LncRNA LUCAT1 contributes to cell proliferation and migration in human pancreatic ductal adenocarcinoma via sponging miR-539

The long noncoding RNA LUCAT1 regulates endometrial receptivity via the miR-495-3p/S100P axis

Recently, interest in investigating the effects of long noncoding RNAs (lncRNAs) on endometrial receptivity (ER) has increased within the field of assisted reproductive technology. Therefore, the objective of this study is to identify and analyze the role of the lncRNA LUCAT1 and to elucidate its specific mechanism in regulating ER. Hub genes associated with ER are identified via Weighted gene co-expression network analysis (WGCNA) in two datasets downloaded from the GEO database. These hub genes identified via WGCNA were subsequently validated. The combination of a dual-luciferase assay, qRT‒PCR, western blotting, and other techniques are used to investigate the molecular mechanism by which LUCAT1 regulates S100P. In this study, LUCAT1 expression is shown to significantly affect ER, and the depletion of LUCAT1 leads to impaired ER function. Additionally, LUCAT1 is shown to act as a molecular sponge for miR-495-3p, thereby modulating the expression of S100P. This modulation influences the proliferation, migration, and invasion capabilities of Ishikawa cells, as well as the adhesion of JAR cells to endometrial cells. Therefore, LUCAT1 can regulate ER via the miR-495-3p/S100P axis, which provides experimental evidence for the identification of innovative strategies aimed at enhancing endometrial receptivity.

Long non-coding RNAs: Emerging regulators of invasion and metastasis in pancreatic cancer

BACKGROUND

The invasion and metastasis of pancreatic cancer (PC) are key factors contributing to disease progression and poor prognosis. This process is primarily driven by EMT, which has been the focus of recent studies highlighting the role of long non-coding RNAs (lncRNAs) as crucial regulators of EMT. However, the mechanisms by which lncRNAs influence invasive metastasis are multifaceted, extending beyond EMT regulation alone.

AIM OF REVIEW

This review primarily aims to characterize lncRNAs affecting invasion and metastasis in pancreatic cancer. We summarize the regulatory roles of lncRNAs across multiple molecular pathways and highlight their translational potential, considering the implications for clinical applications in diagnostics and therapeutics.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review focuses on three principal scientific themes. First, we primarily summarize lncRNAs orchestrate various signaling pathways, such as TGF-β/Smad, Wnt/β-catenin, and Notch, to regulate molecular changes associated with EMT, thereby enhancing cellular motility and invasivenes. Second, we summarize the effects of lncRNAs on autophagy and ferroptosis and discuss the role of exosomal lncRNAs in the tumor microenvironment to regulate the behavior of neighboring cells and promote cancer cell invasion. Third, we emphasize the effects of RNA modifications (such as m6A and m5C methylation) on stabilizing lncRNAs and enhancing their capacity to mediate invasive metastasis in PC. Lastly, we discuss the translational potential of these findings, emphasizing the inherent challenges in using lncRNAs as clinical biomarkers and therapeutic targets, while proposing prospective research strategies.

An anti-sense lncRNA of the A-FABP gene regulates the proliferation of hair follicle stem cells via the chi-miR-335-5p/DKK1/β-catenin axis

Hair follicle development relies on both the epithelial-mesenchymal interaction (EMI) and the proliferation of hair follicle stem cells (HFSCs). This intricate process involves numerous regulatory molecules. Increasing evidence suggests that long non-coding RNAs (lncRNAs) play a crucial role in hair follicle development. However, the functions and molecular mechanisms of many lncRNAs in hair follicle development of cashmere goats remain unclear. Based on our previous lncRNA sequencing results in cashmere goats, an unannotated lncRNA differentially expressed at various stages of hair follicle development, named FABP_AS, was detected. Consequently, we aimed at exploring the function and molecular mechanisms of FABP_AS. We constructed a CRISPR/Cas9 knockout system to specifically knock down FABP_AS, providing a reference model for target lncRNA knockout in animal primary cells. Functional experiment results demonstrated that FABP_AS significantly inhibited HFSCs proliferation. Mechanism experiment results revealed that FABP_AS competitively bond to chi-miR-335-5p, promoted DKK1 gene expression, and reduced Wnt/β-catenin signaling pathway activity. In summary, our findings indicated that FABP_AS acted as a miRNA sponge, sequestering chi-miR-335-5p away from the DKK1 gene, thereby suppressing HFSCs proliferation, which would lay the groundwork for a better understanding of the molecular mechanisms of hair follicle development and provide therapeutic targets for hair loss.

