LINC-PINT suppresses tumour cell proliferation, migration and invasion through targeting miR-374a-5p in ovarian cancer

Latest Update on lncRNA in Epithelial Ovarian Cancer-A Scoping Review

Long noncoding RNAs (lncRNAs) are RNA molecules exceeding 200 nucleotides that do not encode proteins yet play critical roles in regulating gene expression at multiple levels, such as chromatin modification and transcription. These molecules are significantly engaged in cancer progression, development, metastasis, and chemoresistance. However, the function of lncRNAs in epithelial ovarian cancer (EOC) has not yet been thoroughly studied. EOC remains challenging due to its complex molecular pathogenesis, characterized by genetic and epigenetic alterations. Emerging evidence suggests that lncRNAs, such as XIST, H19, NEAT1, and MALAT1, are involved in EOC by modulating gene expression and signaling pathways, influencing processes like cell proliferation, invasion, migration, and chemoresistance. Despite extensive research, the precise mechanism of acting of lncRNAs in EOC pathogenesis and treatment resistance still needs to be fully understood, highlighting the need for further studies. This review aims to provide an updated overview of the current understanding of lncRNAs in EOC, emphasizing their potential as biomarkers and therapeutic targets. We point out the gaps in the knowledge regarding lncRNAs' influence on epithelial ovarian cancer (EOC), deliberating on new possible research areas.

LINC-PINT suppresses the progression of acute myeloid leukemia via miR-767-5p/SUZ12-mediated JAK/STAT signaling pathway

BACKGROUND

Long noncoding RNA (lncRNA) long intergenic non-protein-coding RNA, p53-induced transcript (LINC-PINT) has shown a crucial role in cancer cells. However, its function in acute myeloid leukemia (AML) is unclear.

METHODS

The expression levels of LINC-PINT and miR-767-5p in AML patients were measured through quantitative real-time PCR. The interaction between miR-767-5p and LINC-PINT or suppressor of zeste 12 (SUZ12) was verified by RNA immunoprecipitation (RIP) assay and luciferase reporter assay. SUZ12-mediated JAK/STAT signaling pathway was further confirmed using western blotting and immunoprecipitation. Cell proliferation, cell cycle distribution, and apoptosis were evaluated by CCK-8 and flow cytometry. Tumor formation was examined by a nude mice model in vivo.

RESULTS

The low expression of LINC-PINT was significantly related to ELN risk stratification (p = 0.028). Ectopic expression of LINC-PINT restrained the proliferation and cell cycle G1/S transition and promoted apoptosis in AML cell lines (THP-1 and HL-60). LINC-PINT overexpression curbed tumor growth. LINC-PINT positively regulated SUZ12 by functioning as a sponge of miR-767-5p. There was a negative correlation between miR-767-5p and LINC-PINT in AML (r = -0.3316, p = 0.0336). Co-expression of miR-767-5p reversed the impacts of LINC-PINT on AML cells. MiR-767-5p enhanced the aggressiveness of AML, which was counteracted by overexpression of SUZ12. Additionally, SUZ12 downregulated HDAC1 to reduce STAT3 phosphorylation and acetylation in AML cells.

CONCLUSIONS

Overall, LINC-PINT serves as a tumor suppressor in AML through the miR-767-5p/SUZ12-mediated JAK/STAT signaling pathway, presenting a potential therapeutic target for AML.

Research on correlations of miR-374a-5p expression with progression and prognosis of prostate cancer

Prostate cancer (PCa) is a frequently occurring malignant tumor affecting male reproductive system. miR-374a-5p was identified to participate in regulation of several tumors. The aim of the research was to discuss the influence for miR-374a-5p upon PCa progression and prognosis. A total of 112 PCa and 110 benign prostatic hyperplasia tissue samples were collected for the study. Real-time quantitative polymerase chain reaction was adopted to examine miR-374a-5p level in PCa tissues and cells. Kaplan-Meier and Cox model were applied to evaluate prognostic significance of miR-374a-5p for PCa. CCK8 and Transwell assays were carried out to analyze the efficacy of miR-374a-5p in PCa cell proliferation, migration and invasion. miR-374a-5p was under-expressed in PCa tissues and cells. Low expression of miR-374a-5p is linked to less favorable prognosis in PCa sufferers. Additionally, Cox analysis revealed that miR-374a-5p and TNM stage were two independent prognostic factors for PCa. Cellular assays showed that upregulating miR-374a-5p suppressed PCa cell proliferation, migration, and invasion.

