathological processes. However, the role of ATB in colorectal cancer (CRC) stemness remains unclear. In the present study, the functional role of ATB in maintaining stemness of CRC was determined using colony formation and sphere formation assays, and xenograft models. Reverse transcription-quantitative PCR, western blotting and immunohistochemistry were performed to investigate the mechanisms underlying the effects of ATB. Knockdown of ATB impaired colony formation and sphere formation in CRC cells, accompanied by an inhibition of colon tumor growth. Further results suggested that ATB regulated the transcriptional activity of the β-catenin pathway by inhibiting β-catenin expression. In addition, the results confirmed the role of β-catenin in ATB-mediated regulation of stemness in CRC. Collectively, the results indicated that ATB is a promising therapeutic target for CRC.

MicroRNA‑200a promotes esophageal squamous cell carcinoma cell proliferation, migration and invasion through extensive target genes

Despite investigations into microRNA (miRNA) expression in esophageal cancer (EC) tissue, miRNAs that participate in EC pathogenesis and their subsequent mechanisms of action remain to be determined. The present study aimed to identify important miRNAs that contribute to EC development, and to assess miRNA biomarkers that could be used in EC diagnosis, prognosis and therapy. Bioinformatics analysis was performed to reanalyze EC tissue miRNA expression microarray dataset GSE113776, which was followed by in vitro verification of miRNA functions using reverse transcription‑quantitative PCR, western blot analysis and a dual‑luciferase reporter assay. Out of 93 miRNAs extracted, only miR‑200a was significantly increased in EC tissues. Transfection of KYSE150 esophageal squamous cell carcinoma (ESCC) cells with miR‑200a mimics significantly increased their proliferative, migratory and invasive ability, whereas the opposite cell behaviors were observed in ESCC cells transfected with a miR‑200a inhibitor. A total of six miR‑200a target genes [catenin β1 (CTNNB1), cadherin‑1 (CDH1), PTEN, adenomatous polyposis coli (APC), catenin α1 (CTNNA1) and superoxide dismutase 2 (SOD2)] were selected for further analysis based on Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway analysis, protein‑protein interaction network map data and protein expression in esophageal tissue. These target genes were downregulated under miR‑200a expression and upregulated in the presence of the miR‑200a inhibitor. The association between miR‑200a and the 3'‑untranslated region of target genes in ESCC cells was confirmed using a dual‑luciferase reporter assay. In conclusion, the present study demonstrated that miR‑200a may participate in the promotion of ESCC cell proliferation, migration and invasion, and provided novel evidence for the direct interaction between miR‑200a and CTNNB1, CDH1, PTEN, APC, CTNNA1 and SOD2, which may contribute to the observed altered cell behavior.

Down-Regulation of LINC00460 Represses Metastasis of Colorectal Cancer via WWC2

BACKGROUND

Colorectal cancer (CRC) is one of the most prevalent cancers and a common cause of cancer-related death. Long noncoding RNAs have been reported to play an essential role in the development of CRC.

AIMS

This study aimed to investigate the possible function of LINC00460 in CRC.

METHODS

Initially, microarray-based gene expression profiling of CRC was employed to identify differentially expressed genes. Next, the expression of LINC00460 was examined and the cell line presenting with the highest LINC00460 expression was selected for subsequent experimentation. Then, the interaction among LINC00460, ERG, and WWC2 was identified. The effect of LINC00460 on proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT)-related factors as well as tumorigenicity of transfected cells was examined with gain- and loss-of-function experiments.

RESULTS

LINC00460 was robustly induced while WWC2 was poorly expressed in CRC. In addition, LINC00460 could down-regulate WWC2 through interaction with ERG, which led to promoted invasion, migration, and EMT of CRC cells in addition to tumor growth in vivo. Besides, down-regulation of LINC00460 exerted inhibitory effect on these biological activities.

