Lnc-SNHG1 may promote the progression of non-small cell lung cancer by acting as a sponge of miR-497

Constructing lncRNA-miRNA-mRNA networks specific to individual cancer patients and finding prognostic biomarkers

BACKGROUND

The competitive endogenous RNA (ceRNA) hypothesis suggests that microRNAs (miRNAs) mediate a regulatory relation between long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) which share similar miRNA response elements (MREs) to bind to the same miRNA. Since the ceRNA hypothesis was proposed, several studies have been conducted to construct a network of lncRNAs, miRNAs and mRNAs in cancer. However, most cancer-related ceRNA networks are intended for representing a general relation of RNAs in cancer rather than for a patient-specific relation. Due to the heterogeneous nature of cancer, lncRNA-miRNA-mRNA interactions can vary in different patients.

RESULTS

We have developed a new method for constructing a ceRNA network of lncRNAs, miRNAs and mRNAs, which is specific to an individual cancer patient and for finding prognostic biomarkers consisting of lncRNA-miRNA-mRNA triplets. We tested our method on extensive data sets of three types of cancer (breast cancer, liver cancer, and lung cancer) and obtained potential prognostic lncRNA-miRNA-mRNA triplets for each type of cancer.

CONCLUSIONS

Analysis of expression patterns of the RNAs involved in the triplets and survival rates of cancer patients revealed several interesting findings. First, even for the same cancer type, prognostic lncRNA-miRNA-mRNA triplets can be different depending on whether lncRNA and mRNA show opposite or similar expression patterns. Second, prognostic lncRNA-miRNA-mRNA triplets are often more predictive of survival rates than RNA pairs or individual RNAs. Our approach will be useful for constructing patient-specific lncRNA-miRNA-mRNA networks and for finding prognostic biomarkers from the networks.

The crucial roles of long noncoding RNA SNHGs in lung cancer

Lung cancer is one of the most common malignant tumors with growing morbidity and mortality worldwide. Several treatments are used to manage lung cancer, including surgery, radiotherapy and chemotherapy, as well as molecular-targeted therapy. However, the current measures are still far from satisfactory. Therefore, the current research should focus on exploring the molecular mechanism and then finding an effective treatment. Interestingly, we and others have embarked on a line of investigations focused on the mechanism of lung cancer. Specifically, lncRNA small nucleolar RNA host gene has been shown to be associated with biological characteristics and therapeutic resistance of lung cancer. In addition, small nucleolar RNA host genes may be used as diagnostic biomarker in the future. Herein, we will provide a brief review demonstrating the importance of small nucleolar RNA host genes in lung cancer, especially non-small cell lung cancer. Although lncRNA has shown a crucial role in tumor-related research, a large number of studies are needed to validate its clinical application in the future.

Different roles of the insulin-like growth factor (IGF) axis in non-small cell lung cancer

Abstract:

Non-small cell lung cancer (NSCLC) remains one of the deadliest malignant diseases, with high incidence and mortality worldwide. The insulin-like growth factor (IGF) axis, consisting of IGF-1, IGF-2, related receptors (IGF-1R, -2R), and high-affinity binding proteins (IGFBP 1–6), is associated with promoting fetal development, tissue growth, and metabolism. Emerging studies have also identified the role of the IGF axis in NSCLC, including cancer growth, invasion, and metastasis. Upregulation of IGE-1 and IGF-2, overexpression of IGF-1R, and dysregulation of downstream signaling molecules involved in the PI-3K/Akt and MAPK pathways jointly increase the risk of cancer growth and migration in NSCLC. At the genetic level, some noncoding RNAs could influence the proliferation and differentiation of tumor cells through the IGF signaling pathway. The resistance to some promising drugs might be partially attributed to the IGF axis. Therapeutic strategies targeting the IGF axis have been evaluated, and some have shown promising efficacy. In this review, we summarize the biological roles of the IGF axis in NSCLC, including the expression and prognostic significance of the related components, noncoding RNA regulation, involvement in drug resistance, and therapeutic application. This review offers comprehensive understanding of NSCLC and provides insightful ideas for future research.

Long Noncoding RNAs PTPRG Antisense RNA 1 Targets Cyclin D1 to Facilitate Cell Proliferation in Lung Adenocarcinoma

Background: Numerous studies have recorded the function of long noncoding RNAs (lncRNAs) in cancer development, including lung adenocarcinoma (LUAD). Previous studies have reported the crucial role of lncRNA PTPRG antisense RNA 1 (PTPRG-AS1) in various cancers. However, the role of PTPRG-AS1 in LUAD remains unknown. Materials and Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) was applied for detecting PTPRG-AS1 expression in LUAD cell lines. Functional assays and in vivo experiments explored cell proliferation, whereas flow cytometry analysis was used to detect cell cycle. In addition, fluorescent in situ hybridization (FISH) and subcellular fractionation assay measured the localization of PTPRG-AS1 in LUAD cells. RNA pulldown, luciferase reporter, and RNA immunoprecipitation (RIP) assays were used to investigate the interaction of PTPRG-AS1/miR-124-3p/cyclin D1 (CCND1) axis. Results: PTPRG-AS1 expression was notably high in LUAD cell lines. PTPRG-AS1 knockdown suppressed cell proliferation and cycle as well as the level of CCND1. Moreover, miR-124-3p was the mutual target of PTPRG-AS1 and CCND1. In addition, PTPRG-AS1 sponged miR-124-3p to upregulate CCND1 in LUAD cells. Moreover, miR-124-3p depletion reversed the suppression of PTPRG-AS1 silence on LUAD cell behaviors, but then CCND1 knockdown countervailed the promoting influence of downregulated miR-124-3p. Conclusions: PTPRG-AS1 propels cell proliferation and cell cycle of LUAD by targeting miR-124-3p/CCND1 axis.

