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

Bioinformatics-based analysis of the relationship between disulfidptosis and prognosis and treatment response in pancreatic cancer

Tumor formation is closely associated with disulfidptosis, a new form of cell death induced by disulfide stress-induced. The exact mechanism of action of disulfidptosis in pancreatic cancer (PCa) is not clear. This study analyzed the impact of disulfidptosis-related genes (DRGs) on the prognosis of PCa and identified clusters of DRGs, and based on this, a risk score (RS) signature was developed to assess the impact of RS on the prognosis, immune and chemotherapeutic response of PCa patients. Based on transcriptomic data and clinical information from PCa tissue and normal pancreatic tissue samples obtained from the TCGA and GTEx databases, differentially expressed and differentially surviving DRGs in PCa were identified from among 15 DRGs. Two DRGs clusters were identified by consensus clustering by merging the PCa samples in the GSE183795 dataset. Analysis of DRGs clusters about the PCa tumor microenvironment and differential analysis to obtain differential genes between the two DRG clusters. Patients were then randomized into the training and testing sets, and a prognostic prediction signature associated with disulfidptosis was constructed in the training set. Then all samples were divided into high-disulfidptosis-risk (HDR) and low-disulfidptosis-risk (LDR) subgroups based on the RS calculated from the signature. The predictive efficacy of the signature was assessed by survival analysis, nomograms, correlation analysis of clinicopathological characteristics, and the receiver operating characteristic (ROC) curves. To assess differences between different risk subgroups in immune cell infiltration, expression of immune checkpoint molecules, somatic gene mutations, and effectiveness of immunotherapy and chemotherapy. The GSE57495 dataset was used as external validation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of DRGs. A total of 12 DRGs with differential expression and prognosis in PCa were identified, based on which a risk-prognosis signature containing five differentially expressed genes (DEGs) was developed. The signature was a good predictor and an independent risk factor. The nomogram and calibration curve shows the signature's excellent clinical applicability. Functional enrichment analysis showed that RS was associated with tumor and immune-related pathways. RS was strongly associated with the tumor microenvironment, and analysis of response to immunotherapy and chemotherapy suggests that the signature can be used to assess the sensitivity of treatments. External validation further demonstrated the model's efficacy in predicting the prognosis of PCa patients, with RT-qPCR and immunohistochemical maps visualizing the expression of each gene in PCa cell lines and the tissue. Our study is the first to apply the subtyping model of disulfidptosis to PCa and construct a signature based on the disulfidptosis subtype, which can provide an accurate assessment of prognosis, immunotherapy, and chemotherapy response in PCa patients, providing new targets and directions for the prognosis and treatment of PCa.

LncRNA UCA1 promotes pancreatic cancer cell migration by regulating mitochondrial dynamics via the MAPK pathway

PURPOSE

Long non-coding RNA urothelial cancer associated 1 (UCA1) serves as an oncogene in various cancers. However, the mechanism underlying the role of UCA1 in pancreatic cancer remains unclear. This study aimed to explore the role of UCA1 in pancreatic cancer.

METHODS

The expression and prognosis of UCA1 were analyzed using The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. The results were validated by immunohistochemistry (IHC) and qRT-PCR. The biofunctions of UCA1 were analyzed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). The migration abilities and mitochondrial dynamics of PC cells were examined using the Transwell assay, mitochondrial membrane potential (MMP), and fluorescence. The mitochondrial-related protein and MAPK/ERK pathway markers were evaluated using western blotting.

RESULTS

UCA1 expression was significantly higher in pancreatic cancer tissues than in normal tissues. High UCA1 expression indicated poor clinical outcomes and was associated with clinical features in patients with pancreatic cancer. Additionally, high UCA1 expression is a potential independent marker for poor prognosis. Subsequently, we demonstrated that UCA1 enhanced the migration capability, increased MMP, enhanced mitochondrial fusion, and inhibited mitochondrial autophagy in pancreatic cancer cells via the MAPK/ERK pathway.

CONCLUSION

UCA1 promotes the migration by regulating the mitochondrial dynamics of pancreatic cancer cells via the MAPK/ERK pathway. Our findings suggest that UCA1 may serve as a potential biomarker in pancreatic cancer prognosis.

Crosstalk between long noncoding RNA and microRNA in Cancer

miRNAs and lncRNAs play a central role in cancer-associated gene regulations. The dysregulated expression of lncRNAs has been reported as a hallmark of cancer progression, acting as an independent prediction marker for an individual cancer patient. The interplay of miRNA and lncRNA decides the variation of tumorigenesis that could be mediated by acting as sponges for endogenous RNAs, regulating miRNA decay, mediating intra-chromosomal interactions, and modulating epigenetic components. This paper focuses on the influence of crosstalk between lncRNA and miRNA on cancer hallmarks such as epithelial-mesenchymal transition, hijacking cell death, metastasis, and invasion. Other cellular roles of crosstalks, such as neovascularization, vascular mimicry, and angiogenesis were also discussed. Additionally, we reviewed crosstalk mechanism with specific host immune responses and targeting interplay (between lncRNA and miRNA) in cancer diagnosis and management.

Roles of lncRNAs in pancreatic ductal adenocarcinoma: Diagnosis, treatment, and the development of drug resistance

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, primarily due to its late diagnosis, high propensity to metastasis, and the development of resistance to chemo-/radiotherapy. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) are intimately involved in the treatment resistance of pancreatic cancer cells via interacting with critical signaling pathways and may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC.

DATA SOURCES

We carried out a systematic review on lncRNAs-based research in the context of pancreatic cancer and presented an overview of the updated information regarding the molecular mechanisms underlying lncRNAs-modulated pancreatic cancer progression and drug resistance, together with their potential value in diagnosis, prognosis, and treatment of PDAC. Literature mining was performed in PubMed with the following keywords: long non-coding RNA, pancreatic ductal adenocarcinoma, pancreatic cancer up to January 2022. Publications relevant to the roles of lncRNAs in diagnosis, prognosis, drug resistance, and therapy of PDAC were collected and systematically reviewed.

RESULTS

LncRNAs, such as HOTAIR, HOTTIP, and PVT1, play essential roles in regulating pancreatic cancer cell proliferation, invasion, migration, and drug resistance, thus may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC. They participate in tumorigenesis mainly by targeting miRNAs, interacting with signaling molecules, and involving in the epithelial-mesenchymal transition process.

CONCLUSIONS

The functional lncRNAs play essential roles in pancreatic cancer cell proliferation, invasion, migration, and drug resistance and have potential values in diagnosis, prognostic prediction, and treatment of PDAC.

The Functional Role of LncRNA UCA1 in Pancreatic Cancer: a mini-review

Pancreatic cancer (PaC) is a common malignant tumor of the digestive tract, with a 5-year survival rate of less than 5% and high mortality rate in the world. LncRNAs have been showed to possess multiple biological functions in growth, differentiation, and proliferation, which play an important role in different biological processes and diseases, especially in the development of tumors. LncRNA UCA1, which is firstly identified in human bladder cancer, has been showed to be a tumor promoter in pancreatic cancer. Recent researches have showed that UCA1 might promote pancreatic carcinogenesis and progression, and correlate with drug resistance. In this review, we address the biological function and regulatory mechanism of UCA1 in pancreatic cancer, which might give a new approach for clinical diagnosis and treatment.

