Long non-coding RNA CCAT1 promotes gallbladder cancer development via negative modulation of miRNA-218-5p

Long non-coding RNAs in Oral squamous cell carcinoma: biologic function, mechanisms and clinical implications

There is growing evidence that regions of the genome that cannot encode proteins play an important role in diseases. These regions are usually transcribed into long non-coding RNAs (lncRNAs). LncRNAs, little or no coding potential, are defined as capped transcripts longer than 200 nucleotides. New sequencing technologies have shown that a large number of aberrantly expressed lncRNAs are associated with multiple cancer types and indicated they have emerged as an important class of pervasive genes during the development and progression of cancer. However, the underlying mechanism in cancer is still unknown. Therefore, it is necessary to elucidate the lncRNA function. Notably, many lncRNAs dysregulation are associated with Oral squamous cell carcinoma (OSCC) and affect various aspects of cellular homeostasis, including proliferation, survival, migration or genomic stability. This review expounds the up- or down-regulation of lncRNAs in OSCC and the molecular mechanisms by which lncRNAs perform their function in the malignant cell. Finally, the potential of lncRNAs as non-invasive biomarkers for OSCC diagnosis are also described. LncRNAs hold promise as prospective novel therapeutic targets, but more research is needed to gain a better understanding of their biologic function.

The functions and oncogenic roles of CCAT1 in human cancer

In various human cancers, long non-coding RNAs (lncRNAs), a novel class of RNAs longer than 200 nucleotides without protein-coding potential, are implicated in a variety of biological processes, such as cell proliferation, invasion, metastasis, and apoptosis through regulation of gene expression at various levels including chromatin, splicing, transcriptional and post-transcriptional levels. However, the mechanisms underlying these are still elusive. Colon cancer-associated transcript 1(CCAT1) has received increased attention among those lncRNAs. Studies have shown high expression pattern and oncogenic role of CCAT1 in different types of cancer, and aberrant expression of CCAT1 has been involved in tumor-genesis, progression, metastasis, and patient survival via regulating different target genes and signaling pathways. In this review, we first introduce the concept, identification, and biological function of CCAT1; we then describe the mechanisms by which CCAT1 regulate the cancer proliferation and progression. In the last, we discuss emerging insights into the role of CCAT1 as potential biomarker and therapeutic target for novel treatment paradigms in cancer.

Red-emitting FIT-PNAs: "On site" detection of RNA biomarkers in fresh human cancer tissues

To date, there are limited approaches for the direct and rapid visualization (on site) of tumor tissues for pathological assessment and for aiding cytoreductive surgery. Herein, we have designed FIT-PNAs (forced-intercalation-peptide nucleic acids) to detect two RNA cancer biomarkers. Firstly, a lncRNA (long noncoding RNA) termed CCAT1, has been shown as an oncogenic lncRNA over-expressed in a variety of cancers. The latter, an mRNA termed KRT20, has been shown to be over-expressed in metastases originating from colorectal cancer (CRC). To these FIT-PNAs, we have introduced the bis-quinoline (BisQ) cyanine dye that emits light in the red region (605-610 nm) of the visible spectrum. Most strikingly, spraying fresh human tissue taken from patients during cytoreductive surgery for peritoneal metastasis of colon cancer with an aqueous solution of CCAT1 FIT-PNA results in bright fluorescence in a matter of minutes. In fresh healthy tissue (from bariatric surgeries), no appreciable fluorescence is detected. In addition, a non-targeted FIT-PNA shows no fluorescent signal after spraying this FIT-PNA on fresh tumor tissue emphasizing the specificity of these molecular sensors. This study is the first to show on-site direct and immediate visualization of an RNA cancer biomarker on fresh human cancer tissues by topical application (spraying) of a molecular sensor.

LncRNA Linc00511 promotes osteosarcoma cell proliferation and migration through sponging miR-765

Long noncoding RNA (lncRNA) Linc00511 is a novel lncRNA, and it was reported to play important roles in the progression and carcinogenesis of several tumors. However, the expression and biological roles of Linc00511 in osteosarcoma were still unknown. In this research, we showed that the expression of Linc00511 was upregulated in osteosarcoma samples and cell lines. Ectopic expression of Linc00511 promoted osteosarcoma cell growth, colony formation, and migration. Moreover, overexpression of Linc00511 enhanced the epithelial-mesenchymal transition progression in osteosarcoma cell. In addition, we showed that elevated expression of Linc00511 suppressed microRNA-765 (miR-765) expression and promoted apurinic/apyrimidinic endonuclease 1 (APE1) expression in osteosarcoma cell. The expression of miR-765 was downregulated in osteosarcoma cells and samples and was negatively related to Linc00511 expression in osteosarcoma tissues. Ectopic expression of miR-765 inhibited osteosarcoma cell growth and migration. Furthermore, we showed that Linc00511 overexpression promoted MG-63 cells proliferation, colony formation, and migration via downregulation of miR-765. These results suggested that Linc00511 played as an oncogene in the development of osteosarcoma.

lncRNA CCAT1 promotes bladder cancer cell proliferation, migration and invasion

OBJECTIVE

To study the expression patterns of long noncoding RNA (lncRNA) colon cancer-associated transcript 1 (CCAT1) and the changes in cell proliferation, apoptosis, migration and invasion induced by silencing CCAT1 in bladder cancer cells.

MATERIALS AND METHODS

The expression levels of CCAT1 were determined using realtime quantitative polymerase chain reaction in cancerous tissues and paired normal tissues from 34 patients with bladder cancer. The relationship between clinical characteristics and CCAT1 expression was analyzed. And then we conducted cell experiments. Bladder urothelial carcinoma cell lines T24 and 5637 cells were transfected with CCAT1 small interfering RNA (siRNA) or scramble siRNA. Cell proliferation and apoptosis changes were determined using a Cell Counting Kit-8 (CCK-8) assay and a fl ow cytometry assay. Migration and invasion changes were measured using a wound healing assay and a trans-well assay. microRNAs (miRNAs) were predicted by Starbase 2.0, and their differential expression levels were studied.

RESULTS

CCAT1 was signifi cantly upregulated in bladder cancer (P < 0.05). CCAT1 upregulation was positively related to tumor stage (P = 0.004), tumor grade (P = 0.001) and tumor size (P = 0.042). Cell proliferation, migration and invasion were promoted by abnormally expressed CCAT1. miRNAs miR-181b-5p, miR-152-3p, miR-24-3p, miR-148a-3p and miR-490-3p were potentially related to the aforementioned functions of CCAT1.

CONCLUSION

CCAT1 plays an oncogenic role in urothelial carcinoma of the bladder. In addition, CCAT1 may be a potential therapeutic target in this cancer.

Long Noncoding RNA MALAT1 Acts as a Competing Endogenous RNA to Regulate TGF-β2 Induced Epithelial-Mesenchymal Transition of Lens Epithelial Cells by a MicroRNA-26a-Dependent Mechanism

The aim of the present study was to characterize whether the long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/miR-26a/Smad4 axis is involved in epithelial–mesenchymal transition (EMT) of lens epithelial cells (LECs). Primary human LECs were separated and cultured. Microarray analysis showed that a total of 568 lncRNAs are differentially expressed in primary HLECs in the presence of TGF-β2 and MALAT1 is mostly significantly dysregulated lncRNAs, which is increased by nearly 17-fold. In addition, upregulation of MALAT1 and downregulation of miR-26a were detected in human posterior capsule opacification (PCO) attached LECs and the LECs obtained from patients with anterior polar cataracts by quantitative RT-PCR (qRT-PCR). Next, our results showed that TGF-β2 induces overexpression of EMT markers in primary HLECs via a MALAT1-dependent mechanism. The mechanism is that MALAT1 negatively regulates miR-26a and miR-26a directly targets Smad4 by luciferase reporter assays and RNA-binding protein immunoprecipitation assay. In summary, TGF-β2 induces MALAT1 overexpression, which in turn MALAT1 acts as a ceRNA targeting Smad4 by binding miR-26a and promotes the progression of EMT of LECs.