LncRNA-SNHG1 promotes macrophage M2-like polarization and contributes to breast cancer growth and metastasis

Breast cancer is one of the most common malignant cancers among women. Cancer cells and adjacent cells determine the development of the disease. Tumor associated macrophages (TAMs) are involved in the regulation of different stages of cancer progression. LncRNAs play an important role in tumor growth and metastasis. However, the function of lncRNA in macrophage and tumor cell interaction is poorly described. Here we reported that lncRNA SNHG1 functioned as a modulator of M2 macrophage polarization and regulated tumor growth and angiogenesis. We indicated that knockdown of SNHG1 inhibited M2 macrophage polarization by suppression of STAT6 phosphorylation. SNHG1 silencing significantly alleviated migration of MCF-7 cells and tube formation of Human Umbilical Vein Endothelial Cells (HUVEC). Furthermore, we found that implantation of cell mixture of MCF-7 cells and macrophages promoted tumor growth and angiogenesis. However, knockdown of SNHG1 in macrophages reversed that effect. Collectively, we demonstrated the important role of lncRNA SNHG1 in macrophages and breast cancer cells interaction. We highlight the essential effect of lncRNA in tumor progression and provide a new method for the prevention and treatment of breast tumor metastasis.

miR-497 defect contributes to gastric cancer tumorigenesis and progression via regulating CDC42/ITGB1/FAK/PXN/AKT signaling

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. MicroRNAs (miRNAs) are known to be important regulators of GC. This study aims to investigate the role of miRNA (miR)-497 in GC. We demonstrated that the expression of miR-497 was downregulated in human GC tissues. After N-methyl-N-nitrosourea treatment, the incidence of GC in miR-497 knockout mice was significantly higher than that in wild-type mice. miR-497 overexpression suppressed GC cell proliferation, cell-cycle progression, colony formation, anti-apoptosis ability, and cell migration and invasion capacity. Additionally, miR-497 overexpression decreased the expression levels of cell division cycle 42 (CDC42) and integrin β1 (ITGB1) and inhibited the phosphorylation of focal adhesion kinase (FAK), paxillin (PXN), and serine-threonine protein kinase (AKT). Furthermore, overexpression of miR-497 inhibited the metastasis of GC cells in vivo, which could be counteracted by CDC42 restoration. Furthermore, the focal adhesion of GC cells was found to be regulated by miR-497/CDC42 axis via ITGB1/FAK/PXN/AKT signaling. Collectively, it is concluded that miR-497 plays an important role in the repression of GC tumorigenesis and progression, partly via the CDC42/ITGB1/FAK/PXN/AKT pathway.

GATA6-AS1 inhibits ovarian cancer cell proliferation and migratory and invasive abilities by sponging miR-19a-5p and upregulating TET2

GATA6 antisense RNA 1 (GATA6-AS1) has been reported to be involved in the progression of several types of cancer. In the present study, the role of GATA6-AS1 in ovarian cancer (OC) was explored. Reverse transcription quantitative PCR was used to detect the expression of GATA6-AS1, microRNA (miR)-19a-5p and tet methylcytosine dioxygenase 2 (TET2) in OC and adjacent normal tissues. Furthermore, OC cells with GATA-AS1 either knocked down or overexpressed were established. The Cell Counting Kit-8 assay was used to evaluate cell proliferation and a Transwell assay was used to assess the migratory and invasive abilities of OC cells. A dual luciferase reporter gene assay was used to determine whether GATA6-AS1 and miR-19a-5p, and miR-19a-5p and TET2, may interact with each other. The results demonstrated that GATA6-AS1 expression level was decreased in OC tissues and cells compared with control groups. In addition, GATA6-AS1 overexpression significantly inhibited the proliferation and migratory and invasive abilities of OC cells, whereas GATA6-AS1 downregulation had the opposite effects. Furthermore, GATA6-AS1 adsorbed miR-19a-5p to repress its expression and GTA6-AS1 indirectly upregulated TET2 expression. Taken together, the findings from this study suggested that GATA6-AS1 could inhibit the proliferation and migratory and invasive abilities of OC cells via regulation of the miR-19a-5p/TET2 axis.

SMILR Aggravates the Progression of Atherosclerosis by Sponging miR-10b-3p to Regulate KLF5 Expression

Over the past few decades, long noncoding RNAs (lncRNAs) have been widely accepted to be involved in various diseases, and smooth muscle enriched long noncoding RNA (SMILR) was reported to participate in the proliferation of vascular smooth muscle cells (VSMCs). Nevertheless, the molecular mechanisms of SMILR in atherosclerosis (AS) have not been fully explored. In this study, VSMCs and human mononuclear cells (U937) treated with oxidized low-density lipoprotein (ox-LDL) were used as cell models of AS. We found that the expression of SMILR was upregulated in the serum of AS patients and ox-LDL-induced AS cell models. SMILR knockdown inhibited cell proliferation while increasing cell apoptosis in the AS cell models. In addition, SMILR acted as a sponge for miR-10b-3p, and miR-10b-3p counteracted SMILR-mediated regulation of AS. Moreover, we confirmed that miR-10b-3p could bind with KLF5, and SMILR regulated KLF5 expression by competitively binding miR-10b-3p. Furthermore, miR-10b-3p modulated cell proliferation and apoptosis in AS by targeting KLF5. Finally, miR-10b-3p regulated AS progression in vivo by targeting KLF5. Overall, our study demonstrated that SMILR participated in the progression of AS by targeting the miR-10b-3p/KLF5 axis, which may provide some clues for future studies of AS.