CONCLUSION

Taken together, the key findings of the current study provided evidence suggesting that silencing of LINC00460 could potentially suppress EMT of CRC cells by increasing WWC2 via ERG, and highlighting that knockdown of LINC00460 could serve as a therapeutic target for CRC treatment.

The long non-coding RNA H19: an active player with multiple facets to sustain the hallmarks of cancer

Cancer cells exhibit hallmarks in terms of proliferation, resistance to cell death, angiogenesis, invasion, metastasis, and genomic instability. Despite the progress in cancer research and the comprehension of tumorigenesis mechanisms, cancer remains a major issue in public health. A better understanding of the molecular factors associated with the appearance or progression of cancer may allow the development of therapeutic alternatives. Increasing data highlight the role of long non-coding RNAs in many diseases, including cancer. The long non-coding RNA H19 was the first discovered riboregulator, and it has been shown to be involved at multiple steps of tumorigenesis. Indeed, this lncRNA exert its action at various molecular scales. Understanding the role of H19 in cancer progression may allow to set up therapeutic strategies to prevent tumor expansion and metastatic dissemination. In this review, we will summarize the overexpression of the long non-coding RNA H19 in several types of cancer and the multiple implications of the long non-coding RNA H19 in the different hallmarks that define human cancer.

The role of long non-coding RNA H19 in breast cancer

Breast cancer is the most common malignant tumor in women in the majority of countries, such as China, Britain and Australia, and its morbidity and mortality rates remain very high. Long non-coding RNAs (lncRNAs) are non-coding RNAs (ncRNAs) >200 nucleotides in length that lack open reading frames. LncRNA H19 is a transcription product of the H19 gene, and the aberrant expression of H19 can be demonstrated in various types of tumor cell. The purpose of the present review was to elaborate the role of H19 in breast cancer. H19 can regulate gene expression in breast cancer at multiple levels, including epigenetic, transcriptional and posttranscriptional. The abnormal expression of H19 is closely associated with the tumorigenesis and progression of breast cancer via different underlying molecular mechanisms, such as encoding microRNA-675, competing endogenous RNA regulation and interacting with MYC. A large number of clinical studies have suggested that H19 can serve as a potential biomarker for the diagnosis of breast cancer. High expression levels of H19 increases the drug resistance of breast cancer cells and is associated with poor prognosis within patients with breast cancer. Therefore, serum H19 levels may have momentous significance in the clinical setting.

Long non-coding RNAs in non-small cell lung cancer: functions and distinctions from other malignancies

Lung cancer leads to the most cancer-related death in the world. It was shown from the increasing evidences that long non-coding RNAs (lncRNAs) are emerging as molecules for diagnosis, prognosis and even therapy of lung cancer and other malignancies. The biological functions or involved signaling pathways of lncRNAs are always found to be inconsistent among different types of malignancies. However, no available literature has systemically summarized differences in the functions and underlying molecular mechanisms of lncRNAs between lung cancer and other cancers. In this review, the biological functions and molecular mechanisms of lncRNAs in lung cancer were introduced. Furthermore, their functional differences between lung cancer and other malignancies were discussed. Finally, their potential clinical applications in future lung cancer therapy were focused on.

Genome-wide discovery and characterization of long noncoding RNAs in patients with multiple myeloma

Background

Long noncoding RNAs (lncRNAs) are involved in a wide range of biological processes in tumorigenesis. However, the role of lncRNA expression in the biology, prognosis, and molecular classification of human multiple myeloma (MM) remains unclear, especially the biological functions of the vast majority of lncRNAs. Recently, lncRNAs have been identified in neoplastic hematologic disorders. Evidence has accumulated on the molecular mechanisms of action of lncRNAs, providing insight into their functional roles in tumorigenesis. This study aimed to characterize potential lncRNAs in patients with MM.

Methods

In this study, the whole-transcriptome strand-specific RNA sequencing of samples from three newly diagnosed patients with MM was performed. The whole transcriptome, including lncRNAs, microRNAs, and mRNAs, was analyzed. Using these data, MM lncRNAs were systematically analyzed, and the lncRNAs involved in the occurrence of MM were identified.

