LncRNA-UCA1 enhances cell proliferation and 5-fluorouracil resistance in colorectal cancer by inhibiting miR-204-5p. Sci Rep. 2016;6:23892. [PMID: 27046651 PMCID: PMC4820696 DOI: 10.1038/srep23892]

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

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

Silencing of Urothelial Carcinoma Associated 1 Inhibits the Proliferation and Migration of Medulloblastoma Cells

Background

UCA1 is a long non-coding RNA that has been found to be aberrantly upregulated in various cancers. The aim of this study was to determine the expression level and function of UCA1 in medulloblastoma, the most common malignant brain tumor during childhood.

Material/Methods

Real-time PCR was used to detect the expression of UCA1 in medulloblastoma specimens and cell lines. Lentiviral-mediated expression of a short hairpin RNA (shRNA) targeting UCA1 or a negative control shRNA was also achieved with the medulloblastoma cell line, Daoy. Cell proliferation and cell cycle progression were subsequently characterized with cell counting kit (CCK)-8 and flow cytometry. Cell migration was examined in wound healing and Transwell migration assays.

Results

Levels of UCA1 mRNA were higher in the medulloblastoma specimens (p<0.05) and cell lines (p<0.05) compared to the corresponding nontumor adjacent tissue specimens and a glioblastoma cell line, respectively. For the Daoy cells with silenced UCA1, their proliferation was reduced by 30% compared to the Daoy cells expressing a negative control shRNA (p=0.017). Cell cycle arrest in the G0/G1 phase, resulting in a decreased number of cells in the S phase, as well as reduced cell migration in both wound scratch healing (p=0.001) and Transwell migration assays (p=0.021) were also observed for the Daoy cells with silenced UCA1.

Conclusions

UCA1 was highly expressed in part of medulloblastoma specimens and cell lines examined. In addition, knockdown of UCA1 significantly inhibited the proliferation and migration of medulloblastoma cells in vitro.

LncRNA-XIST interacts with miR-29c to modulate the chemoresistance of glioma cell to TMZ through DNA mismatch repair pathway

Temozolomide (TMZ) is the most commonly used alkylating agent in glioma chemotherapy. However, growing resistance to TMZ remains a major challenge for clinicians. Recent evidence emphasizes the key regulatory roles of non-coding RNAs (lncRNAs and miRNAs) in tumor biology, including the chemoresistance of cancers. However, little is known about the role and regulation mechanisms of lncRNA cancer X-inactive specific transcripts (XIST) in glioma tumorigenesis and chemotherapy resistance. In the present study, higher XIST expression was observed in glioma tissues and cell lines, which was related to poorer clinicopathologic features and shorter survival time. XIST knockdown alone was sufficient to inhibit glioma cell proliferation and to amplify TMZ-induced cell proliferation inhibition. Moreover, XIST knockdown can sensitize TMZ-resistant glioma cells to TMZ. XIST can inhibit miR-29c expression by directly targetting TMZ-resistant glioma cells. DNA repair protein O⁶-methylguanine-DNA methytransferase (MGMT) plays a key role in TMZ resistance; transcription factor specificity protein 1 (SP1), a regulator of DNA mismatch repair (MMR) key protein MSH6, has been reported to be up-regulated in TMZ-resistant glioma cell lines. In the present study, we show that XIST/miR-29c coregulates SP1 and MGMT expression in TMZ-resistant glioma cell lines. Our data suggest that XIST can amplify the chemoresistance of glioma cell lines to TMZ through directly targetting miR-29c via SP1 and MGMT. XIST/miR-29c may be a potential therapeutic target for glioma treatment.

Serum long noncoding RNA urothelial carcinoma-associated 1: A novel biomarker for diagnosis and prognosis of hepatocellular carcinoma

Objective

Long noncoding RNAs (lncRNAs) offer great potential as cancer biomarkers. This study was performed to assess the applicability of serum lncRNA urothelial carcinoma-associated 1 (UCA1) as a diagnostic and/or prognostic biomarker for hepatocellular carcinoma (HCC).

Methods

We examined UCA1 expression in serum samples from 105 patients with HCC, 105 patients with benign liver disease (BLD), and 105 healthy volunteers using reverse-transcription polymerase chain reaction and analyzed the relationship between serum UCA1 and clinicopathological parameters of HCC as well as survival.

Results

Expression of serum UCA1 was significantly higher in patients with HCC and allowed for discrimination of HCC from BLD and healthy controls. High expression of serum UCA1 was significantly associated with a high tumor grade, large tumor size, positive vascular invasion, and advanced TNM stage. Multivariate analysis revealed that a high serum UCA1 level was an independent unfavorable prognostic factor for HCC.

Conclusions

Our results confirm the upregulation of serum UCA1 expression in HCC and indicate its clinical value as a noninvasive biomarker for HCC screening and prognostic prediction.

Hypoxic exosomes facilitate bladder tumor growth and development through transferring long non-coding RNA-UCA1

Background

To overcome the hostile hypoxic microenvironment of solid tumors, tumor cells secrete a large number of non-coding RNA-containing exosomes that facilitate tumor development and metastasis. However, the precise mechanisms of tumor cell-derived exosomes during hypoxia are unknown. Here, we aim to clarify whether hypoxia affects tumor growth and progression by transferring long non-coding RNA-urothelial cancer-associated 1 (lncRNA-UCA1) enriched exosomes secreted from bladder cancer cells.

Methods

We used bladder cancer 5637 cells with high expression of lncRNA-UCA1 as exosome-generating cells and bladder cancer UMUC2 cells with low expression of lncRNA-UCA1 as recipient cells. Exosomes derived from 5637 cells cultured under normoxic or hypoxic conditions were isolated and identified by transmission electron microscopy, nanoparticle tracking analysis and western blotting analysis. These exosomes were co-cultured with UMUC2 cells to evaluate cell proliferation, migration and invasion. We further investigated the roles of exosomal lncRNA-UCA1 derived from hypoxic 5637 cells by xenograft models. The availability of lncRNA-UCA1 in serum-derived exosomes as a biomarker for bladder cancer was also assessed.

Results

We found that hypoxic exosomes derived from 5637 cells promoted cell proliferation, migration and invasion, and hypoxic exosomal RNAs could be internalized by three bladder cancer cell lines. Importantly, lncRNA-UCA1 was secreted in hypoxic 5637 cell-derived exosomes. Compared with normoxic exosomes, hypoxic exosomes derived from 5637 cells showed the higher expression levels of lncRNA-UCA1. Moreover, Hypoxic exosomal lncRNA-UCA1 could promote tumor growth and progression though epithelial-mesenchymal transition, in vitro and in vivo. In addition, the expression levels of lncRNA-UCA1 in the human serum-derived exosomes of bladder cancer patients were higher than that in the healthy controls.

