MiR-1 targets PIK3CA and inhibits tumorigenic properties of A549 cells

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.

MicroRNA-1-3p affects lung adenocarcinoma progression through E2F8 and regulating NF-кB pathway

E2F8 can modulate development and progression of various cancers including cervical cancer, breast cancer and hepatocellular carcinoma. But its mechanism in lung adenocarcinoma (LUAD) remains underexplored. In this study, we conducted a series of experiments including qRT-PCR, western blot, CCK-8, scratch healing assay, Transwell, and flow cytometry. Through these assays, we confirmed the notable overexpression of E2F8 in LUAD and its promoting effects on LUAD cell proliferation, migration and invasion. Subsequently, microRNA-1-3p that was negatively associated with E2F8 expression was identified through bioinformatics analysis. qRT-PCR was then carried out for quantification of microRNA-1-3p expression, which displayed low microRNA-1-3p expression in LUAD cells. In addition, dual-luciferase reporter gene assay was utilized for validating the targeted relationship between microRNA-1-3p and E2F8. The results denoted that microRNA-1-3p could bind to the promoter region of E2F8. Finally, the results of rescue experiment revealed that microRNA-1-3p negatively modulated E2F8 level. It regulated NF-κB pathway to repress LUAD cell proliferative, migratory, and invasive properties, lead to cell cycle arrest in G0/G1 phase, and enhance cell apoptosis level. This study unraveled that microRNA-1-3p/E2F8 constrained LUAD malignant progression through NF-κB pathway, which may provide possible targets for LUAD diagnosis and treatment.

MicroRNA-1: Diverse role of a small player in multiple cancers

The process of cancer initiation and development is a dynamic and complex mechanism involving multiple genetic and non-genetic variations. With the development of high throughput techniques like next-generation sequencing, the field of cancer biology extended beyond the protein-coding genes. It brought the functional role of noncoding RNAs into cancer-associated pathways. MicroRNAs (miRNAs) are one such class of noncoding RNAs regulating different cancer development aspects, including progression and metastasis. MicroRNA-1 (miR-1) is a highly conserved miRNA with a functional role in developing skeletal muscle precursor cells and cardiomyocytes and acts as a consistent tumor suppressor gene. In humans, two discrete genes, MIR-1-1 located on 20q13.333 and MIR-1-2 located on 18q11.2 loci encode for a single mature miR-1. Downregulation of miR-1 has been demonstrated in multiple cancers, including lung, breast, liver, prostate, colorectal, pancreatic, medulloblastoma, and gastric cancer. A vast number of studies have shown that miR-1 affects the hallmarks of cancer like proliferation, invasion and metastasis, apoptosis, angiogenesis, chemosensitization, and immune modulation. The potential therapeutic applications of miR-1 in multiple cancer pathways provide a novel platform for developing anticancer therapies. This review focuses on the different antitumorigenic and therapeutic aspects of miR-1, including how it regulates tumor development and associated immunomodulatory functions.

The CUL4B-miR-372/373-PIK3CA-AKT axis regulates metastasis in bladder cancer

CUL4B, which acts as a scaffold protein in CUL4B-RING ubiquitin ligase (CRL4B) complexes, participates in a variety of biological processes. Previous studies have shown that CUL4B is often overexpressed and exhibits oncogenic activities in a variety of solid tumors. However, the roles and the underlying mechanisms of CUL4B in bladder cancer (BC) were poorly understood. Here, we showed that CUL4B levels were overexpressed and positively correlated with the malignancy of BC, and CUL4B could confer BC cells increased motility, invasiveness, stemness, and chemoresistance. The PIK3CA/AKT pathway was identified as a critical downstream mediator of CUL4B-driven oncogenicity in BC cells. Furthermore, we demonstrated that CRL4B epigenetically repressed the transcription of miR-372/373, via catalyzing monoubiquitination of H2AK119 at the gene cluster encoding miR-372/373, leading to upregulation of PIK3CA and activation of AKT. Our findings thus establish a critical role for the CUL4B-miR-372/373-PIK3CA/AKT axis in the pathogenesis of BC and have important prognostic and therapeutic implications in BC.