CCAT1 lncRNA Promotes Inflammatory Bowel Disease Malignancy by Destroying Intestinal Barrier via Downregulating miR-185-3p

BACKGROUND

The long noncoding RNA (lncRNA) colon cancer-associated transcript-1 (CCAT1) has been reported to play a vital role in the development of cancer. Although the link between inflammation and cancer initiation is well established, whether CCAT1 is involved in inflammation and promotes inflammatory bowel disease (IBD) malignancy remains undetermined. We aimed to investigate the expression of CCAT1 in IBD and the effect of CCAT1 overexpression on intestinal epithelial barrier function.

METHODS

The relationship between CCAT1 and the inflammation-related pathway was analyzed in both colorectal cancer (CRC) and IBD patients. Gene expression was detected by real-time polymerase chain reaction and Western blot. Transepithelial electrical resistance (TEER) and FD-4 flux measurement were used to test the effect of CCAT1 and miR-185-3p on intestinal epithelial barrier function. Luciferase assay was performed to validate the target site of miR-185-3p on 3'-UTR of MLCK mRNA.

RESULTS

Gene set enrichment analysis revealed that several inflammation-related genes were enriched in the CCAT1 high-expressed group of CRC patients. The relationship between CCAT1 and inflammation activation in IBD patients was further confirmed. CCAT1 expression positively correlated with MLCK, which acts as a protein kinase to phosphorylate myosin light chain and induces tight junction protein distribution, whereas it was negatively correlated with miR-185-3p in IBD tissues. We also determined that CCAT1 overexpression increased Caco-2 monolayer permeability and upregulated MLCK. Furthermore, CCAT1-induced MLCK overexpression and IBD disease progression were significantly attenuated by miR-185-3p.

CONCLUSIONS

The CCAT1/miR-185-3p/MLCK signaling pathway is strongly activated to destroy barrier function and promotes the pathogenesis of IBD.

Analysis of long non-coding RNAs in neonatal piglets at different stages of porcine deltacoronavirus infection

BACKGROUND

PDCoV (Porcine Deltacoronavirus) is a novel porcine coronavirus that causes intestinal necrosis of piglets, thinning of the intestinal wall and severe villus atrophy in the small intestine. PDCoV is a highly contagious infectious disease characterized by diarrhea, dehydration and vomiting. It has been reported that lncRNA has a significant effect on viral replication and increased or decreased virulence. At present, there is almost no research on lncRNA related to PDCoV infection. With the development of the research, a large number of lncRNAs related to PDCoV infection have been discovered. Identifying the role of these lncRNAs in the infection process facilitates the screening of diagnostically significant biomarkers.

RESULTS

Using high throughput sequencing to screen differentially expressed long non-coding RNA (lncRNA) during PDCoV infection, we identified 99, 41 and 33 differentially expressed lncRNAs in the early, middle and late stages of infection, respectively. These lncRNAs were involved in glycolysis / gluconeogenesis, histidine metabolism and pentose and Chloroalkane and chloroalkene degradation pathway. We obtained expression data of miRNAs, lncRNAs and mRNAs during PDCoV infection and constructed and investigated an interaction network. The qRT-PCR validation results of 6 differentially expressed lncRNAs were consistent with RNA-Seq results.

CONCLUSIONS

This study is the first to examine differentially expressed lncRNAs after PDCoV infection of piglets. These results can provide new insights into PDCoV infection and antiviral strategies.

HULC functions as an oncogene in ovarian carcinoma cells by negatively modulating miR-125a-3p

The aberrant expression of highly upregulated in liver cancer (HULC) has been reported to participate in ovarian cancer development. A recent research has revealed that HULC-modulated microRNAs (miRNAs) in tumorigenesis. To confirm the functions of HULC on tumorigenesis of ovarian, we explored the effects of HULC expression on ovarian cancer cell development, as well as the underlying mechanism. We transfected SKOV3 cells with pEX-HULC, sh-HULC, and miR-125a-3p mimic as well as their corresponding negative controls (pEX-3, sh-NC, and NC) to alter the expression of HULC and miR-125a-3p, which were analyzed by quantitative reverse transcription PCR (qRT-PCR). Expression of proteins associated with cell cycle, apoptosis, and signaling pathways was determined by Western blot assay. The proliferation, apoptosis, migration, and invasion were explored by bromodeoxyuridine (BrdU) incorporation assay, Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) method, and transwell migration and invasion assays, respectively. HULC overexpression promoted proliferation, migration, and invasion, while inhibited apoptosis of SKOV3 cells. In addition, HULC negatively regulated the expression of miR-125a-3p. Besides, miR-125a-3p mimic reversed the effects of HULC on proliferation, migration, and invasion as well as apoptosis of SKOV3 cells. Moreover, we found that HULC enhanced phosphorylated expression of regulatory factors in phosphatidylinositol 3 kinase/protein kinase B/mammalian targets of rapamycin (PI3K/AKT/mTOR) signaling pathway by downregulating expression of miR-125a-3p. Overexpression of HULC promoted ovarian carcinoma development by activating PI3K/AKT/mTOR signaling pathway via downregulating miR-125a-3p.

Correlations of lncRNAs with cervical lymph node metastasis and prognosis of papillary thyroid carcinoma

Background

Cervical lymph node metastasis is an important prognostic indicator for papillary thyroid carcinoma (PTC) and affects treatment strategies for PTC. lncRNAs essentially contribute to the biological functions of tumors. This study aimed to identify the lncRNAs associated with cervical lymph node metastasis and prognosis of PTC and their potential pathophysiological mechanisms.

Materials and methods

PTC-associated lncRNAs were selected from The Cancer Genome Atlas database, and correlations among lncRNAs, lymph node metastasis, tumor staging, and prognosis of PTC were analyzed in silico. These correlations were then validated through quantitative reverse transcription PCR (qRT-PCR) and immunohistochemistry (IHC).

Results

In silico analysis showed that FAM95B1 and UCA1 were significantly correlated with cervical lymph node metastasis, tumor staging, and PTC prognosis (P<0.05). qRT-PCR analysis revealed high UCA1 expression in PTC tissues and correlations between UCA1 expression levels and cervical lymph node metastasis and tumor staging in PTC, that is, higher UCA1 expression resulted in poorer PTC prognosis. IHC analysis revealed that a high expression of UCA1 was accompanied by a high expression of metastasis-related proteins (MMP-2 and MMP-9), thereby validating the correlation of UCA1 expression with metastasis.

Conclusion

FAM95B1 and UCA1 expression was significantly correlated with the occurrence and progression of PTC. The expression levels of UCA1 significantly affected the prognosis of PTC patients and were significantly correlated with tumor staging and cervical lymph node metastasis.

Upregulated long noncoding RNA LOC105375913 induces tubulointerstitial fibrosis in focal segmental glomerulosclerosis

Tubulointerstitial fibrosis impacts renal prognosis of focal segmental glomerulosclerosis (FSGS). Based on transcriptomic analysis, we found that the level of LOC105375913 was increased in tubular cells of FSGS patients. C3a induced the expression of LOC105375913, which promoted the expression of fibronectin and collagen I in tubular cells. Silence of snail reversed the level of fibronectin and collagen I in cells overexpressing LOC105375913. MiR-27b was predicted and confirmed to regulate the expression of snail in tubular cells, and LOC105375913 contained the response element of miR-27b. The competitive binding between LOC105375913 and miR-27b increased the level of snail and promoted fibrogenesis in tubular cells. Upstream, p38 and XBP-1s regulated the expression of LOC105375913. Inhibition of p38 or silence of XBP-1s decreased the level of LOC105375913, and suppressed the expression of snail, fibronectin and collagen I in tubular cells treated with C3a. Overexpression of LOC105375913 decreased the level of miR-27b, increased the level of snail and caused tubulointerstitial fibrosis in mice. In conclusion, the activation of C3a/p38/XBP-1s pathway induces the expression of LOC105375913 in tubular cells, and LOC105375913 increases the level of snail and induces tubulointerstitial fibrosis through competitive binding of miR-27b in tubular cells of FSGS patients.

