Long non-coding RNA Unigene56159 promotes epithelial-mesenchymal transition by acting as a ceRNA of miR-140-5p in hepatocellular carcinoma cells. Cancer Lett. 2016;382:166-175. [PMID: 27597739 DOI: 10.1016/j.canlet.2016.08.029]

Transcriptional landscape of long non-coding RNAs (lncRNAs) and its implication in viral diseases

Long non-coding RNAs (lncRNAs) are RNA transcripts of size >200 bp that do not translate into proteins. Emerging data revealed that viral infection results in systemic changes in the host at transcriptional level. These include alterations in the lncRNA expression levels and triggering of antiviral immune response involving several effector molecules and diverse signalling pathways. Thus, lncRNAs have emerged as an essential mediatory element at distinct phases of the virus infection cycle. The complete eradication of the viral disease requires more precise and novel approach, thus manipulation of the lncRNAs could be one of them. This review shed light upon the existing knowledge of lncRNAs wherein the implication of differentially expressed lncRNAs in blood-borne, air-borne, and vector-borne viral diseases and its promising therapeutic applications under clinical settings has been discussed. It further enhances our understanding of the complex interplay at host-pathogen interface with respect to lncRNA expression and function.

Dysregulated microRNAs as a biomarker for diagnosis and prognosis of hepatitis B virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignancy with a high incidence and fatality rate worldwide. Hepatitis B virus (HBV) infection is one of the most important risk factors for its occurrence and development. Early detection of HBV-associated HCC (HBV-HCC) can improve clinical decision-making and patient outcomes. Biomarkers are extremely helpful, not only for early diagnosis, but also for the development of therapeutics. MicroRNAs (miRNAs), a subset of non-coding RNAs approximately 22 nucleotides in length, have increasingly attracted scientists' attention due to their potential utility as biomarkers for cancer detection and therapy. HBV profoundly impacts the expression of miRNAs potentially involved in the development of hepatocarcinogenesis. In this review, we summarize the current progress on the role of miRNAs in the diagnosis and treatment of HBV-HCC. From a molecular standpoint, we discuss the mechanism by which HBV regulates miRNAs and investigate the exact effect of miRNAs on the promotion of HCC. In the near future, miRNA-based diagnostic, prognostic, and therapeutic applications will make their way into the clinical routine.

Mechanism and function of miR-140 in human cancers: A review and in silico study

MicroRNA-140 (miR-140) acts as a tumor suppressor and plays a vital role in cell biological functions such as cell proliferation, apoptosis, and DNA repair. The expression of this miRNA has been shown to be considerably decreased in cancer tissues and cell lines compared with normal adjacent tissues. Consequently, aberrant expression of some miR-140 target genes can lead to the initiation and progression of various human cancers, such as breast cancer, gastrointestinal cancers, lung cancer, and prostate cancer. The dysregulation of the miR-140 network also affects cell proliferation, invasion, metastasis, and apoptosis of cancer cells by affecting various signaling pathways. Besides, up-regulation of miR-140 could enhance the efficacy of chemotherapeutic agents in different cancer. We aimed to cover most aspects of miR-140 function in cancer development and address its importance in different stages of cancer progression.

Integrative network analysis reveals subtype-specific long non-coding RNA regulatory mechanisms in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSC) is one of most common malignancies with high mortality worldwide. Importantly, the molecular heterogeneity of HNSC complicates the clinical diagnosis and treatment, leading to poor overall survival outcomes. To dissect the complex heterogeneity, recent studies have reported multiple molecular subtyping systems. For instance, HNSC can be subdivided to four distinct molecular subtypes: atypical, basal, classical, and mesenchymal, of which the mesenchymal subtype is characterized by upregulated epithelial-mesenchymal transition (EMT) and associated with poorer survival outcomes. Despite a wealth of studies into the complex molecular heterogeneity, the regulatory mechanism specific to this aggressive subtype remain largely unclear. Herein, we developed a network-based bioinformatics framework that integrates lncRNA and mRNA expression profiles to elucidate the subtype-specific regulatory mechanisms. Applying the framework to HNSC, we identified a clinically relevant lncRNA LNCOG as a key master regulator mediating EMT underlying the mesenchymal subtype. Five genes with strong prognostic values, namely ANXA5, ITGA5, CCBE1, P4HA2, and EPHX3, were predicted to be the putative targets of LNCOG and subsequently validated in other independent datasets. By integrative analysis of the miRNA expression profiles, we found that LNCOG may act as a ceRNA to sponge miR-148a-3p thereby upregulating ITGA5 to promote HNSC progression. Furthermore, our drug sensitivity analysis demonstrated that the five putative targets of LNCOG were also predictive of the sensitivities of multiple FDA-approved drugs. In summary, our bioinformatics framework facilitates the dissection of cancer subtype-specific lncRNA regulatory mechanisms, providing potential novel biomarkers for more optimized treatment of HNSC.

Down-Regulation of lncRNA MBNL1-AS1 Promotes Tumor Stem Cell-like Characteristics and Prostate Cancer Progression through miR-221-3p/CDKN1B/C-myc Axis

The recurrence, progression, and drug resistance of prostate cancer (PC) is closely related to the cancer stem cells (CSCs). Therefore, it is necessary to find the key regulators of prostate cancer stem cells (PCSCs). Here, we analyzed the results of a single-class logistic regression machine learning algorithm (OCLR) to identify the PCSC-associated lncRNA MBNL1-AS1. The effects of MBNL1-AS1 on the stemness of CSCs was assessed using qPCR, western blot and sphere-forming assays. The role of MBNL1-AS1 in mediating the proliferation and invasion of the PC cell lines was examined using Transwell, wounding-healing, CCK-8, EdU and animal assays. Dual-luciferase and ChIRP assays were used to examine the molecular mechanism of MBNL1-AS1 in PCSCs. MBNL1-AS1 was shown to be negatively correlated with stemness index (mRNAsi), and even prognosis, tumor progression, recurrence, and drug resistance in PC patients. The knockdown of MBNL1-AS1 significantly affected the stemness of the PC cells, and subsequently their invasive and proliferative abilities. Molecular mechanism studies suggested that MBNL1-AS1 regulates CDKN1B through competitive binding to miR-221-3p, which led to the inhibition of the Wnt signaling pathway to affect PCSCs. In conclusion, our study identified MBNL1-AS1 as a key regulator of PCSCs and examined its mechanism of action in the malignant progression of PC.

Long noncoding RNAs in hepatitis B virus replication and oncogenesis

Several diverse long noncoding RNAs (lncRNAs) have been identified to be involved in hepatitis B virus (HBV) replication and oncogenesis, especially those dysregulated in HBV-related hepatocellular carcinoma (HCC). Most of these dysregulated lncRNAs are modulated by the HBV X protein. The regulatory mechanisms of some lncRNAs in HBV replication and oncogenesis have been characterized. Genetic polymorphisms of several lncRNAs affecting HBV replication or oncogenesis have also been studied. The prognosis of HCC remains poor. It is important to identify novel tumor markers for early diagnosis and find more therapeutic targets for effective treatments of HCC. Some dysregulated lncRNAs in HBV-related HCC may become biomarkers for early diagnosis and/or the therapeutic targets of HCC. This mini-review summarizes these findings briefly, focusing on recent developments.

LncRNA LINC00924 upregulates NDRG2 to inhibit epithelial-mesenchymal transition via sponging miR-6755-5p in hepatitis B virus-related hepatocellular carcinoma

Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is a life-threatening cancer. Long noncoding RNAs participate in HBV-related HCC progression. Based on the bioinformatics analysis, LINC00924 downregulation is positively related to unfavorable outcomes in patients with HBV-related HCC. Herein, we detected the biological functions and regulatory system of LINC00924 in HCC. The LINC00924 downregulation in HBV-related HCC tissues and cells was revealed by reverse transcription-quantitative polymerase chain reaction. Functionally, as Transwell assays and western blotting indicated, LINC00924 elevation inhibited HCC cell invasion and epithelial-mesenchymal transition (EMT). The binding site between LINC00924 and miR-6755-5p was determined by luciferase reporter assays. miR-6755-5p was confirmed to target NDRG2. miR-6755-5p upregulation decreased NDRG2 messenger RNA (mRNA) and protein levels. The mRNA and protein levels of NDRG2 were downregulated in tissues and cells. NDRG2 knockdown attenuated the inhibition induced by LINC00924 overexpression on invasion and EMT of HCC cells. In summary, LINC00924 increases NDRG2 expression to inhibit EMT by targeting miR-6755-5p in HBV-related HCC.

