Long noncoding RNA LINC00961 inhibits cell proliferation and induces cell apoptosis in human non-small cell lung cancer

Micropeptide hSPAR regulates glutamine levels and suppresses mammary tumor growth via a TRIM21-P27KIP1-mTOR axis

mTOR plays a pivotal role in cancer growth control upon amino acid response. Recently, CDK inhibitor P27KIP1 has been reported as a noncanonical inhibitor of mTOR signaling in MEFs, via unclear mechanisms. Here, we find that P27KIP1 degradation via E3 ligase TRIM21 is inhibited by human micropeptide hSPAR through its C-terminus (hSPAR-C), causing P27KIP1's cytoplasmic accumulation in breast cancer cells. Furthermore, hSPAR/hSPAR-C also serves as an inhibitor of glutamine transporter SLC38A2 expression and thereby decreases the cellular glutamine levels specifically in cancer cells. The resultant glutamine deprivation sequentially triggers translocation of cytoplasmic P27KIP1 to lysosomes, where P27KIP1 disrupts the Ragulator complex and suppresses mTORC1 assembly. Administration of hSPAR or hSPAR-C significantly impedes breast cancer cell proliferation and tumor growth in xenograft models. These findings define hSPAR as an intrinsic control factor for cellular glutamine levels and as a novel tumor suppressor inhibiting mTORC1 assembly.

Shedding light on function of long non-coding RNAs (lncRNAs) in glioblastoma

The brain tumors and especially glioblastoma, are affecting life of many people worldwide and due to their high mortality and morbidity, their treatment is of importance and has gained attention in recent years. The abnormal expression of genes is commonly observed in GBM and long non-coding RNAs (lncRNAs) have demonstrated dysregulation in this tumor. LncRNAs have length more than 200 nucleotides and they have been located in cytoplasm and nucleus. The current review focuses on the role of lncRNAs in GBM. There two types of lncRNAs in GBM including tumor-promoting and tumor-suppressor lncRNAs and overexpression of oncogenic lncRNAs increases progression of GBM. LncRNAs can regulate proliferation, cell cycle arrest and metastasis of GBM cells. Wnt, STAT3 and EZH2 are among the molecular pathways affected by lncRNAs in GBM and for regulating metastasis of GBM cells, these RNA molecules mainly affect EMT mechanism. LncRNAs are involved in drug resistance and can induce resistance of GBM cells to temozolomide chemotherapy. Furthermore, lncRNAs stimulate radio-resistance in GBM cells. LncRNAs increase PD-1 expression to mediate immune evasion. LncRNAs can be considered as diagnostic and prognostic tools in GBM and researchers have developed signature from lncRNAs in GBM.

Modulation of long noncoding RNAs by polyphenols as a novel potential therapeutic approach in lung cancer: A comprehensive review

Lung cancer stands as a formidable global health challenge, necessitating innovative therapeutic strategies. Polyphenols, bioactive compounds synthesized by plants, have garnered attention for their diverse health benefits, particularly in combating various cancers, including lung cancer. The advent of whole-genome and transcriptome sequencing technologies has illuminated the pivotal roles of long noncoding RNAs (lncRNAs), operating at epigenetic, transcriptional, and posttranscriptional levels, in cancer progression. This review comprehensively explores the impact of polyphenols on both oncogenic and tumor-suppressive lncRNAs in lung cancer, elucidating on their intricate regulatory mechanisms. The comprehensive examination extends to the potential synergies when combining polyphenols with conventional treatments like chemotherapy, radiation, and immunotherapy. Recognizing the heterogeneity of lung cancer subtypes, the review emphasizes the need for the integration of nanotechnology for optimized polyphenol delivery and personalized therapeutic approaches. In conclusion, we collect the latest research, offering a holistic overview of the evolving landscape of polyphenol-mediated modulation of lncRNAs in lung cancer therapy. The integration of polyphenols and lncRNAs into multidimensional treatment strategies holds promise for enhancing therapeutic efficacy and navigating the challenges associated with lung cancer treatment.