A review on the importance of miRNA-135 in human diseases

MicroRNA-135 (miR-135) is a microRNA which is involved in the pathoetiology of several neoplastic and non-neoplastic conditions. Both tumor suppressor and oncogenic roles have been reported for this miRNA. Studies in prostate, renal, gallbladder and nasopharyngeal cancers as well as glioma have shown down-regulation of miR-135 in cancerous tissues compared with controls. These studies have also shown the impact of miR-135 down-regulation on enhancement of cell proliferation and aggressive behavior. Meanwhile, miR-135 has been shown to be up-regulated in bladder, oral, colorectal and liver cancers. Studies in breast, gastric, lung and pancreatic cancers as well as head and neck squamous cell carcinoma have reported dual roles for miR-135. Dysregulation of miR-135 has also been noted in various non-neoplastic conditions such as Alzheimer’s disease, atherosclerosis, depression, diabetes, Parkinson, pulmonary arterial hypertension, nephrotic syndrome, endometriosis, epilepsy and allergic conditions. In the current review, we summarize the role of miR-135 in the carcinogenesis as well as development of other disorders.

Emerging roles of long noncoding RNAs in chemoresistance of pancreatic cancer

Pancreatic cancer is one of the most common causes of cancer death in the world due to the lack of early symptoms, metastasis occurrence and chemoresistance. Therefore, early diagnosis by detection of biomarkers, blockade of metastasis, and overcoming chemoresistance are the effective strategies to improve the survival of pancreatic cancer patients. Accumulating evidence has revealed that long noncoding RNA (lncRNA) and circular RNAs (circRNAs) play essential roles in modulating chemosensitivity in pancreatic cancer. In this review article, we will summarize the role of lncRNAs in drug resistance of pancreatic cancer cells, including HOTTIP, HOTAIR, PVT1, linc-ROR, GAS5, UCA1, DYNC2H1-4, MEG3, TUG1, HOST2, HCP5, SLC7A11-AS1 and CASC2. We also highlight the function of circRNAs, such as circHIPK3 and circ_0000284, in regulation of drug sensitivity of pancreatic cancer cells. Moreover, we describe a number of compounds, including curcumin, genistein, resveratrol, quercetin, and salinomycin, which may modulate the expression of lncRNAs and enhance chemosensitivity in pancreatic cancers. Therefore, targeting specific lncRNAs and cicrRNAs could contribute to reverse chemoresistance of pancreatic cancer cells. We hope this review might stimulate the studies of lncRNAs and cicrRNAs, and develop the new therapeutic strategy via modulating these noncoding RNAs to promote chemosensitivity of pancreatic cancer cells.

Prognostic and immune-related value of STK17B in skin cutaneous melanoma

Skin cutaneous melanoma (SKCM) is a common cancer of which mortality is increasing continuously. Our study conducted a series of analyses on the clinical significance of Serine/threonine kinase 17B (STK17B) in SKCM to provide a new biomarker for diagnosis and treatment. The RNA-sequence data were obtained from The Cancer Genome Atlas and Genotype-Tissue Expression databases. The data of 468 SKCM patients were divided into STK17B high- and low-expression groups and analyzed by Bioconductor package to identify the differential expressed genes. The R package of "clusterProfiler" was used for Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene-Set Enrichment Analysis analyses. A protein-protein interaction network and immune infiltration landscape were respectively constructed via STRING database and ssGSEA. STK17B had lower expression in SKCM than normal tissues. Besides, STK17B expression was significantly related to some clinicopathological characteristics in SKCM patients including T stage, Breslow depth, radiation therapy, melanoma Clark level, and pathologic stage. The Kaplan-Meier curve analyses revealed that the low expression of STK17B was correlated with poor overall survival and disease-specific survival. We constructed nomograms to predict the 1-, 3-, and 5-year survival of SKCM patients. The function enrichment analyses showed STK17B-related differential expressed genes were enriched in cellular differentiation and immune-related progress. STK17B expression level were positively correlated with infiltrating level of immune cells. In this study, we found that STK17B, which played an important role in immune infiltration, could be a new biomarker for diagnosis and prognosis in SKCM patients.

Exosomal lncRNA UCA1 Derived From Pancreatic Stellate Cells Promotes Gemcitabine Resistance in Pancreatic Cancer via the SOCS3/EZH2 Axis

Objective

Pancreatic cancer is associated with poor prognosis and dismal survival rates. This study aims to investigate roles of lncRNA UCA1-loaded exosomes secreted by pancreatic stellate cells (PSCs) in Gemcitabine (Gem) resistance of pancreatic cancer under hypoxia, which involves the methylation of SOCS3 and EZH2 recruitment.

Methods

The exosomes were isolated from PSCs and hypoxic PSCs (HPSCs), and co-cultured with pancreatic cancer cells transduced with manipulated lncRNA UCA1, EZH2, and SOCS3. The interaction among lncRNA UCA1, EZH2, and SOCS3 was characterized by RIP and ChIP assays. Next, MTT assay, flow cytometry and TUNEL staining and Transwell assay were used to detect cell viability, apoptosis, invasion, and migration. Gem-resistant pancreatic cancer cell line (GemMIA-R3) was established, which was applied in a mouse xenograft model of pancreatic cancer, with MTT assay to determine Gem sensitivity.

Results

LncRNA UCA1 was highly expressed, while SOCS3 was poorly expressed in pancreatic cancer tissues. Hypoxia induced activation of PSCs and promoted release of exosomes. LncRNA UCA1 delivered by hypoxic PSC-derived exosomes (HPSC-EXO) regulated histone methylation level in SOCS3 gene region through recruitment of EZH2. In vitro and in vivo experimental results confirmed that lncRNA UCA1-loaded HPSC-EXO promoted malignant phenotypes, inhibited apoptosis, and promoted Gem resistance of pancreatic cancer cells as well as tumorigenesis in mice.

Conclusion

Under hypoxic conditions, exosomes secreted by hypoxia-induced PSCs deliver lncRNA UCA1 into pancreatic cancer cells, where lncRNA UCA1 recruits EZH2 and regulates histone methylation level in SOCS3 gene region, thereby augmenting pancreatic cancer resistance to Gem.

Long Noncoding Competing Endogenous RNA Networks in Pancreatic Cancer

Pancreatic cancer (PC) is a highly malignant disease characterized by insidious onset, rapid progress, and poor therapeutic effects. The molecular mechanisms associated with PC initiation and progression are largely insufficient, hampering the exploitation of novel diagnostic biomarkers and development of efficient therapeutic strategies. Emerging evidence recently reveals that noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRNAs), extensively participate in PC pathogenesis. Specifically, lncRNAs can function as competing endogenous RNAs (ceRNAs), competitively sequestering miRNAs, therefore modulating the expression levels of their downstream target genes. Such complex lncRNA/miRNA/mRNA networks, namely, ceRNA networks, play crucial roles in the biological processes of PC by regulating cell growth and survival, epithelial-mesenchymal transition and metastasis, cancer stem cell maintenance, metabolism, autophagy, chemoresistance, and angiogenesis. In this review, the emerging knowledge on the lncRNA-associated ceRNA networks involved in PC initiation and progression will be summarized, and the potentials of the competitive crosstalk as diagnostic, prognostic, and therapeutic targets will be comprehensively discussed.

