The expression of tubulin cofactor A (TBCA) is regulated by a noncoding antisense Tbca RNA during testis maturation

Making Sense of Antisense lncRNAs in Hepatocellular Carcinoma

Transcriptome complexity is emerging as an unprecedented and fascinating domain, especially by high-throughput sequencing technologies that have unveiled a plethora of new non-coding RNA biotypes. This review covers antisense long non-coding RNAs, i.e., lncRNAs transcribed from the opposite strand of other known genes, and their role in hepatocellular carcinoma (HCC). Several sense-antisense transcript pairs have been recently annotated, especially from mammalian genomes, and an understanding of their evolutionary sense and functional role for human health and diseases is only beginning. Antisense lncRNAs dysregulation is significantly involved in hepatocarcinogenesis, where they can act as oncogenes or oncosuppressors, thus playing a key role in tumor onset, progression, and chemoradiotherapy response, as deduced from many studies discussed here. Mechanistically, antisense lncRNAs regulate gene expression by exploiting various molecular mechanisms shared with other ncRNA molecules, and exploit special mechanisms on their corresponding sense gene due to sequence complementarity, thus exerting epigenetic, transcriptional, post-transcriptional, and translational controls. The next challenges will be piecing together the complex RNA regulatory networks driven by antisense lncRNAs and, ultimately, assigning them a function in physiological and pathological contexts, in addition to defining prospective novel therapeutic targets and innovative diagnostic tools.

LncRNA LIFR-AS1 overexpression suppressed the progression of serous ovarian carcinoma

Background

Serous ovarian carcinoma (SOC) is a common malignant tumor in female reproductive system. Long noncoding RNA (lncRNA) LIFR‐AS1 is a tumor suppressor gene in colorectal cancer, but its effect and underlying mechanism in SOC are still unclear. Therefore, this study focuses on unveiling the regulatory mechanism of LIFR‐AS1 in SOC.

Methods

The relationship between LIFR‐AS1 expression and prognosis of SOC patients was analyzed by TCGA database and Starbase, and then, the LIFR‐AS1 expression in SOC tissues and cells was detected by quantitative real‐time PCR (qRT‐PCR) and in situ hybridization (ISH). Besides, the relationship between LIFR‐AS1 and clinical characteristics was analyzed. Also, the effects of LIFR‐AS1 on the biological behaviors of SOC cells were measured by Cell Counting Kit‐8, colony formation, and wound‐healing and Transwell assays, respectively. Western blot and qRT‐PCR were employed to determine the protein expressions of genes related to proliferation (PCNA), apoptosis (cleaved caspase‐3), epithelial‐mesenchymal transition (E‐cadherin, N‐cadherin, and Snail).

Results

LIFR‐AS1 was lowly expressed in SOC, which was correlated with the poor prognosis of SOC patients. Low expression of LIFR‐AS1 in SOC was associated with the tumor size, clinical stage, lymph node metastasis, and distant metastasis. LIFR‐AS1 overexpression promoted the expressions of cleaved caspase‐3 and E‐cadherin while suppressing the malignant behaviors (proliferation, migration, and invasion) of SOC cells, the expressions of PCNA, N‐cadherin, and Snail. Besides, silencing LIFR‐AS1 exerted the effects opposite to overexpressed LIFR‐AS1.

Conclusion

LIFR‐AS1 overexpression inhibits biological behaviors of SOC cells, which may be a new therapeutic method.

LncRNA-Chromatin Pull-Down Using Biotin-Conjugated DNA Probes

Long noncoding RNAs (lncRNAs) are a class of RNA molecules that have been associated with several important biological processes and linked to numerous diseases. Due to their cell type- and tissue specific expression, lncRNAs are involved in a wide range of molecular pathways. To fully understand how a lncRNA is linked to a biological process, its mechanism of action needs to be uncovered. Nuclear retained lncRNAs have been described to modulate gene expression directly or indirectly by interacting with chromatin and associated factors. Described here is an RNA pull-down strategy, which enables the identification of chromatin regions directly bound by a lncRNA of interest. This method is an important step toward investigating how lncRNAs regulate gene expression and/or chromatin states.