Ultrasound-Mediated Gene Therapy of Hepatocellular Carcinoma Using Pre-microRNA Plasmid-Loaded Nanodroplets

The PIK3 CA gene encodes the p110α protein subunit and is one of the most efficient cancer genes in solid and hematological tumors including hepatocellular carcinoma (HCC). There are currently ongoing therapies against tumors based on PIK3 CA inhibition. Because microRNAs (miRNAs) play an important role in post-transcriptional regulation and are also involved in the inhibition of PIK3 CA expression to suppress cancer cell proliferation, overexpression of tumor-suppressive miRNA is a promising therapeutic approach for HCC therapy. The successful and localized delivery of miRNA overexpression vectors (pre-miRNA plasmids) is very important in improving the therapeutic efficacy of this miRNA therapy strategy. In the study described here, submicron acoustic phase-shifted nanodroplets were used to efficiently deliver pre-miRNA plasmid in vitro and in vivo for HCC therapy under focused ultrasound (US) activation. Briefly, six miRNAs, inhibiting PIK3 CA and downregulated in HCC, were selected through summary and analysis of the currently existing literature data. Quantitative real-time polymerase chain reaction (qRT-PCR), Western blot and cell apoptosis assay revealed that pre-miR-139, -203a, -378a and -422a plasmids among the six miRNA overexpression vectors could suppress growth of the hepatoma cell line SMMC-7721. These four pre-miRNA plasmids were then electrostatically adhered to positively charged lipid-shelled nanodroplets to obtain plasmid-loaded nanodroplets (PLNDs). The PLND-generated microbubbles oscillated and even collapsed under US exposure to release the loaded pre-miRNA plasmids and enhance their cellular uptake through consequent sonoporation, that is, formation of small pores on the cell membrane induced by the mechanical effects of PLND cavitation. Fluorescence microscopy results revealed that PLNDs could effectively deliver the aforementioned four pre-miRNA plasmids into SMMC-7721 cells in vitro under 1.2-MHz 60-cycle sinusoid US exposure with a peak negative pressure >5.5 MPa at a 40-Hz pulse repetition frequency. Plasmid delivery efficiency and cell viability positively correlated with the inertial cavitation dose that was determined mainly by peak negative pressure. Furthermore, PLNDs combined with US were evaluated in vivo to deliver these four pre-miRNAs plasmids and verify their therapeutic efficacy in subcutaneous tumor of the mouse xenograft HCC model. The results revealed that the PLNDs loaded with pre-miR-139 and -378a plasmids could effectively suppress tumor growth after US treatment. Thus, combination of pre-miRNA PLNDs with US activation seems to constitute a potential strategy for HCC therapy.

LINC01518 knockdown inhibits tumorigenicity by suppression of PIK3CA/Akt pathway in oesophageal squamous cell carcinoma

LncRNA LINC01518 was previously reported to be upregulated in oesophageal squamous cell carcinoma (ESCC) tissues compared with normal tissues. However, there are no previous studies concerning the specific function and molecular mechanism of LINC01518 in ESCC. LINC01518 and miR-1-3p expression levels in ESCC cells were detected by qRT-PCR. Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry analysis, respectively. The relationships between LINC01518, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) and miR-1-3p were explored by luciferase reporter assay. The alteration of the PIK3CA/protein kinase B (Akt) pathway was examined by Western blot. We found that LINC01518 expression was upregulated and miR-1-3p expression was downregulated in ESCC cells. LINC01518 knockdown inhibited cell proliferation and promoted apoptosis in ESCC cells. In addition, LINC01518 functioned as a competing endogenous RNA (ceRNA) for miR-1-3p in ESCC cells and miR-1-3p downregulation blocked the effects of LINC01518 knockdown on cell proliferation and apoptosis in ESCC cells. Moreover, PIK3CA was identified as a target of miR-1-3p and LINC01518 knockdown inhibited the PIK3CA/Akt pathway by upregulating miR-1-3p in ESCC cells. In conclusion, LINC01518 knockdown inhibited tumorigenicity in ESCC cells by suppression of PIK3CA/Akt pathway through upregulating miR-1-3p.

