MicroRNAs in human lung cancer

Effects of miR-132-3p on progress and epithelial mesenchymal transition of non-small cell lung cancer via regulating KLF7

Background

MicroRNAs (miRNAs) often appear as oncogenes or tumor suppressor genes. The aim of this research was to examine miR-132-3p and Kruppel-like factor 7 (KLF7) effects in the development of non-small cell lung cancer (NSCLC).

Methods

We used quantitative reverse transcription polymerase chain reaction (qRT-PCR) to determine miR-132-3p expression in tissue specimens and 6 cells (A549, H1650, H292, H1299, H1944, BEAS-2b). Luciferase report forecasted the targeting relationship between miR-132-3p and KLF7. The expression of KLF7 and interstitial protein was determined by western blot. Proliferation test and Transwell assay were adopted for examining cell development. The Cell Counting Kit-8 (CCK-8) colorimetric method was used to observe the effects of miR-132-3p and KLF7 on the proliferation, metastasis, and invasion of NSCLC tumor cells. In order to determine whether the metastasis of NSCLC tumor cells was epithelial-mesenchymal transition (EMT)-mediated, supplementary experiments with E-cadherin and vimentin were performed.

Results

An increased expression of miR-132-3p was detected in NSCLC. Its mimic promoted the proliferation of tumor cells. As an immediate site of miR-132-3p, KLF7 was reversely adjusted via miR-132-3p and restrained the development of tumor cells in NSCLC, the effects of which were attenuated via KLF7 over-expression. Besides, the presence of EMT-related diversions was confirmed in NSCLC.

Conclusions

By targeting KLF7, miR-132-3p was capable of promoting the proceeding of NSCLC tumor cells. We discovered miR-132-3p/KLF7 route may exhibit curative target for NSCLC.

Gynecologic cancers and non-coding RNAs: Epigenetic regulators with emerging roles

Gynecologic cancers involve the female genital organs, such as the vulva, vagina, cervix, endometrium, ovaries, and fallopian tubes. The occurrence and frequency of gynecologic cancer depends on personal lifestyle, history of exposure to viruses or carcinogens, genetics, body shape, and geographical habitat. For a long time, research into the molecular biology of cancer was broadly restricted to protein-coding genes. Recently it has been realized that non-coding RNAs (ncRNA), including long noncoding RNAs (LncRNAs), microRNAs, circular RNAs and piRNAs (PIWI-interacting RNAs), can all play a role in the regulation of cellular function within gynecological cancer. It is now known that ncRNAs are able to play dual roles, i.e. can exert both oncogenic or tumor suppressive functions in gynecological cancer. Moreover, several clinical trials are underway looking at the biomarker and therapeutic roles of ncRNAs. These efforts may provide a new horizon for the diagnosis and treatment of gynecological cancer. Herein, we summarize some of the ncRNAs that have been shown to be important in gynecological cancers.

miR-331-3p Inhibits Tumor Cell Proliferation, Metastasis, Invasion by Targeting MLLT10 in Non-Small Cell Lung Cancer

Objective

Mounting research has established the role of microRNAs (miRNAs) as oncogenes or anti-oncogenes (tumor suppressors) in the development and progression of several cancers. The purpose of our current study is to delineate the roles and functional mechanisms of miR-331-3p and MLLT10 in non-small cell lung cancer (NSCLC) tumorigenesis.

Patients and Methods

Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was employed to measure miR-331-3p expression levels in twenty-six matched tumor tissues and non-cancerous tissues collected from patients suffering from NSCLC, and from six NSCLC cell lines separately: A549, H1650, H292, H1299, H1944 and BEAS-2b. We employed the dual-luciferase activity assay to check whether the putative gene, MLLT10, was a downstream target of miR-331-3p in NSCLC pathogenesis and development. Western blot was conducted to analyze the protein expression levels of MLLT10 (AF10), E-cadherin, Vimentin, and GAPDH. CCK-8 assay, transwell migration assay, and transwell invasion assay were carried out to observe the functions of miR-331-3p and MLLT10 on NSCLC tumor cell proliferation, metastasis, and invasion, respectively. To identify whether the metastasis of NSCLC tumor cells was EMT-mediated, supplementary experiments involving E-cadherin and Vimentin were implemented.

Results

miR-331-3p was downregulated in NSCLC, which promoted tumor cell proliferation, whereas the overexpression of miR-331-3p inhibited tumor cell proliferation. Being a direct target of miR-331-3p, MLLT10 was negatively modulated by miR-331-3p, which suppressed tumor cell proliferation, migration, and invasion in NSCLC. However, MLLT10 overexpression alleviated the above inhibitory effects. Furthermore, EMT-mediated metastasis was proved to be present in NSCLC.

Conclusion

miR-331-3p played a suppressor role in NSCLC tumor cell proliferation, EMT-mediated metastasis, and invasion by targeting MLLT10. Our findings highlighted that miR-331-3p/MLLT10 axis could be useful as a clinical diagnostic marker and therapeutic target in NSCLC patients.

