Long noncoding RNA BCAR4 promotes osteosarcoma progression through activating GLI2-dependent gene transcription

LncRNAs as potential prognosis/diagnosis markers and factors driving drug resistance of osteosarcoma, a review

Osteosarcoma is a common malignancy that often occurs in children, teenagers and young adults. Although the treatment strategy has improved, the results are still poor for most patients with metastatic or recurrent osteosarcomas. Therefore, it is necessary to identify new and effective prognostic biomarkers and therapeutic targets for diseases. Human genomes contain lncRNAs, transcripts with limited or insufficient capacity to encode proteins. They have been implicated in tumorigenesis, particularly regarding the onset, advancement, resistance to treatment, recurrence and remote dissemination of malignancies. Aberrant lncRNA expression in osteosarcomas has been reported by numerous researchers; lncRNAs have the potential to exhibit either oncogenic or tumor-suppressing behaviors and thus, to govern the advancement of this skeletal cancer. They are suspected to influence osteosarcoma cell growth, replication, invasion, migration, remote dissemination and programmed cell death. Additionally, they have been recognized as clinical markers, and may participate in the development of multidrug resistance. Therefore, the study of lncRNAs in the growth, metastasis, treatment and prognosis of osteosarcoma is very important for the active prevention and treatment of osteosarcoma. Consequently, this work reviews the functions of lncRNAs.

LncRNA MALAT1-related signaling pathways in osteosarcoma

Osteosarcoma (OS) is a common and malignant form of bone cancer, which affects children and young adults. OS is identified by osteogenic differentiation and metastasis. However, the exact molecular mechanism of OS development and progression is still unclear. Recently, long non-coding RNAs (lncRNA) have been proven to regulate OS proliferation and drug resistance. LncRNAs are longer than 200 nucleotides that represent the extensive applications in the processing of pre-mRNA and the pathogenesis of human diseases. Metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) is a well-known lncRNA known as a transcriptional and translational regulator. The aberrant expression of MALAT1 has been shown in several human cancers. The high level of MALAT1 is involved in OS cell growth and tumorigenicity by targeting several signaling pathways and miRNAs. Hence, MALAT1 might be a suitable approach for OS diagnosis and treatment. In this review, we will summarize the role of lncRNA MALAT1 in the pathophysiology of OS.

Non-coding RNAs as potential biomarkers in osteosarcoma

Osteosarcoma (OS) is a primary solid malignant tumor that occurs most frequently in the metaphysis of long bones. More likely to happen to children and adolescents. OS has high mortality and disability rate. However, the etiology and pathogenesis of OS have not been fully understood till now. Due to the lack of effective biomarkers, OS cannot be precisely detected in the early stage. With the application of next-generation and high-throughput sequencing, more and more abnormally expressed non-coding RNAs(ncRNAs) have been identified in OS. Growing evidences have suggested the ncRNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), have played an important role in the tumorigenesis and progression of OS. Thus, they can be served as novel biomarkers for diagnosis, treatment and prognosis. This review summarized the application of ncRNA as biomarkers in OS in detail, and discussed the limitation and future improvement of the potential biomarkers.

The crosstalk between long non-coding RNAs and the hedgehog signaling pathway in cancer

Hedgehog (Hh) is a conserved signaling pathway that is involved in embryo development as well as adult tissue maintenance and repair in invertebrates and vertebrates. Abnormal activation of this pathway in various types of malignant drug- and apoptosis-resistant tumors has made it a therapeutic target against tumorigenesis. Thus, understanding the molecular mechanisms that promote the activation or inhibition of this pathway is critical. Long non-coding RNAs (lncRNAs), a subclass of non-coding RNAs with a length of > 200 nt, affect the expression of Hh signaling components via a variety of transcriptional and post-transcriptional processes. This review focuses on the crosstalk between lncRNAs and the Hh pathway in carcinogenesis, outlines the broad role of Hh-related lncRNAs in tumor progression, and illustrates their clinical diagnostic, prognostic, and therapeutic potential in tumors.

Long non-coding RNA DSCAM-AS1 promotes pancreatic cancer progression via regulating the miR-136-5p/PBX3 axis

LncRNA down syndrome cell adhesion molecule antisense 1 (DSCAM-AS1) plays an important role in tumor progression, but its function in pancreatic cancer is unknown. DSCAM-AS1 level was evaluated by in situ hybridization (ISH) assay and qRT-PCR. DSCAM-AS1 was knocked down in pancreatic cancer cells, and its impacts on cell proliferation, invasion, and migration were detected. The binding relationship among DSCAM-AS1, miR-136-5p, and pre-B-cell leukemia homeobox 3 (PBX3) was investigated by bioinformatic analysis and luciferase reporter assay. An in vivo animal model was constructed to determine the role of DSCAM-AS1 in tumor growth. Our results showed that DSCAM-AS1 was elevated in tumor tissues of pancreatic cancer patients and cell lines. DSCAM-AS1 knockdown efficiently inhibited PANC-1 cell proliferation, migration, and invasion and suppressed tumor growth. DSCAM-AS1 could promote PBX3 expression by sponging miR-136-5p, and its function in pancreatic cancer was partially mediated by the miR-136-5p/PBX3 axis. Overall, DSCAM-AS1 knockdown inhibits pancreatic cancer progression by modulating the miR-136-5p/PBX3 axis.

Anticancer effects of melatonin via regulating lncRNA JPX-Wnt/β-catenin signalling pathway in human osteosarcoma cells

Osteosarcoma (OS) is a type of malignant primary bone cancer, which is highly aggressive and occurs more commonly in children and adolescents. Thus, novel potential drugs and therapeutic methods are urgently needed. In the present study, we aimed to elucidate the effects and mechanism of melatonin on OS cells to provide a potential treatment strategy for OS. The cell survival rate, cell viability, proliferation, migration, invasion and metastasis were examined by trypan blue assay, MTT, colony formation, wound healing, transwell invasion and attachment/detachment assay, respectively. The expression of relevant lncRNAs in OS cells was determined by real-time qPCR analysis. The functional roles of lncRNA JPX in OS cells were further examined by gain and loss of function assays. The protein expression was measured by western blot assay. Melatonin inhibited the cell viability, proliferation, migration, invasion and metastasis of OS cells (Saos-2, MG63 and U2OS) in a dose-dependent manner. Melatonin treatment significantly downregulated the expression of lncRNA JPX in Saos-2, MG63 and U2OS cells. Overexpression of lncRNA JPX into OS cell lines elevated the cell viability and proliferation, which was accompanied by the increased metastasis. We also found that melatonin inhibited the OS progression by suppressing the expression of lncRNA JPX via regulating the Wnt/β-catenin pathway. Our results suggested that melatonin inhibited the biological functions of OS cells by repressing the expression of lncRNA JPX through regulating the Wnt/β-catenin signalling pathway, which indicated that melatonin might be applied as a potentially useful and effective natural agent in the treatment of OS.

The Role of lncRNAs in Rare Tumors with a Focus on HOX Transcript Antisense RNA (HOTAIR)

Rare cancers are identified as those with an annual incidence of fewer than 6 per 100,000 persons and includes both epithelial and stromal tumors from different anatomical areas. The advancement of analytical methods has produced an accurate molecular characterization of most human cancers, suggesting a “molecular classification” that has allowed the establishment of increasingly personalized therapeutic strategies. However, the limited availability of rare cancer samples has resulted in very few therapeutic options for these tumors, often leading to poor prognosis. Long non coding RNAs (lncRNAs) are a class of non-coding RNAs mostly involved in tumor progression and drug response. In particular, the lncRNA HOX transcript antisense RNA (HOTAIR) represents an emergent diagnostic, prognostic and predictive biomarker in many human cancers. The aim of this review is to highlight the role of HOTAIR in rare cancers, proposing it as a new biomarker usable in the management of these tumors.