LncRNA NORAD promotes thyroid carcinoma progression through targeting miR-202-5p

Long noncoding RNAs (lncRNAs) have been shown to have several functional roles in tumor biology, and they are deregulated in many types of cancer. The role of a novel lncRNA, NORAD, in papillary thyroid carcinoma (PTC) is still unknown. In this study, we demonstrated that NORAD expression was upregulated in PTC cell lines and samples. Ectopic expression of NORAD promoted PTC cell growth, invasion and migration. Overexpression of NORAD promotes epithelial-to-mesenchymal transition (EMT) progression in the PTC cell. Furthermore, overexpression of NORAD suppressed miR-202-5p expression in PTC cells. The data suggested that miR-202-5p expression was downregulated in PTC cell lines and samples and was negatively correlated with NORAD expression in PTC tissues. Overexpression of miR-202-5p suppressed PTC cell growth, invasion and migration. In addition, we demonstrated that elevated expression of NORAD promoted PTC cell growth, invasion and migration by inhibiting miR-202-5p expression. These results suggested that the lncRNA NORAD acts as an oncogene in PTC progression, partly by regulating miR-202-5p expression.

Ginsenoside Rg3 inhibits cell growth, migration and invasion in Caco-2 cells by downregulation of lncRNA CCAT1

BACKGROUND

Colorectal cancer (CRC) is a troublesome disease with high morbidity and mortality. Ginsenoside Rg3 possesses anti-cancer properties. Colon Cancer Associated Transcript 1 (CCAT1) participates in the genesis, development, invasion and metastasis of colorectal cancer. In our study, we explored the effects of Rg3 on CRC cell line Caco-2 by regulating CCAT1.

METHODS

CRC tissue was obtained from hospital and Caco-2 cells were purchased. Caco-2 cells were treated with Rg3 and/or transfected with pc- CCAT1 or pcDNA3.1. The group without Rg3 treatment was treated as control. Cell viability, cell apoptosis, cell migration and invasion were detected by Cell Counting Kit-8 assay, flow cytometry and Transwell chamber migration/invasion assay, respectively. The expression of CyclinD1, apoptosis related proteins (p53, Bcl-2, Bax, pro-/Cleaved-Caspase-3), migration and invasion related proteins (MMP-9 and vimentin), and phosphatidylinositol 3'-kinase (PI3K)/protein kinase B (AKT) related proteins (p/t-PI3K, p/t-AKT) were examined by western blot. The expression of CCAT1 was measured by quantitative real time RCR (qRT-PCR).

RESULTS

Rg3 significantly decreased cell viability, migration and invasion, and promoted apoptosis. Meanwhile, the expression of Cyclin D1, matrix metalloproteinase (MMP)-9 and vimentin was downregulated. The expression of apoptosis-related proteins p53, Bax, and Cleaved-Caspase-3 were upregulated while Bcl-2 was downregulated by the treatment of Rg3 compared with control. Furthermore, CCAT1 was upregulated in CRC tissue and Rg3 negatively regulated CCAT1 expression. Transfection with pc-CCAT1 led to the opposite results as compared with transfection with pcDNA3.1 in Rg3 treated cells. In addition, Rg3 decreased the phosphorylation of PI3K and AKT.

CONCLUSION

Ginsenoside Rg3 inhibits migration and invasion, and promotes apoptosis of Caco-2 cells by suppression expression of LncRNA CCAT1.

Effects of microRNA-513b on cell proliferation, apoptosis, invasion, and migration by targeting HMGB3 through regulation of mTOR signaling pathway in non-small-cell lung cancer

This study aimed to explore the underlying mechanism of miR-513b and HMGB3 in regulating non-small-cell lung cancer (NSCLC). NSCLC tumor, adjacent tissues, and cell lines were extracted, and the expression of miR-513b and HMGB3 were determined by quantitative real-time polymerase chain reaction (RT-qPCR) and western blot analysis. Then, miR-513b was overexpressed in NSCLC cell, and the proliferation, migration, invasion, and apoptosis of cells were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), wound healing, transwell, and flow cytometry, respectively. Regulatory relationship between miR-513b and HMGB3 was determined using luciferase activity reporter assay. Lastly, HMGB3 and/or miR-513b were overexpressed in NSCLC cells, and the proliferation, migration, invasion, and apoptosis of cells were determined. Compared with the controls, the expression of miR-513b was significantly downregulated in the NSCLC tissues and cells lines by RT-qPCR ( p < 0.05). However, the expression of HMGB3 was significantly downregulated at both messenger RNA and protein levels ( p < 0.05). Overexpression of miR-513b could significantly inhibit the proliferation, invasion, migration, and promote apoptosis of NSCLC cells ( p < 0.05). HMGB3 was a target of miR-513b, and overexpression of HMGB3 could obviously reverse the effect of miR-513 on the proliferation, invasion, migration, and apoptosis of NSCLC cells ( p < 0.05). The present results could suggest miR-513b was downregulated in NSCLC and could regulate the proliferation, invasion, migration, and apoptosis of NSCLC cells via HMGB3.

Endometrial Epithelial Cell Apoptosis Is Inhibited by a ciR8073-miR181a-Neurotensis Pathway during Embryo Implantation

Development of the receptive endometrium (RE) from the pre-receptive endometrium (PE) is essential for embryo implantation, but its molecular mechanisms have not been fully understood. In this study, lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA networks were constructed to explore the functions of potential competing endogenous RNAs (ceRNA) during the development of RE in dairy goats. We observed that circRNA8073 (ciR8073) decreased the levels of miR-181a by acting as a miRNA sponge. This effect indirectly increased the expression of neurotensin in endometrial epithelial cells (EECs). Neurotensin then inhibited EEC apoptosis by increasing the expression of BCL-2/BAX in favor of BCL-2 via the MAPK pathway and also induced increased expression of leukemia-inhibitory factor, cyclo-oxygenase 2, vascular endothelial growth factor A, and homeobox A10. We have thus identified a ciR8073-miR181a-neurotensin pathway in the endometrium of dairy goats. Through this pathway, ciR8073 functions as a ceRNA that sequesters miR-181a, thereby protecting neurotensin transcripts from miR-181a-mediated suppression in EECs.

Pivotal prognostic and diagnostic role of the long non‑coding RNA colon cancer‑associated transcript 1 expression in human cancer (Review)

Long non‑coding RNAs (lncRNAs) have been classically defined as regulatory RNA members >200 nucleotides in length, without detectable open‑reading frames to encode proteins. Previous studies have demonstrated that lncRNAs serve critical roles in multiple cancer types. Colon cancer‑associated transcript 1 (CCAT1), a novel cancer‑associated lncRNA, is significantly overexpressed in a number of malignancies. Functionally, as an oncogenic lncRNA, CCAT1 is involved in proliferation, migration, cell cycle progression, apoptosis, chemoresistance and other biological processes of cancer cells through complex regulation mechanisms in the cytoplasm or nucleus. In clinical applications, CCAT1 is additionally positively associated with histological differentiation, tumour node metastasis stage, vascular invasion, overall survival and recurrence‑free survival, which demonstrates its important role as a diagnostic and prognostic marker in cancer. The present review summarises the current research progress of the oncogenic potential and clinical uses of CCAT1 in various human cancer types.

Overexpression of lncRNA EGFR‑AS1 is associated with a poor prognosis and promotes chemotherapy resistance in non‑small cell lung cancer

Chemoresistance is one of the most important biological elements affecting the progression and prognosis of cancer. Long non‑coding RNAs (lncRNAs) are important regulators and are aberrantly expressed in various types of cancer in humans, including non‑small cell lung cancer (NSCLC). The present study aimed to investigate the effect of lncRNAs on NSCLC resistance to chemotherapy. The relative expression level of epidermal growth factor receptor antisense RNA 1 (EGFR‑AS1) was quantified by reverse transcription-quantitative polymerase chain reaction analysis in NSCLC tissues, paired adjacent normal tissues, patient plasma and NSCLC cell lines, and its association with prognosis was assessed by multivariate analysis. The biological functions of EGFR‑AS1 in NSCLC cells were determined in vitro. It was found that EGFR‑AS1 was abnormally upregulated in NSCLC tissues compared with adjacent normal lung tissues. Furthermore, patients with NSCLC with increased expression of EGFR‑AS1 had a poor prognosis. EGFR‑AS1 knockdown significantly inhibited NSCLC malignancy in vitro, including cell proliferation and chemoresistance. Furthermore, the expression levels of EGFR‑AS1 were increased in plasma samples from patients with cisplatin-based chemotherapy resistance. Bioinformatics analysis and a luciferase reporter assay confirmed that EGFR‑AS1 mediated cell proliferation and chemoresistance through directly binding to microRNA‑223. Therefore, EGFR‑AS1 overexpression-induced chemoresistance can contribute to poor prognosis in NSCLC.