Long non-coding RNAs in lung cancer: Unraveling the molecular modulators of MAPK signaling

Lung cancer (LC) continues to pose a significant global medical burden, necessitating a comprehensive understanding of its molecular foundations to establish effective treatment strategies. The mitogen-activated protein kinase (MAPK) signaling system has been scientifically associated with LC growth; however, the intricate regulatory mechanisms governing this system remain unknown. Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of diverse cellular activities, including cancer growth. LncRNAs have been implicated in LC, which can function as oncogenes or tumor suppressors, and their dysregulation has been linked to cancer cell death, metastasis, spread, and proliferation. Due to their involvement in critical pathophysiological processes, lncRNAs are gaining attention as potential candidates for anti-cancer treatments. This article aims to elucidate the regulatory role of lncRNAs in MAPK signaling in LC. We provide a comprehensive review of the key components of the MAPK pathway and their relevance in LC, focusing on aberrant signaling processes associated with disease progression. By examining recent research and experimental findings, this article examines the molecular mechanisms through which lncRNAs influence MAPK signaling in lung cancer, ultimately contributing to tumor development.

LncRNAs and PTEN/PI3K signaling: A symphony of regulation in cancer biology

The Emergence of Long Non-coding RNAs (lncRNAs) as Key Regulators in Diverse Biological Processes: A Paradigm Shift in Understanding Gene Expression and its Impact on Cancer. The PTEN/PI3K pathway, a pivotal signaling cascade involved in cancer progression, orchestrates critical cellular functions such as survival, proliferation, and growth. In light of these advances, our investigation delves into the intricate and multifaceted interplay between lncRNAs and the PTEN/PI3K signaling pathway, unearthing previously undisclosed mechanisms that underpin cancer growth and advancement. These elusive lncRNAs exert their influence through direct targeting of the PTEN/PI3K pathway or by skillfully regulating the expression and activity of specific lncRNAs. This comprehensive review underscores the paramount significance of the interaction between lncRNAs and the PTEN/PI3K signaling pathway in cancer biology, unveiling an auspicious avenue for novel diagnostic tools and targeted therapeutic interventions. In this review, we navigate through the functional roles of specific lncRNAs in modulating PTEN/PI3K expression and activity. Additionally, we scrutinize their consequential effects on downstream components of the PTEN/PI3K pathway, unraveling the intricacies of their mutual regulation. By advancing our understanding of this complex regulatory network, this study holds the potential to revolutionize the landscape of cancer research, paving the way for tailored and efficacious treatments to combat this devastating disease.

Dysregulated LINC00961 Contributes to the Vitality and Migration of NSCLC Via miR-19a-3p/miR-19b-3p/miR-125b-5p

Accumulating evidence implies that long noncoding RNAs participate in non-small cell lung cancer (NSCLC) tumorigenesis. Our current study synthetically analyzed RNA sequencing data downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We identified LINC00961 significantly downregulated in NSCLC tissues. We explored the LINC00961 expression in NSCLC tumor tissues and cell lines with reverse transcription-quantitative polymerase chain reaction analysis. Lentivirus-mediated infection upregulated the expression of LINC00961 in A549 cells. The proliferation and migration capability were also measured in A549 cells. In addition, we performed luciferase reporter gene assay to investigate whether LINC00961 directly interacts with miR-19a-3p/miR-19b-3p/miR-125b-5p. A nude mice model was used to detect the potential biological process of LINC00961 on tumor growth in vivo. The results showed that LINC00961 was significantly down-egulated in NSCLC tissues and cell lines. LV-LINC00961 effectively increased the expression of LINC00961 and decreased the expression of miR-19a-3p/miR-19b-3p/miR-125b-5p. LINC00961 upregulation remarkably inhibited cell proliferation, migration, and invasion while promoting cell apoptosis in A549 cells. Luciferase reporter gene assay revealed that LINC00961 could directly sponge miR-19a-3p/miR-19b-3p/miR-125b-5p. Moreover, overexpressed miR-19a-3p/miR-19b-3p/miR-125b-5p reversed the effect of LINC00961 on cell function of A549 cells. Western blot assays revealed that LINC00961 could partially act as a tumor suppressor via affecting PI3K-AKT/MAPK/mTOR signaling pathway. In addition, overexpressed LINC00961-inhibited tumor growth was demonstrated in vivo. Overexpression of LINC00961 inhibited cell viability, invasion, and induced apoptosis in NSCLC, potentially via suppressing the expression of miR-19a-3p/miR-19b-3p/miR-125b-5p by targeting PI3K-AKT/MAPK/mTOR signaling pathways, which might provide the potential biomarker for NSCLC diagnosis and therapies.