Epigenetic transgenerational inheritance, gametogenesis and germline development†

One of the most important developing cell types in any biological system is the gamete (sperm and egg). The transmission of phenotypes and optimally adapted physiology to subsequent generations is in large part controlled by gametogenesis. In contrast to genetics, the environment actively regulates epigenetics to impact the physiology and phenotype of cellular and biological systems. The integration of epigenetics and genetics is critical for all developmental biology systems at the cellular and organism level. The current review is focused on the role of epigenetics during gametogenesis for both the spermatogenesis system in the male and oogenesis system in the female. The developmental stages from the initial primordial germ cell through gametogenesis to the mature sperm and egg are presented. How environmental factors can influence the epigenetics of gametogenesis to impact the epigenetic transgenerational inheritance of phenotypic and physiological change in subsequent generations is reviewed.

Colchicine Blocks Tubulin Heterodimer Recycling by Tubulin Cofactors TBCA, TBCB, and TBCE

Colchicine has been used to treat gout and, more recently, to effectively prevent autoinflammatory diseases and both primary and recurrent episodes of pericarditis. The anti-inflammatory action of colchicine seems to result from irreversible inhibition of tubulin polymerization and microtubule (MT) assembly by binding to the tubulin heterodimer, avoiding the signal transduction required to the activation of the entire NLRP3 inflammasome. Emerging results show that the MT network is a potential regulator of cardiac mechanics. Here, we investigated how colchicine impacts in tubulin folding cofactors TBCA, TBCB, and TBCE activities. We show that TBCA is abundant in mouse heart insoluble protein extracts. Also, a decrease of the TBCA/β-tubulin complex followed by an increase of free TBCA is observed in human cells treated with colchicine. The presence of free TBCA is not observed in cells treated with other anti-mitotic agents such as nocodazole or cold shock, neither after translation inhibition by cycloheximide. In vitro assays show that colchicine inhibits tubulin heterodimer dissociation by TBCE/TBCB, probably by interfering with interactions of TBCE with tubulin dimers, leading to free TBCA. Manipulation of TBCA levels, either by RNAi or overexpression results in decreased levels of tubulin heterodimers. Together, these data strongly suggest that TBCA is mainly receiving β-tubulin from the dissociation of pre-existing heterodimers instead of newly synthesized tubulins. The TBCE/TBCB+TBCA system is crucial for controlling the critical concentration of free tubulin heterodimers and MT dynamics in the cells by recycling the tubulin heterodimers. It is conceivable that colchicine affects tubulin heterodimer recycling through the TBCE/TBCB+TBCA system producing the known benefits in the treatment of pericardium inflammation.

Long noncoding RNA SLC2A1-AS1 regulates aerobic glycolysis and progression in hepatocellular carcinoma via inhibiting the STAT3/FOXM1/GLUT1 pathway

Hepatocellular carcinoma (HCC) is one of the most lethal malignant diseases worldwide. Despite advances in the diagnosis and treatment of HCC, its overall prognosis remains poor. Recent studies have shown that long noncoding RNAs (lncRNAs) play crucial roles in various pathophysiological processes, including liver cancer. In the current study, we report that lncRNA SLC2A1-AS1 is frequently downregulated in HCC samples, as shown by quantitative real-time polymerase chain reaction analysis. SLC2A1-AS1 deletion is significantly associated with recurrence-free survival in HCC. By performing glucose uptake, lactate production and ATP detection assays, we found that SLC2A1-AS1-mediated glucose transporter 1 (GLUT1) downregulation significantly suppressed glycolysis of HCC. In vitro Cell Counting Kit-8, colony formation, transwell assays as well as in vivo tumorigenesis and metastasis assays showed that SLC2A1-AS1 overexpression significantly suppressed proliferation and metastasis in HCC through the transcriptional inhibition of GLUT1. Results from fluorescence in situ hybridization, ChIP and luciferase reporter assays demonstrated that SLC2A1-AS1 exerts its regulatory role on GLUT1 by competitively binding to transketolase and signal transducer and activator of transcription 3 (STAT3) and inhibits the transactivation of Forkhead box M1 (FOXM1) via STAT3, thus resulting in inactivation of the FOXM1/GLUT1 axis in HCC cells. Our findings will be helpful for understanding the function and mechanism of lncRNA in HCC. These data also highlight the crucial role of SLC2A1-AS1 in HCC aerobic glycolysis and progression and pave the way for further research regarding the potential of SLC2A1-AS1 as a valuable predictive biomarker for HCC recurrence.