MicroRNA‑28 promotes the proliferation of non‑small‑cell lung cancer cells by targeting PTEN

Non-small-cell lung cancer (NSCLC) is the fundamental form of lung cancer and the leading cause of cancer‑related mortality in humans. Numerous studies have identified a role for microRNAs (miRs) in cell proliferation, invasion and metastasis in numerous types of cancer, including lung cancer. In the present study, the functional roles and molecular mechanisms of miR‑28 in NSCLC tumorigenesis were investigated. Reverse transcription‑quantitative PCR (RT‑qPCR) was used to measure miR‑28 expression levels in NSCLC tumor tissues and cell lines. A dual‑luciferase assay was performed to observe the direct interaction between miR‑28 and PTEN in A549 cells. Furthermore, the effect of miR‑28 on the mRNA and protein expression levels of PTEN was examined by RT‑qPCR and western blotting, respectively. A Cell Counting kit‑8 assay was performed to identify the relationship between the miR‑28/PTEN axis and tumor cell proliferation using cells infected with lentivirus (LV)‑anti‑miR‑28 or LV‑anti‑miR‑28 + short hairpin RNA‑PTEN. miR‑28 expression was upregulated in NSCLC tumor tissues and cell lines compared with the control groups. PTEN was identified as the downstream gene of miR‑28 in NSCLC and was negatively regulated by miR‑28. In addition, miR‑28 knockdown suppressed the proliferation of A549 and H292 cells. Cells infected with LV‑anti‑miR‑28 + short hairpin RNA‑PTEN promoted tumor cell proliferation in A549 and H292 cells compared with cells infected with LV‑anti‑miR‑28. Taken together, the present study suggested that miR‑28 might serve as the promoter in the development of NSCLC by targeting PTEN. Therefore, the miR‑28/PTEN axis may serve as a potential diagnostic and therapeutic target for NSCLC.

Circ_PUM1 promotes the development of endometrial cancer by targeting the miR-136/NOTCH3 pathway

Endometrial cancer is one of the most common gynaecological malignancies and the sixth most common cause of cancer-related death among women. Here, we define the role and molecular mechanism of circ_0000043 (hereafter referred to as circ_PUM1) in the development and progression of endometrial carcinoma. QRT-PCR was used to detect the expression of circ_PUM1 in normal endometrial tissue and endometrial carcinoma tissues. Changes in cell function and tumorigenicity in nude mice were examined after circ_PUM1 overexpression or knockdown. Bioinformatic analysis and dual-luciferase reporter assay were used to predict and analyse the miRNAs that circ_PUM1 binds. Gene expression changes were analysed using Western blot. Circ_PUM1 was expressed at significantly higher levels in endometrial cancer tissues than in normal tissues. Up-regulation of circ_PUM1 promoted the proliferation, migration and invasion of endometrial carcinoma cells. Opposite results were observed with circ_PUM1 knockdown, and the tumorigenic ability of endometrial cancer cells after circ_PUM1 knockdown was reduced compared to control cells. Circ_PUM1 is capable of binding to miR-136, and up-regulating its target gene NOTCH3, which can be reversed by overexpression of miR-136. Circ_PUM1 can compete with miR-136, leading to up-regulation of NOTCH3, and thereby promote the development of endometrial cancer.

MicroRNAs in Vascular Eye Diseases

Since the discovery of the first microRNA (miRNA) decades ago, studies of miRNA biology have expanded in many biomedical research fields, including eye research. The critical roles of miRNAs in normal development and diseases have made miRNAs useful biomarkers or molecular targets for potential therapeutics. In the eye, ocular neovascularization (NV) is a leading cause of blindness in multiple vascular eye diseases. Current anti-angiogenic therapies, such as anti-vascular endothelial growth factor (VEGF) treatment, have their limitations, indicating the need for investigating new targets. Recent studies established the roles of various miRNAs in the regulation of pathological ocular NV, suggesting miRNAs as both biomarkers and therapeutic targets in vascular eye diseases. This review summarizes the biogenesis of miRNAs, and their functions in the normal development and diseases of the eye, with a focus on clinical and experimental retinopathies in both human and animal models. Discovery of novel targets involving miRNAs in vascular eye diseases will provide insights for developing new treatments to counter ocular NV.

MiR-338 regulates NFATc1 expression and inhibits the proliferation and epithelial-mesenchymal transition of human non-small-cell lung cancer cells

BACKGROUND

It is well known that nuclear factor of activated T cells c1 (NFATc1) expression is closely associated with progression of many cancers. And we found that miR-338 could directly target the NFATc1. However, the precise mechanisms of miR-338 in non-small-cell lung cancer (NSCLC) have not been well clarified. Our study aimed to explore the interaction between NFATc1 and miR-338 in NSCLC.

METHODS

Quantitative RT-PCR was utilized to determine the expressions of NFATc1 and miR-338 in NSCLC tissues and cell lines. And the cell proliferation and epithelial-mesenchymal transition (EMT) were assessed to determine the functional roles of miR-338 and NFATc1 in NSCLC cells. NFATc1 expression was detected using quantitative RT-PCR and western blotting, respectively. Luciferase reporter assays were performed to validate NFATc1 as a target of miR-338 in NSCLC cells.

RESULTS

In this study, our results showed that NFATc1 expression was significantly up-regulated in NSCLC tissues and cell lines, and the miR-338 level was dramatically down-regulated. Moreover high NFATc1 expression was closely associated with low miR-338 level in NSCLC tissues. Moreover introduction of miR-338 significantly inhibited proliferation and EMT of NSCLC cells. Bioinformatics analysis predicted that the NFATc1 was a potential target gene of miR-338. We demonstrated that miR-338 could directly target NFATc1 by using luciferase reporter assay. Besides, knockdown of NFATc1 had the similar effects with miR-338 overexpression on NSCLC cells. Up-regulation of NFATc1 in NSCLC cells partially abolished the inhibitory effects of miR-338 mimic.

