Long noncoding RNA SchLAH suppresses metastasis of hepatocellular carcinoma through interacting with fused in sarcoma

LncRNA CASC9 enhances the stability of SOCS-1 by combining with FUS to alleviate sepsis-induced liver injury

BACKGROUND

Liver injury plays a major role in the development of sepsis. Liver damage after sepsis is an independent risk factor for multiple organ failure and death. Cancer susceptibility candidate 9 (CASC9) exerts a protective effect on sepsis-induced acute lung injury (ALI). However, the role and underlying mechanism haven't been fully evaluated.

METHODS

Animal and cell models of sepsis were established in vivo and in vitro experiments. The histological and apoptosis analyses of liver tissues were tested by hematoxylin-eosin (HE) staining and terminal dUTP nick end labeling (TUNEL) assay, respectively. Serum levels of inflammatory cytokines were detected via using an enzyme-linked immunosorbent assay (ELISA). The expressions of CASC9, suppressor of cytokine signaling (SOCS)-1, Bcl-2, Bax, Bad, and caspase3 were measured by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. Cell counting kit-8 (CCK-8) and flow cytometry were applied to examine cell viability and apoptosis, respectively. RNA immunoprecipitation (RIP) and RNA-pull down assay were used to verify the binding relationships among CASC9, SOCS-1 and FUS.

RESULTS

CASC9 and SOCS-1 were lowly expressed in animal and cell models of sepsis liver injury. CASC9 or SOCS-1 overexpression could inhibit cell apoptosis upon lipopolysaccharide (LPS) induction. Meanwhile, the serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and IL-8 were reduced by CASC9 or SOCS-1 overexpression in LPS-induced LO2 cells. Mechanistically, CASC9 interacted with fused in sarcoma (FUS) to stabilize the mRNA of SOCS-1. SOCS-1 silencing antagonized the effects of CASC9 on improving sepsis liver injury.

CONCLUSION

CASC9 overexpression ameliorated the sepsis-induced liver injury, and the probable underlying mechanism may be that CASC9 stabilized the SOCS-1 mRNA by interacting with FUS.

HOXC Cluster Antisense RNA 3, a Novel Long Non-Coding RNA as an Oncological Biomarker and Therapeutic Target in Human Malignancies

HOXC cluster antisense RNA 3 (HOXC-AS3) is a novel long noncoding RNA (lncRNA) that exhibits aberrant expression patterns in various cancer types. Its expression is closely related to clinicopathological features, demonstrating significant clinical relevance across multiple tumors. And HOXC-AS3 plays multifaceted roles in tumor progression, impacting cell proliferation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT), autophagy, senescence, tumor growth, and metastasis. In this review, we summarized and comprehensively analyzed the expression and clinical significance of HOXC-AS3 as a diagnostic and prognostic biomarker for malignancies. Additionally, we presented an in-depth update on HOXC-AS3's functions and regulatory mechanisms in cancer pathogenesis. This narrative review underscores the importance of HOXC-AS3 as a promising lncRNA candidate in cancer research and its potential as a predictive biomarker and therapeutic target in clinical applications.

SLC8A1 antisense RNA 1 suppresses papillary thyroid cancer malignant progression via the FUS RNA binding protein (FUS)/NUMB like endocytic adaptor protein (Numbl) axis

Papillary thyroid cancer (PTC) is one of the most prevalent endocrine malignancies and is associated with severe morbidity and high mortality. This study aimed to explore the role of long non-coding RNA (lncRNA) SLC8A1 antisense RNA 1 (SLC8A1-AS1) in the pathogenesis of PTC. In this study, we explored the function of SLC8A1-AS1 in PTC progression. We observed that the expression of SLC8A1-AS1 was downregulated in clinical PTC samples and PTC cell lines compared to that in normal controls. Cell counting kit (CCK)-8 assays demonstrated that the overexpression of SLC8A1-AS1 significantly reduced the proliferation of PTC cells. Consistently, apoptosis of PTC cells was enhanced by SLC8A1-AS1 overexpression. SLC8A1-AS1 overexpression attenuated the invasion and migration of PTC cells. Mechanistically, SLC8A1-AS1 maintained NUMB like endocytic adaptor protein (Numbl) mRNA stability by interacting with FUS RNA Binding Protein (FUS) in PTC cells. Depletion of Numbl reversed the inhibitory effect of SLC8A1-AS1 overexpression on PTC. Thus, we concluded that SLC8A1-AS1 suppresses PTC progression via the FUS/Numbl axis. Our findings provide novel insights into the mechanism underlying SLC8A1-AS1 attenuation of the malignant development of PTC, improving our understanding of the association between lncRNAs and PTC. SLC8A1-AS1 and FUS may be potential targets for PTC treatment.

New Insights into the Roles of lncRNAs as Modulators of Cytoskeleton Architecture and Their Implications in Cellular Homeostasis and in Tumorigenesis

The importance of the cytoskeleton not only in cell architecture but also as a pivotal element in the transduction of signals that mediate multiple biological processes has recently been highlighted. Broadly, the cytoskeleton consists of three types of structural proteins: (1) actin filaments, involved in establishing and maintaining cell shape and movement; (2) microtubules, necessary to support the different organelles and distribution of chromosomes during cell cycle; and (3) intermediate filaments, which have a mainly structural function showing specificity for the cell type where they are expressed. Interaction between these protein structures is essential for the cytoskeletal mesh to be functional. Furthermore, the cytoskeleton is subject to intense spatio-temporal regulation mediated by the assembly and disassembly of its components. Loss of cytoskeleton homeostasis and integrity of cell focal adhesion are hallmarks of several cancer types. Recently, many reports have pointed out that lncRNAs could be critical mediators in cellular homeostasis controlling dynamic structure and stability of the network formed by cytoskeletal structures, specifically in different types of carcinomas. In this review, we summarize current information available about the roles of lncRNAs as modulators of actin dependent cytoskeleton and their impact on cancer pathogenesis. Finally, we explore other examples of cytoskeletal lncRNAs currently unrelated to tumorigenesis, to illustrate knowledge about them.

MetaLnc9-Antisense RNA Contributes to Lung Cancer Metastasis via Modulating RNA-RNA Duplex with MetaLnc9

Lung cancer is a common life-threatening tumor with high malignancy and high invasiveness. Long non-coding RNAs (lncRNAs) are involved in almost every stage of tumor initiation and progression. Here, we identified an antisense lncRNA, MetaLnc9 antisense (Metalnc9-AS), which arises from the antisense strand of Metalnc9, located on chr9q34.11, while its biological function and mechanism are not clear in lung cancer. In this study, we demonstrated that the expression of Metalnc9-AS was upregulated in non-small cell lung cancer (NSCLC) tissues compared with corresponding non-tumorous tissues. The gain of MetaLnc9-AS was highly associated with the malignant features of NSCLC. Overexpression of MetaLnc9-AS enhanced tumor metastasis in vitro and in vivo. Mechanically, MetaLnc9-AS could form an RNA-RNA hybrid with its cognate sense counterpart, MetaLnc9, to regulate its expression in NSCLC cells, and that such complexes were protected from ribonuclease degradation. Thus, Metalnc9-AS might be a potential and effective treatment for NSCLC.