Long non‑coding RNA lung cancer‑associated transcript 1 regulates ferroptosis via microRNA‑34a‑5p‑mediated GTP cyclohydrolase 1 downregulation in lung cancer cells

Ferroptosis, a recently discovered type of programmed cell death triggered by excessive accumulation of iron‑dependent lipid peroxidation, is linked to several malignancies, including non‑small cell lung cancer. Long non‑coding RNAs (lncRNAs) are involved in ferroptosis; however, data on their role and mechanism in cancer therapy remains limited. Therefore, the aim of the present study was to identify ferroptosis‑associated mRNAs and lncRNAs in A549 lung cancer cells treated with RAS‑selective lethal 3 (RSL3) and ferrostatin‑1 (Fer‑1) using RNA sequencing. The results demonstrated that lncRNA lung cancer‑associated transcript 1 (LUCAT1) was significantly upregulated in lung adenocarcinoma and lung squamous cell carcinoma tissues. Co‑expression analysis of differentially expressed mRNAs and lncRNAs suggested that LUCAT1 has a crucial role in ferroptosis. LUCAT1 expression was markedly elevated in A549 cells treated with RSL3, which was prevented by co‑incubation with Fer‑1. Functionally, overexpression of LUCAT1 facilitated cell proliferation and reduced the occurrence of ferroptosis induced by RSL3 and Erastin, while inhibition of LUCAT1 expression reduced cell proliferation and increased ferroptosis. Mechanistically, downregulation of LUCAT1 resulted in the downregulation of both GTP cyclohydrolase 1 (GCH1) and ferroptosis suppressor protein 1 (FSP1). Furthermore, inhibition of LUCAT1 expression upregulated microRNA (miR)‑34a‑5p and then downregulated GCH1. These results indicated that inhibition of LUCAT1 expression promoted ferroptosis by modulating the downregulation of GCH1, mediated by miR‑34a‑5p. Therefore, the combination of knocking down LUCAT1 expression with ferroptosis inducers may be a promising strategy for lung cancer treatment.

Non-Coding RNAs as Key Regulators in Lung Cancer

For several decades, most lung cancer investigations have focused on the search for mutations in candidate genes; however, in the last decade, due to the fact that most of the human genome is occupied by sequences that do not code for proteins, much attention has been paid to non-coding RNAs (ncRNAs) that perform regulatory functions. In this review, we principally focused on recent studies of the function, regulatory mechanisms, and therapeutic potential of ncRNAs including microRNA (miRNA), long ncRNA (lncRNA), and circular RNA (circRNA) in different types of lung cancer.

Non-coding RNAs' function in cancer development, diagnosis and therapy

While previous research on cancer biology has focused on genes that code for proteins, in recent years it has been discovered that non-coding RNAs (ncRNAs)play key regulatory roles in cell biological functions. NcRNAs account for more than 95% of human transcripts and are an important entry point for the study of the mechanism of cancer development. An increasing number of studies have demonstrated that ncRNAs can act as tumor suppressor genes or oncogenes to regulate tumor development at the epigenetic level, transcriptional level, as well as post-transcriptional level. Because of the importance of ncRNAs in cancer, most clinical trials have focused on ncRNAs to explore whether ncRNAs can be used as new biomarkers or therapies. In this review, we focus on recent studies of ncRNAs including microRNAs (miRNAs), long ncRNAs (lncRNAs), circle RNAs (circRNAs), PIWI interacting RNAs (piRNAs), and tRNA in different types of cancer and explore the application of these ncRNAs in the development of cancer and the identification of relevant therapeutic targets and tumor biomarkers. Graphical abstract drawn by Fidraw.

