Upregulation of the long non-coding RNA PlncRNA-1 promotes esophageal squamous carcinoma cell proliferation and correlates with advanced clinical stage

Long non-coding RNAs as pathophysiological regulators, therapeutic targets and novel extracellular vesicle biomarkers for the diagnosis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic relapsing disease of the gastrointestinal (GI) system that includes two groups, Crohn's disease (CD) and ulcerative colitis (UC). To cope with these two classes of IBD, the investigation of pathogenic mechanisms and the discovery of new diagnostic and therapeutic approaches are crucial. Long non-coding RNAs (lncRNAs) which are non-coding RNAs with a length of longer than 200 nucleotides have indicated significant association with the pathology of IBD and strong potential to be used as accurate biomarkers in diagnosing and predicting responses to the IBD treatment. In the current review, we aim to investigate the role of lncRNAs in the pathology and development of IBD. We first describe recent advances in research on dysregulated lncRNAs in the pathogenesis of IBD from the perspective of epithelial barrier function, intestinal immunity, mitochondrial function, and intestinal autophagy. Then, we highlight the possible translational role of lncRNAs as therapeutic targets, diagnostic biomarkers, and predictors of therapeutic response in colon tissues and plasma samples. Finally, we discuss the potential of extracellular vesicles and their lncRNA cargo in the pathophysiology, diagnosis, and treatment of IBD.

Long non-coding RNAs in cancer: multifaceted roles and potential targets for immunotherapy

Cancer remains a major global health concern with high mortality rates mainly due to late diagnosis and poor prognosis. Long non-coding RNAs (lncRNAs) are emerging as key regulators of gene expression in human cancer, functioning through various mechanisms including as competing endogenous RNAs (ceRNAs) and indirectly regulating miRNA expression. LncRNAs have been found to have both oncogenic and tumor-suppressive roles in cancer, with the former promoting cancer cell proliferation, migration, invasion, and poor prognosis. Recent research has shown that lncRNAs are expressed in various immune cells and are involved in cancer cell immune escape and the modulation of the tumor microenvironment, thus highlighting their potential as targets for cancer immunotherapy. Targeting lncRNAs in cancer or immune cells could enhance the anti-tumor immune response and improve cancer immunotherapy outcomes. However, further research is required to fully understand the functional roles of lncRNAs in cancer and the immune system and their potential as targets for cancer immunotherapy. This review offers a comprehensive examination of the multifaceted roles of lncRNAs in human cancers, with a focus on their potential as targets for cancer immunotherapy. By exploring the intricate mechanisms underlying lncRNA-mediated regulation of cancer cell proliferation, invasion, and immune evasion, we provide insights into the diverse therapeutic applications of these molecules.

A Pleiotropic Role of Long Non-Coding RNAs in the Modulation of Wnt/β-Catenin and PI3K/Akt/mTOR Signaling Pathways in Esophageal Squamous Cell Carcinoma: Implication in Chemotherapeutic Drug Response

Despite the availability of modern techniques for the treatment of esophageal squamous cell carcinoma (ESCC), tumor recurrence and metastasis are significant challenges in clinical management. Thus, ESCC possesses a poor prognosis and low five-year overall survival rate. Notably, the origin and recurrence of the cancer phenotype are under the control of complex cancer-related signaling pathways. In this review, we provide comprehensive knowledge about long non-coding RNAs (lncRNAs) related to Wnt/β-catenin and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway in ESCC and its implications in hindering the efficacy of chemotherapeutic drugs. We observed that a pool of lncRNAs, such as HERES, TUG1, and UCA1, associated with ESCC, directly or indirectly targets various molecules of the Wnt/β-catenin pathway and facilitates the manifestation of multiple cancer phenotypes, including proliferation, metastasis, relapse, and resistance to anticancer treatment. Additionally, several lncRNAs, such as HCP5 and PTCSC1, modulate PI3K/Akt/mTOR pathways during the ESCC pathogenesis. Furthermore, a few lncRNAs, such as AFAP1-AS1 and LINC01014, block the efficiency of chemotherapeutic drugs, including cisplatin, 5-fluorouracil, paclitaxel, and gefitinib, used for ESCC treatment. Therefore, this review may help in designing a better therapeutic strategy for ESCC patients.

Long noncoding RNA CBR3-AS1 mediates tumorigenesis and radiosensitivity of non-small cell lung cancer through redox and DNA repair by CBR3-AS1 /miR-409-3p/SOD1 axis

The long noncoding RNA CBR3-AS1 has important functions in various cancers. However, the biological functions of CBR3-AS1 in non-small cell lung cancer (NSCLC) remain unclear. This study aimed to investigate the roles and molecular mechanisms of CBR3-AS1 in NSCLC tumorigenesis and radiosensitivity. Here, we demonstrate CBR3-AS1 overexpression in NSCLC tissue compared with adjacent normal tissue. CBR3-AS1 downregulation reduced proliferation, invasion, and migration; inhibited cell cycle progression; and promoted apoptosis of NSCLC cells. CBR3-AS1 also promoted tumor growth in vivo. CBR3-AS1 may regulate the expression and functions of the miR-409-3p target gene SOD1. CBR3-AS1 expression was negatively correlated with radiosensitivity. CBR3-AS1 downregulation decreased post-irradiation SOD1 expression, increased γH2AX formation, raised levels of reactive oxygen species, and promoted apoptosis. Our results suggest that CBR3-AS1 functions as an oncogene through the CBR3-AS1/miR-409-3p/SOD1 pathway, and may represent a new therapeutic target, especially to regulate radiosensitivity in NSCLC.

LncRNA PlncRNA-1 accelerates the progression of prostate cancer by regulating PTEN/Akt axis

Long non-coding RNAs are key regulators of tumor development and progression, with the potential to be biomarkers of tumors. This study aimed to explore the role of PlncRNA-1 in the progression of prostate cancer (PCa). We found that PlncRNA-1 was up-regulated in 85.29% of PCa tissues and could predict the T stage of PCa patients to a certain extent. Results showed that inhibition of PlncRNA-1 expression potentially promoted cell apoptosis, suppressed the proliferation, migration, and invasion of cells, and triggered G2/M cycle arrest in vitro and in vivo. PlncRNA-1 was mainly localized in the nucleus and PlncRNA-1 expression and phosphatase and tensin homologue (PTEN) expression were negatively correlated. Mechanistically, knockdown of PlncRNA-1 increased expression levels of PTEN protein and phosphorylated PTEN protein, and decreased expression levels of Akt protein and phosphorylated Akt protein. Rescue experiments demonstrated that PTEN inhibitors abolished the changes in PTEN/Akt pathway caused by PlncRNA-1 interference. PlncRNA-1 can promote the occurrence and development of PCa via the PTEN/Akt pathway. PlncRNA-1 may, therefore, be a new candidate target for the treatment of PCa.

Involvement of long non-coding RNAs in the progression of esophageal cancer

Esophageal cancer (EC) is one of the most common malignant tumors of the digestive system with high incidence and mortality rate worldwide. Therefore, exploring the pathogenesis of EC and searching for new targeted therapies are the current research hotspot for EC treatment. Long non‐coding RNAs (lncRNAs) are endogenous RNAs with more than 200 nucleotides, but without protein‐coding function. In recent years, lncRNAs have gradually become the focuses in the field of non‐coding RNA. Some lncRNAs have been proved to be closely related to the pathogenesis of EC. Many lncRNAs are abnormally expressed in EC and participate in many biological processes including cell proliferation, apoptosis, and metastasis by inhibiting or promoting target gene expression. LncRNAs can also regulate the progression of EC through epithelial‐mesenchymal transformation (EMT), which is closely related to the occurrence, development, and prognosis of EC. In this article, we review and discuss the involvement of lncRNAs in the progression of EC.

LncRNA CBR3-AS1 regulates of breast cancer drug sensitivity as a competing endogenous RNA through the JNK1/MEK4-mediated MAPK signal pathway

Background

Adriamycin (ADR) resistance is one of the main obstacles to improving the clinical prognosis of breast cancer patients. Long noncoding RNAs (lncRNAs) can regulate cell behavior, but the role of these RNAs in the anti-ADR activity of breast cancer remains unclear. Here, we aim to investigate the imbalance of a particular long noncoding RNA, lncRNA CBR3 antisense RNA 1 (CBR3-AS1), and its role in ADR resistance.