Conversely, knockdown of miR-374a-5p facilitated PCa cell proliferation, migration, and invasion. miR-374a-5p expression decreased in PCa and was remarkably related to poor prognosis in PCa patients. miR-374a-5p acts in PCa by inhibiting cell proliferation, migration, and invasion. Consequently, miR-374a-5p has potential to act as a prognostic biomarker and a target for clinical therapeutic intervention in PCa.

Long Non-Coding RNAs in Ovarian Cancer: Mechanistic Insights and Clinical Applications

Background/Objectives: Ovarian cancer is a leading cause of gynecological cancer mortality worldwide, often diagnosed at advanced stages due to vague symptoms and the lack of effective early detection methods. Long non-coding RNAs (lncRNAs) have emerged as key regulators in cancer biology, influencing cellular processes such as proliferation, apoptosis, and chemoresistance. This review explores the multifaceted roles of lncRNAs in ovarian cancer pathogenesis and their potential as biomarkers and therapeutic targets. Methods: A comprehensive literature review was conducted to analyze the structural and functional characteristics of lncRNAs and their contributions to ovarian cancer biology. This includes their regulatory mechanisms, interactions with signaling pathways, and implications for therapeutic resistance. Advanced bioinformatics and omics approaches were also evaluated for their potential in lncRNA research. Results: The review highlights the dual role of lncRNAs as oncogenes and tumor suppressors, modulating processes such as cell proliferation, invasion, and angiogenesis. Specific lncRNAs, such as HOTAIR and GAS5, demonstrate significant potential as diagnostic biomarkers and therapeutic targets. Emerging technologies, such as single-cell sequencing, provide valuable insights into the tumor microenvironment and the heterogeneity of lncRNA expression. Conclusions: LncRNAs hold transformative potential in advancing ovarian cancer diagnosis, prognosis, and treatment. Targeting lncRNAs or their associated pathways offers promising strategies to overcome therapy resistance and enhance personalized medicine. Continued research integrating omics and bioinformatics will be essential to unlock the full clinical potential of lncRNAs in ovarian cancer management.

GATA2‑miR‑374a axis promotes vascular smooth muscle cells proliferation, migration via targeting circTADA2A/RORA axis

Evidence has shown that microRNAs (miRNAs/miRs) play key roles in biological functions of vascular smooth muscle cells (VSMCs). However, the role of miR-374a in VSMCs remains to be elucidated. The present study aimed to explore the influence of miR-374a on VSMCs and its molecular mechanism. The expression level of miR-374a was measured by reverse transcription-quantitative (RT-q) PCR. MTT and Transwell assay were employed to assess the role of miR-374a in proliferation and migration of VSMCs. To order to determine miR-374a targets, a dual-luciferase reporter assay was conducted, which was further verified by rescue experiments. Chromatin Immunoprecipitation Assay and JASPAR databases were applied to explore the regulatory association between GATA binding protein 2 (GATA2) and miR-374a. Western blotting or RT-qPCR were employed to detect the protein expression levels of GATA2 or RAR-related orphan receptor A (RORA). The present study found that miR-374a was elevated in VSMCs following treatment with platelet-derived growth factor-BB (PDGF-BB) compared with that in control group. In addition, the results demonstrated that a higher expression of a miR-374a could promote proliferation and migration of VSMCs while miR-374a inhibitor suppressed the PDGF-BB-induced proliferation and migration of VSMCs in vitro. Furthermore, circTADA2A bound to miR-374a and then upregulated RORA expression, which resulted in inhibition in VSMCs proliferation and migration. On the other hand, the result indicated that GATA2 overexpression could augment the proliferation, migration of PDGF-bb-induced VSMCs, which could be rescued by miR-374a inhibitor. The findings suggested that the GATA2/circTADA2A-miR-374a axis promoted the proliferation and migration of VSMCs by targeting RORA, which were closely related to atherosclerosis (AS). Thus the results might offer a new therapeutic target for AS.