The RNA interactome in the Hallmarks of Cancer

Ribonucleic acid (RNA) molecules are indispensable for cellular homeostasis in healthy and malignant cells. However, the functions of RNA extend well beyond that of a protein-coding template. Rather, both coding and non-coding RNA molecules function through critical interactions with a plethora of cellular molecules, including other RNAs, DNA, and proteins. Deconvoluting this RNA interactome, including the interacting partners, the nature of the interaction, and dynamic changes of these interactions in malignancies has yielded fundamental advances in knowledge and are emerging as a novel therapeutic strategy in cancer. Here, we present an RNA-centric review of recent advances in the field of RNA-RNA, RNA-protein, and RNA-DNA interactomic network analysis and their impact across the Hallmarks of Cancer. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.

CO2-Induced Ocean Acidification Alters the Burrowing Behavior of Manila Clam Ruditapes philippinarum by Reversing GABAA Receptor Function

Biological burrowing behavior is an important driver shaping ecosystems that is being threatened by CO₂-induced ocean acidification; however, the effects of ocean acidification on burrowing behavior and its neurological mechanism remain unclear. This study showed that elevated pCO₂ significantly affected the burrowing behaviors of the Manila clam Ruditapes philippinarum, such as increased foot contraction, burrowing time, and intrabottom movement and decreased burrowing depth. Delving deeper into the mechanism, exposure to elevated pCO₂ significantly decreased extracellular pH and increased [HCO₃^-]. Moreover, an indicator GABA_A receptor, a neuroinhibitor for movement, was found to be closely associated with behavioral changes. In situ hybridization confirmed that the GABA_A receptor was widely distributed in ganglia and foot muscles, and elevated pCO₂ significantly increased the mRNA level and GABA concentration. However, the increase in GABA_A receptor and its ligand did not suppress the foot movement, but rather sent "excitatory" signals for foot contraction. The destabilization of acid-base homeostasis was demonstrated to induce an increase in the reversal potential for GABA_A receptor and an alteration in GABA_A receptor function under elevated pCO₂. This study revealed that elevated pCO₂ affects the burrowing behavior of Manila clams by altering GABA_A receptor function from inhibitory to excitatory.

Roles of lncRNAs in pancreatic ductal adenocarcinoma: Diagnosis, treatment, and the development of drug resistance

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, primarily due to its late diagnosis, high propensity to metastasis, and the development of resistance to chemo-/radiotherapy. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) are intimately involved in the treatment resistance of pancreatic cancer cells via interacting with critical signaling pathways and may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC.

DATA SOURCES

We carried out a systematic review on lncRNAs-based research in the context of pancreatic cancer and presented an overview of the updated information regarding the molecular mechanisms underlying lncRNAs-modulated pancreatic cancer progression and drug resistance, together with their potential value in diagnosis, prognosis, and treatment of PDAC. Literature mining was performed in PubMed with the following keywords: long non-coding RNA, pancreatic ductal adenocarcinoma, pancreatic cancer up to January 2022. Publications relevant to the roles of lncRNAs in diagnosis, prognosis, drug resistance, and therapy of PDAC were collected and systematically reviewed.

RESULTS

LncRNAs, such as HOTAIR, HOTTIP, and PVT1, play essential roles in regulating pancreatic cancer cell proliferation, invasion, migration, and drug resistance, thus may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC. They participate in tumorigenesis mainly by targeting miRNAs, interacting with signaling molecules, and involving in the epithelial-mesenchymal transition process.

CONCLUSIONS

The functional lncRNAs play essential roles in pancreatic cancer cell proliferation, invasion, migration, and drug resistance and have potential values in diagnosis, prognostic prediction, and treatment of PDAC.

