MiR-485 inhibits metastasis and EMT of lung adenocarcinoma by targeting Flot2

Fat mass and obesity-associated protein (FTO)-induced upregulation of flotillin-2 (FLOT2) contributes to cancer aggressiveness in diffuse large B-cell lymphoma (DLBCL) via activating the PI3K/Akt/mTOR signal pathway

The role of fat mass and obesity-associated protein (FTO)-mediated N6-methyladenosine (m6A)-demethylation has been investigated in various types of cancers, but it is still unclear whether FTO participates in the progression of diffuse large B-cell lymphoma (DLBCL). Here, by conducting Real-Time qPCR and Western Blot analysis, we verified that FTO was especially enriched in the DLBCL cells (RCK-8, LY-3, DHL-6 and U2932) compared to normal WIL2S cells. Then, the overexpression and silencing vectors for FTO were delivered into the LY-3 and U2932 cells, and our functional experiments confirmed that silencing of FTO suppressed cell viability and division, and induced apoptotic cell death in the DLBCL cells, whereas FTO-overexpression exerted opposite effects. Further mechanical experiments showed that FTO demethylated m6A modifications in flotillin-2 (FLOT2) mRNA to sustain its stability for FLOT2 upregulation, and elevated FLOT2 subsequently increased the expression levels of phosphorylated PI3K (p-PI3K), p-Akt and p-mTOR to activate the tumor-initiating PI3K/Akt/mTOR signal pathway. Of note, FLOT2 also serve as an oncogene to enhance cancer malignancy in DLBCL, and the rescuing experiments showed that FTO-ablation induced suppressing effects on the malignant phenotypes in DLBCL were all abrogated by overexpressing FLOT2. Taken together, those data hinted that FTO-mediated m6A-demethylation upregulated FLOT2 to activate the downstream PI3K/Akt/mTOR signal pathway, leading to the aggressiveness of DLBCL, which potentially provided diagnostic, therapeutic and prognostic biomarkers for DLBCL.

PI3K/AKT pathway as a pivotal regulator of epithelial-mesenchymal transition in lung tumor cells

Lung cancer, as the leading cause of cancer related deaths, is one of the main global health challenges. Despite various progresses in diagnostic and therapeutic methods, there is still a high rate of mortality among lung cancer patients, which can be related to the lack of clinical symptoms to differentiate lung cancer from the other chronic respiratory disorders in the early tumor stages. Most lung cancer patients are identified in advanced and metastatic tumor stages, which is associated with a poor prognosis. Therefore, it is necessary to investigate the molecular mechanisms involved in lung tumor progression and metastasis in order to introduce early diagnostic markers as well as therapeutic targets. Epithelial-mesenchymal transition (EMT) is considered as one of the main cellular mechanisms involved in lung tumor metastasis, during which tumor cells gain the metastatic ability by acquiring mesenchymal characteristics. Since, majority of the oncogenic signaling pathways exert their role in tumor cell invasion by inducing the EMT process, in the present review we discussed the role of PI3K/AKT signaling pathway in regulation of EMT process during lung tumor metastasis. It has been reported that the PI3K/AKT acts as an inducer of EMT process through the activation of EMT-specific transcription factors in lung tumor cells. MicroRNAs also exerted their inhibitory effects during EMT process by inhibition of PI3K/AKT pathway. This review can be an effective step towards introducing the PI3K/AKT pathway as a suitable therapeutic target to inhibit the EMT process and tumor metastasis in lung cancer patients.

Advances in the role of microRNAs associated with the PI3K/AKT signaling pathway in lung cancer

Cancer has long been a topic of great interest in society and a major factor affecting human health. Breast, prostate, lung, and colorectal cancers are the top four tumor types with the greatest incidence rates in 2020, according to the most recent data on global cancer incidence. Among these, lung cancer had the highest fatality rate. Extensive research has shown that microRNAs, through different signaling pathways, play crucial roles in cancer development. It is considered that the PI3K/AKT signaling pathway plays a significant role in the development of lung cancer. MicroRNAs can act as a tumor suppressor or an oncogene by altering the expression of important proteins in this pathway, such as PTEN and AKT. In order to improve the clinical translational benefit of microRNAs in lung cancer research, we have generalized and summarized the way of action of microRNAs linked with the PI3/AKT signaling pathway in this review through literature search and data analysis.

Nanotechnology-empowered lung cancer therapy: From EMT role in cancer metastasis to application of nanoengineered structures for modulating growth and metastasis

Lung cancer is one of the leading causes of death in both males and females, and it is the first causes of cancer-related deaths. Chemotherapy, surgery and radiotherapy are conventional treatment of lung cancer and recently, immunotherapy has been also appeared as another therapeutic strategy for lung tumor. However, since previous treatments have not been successful in cancer therapy and improving prognosis and survival rate of lung tumor patients, new studies have focused on gene therapy and targeting underlying molecular pathways involved in lung cancer progression. Nanoparticles have been emerged in treatment of lung cancer that can mediate targeted delivery of drugs and genes. Nanoparticles protect drugs and genes against unexpected interactions in blood circulation and improve their circulation time. Nanoparticles can induce phototherapy in lung cancer ablation and mediating cell death. Nanoparticles can induce photothermal and photodynamic therapy in lung cancer. The nanostructures can impair metastasis of lung cancer and suppress EMT in improving drug sensitivity. Metastasis is one of the drawbacks observed in lung cancer that promotes migration of tumor cells and allows them to establish new colony in secondary site. EMT can occur in lung cancer and promotes tumor invasion. EMT is not certain to lung cancer and it can be observed in other human cancers, but since lung cancer has highest incidence rate, understanding EMT function in lung cancer is beneficial in improving prognosis of patients. EMT induction in lung cancer promotes tumor invasion and it can also lead to drug resistance and radio-resistance. Moreover, non-coding RNAs and pharmacological compounds can regulate EMT in lung cancer and EMT-TFs such as Twist and Slug are important modulators of lung cancer invasion that are discussed in current review.

Altered miRNA Expression Profiles in the Serum of Beagle Dogs Experimentally Infected with Toxocara canis

Toxocara canis is a neglected roundworm, which can cause debilitating disease in dogs and humans worldwide. Serum is an excellent material for monitoring the occurrence of many diseases. However, no information is available on the expression of microRNAs (miRNAs) in the serum of dogs infected with T. canis. In this study, RNA-seq analysis was performed to identify the serum miRNA profiles in Beagle dogs infected with T. canis at different stages of infection. A total of 3, 25 and 25 differently expressed miRNAs (DEmiRNAs) were identified in dog serum at 24 h post-infection (hpi), 10 days post-infection (dpi) and 36 dpi, respectively, such as cfa-let-7g, cfa-miR-16, cfa-miR-92b, cfa-miR-93, cfa-miR-122, cfa-miR-485 and cfa-miR-451. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that these miRNAs could regulate the pathways related to parasitic infectious diseases and immune system, such as amoebiasis, toxoplasmosis, platelet activation, IL-17 signaling pathway and chemokine signaling pathway. These results provide a foundation to explore the underlying regulatory role of miRNAs in definitive hosts after T. canis infection.