Prognostic significance of non-coding RNAs related to the tumorigenic epithelial-mesenchymal transition (EMT) process among ovarian cancer patients: A systematic review and meta-analysis

Introduction

Ovarian cancer is the seventh most prevalent cancer among women. It has high mortality and morbidity and imposes a great burden on healthcare systems worldwide. Unraveling the mechanisms behind the Epithelial-Mesenchymal Transition and finding a panel for predicting the prognosis of the disease may help find the appropriate treatment approaches for the management of the disease. The overarching aim of this systematic review was to define a panel of different types of EMT-associated non-coding RNAs (ncRNAs) with significant prognostic value in all types of ovarian cancers.

Methods

We searched PubMed, Web of Science, Scopus, and Embase till Jun 2024 to retrieve relevant papers. Two independent reviewers screened papers, and discrepancies were resolved by consensus. Publications related to the dysregulation of different types of ncRNAs, including microRNAs, lncRNAs, and circRNAs, only in patients with ovarian cancer were included. The participation of ncRNAs in epithelial-mesenchymal transformation should be assessed via methods evaluating different EMT-related proteins. To assess the quality and risk of bias for the included case-control and cohort studies, refined Newcastle-Ottawa Scale (NOS) and Quadas-2 were recruited. A bivariate meta-analysis was performed to analyze extracted data.

Results

A total of 37 studies with overall 42 non-coding RNAs (15 microRNA, 24 long non-coding RNAs, and 3 circular RNAs) were entered into the analysis. Overall diagnostic odds ratio for ncRNAs in lymph node metastasis, distant metastasis, TNM stage, and clinical stage were 4.19, 3.80, 6.52, and 3.97, respectively. Also, a hazard ratio of 1.39 (P = 0.32) for overall survival was observed. Bioinformatic analyses on the Pan-cancer database demonstrated a significant correlation between low expression of miRNA and high expression of lncRNAs with poor prognosis of ovarian cancer.

Conclusion

Based on the results, the defined panel of ncRNAs can properly predict prognostic factors related to EMT in ovarian cancer without involving potentially invasive methods.

LINC-PINT plays an anti-tumor role in nasopharyngeal carcinoma by binding to XRCC6 and affecting its function

BACKGROUND

LINC-PINT was downregulated in nasopharyngeal carcinoma (NPC) and correlated with treatment efficiency of NPC. However, the underlying mechanism of LINC-PINT in NPC has not yet been fully explored.

METHOD

We used CellTiter luminescent assay, clone formation assay, Hoechst staining, and SYTO-9/PI staining to examine cell viability and cell apoptosis regulated by LINC-PINT in NPC cells. Xenograft tumor model, HE staining, Ki67 staining, and TUNEL assay were conducted to assess the role of LINC-PINT in vivo. Bioinformatics and RNA immunoprecipitation assay was performed to identify the binding protein of LINC-PINT. Fluorescence in situ hybridization and immunofluorescence were utilized to measure the colocalization of XRCC6 with LINC-PINT and DNA-PKcs. Mito-Tracker red CMXRos staining was used to label mitochondria in cells specifically.

RESULT

We found LINC-PINT was downregulated in many tumors (including NPC) and associated with poor prognosis. The cell viability was significantly inhibited and cell apoptosis was remarkably promoted in LINC-PINT overexpressed cells in contrast to control cells. The growth of tumor xenografts was significantly suppressed and the tumor weight was significantly decreased in LINC-PINT overexpression group compared to the control group. Correspondingly, the positive Ki67 foci was decreased while TUNEL foci was increased in LINC-PINT overexpression group. Mechanically, we verified XRCC6 as a new binding protein of LINC-PINT through RNA binding domains prediction, RIP and colocalization of LINC-PINT and XRCC6. By binding to XRCC6, LINC-PINT interfered the formation of DNA-PK complex, regulated mitochondria accumulation status and affected the modification of apoptosis proteins, leading to more cell apoptosis.

CONCLUSION

Our study provided the first evidence that LINC-PINT promotes cell apoptosis in NPC by binding to XRCC6 and affecting its function.

