lncRNA-UCA1 enhances cell proliferation through functioning as a ceRNA of Sox4 in esophageal cancer

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.

lncRNA nuclear-enriched abundant transcript 1 promotes cell proliferation and invasion by targeting miR-186-5p/HIF-1α in osteosarcoma

Increasing evidence shows that the long noncoding RNA nuclear enriched abundant transcript 1 (NEAT1) plays important roles in tumor progression. However, the function and the underlying mechanism of NEAT1 in osteosarcoma (OS) remain unclear. In the present study, we found that NEAT1 expression was significantly upregulated in OS tissues and cell lines. High NEAT1 expression was closely associated with advanced clinicopathologic features and poor overall survival of patients with OS. Using in vitro function assay, we found that NEAT1 could promote the proliferation, invasion, and epithelial-mesenchymal transition (EMT) process of OS cells. NEAT1 could also promote OS cell growth in vivo. In addition, our studies showed that miR-186-5p was a downstream target of NEAT1 in OS. Functionally, miR-186-5p suppressed the proliferation, invasion, and EMT process of OS cells. Furthermore, our data revealed that HIF-1α was a downstream target of miR-186-5p and that NEAT1 could exert its tumor oncogenic roles on OS cells via the miR-186-5p/HIF-1α axis. Taking our results together, we elucidated that the NEAT1/miR-186-5p/HIF-1α axis might be a therapeutic approach for the treatment of OS.

Prognostic Value of Long Noncoding RNAs in Patients with Gastrointestinal Cancer: A Systematic Review and Meta-Analysis

Gastrointestinal cancers (GICs) are a huge threat to human health, which mainly include esophageal, gastric, and colorectal cancers. The purpose of this study was to clarify the prognostic value of long noncoding RNAs (lncRNAs) in GICs. A total of 111 articles were included, and 13103 patients (3123 with esophageal cancer, 4972 with gastric cancer, and 5008 with colorectal cancer) were enrolled in this study. The pooled hazard ratio (HR) values and corresponding 95% confidence interval (95% CI) of overall survival (OS) related to different lncRNA expressions in esophageal, gastric, colorectal, and gastrointestinal cancer patients were 1.92 (1.70–2.16), 1.96 (1.77–2.16), 2.10 (1.87–2.36), and 2.00 (1.87–2.13), respectively. We have identified 74 lncRNAs which were associated closely with poor prognosis of GIC patients, including 58 significantly upregulated lncRNA expression and 16 significantly downregulated lncRNA expression. In addition, 47 of the included studies revealed relative mechanisms and 12 of them investigated the correlation between lncRNAs and microRNAs. Taken together, this meta-analysis supports that specific lncRNAs are significantly related to the prognosis of GIC patients and may serve as novel markers for predicting the prognosis of GIC patients. Furthermore, lncRNAs may have a promising contribution to lncRNA-based targeted therapy and clinical decision-making in the future.

Long non-coding RNA TP73‑AS1 promotes colorectal cancer proliferation by acting as a ceRNA for miR‑103 to regulate PTEN expression

There is an increasing evidence that long non-coding RNAs (lncRNAs) play an important role in tumorigenesis and cancer progression. This study focused on the functional role of P73 antisense RNA 1T (TP73‑AS1), a lncRNA, in colorectal cancer (CRC). We found that TP73‑AS1 expression was significantly low in CRC tissues and cells, and high TP73‑AS1 expression was negatively associated with TNM stage, prognosis, overall survival, and disease-free survival in the CRC patients. Moreover, TP73‑AS1 overexpression dramatically inhibited CRC cell growth, promoted apoptosis, downregulated Bcl‑2 levels, and increased caspase‑3 expression. Furthermore, TP73‑AS1 expression levels were positively associated with PTEN levels in clinical CRC samples. As expected, TP73‑AS1 could upregulate PTEN expression in CRC cells. Mechanistically, PTEN was shown to be the target of miR‑103. Interestingly, TP73‑AS1 overexpression could increase PTEN expression through competitive binding to miR‑103. Functionally, our data show that such TP73‑AS1-induced PTEN expression through binding to miR‑103 facilitated CRC cell proliferation. Thus, we showed that TP73‑AS1 inhibits CRC cell growth by functioning as a ceRNA (competing endogenous RNAs) to regulate PTEN levels. Our findings provide new insights into the underlying molecular mechanisms of TP73‑AS1-mediated CRC.

