Suppression of hepatocellular carcinoma by baculovirus-mediated expression of long non-coding RNA PTENP1 and MicroRNA regulation. Biomaterials. 2015;44:71-81. [PMID: 25617127 DOI: 10.1016/j.biomaterials.2014.12.023]

Angio-LncRs: LncRNAs that regulate angiogenesis and vascular disease

Long noncoding RNAs (lncRNAs) represent a large subgroup of RNAs that are longer than 200 nucleotides and have no apparent protein coding potential. They have diverse functions in different biological processes by regulating chromatin remodeling or protein translation. This review summarizes the recent progress of lncRNAs in angiogenesis and vascular diseases. A general overview of lncRNA functional mechanisms will be introduced. A list of lncRNAs, which are termed "Angio-LncRs", including MALAT1, MANTIS, PUNISHER, MEG3, MIAT, SENCR and GATA6-AS, will be discussed regarding their expression, regulation, function and mechanism of action in angiogenesis. Implications of lncRNAs in vascular diseases, such as atherosclerosis, hypertension, vascular retinopathies and tumor angiogenesis will also be discussed.

The long non-coding RNA PTTG3P promotes cell growth and metastasis via up-regulating PTTG1 and activating PI3K/AKT signaling in hepatocellular carcinoma

Background

Dysfunctions of long non-coding RNA (lncRNAs) have been associated with the initiation and progression of hepatocellular carcinoma (HCC), but the clinicopathologic significance and potential role of lncRNA PTTG3P (pituitary tumor-transforming 3, pseudogene) in HCC remains largely unknown.

Methods

We compared the expression profiles of lncRNAs in 3 HCC tumor tissues and adjacent non-tumor tissues by microarrays. In situ hybridization (ISH) and quantitative real-time polymerase chain reaction (qRT-PCR) were applied to assess the level of PTTG3P and prognostic values of PTTG3P were assayed in two HCC cohorts (n = 46 and 90). Artificial modulation of PTTG3P (down- and over-expression) was performed to explore the role of PTTG3P in tumor growth and metastasis in vitro and in vivo. Involvement of PTTG1 (pituitary tumor-transforming 1), PI3K/AKT signaling and its downstream signals were validated by qRT-PCR and western blot.

Results

We found that PTTG3P was frequently up-regulated in HCC and its level was positively correlated to tumor size, TNM stage and poor survival of patients with HCC. Enforced expression of PTTG3P significantly promoted cell proliferation, migration, and invasion in vitro, as well as tumorigenesis and metastasis in vivo. Conversely, PTTG3P knockdown had opposite effects. Mechanistically, over-expression of PTTG3P up-regulated PTTG1, activated PI3K/AKT signaling and its downstream signals including cell cycle progression, cell apoptosis and epithelial-mesenchymal transition (EMT)-associated genes.

Conclusions

Our findings suggest that PTTG3P, a valuable marker of HCC prognosis, promotes tumor growth and metastasis via up-regulating PTTG1 and activating PI3K/AKT signaling in HCC and might represent a potential target for gene-based therapy.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0841-x) contains supplementary material, which is available to authorized users.

Long non-coding RNA phosphatase and tensin homolog pseudogene 1 suppresses osteosarcoma cell growth via the phosphoinositide 3-kinase/protein kinase B signaling pathway

Osteosarcoma is a common type of human carcinoma, which exhibits a high metastasis and recurrence rate. Previous studies have indicated that long non-coding RNA phosphatase and tensin homolog pseudogene 1 (lnPTENP1) has tumor suppressive action by modulating PTEN expression in different types of tumor cells. However, the potential mechanism by which lnPTENP1 has an effect in osteosarcoma cells remains elusive. In the present study, the role of lnPTENP1 in osteosarcoma cells was investigated and the possible mechanisms by which it functions were explored. It was revealed that lnPTENP1 transfection significantly inhibited osteosarcoma cell growth, proliferation, migration and invasion. LnPTENP1 transfection also significantly promoted apoptosis in Mg63 cells treated with tunicamycin. Further analysis revealed that lnPTENP1 transfection regulated osteosarcoma cell growth via the PI3K/AKT signaling pathway. In vivo assays revealed that lnPTENP1 transfection significantly inhibited osteosarcoma tumor growth and significantly increased the protein expression and phosphorylation levels of PI3K and AKT. In conclusion, the results of the present study indicated that lnPTENP1 may inhibit osteosarcoma cell growth via the PI3K/AKT signaling pathway, which may be a potential novel target for human osteosarcoma therapy.

Long non-coding RNA PTENP1 functions as a ceRNA to modulate PTEN level by decoying miR-106b and miR-93 in gastric cancer

Recent studies have shown that competing endogenous RNAs (ceRNAs) play an important role in the regulation of gene expression, and participate in a wide range of biological processes, including carcinogenesis. Long non-coding RNA PTENP1, the pseudogene of PTEN tumor suppressor, has been reported to exert its tumor suppressive function via modulation of PTEN expression in many malignancies. However, whether a PTENP1∼miRNA∼PTEN ceRNA network exists and how it functions in gastric cancer (GC) remains elusive. In order to identify and characterize the PTENP1∼miRNA∼PTEN ceRNA network in GC, we first determined PTENP1 levels in clinical GC samples and found that PTENP1 and PTEN were concurrently downregulated in these samples. We further demonstrated that PTENP1 could act as a ceRNA to sponge miR-106b and miR-93 from targeting PTEN for downregulation using a novel ceRNA in vitro gradient assay. Thus, we revealed a tumor suppressive role of PTENP1 as ceRNA in GC and pinpointed the specific miRNAs decoyed by PTENP1, highlighting the emerging roles of ceRNAs in the biological regulation of GC cells and their possible clinical significance.

Non-coding RNAs in hepatocellular carcinoma: molecular functions and pathological implications

Hepatocellular carcinoma (HCC) is a leading lethal malignancy worldwide. However, the molecular mechanisms underlying liver carcinogenesis remain poorly understood. Over the past two decades, overwhelming evidence has demonstrated the regulatory roles of different classes of non-coding RNAs (ncRNAs) in liver carcinogenesis related to a number of aetiologies, including HBV, HCV and NAFLD. Among the ncRNAs, microRNAs, which belong to a distinct class of small ncRNAs, have been proven to play a crucial role in the post-transcriptional regulation of gene expression. Deregulation of microRNAs has been broadly implicated in the inactivation of tumour-suppressor genes and activation of oncogenes in HCC. Modern high-throughput sequencing analyses have unprecedentedly identified a very large number of non-coding transcripts. Divergent groups of long ncRNAs have been implicated in liver carcinogenesis through interactions with DNA, RNA or proteins. Overall, ncRNAs represent a burgeoning field of cancer research, and we are only beginning to understand the importance and complicity of the ncRNAs in liver carcinogenesis. In this Review, we summarize the common deregulation of small and long ncRNAs in human HCC. We also comprehensively review the pathological roles of ncRNAs in liver carcinogenesis, epithelial-to-mesenchymal transition and HCC metastasis and discuss the potential applications of ncRNAs as diagnostic tools and therapeutic targets in human HCC.