An immune-related lncRNA signature for the prognosis of pancreatic adenocarcinoma

Recent evidence suggests that aberrant expression of long non-coding RNA (lncRNA) can drive the initiation and progression of malignancies. However, little is known about the prognostic potential of lncRNA. We aimed at constructing a lncRNA-based signature to improve the prognosis prediction of pancreatic adenocarcinoma (PAAD). The PAAD samples with clinical information were obtained from The Cancer Genome Atlas and International Cancer Genome Consortium. We established an eight-IRlncRNA signature in a training cohort. The prognostic value of eight-IRlncRNA signature was validated in two distinct cohorts when compared to other four prognostic models. We continued to analyze its independence in subgroups by univariate and multivariate Cox regression. We constructed a nomogram for clinicopathologic features and 1-, 3-, and 5-year overall survival performance. Moreover, Gene set enrichment analysis and Gene Set Variation Analysis distinguished the typical functions between high- and low-risk groups. In addition, we further observed the different correlations of immune cell between eight IRlncRNAs. Eight-IRlncRNA signature appears to be a good performer to predict the survival capability of PAAD patients, and the nomogram will enable PAAD patients to be more accurately managed in clinical practice.

The lncRNA 'UCA1' modulates the response to chemotherapy of ovarian cancer through direct binding to miR-27a-5p and control of UBE2N levels

Ovarian cancer (OC) is the leading cause of death in patients with gynecologic cancers. Due to late diagnosis and resistance to chemotherapy, the 5‐year survival rate in patients with OC is below 40%. We observed that UCA1, a lncRNA previously reported to play an oncogenic role in several malignancies, is overexpressed in the chemoresistant OC cell line OAW42‐R compared to their chemotherapy‐sensitive counterpart OAW42. Additionally, UCA1 overexpression was related to poor prognosis in two independent patient cohorts. Currently, the molecular mechanisms through which UCA1 acts in OC are poorly understood. We demonstrated that downregulation of the short isoform of UCA1 sensitized OC cells to cisplatin and that UCA1 acted as competing endogenous RNA to miR‐27a‐5p. Upon UCA1 downregulation, miR‐27a‐5p downregulated its direct target UBE2N leading to the upregulation of BIM, a proapoptotic protein of the Bcl2 family. The upregulation of BIM is the event responsible for the sensitization of OC cells to cisplatin. In order to model response to therapy in patients with OC, we used several patient‐derived organoid cultures, a model faithfully mimicking patient’s response to therapy. Inhibition of UBE2N sensitized patient‐derived organoids to platinum salts. In conclusion, response to treatment in patients with OC is regulated by the UCA1/miR‐27a‐5p/UBE2N axis, where UBE2N inhibition could potentially represent a novel therapeutic strategy to counter chemoresistance in OC.

Clinical value of microRNA-135a and MMP-13 in colon cancer

The aim of the present study was to investigate the expression and prognostic value of microRNA-135a (miR-135a) and matrix metalloproteinase-13 (MMP-13) in serum of colon cancer (CC). A total of 117 cases of patients admitted to Sheng Li Oil Field Central Hospital from May 2015 to May 2017 were enrolled in the research group (RG), and 120 cases of subjects undergoing normal health examination were included in the control group (CG). The expression of miR-135 and MMP-13 in peripheral blood of the two groups were compared, and their values were analyzed. It was found that miR-135a was decreased and MMP-13 was increased in the RG (P<0.050), both of which were closely related to the pathological features and prognosis of CC (P<0.050), and was also significantly correlated with CEA (P<0.001). ROC curve analysis showed that both of them had great predictive value for the occurrence, prognosis and death of CC. In conclusion, miR-135a was low expressed in CC, while MMP-13 was increased in CC, suggesting that the combined detection of the two had a good diagnostic effect on the occurrence of CC, and was closely related to the prognosis of CCC patients, which might be an excellent potential indicator for the diagnosis and treatment of CC in the future.

Long noncoding RNAs: role and contribution in pancreatic cancer

Noncoding RNAs are proclaimed to be expressed in various cancer types and one such type is found to be pancreatic ductal adenocarcinoma (PDAC). The long noncoding RNAs (LncRNAs) affect the migration, invasion, and growth of tumor cells by playing important roles in the process of epigenesis, post-transcription, and transcriptional regulation along with the maintenance of apoptosis and cell cycle. It is quite subtle whether the alterations in lncRNAs would impact PDAC progression and development. This review throws a spotlight on the lncRNAs associated with tumor functions: MALAT-1, HOTAIR, HOXA13, H19, LINC01559, LINC00460, SNHG14, SNHG16, DLX6-AS1, MSC-AS1, ABHD11-AS1, DUXAP8, DANCR, XIST, DLEU2, etc. are upregulated lncRNAs whereas GAS5, HMlincRNA717, MIAT, LINC01111, lncRNA KCNK15-AS1, etc. are downregulated lncRNAs inhibiting the invasion and progression of PDAC. These data provided helps in the assessment of lncRNAs in the development, metastasis, and occurrence of PDAC and also play a vital role in the evolution of biomarkers and therapeutic agents for the treatment of PDAC.

Long Noncoding RNA UCA1 in Gastrointestinal Cancers: Molecular Regulatory Roles and Patterns, Mechanisms, and Interactions

The rising trend of gastrointestinal (GI) cancer has become a global burden due to its aggressive nature and poor prognosis. Long noncoding RNAs (lncRNAs) have recently been reported to be overexpressed in different GI cancers and may contribute to cancer progression and chemoresistance. They are featured with more than 200 nucleotides, commonly polyadenylated, and lacking an open reading frame. LncRNAs, particularly urothelial carcinoma-associated 1 (UCA1), are oncogenes involved in regulating cancer progression, such as cell proliferation, invasion, migration, and chemoresistance, particularly in GI cancer. This review was aimed to present an updated focus on the molecular regulatory roles and patterns of lncRNA UCA1 in progression and chemoresistance of different GI cancers, as well as deciphering the underlying mechanisms and its interactions with key molecules involved, together with a brief presentation on its diagnostic and prognostic values. The regulatory roles of lncRNA UCA1 are implicated in esophageal cancer, gastric cancer, pancreatic cancer, hepatobiliary cancer, and colorectal cancer, where they shared similar molecular mechanisms in regulating cancer phenotypes and chemoresistance. Comparatively, gastric cancer is the most intensively studied type in GI cancer. LncRNA UCA1 is implicated in biological roles of different GI cancers via interactions with various molecules, particularly microRNAs, and signaling pathways. In conclusion, lncRNA UCA1 is a potential molecular target for GI cancer, which may lead to the development of a novel chemotherapeutic agent. Hence, it also acts as a potential diagnostic and prognostic marker for GI cancer patients.