NCK1-AS1 promotes the progression of melanoma by accelerating cell proliferation and migration via targeting miR-526b-5p/ADAM15 axis

Background

Long non-coding RNAs (lncRNAs) are vital regulators of gene expression and cellular processes in multiple cancers, including melanoma. Nevertheless, the function of lncRNA NCK1-antisense 1 (NCK1-AS1) in melanoma remains unknown.

Methods

RT-qPCR was used to analyze the expression of NCK1-AS1, microRNA-526b-5p (miR-526b-5p) and ADAM metallopeptidase domain 15 (ADAM15). Cell proliferation was determined by CCK-8, colony formation and EdU assays. Cell migration was assessed by transwell migration and wound healing assays. Mechanism experiments including luciferase reporter, RIP and RNA pull down assays were conducted to demonstrate the interactions between RNAs. Xenograft model was established to verify the function of NCK1-AS1 and miR-526b-5p in melanoma in vivo.

Results

NCK1-AS1 was overexpressed in melanoma cell lines and NCK1-AS1 knockdown hampers the proliferation and migration of melanoma cells. Besides, miR-526b-5p binds to NCK1-AS1 in melanoma and ADAM15 was validated as its downstream target. Further, the inhibitory effects of NCK1-AS1 knockdown on cell proliferation and migration in melanoma were reversed by the depletion of miR-526b-5p and further counteracted by ADAM15 knockdown. The growth of melanoma tumors was hindered by the down-regulation of NCK1-AS1 or up-regulation of miR-526b-5p.

Conclusion

NCK1-AS1 facilitates cell proliferation and migration in melanoma via targeting miR-526b-5p/ADAM15 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02055-y.

Long Non-Coding RNA Small Nucleolar RNA Host Gene 1 and MicroRNA-100-3p Expression in Endometrial Carcinoma and Its Effect on the Proliferation and Apoptosis of Ishikawa Cells

The aim of this study was to explore LncRNA SNHG1 and miRNA-100-3p expression in endometrial carcinoma and its effect on the proliferation and apoptosis of Ishikawa cells. A qRT-PCR assay was conducted to determine SNHG1 and miRNA-100-3p expression in endometrial cancer tissues and paracancerous tissues. Human endometrial cancer Ishikawa cells were cultured in vitro. Si-NC, si-SNHG1, si-SNHG1, anti-miRNA-NC, and si-SNHG1 were transfected into Ishikawa cells with anti-miRNA-519b-3p. A qRT-PCR assay was performed to determine SNHG1 and miRNA-100-3p expression, and the CCK-8 method was used to determine cell proliferation. Flow cytometry was conducted to determine cell cycle and apoptosis rate and a dualluciferase reporter experiment was carried out to test the targeting association between SNHG1 and miRNA-100-3p. Cleave Caspase-3, CHOP, and ATF4 expression were determined with the Western Blot method. SNHG1 expression level and miRNA-519b-3p expression level were much higher and much lower, respectively, in endometrial cancer tissues than in paracancerous tissues (P < 0.05). Transfection of si-SNHG1 can greatly attenuate cell viability and S cell ratio (P < 0.05), and increase G0/G1 cell ratio, apoptosis rate, Cleaved Caspase-3, CHOP, and ATF4 protein level (P < 0.05) compared to the si-NC group. Furthermore, the double luciferase reporter experiment confirmed that SNHG1 can competitively combine withmiRNA-100-3p. Also, co-transfection of si-SNHG1 and anti-miRNA-100-3p could significantly increase cell viability and S cell ratio (P < 0.05), and decrease G0/G1 cell ratio and apoptosis rate, and Cleaved Caspase-3, CHOP, and ATF4 protein levels compared to si-SNHG1+anti-miRNA-NC (P < 0.05). Interfering with SNHG1 could inhibit the proliferation of Ishikawa cells and promote apoptosis by upregulating miRNA-100-3p expression.

LINC01783 facilitates cell proliferation, migration and invasion in non-small cell lung cancer by targeting miR-432-5p to activate the notch pathway

Background

Non-small cell lung cancer (NSCLC) is a common malignancy around the globe. Increasing long non-coding RNAs (lncRNAs) have been confirmed to be associated with the progression of cancers, including NSCLC. Long intergenic non-protein coding RNA 1783 (LINC01783) is a novel lncRNA and its regulatory function as competing endogenous RNA (ceRNA) has not been studied in NSCLC.

Methods

RT-qPCR measured the expression level of LINC01783 in NSCLC cells. CCK-8, EdU, transwell and wound healing assays were conducted to detect cell proliferation, migration and invasion in NSCLC. The relationship between miR-432-5p and LINC01783 along with delta like 1 (DLL-1) was illustrated by RNA pull down, RIP and luciferase reporter assays.

Results

LINC01783 was found remarkably increased in NSCLC cell lines, and down-regulation of LINC01783 suppressed cell proliferation, migration and invasion. Then, we discovered Notch pathway was related to the progression of NSCLC, and DLL-1 expression was reduced by LINC01783 knockdown. Furthermore, DLL-1 overexpression could counteract the suppressive effects of LINC01783 down-regulation on the growth of NSCLC cells. MiR-432-5p was observed to be the mutual miRNA that could bind with both LINC01783 and DLL-1. Overexpression of miR-432-5p inhibited DLL-1 expression. In the rescue assays, miR-432-5p depletion offset the impacts of LINC01783 knockdown, and then DLL-1 silence recovered the influence of miR-432-5p down-regulation on NSCLC cell growth.

Conclusion

LINC01783 aggravates NSCLC cell growth by regulating Notch pathway and sponging miR-432-5p, being a potential target in the treatment for NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01912-0.