CX-3543 Promotes Cell Apoptosis through Downregulation of CCAT1 in Colon Cancer Cells

Aim

Colon cancer-associated transcript-1 (CCAT1), located in the vicinity of transcription factor c-Myc, was first identified in colon cancer. A small-molecule compound CX3543 (Quarfloxin) selectively targeting Myc G-quadruplexes has entered phase II clinical trials for neuroendocrine carcinomas. The aim of the study was to explore the relationship between CX3543, CCAT1, and cell apoptosis in colon cancer cells.

Methods

Semiquantitative PCR was used to detect the relative expression of CCAT1 in colon cancer (CC) tissues and HT29 cell lines. Real-time PCR (RT-PCR) was also used to investigate the expression of CCAT1 and c-Myc after HT29 cells being treated by CX3543 for 24 h. Cell apoptosis assay and cell proliferation assay were conducted in HT29 cells after being treated by CX3543.

Results

The results showed that the expression of CCAT1 was remarkably increased in CC tissues and HT29 cells compared to controls. CX3543 treatment reduced the expression of c-Myc and CCAT1 and promoted cell apoptosis and inhibited cell proliferation. After the expression of CCAT1 was inhibited by sh-CCAT1 transfection, the cell apoptosis rate was higher than that of control group. After the cells were treated by CCAT1 overexpression plasmid transfection and CX3543, the cell apoptosis rate was lower than that of control group. In vivo results showed that CX3543 inhibited the xenograft tumor growth of rats through downregulation of CCAT1.

Conclusion

Our study demonstrated that CX3543 could inhibit the progression of colon cancer by downregulating CCAT1 expression and might be a potential drug for the treatment of colon cancer.

The long noncoding RNA LOC105374325 causes podocyte injury in individuals with focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a common kidney disease that results in nephrotic syndrome. FSGS arises from dysfunction and apoptosis of podocytes in the glomerulus of the kidney, leading to podocytopathy. The molecular mechanisms underlying podocyte apoptosis remain incompletely understood. Using an array of gene expression profiling, PCR, and in situ hybridization assay, we found here that the levels of the long noncoding RNA LOC105374325 were elevated in the renal podocytes of individuals with FSGS. We also observed that the microRNAs miR-34c and miR-196a/b down-regulated the expression of the apoptosis regulators BCL2-associated X, apoptosis regulator (Bax), and BCL2 antagonist/killer 1 (Bak) in podocytes. Competitive binding between LOC105374325 and miR-34c or miR-196a/b increased Bax and Bak levels and caused podocyte apoptosis. Of note, the mitogen-activated protein kinase P38 and the transcription factor CCAAT enhancer-binding protein β (C/EBPβ) up-regulated LOC105374325 expression. P38 inhibition or C/EBPβ silencing decreased LOC105374325 levels and inhibited apoptosis in adriamycin-treated podocytes. LOC105374325 overexpression decreased miR-34c and miR-196a/b levels, increased Bax and Bak levels, and induced proteinuria and focal segmental lesions in mice. In conclusion, activation of the P38/C/EBPβ pathway stimulates the expression of LOC105374325, which, in turn, increases Bax and Bak levels and causes apoptosis by competitively binding to miR-34c and miR-196a/b in the podocytes of individuals with FSGS.

Long non-coding RNA ANRIL promotes tumorgenesis through regulation of FGFR1 expression by sponging miR-125a-3p in head and neck squamous cell carcinoma

ANRIL (CDKN2B antisense RNA 1, CDKN2B-AS1) is involved in the progression of various cancers. However, its role in head and neck squamous cell carcinoma (HNSCC) remains unclear. In this study, we found that ANRIL expression was upregulated in HNSCC and correlated with tumor progression. Further functional analysis showed that knockdown of ANRIL significantly inhibited proliferation in vivo and in vitro. ANRIL functioned as a ceRNA (competing endogenous RNAs) for miR-125a-3p and upregulated FGFR1 (fibroblast growth factor receptor-1), which could promote tumor growth. Moreover, we confirmed that ANRIL promoted HNSCC activity via FGFR1 with a FGFR1 inhibitor in vivo and in vitro. Thus, it could be concluded that ANRIL promoted the progression of HNSCC via miR-125a-3p/FGFR1/MAPK signaling, which might provide a new target for the diagnosis and treatment of HNSCC.

Down-regulation of long non-coding RNA GAS5-AS1 and its prognostic and diagnostic significance in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common solid tumor in global range, with high degree of malignancy and poor prognosis. But the relationship between the expression of GAS5-AS1 and HCC is not documented. This study aimed to profile GAS5-AS1 expression signature and then to explore its clinical significance in HCC.

METHODS

Quantitative real-time PCR (RT-qPCR) was performed to detect the expression of GAS5-AS1 in 83 pairs of HCC surgical tissues and adjacent normal liver tissues. We also performed RT-qPCR on plasma samples of 156 patients and 58 healthy controls.

RESULTS

We found that GAS5-AS1 was down-regulated in HCC tissues (P< 0.01). Correlation analysis showed that the expression of GAS5-AS1 was notably associated with differentiation (High/Moderate vs Low, P= 0.031), tumor-node-metastasis (TNM) stage (I∼II vs III∼IV, P= 0.020) and glucose levels (< 6.2 vs≧ 6.2, P= 0.047) in HCC patients. The overall survival analysis showed that patients with lower GAS5-AS1 expression had a relatively poor prognosis. Univariate and multivariate analysis elaborated that GAS5-AS1 was an independent prognostic factor for HCC patients. The area under the ROC (AUCROC) demonstrated that GAS5-AS1 presented a high accuracy (AUC = 0.824, 95% CI: 0.741-0.906) for distinguishing HCC from the cirrhosis. When differentiating HCC cases with AFP < 200 ng/ml from the cirrhosis and hepatitis B whose AFP levels were also below 200 ng/ml, GAS5-AS1 had the high sensitivity (89.5%, 89.5%, respectively).

CONCLUSIONS

GAS5-AS1 could be considered as a potential prognostic and diagnostic marker in HCC. However, the potential clinical application value of GAS5-AS1 still needs to be further illustrated.

The emerging roles of long non-coding RNA in gallbladder cancer tumorigenesis

Accumulating evidence suggests that long non-coding RNAs (lncRNAs) have important regulatory functions in gallbladder cancer (GBC) tumorigenesis and can serve as potential novel markers and/or targets for GBC. In this review, we critically discuss the emerging alteration of lncRNAs in GBC, the lncRNAs induced epigenetic regulation, the interaction of lncRNAs with microRNAs and lncRNAs effects on tumor-related signaling pathways. Additionally, contributions of lncRNAs in epithelial-mesenchymal transition process and energy metabolism reprogramming in GBC are also addressed. This may pave new ways towards the determination of GBC pathogenesis and lead to the development of new preventive and therapeutic strategies for GBC.