The Functional Role of Long Non-coding RNA UCA1 in Human Multiple Cancers: a Review Study

In various cancers, high-grade tumor and poor survival rate in patients with upregulated lncRNAs UCA1 have been confirmed. Urothelial carcinoma associated 1 (UCA1) is an oncogenic non-coding RNA with a length of more than 200 nucleotides. The UCA1 regulate critical biological processes that are involved in cancer progression, including cancer cell growth, invasion, migration, metastasis, and angiogenesis. So It should not surprise that UCA1 overexpresses in variety of cancers type, including pancreatic cancer, ovarian cancer, gastric cancer, colorectal cancer, breast cancer, prostate cancer, endometrial cancer, cervical cancer, bladder cancer, adrenal cancer, hypopharyngeal cancer, oral cancer, gallbladder cancer, nasopharyngeal cancer, laryngeal cancer, osteosarcoma, esophageal squamous cell carcinoma, renal cell carcinoma, cholangiocarcinoma, leukemia, glioma, thyroid cancer, medulloblastoma, hepatocellular carcinoma and multiple myeloma. In this article, we review the biological function and regulatory mechanism of UCA1 in several cancers and also, we will discuss the potential of its as cancer biomarker and cancer treatment.

lncRNA-XLOC_012370 Promotes the Development of Pancreatic Cancer and Inactivates the NF-κB Pathway Through miR-140-5p

Pancreatic cancer is a high incidence, high degree of malignancy, and high mortality in the digestive system tumor. The incidence of pancreatic cancer in China has increased nearly six folds in the past 20 years, ranking fifth in the mortality rate of malignant tumors, so it is particularly important to actively explore clinical indicators with better diagnostic significance for pancreatic cancer. LncRNA performs an essential regulatory function in the occurrence, development, and metastasis of many kinds of tumors, playing both a carcinogenic role and a tumor suppressor gene. Here, we demonstrated the function and mechanism of LncRNA-XLOC_012370 in the development of pancreatic cancer. In our research, the abnormal upregulation of XLOC_012370 was observed in pancreatic cancer patients’ tumor tissues. XLOC_012370 was related to tumor stage, lymph node metastasis, and overall survival. Silencing of XLOC_012370 prevented the proliferation, migration, and invasion via the NF-κB signal pathway. Further, miR-140-5p was identified as the target and downstream of XLOC_012370 and involved in pancreatic cancer progression. In vivo, knockdown of XLOC_012370 inhibited tumor growth via the NF-κB signal pathway. In conclusion, lncRNA-XLOC_012370 is closely related to some malignant clinicopathological features and prognosis of pancreatic cancer. Thus the miR-140-5p/NF-κB signal pathway might represent a promising treatment strategy to combat pancreatic cancer.

Transcriptome Analysis of the Chicken Follicular Theca Cells with miR-135a-5p Suppressed

As a class of transcription regulators, numerous miRNAs have been verified to participate in regulating ovary follicular development in chickens (Gallus gallus). Previously we showed that gga-miR-135a-5p has significant differential expression between high and low-yield chicken ovaries, and the abundance of gga-miR-135a-5p is significantly higher in follicular theca cells than in granulosa cells. However, the exact role of gga-miR-135a-5p in chicken follicular theca cells is unclear. In this study, primary chicken follicular theca cells were isolated and then transfected with gga-miR-135a-5p inhibitor. Transcriptome sequencing was performed in chicken follicular theca cells with or without transfection. Differentially expressed genes (DEGs) were analyzed using bioinformatics. A dual-luciferase reporter assay was used to verify the target relationship between gga-miR-135a-5p and predicted targets within the DEGs. Compared with the normal chicken follicle theca cells, 953 up-regulated and 1060 down-regulated genes were detected in cells with gga-miR-135a-5p inhibited. The up-regulated genes were significantly enriched in Gene Ontology terms and pathways involved in cell proliferation and differentiation. In chicken follicular theca cells, Krüppel-like factor 4 (KLF4), ATPase phospholipid transporting 8A1 (ATP8A1), and Complexin-1 (CPLX1) were significantly up-regulated when the expression of gga-miR-135a-5p was inhibited. In addition, KLF4, ATP8A1, and CPLX1 confirmed as targets of gga-miR-135a-5p by using a dual-luciferase assay in vitro. The results suggest that gga-mir-135a-5p may involve in proliferation and differentiation in chicken ovarian follicular theca cells by targeting KLF4, ATP8A1, and CPLX1.

Down-regulation of lncRNA UCA1 enhances radiosensitivity in prostate cancer by suppressing EIF4G1 expression via sponging miR-331-3p

BACKGROUND

We aimed to explore the role of long noncoding RNA urothelial carcinoma-associated 1 (lncRNA UCA1) and its underlying mechanism in the radioresistance of prostate cancer (PCa).

METHODS

QRT-PCR was conducted to measure the expression of UCA1, microRNA-331-3p (miR-331-3p) and eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) in PCa tissues and cells. The relative protein level was determined by western blot assay. Cell proliferation and apoptosis were detected by MTT, colony formation assay, and flow cytometry, respectively. The target interaction between miR-331-3p and UCA1 or EIF4G1 was predicted through bioinformatics analysis, and verified by dual-luciferase reporter gene assay system.

RESULTS

The high levels of UCA1 and EIF4G1 as well as the low level of miR-331-3p were observed in PCa tissues and cell lines. UCA1 and EIF4G1 expression were significantly upregulated by Gy radiation treatement. UCA1 or EIF4G1 knockdown repressed cell growth and enhanced cell apoptosis in 22RV1 and DU145 cells under radiation. Moreover, overexpression of EIF4G1 abolished UCA1 knockdown-induced effect on 6 Gy irradiated PCa cells. UCA1 sponged miR-331-3p to regulate EIF4G1 expression.

CONCLUSIONS

LncRNA UCA1 deletion suppressed the radioresistance to PCa by suppressing EIF4G1 expression via miR-331-3p. UCA1 acted as a potential regulator of radioresistance of PCa, providing a promising therapeutic target for PCa.

Hypoxic Tumor-Derived Exosomal Long Noncoding RNA UCA1 Promotes Angiogenesis via miR-96-5p/AMOTL2 in Pancreatic Cancer

The hypoxic microenvironment, an important feature of solid tumors, promotes tumor cells to release exosomes and enhances tumor angiogenesis. However, the detailed functions of hypoxic exosomes and the mechanisms underlying their effects in pancreatic cancer (PC) remain mysterious. Here, we observed that hypoxic exosomes derived from PC cells promoted cell migration and tube formation of human umbilical vein endothelial cells (HUVECs). The long noncoding RNA (lncRNA) UCA1, a key factor, was highly expressed in exosomes derived from hypoxic PC cells and could be transferred to HUVECs through the exosomes. In addition, the expression levels of UCA1 in exosomes derived from PC patients' serum were higher than in healthy controls and were associated with poor survival of PC patients. Moreover, hypoxic exosomal UCA1 could promote angiogenesis and tumor growth both in vitro and in vivo. With respect to the functional mechanism, UCA1 acted as a sponge of microRNA (miR)-96-5p, relieving the repressive effects of miR-96-5p on the expression of its target gene AMOTL2. Collectively, these results indicate that hypoxic exosomal UCA1 could promote angiogenesis and tumor growth through the miR-96-5p/AMOTL2/ERK1/2 axis and therefore, serve as a novel target for PC treatment.