Diversity of Dysregulated Long Non-Coding RNAs in HBV-Related Hepatocellular Carcinoma

Infection with the hepatitis B virus (HBV) continues to pose a major threat to public health as approximately 292 million people worldwide are currently living with the chronic form of the disease, for which treatment is non-curative. Chronic HBV infections often progress to hepatocellular carcinoma (HCC) which is one of the world’s leading causes of cancer-related deaths. Although the process of hepatocarcinogenesis is multifaceted and has yet to be fully elucidated, several studies have implicated numerous long non-coding RNAs (lncRNAs) as contributors to the development of HCC. These host-derived lncRNAs, which are often dysregulated as a consequence of viral infection, have been shown to function as signals, decoys, guides, or scaffolds, to modulate gene expression at epigenetic, transcriptional, post-transcriptional and even post-translational levels. These lncRNAs mainly function to promote HBV replication and oncogene expression or downregulate tumor suppressors. Very few lncRNAs are known to suppress tumorigenesis and these are often downregulated in HCC. In this review, we describe the mechanisms by which lncRNA dysregulation in HBV-related HCC promotes tumorigenesis and cancer progression.

FAM83H-AS1/miR-485-5p/MEF2D axis facilitates proliferation, migration and invasion of hepatocellular carcinoma cells

Background

Abundant evidence has manifested that long noncoding RNAs (lncRNAs) are closely implicated in human cancers, including hepatocellular carcinoma (HCC). Remarkably, lncRNA FAM83H antisense RNA 1 (FAM83H-AS1) has been reported to be a tumor-propeller in multiple cancers. However, its effect on HCC progression remains unknown.

Methods

FAM83H-AS1 expression was analyzed by RT-qPCR. Colony formation, EdU, and flow cytometry as well as transwell assays were implemented to analyze the biological functions of FAM83H-AS1 on HCC progression. Luciferase reporter, RIP and RNA pull-down assays were implemented to detect the interaction among FAM83H-AS1, microRNA-485-5p (miR-485-5p), and myocyte enhancer factor 2D (MEF2D) in HCC cells.

Results

FAM83H-AS1 expression in HCC cells was markedly elevated. FAM83H-AS1 accelerated cell proliferation, migration and invasion whereas inhibiting cell apoptosis in HCC. Besides, we confirmed that FAM83H-AS1 acts as a miR-485-5p sponge in HCC cells. Additionally, MEF2D was verified to be a direct target of miR-485-5p. FAM83H-AS1 could upregulate MEF2D expression via sponging miR-485-5p. Further, rescue experiments testified that MEF2D upregulation or miR-485-5p downregulation offset the repressive effect of FAM83H-AS1 depletion on HCC cell progression.

Conclusions

FAM83H-AS1 facilitates HCC malignant progression via targeting miR-485-5p/MEF2D axis, suggesting that FAM83H-AS1 may be a promising biomarker for HCC treatment in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08923-0.

LINC01534 Promotes the Aberrant Metabolic Dysfunction and Inflammation in IL-1β-Simulated Osteoarthritic Chondrocytes by Targeting miR-140-5p

OBJECTIVE

Long non-coding RNA 01534 (LINC01534) is highly expressed in the tissues of patients with osteoarthritis (OA). This study investigated the mechanism of LINC01534 on abnormal metabolic dysfunction in OA chondrocytes induced by interleukin-1β (IL-1β).

METHODS

The quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expressions of LINC01534, aggrecan, collagen II, and matrix metalloproteinase (MMPs) in OA cartilage tissue or OA chondrocyte model induced by IL-1β. The expressions of aggrecan and collagen II in the chondrocyte were detected by Western blot. The levels of tumor necrosis factor-α (TNF-α), IL-8, IL-6, MMP-13, MMP-9, MMP-3, and prostaglandin E2 (PGE2) in chondrocyte were determined by enzyme-linked immunosorbernt assay. Bioinformatics, dual luciferin gene reporting, RNA pulldown, and Northern blot were used to determine the interaction between LINC01534 and miR-140-5p.

RESULTS

The results showed that LINC01534 was upregulated in both OA cartilage tissue and OA chondrocyte model. In addition, silencing LINC01534 significantly alleviated the inhibitory effect of IL-1β on expressions of aggrecan and collagen II in chondrocytes, and significantly downregulated the expression of matrix metalloproteinases in IL-1β-induced chondrocytes. Meanwhile, silencing LINC01534 also significantly inhibited the productions of proinflammatory factors NO, PGE2, TNF-α, IL-6, and IL-8 in the IL-1β-induced chondrocytes. Furthermore, miR-140-5p was confirmed to be a direct target of LINC01534. More importantly, inhibition of miR-140-5p significantly reversed the inhibitory effect of silencing LINC01534 on abnormal matrix degradation in the IL-1β-induced chondrocyte model of OA.

CONCLUSION

Therefore, LINC01534 could promote the abnormal matrix degradation and inflammatory response of OA chondrocytes through the targeted binding of miR-140-5p.

LncRNA TUG1 attenuates ischaemia-reperfusion-induced apoptosis of renal tubular epithelial cells by sponging miR-144-3p via targeting Nrf2

Renal ischaemia/reperfusion (I/R) injury may induce kidney damage and dysfunction, in which oxidative stress and apoptosis play important roles. Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are reported to be closely related to renal I/R, but the specific molecular mechanism is still unclear. The purpose of this research was to explore the regulatory effect of lncRNA TUG1 on oxidative stress and apoptosis in renal I/R injury. This research revealed that in renal I/R injury and hypoxia/reperfusion (H/R) injury in vitro, the expression level of lncRNA TUG1 was upregulated, and oxidative stress levels and apoptosis levels were negatively correlated with the expression level of lncRNA TUG1. Using bioinformatics databases such as TargetScan and microRNA.org, microRNA-144-3p (miR-144-3p) was predicted to be involved in the association between lncRNA TUG1 and Nrf2. This study confirmed that the level of miR-144-3p was significantly reduced following renal I/R injury and H/R injury in vitro, and miR-144-3p was determined to target Nrf2 and inhibit its expression. In addition, lncRNA TUG1 can reduce the inhibitory effect of miR-144-3p on Nrf2 by sponging miR-144-3p. In summary, our research shows that lncRNA TUG1 regulates oxidative stress and apoptosis during renal I/R injury through the miR-144-3p/Nrf2 axis, which may be a new treatment target for renal I/R injury.

LncRNA FAM230B Promotes Gastric Cancer Growth and Metastasis by Regulating the miR-27a-5p/TOP2A Axis

AIM

Long non-coding RNAs serve as key components of competing endogenous RNA (ceRNA) networks that underlie tumorigenesis. We investigated the pathogenic roles of lncRNA FAM230B and its molecular mechanism in gastric cancer (GC).

METHOD

The levels of FAM230B expression in five gastric cancer cell lines and in human gastric mucosal cells were compared by quantitative RT-PCR. To analyze the function of FAM230B in GC, we overexpressed FAM230B in AGS cells, silenced FAM230B in MGC-803 cells, and tested the effect of FAM230B on tumor growth in nude mice. The interaction between miR-27a-5p and FAM230B was predicted by a bioinformatics analysis and then verified with a dual-luciferase reporter assay. We also further investigated the role and mechanism of FAM230B by forcing overexpression of miR-27a-5p in MGC-803 gastric cancer cells.

RESULTS

We found that FAM230B was highly expressed in gastric cancer cell lines and mainly located in the cytoplasm. FAM230B overexpression promoted the proliferation, migration, and invasion of AGS cells and repressed their apoptosis; it also facilitated tumor growth in vivo. In contrast, FAM230B knockdown suppressed the proliferation, migration, and invasion of MGC0803 cells, but enhanced their apoptosis and inhibited tumor growth in vivo. MiR-27a-5p expression was suppressed by FAM230B overexpression in AGS cells. MiR-27a-5p inhibited the proliferation, migration, and invasion of gastric cancer cells, and promoted the apoptosis of gastric cancer cells by reducing TOP2A (topoisomerase 2 alpha) expression.

CONCLUSION

Our study showed that lncRNA FAM230B might function to promote GC. FAM230B functioned as a ceRNA by sponging miR-27a-5p and enhancing TOP2A expression.

Exosome-mediated transfer of circHIPK3 promotes trastuzumab chemoresistance in breast cancer

Breast cancer (BC) remains a public health dilemma in the world and it is one of the leading causes of death among women. Trastuzumab is a kind of commonly-used drugs in the treatment of BC, which especially can provide substantial benefits for HER2-positive BC. However, its long-time usage results in the emergence of resistance, which cuts down its efficacy in BC and leads to a poorer overall survival rate. Hence, the attempt of this study was to investigate how the drug resistance was enhanced. It has been identified that circHIPK3 could act as an oncogene in BC and promoted cell development through and a series of function assays. However, the underlying regulatory mechanism of circHIPK3 is not well established in trastuzumab resistance to date. Furthermore, we found the functional role of exosomes in trastuzumab chemoresistance and discovered that exosomes derived from trastuzumab-resistant cells could enhance the drug resistance of trastuzumab-sensitive cells. In last decades, competing endogenous RNA (ceRNA) has been a hot topic to investigate potential mechanism in cells. We subsequently performed mechanism experiments and rescue assays to verify circHIPK3 acted as a ceRNA in BC cells. In conclusion, we uncovered the regulatory mechanism by which exosome-transmitted circHIPK3 could promote trastuzumab chemoresistance of drug-sensitive BC cells.