CONCLUSIONS

Overexpression of miR-338 inhibited cell proliferation and EMT of NSCLC cells by directly down-regulating NFATc1 expression.

MicroRNA and mRNA Interaction Network Regulates the Malignant Transformation of Human Bronchial Epithelial Cells Induced by Cigarette Smoke

This study analyzes the correlation and interaction of miRNAs and mRNAs and their biological function in the malignant transformation of BEAS-2B cells induced by cigarette smoke (CS). Normal human bronchial epithelial cells (BEAS-2B) were continuously exposed to CS for 30 passages (S30) to establish an in vitro cell model of malignant transformation. The transformed cells were validated by scratch wound healing assay, transwell migration assay, colony formation and tumorigenicity assay. The miRNA and mRNA sequencing analysis were performed to identify differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) between normal BEAS-2B and S30 cells. The miRNA-seq data of lung cancer with corresponding clinical data obtained from TCGA was used to further identify lung cancer-related DEMs and their correlations with smoking history. The target genes of these DEMs were predicted using the miRDB database, and their functions were analyzed using the online tool “Metascape.” It was found that the migration ability, colony formation rate and tumorigenicity of S30 cells enhanced. A total of 42 miRNAs and 753 mRNAs were dysregulated in S30 cells. The change of expression of top five DEGs and DEMs were consistent with our sequencing results. Among these DEMs, eight miRNAs were found dysregulated in lung cancer tissues based on TCGA data. In these eight miRNAs, six of them including miR-96-5p, miR-93-5p, miR-106-5p, miR-190a-5p, miR-195-5p, and miR-1-3p, were found to be associated with smoking history. Several DEGs, including THBS1, FN1, PIK3R1, CSF1, CORO2B, and PREX1, were involved in many biological processes by enrichment analysis of miRNA and mRNA interaction. We identified the negatively regulated miRNA-mRNA pairs in the CS-induced lung cancer, which were implicated in several cancer-related (especially EMT-related) biological process and KEGG pathways in the malignant transformation progress of lung cells induced by CS. Our result demonstrated the dysregulation of miRNA-mRNA profiles in cigarette smoke-induced malignant transformed cells, suggesting that these miRNAs might contribute to cigarette smoke-induced lung cancer. These genes may serve as biomarkers for predicting lung cancer pathogenesis and progression. They can also be targets of novel anticancer drug development.

HisCoM-mimi: Software for Hierarchical Structural Component Analysis for miRNA-mRNA Integration Model for Binary Phenotypes

To identify miRNA-mRNA interaction pairs associated with binary phenotypes, we propose a hierarchical structural component model for miRNA-mRNA integration (HisCoM-mimi). Information on known mRNA targets provided by TargetScan is used to perform HisCoM-mimi. However, multiple databases can be used to find miRNA-mRNA signatures with known biological information through different algorithms. To take these additional databases into account, we present our advanced application software for HisCoM-mimi for binary phenotypes. The proposed HisCoM-mimi supports both TargetScan and miRTarBase, which provides manually-verified information initially gathered by text-mining the literature. By integrating information from miRTarBase into HisCoM-mimi, a broad range of target information derived from the research literature can be analyzed. Another improvement of the new HisCoM-mimi approach is the inclusion of updated algorithms to provide the lasso and elastic-net penalties for users who want to fit a model with a smaller number of selected miRNAs and mRNAs. We expect that our HisCoM-mimi software will make advanced methods accessible to researchers who want to identify miRNA-mRNA interaction pairs related with binary phenotypes.

MiR-106a directly targets LIMK1 to inhibit proliferation and EMT of oral carcinoma cells

Background

LIM kinase 1 (LIMK1) expression levels are closely associated with microRNA (miRNA) processing. Higher levels of LIMK1 are reported during the progression of many cancers. Our study explored the interaction between LIMK1 and miR-106a in oral squamous cell carcinoma (OSCC).

Methods

Quantitative RT-PCR was performed to detect the levels of LIMK1 and miR-106a in OSCC tissues and cell lines. The rates of cell proliferation and epithelial-mesenchymal transition (EMT) were assessed to determine the biological functions of miR-106a and LIMK1 in OSCC cells. The mRNA and protein levels of LIMK1 were measured using quantitative RT-PCR and western blotting. Luciferase assays were performed to validate LIMK1 as an miR-106a target in OSCC cells.

Results

We found that the level of miR-106a significantly decreased and the expression of LIMK1 significantly increased in OSCC tissues and cell lines. There was a close association between these changes. Knockdown of LIMK1 significantly inhibited the proliferation and EMT of OSCC cells. The bioinformatics analysis predicted that LIMK1 is a potential target gene of miR-106a and the luciferase reporter assay confirmed that miR-106a could directly target LIMK1. Introduction of miR-106a to OSCC cells had similar effects to LIMK1 silencing. Overexpression of LIMK1 in OSCC cells partially reversed the inhibitory effects of the miR-106a mimic.

Conclusion

MiR-106a inhibited the cell proliferation and EMT of OSCC cells by directly decreasing LIMK1 expression.

