Long non-coding RNAs, ASAP1-IT1, FAM215A, and LINC00472, in epithelial ovarian cancer

A novel prognostic model of breast cancer based on cuproptosis-related lncRNAs

OBJECTIVE

Breast cancer (BC) is a deadly form of malignancy responsible for the death of a large number of women every year. Cuproptosis is a newly discovered form of cell death that may have implications for the prognosis of BC. Long non-coding RNAs (lncRNAs) have been shown to be involved in the progression and development of BC. Here within, a novel model capable of predicting the prognosis of patients with BC was established based on cuproptosis-related lncRNAs.

METHODS

Data of breast cancer patients was downloaded, including clinical information from The Cancer Genome Atlas (TCGA) database and lncRNAs related to cuproptosis were isolated. In total, nine lncRNAs related to copper death were obtained by Cox regression model based on Least Absolute Shrinkage and Selector Operation (LASSO) algorithm for model construction. The model was verified by overall survival (OS), progression-free survival (PFS) and receiver operating characteristic (ROC) curve. The differences in immune function, tumor mutation burden (TMB) and tumor immune dysfunction and exclusion (TIDE) between patients with different risk scores were analyzed.

RESULTS

Based on cuproptosis-related lncRNAs, a prognostic model for predicting BC was constructed. Each patient was assigned a risk score based on our model formula. We found that patients with higher risk scores had significantly lower OS and PFS, increased TMB, and higher sensitivity to immunotherapy.

CONCLUSIONS

The model established in this study based on cuproptosis-related lncRNAs may be capable of improving the OS of patients with BC.

Oncogenic lncRNA FAM215A promotes the malignant cell phenotypes of acute myeloid leukemia (AML) cell lines

Acute myeloid leukemia (AML) is a form of blood cancer that arise as a result of clonal proliferation of malignant myeloid precursors acquiring genetic abnormalities. Primary resistance to initial treatment and disease recurrence continues to be huge challenge in treating AML. Herein, GSE114868 was analyzed for differentially-expressed lncRNAs between AML patients' mononucleated cells and healthy normal control mononucleated cells and 191 lncRNAs were significantly deregulated in AML patients' mononucleated cells. The correlation between candidate lncRNAs and AML patients' overall survival was analyzed and 6 lncRNAs, including MIR181A1HG, TRAF3IP2-AS1, STARD4-AS1, E2F3-IT1, FAM215A, and HHIP-AS1 were dramatically linked to AML patients' OS. Using a Cox proportional-hazards model, we identified risk factors and found FAM215A as a risk factor for AML patients' prognosis. The expression level of FAM215A showed to be upregulated within blood samples and cells. Genes correlated with FAM215A were correlated to cell division, modulation of cell apoptosis, and modulation of programmed cell death. FAM215A knockdown inhibited AML cell viability, elicited G0/G1-phase arrest of cell cycle, enhanced cell apoptosis, increased proapoptotic Bax and cleaved-caspase3 levels, and decreased antiapoptotic Bcl2. FAM215A overexpression exerted opposite effects on AML cells. Conclusively, FAM215A serves as an oncogenic lncRNA in AML, promoting cell viability, relieving cell cycle arrest, and suppressing cell apoptosis. FAM215A might be un underlying biological prognostic marker and therapeutic target for AML.

DNA Methylation of a Group of Long Non-Coding RNA Genes at Different Stages of Ovarian Cancer Dissemination

There are three types of metastases in ovarian cancer: lymphogenous, hematogenous, and peritoneal. Dissemination of the tumor in the peritoneum is directly related with the development of ascites and a poor prognosis. The purpose of this study is to determine changes in the methylation level of a group of long non-coding RNA (lncRNA) genes at different stages of ovarian cancer progression. The methylation level of 7 lncRNA genes (LINC00472, LINC00886, MAFG-DT, SNHG1, SNHG6, TP53TG1, and TUG1) was studied by quantitative methyl-specific PCR in 93 samples of ovarian tumors and 75 paired samples of histologically normal tissue, as well as in 29 peritoneal macroscopic metastases. Using the nonparametric Mann-Whitney test, a significant (p<0.001) increase in the level of methylation of the LINC00886, SNHG1, SNHG6, and TUG1 genes in the tumor tissue was shown. For the LINC00472, LINC00886, and SNHG6 genes, a significant relationship was found with the clinical stage (p≤0.001), as well as with the appearance of metastases for the LINC00472 (p<0.001) and SNHG6 (p=0.005) genes. There was a significant increase in the level of methylation of MAFG-DT and TP53TG1 (p<0.001) genes, as well as a decrease in LINC00886 (p=0.003) in peritoneal metastases relative to the primary focus. Methylation of the LINC00472 and SNHG6 genes can be considered as a factor in initiating ovarian cancer metastasis, and methylation of the LINC00886, MAFG-DT, and TP53TG1 genes as a colonization factor for metastases in the peritoneum. Thus, a relationship between methylation of a group of lncRNA genes at different stages of ovarian cancer dissemination was shown, which is important for understanding the mechanisms of these processes and for developing innovative approaches to ovarian cancer therapy.

Non-coding RNAs in gynecologic cancer

The term "gynecologic cancer" pertains to neoplasms impacting the reproductive tissues and organs of women encompassing the endometrium, vagina, cervix, uterus, vulva, and ovaries. The progression of gynecologic cancer is linked to various molecular mechanisms. Historically, cancer research primarily focused on protein-coding genes. However, recent years have unveiled the involvement of non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs (LncRNAs), and circular RNAs, in modulating cellular functions within gynecological cancer. Substantial evidence suggests that ncRNAs may wield a dual role in gynecological cancer, acting as either oncogenic or tumor-suppressive agents. Numerous clinical trials are presently investigating the roles of ncRNAs as biomarkers and therapeutic agents. These endeavors may introduce a fresh perspective on the diagnosis and treatment of gynecological cancer. In this overview, we highlight some of the ncRNAs associated with gynecological cancers.

Up-regulation of BOK-AS1, FAM215A and FEZF1-AS1 lncRNAs and their potency as moderate diagnostic biomarkers in gastric cancer

BACKGROUND

Gastric cancer is the fifth most frequent cancer worldwide and the fourth leading cause of death from cancer, a complex multifactorial neoplasm. LncRNAs are regulatory RNA molecules larger than 200 nucleotides, which can have profound effects on the oncogenic process of various types of cancer. Therefore, these molecules can be used as diagnostic and therapeutic biomarkers. This study aimed to determine the differences in BOK-AS1, FAM215A, and FEZF1-AS1 gene expression between tumor tissue and adjacent healthy non-tumor tissue of gastric cancer (GC) patients.

METHODS

In this study one hundred pairs of cancerous and non-cancerous marginal tissues were gathered. Next, RNA extraction and cDNA synthesis were achieved for all of the samples. Then, the qRT-PCR was performed to measure the expression of BOK-AS1, FAM215A and FEZF1-AS1 genes.

RESULTS

All BOK-AS1, FAM215A and FEZF1-AS1 genes showed significantly increased expression in tumor tissues compared with non-tumor tissues. The outcome of the ROC analysis demonstrated that BOK-AS1, FAM215A, and FEZF1-AS1 may act as mean biomarkers with AUC of 0.7368, 0.7163 and 0.7115, specificity of 64%, 61% and 59%, and sensitivity of 74%, 70%, and 74% respectively.

CONCLUSION

Based on the increased expression of the BOK-AS1, FAM215A and FEZF1-AS1 genes in GC patients, this study suggests that these genes may function as oncogenic factors. Furthermore, the mentioned genes can be considered as intermediate biomarkers for diagnosis and treatment of gastric cancer. In addition, no association between these genes and clinicopathological features was observed.

Identification of lncRNAs Deregulated in Epithelial Ovarian Cancer Based on a Gene Expression Profiling Meta-Analysis

Epithelial ovarian cancer (EOC) is one of the deadliest gynecological cancers worldwide, mainly because of its initially asymptomatic nature and consequently late diagnosis. Long non-coding RNAs (lncRNA) are non-coding transcripts of more than 200 nucleotides, whose deregulation is involved in pathologies such as EOC, and are therefore envisaged as future biomarkers. We present a meta-analysis of available gene expression profiling (microarray and RNA sequencing) studies from EOC patients to identify lncRNA genes with diagnostic and prognostic value. In this meta-analysis, we include 46 independent cohorts, along with available expression profiling data from EOC cell lines. Differential expression analyses were conducted to identify those lncRNAs that are deregulated in (i) EOC versus healthy ovary tissue, (ii) unfavorable versus more favorable prognosis, (iii) metastatic versus primary tumors, (iv) chemoresistant versus chemosensitive EOC, and (v) correlation to specific histological subtypes of EOC. From the results of this meta-analysis, we established a panel of lncRNAs that are highly correlated with EOC. The panel includes several lncRNAs that are already known and even functionally characterized in EOC, but also lncRNAs that have not been previously correlated with this cancer, and which are discussed in relation to their putative role in EOC and their potential use as clinically relevant tools.