MiR-485-5p Suppress the Malignant Characteristics of the Lung Adenocarcinoma via Targeting NADPH Quinone Oxidoreductase-1 to Inhibit the PI3K/Akt

Lung adenocarcinoma (LUAD), a prevalent form of non-small cell lung cancer (NSCLC), has a high incidence and mortality rate. However, its molecular regulatory mechanisms have yet to be fully understood. The purpose of this study was to look into how NADPH quinone oxidoreductase-1 (NQO1) and it miR-485-5p and affected LUAD cells. The levels of miR-485-5p and NQO1 expression in LUAD cells and tissues were determined by means of quantitative reverse transcription polymerase chain reaction. The viability, proliferation, migration, and apoptosis of LUAD cells were assessed using cell counting Kit-8, 5-bromo-2'-deoxyuridine, transwell, and caspase-3 assays, respectively. Western blot experiments were used to examine the relative protein expression of matrix metallopeptidase 2 and matrix metallopeptidase 9, as well as the phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt) in LUAD cells. Luciferase and RNA pull-down experiments were also conducted for the verification of miR-485-5p's underlying relationship with NQO1. In our study, we found that LUAD cells and tissues had miR-485-5p downregulation and NQO1 upregulation. The experimental outcomes indicated that miR-485-5p overexpression in LUAD cells reduced their malignant behaviors, suppressed PI3K and Akt phosphorylation, and facilitated apoptosis. The results also revealed that NQO1 was a direct miR-485-5p target, and that NQO1 could reverse miR-485-5p's inhibitory effect on the malignant phenotype of LUAD cells. Furthermore, it was also observed that through targeting NQO1, miR-485-5p could suppress LUAD cell migration and proliferation, further blocking the phosphorylation of PI3K and Akt and inducing apoptosis among LUAD cells. In conclusion, the miR-485-5/NQO1 axis regulates LUAD progression through the PI3K/Akt pathway.

The miR-4732-5p/XPR1 axis suppresses the invasion, metastasis, and epithelial-mesenchymal transition of lung adenocarcinoma via the PI3K/Akt/GSK3β/Snail pathway

The roles of microRNAs (miRNAs) in the occurrence, metastasis, and prognosis of lung adenocarcinoma (LUAD) have been drawing extensive attention from researchers. The aim of this study is to identify the effects of miR-4732-5p on the migration, invasion, and metastasis of LUAD. In this study, we found that the expression of miR-4732-5p was decreased in LUAD based on the data derived from The Cancer Genome Atlas (TCGA) database, tissues, and cell lines. LUAD patients with a low expression of miR-4732-5p exhibited a lower survival rate. Meanwhile, miR-4732-5p could directly target xenotropic and polytropic retrovirus receptor 1 (XPR1), and elevated XPR1 was observed in LUAD mRNA microarrays, Gene Expression Omnibus (GEO), and The Human Protein Atlas (HPA) database. Overexpression of miR-4732-5p significantly inhibits the migration, invasion, and metastasis of LUAD in vitro and in vivo, which can be reversed by overexpression of XPR1. We also found that the PI3K/Akt/GSK3β/Snail pathway induced by EGF induced EMT could be inhibited by miR-4732-5p overexpression and XPR1 knockdown. The migration and invasion of LUAD could be converted by cytoskeletal rearrangements, and the polymerization of EGF induced F-actin in A549 cells could be inhibited by elevated miR-4732-5p. Our results suggest that miR-4732-5p exerts anti-tumor effects on the invasion and metastasis of LUAD by regulating XPR1 in vivo and in vitro, indicating that the miR-4732-5p/XPR1 axis may be a potential target for LUAD therapeutic intervention.

Circular RNA (circ)_0129047 upregulates bone morphogenetic protein receptor type 2 expression to inhibit lung adenocarcinoma progression by sponging microRNA (miR)-1206

Circular RNAs (circRNAs) play significant roles in the tumorigenesis and progression of various cancers, including lung adenocarcinoma (LAC). However, their underlying biological functions in LAC remain unclear. Here, we investigated the tumor suppressor role of the newly identified circRNA, circ_0129047, in LAC tumorigenesis and progression. The expression levels of circ_0129047, microRNA (miR)-1206, and bone morphogenetic protein receptor type 2 (BMPR2) mRNA in LAC cells and tissues were monitored using reverse transcription-quantitative polymerase chain reaction. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were used to confirm the targeting relationships among circ_0129047, miR-1206, and BMPR2 mRNA. Functional experiments for A549 and PC9 cells were performed using cell counting kit-8, bromodeoxyuridine enzyme-linked immunosorbent, caspase-3 activity, cell adhesion, wound healing, and transwell assays. Circ_0129047 expression levels were reduced in LAC cells and tissues. Mechanistically, we discovered that circ_0129047 could sponge miR-1206, and miR-1206 could directly target BMPR2. In addition, circ_0129047 or BMPR2 knockdown facilitated the viability, proliferation, adhesion, migration, and invasion, while inhibiting the apoptosis of LAC cells. Furthermore, the inhibitory effects of circ_0129047 or BMPR2 overexpression on the malignant phenotype of LAC cells could be reversed by the overexpression of miR-1206. In conclusion, circ _0129047 was found to play a tumor suppressive role in LAC progression; it upregulated BMPR2 expression to inhibit LAC progression by sponging miR-1206.

Abbreviations: non-small cell lung cancer (NSCLC); small cell lung cancer (SCLC); lung adenocarcinoma (LAC); Circular RNA (circRNA); MicroRNA (miRNA); bone morphogenetic protein (BMP); squamous cell lung cancer (SCC); RNA immunoprecipitation (RIP)

Effect of FLOT2 Gene Expression on Invasion and Metastasis of Colorectal Cancer and Its Molecular Mechanism under Nanotechnology and RNA Interference