Methods

Microarray analysis of ADR-resistant breast cancer cells was performed to identify CBR3-AS1. CCK-8 and colony formation assays were used to detect the sensitivity of breast cancer cells to ADR. Dual-luciferase reporter, RNA pulldown, IHC and western blot analyses were used to verify the relationship between the expression of CBR3-AS1, miRNA and target genes. For in vivo experiments, the effect of CBR3-AS1 on breast cancer resistance was observed in a xenograft tumor model. The role of CBR3-AS1 in influencing ADR sensitivity was verified by clinical breast cancer specimens from the TCGA, CCLE, and GDSC databases.

Results

We found that CBR3-AS1 expression was significantly increased in breast cancer tissues and was closely correlated with poor prognosis. CBR3-AS1 overexpression promoted ADR resistance in breast cancer cells in vitro and in vivo. Mechanistically, we identified that CBR3-AS1 functioned as a competitive endogenous RNA by sponging miR-25-3p. MEK4 and JNK1 of the MAPK pathway were determined to be direct downstream proteins of the CBR3-AS1/miR-25-3p axis in breast cancer cells.

Conclusions

In summary, our findings demonstrate that CBR3-AS1 plays a critical role in the chemotherapy resistance of breast cancer by mediating the miR-25-3p and MEK4/JNK1 regulatory axes. The potential of CBR3-AS1 as a targetable oncogene and therapeutic biomarker of breast cancer was identified.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01844-7.

Hypomethylation of PlncRNA-1 promoter enhances bladder cancer progression through the miR-136-5p/Smad3 axis

Apart from being potential prognostic biomarkers and therapeutic targets, long non-coding RNAs (lncRNAs) modulate the development and progression of multiple cancers. PlncRNA-1 is a newly discovered lncRNA that exhibits the above properties through multiple regulatory pathways. However, the clinical significance and molecular mechanisms of PlncRNA-1 in bladder cancer have not been established. PlncRNA-1 was found to be overexpressed in 71.43% of bladder cancer tissues. Moreover, the expression level correlated with tumor invasion, T stage, age, and number of tumors, but not with gender, recurrent status, preoperative treatment, pathological grade, and tumor size. The expression level of PlncRNA-1 can, to a certain extent, be used as a predictor of the degree of tumor invasion and T stage among BC patients. Inhibiting PlncRNA-1 expression impaired the proliferation, migration, and invasion of T24 and 5637 bladder cancer cells in vitro and in vivo. Specifically, PlncRNA-1 promoter in BC tissues was found to be hypomethylated at position 131 (36157603 on chromosome 21). PlncRNA-1 promoter hypomethylation induces the overexpression of PlncRNA-1. In addition, PlncRNA-1 modulated the expression of smad3 and has-miR-136-5p (miR-136). Conversely, miR-136 regulated the expression of PlncRNA-1 and smad3. PlncRNA-1 mimics competitive endogenous RNA (ceRNA) in its regulation of smad3 expression by binding miR-136. Rescue analysis further revealed that modulation of miR-136 could reverse the expression of smad3 and epithelial–mesenchymal transition (EMT) marker proteins impaired by PlncRNA-1. In summary, PlncRNA-1 has important clinical predictive values and is involved in the post-transcriptional regulation of smad3. The PlncRNA-1/miR-136/smad3 axis provides insights into the regulatory mechanism of BC, thus may serve as a potential therapeutic target and prognostic biomarker for cancer.

Long noncoding RNAs in head and neck squamous cell carcinoma: biological functions and mechanisms

Head and neck squamous cell carcinoma (HNSCC) is the primary malignant tumor of the oral cavity, larynx, nasopharynx, esophagus and tongue. Although several novel therapeutic methods for HNSCC have been developed, the final therapeutic effect on the patient is still not satisfactory. Thus, it is imperative that scientists identify novel distinguishable markers with specific molecular characteristics that can be used in therapeutic and prognostic evaluation. Previous reports have shown that long noncoding RNAs (lncRNAs) are important regulators of gene expression in many cancers, including head and neck squamous cell carcinomas. Translational studies of lncRNAs in HNSCC are urgently required before their application as a treatment can be realized. We aimed to address the most relevant findings on lncRNAs as biomarkers or treatment targets in head and neck squamous cell carcinoma and to summarize their discovered pathways and mechanisms of action to reveal the possible future applications of these novel biomarkers in clinical translational research.

LncRNA WEE2-AS1 promotes proliferation and inhibits apoptosis in triple negative breast cancer cells via regulating miR-32-5p/TOB1 axis

Triple negative breast cancer (TNBC) is a malignant breast cancer subtype with poor prognosis. Recent studies have revealed the critical roles of dysregulated long non-coding RNAs (lncRNAs) in many cancer types, including TNBC. LncRNA WEE2 antisense RNA 1 (WEE2-AS1) has been reported to be able to promote the progression of hepatocellular carcinoma, but the function of WEE2-AS1 in TNBC is still unknown. Therefore, in this study, we specifically researched the role of WEE2-AS1 and probed its molecular mechanism in TNBC cells. Our results showed that WEE2-AS1 was up-regulated in TNBC cell lines, and WEE2-AS1 knockdown could inhibit TNBC cell proliferation, promote apoptosis, and suppress migration and invasion. Further, we found that miR-32-5p was down-regulated in TNBC cells and could be sponged by WEE2-AS1. Moreover, miR-32-5p could target its downstream gene transducer of ERBB2, 1 (TOB1), which was highly expressed and could play the oncogenic role in TNBC cells. Through rescue assays, we proved that WEE2-AS1/miR-32-5p/TOB1 axis could modulate cancer progression in TNBC cells. In conclusion, our results demonstrated the oncogenic function of lncRNA WEE2-AS1 in TNBC cells, providing a novel insight into TNBC therapy.

Long non-coding RNA LINC00337 induces autophagy and chemoresistance to cisplatin in esophageal squamous cell carcinoma cells via upregulation of TPX2 by recruiting E2F4

Esophageal cancer represents the eighth most frequently occurring cancer, as well as the sixth most widespread cause of cancer-related deaths. In recent years, accumulating evidence has implicated long non-coding RNAs in the progression of esophageal squamous cell carcinoma (ESCC). The aim of the present study was to investigate the potential involvement and underlying mechanisms of LINC00337 in ESCC. Expression patterns of LINC00337 and targeting protein for Xenopus kinesin-like protein 2 (TPX2) in ESCC tissues and cells were detected using RT-qPCR and immunohistochemical staining. Next, the interactions among LINC00337, E2F4, and TPX2 were identified using chromatin immunoprecipitation, dual-luciferase reporter, and RNA-binding protein immunoprecipitation assays, suggesting that LINC00337 could recruit E2F4 to enhance the transcription of TPX2. Thereafter, the regulatory roles of LINC00337 and TPX2 in ESCC were analyzed by altering the expression of LINC00337 or TPX2 in ESCC cells following treatment with cisplatin (DDP). The levels of autophagy-related proteins Beclin1 and LC3II/LC3I, viability, autophagy, apoptosis, and chemoresistance of ESCC cells to DDP were measured following transfection treatment with different plasmids. Additionally, the role of the LINC00337/E2F4/TPX2 axis was assessed in vivo by measuring tumor formation in nude mice. The results demonstrated that LINC00337 upregulated TPX2, consequently leading to elevated levels of Beclin1 and LC3II/LC3I, promoted cell viability and autophagy, while inhibiting apoptosis and chemosensitivity to DDP in ESCC. In sum, the current study evidenced that the overexpression of LINC00337 could potentially enhance ESCC cell autophagy and chemoresistance to DDP via the upregulation of TPX2 by recruiting E2F4. Thus, LINC00337 may serve as a potential candidate for the treatment of ESCC.