The tumor therapeutic potential of long non-coding RNA delivery and targeting

Long non-coding RNAs (lncRNAs) is a type of RNA over 200 nt long without any protein coding ability, which has been investigated relating to crucial biological function in cells. There are many key lncRNAs in tumor/normal cells that serve as a biological marker or a new target for tumor treatment. However, compared to some small non-coding RNA, lncRNA-based drugs are limited in clinical application. Different from other non-coding RNA, like microRNAs, most lncRNAs have a high molecular weight and conserved secondary structure, making the delivery of lncRNAs more complex than the small non-coding RNAs. Considering that lncRNAs constitute the most abundant part of the mammalian genome, it is critical to further explore lncRNA delivery and the subsequent functional studies for potential clinical application. In this review, we will discuss the function and mechanism of lncRNAs in diseases, especially cancer, and different approaches for lncRNA transfection using multiple biomaterials.

Regulatory Roles of Noncoding RNAs in the Progression of Gastrointestinal Cancers and Health Disparities

Annually, more than a million individuals are diagnosed with gastrointestinal (GI) cancers worldwide. With the advancements in radio- and chemotherapy and surgery, the survival rates for GI cancer patients have improved in recent years. However, the prognosis for advanced-stage GI cancers remains poor. Site-specific GI cancers share a few common risk factors; however, they are largely distinct in their etiologies and descriptive epidemiologic profiles. A large number of mutations or copy number changes associated with carcinogenesis are commonly found in noncoding DNA regions, which transcribe several noncoding RNAs (ncRNAs) that are implicated to regulate cancer initiation, metastasis, and drug resistance. In this review, we summarize the regulatory functions of ncRNAs in GI cancer development, progression, chemoresistance, and health disparities. We also highlight the potential roles of ncRNAs as therapeutic targets and biomarkers, mainly focusing on their ethnicity-/race-specific prognostic value, and discuss the prospects of genome-wide association studies (GWAS) to investigate the contribution of ncRNAs in GI tumorigenesis.

lncRNA LUCAT1/ELAVL1/LIN28B/SOX2 Positive Feedback Loop Promotes Cell Stemness in Triple-Negative Breast Cancer

Background. Triple-negative breast cancer (TNBC), as a subtype of breast cancer (BC), features an aggressive nature. Long noncoding RNAs (lncRNAs) are proved to get involved in the processes of cancers. lncRNA lung cancer associated transcript 1 (LUCAT1) has been reported in multiple cancers. The role of LUCAT1 in TNBC and its latent regulatory mechanism were investigated. Methods. RT-qPCR was performed to examine LUCAT1 expression. Functional experiments were implemented to disclose the role of LUCAT1 in TNBC. The underlying regulatory mechanism of LUCAT1 in TNBC was explored by chromatin immunoprecipitation (ChIP), RNA-binding protein immunoprecipitation (RIP), luciferase reporter, and RNA pull-down assays. Results. LUCAT1 is significantly overexpressed in TNBC cells. LUCAT1 interference impedes cell stemness in TNBC cells. SRY-box transcription factor 2 (SOX2) is an active transcription factor of LUCAT1. LUCAT1 recruits ELAV-like RNA binding protein 1 (ELAVL1) protein to stabilize lin-28 homolog B (LIN28B) mRNA, thereby further modulating SOX2 expression, which forms a positive feedback loop. Conclusion. The lncRNA LUCAT1/ELAVL1/LIN28B/SOX2 positive feedback loop promotes cell stemness in TNBC. The exploration of the mechanisms underlying TNBC stemness might be beneficial to TNBC treatment.

New Insights into the Importance of Long Non-Coding RNAs in Lung Cancer: Future Clinical Approaches

