Long non-coding RNA CCAT2 promotes cholangiocarcinoma cells migration and invasion by induction of epithelial-to-mesenchymal transition

Role of long non-coding RNAs in cholangiocarcinoma: A systematic review and meta-analysis

BACKGROUND

Cholangiocarcinoma (CCA), as a rare malignancy of the biliary tree, has a poor prognosis most of the time. CCA is highly epigenetically regulated and several long non-coding RNAs (lncRNA) have been investigated to have a diagnostic and prognostic role in CCA. The current study aimed to assess the studies finding relevant lncRNAs in CCA systematically.

METHODS

International databases, including PubMed, Cochrane Library, and Embase, were comprehensively searched in order to identify studies investigating any lncRNA in CCA. After screening by title/abstract and full-text, necessary data were extracted. Random-effect meta-analysis was performed for pooling the areas under the curve (AUCs), specificity, and sensitivity of lncRNAs for the diagnosis of CCA.

RESULTS

A total of 33 studies were chosen to be included in the final analysis, comprised of 2677 patients. Meta-analysis of AUCs for evaluation of CCA resulted in pooled AUC of 0.79 (95% CI: 0.75-0.82; I2 = 69.11, p < .01). Additionally, overall sensitivity of 0.80 (95% CI 0.75-0.84) and specificity of 0.77 (95% CI: 0.68-0.84) were observed. Measurement of lncRANs in the assessment of CCA also improved overall survival significantly (effect size 1.61, 95% CI: 1.39-1.82). A similar result was found for progression-free survival (effect size 1.57, 95% CI: 1.20-1.93).

CONCLUSION

Based on our findings, lncRNAs showed promising results as biomarkers in the diagnosis of CCA since they had acceptable sensitivity and specificity, in addition to the fact that improved survival in this poor prognosis cancer. Further studies might be needed to address this issue and find the best clinically useful lncRNA.

Long non-coding RNA colon cancer-associated transcript 2: role and function in human cancers

ABSTRACT

Long non-coding RNAs (lncRNAs) are a family of non-protein-coding RNAs that span a length of over 200 nucleotides. Research reports have illustrated that lncRNAs are involved in various cellular processes and that their abnormal expression leads to the occurrence and development of various tumors. Colon cancer-associated transcript 2 (CCAT2) was first reported as an oncogene in colon cancer. LncRNA CCAT2 is abnormally expressed in hepatocellular carcinoma, cholangiocarcinoma, lung cancer, breast cancer, ovarian cancer, glioma, and other tumors. In tumor tissues, abnormally overexpressed CCAT2 can affect cell proliferation, migration, epithelial-mesenchymal transition, apoptosis, and other biological behaviors through endogenous RNAs mechanisms, various signaling pathways, transcriptional regulation, and other complex mechanisms. Additionally, the overexpression of CCAT2 is also closely related to the tumor size, tumor node metastasis (TNM) stage, survival time, and other prognostic factors, suggesting that it is a potential prognostic indicator. This article reviews the biological functions of CCAT2 and its mechanisms of action in tumors from previous studies. In this review, we attempt to provide a molecular basis for future clinical applications of lncRNA CCAT2.

Construction of novel lncRNA-miRNA-mRNA ceRNA networks associated with prognosis of hepatitis C virus related hepatocellular carcinoma

Background

Hepatitis C virus (HCV) infection contribute to liver fibrosis and cirrhosis, which significantly increases the risk of hepatocellular carcinoma (HCC) development. Previous studies have demonstrated the pivotal role of competitive endogenous RNA (ceRNA) networks in tumorigenesis and cancer progression. Consequently, we herein seek to identify and evaluate the prognostic relevance of a novel ceRNA network associated with HCV-related HCC.