Long non-coding RNA SNHG16 regulates E2F1 expression by sponging miR-20a-5p and aggravating proliferative diabetic retinopathy

Long non-coding RNAs (lncRNAs) were reported that related to microvascular dysfunction in diabetic retinopathy (DR), but the potential mechanism remains unknown. This study was designed to elucidate the effects of lncRNA SNHG16 in proliferative DR progression. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to measure the levels of SNHG16 and miR-20a-5p from peripheral blood samples of different participants. Pearson's correlation analysis on the plasma data was applied to detect correlations between SNHG16 and miR-20a-5p. Finally, the interactions of miR-20a-5p and SNHG16 or E2F1 were assessed by luciferase reporter assays. SNHG16 and E2F1 were increased and miR-20a-5p was decreased in proliferative DR both in vivo and in vitro, when compared with control or non-proliferative DR. E2F1 was identified as the target of miR-20a-5p. MiR-20a-5p interacted with SNHG16 and E2F1, and was controlled by SNHG16. The regulation of SNHG16 on E2F1 was mediated by miR-20a-5p. Cells transfected with SNHG16 OE plasmid markedly increased cell apoptosis and vessel-like formation, whereas the miR-20a-5p mimic partially reversed these effects. Transfection with si-E2F1 plasmid rescued SNHG16 overexpression-aggravated proliferative DR. This study indicated that SNHG16 regulated E2F1 expression by sponging miR-20a-5p and aggravating proliferative DR.

Long noncoding RNA network: Novel insight into hepatocellular carcinoma metastasis (Review)

Hepatocellular carcinoma (HCC) is one of the most common, aggressive malignancies with poor prognosis and high mortality. Although great progress has been made in recent decades, overall survival of HCC patients remains unsatisfactory due to high recurrence and metastasis. Accordingly, understanding and clarifying the underlying molecular mechanisms of metastasis has become increasingly important. Recently, accumulated reports have supported that long noncoding RNAs (lncRNAs) are dysregulated in HCC and are involved in various pivotal biological processes, including metastasis. The aim of this review was to investigate the dysregulation of lncRNAs in HCC and their function as oncogenes or tumour suppressors. Furthermore, reciprocal regulatory networks between lncRNAs and various molecules that were identified in HCC metastasis, including regulating epithelial-mesenchymal transition (EMT), controlling metastasis-associated genes, and regulating tumour angiogenesis were examined. Numerous reports and information on lncRNAs may help identify lncRNAs that are potential novel diagnostic markers, prognostic markers and therapeutic targets.

BBOX1-AS1 Accelerates Gastric Cancer Proliferation by Sponging miR-3940-3p to Upregulate BIRC5 Expression

BACKGROUND

Gastric cancer (GC) is one type of the most general malignancies in the globe. Research increasingly suggests long non-coding RNAs (lncRNAs) exert crucial roles in GC. However, the function of BBOX1-AS1 in GC has not been reported yet, it needs more explorations.

AIMS

The aim of the study is to figure out the role and related regulation mechanism of BBOX1-AS1 in GC.

METHODS

RT-qPCR assay was applied to detect genes expression. The role of BBOX1-AS1 in GC was investigated by cell counting kit-8, colony formation, tunel detection, and western blot assays. The binding ability between miR-3940-3p and BBOX1-AS1 (or BIRC5) by RIP, RNA pull-down and luciferase reporter assays.

RESULTS

The expression of BBOX1-AS1 presented significantly upregulation in GC tissues and cells. Moreover, upregulation of BBOX1-AS1 promoted GC cell proliferation, and inhibited GC cell apoptosis. However, downregulation of BBOX1-AS1 led to opposite results. Furtherly, we discovered that BBOX1-AS1 bound with miR-3940-3p and also negatively regulated miR-3940-3p. Besides, it proved that miR-3940-3p interplayed with BIRC5 and negatively regulated BIRC5. Through rescue experiments, we proved that BIRC5 reversed miR-3940-3p-mediated cell proliferation or apoptosis in BBOX1-AS1-dysregulated GC cells.

CONCLUSIONS

BBOX1-AS1 accelerates GC proliferation by sponging miR-3940-3p to upregulate BIRC5 expression, which may guide a new direction into the therapeutic strategies of GC.

Hepatitis B virus X protein promotes vimentin expression via LIM and SH3 domain protein 1 to facilitate epithelial-mesenchymal transition and hepatocarcinogenesis

BACKGROUND

Hepatitis B virus (HBV) X protein (HBX) has been reported to be responsible for the epithelial-mesenchymal transition (EMT) in HBV-related hepatocellular carcinoma (HCC). Vimentin is an EMT-related molecular marker. However, the importance of vimentin in the pathogenesis of HCC mediated by HBX has not been well determined.

METHODS

The expression of vimentin induced by HBX, and the role of LIM and SH3 domain protein 1 (LASP1) in HBX-induced vimentin expression in hepatoma cells were examined by western blot and immunohistochemistry analysis. Both the signal pathways involved in the expression of vimentin, the interaction of HBX with vimentin and LASP1, and the stability of vimentin mediated by LASP1 in HBX-positive cells were assessed by western blot, Co-immunoprecipitation, and GST-pull down assay. The role of vimentin in EMT, proliferation, and migration of HCC cells mediated by HBX and LASP1 were explored with western blot, CCK-8 assay, plate clone formation assay, transwell assay, and wound healing assay.

RESULTS

Vimentin expression was increased in both HBX-positive hepatoma cells and HBV-related HCC tissues, and the expression of vimentin was correlated with HBX in HBV-related HCC tissues. Functionally, vimentin was contributed to the EMT, proliferation, and migration of hepatoma cells mediated by HBX. The mechanistic analysis suggested that HBX was able to enhance the expression of vimentin through LASP1. On the one hand, PI3-K, ERK, and STAT3 signal pathways were involved in the upregulation of vimentin mediated by LASP1 in HBX-positive hepatoma cells. On the other hand, HBX could directly interact with vimentin and LASP1, and dependent on LASP1, HBX was capable of promoting the stability of vimentin via protecting it from ubiquitination mediated protein degradation. Besides these, vimentin was involved in the growth and migration of hepatoma cells mediated by LASP1 in HBX-positive hepatoma cells.

CONCLUSION

Taken together, these findings demonstrate that, dependent on LASP1, vimentin is crucial for HBX-mediated EMT and hepatocarcinogenesis, and may serve as a potential target for HBV-related HCC treatment. Video abstract.

Novel lncRNA LINC00941 Promotes Proliferation and Invasion of Colon Cancer Through Activation of MYC

Purpose

We conducted the study to elucidate how LncRNA LINC00941 affects colon cancer progression and its possible regulatory mechanism.

Methods

The expression level of LINC00941 in colon cancer tissues and cells was detected by qRT-PCR. The function of LINC00941 on colon cancer cell proliferation, migration, and invasion was detected by CCK-8 and Transwell assay respectively. The target interactions among LINC00941, miR-205-5p, and MYC were further confirmed by dual-luciferase reporter gene assays and RNA pull-down experiments. Meanwhile, in vivo experiments were carried out to study the role of LINC00941 in the xenotransplantation model.

Results

LINC00941 expression level was elevated in colon cancer tissues and cells. LINC00941 overexpression accelerated proliferation, migration, and invasion of colon cancer cells, while the LINC00941 knockdown showed the opposite results. In addition, LINC00941 regulated the expression of MYC by sponging miR-205-5p as a competitive endogenous RNA, and miR-205-5p knockdown reversed the tumor inhibition of LINC00941 knockdown on colon cancer cells. Xenograft model assay confirmed that LINC00941 silencing could inhibit colon cancer cell growth and metastasis.

Conclusion

LINC00941 may markedly promote colon cancer progression by acting on the miR-205-5p/MYC axis as a ceRNA, which offers novel clues for lncRNA to guide the treatment and prognosis of colon cancer.

Hepatitis B Virus DNA Polymerase Restrains Viral Replication Through the CREB1/HOXA Distal Transcript Antisense RNA Homeobox A13 Axis

BACKGROUND AND AIMS

Long noncoding RNAs (lncRNAs) have been associated with infection and hepatitis B virus (HBV)-related diseases, though the underlying mechanisms remain unclear.

APPROACH AND RESULTS

We obtained HBV-HCC lncRNA profiles by deep sequencing and found HOXA distal transcript antisense RNA (HOTTIP) to be significantly up-regulated. RT-qPCR indicated that HOTTIP is highly expressed in HBV-positive hepatoma tissue and induced by HBV in vitro. Virological experiments showed that HOTTIP significantly suppresses the generation of hepatitis B viral surface antigen, hepatitis B viral e antigen and HBV replication. Homeobox A13 (HOXA13), a downstream factor of HOTTIP, was found to bind to HBV enhancer I and X promotor to repress the production of HBV pregenome RNA (pgRNA) and total RNA as well as HBV replication, suggesting that HOXA13 mediates HOTTIP-induced suppression of HBV replication. More interestingly, HBV DNA polymerase (DNA pol) binds to and stabilizes cAMP-responsive element-binding protein 1 (CREB1) mRNA to facilitate translation of the protein, which, in turn, binds to the regulatory element of HOTTIP to promote its expression.