The cox-filter method identifies respective subtype-specific lncRNA prognostic signatures for two human cancers

BACKGROUND

The most common histological subtypes of esophageal cancer are squamous cell carcinoma (ESCC) and adenocarcinoma (EAC). It has been demonstrated that non-marginal differences in gene expression and somatic alternation exist between these two subtypes; consequently, biomarkers that have prognostic values for them are expected to be distinct. In contrast, laryngeal squamous cell cancer (LSCC) has a better prognosis than hypopharyngeal squamous cell carcinoma (HSCC). Likewise, subtype-specific prognostic signatures may exist for LSCC and HSCC. Long non-coding RNAs (lncRNAs) hold promise for identifying prognostic signatures for a variety of cancers including esophageal cancer and head and neck squamous cell carcinoma (HNSCC).

METHODS

In this study, we applied a novel feature selection method capable of identifying specific prognostic signatures uniquely for each subtype - the Cox-filter method - to The Cancer Genome Atlas esophageal cancer and HSNCC RNA-Seq data, with the objectives of constructing subtype-specific prognostic lncRNA expression signatures for esophageal cancer and HNSCC.

RESULTS

By incorporating biological relevancy information, the lncRNA lists identified by the Cox-filter method were further refined. The resulting signatures include genes that are highly related to cancer, such as H19 and NEAT1, which possess perfect prognostic values for esophageal cancer and HNSCC, respectively.

CONCLUSIONS

The Cox-filter method is indeed a handy tool to identify subtype-specific prognostic lncRNA signatures. We anticipate the method will gain wider applications.

Biological and clinical relevance of metastasis-associated long noncoding RNAs in esophageal squamous cell carcinoma: A systematic review

Esophageal squamous cell carcinoma (ESCC) is a foremost cancer-related death worldwide owing to rapid metastasis and poor prognosis. Metastasis, as the most important reason for death, is biologically a multifaceted process involving a range of cell signaling pathways. Long noncoding RNAs (lncRNAs), as transcriptional regulators, can regulate numerous genomic processes and cellular processes such as cell proliferation, migration, and invasion. LncRNAs have also been shown to involve in/regulate the cancer metastasis-related signaling pathways. Hence, they have increasingly been brought to international attention in molecular oncology research. A number of researchers have attempted to reveal the biological and clinical relevance of lncRNAs in ESCC tumourigenesis and metastasis. The aberrant expression of these molecules in ESCC has regularly been reported to involve in various cellular processes and clinical features, including diagnosis, prognosis, and therapeutic responses. Here, we especially consider the pathways in which lncRNAs act as metastasis-mediated effectors, mainly by interacting with epithelial-mesenchymal transition-associated factors. We review the biological roles of lncRNAs through involving in ESCC metastasis as well as the clinical significance of the metastasis-related lncRNAs in cancer diagnosis and prognosis.

lncRNA GAS5-promoted apoptosis in triple-negative breast cancer by targeting miR-378a-5p/SUFU signaling

PURPOSE

Long-chain noncoding RNAs (lncRNAs) are involved in regulating the sensitivity of cancer cells to chemotherapeutic drugs, but the specific mechanism of action is not well understood. The aim of this study was to investigate the effect of lncRNA growth-stasis specific transcript 5 (GAS5) on triple-negative breast cancer (TNBC).

METHODS

Quantitative real-time polymerase chain reaction and flow cytometry were used to screen lncRNA associated with tumor resistance. Double luciferase reporter gene assay, flow cytometry, and Western blot assay were used to determine whether miRNA 378a-5p and SUFU were involved in tumor cell apoptosis induced by lncRNA GAS5. A mouse model of subcutaneous xenografts was established to investigate the relationship between lncRNA GAS5 and tumor resistance in vivo.

RESULTS

In this study, the expression of lncRNA GAS5 was significantly downregulated in cells treated with paclitaxel (PTX) or cisplatin (CIS). Furthermore, TNBC cells with low expression of lncRNA GAS5 had a lower percentage of apoptosis under stress conditions, especially in serum-free medium. More interestingly, the expression level of lncRNA GAS5 in TNBC patients was associated with tumor resistance to PTX and CIS. In addition, RNA immunoprecipitation experiments confirmed that lncRNA GAS5 and miR-378 could directly bind to each other. Moreover, the miR-378a-5p target of SUFU could promote lncRNA GAS5-induced apoptosis of TNBC cells. Finally, lncRNA GAS5 overexpressed MDA-231R could enhance the sensitivity of TNBC to PTX.

CONCLUSION

The above results confirmed that lncRNA GAS5 could induce apoptosis in TNBC cells by targeting miR-378a-5p/SUFU signaling.

Long noncoding RNA lnc-ABCA12-3 promotes cell migration, invasion, and proliferation by regulating fibronectin 1 in esophageal squamous cell carcinoma

Long noncoding RNAs (lncRNAs) have been shown to play important roles in human cancers, including esophageal squamous cell carcinoma (ESCC). We previously demonstrated that a novel lncRNA, lnc-ABCA12-3, was overexpressed in ESCC tissues. However, the exact function of lnc-ABCA12-3 is unknown. In the current study, we aimed to evaluate the expression of lnc-ABCA12-3 in ESCC and to explore the potential mechanism of lnc-ABCA12-3 in cell migration, invasion, and proliferation. We showed that lnc-ABCA12-3 was upregulated in ESCC tumor tissues and cell lines. The increased expression of lnc-ABCA12-3 was positively associated with advanced tumor-node-metastasis stages and poor prognosis. The knockdown of lnc-ABCA12-3 inhibited the cell migration, invasion, and proliferation abilities of KYSE-510 and Eca-109 cells. We also found that fibronectin 1 (FN1) was upregulated in ESCC tumor tissues. The expression of FN1 messenger RNA was positively correlated with the expression of lnc-ABCA12-3 in ESCC tumor tissues. After lnc-ABCA12-3 knockdown, the expression of FN1 was downregulated. In addition, the overexpression of FN1 restored the abilities of cell migration, invasion and proliferation in Eca-109 cells. Further studies indicated that lnc-ABCA12-3 acted as a competing endogenous RNA for miR-200b-3p to regulate FN1 expression. In conclusion, these results suggest that lnc-ABCA12-3 is a novel oncogene in tumorigenesis and that its high expression is related to a poor prognosis for patients with ESCC. lnc-ABCA12-3 promotes cell migration, invasion, and proliferation via the regulation of FN1 in ESCC. Our data suggest that lnc-ABCA12-3 might serve as a potential prognostic biomarker and therapeutic target for ESCC.

Multi-Targeting by β-Elemene and Its Anticancer Properties: A Good Choice for Oncotherapy and Radiochemotherapy Sensitization

Several studies have focused on chemical agents, tailored from natural edible products, used to prevent and treat various diseases. β-elemene is a well-known compound derived from Curcuma wenyujin that possesses a wide spectrum of anticancer properties under preclinical and clinical conditions. Several studies have demonstrated its inhibitory effect both in humans and animals with cancers. Numerous in vivo and in vitro experimental models have revealed that β-elemene can modulate multiple molecular pathways involved in carcinogenesis. In general, (1) β-elemene itself can inhibit and kill tumor cells through a variety of mechanisms, and (2) can synergistically enhance the effect of radiotherapy and/or chemotherapy, (3) also can regulate autoimmune in the treatment of tumors. In this article, we critically focused on the available scientific evidence discussing the use of β-elemene in cancer prevention, and its molecular targets and mechanisms of action in different types of cancer. In addition, we have discussed its sources, chemistry, bioavailability, and future research directions.

Long Non-coding RNAs as Important Biomarkers in Laryngeal Cancer and Other Head and Neck Tumours

Head and neck carcinoma (HNC) is a heterogeneous disease encompassing a variety of tumors according to the origin. Laryngeal cancer (LC) represents one of the most frequent tumors in the head and neck region. Despite clinical studies and advance in treatment, satisfactory curative strategy has not yet been reached. Therefore, there is an urgent need for the identification of specific molecular signatures that better predict the clinical outcomes and markers that serve as suitable therapeutic targets. Long non-coding RNAs (lncRNA) are reported as important regulators of gene expression and represent an innovative pharmacological application as molecular biomarkers in cancer. The purpose of this review is to discuss the most relevant epigenetic and histological prognostic biomarkers in HNC, with particular focus on LC. We summarize the emerging roles of long non-coding RNAs in HNC and LC development and their possible use in early diagnosis.