The study is aimed at investigating the effect of the FLOT2 gene on invasion and metastasis of colorectal cancer (CRC) cells and the corresponding molecular mechanism by preparing polylysine-silicon nanoparticles. Specifically, polylysine was used to modify the silica nanoparticles prepared by the emulsification method to obtain polylysine-silicon nanoparticles. The characterization of polylysine-silicon nanoparticles was completed by nanoparticle size analyzer, laser particle size potentiometer, and transmission microscope. The influence of polylysine-silicon nanoparticles on the survival rate of CRC cell line HT-29 was detected using the method of 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT). The FLOT2-siRNA expression vector was constructed and transfected with HT-29. The HT-29 transfected with empty plasmid was used as the negative control (NC). Western Blot (WB) and reverse transcription-polymerase chain reaction (RT-PCR) were used to detect expression levels of FLOT2 gene and epithelial-mesenchymal transition- (EMT-) related genes. Transwell invasion assay, Transwell migration assay, and CCK8 assay were used to detect the cell invasion, migration, and proliferation. The results showed that the average particle size of polylysine-silicon nanoparticles was 30 nm, the potential was 19.65 mV, the particle size was 65.8 nm, and the dispersion coefficient was 0.103. At the same concentration, the toxicity of silicon nanoparticles to HT-29 was significantly lower than that of liposome reagent, and the transfection efficiency was 60%, higher than that of liposome reagent (40%). The mRNA level and protein expression of the FLOT2 gene in the FLOT2-siRNA group were significantly lower than those in the NC group (P < 0.01). The optical density (OD) value of the NC group and the blank control (CK) group were significantly higher than that of FLOT2-siRNA cells (P < 0.01). The OD value of FLOT2-siRNA cells was lower than that of NC cells at 48 h, 72 h, and 96 h (P < 0.01). The mRNA levels and protein expressions of MMP2 and vimentin in the FLOT2-siRNA group were significantly lower than those in the NC group and CK group (P < 0.01). The mRNA level and protein expression of the E-cadherin gene in the FLOT2-siRNA group were significantly higher than those in the NC group and CK group (P < 0.01). In conclusion, an RNA interference plasmid with high transfection efficiency and low cytotoxicity was established based on nanotechnology. siRNA-mediated FLOT2 protein inhibits the invasion, migration, and proliferation of CRC cells by regulating the expression changes of EMT-related genes, which provides a scientific basis for clinical treatment of CRC.

Real-world PM2.5 exposure induces pathological injury and DNA damage associated with miRNAs and DNA methylation alteration in rat lungs

Fine particulate matter (PM_2.5) has been demonstrated to threaten public health and increase lung cancer risk. DNA damage is involved in the pathogenesis of lung cancer. However, the mechanisms of epigenetic modification of lung DNA damage are still unclear. This study developed a real-world air PM_2.5 inhalation system and exposed rats for 1 and 2 months, respectively, and investigated rat lungs pathological changes, inflammation, oxidative stress, and DNA damage effects. OGG1 and MTH1 expression was measured, along with their DNA methylation status and related miRNAs expression. The results showed that PM_2.5 exposure led to pathological injury, influenced levels of inflammatory cytokines and oxidative stress factors in rat lungs. Of note, 2-month PM_2.5 exposure aggravated pathological injury. Besides, PM_2.5 significantly elevated OGG1 expression and suppressed MTH1 expression, which was correlated to oxidative stress and partially mediated by reducing OGG1 DNA methylation status and increasing miRNAs expression related to MTH1 in DNA damage with increases of γ-H2AX, 8-OHdG and GADD153. PM_2.5 also activated c-fos and c-jun levels and inactivated PTEN levels in rat lungs. These suggested that epigenetic modification was probably a potential mechanism by which PM_2.5-induced genotoxicity in rat lungs.

Flotillin membrane domains in cancer

Flotillins 1 and 2 are two ubiquitous, highly conserved homologous proteins that assemble to form heterotetramers at the cytoplasmic face of the plasma membrane in cholesterol- and sphingolipid-enriched domains. Flotillin heterotetramers can assemble into large oligomers to form molecular scaffolds that regulate the clustering of at the plasma membrane and activity of several receptors. Moreover, flotillins are upregulated in many invasive carcinomas and also in sarcoma, and this is associated with poor prognosis and metastasis formation. When upregulated, flotillins promote plasma membrane invagination and induce an endocytic pathway that allows the targeting of cargo proteins in the late endosomal compartment in which flotillins accumulate. These late endosomes are not degradative, and participate in the recycling and secretion of protein cargos. The cargos of this Upregulated Flotillin–Induced Trafficking (UFIT) pathway include molecules involved in signaling, adhesion, and extracellular matrix remodeling, thus favoring the acquisition of an invasive cellular behavior leading to metastasis formation. Thus, flotillin presence from the plasma membrane to the late endosomal compartment influences the activity, and even modifies the trafficking and fate of key protein cargos, favoring the development of diseases, for instance tumors. This review summarizes the current knowledge on flotillins and their role in cancer development focusing on their function in cellular membrane remodeling and vesicular trafficking regulation.

STAT1-induced upregulation of lncRNA RHPN1-AS1 predicts a poor prognosis of hepatocellular carcinoma and contributes to tumor progression via the miR-485/CDCA5 axis

Long noncoding RNAs (lncRNAs) act as a critical regulator in tumor progression, but few lncRNAs have been functionally characterized in hepatocellular carcinoma (HCC). Using The Cancer Genome Atlas datasets and bioinformatic technology, we screened and identified a novel HCC-related lncRNA, RHPN1 antisense RNA 1 (RHPN1-AS1). We found that the levels of RHPN1-AS1 were distinctly upregulated in both HCC tissues and cell lines. RHPN1-AS1 was activated by the transcription factor STAT1. Clinical investigations suggested that higher levels of RHPN1-AS1 were distinctly correlated with histologic grade, advanced tumor, node, metastasis stage, and poorer clinical prognosis. Multivariate assays identified high RHPN1-AS1 expression as an unfavorable prognostic biomarker for patients with HCC. Functional study revealed that knockdown of RHPN1-AS1 was able to suppress cells proliferation and metastasis, and promote cell apoptosis. Further mechanistic investigation suggested that RHPN1-AS1 could promote CDCA5 expressions by functioning as a competing endogenous RNA for miR-485. This interaction resulted in consequentially suppression of HCC cells proliferation, migration, and invasion. Our findings for the first time illustrate how RHPN1-AS1 displayed its tumor-promotive roles in HCC and may offer a new biomarker and a potential therapeutic target for patients with HCC.

MiR-490-3p Inhibits the Malignant Progression of Lung Adenocarcinoma

Objective

To investigate the effects of miR-490-3p on the proliferation, migration, invasion and apoptosis of lung adenocarcinoma (LUAD) cells through the Wnt/β-catenin signaling pathway.

Methods

Differentially expressed miRNAs in LUAD tissues were analyzed by bioinformatics and the target miRNA went through GSEA enrichment analysis. qRT-PCR was used to detect the expression of miR-490-3p in human LUAD cells and normal bronchial cells. The constructed vectors were transfected into the LUAD cell lines using Lipofectamine 2000. Cell viability was detected by MTT, cell migration and invasion were detected by transwell assay, and cell apoptosis was detected by flow cytometry. Western blot was performed to detect the expression levels of the proteins related to the Wnt/β-catenin pathway and cell apoptosis. Xenograft tumor mouse models were used for in vivo validation.

Results

The results of qRT-PCR showed that miR-490-3p was relatively lowly expressed in LUAD cells, and the expression level was different in different LUAD cell lines. The results of MTT, transwell and flow cytometry exhibited that miR-490-3p could significantly inhibit the proliferation, migration, invasion and increase cell apoptosis rate of LUAD cells. Western blot results showed that miR-490-3p promoted the expression of Bax, Caspase-3 and E-cadherin as well as the phosphorylation of GSK-3β and inhibited the expression of Bcl-2, β-catenin and C-myc. Additionally, animal experiments were performed to prove that miR-490-3p suppressed LUAD malignant progression in vivo.