LncRNA ZEB1-AS1 promotes pancreatic cancer progression by regulating miR-505-3p/TRIB2 axis

Long noncoding RNAs (lncRNAs) are crucial regulatory factors in the development and progression of human malignancies. The purpose of this study was to investigate the potential mechanism of ZEB1-AS1 in pancreatic cancer (PC). The expression of ZEB1-AS1 in PC tissues and cells was assessed by RT-qPCR. The overall survival rate was evaluated using the Kaplan-Meier analysis. The association between ZEB1-AS1 and miR-505 was verified by dual-luciferase reporter assay. CCK-8 assay was employed to analyze PC cell viability. Transwell assay was employed to detect the migration and invasion of PC cells. Our results revealed that ZEB1-AS1 expression was significantly upregulated in PC tissues and cells, and the high expression of ZEB1-AS1 indicated the low overall survival rate in PC patients. Loss-of-function and gain-of-function assays indicated that knockdown of ZEB1-AS1 inhibited the cell viability, migration and invasion of PC cells, while overexpression of ZEB1-AS1 promoted PC cell progression. Moreover, ZEB1-AS1 upregulated TRIB2 expression via sponging miR-505. Finally, rescue assays demonstrated that TRIB2 overexpression partially abrogated the inhibitory effect of ZEB1-AS1 knockdown on the viability, migration and invasion of PC cells. These results confirmed that ZEB1-AS1 promoted the tumorigenesis of PC through the miR-505/TRIB2 axis, which indicated that ZEB1-AS1 might function as a biomarker for PC treatment and provide a new therapeutic direction in PC.

Aberrant LncRNA Expression in Leukemia

Leukemia is a common malignant cancer of the hematopoietic system, whose pathogenesis has not been fully elucidated. Long noncoding RNAs (lncRNAs) are transcripts longer than 200 nucleotides without protein-coding function. Recent studies report their role in cellular processes such as the regulation of gene expression, as well as in the carcinogenesis, occurrence, development, and prognosis of various tumors. Evidence indicating relationships between a variety of lncRNAs and leukemia pathophysiology has increased dramatically in the previous decade, with specific lncRNAs expected to serve as diagnostic biomarkers, novel therapeutic targets, and predictors of clinical outcomes. Furthermore, these lncRNAs might offer insight into disease pathogenesis and novel treatment options. This review summarizes progress in studies on the role(s) of lncRNAs in leukemia.

The miR-1224-5p/ELF3 Axis Regulates Malignant Behaviors of Pancreatic Cancer via PI3K/AKT/Notch Signaling Pathways

Purpose

Aberrant expression of microRNAs contributes to the progression of pancreatic cancer by targeting downstream genes. A novel regulatory axis, miR-1224-5p/ELF3, was identified by bioinformatic analysis and experimental verification. Studies of the underlying molecular mechanisms behind this axis lead to a better understanding of the development of pancreatic cancer.

Materials and Methods

The differential expression of miR-1224-5p and ELF3 was verified based on Gene Expression Omnibus (GEO) datasets and clinical samples. The relationship between miR-1224-5p and ELF3 was demonstrated by luciferase assay and Western blot. The related signaling pathways of the miR-1224-5p/ELF3 axis in pancreatic cancer were investigated by gene set enrichment analysis (GSEA) and verified by Western blot. An analysis between ELF3 expression and immune infiltration was performed. Cellular and animal experiments were utilized to explore the effects of miR-1224-5p and ELF3 in pancreatic cancer.

Results

Suppressed expression of miR-1224-5p in pancreatic tumor tissues and cancer cells was identified first. Furthermore, miR-1224-5p is correlated with clinicopathological features, and decreased expression of miR-1224-5p indicates poor prognosis. miR-1224-5p serves as a tumor suppressor and inhibits malignant behaviors of pancreatic cancer based on in vivo and in vitro assays. The putative target gene ELF3 was predicted by bioinformatic analysis and confirmed by dual-luciferase reporter assay. Overexpression of ELF3 can improve the malignant behaviors of pancreatic cancer and demonstrates poor prognosis and advanced clinical stage. The inhibitory role of miR-1224-5p in pancreatic cancer is manifested by its direct targeting of ELF3. A negative correlation between ELF3 expression and immune cell infiltration was identified, suggesting an immunosuppressive state resulting from ELF3 overexpression. The PI3K/AKT/Notch signaling pathways and epithelial-to-mesenchymal transition (EMT) are important underlying mechanisms.

Conclusion

The miR-1224-5p/ELF3 axis may serve as a new diagnostic, therapeutic, and prognostic biomarker in pancreatic cancer. The related PI3K/AKT/Notch/EMT signaling pathways greatly promote the elucidation of the progression of pancreatic cancer.

Retrotransposons Manipulating Mammalian Skeletal Development in Chondrocytes

Retrotransposons are genetic elements that copy and paste themselves in the host genome through transcription, reverse-transcription, and integration processes. Along with their proliferation in the genome, retrotransposons inevitably modify host genes around the integration sites, and occasionally create novel genes. Even now, a number of retrotransposons are still actively editing our genomes. As such, their profound role in the evolution of mammalian genomes is obvious; thus, their contribution to mammalian skeletal evolution and development is also unquestionable. In mammals, most of the skeletal parts are formed and grown through a process entitled endochondral ossification, in which chondrocytes play central roles. In this review, current knowledge on the evolutional, physiological, and pathological roles of retrotransposons in mammalian chondrocyte differentiation and cartilage development is summarized. The possible biological impact of these mobile genetic elements in the future is also discussed.

MiR-135a biogenesis and regulation in malignancy: a new hope for cancer research and therapy

MicroRNAs (miRNAs) are evolutionarily conserved small non-coding RNAs that affect posttranscriptional regulation by binding to the 3′-untranslated region of target messenger RNAs. MiR-135a is a critical miRNA that regulates gene expression, and many studies have focused on its function in cancer research. MiR-135a is dysregulated in various cancers and regulates cancer cell proliferation and invasion via several signaling pathways, such as the MAPK and JAK2/STAT3 pathways. MiR-135a has also been found to promote or inhibit the epithelial-mesenchymal transition and chemoresistance in different cancers. Several studies have discovered the value of miR-135a as a novel biomarker for cancer diagnosis and prognosis. These studies have suggested the potential of therapeutically manipulating miR-135a to improve the outcome of cancer patients. Although these findings have demonstrated the role of miR-135a in cancer progression and clinical applications, a number of questions remain to be answered, such as the dual functional roles of miR-135a in cancer. In this review, we summarize the available studies regarding miR-135a and cancer, including background on the biogenesis and expression of miR-135a in cancer and relevant signaling pathways involved in miR-135a-mediated tumor progression. We also focus on the clinical application of miR-135a as a biomarker in diagnosis and as a therapeutic agent or target in cancer treatment, which will provide a greater level of insight into the translational value of miR-135a.