Conclusion

Together, our results demonstrate that hypoxic bladder cancer cells remodel tumor microenvironment to facilitate tumor growth and development though secreting the oncogenic lncRNA-UCA1-enriched exosomes and exosomal lncRNA-UCA1 in human serum has the possibility as a diagnostic biomarker for bladder cancer.

Electronic supplementary material

The online version of this article (10.1186/s12943-017-0714-8) contains supplementary material, which is available to authorized users.

Long noncoding RNA XIST is a prognostic factor in colorectal cancer and inhibits 5-fluorouracil-induced cell cytotoxicity through promoting thymidylate synthase expression

A major reason for the failure of advanced colorectal cancer (CRC) treatment is the occurrence of chemoresistance to 5-fluorouracil (5FU)-based treatment. Recent studies have shown that long non-coding RNAs (lncRNAs) are critical regulators in chemoresistance. By using the next generation HiSeq sequencing assay, we identified lncRNAs showing differential expression levels in 5FU resistant and non-resistant CRC patients. RT-qPCR was then performed for validation in tissues and serum samples, and lncRNA XIST was verified to be up-regulated in non-responding patients and have considerable diagnostic potential to identify responding patients from non-responding patients. In addition, increased serum XIST level was associated with poor response and lower survival rate in CRC patients receiving 5FU-based treatment. Subsequently, the 5FU resistant (5FU-R) cell lines were established, and lncRNA XIST was significantly up-regulated HT29 5FU-R and HCT116 5FU-R cells. Furthermore, knockdown of XIST reversed 5FU resistance while enhanced XIST could restrained the 5FU-induced cell cytotoxcity in both CRC cell lines. Western blotting and immunofluorescence analysis indicated that XIST promoted the expression of thymidylate synthase, a critical 5FU-targetd enzyme. In conclusion, our integrated approach demonstrates that increased expression of lncRNA XIST3 in CRC confers a potent poor therapeutic efficacy, and that lncRNA XIST participated in 5FU resistance through promoting the expression of thymidylate synthase. Thus, specific silence oflncRNA XIST could be a future direction to develop a novel therapeutic strategy to overcome 5FU resistance of CRC patients.

Long nonding RNA UCA1 regulates neural stem cell differentiation by controlling miR-1/Hes1 expression

Neural stem cells are able to self-renew and generate glial and neuronal lineages. Neural stem cell may serve as therapeutic method for neurological disorders including spinal cord injuries, Parkinson's disease, Huntington's disease and Alzheimer's disease. Long noncoding RNAs (lncRNAs) are longer than 200 nucleotides with limited protein-coding capacity. Recent studies have demonstreated that lncRNAs play an important role in several cellular processes including cell differentiation, cell development, proliferation, apoptosis, invasion and migration. However, the role of lncRNA human urothelial carcinoma associated 1 (UCA1) in the development of neural stem cells remains unknown. In this study, we showed that the expression of UCA1 was upregulated in the neural stem cell in a time-dependent manner. Knockdown of UCA1 suppressed the neural stem cell proliferation. Inhibition of UCA1 decreased the expression of nestin and the formation of neurosphere. Moreover, knockdown of UCA1 suppressed the neural stem cell differentiation to astrocyte and promoted the neural stem cell differentiation to neuron. Furthermore, we demonstrated that knockdown of UCA1 increased the expression of miR-1 in the neural stem cell and suppressed the expresion of Hes1, which is one target gene of miR-1. In addition, ectopic expression of Hes1 could impair siUCA1-induced neural stem cells proliferation. Overexpression of Hes1 suppressed siUCA1-induced β-tubulin expression and promoted siUCA1-inhibited GFAP expression in the neural stem cell. These results suggested that UCA1 regulated the neural stem cell proliferation and differentiation through regulating Hes1 expression.

LncRNAs: the bridge linking RNA and colorectal cancer

Long noncoding RNAs (lncRNAs) are transcribed by genomic regions (exceeding 200 nucleotides in length) that do not encode proteins. While the exquisite regulation of lncRNA transcription can provide signals of malignant transformation, lncRNAs control pleiotropic cancer phenotypes through interactions with other cellular molecules including DNA, protein, and RNA. Recent studies have demonstrated that dysregulation of lncRNAs is influential in proliferation, angiogenesis, metastasis, invasion, apoptosis, stemness, and genome instability in colorectal cancer (CRC), with consequent clinical implications. In this review, we explicate the roles of different lncRNAs in CRC, and the potential implications for their clinical application.

HspB5 correlates with poor prognosis in colorectal cancer and prompts epithelial-mesenchymal transition through ERK signaling

Alpha B-crystallin (HspB5) is abnormally expressed in tumor tissues and portends a poor prognosis in cancer patients. However, the role of HspB5 in colorectal cancer (CRC) is still unclear. Seventy CRC patients and 40 healthy volunteers were sampled from August 2012 to March 2015 in order to determine the clinical significance of HspB5. In vitro cellular studies were used to validate its molecular mechanisms in CRC. Our clinical data indicated that HspB5 was up-regulated, and had a positive association with TNM stage CRC patients. The expression level of HspB5 in CRC patients was closely correlated with MMP7 and E-cadherin, two core epithelial–mesenchymal transition (EMT) gene products. The in vitro studies revealed that high HspB5 expression could prompt tumor cell proliferation and invasion, as well as EMT. Gene-microarray analysis suggested three significant signaling pathways (PI3K, p38 and ERK) were involved in HspB5-induced EMT. Signal transduction pathway inhibitors and HspB5 gene knockdown models suggested that HspB5 promotes CRC tumorigenesis and EMT progression through ERK signaling pathways. In summary, HspB5 maybe trigger the EMT in CRC by activating the ERK signaling pathway. It is a potential tumor biomarker for CRC diagnosis and prognosis.