RSPH14 regulates the proliferation, cell cycle progression and apoptosis of non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the most common subtype of lung cancer and it is characterized by a high incidence. It is important to understand the molecular mechanisms that determine the progression and metastasis of NSCLC in order to develop more effective therapies and identify novel diagnostic indicators of NSCLC. RSPH14 has been reported to be related to multiple human diseases, including duodenal adenocarcinoma and meningiomas, but the role of RSPH14 in NSCLC remains unclear. The present study aimed to investigate the molecular function and clinical significance of RSPH14 in NSCLC. Analyses of public datasets and clinical samples demonstrated that RSPH14 expression was upregulated in NSCLC samples compared with normal samples. In addition, high RSPH14 expression was associated with a shorter overall survival time in patients with NSCLC. Notably, RSPH14 knockdown suppressed the proliferation and cell cycle progression, and enhanced the apoptosis of NSCLC cells. Mechanically, Tandem Mass Tag analysis demonstrated that RSPH14 can affect multiple processes, including the AMPK signaling pathway, calcium ion import regulation, glucose transmembrane transporter activity, and glucose transmembrane transport. Taken together, the results of the present study suggest that RSPH14 may be a promising prognostic factor and therapeutic target for NSCLC.

Aberrant hypermethylation induced downregulation of antisense lncRNA STXBP5-AS1 and its sense gene STXBP5 correlate with tumorigenesis of glioma

AIMS

The expression of antisense lncRNA STXBP5-AS1 and its sense gene STXBP5 were found to be downregulated in glioma by RNA sequencing; however, the function and mechanism of both two genes in the development of glioma have not been studied.

MATERIALS AND METHODS

QRT-PCR and western blot were used to determine the transcriptional and translational levels of moleculars. MSP and BSP assays were used to evaluate the methylation status of promoter CpG island. MTT, EdU, flow cytometry, and transwell assays were used to reveal biological effects. The in vivo mice model was used to validate the role of target genes in tumorigenesis.

KEY FINDINGS

The mRNA and protein expression of STXBP5 was significantly downregulated in glioma tissues and positively correlated with prognosis. STXBP5-AS1 was downregulated in glioma cells and tissues, and associated with tumor size and clinical stages. Both of two genes were significantly restored in cells treatment with 5-Aza. The promoter CpG island of STXBP5/STXBP5-AS1 was hypermethylated in glioma cells, but partially methylated in NHA cells. We found that promoter methylation frequency was significantly higher in glioma tissues. Functionally, overexpression of STXBP5 and STXBP5-AS1 inhibited cell proliferation, migration, and invasion and promoted apoptosis in vitro, whereas depletion of STXBP5 and STXBP5-AS1 showed opposite effects. Both the mRNA and protein expression of STXBP5 were positively regulated by STXBP5-AS1. Ectopic expression of STXBP5 and STXBP5-AS1 suppressed tumor formation in vivo.

SIGNIFICANCE

Our findings suggested that epigenetically silenced STXBP5-AS1 and STXBP5 might act as novel tumor suppressors of glioma.

The Impact of lncRNAs and miRNAs on Apoptosis in Lung Cancer

Apoptosis is a coordinated cellular process that occurs in several physiological situations. Dysregulation of apoptosis has been documented in numerous pathological situations, particularly cancer. Non-coding RNAs regulate apoptosis via different mechanisms. Lung cancer is among neoplastic conditions in which the role of non-coding RNAs in the regulation of apoptosis has been investigated. Non-coding RNAs that regulate apoptosis in lung cancer have functional interactions with PI3K/Akt, PTEN, GSK-3β, NF-κB, Bcl-2, Bax, p53, mTOR and other important cancer-related pathways. Globally, over-expression of apoptosis-blocking non-coding RNAs has been associated with poor prognosis of patients, while apoptosis-promoting ones have the opposite effect. In the current paper, we describe the impact of lncRNAs and miRNAs on cell apoptosis in lung cancer.