A review on the role of LINC00472 in malignant and non-malignant disorders

Long intergenic non-protein coding RNA 472 (LINC00472) has been shown to regulate diverse cellular functions and contribute to the etiology of human disorders. LINC00472 gene is located on 6q13 and has different alternatively spliced transcripts. Expression pattern and function of LINC00472 have been evaluated in different types of cancers and some other disorders, including atherosclerosis, sepsis-induced acute hepatic injury, atrial fibrillation, neuropathic pain, primary biliary cholangitis and sepsis-induced cardiac dysfunction. This lincRNA can serve as a sponge for miR-24-3p, miR-196b-5p, miR-23a-3p, miR-93-5p, miR-4311, miR-455-3p and a number of other miRNAs. LINC00472 is able to regulate several pathways, including MEK/ERK, NF-kB, PTEN/PI3K/AKT, and STAT3 signaling pathways. This raises some concerning aspects that need to be investigated further and clarified in relation to diseases. Increasing our understanding of LINC00472's crucial roles will open new doors for creating effective therapeutic approaches against cancer and related diseases. The current study aims at providing an overview of functions of LINC00472 in malignant and non-malignant disorders.

Targeting Non-Coding RNAs for the Development of Novel Hepatocellular Carcinoma Therapeutic Approaches

Hepatocellular carcinoma (HCC) remains a global health challenge, representing the third leading cause of cancer deaths worldwide. Although therapeutic advances have been made in the few last years, the prognosis remains poor. Thus, there is a dire need to develop novel therapeutic strategies. In this regard, two approaches can be considered: (1) the identification of tumor-targeted delivery systems and (2) the targeting of molecule(s) whose aberrant expression is confined to tumor cells. In this work, we focused on the second approach. Among the different kinds of possible target molecules, we discuss the potential therapeutic value of targeting non-coding RNAs (ncRNAs), which include micro interfering RNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). These molecules represent the most significant RNA transcripts in cells and can regulate many HCC features, including proliferation, apoptosis, invasion and metastasis. In the first part of the review, the main characteristics of HCC and ncRNAs are described. The involvement of ncRNAs in HCC is then presented over five sections: (a) miRNAs, (b) lncRNAs, (c) circRNAs, (d) ncRNAs and drug resistance and (e) ncRNAs and liver fibrosis. Overall, this work provides the reader with the most recent state-of-the-art approaches in this field, highlighting key trends and opportunities for more advanced and efficacious HCC treatments.

Identification of a novel ferroptosis-related gene signature associated with prognosis, the immune landscape, and biomarkers for immunotherapy in ovarian cancer

Ferroptosis has been implicated in tumor progression and immunoregulation. Identification of ferroptosis-related prognostic gene is important for immunotherapy and prognosis in ovarian cancer (OV). We assessed the potential predictive power of a novel ferroptosis-related gene (FRG) signature for prognosis and immunotherapy in Asian and Caucasian OV populations. We collected gene expression profiles and clinicopathological data from public databases. The least absolute shrinkage and selection operator Cox regression algorithm was used to construct the FRG signature. Receiver operating characteristic (ROC) curve, Kaplan-Meier method, Cox regression model were used to evaluate the clinical benefits of FRG signature. Gene functional and gene set enrichment analyses were used for functional annotation and immune landscape analysis. A 15-FRG signature was constructed and used to stratify patients into two risk groups. Patients in the high-risk group had significantly worse survival. The risk score was a significant independent risk factor for OS. The area under the ROC curve indicated the good prediction performance of the FRG signature. Notably, the low-risk group showed a significant enrichment in immune-related pathways and a “hot” immune status. The risk score was found to be an efficient and robust predictor of response to immunotherapy. In conclusion, our study identified a novel 15-FRG prognostic signature that can be used for prognostic prediction and precision immunotherapy in Asian and Caucasian OV populations.

Novel Role of Long Non-Coding RNA ASAP1-IT1 in Progression of Hepatocellular Carcinoma

The long non-coding RNA (lncRNA) ASAP1-IT1 has been recently shown to aberrantly increase in ovarian and bladder cancer, while its role in other malignancies remains unexplored. This study was to characterize the expression and assess the potential role of ASAP1-IT1 in hepatocellular carcinoma (HCC). Fifty-four paired HCC and histologically normal tissues were obtained from HCC patients. Human HCC cell lines (HepG2, Huh7, SMMC-7721, and BEL-7402) and a normal liver cell line (LO2) were used for in vitro studies. ASAP1-IT1-specific siRNAs were used to silence ASAP1-IT1 expression, while the pcDNA-ASAP1-IT1 vector was constructed to up-regulate its expression. In situ hybridization and qRT-PCR were performed to characterize subcellular localization and expression of ASAP1-IT1. Cell proliferation and migration assays were conducted to examine the role of ASAP1-IT1 in the progression of HCC. In silico analysis was conducted to predict putative miRNA binding sites, which were validated by luciferase reporter assays. ASAP1-IT1 levels were significantly increased in HCC tissues and cells compared with controls. Notably, higher ASAP1-IT1 levels were significantly associated with poorer prognosis of HCC patients. In situ hybridization analysis revealed that ASAP1-IT1 was mainly localized in the nucleus of hepatoma cells and differentially expressed in trabecular, compact, and pseudoglandular forms of liver cancer. Furthermore, knockdown of ASAP1-IT1 significantly suppressed cell proliferation and migration, while its overexpression significantly promoted cell proliferation and migration of HCC cells. Mechanistically, ASAP1-IT1 might exert its role in HCC progression, at least in part, by directly interacting with miR-221-3p. In conclusion, ASAP1-IT1 is abnormally elevated in HCC, and higher levels are correlated with poorer prognosis. An underlying mechanism has been proposed for ASAP1-IT1-associated promotion of proliferation and migration in HCC cells. These findings have provided evidence supporting the oncogenic role of ASAP1-IT1 in HCC.

Serum-Based lncRNA ANRIL, TUG1, UCA1, and HIT Expressions in Breast Cancer Patients

Breast cancer is a heterogeneous disease and is the most common and prevalent form of malignancy diagnosed in women. lncRNAs are found to be frequently dysregulated in cancer, and its expression plays a critical role in tumorigenesis. The study included 100 histopathologically confirmed, newly diagnosed untreated patients of invasive ductal carcinoma (IDC) of breast cancer patients and 100 healthy subjects. After blood collection, the serum was separated and total RNA was extracted, cDNA was synthesized using 100 ng of total RNA, and lncRNA (ANRIL, TUG1, UCA1, and HIT) expression was analyzed. Increased ANRIL (3.83-fold), TUG1 (7.64-fold), UCA1 (7.82-fold), and HIT (3.31-fold) expressions were observed in breast cancer patients compared to healthy controls. Relative expression of lncRNAs UCA-1 (p = 0.010) and HIT-1 (p < 0.0001) was significantly elevated in patients with advanced breast cancer stage compared to those with early-stage disease. While lncRNA TUG-1 expression was found to be higher in patients with early-stage tumors than those with advanced-stage tumors (p = 0.06), lncRNA ANRIL showed increased expression in patients with PR positive status (p = 0.04). However, we found a significant difference in lncRNA HIT expression in HER-2 positive breast cancer patients compared to HER-2 negative breast cancer patients (p = 0.005). An increase in the expression of serum lncRNAs ANRIL (p < 0.0001), UCA-1 (p = 0.004), and HIT (p < 0.0001) was observed in the distant organ metastatic breast cancer patients. In the ROC curve concerning lymph node involvement, the sensitivity and specificity of lncRNA HIT were 68% and 58%, respectively (p value = 0.007). In the ROC curve w.r.t. stages of disease, the sensitivity and specificity of lncRNA HIT were 80% and 50%, respectively (p value < 0.0001). Better sensitivity and specificity were observed for lncRNA HIT (sensitivity 91% and specificity 78%; p value < 0.0001) and ANRIL (sensitivity 70% and specificity 60%; p value < 0.0001) w.r.t distant organ metastases.

LINC00472 suppresses oral squamous cell carcinoma growth by targeting miR-455-3p/ELF3 axis

LINC00472 is reported to play a role in suppressing tumors in cancers such as lung cancer and hepatocellular carcinoma, among others. We made investigations into the effects of LINC00472 in oral squamous cell carcinoma (OSCC) progression to explore the underlying molecular mechanisms. By qRT-PCR, we assessed the LINC00472 expression in OSCC tissues and cells and performed functional analysis to investigate how LINC00472/miR-455-3p/ELF3 impacts OSCC cell proliferation, apoptosis, and cell cycle. The role that LINC00472 plays in OSCC tumor growth was examined by establishing a xenograft model. Down-regulation of LINC00472 occurred in tissues and cells of an OSCC tumor. LINC00472 overexpression caused OSCC cell proliferation to be inhibited, cell apoptosis to be promoted, and cell cycle arrest to be induced. As a competing endogenous RNA (ceRNA), LINC00472 can block miR-455-3p function and further promote ELF3 expression. The overexpression of miR-455-3p or ELF3 knockdown was shown to be capable of reversing the anti-tumor effects of LINC00472 in OSCC. In vivo experiments confirmed the tumor-suppressing role of LINC00472 in the progression of OSCC. In short, we found that the novel LINC00472 inhibits OSCC growth via the miR-455-3p/ELF3 axis. LINC00472 and its targeted miR-455-3p/ELF3 axis may represent valuable targets for treating OSCC.