Long noncoding RNA HAGLROS regulates apoptosis and autophagy in colorectal cancer cells via sponging miR-100 to target ATG5 expression

The aim of this study was to explore the relationship between the expression of HOXD antisense growth-associated long noncoding RNA (HAGLROS) and prognosis of patients with colorectal cancer (CRC), as well as the roles and regulatory mechanism of HAGLROS in CRC development. The HAGLROS expression in CRC tissues and cells was detected. The correlation between HAGLROS expression and survival time of CRC patients was investigated. Moreover, HAGLROS was overexpressed and suppressed in HCT-116 cells, followed by detection of cell viability, apoptosis, and the expression of apoptosis-related proteins and autophagy markers. Furthermore, the association between HAGLROS and miR-100 and the potential targets of miR-100 were investigated. Besides, the regulatory relationship between HAGLROS and PI3K/AKT/mTOR pathway was elucidated. The results showed that HAGLROS was highly expressed in CRC tissues and cells. Highly expression of HAGLROS correlated with a shorter survival time of CRC patients. Moreover, knockdown of HAGLROS in HCT-116 cells induced apoptosis by increasing the expression of Bax/Bcl-2 ratio, cleaved-caspase-3, and cleaved-caspase-9, and inhibited autophagy by decreasing the expression of LC3II/LC3I and Beclin-1 and increasing P62 expression. Furthermore, HAGLROS negatively regulated the expression of miR-100, and HAGLROS controlled HCT-116 cell apoptosis and autophagy through negatively regulation of miR-100. Autophagy related 5 (ATG5) was verified as a functional target of miR-100 and miR-100 regulated HCT-116 cell apoptosis and autophagy through targeting ATG5. Besides, HAGLROS overexpression activated phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway. In conclusion, a highly expression of HAGLROS correlated with shorter survival time of CRC patients. Downregulation of HAGLROS may induce apoptosis and inhibit autophagy in CRC cells by regulation of miR-100/ATG5 axis and PI3K/AKT/mTOR pathway.

Epigenetic Regulation by lncRNAs: An Overview Focused on UCA1 in Colorectal Cancer

Colorectal cancers have become the second leading cause of cancer-related deaths. In particular, acquired chemoresistance and metastatic lesions occurring in colorectal cancer are a major challenge for chemotherapy treatment. Accumulating evidence shows that long non-coding (lncRNAs) are involved in the initiation, progression, and metastasis of cancer. We here discuss the epigenetic mechanisms through which lncRNAs regulate gene expression in cancer cells. In the second part of this review, we focus on the role of lncRNA Urothelial Cancer Associated 1 (UCA1) to integrate research in different types of cancer in order to decipher its putative function and mechanism of regulation in colorectal cancer cells. UCA1 is highly expressed in cancer cells and mediates transcriptional regulation on an epigenetic level through the interaction with chromatin modifiers, by direct regulation via chromatin looping and/or by sponging the action of a diversity of miRNAs. Furthermore, we discuss the role of UCA1 in the regulation of cell cycle progression and its relation to chemoresistance in colorectal cancer cells.

SATB1 3'-UTR and lncRNA-UCA1 competitively bind to miR-495-3p and together regulate the proliferation and invasion of gastric cancer

High expression of special AT-rich-binding protein 1 (SATB1) correlates with the advanced TNM stage and short overall and recurrence-free survival of gastric cancer (GC). A bioinformatic analysis revealed that SATB1 3'-untranslated region (3'-UTR) and long noncoding RNA UCA1 (lncRNA-UCA1) might competitively bind to microRNA-495-3p (miR-495-3p). Interestingly, lncRNA-UCA1 is also an important contributor to GC. The current study aimed to demonstrate the potential interaction among SATB1/miR-495-3p/lncRNA-UCA1 network and their effects on GC proliferation and invasion. The expression in GC and paracancerous normal tissues were assessed using real-time polymerase chain reaction and Western blot analysis. Luciferase reporter, RNA pull-down, and transfection assays were performed to determine the interaction among SATB1/miR-495-3p/lncRNA-UCA1 network in GC cells. GC proliferation and invasion were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, transwell invasion, and colony formation assays. Results showed higher expression of SATB1 and lncRNA-UCA1 but lower miR-495-3p expression in GC than in the normal tissues. In luciferase reporter assay, miR-495-3p bound to three seed sequences in SATB1 3'-UTR but only one in lncRNA-UCA1. SATB1 knockdown increased the combination of miR-495-3p with lncRNA-UCA1 but decreased lncRNA-UCA1 expression. Decreased lncRNA-UCA1 was also observed with the mimics increased miR-495-3p. These data suggested that SATB1 3'-UTR functions as a competing endogenous RNA of miR-495-3p and positively regulates lncRNA-UCA1. LncRNA-UCA1 knockdown only decreased SATB1 expression in MKN-45 cells but not in BGC-823 cells, which suggested that the regulatory effect of lncRNA-UCA1 on SATB1 by sponging miR-495-3p is cell-dependent. This study further identified that SATB1/miR-495-3p/lncRNA-UCA1 network is implicated in GC proliferation and invasion. The current study firstly revealed that SATB1 interacts with miR-495-3p/lncRNA-UCA1 network, whereby enhancing GC proliferation and invasion.