Role of Long Noncoding RNA 799 in the Metastasis of Cervical Cancer through Upregulation of TBL1XR1 Expression

Long noncoding RNAs (lncRNAs) are closely associated with the molecular mechanisms underlying cancer development, and it would be highly useful to study their expression and mechanisms in cervical cancer too. The current study investigated lncRNA799 expression in cervical cancer in order to determine its clinical importance in the progression of cervical cancer. lncRNA799 expression was studied in 218 cervical cancer samples. Expression of lncRNA799 was significantly higher in the cervical cancer tissue than in the adjacent normal tissue. Overexpression of lncRNA799 was found to have a significant correlation with FIGO stage, SCC-Ag level, and lymphatic metastasis, and it was also associated with poor survival. Ectopic expression of lncRNA799 promoted the metastasis of SiHa cells, whereas lncRNA799 knockdown had an inhibitory effect on metastasis. Western blot analysis demonstrated that lncRNA799 promotes the expression of transducing β-like protein 1-related protein (TBL1XR1), and that lncRNA799 and TBL1XR1 expression show strong correlation in cervical cancer. Moreover, lncRNA799 modulated the expression of TBL1XR1 by acting as a competitive endogenous RNA (ceRNA) for miR-454-3P. The results indicate that lncRNA799 could be used as a novel marker of cervical cancer prognosis. Thus, targeting the ceRNA network involving lncRNA799 could be a potential treatment strategy against cervical cancer.

Long noncoding RNA MEG3 regulates LATS2 by promoting the ubiquitination of EZH2 and inhibits proliferation and invasion in gallbladder cancer

Gallbladder cancer (GBC) is the most common type of biliary tract cancer worldwide. Long noncoding RNAs (lncRNAs) play essential roles in physiological and pathological development. LncRNA MEG3, a tumor suppressor, has been reported to play important roles in some cancers, but the role of MEG3 in GBC remains largely unknown. The purpose of the present study was to explore the role of MEG3 in proliferation and invasion and the potential molecular mechanism in GBC. We found that MEG3 was downregulated in GBC tissues and cells, and low expression of MEG3 was correlated with poor prognostic outcomes in patients. Overexpression of MEG3 inhibited GBC cell proliferation and invasion, induced cell apoptosis and decreased tumorigenicity in nude mice. Moreover, we found that MEG3 was associated with EZH2 and attenuated EZH2 by promoting its ubiquitination. Furthermore, MEG3 executed its functions via EZH2 to regulate the downstream target gene LATS2. Taken together, these findings suggest that MEG3 is an effective target for GBC therapy and may facilitate the development of lncRNA-directed diagnostics and therapeutics against GBC.

Long non-coding RNA CRNDE promotes the proliferation, migration and invasion of hepatocellular carcinoma cells through miR-217/MAPK1 axis

Hepatocellular carcinoma (HCC) is an invasive malignant tumour and the second major cause of cancer‐related deaths over the world. CRNDE and miR‐217 are non‐coding RNAs which play critical roles in cell growth, proliferation, migration. Mitogen‐activated protein kinase 1 (MAPK1) also participates in cancer cell process. Hence, this study aimed at investigating the effect of CRNDE on migration and invasion of HCC and figuring out the role of miR‐217 and MAPK1 in this process. The overexpression of CRNDE was demonstrated by a microarray‐based lncRNA profiling study. CRNDE expression in HCC was verified by qRT‐PCR. MTT assay and BrdU staining were applied to detect cell proliferation level. Transwell assay was utilized to examine cell migration and invasiveness abilities. Wound healing assay was performed for further exploration of cell migration capacity. MiR‐217 was predicted by bioinformatics. The dual luciferase reporter assay was performed to corroborate the targeting relationship between CRNDE, miR‐217 and MAPK1. MAPK1, the downstream target of miR‐217, was predicted using bioinformatics and was further confirmed by qRT‐PCR and Western blot. The interaction between CRNDE, miR‐217 and MAPK1 was studied by qRT‐PCR, Western blot, MTT, BrdU, transwell assay and wound healing assay. CRNDE was up‐regulated in HCC tissues and HCC cell lines. The high expression of CRNDE facilitated cell proliferation, migration and invasion, while the inhibited one affected on the contrary. MiR‐217, negatively correlated with CRNDE expression, was the target of CRNDE and was more lowly expressed in HCC. With the high expression of miR‐217, HCC cell proliferation, migration and invasion were suppressed. MAPK1, the possible target of miR‐217, was negatively correlated with miR‐217 but positively correlated with CRNDE and had the same effect in HCC formation process as CRNDE. Long non‐coding RNA CRNDE promotes the proliferation, migration and invasion of HCC cells through miR‐217/MAPK1 axis.

The lncRNA CCAT1 upregulates TGFβR1 via sponging miR-490-3p to promote TGFβ1-induced EMT of ovarian cancer cells

Background

Ovarian cancer is the fifth leading cause of cancer deaths in women worldwide. LncRNACCAT1 was reported to play a critical role in cell metastasis of ovarian cancer. However, little is known about the detailed mechanism of how CCAT1 enhances TGFβ1-induced EMT of ovarian cancer cells.

Methods

We used RT-qPCR to examine the level of miR-490-3p and CCAT1 and western blot to detect the protein level of TGFβR1 and EMT-associated markers. We utilized luciferase reporter assay to confirm the direct interaction of CCAT1 or TGFβ1 with miR-490-3p. Wound healing and invasion assay were employed to investigate the role of CCAT1 and miR-490-3p in the TGFβ1-induced migration and cell invasion of ovarian cancer cells, respectively.

Results

TGFβ1 stimulated the expression of CCAT1. And CCAT1 knockdown decreased cell migration, invasion and EMT-associated markers expression of ovarian cancer cells treated with TGFβ1. CCAT1 directly targeted and downregulated miR-490-3p, then increasing TGFβR1 level. miR-490-3p was shown to regulate cell invasion, migration and EMT markers expression via TGFβR1. In addition, we also observed that miR-490-3p was essential for TGFβ1-induced tumor cell invasion and migration influenced by CCAT1. CCAT1 level was significantly higher in tumors than adjacent normal tissue, in contrast, miR-490-3p level was lower in ovarian tumors.

Conclusion

Here, we reveal that CCAT1 contributes to TGFβ1-induced EMT of ovarian tumor cells through miR-490-3p/TGFR1 axis. These findings will provide deep insights into the mechanism by which CCAT1 exerts its oncogenic role in ovarian cancer progression and facilitate developing novel therapeutical therapies for treating ovarian cancer.

Identification of abnormally expressed lncRNAs induced by PM2.5 in human bronchial epithelial cells

To investigate the effect of stimulation of human bronchial epithelial cells (HBECs) by arterial traffic ambient PM2.5 (TAPM2.5) and wood smoke PM2.5 (WSPM2.5) on the expression of long non-coding RNAs (lncRNAs) in order to find new therapeutic targets for treatment of chronic obstructive pulmonary disease (COPD). HBECs were exposed to TAPM2.5 and WSPM2.5 at a series of concentrations. The microarray analysis was used to detect the lncRNA and mRNA expression profiles. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and gene ontology (GO) enrichment were conducted to analyze the differentially expressed lncRNAs and mRNAs. Quantitative real-time PCR (qRT-PCR) was performed to confirm the differential expression of lncRNAs. Western blot was performed to study the expression of autophagy and apoptosis-associated proteins. Flow cytometry was used to detect the apoptotic cells. The results indicated that fine particulate matter (PM2.5)-induced cell damage of HBECs occurred in a dose-dependent manner. The microarray analysis indicated that treatment with TAPM2.5 and WSPM2.5 led to the alteration of lncRNA and mRNA expression profiles. LncRNA maternally expressed gene 3 (MEG3) was significantly up-regulated in HBECs after PM2.5 treatment. The results of Western blot showed that PM2.5 induced cell apoptosis and autophagy by up-regulating apoptosis-associated gene, caspase-3, and down-regulating autophagy-associated markers, Bcl-2 and LC3 expression. In addition, we demonstrated that TAPM2.5 and WSPM2.5 accelerated apoptosis of human bronchial (HBE) cells, silencing of MEG3 suppressed apoptosis and autophagy of HBE cells. These findings suggested that the lncRNA MEG3 mediates PM2.5-induced cell apoptosis and autophagy, and probably through regulating the expression of p53.

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 noncoding RNA MALAT1 acts as a competing endogenous RNA to regulate Amadori-glycated albumin-induced MCP-1 expression in retinal microglia by a microRNA-124-dependent mechanism

OBJECTIVE

To determine whether the long noncoding RNA MALAT1 may be involved in the inflammatory effect of Amadori-glycated albumin (AGA) in retinal microglia via a microRNA-124 (miR-124)-dependent mechanism.