Long Noncoding RNA 00472: A Novel Biomarker in Human Diseases

Long non-coding RNAs (lncRNAs) play important roles in human diseases. They control gene expression levels and influence various biological processes through multiple mechanisms. Functional abnormalities in lncRNAs are strongly associated with occurrence and development of various diseases. LINC00472, which is located on chromosome 6q13, is involved in several human diseases, particularly cancers of the breast, lung, liver, osteosarcoma, bladder, colorectal, ovarian, pancreatic and stomach. Importantly, LINC00472 can be used as a biomarker for breast cancer cell sensitivity to chemotherapeutic regimens, including doxorubicin. LINC00472 is regulated by microRNAs and several signaling pathways. However, the significance of LINC00472 in human diseases has not been clearly established. In this review, we elucidate on the significance of LINC00472 in various human diseases, indicating that LINC00472 may be a diagnostic, prognostic as well as therapeutic target for these diseases.

LINC00472 suppressed by ZEB1 regulates the miR-23a-3p/FOXO3/BID axis to inhibit the progression of pancreatic cancer

The tumour-suppressive role of LINC00472 has been extensively reported in various human cancers such as lung, colon and ovarian cancers, yet its function in pancreatic cancer remains unidentified. Here, the current research aimed to explore the role and regulatory axis mediated by LINC00472 in the progression of pancreatic cancer. RT-qPCR was adopted to determine LINC00472 expression in the harvested pancreatic cancer tissues and adjacent normal tissues. Loss-of-function and gain-of-function experiments were performed to examine the effects of LINC00472 on proliferation and apoptosis in vitro and tumorigenesis in vivo. Immunoblotting was performed to detect the expression of several proliferation and apoptosis-related proteins. Bioinformatic analysis, dual-luciferase reporter assay and RNA pull-down were conducted to profile the relationships between LINC00472 and miR-23a-3p, between miR-23a-3p and FOXO3 and between FOXO3 and BID. The LINC00472 expression was down-regulated by ZEB1 in the pancreatic cancer cells and tissues. LINC00472 could competitively bind to miR-23a-3p to enhance the expression of FOXO3, which consequently could promote the BID expression, thereby suppressing proliferation and promoting the apoptosis of pancreatic cancer cells. Meanwhile, the inhibitory role of LINC00472 in tumorigenesis was validated in vivo, and the LINC00472-mediated miR-23a-3p/FOXO3/BID axis was also demonstrated in the nude mouse tumour formation model. The study substantiated the antitumour activity of LINC00472 in pancreatic cancer and proposed a regulatory axis in which LINC00472 competitively binds to miR-23a-3p to enhance the FOXO3 expression and promote BID expression. Consequently, these findings provide theoretical basis for developing potential targets for the treatment of pancreatic cancer.

Coordinated action of human papillomavirus type 16 E6 and E7 oncoproteins on competitive endogenous RNA (ceRNA) network members in primary human keratinocytes

Background

miRNAs and lncRNAs can regulate cellular biological processes both under physiological and pathological conditions including tumour initiation and progression. Interactions between differentially expressed diverse RNA species, as a part of a complex intracellular regulatory network (ceRNA network), may contribute also to the pathogenesis of HPV-associated cancer. The purpose of this study was to investigate the global expression changes of miRNAs, lncRNAs and mRNAs driven by the E6 and E7 oncoproteins of HPV16, and construct a corresponding ceRNA regulatory network of coding and non-coding genes to suggest a regulatory network associated with high-risk HPV16 infections. Furthermore, additional GO and KEGG analyses were performed to understand the consequences of mRNA expression alterations on biological processes.

Methods

Small and large RNA deep sequencing were performed to detect expression changes of miRNAs, lncRNAs and mRNAs in primary human keratinocytes expressing HPV16 E6, E7 or both oncoproteins. The relationships between lncRNAs, miRNAs and mRNAs were predicted by using StarBase v2.0, DianaTools-LncBase v.2 and miRTarBase. The lncRNA-miRNA-mRNA regulatory network was visualized with Cytoscape v3.4.0. GO and KEEG pathway enrichment analysis was performed using DAVID v6.8.

Results

We revealed that 85 miRNAs in 21 genomic clusters and 41 lncRNAs were abnormally expressed in HPV E6/E7 expressing cells compared with controls. We constructed a ceRNA network with members of 15 lncRNAs – 43 miRNAs – 358 mRNAs with significantly altered expressions. GO and KEGG functional enrichment analyses identified numerous cancer related genes, furthermore we recognized common miRNAs as key regulatory elements in biological pathways associated with tumorigenesis driven by HPV16.

Conclusions

The multiple molecular changes driven by E6 and E7 oncoproteins resulting in the malignant transformation of HPV16 host cells occur, at least in part, due to the abnormal alteration in expression and function of non-coding RNA molecules through their intracellular competing network.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08361-y.

Functional roles of non-coding RNAs regulated by thyroid hormones in liver cancer

Recent reports have shown the important role of the non-coding part of human genome RNA (ncRNA) in cancer formation and progression. Among several kinds of ncRNAs, microRNAs (miRNA) play a pivotal role in cancer biology. Accumulating researches have been focused on the importance of non-coding genes in various diseases. In addition to miRNAs, long non-coding RNAs (lncRNAs) have also been extensively documented. Recently, the study of human liver cancer has gradually shifted to these non-coding RNAs that were originally considered "junk". Notably, dysregulated ncRNAs maybe influence on cell proliferation, angiogenesis, anti-apoptosis, and metastasis. Thyroid hormones play critical roles in human development and abnormalities in thyroid hormone levels are associated with various diseases, such as liver cancer. Thyroid hormone receptors (TR) act as ligand-activated nuclear transcription factors to affect multiple functions through the gene-level regulation in the cells and several studies have revealed that thyroid hormone associated with ncRNAs expression. TR actions are complex and tissue- and time-specific, aberrant expression of the various TR isoforms have different effects and are associated with different types of tumor or stages of development. In this review, we discuss various aspects of the research on the thyroid hormones modulated ncRNAs to affect the functions of human liver cells.

Research Progress in Prognostic Factors and Biomarkers of Ovarian Cancer

Ovarian cancer is a serious threat to women's health; its early diagnosis rate is low and prone to metastasis and recurrence. The current conventional treatment for ovarian cancer is a combination of platinum and paclitaxel chemotherapy based on surgery. The recurrence and progression of ovarian cancer with poor prognosis is a major challenge in treatment. With rapid advances in technology, understanding of the molecular pathways involved in ovarian cancer recurrence and progression has increased, biomarker-guided treatment options can greatly improve the prognosis of patients. This review systematically discusses and summarizes existing and new information on prognostic factors and biomarkers of ovarian cancer, which is expected to improve the clinical management of patients and lead to effective personalized treatment.

Non-Coding RNAs as Biomarkers of Tumor Progression and Metastatic Spread in Epithelial Ovarian Cancer

Simple Summary

Despite advances in cancer research in recent years, efficient predictive biomarkers of tumor progression and metastatic spread for ovarian cancer are still missing. Therefore, we critically address recent findings in the field of non-coding RNAs (microRNAs and long non-coding RNAs) and DNA methylation in ovarian cancer patients as promising novel biomarkers of ovarian cancer progression.

Abstract

Ovarian cancer is one of the most common causes of death among gynecological malignancies. Molecular changes occurring in the primary tumor lead to metastatic spread into the peritoneum and the formation of distant metastases. Identification of these changes helps to reveal the nature of metastases development and decipher early biomarkers of prognosis and disease progression. Comparing differences in gene expression profiles between primary tumors and metastases, together with disclosing their epigenetic regulation, provides interesting associations with progression and metastasizing. Regulatory elements from the non-coding RNA families such as microRNAs and long non-coding RNAs seem to participate in these processes and represent potential molecular biomarkers of patient prognosis. Progress in therapy individualization and its proper targeting also rely upon a better understanding of interactions among the above-listed factors. This review aims to summarize currently available findings of microRNAs and long non-coding RNAs linked with tumor progression and metastatic process in ovarian cancer. These biomolecules provide promising tools for monitoring the patient’s response to treatment, and further they serve as potential therapeutic targets of this deadly disease.