Knockdown of long noncoding RNA urothelial carcinoma associated 1 inhibits colorectal cancer cell proliferation and promotes apoptosis via modulating autophagy

Long noncoding RNA urothelial carcinoma associated 1 (UCA1) has been implicated in the growth and metastasis of colorectal cancer (CRC), and autophagy contributes to tumorigenesis and cancer cell survival. However, the regulatory role of UCA1 in CRC cell viability by modulating autophagy remains unclear. In the present study, a significant positive correlation was observed between UCA1 and microtubule-associated protein 1 light chain 3 (LC3) levels, and the elevated UCA1 was negatively correlated with the PKB/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway in 293T cells. Downregulation of UCA1 inhibited autophagy activation and cell proliferation, whereas the apoptosis was increased and the cell cycle was arrested in G2 stage. The next results showed that UCA1 was markedly upregulated in Caco-2 cells. Knockdown of UCA1 significantly decreased the LC3-II and autophagy-related gene 5 (ATG5) protein levels and resulted in an increase in p62 expression. Conversely, the autophagy activator rapamycin (RAPA) reversed the effects. Furthermore, downregulated UCA1 decreased Caco-2 cells population in the G1 phase and increased the cells number in G2 phage. The cell proliferation was inhibited, and apoptosis rate was promoted. More important, RAPA could also abrogate the changes induced by knockdown of UCA1. Collectively, these data demonstrated that downregulated UCA1 induced autophagy inhibition, resulting in suppressing cell proliferation and promoting apoptosis, which suggested that UCA1 might serve as a potential new oncogene to regulate CRC cells viability by modulating autophagy.

Predictive role of UCA1-containing exosomes in cetuximab-resistant colorectal cancer

Background

Primary or acquired resistance to cetuximab often occurs during targeted therapy in metastatic colorectal cancer (mCRC) patients. In many cancers, the key role of the long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) in anticancer drug resistance has been confirmed. Emerging evidence has shown that specific exosomal lncRNAs may serve as meaningful biomarkers. In this study, we hypothesize that exosomal UCA1 might predict the response to cetuximab in CRC patients.

Methods

First, acquired cetuximab-resistant cell lines were generated, and UCA1 expressions in these cells and their exosomes were compared. We also systematically evaluate the stability of exosomal UCA1. Thereafter, the predictive value of exosomal UCA1 in CRC patients treated with cetuximab was evaluated. Finally, through cell apoptosis assays and immunofluorescence staining, we analyzed the role of UCA1-containing exosomes in conferring cetuximab resistance.

Results

UCA1 expression was markedly higher in cetuximab-resistant cancer cells and their exosomes. Exosomal UCA1 was shown to be detectable and stable in serum from CRC patients. In addition, circulating UCA1-containing exosomes could predict the clinical outcome of cetuximab therapy in CRC patients, and UCA1 expression was considerably higher in the progressive disease/stable disease patients than in the partial response/complete response patients. Furthermore, exosomes derived from cetuximab-resistant cells could alter UCA1 expression and transmit cetuximab resistance to sensitive cells.

Conclusions

We discovered a novel role of UCA1-containing exosomes, showed their capability to transmit drug resistance and investigated their potential clinical use in predicting cetuximab resistance.

Knockdown of lncRNA UCA1 inhibits proliferation and invasion of papillary thyroid carcinoma through regulating miR-204/IGFBP5 axis

Background

Long noncoding RNA (LncRNA) UCA1 has been reported to function as an oncogene in multiple cancers. However, the biological roles and underlying mechanism of UCA1 in papillary thyroid carcinoma (PTC) remain unclear. This study aimed to investigate the underlying function of UCA1 on thyroid cancer progression.

Materials and methods

A series of experiments involving Cell Counting Kit-8, wound-healing, and transwell invasion assays were conducted to determine the cellular capabilities of proliferation, migration, and invasion, respectively. Binding sites between UCA1 and miR-204 were identified using a luciferase reporter system, whereas mRNA and protein expression of target genes were determined by real-time quantitative reverse transcription-PCR (qRT-PCR) and Western blot, respectively.

Results

The results revealed that UCA1 was upregulated in PTC tissue and cell lines. UCA1 knockdown significantly suppressed the cell proliferation, migration, and invasion of TPC-1 cells. Bioinformatics analysis and luciferase reporter assay verified the complementary binding within UCA1 and miR-204 at the 3′-UTR. Moreover, miR-204 inhibition reversed the UCA1 knockdown-mediated inhibitory effect on cell proliferation, migration, and invasion. We also found that UCA1 could regulate expression of IGFBP5, a direct target of miR-204 in PTC.

Conclusion

Our study demonstrated that UCA1 exerts activity of oncogenes in PTC through regulating miR-204/IGFBP5 axis.

Dysregulation of KCNQ1OT1 promotes cholangiocarcinoma progression via miR-140-5p/SOX4 axis

It is commonly recognized that aberrant expression of long non-coding RNAs (lncRNAs) is an important cause of cancer progression. The oncogenic property of KCNQ1OT1 has been identified in several malignant tumors. Here, we decided to explore the biological function and molecular mechanism of KCNQ1OT1 in cholangiocarcinoma (CCA). The expression conditions of KCNQ1OT1 in different tissues and cell lines were examined with qRT-PCR analysis. As expected, KCNQ1OT1 was highly expressed in CCA tissues and cell lines. Results of functional assays revealed the oncogenic function of KCNQ1OT in cholangiocarcinoma progression. The positive effect of KCNQ1OT1 on cell proliferation, invasion and epithelial-mesenchymal transition was identified by performing MTT assay, colony formation assay, transwell invasion assay and western blotting. Whereas, the negative effect of KCNQ1OT1 on the cell apoptosis was tested with flow cytometry analysis. Mechanism investigation revealed that KCNQ1OT1 can act as a ceRNA to improve CCA progression by regulating miR-140-5p/SOX4 axis. Recue assays were conducted to demonstrate the actual effects of KCNQ1OT1-miR-140-5p-SOX4 pathway on CCA progression.