Long noncoding RNA Gas5 induces cell apoptosis and inhibits tumor growth via activating the CHOP-dependent endoplasmic reticulum stress pathway in human hepatoblastoma HepG2 cells

In recent years, long noncoding RNAs (lncRNAs) have been demonstrated to be important tumor-associated regulatory factors. LncRNA growth arrest-specific transcript 5 (Gas5) acts as an anti-oncogene in most cancers. Whether Gas5 acts as an oncogene or anti-oncogene in hepatocellular carcinoma (HCC) remains unclear. In the present study, the expression and role of Gas5 in HCC were investigated in vitro and in vivo. Lower expression levels of Gas5 were determined in HCC tissues and cells by quantitative reverse transcription-polymerase chain reaction. Overexpressed Gas 5 lentiviral vectors were constructed to analyze their influence on cell viability, migration, invasion, and apoptosis. Fluorescence in situ hybridization was used to identify the subcellular localization of Gas5. Protein complexes that bound to Gas5 were isolated from HepG2 cells through pull-down experiments and analyzed by mass spectrometry. A series of novel Gas5-interacting proteins were identified and bioinformatics analysis was carried out. These included ribosomal proteins, proteins involved in protein folding, sorting, and transportation in the ER, some nucleases and protein enzymes involved in gene transcription, translation, and other proteins with various functions.78 kDa glucose-regulated protein (GRP78) was identified as a direct target of Gas5 by Rip-qPCR and Western blot analysis assay. Gas5 inhibited HepG2 cell growth and induced cell apoptosis via upregulating CHOP to activate the ER stress signaling pathway. Further studies indicated that the knockdown of CHOP by shRNA partially reversed Gas5-mediated apoptosis in HepG2 cells. Magnetic resonance imaging showed that the ectopic expression of Gas5 inhibited the growth of HCC in nude mice. These findings suggest that Gas5 functions as a tumor suppressor and induces apoptosis through activation of ER stress by targeting the CHOP signal pathway in HCC.

Exosomal lncRNA FOXD3-AS1 upregulates ELAVL1 expression and activates PI3K/Akt pathway to enhance lung cancer cell proliferation, invasion, and 5-fluorouracil resistance

Long non-coding RNA (lncRNA) FOXD3-AS1 expression is upregulated in lung cancer; however, its effect and mechanism on 5-fluorouracil (5-FU) resistance remain unclear. In this study, we determined the effects of FOXD3-AS1-enriched exosomes derived from lung cancer cells on the proliferation, invasion, and 5-FU resistance of lung cancer cells. Online bioinformatics database analysis showed that FOXD3-AS1 was upregulated in lung cancer progression. Real-time quantitative PCR results confirmed that FOXD3-AS1 expression was upregulated in lung cancer tissues and cell lines, and FOXD3-AS1 was greatly enriched in lung cancer cell-derived exosomes. ELAV-like RNA-binding protein 1 (ELAVL1) was identified as an RNA-binding protein of FOXD3-AS1. The lung cancer cell-derived exosomes promoted A549 cell proliferation and invasion and inhibited apoptosis caused by 5-FU, and transfection of si-FOXD3-AS1 or si-ELAVL1 in exosome-incubated A549 cells reversed these effects. Moreover, exosome-incubated A549 cells were co-transfected with si-FOXD3-AS1 and pcDNA-ELAVL1, showing the same cell proliferation, invasion, and 5-FU resistance as those of A549 cells treated with lung cancer cell-derived exosomes alone. Mechanistic studies identified that lung cancer cell-derived exosomes activated the PI3K/Akt pathway, and transfection of si-FOXD3-AS1 or treatment with the PI3K inhibitor LY294002 reversed the activation of the PI3K/Akt axis induced by exosomes. In conclusion, our study revealed that lung cancer cell-derived exosomal FOXD3-AS1 upregulated ELAVL1 expression and activated the PI3K/Akt pathway to promote lung cancer progression. Our findings provide a new strategy for lung cancer treatment.

LncRNA SNHG17 Contributes to Proliferation, Migration, and Poor Prognosis of Hepatocellular Carcinoma

Long noncoding RNAs (lncRNAs) have been substantially reported to have critical roles in regulating tumorigenesis in recent years. However, the expression pattern and biological function of SNHG17 in hepatocellular carcinoma (HCC) remain unclear. Bioinformatics analysis and qRT-PCR were performed to detect the expression pattern of SNHG17 in HCC tissues, adjacent nontumorous tissues, and cell lines. The effect of SNHG17 on proliferation, migration, and apoptosis of HCC was investigated by knockdown and overexpressing SNHG17 in HCC cell lines. RNA sequencing was utilized to explore the underlying mechanism. Utilizing publicly available TCGA-LIHC, GSE102079 HCC datasets, and qRT-PCR, we found SNHG17 was significantly upregulated in HCC tissues and cell lines and was notably associated with larger tumor size, poorly differentiation, presence of vascular invasion, and advanced TNM stage. Furthermore, gain- and loss-of-function studies demonstrated that SNHG17 promoted cell proliferation and migration and inhibited apoptosis of HCC. By employing RNA sequencing, we found knockdown of SNHG17 caused 1037 differentially expressed genes, highly enriched in several pathways, including metabolic, PI3K-Akt, cell adhesion, regulation of cell proliferation, and apoptotic pathway; among them, 92 were overlapped with SNHG17-related genes in the TCGA-LIHC dataset. Furthermore, ERH, TBCA, TDO2, and PDK4 were successfully validated and found significantly dysregulated in HCC tissues. Moreover, HCC patients with higher SNHG17 expression had a relatively poor overall survival and disease-free survival, and ERH and PDK4 also played a marked role in the prognosis of HCC. Broadly, our findings illustrate that SNHG17 acts as a noncoding oncogene in HCC progression, suggesting its potential value as a novel target for HCC therapy.

NBPF4 mitigates progression in colorectal cancer through the regulation of EZH2-associated ETFA

Colorectal cancer (CRC) is one of the leading causes of death worldwide, and hence, there is a need to elucidate the molecular mechanisms contributing to the progression of CRC. In this study, we aimed at assessing the role of long non‐coding RNA NBPF4 on the tumorigenesis of CRC. Silencing or overexpression experiments were performed on HCT116 and SW260 in vitro models. BALB/c athymic female nude mice aged 5–6 weeks were used as in vivo models. To assess the relationship between NBPF4 and its regulatory RNA pull‐down assay, RNA immunoprecipitation, luciferase activity, Western blotting and qRT‐PCR were employed. Initially, we identified that NBPF4 was downregulated in CRC tissues and cell lines. Furthermore, we observed that NBPF4 decreased tumorigenesis in both in vitro and in vivo models. Additionally, we identified that ETFA was highly expressed in CRCs and was negatively associated with NBPF4. Subsequently, we identified that EZH2, a transcriptional factor, activated ETFA by enhancing the methylation of its promoter, and EZH2 was also highly regulated in CRCs. Using COAD and READ databases, we confirmed that EZH2 and ETFA were positively correlated. Furthermore, we identified NBPF4 and EZH2 were targets for ZFP36, which bound and positively regulated NBPF4. This prevented NBPF4 from binding to its negative regulator miR‐17‐3p. Our results demonstrated that NBPF4 downregulated EZH2 and stabilized itself by binding to ZFP36, thus escaping from inhibition by miR‐17‐3p, which allowed mitigation of CRC through inhibition of ETFA.