Vitamin D receptor upregulates lncRNA TOPORS-AS1 which inhibits the Wnt/β-catenin pathway and associates with favorable prognosis of ovarian cancer

Long non-coding RNAs (lncRNAs) have important biological functions, but their involvement in ovarian cancer remains elusive. We analyzed high-throughput data to identify lncRNAs associated with ovarian cancer outcomes. Our search led to the discovery of lncRNA TOPORS Antisense RNA 1 (TOPORS-AS1). Patients with high TOPORS-AS1 expression had favorable overall survival compared to low expression. This association was replicated in our study and confirmed by meta-analysis. In vitro experiments demonstrated that overexpressing TOPORS-AS1 in ovarian cancer cells suppressed cell proliferation and inhibited aggressive cell behaviors, including migration, invasion, and colony formation. Analysis of tumor cell transcriptomes indicated TOPORS-AS1′s influence on the Wnt/β-catenin signaling. Additional experiments revealed that TOPORS-AS1 increased the phosphorylation of β-catenin and suppressed the expression of CTNNB1, disrupting the Wnt/β-catenin pathway. Our experiments further discovered that vitamin D receptor (VDR) upregulated TOPORS-AS1 expression and that inhibition of β-catenin by TOPORS-AS1 required a RNA binding protein, hnRNPA2B1 (heterogeneous nuclear ribonucleoprotein A2B1). Taken together, these findings suggest that TOPORS-AS1 may behave like a tumor suppressor in ovarian cancer through interrupting the Wnt/β-catenin signaling and that VDR upregulates the expression of TOPORS-AS1. Assessing TOPORS-AS1 expression in ovarian cancer may help predict disease prognosis and develop treatment strategy

The role of altered long noncoding RNAs in overall survival of ovarian cancer: A systematic review and meta-analysis

In recent years, tremendous research efforts have been focused on investigating the effect of dysregulation of lncRNAs on cancer progression, most of which confirm a positive link. This inspired us to conduct the present meta-analysis to explore whether aberrant expression of multiple lncRNAs has a role in patients' outcome in ovarian cancer. This comprehensive meta-analysis pertains to the evaluation of association between dysregulated lncRNAs expression level with eventual outcome and clinicopathological characteristics of ovarian cancer patients. We systematically searched PubMed, Web of Science, and Scopus to find all eligible articles. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) for overall survival, disease-free survival and progression-free survival were measured with a fixed or random effects model. A total of 34 studies were included in the meta-analysis. Dysregulation of lncRNAs were contributed to shorter overall survival (34 studies, 1180 patients HR = 2.12, 95% CI: 1.73 ± 2.60, random-effects) in ovarian cancer. Furthermore, altered lncRNAs were also related to decreased progression-free survival (8 studies, 1180 patients HR: 1.88, 95% CI: (1.35-2.62) and disease-free survival (2 studies, 285 patients, HR: 6.07, 95% CI: 1.28-28.78) in this disease. Our analyses supported the robust prognostic significance of altered lncRNAs in ovarian cancer. However, more extended studies are encouraged to evaluate the clinical application potential of these lncRNAs in the prognosis evaluation of ovarian cancer.

Long non‑coding RNA ASAP1‑IT1 suppresses ovarian cancer progression by regulating Hippo/YAP signaling

Long non‑coding RNAs (lncRNAs) are a class of non‑protein coding transcripts that are involved in the regulation of gene expression in mammalian cells. Transcriptional co‑activator Yes associated protein 1 (YAP1) plays a key role in the progression of ovarian cancer. However, the regulation of Hippo/YAP signaling in ovarian cancer remains elusive. In the present study, the expression levels of lncRNA ASAP1‑IT1 were investigated. The analysis indicated that lncRNA ASAP1‑IT1 expression was downregulated in ovarian tumor samples and ovarian cancer cells. The overexpression of ASAP1‑IT1 inhibited ovarian cancer cell proliferation and induced cell apoptosis. Bioinformatics analysis predicted that miR‑2278, a previously reported upregulated miRNA in ovarian tumors, may bind to ASAP1‑IT1. Dual luciferase assay confirmed the direct regulatory association between ASAP1‑IT1 and miR‑2278. In addition, the data demonstrated that large tumor suppressor 2 (LATS2) was a target gene of miR‑2278, whose expression was upregulated by ASAP1‑IT1 in ovarian cancer cells. By regulating the expression of LATS2, ASAP1‑IT1 induced the downregulation of YAP1 expression in ovarian cancer cells. Moreover, the silencing of LATS2 attenuated the inhibition of cell proliferation and the apoptosis induced by ASAP1‑IT1 overexpression in ovarian cancer cells. The association among the expression levels of ASAP1‑IT1, miR‑2278 and LATS2 was observed in specimens obtained from patients with ovarian cancer. Taken together, the data presented herein demonstrate that ASAP1‑IT1 functions as a potential tumor suppressor lncRNA by upregulating LATS2 expression in ovarian cancer.

Construction and Validation of Predictive Model to Identify Critical Genes Associated with Advanced Kidney Disease

Background

Chronic kidney disease (CKD) is characterized by progressive renal function loss, which may finally lead to end-stage renal disease (ESRD). The study is aimed at identifying crucial genes related to CKD progressive and constructing a disease prediction model to investigate risk factors.

Methods

GSE97709 and GSE37171 datasets were downloaded from the GEO database including peripheral blood samples from subjects with CKD, ESRD, and healthy controls. Differential expressed genes (DEGs) were identified and functional enrichment analysis. Machine learning algorithm-based prediction model was constructed to identify crucial functional feature genes related to ESRD.

Results

A total of 76 DEGs were screened from CDK vs. normal samples while 10,114 DEGs were identified from ESRD vs. CDK samples. For numerous genes related to ESRD, several GO biological terms and 141 signaling pathways were identified including markedly upregulated olfactory transduction and downregulated platelet activation pathway. The DEGs were clustering in three modules according to WGCNA access, namely, ME1, ME2, and ME3. By construction of the XGBoost model and dataset validation, we screened cohorts of genes associated with progressive CKD, such as FZD10, FOXD4, and FAM215A. FZD10 represented the highest score (F score = 21) in predictive model.

Conclusion

Our results demonstrated that FZD10, FOXD4, PPP3R1, and UCP2 might be critical genes in CKD progression.

LncRNA HOXB-AS3 promotes growth, invasion and migration of epithelial ovarian cancer by altering glycolysis

HEADING AIMS

LncRNA HOXB-AS3 is proved as an oncogene in tumors. Herein, we determine the function and mechanism of HOXB-AS3 in epithelial ovarian cancer (EOC) cells.

MATERIALS AND METHODS

Chi-square test, Kaplan-Meier (KM) analysis and Cox regression analysis were used to analyze the clinicopathological features of HOXB-AS3 in EOC patients. CCK8, transwell and wound healing assay were used to test the function of HOXB-AS3. Luciferase reporter assay, western blot and glycolysis rate assay were used for further mechanistic studies.

KEY FINDINGS

HOXB-AS3 was abundantly expressed in EOC tissues, and higher levels of HOXB-AS3 in EOC patients were significantly associated with disease status and overall survival status. EOC patients with high levels of HOXB-AS3 had strikingly shorter disease-free survival (DFS) and overall survival (OS) times than those with low levels. HOXB-AS3 also might as an independent prognostic factor. Further study revealed knockdown of HOXB-AS3 significantly inhibited the proliferation, invasion and migration of EOC cells. Mechanistic investigations suggested that knockdown of HOXB-AS3 could decrease lactate dehydrogenase A (LDHA) expression and the extracellular acidification rate (ECAR) by sponging miR-378a-3p.

SIGNIFICANCE

To our knowledge, this is the first study to suggest that HOXB-AS3 could crosstalk with miRNA in the cytoplasm and alter glycolysis in cancer cells. Our results improve our understanding of the mechanism of HOXB-AS3 and suggest that HOXB-AS3 can act as a predictor of OS and a target for EOC therapies.