Novel Molecular Characterization of Colorectal Primary Tumors Based on miRNAs

microRNAs (miRNA) expression in colorectal (CR) primary tumours can facilitate a more precise molecular characterization. We identified and validated a miRNA profile associated with clinical and histopathological features that might be useful for patient stratification. In situ hybridization array using paraffin-embedded biopsies of CR primary tumours were used to screen 1436 miRNAs. 17 miRNAs were selected for validation by quantitative reverse transcription polymerase chain reaction (qRT-PCR) (n = 192) and were further correlated with clinical and histopathological data. We demonstrated that miRNAs associated to Colorectal Cancer (CRC) diagnosis age (over 50s and 60s) included miR-1-3p, miR-23b-3p, miR-27b-3p, miR-143-3p, miR-145-5p and miR-193b-5p. miR-23b-3p and miR-24-3p discriminated between Lynch Syndrome and sporadic CRC. miR-10a-5p, miR-20a-5p, miR-642b and Let-7a-5p were associated to stroma abundance. miR-642b and Let-7a-5p were associated with to peritumoral inflammation abundance. miR-1-3p, miR-143-3p and miR-145-5p correlated with mucinous component. miR-326 correlated with tumour location (right or left sided). miR-1-3p associated with tumour grade. miR-20a-5p, miR-193b-5p, miR-320a, miR-326 and miR-642b-3p associated to tumour stage and progression. Remarkably, we also demonstrated that miR-1-3p and miR-326 expression significantly associated with patient overall survival (OS). Hierarchical clustering and bioinformatics analysis indicated that selected miRNAs could re-classify the patients and work cooperatively, modulating common target genes involved in colorectal cancer key signalling pathways. In conclusion, molecular characterization of CR primary tumours based on miRNAs could lead to more accurate patient reclassification and may be useful for efficient patient management.

MiR-1-3p Inhibits Lung Adenocarcinoma Cell Tumorigenesis via Targeting Protein Regulator of Cytokinesis 1

Lung adenocarcinoma (LUAD) is one of the most lethal malignancies, posing a threat to human health. However, the molecular mechanisms underlying LUAD development remain largely unknown. In this study, we found that miR-1-3p was significantly downregulated in human LUAD tissues and cell lines and played an inhibitory role in LUAD cell tumorigenesis, as evidenced by the significantly reduced viability, migration, and invasion of LUAD cells in response to miR-1-3p overexpression. Mechanistically, microRNA (miR)-1-3p physically interacted with the 3′-untranslated region (UTR) of protein regulator of cytokinesis 1 (PRC1) mRNA, leading to downregulation of PRC1. Overexpression of PRC1 reversed the inhibitory effects of miR-1-3p on LUAD cell tumorigenesis, suggesting that the miR-1-3p/PRC1 axis is majorly involved in suppressing LUAD development and progression. Consistently, PRC1 was dramatically induced in LUAD tissues and cell lines as well as associated with a poor prognosis in LUAD patients. Taken together, our study identified the miR-1-3p/PRC1 axis as an important regulatory mechanism contributing to LUAD inhibition and provided valuable clues for the future development of therapeutic strategies against LUAD.

miR-1-3p and miR-206 sensitizes HGF-induced gefitinib-resistant human lung cancer cells through inhibition of c-Met signalling and EMT

Hepatocyte growth factor (HGF) overexpression is an important mechanism in acquired epidermal growth factor receptor (EGFR) kinase inhibitor gefitinib resistance in lung cancers with EGFR activating mutations. MiR-1-3p and miR-206 act as suppressors in lung cancer proliferation and metastasis. However, whether miR-1-3p and miR-206 can overcome HGF-induced gefitinib resistance in EGFR mutant lung cancer is not clear. In this study, we showed that miR-1-3p and miR-206 restored the sensitivities of lung cancer cells PC-9 and HCC-827 to gefitinib in present of HGF. For the mechanisms, we demonstrated that both miR-1-3p and miR-206 directly target HGF receptor c-Met in lung cancer. Knockdown of c-Met mimicked the effects of miR-1-3p and miR-206 transfections Meanwhile, c-Met overexpression attenuated the effects of miR-1-3p and miR-206 in HGF-induced gefitinib resistance of lung cancers. Furthermore, we showed that miR-1-3p and miR-206 inhibited c-Met downstream Akt and Erk pathway and blocked HGF-induced epithelial-mesenchymal transition (EMT). Finally, we demonstrated that miR-1-3p and miR-206 can increase gefitinib sensitivity in xenograft mouse models in vivo. Our study for the first time indicated the new function of miR-1-3p and miR-206 in overcoming HGF-induced gefitinib resistance in EGFR mutant lung cancer cell.