Methods

Differentially expressed genes (DEGs) in GSE140846 dataset from GEO were identified using Network Analyst, and GO, KEGG and Reactome analyses were performed. Furthermore, a protein-protein interaction network was generated, and hub genes were detected. Hub gene expression levels, as well as those of their upstream lncRNAs and miRNAs and associated survival analyses were conducted using appropriate bioinformatics databases. Predicted target relationships were used to establish putative ceRNA networks for HCV-related HCC.

Results

A total of 372 and 360 up- and down-regulated DE-mRNA were identified, which were associated with nuclear division, cell cycle, and ATPase activity. A PPI network containing 704 DE-mRNAs was constructed, and the 6 hub gene with the highest degree of connectivity were selected for subsequent analysis. We discovered that 22 miRNAs and 4 lncRNAs upstream of 11 hub gene were significantly associated with poor prognosis of HCV-related HCC, and used them to constructe a prognostic ceRNA network. Further experiments confirmed the ceRNA-regulatory relationship of BUB1-hsa-miR-193a-3p-MALAT1.

Conclusion

This study provides novel insights into the lncRNA-miRNA-mRNA ceRNA network, and reveals potential lncRNA biomarkers in HCV related HCC.

Long Non-Coding RNAs as Molecular Biomarkers in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a biliary system cancer that has the characteristics of strong invasiveness, poor prognosis, and few therapy choices. Furthermore, the absence of precise biomarkers for early identification and prognosis makes it hard to intervene in the early phase of initial diagnosis or recurring cholangiocarcinoma following surgery. Encouragingly, previous studies found that long non-coding RNA (lncRNA), a subgroup of RNA that is more than 200 nucleotides long, can affect cell proliferation, migration, apoptosis, and even drug resistance by altering numerous signaling pathways, thus reaching pro-cancer or anti-cancer outcomes. This review will take a retrospective view of the recent investigations on the work of lncRNAs in cholangiocarcinoma progression and the potential of lncRNAs serving as promising clinical biomarkers and therapeutic targets for CCA.

Linc01513 inhibits the malignant potential of Nasopharyngeal carcinoma by binding to PTBP1

LncRNAs are reported to be involved in tumor proliferation, invasion and metastasis, and are considered as potential biomarkers and therapeutic targets for human cancer, including head and neck cancer. In this study, we screened the differentially low-expressed linc01513 by bioinformatic to detect its expression and biological effect on nasopharyngeal carcinoma (NPC). MTT was used to evaluate the effect of linc01513 on the proliferation of NPC cells. Wound healing assay was used to determine the cells migration ability. The matrix transwell was used to further detect the role of linc01513 in cell invasion. Western blot was used to detect the expression of epithelial-mesenchymal transformation (EMT)-induced transcription factors E-cadherin, vimentin and Slug. The results showed that silence of linc01513 could promoted the proliferation, migration and invasion of NPC cells. The in vivo experiment showed that overexpression of linc01513 could inhibit the volume and weight of xenograft tumors. Database prediction, RNA pull-down and RIP experiments suggested that linc01513 may play an anti-tumor effect by inhibiting PTBP1 protein level. It is suggested that linc01513 directly binds to PTBP1 protein and mediates the EMT process and malignant biological behavior of NPC cells, which provides a new molecular marker for the prognosis and treatment of NPC.

Cholangiocarcinoma and liver transplantation: What we know so far?

Cholangiocarcinoma (CCA) is a type of cancer with increasing prevalence around the world that originates from cholangiocytes, the epithelial cells of the bile duct. The tumor begins insidiously and is distinguished by high grade neoplasm, poor outcome, and high risk for recurrence. Liver transplantation has become broadly accepted as a treatment option for CCA. Liver transplantation is expected to play a crucial role as palliative and curative therapy for unresectable hilar CCA and intrahepatic CCA. The purpose of this study was to determine which cases with CCA should be subjected to liver transplantation instead of resection, although reported post-transplant recurrence rate averages approximately 20%. This review also aims to highlight the molecular current frontiers of CCA and directions of liver transplantation for CCA.