Encapsulated miR-200c and Nkx2.1 in a nuclear/mitochondria transcriptional regulatory network of non-metastatic and metastatic lung cancer cells

BACKGROUND

MicroRNAs are noncoding RNA molecules of ~ 22 nucleotides with diagnostic and therapeutic action [Curr Drug Targets, 2015. 16(12): p. 1381-403], affecting the expression of mRNAs involved in invasion, migration, and development [Oncotarget, 2015. 6(9): p. 6472-98, Cancer Manag Res, 2014. 6: p. 205-16]. miR-200c is part of the miR-200c/141 cluster on chromosome 12p13. Its mechanism of action when encapsulated is critical in lung cancer when patients express changes in miRNAs. miR-200c be a potential biomarkers for various lung diseases. As a potential therapy, miR-200c can impacts lives as target lung cancer is a leading cause of death with about 234,000 cases annually, high heterogeneity, complex screening, and a 5-year survival rate of 16% [CA Cancer J Clin, 2016.66(1): p. 7-30]. Encapsulated miR-200c efficiently enhances bioavailability, pharmacokinetics of therapeutics and targeting to cells, improves efficacy and provides potential cure.

METHODS

The functions of miR-200c were determined in non-metastatic KW-634 and metastatic 821-T4 and 821-LN mouse lung cancer cell lines after various Nano vehicle treatments. Viability and cytotoxicity were determined by cell cycle and quantitative real-time PCR analyses were used to quantify levels of miR-200c and its target genes. In situ hybridization was used to visualize patterns of expression of miR-200c and others in the lung and many organs. Next-generation sequencing accession number GSE125000, invasion and migration assays using transwell chambers, and ActivSignal were used to elucidate the activation and inhibition profiles and perform direct expression measurements and modification of cellular components.

RESULTS

Due to their effectiveness as intracellular vesicles transporting miR-200c into, out, and between parts of the cells, miR-200c is encapsulated with cholesterol, an integral part of the biological membranes with very important physical properties of the vehicle. Nano miR-200c showed efficient cellular uptake in KW-634, 821-T4, and 821-LN cells with important changes in gene expression and new isoforms. In KW-634, when treated with encapsulated miR-200c and compare to the non-encapsulated control; miR-29b increased by 5261-fold, and in 821-T4/LN, miR-1247 increased by 150-fold. Conversely, miR-1247 and miR-675 decreased by 348 and 1029.5-fold, respectively. miR-189 decreased by 34-fold in treated 821-T4 cells. A reduction of growth was observed only after 48 h of treatment with Nano miR-200c. Moreover, labeling the vehicle with carboxy-fluorescein showed that the encapsulated particles enter the nucleus and mitochondria. Encapsulated miR-200c by entering the cells, the nucleus and mitochondria, trigger changes in cell cycle phases with 4 up to 12 fold percentage in G2 and S phase respectively compare to miR-200c. Endogenous expression of Nkx2.1, miR-200c, and their targets Myb, Nfib, Six4 and Six1 showed an inverse correlation, as observed in development.

CONCLUSIONS

Little is known about miR-200c involvement in regulatory processes. Nano miR-200c affects invasion and migration mechanisms. The expression of encapsulated miR-200c contributes to the inhibition/activation of Kras, EMT, Hippo, regulatory pathways and blockers of metastasis. Delivery of miR-200c increases the expression of miR-29b, an EMY regulator, and miR-1247, an inhibitor of cancer genes, both tumor suppressors involved in lung metastasis. Encapsulated miR-200c act on different proteins that regulates cell cycle pathways. These findings represent a part of a regulatory network providing new insights towards improvement of therapy.

Inhibition of microRNA‑939 suppresses the development of human non‑small cell lung cancer via the upregulation of tissue inhibitor of metalloproteinases 2

Numerous microRNAs (miRNA/miRs) have been reported to be associated with the initiation and progression of non‑small cell lung cancer (NSCLC). The aim of the present study was to examine the expression and biological role of miR‑939 in human NSCLC, in vitro. Reverse transcription‑quantitative polymerase chain reaction analysis was used to evaluate the expression of miR‑939 in NSCLC tissues. Cell Counting Kit‑8, 5‑ethynyl‑29‑deoxyuridine and Transwell assays were also used to determine the effects of miR‑939 on tumor cell proliferation and invasion in two human NSCLC cell lines (H1299 and SPCA1). Furthermore, tissue inhibitor of metalloproteinases 2 (TIMP2) was confirmed to be a target of miR‑939 by luciferase reporter assay, western blotting and bioinformatics analysis. Following downregulation of miR‑939 expression, cell proliferative and invasive abilities were significantly suppressed. Collectively, these findings indicated that the knockdown of miR‑939 may inhibit cell proliferation and invasion by regulating the expression of TIMP2 in NSCLC cells. Thus, miR‑939 may be a potential target in the treatment of NSCLC, although this requires further investigation.

Long non-coding RNA OGFRP1 regulates LYPD3 expression by sponging miR-124-3p and promotes non-small cell lung cancer progression

Long noncoding RNA (OGFRP1) has been reported to be involved in the progression of non-small cell lung cancer (NSCLC). However, the expression pattern, functions and molecular mechanisms of OGFRP1 in NSCLC remains unclear. In the present study, we found that OGFRP1 expression was significantly up-regulated in both NSCLC tissues and cell lines, and the upregulation of OGFRP1 expression is a powerful predictor of advanced clinical stage, lymph nodes metastasis and poor prognosis for NSCLC patients. Loss-of-function assay indicated that knockdown of OGFRP1 inhibited proliferation, migration and invasion, and induced apoptosis in vitro. Mechanistically, OGFRP1 could directly bind to miR-124-3p and effectively act as a competing endogenous RNA (ceRNA) for miR-124-3p to promote the expression of the target gene LYPD3. Taken together, OGFRP1 contributed to progression of NSCLC at least partly through upregulating LYPD3 expression by sponging miR-124-3p, indicating that OGFRP1 may be a novel prognostic biomarker and therapeutic target in NSCLC.