Keep your eyes peeled for long noncoding RNAs: Explaining their boundless role in cancer metastasis, drug resistance, and clinical application

Cancer metastasis and drug resistance are two major obstacles in the treatment of cancer and therefore, the leading cause of cancer-associated mortalities worldwide. Hence, an in-depth understanding of these processes and identification of the underlying key players could help design a better therapeutic regimen to treat cancer. Earlier thought to be merely transcriptional junk and having passive or secondary function, recent advances in the genomic research have unravelled that long noncoding RNAs (lncRNAs) play pivotal roles in diverse physiological as well as pathological processes including cancer metastasis and drug resistance. LncRNAs can regulate various steps of the complex metastatic cascade such as epithelial-mesenchymal transition (EMT), invasion, migration and metastatic colonization, and also affect the sensitivity of cancer cells to various chemotherapeutic drugs. A substantial body of literature for more than a decade of research evince that lncRNAs can regulate gene expression at different levels such as epigenetic, transcriptional, posttranscriptional, translational and posttranslational levels, depending on their subcellular localization and through their ability to interact with DNA, RNA and proteins. In this review, we mainly focus on how lncRNAs affect cancer metastasis by modulating expression of key metastasis-associated genes at various levels of gene regulation. We also discuss how lncRNAs confer cancer cells either sensitivity or resistance to various chemo-therapeutic drugs via different mechanisms. Finally, we highlight the immense potential of lncRNAs as prognostic and diagnostic biomarkers as well as therapeutic targets in cancer.

Effect of lncRNA XLOC_005950 knockout by CRISPR/Cas9 gene editing on energy metabolism and proliferation in osteosarcoma MG63 cells mediated by hsa-miR-542-3p

Cancer cells use glucose via glycolysis to maintain tumor cell proliferation. However, the effect of long non-coding RNAs (lncRNAs) on glycolysis in osteosarcoma (OS) cells remains unclear. The present study aimed to investigate the involvement of the lncRNA XLOC_005950/hsa-microRNA (miR)-542-3p/phosphofructokinase, muscle (PFKM) axis in the regulation of glucose metabolism, cell proliferation and apoptosis in the progression of OS. lncRNA XLOC_005950, hsa-miR-542-3p and PFKM expression in OS tissues and cells was detected via reverse transcription-quantitative PCR analysis. CRISPR/Cas9 gene editing was used to knockout lncRNA XLOC_005950 expression in MG63 cells. Cell Counting Kit-8 assay, flow cytometry, PFKM activity, and glucose and lactic acid content determination were performed to assess the effects of lncRNA XLOC_005950 knockout and overexpression of hsa-miR-542-3p on the phenotypes of OS cells. The dual-luciferase reporter assay was performed to confirm the targeting associations between lncRNA XLOC_005950, hsa-miR-542-3p and PFKM. The results demonstrated that lncRNA XLOC_005950 expression was upregulated in OS tissues and cells. Functional experiments indicated that lncRNA XLOC_005950 knockout decreased PFKM activity, the intracellular glucose and lactic acid content, and cell proliferation, while increasing apoptosis of OS cells. Furthermore, lncRNA XLOC_005950 knockout upregulated hsa-miR-542-3p expression and downregulated PFKM expression. Overexpression of hsa-miR-542-3p suppressed PFKM expression. Furthermore, lncRNA XLOC_005950, as the molecular sponge of miR-542-3p in OS, modulated the downstream target gene, PFKM. Taken together, the results of the present study suggest that lncRNA XLOC_005950 knockout may inhibit the progression of OS via hsa-miR-542-3p-mediated regulation of PFKM expression.

LncRNA BCAR4 expression and predicts the clinical response to neoadjuvant chemotherapy in patients with locally advanced breast cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) is an important treatment for locally advanced breast cancer (LABC). However, there are no effective biomarkers to predict the efficacy. Therefore, there is an urgent need for new biomarkers to predict the response of LABC to NAC. LncRNA BCAR4 has been detected in a variety of malignant tumor tissues and used as a new biomarker for diagnosis and prognosis. However, LncRNA BCAR4 predicts the response of LABC to NAC is unclear.

OBJECTIVE

Explore the predictive effect of LncRNA BCAR4 on the efficacy of NAC for LABC in three different evaluation systems.

METHODS

First, the TCGA database was used to analyze the expression of LncRNA BCAR4 in 33 kinds of malignant tumors, and further explore its expression in breast cancer and its impact on the survival and prognosis of breast cancer. Furthermore, quantitative methods were used to measure the expression level of LncRNA BCAR4 in cancer tissues of 48 LABC patients, and the correlation between LncRNA BCAR4 and clinicopathological status and response to NAC under the evaluation system of 3, RECIST1.1, Miller-Payne (MP) score and whether it reaches pCR,was analyzed.

RESULTS

TCGA data analysis found that LncRNA is highly expressed in a variety of malignant tumor tissues, including breast cancer. And relatively low expression, the shorter the overall survival time of high expression patients. The high expression of LncRNA BCAR4 is related to the size of the tumor, and there are differences in expression between stage I and other stages, but there is no obvious correlation with the positive lymph node and hormone receptor status. Among the three evaluation systems, only in the RECIST 1.1 evaluation system LncRNA BCAR4 has a predictive effect on NAC for LABC. The expression of LncRNA BCAR4 has no significant correlation with clinical stage, Ki-67% and hormone receptor status, and has no significant correlation with whether patients with locally advanced breast cancer obtain pCR during neoadjuvant chemotherapy.

CONCLUSION

LncRNA BCAR4 is highly expressed in LABC tissues and may be an effective marker for predicting the efficacy of NAC for LABC.

Silencing of the Long Non-Coding RNA TTN-AS1 Attenuates the Malignant Progression of Osteosarcoma Cells by Regulating the miR-16-1-3p/TFAP4 Axis

Objectives

Osteosarcoma (OS) is a type of bone malignancy. This study attempted to explore the effect of long non-coding RNA TTN-AS1 (TTN-AS1) on OS and to determine its molecular mechanisms.

Methods

The expression of TTN-AS1, microRNA-16-1-3p (miR-16-1-3p), and transcription factor activating enhancer binding protein 4 (TFAP4) in OS was assessed using qRT-PCR. The OS cell proliferation, migration, and invasion were measured using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound-healing, and transwell assays. N-cadherin and MMP-2 protein level was determined with western blot. Interactions between TTN-AS1 and miR-16-1-3p or TFAP4 and miR-16-1-3p were confirmed using the dual-luciferase reporter assay. Additionally, an OS xenograft tumor model was constructed to assess the effect of TTN-AS1 on tumor growth.

Results

TTN-AS1 and TFAP4 expression was increased in OS, while miR-16-1-3p expression was decreased. TTN-AS1 silencing restrained OS cell proliferation, migration, invasion, N-cadherin and MMP-2 protein expression, and hindered tumor growth. MiR-16-1-3p overexpression retarded the malignant behavior of OS cells. TTN-AS1 played a carcinostatic role by down-regulating miR-16-1-3p in the OS cells. Moreover, miR-16-1-3p inhibition or TFAP4 elevation weakened the suppressive effect of TTN-AS1 silencing on OS cell tumor progression.

Conclusion

TTN-AS1 promoted the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of OS cells via mediating the miR-16-1-3p/TFAP4 axis. TTN-AS1 may be a critical target for improving OS.