Roles of lncRNA UCA1-miR-18a-SOX6 axis in preventing hypoxia injury following cerebral ischemia

The present study aimed to elucidate the roles and possible molecular mechanisms of long noncoding RNA (lncRNA) urothelial carcinoma associated 1 (UCA1) in neuronal pheochromocytoma (PC)-12 cells under hypoxic conditions. The neuronal PC-12 cells were exposed to hypoxic and normoxic conditions followed by the measurement of the expression of lncRNA UCA1. In addition, the cells were transfected with short hairpin RNAs (sh-RNAs) against UCA1 (sh-UCA1), SOX6 (sh-SOX6), negative control (sh-NC), pEX-SOX6, pEX, miR-18a mimic, mimic NC, miR-18a inhibitor, and inhibitor NC. Under different treatments of transfection, cell viability and migration and invasion potential were analyzed. In addition, the induction of apoptosis was investigated by studying the expression profiles of apoptosis-related proteins. Hypoxia treatment significantly enhanced the expression of UCA1, which in turn induced injury in PC-12 cells characterized by the inhibition of cell viability, the reduction in migration and invasion potential, and the promotion of cell apoptosis. Moreover, the suppression of UCA1 alleviated the hypoxia injury. In addition, the relationship between UCA1 and miR-18a and between miR-18a and SRY-box containing gene 6 (SOX6) were explored. MiR-18a was found to be a direct target of UCA1, an upregulation of which mediated the effects of suppression of UCA1 (alleviated hypoxic injury). Besides, SOX6 was found to be a target of miR-18a whose expression could be negatively regulated by miR-18a. An overexpression of SOX6 could also aggravate hypoxia injury in PC-12 cells, whereas a knockdown of SOX6 exhibited contrary results. Our findings indicated that the down-regulation of UCA1 promoted the expression of miR-18a that led to a reduction in the expression of its target protein, SOX6, thereby contributing to the hypoxia injury following cerebral ischemia.

Non-Coding RNAs as Predictive Biomarkers to Current Treatment in Metastatic Colorectal Cancer

The onset and selection of resistant clones during cancer treatment with chemotherapy or targeted therapy is a major issue in the clinical management of metastatic colorectal cancer patients. It is possible that a more personalized treatment selection, using reliable response-to-therapy predictive biomarkers, could lead to an improvement in the success rate of the proposed therapies. Although the process of biomarker selection and validation could be a long one, requiring solid statistics, large cohorts and multicentric validations, non-coding RNAs (ncRNAs) and in particular microRNAs, proved to be extremely promising in this field. Here we summarize some of the main studies correlating specific ncRNAs with sensitivity/resistance to chemotherapy, anti-VEGF therapy, anti-EGFR therapy and immunotherapy in colorectal cancer (CRC).

Dysregulated lncRNA-UCA1 contributes to the progression of gastric cancer through regulation of the PI3K-Akt-mTOR signaling pathway

The long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been recently shown to be dysregulated during disease occurrence and to play an important role in the progression of several cancers. However, the biological role and potential regulation mechanism of UCA1 in the carcinogenesis of gastric cancer remain unclear. In the present study, we found that UCA1 was aberrantly upregulated in gastric cancer tissues and gastric cancer cell lines, and was associated with TNM stage and metastasis. UCA1 silencing significantly inhibited gastric cancer BGC-823 cell proliferation and increased its apoptosis. We also found that UCA1 played an important role in the migration and invasion of gastric cancer cells in vitro and in vivo. The molecular mechanism of UCA1 suggested that UCA1 regulates the PI3K-Akt-mTOR signaling proteins and their downstream mediators, to alter gastric cancer progression in vitro and in vivo. Collectively, the results showed a pivotal role of UCA1 in the tumorigenesis of gastric cancer. In addition, the study characterized a novel lncRNA-mRNA regulatory network, which may lead to a better understanding of the pathogenesis of gastric cancer and assist in lncRNA-directed diagnosis and therapy for this malignancy.

The prognostic value of abnormally expressed lncRNAs in colorectal cancer: A meta-analysis

BACKGROUND

Colorectal cancer (CRC) is the third most prevalent cancer type and the third leading cause of cancer-related deaths worldwide, it is urgently needed to discover a new marker for the progress of CRC. Many long noncoding RNAs (lncRNAs) have been reported to be abnormally expressed in CRC, and may be feasible as effective biomarkers and prognostic factors. The aim of this study was to identify the prognostic value of various lncRNAs in CRC.

METHODS

Pubmed, Web of Science, Embase and Cochrane Library were searched for potentially related studies. A total of 34 eligible studies including 30 on overall survival (OS), 7 on disease-free survival (DFS), 1 on relapse-free survival (RFS), 2 on disease-specific survival (DSS) and 29 on clinicopathological features were qualified from the databases.

RESULTS

The results showed that the expression levels of lncRNAs were significantly associated with poor OS (hazard ratio (HR) = 2.08, 95% confidence interval (CI) = 1.68-2.57, P<0.001, I2 = 70%), DFS (HR = 1.79, 95% CI = 1.54-2.08, P<0.001, I2 = 6%) and DSS (HR = 0.11, 95% CI = 0.02-0.54, P = 0.007, I2 = 14%). Subgroup analysis further showed that lncRNA transcription level was significantly associated with tumor differentiation (odds ratio (OR) = 0.51, 95% CI = 0.34-0.77, P = 0.001), lymph node metastasis (OR = 1.63, 95% CI = 1.23-2.17, P = 0.0007), distant metastasis (OR = 2.06, 95% CI = 1.29-3.30, P = 0.002), TNM stage (OR = 0.44, 95% CI = 0.32-0.62, P<0.001), tumor invasion depth (OR = 0.48, 95% CI = 0.39-0.60, P<0.001).

CONCLUSIONS

The meta-analysis demonstrated that abnormal lncRNA transcription level may serve as a promising indicator for prognostic of patients with CRC.

Downregulated USP3 mRNA functions as a competitive endogenous RNA of SMAD4 by sponging miR-224 and promotes metastasis in colorectal cancer

Increasing evidence shows that competitive endogenous RNAs (ceRNAs) can affect the expression of other transcripts by sequestering common microRNAs (miRNAs), and participate in tumourigenesis. As a potent tumour suppressor in colorectal cancer (CRC), SMAD4 is regulated by many miRNAs. However, the regulation of SMAD4 by ceRNAs has never been examined. In the present study, we found that USP3 modulated SMAD4 expression in a miRNA dependent, and protein-coding gene independent manner. USP3 and SMAD4 were directly targeted by miR-224, and overexpression of the USP3 3'UTR could inhibit metastasis caused by the loss of USP3. The correlation of USP3, SMAD4 and miR-224 expression was further verified in CRC specimens. Additionally, the loss of USP3 was associated with distal metastasis and a poor prognosis. Altogether, our study demonstrates USP3 as a bona fide SMAD4 ceRNA. The results from this study may provide new insights into the prevention and treatment of CRC.