MicroRNA-519 inhibits hypoxia-induced tumorigenesis of pancreatic cancer by regulating immune checkpoint PD-L1

Pancreatic cancer is highly prevalent and exhibits a high incidence and mortality rate. Hypoxia contributes to tumorigenesis and the progression of pancreatic cancer. To the best of our knowledge, the role of microRNA (miR)-519 has not been investigated in hypoxia-induced pancreatic cancer progression. The purpose of the present study was to elucidate the mechanism underlying miR-519-mediated regulation of pancreatic cancer progression. Reverse transcription-quantitative PCR and western blotting were performed to investigate miR-519 and programmed death ligand 1 (PD-L1) mRNA and protein levels, respectively. Additionally, a Transwell assay was performed to examine the invasiveness of PANC-1 and SW1990 cells. Cells were subsequently stained with Annexin V to determine the apoptotic rate of cells. Furthermore, bioinformatics analysis and a dual-luciferase reporter assay were performed to confirm the direct association between miR-519 and PD-L1, and a xenograft experiment was conducted to test the role of miR-519 in vivo. The results revealed that the expression levels of miR-519 in pancreatic cancer cells were reduced following hypoxia treatment. Furthermore, transfection with miR-519 mimics inhibited PANC-1 and SW1990 cell invasiveness, and induced apoptosis under hypoxic conditions. PD-L1 was also identified as a downstream target of miR-519, and rescued the miR-519 mimic-attenuated tumorigenesis of pancreatic cancer cells under hypoxic conditions. Additionally, treatment with miR-519 mimics significantly suppressed the tumor growth of PANC-1 cells. The results of the present study indicated a novel mechanism of miR-519-mediated tumorigenesis in pancreatic cancer cells under hypoxic conditions. The conclusions may be crucial for the improvement of future pancreatic cancer treatment.

Oncogenic Role and Prognostic Value of MicroRNA-937-3p in Patients with Breast Cancer

Purpose

Breast cancer is the most common female tumor in the world. MicroRNA has been reported to play an important role in the progression of breast cancer. The purpose of this study was to explore the role of miR-937-3p in breast cancer.

Patients and methods

Expression of miR-937-3p in breast cancer tissues and serums was detected from The Cancer Genome Atlas (TCGA), the Gene Expression Omnibus (GEO) and patients' samples. Kaplan-Meier plotter identified the association between miR-937-3p and prognosis.

Results

The analysis of TCGA, GEO and qRT-PCR suggested that the level of miR-937-3p was increased in breast cancer tissues and serum compared with adjacent normal breast tissues and healthy persons, respectively. The decreased expression of miR-937-3p inhibited breast cancer proliferation, migration and invasion. CCRL2 was the target of miR-937-3p. In contrast to miR-937-3p, the level of CCRL2 was decreased in breast cancer tissues. Luciferase reporter assay revealed that miR-937-3p directly bound to the 3'-UTR of CCRL2. Double knockdown of CCRL2 and miR-937-3p promoted breast cancer cell proliferation, migration and invasion, suggesting that miR-937-3p promoted breast cancer cell proliferation, migration and invasion by targeting CCRL2. The Kaplan-Meier survival analysis suggested that breast cancer patients with high level of miR-937-3p or low level of CCRL2 had a reduced overall survival (OS).

Conclusion

miR-937-3p plays an important role in the diagnosis and prognosis of breast cancer. Inhibition of miR-937-3p expression may be a novel targeted therapy for breast cancer.

The prognostic value and mechanisms of lncRNA UCA1 in human cancer

Long noncoding RNAs (lncRNAs), longer than 200 nucleotides in length, play important roles in the development and progression of various cancers. An increasing number of studies have revealed that lncRNAs function as potential oncogenes or tumor suppressors to influence biological processes, such as cell growth, invasion, migration and apoptosis. Urothelial carcinoma associated 1 (UCA1), an oncogenic lncRNA, was first found in bladder cancer and highly expressed in multiple cancers, including gastric cancer, colorectal cancer, lung cancer and breast cancer. UCA1 promotes tumorigenesis mainly via binding to tumor-suppressive microRNAs (miRNAs), activating several pivotal signaling pathways and alteration of epigenetic and transcriptional regulation. In addition, high expression of UCA1 is related to poor clinicopathological features especially for shorter overall survival, suggesting that UCA1 might be regarded as a prognosis biomarker in human cancers. In the present review, we summarized current studies on UCA1 to explore its prognostic value and underlying regulation mechanisms in the development of multiple cancers in order to provide a glimmer of hope for the prevention and treatment of malignant tumors.

Crosstalk between the lncRNA UCA1 and microRNAs in cancer

Long non-coding RNAs (lncRNAs) are a major subset of highly conserved non-coding RNAs (ncRNAs) that consist of at least 200 nucleotides and have limited protein-coding potential. Cumulative data have shown that lncRNAs are deregulated in many types of cancer and may control pathophysiological processes of cancer at various levels, including transcription, post-transcription and translation. Recently, lncRNAs have been demonstrated to interact with microRNAs (miRNAs), another major subset of ncRNAs, which regulate physiological and pathological processes by inhibiting target mRNA translation or promoting mRNA degradation. The lncRNA urothelial carcinoma-associated 1 (UCA1) has recently gained much attention as it is overexpressed in many types of cancer and is involved in carcinogenesis. Here, we review the crosstalk between UCA1 and miRNAs during the pathogenesis of cancer, with a focus on cancer-cell proliferation, invasion, drug resistance, and metabolism.

Super-Enhancer-Associated LncRNA UCA1 Interacts Directly with AMOT to Activate YAP Target Genes in Epithelial Ovarian Cancer

Long noncoding RNAs (lncRNAs) have emerged as critical regulators of tumorigenesis, and yet their mechanistic roles remain challenging to characterize. Here, we integrate functional proteomics with lncRNA-interactome profiling to characterize Urothelial Cancer Associated 1 (UCA1), a candidate driver of ovarian cancer development. Reverse phase protein array (RPPA) analysis indicates that UCA1 activates transcription coactivator YAP and its target genes. In vivo RNA antisense purification (iRAP) of UCA1 interacting proteins identified angiomotin (AMOT), a known YAP regulator, as a direct binding partner. Loss-of-function experiments show that AMOT mediates YAP activation by UCA1, as UCA1 enhances the AMOT-YAP interaction to promote YAP dephosphorylation and nuclear translocation. Together, we characterize UCA1 as a lncRNA regulator of Hippo-YAP signaling and highlight the UCA1-AMOT-YAP signaling axis in ovarian cancer development.

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A super-enhancer drives the expression of lncRNA UCA1 in EOC

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Inactivation of UCA1 impairs tumor growth in vivo

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UCA1 activates transcription coactivator YAP and its target genes

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UCA1 promotes YAP dephosphorylation and nuclear translocation via AMOTp130

The UCA1/KRAS axis promotes human pancreatic ductal adenocarcinoma stem cell properties and tumor growth

Emerging evidence indicates that the long noncoding RNA UCA1 is upregulated in multiple cancers, including pancreatic ductal adenocarcinoma (PDAC), and plays a critical role in various complex biological processes. However, the functional roles of UCA1 in PDAC remain to be clarified. In the current study, we showed that UCA1 significantly promoted cell proliferation and tumor growth both in vitro and in vivo, and enhanced stemness maintenance of PDAC cell lines. Moreover, we found that UCA1 overexpression increased the activity and expression of oncogenic KRAS. Mechanistically, upregulated UCA1 increased phospho-KRAS protein levels by interacting with hnRNPA2B1, and KRAS facilitated high cytoplasmic accumulation of hnRNPA2B1. Additionally, we identified that UCA1 functioned as a competing endogenous RNA (ceRNA) to increase the expression of KRAS via sponging miR-590-3p, and in turn, KRAS promoted UCA1 expression. Collectively, these findings suggest that the UCA1-KRAS axis plays a crucial role in PDAC progression and that UCA1 may serve as a target for new PDAC therapies.