Silenced SNHG1 Inhibited Epithelial-Mesenchymal Transition and Inflammatory Response of ARPE-19 Cells Induced by High Glucose

PURPOSE

The lncRNA small nucleolar RNA host gene 1 (SNHG1) is a cerebral infarction-associated gene, its biological role and mechanism in diabetic retinopathy remain to be illuminated. The present study was designed to investigate the role of SNHG1 in high glucose induced human retinal pigment epithelial cells (ARPE-19).

METHODS

ARPE-19 cells were cultured and exposed to 60 mM high glucose for 48h, and 5.5mM glucose-exposed ARPE-19 cells were used as the control. The levels of the epithelial-mesenchymal transition (EMT) markers E-cadherin, ZO-1, vimentin and α-SMA were measured, and the Cell inflammatory response was evaluated by detecting IL-6 and IL-1β levels. Then, cell migration, proliferation and apoptosis were detected. The expression of the lncRNA SNHG1 in ARPE-19 cells was detected by quantitative real-time PCR. SNHG1 was knocked down by small interfering RNA (siRNA) transfection. The effects of SNHG1 inhibition on inflammation, EMT, migration, proliferation and apoptosis were observed.

RESULTS

The results showed that the expression of SNHG1 was significantly increased in ARPE-19 cells exposed to high glucose. Silencing SNHG1 reduced the expression of vimentin, α-SMA, and the expression of inflammatory chemokines IL-6 and IL-1β, inhibited migration and proliferation, elevated the expression of E-cadherin and ZO-1, and promoted apoptosis in ARPE-19 cells.

CONCLUSION

The lncRNA SNHG1 is involved in hyperglycemia-induced EMT and the inflammatory response of ARPE-19 cells and provides a new understanding of the pathogenesis of DR.

Lnc-OIP5-AS1 exacerbates aorta wall injury during the development of aortic dissection through upregulating TUB via sponging miR-143-3p

AIMS

Dysfunction of major cells constituting the aortic wall is the pathological basis for AD development. Determining whether non-coding RNAs can influence AD progression by regulating these cellular functions and identifying some specific non-coding RNAs is of great significance in uncovering molecular mechanisms of the development of AD.

MAIN METHODS

Microarray analyses and hierarchical clustering analysis were used to select candidate lncRNAs and miRNAs associated with AD. Dual-luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down assay were performed to verify the direct bonding relationship between genes. The regulatory effects of genes on cell function were examined in a series of experiments.

KEY FINDINGS

We found that lnc-OIP5-AS1 was upregulated, whereas miR-143-3p was downregulated in cells treated with angiotensin II (AngII) and AD tissues. Lnc-OIP5-AS1 functioned as a competing endogenous RNA (ceRNA) of miR-143-3p to suppress the proliferation and mobility, but promote apoptosis of HAECs and HASMCs, and simultaneously result in the imbalances between MMP-2/9 and TIMP-2/1 in HASMCs and the excessive secretion of IL-6, IL-1β, and IL-17A of HAAFs. Moreover, overexpression or silence of TUB, a target gene of miR-143-3p, counteracted the influence of miR-143-3p or lnc-OIP5-AS1 on cells, respectively.

SIGNIFICANCE

Our findings revealed that lncRNA OIP5-AS1 exacerbates aorta intima, media, and adventitia injury in the development of AD through upregulating TUB via sponging miR-143-3p and also support more detailed future studies by providing a novel molecular basis underlying AD formation.

Large Scale Molecular Studies of Pituitary Neuroendocrine Tumors: Novel Markers, Mechanisms and Translational Perspectives

Simple Summary

Pituitary neuroendocrine tumors are non-cancerous tumors of the pituitary gland, that may overproduce hormones leading to serious health conditions or due to tumor size cause chronic headache, vertigo or visual impairment. In recent years pituitary neuroendocrine tumors are studied with the latest molecular biology methods that simultaneously investigate a large number of factors to understand the mechanisms of how these tumors develop and how they could be diagnosed or treated. In this review article, we have studied literature reports, compiled information and described molecular factors that could affect the development and clinical characteristics of pituitary neuroendocrine tumors, discovered factors that overlap between several studies using large scale molecular analysis and interpreted the potential involvement of these factors in pituitary tumor development. Overall, this study provides a valuable resource for understanding the biology of pituitary neuroendocrine tumors.

Abstract

Pituitary neuroendocrine tumors (PitNETs) are non-metastatic neoplasms of the pituitary, which overproduce hormones leading to systemic disorders, or tumor mass effects causing headaches, vertigo or visual impairment. Recently, PitNETs have been investigated in large scale (exome and genome) molecular analyses (transcriptome microarrays and sequencing), to uncover novel markers. We performed a literature analysis on these studies to summarize the research data and extrapolate overlapping gene candidates, biomarkers, and molecular mechanisms. We observed a tendency in samples with driver mutations (GNAS, USP8) to have a smaller overall mutational rate, suggesting driver-promoted tumorigenesis, potentially changing transcriptome profiles in tumors. However, direct links from drivers to signaling pathways altered in PitNETs (Notch, Wnt, TGF-β, and cell cycle regulators) require further investigation. Modern technologies have also identified circulating nucleic acids, and pinpointed these as novel PitNET markers, i.e., miR-143-3p, miR-16-5p, miR-145-5p, and let-7g-5p, therefore these molecules must be investigated in the future translational studies. Overall, large-scale molecular studies have provided key insight into the molecular mechanisms behind PitNET pathogenesis, highlighting previously reported molecular markers, bringing new candidates into the research field, and reapplying traditional perspectives to newly discovered molecular mechanisms.