Long non-coding RNAs in esophageal cancer: molecular mechanisms, functions, and potential applications

Esophageal cancer (EC) is the sixth leading cause of cancer-related death worldwide. The lack of early diagnostic biomarkers and effective prognostic indicators for metastasis and recurrence has resulted in the poor prognosis of EC. In addition, the underlying molecular mechanisms of EC development have yet to be elucidated. Accumulating evidence has demonstrated that lncRNAs play a vital role in the pathological progression of EC. LncRNAs may regulate gene expression through the recruitment of histone-modifying complexes to the chromatin and through interactions with RNAs or proteins. Recent evidence has demonstrated that the dysregulation of lncRNAs plays important roles in the proliferation, metastasis, invasion, angiogenesis, apoptosis, chemoradiotherapy resistance, and stemness of EC, which suggests potential clinical implications. In this review, we highlight the emerging roles and regulatory mechanisms of lncRNAs in the context of EC and discuss their potential clinical applications as diagnostic and prognostic biomarkers.

LncRNA UCA1 sponges miR-204-5p to promote migration, invasion and epithelial-mesenchymal transition of glioma cells via upregulation of ZEB1

Long non-coding RNA urothelial carcinoma associated 1 (lncRNA UCA1) promotes cancer progression and enhances chemoresistance through miR-204-5p in a few cancers. However, no studies have investigated whether UCA1 regulates glioma metastasis through miR-204-5p and its target. In the present study, cell migration, invasion and epithelial-mesenchymal transition (EMT) were evaluated in glioma cells overexpressing UCA1. The relationships among UCA1, miR-204-5p and ZEB1 were examined by real-time PCR, western blotting and dual-luciferase reporter assays. The effect of UCA1 knockdown on xenograft tumor growth was investigated. The levels of miR-204-5p, fibronectin, COL5 A1 and ZEB1 in tumor tissues were also determined. The results showed that UCA1 overexpression promoted cell migration, invasion and EMT. UCA1 interacted with miR-204-5p and decreased its level. ZEB1 was identified as a direct target of miR-204-5p and miR-204-5p negatively regulated ZEB1 expression. Moreover, UCA1 sponged miR-204-5p and partially rescued the inhibitory effect of miR-204-5p on ZEB1. In our in vivo studies, UCA1 knockdown reduced tumor volume and tumor weight. In addition, the levels of fibronectin, COL5 A1 and ZEB1 were decreased, while miR-204-5p level was increased. The present study provides the first evidence that UCA1 promotes glioma metastasis through the miR-204-5p/ZEB1 axis, contributing to the understanding of the pathogenesis of glioma.

Long noncoding RNA UCA1 promotes anaplastic thyroid cancer cell proliferation via miR‑135a‑mediated c‑myc activation

The long non‑coding RNA (lncRNA), urothelial carcinoma‑associated 1 (UCA1), has been demonstrated to be dysregulated and serves a role in the progression of several cancer types. However, the exact effects and underlying molecular mechanisms of UCA1 in anaplastic thyroid cancer (ATC) remain unknown. The aim of the present study was to investigate the detailed function and the mechanism of UCA1 in the regulation of ATC cell progression. The present study identified that the expression levels of UCA1, in ATC cell lines and tissues, were significantly upregulated compared with normal human thyroid cell line and adjacent non‑cancerous tissues, respectively. UCA1 knockdown significantly inhibited ATC cell viability, proliferation, migration and invasion and the expression level of c‑myc proto‑oncogene (c‑myc) in vitro, and suppressed ATC tumor growth in vivo. In addition, using luciferase assays, it was confirmed that miR‑135a directly bound to UCA1 and the 3' untranslated region of c‑myc, and UCA1 competed with c‑myc for miR‑135a binding. miR‑135a inhibition may upregulate c‑myc expression, however, the upregulation of c‑myc may be partially reduced by short hairpin UCA1. The present results illustrated that UCA1 promoted ATC cell proliferation through acting as a competing endogenous RNA by binding miR‑135a. In conclusion, in the present study, UCA1 served as an oncogenic long non‑coding RNA promoting ATC cell proliferation and may be a potential target for human ATC treatment.

Long non‑coding RNA UCA1 promotes papillary thyroid cancer cell proliferation via miR‑204‑mediated BRD4 activation

Long non‑coding RNA (lncRNA) urothelial carcinoma‑associated 1 (UCA1) has been used in tumor development and progression in many types of cancer. However, the function and mechanism underlying the action of UCA1 in papillary thyroid cancer (PTC) remains unclear. Therefore, these topics were investigated in the present study by in vitro and in vivo experiments. It was demonstrated that the expression level of UCA1 was more significantly upregulated in PTC cell lines and tissues when compared with the immortal human thyroid follicular cell line and adjacent normal tissues, respectively. UCA1 knockdown significantly inhibited PTC cell viability, colony formation and the bromodomain containing 4 (BRD4) expression level in vitro, and retarded PTC tumor growth in vivo. In the previous study, microRNA (miR)‑204 inhibited thyroid cancer progression and was regulated by UCA1 in other types of cancer. In addition, by conducting dual luciferase reporter assays, it was confirmed that miR‑204 directly binds to UCA1 and the 3'‑untranslated region of BRD4. Furthermore, UCA1 competed with BRD4 for miR‑204 binding. miR‑204 knockdown enhanced BRD4 expression, which can be partially restored by short hairpin‑UCA1. The results of the present study illustrated that UCA1 promotes PTC progression by acting as a competing endogenous RNA by sponging miR‑204. In conclusion, UCA1 may be regarded as an oncogenic lncRNA, promoting PTC cell proliferation, and be a potential target for human PTC treatment.