Emerging roles of long noncoding RNAs in cholangiocarcinoma: Advances and challenges

Cholangiocarcinoma (CCA), a cancer with a relatively low incidence rate, is usually associated with poor prognosis. Current modalities for the diagnosis and treatment of CCA patients are still far from satisfactory. In recent years, numerous long noncoding RNAs (lncRNAs) have been identified as crucial players in the development of various cancers, including CCA. Abnormally expressed lncRNAs in CCA, regulated by some upstream molecules, significantly influence the biological behavior of tumor cells and are involved in tumor development through various mechanisms, including interactions with functional proteins, participation in competing for endogenous RNA (ceRNA) regulatory networks, activation of cancer‐related signaling pathways and epigenetic modification of gene expression. Furthermore, several lncRNAs are closely associated with the clinicopathological features of CCA patients, and are promising biomarkers for diagnosing and prognostication of CCA. Some of these lncRNAs play an important role in chemotherapy drug resistance. In addition, lncRNAs have also been shown to be involved in the inflammation microenvironment of CCA and malignant outcome of CCA risk factors, such as cholestatic liver diseases. In view of the difficulty of diagnosing CCA, more attention should be paid to detectable lncRNAs in the serum or bile. This review summarizes the recent knowledge on lncRNAs in CCA and provides a new outlook on the molecular mechanisms of CCA development from the perspective of lncRNAs. Moreover, we also discussed the limitations of the current studies and differential expression of lncRNAs in different types of CCA.

Omics-Based Platforms: Current Status and Potential Use for Cholangiocarcinoma

Cholangiocarcinoma (CCA) has been identified as a highly malignant cancer that can be transformed from epithelial cells of the bile duct, including intrahepatic, perihilar and extrahepatic. High-resolution imaging tools (abdominal ultrasound, computed tomography and percutaneous transhepatic cholangial drainage) are recruited for diagnosis. However, the lack of early diagnostic biomarkers and treatment evaluation can lead to serious outcomes and poor prognosis (i.e., CA19-9, MUC5AC). In recent years, scientists have established a large number of omics profiles to reveal underlying mechanisms and networks (i.e., IL-6/STAT3, NOTCH). With these results, we achieved several genomic alteration events (i.e., TP53_mut, KRAS_mut) and epigenetic modifications (i.e., DNA methylation, histone modification) in CCA cells and clinical patients. Moreover, we reviewed candidate gene (such as NF-kB, YAP1) that drive gene transcription factors and canonical pathways through transcriptomics profiles (including microarrays and next-generation sequencing). In addition, the proteomics database also indicates which molecules and their directly binding status could trigger dysfunction signatures in tumorigenesis (carbohydrate antigen 19-9, mucins). Most importantly, we collected metabolomics datasets and pivotal metabolites. These results reflect the pharmacotherapeutic options and evaluate pharmacokinetic/pharmacodynamics in vitro and in vivo. We reversed the panels and selected many potentially small compounds from the connectivity map and L1000CDS² system. In this paper, we summarize the prognostic value of each candidate gene and correlate this information with clinical events in CCA. This review can serve as a reference for further research to clearly investigate the complex characteristics of CCA, which may lead to better prognosis, drug repurposing and treatment strategies.

EMT signaling: potential contribution of CRISPR/Cas gene editing

Epithelial to mesenchymal transition (EMT) is a complex plastic and reversible cellular process that has critical roles in diverse physiological and pathological phenomena. EMT is involved in embryonic development, organogenesis and tissue repair, as well as in fibrosis, cancer metastasis and drug resistance. In recent years, the ability to edit the genome using the clustered regularly interspaced palindromic repeats (CRISPR) and associated protein (Cas) system has greatly contributed to identify or validate critical genes in pathway signaling. This review delineates the complex EMT networks and discusses recent studies that have used CRISPR/Cas technology to further advance our understanding of the EMT process.