PTEN/PTENP1: 'Regulating the regulator of RTK-dependent PI3K/Akt signalling', new targets for cancer therapy

Regulation of the PI-3 kinase (PI3K)/Akt signalling pathway is essential for maintaining the integrity of fundamental cellular processes, cell growth, survival, death and metabolism, and dysregulation of this pathway is implicated in the development and progression of cancers. Receptor tyrosine kinases (RTKs) are major upstream regulators of PI3K/Akt signalling. The phosphatase and tensin homologue (PTEN), a well characterised tumour suppressor, is a prime antagonist of PI3K and therefore a negative regulator of this pathway. Loss or inactivation of PTEN, which occurs in many tumour types, leads to overactivation of RTK/PI3K/Akt signalling driving tumourigenesis. Cellular PTEN levels are tightly regulated by a number of transcriptional, post-transcriptional and post-translational regulatory mechanisms. Of particular interest, transcription of the PTEN pseudogene, PTENP1, produces sense and antisense transcripts that exhibit post-transcriptional and transcriptional modulation of PTEN expression respectively. These additional levels of regulatory complexity governing PTEN expression add to the overall intricacies of the regulation of RTK/PI-3 K/Akt signalling. This review will discuss the regulation of oncogenic PI3K signalling by PTEN (the regulator) with a focus on the modulatory effects of the sense and antisense transcripts of PTENP1 on PTEN expression, and will further explore the potential for new therapeutic opportunities in cancer treatment.

Interaction and cross-talk between non-coding RNAs

Non-coding RNA (ncRNA) has been shown to regulate diverse cellular processes and functions through controlling gene expression. Long non-coding RNAs (lncRNAs) act as a competing endogenous RNAs (ceRNAs) where microRNAs (miRNAs) and lncRNAs regulate each other through their biding sites. Interactions of miRNAs and lncRNAs have been reported to trigger decay of the targeted lncRNAs and have important roles in target gene regulation. These interactions form complicated and intertwined networks. Certain lncRNAs encode miRNAs and small nucleolar RNAs (snoRNAs), and may regulate expression of these small RNAs as precursors. SnoRNAs have also been reported to be precursors for PIWI-interacting RNAs (piRNAs) and thus may regulate the piRNAs as a precursor. These miRNAs and piRNAs target messenger RNAs (mRNAs) and regulate gene expression. In this review, we will present and discuss these interactions, cross-talk, and co-regulation of ncRNAs and gene regulation due to these interactions.

Autophagy Modulation in Cancer: Current Knowledge on Action and Therapy

In the last two decades, accumulating evidence pointed to the importance of autophagy in various human diseases. As an essential evolutionary catabolic process of cytoplasmatic component digestion, it is generally believed that modulating autophagic activity, through targeting specific regulatory actors in the core autophagy machinery, may impact disease processes. Both autophagy upregulation and downregulation have been found in cancers, suggesting its dual oncogenic and tumor suppressor properties during malignant transformation. Identification of the key autophagy targets is essential for the development of new therapeutic agents. Despite this great potential, no therapies are currently available that specifically focus on autophagy modulation. Although drugs like rapamycin, chloroquine, hydroxychloroquine, and others act as autophagy modulators, they were not originally developed for this purpose. Thus, autophagy may represent a new and promising pharmacologic target for future drug development and therapeutic applications in human diseases. Here, we summarize our current knowledge in regard to the interplay between autophagy and malignancy in the most significant tumor types: pancreatic, breast, hepatocellular, colorectal, and lung cancer, which have been studied in respect to autophagy manipulation as a promising therapeutic strategy. Finally, we present an overview of the most recent advances in therapeutic strategies involving autophagy modulators in cancer.

Over-expression of oncigenic pesudogene DUXAP10 promotes cell proliferation and invasion by regulating LATS1 and β-catenin in gastric cancer

BACKGROUND

Recently, the pesudogenes have emerged as critical regulators in human cancers tumorigenesis and progression, and been identified as a key revelation in post-genomic biology. However, the expression pattern, biological function and mechanisms responsible for these molecules in human gastric cancer (GC) are not fully understood.

METHODS

In this study, we globally assessed the transcriptomic differences of pesudogenes in gastric cancer using publicly available microarray data. DUXAP10 expression levels in GC tissues and cells was detected using quantitative real-time PCR (qPCR). DUXAP10 siRNAs and over-expression vector were transfected into GC cells to down-regulate or up-regulate DUXAP10 expression. Loss- and gain-of function assays were performed to investigate the role of DUXAP10 in GC cells cell proliferation, and invasion. RIP, RNA pulldown, and ChIP assays were used to determine the mechanism of DUXAP10's regulation of underlying targets.

RESULTS

The pesudogene DUXAP10 is the only pseudogene that significantly over-expressed in all four GEO datasets, and frequently over-expressed in many other cancers including Liver Hepatocellular carcinoma, Bladder cancer, and Esophageal Cancer. High DUXAP10 expression is associated with GC patients poor prognosis, and knockdown of DUXAP10 significantly inhibits cells proliferation, migration and invasion in GC. Mechanistic investigation shows that DUXAP10 can interact with PRC2 and LSD1 to repress LATS1 expression at transcriptional level, and bind with HuR to maintain the stability of β-catenin mRNA and increase its protein levels at post-transcriptional level.

CONCLUSIONS

Overall, our findings illuminate how increased DUXAP10 confers an oncogenic function in GC development and progression that may serve as a candidate prognostic biomarker and target for clinical management of GC.

Construction of a lncRNA-mediated feed-forward loop network reveals global topological features and prognostic motifs in human cancers

Long non-coding RNAs (lncRNAs), transcription factors and microRNAs can form lncRNA-mediated feed-forward loops (L-FFLs), which are functional network motifs that regulate a wide range of biological processes, such as development and carcinogenesis. However, L-FFL network motifs have not been systematically identified, and their roles in human cancers are largely unknown. In this study, we computationally integrated data from multiple sources to construct a global L-FFL network for six types of human cancer and characterized the topological features of the network. Our approach revealed several dysregulated L-FFL motifs common across different cancers or specific to particular cancers. We also found that L-FFL motifs can take part in other types of regulatory networks, such as mRNA-mediated FFLs and ceRNA networks, and form the more complex networks in human cancers. In addition, survival analyses further indicated that L-FFL motifs could potentially serve as prognostic biomarkers. Collectively, this study elucidated the roles of L-FFL motifs in human cancers, which could be beneficial for understanding cancer pathogenesis and treatment.

Competing endogenous RNA networks in human cancer: hypothesis, validation, and perspectives

Non-coding RNAs represent a majority of the human transcriptome. However, less is known about the functions and regulatory mechanisms of most non-coding species. Moreover, little is known about the potential non-coding functions of coding RNAs. The competing endogenous RNAs (ceRNAs) hypothesis is proposed recently. This hypothesis describes potential communication networks among all transcript RNA species mediated by miRNAs and miRNA-recognizing elements (MREs) within RNA transcripts. Here we review the evolution of the ceRNA hypothesis, summarize the validation experiments and discusses the significance and perspectives of this hypothesis in human cancer.

[Role of lncRNA PTENP1 in tumorigenesis and progression of bladder cancer and the molecular mechanism]

OBJECTIVE

To explore the molecular mechanism underlying the biological function of lncRNA PTENP1 in bladder cancer.

METHODS

Expressions of PTENP1, PTEN and miR-17 were examined by quantitative reverse transcriptase PCR (qRT-PCR) in 12 bladder cancer tissues. The expression of PTEN was examined by Western blotting in bladder cancer cell lines T24 and 5637 overexpressing PTENP1. Luciferase reporter assay was performed to confirm the targeting of miR-17 to PTENP1 and PTEN. T24 and 5637 cell lines with stable overexpression of PTENP1 and mir-17 were used to investigate effect of PTNE and miR-17 on the function of PTENP1 in bladder cancer.