Immune Infiltration Subtypes Characterization and Identification of Prognosis-Related lncRNAs in Adenocarcinoma of the Esophagogastric Junction

The incidence of adenocarcinoma of the esophagogastric junction (AEG) has markedly increased worldwide. However, the precise etiology of AEG is still unclear, and the therapeutic options thus remain limited. Growing evidence has implicated long non-coding RNAs (lncRNAs) in cancer immunomodulation. This study aimed to examine the tumor immune infiltration status and assess the prognostic value of immune-related lncRNAs in AEG. Using the ESTIMATE method and single-sample GSEA, we first evaluated the infiltration level of 28 immune cell types in AEG samples obtained from the TCGA dataset (N=201). Patients were assigned into high- and low-immune infiltration subtypes based on the immune cell infiltration’s enrichment score. GSEA and mutation pattern analysis revealed that these two immune infiltration subtypes had distinct phenotypes. We identified 1470 differentially expressed lncRNAs in two immune infiltration subtypes. From these differentially expressed lncRNAs, six prognosis-related lncRNAs were selected using the Cox regression analysis. Subsequently, an immune risk signature was constructed based on combining the values of the six prognosis-associated lncRNAs expression levels and multiple regression coefficients. To determine the risk model’s prognostic capability, we performed a series of survival analyses with Kaplan–Meier methods, Cox proportional hazards regression models, and the area under receiver operating characteristic (ROC) curve. The results indicated that the immune-related risk signature could be an independent prognostic factor with a significant predictive value in patients with AEG. Furthermore, the immune-related risk signature can effectively predict the response to immunotherapy and chemotherapy in AEG patients. In conclusion, the proposed immune-related lncRNA prognostic signature is reliable and has high survival predictive value for patients with AEG and is a promising potential biomarker for immunotherapy.

The role of long non-coding RNA BCAR4 in human cancers

Long non-coding RNA (lncRNA) is a type of non-coding RNA with length of nucleotides > 200 bp. Increasing evidences show that lncRNA breast cancer antiestrogen resistance 4 (BCAR4) plays an important role in the occurrence and development of various human cancers. It is found that BCAR4 is highly expressed in diverse tumor tissues and cells, and the high expression of BCAR4 is usually associated with poor prognosis. BCAR4 is considered as an oncogene in human cancers. By competing endogenous RNA (ceRNA) mechanism and regulating different signaling pathways, BCAR4 participates in the proliferation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT), metastasis and tumorigenesis of different cancers. In addition, overexpression of BCAR4 promotes drug resistance of tumor cells. Therefore, BCAR4 is a promising biomarker for cancer diagnosis and prognosis, and it is a potential target for cancer therapy. This paper reviews studies focusing on the relationship between BCAR4 and cancers in recent years and aims to summarize the effect and mechanism of BCAR4 in human cancers.

DNA damage response and repair in osteosarcoma: Defects, regulation and therapeutic implications

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents which has the survival rate of 20% in its advanced stages. Osteosarcomas are mostly resistance to our common treatments. DNA damage response (DDR) is a specialized multistep process containing abundant proteins which are necessary for the survival of any cell and organism. DDR machinery detects a diversity of DNA lesions and inhibits the cell cycle progression if these lesions are not repairable. DDR is involved in aging, age-related diseases, and cancer. In recent years, DDR inhibitors have gained the attention of researches due to their potentials in offering novel therapeutic targets and improving the response of many cancers to either chemo- or radio-therapy. In this regard, we tried to gather a great body of evidence about the role of DDR ingredients in osteosarcoma's initiation/progression, prognosis, and treatment.

The value of lncRNAs as prognostic biomarkers on clinical outcomes in osteosarcoma: a meta-analysis

Background

In recent years, emerging studies have demonstrated critical functions and potential clinical applications of long non-coding RNA (lncRNA) in osteosarcoma. To further validate the prognostic value of multiple lncRNAs, we have conducted this updated meta-analysis.

Methods

Literature retrieval was conducted by searching PubMed, Web of Science and the Cochrane Library (last update by October 2, 2019). A meta-analysis was performed to explore association between lncRNAs expression and overall survival (OS) of osteosarcoma patients. Relationships between lncRNAs expression and other clinicopathological features were also analyzed respectively.

Results

Overall, 4351 patients from 62 studies were included in this meta-analysis and 25 lncRNAs were identified. Pooled analyses showed that high expression of 14 lncRNAs connoted worse OS, while two lncRNAs were associated with positive outcome. Further, analysis toward osteosarcoma clinicopathologic features demonstrated that overexpression of TUG1 and XIST indicated poor clinical parameters of patients.

Conclusions

This meta-analysis has elucidated the prognostic potential of 16 lncRNAs in human osteosarcoma. Evidently, desperate expression and functional targets of these lncRNAs offer new approaches for prognosis and therapy of osteosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07882-w.

LncRNA, Important Player in Bone Development and Disease

BACKGROUND

Bone is an important tissue and its normal function requires tight coordination of transcriptional networks and signaling pathways, and many of these networks/ pathways are dysregulated in pathological conditions affecting cartilage and bones. Long non-coding RNA (lncRNA) refers to a class of RNAs with a length of more than 200 nucleotides, lack of protein-coding potential, and exhibiting a wide range of biological functions. Although studies on lcnRNAs are still in their infancy, they have emerged as critical players in bone biology and bone diseases. The functions and exact mechanism of bone-related lncRNAs have not been fully classified yet.

OBJECTIVE

The objective of this article is to summarize the current literature on lncRNAs on the basis of their role in bone biology and diseases, focusing on their emerging molecular mechanism, pathological implications and therapeutic potential.

DISCUSSION

A number of lncRNAs have been identified and shown to play important roles in multiple bone cells and bone disease. The function and mechanism of bone-related lncRNA remain to be elucidated.

CONCLUSION

At present, majority of knowledge is limited to cellular levels and less is known on how lncRNAs could potentially control the development and homeostasis of bone. In the present review, we highlight some lncRNAs in the field of bone biology and bone disease. We also delineate some lncRNAs that might have deep impacts on understanding bone diseases and providing new therapeutic strategies to treat these diseases.

Tumor-associated macrophages promote human hepatoma Huh-7 cell migration and invasion through the Gli2/IGF-II/ERK1/2 axis by secreting TGF-β1

AIM

In this study, we explored the ability of TAMs to affect the malignant phenotype of human hepatoma Huh-7 cells through the Gli2/IGF-II/ERK1/2 pathway.

METHODS

The TAMs were characterized by flow cytometry and ELISA assays. Huh-7 cells were treated with conditioned medium of TAMs (TAMs-CM), and the proliferation, migration and invasion abilities were measured by CCK-8, Transwell and scratch assays. The levels of TGF-β1, Gli2, IGF-II and related proteins in the ERK1/2 pathway and the epithelial-mesenchymal transition (EMT) process were examined by RT-qPCR and western blot. Huh-7 cells were injected subcutaneously into nude mice with TAMs to explore the role of TAMs in tumor growth.

RESULTS

The expression levels of TGF-β1, Gli2 and IGF-II and the cell proliferation, migration and invasion abilities were elevated in Huh-7 cells treated with TAMs-CM. TGF-β1 was upregulated in the conditioned medium and was found to be involved in the promotion of migration, invasion and the EMT of Huh-7 cells. The activation of TGF-β1 signaling increased the expression of Gli2. Knockdown of Gli2 decreased the expression of IGF-II and also reversed the promotional effect of the conditioned medium on migration, invasion and the EMT of Huh-7 cells. TGF-β1/Gli2/IGF-II signaling was shown to promote the malignant phenotype of Huh-7 cells by activating the ERK1/2 signaling pathway. Further, TGF-β1 knockdown attenuated the influence of TAMs on tumor growth in mouse model.

CONCLUSION

The TGF-β1 secreted by TAMs promotes the migration, invasion and EMT of human hepatoma Huh-7 cells through the Gli2/IGF-II/ERK1/2 pathway.

