Non-coding RNA CCAT1 Research Articles

Long noncoding RNA CCAT1 inhibits miR-613 to promote nonalcoholic fatty liver disease via increasing LXRα transcription.

Nonalcoholic fatty liver disease (NAFLD) is regarded as a threat to public health; however, the pathologic mechanism of NAFLD is not fully understood. We attempted to identify abnormally expressed long noncoding RNA (lncRNAs) and messenger RNA that may affect the occurrence and development of NAFLD in this study. The expression of differentially expressed lncRNAs in NAFLD was determined in oleic acid (OA)-treated L02 cells, and the functions of CCAT1 in lipid droplet formation were evaluated in vitro. Differentially expressed genes (DEGs) were analyzed by microarray analysis, and DEGs related to CCTA1 were selected and verified by weighted correlation network analysis. The dynamic effects of LXRα and CCTA1 on lipid droplet formation and predicted binding was examined. The binding between miR-631 and CCAT1 and LXRα was verified. The dynamic effects of miR-613 inhibition and CCTA1 silencing on lipid droplet formation were examined. The expression and correlations of miR-631, CCAT1, and LXRα were determined in tissue samples. As the results show, CCAT1 was induced by OA and upregulated in NAFLD clinical samples. CCAT1 silencing significantly suppressed lipid droplet accumulation in vitro. LXRα was positively correlated with CCAT1. By inhibiting miR-613, CCAT1 increased the transcription of LXRα and promoted LXRα expression. The expression of LXRα was significantly increased in NAFLD tissues and was positively correlated with CCAT1. In conclusion, CCAT1 increases LXRα transcription by serving as a competing endogenous RNA for miR-613 in an LXRE-dependent manner, thereby promoting lipid droplet formation and NAFLD. CCAT1 and LXRα might be potent targets for NAFLD treatment.

Long non-coding RNA CCAT1 promotes colorectal cancer progression by regulating miR-181a-5p expression.

The vital roles of long noncoding RNAs (lncRNAs) have been implicated in growing number of studies in tumor development. LncRNA CCAT1 has been recognized as associated with tumor development, yet its relation with colorectal cancer (CRC) remains elusive. Our study aimed at elucidating the function and mechanisms of long non-coding RNA CCAT1 in CRC. From a lncRNA profile dataset of 38 pairs of matched tumor-control colon tissues from colorectal patients housed in The Cancer Genome Atlas (TCGA), we detected 10 upregulated and 10 down-regulated lncRNAs in CRC. Fifty cases of CRC patients were enrolled to analyze the correlation between the expression of CCAT1 and clinical pathology. The inverse correlation of expression and target relationship between CCAT1 and miR-181a-5p were verified using qRT-PCR and dual-luciferase reporter gene assay. Cell viability, colony formation ability, aggression and apoptosis were determined by MTT assay, colony formation assay, Transwell and wound healing assays and flow cytometry analysis. Furthermore, Xenograft model was used to show that knockdown of CCAT1 inhibits tumor growth in vivo. The expression of lncRNA CCAT1 was significantly upregulated in CRC tissues. The CCAT1 expression was positively associated with cancer stage (American Joint Committee on Cancer stage, P<0.05). CCAT1 promoted cell proliferation, growth and mobility by targeting miR-181a-5p and the silence of CCAT1 increased the cell apoptosis. Same effect was observed in an in vivo xenograft model, which the tumor size and pro-tumor proteins were significantly diminished by knocking down of CCAT1.