RESULTS

The expression of miR-17 was up-regulated and PTENP1 and PTEN were down-regulated in bladder cancer tissues, where a positive correlation was found between PTENP1 and PTEN expressions and a negative correlation between PTENP1 and miR-17 (P<0.05). Overexpression of PTENP1 in bladder cancer cell lines T24 and 5637 obviously enhanced the expression of PTEN protein. miR-17 was found to target both PTENP1 and PTEN and promote the growth of bladder cancer. miR-17 could partially restore the tumor-suppressing activity of PTENP1 in bladder cancer.

CONCLUSION

By binding with miR-17, lncRNA PTENP1 functions as a PTEN competing endogenous RNA (ceRNA) to suppress the progression of bladder cancer.

Long noncoding RNAs act as regulators of autophagy in cancer

Long noncoding RNAs (lncRNAs) have emerged as critical regulators in various cellular processes. Studies have disclosed an important function of lncRNAs in the regulation of autophagy, a crucial cellular homeostatic mechanism that plays a pro-survival or pro-death role in cancer. Deregulation of lncRNAs can contribute to tumorigenesis and cancer progression, wherein lncRNAs can act as oncogenes or tumor suppressors. In this review, we highlight the recent advances in understanding the relationship between lncRNAs and autophagy regulation in cancer. Exploiting the newly emerging knowledge of the lncRNA-autophagy-cancer axis may provide novel targets for cancer therapy.

Long Noncoding RNAs as a Key Player in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major malignancy in the liver and has emerged as one of the main cancers in the world with a high mortality rate. However, the molecular mechanisms of HCC are still poorly understood. Long noncoding RNAs (lncRNAs) have recently come to the forefront as functional non-protein-coding RNAs that are involved in a variety of cellular processes ranging from maintaining the structural integrity of chromosomes to gene expression regulation in a spatiotemporal manner. Many recent studies have reported the involvement of lncRNAs in HCC which has led to a better understanding of the underlying molecular mechanisms operating in HCC. Long noncoding RNAs have been shown to regulate development and progression of HCC, and thus, lncRNAs have both diagnostic and therapeutic potentials. In this review, we present an overview of the lncRNAs involved in different stages of HCC and their potential in clinical applications which have been studied so far.

Pseudogenes of annexin A2, novel prognosis biomarkers for diffuse gliomas

Diffuse gliomas is a kind of common malignant primary brain tumor. Pseudogenes have multilayered biological function in the progression of human cancers. In this study, Differentially Expressed Pseudogenes (DEPs) between glioblastomas and non-tumor controls were found by bioinformatics analysis, of which the annexin A2 pseudogenes (ANXA2P1, ANXA2P2 and ANXA2P3) were significantly up-regulated, along with the parent gene annexin A2 (ANXA2). Among four glioblastoma subtypes, ANXA2P1 and ANXA2P2 were preferentially expressed in mesenchymal subtype and less expressed in proneural subtype. Meanwhile, Pearson’s correlation analysis revealed that the expression level of ANXA2 was positively correlated with ANXA2 pseudogenes expression. Then, the expression patterns of ANXA2 and its pseudogenes were validated in diffuse glioma specimens (n=99) and non-tumor tissues (n=12) by quantitative real-time PCR (qRT-PCR). Additionally, Kaplan–Meier analysis revealed that highly expressed ANXA2 and annexin A2 pseudogenes were associated with the poor survival outcome of glioma patients. Cox regression analyses suggested that ANXA2, ANXA2P1 and ANXA2P2 were the independent prognosis factors for gliomas. Furthermore, down-regulation of ANXA2 and ANXA2 pseudogenes might contribute to the improvement of patients’ survival who received chemotherapy and radiotherapy. These results demonstrated that ANXA2 pseudogenes and ANXA2 could be used as the novel biomarkers for diagnosis, prognosis and target therapy of gliomas.

Long non-coding RNA00364 represses hepatocellular carcinoma cell proliferation via modulating p-STAT3-IFIT2 signaling axis

The effects of long non-coding RNAs (lncRNAs) on hepatocellular carcinoma (HCC) remain largely unclear. In this study, we identified an interferon (IFN)-γ-induced LncRNA, LncRNA00364, in HCC by microarray. LncRNA00364 displays lower expression in HCC tumor samples compared to paired normal controls. Overexpression of LncRNA00364 inhibits cell proliferation, G1/S cell cycle progression and promotes apoptosis in HCC cell lines. Consistently, LncRNA00364 overexpression leads to decreased HCC tumor formation in vivo. Mechanistically, LncRNA00364 specifically binds with STAT3, resulting in inhibition of STAT3 phosphorylation and therefore leads to upregulation of IFIT2. In a clinical setting, LncRNA00364 shows an independent prognostic indicator for overall survival and cumulative recurrence in HCC patients, and correlates with IFIT2. Therefore, our study provides new insights into a novel therapeutic avenue targeting the LncRNA00364 signaling axis in HCC.

Divergent Activity of the Pseudogene PTENP1 in ER-Positive and Negative Breast Cancer

Transcripts derived from the PTEN pseudogene (PTENP1) function as decoys to adsorb miRNAs targeting the PTEN tumor suppressor for degradation, and PTENP1 upregulation is known to inhibit growth in preclinical cancer models. Here, PTENP1 3'UTR transduction influences PTEN, AKT/mTOR signaling, and tumor progression in estrogen receptor (ER)-positive and -negative breast cancer cells. PTENP1 upregulation decreases PTEN gene expression in the ER-positive MCF7 and T47D human breast carcinoma cells and accelerates MCF7 tumor growth in vivo Of note, PTENP1 transduction significantly decreases ERα (ESR1) mRNA and protein levels in MCF7 xenografts with a concomitant increase in hsa-miR-26a, a miRNA known to target ESR1 In the ER-negative MDA-MB-231 and C3HBA breast cancer cells, upregulation of PTENP1 increases PTEN gene expression with no influence on hsa-miR-26a, ESR1, or ERα expression. While PTENP1 transduction did not influence the growth rate of human MDA-MB-231 xenografts, PTENP1 upregulation profoundly reduces its metastatic propensity. Furthermore, PTENP1 significantly inhibits the growth rate of ER-negative C3HBA murine breast cancer xenografts. PTENP1 transduction had no influence on doxorubicin cytotoxicity in ER-positive MCF7 cells but an increase in doxorubicin sensitivity was observed in the ER-negative MDA-MB-231 cells. In summary, while PTENP1 upregulation decreased PTEN transcript levels and stimulated the growth of ER-positive breast cancers, increased PTEN transcript levels and inhibited tumor progression was observed in the ER-negative cells.Implications: This report highlights the profound biological activity of PTENP1 in breast cancer, which is dictated by the hormone receptor status. Mol Cancer Res; 16(1); 78-89. ©2017 AACR.

Long non-coding RNAs involved in autophagy regulation

Autophagy degrades non-functioning or damaged proteins and organelles to maintain cellular homeostasis in a physiological or pathological context. Autophagy can be protective or detrimental, depending on its activation status and other conditions. Therefore, autophagy has a crucial role in a myriad of pathophysiological processes. From the perspective of autophagy-related (ATG) genes, the molecular dissection of autophagy process and the regulation of its level have been largely unraveled. However, the discovery of long non-coding RNAs (lncRNAs) provides a new paradigm of gene regulation in almost all important biological processes, including autophagy. In this review, we highlight recent advances in autophagy-associated lncRNAs and their specific autophagic targets, as well as their relevance to human diseases such as cancer, cardiovascular disease, diabetes and cerebral ischemic stroke.