Non-Coding RNAs and Resistance to Anticancer Drugs in Gastrointestinal Tumors

Non-coding RNAs are important regulators of gene expression and transcription. It is well established that impaired non-coding RNA expression especially the one of long non-coding RNAs and microRNAs is involved in a number of pathological conditions including cancer. Non-coding RNAs are responsible for the development of resistance to anticancer treatments as they regulate drug resistance-related genes, affect intracellular drug concentrations, induce alternative signaling pathways, alter drug efficiency via blocking cell cycle regulation, and DNA damage response. Furthermore, they can prevent therapeutic-induced cell death and promote epithelial-mesenchymal transition (EMT) and elicit non-cell autonomous mechanisms of resistance. In this review, we summarize the role of non-coding RNAs for different mechanisms resulting in drug resistance (e.g., drug transport, drug metabolism, cell cycle regulation, regulation of apoptotic pathways, cancer stem cells, and EMT) in the context of gastrointestinal cancers.

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.

Long noncoding RNA HAGLROS regulates cell apoptosis and autophagy in lipopolysaccharides-induced WI-38 cells via modulating miR-100/NF-κB axis

Pneumonia is a lower respiratory disease caused by pathogens or other factors. This study aimed to explore the roles and mechanism of long noncoding RNA HAGLROS in lipopolysaccharides (LPS)-induced inflammatory injury in pneumonia. The HAGLROS expression in serum of patients with acute stage pneumonia was detected. To induce pulmonary injury, WI-38 human lung fibroblasts were stimulated with lipopolysaccharides (LPS). The HAGLROS expressions in LPS-treated WI-38 cells and the effects of HAGLROS knockdown on the viability, apoptosis, and autophagy of LPS-induced cells were detected. Moreover, the regulatory relationship between HAGLROS and miR-100 was explored as well as the functional targets of miR-100 were identified. Furthermore, the regulatory relationship between miR-100 and PI3K/AKT/NF-κB pathway was elucidated. LncRNA HAGLROS was higher expressed in serum of patients with acute stage pneumonia compared with that in serum of healthy control. LPS caused WI-38 cell injury and increased HAGLROS levels. Downregulation of HAGLROS alleviated LPS-induced cell injury via increasing cell viability, and inhibiting apoptosis and autophagy. Moreover, there was a negative correlation between HAGLROS and miR-100, and the effects of HAGLROS downregulation on LPS-induced apoptosis and autophagy in WI-38 cells were by regulation of miR-100. Furthermore, NFΚB3 was verified as a functional target of miR-100 and effects of miR-100 inhibition on LPS-induced WI-38 cell injury were alleviated by knockdown of NFΚB3. Besides, Knockdown of HAGLROS inhibited the activation of PI3K/AKT/NF-κB pathway. Our findings reveal that downregulation of HAGLROS may alleviate LPS-induced inflammatory injury in WI-38 cells via modulating miR-100/NF-κB axis. HAGLROS/miR-100/NF-κB axis may provide a new strategy for treating acute stage of pneumonia.

The prognostic significance of UCA1 for predicting clinical outcome in patients with digestive system malignancies

Background

Urothelial Carcinoma Associated 1 (UCA1) was an originally identified lncRNA in bladder cancer. Previous studies have reported that UCA1 played a significant role in various types of cancer. This study aimed to clarify the prognostic value of UCA1 in digestive system cancers.

Results

The meta-analysis of 15 studies were included, comprising 1441 patients with digestive system cancers. The pooled results of 14 studies indicated that high expression of UCA1 was significantly associated with poorer OS in patients with digestive system cancers (HR: 1.89, 95 % CI: 1.52–2.26). In addition, UCA1 could be as an independent prognostic factor for predicting OS of patients (HR: 1.85, 95 % CI: 1.45–2.25). The pooled results of 3 studies indicated a significant association between UCA1 and DFS in patients with digestive system cancers (HR = 2.50; 95 % CI = 1.30–3.69). Statistical significance was also observed in subgroup meta-analysis. Furthermore, the clinicopathological values of UCA1 were discussed in esophageal cancer, colorectal cancer and pancreatic cancer.

Materials and methods

A comprehensive retrieval was performed to search studies evaluating the prognostic value of UCA1 in digestive system cancers. Many databases were involved, including PubMed, Web of Science, Embase and Chinese National Knowledge Infrastructure and Wanfang database. Quantitative meta-analysis was performed with standard statistical methods and the prognostic significance of UCA1 in digestive system cancers was qualified.