Differentiation of Long Non-Coding RNA and mRNA Expression Profiles in Male and Female Aedes albopictus

The Asia tiger mosquito (Aedes albopictus) is an important vector of arboviruses, and females can transmit pathogens such as the dengue, zika, and chikungunya viruses. Understanding sex-related differences in this mosquito is fundamental for vector control. However, there are no reports of systematic characterization of long non-coding RNAs (lncRNAs) in male and female Ae. albopictus. To investigate the roles of coding and non-coding RNAs in both sexes of Ae. albopictus, RNA sequencing was performed on male and female samples. The results showed 305 differentially expressed protein-coding genes (DEGs) between males and females, of which 198 were highly expressed in males and 125 were highly expressed in females. Sex-associated gene ontology terms were enriched. Analysis with the FEELnc software identified 2,623 novel lncRNAs, of which 26 showed male high expression and 11 showed female high expression. Quantitative real-time PCR of randomly selected DEGs and lncRNAs supported the validity of the RNA sequencing results. Knocking down male high-expressed gene AALF000433 in male adults reduced the egg hatching rate. This study provides valuable data on sex-specific expression of protein-coding genes and lncRNAs in adult Ae. albopictus, which will guide further studies aimed at understanding sex development and determination mechanisms in this species.

Non-coding RNA regulation in reproduction: Their potential use as biomarkers

Non-coding RNAs (ncRNAs) are crucial regulatory elements in most biological processes and reproduction is also controlled by them. The different types of ncRNAs, as well as the high complexity of these regulatory pathways, present a complex scenario; however, recent studies have shed some light on these questions, discovering the regulatory function of specific ncRNAs on concrete reproductive biology processes. This mini review will focus on the role of ncRNAs in spermatogenesis and oogenesis, and their potential use as biomarkers for reproductive diseases or for reproduction success.

lncRNA FEZF1-AS1 Is Associated With Prognosis in Lung Adenocarcinoma and Promotes Cell Proliferation, Migration, and Invasion

Long noncoding RNAs (lncRNAs) have been reported to play important roles in tumorigenesis. In the present study, we demonstrated that lncRNA forebrain embryonic zinc finger protein 1 (FEZF1) antisense RNA1 (FEZF1-AS1) is markedly upregulated in human lung adenocarcinoma (LAD) tissues and cell lines and is associated with poor prognosis. Loss of function revealed that deletion of FEZF1-AS1 expression significantly inhibited the LAD cell proliferation, invasion, and migration. Further studies revealed that downregulation of FEZF1-AS1 reduced mRNA and protein expression of its sense-cognate gene FEZF1 in LAD cells, and vice versa. Correlation analysis indicated that there was a positive correlation between FEZF1-AS1 and FEZF1 expression in LAD tissues. Additionally, rescue assay confirmed that the function of FEZF1-AS1 in LAD was mediated by FEZF1. Our findings suggested that dysregulation of FEZF1-AS1 contributed to the progression of LAD, which might be a potential target for LAD therapy.

lncRNAs in Plant and Animal Sexual Reproduction

Long noncoding RNAs (lncRNAs) are transcripts over 200 base pairs in length with no discernible protein-coding potential. Multiple lines of evidence point to lncRNAs as master regulators, controlling the expression of protein-coding genes. Studies in plants and animals consistently show high expression of lncRNAs in reproductive organs in a cell- and tissue-specific manner. Sexual reproduction is a complex process that involves cell fate specification and specialized cell division requiring precise coordination of gene expression in response to intrinsic and extrinsic signals. The roles of lncRNAs as master regulators of gene expression and chromatin organization might make them particularly suited for coordination and control of molecular processes involved in sexual reproduction.