RETRACTED: Knockdown of long non-coding RNA CCAT1 suppresses proliferation and EMT of human cervical cancer cell lines by down-regulating Runx2

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Following the concerns raised about the background pattern of the Western Blots from Figures 3A and 3C, the corresponding author has contacted the journal to request the retraction of the article. Given the comments of Dr Elisabeth Bik regarding this article “This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Long non-coding RNA CCAT2 promotes oncogenesis in triple-negative breast cancer by regulating stemness of cancer cells

Triple-negative breast cancers (TNBC) are more aggressive due to lacking receptors for hormone therapy and maintaining stemness features in cancer cells. Herein we found long non-coding RNA CCAT2 overexpressed specially in TNBC, and in breast cancer stem cells (BCSC) as well. Enforced overexpression and targeted knockdown demonstrated the oncogenic function of CCAT2 both in vitro and in vivo. CCAT2 promoted the expression of stemness markers including OCT4, Nanog and KLF4, increased mammosphere formation and induced ALDH+ cancer stem cell population in TNBC. A chromosomally adjacent gene OCT4-PG1, as a pseudogene of OCT4, was upregulated by CCAT2, and positively regulated the stemness features of TNBC cells. miR-205 was identified as a target gene of CCAT2 in TNBC. Point-mutation in CCAT2 impaired the sponge inhibition of miR-205. Overexpression of miR-205 rescued the oncogenic phenotypes induced by CCAT2. In addition, Notch2, as a target gene of miR-205, was downregulated by miR-205 and upregulated by CCAT2 in TNBC. Collectively, the current study revealed a novel function of CCAT2 in promoting tumor initiation and progression in TNBC through upregulating OCT4-PG1 expression and activating Notch signaling. These findings not only demonstrated a lncRNA-based therapeutic strategy in treatment of TNBC, but also added a node to the regulatory network of CCAT2 that controls aggressiveness of breast cancer stem cells.

Long non-coding RNA CCAT1 is a prognostic biomarker for the progression of oral squamous cell carcinoma via miR-181a-mediated Wnt/β-catenin signaling pathway

ABSTRACT Oral squamous cell carcinoma (OSCC) ranks as the sixth most common carcinoma worldwide, and the third most common carcinoma in developing countries as well. Recently, the aberrant expression of lncRNA CCAT1 has been revealed to play an important role in the development of several cancers. However, its role in OSCC remains unknown. The expression levels of CCAT1 and miR-181a were determined in 15 paired primary OSCC tissues and their adjacent noncancerous tissues and cell lines with qPCR. shRNA against CCAT1 was employed to investigate the impact of CCAT1 on proliferation and metastasis. Then dual luciferase reporter and RIP assays were utilized to study the interaction between CCAT1 and miR-181a. Cells transfected with sh-CCAT1 or treated with miR-181a inhibitor were subjected to western blot to investigate the role of Wnt/β-catenin signaling in CCAT1-mediated proliferation and metastasis. Finally, the role of CCAT1 in OSCC was confirmed with tumor xenografts mice model. CCAT1 was upregulated in OSCC tissues and cell lines. Knockdown of CCAT1 inhibited the proliferation, migration and invasion of OSCC cells, while the cell apoptosis was enhanced. Luciferase and RIP assays revealed that miR-181a was a direct target of CCAT1. Inhibition of miR-181a partially reversed the efficacy of sh-CCAT1. Moreover, sh-CCAT1 inhibited OSCC tissues growth through inhibiting Wnt signaling in a miR-181a-dependent manner in vivo. lncRNA CCAT1 activated Wnt/β-catenin signaling via inhibiting miR-181a, resulting in the cell proliferation, migration and invasion of OSCC, suggesting that CCAT1 might serve as a potential target of OSCC treatment. Abbreviation: LncRNA: long non-coding RNA; OSCC: oral squamous cell carcinoma; 3’ UTR: 3’ untranslated region; ANOVA: one-way analysis of variance; CDK: cyclin-dependent kinase; ceRNA: competing endogenous RNA; FBS: fetal bovine serum; HGF: human gingival fibroblasts; MAPK: mitogen-activated protein kinase; miRNA: micro RNA; ncRNA: noncoding RNAs; PBS: phosphate-buffered saline; PI3K: phosphatidylinositol 3-kinase

RETRACTED ARTICLE: Long non-coding RNA CCAT2 acts as an oncogene in osteosarcoma through regulation of miR-200b/VEGF