Long non-coding RNA LINC-PINT as a novel prognostic biomarker in human cancer: a meta-analysis and machine learning

Long intergenic non-protein coding RNA, P53 induced transcript (LINC-PINT) exhibits different expression patterns in the majority of tumors, yet its relationship with cancer prognosis remains a subject of debate. This study aims to comprehensively investigate the prognostic significance of LINC-PINT in diverse human cancer. A systematic search was conducted in PubMed, Embase, Cochrane Library, and Web of Science databases to identify pertinent studies exploring the correlation between LINC-PINT expression and cancer patients. Moreover, bioinformatics analysis and in vitro validation were used to validate the results of the meta-analysis and to investigate the potential oncogenic mechanism of LINC-PINT. The meta-analysis encompassed 8 studies, involving 911 patients. The pooled analysis demonstrated a significant association between upregulation of LINC-PINT expression and better survival (P = 0.002) during the cancers. Meanwhile, its downregulation was correlated with advanced tumor staging (P = 0.04) and tumor differentiation (P = 0.03). Additionally, bioinformatics analysis showed that LINC-PINT expression was observed to be linked with Tumor Mutational Burden (TMB) and Microsatellite Instability (MSI) in tumors, the results of bioinformatics were verified by qRT-PCR. And functional enrichment analysis hinted at its involvement in tumorigenesis and tumor progression. Dysregulated LICN-PINT expression is associated with the clinical prognostic and pathological features of various cancers, exhibiting substantial potential as a novel prognostic biomarker.

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.

The Role of EMT-Related lncRNAs in Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest cancers worldwide; late diagnosis and drug resistance are two major factors often responsible for high morbidity and treatment failure. Epithelial-to-mesenchymal transition (EMT) is a dynamic process that has been closely linked with cancer. Long non-coding RNAs (lncRNAs) have been also associated with several cancer-related mechanisms, including EMT. We conducted a literature search in the PubMed database in order to sum up and discuss the role of lncRNAs in regulating OC-related EMT and their underlying mechanisms. Seventy (70) original research articles were identified, as of 23 April 2023. Our review concluded that the dysregulation of lncRNAs is highly associated with EMT-mediated OC progression. A comprehensive understanding of lncRNAs' mechanisms in OC will help in identifying novel and sensitive biomarkers and therapeutic targets for this malignancy.

PINTology: A short history of the lncRNA LINC-PINT in different diseases

LINC-PINT is a p53-induced long intergenic noncoding transcript that plays a crucial role in many diseases, especially cancer. This long noncoding RNA (lncRNA) gene produces in total 102 (LNCipedia) alternatively spliced variants (LINC-PINT:1 to LINC-PINT:102). The functions of known variants include RNA transcripts, host transcripts for circular RNA (circRNA) generation and as sources for the translation of short peptides. In most human tumors, LINC-PINT is down-regulated where it serves as a tumor suppressor. However, the diversity of its functions in other maladies signifies its general clinical importance. Current LINC-PINT molecular functions include RNA-protein interactions, miRNA sponging and epigenetic modulation with these mechanisms operating in different cellular contexts to exert effects on biological processes ranging from DNA damage responses, cell cycle and growth arrest, senescence, cell migration and invasion, and apoptosis. Genetic polymorphisms in LINC-PINT have also been functionally associated with cancer and other pathologies including the autoimmune diseases pemphigus foliaceus and arthritis. Hence, LINC-PINT shows great potential as a clinical biomarker, especially for the diagnosis and prognosis of cancer. In this review, we explore the current knowledge highlighting the distinctive molecular functions of LINC-PINT in specific cancers and other disease states. This article is categorized under: RNA in Disease and Development > RNA in Disease.