Conclusion

MiR-490-3p inhibited the proliferation, migration, invasion and promoted the apoptosis of LUAD cells by down-regulating the Wnt/β-catenin signaling pathway, suggesting that miR-490-3p may be an indicator for early diagnosis and prognosis of LUAD.

linc00968 inhibits the tumorigenesis and metastasis of lung adenocarcinoma via serving as a ceRNA against miR-9-5p and increasing CPEB3

Increasing evidence confirms that long noncoding RNAs (lncRNAs) exert vital functions in multiple biological process among malignant cancers. In the current study, we uncovered that linc00968 was downregulated in lung adenocarcinoma (LUAD). Furthermore, the low level of linc00968 was correlated with worse prognosis in patients with LUAD. Upregulation of linc00968 restrained the growth and metastatic phenotypes of LUAD cell in vitro and in vivo. Using bioinformation methods and luciferase reporter assay, we identified that linc00968 acted as a competing endogenous RNA (ceRNA) via sponging miR-9-5p to modulate the level of Cytoplasmic Polyadenylation Element Binding Protein 3 (CPEB3) in LUAD. In addition, LUAD cell migration, colony formation and epithelial-mesenchymal transition (EMT) process were suppressed by linc00968 while these aggressive traits were reversed by miR-142-5p or CPEB3 silencing. Altogether, our work disclosed that linc00968 played a critical role in LUAD and linc00968/miR-9-5p/CPEB3 regulatory axis might be a potential treatment target in LUAD.

miRNA-425-5p enhances lung cancer growth via the PTEN/PI3K/AKT signaling axis

Background

miRNAs regulate a multitude of cellular processes and their aberrant regulation is linked to human cancer. However, the role of miR-425-5p in lung cancer (LCa) is still largely unclear. Here, we explored the role of miR-425-5p during LCa tumorigenesis.

Methods

Cell proliferation was evaluated by cell counting Kit-8 and colony formation assay. Western blot and real-time PCR were accordingly used to detect the relevant proteins, miRNA and gene expression. Luciferase reporter assays were used to illustrate the interaction between miR-425-5p and PTEN.

Results

We demonstrate that miR-425-5p is overexpressed in LCa tissue and enhances the proliferative and colony formation capacity of the LCa cell lines A549 and NCI-H1299. Through predictive binding assays, PTEN was identified as a direct gene target and its exogenous expression inhibited the pro-cancer effects of miR-425-5p. Through its ability to down-regulate PTEN, miR-425-5p activated the PI3K/AKT axis.

Conclusion

We conclude that miR-425-5p promotes LCa tumorigenesis through PTEN/PI3K/AKT signaling.

Reduced levels of miR-485-5p in HPV-infected cervical cancer promote cell proliferation and enhance invasion ability

Cervical cancer (CC) is the most common gynecological malignancy, with high incidence and mortality rates in China. The microRNA miR‐485‐5p has previously been reported to serve as a negative regulator of tumorigenesis in breast cancer and hepatocellular carcinoma, and miR‐485‐5p has been observed to be differentially expressed between CC and normal control tissue. Here, we confirmed that miR‐485‐5p expression is lower in CC than in adjacent normal tissue and proceeded to investigate the effects of miR‐485 on tumor behavior in CC cell lines. We report that miR‐485‐5p transcription is decreased in HPV‐infected CC tissue, and levels of miR‐485 in clinical samples are positively correlated with the 5‐year overall survival rate. The Transwell assay showed that miR‐485‐5p inhibited cell invasion and migration but had no influence on apoptosis and cell proliferation. Using a luciferase reporter assay, we demonstrated that miR‐485‐5p partially abrogated cell migration and proliferation by targeting FLOT‐1 mRNA. Transfection of HPV‐infected cervical carcinoma cells with an adenovirus vector encoding human FLOT‐1 partially diminished the inhibitory effects of miR‐485 on cell invasion. Taken, together, these data demonstrated that miR‐485‐5p suppresses the invasion of cancer cells by targeting FLOT‐1 in HPV‐infected cervical carcinoma cells.

LINC01224 Exhibits Cancer-Promoting Activity in Epithelial Ovarian Cancer Through microRNA-485-5p-Mediated PAK4 Upregulation

Purpose

Long intergenic non-protein coding RNA 1224 (LINC01224) plays vital roles in the tumorigenesis and progression of hepatocellular carcinoma. Here, we determined LINC01224 expression in epithelial ovarian cancer (EOC) tissues and cells. We also assessed the effects of LINC01224 knockdown on the malignant phenotype of EOC cells both in vitro and in vivo. Furthermore, the detailed molecular mechanisms underlying the oncogenic actions of LINC01224 in EOC cells were elucidated.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect LINC01224 expression in EOC tissues and cells. EOC cells were transfected with small interfering RNAs, and cell proliferation, apoptosis, migration, and invasion were assessed using Cell Counting Kit-8 assay, flow cytometry, cell migration assays, and cell invasion assays, respectively. Using tumor xenografts, the effects of LINC01224 silencing on EOC tumor growth were analyzed in vivo. The mechanism underlying LINC01224 regulation of malignant processes in EOC cells was explored using bioinformatics, RNA immunoprecipitation assay, qRT-PCR, Western blotting, and rescue experiments.

Results

LINC01224 expression was upregulated in EOC tissues and cells. LINC01224 upregulation was correlated to tumor size, the International Federation of Gynecology and Obstetrics stage, and lymph node metastasis. LINC01224 depletion in EOC cells suppressed cell proliferation, migration, and invasion and facilitated cell apoptosis in vitro. LINC01224 downregulation also hindered EOC tumor growth in vivo. Mechanistically, LINC01224 served as a competing endogenous RNA for microRNA-485-5p (miR-485-5p) and consequently increased p21-activated kinase 4 (PAK4) expression in EOC cells. Furthermore, miR-485-5p inhibition or PAK4 upregulation significantly abrogated the effects of LINC01224 depletion in EOC cells.

Conclusion

LINC01224/miR-485-5p/PAK4 formed a competing endogenous RNA network regulating the aggressive behavior of EOC. Therefore, targeting this pathway may be an attractive therapeutic strategy for EOC.

Flotillin-2 predicts poor prognosis and promotes tumor invasion in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a highly malignant neoplasm arising from the intrahepatic bile ducts. As a scaffold protein of lipid rafts, flotillin-2 is upregulated in several types of cancer and promotes tumor progression and metastasis. To the best of our knowledge, the present study was the first to detect the upregulation of flotillin-2 in iCCA tissues compared with matched adjacent non-tumor tissues. In addition, immunohistochemistry was used to investigate the expression of flotillin-2 in a microarray consisting of 92 iCCA tissues. A total of 59 samples (64.1%) exhibited high flotillin-2 expression, which was significantly related to lymph node metastasis (P=0.029) and tumor-node-metastasis stage (P=0.016). Further in vitro study demonstrated that knockdown of flotillin-2 inhibited the invasive capability of iCCA cell lines, further supporting the participation of flotillin-2 in cancer invasion and metastasis. Moreover, Kaplan-Meier analysis showed patients with high flotillin-2 expression had worse overall survival outcomes. The multivariate Cox proportional hazards model further revealed that high flotillin-2 expression was an independent indicator (P=0.005) of poor prognosis for patients with iCCA. Collectively, the present study revealed that as a promoter of invasion and an independent marker of poor prognosis, flotillin-2 may serve as a potential target for the development of novel therapeutic agents for iCCA.