We, the Editors and Publisher of the journal Artificial Cells, Nanomedicine, and Biotechnology, have retracted the following article: Juntao Liu, Dehai Kong, Deping Sun & Jianmin Li (2019) Long non-coding RNA CCAT2 acts as an oncogene in osteosarcoma through regulation of miR-200b/VEGF. Artificial Cells, Nanomedicine, and Biotechnology, 47(1), 2994–3003, DOI: 10.1080/21691401.2019.1640229 Since publication, concerns have been raised about the integrity of the data in the article. When approached for an explanation, the authors checked their data and confirmed there are fundamental errors present. Therefore, they have agreed to the retraction of this article. The authors apologise for this oversight. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

Long non-coding RNA CCAT2 regulates proliferation, drug sensitivity and metastasis of ovarian cancer

IntroductionReports suggest that lncRNAs have implications in the development of several diseases including cancer. It is therefore believed that lncRNAs may act as therapeutic targets for cancer treatment. The treatment of ovarian cancer is mainly obstructed by lack of biomarkers and efficient drug targets. Against this backdrop, this study was undertaken to reveal the role and therapeutic implications of lncRNA CCAT2 in ovarian cancer.Material and methodsExpression analysis was carried out with quantitative real-time polymerase chain reaction (qRT-PCR). Transfections were carried out using Lipofectamine 2000 reagent. Cell counting kit 8 (CCK-8) assays were used to determine the cell viability. AO/EB and annexin V/propidium iodide (PI) were used for detection of apoptosis. Wound healing and transwell assays were used to determine cell migration and invasion. The expression of the proteins was estimated by western blotting.ResultsThe results showed that the expression of CCAT2 was significantly overexpressed in ovarian cancer tissues and cell lines. Si-RNA mediated silencing of CCAT2 resulted in the decrease of proliferation rate and colony formation potential of the OVACAR-3 cells via induction of apoptotic cell death, which was also accompanied by cleavage of PARP, downregulation of Bcl-2 and upregulation of Bax, caspase-3 and caspase-9. Suppression of CCAT2 enhanced the chemosensitivity of the OVACAR-3 cells to cisplatin and also decreased their migration and invasion.ConclusionsThe findings of this study revealed that lncRNA CCAT2 suppression inhibits the proliferation, drug sensitivity, and metastasis of ovarian cancer and may prove beneficial in ovarian cancer management.

Long non-coding RNA CCAT1 promotes cervical cancer cell proliferation and invasion by regulating the miR-181a-5p/MMP14 axis

ABSTRACTCervical cancer is a serious threat to women’s health and is the third most common malignancy in women worldwide. Recent studies indicate that the long non-coding RNA CCAT1 plays a role in the malignant behavior of many tumors. However, the role of CCAT1 in cervical cancer is still unknown. Our aim is to evaluate the expression and investigate the regulatory role and potential mechanism of CCAT1 in cervical cancer. CCAT1 expression was measured by qRT-PCR. In addition, CCK-8 assays, colony formation assays, qRT-PCR assays, Transwell assays and xenograft experiments were performed to determine the role of CCAT1 in the proliferation and invasion in cervical cancer cells. The expression of CCAT1 in the cervical cancer tissues was higher than in the adjacent normal tissues. Overexpressing CCAT1 promoted cervical cancer cell proliferation, colony formation, and invasion in vitro. Elevated CCAT1 suppressed miR-181a expression, which was accompanied by an increased expression of MMP14 and HB-EGF. In contrast, knocking down CCAT1 resulted in increased expression of miR-181a, along with decreased expression of MMP14 and HB-EGF. Thus, CCAT1 is a key oncogenic lncRNA associated with cervical cancer and plays a role in promoting cervical cancer cell proliferation and invasion by regulating the miR-181a-5p/MMP14 axis.

LncRNA CCAT1 promotes cell proliferation and differentiation via negative modulation of miRNA-218 in human DPSCs.