LincRNA-p21 leads to G1 arrest by p53 pathway in esophageal squamous cell carcinoma

Background: Esophageal squamous cell carcinoma (ESCC) is the fourth most common cause of cancer death in China. Long noncoding RNAs have emerged as critical regulators in cancer. Long intergenic noncoding RNA-p21, a kind of Long noncoding RNAs, LincRNA-p21 have been discussed dysregulated in several cancers, but its role in ESCC remains unknown. This study investigated the role of LincRNA-p21 in ESCC.

Materials and methods: The LincRNA-p21 expression level and its association with esophageal cancer was determined in 64 tumor tissues of esophageal squamous cell carcinoma patients and cells using quantitative real-time reverse transcription PCR. Fluorescence in situ hybridization of single-RNA molecular probes was used to determine subcellular localization of LincRNA-p21. CCK8 and EdU assays were used for proliferation assay, flow cytometry was performed for apoptosis and cell-cycle distribution, and 24-well Mill cell chamber was made for measuring the abilities of migration and invasion after transfected with lentivirus-expressing LincRNA-p21 in EC109 cells. Then, quantitative real-time reverse transcription PCR and Western blot detected the expression of p21. Further, UC2288, an inhibitor of p21, was used to decrease the level of p21, and flow cytometry was used to detect cell cycle. Finally, screening for differential pathways from microarray analysis and expression of p53 and cyclin D were detected by Western blot.

Results:LincRNA-p21 expression level was remarkably lower in tumor tissues versus nontumor tissues and lower in EC109 cells versus Het-1A cells. Statistical analysis found that LincRNA-p21 might enhance the risk of ESCC. We observed that LincRNA-p21 was expressed both in the nucleus and cytoplasm, and a larger proportion of LincRNA-p21 was observed in the cytoplasm. The results demonstrated that upregulating the expression of LincRNA-p21 could inhibit cell proliferation, migration, invasion, and the transition of cell cycle from G1 and promoted apoptosis of EC109. Then, we found that LincRNA-p21 promotes the expression of p21. Decreasing the level of p21 revealed that cell-cycle arrest was restored. Pathway analysis found p53 pathway was downregulated, and upregulation of LincRNA-p21 inhibited the expression of cyclin D.

Conclusion: Our study suggests that LincRNA-p21 plays as a tumor inhibitor in ESCC development and LincRNA-p21 might induce G1 arrest through p53 signal pathway.

Upregulation of the long non-coding RNA CBR3-AS1 predicts tumor prognosis and contributes to breast cancer progression

Breast cancer is the most common female malignancy and the major cause of cancer-related death in women. Long non-coding RNAs (lncRNAs), as oncogenic or tumor suppressor factor, involved in the development and progression of various cancers. In this study, we sought to investigate the function of lncRNA CBR3-AS1 in breast cancer. We evaluated the expression pattern of CBR3-AS1 in breast cancer tissues and cell lines, explored the correlation between CBR3-AS1 expression and the survival time of breast cancer patients, and probed the effect of CBR3-AS1 on tumor progression of breast cancer through loss-of-function and gain-of-function strategies. Our results showed that CBR3-AS1 was overexpressed in breast cancer tissues and cell lines and predicted the prognosis of breast cancer patients. And CBR3-AS1 exerted biological function as an oncogenic lncRNA, involved in the regulation of cell proliferation, colony formation, apoptosis and tumor growth in breast cancer. Taken together, CBR3-AS1 was up-regulated in breast cancer and promoted the risk of breast cancer. It may be a novel therapeutic target and potential prognostic marker for breast cancer.

Upregulation of long noncoding RNA LINC00152 promotes proliferation and metastasis of esophageal squamous cell carcinoma

Purpose: Esophageal cancer is a major cause of cancer-related mortality worldwide. The long noncoding RNA LINC00152 has been confirmed to play an oncogenic role in many cancers. However, the expression pattern and function of LINC00152 in human esophageal squamous cell carcinoma (ESCC) remain unclear.

Materials and methods: We evaluated LINC00152 expression in ESCC by qPCR and in situ hybridization. Proliferation, apoptosis, cell cycle, migration and invasion were examined in ESCC cells knocked down for LINC00152 knockdown by siRNA. Furthermore, an mRNA microarray was performed in ESCC cells with LINC00152 knockdown.

Results: LINC00152 was significantly upregulated in human ESCC clinical samples (P<0.001) and cell lines (P=0.008), and LINC00152 overexpression was related to lymphatic metastasis (P=0.03) and advanced pTNM classification (P=0.005). Furthermore, ESCC patients with LINC00152 overexpression had significantly shorter overall survival (P=0.007), and LINC00152 overexpression was an independent risk factor for overall survival of ESCC patients. LINC00152 knockdown inhibited the proliferation, migration and invasion of ESCC cells in vitro. In addition, mechanistic investigations through mRNA array and immunoblot analyses demonstrated that LINC00152 regulated the expression of several cell cycle-related proteins and SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) interactions in vesicular transport pathway proteins.

Conclusion: Our research indicated that LINC00152 exhibits oncogenic functions in ESCC and may represent a potential new target for ESCC therapy.

Overexpression of long noncoding RNA LINC01419 in esophageal squamous cell carcinoma and its relation to the sensitivity to 5-fluorouracil by mediating GSTP1 methylation

BACKGROUND

Genome-wide sequencing investigations have identified numerous long noncoding RNAs (lncRNAs) among mammals, many of which exhibit aberrant expression in cancers, including esophageal squamous cell carcinoma (ESCC). Herein, this study elucidates the role and mechanism by which LINC01419 regulates the DNA methylation of glutathione S-transferase pi 1 (GSTP1) in relation to ESCC progression and the sensitivity of ESCC cells to 5-fluorouracil (5-FU).

METHODS

LINC01419 and GSTP1 levels were quantified among 38 paired ESCC and adjacent tissue samples collected from patients with ESCC. To ascertain the contributory role of LINC01419 in the progression of ESCC and identify the interaction between LINC01419 and GSTP1 promoter methylation, LINC01419 was overexpressed or silenced, and the DNA methyltransferase inhibitor 5-Aza-CdR was treated.

RESULTS

Data from the GEO database (GSE21362) and the Cancer Genome Atlas displayed elevated levels of LINC01419 and downregulated levels of GSTP1 in the ESCC tissues and cells. The silencing of LINC01419 led to decreased proliferation, increased apoptosis, and enhanced sensitivity to 5-FU in ESCC cells. Notably, LINC01419 could bind to the promoter region of the GSTP1 gene, resulting in elevated GSTP1 methylation and reduced GSTP1 levels via the recruitment of DNA methyltransferase among ESCC cells, whereby ESCC progression was stimulated accompanied by reduced ESCC cell sensitivity to 5-FU. GSTP1 demethylation by 5-Aza-CdR was observed to reverse the effects of LINC01419 overexpression in ESCC cells and the response to 5-FU.

CONCLUSION

Highly expressed LINC01419 in ESCC promotes GSTP1 methylation, which ultimately acts to promote the event of ESCC and diminish the sensitivity of ESCC cells to 5-FU, highlighting a novel potential strategy to improve 5-FU-based chemotherapy in ESCC.

LONG-NONCODING RNAs in gastroesophageal cancers

Despite continuing improvements in multimodal therapies, gastro-esophageal malignances remain widely prevalent in the population and is characterized by poor overall and disease-free survival rates. Due to the lack of understanding about the pathogenesis and absence of reliable markers, gastro-esophageal cancers are associated with delayed diagnosis. The increasing understanding about cancer's molecular landscape in the recent years, offers the possibility of identifying 'targetable' molecular events and in particular facilitates novel treatment strategies and development of biomarkers for early stage diagnosis. At least 98% of our genome is actively transcribed into non-coding RNAs encompassing long non-coding RNAs (lncRNAs) constituted of transcripts longer than 200 nucleotides with no protein-coding capacity. Many studies have demonstrated that lncRNAs are functional genomic elements playing pivotal roles in main oncogenic processes. LncRNA can act at multiple levels developing a complex molecular network that can modulate directly or indirectly the expression of genes involved in tumorigenesis. In this review, we focus on lncRNAs as emerging players in gastro-esophageal carcinogenesis and critically assess their potential as reliable noninvasive biomarkers and in next generation targeted therapies.