Non-Coding RNAs in Invadopodia: New Insights Into Cancer Metastasis

Invadopodia are actin-rich structures and their formation is implicated in cancer invasion and metastasis. Growing evidence has shown that noncoding RNAs (ncRNAs) play important roles in pathological conditions, including tumorigenesis and metastasis. Although this is still a new area of research, ncRNAs appear to be promising biomarkers and therapeutic targets for cancer metastasis. However, understanding the roles of ncRNAs in invadopodia is still in the early stages and far from clinical application. In this mini-review, we summarize the roles of ncRNAs in invadopodia functions and discuss them in a therapeutic context. The current challenges and gaps in this field are also raised, and we provide some open questions to facilitate new ideas in targeting invadopodia in anticancer therapy.

The mutual regulatory loop between TPTEP1 and miR-1303 in leukemogenesis of acute myeloid leukemia

Background

Non-coding RNAs (ncRNAs) have been identified as key regulators during the pathogenesis and development of cancers. However, most of ncRNAs have never been explored in acute myeloid leukemia (AML).

Methods

Gene expression was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Functional assays were performed to assess the cellular processes in AML cells. The relationship between genes was verified by means of a series of mechanism assays.

Results

Transmembrane phosphatase with tensin homology pseudogene 1 (TPTEP1) was notably downregulated in AML cells, and functionally acted as a proliferation-inhibitor. Additionally, TPTEP1 suppressed AML cell growth by inactivating c-Jun N-terminal kinase (JNK)/c-JUN signaling pathway. MicroRNA (MiR)-1303, as an oncogene, was predicted and validated as a target of c-JUN in AML cells. Also, TPTEP1 interacted with miR-1303 and they were mutually silenced by each other in AML cells. Furthermore, the effect of TPTEP1 overexpression on AML cell proliferation was counteracted under miR-1303 upregulation.

Conclusion

Our findings unmasked a feedback loop of TPTEP1/JNK/c-JUN/miR-1303 axis in AML cells, suggesting TPTEP1 and miR-1303 as potential targets for developing therapeutic strategies for AML patients.

The Impact of Long Non-Coding RNAs in the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the utmost deadly human malignancies. This type of cancer has been associated with several environmental, viral, and lifestyle risk factors. Among the epigenetic factors which contribute in the pathogenesis of HCC is dysregulation of long non-coding RNAs (lncRNAs). These transcripts modulate expression of several tumor suppressor genes and oncogenes and alter the activity of cancer-related signaling axes. Several lncRNAs such as NEAT1, MALAT1, ANRIL, and SNHG1 have been up-regulated in HCC samples. On the other hand, a number of so-called tumor suppressor lncRNAs namely CASS2 and MEG3 are down-regulated in HCC. The interaction between lncRNAs and miRNAs regulate expression of a number of mRNA coding genes which are involved in the pathogenesis of HCC. H19/miR-15b/CDC42, H19/miR-326/TWIST1, NEAT1/miR-485/STAT3, MALAT1/miR-124-3p/Slug, MALAT1/miR-195/EGFR, MALAT1/miR-22/SNAI1, and ANRIL/miR-144/PBX3 axes are among functional axes in the pathobiology of HCC. Some genetic polymorphisms within non-coding regions of the genome have been associated with risk of HCC in certain populations. In the current paper, we describe the recent finding about the impact of lncRNAs in HCC.

Linc-SCRG1 accelerates progression of hepatocellular carcinoma as a ceRNA of miR26a to derepress SKP2

BACKGROUND

Increasing evidence has demonstrated that long noncoding RNAs (lncRNAs) have regulatory functions in hepatocellular carcinoma (HCC). The link between lincSCRG1 and HCC remains unclear.

METHODS

To explore the lincSCRG1 regulation axis, bioinformatics, RIP and luciferase reporter assay were performed. The expressions of lincSCRG1-miR26a-SKP2 were detected in HCC tissues and cell lines through qPCR and western blot. The functions of HCC cells were investigated through in vitro assays (MTT, colony formation, transwell and flow cytometry) and the inner effect of lincSCRG1-miR26a in vivo was evaluated by xenografts and liver metatstatic nude mice models.

RESULTS

LincSCRG1 was found to be strongly elevated in human HCC tissues and cell lines. MiR26a and S phase kinase-related protein 2 (SKP2) were predicted as the target miRNA for lincSCRG1 and the target gene for miR26a with direct binding sites, respectively. LincSCRG1 was verified as a competing endogenous RNA (ceRNA) via negative regulation of miR26a and derepression of SKP2 in HCC cells. Both overexpression of lincSCRG1 (ov-lincSCRG1) and inhibition of miR26a (in-miR26a) obviously stimulated cellular viability, colony formation, migration and proliferation of S phase cells and also significantly increased the protein levels of cyclinD1, CDK4, MMP2/3/9, Vimentin, and N-cadherin or inhibited the protein level of E-cadherin of HCC cells, while knockdown of lincSCRG1 (sh-lincSCRG1) and upregulation of miR26a (mi-miR26a) had the opposite effects on HCC cells. Cotransfection of in-miR26a or overexpression of SKP2 (ov-SKP2) with sh-lincSCRG1 could rescue the anticancer functions of sh-lincSCRG1, including suppressing proliferation and migration of HCC cells. Additionally, sh-lincSCRG1 could effectively inhibit the growth of subcutaneous xenograft tumours and lung metastasis, while the anticancer effect of sh-lincSCRG1 could be reversed by cotransfection of in-miR26a.

CONCLUSIONS

LincSCRG1 acts as a ceRNA of miR26a to restrict its ability to derepress SKP2, thereby inducing the proliferation and migration of HCC cells in vitro and in vivo. Depletion of lincSCRG1 could be used as a potential therapeutic approach in HCC.

lncRNA DUXAP8 Facilitates Multiple Malignant Phenotypes and Resistance to PARP Inhibitor in HCC via Upregulating FOXM1

In this study, we examined the clinical significance and molecular mechanisms of a long non-coding RNA (lncRNA), double homeobox A pseudogene 8 (DUXAP8) in hepatocellular carcinoma (HCC). DUXAP8 expression was compared using quantitative real-time PCR in HCC versus adjacent tissues and in HCC cell lines versus normal hepatic epithelial cells. The correlations between DUXAP8 level and clinicopathological features were analyzed. Assays including MTT, colony-forming analysis, Transwell assay, western blot, xenograft formation, experimental metastasis, luciferase assay, RNA pull-down, and RNA immunoprecipitation were used to examine DUXAP8-induced malignant phenotypes, its regulation on forkhead box protein M1 (FOXM1), and the importance of FOXM1 in mediating DUXAP8 phenotypes. Our results showed that DUXAP8 was significantly upregulated in HCC tissues or cell lines associated with tumors of advanced grades, tumors that were positive for lymph node metastasis, and patients with poor overall survival. DUAXP8 was essential in maintaining multiple malignant phenotypes (including resistance to olaparib) both in vitro and in vivo. Mechanistically, DUXAP8 upregulated FOXM1 expression by sponging miR-485-5p and interacting with the RNA-binding protein Fused in Sarcoma (FUS). Functionally, FOXM1 essentially mediated the oncogenic phenotypes of DUXAP8. Collectively, DUXAP8 acts through two distinct mechanisms to upregulate FOXM1 and becomes a pleotropic oncogenic lncRNA in HCC.