To investigate the expression of Long non-coding RNA (LncRNA) CCAT1 and potential functions in promoting cell proliferation and differentiation, via miRNA-218 in human adult Dental Pulp Stem Cells (DPSCs). CCAT1 expressions in Periodontal Ligament Cells (PDLCs), DPSCs, differentiated main population (MP) cells and stem-cell-enriched Side Population (SP) cells in DPSCs were detected by qRT-PCR. MTT assay and ELISA assay were performed to evaluate the DPSCs cell proliferation and differentiation. The correlation between miR-218 and CCAT1 was detected by statistical analysis. The bioinformatics and luciferase assay were performed to explore the interaction and binding site of CCAT1 and miR-218. Results showed the CCAT1 expression was up-regulated in DPSCs cells. And the expression level in MP cell was higher than SP cell. MTT assay and showed overexpression CCAT1 significantly increased cell proliferation of DPSCs. ELISA assay showed the expressions of collagen I, Osteopontin (OPN) and Osteocalcin (OCN) were significantly increased in DPSCs compared with control (p<0.05). The bioinformatics and luciferase assay showed that the CCAT1 directly interacted with miR-218. In addition, miR-218 expression was negatively correlated with CCAT1 expression in DPSCs CONCLUSIONS: For the first time, we found that lncRNA-CCAT1 was upregulated in DPSCs, which could promote cell proliferation and differentiation by repressing the expression of miR-218.

LncCCAT1 Promotes Breast Cancer Stem Cell Function through Activating WNT/β-catenin Signaling.

Background: Breast cancer stem cells (BCSCs) play an essential role in facilitating breast cancer relapse and metastasis. The underlying mechanism, however, remains incompletely understood. In the current study, we investigated the clinical significance, biological function and mechanism of a long noncoding RNA CCAT1 (LncCCAT1) in BCSCs.Methods: Firstly, lncRNAs expression in poorly differentiated breast cancer tissues and BCSCs were measured by lncRNA microarray and confirmed in breast cancer tissues and cell lines. The functional roles and mechanisms of LncCCAT1 were further investigated by gain and loss of function assays in vitro and in vivo.Results: LncCCAT1 is markedly upregulated in breast cancer tissues BCSCs and is correlated with poor outcomes in breast cancer patients. Overexpression of LncCCAT1 contributes to the proliferation, stemness, migration and invasion capacities of BCSCs. Mechanistic investigation suggests that LncCCAT1 can interact with miR-204/211, miR-148a/152 and Annexin A2(ANXA2), then upregulate T-cell factor 4 (TCF4) or promote translocation of β-catenin to the nucleus where it activates TCF4, leading to the activation of wingless/integrated (Wnt) signaling. Furthermore, TCF4 can also bind to the promoter of LncCCAT1 to promote LncCCAT1 transcription, thus forming a positive feedback regulatory circuit of LncCCAT1-TCF4-LncCCAT1 in BCSCs.Conclusions: LncCCAT1 plays an important role in breast cancer progression and may serve as a novel target for breast cancer diagnosis and therapy.

Long noncoding RNA CCAT2 functions as a competitive endogenous RNA to regulate FOXC1 expression by sponging miR-23b-5p in lung adenocarcinoma.

Long noncoding RNA (lncRNA) may regulate the process of tumor formation. Although lncRNA CCAT2 has been identified as a key point in many diseases, its pathophysiological mechanism in lung adenocarcinoma remains unknown. We measured the expression level of CCAT2 in lung adenocarcinoma cells and normal lung epithelial cell line BEAS-2B by quantitative real-time polymerase chain reaction (qRT-PCR). As well, cell migration and proliferation were detected by transwell detection and CCK8 assay. At the same time, the new target point of CCAT2 was confirmed with bioinformatics analysis and dual-luciferase reporter assay. In addition, potential mechanisms were studied by Western blot analysis and RNA immunoprecipitation (RIP) analysis. The expression of CCAT2 was upregulated obviously in lung adenocarcinoma cells. Cell function analysis showed that upregulation of CCAT2 significantly promoted cell proliferation and migration, and reduction of CCAT2 inhibited cell migration and proliferation. In addition, CCAT2 positively regulated the expression of FOXC1 by competitive binding with miR-23b-5p. These findings indicated that CCAT2 may act as a competitive endogenous RNA (ceRNA) to regulate FOXC1 expression by competitively binding miR-23b-5p in lung adenocarcinoma.