METHODS

Diabetes mellitus was induced by streptozotocin (STZ) injection. The expression of monocyte chemotactic protein-1 (MCP-1) in the retinas of rats was determined using quantitative reverse transcription-PCR (qRT-PCR) analyses and enzyme-linked immunosorbent assay (ELISA). Both qRT-PCR and ELISA were used to detect the levels of MCP-1 mRNA and soluble MCP-1 protein in the primary rat retinal microglia treated with AGA. The regulation of a putative target of miR-124 was validated by luciferase reporter assays.

RESULTS

MALAT1 knockdown ameliorated diabetic retinopathy (DR) and inhibited MCP-1 release in the retinas of STZ-induced diabetic rats. The cultured retinal microglial cells treated with AGA-released MCP-1 in a dose- and time-dependent manner. In addition, AGA consistently induced MALAT1 expression in the retinal microglial cells. Next, we demonstrated that the expression of MCP-1 is controlled by miR-124, which binds to the 3'-UTR of MCP-1 in microglial cells. Luciferase reporter assays and RNA-binding protein immunoprecipitation assays showed that MALAT1 targets miR-124. Finally, we demonstrated that MALAT1 acts as a competing endogenous RNA by directly binding to miR-124 to regulate AGA-induced MCP-1 expression in microglial cells.

CONCLUSIONS

MALAT1-miR-124-MCP-1 signaling pathway may be involved in AGA-induced MCP-1 expression in microglial cells, which may provide a new approach for the treatment of DR.

Long Noncoding RNAs: Advances in Lipid Metabolism

Long noncoding RNAs (lncRNAs) are an important group of pervasive noncoding RNAs (>200nt) proposed to be crucial regulators of numerous physiological and pathological processes. Through interactions with RNA, chromatin, and protein, lncRNAs modulate mRNA stability, chromatin structure, and the function of proteins (including transcription factors). In addition, to their well-known roles in the modulation of cell growth, apoptosis, neurological disease progression and cancer metastasis, these large molecules have also been identified as likely mediators of lipid metabolism. In particular, lncRNAs orchestrate adipogenesis; fatty acid, cholesterol, and phospholipid metabolism and transport; and the formation of high-density and low-density lipoproteins (HDLs and LDLs). LncRNAs also appear to target several transcription factors that play essential roles in the regulation of lipid metabolism, such as liver X receptors (LXRs), sterol regulatory element binding proteins (SREBPs), and peroxisome proliferator-activated receptor γ (PPARγ). Better understanding the regulatory roles of lncRNAs in dyslipidemia, atherosclerosis, and adipogenesis will reveal appropriate strategies to treat these diseases. In this review, we review recent progress in lncRNA-mediated regulation of lipid metabolism, as well as its role in the regulation of adipogenesis.

LINC01287 regulates tumorigenesis and invasion via miR-298/MYB in hepatocellular carcinoma

Recently, it was reported that long non‐coding RNAs (lncRNAs) participated in promoting hepatocellular carcinoma (HCC) initiation and progression. Herein, we reported that the expression level of LINC01287 was elevated in HCC cell lines and tissues. LINC01287 down‐regulation inhibited HCC cells growth and invasion both in vitro and in vivo. LINC01287 exerted as a ceRNA and negatively regulated miR‐298 expression. MYB was identified as a downstream target of miR‐298. The miR‐298/MYB axis mediated LINC01287's effect on HCC. To the best of our knowledge, our findings provided the first evidence that LINC01287 functioned as an oncogene in HCC. LINC01287 may be a candidate prognostic biomarker and a target for new therapies in HCC patients.

Long noncoding RNA HEGBC promotes tumorigenesis and metastasis of gallbladder cancer via forming a positive feedback loop with IL-11/STAT3 signaling pathway

Background

Gallbladder cancer (GBC) is a highly malignant cancer with poor prognosis. Several long noncoding RNAs (lncRNAs) have been reported to be involved in the tumorigenesis and progression of GBC. However, the expressions, clinical significances, and roles of most other lncRNAs in GBC are still unknown.

Methods

The differentially expressed lncRNAs in GBC were screened through re-analyzing the public available microarray datasets. The expression of lncRNA high expressed in gallbladder cancer (lncRNA-HEGBC) in GBC was measured by qRT-PCR. The correlations between HEGBC with clinicopathological characteristics and prognosis were analyzed by Pearson chi-square test and log-rank test. A series of in vitro and in vivo, gain-of and loss-of function assays were performed to investigate the roles of HEGBC in GBC cell proliferation, apoptosis, migration, tumor growth and metastasis. The interactions between HEGBC and IL-11/STAT3 signaling were explored using chromatin isolation by RNA purification (ChIRP), chromatin immunoprecipitation (ChIP), enzyme linked immunosorbent assay (ELISA), qRT-PCR, western blot, and luciferase reporter assays.

Results

We identified a novel lncRNA HEGBC, which is upregulated in GBC and positively associated with advanced TNM stages and poor prognosis of GBC patients. Overexpression of HEGBC increased GBC cell viability, inhibited GBC cell apoptosis, promoted GBC cell migration, and promoted GBC tumor growth and metastasis in vivo. Conversely, depletion of HEGBC decreased GBC cell viability, promoted GBC cell apoptosis, inhibited GBC cell migration, and inhibited GBC tumor growth and metastasis in vivo. Mechanistic investigations showed that HEGBC bound to the promoter of IL-11, increased IL-11 transcription, induced IL-11 autocrine, and activated IL-11/STAT3 signaling pathway. Furthermore, STAT3 also bound to the promoter of HEGBC and activated HEGBC expression. Thus, HEGBC/IL-11/STAT3 formed a positive regulatory loop in GBC. Depletion of IL-11 attenuated the oncogenic roles of HEGBC in GBC.

Conclusions

Our findings identified a novel lncRNA HEGBC, which is upregulated and indicts poor prognosis of GBC. HEGBC exerts oncogenic roles in GBC via forming a positive regulatory loop with IL-11/STAT3 signaling. Our data suggested that HEGBC could be a potential prognostic biomarker and therapeutic target for GBC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0847-7) contains supplementary material, which is available to authorized users.

LINC01287/miR-298/STAT3 feedback loop regulates growth and the epithelial-to-mesenchymal transition phenotype in hepatocellular carcinoma cells

Background

The long non-coding RNAs (lncRNAs) have participated in the promotion of hepatocellular carcinoma (HCC) initiation and progression. Nevertheless, the biological role and underlying mechanism of LINC01287 in HCC has never been reported.

Methods

The TGCA database was used to explore the abnormal expression of lncRNAs in HCC. Real-time PCR and in situ hybridization assays were used to examine the expression of LINC01287 in HCC tissues. The clinicopathological characteristics of HCC patients in relation to LINC01287 expression were then analyzed. Infection of cells with the si-LINC01287 lentiviral vector was performed to down-regulate LINC01287 expression in HCC cells. MTT and colony formation assays were performed to examine cell growth ability, and FACS analysis was performed to examine the cell cycle and apoptosis. A Boyden assay was used to examine HCC cell invasion ability, and RNA immunoprecipitation tested the interaction between LINC01287 and miR-298. A luciferase reporter assay was used to examine whether STAT3 was a direct target of miR-298, and chromatin immunoprecipitation (ChIP) was used to examine the potential binding of c-jun to the miR-298 promoter.

Results

We revealed that the expression of LINC01287 was increased in HCC cell lines, as well as tissues. Knockdown of LINC01287 decreased HCC cell growth and invasion both in vitro and in vivo. LINC01287 can negatively regulate miR-298 expression by acting as a ceRNA. miR-298 directly targeted STAT3 and inhibited its expression. LINC01287 exerted its function via the miR-298/STAT3 axis in HCC. Interestingly, STAT3 elevated LINC01287 expression via c-jun, which bound to the LINC01287 promoter. A feedback loop was also discovered between LINC01287 and the miR-298/STAT3 axis.