LncRNA-RP11-296A18.3/miR-138/HIF1A Pathway Regulates the Proliferation ECM Synthesis of Human Nucleus Pulposus Cells (HNPCs)

During the process of Intervertebral disc degeneration (IDD), nucleus pulposus apoptosis increases, extracellular matrix (ECM) alters and/or degrades, abnormal proliferation of cells forms cell clusters, and the expression of various inflammatory factors increases. Thus, regulation of human nucleus pulposus cell (HNPC) proliferation and ECM synthesis present promising strategies for IDD treatment. Accumulating evidence indicates that non-coding RNAs are involved in various cellular processes, including cell proliferation, differentiation, apoptosis, and metastasis. High expression of long non-coding RNA (lncRNA) RP11-296A18.3, as well as a low expression of miR-138 during the IDD process has been reported; yet their functional roles in HNPC proliferation and ECM synthesis still remain unclear. MTT and BrdU assays showed that knockdown of RP11-296A18.3 inhibited the proliferation of HNPC. The ECM marker, MMP-13 and Collagen I expressions were also reduced. Bioinformatics target prediction, qPCR, and luciferase assays identified LncRNA-RP11-296A18.3 interacted with miR-138. Moreover, RP11-296A18.3 regulates HNPC proliferation and ECM synthesis through miR-138. As the target gene of miR-138, hypoxia-inducible factor 1-alpha (HIF1A) was closely associated with cell proliferation which was also regulated by RP11-296A18.3 via miR-138. Immunochemistry and qPCR results showed that miR-138 expression was inversely correlated to RP11-296A18.3 and HIF1A in IDD tissues, respectively; RP11-296A18.3 was positively correlated to HIF1A. We revealed that RP11-296A18.3 promote HIF1A expression through sponging miR-138, thus to promote HNPC proliferation and ECM synthesis. Targeting RP11-296A18.3 to rescue miR-138 expression in HNPCs and IDD tissues presents a promising strategy for IDD improvement. J. Cell. Biochem. 118: 4862-4871, 2017. © 2017 Wiley Periodicals, Inc.

State of the art technologies to explore long non-coding RNAs in cancer

Long non‐coding RNAs (lncRNAs) comprise a vast repertoire of RNAs playing a wide variety of crucial roles in tissue physiology in a cell‐specific manner. Despite being engaged in myriads of regulatory mechanisms, many lncRNAs have still remained to be assigned any functions. A constellation of experimental techniques including single‐molecule RNA in situ hybridization (sm‐RNA FISH), cross‐linking and immunoprecipitation (CLIP), RNA interference (RNAi), Clustered regularly interspaced short palindromic repeats (CRISPR) and so forth has been employed to shed light on lncRNA cellular localization, structure, interaction networks and functions. Here, we review these and other experimental approaches in common use for identification and characterization of lncRNAs, particularly those involved in different types of cancer, with focus on merits and demerits of each technique.

Long non-coding RNA UCA1 can predict tumor lymph node metastasis

Numerous studies suggested that long non-coding RNA UCA1 was highly expressed and played critical roles in the development and progression of various cancerous tissues and cells. However, little is known about the association between UCA1 and tumor lymph node metastasis. In our study, a systematic review was conducted to evaluate the association between UCA1 expression and tumor lymph node metastasis and explore whether UCA1 can be a potential molecular marker for predicting the multiple tumor lymph node metastasis. The meta-analysis result showed that the number of lymph node metastasis in different tumorous types of UCA1 high-expression group was significantly higher compared with UCA1 low-expression group (pooled odds ratio = 2.13, 95% confidence interval: 1.60-2.84, p < 0.05). To verify whether the above result was still valid in specific tumor type, we conducted a meta-analysis including four articles on colorectal cancer (pooled odds ratio = 2.07, 95% confidence interval: 1.28-3.34, p < 0.05). Based on the existing results, it can be explained that the long non-coding RNA UCA1 was significantly associated with lymph node metastasis and both the results revealed that compared with UCA1 low-expression group, the lymph node metastasis rate of UCA1 high-expression group was statistically significantly elevated. Therefore, long non-coding RNA UCA1 has the potential of being a biological marker for predicting lymph node metastasis.

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.

Colorectal Cancer: From the Genetic Model to Posttranscriptional Regulation by Noncoding RNAs

Colorectal cancer is the third most common form of cancer in developed countries and, despite the improvements achieved in its treatment options, remains as one of the main causes of cancer-related death. In this review, we first focus on colorectal carcinogenesis and on the genetic and epigenetic alterations involved. In addition, noncoding RNAs have been shown to be important regulators of gene expression. We present a general overview of what is known about these molecules and their role and dysregulation in cancer, with a special focus on the biogenesis, characteristics, and function of microRNAs. These molecules are important regulators of carcinogenesis, progression, invasion, angiogenesis, and metastases in cancer, including colorectal cancer. For this reason, miRNAs can be used as potential biomarkers for diagnosis, prognosis, and efficacy of chemotherapeutic treatments, or even as therapeutic agents, or as targets by themselves. Thus, this review highlights the importance of miRNAs in the development, progression, diagnosis, and therapy of colorectal cancer and summarizes current therapeutic approaches for the treatment of colorectal cancer.

Meta-signature LncRNAs serve as novel biomarkers for colorectal cancer: integrated bioinformatics analysis, experimental validation and diagnostic evaluation

The aim of this study is to explore the differentially expressed lncRNAs, which may have potential biological function and diagnostic value in colorectal cancer (CRC). Through integrated data mining, we finally identified nine differentially expressed lncRNAs and their potential mRNA targets. After a series of bioinformatics analyses, we screened significant pathways and GO terms that are related to the up-regulated and down-regulated transcripts respectively. Meanwhile, the nine lncRNAs were validated in 30 paired tissues and cell lines by qRT-PCR and the results were basically consistent with the microarray data. We also tested the nine lncRNAs in the serum of 30 CRC patients matched with the CRC tissue, 30 non-cancer patients and 30 health controls. Finally, we found that BLACAT1 was significant for the diagnosis of CRC. The area under the curve (AUC), sensitivity and specificity were 0.858 (95% CI: 0.765-0.951), 83.3% and 76.7% respectively between CRC patients and health controls. Moreover, BLACAT1 also had distinct value to discriminate CRC from other non-cancer diseases. The results indicated that the differentially expressed lncRNAs and their potential target transcripts could be considered as potential therapeutic targets for CRC patients. Meanwhile, lncRNA BLACAT1 might represent a new supplementary biomarker for the diagnosis of CRC.

Upregulation of the long noncoding RNA UCA1 affects the proliferation, invasion, and survival of hypopharyngeal carcinoma

Background

Several long noncoding RNAs (lncRNAs) are involved in oncogenesis.