PlncRNA-1 is overexpressed in retinoblastoma and regulates retinoblastoma cell proliferation and motility through modulating CBR3

PlncRNA-1 has been suggested to function as an oncogenic role in prostate cancer, colorectal cancer, hepatocellular carcinoma, esophageal squamous cell carcinoma, and gastric cancer. The expression pattern of PlncRNA-1 in retinoblastoma remained unknown. Therefore, the aim of this study was to explore the clinical significance of PlncRNA-1 in retinoblastoma patient and the biological function and molecular mechanism of PlncRNA-1 in regulating retinoblastoma cell proliferation, migration, and invasion. The results showed the level of PlncRNA-1 expression was obviously increased in retinoblastoma tissues and cell lines compared with compared with normal retina tissues and retina cell lines, respectively. Meanwhile, patients with advanced stage retinoblastoma had higher levels of PlncRNA-1 expression than patients with early stage retinoblastoma. There was an inverse correlation between PlncRNA-1 expression and CBR3 expression in retinoblastoma tissues, and PlncRNA-1 negatively regulated mRNA and protein expressions of CBR3. The in vitro experiments showed that down-regulation of PlncRNA-1 expression suppressed retinoblastoma cell proliferation, migration and invasion through up-regulating CBR3. In conclusion, PlncRNA-1 serves as an oncogenic lncRNA in regulating retinoblastoma cell proliferation, migration, and invasion through proliferation, migration, and invasion through up-regulating CBR3. © 2018 IUBMB Life, 70(10):969-975, 2018.

Emerging role of lncRNAs in the normal and diseased intestinal barrier

OBJECTIVE

A significant effort has been made to understand the intestinal barrier, but the effective means to prevent, reduce, and restore intestinal mucosal damage remains unclear. Recently, a few of studies have explained the mechanism of the intestinal barrier in long noncoding RNAs (lncRNAs). This review aims to summarize recent views on the function of lncRNAs in the intestinal barrier and discuss the emerging role of lncRNAs in intestinal barrier diseases caused by inflammatory diseases.

METHODS

Observations led us to believe that lncRNAs participate in inflammatory responses, cell proliferation, and control microbial susceptibility. In view of these, lncRNAs have been proved to involve in the intestinal barrier.

RESULTS

lncRNAs directly or indirectly affect TJ mRNA translation and intestinal epithelial cells (IECs) paracellular permeability, as well as IECs proliferation and susceptibility to apoptosis, to modulate the function of the intestinal barrier. miRNAs play a pivotal role in this process.

CONCLUSIONS

lncRNAs have been shown to be fundamentally involved in intestinal mucosal regeneration, protection, and epithelial barrier function. It may emerge as new and potential factors to be evaluated in the intestinal barrier diseases caused by acute pancreatitis, inflammatory bowel diseases, and imbalance of intestinal flora.

Long non-coding RNAs: crucial regulators of gastrointestinal cancer cell proliferation

Studies of long non-coding RNAs (lncRNAs) have been prevalent in the field of non-coding RNA regulation in recent years. LncRNAs exert crucial effects on malignant cell processes in the gastrointestinal system, including proliferation. Aberrant lncRNA expression, through both oncogenes and tumor suppressor genes, is instrumental to tumor cell proliferation. Here, we summarize the different molecular mechanisms and relevant signaling pathways through which multifarious lncRNAs regulate cell proliferation and we show that lncRNAs are potential biomarkers for gastrointestinal cancers.

LncRNA PlncRNA-1 overexpression inhibits the growth of breast cancer by upregulating TGF-β1 and downregulating PHGDH

OBJECTIVE

To investigate the role of lncRNA PlncRNA-1 in the pathogenesis of breast cancer.

METHODS

A total of 78 patients with breast cancer as well as 48 healthy females were included in this study. Expression in tumor tissues and adjacent healthy tissues of breast cancer patients, as well as in breast tissues and serum of both patients and healthy control was detected by qRT-PCR. Cell proliferation was detected by CCK-8 assay, and cell apoptosis was tested by MTT assay. PlncRNA-1 overexpression cell lines were constructed and the effects on TGF-β1 as well as phosphoglycerate dehydrogenase (PHGDH) were explored by western blot.

RESULTS

Expression levels of PlncRNA-1 were significantly lower in tumor tissues than those in adjacent healthy tissues. Significantly lower expression levels of PlncRNA-1 were also found in breast cancer patients than those in healthy controls in both breast tissue and serum. Upregulation of PlncRNA-1 promoted the expression of TGF-β1, but inhibited the expression of PHGDH. LncRNA PlncRNA-1 overexpression reduced the proliferation rate, but increased the apoptosis rate of breast cancer cells, while treatment with TGF-β inhibitor reduced those effects of PlncRNA-1 overexpression.

CONCLUSION

LncRNA PlncRNA-1 overexpression inhibits the growth of breast cancer by upregulating TGF-β1 and downregulating PHGDH.

LncRNA CBR3-AS1 predicts unfavorable prognosis and promotes tumorigenesis in osteosarcoma

LncRNA CBR3-AS1 has been suggested to promote malignancy in several types of human cancers, but the clinical significance and biological function of lncRNA CBR3-AS1 in osteosarcoma is still unknown. The purpose of our study is to explore the clinical significance of lncRNA CBR3-AS1 in osteosarcoma patients and the biological function in osteosarcoma cells. In our results, we found lncRNA CBR3-AS1 was highly-expressed in osteosarcoma tissues and cell lines, and associated with Enneking stage, distant metastasis and histological grade. Survival analysis indicated that the high-expression of lncRNA CBR3-AS1 was an independent poor prognostic factor for osteosarcoma patients. Loss-of-function studies showed knockdown of lncRNA CBR3-AS1 suppressed osteosarcoma cells proliferation, migration and invasion, and promotes cells apoptosis, but had no effect on cell-cycle distribution. There was no association between lncRNA CBR3-AS1 and CBR3 expression in osteosarcoma tissues, and knockdown of lncRNA CBR3-AS1 had no effect on CBR3 mRNA and protein expression osteosarcoma cells. In conclusion, lncRNA CBR3-AS1 serves an oncogenic role to regulate osteosarcoma cells proliferation, migration, invasion and apoptosis, and is an independent poor prognostic factor for osteosarcoma patients.

Unraveling the oral cancer lncRNAome: Identification of novel lncRNAs associated with malignant progression and HPV infection

OBJECTIVES

The role of long non-coding RNA (lncRNA) expression in human head and neck squamous cell carcinoma (HNSCC) is still poorly understood. In this study, we aimed at establishing the onco-lncRNAome profiling of HNSCC and to identify lncRNAs correlating with prognosis and patient survival.

MATERIALS AND METHODS

The Atlas of Noncoding RNAs in Cancer (TANRIC) database was employed to retrieve the lncRNA expression information generated from The Cancer Genome Atlas (TCGA) HNSCC RNA-sequencing data. RNA-sequencing data from HNSCC cell lines were also considered for this study. Bioinformatics approaches, such as differential gene expression analysis, survival analysis, principal component analysis, and Co-LncRNA enrichment analysis were performed.

RESULTS

Using TCGA HNSCC RNA-sequencing data from 426 HNSCC and 42 adjacent normal tissues, we found 728 lncRNA transcripts significantly and differentially expressed in HNSCC. Among the 728 lncRNAs, 55 lncRNAs were significantly associated with poor prognosis, such as overall survival and/or disease-free survival. Next, we found 140 lncRNA transcripts significantly and differentially expressed between Human Papilloma Virus (HPV) positive tumors and HPV negative tumors. Thirty lncRNA transcripts were differentially expressed between TP53 mutated and TP53 wild type tumors. Co-LncRNA analysis suggested that protein-coding genes that are co-expressed with these deregulated lncRNAs might be involved in cancer associated molecular events. With consideration of differential expression of lncRNAs in a HNSCC cell lines panel (n=22), we found several lncRNAs that may represent potential targets for diagnosis, therapy and prevention of HNSCC.