A nine-lncRNA signature predicts distant relapse-free survival of HER2-negative breast cancer patients receiving taxane and anthracycline-based neoadjuvant chemotherapy

Multi-gene prognostic signatures of long non-coding RNAs (lncRNAs) provide new insights into mechanisms of HER2-negative breast cancer development and progression, and predict distant relapse-free survival (DRFS) of patients receiving taxane and anthracycline-based neoadjuvant chemotherapy. The aim of this study was to develop such a multi-lncRNAs signature. Optimal multiple candidate signature lncRNAs associated with DRFS were firstly identified by a univariate Cox proportional hazard regression survival analysis and a robust likelihood-based survival analysis of the GEO dataset GSE25055. A nine-lncRNA prognostic risk score model Risk Score = 0.0289 × EXP_LOC100507388 - 0.0814 × EXP_LINC00094 - 0.2422 × EXP_SMG7-AS1 - 0.2433 × EXP_PP14571 + 0.4690 × EXP_ASAP1-IT1 - 0.2483 × EXP_LOC103344931 - 0.2464 × EXP_FAM182A + 0.3349 × EXP_HCG26 - 0.0216 × EXP_LINC00963 was built according to the coefficients of multivariate survival analysis of the association between the candidate lncRNAs and survival. EXP_lncRNA was the standardized log2-transformed expression level of the gene. According to this model, higher scores predicted lower survival probability. The area under Receiver operating characteristic (ROC) curve (AUC) was 0.777 to 0.823 from 1- to 7- year survival rate. The model and its individual lncRNAs differentiated survival probability between the higher scores (expression) and the lower scores (expression). The nine-lncRNA signature had the robust prognostic power compared with ER, PR, tumor size (T), lymph node invasion (N), TNM stage, pathologic response, chemosensitivity prediction and PAM50 signature. These results were consistent with those based on the GEO dataset GSE25065. The predictive nomograms integrating both the nine-lncRNA signature classifier and clinical-pathological risk factors were robust in predicting 1-, 3- and 5- year survival probabilities. These results supported that the nine-lncRNA signature was a robust and effective model in predicting DRFS of patients with HER2-negative breast cancer following taxane and anthracycline-based neoadjuvant chemotherapy.

LncRNA HOTTIP promotes the proliferation and invasion of ovarian cancer cells by activating the MEK/ERK pathway

Recent studies have revealed that long non-coding RNAs (lncRNAs) serve important roles in carcinogenesis and that this type of gene may be used as biomarkers in cancer. A high level of lncRNA HOXA distal transcript antisense RNA (HOTTIP) is associated with unfavorable prognosis for patients with ovarian cancer (OC), but the mechanism of HOTTIP involved in OC development remains to be elucidated. The present study aimed to investigate the mechanism of HOTTIP in metastasis-associated OC cell behaviors. HOTTIP levels in ovarian cells were quantified by reverse transcription-quantitative PCR, cell proliferation was analyzed by colony formation assay, and apoptosis was assessed by flow cytometry. Cell migratory and invasive abilities were evaluated by wound healing and Transwell assays, respectively. The expression levels of mitogen-activated protein kinase kinase (MEK)/ERK pathway-associated proteins were detected by western blotting. The results demonstrated that knockdown of HOTTIP in OC cells significantly reduced the phosphorylation levels of MEK and ERK, inhibited the proliferation and invasion of OC cells and promoted their apoptosis. Furthermore, the effects of HOTTIP on cell migration and invasion were partly associated with the epithelial-mesenchymal transition (EMT) process. Proliferation, invasion and EMT of OC cells were enhanced following overexpression of HOTTIP; however, these effects were reversed by the MEK/ERK pathway inhibitor U0126. In conclusion, HOTTIP was demonstrated to promote the proliferation, migration and invasion of OC cells by activating the MEK/ERK pathway. Therefore, HOTTIP may serve as a potential therapeutic target for OC.

Inhibition of Lnc-OC1 Induced Cell Apoptosis and Decreased Cell Viability by Releasing miR-34a and Inhibiting PD-L1 in Endometrial Carcinoma

Now, there is a growing awareness of the role to long non-coding RNAs (lncRNAs) in tumorigenesis and progression of a variety of malignancies including endometrial carcinoma (EC). Here, we explored the potential molecular mechanism of Lnc-OC1, a novel lncRNA, in the development of EC. Our results suggested that Lnc-OC1 was significantly upregulated in EC tissues comparing with normal tissues. Besides, Lnc-OC1 was higher expressed in the more advanced stage of EC. Therefore, Lnc-OC1 might be a crucial regulator in the progress of EC. Moreover, knockdown of Lnc-OC1 leaded to an inhibition of cell viability and a raise of cell apoptosis. In addition, Lnc-OC1 could sponge miR-34a and thus decrease its expression. miR-34a was proved to be a tumor suppressor in different malignance, hence downregulating Lnc-OC1 helped to alleviate EC by releasing miR-34a. Furthermore, rescue experiments significantly indicated that knockdown of Lnc-OC1 inhibited cell growth through repressing PD-L1 expression at least partially. Concisely, our results proved that Lnc-OC1/miR-34a/PD-L1 axis might serve as a therapeutic target of EC.

Flaming the fight against cancer cells: the role of microRNA-93

There have been attempts to develop novel anti-tumor drugs in cancer therapy. Although satisfying results have been observed at a consequence of application of chemotherapeutic agents, the cancer cells are capable of making resistance into these agents. This has forced scientists into genetic manipulation as genetic alterations are responsible for generation of a high number of cancer cells. MicroRNAs (miRs) are endogenous, short non-coding RNAs that affect target genes at the post-transcriptional level. Increasing evidence reveals the potential role of miRs in regulation of biological processes including angiogenesis, metabolism, cell proliferation, cell division, and cell differentiation. Abnormal expression of miRs is associated with development of a number of pathologic events, particularly cancer. MiR-93 plays a significant role in both physiological and pathological mechanisms. At the present review, we show how this miR dually affects the proliferation and invasion of cancer cells. Besides, we elucidate the oncogenesis or oncosuppressor function of miR-93.

miR-744-5p inhibits cellular proliferation and invasion via targeting ARF1 in epithelial ovarian cancer

miR-744-5p has been demonstrated to play an important role in cancer progression. However, the functions of miR-744-5p in epithelial ovarian cancer (EOC) are not well clarified. In this study, our aim was to investigate the role of miR-744-5p and its underlying molecular mechanism in cell progression of EOC. EOC clinical tissues and matched adjacent ovarian epithelial tissues were collected from 18 patients. Tissues and cell lines were analyzed by qPCR or Western blot to investigate the expression of miR-744-5p and ARF1 in EOC. Cell proliferative capacity was assessed by CCK8 and colony formation assays. Wound healing and transwell assays were performed to evaluate cell migration and invasion. The potential binding relation between miR-744-5p and IRF1 was demonstrated by dual luciferase report assay. The results showed that expression of miR-744-5p was low in EOC clinical tissues and cells. Overexpression of miR-744-5p inhibited proliferation, migration, and invasion of EOC cells. Further mechanistic study identified that ARF1 is a target of miR-744-5p, which is negatively correlated with the expression of miR-744-5p, and overexpression of ARF1 could reverse the inhibition of miR-744-5p on the proliferation, migration, and invasion of EOC cells. Taken together, our results indicated that miR-744-5p attenuated EOC progression via targeting IRF1, providing potential guidance for the clinical treatment of ovarian cancer.

Dysregulated FAM215A Stimulates LAMP2 Expression to Confer Drug-Resistant and Malignant in Human Liver Cancer

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human malignancies worldwide. Long non-coding (lnc) RNAs regulate complex cellular functions, such as cell growth, differentiation, metabolism, and metastasis. Although deregulation of lncRNA expression has been detected in HCC, many of the hepato-carcinogenesis-associated lncRNAs remain yet unidentified. Here, we aimed to investigate the involvement of a specific HCC-dysregulated lncRNA, FAM215A, and characterize its molecular regulation mechanism. We show for the first time that FAM215A is overexpressed in HCC, and its expression level correlates with tumor size, vascular invasion, and pathology stage. Overexpression of FAM215A accelerates cell proliferation and metastasis in HCC cells. According to Gene Expression Omnibus Dataset analysis, FAM215A is induced in doxorubicin (DOX)-resistant HCC cells. Overexpression of FAM215A increases DOX resistance in two HCC cell lines, and this is associated with enhanced expression of lysosome-associated membrane protein 2 (LAMP2). FAM215A interacts with LAMP2 to protect it from ubiquitination. Together, our results show that the lncRNA, FAM215A, is highly expressed in HCC, where it interacts with and stabilizes LAMP2 to increase tumor progression while decreasing doxorubicin sensitivity.

Development of an autophagy-related gene expression signature for prognosis prediction in prostate cancer patients

Background

Prostate cancer (PCa) is one of the most prevalent cancers that occur in men worldwide. Autophagy-related genes (ARGs) may play an essential role in multiple biological processes of prostate cancer. However, ARGs expression signature has rarely been used to investigate the association between autophagy and prognosis in PCa. This study aimed to identify and assess prognostic ARGs signature to predict overall survival (OS) and disease-free survival (DFS) in PCa patients.

Methods

First, a total of 234 autophagy-related genes were obtained from The Human Autophagy Database. Then, differentially expressed ARGs were identified in prostate cancer patients based on The Cancer Genome Atlas (TCGA) database. The univariate and multivariate Cox regression analysis was performed to screen hub prognostic ARGs for overall survival and disease-free survival, and the prognostic model was constructed. Finally, the correlation between the prognostic model and clinicopathological parameters was further analyzed, including age, T status, N status, and Gleason score.