Comprehensive Characterization of Prognostic Long Noncoding RNAs in Osteosarcoma

The molecular mechanism of osteosarcoma (OS) based on protein-coding genes has largely been studied in the past decades. However, much remains to be explored when it comes to the role that long noncoding RNAs (lncRNAs) play in the pathogenesis and progression of OS and how they are associated with OS metastasis. In the present study, we collected RNA-seq-based gene expression data of 82 OS samples from the Therapeutically Applicable Research To Generate Effective Treatments (TARGET) database, along with their clinical information. We found that 50 lncRNAs were significantly associated with patients' survival by univariable Cox regression model. Moreover, we built multivariable Cox regression model based on 7 lncRNAs and successfully stratified patients into two risk groups, which exhibited significantly different prognostic outcomes. Significantly enriched Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways detected by differential expression analysis on DEGs between the two groups with different prognostic outcomes were both immune-related, indicating that such GO terms and pathways are critical for OS survival. Among the seven lncRNA signatures, AC011442.1 was predicted to act as an oncogenic driver in OS by correlation analysis of copy number alteration (CNA) and lncRNA expression, and it was predicted to regulate AMPK and hedgehog signaling pathways. In summary, the identification of novel prognostic lncRNAs in OS could not only improved our understanding of the lncRNAs involved in OS tumorigenesis or progression but also assist the diagnosis and development of molecularly targeted therapies for OS, which in turn benefit patients' survival.

The Role of Long Noncoding RNAs in Antiestrogen Resistance in Breast Cancer: An Overview and Update

As a standard treatment, endocrine therapy has dramatically enhanced the prognosis of patients with estrogen receptor (ER)-positive breast cancer, which accounts for nearly 70% of all breast cancers. Antiestrogen drugs such as tamoxifen and aromatase inhibitors are the standard treatment options for ERα-positive breast cancer. However, acquired antiestrogen resistance is still the leading cause of disease recurrence and progression. Evidence has shown that long noncoding RNAs (lncRNAs) play an essential role in the development of antiestrogen resistance in ER-positive breast cancer and can serve as biomarkers or potential therapeutic targets. This review highlights the role of lncRNAs in the development of antiestrogen resistance in breast cancer.

BCAR4 activates GLI2 signaling in prostate cancer to contribute to castration resistance

Long non-coding RNAs (lncRNAs) have been found essential for tumorigenesis of prostate cancer (PC), but its role in the regulation of castration-resistant prostate cancer (CRPC) is poorly identified. Here, we showed that a lncRNA, Breast-Cancer Anti-Estrogen Resistance 4 (BCAR4), which plays a pivotal role in the tamoxifen-resistance of breast cancer, was significantly upregulated in CRPC, but not in castration-sensitive prostate cancer (CSPC), compared to normal prostate tissue. High BCAR4 levels in CRPC were correlated with poor patients' overall survival. Androgen increased growth and migration of androgen receptor (AR)-positive PC346 cells, which was abolished by the antagonist of androgen. Overexpression of BCAR4 in PC346 cells increased cell growth and migration, but turned the cells insensitive to androgen. On the other hand, growth and migration of AR-negative DU145 cells are insensitive to androgen, while depletion of BCAR4 in DU145 cells not only decreased cell growth, but also turned the cells sensitive again to androgen. Moreover, BCAR4 activated GLI2 downstream genes, and correlated with the levels of these GLI2-target genes in CRPC. Depletion of GLI2 abolished the effects of BCAR4 on cell growth and migration. Together, our data suggest that BCAR4 may activate GLI2 signaling in PC to contribute to castration resistance.

Identification of lncRNA NEAT1/miR-21/RRM2 axis as a novel biomarker in breast cancer

As a major disease that threatens the health of women worldwide, breast cancer (BC) lacks effective molecular markers in the clinic at the same time. We aim at finding a new biomarker of BC. In our study, through the Gene Expression Omnibus database chip, a total of 1393 pairs of microRNA-messenger RNA (miRNA-mRNA) networks and 35754 pairs of long noncoding RNA-miRNA networks were obtained. We found out that NEAT1/miR-21/RRM2 axis may play a role in BC diagnosis and prognosis. The real-time quantitative reverse transcription-polymerase chain reaction test was used to analyze the mRNA level of NEAT1, miR-21, and RRM2. Western blot was used to detect the protein level of RRM2. Through the 5-ethynyl-2'-deoxyuridine assay, the proliferation of MDA-MB-231 cells was detected. Through wound healing and transwell assay, the migration of MDA-MB-231 cells was detected. Altogether, our data indicated that NEAT1, miR-21, and RRM2 were upregulated in several BC cell lines. Overexpressed of miR-21 in MDA-MB-231 cells promote proliferation and migration. Besides, our results demonstrated that overexpressed of miR-21 upregulated the level of RRM2. Accordingly, miR-21/RRM2 might be a new diagnosis and treatment target of BC.

The Value of LncRNA BCAR4 as a Prognostic Biomarker on Clinical Outcomes in Human Cancers

Background: This updated meta-analysis aimed to analyze available data to explore the prognostic value of long noncoding RNA breast cancer anti-estrogen resistance 4 (BCAR4) in various human malignancies. Methods: Literature retrieval was performed by systematic searching several authoritative databases, including Pubmed, PMC database, Web of Science, the Cochrane Library, Embase, and CNKI database up to Feb 10, 2019. Data were extracted and subsequently crosschecked, and discrepancies were discussed to reach consensus. Quality of the eligible studies was evaluated by Newcastle-Ottawa Scale (NOS). The fixed- or random-effects model was used to calculate the pooled the hazard ratios (HRs) or odds ratios (ORs) and the 95% confidence interval (95% CI). Publication bias was detected by using Begg's funnel plot and Egger's test. Results: A total 1,128 cancer patients from thirteen studies were included and pooled in the present meta-analysis. High expression levels of BCAR4 were correlated with unfavorable overall survival (OS) (HR=2.23, 95% CI: 1.84-2.71), but not progression-free survival (PFS) (HR=1.30, 95% CI: 0.80-2.11). Subgroup stratified analysis showed that tumor type, sample size, follow-up months, and survival analysis method did not alter the predictive value of BCAR4 on OS in various cancers. Furthermore, elevated BCAR4 level was markedly correlated with advanced clinical stage (III/IV) (OR=3.28, 95% CI: 2.33-4.60), and dramatically predicted lymph node metastasis (OR=3.00, 95% CI: 1.95-4.63, P<0.00001) and distant metastasis (OR=3.36, 95% CI: 1.88-5.98, P<0.0001), but not associated with age, gender or tumor size. No obvious heterogeneity was noted for correlation between BCAR4 expression and OS across these studies. Conclusions: High expression of BCAR4 was correlated with unfavorable overall survival outcome and clinical features including metastasis and progression, implicating an independent prognostic value for BCAR4 in human cancers.

Inhibition of long non-coding RNA-AWPPH decreases osteosarcoma cell proliferation, migration and invasion

Long non-coding RNAs (lncRNAs) serve a crucial role in various types of cancer. The lncRNA AWPPH has been reported to promote hepatocellular carcinoma and bladder cancer progression. However, to the best of our knowledge, the biological roles of AWPPH in osteosarcoma (OS) remain unclear. In the present study, the levels of AWPPH in OS tissues and cell lines were determined by reverse transcription-quantitative polymerase chain reaction. An MTT assay was used to detect OS cell proliferation. The levels of proteins associated with the PI3K/Akt signaling pathway and apoptosis were determined by western blotting. Wound-healing and Transwell assays were conducted to determine cell migration and invasion, respectively. The results demonstrated that AWPPH was highly expressed in OS tissues and cells. Functional analyses revealed that AWPPH depletion significantly inhibited OS cell proliferation and migration, and promoted OS cell apoptosis. Furthermore, AWPPH downregulation significantly inhibited the PI3K/AKT pathway. The present study demonstrated that AWPPH was highly expressed in OS, and that AWPPH promoted OS cell proliferation and migration, and inhibited OS cell apoptosis, which may be mediated by PI3K/AKT pathway activation.