Association of microRNA-423 rs6505162 C>A polymorphism with susceptibility and metastasis of colorectal carcinoma

Studies have evaluated the association between the SNP miRNA-423 rs6505162 C>A and cancer risk in several cancers with contradictory outcomes. It was reported that miRNA-423 rs6505162 C>A polymorphism was associated with the overall survival and the recurrence-free survival of colorectal carcinoma. However, no studies have reported the association between miRNA-423 rs6505162 C>A polymorphism and susceptibility of colorectal carcinoma.In this study, we investigated the association between miRNA-423 polymorphism with risk and clinicopathological parameters of colorectal carcinoma. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to genotype 117 colorectal carcinoma patients and 84 healthy controls.Our data indicated the frequencies of rs6505162 genotypes and alleles were significantly different between colorectal carcinoma patients and controls. Compared with CC homozygote, the AC heterozygote exhibited a significantly decreased risk of colorectal carcinoma; and the combination of AC and AA genotype was associated with decreased risk of colorectal carcinoma. The allele distribution of rs6505162 was significantly different between cases and controls. Furthermore, miR-423 rs6505162 C>A genotype showed a significant association with metastasis in patients (P = .022).Our study suggested that miR-423 rs6505162 C>A polymorphism was associated with the susceptibility and metastasis of colorectal carcinoma, and that miR-423 rs6505162 C>A polymorphism might be a potential biomarker for colorectal carcinoma.

miRNAs as potential regulators of mTOR pathway in renal cell carcinoma

Renal cell carcinoma (RCC) is the most commonly occurring solid cancer of the adult kidney with the majority of RCC cases being detected accidentally. The most aggressive subtype is clear cell RCC (ccRCC). miRNAs, a family of small noncoding RNAs regulating gene expression have been identified as key biological modulators. The von Hippel-Lindau pathway is one of the signaling pathways involved in the pathophysiology of ccRCC. Another oncogenic mechanism involves the activation of PI3K/AKT/mTOR signaling and serves as a central regulator of cell metabolism, proliferation and survival. Several studies have described the involvement of miRNA dysregulation in the pathogenesis and progression of ccRCC. These molecules can be considered as potential diagnostic and prognostic biomarkers, allowing response to therapy to be monitored.

MicroRNA-1 inhibits tumorigenicity of esophageal squamous cell carcinoma and enhances sensitivity to gefitinib

Dysregulation of microRNAs in various types of human cancer promote or suppress oncogenesis. MicroRNA (miR)-1 was previously revealed to function as a tumor suppressor in prostate cancer cells, and its expression was associated with reduced metastatic potential in lung cancer. The present study investigated the role of miR-1 and its association with phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) in the pathophysiology of esophageal squamous cell carcinoma (ESCC), and analyzed the effects of miR-1 inhibitor or mimics on sensitivity to epidermal growth factor receptor-tyrosine kinase inhibitors, the alterations of cell cycle distribution and apoptosis in ESCC cells. Compared with normal tissues, the level of miR-1 expression was significantly lower and PIK3CA expression was higher in ESCC tissues. The level of miR-1 expression was also inversely associated with the level of PIK3CA mRNA expression. Low miR-1 and high PIK3CA expression levels were strongly associated with lymph node metastasis, and the level of miR-1 expression was negatively associated with clinical Tumor-Node-Metastasis stage. Furthermore, exogenous expression of miR-1 inhibited growth, arrested cell cycle in the G₁ phase and increased apoptosis in ESCC cells, whereas it decreased PIK3CA protein expression levels. Furthermore, overexpression of miR-1 increased the sensitivity of ESCC cells to the anticancer drug, gefitinib. A possible mechanism for this increased sensitivity to gefitinib may be inactivation of the PIK3CA signaling pathway. To the best of our knowledge, this is the first time that the results of the present study demonstrated that miR-1 upregulation may be a potential strategy for the treatment of human ESCC.