Potential ceRNA networks involved in autophagy suppression of pancreatic cancer caused by chloroquine diphosphate: A study based on differentially‑expressed circRNAs, lncRNAs, miRNAs and mRNAs

Autophagy has been reported to be involved in the occurrence and development of pancreatic cancer. However, the mechanism of autophagy‑associated non‑coding RNAs (ncRNAs) in pancreatic cancer remains largely unknown. In the present study, microarrays were used to detect differential expression of mRNAs, microRNAs (miRNAs), long ncRNAs (lncRNAs) and circular RNAs (circRNAs) post autophagy suppression by chloroquine diphosphate in PANC‑1 cells. Collectively, 3,966 mRNAs, 3,184 lncRNAs and 9,420 circRNAs were differentially expressed. Additionally, only two miRNAs (hsa‑miR‑663a‑5p and hsa‑miR‑154‑3p) were underexpressed in the PANC‑1 cells in the autophagy‑suppression group. Furthermore, miR‑663a‑5p with 9 circRNAs, 8 lncRNAs and 46 genes could form a prospective ceRNA network associated with autophagy in pancreatic cancer cells. In addition, another ceRNA network containing miR‑154‑3p, 5 circRNAs, 2 lncRNAs and 11 genes was also constructed. The potential multiple ceRNA, miRNA and mRNA associations may serve pivotal roles in the autophagy of pancreatic cancer cells, which lays the theoretical foundation for subsequent investigations on pancreatic cancer.

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.

lncRNA differentiation antagonizing nonprotein coding RNA overexpression accelerates progression and indicates poor prognosis in pancreatic ductal adenocarcinoma

Background

lncRNA differentiation antagonizing nonprotein coding RNA (lncRNA DANCR) has been suggested to play an oncogenic role in multiple cancers. However, to the best of our knowledge, the clinical significance and role of DANCR in pancreatic ductal adenocarcinoma (PDAC) has not been illuminated till now. The present study aims to identify the functional role of DANCR in PDAC.

Methods

The expression of DANCR was detected in PDAC cells and tissues. The correlation of DANCR expression and PDAC clinicopahological features was analysed. Kaplan-Meier method was used to depict the overall survival (OS) rate and shorter progression-free survival (PFS) of PDAC patients, and Log-rank test was performed to analyse the difference. Univariate and multivariate COX regression model were utilized to analyse the risk factors for prognosis. Transwell assay and Matrigel assay were conducted to detect the effect of DANCR on the migration and invasion of PDAC cells, respectively. Colony formation assay and Cell Counting Kit-8 (CCK-8) assay were performed to evaluate the function of DANCR on proliferation. The mechanisms of DANCR exerting its function were also explored.

Results

DANCR was revealed to promote PDAC progression, with relatively higher expression levels in PDAC cell lines and tissues. Correlation analysis of the clinicopathological features and DANCR expression found that high DANCR expression was statistically correlated with vascular invasion (P=0.013), advanced T stage (P=0.005), lymph node metastasis (P<0.001) and advanced TNM stage (P<0.001). Notably, survival analysis discovered that high DANCR expression predicted lower OS rate and shorter PFS period. In addition, high DANCR expression was identified as an independent risk factor for poor OS (HR=1.199, 95% CI=1.113–1.290, P<0.001) and PFS (HR=1.199, 95% CI=1.114–1.290, P<0.001) of PDAC. Moreover, in vitro assays detected that the migration and invasion of Panc1 cells with DANCR deficiency were significantly suppressed in the Transwell assay and the Matrigel assay. However, the motility of BxPC3 cells with DANCR overexpression was obviously increased. In addition, the loss of DANCR suppressed the proliferation of Panc1 cells in the CCK-8 assay and the colony formation assay, while ectopic expression of DANCR in BxPC3 cells promoted the proliferation. Besides, microRNA-33a-5p/AXL signaling pathway may be involved in mediating the function of DANCR.

Conclusion

Overexpression of lncRNA DANCR in PDAC is associated with cancer progression and predicts poor OS and PFS. DANCR could promote the proliferation and metastasis of PDAC cells. DANCR may serve as a potential prognostic marker and therapeutic target in PDAC.

Long noncoding RNA UCA1 promotes the proliferation, invasion, and migration of nasopharyngeal carcinoma cells via modulation of miR-145

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a common malignant tumor characterized by highly malignant local invasion and distant metastasis. Recently, increasing attention has been paid to long noncoding RNAs (lncRNAs), which play significant roles in tumorigenesis and progression. However, little is known about the potential role of the lncRNA urothelial carcinoma-associated 1 (UCA1) in NPC cell invasion and migration.

METHODS

Real-time quantitative PCR was used to analyze the expression of lncRNA UCA1 in NPC cell lines and NP69. lncRNA UCA1 knock-down nasopharyngeal carcinoma cell line models were established through siRNA. Cell viability was evaluated by Cell counting kit-8 and Colony forming assay. The migration and invasion capacities were evaluated by wound healing and transwell migration and invasion assays. Western blot analysis were used to examine protein changes followed by UCA1 knock-down.

RESULTS

Our study confirmed that UCA1 was upregulated in NPC cell lines and involved in NPC tumorigenesis according to our established UCA1-associated competing endogenous RNA network. Moreover, functional analyses indicated that the downregulation of UCA1 exerted inhibitory effects on cell proliferation, invasion, and migration. Mechanistic analyses revealed that UCA1 was the target of miR-145 and functioned as a sponge to repress miR-145 expression. Rescue experiments suggested that lncRNA UCA1 reversed the miR-145-mediated inhibition on oncogene ADAM17 expression, thus promoting the proliferation, invasion, and migration of NPC cells.

CONCLUSION

LncRNA UCA1 functions as a tumor promoter in NPC. UCA1 promotes the proliferation and invasion of NPC cells by sponging miR-145, functionally altering ADAM17 expression targeted by miR-145. Our exploration of the underlying mechanism of UCA1 in NPC may provide novel therapeutic targets for NPC.

Long non-coding RNA CUDR promotes malignant phenotypes in pancreatic ductal adenocarcinoma via activating AKT and ERK signaling pathways

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, with a marked potential for invasion and metastasis. Emerging evidence has suggested that dysregulation of long non-coding RNAs (lncRNAs) is associated with the development of multiple types of cancer. However, the function of lncRNAs in PDAC is poorly known. In the present study, a microarray assay was used to screen for differently expressed lncRNAs in PDAC and it was identified that cancer upregulated drug resistance (CUDR) was upregulated in PDAC. CUDR increased PDAC cell proliferation, migration and invasion, inhibited apoptosis, and promoted drug resistance; it also regulated the PDAC cell epithelial-mesenchymal transition. The CUDR-induced PDAC malignant phenotypes is via the protein kinase B and extracellular-signal-regulated kinase signaling pathways. Downregulation of CUDR may be a novel therapeutic strategy to prevent PDAC development and drug resistance in the future.

Long non-coding RNAs in the failing heart and vasculature

Following completion of the human genome, it became evident that the majority of our DNA is transcribed into non-coding RNAs (ncRNAs) instead of protein-coding messenger RNA. Deciphering the function of these ncRNAs, including both small- and long ncRNAs (lncRNAs), is an emerging field of research. LncRNAs have been associated with many disorders and a number have been identified as key regulators in the development and progression of disease, including cardiovascular disease (CVD). CVD causes millions of deaths worldwide, annually. Risk factors include coronary artery disease, high blood pressure and ageing. In this review, we will focus on the roles of lncRNAs in the cellular and molecular processes that underlie the development of CVD: cardiomyocyte hypertrophy, fibrosis, inflammation, vascular disease and ageing. Finally, we discuss the biomarker and therapeutic potential of lncRNAs.