Long non-coding RNA FEZF1-AS1 facilitates cell proliferation and migration in colorectal carcinoma

Long non-coding RNAs (lncRNA) have been shown to play important roles in the development and progression of cancer. Here, we discovered a novel long noncoding RNA (lncRNA) FEZF1 antisense RNA1 (FEZF1-AS1) is markedly upregulated in human primary colorectal carcinoma (CRC) and associated with CRC metastasis and poor prognosis. Moreover, the downregulation of FEZF1-AS1 expression significantly inhibited the CRC cells proliferation, migration and invasiveness, suppressed S-phase entry in vitro, and repressed tumor growth and metastasis in vivo. In contrast, overexpression of FEZF1-AS1 could promote the aggressive behaviors of CRC cells. We further discovered that the downregulation of FEZF1-AS1 reduced its sense-cognate gene FEZF1 mRNA and protein expression in CRC cells. There was a positive correlation between FEZF1-AS1 and FEZF1 expression in CRC. Moreover, FEZF1 knockdown also significantly suppressed CRC cell proliferation, migration, and invasion. Our findings indicate that the dysregulation of FEZF1-AS1 participates in colorectal tumorigenesis and progression, which might be achieved, at least in part, through FEZF1 induction.

Prognostic role of long noncoding RNA ZFAS1 in cancer patients: a systematic review and meta-analysis

Long noncoding RNA ZFAS1 has been identified as a crucial role in the tumorigenesis of malignant tumors. Numerous studies reported that the expression levels of ZFAS1 in tumor tissues were dramatically higher than that in adjacent normal tissues. We conducted a meta-analysis to investigate the correlation between ZFAS1 expression and clinical outcomes of cancer patients. The databases of PubMed, EMBASE, Web of Science, Cochrane Library, CNKI and WanFang were retrieved for eligible studies. A total of 841 patients from 9 studies were eventually included. Our results demonstrated that increased ZFAS1 expression was significantly associated with poor OS in cancer patients (HR = 2.13, 95% CI = 1.71–2.65, P < 0.001). Patients with high ZFAS1 expression presented shorter RFS than those with low ZFAS1 expression (HR = 2.00, 95% CI = 1.45–2.77, P < 0.001). The clinicopathological parameters analysis demonstrated that increased ZFAS1 expression was significantly associated with vascular invasion (OR = 2.26, 95% CI = 1.36–3.78, P = 0.002), lymph node metastasis (OR = 2.98, 95% CI = 2.12–4.19, P < 0.001) and advanced TNM stage (OR = 3.00, 95% CI = 2.18–4.12, P < 0.001). In conclusion, lncRNA ZFAS1 might serve as a prognostic biomarker for cancer patients and increased ZFAS1 expression may be closely related to advanced characteristics of cancer.

Downregulation of ZEB2-AS1 decreased tumor growth and metastasis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most common types of cancer worldwide and prognosis remains poor. Previous studies have suggested that long non-coding RNAs (lncRNAs) may be key regulators of tumor development and progression in HCC. It has been determined that 61–72% of transcribed regions contain lncRNAs in the antisense orientation (aslncRNAs). However, the function of aslncRNAs in HCC remains to be elucidated. The present study investigated the function of the aslncRNA zinc finger E-box binding homeobox 2 antisense RNA 1 (ZEB2-AS1) in 40 HCC tissues and 5 different human HCC cell lines using reverse transcription-quantitative polymerase chain reaction. Additionally, the expression levels of ZEB2-AS1 were downregulated by transfection of small interfering RNAs (siRNAs) to determine whether ZEB2-AS1 is capable of affecting cell proliferation, invasion and metastasis by regulating ZEB2, vimentin, fibronectin, E-cadherin and N-cadherin expression levels. The results of the present study demonstrated that the expression levels of ZEB2-AS1 were greater in HCC tissues when compared with the adjacent normal tissues. Furthermore, ZEB2-AS1 expression was significantly associated with the size of the primary tumor, intrahepatic metastasis and tumor-node-metastasis stage. The Kaplan-Meier survival curves suggested that patients with high ZEB2-AS1 expression levels experienced the lowest overall and recurrence-free survival rates compared with those that had low expression levels. In addition, the current study demonstrated that the downregulation of ZEB2-AS1 was associated with decreased tumor growth and metastasis in HCC by the regulation of the expression levels of epithelial mesenchymal transition-induced markers. In conclusion, lncRNA ZEB2-AS1 may be used as a valuable biomarker in patients with HCC.