Results

The results revealed that MM lncRNAs had distinctive characteristics different from those of other malignant tumors. Further, the functions of a set of lncRNAs preferentially expressed in MM were verified, and several lncRNAs were identified as competing endogenous RNAs. More importantly, the aberrant expression of certain lncRNAs, including maternally expressed gene3, colon cancer–associated transcript1, and coiled-coil domain-containing 26, as well as some novel lncRNAs involved in the occurrence of MM was established. Further, lncRNAs were related to some microRNAs, regulated each other, and participated in MM development.

Conclusions

Genome-wide screening and functional analysis enabled the identification of a set of lncRNAs involved in the occurrence of MM. The interaction exists among microRNAs and lncRNAs.

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).

Loss of ferrochelatase is protective against colon cancer cells: ferrochelatase a possible regulator of the long noncoding RNA H19

Background

Ferrochelatase (FECH) is the last enzyme of the heme biosynthesis pathway. Deficiency in FECH was associated with many diseases, including protoporphyria. Correlation studies showed that variations of FECH expression was detected in human carcinomas and more specifically in colon cancer. Nevertheless, the potential role of FECH in colon cancer carcinogenesis in vitro was not depicted yet.

Methods

A small interfering RNA (siRNA) was used to knockdown FECH in human Caco-2 colon cancer cells. The effect of FECH down-regulation on the cellular proliferation, the migration and the expression of target genes was assessed in cancer cells and compared to human normal fibroblasts.

Results

Following FECH down-regulation, our results demonstrated that the proliferation of Caco-2 cells was not affected. Furthermore, the migration of cancer and normal cells was affected, only when an additional stress factor (H₂O₂) was applied to the medium. The expression of twist, snail, hypoxia induced factor (HIF-1α) and vascular endothelial growth factor (VEGF) was reduced in Caco-2 cells. Conversely, VEGF and HIF-1α expression were upregulated by up to 2 folds in control fibroblasts. Interestingly, the pro-carcinogenic long noncoding RNA (LncRNA) H19 was 70% down-regulated in Caco-2 cells upon FECH down regulation whereas no effect was observed in normal fibroblasts.

Conclusions

In conclusion, we showed that loss of FECH is protective against colon cancer tumorigenesis in vitro and this effect could possibly be mediated through inhibition of H19.

Diagnostic and prognostic potential of tissue and circulating long non-coding RNAs in colorectal tumors

Long non-coding RNAs (lncRNAs) are members of the non-protein coding RNA family longer than 200 nucleotides. They participate in the regulation of gene and protein expression influencing apoptosis, cell proliferation and immune responses, thereby playing a critical role in the development and progression of various cancers, including colorectal cancer (CRC). As CRC is one of the most frequently diagnosed malignancies worldwide with high mortality, its screening and early detection are crucial, so the identification of disease-specific biomarkers is necessary. LncRNAs are promising candidates as they are involved in carcinogenesis, and certain lncRNAs (e.g., CCAT1, CRNDE, CRCAL1-4) show altered expression in adenomas, making them potential early diagnostic markers. In addition to being useful as tissue-specific markers, analysis of circulating lncRNAs (e.g., CCAT1, CCAT2, BLACAT1, CRNDE, NEAT1, UCA1) in peripheral blood offers the possibility to establish minimally invasive, liquid biopsy-based diagnostic tests. This review article aims to describe the origin, structure, and functions of lncRNAs and to discuss their contribution to CRC development. Moreover, our purpose is to summarise lncRNAs showing altered expression levels during tumor formation in both colon tissue and plasma/serum samples and to demonstrate their clinical implications as diagnostic or prognostic biomarkers for CRC.