Long Noncoding RNA SNHG7, a Molecular Sponge for microRNA-485, Promotes the Aggressive Behavior of Cervical Cancer by Regulating PAK4

Purpose

A long noncoding RNA called small nucleolar RNA host gene 7 (SNHG7) is known to be a key regulator of biological processes in multiple human cancer types. In this study, our aims were to determine the expression status of SNHG7 in cervical cancer, to figure out the detailed roles of SNHG7 in cervical cancer cells, and to identify the mechanism underlying the activity of SNHG7 in cervical cancer.

Methods

Reverse-transcription quantitative PCR was performed to measure SNHG7 expression in cervical cancer. A Cell Counting Kit-8 assay, flow-cytometric analysis, cell migration and invasion assays, and a tumor xenograft experiment were conducted to respectively determine the effects of SNHG7 on cervical cancer cell proliferation, apoptosis, migration, and invasion in vitro and tumor growth in vivo.

Results

SNHG7 was found to be markedly upregulated in cervical cancer tissues and cell lines. Higher SNHG7 expression significantly correlated with FIGO stage, lymph node metastasis, the depth of cervical invasion, and shorter overall survival in patients with cervical cancer. Functional experiments indicated that a SNHG7 knockdown attenuated proliferation, migration, and invasiveness and promoted apoptosis of cervical cancer cells in vitro. The SNHG7 knockdown also slowed tumor growth in vivo. Further investigation showed that SNHG7 acts as a competing endogenous RNA for microRNA-485 (miR-485) in cervical cancer cells, and the inhibitory actions of the SNHG7 knockdown on the malignant phenotype were reversed by miR-485 inhibition. P21-activated kinase 4 (PAK4) was identified as a direct target gene of miR-485 in cervical cancer, and PAK4 expression was promoted by SNHG7.

Conclusion

SNHG7 functions as an oncogenic RNA in cervical cancer, competitively binds to miR-485, and thereby upregulates PAK4. This SNHG7–miR-485–PAK4 regulatory network may provide insights into the pathogenesis of cervical cancer, and can help in the identification of novel diagnostic and therapeutic approaches for cervical cancer.

Actin-like protein 8 promotes cell proliferation, colony-formation, proangiogenesis, migration and invasion in lung adenocarcinoma cells

Background

Non‐small cell lung cancer (NSCLC) is the leading cause of cancer‐associated mortality worldwide of which lung adenocarcinoma (LUAD) is the most common. The identification of oncogenes and effective drug targets is the key to individualized LUAD treatment. Actin‐like protein 8 (ACTL8), a member of the cancer/testis antigen family, is associated with tumor growth and patient prognosis in various types of cancer. However, whether ACTL8 is involved in the development of LUAD remains unknown. The aim of the present study was to demonstrate the role of ACTL8 in human LUAD cells.

Methods

The expression of ACTL8 in LUAD tissues and cell lines was assessed using immunohistochemistry and western blotting. Additionally, plasmids expressing ACTL8‐specific short hairpin RNAs were used to generate lentiviruses which were subsequently used to infect A549 and NCI‐H1975 human LUAD cells. Cell proliferation, migration, invasion and apoptosis, as well as cell cycle progression and the expression of protein markers of epithelial to mesenchymal transition were investigated. A549 cell tumor growth in nude mice was also examined.

Results

The results showed that ACTL8 was highly expressed in A549 and NCI‐H1975 LUAD cell lines. Additionally, ACTL8‐knockdown inhibited proliferation, colony formation, cell cycle progression, migration and invasion, and increased apoptosis in both cell lines. Furthermore, in vivo experiments in nude mice revealed that ACTL8‐knockdown inhibited A549 cell tumor growth.

Conclusion

These results suggest that ACTL8 serves an oncogenic role in human LUAD cells, and that ACTL8 may represent a potential therapeutic target for LUAD.

Key points

Our results suggest that ACTL8 serves an oncogenic role in human LUAD cells, and that ACTL8 may represent a potential therapeutic target for LUAD.

The study of mechanism of miR-34c-5p targeting FLOT2 to regulate proliferation, migration and invasion of osteosarcoma cells

Objective: Osteosarcoma is one of the most common malignancies in children and adolescents. Studies have shown that miR-34c-5p is involved in the progression of various cancers. To explore the effects of miR-34c-5p on the proliferation, migration and invasion of osteosarcoma cells and its potential mechanism. Methods: qRT-PCR was used to detect the expression levels of miR-34c-5p and FLOT2 mRNA in osteosarcoma tissues and cells. Western Blot was used to detect protein expression. MTT assay used to detect cell viability. Transwell was used to detect cell migration and invasion in each group. Dual luciferase reporter gene assay was used to detect luciferase activity. Results: The expression of miR-34c-5pwas significantly decreased in osteosarcoma tissues and cells and the expression level of FLOT2 mRNA was significantly increased. Overexpression of miR-34c-5p and inhibition of FLOT2 inhibited the proliferation, migration and invasion of osteosarcoma cells and inhibited the expression of Cyclin D1, MMP-2 and MMP-9 proteins and promoted the expression of p21 protein. miR-34c-5p targeted to regulate the expression of FLOT2. Overexpression of FLOT2 reversed the inhibitory effect of miR-34c-5p overexpression on proliferation, migration and invasion of osteosarcoma cell lines. Conclusion: miR-34c-5p can inhibit the proliferation, migration and invasion of osteosarcoma cells. The mechanism may be related to targeting FLOT2, which will provide a new target for the prevention and treatment of osteosarcoma.

Long non-coding RNA LINC00707 acts as a competing endogenous RNA to enhance cell proliferation in colorectal cancer

Long non-coding RNAs (lncRNAs) have been indicated to serve critical roles in cancer development and progression. Long intergenic non-protein coding RNA 70 (LINC00707) was recently reported to be an oncogene involved in the tumorigenesis of several types of human cancer. However, the clinical role, biological functions and molecular mechanism of LINC00707 in colorectal cancer (CRC) remain unclear. The aim of the present study was to investigate the biological effects and mechanism of LINC00707 in CRC. Reverse transcription-quantitative PCR was used to detect the expression levels of LINC00707 in 65 CRC tissue samples and CRC cell lines (HCT116, HT29 and SW480). Cell Counting Kit-8 and colony formation assays were performed to investigate the effects of LINC00707 on CRC cell proliferation. A dual-luciferase reporter assay was conducted to investigate the mechanisms of LINC00707 in CRC. The upregulation of LINC00707 expression was significantly associated with tumor size, stage and poor survival in patients with CRC. LINC00707 also acted as an independent prognostic factor for CRC. Functional analyses revealed that the knockdown of LINC00707 could inhibit CRC cell proliferation. Furthermore, bioinformatics analysis demonstrated that microRNA (miR)-485-5p could directly bind to LINC00707, which was confirmed by a dual-luciferase reporter assay. In conclusion, the upregulation of LINC00707 is associated with a shorter survival time in patients with CRC. Knockdown of LINC00707 may inhibit the proliferation of CRC cells by binding with miR-485-5p.