Conclusions

Our data indicated that LINC01287 played an oncogenic role in HCC growth and metastasis and that this lncRNA might serve as a novel molecular target for the treatment of HCC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0831-2) contains supplementary material, which is available to authorized users.

MicroRNAs as Immunotherapy Targets for Treating Gastroenterological Cancers

Gastroenterological cancers are the most common cancers categorized by systems and are estimated to comprise 18.4% of all cancers in the United States in 2017. Gastroenterological cancers are estimated to contribute 26.2% of cancer-related death in 2017. Gastroenterological cancers are characterized by late diagnosis, metastasis, high recurrence, and being refractory to current therapies. Since the current targeted therapies provide limited benefit to the overall response and survival, there is an urgent need for developing novel therapeutic strategy to improve the outcome of gastroenterological cancers. Immunotherapy has been developed and underwent clinical trials, but displayed limited therapeutic benefit. Since aberrant expressions of miRNAs are found in gastroenterological cancers and miRNAs have been shown to regulate antitumor immunity, the combination therapy combining the traditional antibody-based immunotherapy and novel miRNA-based immunotherapy is promising for achieving clinical success. This review summarizes the current knowledge about the miRNAs and long noncoding RNAs that exhibit immunoregulatory roles in gastroenterological cancers and precancerous diseases of digestive system, as well as the miRNA-based clinical trials for gastroenterological cancers. This review also analyzes the ongoing challenge of identifying appropriate therapy candidates for complex and dynamic tumor microenvironment, ensuring efficient and targeted delivery to specific cancer tissues, and developing strategy for avoiding off-target effect.

Identification of long non-coding RNA CCAT1 as an oncogene in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common type of cancer worldwide. Long non-coding RNAs (lncRNAs) have been demonstrated to be associated with the development of multiple types of human cancer. The present study aimed to identify the potential role of lncRNA colon cancer associated transcript 1 (CCAT1) in NPC. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of CCAT1 in NPC tissues and cell lines. The function of CCAT1 in the proliferation, migration, invasion and apoptosis of NPC cells was detected by MTT, cell scratch, Transwell, flow cytometry and caspase-3 ELISA assays, respectively. The results indicated that the expression levels of CCAT1 were significantly upregulated in NPC tissues compared with normal nasopharyngeal epithelial tissues. CCAT1 expression was also higher in SUNE-1 and C666-1 cells compared with NP69 cells. Furthermore, the knockdown of CCAT1 was indicated to inhibit growth, migration and invasion, and induce apoptosis in NPC cells. In conclusion, the present study is, to the best of our knowledge, the first to provide new findings that support an oncogenic role of CCAT1 in NPC. Further research is required to define the potential molecular mechanism of CCAT1 in the development of NPC.

LncRNA LINC00152 promoted glioblastoma progression through targeting the miR-107 expression

Long non-coding RNAs (lncRNAs) LINC00152 plays important roles in the progression of some tumors. However, the role of LINC00152 in human l glioblastoma is still unknown. In this study, we indicated that LINC00152 expression level was upregulated in glioblastoma tissues and cell lines. Overexpression of LINC00152 promoted the U87 and LN229 cell proliferation and invasion. Moreover, overexpression of LINC00152 suppressed the E-cadherin expression, where ectopic expression of LINC00152 promoted the N-cadherin, Vimentin, and Snail expression. These results suggested that LINC00152 enhanced epithelial-to-mesenchymal transition (EMT) program in the glioblastoma cell. Overexpression of LINC00152 suppressed the miR-107 expression in the U87 cell and enhanced the HMGA2 expression, which is a direct target gene of miR-107. In addition, we showed that the miR-107 expression was downregulated in the glioblastoma tissues and cell lines. Interesting, the expression of LINC00152 was negatively related with miR-107 expression in the glioblastoma tissues. Furthermore, LINC00152 promoted the glioblastoma cell proliferation and invasion through inhibiting miR-107 expression. These data suggested that LINC00152 acted as oncogene roles in the glioblastoma cell partly through targeting the miR-107 expression.

Crosstalk among lncRNAs, microRNAs and mRNAs in the muscle 'degradome' of rainbow trout

In fish, protein-coding and noncoding genes involved in muscle atrophy are not fully characterized. In this study, we characterized coding and noncoding genes involved in gonadogenesis-associated muscle atrophy, and investigated the potential functional interplay between these genes. Using RNA-Seq, we compared expression pattern of mRNAs, long noncoding RNAs (lncRNAs) and microRNAs of atrophying skeletal muscle from gravid females and control skeletal muscle from age-matched sterile individuals. A total of 852 mRNAs, 1,160 lncRNAs and 28 microRNAs were differentially expressed (DE) between the two groups. Muscle atrophy appears to be mediated by many genes encoding ubiquitin-proteasome system, autophagy related proteases, lysosomal proteases and transcription factors. Transcripts encoding atrogin-1 and mir-29 showed exceptional high expression in atrophying muscle, suggesting an important role in bulk muscle proteolysis. DE genes were co-localized in the genome with strong expression correlation, and they exhibited extensive 'lncRNA-mRNA', 'lncRNA-microRNA', 'mRNA-microRNA' and 'lncRNA-protein' physical interactions. DE genes exhibiting potential functional interactions comprised the highly correlated 'lncRNA-mRNA-microRNA' gene network described as 'degradome'. This study pinpoints extensive coding and noncoding RNA interactions during muscle atrophy in fish, and provides valuable resources for future mechanistic studies.

Overexpression of the long noncoding RNA CCAT1 promotes metastasis via epithelial-to-mesenchymal transition in lung adenocarcinoma

The long noncoding RNA (lncRNA) colon cancer-associated transcript 1 (CCAT1) has been identified as an oncogene in multiple types of human malignancy, and the aberrant expression of CCAT1 has been associated with the tumorigenesis and progression of cancer. However, the underlying mechanism of how CCAT1 affects malignant behaviors in lung adenocarcinoma cells remains unknown. In the current study, the expression of CCAT1 was identified to be increased in lung adenocarcinoma tissues (n=96) by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and its expression level was associated with epidermal growth factor receptor (EGFR) expression (P=0.011), lymphatic metastasis (P=0.003) and tumor node metastasis (TNM) stage (P=0.003). In vitro, by using Transwell assays, the overexpression of CCAT1 was demonstrated to promote the migration and invasion of H358 lung adenocarcinoma cells; while downregulation of CCAT1 expression inhibited H1650 cell migration and invasion. Furthermore, western blot analysis indicated that aberrant CCAT1 expression may induce epithelial-to-mesenchymal transition (EMT) by regulating the expression levels of EMT markers (E-cadherin, N-cadherin and vimentin). In conclusion, these results indicate that CCAT1 is able to promote the metastasis of lung adenocarcinoma cells by inducing EMT.

The effects of aberrant expression of LncRNA DGCR5/miR-873-5p/TUSC3 in lung cancer cell progression

Lung cancer is the most common cause of cancer‐related mortality worldwide, and nonsmall cell lung cancer (NSCLC) accounts for 80% of all pulmonary carcinomas. Recently, long noncoding RNAs (lncRNAs) have been paid attention for exploring treatment of various diseases. Upregulation of DiGeorge syndrome critical region gene 5 (DGCR5) predicts better lung squamous cell carcinoma prognosis; therefore, we explore the role of DGCR5 in lung cancer in our present study. Consecutive patients with LC were treated in our hospital between January 2015 and January 2016. qRT‐PCR demonstrated that DGCR5 was significantly lower in neoplastic tissues than in non‐neoplastic tissues. For in vitro experiments, cell growth, migration, and invasion were significantly lower in A549 cells transfected with pcDNA3.1‐DGCR5 than pcDNA3.1, which were verified by 5‐diphenyltetrazolium bromide (MTT) assay, scratch test, and transwell assay, respectively, with no significant induction on cell apoptosis that was demonstrated by flow cytometry (FCM) assay. Bioinformatics analysis predicted that 3’ untranslated region (UTR) of tumor suppressor candidate 3 (TUSC3, 49‐55 bp) and DGCR5 (801‐807 bp) shared a common hsa‐miR‐873‐5p binding site, and the direct interaction between DGCR5 and hsa‐miR‐873‐5p or hsa‐miR‐873‐5p and TUSC3 was verified by dual‐luciferase reporter assay. qRT‐PCR demonstrated that hsa‐miR‐873‐5p was dramatically higher and TUSC3 was significantly lower in neoplastic tissues than in non‐neoplastic tissues. DGCR5 decreased the protein level of TUSC3 by miR‐873‐5p which was demonstrated by Western blot and immunofluorescence. The role of DGCR5 in tumorigenesis in vivo was consistent with in vitro assays, Ki‐67‐positive cell number (exhibited by immunohistochemical staining), tumor size, and tumor weight of A549‐DGCR5 group were significantly lower in comparison with A549‐control group.