Methods and Results

Our microarray analysis showed that numerous lncRNAs are dysregulated in hypopharyngeal squamous cell carcinoma (HSCC) tumor tissues as compared with normal tissues. Among those lncRNAs, urothelial carcinoma-associated 1 (UCA1) has been found to have an oncogenic role in HSCC. We confirmed the upregulation of UCA1 in HSCC by assessing its expression levels in a cohort of 53 patient tumors and paired non-tumor samples. In addition, we found that high UCA1 expression was significantly associated with advanced T category, late clinical stage, greater lymphatic invasion, and worse prognosis. Furthermore, in vitro experiments demonstrated that UCA1 functioned as an oncogene by promoting the proliferation and invasion and preventing the apoptosis of HSCC cells.

Conclusions

Taken together, our findings for the first time identify the role of UCA1 as a tumor promoter and a pro-metastatic factor in HSCC, demonstrating that UCA1 is a potential prognostic biomarker and therapeutic target in HSCC.

Long non-coding RNA UCA1 regulates the expression of Snail2 by miR-203 to promote hepatocellular carcinoma progression

PURPOSE

Long non-coding RNA (LncRNA) urothelial carcinoma-associated 1 (UCA1) is reported to be dysregulated in hepatocellular carcinoma (HCC) progression. However, the functions of UCA1 in HCC still need further study. The aim is to detect the role of UCA1 involving in HCC cells proliferation and invasion, and epithelial-mesenchymal transition (EMT).

METHODS

The quantitative real-time PCR was used to detect the UCA1 and miR-203 expression levels in 60 cases' HCC tissues and adjacent normal tissues. Western blotting analysis was performed to detect the EMT markers E-cadherin, Vimentin and transcription factor Snail1, Snail2 expression. Luciferase reporter assay, RNA immunoprecipitation (RIP) and pull-down assays were used to evaluate whether miR-203 was a target of UCA1.

RESULTS

Our results showed that UCA1 was markedly upregulated in HCC tissues and higher UCA1 expression in HCC was positively associated with tumor size, vascular invasion and American Joint Committee on Cancer (AJCC) stage (P < 0.05). Furthermore, gain-of-function and loss-of-function analysis showed that UCA1 knockdown inhibited HCC cells proliferation and invasion in vitro and xenograft tumour growth in vivo. Moreover, UCA1 overexpression promoted cell epithelial-mesenchymal transition (EMT) in HCC via effectively sponging to miR-203 and thereby activating the expression of transcription factor Snail2.

CONCLUSIONS

Our results identified that UCA1/miR-203/Snail2 pathway might involve in HCC progression. Inhibition of UCA1 acted as a promising therapeutic target for HCC patients.

UCA1 Regulates the Growth and Metastasis of Pancreatic Cancer by Sponging miR-135a

Pancreatic cancer (PC) is a devastating malignant disease with a poor prognosis. This study aimed to investigate the role of urothelial carcinoma associated 1 (UCA1) in the progression of PC. Our results revealed that long noncoding RNA (lncRNA) UCA1 was overexpressed in PC tissues compared with adjacent histologically normal tissues. A downregulated level of UCA1 was also detected in five human PC cell lines (SW1990, BxPC-3, MiaPaCa-2, PANC-1, and CAPAN-1) compared with normal pancreatic duct epithelial HPDE cells. The proliferation of PC cells was inhibited after UCA1 was suppressed by a lentiviral vector. The cell apoptosis rate was largely promoted by downregulating UCA1. Further research revealed that microRNA (miRNA)-135a is a direct target of UCA1. The expression of miR-135a was decreased in PC tissues and cell lines compared with control groups. In addition, the decreased level of miR-135a was elevated by adding miR-135a mimic in SW1990 cells transfected with lncRNA UCA1. Similarly, an upregulated level of miR-135a was downregulated by adding miR-135a inhibitor in SW1990 cells transfected with UCA1 siRNA. Luciferase activity assay further confirmed the targeting relationship between UCA1 and miR-135a. Moreover, miR-135a reversed the effect of UCA1 on cell apoptosis rate and cell viability in SW1990 cells. The migration and invasion capacities of PC cells were suppressed by UCA1. siRNA was then enhanced by the miR-135a inhibitor. In vivo, UCA1 siRNA effectively suppressed tumor growth and the expression of migration markers. Taken together, our research revealed that UCA1 works as an oncogene by targeting miR-135a. The UCA1–miR-135a pathway regulated the growth and metastasis of PC, providing new insight in the treatment of PC.

Noncoding RNAs in the development, diagnosis, and prognosis of colorectal cancer

More than 90% of the human genome is actively transcribed, but less than 2% of the total genome encodes protein-coding RNA, and thus, noncoding RNA (ncRNA) is a major component of the human transcriptome. Recently, ncRNA was demonstrated to play important roles in multiple biological processes by directly or indirectly interfering with gene expression, and the dysregulation of ncRNA is associated with a variety of diseases, including cancer. In this review, we summarize the function and mechanism of miRNA, long intergenic ncRNA, and some other types of ncRNAs, such as small nucleolar RNA, circular ncRNA, pseudogene RNA, and even protein-coding mRNA, in the progression of colorectal cancer (CRC). We also presented their clinical application in the diagnosis and prognosis of CRC. The summary of the current state of ncRNA in CRC will contribute to our understanding of the complex processes of CRC initiation and development and will help in the discovery of novel biomarkers and therapeutic targets for CRC diagnosis and treatment.

Long non-coding RNA UCA1 promotes cell progression by acting as a competing endogenous RNA of ATF2 in prostate cancer

Prostate cancer (PCa) is a leading cause of cancer-related deaths in elder men. This disease has limited therapeutic options and poor prognosis as the underlying molecular mechanisms are not clearly understood. LncRNA UCA1 functions as an oncogene in many types of cancers. However, the role of UCA1 in PCa remains unclear. In the present study, we showed that UCA1 was significantly up-regulated in PCa cell lines and tissue samples. High UCA1 expression was positively associated with high gleason score, advanced TNM stage and shorter overall survival of PCa patients. Inhibition of UCA1 suppressed PCa cells proliferation, migration and invasion in vitro. Moreover, UCA1 depletion inhibited the growth of PCa cells in vivo. In addition, we found that ATF2 was a direct target gene of UCA1. UCA1 regulated ATF2 expression through functioning as a competing endogenous RNA (ceRNA). UCA1 directly interacted with miR-204 and decreased the binding of miR-204 to ATF2 3'UTR, which suppressed the degradation of ATF2 mRNA by miR-204. In summary, we unveil a branch of the UCA1-miR-204-ATF2 pathway that regulates the progression of PCa. The inhibition of UCA1 expression may be a promising strategy for PCa therapy.