LncRNA, a new component of expanding RNA-protein regulatory network important for animal sperm development

Spermatogenesis is one of the fundamental processes of sexual reproduction, present in almost all metazoan animals. Like many other reproductive traits, developmental features and traits of spermatogenesis are under strong selective pressure to change, both at morphological and underlying molecular levels. Yet evidence suggests that some fundamental features of spermatogenesis may be ancient and conserved among metazoan species. Identifying the underlying conserved molecular mechanisms could reveal core components of metazoan spermatogenic machinery and provide novel insight into causes of human infertility. Conserved RNA-binding proteins and their interacting RNA network emerge to be a common theme important for animal sperm development. We review research on the recent addition to the RNA family - Long non-coding RNA (lncRNA) and its roles in spermatogenesis in the context of the expanding RNA-protein network.

Differential Expression of Long Noncoding RNAs between Sperm Samples from Diabetic and Non-Diabetic Mice

To investigate the potential core reproduction-related genes associated with the development of diabetes, the expression profiles of long noncoding RNA (lncRNA) and messenger RNA (mRNA) in the sperm of diabetic mice were studied. We used microarray analysis to detect the expression of lncRNAs and coding transcripts in six diabetic and six normal sperm samples, and differentially expressed lncRNAs and mRNAs were identified through Volcano Plot filtering. The function of differentially expressed mRNA was determined by pathway and gene ontology (GO) analysis, and the function of lncRNAs was studied by subgroup analysis and their physical or functional relationships with corresponding mRNAs. A total of 7721 lncRNAs and 6097 mRNAs were found to be differentially expressed between the diabetic and normal sperm groups. The diabetic sperm exhibited aberrant expression profiles for lncRNAs and mRNAs, and GO and pathway analyses showed that the functions of differentially expressed mRNAs were closely related with many processes involved in the development of diabetes. Furthermore, potential core genes that might play important roles in the pathogenesis of diabetes-related low fertility were revealed by lncRNA- and mRNA-interaction studies, as well as coding-noncoding gene co-expression analysis based on the microarray expression profiles.

Long non-coding RNA regulation of reproduction and development

Noncoding RNAs (ncRNAs) have long been known to play vital roles in eukaryotic gene regulation. Studies conducted over a decade ago revealed that maturation of spliced, polyadenylated coding mRNA occurs by reactions involving small nuclear RNAs and small nucleolar RNAs; mRNA translation depends on activities mediated by transfer RNAs and ribosomal RNAs, subject to negative regulation by micro RNAs; transcriptional competence of sex chromosomes and some imprinted genes is regulated in cis by ncRNAs that vary by species; and both small-interfering RNAs and piwi-interacting RNAs bound to Argonaute-family proteins regulate post-translational modifications on chromatin and local gene expression states. More recently, gene-regulating noncoding RNAs have been identified, such as long intergenic and long noncoding RNAs (collectively referred to as lncRNAs)--a class totaling more than 100,000 transcripts in humans, which include some of the previously mentioned RNAs that regulate dosage compensation and imprinted gene expression. Here, we provide an overview of lncRNA activities, and then review the role of lncRNAs in processes vital to reproduction, such as germ cell specification, sex determination and gonadogenesis, sex hormone responses, meiosis, gametogenesis, placentation, non-genetic inheritance, and pathologies affecting reproductive tissues. Results from many species are presented to illustrate the evolutionarily conserved processes lncRNAs are involved in.