In mammals, a large part of the gene expression products come from the non-coding ribonucleotide sequences of the protein. These short and long sequences are within the range of tens to hundreds of nucleotides, encompassing more than 200 RNA molecules, and their function is known as the molecular structure of long non-coding RNA (lncRNA). LncRNA molecules are unique nucleotides that have a substantial role in epigenetic regulation, transcription, and post-transcriptional modifications in different ways. According to the results of recent studies, lncRNAs have been shown to assume various roles, including tumor suppression or oncogenic functions in common types of cancer such as lung and breast cancer. These non-coding RNAs (ncRNAs) play a pivotal role in activating transcription factors, managing the ribonucleoproteins, the framework for collecting co-proteins, intermittent processing regulations, chromatin status alterations, and maintaining the control within the cell. Cutting-edge technologies have been introduced to disclose several types of lncRNAs within the nucleus and the cytoplasm, which have accomplished important achievements that are applicable in medicine. Due to these efforts, various data centers have been created to facilitate and modify scientific information related to these molecules, including detection, classification, biological evolution, gene status, spatial structure, status, and location of these small molecules. In the present study, we attempt to present the impacts of these ncRNAs on lung cancer with an emphasis on their mechanisms and functions.

SNHG9 promotes Hepatoblastoma Tumorigenesis via miR-23a-5p/Wnt3a Axis

Background: Hepatoblastoma is a common hepatic tumor occurring in children between 0-5 years. Accumulating studies have shown lncRNA's potential role in distinct cancer progression and development, including hepatoblastoma. SnoRNA host gene 9 (SNHG9) is associated with the progression of distinct human cancers, but, its specific molecular mechanisms in hepatoblastoma is not unknown.

Methods: In this study, we estimated SNHG9 expression in hepatoblastoma tissue and cell lines by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Next, we downregulated and upregulated SNHG9 expression in hepatoblastoma cell lines and then determined cell proliferation (CCK-8), colony formation, and cellular apoptosis activity. The dual luciferase reporter activity, RNA immunoprecipitation (RIP), biotin RNA pull down and Spemann's Pearson correlation coefficient assay were performed to establish the interaction between SNHG9, WNt3a and miR- 23a-5p. A xenograft in-vivo tumorgenicity test was performed to elucidate the role of SNHG9 hepatoblastoma in tumorigenesis. SNHG9 role in Cisplatin drug resistance in hepatoblastoma was also determined.

Results: SNHG9 was significantly upregulated in hepatoblastoma tissue and cell lines. SNHG9 overexpression on HUH6 & HepG2 resulted in a significant increase in cell proliferation and clonogenic activity while SNHG9 knock down resulted in a sustained inhibition of cell proliferation and clonogenic activity. Dual luciferase activity, RNA immunoprecipitation and biotin pull down confirmed the direct interaction of miR-23a-5p with SNHG9. The xenograft tumorgenicity test showed SNHG9 downregulation significantly inhibited the tumor growth in BALB/c mice. ROC and Kaplan-Meier analysis showed potential prognostic and diagnostic importance of SNHG9 in hepatoblastoma.

Conclusion: We concluded that SNHG9/miR-23a-5p/Wnt3a axis promotes the progression hepatoblastoma tumor.

Long non-coding RNA LUCAT1 inhibits myocardial oxidative stress and apoptosis after myocardial infarction via targeting microRNA-181a-5p

This study hoped to explore the effects and mechanism of long non-coding RNA (lncRNA) LUCAT1 regulating microRNA-181a-5p (miR-181a-5p) on oxidative stress and apoptosis of cardiomyocytes induced by H₂O₂. Totally, 72 patients with acute myocardial infarction (AMI) were included. H9c2 cardiomyocytes were cultured in vitro, and the H₂O₂ model of cardiomyocytes was established. The expression levels of LUCAT1 and miR-181a-5p were detected by qRT-PCR after H₂O₂ induction. The contents of reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) in cells were detected. The survival rate of the cells was detected by the Cell Counting Kit-8 (CCK-8) method; the apoptosis was detected by flow cytometry. The luciferase reporter experiment and quantitative real-time PCR (qRT-PCR) were used to verify the targeted relationship between LUCAT1 and miR-181a-5p. LUCAT1 was lowly expressed in the AMI patients. After H₂O₂ induction, the expression of LUCAT1 in H9c2 cells lessened significantly, while the expression of miR-181a-5p elevated significantly (P < 0.001). Transfection of p-LUCAT1 significantly reversed the decreased SOD levels, the increased MDA and ROS content, and the elevated tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) in H₂O₂-stimulated cells (P < 0.001). Upregulation of LUCAT1 contributed to the mitigation of H₂O₂ injury by promoting viable cells and repressing apoptotic cells (P < 0.01). LUCAT1 targeted miR-181a-5p and negatively regulated miR-181a-5p expression (P < 0.001). Collectively, LUCAT1 played a protective role on oxidative stress injury, inflammation, viability, and apoptosis of cardiomyocytes induced by H₂O₂ via regulating miR-181a-5p.