CONCLUSIONS

Our findings demonstrate that HBV DNA pol attenuates HBV replication through activation of the CREB1-HOTTIP-HOXA13 axis. These findings shed light on the mechanism by which HBV restrains replication to contribute to persistent infection.

microRNA-140: A miRNA with diverse roles in human diseases

MicroRNA-140 (miR-140) has been shown to be associated with the pathogenesis of a wide range of pathologies including osteoarthritis, osteoporosis, renal fibrosis, ischemic conditions, and most importantly neoplasia. This miRNA has been shown to be down-regulated in a diversity of cancers namely breast cancer, gastrointestinal cancers, lung cancer, and prostate cancer. miR-140 has a lot of immune-related targets. Moreover, several miR-140 targets regulate cell proliferation, cell cycle transition, and apoptosis. This miRNA has been shown to be sponged by a number of lncRNAs and circ-RNAs. miR-140 has essential roles in the determination of the sensitivity of neoplastic cells to chemotherapeutic agents such as temozolomide, doxorubicin, and cisplatin. Besides, expression quantities of miR-140 in cancer tissues can be used for the prediction of clinical outcomes of patients with neoplasia. In the present paper, we describe the impact of miR-140 in neoplastic and non-neoplastic disorders.

LncRNAs and their regulatory networks in breast muscle tissue of Chinese Gushi chickens during late postnatal development

BACKGROUND

Chicken skeletal muscle is an important economic product. The late stages of chicken development constitute the main period that affects meat production. LncRNAs play important roles in controlling the epigenetic process of growth and development. However, studies on the role of lncRNAs in the late stages of chicken breast muscle development are still lacking. In this study, to investigate the expression characteristics of lncRNAs during chicken muscle development, 12 cDNA libraries were constructed from Gushi chicken breast muscle samples from 6-, 14-, 22-, and 30-week-old chickens.

RESULTS

A total of 1252 new lncRNAs and 1376 annotated lncRNAs were identified. Furthermore, 53, 61, 50, 153, 117, and 78 DE-lncRNAs were found in the W14 vs. W6, W22 vs. W14, W22 vs. W6, W30 vs. W6, W30 vs. W14, and W30 vs. W22 comparison groups, respectively. After GO enrichment analysis of the DE-lncRNAs, several muscle development-related GO terms were found in the W22 vs. W14 comparison group. Moreover, it was found that the MAPK signaling pathway was one of the most frequently enriched pathways in the different comparison groups. In addition, 12 common target DE-miRNAs of DE-lncRNAs were found in different comparison groups, some of which were muscle-specific miRNAs, such as gga-miR-206, gga-miR-1a-3p, and miR-133a-3p. Interestingly, the precursors of four newly identified miRNAs were found to be homologous to lncRNAs. Additionally, we found some ceRNA networks associated with muscle development-related GO terms. For example, the ceRNA networks contained the DYNLL2 gene with 12 lncRNAs that targeted 2 miRNAs. We also constructed PPI networks, such as IGF-I-EGF and FZD6-WNT11.

CONCLUSIONS

This study revealed, for the first time, the dynamic changes in lncRNA expression in Gushi chicken breast muscle at different periods and revealed that the MAPK signaling pathway plays a vital role in muscle development. Furthermore, MEF2C and its target lncRNA may be involved in muscle regulation through the MAPK signaling pathway. This research provided valuable resources for elucidating posttranscriptional regulatory mechanisms to promote the development of chicken breast muscles after hatching.

Comprehensive analysis of key lncRNAs in HCV-positive hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Despite the therapeutic advances in HCC in the past few decades, the mortality rate of HCC is still high. Hepatitis C (HCV) infection is one of the major etiological risk factors of HCCs. However, the underlying mechanisms of HCV-induced hepatocarcinogenesis remain largely unclear.

MATERIAL AND METHODS

Our study represented the comprehensive analysis of differentially expressed lncRNAs in HCV-positive HCC for the first time by analyzing the public dataset GSE17856. Co-expression network and gene ontology (GO) analysis revealed the functions of those differentially expressed lncRNAs.

RESULTS

We identified 256 upregulated lncRNAs and 198 downregulated lncRNAs in HCV- positive HCC compared to the normal liver tissues. Co-expression network and GO analysis showed that these lncRNAs were involved in regulating metabolism, energy pathways, proliferation and the immune response. Seven lncRNAs (LOC341056, CCT6P1, PTTG3P, LOC643387, LOC100133920, C3P1 and C22orf45) were identified as key lncRNAs and co-expressed with more than 100 differentially expressed genes (DEGs) in HCV-related HCC. Kaplan-Meier analysis showed that higher expression levels of LOC643387, PTTG3P, LOC341056, CCT6P1 and lower expression levels of C3P1 and C22orf45 were associated with shorter survival time in the TCGA dataset.

CONCLUSIONS

We believe that this study can provide novel potential therapeutic and prognostic biomarkers for HCV-positive HCC.

Catalpol inhibits the proliferation, migration and metastasis of HCC cells by regulating miR‑140‑5p expression

Hepatocellular carcinoma (HCC) is a frequent malignant tumor. Catalpol is a Chinese medicine extract with a number of pharmacologically active properties. The present study aimed to investigate the effects and mechanisms of catalpol in HCC. HCC cells were treated with catalpol in the presence or absence of microRNA (miR)-140-5p inhibitor, and assays to determine cell viability, proliferation, invasion and migration were performed. Reverse transcription-quantitative PCR and western blotting were performed to determine the mRNA and protein expression levels of miR-140-5p, vimentin, N-Cadherin and E-Cadherin. Moreover, cells were treated with catalpol in the absence or presence of transforming growth factor (TGF)-β1, and the cell morphology was observed under a microscope. The results demonstrated that catalpol inhibited cell proliferation, invasion and migration, and decreased the expression levels of vimentin and N-cadherin, but increased the expression levels of E-cadherin and miR-140-5p. Catalpol inhibited morphological changes in epithelial-mesenchymal transformation (EMT) of cells induced by TGF-β1. Following inhibition of miR-140-5p expression, the proliferation, invasion and migration of HCC cells were promoted, E-cadherin expression was decreased, and the levels of vimentin and N-cadherin were increased. The miR-140-5p inhibitor effectively reversed the inhibitory effect of catalpol on cell proliferation, invasion and migration. Thus, the results suggested that the antitumor potential of catalpol in HCC may be exerted by regulating the expression of miR-140-5p to inhibit proliferation, invasion, migration and EMT of HCC cells.

miR-140-3p inhibits bladder cancer cell proliferation and invasion by targeting FOXQ1

Upregulation of the forkhead box protein Q1 (FOXQ1) promotes bladder cancer (BCa) cell growth and metastasis. Factors affecting FOXQ1 expression at the post-transcriptional level have not yet been identified. We performed cell proliferation, cell invasion, and tumorigenesis experiments to characterize the relationship between FOXQ1 and miR-140-3p. We found that FOXQ1 was significantly upregulated and miR-140-3p was significantly downregulated in BCa tissues. We also identified an inverse correlation between miR-140-3p and FOXQ1 expression in BCa tissues. Overexpression of miR-140-3p reduced FOXQ1 expression, suppressing BCa cell proliferation and invasion. A luciferase assay confirmed that miR-140-3p bound to the 3’-UTR of FOXQ1 mRNA and decreased its expression. In addition, we used a mouse xenograft model to demonstrate that miR-140-3p suppressed tumor cell growth in vivo. Our findings suggest that miR-140-3p suppresses BCa cell proliferation and invasion by directly decreasing FOXQ1 expression.

Epigenetic silencing of CDKN1A and CDKN2B by SNHG1 promotes the cell cycle, migration and epithelial-mesenchymal transition progression of hepatocellular carcinoma

Enhanced SNHG1 (small nucleolar RNA host gene 1) expression has been found to play a critical role in the initiation and progression of hepatocellular carcinoma (HCC) with its detailed mechanism largely unknown. In this study, we show that SNHG1 promotes the HCC progression through epigenetically silencing CDKN1A and CDKN2B in the nucleus, and competing with CDK4 mRNA for binding miR-140-5p in the cytoplasm. Using bioinformatics analyses, we found hepatocarcinogenesis is particularly associated with dysregulated expression of SNHG1 and activation of the cell cycle pathway. SNHG1 was upregulated in HCC tissues and cells, and its knockdown significantly inhibited HCC cell cycle, growth, metastasis, and epithelial–mesenchymal transition (EMT) both in vitro and in vivo. Chromatin immunoprecipitation and RNA immunoprecipitation assays demonstrate that SNHG1 inhibit the transcription of CDKN1A and CDKN2B through enhancing EZH2 mediated-H3K27me3 in the promoter of CDKN1A and CDKN2B, thus resulting in the de-repression of the cell cycle. Dual-luciferase assay and RNA pulldown revealed that SNHG1 promotes the expression of CDK4 by competitively binding to miR-140-5p. In conclusion, we propose that SNHG1 formed a regulatory network to confer an oncogenic function in HCC and SNHG1 may serve as a potential target for HCC diagnosis and treatment.