Results

The OS-related prognostic model was constructed based on the five ARGs (FAM215A, FDD, MYC, RHEB, and ATG16L1) and significantly stratified prostate cancer patients into high- and low-risk groups in terms of OS (HR = 6.391, 95% CI = 1.581– 25.840, P < 0.001). The area under the receiver operating characteristic curve (AUC) of the prediction model was 0.84. The OS-related prediction model values were higher in T3-4 than in T1-2 (P = 0.008), and higher in Gleason score  > 7 than  ≤ 7 (P = 0.015). In addition, the DFS-related prognostic model was constructed based on the 22 ARGs (ULK2, NLRC4, MAPK1, ATG4D, MAPK3, ATG2A, ATG9B, FOXO1, PTEN, HDAC6, PRKN, HSPB8, P4HB, MAP2K7, MTOR, RHEB, TSC1, BIRC5, RGS19, RAB24, PTK6, and NRG2), with AUC of 0.85 (HR = 7.407, 95% CI = 4.850–11.320, P < 0.001), which were firmly related to T status (P < 0.001), N status (P = 0.001), and Gleason score (P < 0.001).

Conclusions

Our ARGs based prediction models are a reliable prognostic and predictive tool for overall survival and disease-free survival in prostate cancer patients.

Down-regulation of LINC00472 promotes osteosarcoma tumorigenesis by reducing FOXO1 expressions via miR-300

BACKGROUND

Osteosarcoma (OS) is one of the most common types of primary bone tumors which poses negative effects on the bones of both young children and adolescents. LncRNA LINC00472 has been reported to be involved with poor prognostics in breast cancer and ovarian cancer. As a new lncRNA, its role in OS remains to be elusive. Herein, we are focused to explore its regulatory mechanism in the development of OS.

METHODS

qRT-PCR was utilized to examine the expressions of LINC00472 and miR-300 in OS tissues and cell lines. OS cell lines of U2OS and MG63 were used to investigate the biological function of LINC00472. Xenograft tumor model was built in nude mice with MG63 cells.

RESULTS

The expressions of LINC00472 were inhibited in OS tissues and cells, and were negatively related to the expressions of miR-300. LINC00472 directly targeted miR-300. FOXO1 was inhibited in OS tissues and its expressions were negatively related to the expressions of miR-300. LINC00472 over-expressions decreased cell proliferation abilities and colony formation abilities. These effects were mediated by miR-300. The silence of LINC00472 and over-expressions of miR-300 suppressed FOXO1 expressions. LINC00472 greatly reduced tumor growth in vivo and this effect was attenuated by miR-300 mimic.

CONCLUSIONS

From all the experiments and observations, we demonstrated that LINC00472 could be a potential tumor suppressor in OS through interacting with miR-300 and FOXO1.

Long non-coding RNAs: How to regulate the metastasis of non-small-cell lung cancer

Non–small‐cell lung cancer (NSCLC) has become the most lethal human cancer because of the high rate of metastasis. Hence, clarifying the molecular mechanism underlying NSCLC metastasis is very important to improve the prognosis of patients with NSCLC. Long non‐coding RNAs (LncRNAs) are a class of RNA molecules longer than 200 nucleotides, which can participate in diverse biological processes. About 18% of human LncRNAs were recently found to be associated with tumours. Many studies indicated that aberrant expression of LncRNAs played key roles in the progression and metastasis of NSCLC. According to the function in tumours, LncRNAs can be divided into two classes: oncogenic LncRNAs and tumour‐suppressor LncRNAs. In this review, we summarized the main molecular mechanism of LncRNAs regulating NSCLC metastasis, including three aspects: (a) LncRNAs interact with miRNAs as ceRNAs; (b) LncRNAs bind with target proteins; and (c) LncRNAs participate in the transduction of different signal pathways. Then, LncRNAs can exert their function to regulate the metastasis of NSCLC through influencing the progression of epithelial‐mesenchymal transition (EMT) and the properties of cancer stem cell (CSC). But, it is necessary to do some further research to demonstrate the LncRNAs particular regulatory mechanism of inhibiting the metastasis of NSCLC and explore new drugs targeting LncRNAs.

Long non-coding RNA LINC00472 suppresses hepatocellular carcinoma cell proliferation, migration and invasion through miR-93-5p/PDCD4 pathway

Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer and the second leading cause of cancer-related deaths. In the present study, we have demonstrated that long non-coding RNA (lncRNA) LINC00472 was low expressed in human HCC tissues and cell lines compared with adjacent non-tumor liver tissues and normal liver cell lines respectively. LINC00472 was also low expressed in HCC tissues from patients with metastasis compared with tissues from patients without metastasis. Expression level of LINC00472 was positively correlated with patient overall survival (OS) rate. Forced expression of LINC00472 suppressed cell proliferation, migration, invasion and promoted cell apoptosis in HCC cells Huh-7 and SMMC-7721. MiR-93-5p was a direct target of LINC00472, and miR-93-5p directly targeted PDCD4. The miR-93-5p/PDCD4 pathway mediated the suppressing role of LINC00472 in HCC cells. Therefore, LINC00472 was an important tumor suppressor in human HCC, which could be used as a bio-marker for HCC therapy.

LINC00472 Acts as a Tumor Suppressor in NSCLC through KLLN-Mediated p53-Signaling Pathway via MicroRNA-149-3p and MicroRNA-4270

Long non-coding RNAs and microRNAs (miRNAs) have been reported to participate in the progression of non-small-cell lung cancer (NSCLC). Long intergenic non-protein-coding RNA 472 (LINC00472), miR-149-3p, and miR-4270 were found to be involved in tumor activities, suggesting potential roles in NSCLC. Thus, this study aimed to examine the ability of LINC00472 to influence the progression of NSCLC with the involvement of miR-149-3p and miR-4270. Initially, differentially expressed long non-coding RNAs (lncRNAs), downstream regulatory miRNAs, and genes related to NSCLC were identified. Next, the interaction among LINC00472, miR-149-3p and miR-4270, and KLLN and the p53-signaling pathway was determined. The effect of LINC00472 on the expression of E-cadherin, N-cadherin, and Vimentin was examined through gain-of-function and loss-of-function experiments. Lastly, the effects of LINC00472 on NSCLC tumor growth were assessed in vivo. LINC00472 and KLLN were found to exhibit low levels, while miR-149-3p and miR-4270 were highly expressed in NSCLC. In addition, the overexpression of LINC00472 was observed to upregulate KLLN and activate the p53-signaling pathway, which ultimately inhibited the invasion, migration, and EMT of NSCLC cells via miR-149-3p and miR-4270, corresponding to decreased N-cadherin and Vimentin and increased E-cadherin. The overexpression of LINC00472 exerted an inhibitory effect on tumor growth in vivo. Taken together, the key evidence suggests that the overexpression of LINC00472 can downregulate miR-149-3p and miR-4270 to upregulate KLLN and activate the p53-signaling pathway, thus inhibiting the development of NSCLC. This study highlights the potential of LINC00472 as a promising therapeutic target for NSCLC treatment.

Functions and roles of long noncoding RNA in cholangiocarcinoma

Cholangiocarcinoma (CCA) is one of the most fatal cancers in humans, with a gradually increasing incidence worldwide. The efficient diagnostic and therapeutic measures for CCA to reduce mortality are urgently needed. Long noncoding RNAs (lncRNAs) may provide the potential diagnostic and therapeutic option for suppressing the CCA development. LncRNAs are a type of non-protein-coding RNAs, which are larger than 200 nucleotides in length. Increasing evidence reveals that lncRNAs exhibit critical roles in the carcinogenesis and development of CCA. Deregulation of lncRNAs impacts the proliferation, migration, invasion, and antiapoptosis of CCA cells by multiple sophisticated mechanisms. Consequently, lncRNAs likely represent promising biomarkers or intervention targets of CCA. In this review, we summarize current studies regarding the biological functions and regulatory mechanisms of diverse lncRNAs in CCA.

MEG3: an Oncogenic Long Non-coding RNA in Different Cancers

Long noncoding RNAs (lncRNAs) have recently considered as central regulators in diverse biological processes and emerged as vital players controlling tumorigenesis. Several lncRNAs can be classified into oncogenes and tumor suppressor genes depending on their function in cancer. A maternally expressed gene 3 (MEG3) gene transcripts a 1.6 kb lncRNA whose act as an antitumor component in different cancer cells, such as breast, liver, glioma, colorectal, cervical, gastric, lung, ovarian and osteosarcoma cancer cells. The present review highlights biological function of MEG3 to repress tumor through regulating the major tumor suppressor genes p53 and Rb, inhibiting angiogenesis-related factor, or controlling miRNAs. On the other hand, previous studies have also suggested that MEG3 mediates epithelial-mesenchymal transition (EMT). However, deregulation of MEG3 is associated with the  development and progression of cancer, suggesting that MEG3 may function as a potential biomarker and therapeutic target for human cancers.

Long Noncoding RNA LINC00472 Inhibits Proliferation and Promotes Apoptosis of Lung Adenocarcinoma Cells via Regulating miR-24-3p/ DEDD

OBJECTIVE

We aimed to detect the role of LINC00472 via regulating miR-24-3p and death effector domain-containing DNA-binding protein in lung adenocarcinoma.