lncRNAs as Potential Targets in Small Cell Lung Cancer: MYC -dependent Regulation

BACKGROUND

Small Cell Lung Cancer (SCLC) is a highly aggressive malignancy. MYC family oncogenes are amplified and overexpressed in 20% of SCLCs, showing that MYC oncogenes and MYC regulated genes are strong candidates as therapeutic targets for SCLC. c-MYC plays a fundamental role in cancer stem cell properties and malignant transformation. Several targets have been identified by the activation/repression of MYC. Deregulated expression levels of lncRNAs have also been observed in many cancers.

OBJECTIVE

The aim of the present study is to investigate the lncRNA profiles which depend on MYC expression levels in SCLC.

METHODS

Firstly, we constructed lentiviral vectors for MYC overexpression/inhibition. MYC expression is suppressed by lentiviral shRNA vector in MYC amplified H82 and N417 cells, and overexpressed by lentiviral inducible overexpression vector in MYC non-amplified H345 cells. LncRNA cDNA is transcribed from total RNA samples, and 91 lncRNAs are evaluated by qRT-PCR.

RESULTS

We observed that N417, H82 and H345 cells require MYC for their growth. Besides, MYC is not only found to regulate the expressions of genes related to invasion, stem cell properties, apoptosis and cell cycle (p21, Bcl2, cyclinD1, Sox2, Aldh1a1, and N-Cadherin), but also found to regulate lncRNAs. With this respect, expressions of AK23948, ANRIL, E2F4AS, GAS5, MEG3, H19, L1PA16, SFMBT2, ZEB2NAT, HOTAIR, Sox2OT, PVT1, and BC200 were observed to be in parallel with MYC expression, whereas expressions of Malat1, PTENP1, Neat1, UCA1, SNHG3, and SNHG6 were inversely correlated.

CONCLUSION

Targeting MYC-regulated genes as a therapeutic strategy can be important for SCLC therapy. This study indicated the importance of identifying MYC-regulated lncRNAs and that these can be utilized to develop a therapeutic strategy for SCLC.

ARID1B/SUB1-activated lncRNA HOXA-AS2 drives the malignant behaviour of hepatoblastoma through regulation of HOXA3

It has been becoming increasingly evident that long non‐coding RNAs (lncRNAs) play important roles in various human cancers. However, the biological processes and clinical significance of most lncRNAs in hepatoblastoma (HB) remain unclear. In our previous study, genome‐wide analysis with a lncRNA microarray found that lncRNA HOXA‐AS2 was up‐regulated in HB. Stable transfected cell lines with HOXA‐AS2 knockdown or overexpression were constructed in HepG2 and Huh6 cells, respectively. Our data revealed knockdown of HOXA‐AS2 increased cell apoptosis and inhibited cell proliferation, migration and invasion in HB. Up‐regulation of HOXA‐AS2 promoted HB malignant biological behaviours. Mechanistic investigations indicated that HOXA‐AS2 was modulated by chromatin remodelling factor ARID1B and transcription co‐activator SUB1, thereby protecting HOXA3 from degradation. Therefore, HOXA‐AS2 positively regulates HOXA3, which might partly demonstrate the involvement of HOXA3 in HOXA‐AS2‐mediated HB carcinogenesis. In conclusion, HOXA‐AS2 is significantly overexpressed in HB and the ARID1B/HOXA‐AS2/HOXA3 axis plays a critical role in HB tumorigenesis and development. These results might provide a potential new target for HB diagnosis and therapy.