LncRNA MM2P-induced, exosome-mediated transfer of Sox9 from monocyte-derived cells modulates primary chondrocytes

Monocyte-derived cells were shown to promote cartilage repair in osteoarthritis. The role of the long non-coding RNA (lncRNA) MM2P in this function of monocyte-derived cells remained unexplored. Treatment of RAW264.7 murine macrophages and mouse bone marrow-derived macrophages with IL-4 or IL-13 upregulated MM2P expression, upstream of STAT3 and STAT6 phosphorylation. Specifically, MM2P blocked SHP2-mediated dephosphorylation of STAT3 at Try705 and interacted with the RNA-binding protein FUS. In turn, p-STAT3 increased the Sox9 gene expression. These cells released Sox9 mRNA and protein-containing exosomes, as demonstrated by a transmission electron microscope, nanoparticle tracking analysis, and detection of typical surface markers. Their culture supernatant promoted the differentiation of mouse primary chondrocytes, i.e., upregulated the expression of Col1a2 and Acan genes and promoted the secretion of extracellular matrix components proteoglycan and type II collagen. These effects were mediated by Sox9 mRNA and protein delivered to chondrocytes by exosomes. Together, ex vivo treatment of monocyte-derived cells with IL-4 or IL-13 promoted chondrocyte differentiation and functions through exosome-mediated delivery of Sox9 mRNA and protein.

LncRNA ANRIL promotes cell growth, migration and invasion of hepatocellular carcinoma cells via sponging miR-144

Antisense non-coding RNA in the INK4A locus (ANRIL) has been recognized as a cancer-related lncRNA in hepatocellular carcinoma previously. This study aimed to reveal the functional effects and mechanisms of ANRIL on hepatocellular carcinoma cells in vitro. The expression of ANRIL in hepatocellular carcinoma cell lines (MHCC97 and Li-7) and non-tumourigenic liver cell line THLE-3 was detected by qRT-PCR. The expression of ANRIL, miR-144 and PBX3 in hepatocellular carcinoma cells was altered simultaneously or respectively by vector/oligonucleotide transfection. Then, cell viability, migration, invasion, apoptotic cell rate, protein expression of apoptosis-related factors were assessed. The correlation between ANRIL, miR-144 and PBX3 was explored. ANRIL was highly expressed in MHCC97 and Li-7 cells when compared to THLE-3 cells. ANRIL overexpression promoted cell viability, migration, invasion and suppressed apoptosis of MHCC97 and Li-7 cells. ANRIL negatively regulated miR-144, and oncogenic effects of ANRIL were attenuated when miR-144 was overexpressed. PBX3 was a direct target of miR-144. miR-144 overexpression blocked PI3K/AKT and JAK/STAT signalling pathways via targeting PBX3. Our data documented that ANRIL promoted hepatocellular carcinoma cells growth, migration and invasion. One of the possible mechanisms responsible for the tumour-promoting actions is that ANRIL sponging miR-144 to derepress PBX3.

Long noncoding RNA EPB41L4A-AS1 functions as an oncogene by regulating the Rho/ROCK pathway in colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors worldwide. In terms of cancer-related death, colon cancer ranks second and third among men and women, respectively, and the incidence is increasing annually. Accumulating evidence have indicated that long noncoding RNA (lncRNA) plays an important role in tumorigenesis. In this study, we found that lncRNA EPB41L4A-AS1 was highly expressed in CRC tissues and was associated with poor prognosis and tumor metastasis in patients with CRC. In vitro studies showed that the knockdown of EPB41L4A-AS1 inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition of CRC cells. Mechanically, we found that EPB41L4A-AS1 may participate in the development of CRC by activating the Rho/Rho-associated protein kinase signaling pathway. Collectively, these results demonstrated that EPB41L4A-AS1 can promote the proliferation, invasion, and migration of CRC, and it may be a novel biomarker for the diagnosis and targeted treatment of CRC.

Knockdown of LINC00662 represses AK4 and attenuates radioresistance of oral squamous cell carcinoma

Background

LncRNAs play crucial roles in the development of carcinomas. However, the investigation of LINC00662 in Oral squamous cell carcinoma (OSCC) is still elusive.

Methods

qRT-PCR assay tested the expression levels of LINC00662, hnRNPC and AK4. With exposure to irradiation, CCK-8, colony formation, flow cytometry and western blot experiments, respectively determined the function of LINC00662 in the radiosensitivity of OSCC cells. Then RIP and western blot assays affirmed the interaction between hnRNPC protein and LINC00662 or AK4. Finally, rescue assays validated the regulation mechanism of LINC00662 in the radioresistance of OSCC.

Results

In the present report, LINC00662 was overexpressed in OSCC and its silencing could alleviate radioresistance of OSCC. Furthermore, the interaction between hnRNPC protein and LINC00662 or AK4 was uncovered. Besides, LINC00662 regulated AK4 mRNA stability through binding to hnRNPC protein. To sum up, LINC00662 modulated the radiosensitivity of OSCC cells via hnRNPC-modulated AK4.

Conclusion

The molecular mechanism of the LINC00662/hnRNPC/AK4 axis was elucidated in OSCC, which exhibited a promising therapeutic direction for patients with OSCC.

LINC00689 promotes prostate cancer progression via regulating miR-496/CTNNB1 to activate Wnt pathway

Background

Accumulating evidence has proved the significant influence of long non-coding RNAs (lncRNAs) in cancer formation and development, including PCa.

Methods

The role of LINC00689 in PCa was confirmed by RT-qPCR, MTT, colony formation, flow cytometry, western blot and transwell assays. Besides, the binding ability between LINC00689 and miR-496 was validated by using luciferase reporter assay. Then RT-qPCR, RIP and luciferase reporter and western blot assays were employed to verify the interactions among LINC00689, miR-496 and CTNNB1. Furthermore, the rescuing role of CTNNB1 in Wnt pathway was proved by RT-qPCR, TOP/FOP Flash and western blot assays.

Results

LINC00689 was upregulated in PCa tissues and cells as well as at the terminal stage. Further, knock down of LINC00689 repressed PCa cell proliferation, migration and invasion, and initiated PCa cell apoptosis. Additionally, miR-496 inhibitor and pcDNA3.1/CTNNB1 could neutralize the prohibitive effects of LINC00689 silencing on cell proliferation, migration and invasion, meanwhile, could offset the encouraging role of knocking down LINC00689 in cell apoptosis. Moreover, CTNNB1 upregulation exerted redemptive function in Wnt pathway inhibited by LINC00689 depletion.

Conclusions

To sum up, LINC00689 promotes PCa progression via regulating miR-496/CTNNB1 to activate Wnt pathway, which may contribute to research about new targets for PCa treatment.

LncRNA TMPO-AS1 promotes hepatocellular carcinoma cell proliferation, migration and invasion through sponging miR-329-3p to stimulate FOXK1-mediated AKT/mTOR signaling pathway

Purpose

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer‐related death worldwide. Numerous analyses have revealed the abnormal expression of long non‐coding RNAs (lncRNAs) in HCC cells. This study aims to explore biological functions of lncRNA TMPO‐AS1 (TMPO antisense RNA 1) in HCC cell proliferation, apoptosis, invasion and migration.

Methods

The gene expression in HCC tissues and cell lines were measured by qRT‐PCR. The role of TMPO‐AS1 in HCC was confirmed by CCK‐8, colony formation, TUNEL, transwell and western blot as well as by in vivo experiments. RNA pull down and luciferase reporter assays were utilized to prove the binding relationship between TMPO‐AS1/FOXK1 (forkhead box K1) andmiR‐329‐3p. Rescue assays elucidated the regulatory effects of TMPO‐AS1/miR‐329‐3p/FOXK1/AKT/mTOR pathway on cellular activities in HCC.