Long non-coding RNAs as biomarkers and therapeutic targets: Recent insights into hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer worldwide, and the survival rates of patients with HCC remains quite low after 5years. Long non-coding RNAs (LncRNAs) are a novel class of non-coding RNAs that are capable of regulating gene expression at various levels. Recent works have demonstrated that lncRNAs are often dysregulated in HCC, and the dysregulation of some of these lncRNAs are associated with the clinicopathological features of HCC. They regulate cell proliferation, apoptosis, autophagy, Epithelial-Mesenchymal Transition (EMT), invasion and metastasis of HCC by modulating gene expression and cancer-related signaling pathways, and thus contribute to the onset and progression of HCC. In this review, we provide a comprehensive survey of dysregulated lncRNAs in HCC, with particular focus on the functions and regulatory mechanisms of several essential and important lncRNAs, and discuss their potential clinical application as early diagnostic and/or prognostic biomarkers or therapeutic targets for HCC.

HOXD-AS1 functions as an oncogenic ceRNA to promote NSCLC cell progression by sequestering miR-147a

Non-small cell lung cancer (NSCLC) is one of the most common malignancies worldwide, and it occurs at a higher frequency in males. HOXD-AS1, an important cancer-associated long noncoding RNA (lncRNA), contributes to the development and progression of several cancers. However, the exact roles of HOXD-AS1 in NSCLC progression are still unknown. Here, we investigated the underlying mechanisms of HOXD-AS1 in human NSCLC tissues. We found that lncRNA HOXD-AS1 was specifically upregulated (P<0.001) in NSCLC tissues and promoted cancer cell growth by targeting miR-147a. Moreover, HOXD-AS1 expression positively correlated with NSCLC clinical pathologic characteristics (tumor size, P=0.006; tumor stage, P=0.044; recurrence, P=0.031) and survival rate (P=0.003). HOXD-AS1 knockdown reduced proliferation and promoted apoptosis of NSCLC cells. The dual-luciferase reporter assay showed that HOXD-AS1 could negatively regulate the expression of miR-147a. miR-147a inhibition abrogated the effect of HOXD-AS1 knockdown on the proliferation and apoptosis of NSCLC cells. Furthermore, HOXD-AS1 positively regulated the expression of pRB (a tumor suppressor protein) in NSCLC cells. Taken together, our data indicated that HOXD-AS1 might be an oncogenic lncRNA that promotes proliferation of NSCLC and could be a therapeutic target in NSCLC.

LncRNA-ATB: An indispensable cancer-related long noncoding RNA

OBJECTIVES

Long non-coding RNAs (lncRNAs) are a group of non-protein-coding RNAs that are greater than 200 nucleotides in length. Increasing evidence indicates that lncRNAs, which may serve as either oncogenes or tumour suppressor genes, play a vital role in the pathophysiology of human diseases, especially in tumourigenesis and progression. Deregulation of lncRNAs impacts different cellular processes, such as proliferation, dedifferentiation, migration, invasion and anti-apoptosis. The aim of this review was to explore the molecular mechanism and clinical significance of long non-coding RNA-activated by transforming growth factor β (lncRNA-ATB) in various types of cancers.

MATERIALS AND METHODS

In this review, we summarize and analyze current studies concerning the biological functions and mechanisms of lncRNA-ATB in tumour development. The related studies were obtained through a systematic search of Pubmed, Web of Science, Embase and Cochrane Library.

RESULTS

Long non-coding RNAs-ATB is a novel cancer-related lncRNA that was recently found to exhibit aberrant expression in a variety of malignancies, including hepatocellular carcinoma, colorectal cancer, gastric cancer, and lung cancer. Dysregulation of lncRNA-ATB has been shown to contribute to proliferation, migration and invasion of cancer cells. Long non-coding RNAs-ATB promotes tumourigenesis and progression mainly through competitively binding miRNAs to induce epithelial-mesenchymal transition (EMT).

CONCLUSIONS

Long non-coding RNAs-ATB likely represents a feasible cancer biomarker or therapeutic target.

Polymorphisms in lncRNA PTENP1 and the Risk of Gastric Cancer in a Chinese Population

Long noncoding RNA (lncRNA) phosphatase and tensin homolog pseudogene 1 (PTENP1) is significantly downregulated in gastric cancer (GC), playing critical roles in GC progression. However, the association between PTENP1 genetic variants and GC risk has not yet been reported. Using TaqMan technology, three lncRNA PTENP1 tag single nucleotide polymorphisms (tagSNPs) (rs7853346 C>G, rs865005 C>T, and rs10971638 G>A) were genotyped in 768 GC patients and 768 cancer-free controls in a Chinese population. We found that subjects with rs7853346 G allele had a remarkably decreased risk of GC, compared with those carrying C allele (P = 0.011 in an additive model, P = 0.033 after Bonferroni's correction). The further stratified analyses showed that the link between variant genotypes of rs7853346 and decreased GC risk was more obvious in older subjects (≥60 years), nonsmokers, nondrinkers, and subjects without family history of GC. We also found that relative PTENP1 mRNA expression levels were higher in rs7853346 CG/GG genotype carriers than those with common genotype in both GC and normal tissues (P < 0.05). Besides, bioinformatics analyses revealed that rs7853346 may change the local folding structure and alter the target microRNAs (miRNAs) of PTENP1. In conclusion, our results suggested that lncRNA PTENP1 polymorphism rs7853346 may predict GC susceptibility.

Long non-coding RNA PTENP1 inhibits proliferation and migration of breast cancer cells via AKT and MAPK signaling pathways

We aimed to investigate the influence of long non-coding RNA (lncRNA) PTEN pseudogene-1 (PTENP1) on the proliferation, migration and cycle of breast cancer cells and its mechanism. Lentiviral vectors expressing PTENP1 were synthesized and breast cancer cells MCF7 were transfected with LV003-GFP-PTENP1 and LV003-GFP, respectively. The proliferation capacities of breast cancer cells were detected using CCK-8 assay, and the migration capacities of breast cancer cells were detected using scratch assay; flow cytometry was used to detect the cell cycles and Western blot was used to detect the expression levels of cyclin A2, CDK2, p-p44/42 MAPK, t-p44/42 MAPK, p-p38 MAPK, t-p38 MAPK, p-AKT, t-AKT in AKT and MAPK pathways. The absorbance values (A450) of cells in experimental group at 48 and 72 h were 1.4±0.3 and 2.3±0.47, respectively, which were significantly lower than those in control group (3.2±0.39, 3.4±0.58) (P<0.05). The number of cell colonies in experimental group was (48±13), which was significantly lower than that in control group (159±16) (P<0.01). The cell migration rate in experimental group was 22.8±3.3%, which was significantly lower than that in control group 61.8±5.2% (P<0.01). Western blot detection showed that the expression levels of cyclin A2, CDK2, p-AKT, p-p44/42 MAPK and p-p38 MAPK in experimental group were significantly decreased compared with those in control group. LncRNA PTENP1 can inhibit the proliferation and migration of breast cancer cells via the AKT and MAPK signaling pathways.