Non-coding RNAs and lipids mediate the function of extracellular vesicles in cancer cross-talk

Research on extracellular vesicles (EVs) has been expanded, especially in the field of cancer. The cargoes in EVs, especially those in small EVs such as exosomes include microRNAs (miRNAs), mRNA, proteins, and lipids, are assumed to work cooperatively in the tumor microenvironment. In 2007, it was reported that miRNAs were abundant among the non-coding RNAs present in exosomes. Since then, many studies have investigated the functions of miRNAs and have tried to apply these molecules to aid in the diagnosis of cancer. Accordingly, many reviews of non-coding RNAs in EVs have been published for miRNAs. This review focuses on relatively new cargoes, covering long noncoding (lnc) RNAs, circular RNAs, and repeat RNAs, among non-coding RNAs. These RNAs, regardless of EV or cell type, have newly emerged due to the innovation of sequencing technology. The poor conservation, low quantity, and technical difficulty in detecting these RNA types have made it difficult to elucidate their functions and expression patterns. We herein summarize a limited number of studies. Although lipids are major components of EVs, current research on EVs focuses on miRNA and protein biology, while the roles of lipids in exosomes have not drawn attention. However, several recent studies revealed that phospholipids, which are components of the EV membrane, play important roles in the intercommunication between cells and in the generation of lipid mediators. Here, we review the reported roles of these molecules, and describe their potential in cancer biology.

Identification of a prognostic long noncoding RNA signature in lung squamous cell carcinoma: a population-based study with a mean follow-up of 3.5 years

Background

Lung squamous cell carcinoma (LSCC) is a form of cancer that is associated with high rates of relapse, poor responsiveness to therapy, and a relatively poor prognosis. The relationship between long non-coding RNA (lncRNA) expression and LSCC patient prognosis remains to be established.

Methods

In the present study, we discovered that lncRNAs were differentially expressed in LSCC tumor tissues relative to normal control tissues, and we explored the prognostic relevance of these lncRNA expression patterns using data from the Cancer Genome Atlas (TCGA).

Results

These multidimensional data were analyzed in order to identify lncRNA signatures that were associated with LSCC patient survival outcomes. Kaplan-Meier survival curves revealed prognostic capabilities for three of these lncRNAs (LINC02555, APCDD1L-DT and OTX2-AS1). A Cox regression analysis revealed this three-lncRNA signature to be significantly associated with patient survival. Further GO and KEGG analyses revealed that the predicted target genes of these three lncRNAs were also potentially involved in cancer-associated pathways.

Conclusions

Together these results thus indicate that this novel three-lncRNA signature can be used to predict LSCC patient prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-021-00588-2.

Genome-wide DNA methylation and RNA expression differences correlate with invasiveness in melanoma cell lines

Aims & objectives: The aim of this study was to investigate the role of DNA methylation in invasiveness in melanoma cells. Materials & methods: The authors carried out genome-wide transcriptome (RNA sequencing) and reduced representation bisulfite sequencing methylome profiling between noninvasive (n = 4) and invasive melanoma cell lines (n = 5). Results: The integration of differentially expressed genes and differentially methylated fragments (DMFs) identified 12 DMFs (two in AVPI1, one in HMG20B, two in BCL3, one in NTSR1, one in SYNJ2, one in ROBO2 and four in HORMAD2) that overlapped with either differentially expressed genes (eight DMFs and six genes) or cis-targets of lncRNAs (five DMFs associated with cis-targets and four differentially expressed lncRNAs). Conclusions: DNA methylation changes are associated with a number of transcriptional differences observed in noninvasive and invasive phenotypes in melanoma.

Emerging role of tumor-related functional peptides encoded by lncRNA and circRNA

Non-coding RNAs do not encode proteins and regulate various oncological processes. They are also important potential cancer diagnostic and prognostic biomarkers. Bioinformatics and translation omics have begun to elucidate the roles and modes of action of the functional peptides encoded by ncRNA. Here, recent advances in long non-coding RNA (lncRNA) and circular RNA (circRNA)-encoded small peptides are compiled and synthesized. We introduce both the computational and analytical methods used to forecast prospective ncRNAs encoding oncologically functional oligopeptides. We also present numerous specific lncRNA and circRNA-encoded proteins and their cancer-promoting or cancer-inhibiting molecular mechanisms. This information may expedite the discovery, development, and optimization of novel and efficacious cancer diagnostic, therapeutic, and prognostic protein-based tools derived from non-coding RNAs. The role of ncRNA-encoding functional peptides has promising application perspectives and potential challenges in cancer research. The aim of this review is to provide a theoretical basis and relevant references, which may promote the discovery of more functional peptides encoded by ncRNAs, and further develop novel anticancer therapeutic targets, as well as diagnostic and prognostic cancer markers.