Long intergenic noncoding RNA 00707 promotes colorectal cancer cell proliferation and metastasis by sponging miR-206

Background: The incidence and mortality of colorectal cancer (CRC) are rising worldwide. Long-noncoding RNAs (lncRNAs) are known to play key roles in the development of human cancers, including CRC. However, the function and underlying mechanism of long intergenic noncoding RNA 00707 (LINC00707) in the development of CRC are unknown.

Materials and methods: The expression of LINC00707 and miR-206 in tissue samples or cell lines was measured by quantitative reverse transcription PCR (qRT-PCR). The protein expression of neurogenic locus notch homolog protein 3 (NOTCH3) and transmembrane 4 L6 family member 1 (TM4SF1) was assessed by Western blotting. Cell proliferation, migration, and invasion were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and transwell assays. Luciferase reporter assay and biotin-coupled miRNA capture assay were used to explore the relationship between LINC00707 and miR-206 expression.

Results: The expression of LINC00707 was significantly upregulated in CRC tissues as compared with the adjacent non-CRC tissues. LINC00707 expression was significantly correlated with tumor size, lymphatic metastasis, and distant metastasis, but not significantly correlated with age and gender. Knockdown of LINC00707 expression significantly inhibited LoVo and HCT116 cell proliferation, migration, and invasion. LINC00707 acted as a molecular sponge by competing for miR-206 and indirectly modulating the expression of its targets, NOTCH3 and TM4SF1.

Conclusion: LINC00707 promotes CRC cell proliferation and metastasis by sponging miR-206, suggestive of its potential application for CRC treatment.

The miRNA hsa-miR-6515-3p potentially contributes to lncRNA H19-mediated-lung cancer metastasis

Aberrant expression of long noncoding RNAs (lncRNAs) contributes to all phenotypes of cancer including metastasis, which is a major cause of death in many advanced malignancies. One particular lncRNA, H19, is found to be a crucial player in cancer progression by modulating multiple microRNAs (miRNAs). In this study, we screened miRNAs possibly associated with H19 using lung carcinoma cell lines and patient with lung cancer tissues, and selected one possible hit, hsa‐miR‐6515‐3p, to perform in vitro functional assays. Its inhibition leads to decreased proliferation and migration of SPC‐A1 lung cancer cells and is in good correlation with H19‐knockdown groups. These results indicate that H19 may be an epigenetic regulator of miR‐6515‐3p, and its dysregulation may contribute to lung cancer progression and metastasis.

LncRNA-SNHG15 enhances cell proliferation in colorectal cancer by inhibiting miR-338-3p

The incidence and death rate of colorectal cancer (CRC) is very high, which brings great need to understand the early molecular events of CRC. These studies demonstrate that long noncoding RNA (lncRNA) plays an important role in the occurrence and development of human cancer. Small nucleolar RNA host gene 15 (SNHG15) was recently identified as a cancer‐related lncRNA. In this study, we aimed to evaluate the function and mechanism of SNHG15 in CRC. The expression of SNHG15 was detected by quantitative RT‐PCR (qRT‐PCR) in CRC tissues and matched noncancerous tissues (NCTs). CCK‐8 assay, colony formation assay, flow cytometric analysis, and nude mouse xenograft mode were used to examine the tumor‐promoting function of SNHG15 in vitro and in vivo. The binding relationship between SNHG15, miR‐338‐3p and the target genes of miR‐338‐3p were screened and identified by databases, qRT‐PCR, dual luciferase reporter assay and western blot. Our results showed that SNHG15 was up‐regulated in CRC tissues compared with paired NCTs (P < 0.0001). High level of SNHG15 expression predicted poor prognosis of CRC (P = 0.0051). SNHG15 overexpression could promote cell proliferation and inhibit cell apoptosis. Animal experiments showed that up‐regulation of SNHG15 promoted tumor growth in vivo. The results of mechanism experiments showed that SNHG15 could bind to miR‐338‐3p and block its inhibition on the expression and activity of FOS or RAB14. In conclusion SNHG15 promotes cell proliferation through SNHG15/miR‐338‐3p/FOS‐RAB14 axis in CRC.