SNHG1 knockdown upregulates miR-376a and downregulates FOXK1/Snail axis to prevent tumor growth and metastasis in HCC

Long non-coding RNAs (lncRNAs), microRNAs (miRNAs or miRs), and genes are emerging players in cancer progression. In the present study, we explored the roles and interactions of oncogenic lncRNA small nucleolar RNA host gene 1 (SNHG1), miR-376, forkhead box protein K1 (FOXK1), and Snail in hepatocellular carcinoma (HCC). Expression of SNHG1, miR-376, and FOXK1 in HCC was characterized in clinical HCC tissues of 75 patients with HCC. The interactions between SNHG1 and miR-376 and between miR-376 and FOXK1 were predicted and confirmed by dual-luciferase reporter gene and RNA immunoprecipitation assays. Overexpression and knockdown experiments were performed in HCC cells to examine the effects of the SNHG1/miR-376/FOXK1/Snail axis on viability, apoptosis, invasiveness, and migrating abilities. Their effects on tumor growth and metastasis were validated in nude mouse models. SNHG1 and FOXK1 were upregulated, and miR-376a was downregulated in HCC. SNHG1 knockdown contributed to suppression of HCC cell viability, invasion, and migration properties and promotion of apoptosis. SNHG1 could competitively bind to miR-376a to upregulate its target gene FOXK1, which upregulated Snail. SNHG1 knockdown delayed cancer progression both in vitro and in vivo by upregulating miR-376a and downregulating FOXK1 and Snail. SNHG1 knockdown exerts anti-tumor activity in HCC, suggesting a therapeutic target.

Lung cancer cells and their sensitivity/resistance to cisplatin chemotherapy: Role of microRNAs and upstream mediators

Cisplatin (CP) is a well-known chemotherapeutic agent with excellent clinical effects. The anti-tumor activity of CP has been demonstrated in different cancers such as breast, cervical, reproductive, lung, brain, and prostate cancers. However, resistance of cancer cells to CP chemotherapy has led to its failure in eradication of cancer cells, and subsequent death of patients with cancer. Fortunately, much effort has been put to identify molecular pathways and mechanisms involved in CP resistance/sensitivity. It seems that microRNAs (miRs) are promising candidates in mediating CP resistance/sensitivity, since they participate in different biological aspects of cells such as proliferation, migration, angiogenesis, and differentiation. In this review, we focus on miRs and their regulation in CP chemotherapy of lung cancer, as the most malignant tumor worldwide. Oncogenic miRs trigger CP resistance in lung cancer cells via targeting various pathways such as Wnt/β-catenin, Rab6, CASP2, PTEN, and Apaf-1. In contrast, onco-suppressor miRs inhibit oncogene pathways such as STAT3 to suppress CP resistance. These topics are discussed to determine the role of miRs in CP resistance/sensitivity. We also describe the upstream modulators of miRs such as lncRNAs, circRNAs, NF-κB, SOX2 and TRIM65 and their association with CP resistance/sensitivity in lung cancer cells. Finally, the effect of anti-tumor plant-derived natural compounds on miR expression during CP sensitivity of lung cancer cells is discussed.

Long non-coding RNA CCAT1 promotes non-small cell lung cancer progression by regulating the miR-216a-5p/RAP2B axis

The long non-coding RNA colon cancer-associated transcript 1 (CCAT1) has been investigated to involve in the progression of non-small cell lung cancer (NSCLC). Thus, this study aims to explore the detailed molecular mechanisms of CCAT1 in NSCLC. The expression of CCAT1, miR-216a-5p, RAP2B, Bax, Bcl-2, and cleaved caspase 3 was detected by qRT-PCR or Western blot. Cell proliferation, apoptosis, migration, and invasion were analyzed using cell counting kit-8, flow cytometry or Transwell assays, respectively. The interaction between miR-216a-5p and CCAT1 or RAP2B was analyzed by luciferase reporter, RNA immunoprecipitation, and pull-down assays. The expression of CCAT1 was elevated in NSCLC, and CCAT1 deletion could inhibit NSCLC cell proliferation, migration, and invasion but induce apoptosis in vitro as well as imped tumor growth in vivo. MiR-216a-5p was confirmed to be a target of CCAT1, and silencing miR-216a-5p could reverse CCAT1 depletion-mediated inhibitory effects on cell tumorigenesis in NSCLC. Besides that, miR-216a-5p was decreased in NSCLC, and miR-216a-5p restoration inhibited cell tumorigenesis by regulating RAP2B, which was verified to be a target of miR-216a-5p. Additionally, co-expression analysis suggested that CCAT1 indirectly regulated RAP2B level by targeting miR-216a-5p in NSCLC cells. Taken together, CCAT1 deletion could inhibit cell progression in NSCLC through miR-216a-5p/RAP2B axis, indicating a novel pathway underlying NSCLC cell progression and providing new potential targets for NSCLC treatment.

The ceRNA network of lncRNA and miRNA in lung cancer

Since lung cancer is a major causative for cancer-related deaths, the investigations for discovering biomarkers to diagnose at an early stage and to apply therapeutic strategies have been continuously conducted. Recently, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are being exponentially studied as promising biomarkers of lung cancer. Moreover, supportive evidence provides the competing endogenous RNA (ceRNA) network between lncRNAs and miRNAs participating in lung tumorigenesis. This review introduced the oncogenic or tumor-suppressive roles of lncRNAs and miRNAs in lung cancer cells and summarized the involvement of the lncRNA/miRNA ceRNA networks in carcinogenesis and therapeutic resistance of lung cancer.