LncRNA PCAT-1 upregulates RAP1A through modulating miR-324-5p and promotes survival in lung cancer

INTRODUCTION

Lung cancer is the malignant tumor with the fastest increase in morbidity and mortality and the greatest threat to human health and life. Long non-coding RNA (lncRNA) is emerging as an important regulator in many cancers. Recently, it was found that lncRNA prostate cancer associated transcript 1 (PCAT-1) was up-regulated in lung cancer, playing oncogenic roles. However, the underlying regulatory mechanism of PCAT-1 remains unknown.

MATERIAL AND METHODS

The expression levels of PCAT-1 and miR-324-5p were analyzed by real-time PCR, and RAP1A expression was determined by western blotting. RNA pull-down, luciferase and western blotting assays were used to examine the target relationship between PCAT-1 and miR-324-5p or that between miR-324-5p and RAP1A. The functional effects of PCAT-1 and miR-324-5p were examined using cell viability and cell apoptosis assays.

RESULTS

PCAT-1 overexpression remarkably promoted cell proliferation and suppressed cell apoptosis. Mechanistic investigations demonstrated that PCAT-1 can interact with miR-324-5p and repress its expression, thereby increasing the expression of its target RAP1A. Additionally, rescue experiments revealed that PCAT-1 served as an oncogene partly through sponging miR-324-5p and upregulating RAP1A in lung cancer cells.

CONCLUSIONS

Our findings demonstrate that on account of the dual function of pro-proliferation and anti-apoptosis, PCAT-1/miR-324-5p/RAP1A may be novel candidates for application in the diagnosis, prognosis and therapy of lung cancer.

Long non-coding RNA in lung cancer

Lung cancer is the leading cause of cancer-related death worldwide. Owing to the difficulty in early diagnosis and the lack of effective treatment strategies, the 5-year survival rates for lung cancer remain very low. With the development of whole genome and transcriptome sequencing technology, long non-coding RNA (lncRNA) has attracted increasing attention. LncRNAs regulate gene expression at the epigenetic, transcriptional and post-transcriptional levels and are widely involved in a variety of diseases, including tumorigenesis. In lung cancer studies, multiple differentially expressed lncRNAs have been identified; several lncRNAs were identified as oncogenic lncRNAs with tumor-driving effects, while other lncRNAs play a role in tumor inhibition and are called tumor-suppressive lncRNAs. These tumor-suppressive lncRNAs are involved in multiple physiological processes such as cell proliferation, apoptosis, and metastasis and thus participate in tumor progression. In this review, we discussed the oncogenic and tumor-suppressive lncRNAs in lung cancer, as well as their biological functions and regulatory mechanisms. Furthermore, we found the potential significance of lncRNAs in clinical diagnosis and treatment.

Linc00961 inhibits the proliferation and invasion of skin melanoma by targeting the miR‑367/PTEN axis