Role of noncoding RNAs in cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is a malignant tumour originating from biliary epithelial cells, and is increasing in incidence. Radical surgery is the main treatment. However, the pathogenesis of CCA is unclear. Noncoding RNAs (ncRNAs) are non‑protein‑coding RNAs produced by genomic transcription that include microRNAs (miRNAs), circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs). They play important roles in gene expression, epigenetic modification, cell proliferation, differentiation and reproduction. ncRNAs also serve key roles in cancer development. Numerous studies have been carried out on ncRNAs, and associated publications have shown that ncRNAs are closely associated with the physiological and pathological mechanisms of CCA. The findings of these studies can provide new insights into the diagnosis, treatment and prognosis of CCA. The present review summarizes the pathophysiological mechanisms of different types of ncRNAs, including miRNAs, circRNAs and lncRNAs in CCA, and their applications in the diagnosis and treatment of CCA.

A Comprehensive Exploration of the lncRNA CCAT2: A Pan-Cancer Analysis Based on 33 Cancer Types and 13285 Cases

Whether the lncRNA CCAT2 expression level affects the clinical progression and outcome of cancer patients has not yet been fully elucidated. There is still an inconsistent view regarding the correlation between CCAT2 expression and clinicopathological factors, including survival data. Besides, the regulation mechanism of CCAT2 in human cancer is still unclear. Our study analyzed a large number of publication data and TCGA databases to identify the association of CCAT2 expression with clinicopathological factors and to explore the regulatory mechanisms in human cancers. We designed a comprehensive study to determine the expression of CCAT2 in human cancer by designing a meta-analysis of 20 selected studies and the TCGA database, using StataSE 12.0 to explore the relationship between CCAT2 expression and both the prognosis and clinicopathological features of 33 cancer types and 13285 tumor patients. Moreover, we performed GO and KEGG pathway enrichment analyses on potential target genes of CCAT2 collected from GEPIA and LncRNA2Target V2.0. The level of CCAT2 expression in tumor tissues is higher than that in paired normal tissues and is significantly associated with a poor prognosis in cancer patients. Besides, overexpression of CCAT2 was significantly associated with tumor size, clinical stage, and TNM classification. Meanwhile, CCAT2 expression is the highest in stage II of human cancer, followed by stage III. Finally, 111 validated target gene symbols were identified, and GO and KEGG demonstrated that the CCAT2 validation target was significantly enriched in several pathways, including microRNAs in the cancer pathway. In summary, CCAT2 can be a potential biomarker associated with the progression and prognosis of human cancer.

lncRNA CCAT2 Enhanced Resistance of Glioma Cells Against Chemodrugs by Disturbing the Normal Function of miR-424

Background

Aggressive metastasis of tumor cells assumed a constructive role in strengthening chemoresistance of tumors, so this investigation was intended to elucidate if lncRNA CCAT2 sponging downstream miR-424 regulated chemotolerance of glioma cells by boosting metastasis of glioma cells.

Methods

One hundred and twenty-eight pairs of glioma tissues and corresponding adjacent tissues were resected from glioma patients during their operation, and we also purchased a series of glioma cell lines, including U251, U87, A172 and SHG44. Furthermore, pcDNA3.1-CCAT2, si-CCAT2, miR-424 mimic and miR-424 inhibitor were transfected into SHG44 and U251 cell lines, so as to evaluate impacts of CCAT2 and miR-424 on chemosensitivity of the glioma cells. Besides, proliferation, invasion and metastasis of the cells were determined through the implementation of colony formation assay, transwell assay and scratch assay.

Results

Glioma tissues and cells were monitored with higher CCAT2 expression and lower miR-424 expression than adjacent normal tissues and NHA cell line (P<0.05). Among the glioma cell lines, the SHG44 cell line showed the strongest resistance against teniposide, temozolomide and cisplatin (P<0.05), whereas the U251 cell line was more sensitive to teniposide, temozolomide, vincristine and cisplatin than any other cell line (P<0.05). Besides, pcDNA3.1-CCAT2 and miR-424 inhibitor could enhance tolerance of glioma cell lines against drugs (P<0.05). Moreover, in-vitro transfection of si-CCAT2 and miR-424 mimic could significantly retard proliferation, invasion and migration of SHG44 and U251 cells (P<0.05), and CCAT2 was found to negatively regulate miR-424 expression by sponging it (P<0.05). In addition, CHK1 was deemed as the molecule targeted by upstream miR-424, and its overexpression can changeover the effects of miR-424 mimic on proliferation and metastasis of SHG44 and U251 cells.