LINC00987 Ameliorates COPD by Regulating LPS-Induced Cell Apoptosis, Oxidative Stress, Inflammation and Autophagy Through Let-7b-5p/SIRT1 Axis

Background

Chronic obstructive pulmonary disease (COPD) is the third cause of disease-related death and brings a heavy burden to human health. Long non-coding RNA (lncRNA) was revealed to participate in COPD pathogenesis. This study aims to establish the effects and regulatory mechanism of lncRNA long intergenic non-coding 00987 (LINC00987) in lipopolysaccharide (LPS)-induced apoptosis, oxidative stress, inflammation and autophagy in BEAS-2B cells.

Methods

The expression levels of LINC00987 and let-7b-5p were detected by real-time quantitativepolymerase chain reaction (RT-qPCR). The expression of apoptosis-associated proteins, oxidative stress (ROS)-related proteins, autophagy-related proteins and sirtuin1 (SIRT1) protein was determined by Western blot. Cell viability was illustrated by cell counting kit-8 (CCK-8) assay. Cell apoptosis was investigated by caspase3 activity and apoptosis analysis assays. ROS, inflammation and autophagy were demonstrated by detecting reactive ROS level and superoxide dismutase (SOD) activity, enzyme-linked immunosorbent assay (ELISA) and Western blot analysis, respectively. The binding sites between let-7b-5p and LINC00987 or SIRT1 were predicted by lncBase or miRWalk online database, and identified by dual-luciferase reporter assay.

Results

LINC00987 expression was strikingly downregulated and let-7b-5p expression was obviously upregulated in COPD tissues and LPS-induced BEAS-2B cells compared with control groups. LINC00987 overexpression promoted BEAS-2B cells against LPS-mediated viability, apoptosis, oxidative stress, inflammation and autophagy, whereas these effects were attenuated by let-7b-5p mimic or SIRT1 knockdown. Furthermore, LINC00987 sponged let-7b-5p and let-7b-5p bound to SIRT1.

Conclusion

LINC00987 ameliorated COPD through modulating LPS-induced cell apoptosis, oxidative stress, inflammation and autophagy via sponging let-7b-5p to associate with SIRT1. This finding will provide a theoretical basis for the research of LncRNA-mediated treatment in COPD.

Regulation of microRNA-497 expression in human cancer

MicroRNAs (miRNAs/miRs) are a type of non-coding single-stranded RNA, with a length of ~22 nt, which are encoded by endogenous genes and are involved in the post-transcriptional regulation of gene expression in animals and plants. Studies have demonstrated that miRNAs play an important role in the occurrence, development, metastasis, diagnosis and treatment of cancer. In recent years, miR-497 has been identified as one of the key miRNAs in a variety of cancer types and has been shown to be downregulated in a variety of solid tumors. However, the regulation of miR-497 expression involves a complex network, which is affected by several factors. The aim of the present review was to summarize the mechanism of regulation of miR-497 expression at the pre-transcriptional and transcriptional levels in cancer, as well as the role of miR-497 expression imbalance in cancer diagnosis, treatment and prognosis. The regulatory mechanisms of miR-497 expression may aid in our understanding of the causes of miR-497 expression imbalance and provide a reference value for further research on the diagnosis and treatment of cancer.

LncRNA SNHG1 was down-regulated after menopause and participates in postmenopausal osteoporosis

The functions of long (>200 nt) non-coding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) have only been investigated in cancer biology. We found that plasma LncRNA SNHG1 was down-regulated in postmenopausal than in premenopausal females. Among postmenopausal females, the ones with postmenopausal osteoporosis showed much lower expression levels of plasma lncRNA SNHG1. A 6-year follow-up study on postmenopausal females revealed that plasma lncRNA SNHG1 decreased in females with postmenopausal osteoporosis but not in healthy postmenopausal females. Levels of plasma lncRNA SNHG1 at 12 months before diagnosis is sufficient to distinguish postmenopausal osteoporosis patients from healthy controls. After treatment, plasma lncRNA SNHG1 were significantly up-regulated. Therefore, lncRNA SNHG1 was down-regulated after menopause and plasma level of lncRNA SNHG1 may serve as a biomarker for the diagnosis and treatment of postmenopausal osteoporosis.

LncRNA CDKN2B-AS1 Promotes Cell Viability, Migration, and Invasion of Hepatocellular Carcinoma via Sponging miR-424-5p

Objective

Hepatocellular carcinoma (HCC) results in high mortality and metastasis. In this study, the effects of long non-coding RNA (lncRNA) CDKN2B-AS1 on the progression of HCC were investigated.

Materials and Methods

LncRNA CDKN2B-AS1 expression of HCC cancer and adjacent tissues, and HCC cells were detected. Subsequently, CDKN2B-AS1 was overexpressed and silenced in HCC cells to observe the effects of CDKN2B-AS1 on the cell viability, migration, invasion, and epithelial–mesenchymal transition (EMT) of HCC cells by performing cell counting kit-8 (CCK-8), wound-healing, Transwell, and Western blot. The target gene of CDKN2B-AS1 was predicted and verified to be miR-424-5p, whose expression in HCC cells with up- or down-regulation of CDKN2B-AS1 expression was determined. Moreover, the effects of miR-424-5p on cell viability, migration, and invasion and EMT of HCC cells were investigated with miR-424-5p up-regulation or down-regulation, together with overexpression or silencing of CDKN2B-AS1.

Results

CDKN2B-AS1 expression was increased in HCC tissues and cells. Silencing of CDKN2B-AS1 suppressed cell viability, migration, invasion, and EMT, while overexpression of CDKN2B-AS1 produced the opposite results. Furthermore, CDKN2B-AS1 was predicted and verified to target miR-424-5p and was confirmed to negatively modulate miR-424-5p expression. Moreover, overexpression of miR-424-5p partially suppressed the previously high cell viability, migration, and invasion, and activated EMT resulted from up-regulation of CDKN2B-AS1, while silencing of miR-424-5p elevated the cellular processes inhibited by silencing the expression of CDKN2B-AS1.