MiR-133b inhibits colorectal cancer metastasis via lncRNA-LUCAT1

Aim: Colorectal cancer (CRC) is a common malignant tumor of the digestive system. Metastasis is the leading cause of poor prognosis of CRC patients, warranting further study of the molecular mechanism of metastasis in CRC and identification of new therapeutic targets. MiR-133b has been proven to play an important role in tumorigenesis by directly targeting coding genes. However, whether miR-133b can regulate tumorigenesis via long noncoding RNA (lncRNA) remains unclear. Methods: We systematically analyzed the expression level and correlation of miR-133b and LUCAT1 in cancer tissues and adjacent tissues from 30 patients with CRC. The effects of miR-133b and LUCAT1 on the invasive ability of CRC cells were detected by a transwell assay. The relationship between miR-133b and LUCAT1 was investigated by cells transfection experiments, rescue experiments and luciferase reporter assays. The binding of LUCAT1 and EZH2 was detected by RNA immunoprecipitation assay. Results: MiR-133b was expressed at low levels in CRC tissues, and LUCAT1 was highly expressed, with an inverse correlation between them. LUCAT1 promoted the migration and invasion of HCT116 and SW620 cells. Overexpression of LUCAT1 attenuated the inhibition of cell migration and invasion induced by miR-133b. However, the dual luciferase assay showed that miR-133b did not directly target LUCAT1. Conclusion: MiR-133b affects CRC metastasis via the LUCAT1/EZH2 complex. MiR-133b and LUCAT1 may be potential targets for antimetastasis therapy in CRC.

Role of lncRNA LUCAT1 in cancer

Long non-coding RNAs (lncRNAs) are RNA molecules with a transcript length of more than 200 nt and lack a protein-coding ability. They regulate gene expression by interacting with protein, RNA, and DNA. Their function is closely related to their subcellular localization. In the nucleus, lncRNAs regulate gene expression at the epigenetic and transcriptional levels, and in the cytoplasm, they regulate gene expression at the post-transcriptional and translational levels. Abnormalities in lncRNAs have been confirmed to exhibit tumor suppressor or carcinogenic effects and play an important role in the development of tumors. In particular, the lung cancer-related transcript 1 (LUCAT1) located in the antisense strand of the q14.3 region of chromosome 5 was first discovered in smoking-related lung cancer. Increasing evidence have showed that LUCAT1 is involved in breast cancer, ovarian cancer, thyroid cancer, renal cell carcinoma. It is highly expressed in liver cancer and other malignant tumors and has been confirmed to be induce various malignant tumors. It regulates tumor proliferation, invasion, and migration via various mechanisms and is related to the clinicopathological characteristics of tumor patients. Thus, LUCAT1 is a potential prognostic biological marker and therapeutic target for cancer. This article reviews its expression, function, and molecular mechanism in various malignant tumors.

Long Non-Coding RNA LUCAT1 Promotes Progression of Thyroid Carcinoma by Reinforcing ADAM10 Expression Through Sequestering microRNA-493

Background

Long non-coding RNA (lncRNA) LUCAT1 has recently been recognized as an oncogene in several malignancies. This study was launched to probe its role in thyroid carcinoma (TC) development and the implicated molecules.

Methods

LUCAT1 expression in TC cell lines and in normal thyroid follicular epithelial cell line Nthy-ori3-1 was determined by RT-qPCR. Binding relationships between LUCAT1 and microRNA (miR)-493, and between miR-493 and a disintegrin and metalloproteinase-10 (ADAM10) were predicted on a bioinformatics system and then validated through luciferase reporter gene assays. Expression of miR-493 and ADAM10 in TC cells was determined. Gain- and loss-of functions of LUCAT1, miR-493 and ADAM10 were performed to explore their influences on the behaviors of TC cells. Xenograft tumors were induced in nude mice for in vivo studies.