TWIST1 methylation by SETD6 selectively antagonizes LINC-PINT expression in glioma

Gliomas are one of the most common and lethal brain tumors among adults. One process that contributes to glioma progression and recurrence is the epithelial to mesenchymal transition (EMT). EMT is regulated by a set of defined transcription factors which tightly regulate this process, among them is the basic helix-loop-helix family member, TWIST1. Here we show that TWIST1 is methylated on lysine-33 at chromatin by SETD6, a methyltransferase with expression levels correlating with poor survival in glioma patients. RNA-seq analysis in U251 glioma cells suggested that both SETD6 and TWIST1 regulate cell adhesion and migration processes. We further show that TWIST1 methylation attenuates the expression of the long-non-coding RNA, LINC-PINT, thereby promoting EMT in glioma. Mechanistically, TWIST1 methylation represses the transcription of LINC-PINT by increasing the occupancy of EZH2 and the catalysis of the repressive H3K27me3 mark at the LINC-PINT locus. Under un-methylated conditions, TWIST1 dissociates from the LINC-PINT locus, allowing the expression of LINC-PINT which leads to increased cell adhesion and decreased cell migration. Together, our findings unravel a new mechanistic dimension for selective expression of LINC-PINT mediated by TWIST1 methylation.

Emerging role of lncRNA ELDR in development and cancer

Whole-genome sequencing and transcriptome analysis revealed more than 90% of the human genome transcribes noncoding RNAs including lncRNAs. From the beginning of the 21st century, lncRNAs have gained widespread attention as a new layer of regulation in biological processes. lncRNAs are > 200 nucleotides in size, transcribed by RNA polymerase II, and share many similarities with mRNAs. lncRNA interacts with DNA, RNA, protein, and miRNAs, thereby regulating many biological processes. In this review, we have focused mainly on LINC01156 [also known as the EGFR long non-coding downstream RNA (ELDR) or Fabl] and its biological importance. ELDR is a newly identified lncRNA and first reported in a mouse model, but it has a human homolog. The human ELDR gene is closely localized downstream of epidermal growth factor receptor (EGFR) gene at chromosome 7 on the opposite strand. ELDR is highly expressed in neuronal stem cells and associated with neuronal differentiation and mouse brain development. ELDR is upregulated in head and neck cancer, suggesting its role as an oncogene and its importance in prognosis and therapy. Publicly available RNA-seq data further support its oncogenic potential in different cancers. Here, we summarize all the aspects of ELDR in development and cancer, highlighting its future perspectives in the context of mechanism.

dbEssLnc: A manually curated database of human and mouse essential lncRNA genes

Long non-coding RNAs (lncRNAs) play important roles in many biological processes. Knocking out or knocking down some lncRNAs will lead to lethality or infertility. These lncRNAs are called essential lncRNAs. Knowledges of essential lncRNAs are important in establishing minimal genomes of living cells, developing drug therapies and early diagnostic approaches for complex diseases. However, existing databases focus on collecting essential coding genes. Essential non-coding gene records are rare in existing databases. A comprehensive collection of essential non-coding genes, particularly essential lncRNA genes, is demanded. We manually curated 207 essential lncRNAs from literatures for establishing a database on essential lncRNAs, which is named as dbEssLnc (Database of essential lncRNAs). The dbEssLnc database has a web-based user-friendly interface for the users to browse, to search, to visualize and to blast search records in the database. The dbEssLnc database is freely accessible at https://esslnc.pufengdu.org. All data and source codes for mirroring the dbEssLnc database have been deposited in GitHub (https://github.com/yyZhang14/dbEssLnc).

LINC-DUBR Suppresses Malignant Progression of Ovarian Cancer by Downregulating miR-107 to Induce SMAC Expression

Background

LINC-DUBR may be a potential therapeutic target in ovarian cancer (OC). The purpose of this research was to explore the impact of miR-107 on the tumorigenicity of OC and its underlying molecular mechanisms.

Methods

RT-qPCR was adopted to measure the expression of LINC-DUBR and miR-107 in ovarian cancer tissues and cells. CCK-8 assays and transwell chamber assays were conducted to evaluate the impacts of LINC-DUBR and miR-107 on the proliferation and invasion of human ovarian cancer cells (SKOV3). In addition, we determined the relationship between LINC-DUBR, miR-107, and SMAC using TargetScan and luciferase reporter assay. The protein expression of SMAC was determined by western blot.