lncRNA CCAT1 promotes cell proliferation, migration, and invasion by down-regulation of miR-143 in FTC-133 thyroid carcinoma cell line

Thyroid cancer is a common malignant tumor. Long non-coding RNA colon cancer-associated transcript 1 (lncRNA CCAT1) is highly expressed in many cancers; however, the molecular mechanism of CCAT1 in thyroid cancer remains unclear. Hence, this study aimed to investigate the effect of CCAT1 on human thyroid cancer cell line FTC-133. FTC-133 cells were transfected with CCAT1 expressing vector, CCAT1 shRNA, miR-143 mimic, and miR-143 inhibitor, respectively. After different treatments, cell viability, proliferation, migration, invasion, and apoptosis were measured. Moreover, the regulatory relationship of CCAT1 and miR-143, as well as miR-143 and VEGF were tested using dual-luciferase reporter assay. The relative expressions of CCAT1, miR-143, and VEGF were tested by qRT-PCR. The expressions of apoptosis-related factors and corresponding proteins in PI3K/AKT and MAPK pathways were analyzed using western blot analysis. The results suggested that CCAT1 was up-regulated in the FTC-133 cells. CCAT1 suppression decreased FTC-133 cell viability, proliferation, migration, invasion, and miR-143 expression, while it increased apoptosis and VEGF expression. CCAT1 might act as a competing endogenous RNA (ceRNA) for miR-143. Moreover, CCAT1 activated PI3K/AKT and MAPK signaling pathways through inhibition of miR-143. This study demonstrated that CCAT1 exhibited pro-proliferative and pro-metastasis functions on FTC-133 cells and activated PI3K/AKT and MAPK signaling pathways via down-regulation of miR-143. These findings will provide a possible target for clinical treatment of thyroid cancer.

Genome-wide analysis of differentially expressed profiles of mRNAs, lncRNAs and circRNAs during Cryptosporidium baileyi infection

Background

Cryptosporidium baileyi is the most common Cryptosporidium species in birds. However, effective prevention measures and treatment for C. baileyi infection were still not available. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) play important roles in regulating occurrence and progression of many diseases and are identified as effective biomarkers for diagnosis and prognosis of several diseases. In the present study, the expression profiles of host mRNAs, lncRNAs and circRNAs associated with C. baileyi infection were investigated for the first time.

Results

The tracheal tissues of experimental (C. baileyi infection) and control chickens were collected for deep RNA sequencing, and 545,479,934 clean reads were obtained. Of them, 1376 novel lncRNAs were identified, including 1161 long intergenic non-coding RNAs (lincRNAs) and 215 anti-sense lncRNAs. A total of 124 lncRNAs were found to be significantly differentially expressed between the experimental and control groups. Additionally, 14,698 mRNAs and 9085 circRNAs were identified, and significantly different expressions were observed for 1317 mRNAs and 104 circRNAs between two groups. Bioinformatic analyses of gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for their targets and source genes suggested that these dysregulated genes may be involved in the interaction between the host and C. baileyi.

Conclusions

The present study revealed the expression profiles of mRNAs, lncRNAs and circRNAs during C. baileyi infection for the first time, and sheds lights on the roles of lncRNAs and circRNAs underlying the pathogenesis of Cryptosporidium infection.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4754-2) contains supplementary material, which is available to authorized users.

Long non-coding RNA CCAT1 as a diagnostic and prognostic molecular marker in various cancers: a meta-analysis

PURPOSE

Long non-coding RNA colon cancer-associated transcript-1 (CCAT1) is newly found to be related with diagnoses and prognosis of cancer. This meta-analysis was performed to investigate the relationship between CCAT1 expression and clinical parameters, including survival condition, lymph node metastasis and tumor node metastasis grade.

MATERIALS AND METHODS

The primary literatures were collected through initial search criteria from electronic databases, including PubMed, OVID Evidence-based medicine Reviews and others (up to May 12, 2017). Eligible studies were identified and selected by the inclusion and exclusion criteria. Data was extracted and computed into Hazard ratio (HR) for the assessment of overall survival, subgroup analyses were prespecified based on the digestive tract cancer or others. Analysis of different CCAT1 expression related with lymph node metastasis or tumor node metastasis grade was conducted. Risk of bias was assessed by the Newcastle-Ottawa Scale.

RESULTS

9 studies were included. This meta-analysis showed that high CCAT1 expression level was related to poor overall survival, the pooled HR was 2.42 (95% confidence interval, CI: 1.86-3.16; P < 0.001; fix- effects model), similarly in the cancer type subgroups: digestive tract cancer (HR, 2.42; 95% CI, 1.79-3.29; P < 0.001; fix- effects model) and others (HR, 2.42; 95% CI, 1.42-4.13; P = 0.001; fix- effects model). The analysis showed that high CCAT1 was strongly related to positive lymph node metastasis (Odds ratio, OR: 3.24; 95% CI, 2.04-5.16; P < 0.001; fix- effects model), high tumor node metastasis stage (OR, 3.87; 95% CI, 2.53-5.92; P < 0.001; fix- effects model).

CONCLUSIONS

In conclusion, this meta-analysis revealed that CCAT1 had potential as a diagnostic and prognostic biomarker in various cancers.

Long non-coding RNA UCA1 promotes gallbladder cancer progression by epigenetically repressing p21 and E-cadherin expression

A growing number of studies indicated that long non-coding RNAs (lncRNAs) determine some cellular processes in cancer, such as proliferation, metastasis and differentiation. Urothelial carcinoma associated 1 (UCA1), an lncRNA, had been reported for its overexpression and oncogenic effect on various human cancers. In this study, we found that UCA1 was significantly overexpressed in gallbladder cancer (GBC) and positively correlated with tumor size, lymph node metastasis, TNM stage and short survival time. Moreover, UCA1 promoted GBC cell proliferation and metastasis in vitro and tumor growth in vivo. Mechanically, we identified that UCA1 promoted GBC progression through recruiting enhancer of zeste homolog 2 (EZH2) to the promoter of p21 and E-cadherin, and epigenetically suppressing their transcript.

Silencing of Long Noncoding RNA MIR22HG Triggers Cell Survival/Death Signaling via Oncogenes YBX1, MET, and p21 in Lung Cancer

The long noncoding RNA (lncRNA) MIR22HG has previously been identified as a prognostic marker in hepatocellular carcinoma. Here, we performed a comprehensive analysis of lncRNA expression profiles from RNA-Seq data and report that MIR22HG plays a similar role in lung cancer. Analysis of 918 lung cancer and normal lung tissues and lung cancer cell lines revealed that MIR22HG was significantly downregulated in lung cancer; this decreased expression was associated with poor patient survival. MIR22HG bound and stabilized the YBX1 protein. Silencing of MIR22HG triggered both cell survival and cell death signaling through dysregulation of the oncogenes YBX1, MET, and p21. In this MIR22HG network, p21 played an oncogenic role by promoting cell proliferation and antiapoptosis in lung cancers. MIR22HG played a tumor-suppressive role as indicated by inhibition of multiple cell cycle-related genes in human primary lung tumors. These data show that MIR22HG has potential as a new diagnostic and prognostic marker and as a therapeutic target for lung cancer.Significance: The lncRNA MIR22HG functions as a tumor suppressor, with potential use a diagnostic/prognostic marker and therapeutic target in lung cancer. Cancer Res; 78(12); 3207-19. ©2018 AACR.