MicroRNA-203 suppresses proliferation in liver cancer associated with PIK3CA, p38 MAPK, c-Jun, and GSK3 signaling

Primary liver cancer (hepatocellular carcinoma, HCC) is a leading cause of cancer-related deaths, and alternative ways to treat this disease are urgently needed. In recent years, novel approaches to cancer treatment have been based on microRNAs, small non-coding RNA molecules that play a crucial role in cancer progression by regulating gene expression. Overexpression of some microRNAs has shown therapeutic potential, but whether or not this was the case for microRNA-203 (miR-203) in liver cancer was unknown. Therefore, the aim of this study was to investigate the effect of miR-203 overexpression in liver cancer and explore the related mechanisms. Liver cancer cells from the HepG2 and Hep3B cell lines were transfected with either miR-203 mimics or negative control RNA, and then the cells were subjected to cell viability, cell proliferation, and Western blotting assays. As a result of microRNA-203 overexpression, HepG2 and Hep3B cell viability and cell proliferation significantly declined. Furthermore, microRNA-203 overexpression led to inhibited expression of phosphatidylinositol-4,5-bisphosphate 3-kinase (PIK3)/protein kinase B (Akt), c-Jun, and p38 mitogen-activated protein kinases (p38 MAPK), and restored glycogen synthase kinase 3 (GSK 3) activity in HepG2 cells. Our results suggest that c-Jun, p38 MAPK, PIK3CA/Akt, and GSK3 signaling involved in the effect of miR-203 on the proliferation of HCC cells.

Next-generation sequencing identifies high frequency of mutations in potentially clinically actionable genes in sebaceous carcinoma

Sebaceous carcinoma (SC) is a rare but aggressive malignancy with frequent recurrence and metastases. Surgery is the mainstay of therapy, but effective systemic therapies are lacking because the molecular alterations driving SC remain poorly understood. To identify these, we performed whole-exome next-generation sequencing of 409 cancer-associated genes on 27 SCs (18 primary/locally recurrent ocular, 5 paired metastatic ocular, and 4 primary extraocular) from 20 patients. In ocular SC, we identified 139 non-synonymous somatic mutations (median/lesion 3; range 0-23). Twenty-five of 139 mutations (18%) occurred in potentially clinically actionable genes in 6 of 16 patients. The most common mutations were mutations in TP53 (n = 9), RB1 (n = 6), PIK3CA (n = 2), PTEN (n = 2), ERBB2 (n = 2), and NF1 (n = 2). TP53 and RB1 mutations were restricted to ocular SC and correlated with aberrant TP53 and RB protein expression. Systematic pathway analyses demonstrated convergence of these mutations to activation of the PI3K signalling cascade, and PI3K pathway activation was confirmed in tumours with PTEN and/or PIK3CA mutations. Considerable inter-tumoural heterogeneity was observed between paired primary and metastatic ocular SCs. In primary extraocular SC, we identified 77 non-synonymous somatic mutations (median/lesion 22.5; range 3-29). This overall higher mutational load was attributed to a microsatellite instability phenotype in three of four patients and somatically acquired mutations in mismatch repair genes in two of four patients. Eighteen of 77 mutations (23%) were in potentially clinically actionable genes in three of four patients, including BTK, FGFR2, PDGFRB, HRAS, and NF1 mutations. Identification of potentially clinically actionable mutations in 9 of 20 SC patients (45%) underscores the importance of next-generation sequencing to expand the spectrum of genotype-matched targeted therapies. Frequent activation of PI3K signalling pathways provides a strong rationale for application of mTOR inhibitors in the management of this disease. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Thrombospondin-1 and microRNA-1 expression in response to multiwalled carbon nanotubes in alveolar epithelial cells

Thrombospondin-1 (TSP-1) is a glycoprotein that plays a role in extracellular matrix (ECM) remodeling. Previously, we have shown that multiwalled carbon nanotubes (MWCNT) regulate ECM components TGFβ and its target Col3A1 in alveolar epithelial cells. In this study, we investigated the effect of MWCNT on TSP-1 and microRNA-1 (miR-1) in the regulation of TGFβ in ECM remodeling using alveolar epithelial A549 cells. A549 cells were treated with MWCNT (20 or 50 µg/mL) for 6 or 24 h and the expression of TSP-1 and miR-1, and the exogenous miR-1 effect on cell morphology were analyzed. MWCNT induced in a time- and dose-dependent manner the expression of TSP-1. miR-1 was suppressed by MWCNT after 6 or 24 h of treatment regardless of the dose. TSP-1 and miR-1 negatively correlated with each other, r = -0.58. Exogenous administration of miR-1 induced alveolar epithelial cell morphology changes including cell clustering, whereas inhibition of miR-1 induced less cell to cell contact, cell rounding, and cellular projections. IntAct molecular network interactions analysis revealed that TSP-1 interacts with 21 molecular factors including ECM genes, and molecules. These results indicate a relationship between that TSP-1, MWCNT, and TGFβ, and suggest TSP-1 may play a role in MWCNT-induced TGFβ and ECM remodeling. Moreover, these data also suggest an inverse relationship between TSP-1 and miR-1 and a potential role of miR-1 in MWCNT-induced fibrotic signaling. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1596-1606, 2017.