RETRACTED: Long non-coding RNA UCA1 targets miR-185-5p and regulates cell mobility by affecting epithelial-mesenchymal transition in melanoma via Wnt/β-catenin signaling pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Several figures presented in the manuscript appear to have been doctored. The journal has tried to contact the authors of this article but at the time of publication of this notice has not received any response. As there is no explanation for the picture manipulations, the Editor-in-Chief of Gene has lost confidence in the validity of this work and has decided to retract it.

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.

Aberrant lncRNA Expression in Multiple Myeloma

Multiple myeloma (MM), a type of malignant tumor, is characterized by dysplasia of clonal plasma cells in the bone marrow. People with MM will have damaged organs or tissues due to secretion of large amounts of monoclonal immunoglobulin or fragments (M protein). Despite improved survivability by novel treatment strategies over the last decade, MM is still incurable by current therapies. Long noncoding RNAs (lncRNAs), with length of more than 200 nucleotides, have been reported to act as important regulators in many diseases, including MM. Recent studies have reported aberrant lncRNA expression in MM; these dysregulated lncRNAs can play oncogenic and/or tumor-suppressive roles in the development and progression of MM. In this article, we present a general overview on the role of lncRNAs in MM pathogenesis and discuss their potential as prognostic biomarkers and targets for treatment.

Downregulation of miR‑135a predicts poor prognosis in acute myeloid leukemia and regulates leukemia progression via modulating HOXA10 expression

MicroRNA‑135a (miR‑135a) has been shown to exert important roles in various human cancer types, such as glioblastoma, thyroid carcinoma and renal carcinoma. However, the function of miR‑135a in acute myeloid leukemia (AML) remains largely unknown. In the present study, it was demonstrated that miR‑135a expression was significantly downregulated in AML cells compared with normal control cells. Furthermore, the downregulation of miR‑135a in patients with AML predicted poor prognosis. Through functional experiments, overexpression of miR‑135a was demonstrated to significantly inhibit the proliferation and cell cycle of AML cells, while it promoted cellular apoptosis. miR‑135a directly targeted HOXA10 in AML cells. miR‑135a overexpression significantly suppressed the mRNA and protein levels of HOXA10 in AML cells. Moreover, there was an inverse association between miR‑135a expression and HOXA10 level in AML samples. Additionally, by ectopic expression of HOXA10, restoration of HOXA10 significantly abolished the effects of miR‑135a overexpression on AML cell proliferation, cell cycle and apoptosis. In conclusion, the present study demonstrated that miR‑135a serves as a tumor suppressor in AML by targeting HOXA10, and miR‑135a may be a promising prognostic biomarker for AML patients.

LncRNA UCA1 promotes migration and invasion in pancreatic cancer cells via the Hippo pathway

Although overexpression of the long non-coding RNA (lncRNA) UCA1 has been implicated in several human cancers, its biological function in pancreatic cancer remains to be clarified. In this study, we reported that UCA1 expression was significantly increased in pancreatic cancer tissues and correlated with clinicopathological features, tumor stage, and poorer patient outcome. We further showed that UCA1 promoted cell migration and invasion of pancreatic cancer cells. Importantly, we found that UCA1 overexpression inhibited YAP phosphorylation, and increased YAP expression. Mechanistically, UCA1 interacted with MOB1, Lats1, and YAP, forming shielding composites. Moreover, we demonstrated that UCA1 increased YAP nuclear localization and stabilization, and improved TEAD luciferase activity. In turn, YAP promotes UCA1 expression. Collectively, the present study provides insights into the mechanistic regulation of UCA1 promoting pancreatic cancer progression through the Hippo signaling pathway. UCA1 may serve as a candidate biomarker for poor prognosis and a target for new pancreatic cancer therapies.

miR-135a Confers Resistance to Gefitinib in Non-Small Cell Lung Cancer Cells by Upregulation of RAC1

The EGFR tyrosine kinase inhibitor gefitinib is used in therapy for non-small cell lung cancer (NSCLC). However, the therapeutic efficacy of gefitinib is known to be impeded by mutations of EGFR. The aim of the present study was to reveal the role of miR-135a in gefitinib resistance of NSCLC cells. Human NSCLC cell lines, NCI-H1650 and NCI-H1975, were transfected with miR-135a mimic/inhibitor or miR-135a inhibitor plus pEX-RAC1 (a RAC1-expressing vector). The effects of miR-135a and RAC1 expression on cell viability, apoptosis, migration, and invasion were then detected. The transfected cells were exposed to 0-20 μM gefitinib, and cell viability was then detected at 48 h posttreatment. Western blot analysis was performed to detect the expression changes of main factors in the PI3K/AKT pathway. miR-135a overexpression promoted viability, migration, and invasion, but inhibited apoptosis of NCI-H1650 and NCI-H1975 cells. Cell viability was significantly reduced by gefitinib, and the LC50 values of gefitinib in NCI-H1650 and NCI-H1795 cells were 0.845 and 0.667 μM, respectively. miR-135a overexpression could increase cell viability even under high concentrations of gefitinib. Rac1 was not predicted as a target of miR-135a, while miR-135a could upregulate the expression of RAC1. miR-135a promoted cell growth and metastasis and activated the PI3K/AKT signaling pathway via a RAC1-dependent manner. To conclude, this study demonstrated that miR-135a confers NSCLC cell resistance to gefitinib via upregulation of RAC1. Therapies designed to downregulate miR-135a may help NSCLC patients to overcome gefitinib resistance.

Clinicopathological and Prognostic Role of Long Noncoding RNA Linc00152 in Various Human Neoplasms: Evidence from Meta-Analysis

Recent researches have demonstrated that long noncoding RNA linc00152 was aberrantly upregulated in multiple tumor types. High expression of linc00152 was associated with poor outcomes in cancer patients. Therefore, we conducted this meta-analysis to evaluate its potential value as a prognostic predictor in various human neoplasms. Eligible studies were searched through several electronic databases including PubMed, Embase, Web of Science, and the Cochrane Library. Eight original studies including 752 cancer patients were ultimately enrolled. Statistical analysis suggested that overexpression of linc00152 was significantly correlated with unfavorable overall survival (OS) (HR = 2.05, 95% CI: 1.59–2.64) and disease-free/progression-free survival (DFS/PFS) (HR = 3.52, 95% CI: 1.82–6.79) in cancer patients. In addition, a significant correlation was observed between aberrant linc000152 expression and lymph node metastasis (LNM) (OR = 2.49, 95% CI: 1.57–3.94) but not in vessel invasion (VI) (OR = 1.02, 95% CI: 0.54–1.93) and distant metastasis (DM) (OR = 0.600, 95% CI: 0.213–1.689). Our meta-analysis demonstrated that high linc00152 expression significantly predicted inferior OS and DFS/PFS in multiple neoplasms, as well as advanced LNM and VI. Linc00152 may serve as a potential indicator in predicting poor outcomes and metastases of diverse cancers.