Downregulation of the long non‑coding RNA FOXD2‑AS1 inhibits cell proliferation, migration and invasion in osteosarcoma

Increasing amounts of long noncoding RNAs (lncRNAs) have been shown to be involved in the development of cancer. Recently, aberrant expression of the lncRNA forkhead box D2 adjacent opposite strand RNA1 (FOXD2-AS1) has been reported to be involved in the progression of several types of human cancer. However, the function and mechanism of FOXD2-AS1 in osteosarcoma (OS) are currently unclear. The present study aimed to investigate the function and mechanism of FOXD2-AS1 in OS. Firstly, it was revealed that the expression levels of FOXD2-AS1 were significantly upregulated in OS tissues and cells, compared with in adjacent tissues and normal cells, as determined using reverse transcription-quantitative polymerase chain reaction. Notably, the overall survival of patients with relatively high FOXD2-AS1 expression in OS tissues was significantly lower than that of patients with relatively low expression, as determined using Kaplan-Meier analysis. In addition, loss-of-function experiments were performed in vivo and in vitro to study the biological effects of FOXD2-AS1. The SOSP-9607 and U2OS OS cell lines were infected with lentivirus-mediated FOXD2-AS1 short hairpin RNA; subsequently, the alterations in cell phenotype and downstream molecules were evaluated. Knockdown of FOXD2-AS1 inhibited the proliferation, migration and invasion of OS cells. Furthermore, the number of cells in the S phase was significantly decreased, which was consistent with the results of the Cell Counting kit 8 proliferation assay. The expression levels of ribonucleotide reductase regulatory subunit M2 and phosphoglycerate dehydrogenase were decreased, as determined by western blotting, following FOXD2-AS1 knockdown. Finally, in a nude mouse model of tumorigenesis, it was revealed that, when FOXD2-AS1 expression was downregulated, tumor growth was significantly reduced and pulmonary metastatic nodules were markedly reduced. The results of the present study suggested that decreased FOXD2-AS1 expression may inhibit the growth, migration and invasion of tumor cells, and it may regulate downstream gene expression. In conclusion, these findings indicated that FOXD2-AS1 may be used as a potential therapeutic target and early tumor marker for the diagnosis and prognosis of OS.

Prognostic value of long non-coding RNA breast cancer anti-estrogen resistance 4 in human cancers: A meta-analysis

BACKGROUND

Since long non-coding RNA breast cancer anti-estrogen resistance 4 (lncRNA BCAR4) is dysregulated in various types of cancers, we conducted a meta-analysis to determine its prognostic value in cancer.

METHODS

PubMed, EMBASE database, and CENTRAL were systematically searched.Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were collected to estimate the prognostic value. Odds ratios (ORs) and their 95% CIs were used to assess the association between lncRNA BCAR4 expression and clinicopathological features, including tumor size, differentiation, lymph node metastasis, distant metastasis, and tumor stage.

RESULTS

Ten studies with 890 patients were included in this meta-analysis. The pooled results indicated that high lncRNA BCAR4 expression was associated with poor overall survival (OS) (HR 2.80, 95% CI: 2.08-3.78; P < .001). Overexpression of lncRNA BCAR4 was related to lymph node metastasis (OR 3.68, 95% CI: 2.25-6.00; P < .001), high tumor stage (OR 3.19, 95% CI: 1.98-5.13; P < .001), and distant metastasis (OR 3.83, 95% CI: 2.15-6.82; P < .001), but not to tumor size.

CONCLUSIONS

Therefore, lncRNA BCAR4 overexpression is associated with poor OS and advanced clinicopathological features, and lncRNA BCAR4 may be a novel prognostic biomarker in cancer patients. However, further high-quality studies are needed to confirm these findings.

Epigenetic modulation of BRCA-1 and MGMT genes, and histones H4 and H3 are associated with breast tumors

Aberrant patterns in promoter methylation of tumor-suppressor genes and posttranslational modifications of histone proteins are considered as major features of malignancy. In this study, we aimed to investigate promoter methylation of three tumor-suppressor genes (BRCA-1, MGMT, and P16) and three histone marks (H3K9ac, H3K18ac, and H4K20me3) in patients with breast tumors. This case-control study included 27 patients with malignant breast tumors (MBT) and 31 patients with benign breast tumors (BBT). The methylation-specific PCR was used for determining promoter methylation of BRCA-1, MGMT, and P16 genes. Western blot analysis was performed to detect histone lysine acetylation (H3K9ac and H3K18ac) and lysine methylation (H4K20me3). BRCA-1 promoter methylation was detected in 44.4% of the MBT whereas this alteration was found in 9.7% of BBT (P = 0.005). The Kaplan-Meier analysis indicated that hypermethylation in BRCA-1 promoter was significantly associated with poor overall survival of patients with breast cancer (P = 0.039). MGMT promoter methylation was identified in 18.5% of MBT and 0.0% of the BBT (P = 0.01). The frequency of P16 promoter methylation was 25.8% in BBT and 11.1% in MBT (P = 0.12). As compared with BBT, MBT samples displayed the aberrant patterns of histones marks with hypomethylation of H4K20 and hypoacetylation of H3K18 (P = 0.03 and P = 0.04, respectively). There was a negative significant correlation between H3K9ac levels and tumor size in MBT group (r = -0.672; P = 0.008). The present findings suggest that promoter hypermethylation of MGMT and BRCA-1 genes along with alterations in H3K18ac and H4K20me3 levels may have prognostic values in patients with breast cancer. Moreover, the detection of these epigenetic modifications in breast tumors could be helpful in finding new methods for breast cancer therapy.

Long noncoding RNA DNAJC3-AS1 promotes osteosarcoma progression via its sense-cognate gene DNAJC3

Long noncoding RNAs have been proved to play essential roles in tumor development and progression. In this study, we focused on DNAJC3-AS1 and investigated its biological function and clinical significance in osteosarcoma. We detected the expression of DNAJC3-AS1 in 30 pairs of matched osteosarcoma and adjacent nontumorous specimens and osteosarcoma cell lines and analyzed association between DNAJC3-AS1 levels and clinicopathological factors. We found that DNAJC3-AS1 expression was up-regulated in osteosarcoma. High level of DNAJC3-AS1 was correlated with high differentiated degree (P = 0.018) and advanced Enneking stage (P = 0.016). Mechanistically, DNAJC3-AS1 enhanced cell proliferation, migration, and invasion in vitro and in vivo and reduced sensitivity of osteosarcoma to cisplatin. These effects of DNAJC3-AS1 were reversed by down-regulation of its sense-cognate gene DNAJC3. Thus, DNAJC3-AS1 promotes osteosarcoma development and progression by regulating DNAJC3 and might be a biomarker and therapeutic target for osteosarcoma.

Long noncoding RNA Breast cancer antiestrogen resistance 4 is associated with cancer progression and its significant prognostic value

Breast cancer antiestrogen resistance 4 (BCAR4) is a novel long noncoding RNA. It was originally identified in a screen for genes responsible for the development of resistance to antiestrogens in breast cancer cells and plays a major role in various tumors. However, the clinical diagnostic role of BCAR4 in tumors is not completely understood. This current meta-analysis aimed to comprehensively explore the potential role of BCAR4 as a prognostic biomarker in a number of cancers. Five public databases PubMed, EMBASE, Web of Science, Wiley Online Library, and Medline were used to search for articles. Nine studies comprising 1,293 patients were included in this meta-analysis. The results of analysis showed that BCAR4 expression in human cancer was significantly associated with poor overall survival (hazard ratio [HR] = 1.98, confidence interval [CI]: [1.71-2.29]), p < 0.00001, and high BCAR4 expression was associated with clinical stage (OR and its 95% CI was 3.30 [1.99-5.46], p < 0.00001), distant metastasis (OR = 3.83, 95% CI: 2.15-6.82, p < 0.00001), and lymph node metastasis (OR and its 95% CI was 2.91 [1.62-5.25], p = 0.0004) in patients with cancer. Furthermore, the results revealed the prognostic significance of BCAR4 in gastrointestinal malignancy, breast cancer, and osteosarcoma (HR and its 95% CI were 2.05 [1.56-2.68], p < 0.00001; 1.78 [1.46-2.16], p < 0.00001; and 2.47 [1.41-4.34], p < 0.00001, respectively). This meta-analysis indicated the potential value of BCAR4 as a biomarker for predicting a poor prognosis in patients with cancer.