SPARC overexpression alters microRNA expression profiles involved in tumor progression

Medulloblastoma is the most common malignant brain tumor in children. SPARC (secreted protein acidic and rich in cysteine), a multicellular non-structural glycoprotein is known to be involved in multiple processes in various cancers. Previously, we reported that SPARC expression significantly impairs medulloblastoma tumor growth in vitro and in vivo and also alters chemo sensitivity. MicroRNAs are a class of post-transcriptional gene regulators with critical functions in tumor progression. In addition, microRNA (miRNA) expression changes are also involved in chemo-resistance. Herein, we assessed microRNA (miRNA) profiling to identify the functional network and biological pathways altered in SPARC-overexpressed medulloblastoma cells. A total of 27 differentially expressed miRNAs were identified between the control and SPARC-overexpressed samples. Potential messenger RNA (mRNA) targets of the differentially expressed miRNA were identified using Ingenuity Pathway Analysis (IPA). Network-based functional analyses were performed on the available human protein interaction and miRNA-gene association data to highlight versatile miRNAs among the significantly deregulated miRNAs using the IPA, and the biological pathway analysis using the PANTHER web-based tool. We have identified six miRNAs (miR-125b1*, miR-146a-5p, miR-181a-5p, miR-204-5p, miR-219-5p and miR-509-3p) that are associated with SPARC sensitivity by comparison of miRNA expression patterns from the SPARC treated cells with the control cells. Furthermore, pathway enrichment analysis outline that these six microRNAs mainly belong to biological processes related to cancer related signaling pathways. Collectively, these studies have the potential to indicate novel biomarkers for treatment response and can also be applied to develop novel therapeutic treatment for medulloblastoma.

A long noncoding RNA UCA1 promotes proliferation and predicts poor prognosis in glioma

BACKGROUND

Acting as a proto-oncogene, long noncoding RNAs (lncRNAs) urothelial carcinoembryonic antigen 1 (UCA1) plays a key role in the occurrence and development of several human tumors. However, the expression and biological functions of UCA1 in glioma are less known. This study discussed the expression of UCA1 in glioma and its effect on the proliferation and cell cycle of glioma cells.

METHOD

LncRNA UCA1 expressions in 64 glioma samples (Grade I-II in 22 cases and Grade III-IV in 42 cases, according to WHO criteria) and 10 normal brain samples were detected using real-time fluorescence quantitative PCR. On this basis, the correlations of UCA1 to clinicopathological characteristics and prognosis of glioma were assessed. Then, using qPCR, the lncRNA UCA1 expressions in glioma cell lines and astrocytes were detected. UCA1-overexpressing glioma cell lines U87 and U251 were further detected after siRNA transfection of these two cell lines, and the impact on cell proliferation and cell cycle was assessed with CCK-8 (cell counting kit-8) assay and flow cytometry method (FCM), respectively. The expression of cyclin D1, a cell cycle-related protein, was detected using Western Blot.

RESULT

LncRNA UCA1 expression in the glioma samples was obviously higher as compared with the normal brain samples (P < 0.001), and the expression was correlated significantly with grading of the tumors (P < 0.05). However, lncRNA UCA1 expression was not correlated with age, gender, tumor size and KPS score (P > 0.05). After interference of UCA1 expression by siRNA transfection, the proliferation of both U251 and SHG-44 cells was inhibited (P < 0.05), with more cells arrested in G0/G1 (P < 0.05). Moreover, cyclin D1 expression was also downregulated considerably.

CONCLUSION

LncRNA UCA1 can promote the proliferation and cell cycle progression of glioma cells by upregulating cyclin D1 transcription. So UCA1 may serve as an independent prognostic indicator and a novel therapeutic target for glioma.

Role of long noncoding RNA UCA1 as a common molecular marker for lymph node metastasis and prognosis in various cancers: a meta-analysis

Accumulating evidences indicated that UCA1 expression was up-regulated in various cancers, and high UCA1 expression was correlated with metastasis and prognosis. This meta-analysis collected all eligible studies and explored the relationships between UCA1 expression and lymph node metastasis (LNM) or overall survival (OS). Literature collection was performed by using electronic databases PubMed, Cochrane Library, and Web of Science (up to June 13, 2016). According to the inclusion and exclusion criteria, twelve studies were included in the meta-analysis. The result showed that high UCA1 expression was correlated with more LNM (OR=2.50, 95 %CI: 1.58-3.96, p<0.0001) in a random-effects model (I2=45 %, p=0.08) and could predict poor OS in cancer patients, with pooled hazard ratio (HR) of 1.65 [95% confidence interval (CI) 1.44-1.88, p<0.00001] indicated by a fixed-effects model (I2=35%, p=0.11). In conclusion, the present meta-analysis demonstrated that high expression of UCA1 might serve as a common molecular marker for predicting lymph node metastasis and prognosis in various cancers.

Long non-coding RNAs in anti-cancer drug resistance

Chemotherapy is one of the basic treatments for cancers; however, drug resistance is mainly responsible for the failure of clinical treatment. The mechanism of drug resistance is complicated because of interaction among various factors including drug efflux, DNA damage repair, apoptosis and targets mutation. Long non-coding RNAs (lncRNAs) have been a focus of research in the field of bioscience, and the latest studies have revealed that lncRNAs play essential roles in drug resistance in breast cancer, gastric cancer and lung cancer, et al. Dysregulation of multiple targets and pathways by lncRNAs results in the occurrence of chemoresistance. In this review, we will discuss the mechanisms underlying lncRNA-mediated resistance to chemotherapy and the therapeutic potential of lncRNAs in future cancer treatment.

Long Non-Coding RNAs: A Novel Paradigm for Toxicology

Long non-coding RNAs (lncRNAs) are over 200 nucleotides in length and are transcribed from the mammalian genome in a tissue-specific and developmentally regulated pattern. There is growing recognition that lncRNAs are novel biomarkers and/or key regulators of toxicological responses in humans and animal models. Lacking protein-coding capacity, the numerous types of lncRNAs possess a myriad of transcriptional regulatory functions that include cis and trans gene expression, transcription factor activity, chromatin remodeling, imprinting, and enhancer up-regulation. LncRNAs also influence mRNA processing, post-transcriptional regulation, and protein trafficking. Dysregulation of lncRNAs has been implicated in various human health outcomes such as various cancers, Alzheimer's disease, cardiovascular disease, autoimmune diseases, as well as intermediary metabolism such as glucose, lipid, and bile acid homeostasis. Interestingly, emerging evidence in the literature over the past five years has shown that lncRNA regulation is impacted by exposures to various chemicals such as polycyclic aromatic hydrocarbons, benzene, cadmium, chlorpyrifos-methyl, bisphenol A, phthalates, phenols, and bile acids. Recent technological advancements, including next-generation sequencing technologies and novel computational algorithms, have enabled the profiling and functional characterizations of lncRNAs on a genomic scale. In this review, we summarize the biogenesis and general biological functions of lncRNAs, highlight the important roles of lncRNAs in human diseases and especially during the toxicological responses to various xenobiotics, evaluate current methods for identifying aberrant lncRNA expression and molecular target interactions, and discuss the potential to implement these tools to address fundamental questions in toxicology.