Conclusion

lncRNA CCAT2/miR-424/Chk1 axis might serve as a promising target for improving chemotherapeutic efficacies in glioma treatment.

Colon Cancer-Associated Transcripts 1 and 2: Roles and functions in human cancers

The long noncoding RNAs (lncRNAs) Colon Cancer-Associated Transcripts 1 and 2 (CCAT1 and CCAT2) are located in a recurrently amplified region in cancers. Their proximity with the Myc oncogene and their interactions with its promoter provided further evidence for their contribution in the tumorigenesis processes. Several cell line and clinical studies have shown upregulation of these lncRNAs in diverse malignancies. Moreover, some single nucleotide variants within these genes have been associated with cancer risk or therapeutic response in different populations. Besides, these two lncRNAs act as sponges for some tumor suppressor microRNAs (miRNAs), thus promoting cancer evolution. In the current study, we review recent literature about their expression level, interaction with cancer-related pathways, their role in determination of cell fate and their contribution in malignant phenotype characteristics. Taken together, the current literature shows that these lncRNAs are putative targets for design of novel treatment strategies. Moreover, their expression levels in biopsied samples, exosomes, and sera of patients might be applied as diagnostic biomarkers or markers for patient follow-up.

LINC00491 as a new molecular marker can promote the proliferation, migration and invasion of colon adenocarcinoma cells

Background

Long non-coding RNAs (lncRNAs) play an important role in the pathogenesis of multiple tumors. However, the roles of lncRNAs during colon adenocarcinoma and cancer progression remain unclear. This study aimed identify new lncRNAs that act as molecular markers for the prevention and diagnosis of colon adenocarcinoma.

Methods

RNA sequencing (RNA-Seq) data associated with colon adenocarcinoma were retrieved from the Cancer Genome Atlas (TCGA). Biological processes in Gene Ontology (Go) and the Kyoto Encyclopedia of Genomes (KEGG) were searched for pathways at the significance level. The expression of LINC00491 and its downstream targets were assessed by real-time PCR, Western blotting and dual-luciferase assays. Biological functions of LINC00491 during cell proliferation, migration and invasion were assessed using CCK-8, colony formation assays, wound healing, and transwell invasion assays in colon adenocarcinoma HT-29 and HCT116 cells.

Results

Bioinformatics analysis with the TCGA colon adenocarcinoma dataset showed that LINC00491 was significantly up-regulated in colon adenocarcinoma. Furthermore, we found that LINC00491 positively regulates SERPINE1 expression through sponging miR-145 and promoting the proliferation, migration, and invasion of colon adenocarcinoma cells, thus playing an oncogenic role during colon adenocarcinoma pathogenesis.

Conclusion

LINC00491 functions as a ceRNA to promote SERPINE1 expression by sponging miR-145. LINC00491 serves as a therapeutic target and prognostic biomarker in colon adenocarcinoma.

Long non-coding RNA LOXL1-AS1 acts as a ceRNA for miR-324-3p to contribute to cholangiocarcinoma progression via modulation of ATP-binding cassette transporter A1