Conclusion

The present study revealed that high-expressed CDKN2B-AS1 may associate with the progression of HCC by affecting the cell viability, migration, invasion, and EMT of HCC cells by negatively regulating miR-424-5p.

Long non-coding RNA SNHG1 activates HOXA1 expression via sponging miR-193a-5p in breast cancer progression

Breast cancer is the leading cause of cancer death in women worldwide. Long non-coding RNA small nucleolar RNA host gene 1 (SNHG1) has been reported to be involved in human diseases, including cancer. Here, we found that SNHG1 expression was significantly upregulated in human breast cancer tissues and cell lines. We explored the function of SNHG1 in breast cancer cells using in vitro and in vivo experiments and found that SNHG1 promotes breast cancer metastasis and proliferation. The potential molecular mechanism of SNHG1 in breast cancer cells may involve SNHG1 acting as a sponge of miR-193a-5p to activate the expression of the oncogene HOXA1. In summary, our study reveals a novel SNHG1/miR-193a-5p/HOXA1 competing endogenous RNA regulatory pathway in breast cancer progression and may provide new strategies for breast cancer therapy.

LncRNA MEG3 suppressed the progression of ovarian cancer via sponging miR-30e-3p and regulating LAMA4 expression

Background

Ovarian cancer (OC) is a common female reproductive malignancy with a high mortality rate. Although LAMA4 was observed to be downregulated in OC cells, its mechanism in regulating OC metastasis is still unknown. This study aimed to investigate the effect of LAMA4 and its mechanism on OC.

Methods

To achieve this aim, a microarray analysis was performed to screen out the key genes involved in OC pathogenesis. Western-blot and qRT-PCR assays were also carried out to detect protein and mRNA expressions, respectively. A luciferase reporter assay was further used to confirm the direct interaction of miR-30e-3p with MEG3, and the direct interaction of miR-30e-3p with LAMA4 mRNA. Cytological experiments (CCK8, colony formation assay, wound-healing assay etc.) were then performed to explore the roles of miR-30e-3p, MEG3, and LAMA4 in OC cells.

Results

After carrying out microarray analysis, LAMA4 was confirmed as a key gene associated with OC pathogenesis. Research results proved that miR-30e-3p was markedly upregulated, while MEG3 and LAMA4 were noticeably downregulated in OC tissues and cells. The overexpression of LAMA4 significantly impaired the proliferation, migration, and invasion of OC cells. However, the upregulation of MEG3 increased the expression of LAMA4 by sponging miR-30e-3p, which alleviated the malignancy of OC cells.

Conclusions

Observations showed that forced LAMA4 overexpression could inhibit OC progression, which was regulated by MEG3 via sponging miR-30e-3p. The findings of this research could provide new insights into the mechanism by which MEG3 and LAMA4 exert their anti-oncogenic roles in OC progression.

Trial registration Not applicable

Long Non-Coding RNA PVT1 Regulates BAMBI To Promote Tumor Progression In Non-Small Cell Lung Cancer By Sponging miR-17-5p

Background

Non-small cell lung cancer (NSCLC) is a common malignancy over the world. Previous report indicated that the plasmacytoma variant translocation 1 (PVT1) has been documented to function as an oncogene in various types of human cancers. However, the biological mechanism of PVT1 was still rarely reported in NSCLC.

Methods

The levels of PVT1, miR-17-5p, and bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) in NSCLC tissues (n=64) and cells (H1299 and A549) were detected by qRT-PCR and immunohistochemistry (IHC). The protein level of BAMBI was measured by Western blot assay. Cell viability and apoptotic rate were evaluated by MTT assay and flow cytometry, respectively. The migrated and invaded abilities were assessed by Transwell assay and Wound healing assay. The interactions between miR-17-5p and PVT1 or BAMBI were predicted by starBase v2.0 and TargetScan, respectively, and then dual-luciferase reporter assay and RNA pull-down assay were performed to verify these interactions. The mice model experiments were constructed to further validate the roles of PVT1 in vivo.

Results

The levels of PVT1 and BAMBI were both apparently increased, and miR-17-5p was declined in NSCLC tissues and cells. The depletion of PVT1 or BAMBI blocked cell viability, migrated and invaded abilities but impelled apoptotic rate in A549 and H1299 cells. PVT1 was validated as a sponge to miR-17-5p and BAMBI was a direct target of miR-17-5p. PVT1 promoted cell viability, migrated and invaded abilities but repressed apoptotic rate by targeting BAMBI. MiR-17-5p regulated cell behaviors mediated by PVT1. PVT1 silencing decreased BAMBI expression by sponging miR-17-5p. In addition, PVT1 knockdown blocked the xenograft tumor growth in vivo.

Conclusion

These results manifested that PVT1 modulated BAMBI to promote tumor progression in NSCLC by sponging miR-17-5p. Thus, the novel regulatory pathway may provide a new therapeutic target for NSCLC patients.

LncRNA SNHG1 influences cell proliferation, migration, invasion, and apoptosis of non-small cell lung cancer cells via the miR-361-3p/FRAT1 axis

Background

Non‐small‐cell lung cancer (NSCLC) is the most lethal type of cancer. Long non‐coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified as crucial regulators in the development of NSCLC. The aim of our study was to explore the molecular mechanism of SNHG1 to enable better treatment for NSCLC patients.