PTENP1 inhibits the growth of esophageal squamous cell carcinoma by regulating SOCS6 expression and correlates with disease prognosis

PTEN pseudogene (PTENP1) has a tumor suppressive role in multiple cancers. However, its involvement in esophageal squamous cell carcinoma (ESCC) remains largely unknown. In this study, we set out to identify the role of PTENP1 in the development of ESCC. Gene Expression Omnibus database was employed to investigate the expression of PTENP1 in ESCC. sRNA target Database (StarBase v2.0) was used to query the downstream of PTENP1. Next, both in vitro and in vivo experiments were employed to explore the function. Cell proliferation was evaluated by CCK‐8, soft agar, and colony formation assays. Expression of relative genes was assessed by quantitative real‐time PCR (qRT‐PCR) and Western blotting. 3′UTR luciferase assay was used to confirm the miRNA binding. The clinical significance of PTENP1 was further validated by immunohistochemistry (IHC) and correlation with clinicopathological indicators in additional samples (n = 93). We found expression of PTENP1 in ESCC was lower than that in the corresponding adjacent normal tissues (n = 17). Overexpression of PTENP1 in Eca109 and TE‐1 cells resulted in inhibited proliferation and altered expression of SOCS6‐p‐STAT3‐HIF‐1α pathway both in vitro and in vivo. Subsequent IHC reported a similar trend in human ESCC samples. 3′UTR luciferase assay demonstrated that PTENP1 3′UTR decoyed miR‐17‐5p from binding to SOCS6. Moreover, PTENP1 expression was correlated with clinicopathological indicators to varying degrees, including histological grade, TNM stage, infiltration depth, lymph node metastasis, and overall survival. Taken together, these results suggested an anti‐oncogenic role of PTENP1. Meanwhile, PTENP1 may also serve as a candidate of prognostic indicator for ESCC patients.

Potential applications of MEG3 in cancer diagnosis and prognosis

LncRNAs are emerging as integral functional and regulatory components of normal biological activities and are now considered as critically involved in the development of different diseases including cancer. In this review, we summarized recent findings on maternally expressed gene 3 (MEG3), a noncoding lncRNA, locates in the imprinted DLK1–MEG3 locus on human chromosome 14q32.3 region. MEG3 is expressed in normal tissues but is either lost or decreased in many human tumors and tumor derived cell lines. Studies have demonstrated that MEG3 is associated with cancer initiation, progression, metastasis and chemo-resistance. MEG3 may affect the activities of TP53, MDM2, GDF15, RB1 and some other key cell cycle regulators. In addition, the level of MEG3 showed good correlation with cancer clinicopathological grade. In summary, MEGs is an RNA-based tumor suppressor and is involved in the etiology, progression, and chemosensitivity of cancers. The alteration of MEG3 levels in various cancers suggested the possibility of using MEG3 level for cancer diagnosis and prognosis.

OncomiR-17-5p: alarm signal in cancer?

Soon after microRNAs entered the stage as novel regulators of gene expression, they were found to regulate -and to be regulated by- the development, progression and aggressiveness of virtually all human types of cancer. Therefore, miRNAs in general harbor a huge potential as diagnostic and prognostic markers as well as potential therapeutic targets in cancer. The miR-17-92 cluster was found to be overexpressed in many human cancers and to promote unrestrained cell growth, and has therefore been termed onco-miR-1. In addition, its expression is often dysregulated in many other diseases. MiR-17-5p, its most prominent member, is an essential regulator of fundamental cellular processes like proliferation, autophagy and apoptosis, and its deficiency is neonatally lethal in the mouse. Many cancer types are associated with elevated miR-17-5p expression, and the degree of overexpression might correlate with cancer aggressiveness and responsiveness to chemotherapeutics - suggesting miR-17-5p to be an alarm signal. Liver, gastric or colorectal cancers are examples where miR-17-5p has been observed exclusively as an oncogene, while, in other cancer types, like breast, prostate and lung cancer, the role of miR-17-5p is not as clear-cut, and it might also act as tumor-suppressor. However, in all cancer types studied so far, miR-17-5p has been found at elevated levels in the circulation. In this review, we therefore recapitulate the current state of knowledge about miR-17-5p in the context of cancer, and suggest that elevated miR-17-5p levels in the plasma might be a sensitive and early alarm signal for cancer ('alarmiR'), albeit not a specific alarm for a specific type of tumor.

Long non-coding RNA Igf2as controls hepatocellular carcinoma progression through the ERK/MAPK signaling pathway

Long non-coding RNAs (lncRNAs) serve an important role in numerous human diseases, including cancer. Abnormal expression of lncRNAs has been associated with a number of tumor types; however, the underlying mechanisms through which lncRNA functions have yet to be elucidated. The present study primarily focuses on insulin-like growth factor 2 antisense 1 (Igf2as), a lncRNA reported to be differentially expressed in hepatocellular carcinoma (HCC). Reverse transcription-quantitative polymerase chain reaction analysis was used to determine the level of Igf2as in HCC cells and tissues. Flow cytometry was used to determine the level of cell apoptosis following Igf2as suppression and western blot analysis was used to identify altered protein expression levels. The results demonstrated that Igf2as was upregulated in HCC cells and tissues, and that the inhibition of Igf2as using a targeted small interfering RNA (si-Igf2as), significantly decreased cell proliferation and increased apoptosis. Western blot analysis identified that the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling pathway was inhibited in cells transfected with si-Igf2as. In addition, cell migration was markedly reduced by the knockdown of Igf2as. These results suggest that lncRNA Igf2as may control hepatocellular progression primarily through the regulation of the ERK/MAPK signaling pathway.

Overexpression of long non-coding RNA zinc finger antisense 1 in acute myeloid leukemia cell lines influences cell growth and apoptosis

The association between long non-coding RNA zinc finger antisense 1 (ZFAS1) and acute myeloid leukemia (AML) has not yet been investigated. The present study aimed to assess the potential role of ZFAS1 in AML cell proliferation and apoptosis. The expression of ZFAS1 mRNA in various AML cell lines (HL-60, KG-1, ML-1 and SKNO-1) was measured by reverse transcription-quantitative polymerase chain reaction. The results showed that ZFAS1 expression was increased in all four human AML cell lines compared with the control cell lines (T lymphocytic leukemia or Burkitt's lymphoma). Transfection with small interfering RNA into human AML cells established ZFAS1 knockdown. A cell-counting kit-8 (CCK-8) assay was used to investigate the effect of ZFAS1 on AML cell proliferation and the effect of ZFAS1 on the cell cycle and cell apoptosis was assessed using flow cytometry. Notably, the CCK-8 assay demonstrated that ZFAS1 knockdown inhibited cell proliferation in HL-60 and SKNO-1 cell lines and flow cytometry analysis indicated that ZFAS1 knockdown induced AML cell cycle G1 phase arrest and triggered cell apoptosis. Therefore, the present study indicated that ZFAS1 promoted the proliferation and inhibited the apoptosis of AML cells.

The emergence of noncoding RNAs as Heracles in autophagy

Macroautophagy/autophagy is a catabolic process that is widely found in nature. Over the past few decades, mounting evidence has indicated that noncoding RNAs, ranging from small noncoding RNAs to long noncoding RNAs (lncRNAs) and even circular RNAs (circRNAs), mediate the transcriptional and post-transcriptional regulation of autophagy-related genes by participating in autophagy regulatory networks. The differential expression of noncoding RNAs affects autophagy levels at different physiological and pathological stages, including embryonic proliferation and differentiation, cellular senescence, and even diseases such as cancer. We summarize the current knowledge regarding noncoding RNA dysregulation in autophagy and investigate the molecular regulatory mechanisms underlying noncoding RNA involvement in autophagy regulatory networks. Then, we integrate public resources to predict autophagy-related noncoding RNAs across species and discuss strategies for and the challenges of identifying autophagy-related noncoding RNAs. This article will deepen our understanding of the relationship between noncoding RNAs and autophagy, and provide new insights to specifically target noncoding RNAs in autophagy-associated therapeutic strategies.