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.

Long Noncoding RNA Expression Signatures of Colon Cancer Based on the ceRNA Network and Their Prognostic Value

Background

The specific functional roles of long noncoding RNAs (lncRNAs) as ceRNAs in colon cancer and their potential implications for colon cancer prognosis remain unclear. In the present study, a genome-wide analysis was performed to investigate the potential lncRNA-mediated ceRNA interplay in colon cancer based on the “ceRNA hypothesis.” The prognostic value of the lncRNAs was evaluated.

Methods

A dysregulated lncRNA-associated ceRNA network was constructed based on the miRNA, lncRNA, and mRNA expression profiles in combination with the miRNA regulatory network by using an integrative computational method. Molecular biological techniques, including qPCR and gene knockdown techniques, were used to verify candidate targets in colon cancer. Survival analysis was performed to identify the candidate lncRNAs with prognostic value.

Results

Our network analysis uncovered several novel lncRNAs as functional ceRNAs through crosstalk with miRNAs. The QRT-PCR assays of patient tissues as well as gene knockdown colon cancer cells confirmed the expression of top lncRNAs and their correlation with target genes in the ceRNA network. Functional enrichment analysis predicted that differentially expressed lncRNAs might participate in broad biological functions associated with tumor progression. Moreover, these lncRNAs may be involved in a range of cellular pathways, including the apoptosis, PI3K-AKT, and EGFR signaling pathways. The survival analysis showed that the expression level of several lncRNAs in the network was correlated with the prognosis of patients with colon cancer.

Conclusions

This study uncovered a dysregulated lncRNA-associated ceRNA network in colon cancer. The function of the identified lncRNAs in colon cancer was preliminarily explored, and their potential prognostic value was evaluated. Our study demonstrated that lncRNAs could potentially serve as important regulators in the development and progression of colon cancer. Candidate prognostic lncRNA biomarkers in colon cancer were identified.

The Interaction Between lncRNA SNHG1 and miR-140 in Regulating Growth and Tumorigenesis via the TLR4/NF-κB Pathway in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common primary hepatobiliary carcinoma. The long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) has been reported to contribute to the progression of multiple cancers. Nonetheless, the functions and hidden mechanism of SNHG1 remain unclear in CCA. In this study, the SNHG1 levels were boosted in CCA cell lines, and knockdown of SNHG1 repressed CCA cell proliferation and invasion in vitro. The data also demonstrated that miR-140 could act as a target of SNHG1 in CCA and inhibited CCA cell proliferation and invasion, whereas the inhibition effects were relieved by overexpression of SNHG1. In addition, Toll-like receptor 4 (TLR4), an NF-κB-activating signal, was identified to be a target of miR-140. SNHG1, as a competing endogenous RNA (ceRNA) for miR-140, enhanced TLR4 expression and activated NF-κB signaling, thereby regulating growth and tumorigenesis in CCA. Animal experiments further confirmed this conclusion. Collectively, these findings not only uncovered a key role of SNHG1/miR-140/TLR4/NF-κB signaling axis in CCA tumorigenesis and progression but also denoted the probable utilization of SNHG1 as a therapeutic target for CCA.

Intricate crosstalk between MYC and non-coding RNAs regulates hallmarks of cancer

Myelocytomatosis viral oncogene homolog (MYC) plays an important role in the regulation of many cellular processes, and its expression is tightly regulated at the level of transcription, translation, protein stability, and activity. Despite this tight regulation, MYC is overexpressed in many cancers and contributes to multiple hallmarks of cancer. In recent years, it has become clear that noncoding RNAs add a crucial additional layer to the regulation of MYC and its downstream effects. So far, twenty-five microRNAs and eighteen long noncoding RNAs that regulate MYC have been identified. Thirty-three miRNAs and nineteen lncRNAs are downstream effectors of MYC that contribute to the broad oncogenic role of MYC, including its effects on diverse hallmarks of cancer. In this review, we give an overview of this extensive, multilayered noncoding RNA network that exists around MYC. Current data clearly show explicit roles of crosstalk between MYC and ncRNAs to allow tumorigenesis.