CONCLUSION

LncRNAs profiling could provide novel insights into the potential mechanisms of HNSCC oncogenesis.

TGF-β-induced NKILA inhibits ESCC cell migration and invasion through NF-κB/MMP14 signaling

The transforming growth factor β (TGF-β) signaling pathway plays anti- and pro-tumoral roles in the vast majority of cancers, and long noncoding RNAs have been reported to play key roles in the highly contextual response process. However, the roles of long noncoding RNAs (lncRNAs) in TGF-β signaling in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we performed RNA-seq to compare lncRNAs expression levels between TGF-β1-treated and untreated ESCC cells and observed that NF-kappaB-interacting lncRNA (NKILA) was remarkably upregulated by the classical TGF-β signaling pathway. RNA profiling of 39 pairs ESCC tumor and adjacent nontumor samples using RT-qPCR demonstrated that NKILA is significantly downregulated in ESCC tumor tissues, and NKILA expression levels were significantly decreased in advanced tumor tissues (III and IV) compared to early stages (I and II) (p < 0.01). Gain- and loss-of-function assays showed that NKILA inhibited ESCC cell metastasis in vitro and in vivo, and mechanism studies showed that NKILA repressed MMP14 expression by inhibiting IκBα phosphorylation and NF-κB activation. Collectively, these findings suggest that the TGF-β-induced lncRNA NKILA has potential as an antimetastasis therapy.

KEY MESSAGES

Long noncoding RNA NKILA could be remarkably upregulated by classical TGF-β signal pathway in ESCC. NKILA was significantly downregulated in esophageal squamous cell carcinoma and negatively correlated with TNM stage. NKILA inhibits ESCC cell metastasis via repressing MMP14 expression by suppressing the phosphorylation of IκBα and NF-κB activation.

LncRNA and mRNA integration network reconstruction reveals novel key regulators in esophageal squamous-cell carcinoma

Many experimental and computational studies have identified key protein coding genes in initiation and progression of esophageal squamous cell carcinoma (ESCC). However, the number of researches that tried to reveal the role of long non-coding RNAs (lncRNAs) in ESCC has been limited. LncRNAs are one of the important regulators of cancers which are transcribed dominantly in the genome and in various conditions. The main goal of this study was to use a systems biology approach to predict novel lncRNAs as well as protein coding genes associated with ESCC and assess their prognostic values. By using microarray expression data for mRNAs and lncRNAs from a large number of ESCC patients, we utilized "Weighted Gene Co-expression Network Analysis" (WGCNA) method to make a big coding-non-coding gene co-expression network, and discovered important functional modules. Gene set enrichment and pathway analysis revealed major biological processes and pathways involved in these modules. After selecting some protein coding genes involved in biological processes and pathways related to cancer, we used "LncTar", a computational tool to predict potential interactions between these genes and lncRNAs. By combining interaction results with Pearson correlations, we introduced some novel lncRNAs with putative key regulatory roles in the network. Survival analysis with Kaplan-Meier estimator and Log-rank test statistic confirmed that most of the introduced genes are associated with poor prognosis in ESCC. Overall, our study reveals novel protein coding genes and lncRNAs associated with ESCC, along with their predicted interactions. Based on the promising results of survival analysis, these genes can be used as good estimators of patients' survival, or even can be analyzed further as new potential signatures or targets for the therapy of ESCC disease.

Aberrant expression of PlncRNA-1 and TUG1: potential biomarkers for gastric cancer diagnosis and clinically monitoring cancer progression

Aim: To evaluate PlncRNA-1, TUG1 and FAM83H-AS1 gene expression and their possible role as a biomarker in gastric cancer (GC) progression. Patients & methods: Long noncoding RNA expressions and clinicopathological characteristics were assessed in 70 paired GC tissues. Furthermore, corresponding data from 318 GC patients were downloaded from The Cancer Genome Atlas database. Results: Expression of PlncRNA-1 and TUG1 were significantly upregulated in GC tumoral tissues, and significantly correlated with clinicopathological characters. However, FAM83H-AS1 showed no consistently differential expression. The expression of these three long noncoding RNAs was significantly higher in The Cancer Genome Atlas tumoral tissues. Conclusion: In conclusion, PlncRNA-1 and TUG1 genes may play a critical role in GC progression and may serve as potential diagnostic biomarkers in GC patients.

LncRNA PlncRNA‑1 regulates proliferation and differentiation of hair follicle stem cells through TGF‑β1‑mediated Wnt/β‑catenin signal pathway

The present study demonstrated that hair follicle stem cells (HFSc) have multidirectional differentiation potential and participate in skin wound healing processes. Long non‑coding RNAs (lncRNAs) are defined as non‑protein coding transcripts longer than 200 nucleotides, which are important in the proliferation and differentiation of cells. The purpose of the present study was to investigate the role of PlncRNA‑1 in the proliferation and differentiation of HFSc. Results revealed that PlncRNA‑1, transforming growth factor (TGF)‑β1, Wnt and β‑catenin expression levels were significantly downregulated in HFSc. PlncRNA‑1 transfection promoted proliferation and differentiation of HFSc. TGF‑β1, Wnt and β‑catenin expression levels were upregulated in HFSc following transfection of PlncRNA‑1. Results demonstrated that TGF‑β1 inhibitor LY2109761 blocked proliferation and differentiation of HFSc promoted by PlncRNA‑1 transfection. In addition, TGF‑β1 inhibitor LY2109761 led to decreased Wnt and β‑catenin expression levels in HFSc. Furthermore, PlncRNA‑1 transfection stimulated the cell cycle of HFSc, whereas TGF‑β1 inhibitor LY2109761 inhibited the cell cycle of HFSc and decreased the acceleration of the cell cycle induced by PlncRNA‑1 transfection. In conclusion, these findings suggest that PlncRNA‑1 may promote proliferation and differentiation of HFSc through upregulation of TGF‑β1‑mediated Wnt/β‑catenin signaling pathway.

Long non-coding RNA ANRIL promotes the proliferation, migration and invasion of human osteosarcoma cells

The long antisense non-coding RNA ANRIL is 3.8 kb in length and serves an important role in the tumorigenesis and progression of a number of malignancies. However, its function in human osteosarcoma remains unknown. The present study investigated the role of ANRIL in human osteosarcoma cell lines and clinical tumor samples. The expression of ANRIL was analyzed in 19 osteosarcoma and paired adjacent non-cancerous tissues using reverse transcription-quantitative polymerase chain reaction. Knockdown of ANRIL expression using lentivirus-mediated small interfering RNA was performed to investigate the role of ANRIL in tumor proliferation and metastasis using MTT, colony formation and transwell assays. The results demonstrated that ANRIL expression was upregulated in osteosarcoma tissues when compared with ANCT samples. In addition, knockdown of ANRIL expression in vitro reduced cell proliferation and invasion. These results indicated that ANRIL is upregulated in osteosarcoma tissues, and may promote the proliferation and metastasis of osteosarcoma cells. Therefore, ANRIL may serve as a novel biomarker and target of novel therapies for the treatment of patients with osteosarcoma.