Conclusions

Elevated level of UCA1 indicated the poor clinical outcome for patients with digestive system cancers. It may serve as a new biomarker related to prognosis in digestive system cancers.

Long non-coding RNA XIST exerts oncogenic functions in pancreatic cancer via miR-34a-5p

Long non-coding RNAs (lncRNAs) have been implicated in the occurrence and progression of multiple cancers. In the present study, we investigated the role of lncRNA X inactive-specific transcript (XIST) in the development and progression of pancreatic cancer (PC). Firstly, we found that lncRNA XIST was markedly upregulated in PC tissues and PC cell lines, respectively. Overexpression of XIST significantly promoted the proliferation, migration and invasion, and suppressed cell apoptosis of BxPC-3 cells; knockdown of XIST significantly inhibited the proliferation, migration and invasion, and accelerated cell apoptosis of PANC-1 cells. Furthermore, BxPC-3 and PANC-1 cells transfected with different vectors were injected subcutaneously into nude mice to explore tumor formation. We found that XIST promoted tumor formation in vivo. Subsequently, we found that microRNA-34a-5p (miR‑34a-5p) was downregulated in PC tissues, and predicted a poor prognosis in PC patients. In addition, the results indicated that miR-34a-5p is a target gene of XIST and was significantly negatively correlated with XIST. More importantly, we found that miR-34a-5p rescued the facilitation of malignant behavior mediated by XIST. These results indicated that XIST and miR-34a-5p may be potential effective therapeutic targets for PC.

Long noncoding RNAs show differential expression profiles and display ceRNA potential in cholesteatoma pathogenesis

Cholesteatoma is a pathologically benign but clinically destructive middle ear disease, which is caused by excessive epidermal migration and uncontrolled hyperproliferation of keratinocytes of squamous epithelium, leading to various clinical manifestations and serious complications, such as hearing loss, dizziness, facial paralysis, meningitis, and hydrocephalus. However, the pathogenesis of cholesteatoma is still not fully understood. Herein, we performed microarray analysis to identify the differentially expressed patterns of lncRNAs in cholesteatoma for the first time. Our data indicated that compared with matched normal skin tissue, lncRNA expression profiles were significantly altered in cholesteatoma. A total of 787 lncRNAs were identified (fold change ≥2.0, P<0.05), consisting of 181 upregulated and 606 downregulated lncRNAs. Furthermore, by constructing an lncRNA/miRNA/mRNA competing endogenous RNA (ceRNA) network, we found that lncRNAs, such as lncRNA‑uc001kfc.1, had ceRNA potential in cholesteatoma formation. In conclusion, lncRNAs were aberrantly expressed in cholesteatoma compared with normal skin tissues and may play important roles in cholesteatoma formation. Our findings shed novel light on the molecular mechanism of cholesteatoma pathogenesis and suggest that lncRNAs may be potential therapeutic targets for cholesteatoma.

LncRNA SNHG5/miR-26a/SOX2 signal axis enhances proliferation of chondrocyte in osteoarthritis

Chondrocyte is involved in the destruction of joints in osteoarthritis (OA) patients. The aim of this study was to explore the expression level of small nucleolar RNA host gene 5 (SNHG5) and evaluate its function in chondrocyte. In our current study, the expression levels of SNHG5, miR-26a, and SOX2 in 17 pairs of articular cartilage tissues and in the non-OA group were assessed by real-time quantitative reverse-transcription polymerase chain reaction. Results showed that the levels of SNHG5 and SOX2 were significantly downregulated in OA tissues, while the level of miR-26a was upregulated. MTT, colony formation and cell transwell assays were performed to assess the function of SNHG5 on the cell viability, growth ability, and migration capacity in CHON-001 cells. It was found that SNHG5 could promote chondrocyte cell proliferation and migration. The relationship between SNHG5 and miR-26a was confirmed by RIP and the luciferase reporter assays. SOX2 was identified as a target gene of miR-26a by the luciferase reporter assay. Rescue assay was applied to verify the relationship among SNHG5, miR-26a, and SOX2. Our current study demonstrated that SNHG5 is involved in the mechanism of OA through functioning as a ceRNA to competitively sponge miR-26a, therefore, regulating the expression of SOX2.

Transcriptomic Analysis of Long Non-Coding RNAs and Coding Genes Uncovers a Complex Regulatory Network That Is Involved in Maize Seed Development

Long non-coding RNAs (lncRNAs) have been reported to be involved in the development of maize plant. However, few focused on seed development of maize. Here, we identified 753 lncRNA candidates in maize genome from six seed samples. Similar to the mRNAs, lncRNAs showed tissue developmental stage specific and differential expression, indicating their putative role in seed development. Increasing evidence shows that crosstalk among RNAs mediated by shared microRNAs (miRNAs) represents a novel layer of gene regulation, which plays important roles in plant development. Functional roles and regulatory mechanisms of lncRNAs as competing endogenous RNAs (ceRNA) in plants, particularly in maize seed development, are unclear. We combined analyses of consistently altered 17 lncRNAs, 840 mRNAs and known miRNA to genome-wide investigate potential lncRNA-mediated ceRNA based on “ceRNA hypothesis”. The results uncovered seven novel lncRNAs as potential functional ceRNAs. Functional analyses based on their competitive coding-gene partners by Gene Ontology (GO) and KEGG biological pathway demonstrated that combined effects of multiple ceRNAs can have major impacts on general developmental and metabolic processes in maize seed. These findings provided a useful platform for uncovering novel mechanisms of maize seed development and may provide opportunities for the functional characterization of individual lncRNA in future studies.