Co-activation of super-enhancer-driven CCAT1 by TP63 and SOX2 promotes squamous cancer progression

Squamous cell carcinomas (SCCs) are aggressive malignancies. Previous report demonstrated that master transcription factors (TFs) TP63 and SOX2 exhibited overlapping genomic occupancy in SCCs. However, functional consequence of their frequent co-localization at super-enhancers remains incompletely understood. Here, epigenomic profilings of different types of SCCs reveal that TP63 and SOX2 cooperatively and lineage-specifically regulate long non-coding RNA (lncRNA) CCAT1 expression, through activation of its super-enhancers and promoter. Silencing of CCAT1 substantially reduces cellular growth both in vitro and in vivo, phenotyping the effect of inhibiting either TP63 or SOX2. ChIRP analysis shows that CCAT1 forms a complex with TP63 and SOX2, which regulates EGFR expression by binding to the super-enhancers of EGFR, thereby activating both MEK/ERK1/2 and PI3K/AKT signaling pathways. These results together identify a SCC-specific DNA/RNA/protein complex which activates TP63/SOX2-CCAT1-EGFR cascade and promotes SCC tumorigenesis, advancing our understanding of transcription dysregulation in cancer biology mediated by master TFs and super-enhancers.

Long non-coding RNA-CCAT2 promotes the occurrence of non-small cell lung cancer by regulating the Wnt/β-catenin signaling pathway.

The present study aimed to investigate the biological function of colon cancer-associated transcript 2 (CCAT2) in the occurrence and progression of non-small cell lung carcinoma (NSCLC) and its potential use in the early diagnosis and molecular-targeted therapy of NSCLC. The tumor tissues, para-carcinoma tissues and associated clinical data of 36 patients with NSCLC were collected in order to detect the expression of CCAT2 and assess the impact of factors including histopathological type, Tumor-Node-Metastasis stage and lymph node metastasis on CCAT2 expression. The lung cancer NCI-H1975 cell line was transfected with a small interfering RNA (siRNA) plasmid to determine the effect of si-CCAT2 on NSCLC proliferation, invasion and metastasis. The effect of si-CCAT2 on the expression of nuclear and cytoplasmic β-catenin protein in the lung cancer NCI-H1975 cell line was detected using western blot analysis. The expression levels of CCAT2 in the tumor tissues of patients with NSCLC were significantly higher than those in the normal para-carcinoma tissues (t=8.580, P<0.01). Subsequent to CCAT2 silencing, the proliferation and invasive abilities of NCI-H1975 cells were significantly decreased compared with control cells (P<0.05). In the si-CCAT2 group, the level of nuclear and cytoplasmic β-catenin proteins was decreased, and the activity of the Wnt signaling pathway was significantly inhibited compared with the control cells (P<0.01), and a synergistic effect was exerted with the Wnt signaling inhibitor FH535. CCAT2 may therefore promote the occurrence of NSCLC by regulating the Wnt/β-catenin signaling pathway.

Long non-coding RNA CCAT1 promotes the migration and invasion of prostate cancer PC-3 cells.

To investigate the effect of long non-coding RNA CCAT1 on the proliferation, migration, and invasion of prostate cancer PC-3 cells. The expression of CCAT1 was detected by Real-time PCR. The effect of CCAT1 down-regulation on the proliferation of PC-3 cells was observed by MTT assay. The regulatory of CCAT1 low-expression on the migration ability of PC-3 cells was investigated by transwell assay. The influence of decreased CCAT1 on the invasion ability of PC-3 cells was detected by Matrigel invasion assay. Increased CCAT1 was significantly related to lymph node metastasis in prostate cancer. Low-expression of CCAT1 could suppress cell proliferation. Knockdown of CCAT1 inhibited the migration of PC-3 cells. Down-regulation of CCAT1 attenuated the invasion of PC-3 cells. CCAT1 promoted the growth and the metastasis of prostate cancer. Our findings might provide a potential target for the diagnosis and treatment of prostate cancer.