Long Noncoding RNA PlncRNA-1 Promotes Colorectal Cancer Cell Progression by Regulating the PI3K/Akt Signaling Pathway

Accumulating evidence has indicated that long noncoding RNA (lncRNA) PlncRNA-1 plays an important regulatory role in cancers. However, the expression and biological functions of PlncRNA-1 in colorectal cancer (CRC) are still unclear. In the present study, we determined the expression of PlncRNA-1 in CRC and explored the function of PlncRNA-1 on CRC cell progression. The results showed that PlncRNA-1 was significantly increased in CRC tissues and cell lines; high PlncRNA-1 expression was associated with depth of invasion, lymph node metastasis, and TNM stage of CRC patients. Kaplan–Meier curve analysis showed that patients with high PlncRNA-1 expression had a poor overall survival. PlncRNA-1 knockdown remarkably reduced cell proliferation, migration, and invasion and promoted cell apoptosis in vitro. In vivo xenograft experiments showed that PlncRNA-1 inhibition significantly suppressed tumor growth. Finally, we used an agonist (740Y-P) of the PI3K/Akt signaling pathway; function assays showed that PlncRNA-1 exerted its effects by targeting the PI3K/Akt signaling pathway in CRC. Taken together, our data suggested that PlncRNA-1 might act as an oncogene in CRC progression and serve as a potential biomarker and therapeutic target for the treatment of CRC.

Long noncoding RNA colon cancer associated transcript‑1 promotes the proliferation, migration and invasion of cervical cancer

Previous studies have revealed significant roles for long noncoding RNA (lncRNA) in the tumorigenesis, metastasis and invasion of various tumors, including cervical cancer. The present study aimed to investigate the potential roles of lncRNA colon cancer associated transcript 1 (CCAT1) in the metastasis and invasion of cervical cancer, and to reveal the potential underlying mechanism. The mRNA expression of lncRNA CCAT1 in cervical cancer tissue was measured using the reverse transcription‑quantitative polymerase chain reaction, and the association between lncRNA CCAT1 and the metastasis of cervical cancer was analyzed. The effects of lncRNA CCAT1 expression on HeLa cell viability, and migration and invasion were also analyzed by MTT and Transwell assays. The results demonstrated that lncRNA CCAT1 was highly expressed in the cervical cancer tissue compared with the adjacent normal tissue. High expression of lncRNA CCAT1 was positively associated with tumor size, and there was correlation between high lncRNA CCAT1 expression and a poor survival rate of cervical cancer. The cell viability, and migratory and invasive abilities were suppressed by silencing CCAT1. The results of the present study indicate that lncRNA CCAT1 was highly expressed in cervical cancer, and may serve important roles in promoting the progression and metastasis of cervical cancer.

PART-1 functions as a competitive endogenous RNA for promoting tumor progression by sponging miR-143 in colorectal cancer

LncRNAs were altered in several cancers and played a crucial role in various biological activities and progressions of different diseases, including proliferation, chemical resistance, and metastasis. In the present study, we revealed that prostrate androgen-regulated transcript-1 (PART-1) was highly expressed in colorectal cancer cells and tissues, and knockdown of PART-1 suppressed cell proliferation and metastasis, both in vitro and in vivo. In addition, PART-1 functioned as a ceRNA of DNMT3A, by sponging miR-143. Finally,PART-1 induced tumor progression by regulating DNMT3A.

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.

Transforming Cancer Epigenetics Using Nutritive Approaches and Noncoding RNAs

Cancer is considered one of the leading causes of death in the United States. Although preventive strategies, early detection, and improved treatment options have been developed, novel targets and therapeutics are still needed. Since concluding that cancer is mediated by genetic and epigenetic alterations of the cell, many research groups are now focusing on other means of prevention and therapy via nutrition, epigenetic mechanisms, and non-coding RNAs which have been shown to control gene expression and have many different functions at the cellular level. With the advent of high-throughput sequencing in human cancer, the potential to identify novel biomarkers and therapeutic targets of disease has increased tremendously and led to the identification of many non-coding RNAs that are dysregulated in various cancers. Gene expression and regulation is important in maintaining the homeostasis of normal tissues and cells. Not uncommonly, up- or down-regulation of particular genes are associated with cancer as a result of increased or decreased expression of transcriptional targets. This review focuses on the role of nutrition in cancer and the dysregulation of non-coding RNAs with particular emphasis on long non-coding RNAs and microRNAs in different cancer types.

MiR-34c and PlncRNA1 mediated the function of intestinal epithelial barrier by regulating tight junction proteins in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is originated from uncontrolled inflammation, and desired methods for IBD therapy remains the main difficult. The network comprised with miRNA and lncRNA has been verified to play an important role on diverse human diseases. In this study, we demonstrated the role of miR-34c and lncRNA PlncRNA1 on the function of intestinal barrier.

METHODS

Intestinal epithelial barrier model was constructed based on normal intestinal epithelial cell line Caco-2. 2% DSS was supplemented in the Apical side of the model cells to induce the injury of intestinal epithelial barrier. Real-time PCR or western blot was used to determine mRNA or protein expression of miR-34c, PlncRNA1, Myc-associated zinc finger protein (MAZ), zonula occludens 1 (ZO-1) and occludin.

RESULTS

DSS induced injury of intestinal epithelial barrier, while overexpression of PlncRNA1 seemed to protect intestinal epithelial barrier from injury. Tight junction (TJ) proteins ZO-1 and occludin were regulated by MAZ, while, miR-34c targeted MAZ to regulate its expression, in addition, PlncRNA1 and miR-34c bound together to regulate the expressions of MAZ, ZO-1 and occludin. The protect effects of PlncRNA1 overexpression on intestinal epithelial barrier function was reversed by overexpression of miR-34c.

CONCLUSION

MAZ and TJ proteins were involved in the function of intestinal epithelial barrier, while miR-34c and PlncRNA1 regulated the intestinal dysfunction cooperatively.

Long Noncoding RNA HOTAIR Controls Cell Cycle by Functioning as a Competing Endogenous RNA in Esophageal Squamous Cell Carcinoma

Recent studies have shown that long noncoding RNAs (lncRNAs) play pivotal roles in the initiation and progression of cancer, including esophageal squamous cell carcinoma (ESCC). The lncRNA HOX transcript antisense RNA (HOTAIR) was reported to be dysregulated and correlated with the progression of ESCC. However, the biological role and the underlying mechanism of HOTAIR in the development of ESCC remain unclear. Herein, we found that HOTAIR was aberrantly upregulated in ESCC cells and that HOTAIR depletion inhibited proliferation and led to G1 cell cycle arrest in ESCC cells. Besides, we found that HOTAIR acted as an endogenous sponge to downregulate miR-1 expression by directly binding to miR-1. Furthermore, HOTAIR overturned the effect of miR-1 on the proliferation and cell cycle profile in ESCC cells, which involved the derepression of cyclin D1 (CCND1) expression, a target of miR-1. Taken together, our study elucidated a novel HOTAIR /miR-1/CCND1 regulatory axis in which HOTAIR acted as a competing endogenous RNA by sponging miR-1 and upregulated CCND1 expression, thereby facilitating the tumorigenesis of ESCC. Investigation of this lncRNA/miRNA/mRNA pathway may contribute to a better understanding of ESCC pathogenesis and facilitate the development of lncRNA-directed therapy against this disease.

High expression of long non-coding RNA AFAP1-AS1 predicts chemoradioresistance and poor prognosis in patients with esophageal squamous cell carcinoma treated with definitive chemoradiotherapy

To evaluate the clinical significance of lncRNAs in the resistance to cisplatin-based chemoradiotherapy in esophageal squamous cell carcinoma (ESCC). We focused on lncRNAs which were frequently reported in ESCC or were involved in chemoradiotherapy resistance. LncRNA expressions were examined in paired cisplatin-resistant and parental ESCC cell lines. Dysregulated lncRNAs were further measured in 162 pretreatment biopsy specimens of ESCC who received definitive chemoradiotherapy (dCRT). Then the correlations between lncRNA expression and response to dCRT and prognosis were analyzed. Three lncRNAs (AFAP1-AS1, UCA1, HOTAIR) were found to be deregulated in cisplatin-resistant cells compared with their parent cells. AFAP1-AS1 was significantly up-regulated in tumor tissues compared with adjacent normal tissues (P = 0.006). Furthermore, overexpression of AFAP1-AS1 was closely associated with lymph node metastasis (P < 0.001), distant metastasis (P = 0.016), advanced clinical stage (P = 0.002), and response to dCRT (P < 0.001). Kaplan-Meier survival analysis revealed that high expression of AFAP1-AS1 was significantly associated with shorter progression free survival (PFS) (median, 15 months vs. 27 months, P < 0.001) and overall survival (OS) (median, 29 months vs. 42 months, P < 0.001). In the multivariate analysis, high expression of AFAP1-AS1 was found to be an independent risk factor to predict poor PFS (HR, 1.626; P = 0.027) and OS (HR, 1.888; P = 0.004). Thus, high expression of AFAP1-AS1 could serve as a potential biomarker to predict tumor response and survival. Determination of this lncRNA expression might be useful for selection ESCC patients for dCRT. © 2016 The Authors. Molecular Carcinogenesis published by Wiley Periodicals, Inc.