Long non-coding RNA UCA1 indicates an unfavorable prognosis and promotes tumorigenesis via regulating AKT/GSK-3β signaling pathway in cholangiocarcinoma

Long non-coding RNAs (lncRNAs) have been documented to play key roles in a wide range of pathophysiological processes, including cancer initiation and progression. Recently, the aberrant expression of urothelial carcinoma associated 1 (UCA1) was observed in many types of cancers. However, its clinical relevance and exact effects in cholangiocarcinoma (CCA) remains unknown. In the present study, we aimed to investigate the clinical significance of UCA1 and evaluate its prognostic value in patients with CCA. Besides, the functional roles of UCA1 were detected both in vitro and in vivo. Moreover, potential signaling pathways were explored to clarify the molecular mechanisms underlying CCA cell proliferation. The results indicated that UCA1 transcription is enhanced in both CCA tissue samples and cell lines, and this overexpression is associated with tumor stage (P = 0.007), lymph node invasion (P = 0.027), TNM stage (P = 0.004) and postoperative recurrence (P = 0.033) of CCA patients. Besides, UCA1 could function as an independent prognostic predictor for overall survival in patients with CCA (P = 0.014). For the part of functional assays, knockdown of UCA1 could attenuate CCA cell growth both in vitro and in vivo. Besides, UCA1 facilitates apoptosis via Bcl-2/caspase-3 pathway. In addition, UCA1 regulates migration and invasion potential of CCA cells by affecting EMT. Furthermore, AKT/GSK-3β axis was activated to upregulate CCND1 expression due to overexpression of UCA1 in CCA. To summary, UCA1 might be a potentially useful prognostic biomarker and therapeutic target for CCA.

MicroRNA-320 inhibits cell proliferation and invasion in breast cancer cells by targeting SOX4

Dysregulation of microRNAs (miRs) can contribute to cancer development and progression. In the present study, the function and underlying molecular mechanisms of miR-320 in breast cancer tumorigenesis and progression were investigated. The results of a reverse transcription-quantitative polymerase chain reaction analysis demonstrated that miR-320 was frequently downregulated in breast cancer tissues compared with adjacent normal tissues. In addition, knockdown of miR-320 in breast cancer cell lines promoted cell proliferation and invasion in vitro, whereas miR-320 overexpression had the opposite effect. Furthermore, a Dual-Luciferase reporter assay indicated that SRY-box 4 (SOX4) is a direct target of miR-320, and the restoration of SOX4 in miR-320-overexpressing cells attenuated the tumor-suppressive effects of miR-320. Collectively, these results indicated that miR-320 acts as a tumor suppressor in breast cancer tumorigenesis and progression.

LncRNA-UCA1 enhances MMP-13 expression by inhibiting miR-204-5p in human chondrocytes

Osteoarthritis (OA) is a common degenerative disease characterized by degeneration of articular cartilage. Increasing studies showed that long noncoding RNAs (lncRNAs) play important roles in the cartilage damage. However, little is known about the role of UCA1 in the osteoarthritis. The expression level of UCA1 was upregulated in the OA cartilage. Overexpression of UCA1 suppressed the miR-204-5p expression in the chondrocytes. The expression of miR-204-5p was downregulated in the OA cartilage. Moreover, the expression of miR-204-5p was negatively correlated with the UCA1 expression in the OA cartilage. Elevated expression of UCA1 promoted the chondrocytes cell proliferation and overexpression of miR-204-5p suppressed chondrocytes cell proliferation. In addition, overexpression of UCA1 decreased the expression of the type II collagen and type IV collagen expression in the chondrocytes. Elevated expression of miR-204-5p promoted the type II collagen and type IV collagen expression in the chondrocytes. We idetified MMP-13 was a direct target gene of miR-204-5p in the chondrocytes. Overexpression of UCA1 enhanced the MMP-13 expression in the chondrocytes. Elevated expression of UCA1 regulated the chondrocytes cell proliferation and collagen expression through inhibiting the miR-204-5p expression.These results suggested that UCA1 played as an important regulator of survival and matrix synthesis of chondrocytes partly through suppressing the miR-204-5p expression.

Promotion of glycolysis by HOTAIR through GLUT1 upregulation via mTOR signaling

The long non-coding RNA HOX transcript antisense RNA (HOTAIR) plays a key role in the progression of various carcinomas. However, whether or not HOTAIR influences glucose metabolism and the specific underlying mechanism in hepatocellular carcinoma (HCC) cells remain unclear. In the present study, we found markedly increased HOTAIR expression in 84 HCC tissues and demonstrated that HOTAIR overexpression promoted cell proliferation using Cell Counting Kit-8. The effect on glucose metabolism regulated by HOTAIR in HCC cells was determined by detecting lactate and glucose levels: HOTAIR promoted glycolysis by upregulating glucose transporter isoform 1 (GLUT1) and activating mammalian target of rapamycin (mTOR) signaling, whereas knockdown of HOTAIR suppressed this effect. Our research reveals a novel relationship between HOTAIR and glucose metabolism in HCC cells, and it may be a therapeutic target for diagnosing and treating HCC.