Accumulating evidence has appreciated long non-coding RNAs (lncRNAs) as novel prognostic markers and therapeutic targets in malignant carcinomas. Here, we aim to investigate the value of a novel cancer-related lncRNA, LOXL1-AS1, in cholangiocarcinoma (CCA). LOXL1-AS1 was found overexpressed in CCA tissues screened by high-throughput sequencing technology. Upregulation of LOXL1-AS1 was identified by TCGA database and qRT-PCR analysis. Additionally, upregulation of LOXL1-AS1 was associated with lymph node invasion, advanced TNM stages and unfavorable prognosis. Loss-of-function and gain-of-function experiments were conducted and validated that LOXL1-AS1 could facilitate cell proliferation, migration and invasion and attenuate cell apoptosis. Moreover, luciferase reporter and rescue assays indicated that LOXL1-AS1 functioned as a ceRNA to elevate ATP-binding cassette transporter A1 (ABCA1) level by sponging miR-324-3p and exhibited the malignant phenotypes of CCA cells, thereby playing an oncogenic role in CCA. Taken together, this study reveals that LOXL1-AS1 might act as a potential biomarker and therapeutic target for CCA clinical application.

Functions and roles of long noncoding RNA in cholangiocarcinoma

Cholangiocarcinoma (CCA) is one of the most fatal cancers in humans, with a gradually increasing incidence worldwide. The efficient diagnostic and therapeutic measures for CCA to reduce mortality are urgently needed. Long noncoding RNAs (lncRNAs) may provide the potential diagnostic and therapeutic option for suppressing the CCA development. LncRNAs are a type of non-protein-coding RNAs, which are larger than 200 nucleotides in length. Increasing evidence reveals that lncRNAs exhibit critical roles in the carcinogenesis and development of CCA. Deregulation of lncRNAs impacts the proliferation, migration, invasion, and antiapoptosis of CCA cells by multiple sophisticated mechanisms. Consequently, lncRNAs likely represent promising biomarkers or intervention targets of CCA. In this review, we summarize current studies regarding the biological functions and regulatory mechanisms of diverse lncRNAs in CCA.

E2F1-induced upregulation of long non-coding RNA LMCD1-AS1 facilitates cholangiocarcinoma cell progression by regulating miR-345-5p/COL6A3 pathway

Cholangiocarcinomas (CCA) is a refractory cancer with increasing incidence worldwide. Long non-coding RNAs (lncRNAs) have been shown to associate with the occurrence and development of CCA. A previous study identified upregulation of LMCD1-AS1 in CCA tissues relative to their normal counterparts by Agilent human lncRNA + mRNA arrayV4.0. However, the biological roles and molecular mechanisms of LMCD1-AS1-regulated tumorigenesis and progression of CCA remain to be elucidated. In our study, we confirmed that LMCD1-AS1 expression was significantly higher in CCA tissues and cell lines than in normal tissues and HIBEC, respectively. E2F1 could bind directly to the promoter region of LMCD1-AS1 and activate its transcription. Function study showed depletion of LMCD1-AS1 suppressed cell proliferation, clone formation and invasion, and induced apoptosis of CCA cells. Whereas, ectopic expressed LMCD1-AS1 facilitated CCA cell progression. In addition, LMCD1-AS1 could sponge miR-345-5p in CCA cells. Moreover, collagenVI-alpha3 chain (COL6A3) was found as a downstream target of miR-345-5p by bioinformatic prediction and dual luciferase reporter assay. Furthermore, we demonstrated that the oncogenic role of LMCD1-AS1 is partly dependent on COL6A3 expression. Taken together, we reported a newly identified regulatory mechanism of E2F1/LMCD1-AS1/miR-345-5p/COL6A3 axis, which might lead to a better understanding of CCA tumorigenesis and progression and provide potential therapeutic targets for CCA.

lncRNAs as potential molecular biomarkers in the clinicopathology and prognosis of cholangiocarcinoma: a systematic review and meta-analysis

Background

Cholangiocarcinoma (CCA) is the second most common fatal primary hepatobiliary malignant carcinoma, characterized by early invasion and extremely poor outcomes. It is therefore necessary to identify a novel biomarker to better diagnose CAA and predict its prognosis. Recently, emerging evidence has revealed that some lncRNAs play an important role in the tumorigenesis and progression of CAA. In order to support this search for novel diagnostic and prognostic biomarkers for CAA, we conducted a meta-analysis to analyze the published association between lncRNA expression and its clinical value in CAA.