Autophagy-Regulating microRNAs and Cancer

Macroautophagy (autophagy herein) is a cellular stress response and a survival pathway that is responsible for the degradation of long-lived proteins, protein aggregates, as well as damaged organelles in order to maintain cellular homeostasis. Consequently, abnormalities of autophagy are associated with a number of diseases, including Alzheimers’s disease, Parkinson’s disease, and cancer. According to the current view, autophagy seems to serve as a tumor suppressor in the early phases of cancer formation, yet in later phases, autophagy may support and/or facilitate tumor growth, spread, and contribute to treatment resistance. Therefore, autophagy is considered as a stage-dependent dual player in cancer. microRNAs (miRNAs) are endogenous non-coding small RNAs that negatively regulate gene expression at a post-transcriptional level. miRNAs control several fundamental biological processes, and autophagy is no exception. Furthermore, accumulating data in the literature indicate that dysregulation of miRNA expression contribute to the mechanisms of cancer formation, invasion, metastasis, and affect responses to chemotherapy or radiotherapy. Therefore, considering the importance of autophagy for cancer biology, study of autophagy-regulating miRNA in cancer will allow a better understanding of malignancies and lead to the development of novel disease markers and therapeutic strategies. The potential to provide study of some of these cancer-related miRNAs were also implicated in autophagy regulation. In this review, we will focus on autophagy, miRNA, and cancer connection, and discuss its implications for cancer biology and cancer treatment.

The role of autophagy in hepatocellular carcinoma: friend or foe

Autophagy is an evolutionarily conserved lysosome-dependent catabolic process which degrades cell’s components in order to recycle substrates to exert optimally and adapt to tough circumstances. It is a critical cellular homeostatic mechanism with stress resistance, immunity, antiaging, and pro-tumor or anti-tumor effects. Among these, the role of autophagy in cancer is the most eye-catching that is not immutable but dynamic and highly complex. Basal autophagy acts as a tumor suppressor by maintaining genomic stability in normal cells. However, once a tumor is established, unbalanced autophagy will contribute to carcinoma cell survival under tumor microenvironment and in turn promote tumor growth and development. The dynamic role of autophagy can also apply on hepatocellular carcinoma (HCC). HCC is a highly malignant cancer with high morbidity and poor survival rate. Decline or overexpression of autophagic essential genes such as ATG7, ATG5 or Beclin 1 plays a key role in the occurrence and development of HCC but the exact mechanisms are still highly controversial. Signaling pathways or molecules involving in autophagy, for example PI3K/AKT/mTOR pathway, ERK/MAPK pathway, PERK pathway, p53, LncRNA PTENP1 (Long non-coding RNA PTENP1), microRNA-375 and so on, occupy an important position in the complex role of autophagy in HCC. Here, we discuss the dynamic role, the signaling pathways and the potential prognostic and therapy value of autophagy in HCC.

Protein-Coding Genes' Retrocopies and Their Functions

Transposable elements, often considered to be not important for survival, significantly contribute to the evolution of transcriptomes, promoters, and proteomes. Reverse transcriptase, encoded by some transposable elements, can be used in trans to produce a DNA copy of any RNA molecule in the cell. The retrotransposition of protein-coding genes requires the presence of reverse transcriptase, which could be delivered by either non-long terminal repeat (non-LTR) or LTR transposons. The majority of these copies are in a state of “relaxed” selection and remain “dormant” because they are lacking regulatory regions; however, many become functional. In the course of evolution, they may undergo subfunctionalization, neofunctionalization, or replace their progenitors. Functional retrocopies (retrogenes) can encode proteins, novel or similar to those encoded by their progenitors, can be used as alternative exons or create chimeric transcripts, and can also be involved in transcriptional interference and participate in the epigenetic regulation of parental gene expression. They can also act in trans as natural antisense transcripts, microRNA (miRNA) sponges, or a source of various small RNAs. Moreover, many retrocopies of protein-coding genes are linked to human diseases, especially various types of cancer.

Perspectives of long non-coding RNAs in cancer

A recent advance in transcriptomics has spawned the 'Decade of non-coding RNAs' by potentiating the growing numbers of long non-coding RNA in cancer. LncRNA involvement in cancer denotes its significance beyond our perception as they participate in tumor suppression and promoting oncogenesis, which raises them as a mighty class of effectors or regulators. Aberrantly expressed lncRNAs interact with major protein and coding partners, which ultimately deregulate normal cellular processes and drive the cell towards malignant state. Identification of theses interactions are utmost important as lncRNAs can be ideal targets for therapy. Dysregulation of lncRNAs by genomic alterations like single nucleotide variations and gene fusions are also potential modulators of their secondary structure. In this review, we discuss the various molecular interactions of lncRNAs with major bio-molecules and genetic variations in lncRNA genes and their importance in cancer. This systematic review outlines the vivid role of lncRNAs in cancer context and opens up future conceptual applications.

New Insights into the Epigenetics of Hepatocellular Carcinoma

Hepatocellular Carcinoma (HCC) is one of the most predominant malignancies with high fatality rate. This deadly cancer is rising at an alarming rate because it is quite resistant to radio- and chemotherapy. Different epigenetic mechanisms such as histone modifications, DNA methylation, chromatin remodeling, and expression of noncoding RNAs drive the cell proliferation, invasion, metastasis, initiation, progression, and development of HCC. These epigenetic alterations because of potential reversibility open way towards the development of biomarkers and therapeutics. The contribution of these epigenetic changes to HCC development has not been thoroughly explored yet. Further research on HCC epigenetics is necessary to better understand novel molecular-targeted HCC treatment and prevention. This review highlights latest research progress and current updates regarding epigenetics of HCC, biomarker discovery, and future preventive and therapeutic strategies to combat the increasing risk of HCC.

What Is New in the miRNA World Regarding Osteosarcoma and Chondrosarcoma?

Despite the availability of multimodal and aggressive therapies, currently patients with skeletal sarcomas, including osteosarcoma and chondrosarcoma, often have a poor prognosis. In recent decades, advances in sequencing technology have revealed the presence of RNAs without coding potential known as non-coding RNAs (ncRNAs), which provides evidence that protein-coding genes account for only a small percentage of the entire genome. This has suggested the influence of ncRNAs during development, apoptosis and cell proliferation. The discovery of microRNAs (miRNAs) in 1993 underscored the importance of these molecules in pathological diseases such as cancer. Increasing interest in this field has allowed researchers to study the role of miRNAs in cancer progression. Regarding skeletal sarcomas, the research surrounding which miRNAs are involved in the tumourigenesis of osteosarcoma and chondrosarcoma has rapidly gained traction, including the identification of which miRNAs act as tumour suppressors and which act as oncogenes. In this review, we will summarize what is new regarding the roles of miRNAs in chondrosarcoma as well as the latest discoveries of identified miRNAs in osteosarcoma.

LncRNAs: From Basic Research to Medical Application

This review aimed to summarize the current research contents about long noncoding RNAs (lncRNAs) and some related lncRNAs as molecular biomarkers or therapy strategies in human cancer and cardiovascular diseases. Following the development of various kinds of sequencing technologies, lncRNAs have become one of the most unknown areas that need to be explored. First, the definition and classification of lncRNAs were constantly amended and supplemented because of their complexity and diversity. Second, several methods and strategies have been developed to study the characteristic of lncRNAs, including new species identifications, subcellular localization, gain or loss of function, molecular interaction, and bioinformatics analysis. Third, based on the present results from basic researches, the working mechanisms of lncRNAs were proved to be different forms of interactions involving DNAs, RNAs, and proteins. Fourth, lncRNA can play different important roles during the embryogenesis and organ differentiations. Finally, because of the tissue-specific expression of lncRNAs, they could be used as biomarkers or therapy targets and effectively applied in different kinds of diseases, such as human cancer and cardiovascular diseases.