Long non-coding RNA H19 promotes the migration and invasion of colon cancer cells via MAPK signaling pathway

Long non-coding RNA H19 has been identified to be dysregulated in a number of tumor types, and is closely associated with cancer progression. RAS/mitogen-activated protein kinase (MAPK) is an important intracellular signaling transduction pathway. Activation of the RAS-MAPK signaling pathway is one of the most frequent carcinogenic events in human cancer. However, the mechanism of H19 in promoting the migration and invasion of colorectal cancer (CRC) cells, and the association between H19 and RAS-MAPK signaling pathway is not well understood. The aim of the present study was to investigate the function of H19 on CRC metastasis and invasion, and assess the association between H19 and the RAS-MAPK signaling pathway. The migration and invasion of CRC cells were analyzed using Transwell migration and invasion assays. To elucidate the association between H19 and the RAS-MAPK signaling pathway and determine the expression level of active RAS in CRC cells, Ras activity assay and Western blotting were performed. It was indicated that the overexpression of H19 was able to increase the migration and invasion of CRC cells and this may be mediated by the regulation of RAS activation. Therefore, H19 may promote metastasis and invasion in colorectal cancer by activating the RAS-MAPK signaling pathway.

Genetic variants in lncRNA H19 are associated with the risk of oral squamous cell carcinoma in a Chinese population

To evaluate whether the genetic variants in H19 influence the risk of oral squamous cell carcinoma (OSCC) in a Chinese population, a case-control study was conducted to analyze four functional single nucleotide polymorphisms (SNPs) in H19. The cohort comprised of 444 OSCC cases and 984 healthy controls, and the study further evaluated the biological effect by bioinformatics prediction and functional experiments. Two SNPs, rs217727 and rs2839701, were found to be associated with the risk of OSCC [rs217727: odds ratio (OR) = 1.32, 95% confidence interval (CI) = 1.11-1.58, P = 0.002; rs2839701: OR = 1.23, 95% CI = 1.04-1.46, P = 0.019].Bioinformatics predicted that rs2839701 C>G might alter the secondary structure of H19. In addition, rs2839701 C>G inhibited the transcription activity and was correlated with the decreased expression of downstream gene MRPL23-AS1 that was downregulated in OSCC. The current results suggested that the SNPs in H19 may play a major role in genetic susceptibility to OSCC.

Scutellarin suppresses human colorectal cancer metastasis and angiogenesis by targeting ephrinb2

Tumor induced angiogenesis is an attractive target for anti-cancer drug treatment. Scutellarin, which is a native compound derived from scutellaria altissima leaves, has already been proved to possess anti-tumor activities. Nevertheless, their effects in colorectal cancer metastasis and angiogenesis have not been evaluated. In order to reveal the anti-angiogenic and anti-metastasis capacity of scutellarin, wound healing and Transwell chamber inserts invasion were done in colorectal cancer cells, and cell proliferation as wells colony formation were conducted to identify the proliferation inhibition of colorectal cancer in vitro. The growth inhibition of scutellarin was further definite by a mouse colorectal xenograft model in vivo. Herein, we demonstrated scutellarin suppressed colorectal cancer cell viability and colony formation in vitro, and remarkably reduced tumor growth in vivo mouse xenografts. Additionally, scutellarin restrained colorectal cancer cells-induced angiogenesis, inhibited human umbilical vascular endothelial cells (HUVECs) migration, tube formation of HUVECs, and micro-vessel formation in chick embnyo chorioallantoic menbreme (CAM) assay. Altogether, our results exhibited the evidence that scutellarin inhibit colorectal cancer angiogenesis and metastasis via targeting ephrinb2 signaling, with the potential of an anti-tumor agent for cancer treatment.