Methods

Eligible studies were pooled and analyzed according to our inclusion and exclusion criteria after a comprehensive literature search. Stata 14.0 software was used to analyze the data from relevant studies and to construct a forest plot. Different effect sizes were selected for the meta-analysis.

Results

In total, 24 publications were included in this meta-analysis. After review of their full-text, 16 articles studied the association between lncRNAs and clinicopathological characteristics, 2 discussing diagnosis and 16 discussing prognosis. Our results showed that overexpression of CCAT1 was significantly correlated with tumor stage (I + II vs III + IV) (OR, 4.99; 95% CI 2.77–8.99; P<0.001) and lymph node metastasis in CCA (OR, 4.75; 95% CI 2.65–8.52; P<0.001). Furthermore, elevated CCAT lncRNA family expression predicted a shorter overall survival (HR, 2.09; 95% CI 1.17–3.00; P<0.001), especially CCAT2. Upregulation of CCAT2 was also obviously associated with tumor stage in CCA (OR, 5.29; 95% CI 2.64–10.58; P=0.001).

Conclusion

This is the first meta-analysis to assess the relationship between expression of lncRNAs and the clinical values of patients with CCA. lncRNAs can function as potential molecular biomarkers of the clinicopathology and prognosis of CCA.

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

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

The Advancement of Long Non-Coding RNAs in Cholangiocarcinoma Development

Cholangiocarcinoma (CCA) is a malignancy with increasing incidence in recent years. CCA patients are usually diagnosed at advanced stage due to lack of apparent symptoms and specifically diagnostic markers. Nowadays, surgical removal is the only effective method for CCA whereas overall 5-year-survival rate keeps around 10%. Long-noncoding RNA (lncRNA), a subtype of noncoding RNA, is widely studied to be abnormally expressed in multiple cancers including CCA. LncRNA can promote proliferation, migration, invasion and inhibit apoptosis of CCA. Moreover, lncRNA is negatively correlated with the prognosis of CCA. LncRNA may contribute to the development of CCA via modulating gene transcription, sponging microRNA, regulating CCA-related signaling pathways or protein expression. LncRNA is thought to be potential diagnostic markers and therapeutic targets for CCA.

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

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

LncRNA ASAP1-IT1 positively modulates the development of cholangiocarcinoma via hedgehog signaling pathway

Over the past decades, lncRNAs have attracted more and more attentions of researchers. It has been verified that lncRNAs can modulate multiple biological behaviors in various human cancers. LncRNA ASAP1-IT1 has been certified to be a tumor facilitator in several malignant tumors. This study aims to investigate the effects of dysregulated ASAP1-IT1 on biological processes of Cholangiocarcinoma. The high expression level of ASAP1-IT1 was tested in Cholangiocarcinoma tissues and cells with qRT-PCR. Upregulation of ASAP1-IT predicted the unfavorable prognosis for Cholangiocarcinoma patients. Next, ASAP1-IT1 was knocked down in cancerous cells for loss-of function assay. MTT, colony formation and transwell and western bot assays were performed to demonstrate the specific impacts of ASAP1-IT1 on proliferation, migration and EMT progression of Cholangiocarcinoma. Cells. As a results, the Cholangiocarcinoma progression was inhibited. Hedgehog signaling pathway has been discovered to be a treatment target in Cholangiocarcinoma. In this study, the interaction between ASAP1-IT1 and hedgehog pathway was specifically investigated. Smo and Gli1, two hedgehog-related proteins were examined in Cholangiocarcinoma cells. The results of qRT-PCR and western blot assay suggested that ASAP1-IT1 could positively modulate Smo and Gli1 in Cholangiocarcinoma. Finally, rescue assays were carried out to prove that ASAP1-IT1 could improve Cholangiocarcinoma progression and development via hedgehog signaling pathway.