Genetic testing for high-grade osteosarcoma: a guide for future tailored treatments?

INTRODUCTION

Genetic characterization of osteosarcoma has evolved during the last decade, thanks to the integrated application of conventional and new candidate-driven and genome-wide technologies. Areas covered: This review provides an overview of the state of art in genetic testing applied to osteosarcoma, with particular regard to novel candidate genetic biomarkers that can be analyzed in tumor tissue and blood samples, which might be used to predict toxicity and prognosis, detect disease relapse, and improve patients' selection criteria for tailoring treatment. Expert commentary: Genetic testing based on modern technologies is expected to indicate new osteosarcoma-related prognostic markers and driver genes, which may highlight novel therapeutic targets and patients stratification biomarkers. The definition of tailored or targeted treatment approaches may improve outcome of patients with localized tumors and, even more, of those with metastatic disease, for whom progress in cure probability is highly warranted.

Abnormally expressed long non-coding RNAs in prognosis of Osteosarcoma: A systematic review and meta-analysis

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High LncRNA expression was significantly correlated with the poorer OS prognosis in osteosarcoma patients. However, the cut-off values may be the source of heterogeneity.

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The expression level of LncRNA was positively correlated with alkaline phosphatase, tumor size, metastasis, distant metastasis and Enneking stage.

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This meta-analysis demonstrated that abnormal LncRNAs expression was correlated with advanced clinicopathological features and poor prognosis as a novel predictive biomarker in osteosarcoma.

Background

Numerous studies have reported the relationship between Long non-coding RNAs (LncRNAs) expression and prognosis of osteosarcoma, but less consensus has been reached. Our meta-analysis was conducted to quantitatively assess the relationship between the expression of LncRNAs, prognosis and clinical pathology in osteosarcoma development.

Methods

PubMed,Embase,Web of Science,The Cochrane Library,SionMed,CNKI and WanFang databases were carefully searched to identify eligible studies. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to evaluate the prognostic significance of LncRNAs expression in osteosarcoma. Moreover, meta-regression analysis and subgroup analysis were carried out to explore the potential sources of heterogeneity.

Results

A total of 20 studies comprising 1749 patients were included in present meta-analysis. The results showed that the over-expression of LncRNA had a significant correlation with overall survival (OS) (HR = 2.16, 95% CI:1.68–2.79), and was not related to disease free survival (DFS) (HR = 0.71, 95% CI:0.05–9.53). Subgroup analysis further indicated that LncRNA transcription level was significantly associated with alkaline phosphatase (HR = 2.13, 95% CI:1.58–2.88) , tumor size (< 8/ ≥ 8:HR = 1.97, 95% CI: 1.55–2.62) , metastasis (yes/no: HR = 2.14,95% CI:1.15–3.97) , distant metastasis(presence/absence: HR = 4.02, 95% CI:3.05–5.23) and Enneking stage(IIA /IIB-III:HR = 3.2, 95% CI:2.48–4.14), but not associated with age (≤ 25/ > 25:HR = 1.01, 95% CI:0.78–1.3), gender(female/male: HR = 1.15, 95% CI: 0.96–1.37), tumor site (femur,tibia/elsewhere:HR = 1.15, 95% CI:0.94–1.4) and chemotherapy (yes/no: HR = 1.45, 95% CI:0.46–4.63).

Conclusions

This study demonstrated that abnormal LncRNAs expression might be potential prognostic markers to predict worse overall survival in osteosarcoma patients. However, the cut-off values may be the source of heterogeneity.

LncRNA DLEU1 contributes to colorectal cancer progression via activation of KPNA3

Background

Accumulating evidences show that long noncoding RNAs (lncRNA) play essential roles in the development and progression of various malignancies. However, their functions remains poorly understood and many lncRNAs have not been defined in colorectal cancer (CRC). In this study, we investigated the role of DLEU1 in CRC.

Methods

Quantitative real-time PCR was used to detect the expression of DLEU1 and survival analysis was adopted to explore the association between DLEU1 expression and the prognosis of CRC patients. CRC cells were stably transfected with lentivirus approach and cell proliferation, migration, invasion and cell apoptosis, as well as tumorigenesis in nude mice were performed to assess the effects of DLEU1 in BCa. Biotin-coupled probe pull down assay, RNA immunoprecipitation and Fluorescence in situ hybridization assays were conducted to confirm the relationship between DLEU1 and SMARCA1.

Results

Here we revealed that DLEU1 was crucial for activation of KPNA3 by recruiting SMARCA1, an essential subunit of the NURF chromatin remodeling complex, in CRC. DLEU1 was indispensible for the deposition of SMARCA1 at the promoter of KPNA3 gene. Increased expression of DLEU1 and KPNA3 was observed in human CRC tissues. And higher expression of DLEU1 or KPNA3 in patients indicates lower survival rate and poorer prognosis. DLEU1 knockdown remarkably inhibited CRC cell proliferation, migration and invasion in vitro and in vivo while overexpressing KPNA3 in the meantime reversed it.

Conclusions

Our results identify DLEU1 as a key regulator by a novel DLEU1/SMARCA1/KPNA3 axis in CRC development and progression, which may provide a potential biomarker and therapeutic target for the management of CRC.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0873-2) contains supplementary material, which is available to authorized users.

LncRNA WWOX‑AS1 inhibits the proliferation, migration and invasion of osteosarcoma cells

Recently, numerous long non-coding (lnc)RNAs have been revealed as serving important roles in human gene regulation. Previous studies have suggested that aberrant expression of lncRNAs is associated with cancer progression and metastasis. Previous studies have also demonstrated that decreased expression of WW domain-containing oxidoreductase (WWOX) is associated with poor prognosis in numerous cancer types. However, the effect of WWOX antisense RNA 1 (WWOX-AS1) in the development of cancer remains unknown. The aim of the present study was to investigate the role of WWOX-AS1 in osteosarcoma. The expression levels of WWOX-AS1 in human osteosarcoma cell lines and a normal osteoblastic cell line were investigated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results revealed that WWOX-AS1 expression was downregulated in osteosarcoma tissues. Furthermore, the association between WWOX-AS1 and the prognosis of patients with osteosarcoma was investigated using Kaplan-Meier and log-rank tests. The results suggested that patients exhibiting high WWOX-AS1 expression demonstrated a greater overall survival compared with patients exhibiting low WWOX-AS1 expression. In addition, overexpression and knockdown of WWOX-AS1 was performed using transfection experiments and confirmed by RT-qPCR in MG63 and SAOS2 cells, respectively. The results demonstrated that WWOX-AS1 and WWOX expression were positively correlated. Furthermore, the results of the knockdown and overexpression functional experiments suggested that WWOX-AS1 overexpression inhibited the proliferation, migration and invasion of MG63 cells, and knockdown of WWOX-AS1 enhanced the proliferation, migration and invasion of MG63 cells in SAOS2 cells. In conclusion, the results of the present study suggested that WWOX-AS1 may represent a potential biomarker and therapeutic target for the treatment of osteosarcoma.

Up-regulated BCAR4 contributes to proliferation and migration of cervical cancer cells

OBJECTIVES

Recently, thousands of long non-coding RNAs (lncRNAs) involved in development and metastasis of malignant tumors have been identified. Long non-coding RNA (lncRNA) breast cancer anti-estrogen resistance 4 (BCAR4) has been proved to promote proliferation and metastasis in multiple tumors. However, the function and significance of BCAR4 in cervical cancer are still unclear.

METHODS

In this study, we concentrated on the biological function and clinical significance of BCAR4 in cervical cancer. More specifically, BCAR4 expression was evaluated in cervical cancer tissues and cell lines by qRT-PCR. Moreover, the prognostic factors were assessed by Kaplan-Meier analysis and Cox proportional hazards models. Additionally, functional assays were conducted and the potential mechanism was explored.