Hierarchical structural component modeling of microRNA-mRNA integration analysis

BACKGROUND

Identification of multi-markers is one of the most challenging issues in personalized medicine era. Nowadays, many different types of omics data are generated from the same subject. Although many methods endeavor to identify candidate markers, for each type of omics data, few or none can facilitate such identification.

RESULTS

It is well known that microRNAs affect phenotypes only indirectly, through regulating mRNA expression and/or protein translation. Toward addressing this issue, we suggest a hierarchical structured component analysis of microRNA-mRNA integration ("HisCoM-mimi") model that accounts for this biological relationship, to efficiently study and identify such integrated markers. In simulation studies, HisCoM-mimi showed the better performance than the other three methods. Also, in real data analysis, HisCoM-mimi successfully identified more gives more informative miRNA-mRNA integration sets relationships for pancreatic ductal adenocarcinoma (PDAC) diagnosis, compared to the other methods.

CONCLUSION

As exemplified by an application to pancreatic cancer data, our proposed model effectively identified integrated miRNA/target mRNA pairs as markers for early diagnosis, providing a much broader biological interpretation.

The clinical value of miR-193a-3p in non-small cell lung cancer and its potential molecular mechanism explored in silico using RNA-sequencing and microarray data

miR‐193a‐3p is a tumor‐related miRNA playing an essential role in tumorigenesis and progression of non‐small cell lung cancer (NSCLC). The objective of the present study was to investigate the relationship between miR‐193a‐3p expression and clinical value and to further explore the potential signaling of miR‐193a‐3p in the carcinogenesis of NSCLC. RNA‐sequencing and microarray data were collected from the databases GEO, ArrayExpress and The Cancer Genome Atlas (TCGA). Furthermore, in silico assessments were performed to analyze the prospective pathways and networks of the target genes of miR‐193a‐3p. In total, 453 cases of NSCLC patients and 476 normal controls were included in blood samples, while 920 cases of NSCLC patients and 406 normal controls were included in tissue samples. The pooled positive likelihood ratio, the pooled negative likelihood ratio and the pooled diagnostic odds ratio were calculated to reflect the diagnostic value of miR‐193a‐3p in blood and tissue samples. Moreover, the areas under the curve of the summary receiver operating characteristic curve of blood and tissue were 0.64 and 0.79, respectively. In addition, we found a lower level of miR‐193a in NSCLC tissues than in non‐cancerous controls based on TCGA. A gene ontology (GO) enrichment analysis demonstrated that miR‐193a‐3p could be related to key signaling pathways in NSCLC. Also, several vital pathways were illustrated by KEGG. Lower expression of miR‐193a‐3p in tissue samples of NSCLC may be associated with tumorigenesis and be a predictor of deterioration of NSCLC patients, and pathway analysis revealed crucial signaling pathways correlated with the incidence and progress of NSCLC.

Tiny RNAs and their voyage via extracellular vesicles: Secretion of bacterial small RNA and eukaryotic microRNA

MicroRNAs are small non-coding RNAs that bind to the 3'-untranslated region of target mRNAs and have transcriptional or translational inhibitory function in eukaryotes. Before microRNAs were widely known, bacterial non-coding small RNAs around 50-200 nt in length were discovered whose mechanism of action resembled that of microRNAs. Recently, RNAs that are of similar size to or smaller than microRNAs have been discovered in bacteria and indeed, this class of small RNAs have been found throughout all domains of life. Moreover, recent findings suggest that these tiny RNAs can be released via extracellular vesicles (such as exosomes in eukaryotes and outer membrane vesicles in bacteria), which in turn heralds a new field of research, interkingdom communication. This review discusses two similar classes of small RNAs in evolutionarily distinct eukaryotes and bacteria. In addition to their biogenesis and regulation, we discuss small RNA vehicles and their secretion. Impact statement The possible endogenous functions of small RNAs such as regulatory small RNAs in bacteria and microRNAs in eukaryotes have been extensively studied since they were first discovered. However, their powerful functions should not be seen as limited to their cells of origin. Recently, several papers have demonstrated that small RNAs function as signaling molecules between cells. This is possible because small RNAs can be shuttled around after being incorporated into environmentally protective extracellular vesicles. It is now clearly plausible that secreted small RNAs can regulate other types of cells through biofluids. Given their "common molecule" status, the role of small RNAs in mediating bacteria-human crosstalk is an emerging and competitive area of genetic research. This review provides insight into the function of small RNAs in intercellular and even interkingdom communication.