Antisense long non-coding RNA PCNA-AS1 promotes tumor growth by regulating proliferating cell nuclear antigen in hepatocellular carcinoma

About 61-72% of transcribed regions possess long noncoding RNAs in antisense orientation (Antisense long noncoding RNAs, aslncRNAs). However, the function of aslncRNAs in HCC remains unclear. We found numerous aslncRNAs were deregulated and might be involved in regulatory gene-net of HCC. The PCNA-AS1, antisense to PCNA, is significantly up-regulated in HCC and could promote tumor growth in vitro and in vivo. The effects of PCNA-AS1 rely on regulation of PCNA via forming RNA hybridization to increase PCNA mRNA stability. We concluded that aslncRNAs might act as upstream regulators in HCC and PCNA-AS1 could serve as a novel therapeutic target.

Non-coding RNAs: multi-tasking molecules in the cell

In the last years it has become increasingly clear that the mammalian transcriptome is highly complex and includes a large number of small non-coding RNAs (sncRNAs) and long noncoding RNAs (lncRNAs). Here we review the biogenesis pathways of the three classes of sncRNAs, namely short interfering RNAs (siRNAs), microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs). These ncRNAs have been extensively studied and are involved in pathways leading to specific gene silencing and the protection of genomes against virus and transposons, for example. Also, lncRNAs have emerged as pivotal molecules for the transcriptional and post-transcriptional regulation of gene expression which is supported by their tissue-specific expression patterns, subcellular distribution, and developmental regulation. Therefore, we also focus our attention on their role in differentiation and development. SncRNAs and lncRNAs play critical roles in defining DNA methylation patterns, as well as chromatin remodeling thus having a substantial effect in epigenetics. The identification of some overlaps in their biogenesis pathways and functional roles raises the hypothesis that these molecules play concerted functions in vivo, creating complex regulatory networks where cooperation with regulatory proteins is necessary. We also highlighted the implications of biogenesis and gene expression deregulation of sncRNAs and lncRNAs in human diseases like cancer.

The presence, role and clinical use of spermatozoal RNAs

BACKGROUND Spermatozoa are highly differentiated, transcriptionally inert cells characterized by a compact nucleus with minimal cytoplasm. Nevertheless they contain a suite of unique RNAs that are delivered to oocyte upon fertilization. They are likely integrated as part of many different processes including genome recognition, consolidation-confrontation, early embryonic development and epigenetic transgenerational inherence. Spermatozoal RNAs also provide a window into the developmental history of each sperm thereby providing biomarkers of fertility and pregnancy outcome which are being intensely studied. METHODS Literature searches were performed to review the majority of spermatozoal RNA studies that described potential functions and clinical applications with emphasis on Next-Generation Sequencing. Human, mouse, bovine and stallion were compared as their distribution and composition of spermatozoal RNAs, using these techniques, have been described. RESULTS Comparisons highlighted the complexity of the population of spermatozoal RNAs that comprises rRNA, mRNA and both large and small non-coding RNAs. RNA-seq analysis has revealed that only a fraction of the larger RNAs retain their structure. While rRNAs are the most abundant and are highly fragmented, ensuring a translationally quiescent state, other RNAs including some mRNAs retain their functional potential, thereby increasing the opportunity for regulatory interactions. Abundant small non-coding RNAs retained in spermatozoa include miRNAs and piRNAs. Some, like miR-34c are essential to the early embryo development required for the first cellular division. Others like the piRNAs are likely part of the genomic dance of confrontation and consolidation. Other non-coding spermatozoal RNAs include transposable elements, annotated lnc-RNAs, intronic retained elements, exonic elements, chromatin-associated RNAs, small-nuclear ILF3/NF30 associated RNAs, quiescent RNAs, mse-tRNAs and YRNAs. Some non-coding RNAs are known to act as epigenetic modifiers, inducing histone modifications and DNA methylation, perhaps playing a role in transgenerational epigenetic inherence. Transcript profiling holds considerable potential for the discovery of fertility biomarkers for both agriculture and human medicine. Comparing the differential RNA profiles of infertile and fertile individuals as well as assessing species similarities, should resolve the regulatory pathways contributing to male factor infertility. CONCLUSIONS Dad delivers a complex population of RNAs to the oocyte at fertilization that likely influences fertilization, embryo development, the phenotype of the offspring and possibly future generations. Development is continuing on the use of spermatozoal RNA profiles as phenotypic markers of male factor status for use as clinical diagnostics of the father's contribution to the birth of a healthy child.