Clinical Significance of UCA1 to Predict Metastasis and Poor Prognosis of Digestive System Malignancies: A Meta-Analysis

Purpose. Urothelial carcinoma-associated 1 (UCA1) has been reported to be overexpressed and correlated with progression in various cancers. However, the association between UCA1 expression and some clinicopathological features of digestive system malignancies, such as metastasis and survival, remains inconclusive. Therefore, a meta-analysis was performed to investigate the clinical significance of UCA1 in digestive system malignancies. Methods. Relevant literatures were searched in PubMed, Web of Science, Cochrane Library, and Embase databases updated to May 2016. Results. A total of 1089 patients from 10 studies were included in this meta-analysis. Meta-analysis results showed that digestive system malignancy patients with UCA1 overexpression were significantly more susceptible to developing lymph node metastasis (LNM) (OR = 1.85, 95% CI: 1.28–2.67) and distant metastasis (DM) (OR = 3.14, 95% CI: 1.77–5.58) and suffer from poor overall survival (OS) (HR = 2.31, 95% CI: 1.89–2.82, univariate analysis; HR = 2.24, 95% CI: 1.69–2.98, multivariate analysis) and poor disease-free survival (DFS) (HR = 2.65, 95% CI: 1.59–4.43, univariate analysis; HR = 2.50, 95% CI: 1.62–3.86, multivariate analysis). Conclusion. UCA1 overexpression was correlated with LNM, DM, poor OS, and poor DFS. UCA1 may serve as an indicator for metastasis and poor prognosis in digestive system malignancies.

LncRNA GAS5 contributes to lymphatic metastasis in colorectal cancer

Colorectal cancer (CRC) ranks the third most common type of cancer worldwide. However, the detailed molecular mechanisms underlying these processes are poorly understood. Recent studies have shown that lncRNAs play important roles in carcinogenesis and progression of CRC. The lncRNA growth arrest special 5 (GAS5), was previously identified to be down-regulated and functions as a tumor suppressor gene in many kinds of cancers. In current two-stage, case-control study, we systematically evaluated the potential role of lncRNA GAS5 and its genetic variation rs145204276 in the development and metastasis process of CRC in a Chinese population. We found the allele del of rs145204276 was significantly associated with 21% decreased risk of CRC (OR=0.79; 95% CI=0.70-0.89; P value = 5.21×10-5). Compared with the genotype ins/ins, both the genotype ins/del (OR=0.78; 95% CI=0.68-0.91) and del/del (OR=0.64; 95% CI=0.49-0.84) showed decreased susceptibility. For both in colon and rectum cancers, the associations kept statistically significant (OR=O.78 and 0.80, while P value = 4.56×10-4, and 3.80×10-3, respectively). The results also showed that the carriers of allele del are less likely to get lymph node metastasis (OR=0.80; 95% CI=0.68-0.95; P value = 0.010). Taken together, our findings provided strong evidence for the hypothesis that GAS5 rs145204276 were significantly associated with the susceptibility and progression of CRC.

Long non-coding RNA NEAT1 facilitates pancreatic cancer progression through negative modulation of miR-506-3p

Recently, long non-coding RNAs (lncRNAs) have been shown to have critical regulatory roles in tumourigenesis. Increasing evidence has suggested that lncRNA NEAT1 has been implicated in various types of human cancer. However, the potential biological roles and regulatory mechanisms of NEAT1 in pancreatic cancer (PC) remains unclear. Here, we found that the expression level of NEAT1 was higher in PC tissues compared to the corresponding non-tumor tissues. Besides, our findings indicate that high NEAT1 expression level is closely correlated with tumor progression and poor survival in PC patients. Furthermore, we also found that knockdown of NEAT1 remarkably suppressed cell proliferation by inducing cell cycle arrest and apoptosis promotion in PC cells. Moreover, bioinformatics analysis and luciferase reporter assay revealed that NEAT1 directly bound to the miR-506-3p, which has been reported to act as a tumor suppressor in diverse cancers. Additionally, our results confirmed that the tumor-promoting effects of NEAT1 in PC cells is at least partly through negative modulation of miR-506-3p. Overall, our results suggested that NEAT1 functions as an oncogenic lncRNA in PC, which could be a novel diagnostic and therapeutic target for PC.

Long Non-Coding RNA (lncRNA) Urothelial Carcinoma-Associated 1 (UCA1) Enhances Tamoxifen Resistance in Breast Cancer Cells via Inhibiting mTOR Signaling Pathway

Background

Long non-coding RNA (lncRNA) UCA1 is an oncogene in breast cancer. The purpose of this study was to investigate the role of UCA1 in tamoxifen resistance of estrogen receptor positive breast cancer cells.

Material/Methods

Tamoxifen sensitive MCF-7 cells were transfected for UCA1 overexpression, while tamoxifen resistant LCC2 and LCC9 cells were transfected with UCA siRNA for UCA1 knockdown. qRT-PCR was performed to analyze UCA1 expression. CCK-8 assay, immunofluorescence staining of cleaved caspase-9, and flow cytometric analysis of Annexin V/PI staining were used to assess tamoxifen sensitivity. Western blot analysis was performed to detect p-AKT and p-mTOR expression.

Results

LncRNA UCA1 was significantly upregulated in tamoxifen resistant breast cancer cells compared to tamoxifen sensitive cells. LCC2 and LCC9 cells transfected with UCA1 siRNA had significantly higher ratio of apoptosis after tamoxifen treatment. UCA1 siRNA significantly decreased the protein levels of p-AKT and p-mTOR in LCC2 and LCC9 cells. Enforced UCA1 expression substantially reduced tamoxifen induced apoptosis in MCF-7 cells, while rapamycin treatment abrogated the protective effect of UCA1.

Conclusions

UCA1 upregulation was associated with tamoxifen resistance in breast cancer. Mechanistically, UCA1 confers tamoxifen resistance to breast cancer cells partly via activating the mTOR signaling pathway.