Results

Compared with normal tissues and cells, LINC-DUBR was downregulated and miR-107 was highly expressed in ovarian cancer tissues and cell lines. Overexpression of LINC-DUBR inhibited the cell proliferation and invasive ability in OC cells SKOV3. The luciferase reporter assay proved overexpression of LINC-DUBR repressed cells proliferation and invasion via binding to miR-107 in ovarian cancer. In addition, we found that SMAC was downregulated directly by miR-107 in ovarian cancer. miR-107 mimic significantly increased cell proliferation and invasiveness of SKOV3, while overexpressed SMAC eliminated this effect. Furthermore, miR-107 could regulate the XIAP/caspase-3 signaling pathway in ovarian cancer by targeting SMAC.

Conclusion

LINC-DUBR suppressed malignant progression of ovarian cancer by downregulating miR-107 to induce SMAC expression and involving in the XIAP/caspase-3 signaling pathway.

LncRNA RP11-499E18.1 Inhibits Proliferation, Migration, and Epithelial-Mesenchymal Transition Process of Ovarian Cancer Cells by Dissociating PAK2-SOX2 Interaction

Background: Ovarian cancer (OC)is a deadly gynecological malignancy worldwide. It is urgent to identify diagnostic biomarkers of OC to disclose the underlying mechanism. Methods and Materials: Bioinformatics analysis was used to identify target genes. Gene expression was detected and altered by qRT-PCR and cell transfection, respectively. The interaction between RP11-499E18.1 and PAK2, as well as that between PAK2 and SOX2, was determined using RNA pulldown, RNA immunoprecipitation (RIP), and co-immunoprecipitation (co-IP) assay, respectively. Localizations of RP11-499E18.1, PAK2, and SOX2 were respectively determined employing immunohistochemical (IHC), IF, and FISH. The regulatory effects of RP11-499E18.1, PAK2, and SOX2 on OC cell proliferation, migration, colony formation, epithelial-mesenchymal transition (EMT)-related factor expression, and SOX2 nuclear translocation were determined. Finally, the effects of RP11-499E18.1 and PAK2 expression on the tumor growth in nude mice were determined. Results: RP11-499E18.1, PAK2, and SOX2 were selected in our study. RP11-499E18.1 was downregulated, while PAK2 and SOX2 was upregulated in OC tissues and cells. RP11-499E18.1 coexists in the nucleus and cytoplasm of OC cells. There is an interaction between RP11-499E18.1 and PAK2, as well as PAK2 and SOX2 in OC cells. Alteration of RP11-499E18.1 and PAK2 expression both had no influence on PAK2 and SOX2 levels, but PAK2 upregulation notably augmented p-SOX2 level. RP11-499E18.1 overexpression suppressed OC cell proliferation, migration, and colony formation, as well as SOX2 nuclear translocation. Besides, it inhibited tumor growth in nude mice. However, these effects were notably reversed by PAK2 upregulation and eventually offset by SOX2 knockdown. Additionally, RP11-499E18.1 overexpression reduced PAK2-SOX2 interaction and SOX phosphorylation, and increased the binding of RP11-499E18.1 by PAK2. Conclusion: These lines of evidence demonstrated that RP11-499E18.1 might play its tumor suppressor roles in OC via regulation of the RP11-499E18.1-PAK2-SOX2 axis. This research indicated that RP11-499E18.1 might be used as a diagnostic biomarker for OC in the future.

Long intragenic non-coding RNA p53-induced transcript (LINC-PINT) as a novel prognosis indicator and therapeutic target in cancer

Cancer involves complex etiology factors, multiple stages, and intricate gene mutations. Long non-coding RNAs (lncRNAs) are implicated as molecular mechanisms underlying human genomic activity in various physiologic and pathophysiologic conditions. However, the sophisticated modifications and regulatory processes linking lncRNAs to cancer initiation and progression have not yet been fully explored. Long intragenic non-coding RNA p53-induced transcript (LINC-PINT) is an lncRNA that functions as a tumor suppressor gene involved in various tumors and malignant activities. LINC-PINT is downregulated in nasopharyngeal cancer, renal carcinoma, non-small cell lung cancer, glioblastoma, thyroid cancer, retinoblastoma, ovarian cancer, breast cancer, esophageal squamous cell carcinoma, osteosarcoma, melanoma, and gastric cancer. Furthermore, decreased LINC-PINT expression predicts poor prognosis and advanced clinical tumor stages. Together, these studies indicate that LINC-PINT could serve as a diagnostic and prognostic indicator in cancer. The specific lncRNA regulatory mechanism of LINC-PINT may also be a novel target for cancer therapies.