Results

TMPO‐AS1was upregulated in HCC tissues and cells and its depletion inhibits HCC cell proliferation, invasion, migration, and EMT process as well as tumor growth. Furthermore, TMPO‐AS1 could bind with miR‐329‐3p, which suppressed HCC cell proliferation. FOXK1 served as the target gene of miR‐329‐3p and TMPO‐AS1 upregulated FOXK1 by sponging miR‐329‐3p in HCC cells. Additionally, FOXK1 overexpression or miR‐329‐3p inhibitor neutralized the repressing effects of TMPO‐AS1 knockdown on HCC development. Finally, it verified that TMPO‐AS1 could regulate AKT/mTOR pathway via FOXK1 to promote HCC.

Conclusion

TMPO‐AS1 contributes to HCC progression by sponging miR‐329‐3p to activate FOXK1‐mediated AKT/mTOR signaling pathway.

Eukaryotic initiation Factor 4AIII facilitates hepatocellular carcinoma cell proliferation, migration, and epithelial-mesenchymal transition process via antagonistically binding to WD repeat domain 66 with miRNA-2113

Hepatocellular carcinoma (HCC) is one of the malignant cancers with high incidence and mortality rates worldwide. RNA-binding protein eukaryotic initiation Factor 4A-III (eIF4AIII) is a carcinogene in the biological process of tumors and microRNA (miRNA)-2113 has rarely been studied in cancers, not to mention in HCC. The regulation mechanism between eIF4AIII and miR-2113 involved in HCC is yet to be explored. The purpose of this research is to probe the function role and associated underlying mechanism of eIF4AIII participated in HCC. The results revealed that eIF4AIII was overexpressed in HCC. Lost-of-function assays found that eIF4AIII knockdown, WD (Trp-Asp [tryptophan and asparaginic acid]) repeat domain 66 (WDR66) silence or miR-2113 promotion repressed cell proliferation, migration, and epithelial-mesenchymal transition (EMT) process in HCC. Furthermore, eIF4AIII could interact with WDR66 and further stabilize WDR66 messenger RNA. In addition, WDR66 was a target gene of miR-2113. Besides, WDR66 was antagonistically regulated by eIF4AIII and miR-2113. Rescue assays verified that eIF4AIII promoted HCC cell proliferation, migration, and EMT process via antagonistically binding to WDR66 with miR-2113. Taken together, these findings indicated an important role and a novel mechanism of eIF4AIII in HCC, providing an optional therapy for HCC patients.

Long noncoding RNA HOXC-AS3 facilitates the progression of invasive mucinous adenocarcinomas of the lung via modulating FUS/FOXM1

Invasive mucinous adenocarcinoma of the lung (IMA), a mucinous variant of lung adenocarcinoma, is strongly linked with a worse prognosis. Therefore, a deeper understanding about its molecular mechanism may conduce to a promising IMA therapy. Long non-coding RNAs (lncRNAs) have recently caught great attention for their crucial roles in diverse diseases regarding tumor initiation and progression. However, the potential role of the lncRNA HOXC-AS3 IMA is not well established. Hence, the purpose of present study is to manifest HOXC-AS3-regulated inner mechanism in IMA development. It revealed that HOXC-AS3 was highly expressed in IMA cells. Additionally, it was identified that the significant down-regulation of HOXC-AS3 obstructed cell proliferation and migration in IMA. As far as mechanism is concerned, it found that HOXC-AS3 recruited FUS to stabilize FOXM1 mRNA, accelerating IMA progression. Taken together, these data suggested that HOXC-AS3 may be recognized as a novel therapeutic target for patients with IMA or at least offer new views for molecular therapy.

Comprehensive biological function analysis of lncRNAs in hepatocellular carcinoma

Thousands of long non-coding RNAs (lncRNAs) have been discovered in human genomes by gene chip, next-generation sequencing, and/or other methods in recent years, which represent a significant subset of the universal genes involved in a wide range of biological functions. An abnormal expression of lncRNAs is associated with the growth, invasion, and metastasis of various types of human cancers, including hepatocellular carcinoma (HCC), which is an aggressive, highly malignant, and invasive tumor, and a poor prognosis in China. With a more in-depth understanding of lncRNA research for HCC and the emergence of new molecular-targeted therapies, the diagnosis, treatment, and prognosis of HCC will be considerably improved. Therefore, this review is expected to provide recommendations and directions for future lncRNA research for HCC.

DLX6-AS1 promotes cell proliferation, migration and EMT of gastric cancer through FUS-regulated MAP4K1

Gastric cancer (GC) is the second most prevalent carcinoma resulting in cancer-related deaths in the world, with differences among geographic areas. Although the incidence and mortality rates of GC in Asia are decreasing, the search for diverse and effective therapies of GC is still needed to be fully inquired. The present research explored the expression pattern, functional role and underlying mechanism of DLX6-AS1 in GC. Firstly, we measured DLX6-AS1 expression in GC and then found the elevated level of DLX6-AS1. To further inspect the function role of DLX6-AS1 involved in GC, we performed lost-of-function assays. The silencing of DLX6-AS1 suppressed cell proliferation, migration and EMT process of GC cells. Subsequently, we uncovered that MAP4K1 was also up-regulated in GC and could be positively regulated by DLX6-AS1. Moreover, MAP4K1 down-regulation similarly inhibited GC progression. In addition, DLX6-AS1 stabilized MAP4K1 via modulating FUS. In summary, DLX6-AS1 modulated GC progression through FUS-regulated MAP4K1. Our paper exposed the role and regulatory mechanism of DLX6-AS1 in GC, which suggested a novel and valid therapy for GC patients.

Sp1-induced LncRNA CTBP1-AS2 is a novel regulator in cardiomyocyte hypertrophy by interacting with FUS to stabilize TLR4

Cardiomyocyte hypertrophy is a heart response adapting to increasing cardiac load. Prolonged cardiomyocyte hypertrophy indicates a higher risk of heart failure or even cardiac death. Long noncoding RNAs have been largely reported to modulate human diseases. CTPB1-AS2 is a newly discovered lncRNA reported as an oncogene in papillary thyroid cancer, but its function in cardiomyocyte hypertrophy has never been probed. Toll-like receptor 4 (TLR4) is recognized to play important roles in cardiomyocyte hypertrophy. The present study aimed to investigate the role of CTBP1-AS2 in cardiomyocyte hypertrophy. First, we discovered the low expression of CTBP1-AS2 in normal heart tissues in GETx database. Then, we established cardiomyocyte hypertrophy models on mice and cardiomyocytes through transverse aortic constriction surgery and Ang II treatment. We revealed the up-regulation of CTBP1-AS2 and TLR4 in cardiomyocyte hypertrophy models. Also, we confirmed the positive correlation between CTBP1-AS2 and TLR4 expressions in cardiomyocyte hypertrophy tissues. Loss-of-function assays confirmed that inhibiting CTBP1-AS2 attenuated the Ang II-induced cardiomyocyte hypertrophy. Mechanism research showed that CTBP1-AS2 stabilized TLR4 mRNA by recruiting FUS. Rescue assays certified that CTBP1-AS2 regulated cardiomyocyte hypertrophy through TLR4. Finally, we found Sp1 as an upstream activator for CTBP1-AS2 expression. In conclusion, our study uncovered CTBP1-AS2 as a novel regulator of cardiomyocyte hypertrophy through regulating TLR4, providing a new potential treatment target for cardiomyocyte hypertrophy.