Oncogenic miR-19a and miR-19b co-regulate tumor suppressor MTUS1 to promote cell proliferation and migration in lung cancer

MTUS1 (microtubule-associated tumor suppressor 1) has been identified that can function as a tumor suppressor gene in many malignant tumors. However, the function and mechanisms underlying the regulation of MTUS1 are unclear. In the present study, we reported that miR-19a and miR-19b (miR-19a/b) promote proliferation and migration of lung cancer cells by targeting MTUS1. First, MTUS1 was proved to function as a tumor suppressor in lung cancer and was linked to cell proliferation and migration promotion. Second, an inverse correlation between miR-19a/b expression and MTUS1 mRNA/protein expression was noted in human lung cancer tissues. Third, MTUS1 was appraised as a direct target of miR-19a/b by bioinformatics analysis. Fourth, direct MTUS1 regulation by miR-19a/b in lung cancer cells was experimentally affirmed by cell transfection assay and luciferase reporter assay. Finally, miR-19a/b were shown to cooperatively repress MTUS1 expression and synergistically regulate MTUS1 expression to promote lung cancer cell proliferation and migration. In conclusion, our findings have provided the first clues regarding the roles of miR-19a/b, which appear to function as oncomirs in lung cancer by downregulating MTUS1.

[Expression profile of miR-501-5p in lung adenocarcinoma patients from Xuanwei area]

OBJECTIVE

To investigate the relationship between miR-501-5p expression and the clinicopathological factors in patients with lung adenocarcinoma in Xuanwei area.

METHODS

Surgical specimens of lung adenocarcinoma and paired adjacent tissues from 24 patients with lung adenocarcinoma from Xuanwei area were examined for miR-501-5p expression using microRNA microarray technique and qPCR. Chi-square test was used to analyze the association of miR-501-5P expression with the clinicopathological characteristics of the patients. Multiple regression analysis was performed to analyze the association of miR-501-5p expression with the patients' gender, age, tumor stage, and preoperative CEA level.

RESULTS

MicroRNA microarray analysis and qPCR validation results revealed significantly upregulated expressions of miR-501-5p in patients with lung adenocarcinoma from Xuanwei area (Plt;0.01). The microarray data showed an up-regulation of miR-501-5p by 3.17 folds in lung adenocarcinoma tissue compared with the adjacent tissue (P=0.22376, FDR=0.071395). Chi-square test indicated that miR-501-5p expression level was associated with the patients' age (f=7.168, P=0.014), TNM stage (f=36.627, P<0.01), and preoperative serum CEA level (f=30.045, Plt;0.01), but not with the patients' gender (f=3.612, P=0.071). Multiple regression analysis revealed that miR-501-5p expression was positively correlated with the patients' age, TNM stage of the tumor, and serum CEA (Plt;0.05).

CONCLUSION

miR-501-5p expression is up-regulated in lung adenocarcinoma with significant associations with the patients' age, TNM stages and serum CEA level in patients from Xuanwei area, suggesting its potential role in the tumorigenesis and progression of lung adenocarcinoma in Xuanwei area.

Endogenous microRNA-424 predicts clinical outcome and its inhibition acts as cancer suppressor in human non-small cell lung cancer

PURPOSE

We examined the expression, clinical correlation and functional mechanisms of endogenous microRNA-424 (miR-424) in human non-small cell lung cancer (NSCLC).

METHODS

Expression pattern of endogenous miR-424 was examined by qRT-PCR in clinical samples obtained from 233 NSCLC patients. Correlations between differential miR-424 expression level (low vs. high) and NSCLC patients' clinicopathological parameters or survival were statistically examined. In in vitro NSCLC H596 and SW900 cells, miR-424 was either upregulated or downregulation by lentiviral transduction. Their effects on cancer cell viability, proliferation, and cell-cycle transition were also examined.

RESULTS

MiR-424 expression was not different between NSCLC tumors and healthy lung tissues. However, it is much upregulated in NSCLC tumors associated with patients at advanced clinical stages. Statistical analyses demonstrated that high endogenous miR-424 expression in NSCLC tumors was significantly correlated with patients' advanced clinical stages, aggressive tumor metastasis, and short survival. In addition, Cox regression model predicted that endogenous miR-424 might be an independent prognostic marker in NSCLC. In in vitro NSCLC cell lines, miR-424 downregulation had a significant suppressing effect on cancer proliferation and G1 to S phase cell-cycle transition. On the other hand, miR-424 upregulation had no effect on NSCLC in vitro.

CONCLUSION

High endogenous miR-424 expression in tumors may predict poor prognosis of patients with NSCLC. Inhibiting endogenous miR-424 may also serve an effective cancer suppressor in NSCLC.

MicroRNA-98 Plays a Suppressive Role in Non-Small Cell Lung Cancer Through Inhibition of SALL4 Protein Expression

MicroRNAs (miRs) have been demonstrated to be significantly associated with the development and progression of non-small cell lung cancer (NSCLC). However, the underlying mechanism of miR-98 in mediating the malignant phenotypes of NSCLC cells remains obscure. In this study, we found that miR-98 was significantly downregulated in NSCLC tissues compared to nontumor lung tissues. Downregulation of miR-98 was significantly associated with poor differentiation and advanced clinical stage. Restoration of miR-98 expression significantly decreased the proliferation, migration, and invasion of NSCLC A549 and H1229 cells. SALL4 was identified as a target gene of miR-98, and the protein expression of SALL4 was negatively regulated by miR-98 in NSCLC A549 and H1229 cells. Overexpression of SALL4 promoted A549 and H1229 cell proliferation, migration, and invasion and reversed the suppressive effects of miR-98 on the malignant phenotypes of A549 and H1229 cells. Moreover, SALL4 was found to be significantly upregulated in NSCLC tissues compared to the nontumor lung tissues. We then observed an inverse correlation between the miR-98 and SALL4 levels in NSCLC tissues. In vivo study revealed that miR-98 overexpression suppressed NSCLC growth. In summary, we demonstrate that miR-98 acts as a tumor suppressor in NSCLC cells by inhibiting the protein expression of its target gene SALL4. Therefore, our study highlights the importance of the miR-98/SALL4 axis in NSCLC.