RESULTS

Our study showed that BCAR4 expression was significantly up-regulated in cervical cancer tissue and cell lines. Moreover, patients with high BCAR4 expression showed worse survival outcomes and overexpression of BCAR4 might be an independent prognostic factor in cervical cancer. Furthermore, overexpression of BCAR4 remarkably promoted the proliferation, motility of cervical cancer cells and silencing BCAR4 significantly suppressed the proliferation, migration and invasion of cervical cancer cells. Additionally, overexpression of BCAR4 promoted epithelial-mesenchymal transition (EMT) process and silencing BCAR4 suppressed EMT process in cervical cancer cells.

CONCLUSIONS

The results indicated that BCAR4 might play a crucial role in cervical cancer progression and act as an underlying biomarker for the diagnosis and prognosis of cervical cancer.

Long Noncoding RNA LINC01133 Functions as an miR-422a Sponge to Aggravate the Tumorigenesis of Human Osteosarcoma

Long noncoding RNAs (lncRNAs) have been verified to participate in various types of malignant tumors, including osteosarcoma (OS), which is the most common primary bone tumor with outstanding morbidity. Although an increasing number of lncRNAs have been reported to mediate the occurrence of OS, the potential mechanisms are still unclear. This study intends to uncover the mechanism by which lncRNA LINC01133 functions as an miRNA sponge to mediate OS tumorigenicity. In this study, we found that the expression level of LINC01133 was statistically upregulated in OS tumor tissue and cell lines compared to noncancerous tissues and a normal human osteoplastic cell line. LINC01133 silencing could also observably suppress the proliferation, migration, and invasion of OS cells (HOS and U2-OS). Bioinformatics analysis predicted that LINC01133 specifically targeted miR-422a, which was validated by dual-luciferase reporter assay. Furthermore, functional experiments revealed that miR-422a played a tumor-suppressive role in OS progression and could effectively reverse the function of LINC01133. In summary, our study discovered that lncRNA LINC01133 aggravates the proliferation, migration, and invasion of OS by sponging miR-422a, which provides a novel insight in the tumorigenesis of OS.

lncRNA BCAR4 Increases Viability, Invasion, and Migration of Non-Small Cell Lung Cancer Cells by Targeting Glioma-Associated Oncogene 2 (GLI2)

This study aimed to explore the effects of lncRNA BCAR4 on the viability and aggressiveness of non-small cell lung cancer (NSCLC) cells. qRT-PCR was used to determine the expression of BCAR4 and GLI2 downstream genes in NSCLC tissues and cell lines. Chromatin isolation by RNA purification (CHIRP) and Western blot were employed to measure the expression of the GLI2 downstream proteins. Ki-67 expression in nude mice tumors was tested by immunohistochemistry. MTT assay, wound healing assay, and Transwell assay were used to assess NSCLC cell viability and aggressiveness, respectively. Tumor xenograft was conducted to determine the effects of BCAR4 and GLI2 on NSCLC tumorigenesis in vivo. The expression of BCAR4 in NSCLC tissues and cells was significantly higher than the normal level. The overexpression of BCAR4 promoted NSCLC cell viability, migration, and invasion. The suppression of BCAR4 and GLI2 showed the opposite effects. The overexpression of BCAR4 led to an increase in the expression of GLI2 downstream proteins, while the suppression of BCAR4 and GLI2 reduced their expression. In a tumor xenograft assay, the tumors in mice of the BCAR4 group showed the biggest volume, while those in mice of the si-GLI2 group showed the smallest volume. Ki-67 showed much higher levels in the BCAR4 overexpression group but much lower levels in the si-GLI2 group. In summary, the cooperative mechanism of lncRNA BCAR4 and GLI2 might provide a new opportunity for treating NSCLC.

Role of lncRNAs in the cancer development and progression and their regulation by various phytochemicals

Long non coding RNAs (lncRNAs) are involved in modulating the expression of other non-coding RNAs (ncRNA), such as microRNAs, or target proteins through the epigenetic, transcriptional, or post-transcriptional regulations. Genomic mutations in cancer reside inside regions that do not code for proteins and these regions are often transcribed into long non coding RNAs (lncRNAs). Emerging evidences have revealed an intense involvement of lncRNAs in the cancer development and progression. Recently, emerging evidences have depicted that the phytochemicals interact with lncRNAs to modulate their activities. Such findings are highly important for the identification of therapeutic strategies against diseases that are particularly associated with an aberrant lncRNA signaling. This review aims at deciphering the role of lncRNAs in the cancer development and progression, and their regulation by various phytochemicals.

Altered long non-coding RNAs predict worse outcome in osteosarcoma patients: evidence from a meta-analysis

Long non-coding RNAs (lncRNAs) are emerging as promising prognostic biomarkers in an expanding list of malignant neoplasms. Here, we sought to investigate the strength of associations between lncRNA signatures and clinical outcomes in osteosarcoma. We conducted a systematic search of the online databases from inception to July 2016. Hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) for the primary endpoints of overall survival (OS), progression-free survival (PFS) or event-free survival (EFS) were extracted and meta-analyzed. Our results manifested that altered lncRNAs expression was markedly associated with worse OS (univariate analysis: HR = 3.20, 95% CI: 2.42-4.24, P = 0.000; multivariate analysis: HR = 2.66, 95% CI: 1.92-3.69, P = 0.000), PFS (HR = 2.05, 95% CI: 1.32-3.18, P = 0.001) and EFS (HR = 4.37, 95% CI: 1.64-11.66, P = 0.003) times among osteosarcoma patients. In the pooled analyses stratified by clinicopathological features, levels of lncRNAs were closely correlated with tumor size (pooled P = 0.001), tumor stage (pooled P = 0.003), and distant metastasis (pooled P = 0.002) in osteosarcoma. The results obtained in our work suggest that altered lncRNA signatures predict unfavorable clinical outcomes and are acceptable to be potential prognostic biomarkers in forecasting prognosis of osteosarcoma.

The Role of Long Non-Coding RNAs in Osteosarcoma

Long non-coding RNAs (lncRNAs) constitute non-protein coding transcripts with a size > than 200 nucleotides. They are involved in many cellular processes, such as chromatin remodelling, transcription, and gene expression. They play a role in the development, progression, and invasion of many human cancers, including osteosarcoma. This rare tumor entity predominantly arises in children and young adults. Treatment consists of polychemotherapy and surgical resection, increasing survival rates up to 60%. In the present review, the role of lncRNAs with prognostic, predictive, therapeutic, and diagnostic significance in osteosarcoma is discussed. Moreover, their potential application in clinical practice is highlighted.

Differential long non-coding RNA expression profiles in human oocytes and cumulus cells

Progress in assisted reproductive technologies strongly relies on understanding the regulation of the dialogue between oocyte and cumulus cells (CCs). Little is known about the role of long non-coding RNAs (lncRNAs) in the human cumulus-oocyte complex (COC). To this aim, publicly available RNA-sequencing data were analyzed to identify lncRNAs that were abundant in metaphase II (MII) oocytes (BCAR4, C3orf56, TUNAR, OOEP-AS1, CASC18, and LINC01118) and CCs (NEAT1, MALAT1, ANXA2P2, MEG3, IL6STP1, and VIM-AS1). These data were validated by RT-qPCR analysis using independent oocytes and CC samples. The functions of the identified lncRNAs were then predicted by constructing lncRNA-mRNA co-expression networks. This analysis suggested that MII oocyte lncRNAs could be involved in chromatin remodeling, cell pluripotency and in driving early embryonic development. CC lncRNAs were co-expressed with genes involved in apoptosis and extracellular matrix-related functions. A bioinformatic analysis of RNA-sequencing data to identify CC lncRNAs that are affected by maternal age showed that lncRNAs with age-related altered expression in CCs are essential for oocyte growth. This comprehensive analysis of lncRNAs expressed in human MII oocytes and CCs could provide biomarkers of oocyte quality for the development of non-invasive tests to identify embryos with high developmental potential.