Methods

Quantitative real‐time polymerase chain reaction (qRT‐PCR) was performed to detect the expression of Small nucleolar RNA host gene 1 (SNHG1), miR‐361‐3p and frequently rearranged in advanced T‐cell lymphomas 1 (FRAT1). The protein level of FRAT1 was measured by western blot assay. Cell proliferation was evaluated by methyl thiazolyl tetrazolium (MTT) assay. Cell apoptosis was assessed by flow cytometry assay. The number of migrated and invaded cells were counted by transwell assay. The relationship between miR‐361‐3p and SNHG1 or FRAT1 was confirmed by dual‐luciferase reporter assay.

Results

Our results indicated that SNHG1 and FRAT1 were highly expressed in NSCLC tissues and cells. SNHG1 silencing inhibited proliferation, induced apoptosis and blocked migration and invasion of NSCLC cells. Also, FRAT1 downregulation suppressed proliferation, promoted apoptosis and hindered migration and invasion of NSCLC cells. Further, FRAT1 could recover the effects of SNHG1 silencing on proliferation, apoptosis, migration and invasion of NSCLC cells. SNHG1 sponged miR‐361‐3p and negatively regulated miR‐361‐3p expression. Meanwhile, miR‐361‐3p targeted FRAT1 and inversely modulated FRAT1 expression. In addition, miR‐361‐3p inhibition abated the effect of SNHG1 knockdown on FRAT1 expression.

Conclusion

In conclusion, LncRNA SNHG1 promoted the proliferation, repressed apoptosis and enhanced migration and invasion of NSCLC cells by regulating FRAT1 expression via sponging miR‐361‐3p.

MicroRNA-497-5p Induces Cell Cycle Arrest Of Cervical Cancer Cells In S Phase By Targeting CBX4

Purpose

miR-497-5p can inhibit cervical cancer cell proliferation. However, the underlying mechanism remains to be elucidated.

Methods

Bioinformatics was used to analyze the target genes of miR-497-5p. qRT-PCR and Western blot were used to analyze mRNA and protein expression, respectively. Dual-luciferase reporter assay was used to analyze the direct binding between miR-497-5p and 3'-untranslated region of CBX4. Cell viability was measured with MTT assay. Flow cytometry was performed to detect cell cycle distribution.

Results

Here, using bioinformatics methods we firstly found that miR-497-5p regulated cervical carcinoma proliferation by targeting polycomb chromobox4 (CBX4). Expression of miR-497-5p in cervical carcinoma tissues was negatively correlated with CBX4. A binding region of miR-497-5p in 3'-untranslated region of CBX4 was predicted. Further experiments confirmed that miR-497-5p directly targeted CBX4. Besides, RNA interference of CBX4 inhibited cervical cancer cell proliferation, arrested cells at S phase and reduced the expression of CDK2 and Cyclin A2 proteins. The use of miR-497-5p inhibitor compromised CBX4 interference RNAs induced cycle arrest of cervical cancer cells. Cells co-transfected with miR-497-5p inhibitors and CBX4 interference RNAs had a higher proliferation rate than CBX4 inference RNA-transfected cells.

Conclusion

All together, the present study demonstrates that miR-497-5p inhibits cervical cancer cells proliferation by directly targeting CBX4.

Long non-coding RNA SNHG1 indicates poor prognosis and facilitates disease progression in acute myeloid leukemia

The role of long non-coding RNAs (lncRNAs) in acute myeloid leukemia (AML) is becoming increasingly questioned. Previous studies have reported that the lncRNA small nucleolar RNA host gene 1 (SNHG1) is involved in multiple human malignant tumors, while its expression and role in AML is still unexplored. Here, we show that SNHG1 is highly expressed in AML specimens from non-M3 patients, as well as AML cell lines. Meanwhile, upregulation of SNHG1 is correlated with poor prognosis. Notably, SNHG1 facilitates the proliferation and inhibits the apoptosis of AML cells in vitro Consistent with these findings, knockdown of SNHG1 significantly inhibits AML progression in an immunodeficient mouse model. Mechanistically, we found that an anti-tumor microRNA-101 (miR-101) is upregulated and its target genes are downregulated in AML cells after SNHG1 knockdown. Further investigations display that SNHG1 can serve as a competing endogenous RNA to inhibit miR-101. In conclusion, our data indicate that SNHG1 plays an important role in facilitating AML progression at least in part by negatively regulating miR-101, and provides a new target for treating AML.

Long Noncoding RNA and Epithelial Mesenchymal Transition in Cancer

Epithelial-mesenchymal transition (EMT) is a multistep process that allows epithelial cells to acquire mesenchymal properties. Fundamental in the early stages of embryonic development, this process is aberrantly activated in aggressive cancerous cells to gain motility and invasion capacity, thus promoting metastatic phenotypes. For this reason, EMT is a central topic in cancer research and its regulation by a plethora of mechanisms has been reported. Recently, genomic sequencing and functional genomic studies deepened our knowledge on the fundamental regulatory role of noncoding DNA. A large part of the genome is transcribed in an impressive number of noncoding RNAs. Among these, long noncoding RNAs (lncRNAs) have been reported to control several biological processes affecting gene expression at multiple levels from transcription to protein localization and stability. Up to now, more than 8000 lncRNAs were discovered as selectively expressed in cancer cells. Their elevated number and high expression specificity candidate these molecules as a valuable source of biomarkers and potential therapeutic targets. Rising evidence currently highlights a relevant function of lncRNAs on EMT regulation defining a new layer of involvement of these molecules in cancer biology. In this review we aim to summarize the findings on the role of lncRNAs on EMT regulation and to discuss their prospective potential value as biomarkers and therapeutic targets in cancer.