High PTEN gene expression is a negative prognostic marker in human primary breast cancers with preserved p53 function

Purpose

PTEN is an important tumor suppressor in breast cancer. Here, we examined the prognostic and predictive value of PTEN and PTEN pseudogene (PTENP1) gene expression in patients with locally advanced breast cancer given neoadjuvant chemotherapy.

Methods

The association between pretreatment PTEN and PTENP1 gene expression, response to neoadjuvant chemotherapy, and recurrence-free and disease-specific survival was assessed in 364 patients with locally advanced breast cancer given doxorubicin, 5-fluorouracil/mitomycin, or epirubicin versus paclitaxel in three phase II prospective studies. Further, protein expression of PTEN or phosphorylated Akt, S6 kinase, and 4EBP1 was assessed in a subgroup of 187 tumors.

Results

Neither PTEN nor PTENP1 gene expression level predicted response to any of the chemotherapy regimens tested (n = 317). Among patients without distant metastases (n = 282), a high pretreatment PTEN mRNA level was associated with inferior relapse-free (RFS; p = 0.001) and disease-specific survival (DSS; p = 0.003). Notably, this association was limited to patients harboring TP53 wild-type tumors (RFS; p = 0.003, DSS; p = 0.009). PTEN mRNA correlated significantly with PTENP1 mRNA levels (r_s = 0.456, p < 0.0001) and PTEN protein staining (r_s = 0.163, p = 0.036). However, no correlation between PTEN, phosphorylated Akt, S6 kinase or 4EBP1 protein staining, and survival was recorded. Similarly, no correlation between PTENP1 gene expression and survival outcome was observed.

Conclusion

High intratumoral PTEN gene expression was associated with poor prognosis in patients with locally advanced breast cancers harboring wild-type TP53.

Electronic supplementary material

The online version of this article (doi:10.1007/s10549-017-4160-5) contains supplementary material, which is available to authorized users.

Long non-coding RNAs act as regulators of cell autophagy in diseases (Review)

Identification of long non-coding RNAs (lncRNAs) has provided a substantial increase in our understanding of the non-coding transcriptome. Studies have revealed a crucial function of lncRNAs in the modulation of cell autophagy in vitro and in vivo, further contributing to the hallmarks of disease phenotypes. These findings have profoundly altered our understanding of disease pathobiology, and may lead to the emergence of new biological concepts underlying autophagy-associated diseases, such as the carcinomas. Studies on the molecular mechanism of the lncRNA-autophagy axis may offer additional avenues for therapeutic intervention and biomarker assessment. In this review, we discuss recent findings on the multiple molecular roles of regulatory lncRNAs in the signaling pathways of cell autophagy. The emerging knowledge in this rapidly advancing field will offer novel insights into human diseases, especially cancers.

Expression of PTEN and its pseudogene PTENP1, and promoter methylation of PTEN in non-tumourous thymus and thymic tumours

AIMS

Mutation or promoter methylation of the phosphatase tensin homologue deleted on chromosome 10 tumour suppressor gene (PTEN) promotes some cancers. Moreover, PTENP1 (PTEN pseudogene) transcript regulates PTEN expression and is thought to be associated with tumourigenesis in some cancers. Here, we investigated PTEN expression in thymic epithelium and thymic epithelial tumours.

METHODS

Immunohistochemical analysis of PTEN was performed on two non-tumourous thymus (NT) samples, 33 thymomas (three type A, eight type AB, 11 type B1, six type B2, and five type B3), and four thymic carcinomas (TCs). In 16 cases (two NT, three A, five B1, two B2, one B3 and three TC), analyses of mutations, promoter methylation and comparisons of PTEN mRNA and PTENP1 transcripts were undertaken using PCR-direct sequencing, methylation-specific PCR, and reverse-transcription real-time PCR after target cell collection with laser microdissection.

RESULTS

PTEN protein was not immunohistochemically detected in NT epithelium or types B1 or B2 thymoma cells, but was expressed in type A thymoma and carcinoma cells. Neither PTEN mutations nor promoter methylation were detected in any samples. Statistical analysis revealed that PTEN mRNA expression was highest in NT epithelium and lowest in type A thymoma cells. PTENP1 transcript expression did not significantly differ among NT, thymoma and TC samples.

CONCLUSIONS

We speculated that NT epithelium and types B1/B2 thymoma cells have a mechanism of PTEN translation repression and/or acceleration of protein degradation, whereas type A thymoma cells exhibit transcriptional repression of PTEN mRNA and accelerated translation and/or protein accumulation.

Decreased expression of pseudogene PTENP1 promotes malignant behaviours and is associated with the poor survival of patients with HNSCC

PTENP1, a pseudogene of PTEN, was previously reported to be a tumour suppressor in some cancer types. However, there was no evidence for the biological function and expression of PTENP1 in head and neck squamous cell carcinoma (HNSCC). Here, we evaluated the function and clinical implications of PTENP1 in HNSCC. Using RT-PCR and quantitative real-time PCR (qRT-PCR), we found that the level of PTENP1 was reduced in HNSCC specimens compared with adjacent tissues. A decrease in the PTENP1 copy number, but not in the PTEN copy number, was frequently observed in tumour cell lines (4 of 5 cell lines) by genomic real-time PCR. Decreased PTENP1 expression was significantly associated with a history of alcohol use (P = 0.034). Univariate and multivariate Cox regression analyses revealed that low expression of PTENP1 correlated with worse overall survival (OS, P = 0.005; HR:0.170; Cl:0.049 to 0.590) and disease-free survival (DFS, P = 0.009; HR:0.195; Cl:0.057 to 0.664) rates of HNSCC patients. Furthermore, ectopic PTENP1 expression inhibited the proliferation, colony formation and migration of HNSCC cells and the growth of xenograft HNSCC tumours. These results demonstrate that PTENP1 might play an important role in the initiation and progression of HNSCC.

Silver Nanoparticles Induce HePG-2 Cells Apoptosis Through ROS-Mediated Signaling Pathways

Recently, silver nanoparticles (AgNPs) have been shown to provide a novel approach to overcome tumors, especially those of hepatocarcinoma. However, the anticancer mechanism of silver nanoparticles is unclear. Thus, the purpose of this study was to estimate the effect of AgNPs on proliferation and activation of ROS-mediated signaling pathway on human hepatocellular carcinoma HePG-2 cells. A simple chemical method for preparing AgNPs with superior anticancer activity has been showed in this study. AgNPs were detected by transmission electronic microscopy (TEM) and energy dispersive X-ray (EDX). The size distribution and zeta potential of silver nanoparticles were detected by Zetasizer Nano. The average size of AgNPs (2 nm) observably increased the cellular uptake by endocytosis. AgNPs markedly inhibited the proliferation of HePG-2 cells through induction of apoptosis with caspase-3 activation and PARP cleavage. AgNPs with dose-dependent manner significantly increased the apoptotic cell population (sub-G1). Furthermore, AgNP-induced apoptosis was found dependent on the overproduction of reactive oxygen species (ROS) and affecting of MAPKs and AKT signaling and DNA damage-mediated p53 phosphorylation to advance HePG-2 cells apoptosis. Therefore, our results show that the mechanism of ROS-mediated signaling pathways may provide useful information in AgNP-induced HePG-2 cell apoptosis.