LncRNA XIST acts as a tumor suppressor in prostate cancer through sponging miR-23a to modulate RKIP expression

Accumulating evidences have indicated that aberrant expression of long non-coding RNAs (LncRNAs) is tightly associated with cancer development. Previous studies have reported that lncRNA XIST regulates tumor malignancies in several cancers. However, the underlying mechanism of XIST in prostate cancer remains unclear. In the current study, we found that XIST was down-regulated in prostate cancer specimens and cell lines. Low expression of XIST was correlated with poor prognosis and advanced tumor stage in prostate cancer patients. In gain and loss of function assays, we confirmed that XIST suppressed cellular proliferation and metastasis in prostate cancer both in vitro and in vivo. Furthermore, we found that XIST negatively regulates the expression of miR-23a and subsequently promotes RKIP expression at post-transcriptional level. Consequently, we investigated the correlation between XIST and miR-23a, and identified miR-23a as a direct target of XIST. In addition, over-expression of miR-23a efficiently abrogated the up-regulation of RKIP induced by XIST, suggesting that XIST positively regulates the expression of RKIP by competitively binding to miR-23a. Taken together, our study indicated that lncRNA XIST acts as a tumor suppressor in prostate cancer, and this regulatory effect of XIST will shed new light on epigenetic diagnostics and therapeutics in prostate cancer.

Long noncoding RNA CCAT1 functions as a ceRNA to antagonize the effect of miR-410 on the down-regulation of ITPKB in human HCT-116 and HCT-8 cells

Colorectal cancer is one of the most common malignancies, which has seriously affected people's health. Abnormal expression of long non-coding RNAs and microRNAs are closely related to the process of occurrence, development, invasion and metastasis of colorectal cancer. However, the effect of lnc CCAT1 on human HCT-116/HCT-8 cells and its potential mechanism were investigated. In present study, differential expression of CCAT1, miR-410 and ITPKB were detected in colon cancer tissues and adjacent parts. Then the prediction programs were applied to predict the target genes of miR-410. The complementary bindings of miR-410 with lnc CCAT1 and ITPKB were assessed by luciferase assays. The interaction between LncRNA CCAT1 and miR-410 was analyzed. In addition, the mRNA and protein of ITPKB and apoptosis factors were examined in cells after miR-410 overexpression or silencing. Meanwhile, MTT and flow cytometer were used to detect the cells proliferation and apoptosis level. Results showed that CCAT1 and miR-410 were up-regulated in colon cancer tissues, but ITPKB was down-regulated. Lnc CCAT1 and ITPKB were predicted to be the targets of miR-410 and the prediction were verified by luciferase assays. The expression of lnc CCAT1 and ITPKB were inhibited by miR-410 in human HCT-116/HCT-8 cells. Meanwhile, lnc CCAT1 could lead to a decrease of miR-410. Furthermore, miR-410 overexpression could promote cell proliferation and reduce apoptosis. In summary, these data demonstrated that miR-410 could promote cell proliferation and reduce apoptosis by inhibiting ITPKB expression and the expression of lnc CCAT1 antagonized the effect of miR-410.

Long Noncoding RNAs as Biomarkers in Cancer

Long noncoding RNAs (lncRNAs) are a relatively well-characterized class of noncoding RNA (ncRNA) molecules, involved in the regulation of various cell processes, including transcription, intracellular trafficking, and chromosome remodeling. Their deregulation has been associated with the development and progression of various cancer types, the fact which makes them suitable as biomarkers for cancer diagnosis and prognosis. In recent years, detection of cancer-associated lncRNAs in body fluids of cancer patients has proven itself as an especially valuable method to effectively diagnose cancer. Cancer diagnosis and prognosis employing circulating lncRNAs are preferential when compared to classical biopsies of tumor tissues, especially due to their noninvasiveness, and have great potential for routine usage in clinical practice. Thus, this review focuses on summarizing the perspectives of lncRNAs as biomarkers in cancer, based on evaluating their expression profiles determined in body fluids of cancer patients.