METHODS

Long noncoding RNA, microRNA, and messenger RNA levels were determined using reverse transcription quantitative polymerase chain reaction. The expression of death effector domain-containing DNA-binding protein was determined using Western blot assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay were conducted to explore the proliferation of cells. The cell apoptosis was tested by flow cytometry assay. Target relationships between miR-24-3p, death effector domain-containing DNA-binding protein, and LINC00472 were validated by dual-luciferase reporter gene assay.

RESULTS

LINC00472 and death effector domain-containing DNA-binding protein were found to be underexpressed, whereas miR-24-3p was found overexpressed in lung adenocarcinoma cell lines and tissues. Both LINC00472 and death effector domain-containing DNA-binding protein can bind to miR-24-3p. Overexpression of LINC00472 led to higher death effector domain-containing DNA-binding protein level, demoting cell proliferation while promoting apoptosis. Overexpression of miR-24-3p reduced death effector domain-containing DNA-binding protein level, which facilitated cell proliferation and inhibited cell apoptosis, as well as to some extent restrained the effects of LINC00472. The high expression of miR-24-3p in tumor cells was negatively related to LINC00472 and death effector domain-containing DNA-binding protein, whereas the expression of LINC00472 and that of death effector domain-containing DNA-binding protein were positively correlated.

CONCLUSION

Our findings suggested that LINC00472 contributed to the increase in lung adenocarcinoma cell apoptosis and the inhibition of proliferation via regulating miR-24-3p/ DEDD, which might provide a novel insight into potential therapeutic approach for lung adenocarcinoma.

High expression of long non-coding RNA MALAT1 in breast cancer is associated with poor relapse-free survival

PURPOSE

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified as a prognostic marker for the metastasis of early-stage non-small cell lung cancer (NSCLCs). We studied MALAT1 expression in breast cancer in relation to disease features and patient survival.

METHODS

Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to measure MALAT1 expression in tumor samples of 509 breast cancer patients. Hazards ratios (HRs) and 95% confidence intervals (CIs) were calculated to assess the association between MALAT1 expression and breast cancer survival using the Cox proportional hazards regression model, and the analysis was adjusted for age at surgery, tumor grade, disease stage, and hormone receptor status. Meta-analysis of multiple microarray datasets from online databases and our own study was performed to evaluate the association of MALAT1 with breast cancer survival.

RESULTS

Patients with low-grade or ER-positive tumors had higher expression of MALAT1 compared to those with high-grade (p = 0.013) or ER-negative (p = 0.0002) tumors. Patients with PR-positive tumors also had higher MALAT1 expression than those with PR-negative tumors (p < 0.0001). In patients with positive hormone receptors or low tumor grade, tumors with high MALAT1 expression were more likely to recur. Survival analysis showed that patients with high expression of MALAT1 had a twofold increase in risk of relapse (p = 0.0083) compared to those with low expression. This association remained significant after adjustment for age at surgery, disease stage, tumor grade, and hormone receptor status. Meta-analysis showed that high MALAT1 expression was associated with poor relapse-free survival in patients with hormone receptor-positive tumors (HR 1.44, 95% CI 1.08-1.92).

CONCLUSIONS

High expression of lncRNA MALAT1 is associated with breast cancer relapse and may play a role in tumor progression.

EMT-related long non-coding RNA in hepatocellular carcinoma: A study with TCGA database

Accumulating evidence suggest that dysregulated expression of long non-coding RNA (lncRNA) plays a critical role in human tumorigenesis. However, little is known about the lncRNA implicated in the epithelial-to-mesenchymal transition (EMT) process. In this study, we performed data mining in The Cancer Genome Atlas (TCGA) hepatocellular carcinoma (HCC) data set and identified the a spectrum of differentially expressed lncRNAs implicated the EMT process of HCC, and functionally validated their roles in LM3 cells. Especially, lncRNA WDFY3-AS2-, LINC00472-, MIAT-, and MEG3-associated genes were significantly enriched in EMT-linked pathways. Loss-of-function study showed that genetic silencing of WDFY3-AS3, MIAT, and MEG3, but not LINC00472, resulted in reduced N-cadherin expression, cell migration, and cell invasion. Collectively, our results identify several lncRNAs that regulate the EMT process of HCC, which provides critical information for HCC tumorigenesis and potential therapeutic targets.

Linc00472 suppresses proliferation and promotes apoptosis through elevating PDCD4 expression by sponging miR-196a in colorectal cancer

Long intergenic non-coding RNA Linc00472 has been considered as a tumor suppressor in some cancers. However, the function and mechanism of Linc00472 in colorectal cancer has not been well elucidated. In this study, we found that Linc00472 was down-regulated in colorectal cancer tissues and cells. Elevated Linc00472 expression suppressed proliferation and induced apoptosis in colorectal cancer cells. Moreover, Linc00472 acted as a competing endogenous RNA (ceRNA) of miR-196a to release programmed cell death 4 (PDCD4). Furthermore, miR-196a overexpression or PDCD4 knockdown reversed Linc00472-mediated proliferation inhibition and apoptosis induction in colorectal cancer cells. Ectopic Linc00472 expression hindered tumor growth in vivo. Our study demonstrated that Linc00472 suppressed proliferation and induced apoptosis through up-regulating PDCD4 by decoying miR-196a, which may be an effective therapeutic target for colorectal cancer.

Long non-coding RNAs in ovarian cancer

Long non-coding RNAs (lncRNAs) refer to functional cellular RNAs molecules longer than 200 nucleotides in length. Unlike microRNAs, which have been widely studied, little is known about the enigmatic role of lncRNAs. However, lncRNAs have motivated extensively attention in the past few years and are emerging as potentially important regulators in pathological processes, including in cancer. We now understand that lncRNAs play role in cancer through their interactions with DNA, protein, and RNA in many instances. Moreover, accumulating evidence has recognized that large classes of lncRNAs are functional for ovarian cancer. Nevertheless, the biological phenomena and molecular mechanisms of lncRNAs in ovarian cancer remain to be better identified. In this review, we outline the dysregulated expression of lncRNAs and their potential clinical implications in ovarian cancer, with a particular emphasis on discussing the well characterized mechanisms underlying lncRNAs in ovarian cancer.

LncRNA ASAP1-IT1 positively modulates the development of cholangiocarcinoma via hedgehog signaling pathway

Over the past decades, lncRNAs have attracted more and more attentions of researchers. It has been verified that lncRNAs can modulate multiple biological behaviors in various human cancers. LncRNA ASAP1-IT1 has been certified to be a tumor facilitator in several malignant tumors. This study aims to investigate the effects of dysregulated ASAP1-IT1 on biological processes of Cholangiocarcinoma. The high expression level of ASAP1-IT1 was tested in Cholangiocarcinoma tissues and cells with qRT-PCR. Upregulation of ASAP1-IT predicted the unfavorable prognosis for Cholangiocarcinoma patients. Next, ASAP1-IT1 was knocked down in cancerous cells for loss-of function assay. MTT, colony formation and transwell and western bot assays were performed to demonstrate the specific impacts of ASAP1-IT1 on proliferation, migration and EMT progression of Cholangiocarcinoma. Cells. As a results, the Cholangiocarcinoma progression was inhibited. Hedgehog signaling pathway has been discovered to be a treatment target in Cholangiocarcinoma. In this study, the interaction between ASAP1-IT1 and hedgehog pathway was specifically investigated. Smo and Gli1, two hedgehog-related proteins were examined in Cholangiocarcinoma cells. The results of qRT-PCR and western blot assay suggested that ASAP1-IT1 could positively modulate Smo and Gli1 in Cholangiocarcinoma. Finally, rescue assays were carried out to prove that ASAP1-IT1 could improve Cholangiocarcinoma progression and development via hedgehog signaling pathway.

Role of lncRNAs in ovarian cancer: defining new biomarkers for therapeutic purposes

Long noncoding RNAs (lncRNAs) are a class of noncoding RNA, involved in regulation of diverse physiological and pathological processes. Ovarian cancer is the leading cause of death among all gynecological malignancies in the world and its underlying mechanism is still unclear. LncRNAs exhibit multiple biological functions in various stages of ovarian cancer development. We will discuss and summarize the new and important lncRNAs and their involvement in disease, which might represent promising therapeutic targets. Therapeutic intervention based on silencing or functional inhibition of target lncRNAs will be beneficial for ovarian cancer patients.