MicroRNA-351 eases insulin resistance and liver gluconeogenesis via the PI3K/AKT pathway by inhibiting FLOT2 in mice of gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is known as different degree glucose intolerance that is initially identified during pregnancy. MicroRNAs (miRs) may be a potential candidate for treatment of GDM. Herein, we suggested that miR‐351 could be an inhibitor in the progression of GDM via the phosphoinositide 3‐kinase/protein kinase B (PI3K/AKT) pathway. Microarray analysis was used to identify differentially expressed genes and predict miRs regulating flotillin 2 (FLOT2). Target relationship between miR‐351 and FLOT2 was verified. Gestational diabetes mellitus mice were treated with a series of mimic, inhibitor and small interfering RNA to explore the effect of miR‐351 on insulin resistance (IR), cell apoptosis in pancreatic tissues and liver gluconeogenesis through evaluating GDM‐related biochemical indexes, as well as expression of miR‐351, FLOT2, PI3K/AKT pathway‐, IR‐ and liver gluconeogenesis‐related genes. MiR‐351 and FLOT2 were reported to be involved in GDM. FLOT2 was the target gene of miR‐351. Gestational diabetes mellitus mice exhibited IR and liver gluconeogenesis, up‐regulated FLOT2, activated PI3K/AKT pathway and down‐regulated miR‐351 in liver tissues. Additionally, miR‐351 overexpression and FLOT2 silencing decreased the levels of FLOT2, phosphoenolpyruvate carboxykinase, glucose‐6‐phosphatase, fasting blood glucose, fasting insulin, total cholesterol, triglyceride, glyeosylated haemoglobin and homeostasis model of assessment for IR index (HOMA‐IR), extent of PI3K and AKT phosphorylation, yet increased the levels of HOMA for islet β‐cell function, HOMA for insulin sensitivity index and glucose transporter 2 expression, indicating reduced cell apoptosis in pancreatic tissues and alleviated IR and liver gluconeogenesis. Our results reveal that up‐regulation of miR‐351 protects against IR and liver gluconeogenesis by repressing the PI3K/AKT pathway through regulating FLOT2 in GDM mice, which identifies miR‐351 as a potential therapeutic target for the clinical management of GDM.

miR-186-5p promotes cell growth, migration and invasion of lung adenocarcinoma by targeting PTEN

OBJECTIVE

To explore the expression of miR-186-5p in lung adenocarcinoma (LUAD) and its possible function associated with cancer cell proliferation, migration and invasion.

METHODS

MiR-186-5p expression levels in LUAD samples, human LUAD cell lines H1299 and NCI-H1975, and normal human lung epithelial cell line BEAS-IB were assessed by quantitative real-time PCR (qRT-PCR). H1299 and NCI-H1975 cells were transfected with miR-186-5p mimic or miRNA negative control. CCK-8 assay was performed to evaluate the cell proliferation. Transwell assay and transwell-matrigel™ invasion assay were applied to assess the migration and invasion abilities of H1299 and NCI-H1975 cells.

RESULTS

miR-186-5p expression was significantly up-regulated in LUAD tumor tissues and LUAD cell lines as compared with tumor-adjacent tissues and normal human lung epithelial cells, respectively. MiR-186-5p overexpression remarkably promoted the proliferation, migration and invasion of LUAD cells. Furthermore, phosphatase and tensin homolog (PTEN) was a direct target of miR-186-5p verified by luciferase reporter assay. Overexpression of PTEN significantly suppressed LUAD cells to proliferate, migrate and invade. MiR-186-5p overexpression-induced LUAD cell phenotype could be partially rescued by co-overexpression of miR-186-5p and PTEN.

CONCLUSION

This study demonstrated that miR-186-5p is up-regulated in LUAD, and functionally associated with cell proliferation, migration and invasion. MiR-186-5p promotes the proliferation, migration and invasion of LUAD cells by targeting PTEN. MiR-186-5p may be utilized as a novel molecular marker and therapeutic target of LUAD.

MicroRNA-200c-3p/ZEB2 loop plays a crucial role in the tumor progression of prostate carcinoma

Background

The microRNA (miRNA) miR-200c-3p is involved in the tumorigenesis and progression of a variety of cancers. However, the underlying regulatory role of miR-200c-3p in prostate cancer (PCa) remains unclear.

Methods

Online databases including Oncomine, Linkedomics and StarBase were used to investigate the clinical significance of miR-200c-3p, along with associated gene targets. PCa tissues and adjacent normal tissues were used for the detection of miR-200c-3p expression. A lentivirus overexpressing miR-200c-3p was constructed and transfected into PC3 and DU145 cells. Cell formation of proliferation, migration, and invasion were determined by cell viability and colony-formation assay, wound healing assay, and Matrigel invasion assay, respectively. Epithelial-mesenchymal transition (EMT)-associated markers were determined by qRT-PCR and Western blot. A luciferase reporter assay was performed to determine the direct relationship of miR-200c-3p and ZEB2. The tumor-suppressive role of miR-200c-3p was further confirmed by a xenograft tumor model and immunohistochemical (IHC) staining.

Results

Online database analyses showed that miR-200c-3p was associated with pathologic T and N stage in PCa, and miR-200c-3p was downregulated in PCa tissues. Overexpression of miR-200c-3p was considered a tumor suppressor and was found to significantly suppress the formation of migration and invasion in PCa cells via repression of E-cadherin-induced EMT. The bioinformatic database indicated that ZEB2 has a significant correlation with miR-200c-3p and was upregulated in PCa tissues. Further, ZEB2 expression was suppressed by the upregulation of miR-200c-3p and was identified as a direct target of miR-200c-3p. In addition, repression of ZEB2 could restore the levels of miR-200c-3p in PCa cells in turn, suggesting a potential negative loop between miR-200c-3p and ZEB2. miR-200c-3p also had an antitumor effect by negatively regulating ZEB2 in a xenograft mouse model.

Conclusions

Taken together, the results of our study demonstrated the novel regulatory loop of miR-200c-3/ZEB2 in PCa progression, providing effective therapeutic strategies for PCa in the future.