Long noncoding RNA SNHG14 facilitates colorectal cancer metastasis through targeting EZH2-regulated EPHA7

Accumulating evidence suggested the participation of long noncoding RNAs (lncRNAs) in regulating various biological processes so as to affecting cancer progression. However, the functional role of most lncRNAs in colorectal carcer (CRC) is still largely covered. In the present study, we disclosed SNHG14 as a carcinogene in CRC development, as it was low-expressed in normal colon tissues but markedly upregulated in CRC cell lines. Besides, SNHG14 contributed to CRC cell proliferation, motility and EMT in vitro, and inhibition of it confined CRC tumor growth and liver metastasis in vivo. Next, the mechanistic investigations confirmed that SNHG14-promoted CRC progression was mediated by EPHA7, which was negatively regulated by SNHG14 in CRC via an EZH2-dependent way. Importantly, EZH2 was proved as a transcription factor of EPHA7 and functioned as a repressor in EPHA7 transcription by enhancing methylation on EPHA7 promoter. Meanwhile, SNHG14 increased EZH2 expression in CRC via stabilizing its mRNA by interacting with FUS, and via freeing its mRNA from miR-186-5p-induced silence. All in all, our observations demonstrated that SNHG14 serves as a facilitator in CRC through targeting EZH2-repressed EPHA7 by enhancing EZH2 via recruiting FUS and absorbing miR-186-5p, indicating a promising new road for CRC diagnosis and treatment.

A liver-specific lncRNA, FAM99B, suppresses hepatocellular carcinoma progression through inhibition of cell proliferation, migration, and invasion

BACKGROUND

Increasing evidence has shown that long non-coding RNAs (lncRNAs) are important in hepatocellular carcinoma (HCC) development and progression. In this study, we aim to evaluate the expression of lncRNA FAM99B and its biological function in HCC.

METHODS

The expression level of FAM99B in HCC was assessed based on data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), verified using quantitative real-time polymerase chain reaction (qRT-PCR). HCCLM3 was transfected with lentivirus containing full-length FAM99B to obtain stable overexpressing cell line. Cell Counting Kit 8, clone formation, and transwell assays were used to investigate the effects of FAM99B in HCC progression. In addition, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and PANTHER pathway analyses were conducted to investigate the underlying molecular mechanisms.

RESULTS

FAM99B was found to be downregulated in HCC tissues compared with adjacent normal tissues based on TCGA, GEO, and qRT-PCR data. Our results revealed that downregulated FAM99B was significantly associated with vascular invasion, advanced histologic grade, and T stage. Kaplan-Meier analysis using TCGA data indicated that decreased FAM99B levels were significantly associated with poor overall survival in patients with HCC. Moreover, overexpression of FAM99B significantly inhibited cell proliferation, migration, and invasion in vitro. Pathway analyses showed that the co-expressed genes of FAM99B mainly participated in the pathways "Metabolic pathways" and "Blood coagulation".

CONCLUSION

Our results suggest that FAM99B may serve as a tumor suppressor in HCC and may provide a promising therapy target for patients with HCC.

PKM2, function and expression and regulation

Pyruvate kinase (PK), as one of the key enzymes for glycolysis, can encode four different subtypes from two groups of genes, although the M2 subtype PKM2 is expressed mainly during embryonic development in normal humans, and is closely related to tissue repair and regeneration, with the deepening of research, the role of PKM2 in tumor tissue has received increasing attention. PKM2 can be aggregated into tetrameric and dimeric forms, PKM2 in the dimer state can enter the nuclear to regulate gene expression, the transformation between them can play an important role in tumor cell energy supply, epithelial-mesenchymal transition (EMT), invasion and metastasis and cell proliferation. We will use the switching effect of PKM2 in glucose metabolism as the entry point to expand and enrich the Warburg effect. In addition, PKM2 can also regulate each other with various proteins by phosphorylation, acetylation and other modifications, mediate the different intracellular localization of PKM2 and then exert specific biological functions. In this paper, we will illustrate each of these points.

Ubiquitination and Long Non-coding RNAs Regulate Actin Cytoskeleton Regulators in Cancer Progression

Actin filaments are a major component of the cytoskeleton in eukaryotic cells and play an important role in cancer metastasis. Dynamics and reorganization of actin filaments are regulated by numerous regulators, including Rho GTPases, PAKs (p21-activated kinases), ROCKs (Rho-associated coiled-coil containing kinases), LIMKs (LIM domain kinases), and SSH1 (slingshot family protein phosphate 1). Ubiquitination, as a ubiquitous post-transcriptional modification, deceases protein levels of actin cytoskeleton regulatory factors and thereby modulates the actin cytoskeleton. There is increasing evidence showing cytoskeleton regulation by long noncoding RNAs (lncRNAs) in cancer metastasis. However, which E3 ligases are activated for the ubiquitination of actin-cytoskeleton regulators involved in tumor metastasis remains to be fully elucidated. Moreover, it is not clear how lncRNAs influence the expression of actin cytoskeleton regulators. Here, we summarize physiological and pathological mechanisms of lncRNAs and ubiquitination control mediators of actin cytoskeleton regulators which that are involved in tumorigenesis and tumor progression. Finally, we briefly discuss crosstalk between ubiquitination and lncRNA control mediators of actin-cytoskeleton regulators in cancer.

LncRNAs with miRNAs in regulation of gastric, liver, and colorectal cancers: updates in recent years

Long noncoding RNA (lncRNA) is a kind of RNAi molecule composed of hundreds to thousands of nucleotides. There are several major types of functional lncRNAs which participate in some important cellular pathways. LncRNA-RNA interaction controls mRNA translation and degradation or serves as a microRNA (miRNA) sponge for silencing. LncRNA-protein interaction regulates protein activity in transcriptional activation and silencing. LncRNA guide, decoy, and scaffold regulate transcription regulators of enhancer or repressor region of the coding genes for alteration of expression. LncRNA plays a role in cellular responses including the following activities: regulation of chromatin structural modification and gene expression for epigenetic and cell function control, promotion of hematopoiesis and maturation of immunity, cell programming in stem cell and somatic cell development, modulation of pathogen infection, switching glycolysis and lipid metabolism, and initiation of autoimmune diseases. LncRNA, together with miRNA, are considered the critical elements in cancer development. It has been demonstrated that tumorigenesis could be driven by homeostatic imbalance of lncRNA/miRNA/cancer regulatory factors resulting in biochemical and physiological alterations inside the cells. Cancer-driven lncRNAs with other cellular RNAs, epigenetic modulators, or protein effectors may change gene expression level and affect the viability, immortality, and motility of the cells that facilitate cancer cell cycle rearrangement, angiogenesis, proliferation, and metastasis. Molecular medicine will be the future trend for development. LncRNA/miRNA could be one of the potential candidates in this category. Continuous studies in lncRNA functional discrepancy between cancer cells and normal cells and regional and rational genetic differences of lncRNA profiles are critical for clinical research which is beneficial for clinical practice.