985 - Human Long Non-Coding RNA (LNCRNA) CCAT1 and UCA1 Regulate Proinflammatory Response and Cell Migration in Human and Mouse Intestinal Epithelial Cells

985 - Human Long Non-Coding RNA (LNCRNA) CCAT1 and UCA1 Regulate Proinflammatory Response and Cell Migration in Human and Mouse Intestinal Epithelial Cells

Cancer-associated rs6983267 SNP and its accompanying long noncoding RNA CCAT2 induce myeloid malignancies via unique SNP-specific RNA mutations.

The cancer-risk-associated rs6983267 single nucleotide polymorphism (SNP) and the accompanying long noncoding RNA CCAT2 in the highly amplified 8q24.21 region have been implicated in cancer predisposition, although causality has not been established. Here, using allele-specific CCAT2 transgenic mice, we demonstrate that CCAT2 overexpression leads to spontaneous myeloid malignancies. We further identified that CCAT2 is overexpressed in bone marrow and peripheral blood of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) patients. CCAT2 induces global deregulation of gene expression by down-regulating EZH2 in vitro and in vivo in an allele-specific manner. We also identified a novel non-APOBEC, non-ADAR, RNA editing at the SNP locus in MDS/MPN patients and CCAT2-transgenic mice. The RNA transcribed from the SNP locus in malignant hematopoietic cells have different allelic composition from the corresponding genomic DNA, a phenomenon rarely observed in normal cells. Our findings provide fundamental insights into the functional role of rs6983267 SNP and CCAT2 in myeloid malignancies.

LncRNA CCAT1 promotes the progression of preeclampsia by regulating CDK4.

Preeclampsia is one of the leading causes of maternal and perinatal deaths. This study mainly explored the mechanism of long non-coding RNA (lncRNA) CCAT1 expression in the placenta of preeclampsia patients and its effect on the progression of preeclampsia. We used quantitative reverse transcription PCR (qRT‑PCR) to detect the lncRNA CCAT1 expression in 40 preeclampsia and 40 normal pregnancy placenta samples. CCAT1 expression and its relationship with the clinicopathological parameters of preeclampsia was statistically analyzed. The specific small interfering RNA (si-CCAT1) and plasmid (pcDNA-CCAT1) targeting lncRNA CCAT1 were synthesized and transfected into Bew and JEG-3 cells. The CCAT1 expression in Bew and JEG-3 cells was determined by qRT‑PCR. The effect of overexpression and interference of lncRNA CCAT1 on the proliferation of Bew and JEG-3 cells was observed. The effect of CCAT1 on cell cycle was examined by cell cycle assay. The protein expression was accessed by Western blot. Higher lncRNA CCAT1 expression was found in preeclampsia patients. The systolic blood pressure, diastolic blood pressure and urine protein in preeclampsia patients were significantly higher than those in normal pregnant women. The birth weight of fetus was significantly lower than that of normal pregnant women. However, there was no significant difference in weight and age of patients. According to the CCAT1 expression, preeclampsia patients were assigned into high expression group and low expression group. Higher systolic blood pressure, diastolic blood pressure, and urinary protein levels in CCAT1 high expression group were observed comparing to those in low expression group, while the birth weight in low expression group was significantly higher than the high expression group. In addition, we found that after interference with CCAT1, trophoblast proliferation was significantly increased and cell cycle was significantly accelerated, whereas overexpression of CCAT1 led to the contrary. Western blotting indicated that the expressions of E2F1, cyclin D, CDK2 and CDK4 in BeWo cells were increased after CCAT1 was knocked down. The expressions of E2F1, cyclin D, CDK2 and CDK4 in JEG3 cells were decreased after CCAT1 was overexpressed. LncRNA CCAT1 was highly expressed in preeclampsia and can promote the progression of preeclampsia by inhibiting the expression of CDK4.