Results

LUCAT1 and ADAM10 were highly expressed, while miR-493 was poorly expressed in TC cell lines. LUCAT1 served as a miR-493 sponge to upregulate ADAM10 expression. Silencing of LUCAT1 discouraged proliferation, invasion, and migration but triggered apoptosis of TC cells. By contrast, these changes were abrogated by further miR-493 inhibition or ADAM10 upregulation. The in vitro experiment results were reproduced in vivo. In addition, miR-493 inhibition or ADAM10 overexpression was found to increase the phosphorylation of STAT3 in cells.

Conclusion

This study evidenced that LUCAT1 increases ADAM10 expression through sequestering miR-493, leading to JAK-STAT activation and TC cell growth and metastasis. LUCAT1 and ADAM10 may serve as therapeutic targets for TC treatment.

Long noncoding RNA LINC01559 promotes pancreatic cancer progression by acting as a competing endogenous RNA of miR-1343-3p to upregulate RAF1 expression

Background: An increasing number of studies have shown that lncRNAs are involved in the biological processes of pancreatic cancer (PC). Hence, we investigated the role of a novel noncoding RNA, LINC01559, involved in PC progression.

Results: LINC01559 and RAF1 were highly expressed in PC, while miR-1343-3p had low expression. High expression of LINC01559 was significantly associated with large tumors, lymph node metastasis, and poor prognosis. Functional experiment results revealed that silencing of LINC01559 significantly suppressed PC cell proliferation and metastasis. Meanwhile, LINC01559 could act as a ceRNA to competitively sponge miR-1343-3p to up-regulate RAF1 and activate its downstream ERK pathway

Conclusions: LINC01559 functions as an oncogene in PC progression through acting as a ceRNA of miR-1343-3p. Hence, LINC01559 is a potential diagnostic and therapeutic target.

Methods: RT-qPCR was performed to determine the expression of LINC01559 and miR-1343-3p in PC. Individual patient data were collected to investigate the correlation between clinicopathological features and LINC01559 expression. Subsequently, the expression of LINC01559, miR-1343-3p, and RAF1 was altered using transfection of vectors or inhibitors. Gain- and loss-of-function assays and mechanistic assays were applied to verify the effects of LINC01559, miR-1343-3p, and RAF1 on PC cell proliferation and metastasis in vivo and in vitro.

LncRNA LUCAT1 contributes to cell proliferation and migration in human pancreatic ductal adenocarcinoma via sponging miR-539

Pancreatic ductal adenocarcinoma is one of the most aggressive and dreadful malignancies worldwide. Long noncoding RNAs (lncRNAs) have emerged as vital regulators in the development of human malignancies and other disorders. This study aimed to characterize the role of lncRNA lung cancer-associated transcript 1 (lncRNA LUCAT1), a novel cancer-related lncRNA, in human PDAC. Here we initially analyzed the expression patterns of lncRNA LUCAT1 and evaluated its clinical significance. The qRT-PCR analysis and in situ hybridization staining showed that lncRNA LUCAT1 expression was significantly increased in tumorous tissues compared with adjacent normal tissues. Additionally, we found that increased lncRNA LUCAT1 expression was linked to larger tumor size and lymphatic invasion. Consistently, lncRNA LUCAT1 was remarkably up-regulated in PDAC cell lines. To better understand the biological role of lncRNA LUCAT1, we evaluated the effects of lncRNA LUCAT1 knockdown on PDAC cell proliferation, cell cycle progression, migration, and invasion using MTT assays, flow cytometry, Transwell migration, and invasion assays, respectively. Functional studies demonstrated that lncRNA LUCAT1 knockdown dramatically suppressed PDAC cell proliferation, induced cell cycle arrest and inhibited cell migration and invasion. Tumor xenograft in vivo assays displayed that lncRNA LUCAT1 inhibited tumorigenecity of PDAC cells. Mechanistic studies uncovered that lncRNA LUCAT1 acted as a molecular sponge of miR-539 and that miR-539 mediated the effects of lncRNA LUCAT1 on PDAC cell proliferation, cell cycle progression, and motility. Collectively, our findings may offer some novel insights into understanding lncRNA LUCAT1 in PDAC.