Long intergenic noncoding RNA 00961 (Linc00961) has been identified as a tumor suppressor in various types of cancer. However, the critical roles of Linc00961 in the carcinogenesis and progression of skin melanoma (SM) are yet to be fully elucidated. The present study revealed via reverse transcription‑quantitative PCR analysis that Linc00961 was downregulated in the tissues of patients with SM compared with benign nevi, and in A375, A2058 and SK‑MEL‑28 cell lines compared with human melanocytes. Furthermore, overexpression of Linc00961 inhibited cell proliferation, and promoted the apoptosis of A375 and SK‑MEL‑28 cells in vitro and in vivo, as determined by Cell Counting Kit‑8 and flow cytometry assays, and tumor xenograft studies, respectively. Overexpression of Linc00961 also led to an attenuation of the migration and invasive capabilities of A375 and SK‑MEL‑28 cells, measured using Transwell assays. Functionally, it was demonstrated that Linc00961 acted as a competing endogenous RNA (ceRNA) by competitively sponging microRNA‑367 (miR‑367) in A375 and SK‑MEL‑28 cells; restoration of miR‑367 rescued the inhibitory effects of Linc00961 on A375 and SK‑MEL‑28 cells. Finally, it was observed that phosphate and tension homology deleted on chromosome 10 (PTEN), an established target of miR‑367 in A375 and SK‑MEL‑28 cells, was positively regulated by Linc00961, and its inhibition reversed the inhibitory effects of Linc00961 on the proliferation and invasion of A375 and SK‑MEL‑28 cells. Collectively, the present study revealed that Linc00961 was downregulated in SM, and furthermore, Linc00961 was identified as a ceRNA that inhibits the proliferation and invasion of A375 and SK‑MEL‑28 cells by modulating the miR‑367/PTEN axis.

LncRNA STXBP5-AS1 suppressed cervical cancer progression via targeting miR-96-5p/PTEN axis

Long non-coding RNAs (lncRNAs) play important roles in tumor initiation and progression, including cervical cancer (CC). However, the effects and underlying mechanisms of STXBP5-AS1 in CC are still unknown. The expression of STXBP5-AS1, miR-96-5p, and PTEN in CC was explored by qRT-PCR. CCK-8 and transwell assays were used to determine the roles of STXBP5-AS1 on CC progression. Luciferase report assay and RIP assay were used to explore the correction between STXBP5-AS1, miR-96-5p and PTEN in CC. In our study, we showed that the expression of STXBP5-AS1 and PTEN was reduced while miR-96-5p expression was upregulated in CC. STXBP5-AS1 overexpression significantly reduced CC cells proliferation and invasion ability by suppressing miR-96-5p expression. MiR-96-5p promoted CC cells progression via regulating PTEN expression. Furthermore, STXBP5-AS1 was identified as a ceRNA to upregulate PTEN via sponging miR-96-5p in CC. Taken together, our findings revealed that STXBP5-AS1 might function as a ceRNA to drive CC cells proliferation and invasion via regulating miR-96-5p/PTEN axis.

Comprehensive analysis of differentially expressed long non-coding RNAs in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the primary subtype of lung cancer. Long non-coding RNAs (lncRNAs) have been reported to serve prominent roles in cancer progression. However, the expression patterns and potential roles of lncRNAs in NSCLC remain to be elucidated. In the present study, four public datasets were analyzed to identify differentially expressed lncRNAs (DElncs) in NSCLC. A further dataset, GSE19188, was analyzed to validate the findings. A total of 38 upregulated and 31 downregulated lncRNAs were identified in NSCLC, compared with samples from healthy controls. Among these, 12 lncRNAs were associated with the progression of NSCLC, and dysregulated between high grade (stage III and IV) and low grade (stage II) NSCLC samples. Moreover, dysregulation of lncRNA-SIGLEC17P, GGTA1P, A2M-AS1, LINC00938, GVINP1, LINC00667 and TMPO-AS1 was associated with overall survival time in patients with NSCLC. Co-expression analyses, combined with the construction of protein-protein interaction networks, were performed to reveal the potential roles of key lncRNAs in NSCLC. The present study revealed a series of lncRNAs involved in the progression of NSCLS, which may serve as novel biomarkers for the disease.

Long noncoding RNA STXBP5-AS1 inhibits cell proliferation, migration, and invasion via preventing the PI3K/AKT against STXBP5 expression in non-small-cell lung carcinoma