Integrated analysis of long non-coding RNA‑associated ceRNA network reveals potential lncRNA biomarkers in human lung adenocarcinoma

Accumulating evidence has highlighted the important roles of long non-coding RNAs (lncRNAs) acting as competing endogenous RNAs (ceRNAs) in tumor biology. However, the roles of cancer specific lncRNAs in lncRNA-related ceRNA network of lung adenocarcinoma (LUAD) are still unclear. In the present study, the 465 RNA sequencing profiles in LUAD patients were obtained from the cancer genome atlas (TCGA) database, which provides large sample RNA sequencing data free of charge, and 41 cancer specific lncRNAs, 25 miRNAs and 1053 mRNAs (fold change >2, p<0.05) were identified. Then, the lncRNA-miRNA-mRNA ceRNA network of LUAD was constructed with 29 key lncRNAs, 24 miRNAs and 72 mRNAs. Subsequently, we selected these 29 key lncRNAs to analyze their correlation with clinical features, and 21 of them were aberrantly expressed with tumor pathological stage, TNM staging system, lymph node metastasis and patient outcome assessment, respectively. Furthermore, there were 5 lncRNAs (BCRP3, LINC00472, CHIAP2, BMS1P20 and UNQ6494) positively correlated with overall survival (OS, log-rank p<0.05). Finally, 7 cancer specific lncRNAs were randomly selected to verify the expression in 53 newly diagnosed LUAD patients using qRT-PCR. The expression results between TCGA and qRT-PCR were 100% in agreement. The correlation between AFAP1-AS1 and LINC00472 and clinical features were also confirmed. Thus, our results showed the lncRNA expression profiles and we constructed an lncRNA-miRNA-mRNA ceRNA network in LUAD. The present study provides novel insight for better understanding of lncRNA-related ceRNA network in LUAD and facilitates the identification of potential biomarkers for diagnosis and prognosis.

A computationally constructed ceRNA interaction network based on a comparison of the SHEE and SHEEC cell lines

Long non-coding RNAs (lncRNAs) play critical and complicated roles in the regulation of various biological processes, including chromatin modification, transcription and post-transcriptional processing. Interestingly, some lncRNAs serve as miRNA "sponges" that inhibit interaction with miRNA targets in post-transcriptional regulation. We constructed a putative competing endogenous RNA (ceRNA) network by integrating lncRNA, miRNA and mRNA expression based on high-throughput RNA sequencing and microarray data to enable a comparison of the SHEE and SHEEC cell lines. Using Targetscan and miRanda bioinformatics algorithms and miRTarbase microRNA-target interactions database, we established that 51 miRNAs sharing 13,623 MREs with 2260 genes and 82 lncRNAs were involved in this ceRNA network. Through a biological function analysis, the ceRNA network appeared to be primarily involved in cell proliferation, apoptosis, the cell cycle, invasion and metastasis. Functional pathway analyses demonstrated that the ceRNA network potentially modulated multiple signaling pathways, such as the MAPK, Ras, HIF-1, Rap1, and PI3K/Akt signaling pathways. These results might provide new clues to better understand the regulation of the ceRNA network in cancer.

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

Esophageal cancer (EC) is one of the most common gastrointestinal cancers, which leads to the sixth ranking of cancer-related death. Long non-coding RNAs (lncRNAs) play pivotal roles in many biological processes. lncRNA human urothelial carcinoma associated 1 (UCA1) is significantly upregulated and functions as an important oncogene in many types of human cancers. However, the role of UCA1 in EC and its underlying mechanism remains unclear. In the present study, we demonstrated that UCA1 was significantly upregulated in EC tissues and associated with poor prognosis. Overexpression of UCA1 promoted the proliferation of EC cells, while silence of UCA1 inhibited EC cells growth. Furthermore, we found that Sox4 was a direct target gene of UCA1. UCA1 regulated Sox4 expression through functioning as a competing endogenous RNA (ceRNA). UCA1 directly interacted with miR-204 and decreased the binding of miR-204 to Sox4 3'UTR, which suppressed the degradation of Sox4 mRNA by miR-204. This study provides the first evidence that UCA1 promotes cell proliferation through Sox4 in EC, suggesting that UCA1 and Sox4 may be potential therapeutic targets for EC.

LncRNA UCA1-miR-507-FOXM1 axis is involved in cell proliferation, invasion and G0/G1 cell cycle arrest in melanoma

Recently, the incidence of melanoma has been on the rise. Patients with distant metastasis share poor prognosis. Increasing studies have been conducted to clarify the molecular mechanisms as well as to investigate potential effective therapeutic targets in the development of melanoma. This study focuses on the LncRNA UCA1 and its downstream regulated factors. In our experiments, UCA1 expression was discovered to be upregulated in melanoma tissues and cells, while the depletion of UCA1 led to the inhibition of cell proliferation, invasion and cell cycle arrest. To further our understanding of the mechanisms of UCA1, a system of experiments was built. We found that miR-507 could directly bind to UCA1 at the miRNA recognition site, and that there was a negative correlation between miR-507 and UCA1. Additionally, FOXM1 is a target of miR-507 and can be downregulated by either miR-507 overexpression or UCA1 depletion. Downregulated FOXM1 was analogous to the depletion of UCA1 and the overexpression of miR-507. These results, taken together, provide evidence for a novel UCA1 interaction regulatory network in tumorigenesis of melanoma.

Overexpression of lncRNA UCA1 promotes osteosarcoma progression and correlates with poor prognosis

Long non-coding RNAs (lncRNAs) have been proved to play important roles in the tumorigenesis and development of several human malignancies. Our study aims to investigate the expression and function of lncRNA-UCA1 in osteosarcoma. lncRNA-UCA1 expression was detected in osteosarcoma tissues and cell lines by using qRT-PCR. Association between lncRNA-UCA1 levels and clinicopathological factors and patient's prognosis was analyzed. The roles of lncRNA-UCA1 in regulating osteosarcoma cell proliferation, apoptosis, migration, and invasion were evaluated in vitro. We found that lncRNA-UCA1 expression was upregulated in osteosarcoma tissues and cell lines. High lncRNA-UCA1 expression was significantly correlated with large tumor size, high tumor grade, positive distant metastasis, and advanced clinical stage. Multivariate regression analysis identified lncRNA-UCA1 overexpression as an independent unfavorable prognostic factor. lncRNA-UCA1 knockdown inhibited osteosarcoma cell proliferation, promoted cell apoptosis, and suppressed cell invasion and migration, whereas lncRNA-UCA1 overexpression showed opposite effects. These findings suggested that lncRNA-UCA1 may contribute to osteosarcoma initiation and progression, and would be not only a novel prognostic marker but also a potential therapeutic target for this disease.