Integrated analysis of long non‑coding RNA competing interactions revealed potential biomarkers in cervical cancer: Based on a public database

Cervical cancer (CC) is a common gynecological malignancy in women worldwide. Using an RNA sequencing profile from The Cancer Genome Atlas (TCGA) and the CC patient information, the aim of the present study was to identify potential long non‑coding RNA (lncRNA) biomarkers of CC using bioinformatics analysis and building a competing endogenous RNA (ceRNA) co‑expression network. Results indicated several CC‑specific lncRNAs, which were associated with CC clinical information and selected some of them for validation and evaluated their diagnostic values. Bioinformatics analysis identified 51 CC‑specific lncRNAs (fold‑change >2 and P<0.05), and 42 of these were included in ceRNA network consisting of lncRNA‑miRNA‑mRNA interactions. Further analyses revealed that differential expression levels of 19 lncRNAs were significantly associated with different clinical features (P<0.05). A total of 11 key lncRNAs in the ceRNA network for reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis to detect their expression levels in 31 pairs of CC clinical samples. The results indicated that 7 lncRNAs were upregulated and 4 lncRNAs were downregulated in CC patients. The fold‑changes between the RT‑qPCR experiments and the TCGA bioinformatics analyses were the same. Furthermore, the area under the receiver operating characteristic (ROC) curve of four lncRNAs (EMX20S, MEG3, SYS1‑DBNDD2 and MIR9‑3HG) indicated that their combined use may have a significant diagnostic value in CC (P<0.05). To the best of our knowledge, the present study is the first to have identified CC‑specific lncRNAs to construct a ceRNA network and has also provided new insights for further investigation of a lncRNA‑associated ceRNA network in CC. In additon, the verification results suggested that the method of bioinformatics analysis and screening of lncRNAs was accurate and reliable. To conclude, the use of multiple lncRNAs may thus improve diagnostic efficacy in CC. In addition, these specific lncRNAs may serve as new candidate biomarkers for clinical diagnosis, classification and prognosis of CC.

A Potential Prognostic Long Noncoding RNA Signature to Predict Recurrence among ER-positive Breast Cancer Patients Treated with Tamoxifen

Limited predictable long noncoding RNA (lncRNA) signature was reported in tamoxifen resistance among estrogen receptor (ER)-positive breast cancer (BC) patients. The aim of this study was to identify and assess prognostic lncRNA signature to predict recurrence among ER-positive BC patients treated with tamoxifen. Cohorts from Gene Expression Omnibus (GEO) (n = 298) and The Cancer Genome Atlas (TCGA) (n = 160) were defined as training and validation cohort, respectively. BC relapse associated lnRNAs was identify within training cohort, and the predictable value of recurrence was assessed in both cohorts. A total of 11lncRNAs were recognized to be associated with relapse free survival (RFS) of ER-positive BC patients receiving tamoxifen, who were divided into low-risk and high-risk group on basis of relapse risk scores (RRS). Multivariate cox regression analyses revealed that the RRS is an independent prognostic biomarker in the prediction of ER-positive BC patients' survival. GSEA indicated that high-risk group was associated with several signaling pathways in processing of BC recurrence and metastasis such as PI3K-Akt and Wnt signaling. Our 11-lncRNA based classifier is a reliable prognostic and predictive tool for disease relapse in BC patients receiving tamoxifen.

Long non‑coding RNA regulates hair follicle stem cell proliferation and differentiation through PI3K/AKT signal pathway

Long non-coding RNAs (lncRNAs) are defined as non-coding transcripts (>200 nucleotides) that serve important roles in the proliferation and differentiation of stem cells. Hair follicle stem cells (HFTs) have multidirectional differentiation potential and are able to differentiate into skin, hair follicles and sebaceous glands, serving a role in skin wound healing. The aim of the present study was to analyze the regulatory role of lncRNA AK015322 (IncRNA5322) in HFTs and the potential mechanism of IncRNA5322‑mediated differentiation of HFTs. The results demonstrated that lncRNA5322 transfection promoted proliferation and differentiation in HFTs. It was identified that lncRNA5322 transfection upregulated the expression and phosphorylation of phosphoinositide 3‑kinase (PI3K) and protein kinase B (AKT) in HFTs. It was also observed that lncRNA5322 transfection upregulated microRNA (miR)‑21 and miR‑21 agonist (agomir‑21) eliminated lncRNA5322‑induced expression and phosphorylation of PI3K and AKT. The present study also demonstrated that agomir‑21 blocked IncRNA5322‑induced expression and phosphorylation of PI3K and AKT in HFTs. The results indicated that agomir‑21 transfection also suppressed the IncRNA5322‑induced proliferation and differentiation of HFTs. In conclusion, the results of the present study suggest that lncRNA5322 is able to promote the proliferation and differentiation of HFTs by targeting the miR‑21‑mediated PI3K‑AKT signaling pathway in HFTs.

Prognostic value of abnormally expressed lncRNAs in ovarian carcinoma: a systematic review and meta-analysis

Ovarian cancer (OC) is the most deadly gynecological cancer and it is urgently needed to find a new marker for the progress of OC. Many long noncoding RNAs (lncRNAs) have been reported to be aberrantly expressed in ovarian carcinoma, and may serve as prognostic markers. Therefore, we conducted this meta-analysis to gain a better understanding of the prognostic value of lncRNAs in patients with varian carcinoma. We systematically searched PubMed, EMBASE, and Web of Science. A total of 13 eligible studies, including 10 on clinicopathological features, 13 on prognosis were identified. Pooled hazard ratios (HRs) or odds ratios (OR) and 95% confidence intervals (95% CIs) were calculated using random- or fixed-effects models. Our results revealed that the increased expressions of 8 lncRNAs were associated with poor prognosis and the decreased expressions of 5 lncRNAs were related to poor prognosis in ovarian carcinoma. High HOTAIR expression was associated with shorter overall survival in ovarian cancer (pooled HR: 2.05, 95% CI: 1.51-2.77, P < 0.001). In conclusion, our meta-analysis suggested that LncRNAs could function as potential prognostic markers for ovarian cancer patients and high expression HOTAIR was associated with shorter overall survival in ovarian cancer.

Linc-ing Circulating Long Non-coding RNAs to the Diagnosis and Malignant Prediction of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease that lacks effective biomarkers for early detection. We hypothesized that circulating long non-coding RNAs (lncRNAs) may act as diagnostic markers of incidentally-detected cystic PDAC precursors known as intraductal papillary mucinous neoplasms (IPMNs) and predictors of their pathology/histological classification. Using NanoString nCounter® technology, we measured the abundance of 28 candidate lncRNAs in pre-operative plasma from a cohort of pathologically-confirmed IPMN cases of various grades of severity and non-diseased controls. Results showed that two lncRNAs (GAS5 and SRA) aided in differentiating IPMNs from controls. An 8-lncRNA signature (including ADARB2-AS1, ANRIL, GLIS3-AS1, LINC00472, MEG3, PANDA, PVT1, and UCA1) had greater accuracy than standard clinical and radiologic features in distinguishing 'aggressive/malignant' IPMNs that warrant surgical removal from 'indolent/benign' IPMNs that can be observed. When the 8-lncRNA signature was combined with plasma miRNA data and quantitative 'radiomic' imaging features, the accuracy of predicting IPMN pathological classification improved. Our findings provide novel information on the ability to detect lncRNAs in plasma from patients with IPMNs and suggest that an lncRNA-based blood test may have utility as a diagnostic adjunct for identifying IPMNs and their pathology, especially when incorporated with biomarkers such as miRNAs, quantitative imaging features, and clinical data.

Revealing potential long non-coding RNA biomarkers in lung adenocarcinoma using long non-coding RNA-mediated competitive endogenous RNA network

In our study, we aimed to reveal potential long non-coding RNAs (lncRNA) biomarkers in lung adenocarcinoma (LAD) using lncRNA-mediated competing endogenous RNAs (ceRNAs) network (LMCN). Competing lncRNA-mRNA interactions were identified using the hypergeometric test. Co-expression analysis for the competing lncRNA-mRNA interactions was implemented, and relying on the weight value >0.8, a highly competitive LMCN was further constructed. Degree distribution, betweenness and closeness for LMCN were carried out to analyze the network structure. Functional analyses of mRNAs in LMCN were carried out to further explore the biological functions of lncRNAs. Biclique algorithm was utilized to extract competing modules from the LMCN. Finally, we verified our findings in an independent sample set using qRT-PCR. Based on degrees >60, we identified 4 hubs, including DLEU2, SNHG12, HCP5, and LINC00472. Furthermore, 2 competing modules were identified, and LINC00472 in module 1 functioned as a hub in both LMCN and module. Functional implications of lncRNAs demonstrated that lncRNAs were related to histone modification, negative regulation of cell cycle, neuroactive ligand-receptor interaction, and regulation of actin cytoskeleton. qRT-PCR results demonstrated that lncRNAs LINC00472, and HCP5 were down-regulated in LAD tissues, while the expression level of SNHG12 was up-regulated in LAD tissues. Our study sheds novel light on the roles of lncRNA-related ceRNA network in LAD and facilitates the detection of potential lncRNA biomarkers for LAD diagnosis and treatment. Remarkably, in our study, LINC00472, HCP5, and SNHG12 might be potential biomarkers for LAD management.