Bioselection Reveals miR-99b and miR-485 as Enhancers of Adenoviral Oncolysis in Pancreatic Cancer

Oncolytic viruses are designed for cancer treatment. Cell-virus interactions are key determinants for successful viral replication. Therefore, the extensive reprogramming of gene expression that occurs in tumor cells might create a hurdle for viral propagation. We used a replication-based approach of a microRNA (miRNA) adenoviral library encoding up to 243 human miRNAs as a bioselection strategy to identify miRNAs that facilitate adenoviral oncolytic activity in pancreatic ductal adenocarcinoma. We identify two miRNAs, miR-99b and miR-485, that function as enhancers of adenoviral oncolysis by improving the intra- and extracellular yield of mature virions. An increased adenoviral activity is the consequence of enhanced E1A and late viral protein expression, which is probably mediated by the downregulation of the transcriptional repressors ELF4, MDM2, and KLF8, which we identify as miR-99b or miR-485 target genes. Arming the oncolytic adenovirus ICOVIR15 with miR-99b or miR-485 enhances its fitness and its antitumoral activity. Our results demonstrate the potential of this strategy to improve oncolytic adenovirus potency, and they highlight miR-99b and miR-485 as sensitizers of adenoviral replication.

microRNA-485-5p Functions as a Tumor Suppressor in Colorectal Cancer Cells by Targeting CD147

Colorectal cancer(CRC) is a prevalent malignancy in the world. There is growing evidence that microRNAs (miRNAs) as crucial modulator are in connection with many tumor-related diseases including CRC. Though miR-485-5p has been reported as an anti-oncogene in certain cancers, it remains unclear in CRC. In this research, we found that miR-485-5p was at lower level expression in CRC tissues and cell lines compared to the paired paracancerous tissues and the normal colon epithelial cell line FHC, correspondingly. Furthermore, Experimental up-regulation miR-485-5p in DLD-1 and SW480 cells with mimic could inhibit the ability of proliferation, migration, invasion of CRC cell lines and facilitate cells apoptosis. Also, we confirmed that CD147 existed typically negative regulation by miR-485-5p through binding a conserved sequence specifically within the CD147 3'-untranslated region (3'UTR) and reintroduction of CD147 could rescue the phenotypic changes caused by miR-485-5p. The findings provide evidence to demonstrate the role of miR-485-5p/CD147 interaction in CRC and indicate that miR-485-5p might be exploited therapeutically in CRC.

MicroRNA‑485 targets MACC1 and inhibits cervical cancer cell proliferation and invasion

A large body of evidence has indicated that microRNAs (miRNAs/miRs) have essential roles in the development and progression of cervical cancer. Thus, miRNAs with dysregulated expression are potential biomarkers for cervical cancer diagnosis and prognosis. In the present study, expression levels of miR‑485 were detected in cervical cancer tissues and cell lines. The effects of miR‑485 overexpression on the proliferation and invasion of cervical cancer cells were determined with Cell Counting kit‑8 and Transwell invasion assays. The mechanisms underlying the action of miR‑485 in cervical cancer were investigated using bioinformatics analysis, a luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blot analysis. In addition, the association between miR‑485 and metastasis associated in colon cancer‑1 (MACC1) in cervical cancer tissues was examined. The present study demonstrated that miR‑485 expression was significantly downregulated in cervical cancer tissues and cell lines. Reduced miR‑485 expression in patients with cervical cancer was correlated with International Federation of Gynecology and Obstetrics stage and lymph node metastasis. Furthermore, restored expression of miR‑485 significantly reduced cervical cancer cell proliferation and invasion. MACC1 was identified as a direct target gene of miR‑485 in cervical cancer. MACC1 expression was significantly upregulated in cervical cancer specimens and was inversely correlated with miR‑485 expression. Additionally, the restored expression of MACC1 eliminated the suppressive effects of miR‑485 overexpression on the proliferation and invasion of cervical cancer cells. Notably, the upregulation of miR‑485 suppressed the MET proto‑oncogene, receptor tyrosine kinase (Met)/RAC‑α serine/threonine‑protein kinase (AKT) signaling pathway. These results demonstrated that miR‑485 may perform its tumor suppressive function in cervical cancer by directly targeting MACC1 and inhibiting the Met/AKT signaling pathway. Therefore, the miR‑485/MACC1 axis may be a novel and effective therapeutic target in cervical cancer.

Novel internal regulators and candidate miRNAs within miR-379/miR-656 miRNA cluster can alter cellular phenotype of human glioblastoma

Clustered miRNAs can affect functioning of downstream pathways due to possible coordinated function. We observed 78–88% of the miR-379/miR-656 cluster (C14MC) miRNAs were downregulated in three sub-types of diffuse gliomas, which was also corroborated with analysis from The Cancer Genome Atlas (TCGA) datasets. The miRNA expression levels decreased with increasing tumor grade, indicating this downregulation as an early event in gliomagenesis. Higher expression of the C14MC miRNAs significantly improved glioblastioma prognosis (Pearson’s r = 0.62; p < 3.08e-22). ENCODE meta-data analysis, followed by reporter assays validated existence of two novel internal regulators within C14MC. CRISPR activation of the most efficient internal regulator specifically induced members of the downstream miRNA sub-cluster and apoptosis in glioblastoma cells. Luciferase assays validated novel targets for miR-134 and miR-485-5p, two miRNAs from C14MC with the most number of target genes relevant for glioma. Overexpression of miR-134 and miR-485-5p in human glioblastoma cells suppressed invasion and proliferation, respectively. Furthermore, apoptosis was induced by both miRs, individually and in combination. The results emphasize the tumor suppressive role of C14MC in diffuse gliomas, and identifies two specific miRNAs with potential therapeutic value and towards better disease management and therapy.

MiR-186-5p upregulation inhibits proliferation, metastasis and epithelial-to-mesenchymal transition of colorectal cancer cell by targeting ZEB1

MicroRNA-186-5p (miR-186-5p) is upregulated and exhibits as a crucial oncogene in various human tumors. However, the functions and underlying mechanisms of this microRNA on colorectal cancer remain largely unknown. Here, we report that miR-186-5p share a lower expression in colorectal cancer cell lines (HT116, H29, SW620 and LoVo) than in normal colonic epithelial cell line NCM460. MiR-186-5p overexpression inhibits proliferation, metastasis and epithelial-to-mesenchymal transition (EMT) of colorectal cancer cell line LoVo. Zinc Finger E-Box Binding Homeobox 1 (ZEB1), an EMT related marker, is predicted as a target of miR-186-5p. Luciferase reporter assay, qRT-PCR and western blot analysis showed that miR-186-5p directly targeted the 3'-untranslated regions (3'UTR) of ZEB1 messenger RNA. Further functional experiments indicated that overexpression of miR-186-5p suppress the proliferation and metastasis ability of LoVo, which was consistent with the inhibitory effects by knockdown of ZEB1. Additionally, overexpression of ZEB1 could significantly reverse the miR-186-5p mimics initiated suppression impact of proliferation, metastasis and EMT on LoVo. In summary, miRNA-186-5p affects the proliferation, metastasis and EMT process of colorectal cancer cell by inhibition of ZEB1. Hence, it may serve as a promising therapeutic target for colorectal cancer.