[Long non-coding RNAs and hypoxic-ischemic brain damage]

Long non-coding RNAs (lncRNAs) are transcripts with a complex structure and a length of >200 nt which are unable to encode proteins. The lncRNAs interact with DNA, mRNA, and proteins and regulate gene expression through various mechanisms, thus participating in the regulation of various biological processes. Studies have shown that lncRNAs play important roles in neural development and the pathogenesis of diseases. This article reviews the roles of lncRNAs in hypoxic-ischemic brain damage.

Long non-coding RNA RP5-833A20.1 inhibits proliferation, metastasis and cell cycle progression by suppressing the expression of NFIA in U251 cells

Early reports suggest that nuclear factor IA (NFIA) is important in the pathogenesis of glioma. Our previous study demonstrated that the long non‑coding RNA (lncRNA), RP5‑833A20.1, suppressed the expression of NFIA in THP‑1 macrophage-derived foam cells. However, the effect and possible mechanism of RP5‑833A20.1 on glioma remains to be fully elucidated, and whether the NFIA-dependent pathway is involved in its progression has not been investigated. In the present study, the mechanisms by which RP5‑833A20.1 regulates the expression of NFIA in glioma were investigated. The expression levels of RP5‑833A20.1 and NFIA were determined in U251 cells and clinical samples using reverse transcription‑quantitative polymerase chain reaction (PCR) analysis. The effects of RP5‑833A20.1 on cell proliferation, invasion, cell cycle and apoptosis were evaluated using in vitro assays. The potential changes in protein expression were investigated using western blot analysis. The methylation status of the CpG island in the NFIA promoter was determined using bisulfite PCR (BSP) sequencing. It was found that the expression of RP5‑833A20.1 was downregulated, whereas the expression of NFIA was upregulated in glioma tissues, compared with corresponding adjacent nontumor tissues from 20 patients with glioma. The overexpression of RP5‑833A20.1 inhibited proliferation and cell cycle progression, and induced apoptosis in the U251 cells. The mRNA and protein levels of NFIA were markedly inhibited by overexpression of RP5‑833A20.1 in the U251 cells. The overexpression of RP5‑833A20.1 increased the expression of microRNA‑382‑5p in the U251 cells. The BSP assay revealed that the overexpression of RP5‑833A20.1 enhanced the methylation level of the NFIA promoter. These results demonstrated that RP5‑833A20.1 inhibited tumor cell proliferation, induced apoptosis and inhibited cell‑cycle progression by suppressing the expression of NFIA in U251 cells. Collectively, these results indicated RP5‑833A20.1 as a novel therapeutic target for glioma.

Sleeping Beauty transposition: from biology to applications

Sleeping Beauty (SB) is the first synthetic DNA transposon that was shown to be active in a wide variety of species. Here, we review studies from the last two decades addressing both basic biology and applications of this transposon. We discuss how host-transposon interaction modulates transposition at different steps of the transposition reaction. We also discuss how the transposon was translated for gene delivery and gene discovery purposes. We critically review the system in clinical, pre-clinical and non-clinical settings as a non-viral gene delivery tool in comparison with viral technologies. We also discuss emerging SB-based hybrid vectors aimed at combining the attractive safety features of the transposon with effective viral delivery. The success of the SB-based technology can be fundamentally attributed to being able to insert fairly randomly into genomic regions that allow stable long-term expression of the delivered transgene cassette. SB has emerged as an efficient and economical toolkit for safe and efficient gene delivery for medical applications.

Long non-coding RNAs: potential new biomarkers for predicting tumor invasion and metastasis

Long non-coding RNAs (lncRNAs) play important roles in malignant neoplasia. Indeed, many hallmarks of cancer define that the malignant phenotype of tumor cells are controlled by lncRNAs. Despite a growing number of studies highlighting their importance in cancer, there has been no systematic review of metastasis-associated lncRNAs in various cancer types. Accordingly, we focus on the key metastasis-related lncRNAs and outline their expression status in cancer tissues by reviewing the previous stuides, in order to summarize the nowadays research achivements for lncRNAs related to cancer metastasis. Medline, EMBASE, as well as PubMed databases were applied to study lncRNAs which were tightly associated with tumor invasion and metastasis. Up to now, a substantial number of lncRNAs have been found to have important biological functions. In this review, according to their various features in cancer, lncRNAs were roughly divided into three categories: promoting tumor invasion and metastasis, negative regulation of tumor metastasis and with dual regulatory roles. The present studies may establish the foundation for both further research on the mechanisms of cancer progression and future lncRNA-based clinical applications.

PAFAH1B1 and the lncRNA NONHSAT073641 maintain an angiogenic phenotype in human endothelial cells

AIM

Platelet-activating factor acetyl hydrolase 1B1 (PAFAH1B1, also known as Lis1) is a protein essentially involved in neurogenesis and mostly studied in the nervous system. As we observed a significant expression of PAFAH1B1 in the vascular system, we hypothesized that PAFAH1B1 is important during angiogenesis of endothelial cells as well as in human vascular diseases.

METHOD

The functional relevance of the protein in endothelial cell angiogenic function, its downstream targets and the influence of NONHSAT073641, a long non-coding RNA (lncRNA) with 92% similarity to PAFAH1B1, were studied by knockdown and overexpression in human umbilical vein endothelial cells (HUVEC).

RESULTS

Knockdown of PAFAH1B1 led to impaired tube formation of HUVEC and decreased sprouting in the spheroid assay. Accordingly, the overexpression of PAFAH1B1 increased tube number, sprout length and sprout number. LncRNA NONHSAT073641 behaved similarly. Microarray analysis after PAFAH1B1 knockdown and its overexpression indicated that the protein maintains Matrix Gla Protein (MGP) expression. Chromatin immunoprecipitation experiments revealed that PAFAH1B1 is required for active histone marks and proper binding of RNA Polymerase II to the transcriptional start site of MGP. MGP itself was required for endothelial angiogenic capacity and knockdown of both, PAFAH1B1 and MGP, reduced migration. In vascular samples of patients with chronic thromboembolic pulmonary hypertension (CTEPH), PAFAH1B1 and MGP were upregulated. The function of PAFAH1B1 required the presence of the intact protein as overexpression of NONHSAT073641, which was highly upregulated during CTEPH, did not affect PAFAH1B1 target genes.

CONCLUSION

PAFAH1B1 and NONHSAT073641 are important for endothelial angiogenic function.

Topoisomerase II Inhibitors Can Enhance Baculovirus-Mediated Gene Expression in Mammalian Cells through the DNA Damage Response

BacMam is an insect-derived recombinant baculovirus that can deliver genes into mammalian cells. BacMam vectors carrying target genes are able to enter a variety of cell lines by endocytosis, but the level of expression of the transgene depends on the cell line and the state of the transduced cells. In this study, we demonstrated that the DNA damage response (DDR) could act as an alternative pathway to boost the transgene(s) expression by BacMam and be comparable to the inhibitors of histone deacetylase. Topoisomerase II (Top II) inhibitor-induced DDR can enhance the CMV-IE/enhancer mediated gene expression up to 12-fold in BacMam-transduced U-2OS cells. The combination of a Top II inhibitor, VM-26, can also augment the killing efficiency of a p53-expressing BacMam vector in U-2OS osteosarcoma cells. These results open a new avenue to facilitate the application of BacMam for gene delivery and therapy.