MicroRNA-29a plays a suppressive role in non-small cell lung cancer cells via targeting LASP1

MicroRNA (miR)-29a has been implicated in non-small cell lung cancer (NSCLC), but the mechanism remains largely unclear. LASP1, a cAMP- and cGMP-dependent signaling protein, was recently found to promote proliferation and aggressiveness in NSCLC. However, the regulatory mechanism of LASP1 expression in NSCLC, as well as the relationship between LASP1 and miR-29a, has never been previously studied. In this study, we found that miR-29a was remarkably downregulated and low expression of miR-29a was associated with the malignant progression of NSCLC. Moreover, the expression of LASP1 was markedly increased in NSCLC tissues and cell lines. Bioinformatics analysis and luciferase reporter assay data further identified LASP1 as a target gene of miR-29a, and the expression of LASP1 was negatively mediated by miR-29a at the post-transcriptional level in NSCLC cells. Overexpression of miR-29a reduced the proliferation, migration, and invasion of NSCLC cells, just as the effects of LASP1 knockdown. Moreover, overexpression of LASP1 attenuated the suppressive effect of miR-29a on the malignant phenotypes of NSCLC cells. In addition, upregulation of miR-29a decreased the growth of A549 cells in nude mice and protected the animals from tumor-induced death. Therefore, we demonstrate that miR-29a plays a suppressive role in NSCLC via targeting LASP1, suggesting that the miR-29a/LASP1 axis may become a promising therapeutic target for NSCLC.

miRNA-204 suppresses human non-small cell lung cancer by targeting ATF2

MicroRNAs (miRNAs) play a critical role in cancer development and progression. Deregulated expression of miR-204 has been reported in several cancers, but the mechanism through which miR-204 modulates human non-small cell lung cancer (NSCLC) is largely unknown. In this study, we investigate the expression and functional role of miR-204 in human NSCLC tissues and cell lines. RNA isolation, qRT-PCR, MTT, colony formation assay, cell cycle assay, cell apoptosis assay, cell migration assay, and Western blot were performed. Statistical analysis was performed using SPSS 18.0 software and statistical significance was accepted at p value <0.05. miR-204 level was significantly reduced in NSCLC tissues as compared to that of non-neoplastic tissues. Transient over-expression of miR-204 by transfecting with miR-204 mimics suppressed NSCLC cell proliferation, migration, and induced apoptosis and G1 arrest, whereas inhibition of miR-204 showed the converse effects. Additionally, activating transcription factor 2 (ATF2), an important transcription factor, was demonstrated as a potential target gene of miR-204. Subsequent investigations found a negative correlation between miR-204 level and ATF2 expression in NSCLC tissue samples. Moreover, we observed that miR-204 expression inversely affected endogenous ATF2 expression at both mRNA and protein levels in vitro. Taken together, miR-204 may act as a tumor suppressor by directly targeting ATF2 in NSCLC.

Up-regulation of miR-130b expression level and down-regulation of miR-218 serve as potential biomarker in the early detection of human osteosarcoma

Background

Osteosarcoma (OS) is a primary malignant bone tumor with high morbidity that principally emerges in children and adolescents. MiRNAs regulate a variety of normal physiologic processes and are involved in tumorigenesis and development of multiple malignancies, including OS. This study was aimed to evaluate the clinical significance of miR-130b and miR-218 in osteosarcoma patient.

Methods

We utilized quantitative real-time PCR to evaluate the level of miR-130b and miR-218 expressions in OS patients and normal tissues and their relationship with clinicopathological features and survival in OS patients.

Results

QRT-PCR indicated that miR-130b expression in tumor tissues was strongly elevated than adjacent non-tumor tissues (P < 0.001), while the level of miR-218 expression in osteosarcoma tissues was down-regulated than adjacent non-tumor tissues (P < 0.001). We evaluated the clinical significance of miR-130b and miR-218 in osteosarcoma. Clinical correlation analysis showed that increased expression of miR-130b and decreased expression of miR-218 were significantly associated with advanced tumor stage (x² = 6.285, P < 0.009; x² = 7.172, P < 0.007), distant metastasis (x²  = 5.528; P < 0.001; x² = 4.617, P < 0.001) and size of tumor (x² = 5.01, P = 0.013; x² = 4.271, P = 0.019).

Conclusions

Taken together, our data indicated that high miR-130b level and low level of miR-218 are associated with poor clinicopathological characteristics. Furthermore, miR-130b may play a key role in the progression of osteosarcoma.