The roles of microRNAs related with progression and metastasis in human cancers

Metastasis is an important factor in predicting the prognosis of the patients with cancers and contributes to high cancer-related mortality. Recent studies indicated that microRNAs (miRNAs) played a functional role in the initiation and progression of human malignancies. MicroRNAs are small non-coding RNAs of about 22 nucleotides in length that can induce messenger RNA (mRNA) degradation or repress mRNA translation by binding to the 3' untranslated region (3'-UTR) of their target genes. Overwhelming reports indicated that miRNAs could regulate cancer invasion and metastasis via epithelial-to-mesenchymal transition (EMT)-related and/or non-EMT-related mechanisms. In this review, we concentrate on the underlying mechanisms of miRNAs in regulating cancer progression and metastasis.

The future therapy of endometrial cancer: microRNA's functionality, capability, and putative clinical application

PURPOSE

Endometrial cancer (EC) therapy is characterized by the heterogeneity of EC subtypes resulting in unclear clinical behavior as well as in unsatisfactory treatment options. The available biomarkers, such as cellular tumor antigen p53 (TP53), phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase and dual-specificity protein phosphatase (PTEN), and phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) genes alone might not be sufficient, and thus, new predictive and prognostic biomarkers are urgently required. The biomolecule class of microRNA represents a group of endogenously expressed regulatory factors primarily involved in control of pivotal cancer-related mechanisms including cell cycle, proliferation, apoptosis, and metastasis. Here, we review the current state of science regarding microRNA functionality in EC progression.

Discriminating between Terminal- and Non-Terminal Respiratory Unit-Type Lung Adenocarcinoma Based on MicroRNA Profiles

Lung adenocarcinomas can be classified into terminal respiratory unit (TRU) and non-TRU types. We previously reported that non-TRU-type adenocarcinoma has unique clinical and morphological features as compared to the TRU type. Here we investigated whether micro (mi)RNA expression profiles can be used to distinguish between these two subtypes of lung adenocarcinoma. The expression of 1205 human and 144 human viral miRNAs was analyzed in TRU- and non-TRU-type lung adenocarcinoma samples (n = 4 each) by microarray. Results were validated by quantitative real-time (qRT-)PCR and in situ hybridization. A comparison of miRNA profiles revealed 29 miRNAs that were differentially expressed between TRU- and non-TRU adenocarcinoma types. Specifically, hsa-miR-494 and ebv-miR-BART19 were up regulated by > 5-fold, whereas hsa-miR-551b was down regulated by > 5-fold in the non-TRU relative to the TRU type. The miRNA signature was confirmed by qRT-PCR analysis using an independent set of paired adenocarcinoma (non-TRU-type, n = 21 and TRU-type, n = 12) and normal tissue samples. Non-TRU samples showed increased expression of miR-494 (p = 0.033) and ebv-miR-BART19 (p = 0.001) as compared to TRU-type samples. Both miRNAs were weakly expressed in the TRU type but strongly expressed in the non-TRU type. Neither subtype showed miR-551b expression. TRU- and non-TRU-type adenocarcinomas have distinct miRNA expression profiles, suggesting that tumorigenesis in lung adenocarcinoma occur via different pathways.

MicroRNA-1 properties in cancer regulatory networks and tumor biology

Short non-coding microRNAs have been identified to orchestrate crucial mechanisms in cancer progression and treatment resistance. MicroRNAs are involved in posttranscriptional modulation of gene expression and therefore represent promising targets for anticancer therapy. As mircoRNA-1 (miR-1) exerted to be predominantly downregulated in the majority of examined tumors, miR-1 is classified to be a tumor suppressor with high potential to diminish tumor development and therapy resistance. Here we review the complex functionality of miR-1 in tumor biology.

miR-154 inhibits migration and invasion of human non-small cell lung cancer by targeting ZEB2