Interference of miR-107 with Atg12 is inhibited by HULC to promote metastasis of hepatocellular carcinoma

Highly upregulated in liver cancer (HULC) had a significant predictive effect on tumor growth and metastasis of hepatocellular carcinoma (HCC); however, the mechanisms of HULC on HCC still need to be clarified. We attempted to determine the roles of HULC and miR-107 in autophagy and invasion of HCC. HULC siRNA reduced the level of autophagy. The impact of HULC siRNA on invasion can be reversed by activating autophagy in HCC cell lines. Further studies on HULC and autophagy were conducted. An interacting sequence between HULC and miR-107, as well as miR-107 and Atg12, was predicted by software. The relationship of each pair of molecules was confirmed by luciferase reporter assays. The negative impacts of miR-107 on autophagy and invasion were proved in HCC cell lines. The inhibitor of miR-107-promoted invasion can also be reversed by Atg12 siRNA. The changes of miR-107, Atg12, epithelial-mesenchymal transition, and autophagy in transplanted tumors of mouse models also confirmed the results in HCC cell lines. Finally, we find that HULC acts as an endogenous sponge, which abolishes the binding of miR-107 on the Atg12 3'-UTR and promotes autophagy and metastasis of HCC.

LncRNA HMMR-AS1 promotes proliferation and metastasis of lung adenocarcinoma by regulating MiR-138/sirt6 axis

Purpose: Long noncoding RNAs (lncRNA) play critical roles in cancer development. In this study, we aimed to explore the function and possible molecular mechanism of HMMR-AS1 involved in lung adenocarcinoma (LUAD).

Experimental Design: Firstly, we analyzed HMMR-AS1 expression in LUAD tissues with the sequencing data from The Cancer Genome Atlas (TCGA). Next, we evaluated the effects of HMMR-AS1 on LUAD cell proliferation and apoptosis, and its regulation of miR-138 by acting as a ceRNA. The animal model was used to support the in vitro experimental findings.

Results: HMMR-AS1 expression was significantly upregulated in LUAD tissues and was associated with larger tumor diameter, advanced TNM stage, lymph node metastasis, and shorter survival. Knockdown of HMMR-AS1 induced apoptosis and growth arrest in vitro and inhibited tumorigenesis in mouse xenografts. Mechanistically, HMMR-AS1 functioned as a ceRNA of miR-138, thereby leading to repression of its endogenous target sirt6. Moreover, knockdown of HMMR-AS1 dramatically inhibited tumor growth and metastasis of LUAD in vivo.

Conclusions: Taken together, HMMR-AS1 is significantly over-expressed in LUAD, and HMMR-AS1–miR-138–sirt6 axis play a critical role in LUAD tumorigenesis. Our findings highlight an oncogenic role of HMMR-AS1 in LUAD.

Long Non-Coding RNAs As Epigenetic Regulators in Cancer

Long noncoding RNAs (lncRNAs) constitute large portions of the mammalian transcriptome which appeared as a fundamental player, regulating various cellular mechanisms. LncRNAs do not encode proteins, have mRNA-like transcripts and frequently processed similar to the mRNAs. Many investigations have determined that lncRNAs interact with DNA, RNA molecules or proteins and play a significant regulatory function in several biological processes, such as genomic imprinting, epigenetic regulation, cell cycle regulation, apoptosis, and differentiation. LncRNAs can modulate gene expression on three levels: chromatin remodeling, transcription, and post-transcriptional processing. The majority of the identified lncRNAs seem to be transcribed by the RNA polymerase II. Recent evidence has illustrated that dysregulation of lncRNAs can lead to many human diseases, in particular, cancer. The aberrant expression of lncRNAs in malignancies contributes to the dysregulation of proliferation and differentiation process. Consequently, lncRNAs can be useful to the diagnosis, treatment, and prognosis, and have been characterized as potential cancer markers as well. In this review, we highlighted the role and molecular mechanisms of lncRNAs and their correlation with some of the cancers.

Regulation of laryngeal squamous cell cancer progression by the lncRNA RP11-159K7.2/miR-206/DNMT3A axis

Long non‐coding RNAs (lncRNAs), which are longer than 200 nt, have been proved to play a role in promoting or inhibiting cancer progression. The following study investigated the role and underlying mechanisms of lncRNA RP11‐159K7.2 in laryngeal squamous cell carcinoma (LSCC) progression. Briefly, in situ hybridization (ISH) and real‐time quantitative PCR (RT‐qPCR) showed higher expression of RP11‐159K7.2 in LSCC tissues and cell lines. Patients with low expression level of RP11‐159K7.2 lived longer compared to those with high expression of RP11‐159K7.2 (χ² = 39.111, ***P < 0.001). Multivariate Cox regression analysis suggested that lncRNA RP11‐159K7.2 was an independent prognostic factor for LSCC patients (HR = 2.961, ***P < 0.001). Furthermore, to investigate the potential involvement of RP11‐159K7.2 in the development of LSCC, we knocked out the expression of endogenous RP11‐159K7.2 in TU‐212 cells and AMC‐HN‐8 cells via CRISPR/Cas9 double vector lentiviral system. RP11‐159K7.2 knockout decreased LSCC cell growth and invasion both in vitro and in vivo. Mechanically, we found that RP11‐159K7.2 could positively regulate the expression of DNMT3A by sponging miR‐206. In addition, a feedback loop was also discovered between DNMT3A and miR‐206. To sum up, these findings suggest that lncRNA RP11‐159K7.2 could be used as a potential biomarker for prognosis and treatment of LSCC.

LncRNA-HNF1A-AS1 functions as a competing endogenous RNA to activate PI3K/AKT signalling pathway by sponging miR-30b-3p in gastric cancer

BACKGROUND

Accumulating evidence demonstrated that long noncoding RNAs (lncRNAs) played important regulatory roles in many cancer types. However, the role of lncRNAs in gastric cancer (GC) progression remains unclear.

METHODS

RT-qPCR assay was performed to detect the expression of HNF1A-AS1 in gastric cancer tissues and the non-tumourous gastric mucosa. Overexpression and RNA interference approaches were used to investigate the effects of HNF1A-AS1 on GC cells. Insight into competitive endogenous RNA (ceRNA) mechanisms was gained via bioinformatics analysis, luciferase assays and an RNA-binding protein immunoprecipitation (RIP) assay, RNA-FISH co-localisation analysis combined with microRNA (miRNA)-pulldown assay.

RESULTS

This study displayed that revealed expression of HNF1A-AS1 was associated with positive lymph node metastasis in GC. Moreover, HNF1A-AS1 significantly promoted gastric cancer invasion, metastasis, angiogenesis and lymphangiogenesis in vitro and in vivo. In addition, HNF1A-AS1 was demonstrated to function as a ceRNA for miR-30b-3p. HNF1A-AS1 abolished the function of the miRNA-30b-3p and resulted in the derepression of its target, PIK3CD, which is a core oncogene involved in the progression of GC.

CONCLUSION

This study demonstrated that HNF1A-AS1 worked as a ceRNA and promoted PI3K/AKT signalling pathway-mediated GC metastasis by sponging miR-30b-3p, offering novel insights of the metastasis mechanism in GC.

YY1-induced upregulation of FOXP4-AS1 and FOXP4 promote the proliferation of esophageal squamous cell carcinoma cells

Esophageal squamous cell carcinoma (ESCC) belongs to one of the most common malignant tumors worldwide and possesses high mortality. Long non-coding RNAs (lncRNAs) have been demonstrated to be essential biological participants in the progression of ESCC. On the basis of bio-informatics prediction, forkhead box P4 antisense RNA 1 (FOXP4-AS1) and forkhead box P4 (FOXP4) were upregulated in esophageal carcinoma samples and were positively correlated with each other. The present study aimed to explore the function of FOXP4-AS1 and FOXP4 in ESCC cells. Function assays disclosed that knockdown of FOXP4-AS1 or FOXP4 efficiently suppressed cell proliferation and induced cell apoptosis. Moreover, FOXP4-AS1 positively regulated FOXP4 by interacting with insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) to stabilize FOXP4 messenger RNA. In addition, FOXP4-AS1 could upregulate the expression of FOXP4 by sponging miR-3184-5p. Finally, we found that Yin Yang 1 (YY1) is a transcription factor that can transcriptionally activate both FOXP4-AS1 and FOXP4 in ESCC cells. In a word, YY1-induced upregulation of FOXP4-AS1 and FOXP4 promote the proliferation of ESCC cells.