The role of microRNA in nutritional control

MicroRNAs (miRNAs) are one of a growing class of noncoding RNAs that are involved in the regulation of a wide range of metabolic processes including cellular differentiation, cell proliferation and apoptosis. The generation of miRNA is regulated in complex ways, for example by small interfering RNAs (small nucleolar and nuclear RNAs) and various other metabolites. This complexity of control is likely to explain how a relatively small part of the DNA that codes for proteins has enabled the evolution of such complex organisms as mammals. Non-protein-coding DNA is therefore thought to carry the memory of early evolutionary steps that led to progressively complex metabolic controls. Clinically, miRNAs are becoming increasingly important following the recognition that some congenital abnormalities can be traced to defects in miRNA processing. The potential for manipulating metabolism and affecting disease processes by the pharmaceutical or biological targeting of specific miRNA pathways is now being tested. miRNAs are also released into the extracellular milieu after packaging by cells into nano-sized extracellular vesicles. Such vesicles can be taken up by adjacent and possibly more distant cells, thereby allowing coordinated intercellular communication in specific tissues. Extracellular miRNAs found in the blood stream may also serve as novel biomarkers for both diagnosing specific forms of cancer and assessing the likelihood of metastasis, and as powerful prognostic indices for various cancers. Here, we discuss the role of intracellular and extracellular miRNAs in nutritional control of various (patho)physiological processes. In this review, we provide an update of the presentations from the 25th Marabou Symposium (Stockholm, 14-16 June 2013) entitled 'Role of miRNA in health and nutrition', attended by 50 international experts

MicroRNA-141 is a biomarker for progression of squamous cell carcinoma and adenocarcinoma of the lung: clinical analysis of 125 patients

Lung cancer is the most common malignant tumor worldwide. MicroRNA has become an ideal biomarker for cancer diagnosis, prognosis and therapy. The relationship between microRNA-141 and non-small cell lung cancer (NSCLC) is contradictory. Thus, in current study, we aimed to investigate the level of microRNA-141 in NSCLC tissues and to evaluate its potential clinical value. This study enrolled 125 NSCLC patients (75 males and 50 females) with a median age of 61 years (range, 23-90 years). NSCLC patients included 23 squamous cell carcinomas (SCCs), 101 adenocarcinomas (ADCs) and 1 large cell carcinoma. The expression level of microRNA-141 was significantly higher in NSCLC tissues than in adjacent lung tissues (P < 0.001), detected by real time RT-PCR. Receiver operating characteristic (ROC) exhibited a moderate diagnostic value of microRNA-141 for NSCLC with the area under curve of 0.707. The microRNA-141 expression increased with the larger tumor size (P = 0.002), lymph node metastasis (P = 0.018) and advanced stage (P = 0.022) in NSCLC patients. For subgroup analysis, microRNA-141 expression in SCC was correlated with tumor size (r = 0.490, P = 0.018), and in ADC, microRNA-141 level was positively associated with tumor size (r = 0.222, P = 0.026), lymph node metastasis (r = 0.242, P = 0.015) and TNM stage (r = 0.210, P = 0.035). Furthermore, univariate analysis revealed that the expression of microRNA-141 was an independent prognostic indicator of ADC. In conclusion, microRNA-141 is a potential biomarker for the molecular diagnosis and risk stratification of NSCLC.

Biological Marker Analysis as Part of the CIBERES-RTIC Cancer-SEPAR Strategic Project on Lung Cancer

The aim of the Clinical and Molecular Staging of Stage I-IIp Lung Cancer Project is to identify molecular variables that improve the prognostic and predictive accuracy of TMN classification in stage I/IIp non-small cell lung cancer (NSCLC). Clinical data and lung tissue, tumor and blood samples will be collected from 3 patient cohorts created for this purpose. The prognostic protein signature will be validated from these samples, and micro-RNA, ALK, Ros1, Pdl-1, and TKT, TKTL1 y G6PD expression will be analyzed. Tissue inflammatory markers and stromal cell markers will also be analyzed. Methylation of p16, DAPK, RASSF1a, APC and CDH13 genes in the tissue samples will be determined, and inflammatory markers in peripheral blood will also be analyzed. Variables that improve the prognostic and predictive accuracy of TNM in NSCLC by molecular staging may be identified from this extensive analytical panel.

miR-193a-3p functions as a tumor suppressor in lung cancer by down-regulating ERBB4

ERBB4, one of four ErbB receptor tyrosine kinase family members, plays an important role in the etiology and progression of lung cancer. In this study, we found that the ERBB4 protein levels were consistently up-regulated in lung cancer tissues, whereas the mRNA levels varied randomly, suggesting that a post-transcriptional mechanism was involved in regulating ERBB4 expression. Because microRNAs are powerful post-transcriptional regulators of gene expression, we used bioinformatic analyses to search for microRNAs that can potentially target ERBB4. We identified specific targeting sites for miR-193a-3p in the 3'-UTR of ERBB4. We further identified an inverse correlation between miR-193a-3p levels and ERBB4 protein levels, but not mRNA levels, in lung cancer tissue samples. By overexpressing or knocking down miR-193a-3p in lung cancer cells, we experimentally confirmed that miR-193a-3p directly recognizes the 3'-UTR of the ERBB4 transcript and regulates ERBB4 expression. Furthermore, the biological consequences of the targeting of ERBB4 by miR-193a-3p were examined in vitro via cell proliferation, invasion, and apoptosis assays and in vivo using a mouse xenograft tumor model. We demonstrated that the repression of ERBB4 by miR-193a-3p suppressed proliferation and invasion and promoted apoptosis in lung cancer cells and that miR-193a-3p exerted an anti-tumor effect by negatively regulating ERBB4 in xenograft mice. Taken together, our findings provide the first clues regarding the role of miR-193a-3p as a tumor suppressor in lung cancer through the inhibition of ERBB4 translation.