Disease relevant modifications of the methylome and transcriptome by particulate matter (PM2.5) from biomass combustion

Exposure to particulate matter (PM) is recognized as a major health hazard, but molecular responses are still insufficiently described. We analyzed the epigenetic impact of ambient PM_2.5 from biomass combustion on the methylome of primary human bronchial epithelial BEAS-2B cells using the Illumina HumanMethylation450 BeadChip. The transcriptome was determined by the Affymetrix HG-U133 Plus 2.0 Array. PM_2.5 induced genome wide alterations of the DNA methylation pattern, including differentially methylated CpGs in the promoter region associated with CpG islands. Gene ontology analysis revealed that differentially methylated genes were significantly clustered in pathways associated with the extracellular matrix, cellular adhesion, function of GTPases, and responses to extracellular stimuli, or were involved in ion binding and shuttling. Differential methylations also affected tandem repeats. Additionally, 45 different miRNA CpG loci showed differential DNA methylation, most of them proximal to their promoter. These miRNAs are functionally relevant for lung cancer, inflammation, asthma, and other PM-associated diseases. Correlation of the methylome and transcriptome demonstrated a clear bias toward transcriptional activation by hypomethylation. Genes that exhibited both differential methylation and expression were functionally linked to cytokine and immune responses, cellular motility, angiogenesis, inflammation, wound healing, cell growth, differentiation and development, or responses to exogenous matter. Disease ontology of differentially methylated and expressed genes indicated their prominent role in lung cancer and their participation in dominant cancer related signaling pathways. Thus, in lung epithelial cells, PM_2.5 alters the methylome of genes and noncoding transcripts or elements that might be relevant for PM- and lung-associated diseases.

Comprehensive analysis of aberrantly expressed microRNA profiles reveals potential biomarkers of human lung adenocarcinoma progression

Lung adenocarcinoma (LUAD) is a complex disease that poses challenges for diagnosis and treatment. The aim of the present study is to investigate LUAD-specific key microRNAs (miRNAs) from large-scale samples in The Cancer Genome Atlas (TCGA) database. We used an integrative computational method to identify LUAD-specific key miRNAs related to TNM stage and lymphatic metastasis from the TCGA database. Twenty-five LUAD-specific key miRNAs (fold change >2, p<0.05) from the TCGA database were investigated, and 15 were found to be aberrantly expressed with respect to clinical features. Three miRNAs were correlated with overall survival (log-rank p<0.05). Then, 5 miRNAs were randomly selected for verification of expression in 53 LUAD patient tissues using qRT-PCR. Diagnostic value of these above 5 miRNAs was determined by areas under receiver operating characteristic curves (ROC). Finally, the LUAD-related miRNA miR-30a-3p was selected for verification of biologic function in A549 cells. The results of tests for cell proliferation, apoptosis, and target genes suggested that miR-30a-3p decreases cell proliferation and promotes apoptosis through targeting AKT3. Therefore, miR-30a-3p may be a promising biomarker for the early screening of high-risk populations and early diagnosis of LUAD. Our studies provide insights into identifying novel potential biomarkers for diagnosis and prognosis of LUAD.

DLK1-DIO3 imprinted locus deregulation in development, respiratory disease, and cancer

INTRODUCTION

The imprinted DLK1-DIO3 locus at 14q32.1-32.31 holds biological significance in fetal development, whereby imprinting errors are causal to developmental disorders. Emerging evidence has implicated this locus in other diseases including cancer, highlighting the biological parallels between fetal organ and tumour development. Areas covered: Controlled regulation of gene expression from the imprinted DLK1-DIO3 locus at 14q32.1-32.31 is crucial for proper fetal development. Deregulation of locus gene expression due to imprinting errors has been mechanistically linked to the developmental disorders Kagami-Ogata Syndrome and Temple Syndrome. In adult tissues, deregulation of locus genes has been associated with multiple malignancies although the causal genetic mechanisms remain largely uncharacterised. Here, we summarize the genetic mechanisms underlying the developmental disorders that arise as a result of improper locus imprinting and the resulting developmental phenotypes, emphasizing both the coding and noncoding components of the locus. We further highlight biological parallels common to both fetal development and disease, with a specific focus on lung development, respiratory disease, and lung cancer. Expert commentary: Many commonalities between respiratory and developmental defects have emerged with respect to the 14q32 locus, emphasizing the importance of studying the effects of imprinting on gene regulation patterns at this locus in both biological settings.

microRNA-605 promotes cell proliferation, migration and invasion in non-small cell lung cancer by directly targeting LATS2

Lung cancer is the most common cause of cancer- associated mortality for men and women worldwide. An increasing number of studies have reported that the abnormal expression of microRNAs contributes to the pathogenesis of the majority of human cancer types, including non-small cell lung cancer (NSCLC). The present study aimed to measure microRNA-650 (miR-650) expression in NSCLC and evaluate its function in NSCLC cells. Reverse transcription-quantitative polymerase chain reaction was used to determine miR-650 expression in NSCLC tissue samples and cell lines. Assays for cell proliferation, migration and invasion were performed to investigate the roles of miR-650 on NSCLC progression. Furthermore, the mechanisms underlying the effects of miR-650 on NSCLC cell growth and metastasis were determined. In the current study, miR-650 was demonstrated to be highly expressed in NSCLC tissue samples and cell lines. Inhibition of expression of miR-650 suppressed NSCLC cell proliferation, migration and invasion in vitro. Additionally, large tumor suppressor kinase 2 (LATS2) was identified as a direct target gene of miR-650 in NSCLC. LATS2 was revealed to be significantly downregulated in NSCLC tissues and was negatively correlated with miR-650 expression. Notably, LATS2 re-expression decreased NSCLC cell proliferation, migration and invasion; similar to the effects induced by miR-650 underexpression. In conclusion, the results of the current study suggest that miR-650 may serve as an oncogene by direct targeting LATS2 in NSCLC formation and progression.

microRNA-802 inhibits epithelial-mesenchymal transition through targeting flotillin-2 in human prostate cancer

miRNAs are a class of non-coding RNAs that exert critical roles in various biological processes. The aim of the present study was to identify the functional roles of miR-802 in regulating epithelial-mesenchymal transition (EMT) in prostate cancer (PCa). miR-802 expression was detected in 73 pairs of PCa samples and PCa cell lines (PC3 and DU145 cells) by qRT-PCR. Cell proliferation was detected using MTT assay, and cell apoptosis was evaluated using flow cytometry. Transwell assay was conducted to investigate cell migration and invasion. Expression analysis of a set of EMT markers was performed to explore whether miR-802 is involved in EMT program. Xenograft model was established to investigate the function of miR-802 in carcinogenesis in vivo The direct regulation of Flotillin-2 (Flot2) by miR-802 was identified using luciferase reporter assay. miR-802 was remarkably down-regulated in PCa tissues and cell lines. Gain-of-function trails showed that miR-802 serves as an 'oncosuppressor' in PCa through inhibiting cell proliferation and promoting cell apoptosis in vitro Overexpression of miR-802 significantly suppressed in vivo PCa tumor growth. Luciferase reporter analysis identified Flot2 as a direct target of miR-802 in PCa cells. Overexpressed miR-802 significantly suppressed EMT, migration and invasion in PCa cells by regulating Flot2. We identified miR-802 as a novel tumor suppressor in PCa progression and elucidated a novel mechanism of the miR-802/Flot2 axis in the regulation of EMT, which may be a potential therapeutic target.