YY1-induced lncRNA ZFPM2-AS1 facilitates cell proliferation and invasion in small cell lung cancer via upregulating of TRAF4

Background

Newly identified lncRNA zinc finger protein, FOG family member 2 antisense RNA 1 (ZFPM2-AS1) is identified as an oncogenic gene. However, the role of ZFPM2-AS1 in small cell lung cancer (SCLC) is poorly comprehended.

Methods

The expression of genes in SCLC tissues and cells was measured by qRT-PCR. Colony formation, EdU, CCK-8, transwell and wound healing as well as in vivo assays revealed the function of ZFPM2-AS1 in SCLC. ChIP, luciferase reporter, RIP and RNA pull down assays demonstrated the binding relation among genes.

Results

ZFPM2-AS1 was significantly upregulated in SCLC tissues and cells. ZFPM2-AS1 deficiency attenuated SCLC cell proliferation, invasion and migration. In addition, ZFPM2-AS1 was transcriptionally activated by Yin Yang 1 (YY1) factor. Further, miR-3612 was confirmed as downstream miRNA of ZFPM2-AS1. Moreover, TNF receptor associated factor 4 (TRAF4) was the target gene of miR-3612 in SCLC. ZFPM2-AS1, miR-3612 and TRAF4 jointly constituted a competing endogenous RNA (ceRNA) network in SCLC. Finally, TRAF4 could countervail ZFPM2-AS1 downregulation-mediated function on SCLC cell proliferation and invasion in vitro and tumor growth in vivo.

Conclusion

Our study elucidated the oncogenic effect of ZFPM2-AS1 in SCLC progression, indicating it may be a therapeutic target for SCLC.

Data Mining and Expression Analysis of Differential lncRNA ADAMTS9-AS1 in Prostate Cancer

Long noncoding RNAs (lncRNAs) play important roles in the regulation of gene expression by acting as competing endogenous RNAs (ceRNAs). However, the roles of lncRNA-associated ceRNAs in oncogenesis are not fully understood. The present study aims to determine whether a ceRNA network can serve as a prognostic marker in human prostate cancer (PCa). In order to identify a ceRNA network and the key lncRNAs in PCa, we constructed a differentially expressed lncRNAs (DELs)-differentially expressed miRNAs (DEMis)-differentially expressed mRNAs (DEMs) regulatory network based on the ceRNA theory using data from the Cancer Genome Atlas (TCGA). We found that the DELs-DEMis-DEMs network was composed of 27 DELs nodes, seven DEMis nodes, and three DEMs nodes. The 27 DELs were further analyzed with several public databases to provide meaningful information for understanding the functional roles of lncRNAs in regulatory networks in PCa. We selected ADAMTS9-AS1 to determine its role in PCa and found that ADAMTS9-AS1 significantly influences tumor cell growth and proliferation, suggesting that it plays a tumor suppressive role. In addition, ADAMTS9-AS1 functioned as ceRNA, effectively becoming a sponge for hsa-mir-96 and modulating the expression of PRDM16. These results suggest that ceRNAs could accelerate biomarker discovery and therapeutic strategies for PCa.

Correlation of Long Noncoding RNA SEMA6A-AS1 Expression with Clinical Outcome in HBV-Related Hepatocellular Carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is the seventh most commonly diagnosed cancer and the fourth-leading cause of cancer-related death worldwide. Chronic hepatitis B virus (HBV) is the leading cause of HCC in China. Emerging evidence suggests that long noncoding (lnc)-RNAs are deregulated and are involved in the development of HCC. Our previous study found that HBV X protein can promote HCC by altering lncRNA expression profiles. The purpose of this study was to investigate the expression of the lncRNA semaphorin 6A-antisense RNA 1 (SEMA6A-AS1) and its prognostic value in HBV-related HCC.

METHODS

Samples of HCC tissues and adjacent nontumor tissues were collected from patients who were pathologically diagnosed with HBV-related HCC after hepatectomy. Eligible patients had not received preoperative radiotherapy, chemotherapy, or embolotherapy. Real-time quantitative reverse-transcription polymerase chain reaction was performed to evaluate the expression levels of SEMA6A-AS1 in all tissue specimens. The correlations between SEMA6A-AS1 expression and clinicopathologic characteristics were analyzed using the χ² test and the Fisher exact test. Overall survival curves constructed by the Kaplan-Meier method and univariate analysis made by Cox proportional hazards modeling were used for determining the prognostic significance of SEMA6A-AS1.

FINDINGS

Specimens were collected from 47 patients (45 men, 2 women; mean age, 48.4 [10.7] years). SEMA6A-AS1 expression was significantly downregulated in HBV-related HCC tissues compared with that in adjacent noncancerous hepatic tissues (P < 0.01). Low levels of SEMA6A-AS1 were correlated with high α-fetoprotein level (P = 0.002), high Edmondson-Steiner tumor grade (P = 0.047), high tumor node metastasis stage (P = 0.01), capsular invasion (P = 0.005), and poor clinical response (P = 0.002). Additionally, both Kaplan-Meier estimator and univariate Cox regression analysis revealed that low SEMA6A-AS1 expression was significantly associated with poor overall survival (P < 0.05).

IMPLICATIONS

The results show that low expression of SEMA6A-AS1 was associated with a poor prognosis in patients with HBV-related HCC. It is necessary to determine the function and mechanism of SEMA6A-AS1 in HCC in order to identify it as a prognostic biomarker and therapeutic target.

MiR-135b-5p promotes viability, proliferation, migration and invasion of gastric cancer cells by targeting Krüppel-like factor 4 (KLF4)

INTRODUCTION

The expression of MiR-135b-5p was up-regulated while Krüppel-like factor 4 (KLF4) expression was extremely low in human gastric carcinoma (GC) tissues. This study aimed to explore the role of miR-135b-5p in GC cells and its influence on various cell capacity and viability by targeting KLF4.

MATERIAL AND METHODS

The dual-luciferase reporter assay was first performed and the target relationship between miR-135b-5p and KLF4 was confirmed. Then three GC cell lines and the human normal gastric epithelial cell line (GES1) were analyzed for the expression level of miR-135b-5p and KLF4 mRNA by RT-qPCR. The BGC-823 GC cell line was chosen for subsequent assays.

RESULTS

The expression of miR-135b-5p and KLF4 was manipulated via transfection. The changes of proliferation, invasion, migration, viability, cycle and apoptosis of GC cells were evaluated by MTS, colony formation assay, transwell assay, wound healing assay and flow cytometry assay, respectively. Overexpression of MiR-135b-5p enhanced viability, proliferation, invasion and migration of GC cells, increased cell viability and reduced cell apoptosis. Replenishing of KLF4 functioned oppositely.

CONCLUSIONS

The inhibitory effects of ectopic KLF4 could be attenuated by co-transfection of miR-135b-5p. Collective data suggested that miR-135b-5p has a tumor-promoting role in GC cells via downregulating KLF4. Hence, inhibition of miR-135b-5p could be valuable for treatment of gastric cancer.

Long non‑coding RNA Unigene56159 promotes glioblastoma multiforme cell proliferation and invasion through negatively regulating microRNA‑194‑5p

Long non-coding RNAs (lncRNA) serve a vital role in tumor progression. The present study identified a fundamental role for a novel lincRNA, Unigene56159, in the progression of glioblastoma (GBM). Unigene56159 gene expression was found to be significantly upregulated in tissue samples from patients with GBM as well as in GBM cell lines by reverse transcription-quantitative PCR, while microRNA (miR)-194-5p expression levels were decreased. This higher expression level of Unigene56159 was positively correlated with poor overall survival in patients with GBM. However, the mechanism by which this occurs remains to be elucidated. lncRNAs may act as endogenous miRNA sponges for binding to miRNAs or participating in the competitive endogenous RNAs (ceRNA) regulatory network. Small interfering RNA (siRNA) was used to silence the expression of Unigene56159 and inhibit the proliferation and invasion of GBM cell lines by MTT and Transwell assay. Unigene56159 was found to directly interact with miR-194-5p, and rescue assay was performed to further confirm that Unigene56159 contributed to glioma progression by regulating miR-194-5p. Thus, Unigene56159 may function as a competing endogenous RNA by sequestering miR-194-5p in GBM cells. These findings suggested that Unigene56159 may serve an oncogenic role in GBM and may promote disease progression through interacting with miR-194-5p. This could be a potential therapeutic target for the treatment of GBM.