Long non-coding RNA LINC01133 mediates nasopharyngeal carcinoma tumorigenesis by binding to YBX1

Recently, long non-coding RNAs (lncRNAs) have been reported as the vital regulators of various cancers including nasopharyngeal carcinoma (NPC). An increasing number of studies have suggested that lncRNA LINC01133 is dysregulated and involved in human carcinogenesis. However, the roles of LINC01133 in NPC remain largely unknown. In this work, we demonstrated that LINC01133 was significantly downregulated in NPC tissues and cell lines. Loss and gain of function experiments provided evidence that LINC01133 inhibited NPC cell proliferation, invasion and migration both in vitro and in vivo. Besides, Fluorescence in situ hybridization (FISH) assay was performed to determine the localization of LINC01133 and LINC01133 was observed mainly distributed in the nucleus. Importantly, RNA pull-down and RIP assays showed that LINC01133 directly combined with YBX1, and YBX1 can partly reverse the repression of NPC cell proliferation, migration, and invasion caused by LINC01133. Collectively, our exploration indicate that LINC01133 inhibits the malignant-biological behavior of NPC cells by binding to YBX1, thereby suggesting a novel biomarker for the NPC prognosis and treatment.

MYC upregulated LINC00319 promotes human acute myeloid leukemia (AML) cells growth through stabilizing SIRT6

Long non-coding RNAs (lncRNAs) have been identified by accumulating studies as critical regulator in tumorigenesis and tumor development in human cancers, including in acute myeloid leukemia (AML). This study investigated the function and the underlying mechanism of LINC00319 in AML progression. Firstly, the low expression level of LINC00319 in whole blood of healthy individuals was obtained from UCSC, and its upregulation was detected in AML patients as well as AML cell lines. Besides, the prognostic significance of LINC00319 was revealed in AML patients. Functionally, the loss-of-function assays revealed that LINC00319 silence restrained proliferation but stimulated apoptosis in AML cells. Furthermore, LINC00319 expression was demonstrated proportional to MYC level in AML samples and transcriptionally regulated by MYC. Mechanistically, we identified FUS as a shared RNA binding protein (RBP) interacting with both LINC00319 and SIRT6. And LINC00319 regulated SIRT6 expression at post-transcriptional level through FUS-dependent pathway. Last but not least, SIRT6 overexpression rescued the suppressive effect of LINC00319 knockdown on AML cells growth. Overall, our findings unveiled that LINC00319 contributed to AML leukemogenesis via elevating SIRT6 expression, indicating a possible molecular target of LINC00319 for AML treatment.

1,25(OH)2D3 Attenuates IL-1β-Induced Epithelial-to-Mesenchymal Transition Through Inhibiting the Expression of lncTCF7

The activated form of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], regulates numerous cellular processes, including inhibition of cancer progression. IL-1β has been reported to facilitate cancer development, especially by inducing an epithelial-to-mesenchymal transition (EMT) in several malignant tumors. However, the underlying mechanism of 1,25(OH)2D3 and IL-1β in colorectal cancer (CRC) still remains largely unknown. To fill in this knowledge gap, we measured cell proliferation and invasion by CCK-8 and Transwell assays after stimulation with 1,25(OH)2D3 and IL-1β. E-cadherin and vimentin were chosen as markers of EMT measured by immunofluorescence, quantitative real-time PCR (qRT-PCR), and Western blot. The expression and function of the vitamin D receptor (VDR) was evaluated by Western blot and luciferase reporter assay. qRT-PCR and RNA-FISH were performed to detect the expression and location of lncTCF7 in vitro. The binding sites of VDR in the lncTCF7 promoter were confirmed by a chromatin immunoprecipitation assay. Based on the above experiments, we found that 1,25(OH)2D3 attenuates IL-1β-induced increased proliferation and invasion in colorectal cancer through enhancing VDR, which inhibits the expression of lncTCF7 by directly binding to its promoter region.

The emergence of long non-coding RNAs in hepatocellular carcinoma: an update

Hepatocellular carcinoma (HCC) accounting for roughly 90% of all primary liver neoplasms is the sixth most frequent neoplasm and the second prominent reason of tumor fatality worldwide. As regulators of diverse biological processes, long non-coding RNAs (lncRNAs) are involved in onset and development of neoplasms. With the continuous booming of well-featured lncRNAs in HCC from 2016 to now, we reviewed the newly-presented comprehension about the relationship between lncRNAs and HCC in this study. To be specific, we summarized the overview function and study tools of lncRNAs, elaborated the roles of lncRNAs in HCC, and sketched the molecule mechanisms of lncRNAs in HCC. In addition, the application of lncRNAs serving as biomarkers in early diagnosis and outcome prediction of HCC patients was highlighted.

Systematic analyses of a novel lncRNA-associated signature as the prognostic biomarker for Hepatocellular Carcinoma

Accumulating evidence implies that long noncoding RNAs (lncRNAs) play a crucial role in predicting survival for Hepatocellular carcinoma (HCC) patients. This study aims to capture the current research hotspots of HCC, based on the analysis of publications related to HCC research from 2013 to 2017, and to identify a novel lncRNA signature for HCC prognosis through the data mining in The Cancer Genome Atlas (TCGA). “Prognosis” and “biomarker” were located in the core of the HCC research hotspot. Moreover, long noncoding RNA was the top one research frontier in HCC research. The associations between survival outcome and the expression of lncRNAs were evaluated by the univariate and multivariate Cox proportional hazards regression analyses. Four lncRNAs (LINC00261, TRELM3P, GBP1P1, and CDKN2B‐AS1) were identified as significantly correlated with overall survival (OS). These four lncRNAs were gathered as a single prognostic signature. There was a significant positive correlation between HCC patients with low‐risk scores and overall survival (HR = 1.802, 95%CI [1.224‐2.652], P = .003). Further analysis suggested that the prognostic value of this four‐lncRNA signature was independent in clinical features. The enrichment analysis of prognostic lncRNA‐related gene was performed to find out the related pathways. Our study indicates that this novel lncRNA expression signature may be a useful biomarker of the prognosis for HCC patients, based on bioinformatics analysis.

lncRNA MIAT promotes proliferation and invasion of HCC cells via sponging miR-214

The aberrant expression of long noncoding RNAs (lncRNAs) has been involved in various human tumors including hepatocellular carcinoma (HCC). Our study aimed to investigate the potential molecular mechanism of lncRNA myocardial infarction-associated transcript (MIAT) in HCC. The expression of MIAT and micro-RNA (miR)-214 in HCC tissues and cells was examined by quantitative real-time PCR, and the levels of enhancer of zeste homolog 2 (EZH2) and β-catenin were detected by Western blot assay. Immunoprecipitation analysis was used to detect the level of H3/H4 histone acetylation. RNA pull-down assay was performed to confirm the targeting regulatory relationship between miR-214 and MIAT. Cell viability, proliferation, and invasion were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), [³H]thymidine incorporation, and Transwell assays, respectively. BALB/c nude mice were used to establish a hepatocellular carcinoma animal model with subcutaneous injection of SK-HEP-1 cells. Upregulation of MIAT is related to the proliferation and invasion of HCC, and downregulating MIAT expression inhibited HCC cell proliferation and invasion. The H3/H4 histone acetylation level of MIAT promoter in HCC tissues was higher than that in normal tissues. MIAT negatively regulated miR-214 in HCC cells. Inhibition of miR-214 reversed the influence of MIAT downregulation on HCC cell proliferation and invasion. In nude mouse xenograft models, downregulation of MIAT markedly suppressed the tumor growth of HCC via releasing miR-214. In conclusion, lncRNA MIAT promotes the proliferation and invasion of HCC cells through sponging miR-214, which brings a novel target for the therapy and prognosis of hepatocellular carcinoma. NEW & NOTEWORTHY This is the first research showing long noncoding RNA (lncRNA) myocardial infarction-associated transcript (MIAT) to have a regulatory effect on hepatocellular carcinoma. Micro-RNA (miR)-214 could be sponged by MIAT to promote the proliferation and invasion of hepatocellular carcinoma cells. The lncRNA MIAT/miR-214 axis brings a novel insight for the therapy and prognosis of hepatocellular carcinoma.