Emerging evidence suggests that microRNAs (miRs) play critical roles in the development and progression of non-small cell lung cancer (NSCLC). In a previous study, the present authors demonstrated that miR-154 acts as a tumor suppressor in NSCLC; however, its underlying molecular mechanism and target in NSCLC remain poorly understood. In the present study, ectopic expression of miR-154 remarkably suppressed cell migration and invasion in NSCLC cells. Zinc finger E-box binding homeobox 2 (ZEB2) was identified as a direct target of miR-154 in NSCLC cells. Furthermore, overexpression of miR-154 could decrease the expression of ZEB2 at the messenger RNA and protein levels. Ectopic expression of miR-154 also increased the levels of E-cadherin, an epithelial marker, and decreased the levels of vimentin, a mesenchymal marker, which contributed to suppress epithelial-mesenchymal transition (EMT) and to inhibit cell migration and invasion. In addition, downregulation of ZEB2 exerted similar effects to those caused by miR-154 overexpression on NSCLC cell migration and invasion, while upregulation of ZEB2 could significantly reverse the inhibitory effects on migration and invasion caused by miR-154 on NSCLC cells. These findings demonstrated that miR-154 inhibited migration and invasion of NSCLC cells by regulating EMT through targeting ZEB2, suggesting that miR-154 may be a potential anticancer therapeutic target for NSCLC.

MicroRNAs in congenital heart disease

Congenital heart disease (CHD) is a broad term which encompasses a spectrum of pathology, the most common phenotypes include atrial septal defects (ASDs), ventricular septal defects (VSDs), patent ductus arteriosus (PAD) and tetralogy of Fallot (TOF). The impact of CHD is profound and it is estimated to be responsible for over 40% of prenatal deaths. MicroRNAs (miRs) are small, highly conserved, non-coding RNAs which have complex roles in a variety of pathophysiological states. miRs are post-transcriptional negative regulators of gene expression. Individual miRs are known to exert effects in multiple target genes, therefore the altered expression of a single miR could influence an entire gene network resulting in complex pathological states. Recent evidences suggest a role in the dysregulation of miRs in CHD. Mouse knock out models have contributed to our knowledge base revealing specific patterns of miR expression in cardiovascular physiology and pathological states. Specific miRs necessary for embryonic cardiac development have been revealed. Dysregulation of these miRs has been shown to cause structural abnormalities in the heart and vasculature, thus furthering our understanding of the processes which result in CHD. These advances have provided new insight into the signalling pathways responsible for CHD. Furthermore, this new appreciation for miRs in the development of CHD has uncovered their potential for new therapeutic targets where modulated miR activity may reduce the burden of disease. Here, we summarize current knowledge of the cause-effect relationships of miRs in CHD and consider their potential as a therapeutic targets and biomarkers in this clinical setting.

Mammalian hibernation and regulation of lipid metabolism: a focus on non-coding RNAs

Numerous species will confront severe environmental conditions by undergoing significant metabolic rate reduction. Mammalian hibernation is one such natural model of hypometabolism. Hibernators experience considerable physiological, metabolic, and molecular changes to survive the harsh challenges associated with winter. Whether as fuel source or as key signaling molecules, lipids are of primary importance for a successful bout of hibernation and their careful regulation throughout this process is essential. In recent years, a plethora of non-coding RNAs has emerged as potential regulators of targets implicated in lipid metabolism in diverse models. In this review, we introduce the general characteristics associated with mammalian hibernation, present the importance of lipid metabolism prior to and during hibernation, as well as discuss the potential relevance of non-coding RNAs such as miRNAs and lncRNAs during this process.

Roles of the canonical myomiRs miR-1, -133 and -206 in cell development and disease

MicroRNAs are small non-coding RNAs that participate in different biological processes, providing subtle combinational regulation of cellular pathways, often by regulating components of signalling pathways. Aberrant expression of miRNAs is an important factor in the development and progression of disease. The canonical myomiRs (miR-1, -133 and -206) are central to the development and health of mammalian skeletal and cardiac muscles, but new findings show they have regulatory roles in the development of other mammalian non-muscle tissues, including nerve, brain structures, adipose and some specialised immunological cells. Moreover, the deregulation of myomiR expression is associated with a variety of different cancers, where typically they have tumor suppressor functions, although examples of an oncogenic role illustrate their diverse function in different cell environments. This review examines the involvement of the related myomiRs at the crossroads between cell development/tissue regeneration/tissue inflammation responses, and cancer development.