Long noncoding RNA, tissue differentiation-inducing nonprotein coding RNA is upregulated and promotes development of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the major causes of cancer death worldwide, especially in Eastern Asia. Due to the poor prognosis, it is necessary to further dissect the underlying mechanisms and explore therapeutic targets of ESCC. Recently, studies show that long noncoding RNAs (lncRNAs) have critical roles in diverse biological processes, including tumorigenesis. Increasing evidence indicates that some lncRNAs are widely involved in the development and progression of ESCC, such as HOTAIR, SPRY4-IT1 and POU3F3. An emerging lncRNA, tissue differentiation-inducing nonprotein coding RNA (TINCR), has been studied in human cutaneous squamous cell carcinoma and has critical biological function, but its role in ESCC remains unknown. Here, we evaluated the expression profile of TINCR and its biological function in ESCC. In a cohort of 56 patients, TINCR was significantly overexpressed in ESCC tissues compared with paired adjacent normal tissues. Further, in vitro silencing TINCR via small interfering RNA (siRNA) inhibited the proliferation, migration and invasion of ESCC cells. Meantime, siRNA treatment induced apoptosis and blocked the progression of cell cycle. Taken together, our study suggests that TINCR promotes proliferation, migration and invasion of ESCC cells, acting as a potential oncogene of ESCC.

Circular RNA has_circ_0067934 is upregulated in esophageal squamous cell carcinoma and promoted proliferation

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent and deadly types of cancer worldwide especially in Eastern Asia and the prognosis of ESCC remain poor. Recent evidence suggests that circular RNAs (circRNAs) play important roles in multiple diseases, including cancer. In this study, we characterized a novel circRNA termed hsa_circ_0067934 in ESCC tumor tissues and cell lines. We analyzed a cohort of 51 patients and found that hsa_circ_0067934 was significantly overexpressed in ESCC tissues compared with paired adjacent normal tissues. The high expression level of hsa_circ_0067934 was associated with poor differentiation (P = 0.025), I-II T stage (P = 0.04), and I-II TNM stage (P = 0.021). The in vitro silence of hsa_circ_0067934 by siRNA inhibited the proliferation and migration of ESCC cells and blocked cell cycle progression. Cell fraction analyses and fluorescence in situ hybridization detected that hsa_circ_0067934 was mostly located in the cytoplasm. Our findings suggest that hsa_circ_0067934 is upregulated in ESCC tumor tissue. Our data suggest that hsa_circ_0067934 represents a novel potential biomarker and therapeutic target of ESCC.

High expression of lncRNA PVT1 promotes invasion by inducing epithelial-to-mesenchymal transition in esophageal cancer

The long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been identified as an oncogene in numerous diseases, and aberrant lncRNA PVT1 expression has been associated with the development of cancer. However, the underlying mechanism by which lncRNA PVT1 affects cell invasion in esophageal cancer has been not demonstrated. In the current study, the expression of lncRNA PVT1 was found to be increased in esophageal cancer specimens (n=77) by reverse transcription-quantitative polymerase chain reaction, and was correlated with tumor stage (P=0.009) and metastasis (P<0.001). In vitro, by using transwell assay, upregulation of lncRNA PVT1 promoted the invasion of TE-1 esophageal cancer cells; while downregulation of lncRNA PVT1 inhibited Eca-109 cell invasion. In addition, western blot analysis indicated that upregulation of lncRNA PVT1 may induce epithelial-to-mesenchymal transition (EMT) by regulating the expression levels of EMT markers (E-cadherin, N-cadherin and vimentin). In conclusion, lncRNA PVT1 is able to regulate the invasion of esophageal cancer cells by inducing EMT.

Regulatory non-coding RNA: new instruments in the orchestration of cell death

Non-coding RNA (ncRNA) comprises a substantial portion of primary transcripts that are generated by genomic transcription, but are not translated into protein. The possible functions of these once considered ‘junk' molecules have incited considerable interest and new insights have emerged. The two major members of ncRNAs, namely micro RNA (miRNA) and long non-coding RNA (lncRNA), have important regulatory roles in gene expression and many important physiological processes, which has recently been extended to programmed cell death. The previous paradigm of programmed cell death only by apoptosis has recently expanded to include modalities of regulated necrosis (RN), and particularly necroptosis. However, most research efforts in this field have been on protein regulators, leaving the role of ncRNAs largely unexplored. In this review, we discuss important findings concerning miRNAs and lncRNAs that modulate apoptosis and RN pathways, as well as the miRNA–lncRNA interactions that affect cell death regulation.

Aberrant methylation-mediated downregulation of long noncoding RNA LOC100130476 correlates with malignant progression of esophageal squamous cell carcinoma

BACKGROUND

Dysregulated long non-coding RNAs (lncRNAs) are involved in many complicated human diseases including cancer.

AIMS

To determine the role and methylation status of a new lncRNA LOC100130476 in the pathogenesis of esophageal squamous cell carcinoma (ESCC).

METHODS

One hundred and twenty three ESCC patients with tumor tissues and corresponding adjacent normal tissues were enrolled. The expression level and methylation status of LOC100130476 in esophageal cancer cell lines and primary ESCC samples were respectively detected.

RESULTS

Significant downregulation of LOC100130476 was detected in esophageal cancer cell lines and primary ESCC tumor tissues. Up-regulation of LOC100130476 led to the inhibition of proliferation and invasiveness of the cancer cells. Aberrant hypermethylation of the CpG sites in exon 1 closing to the transcription start site was found to be more tumor-specific and to be more critical for gene silencing. Hypermethylation of these CpG sites was associated with TNM stage and pathological differentiation. ESCC patients in stage III and IV, with low expression or hypermethylation of the CpG sites in exon 1 demonstrated poor patient survival.

CONCLUSIONS

LOC100130476 is down-regulated in ESCC at least partly by hypermethylation of CpG sites in exon 1 and its hypermethylation may have prognostic implications for ESCC patients.

lncRNA uc009yby.1 promotes renal cell proliferation and is associated with poor survival in patients with clear cell renal cell carcinomas

The expression and function of long non-coding RNAs (lncRNAs) in clear cell renal cell carcinoma (ccRCC) remains unclear. The present study measured the expression profiles of three lncRNAs (uc009yby.1, ENST00000514034, and ENST00000450687) using reverse transcription-quantitative polymerase chain reaction, and assessed their signatures in distinguishing ccRCC from matched normal tissues via analysis of receiver operating characteristic (ROC) curves. The expression of uc009yby.1 was inhibited by transfection of renal cells with small interfering RNA, and then the cell proliferation was evaluated by using a Cell Counting Kit-8. The results showed that the expressions of uc009yby.1 and ENST00000514034 were markedly increased in ccRCC compared with the matched normal tissues (P<0.0001 and P=0.0008, respectively), whereas the ENST00000450687 expression was not significantly altered. ROC curves yielded an area under the curve (AUC) value of 0.7000 for uc009yby.1, with sensitivity of 54.29% and specificity of 82.86%; and an AUC value of 0.6627 for ENST00000514034, with sensitivity of 60.00% and specificity of 67.14%. Furthermore, knockdown of uc009yby.1 suppressed renal cell proliferation (Day 0, P=0.7844; Day 1, P=0.0018; Day 2, P=0.0001; Day 3, P<0.000; Day 4, P<0.0001). Taken together, these findings suggest that the expression profiles of uc009yby.1 and ENST00000514034 may serve as novel biomarkers for ccRCC detection, and that uc009yby.1 is strongly associated with renal cell proliferation.