LncRNA expression and implication in osteosarcoma: a systematic review and meta-analysis

Purpose

Osteosarcoma is the most prevalent primary bone tumor in children, adolescents, and older adults, typically presenting with poor survival outcomes. In recent years, ample evidence has shown that many long noncoding RNAs (lncRNAs) have been aberrantly expressed in osteosarcoma, demonstrating their potential to serve as prognostic markers. In this study, we performed a meta-analysis on four lncRNAs (TUG1, UCA1, BCAR4, and HULC) to systematically evaluate their prognostic value in osteosarcoma.

Materials and methods

The eligible articles were systematically searched in PubMed, Web of Science, Embase, and Elsevier ScienceDirect (up to September 22, 2017), and one meta-analysis concerning the association between lncRNA expression and the overall survival (OS) of osteosarcoma patients was performed. Survival outcomes were analyzed by OS. Subgroup analyses were performed.

Results

A total of 1,361 patients with osteosarcoma and 12 lncRNAs from 16 articles were included in the study. Of the listed lncRNAs, the high expression of 10 lncRNAs indicated worse survival outcomes, while only two lncRNAs were shown to positively affect patients’ OS.

Conclusion

This meta-analysis indicated that the abnormally expressed lncRNAs might significantly affect the survival of osteosarcoma patients. Combined use of these lncRNAs may serve as potential novel biomarkers for the indication of clinical outcomes of osteosarcoma patients as well as the selection of adjuvant chemotherapy strategies for clinical treatment of this disease.

LncRNA BCAR4 promotes colon cancer progression via activating Wnt/β-catenin signaling

BCAR4 (Breast Cancer Anti-Estrogen Resistance 4) is a long noncoding RNA that was identified as an oncogene in breast cancer. In our research, we found that the expression level of BCAR4 was upregulated in colon cancer tissues compared to paired normal tissues. What's more, higher BCAR4 expression was correlated with lower survival rate in patients with colon cancer. Mechanistically, we showed that BCAR4 activated Wnt/β-catenin signaling in colon cancer by protecting β-catenin from degradation. We also showed that BCAR4 overexpression promoted cell proliferation and migration in colon cancer. However, silencing BCAR4 inhibited cell growth and promoted apoptosis. Besides, BCAR4 knockdown decreased tumor growth in vivo. These findings indicate that BCAR4 facilitated colon cancer progression by enhancing cell proliferation and inhibiting apoptosis via BCAR4/β-catenin axis. BCAR4 may be a useful new target for treatment of patients with colon cancer.

Long non-coding RNAs in osteosarcoma

Long non-coding RNAs (lncRNAs) with more than 200 nuleotides, have been explored to participate in various cancer types including osteosarcoma (OS), which is the most common kind of primary bone tumors with high morbidity in infants and adolescents. These oncogenic or tumor suppressive lncRNAs regulate OS pathogenesis, such as cell growth, proliferation, invasion, migration, metastasis and cell apoptosis, serve as independent prognostic biomarkers or play a significant role in multidrug resistance (MDR) in OS cells. In this review, we attempt to dissect the participation of lncRNAs in pathogenesis of OS and their potential clinical values, and also provide an outlook for viable biomarkers and therapeutic targets in OS.

LEF1-AS1, a long-noncoding RNA, promotes malignancy in glioblastoma

OBJECTIVES

The long-noncoding RNAs (lncRNAs) are identified as new crucial regulators of diverse cellular processes in glioblastoma (GBM) tissues. However, the expression pattern and biological function of lncRNAs remain largely unknown. Here, for the first time, the effects of lncRNA lymphoid enhancer-binding factor 1 antisense RNA 1 (LEF1-AS1) on GBM progression both in vitro and in vivo are investigated.

MATERIALS AND METHODS

Expression profiles of LEF1-AS1 in GBM specimens were investigated by bioinformatics analyses. LEF1-AS1 expression in GBM tissues was detected using a quantitative polymerase chain reaction. LEF1-AS1 expression was inhibited by transfecting the LEF1-AS1-specific small interfering RNAs (siRNAs) and stable cell lines established were inhibited by transfecting si-LEF1-AS1 viruses. The Cell Counting Kit-8, ethynyl deoxyuridine, and colony formation assay were used to examine proliferation function. The flow cytometry detected cell-cycle change and apoptosis. Migration effects were detected by a Transwell assay. The tumor xenografts and immunohistochemistry were performed to evaluate tumor growth in vivo.

RESULTS

In this study, LEF1-AS1 expression was found significantly upregulated in GBM specimens compared with normal tissues. The 5-year overall survival in GBM patients from The Cancer Genome Atlas with high expression of LEF1-AS1 was inferior to that with low expression. It was confirmed that expression of LEF1-AS1 was higher in GBM tissues than normal ones. Knockdown of LEF1-AS1 significantly inhibited the malignancy of GBM cells, including proliferation and invasion, and promoted cell apoptosis. The result of Western blot assays indicated that knockdown of LEF1-AS1-mediated tumor suppression in GBM cells may be via the reduction of ERK and Akt/mTOR signaling activities. Finally, the in vivo experiment also demonstrated that knockdown LEF1-AS1 inhibited the growth-promoting effect of LEF1-AS1 of U87 cells.

CONCLUSION

Our result indicated that lncRNA LEF1-AS1 acts as an oncogene in GBM and may be a pivotal target for this disease.

Long non-coding RNAs for osteosarcoma in the mouse: a meta-analysis

Osteosarcoma, one of the most common primary bone malignances, is a leading cause of cancer death among children and adolescents. Recently, growing studies have found that long non-coding RNAs (lncRNAs) can interfere with the expression of various genes, and participate in the occurrence and development of malignancies. The purpose of this study is to evaluate the potential functions of lncRNAs as diagnostic biomarkers and therapeutic targets for osteosarcoma in mice, thus to direct the strict design for the future preclinical experiments and clinical trials. We systematically searched PubMed, Web of Science, Embase, China Knowledge Resource Integrated Database, VIP, Chinese BioMedical and Wan Fang Database from their initiation date to June 20, 2017. Two researchers independently screened the literatures and withdrew the data, which used the tumor volume and tumor weight as the outcome measures. A total of 10 studies were included, and the results of this meta-analysis revealed that lncRNAs could serve as the diagnostic biomarkers and therapeutic targets for osteosarcoma; and progression of osteosarcoma in mice could be inhibited via rescuing the abnormally expressed lncRNAs. It is necessary to carry out more rigorous basic experiments before lncRNAs can be further investigated in the clinical trials and used in future clinical practices.

LncRNA ODRUL Contributes to Osteosarcoma Progression through the miR-3182/MMP2 Axis

Recent findings have shown that lncRNA dysregulation is involved in many cancers, including osteosarcoma (OS). In a previous study, we reported a novel lncRNA, ODRUL, that could promote doxorubicin resistance in OS. We now report the function and underlying mechanism of ODRUL in regulating OS progression. We show that ODRUL is upregulated in OS tissues and cell lines and correlates with poor prognosis. ODRUL knockdown significantly inhibits OS cell proliferation, migration, invasion, and tumor growth in vitro and in vivo by decreasing matrix metalloproteinase (MMP) expression. A microarray screen combined with online database analysis showed that miR-3182 is upregulated and MMP2 is downregulated in sh-ODRUL-expressing MG63 cells and that miR-3182 harbors potential binding sites for ODRUL and the 3' UTR of MMP2 mRNA. In addition, miR-3182 expression and function are inversely correlated with ODRUL expression in vitro and in vivo. A luciferase reporter assay demonstrated that ODRUL could directly interact with miR-3182 and upregulate MMP2 expression via its competing endogenous RNA activity on miR-3182 at the posttranscriptional level. Taken together, our study has elucidated the role of oncogenic ODRUL in OS progression and may provide a new target in OS therapy.