Upregulation of long non-coding RNA CCAT1 promotes proliferation and metastasis of esophageal squamous cell carcinoma cells by regulating the miR-543/KRAS axis

// Yu Mao 1 , Lixin Dong 1 , Jia Liu 2 , Liang Li 3 , Le Wang 4 , Yan Zhou 5 , Yanqiu Zhang 1 , Sen Yang 1 , Liyan Cao 1 , Chao Wang 6 and Zhanzhao Fu 1 1 Department of Oncology, The First Hospital of Qinhuangdao, Qinhuangdao, Hebei, China 2 Institute of Basic Medical Sciences, Qilu Hospital, Shandong University, Jinan, China 3 Department of Ultrasound, Beijing Anzhen Hospital, Capital Medical University, Beijing, China 4 Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin Neurological Institute and Laboratory of Neuro-Oncology, Tianjin, China 5 Department of Oncology Radiation, Tianjin Medical University General Hospital, Tianjin, China 6 Department of Thoracic Surgery, The First Hospital of Qinhuangdao, Qinhuangdao, China Correspondence to: Zhanzhao Fu, email: doctors12email@163.com Keywords: ESCC; progression; long non-coding RNA; CCAT1 Received: February 27, 2017 Accepted: August 23, 2017 Published: January 02, 2018 ABSTRACT Dysregulation of long non-coding RNA (lncRNAs) plays vital roles in tumorigenesis and cancer progression. Previous studies have identified the role of the lncRNA CCAT1 as an oncogene in several cancer types, and ectopic expression of CCAT1 predicts a poor prognosis. This study sought to determine the underlying mechanism for this observation in esophageal squamous cell carcinoma (ESCC). We found that CCAT1 was significantly upregulated in human ESCC tumor tissues and cell lines. LncRNA CCAT1 overexpression enhanced cell proliferation, migration, and invasion in vitro and in vivo . Our bioinformatics analysis and RNA immunoprecipitation assays combined with dual-luciferase assays revealed that CCAT1 functions as a microRNA (miRNA) sponge for miR-543. Increased CCAT1 antagonized the functions of miRNA-543 and led to de-repression of its downstream target, KRAS, which is a core oncogene that facilitates ESCC progression. Our findings suggest that CCAT1 increases KRAS expression by sponging miR-543 and thus promotes ESCC progression. This study sheds light on the potential role of lncRNAs as a novel prognostic biomarker and provides a new therapeutic target for ESCC.

Correction: Prognostic value of long non-coding RNA CCAT1 expression in patients with cancer: A meta-analysis.

[This corrects the article DOI: 10.1371/journal.pone.0179346.].

Long noncoding RNA CCAT1 functions as a ceRNA to antagonize the effect of miR-410 on the down-regulation of ITPKB in human HCT-116 and HCT-8 cells.

Colorectal cancer is one of the most common malignancies, which has seriously affected people's health. Abnormal expression of long non-coding RNAs and microRNAs are closely related to the process of occurrence, development, invasion and metastasis of colorectal cancer. However, the effect of lnc CCAT1 on human HCT-116/HCT-8 cells and its potential mechanism were investigated. In present study, differential expression of CCAT1, miR-410 and ITPKB were detected in colon cancer tissues and adjacent parts. Then the prediction programs were applied to predict the target genes of miR-410. The complementary bindings of miR-410 with lnc CCAT1 and ITPKB were assessed by luciferase assays. The interaction between LncRNA CCAT1 and miR-410 was analyzed. In addition, the mRNA and protein of ITPKB and apoptosis factors were examined in cells after miR-410 overexpression or silencing. Meanwhile, MTT and flow cytometer were used to detect the cells proliferation and apoptosis level. Results showed that CCAT1 and miR-410 were up-regulated in colon cancer tissues, but ITPKB was down-regulated. Lnc CCAT1 and ITPKB were predicted to be the targets of miR-410 and the prediction were verified by luciferase assays. The expression of lnc CCAT1 and ITPKB were inhibited by miR-410 in human HCT-116/HCT-8 cells. Meanwhile, lnc CCAT1 could lead to a decrease of miR-410. Furthermore, miR-410 overexpression could promote cell proliferation and reduce apoptosis. In summary, these data demonstrated that miR-410 could promote cell proliferation and reduce apoptosis by inhibiting ITPKB expression and the expression of lnc CCAT1 antagonized the effect of miR-410.