Characterization of long non-coding RNAs to reveal potential prognostic biomarkers in hepatocellular carcinoma

Dysregulation of long non-coding RNAs (lncRNAs) plays critical roles in a variety of biological processes. Recent studies have documented that lncRNAs can function as potential biomarkers in cancer prognosis, however, little is known in hepatocellular carcinoma (HCC). To identify lncRNA signatures that have prognostic values in HCC, we analyzed lncRNA expression profiles of 364 HCC patients from The Cancer Genome Atlas (TCGA) dataset. A set of four lncRNAs was identified to be significantly associated with the overall survival. Based on the four-lncRNA signature, HCC patients can be classified into high- and low-risk subgroups with significantly different survival. This result can be further validated in the testing set and another independent HCC data. Further analyses showed that the prognostic value of four-lncRNA signature was independent of other clinicopathological factors. The potential functions of candidate lncRNAs were further examined using HCC cell lines, suggesting these lncRNAs might contribute to tumor development of HCC. This work indicated that lncRNA signature could be a useful marker to determine the diagnosis and predict the prognosis of HCC.

LncRNAs regulate the cytoskeleton and related Rho/ROCK signaling in cancer metastasis

Some of the key steps in cancer metastasis are the migration and invasion of tumor cells; these processes require rearrangement of the cytoskeleton. Actin filaments, microtubules, and intermediate filaments involved in the formation of cytoskeletal structures, such as stress fibers and pseudopodia, promote the invasion and metastasis of tumor cells. Therefore, it is important to explore the mechanisms underlying cytoskeletal regulation. The ras homolog family (Rho) and Rho-associated coiled-coil containing protein serine/threonine kinase (ROCK) signaling pathway is involved in the regulation of the cytoskeleton. Moreover, long noncoding RNAs (lncRNAs) have essential roles in tumor migration and guide gene regulation during cancer progression. LncRNAs can regulate the cytoskeleton directly or may influence the cytoskeleton via Rho/ROCK signaling during tumor migration. In this review, we focus on the regulatory association between lncRNAs and the cytoskeleton and discuss the pathways and mechanisms involved in the regulation of cancer metastasis.

Behind the curtain of non-coding RNAs; long non-coding RNAs regulating hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is one of the most common and aggressive cancers worldwide. HCC is the fifth common malignancy in the world and the second leading cause of cancer death in Asia. Long non-coding RNAs (lncRNAs) are RNAs with a length greater than 200 nucleotides that do not encode proteins. lncRNAs can regulate gene expression and protein synthesis in several ways by interacting with DNA, RNA and proteins in a sequence specific manner. They could regulate cellular and developmental processes through either gene inhibition or gene activation. Many studies have shown that dysregulation of lncRNAs is related to many human diseases such as cardiovascular diseases, genetic disorders, neurological diseases, immune mediated disorders and cancers. However, the study of lncRNAs is challenging as they are poorly conserved between species, their expression levels aren’t as high as that of mRNAs and have great interpatient variations. The study of lncRNAs expression in cancers have been a breakthrough as it unveils potential biomarkers and drug targets for cancer therapy and helps understand the mechanism of pathogenesis. This review discusses many long non-coding RNAs and their contribution in HCC, their role in development, metastasis, and prognosis of HCC and how to regulate and target these lncRNAs as a therapeutic tool in HCC treatment in the future.

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

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

Prognostic role of long non-coding RNA TUG1 expression in various cancers: a meta-analysis

Several studies were conducted to explore the prognostic role of long non-coding RNA taurine upregulated gene 1 (lncRNA TUG1) expression in various cancers, with contradictory. This study aims to summarize the prognostic role of lncRNA TUG1 expression in various cancers. Embase, PubMed and Cochrane Library were completely retrieved. The cohort studies focusing on the prognostic role of lncRNA TUG1 expression in various cancers were eligible. The endpoints were overall survival (OS) and clinicopathological parameters. 9 studies involving a total of 1,078 patients were identified. The results showed that high lncRNA TUG1 expression was obviously associated with worse OS when compared to the low lncRNA TUG1 expression (HR = 1.37, 95% CI = 1.07–1.76, P = 0.01; I² = 85%). However, No distinct relationship was observed between the lncRNA TUG1 expression and age (OR = 0.99, 95% CI = 0.76–1.28, P = 0.92; I2 = 4%), gender (OR = 0.92, 95% CI = 0.70–1.22, P = 0.57; I² = 0%), diameter (OR = 0.83, 95% CI = 0.34–2.01, P = 0.67; I² = 85%), smoking (OR = 1.09, 95% CI = 0.37–3.21, P = 0.87; I² = 73%), TNM stage (OR = 0.60, 95% CI = 0.25–1.43, P = 0.25; I² = 86%) and lymph node metastasis (OR = 1.07, 95% CI = 0.47–2.45, P = 0.87; I² = 86%). In conclusion, it was revealed that high lncRNA TUG1 expression is an unfavorable predictor of OS in patients with cancers, and lncRNA TUG1 expression is a promising prognostic biomarker for various cancers.

LncSHRG promotes hepatocellular carcinoma progression by activating HES6

Hepatocellular carcinoma, one of the most common cancers, leads to mass mortality worldwide currently. However, the underlying mechanism of its oncogenesis remains to be elucidated. Here we identified that a long noncoding RNA, lncSHRG, was greatly upregulated in human hepatocellular carcinoma samples. We found that lncSHRG was essential for liver cancer cell proliferation and tumor propagation in mice. In mechanism, lncSHRG recruits SATB1 to bind to HES6 promoter and initiates HES6 expression. HES6, which is highly expressed in hepatocellular carcinoma, promotes tumor cell proliferation. High expression level of HES6 is positively correlated with clinical severity and poor prognosis of people with hepatocellular carcinoma. Altogether, our research provides a new insight on the mechanism of hepatocellular carcinoma progression.

Long noncoding RNA SchLAH suppresses metastasis of hepatocellular carcinoma through interacting with fused in sarcoma

Emerging evidence has indicated that deregulation of long non‐coding RNAs (lncRNAs) can contribute to the progression and metastasis of human cancer, including hepatocellular carcinoma (HCC). However, the roles of most lncRNAs in HCC remain largely unknown. Here we found a long noncoding RNA termed SchLAH (seven chromosome locus associated with HCC; also called BC035072) was generally downregulated in HCC. Low expression of SchLAH was significantly correlated with shorter overall survival of HCC patients. In vitro and in vivo assays indicated that overexpression of SchLAH inhibited the migration and lung metastasis of HCC cells. Knockdown of SchLAH by siRNA pool promoted the migration of HCC cells. RNA pull‐down and RNA immunoprecipitation assays demonstrated SchLAH physically interacted with fused in sarcoma (FUS). PCR array analysis showed that RhoA and Rac1 were the downstream effector molecules of SchLAH during HCC metastasis. Knockdown of FUS rescued the mRNA levels of RhoA and Rac1 that were repressed by SchLAH. These results suggest that SchLAH may suppress the metastasis of HCC cells by interacting with FUS, which indicates potential of SchLAH for the prognosis and treatment of HCC.