Long noncoding RNAs participate in carcinogenesis and tumor progression in non-small-cell lung carcinoma (NSCLC), but the mechanisms underlying NSCLC tumorigenesis remain to be fully elucidated. Here, we reported the functional role and potential mechanism of long noncoding RNA syntaxin-binding protein 5-antisense RNA 1 (STXBP5-AS1) in NSCLC. First, our data revealed that the expression levels of STXBP5-AS1 in 31 NSCLC tissues were lower than in adjacent tissues using quantitative polymerase chain reaction (qPCR) and its expression was significantly associated with tumor metastasis of NSCLC patients. Moreover, CCK-8, scratch wound healing and transwell assay suggested that upregulation of STXBP5-AS1 repressed the proliferation, migration, and invasion in A549, NCI-H292, and NCI-H460 cells. To explore the potential mechanism of STXBP5-AS1 in NSCLC, we first investigated the relationship among STXBP5-AS1, STXBP5, and AKT1 in A549 cells. Results indicated that STXBP5-AS1 was negatively related with STXBP5 and AKT1 at messenger RNA expression level using qPCR. In addition, we observed that STXBP5-AS1 had reverse effects on the protein levels of STXBP5 and phosphorylated AKT1 (p-AKT1) in A549 cells via Western blot assay, despite no significant effects on AKT1. Subsequently, LY294002, as the phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) pathway inhibitor, was used to further confirm the regulatory mechanism of STXBP5-AS1, which showed that knockdown of STXBP5-AS1 could rescue the expression of STXBP5 and p-AKT1 protein expression levels in A549 cells. Taken together, our results suggested that STXBP5-AS1, as a tumor suppressor, inhibits cell proliferation, migration, and invasion by preventing the PI3K/AKT against STXBP5 expression in NSCLC.

STAT1-avtiviated LINC00961 regulates myocardial infarction by the PI3K/AKT/GSK3β signaling pathway

Myocardial infarction (MI) remains a severe cardiac disease because of its high incidence and mortality worldwide. A growing body of recent investigations have confirmed that LINC00961 acts as a tumor suppressor in diverse malignancies. However, the biological significance of LINC00961 and its molecular mechanism in MI are still elusive. Hypoxia is the leading cause of MI and induces myocardial injury. In this study, we found the upregulated expression of LINC00961 in cardiomyocytes H9c2 after hypoxia treatment. Knockdown of LINC00961 ameliorated hypoxia-induced cell injury by facilitating cell viability while repressing cell apoptosis. The significant increase of signal transducer and activator of transcription 1 (STAT1) expression and phosphorylation levels was observed in hypoxia-induced cells and proved to exacerbate hypoxia injury. In addition, STAT1 transcriptionally activated LINC00961 by binding to LINC00961 promoter. Furthermore, our results validated that suppressing LINC00961 contributed to the remarkable diminution in the phosphorylation levels of phosphoinositide 3-kinases (PI3K), AKT, and glycogen synthase kinase-3β (GSK3β). Inhibition of PI3K/AKT signaling or GSK3β pathway rescued the effects of LINC00961 knockdown on the hypoxia-induced injury of cardiomyocytes. Namely, we concluded that STAT1-avtiviated LINC00961 accelerated MI via the PI3K/AKT/GSK3β pathway, which may provide clues for the treatment of patients with MI.

Small regulatory polypeptide of amino acid response negatively relates to poor prognosis and controls hepatocellular carcinoma progression via regulating microRNA-5581-3p/human cardiolipin synthase 1

Hepatocellular carcinoma (HCC) is one of the most common malignancies with extremely high rates of occurrence and death. Long noncoding RNAs (lncRNAs) have been increasingly revealed to participate in tumorigenesis and development of multiple human cancers, including HCC. LINC00961 is a novel lncRNA which has been uncovered as a tumor suppressor in lung cancer and glioma. However, the role of LINC00961 in HCC has never been probed yet. Herein, we revealed a marked downregulation of LINC00961 in HCC tissues and cell lines. Correlation of low LINC00961 expression with poor outcomes in patients with HCC suggested LINC00961 as an independent predictor for HCC prognosis. Functionally, LINC00961 overexpression obviously inhibited cell proliferation, migration, and invasion in HCC cells. Mechanistically, LINC00961 regulated cardiolipin synthase 1 (CRLS1) expression via sponging miR-5581-3p. Importantly, both miR-5581-3p upregulation and CRLS1 inhibition led to an acceleration in cellular processes in HCC cells. At length, the rescue assays suggested that LINC00961 functioned in HCC through the miR-5581-3p/CRLS1 axis. On the whole, our findings disclosed that LINC00961 played a suppressive role in HCC progression via modulating miR-5581-3p/CRLS1, thus providing a potentially effective target for the prognosis and treatment of patients with HCC.