Long non‑coding RNAs in HBV‑related hepatocellular carcinoma (Review)

Hepatitis B virus (HBV)‑related hepatocellular carcinoma (HCC) is a global health problem that accounts for more than half of total liver cancer cases in developing countries. Despite the growing number of researches conducted, the molecular mechanism underlying the development of HCC remains elusive. Long non‑coding RNAs (lncRNAs), which are non‑coding RNAs >200 nt in length that were previously considered to be transcriptional noise, have been found to be dysregulated in HBV‑related HCC with the help of high‑throughput omics techniques. Subsequent investigations revealed that aberrant expression of lncRNAs may affect the risk of HBV‑related HCC through diverse mechanisms, including epigenetic silencing of transcriptional activation, alternative splicing, molecular sponging, modulating protein stability, and by serving as precursors of miRNAs. Although the sensitivity and specificity of lncRNAs must be further validated, a number of circulating lncRNAs have been identified as useful biomarkers for HBV‑related HCC. In addition to these findings, recent studies also unveiled that certain genetic polymorphisms in lncRNAs may affect the occurrence and prognosis of HBV‑related HCC. The aim of the present review was to provide an overview of the mechanisms underlying the involvement of lncRNAs in HBV‑related HCC. Subsequently, lncRNAs found to be dysregulated in HBV‑related HCC were focused on and current findings on circulating lncRNAs and their genetic polymorphisms were discussed.

SSTR5‑AS1 functions as a ceRNA to regulate CA2 by sponging miR‑15b‑5p for the development and prognosis of HBV‑related hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) have been implicated in the development and progression of cancer. However, the mechanisms of lncRNAs in hepatitis B virus (HBV) infection-induced hepatocellular carcinoma (HCC) remain unclear. The study aimed to reveal the roles of lncRNAs for HBV-HCC based on the hypothesis of competing endogenous RNA (ceRNA). The lncRNA (GSE27462), miRNA (GSE76903) and mRNA (GSE121248) expression profiles were collected from the Gene Expression Omnibus database. Differentially expressed lncRNAs (DELs), genes (DEGs) and miRNAs (DEMs) were identified using the LIMMA or EdgeR package, respectively. The ceRNA network was constructed based on interaction pairs between miRNAs and mRNAs/lncRNAs. The functions of DEGs in the ceRNA network were predicted using the DAVID database, which was overlapped with the known HCC pathways of Comparative Toxicogenomics Database (CTD) to construct the HCC-related ceRNA network. The prognosis values [overall survival, (OS); recurrence-free survival (RFS)] of genes were validated using the Cancer Genome Atlas (TCGA) data with Cox regression analysis. The present study screened 38 DELs, 127 DEMs and 721 DEGs. A ceRNA network was constructed among 17 DELs, 12 DEMs and 173 DEGs, including the FAM138B-hsa-miR-30c-CCNE2/RRM2 and SSTR5-AS1-hsa-miR-15b-5p-CA2 ceRNA axes. Function enrichment analysis revealed the genes in the ceRNA network that participated in the p53 signaling pathway [cyclin E2 (CCNE2), ribonucleotide reductase M2 subunit (RRM2)] and nitrogen metabolism [carbonic anhydrase 2 (CA2)], which were also included in the pathways of the CTD. Univariate Cox regression analysis revealed that six RNAs (2 DELs: FAM138B, SSTR5-AS1; 2 DEMs: hsa-miR-149, hsa-miR-7; 2 DEGs: CCNE2, RRM2) were significantly associated with OS; while seven RNAs (1 DEL: LINC00284; 3 DEMs: hsa-miR-7, hsa-miR-15b, hsa-miR-30c-2; and 3 DEGs: RRM2, CCNE2, CA2) were significantly associated with RFS. In conclusion, FAM138B-hsa-miR-30c-CCNE2/RRM2 and the SSTR5-AS1-hsa-miR-15b-5p-CA2 ceRNA axes may be important mechanisms for HBV-related HCC.

LINC01342 promotes the progression of ovarian cancer by absorbing microRNA-30c-2-3p to upregulate HIF3A

Ovarian cancer (OC) is a highly prevalent gynecologic malignancy and its mortality is extremely high. Therefore, the development of novel therapeutic approaches for OC is of great significance. In this study, LINC01342 was upregulated in OC tissue in the GSE38666 microarray and in tumor tissue samples collected in our center. The silencing of LINC01342 suppressed the proliferative and metastatic capacities of A2780 and HO8910 cells. Subcellular distribution assays showed that LINC01342 was mainly enriched in the cytoplasm. Subsequently, the downregulation of microRNA-30c-2-3p was proven to be the target of LINC01342. The silencing of microRNA-30c-2-3p enhanced the clonality and migratory capacity of OC cells. Moreover, the silencing of microRNA-30c-2-3p could reverse the inhibited migration and clonality in OC cells caused by LINC01342 knockdown. In addition, hypoxia-inducible factor 3 subunit α (HIF3A) was proven to be the target gene of microRNA-30c-2-3p, which was upregulated. HIF3A was negatively regulated by microRNA-30c-2-3p but positively regulated by LINC01342 in OC cells. An RNA binding protein immunoprecipitation assay showed that microRNA-30c-2-3p, LINC01342, and HIF3A could bind to argonaute RISC catalytic component 2. The overexpression of HIF3A reversed the inhibited migration and clonality in OC cells with LINC01342 knockdown. By analyzing the follow-up data from the enrolled OC patients, the LINC01342 and HIF3A levels were negatively correlated with prognosis, while the microRNA-30c-2-3p level was positively correlated with the same. In short, the upregulated LINC01342 in OC absorbs microRNA-30c-2-3p to release HIF3A. Thus, upregulated HIF3A expression accelerates the progression of OC.

CCL18-induced HOTAIR upregulation promotes malignant progression in esophageal squamous cell carcinoma through the miR-130a-5p-ZEB1 axis

Accumulating evidence indicates that CCL18 and the long non-coding RNA, HOTAIR, have critical roles in cancer progression and metastasis, but the correlation between CCL18 and HOTAIR in esophageal squamous cell carcinoma (ESCC) and their downstream molecular mechanisms remain unclear. Overexpression of CCL18 in ESCC tissues was associated with a worse survival in patients with ESCC. CCL18 enhanced the invasiveness of ESCC cells in a dose-dependent manner, whereas CCL18 knockdown inhibited their invasiveness. In particular, CCL18 expression was positively associated with HOTAIR expression in ESCC tissues. Furthermore, CCL18 upregulated the expression of HOTAIR, and knockdown of HOTAIR alleviated the CCL18-induced invasiveness of ESCC cells. HOTAIR may act as a competing endogenous RNA and could effectively becoming a sponge for miR-130a-5p, thereby modulating the derepression of ZEB1 and promoting epithelial-mesenchymal transition in ESCC. Our study suggests that CCL18 contributes to the malignant progression of esophageal cancer by upregulating HOTAIR expression. HOTAIR overexpression may promote tumor invasiveness and progression in ESCC, given that HOTAIR functions as a miR-130a-5p sponge, positively regulating ZEB1. This provides new therapeutic targets for early diagnosis and treatment of ESCC.

TGFβ1- miR-140-5p axis mediated up-regulation of Flap Endonuclease 1 promotes epithelial-mesenchymal transition in hepatocellular carcinoma

Flap Endonuclease 1 (FEN1) is a known oncogene in an array of cancers, but its role in hepatocellular carcinoma (HCC) remains obscure. In this study, we report that FEN1 expression was elevated in the Cancer Genome Atlas (TCGA) database which was verified in HCC tissue and hepatoma cell lines. Pearson correlation analysis indicated that FEN1 was involved in HCC metastasis. We demonstrated that FEN1 silencing inhibits HCC cell epithelial-mesenchymal transition (EMT), invasion and migration in vitro and significantly suppressed tumor growth and metastasis in vivo. Conversely, FEN1 overexpression in HCC cells enhanced these metastatic processes. We further confirmed that FEN1 was a direct target of miR-140-5p, which was down-regulated in HCC tissues, and negatively correlated with FEN1 expression. Moreover, low miR-140-5p levels and high FEN1 expression predicted a poor clinical outcome. The effects of FEN1 overexpression could be partially abolished by miR-140-5p. miR-140-5p down-regulation and FEN1 overexpression were observed in a TGFβ1 induced EMT model. TGFβ1 mediated EMT could be blocked by miR-140-5p overexpression or FEN1 silencing. Taken together, our findings suggest that FEN1 is regulated by the TGFβ1- miR-140-5p axis and promotes EMT in HCC.

Relationship among porcine lncRNA TCONS_00010987, miR-323, and leptin receptor based on dual luciferase reporter gene assays and expression patterns

Objective

Considering the physiological and clinical importance of leptin receptor (LEPR) in regulating obesity and the fact that porcine LEPR expression is not known to be controlled by lncRNAs and miRNAs, we aim to characterize this gene as a potential target of SSC-miR-323 and the lncRNA TCONS_00010987.