H3K27ac-induced lncRNA PAXIP1-AS1 promotes cell proliferation, migration, EMT and apoptosis in ovarian cancer by targeting miR-6744-5p/PCBP2 axis

We aimed to explore role of lncRNA PAX-interacting protein 1-antisense RNA1 (PAXIP1-AS1) in ovarian cancer (OC). RT-qPCR analysis identified upregulation of PAXIP1-AS1 in OC cell lines. Functionally, PAXIP1-AS1 knockdown inhibited cell proliferation, accelerated cell apoptosis, and suppressed cell migration and epithelial-mesenchymal transition (EMT) process. Upregulation of PAXIP1-AS1 was induced by CBP-mediated H3K27 acetylation (H3K27ac) via bioinformatic analysis and ChIP assay. Furthermore, PAXIP1-AS1 served as a competing endogenous RNA (ceRNA) to regulate PCBP2 expression by sponging microRNA-6744-5p (miR-6744-5p). Restoration experiments showed that overexpressed PCBP2 rescued effects of silenced PAXIP1-AS1 on cell proliferation, apoptosis, migration and EMT. Overall, lncRNA PAXIP1-AS1 activated by H3K27ac functioned as a tumor promoter in OC via mediating miR-6744-5p/PCBP2 axis, which provided promising insight into exploration on OC therapy.

LINC00518 Promotes Cell Proliferation by Regulating the Cell Cycle of Lung Adenocarcinoma Through miR-185-3p Targeting MECP2

Previous studies have shown that long intergenic non-protein coding RNA 00518 (LINC00518) are essential for the cell growth and metastasis of human cancer. However, the role of LINC00518 in lung adenocarcinoma (LUAD) is still unknown. This research put emphasis on the function of LINC00518 on the cell growth of LUAD. The lncRNA, miRNA and mRNA expression were measured by using qRT-PCR. Protein levels were measured by using Western blotting. CCK-8, colony formation assays and transwell assay were performed to evaluate the cell proliferation ability and invasion. Bioinformatic analysis and luciferase reporter assays were chosen to confirm the mechanism of LINC00518 in LUAD. We found that LINC00518 was highly expressed in LUAD specimens and the high-expression was negatively correlated with the overall survival rates. This finding was also proved in the LUAD cell lines. Through a series of in vitro and in vivo experiments, we proved that LICN00518 promoted the cell growth of LUAD by regulating the cell cycle. Moreover, LICN00518 upregulated the expression of MECP2 by mutagenesis of miR-185-3p. The results suggested that LICN00518 could be used as a survival indicator and potential therapeutic target for LUAD patients.

Novel long noncoding RNA LINC02323 promotes cell growth and migration of ovarian cancer via TGF-β receptor 1 by miR-1343-3p

BACKGROUND

This study was aimed at investigating the effects of long noncoding RNA (lncRNA) LINC02323 in ovarian cancer and its possible mechanism.

METHODS

Microarray analysis and QPCR were utilized to identify lncRNA LINC02323 expression in patients with ovarian cancer. MTT assay was used for analysis of ovarian cancer cell proliferation. Western blot was utilized to investigate its possible mechanism.

RESULTS

In patients with ovarian cancer, lncRNA LINC02323 expression was up-regulated and miR-1343-3p expression was down-regulated. Over-expression of lncRNA LINC02323 promoted cell growth and reduced LDH activity levels in vitro model by suppression of miR-1343-3p expression. Down-regulation of lncRNA LINC02323 reduced cell growth and increased LDH activity levels in vitro model by induction of miR-1343-3p expression. Over-expression of miR-1343-3p reduced cell growth and reduced LDH activity levels in vitro model by suppression of TGF-β receptor. Down-regulation of miR-1343-3p promoted cell growth and reduced LDH activity levels in vitro model by induced of TGF-β receptor.

CONCLUSION

Our findings show that Novel long noncoding RNA LINC02323 promotes cell growth of ovarian cancer via TGF-β receptor 1 by miR-1343-3p.