LncRNA UCA1 in anti-cancer drug resistance

The pivotal role of the long non-coding RNA (lncRNA) urothelial carcinoma associated 1 (UCA1) in anti-cancer drug resistance has been confirmed in many cancers. Overexpression of lncRNA UCA1 correlates with resistance to chemotherapeutics such as cisplatin, gemcitabine, 5-FU, tamoxifen, imatinib and EGFR-TKIs, whereas lncRNA UCA1 knockdown restores drug sensitivity. These studies highlight the potential of lncRNA UCA1 as a diagnostic and prognostic biomarker, and a therapeutic target in malignant tumors. In this review, we address the role of lncRNA UCA1 in anti-cancer drug resistance and discuss its potential in future clinical applications.

Plasma Long Noncoding RNA Urothelial Carcinoma Associated 1 Predicts Poor Prognosis in Chronic Heart Failure Patients

Background

Chronic heart failure (CHF) is a leading cause of death worldwide. A long noncoding RNA (lncRNA) named urothelial carcinoma associated 1 (UCA1) is important in multiple diseases. However, the role of UCA1 in CHF is still unknown. Our study investigated whether UCA1 could be applied as an ideal marker to diagnose and evaluate prognosis in CHF.

Material/Methods

Total plasma RNA was extracted from 67 CHF patients and 67 controls. Quantitative real-time polymerase chain reaction was used to determine the plasma level of UCA1. Correlations between UCA1 and clinical parameters were analyzed by Pearson correlation. Receiver operating characteristic curves (ROC) were obtained to analyze the predictive power of UCA1 and BNP for CHF. Kaplan-Meier survival curves were used to evaluate prognosis of CHF within 1 year.

Results

There was no significant difference in elementary data between CHF and controls. Plasma UCA1 was much higher in CHF patients compared with controls. Plasma UCA1 was positively and negatively correlated with brain natriuretic peptide (BNP) and left ventricle ejection fraction (LVEF), respectively. Plasma UCA1 diagnosed CHF with a diagnostic power of 0.89 and a sensitivity and specificity of 100% [95% CI (0.9464–1)] and 76.12% [95%CI (0.6414–0.8569)] (P<0.05), respectively. CHF patients with higher plasma UCA1 had a lower survival rate than those with a lower level, and survival rate predicted by UCA1 had a similar tendency with BNP. However, there was no significant difference between these 2 markers in predicting the prognosis of CHF (P>0.05).

Conclusions

Plasma UCA1 might be an excellent indicator to diagnose CHF and it might predict poor outcomes of CHF.

ZNF148 modulates TOP2A expression and cell proliferation via ceRNA regulatory mechanism in colorectal cancer

BACKGROUND

Competing endogenous RNA (ceRNA) regulation is a novel hypothesized mechanism that states RNA molecules share common target microRNAs (miRNAs) and may competitively combine into the same miRNA pool.

METHODS

Zinc finger protein 148 (ZNF148) and TOP2A expression were analyzed in 742 colorectal cancer (CRC) tissues using immunohistochemistry (IHC). ZNF148 mRNA, TOP2A mRNA, miR101, miR144, miR335, and miR365 expression were estimated in 53 fresh frozen CRC tissues by reverse transcription polymerase chain reaction. Mechanisms underpinning ceRNA were examined using bioinformatics, correlation analysis, RNA interference, gene over-expression, and luciferase assays.

RESULTS

Protein levels of ZNF148 and TOP2A detected by IHC positively correlated (Spearman correlation coefficient [rs] = 0.431, P < 0.001); mRNA levels of ZNF148 and TOP2A also positively correlated (r = 0.591, P < 0.001). Bioinformatics analysis demonstrated that ZNF148 and TOP2A mRNA had 13 common target miRNAs, including miR101, miR144, miR335, and miR365. Correlation analysis demonstrated that levels of ZNF148 mRNA were negatively associated with levels of miR144, miR335, and miR365. Knockdown and overexpression tests showed that ZNF148 mRNA and TOP2A mRNA regulated each other in HCT116 cells, respectively, but not in Dicer-deficient HCT116 cells. Luciferase assays demonstrated that ZNF148 and TOP2A regulated each other through 3'UTR. Overexpression of ZNF148 mRNA and TOP2A mRNA caused significant downregulation of miR101, miR144, miR335, and miR365 in the HCT116 cells. We also found that knockdown of ZNF148 and TOP2A significantly promoted cell growth, and overexpression of ZNF148 and TOP2A inhibited cell proliferation, which was abrogated in Dicer-deficient HCT116 cells.

CONCLUSION

ZNF148 and TOP2A regulate each other through ceRNA regulatory mechanism in CRC, which has biological effects on cell proliferation.