Methods

Bioinformatics analyses revealed that lncRNA TCONS_00010987 and LEPR have SSC-miR-323-binding sites and that LEPR might be a target of lncRNA TCONS_00010987 based on cis prediction. Wild-type and mutant TCONS_00010987-target sequence fragments and wild-type and mutant LEPR 3′-UTR fragments were generated and cloned into pmiR-RB-REPORT^TM-Control vectors to construct respective recombinant plasmids. HEK293T cells were co-transfected with the SSC-miR-323 mimics or a negative control with constructs harboring the corresponding binding sites and relative luciferase activities were determined. Tissue expression patterns of lncRNA TCONS_00010987, SSC-miR-323, and LEPR in Anqing six-end-white (AQ, the obese breed) and Large White (LW, the lean breed) pigs were detected by real-time quantitative polymerase chain reaction; backfat expression of LEPR protein was detected by western blotting.

Results

Target gene fragments were successfully cloned, and the four recombinant vectors were constructed. Compared to the negative control, SSC-miR-323 mimics significantly inhibited luciferase activity from the wild-type TCONS_00010987-target sequence and wild-type LEPR-3′-UTR (p<0.01 for both) but not from the mutant TCONS_00010987-target sequence and mutant LEPR-3′-UTR (p>0.05 for both). Backfat expression levels of TCONS_ 00010987 and LEPR in AQ pigs were significantly higher than those in LW pigs (p<0.01), whereas levels of SSC-miR-323 in AQ pigs were significantly lower than those in LW pigs (p<0.05). LEPR protein levels in the backfat tissues of AQ pigs were markedly higher than those in LW pigs (p<0.01).

Conclusion

LEPR is a potential target of SSC-miR-323, and TCONS_00010987 might act as a sponge for SSC-miR-323 to regulate LEPR expression.

Long non-coding RNA SPRY4-IT1 promotes epithelial-mesenchymal transition of cervical cancer by regulating the miR-101-3p/ZEB1 axis

BACKGROUND

Emerging evidences have indicated that long non-coding RNAs (LncRNAs) play vital roles in cancer development and progression. Previous studies have suggested that overexpression of SPRY4 intronic transcript 1 (SPRY4-IT1) predicates poor prognosis and promotes tumor progress in cervical cancer (CC). However, the underlying mechanism of SPRY4-IT1 in CC remains unknown. The aim of the present study is to evaluate the function and mechanism of SPRY4-IT1 in CC.

METHODS

SPRY4-IT1 was detected by quantitative PCR. Wound-healing assay and Transwell assay were performed to detect cell migration and invasion, respectively. Western blotting assays were used to analyze the protein expression of E-cadherin, N-cadherin and vimentin. Tumor xenografts experiments were performed to detect the effect of SPRY4-IT1 in vivo. Dual luciferase reporter assay was used to investigate potential molecular mechanism of SPRY4-IT1 in CC cells.

RESULTS

SPRY4-IT1 was up-regulated in CC cell lines. Knockdown of SPRY4-IT1 significantly inhibited CC cells migration and invasion in vitro and in vivo Moreover, knockdown of SPRY4-IT1 significantly suppressed the epithelial-mesenchymal transition (EMT) of CC by increased E-cadherin expression and decreased the N-cadherin and vimentin expression. Mechanically, SPRY4-IT1 could directly bind to miR-101-3p and effectively act as a competing endogenous RNA (ceRNA) for miR-101-3p to regulate the expression of the target gene ZEB1Conclusions: Our findings indicate that the SPYR4-IT1/miR-101-3p/ZEB1 axis contributes to CC migration and invasion, which may provide novel insights into the function of lncRNA-driven tumorigenesis of CC.

LncRNA FOXP4-AS1 is activated by PAX5 and promotes the growth of prostate cancer by sequestering miR-3184-5p to upregulate FOXP4

Prostate cancer (PCa) is one of the major men malignancies worldwide. Long noncoding RNAs (lncRNAs) have been reported as essential regulators in human cancers, including PCa. In the present study, lncRNA forkhead box P4 antisense RNA 1 (FOXP4-AS1) was found to be highly expressed in TCGA PCa samples. Upregulation of FOXP4-AS1 was further validated in 64 PCa tissues and predicted poor prognosis in patients with PCa. Functionally, high FOXP4-AS1 level was associated with increased cell proliferation and decreased cell apoptosis, indicating that FOXP4-AS1 exerted oncogenic functions in the tumorigenesis of PCa. Furthermore, FOXP4-AS1 was located in the cytoplasm of PCa cell lines and positively regulated FOXP4. LncRNAs can exert their functions by cooperating with their nearby genes. Mechanistically, FOXP4-AS1 post-transcriptionally regulated FOXP4 by acting as a competing endogenous RNA (ceRNA) in PCa to sponge miR-3184-5p. Considering the upregulation of both FOXP4-AS1 and its nearby gene FOXP4, we further detected the coactivator of FOXP4-AS1 and FOXP4. Mechanism analysis indicated that paired box 5 (PAX5) transcriptionally activated FOXP4-AS1 and FOXP4 in PCa. Collectively, we determined that PAX5-induced upregulation of FOXP4-AS1/FOXP4 axis promoted tumorigenesis of PCa.

Long noncoding RNA BLACAT1 is overexpressed in hepatocellular carcinoma and its downregulation suppressed cancer cell development through endogenously competing against hsa-miR-485-5p

OBJECTIVE

In this work, we explored the expression and mechanistic role of long noncoding RNA (lncRNA), bladder cancer associated transcript 1 (BLACAT1) in human hepatocellular carcinoma (HCC).

METHODS

BLACAT1 expression in bothin vitro HCC cell lines and in vivo human HCC clinical samples were assessed by qRT-PCR. In HeG2 and MHCC97 L cells, BLACAT1 downregulation was induced by lentiviral infection to evaluate its functions in regulating HCC cancer cell proliferation and invasion in vitro, and xenograft in vivo. A BLACAT1 endogenously competing candidate, human microRNA-485-5p (has-miR-485-5p) was assessed in dual-luciferase assay and qRT-PCR in HCC cells. Furthermore, has-miR-485-5p was inhibited in BLACAT1-downregulated HeG2 and MHCC97 L cells to evaluate the correlation of has-miR-485-5p in BLACAT1-associated functional regulation in HCC cells.

RESULTS

BLACAT1was found to be overexpressed in both HCC cells and human HCC tumors. In HeG2 and MHCC97 L cells, lentivirus-induced BLACAT1 downregulation inhibited cancer cellin vitro proliferation and invasion, and in vivo xenograft growth. Has-miR-485-5p was confirmed to be bound by BLACAT1 and its expression in HCC cells inversely regulated by BLACAT1. Then, has-miR-485-5p downregulation reversed the inhibitory effects of BLACAT1 downregulation on HCC cancer cell in vitro functions.

CONCLUSION

BLACAT1 is aberrantly upregulated in HCC and its inhibition had tumor suppressing effects in human HCC, possibly through endogenously competing against has-miR-485-5p. The BLACAT1/ has-miR-485-5p regulatory axis may be a molecular target for future HCC therapy.

microRNA-301b-3p downregulation underlies a novel inhibitory role of long non-coding RNA MBNL1-AS1 in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is the second most prevalent cause of cancer-related fatality. Long non-coding RNAs (lncRNAs) have been observed to exercise functions in NSCLC. Here, the current study aimed to explore the potential mechanism of lncRNA MBNL1-AS1 in NSCLC.

METHODS

Microarray analysis was performed to screen the differentially expressed lncRNA associated with NSCLC and its potential mechanism. The lncRNA MBNL1-AS1 expression was quantified in 56 paired NSCLC and adjacent normal tissue samples. In an attempt to outline the function of lncRNA MBNL1-AS1 in NSCLC and to identify the interaction among lncRNA MBNL1-AS1, microRNA-301b-3p (miR-301b-3p) and TGFBR2, ectopic expression, depletion, and reporter assay experiments were conducted to detect CSC proliferation, migration, invasion, drug resistance, and sphere formation in NSCLC.

RESULTS

Initially, the intersection among lncRNA MBNL1-AS1, miR-301b-3p, and TGFBR2 was observed in NSCLC. While a poor expression of lncRNA MBNL1-AS1 and TGFBR2, along with a high expression of miR-301b-3p was observed in NSCLC tissues. A demonstration of lncRNA MBNL1-AS1 restoration significantly decreased CSC proliferation, migration, invasion, drug resistance, and sphere formation in NSCLC. LncRNA MBNL1-AS1 functioned as a sponge of miR-301b-3p, which inverted the inhibitory role of lncRNA MBNL1-AS1 in CSC proliferation, migration, invasion, drug resistance, and sphere formation in NSCLC. LncRNA MBNL1-AS1 positively regulated TGFBR2 which was a target gene of miR-301b-3p. At last, upregulated lncRNA MBNL1-AS1 or depleted miR-301b-3p suppressed the xenograft tumor formation in vivo.

CONCLUSION

Collectively, the present study suggests an inhibitory role of lncRNA MBNL1-AS1 in CSC drug resistance of NSCLC by upregulating miR-301b-3p-targeted TGFBR2.