Downregulation of miR-19a exhibits inhibitory effects on metastatic renal cell carcinoma by targeting PIK3CA and inactivating Notch signaling in vitro

Metastasis seriously affects the clinical outcome of renal cell carcinoma patients. Despite the approval of several targeted therapies that have led to an improvement in the progression-free survival rate for these patients, advanced and metastatic renal cell carcinoma remains difficult to treat. Recently, microRNAs have been found to play a critical role in the metastatic dissemination of renal cell carcinoma cells. In the present study, we found that miR-19a expression was significantly upregulated in metastatic clear cell renal carcinoma than that in adjacent and primary carcinoma tissues using qPCR and in situ hybridization experiments. In addition, the results were confirmed in renal carcinoma cell lines. miR-19a expression in the cell lines derived from a metastatic site was higher than that in cell lines derived from a primary site. By gain- and loss-of-function experiments, we found that miR-19a acted as an oncogenic miRNA regulating renal cancer cell proliferation, migration and invasion by directly targeting PIK3CA. Furthermore, we also explored the downstream molecules of miR-19a/PIK3CA signaling. We found that Notch signaling was induced by upregulation of miR-19a, and inactivation of Notch signaling attenuated the cell proliferation, migration and invasion promoted by miR-19a. Thus, we provide evidence demonstrating that downregulation of miR-19a may be therapeutically beneficial for metastatic renal carcinoma.

Identical MicroRNAs Regulate Liver Protection during Anaesthetic and Ischemic Preconditioning in Rats: An animal study

Anaesthetic preconditioning (APC) and ischemic preconditioning (IPC) ameliorate liver ischemia-reperfusion (I/R) injury and are important for regulating hepatic I/R injury. MicroRNAs (miRNAs) are short, noncoding RNA molecules of 21-23 nucleotides in length, and are currently under intensive investigation regarding their ability to regulate gene expression in a wide range of species. miRNA activity is involved in controlling a wide range of biological functions and processes. We evaluated whether APC and IPC are mediated by the same miRNAs by performing comprehensive miRNA screening experiments in a rat model of hepatic I/R injury. Twenty-one rats were randomly divided into three groups (n = 7/group): control (mock preconditioning), APC, and IPC. Control rats were subjected to 60 min of hepatic ischemia followed by 4 h of reperfusion, whereas the APC and IPC groups were preconditioned with 2% sevoflurane and hepatic ischemia for 10 min prior to ischemia-reperfusion, respectively. Liver samples were collected to measure miRNA levels after 3 h of reperfusion, and gene networks and canonical pathways were identified using Ingenuity Pathway Analysis (IPA). Blood samples were collected to measure the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Although haemodynamic parameters did not vary among the groups, AST and ALT levels were significantly higher in the control group than in the APC and IPC groups. Comprehensive miRNA screening experiments revealed that most miRNAs altered in the APC group were common to those in the IPC group. IPA identified five miRNAs related to the Akt-glycogen synthase kinase-3β (GSK-3β)-cyclin D1 pathway that were significantly affected by both preconditioning strategies. The application of either APC or IPC to ameliorate hepatic I/R injury results in expression of several common miRNAs that are related to the Akt-GSK-cyclin D1 pathway.

MicroRNA-1 (miR-1) inhibits gastric cancer cell proliferation and migration by targeting MET

MicroRNAs (miRs) are short endogenous non-coding RNAs that act as posttranscriptional regulatory factors of gene expression. Downregulation of miR-1 has been reported in gastric cancer; however, the mechanisms underlying its functions via target genes in gastric cancer remain largely unknown. The purpose of this study was to investigate the mechanism by which miR-1 inhibits gastric cancer cell proliferation and migration. The effects of miR-1 on gastric cancer cell proliferation and migration were determined by MTT and wound-healing assays. Cell protein expression of the miR-1 target gene MET was analyzed by Western blotting. Finally, MET expression was evaluated by immunohistochemistry in a stomach tumor tissue microarray (TMA). Ectopic expression of miR-1 inhibited proliferation and migration in both AGS and SGC-7901 gastric cancer cell lines. miR-1 directly targets the MET gene and downregulates its expression. MET siRNA also inhibited proliferation and migration in both cell lines. Immunohistochemistry revealed significantly higher MET expression levels in gastric cancer tissues compared with matched adjacent non-cancer tissues. These findings indicate that the miR-1/MET pathway is a potential therapeutic target due to its crucial role in gastric cancer cell proliferation and migration.

Comparative Analysis of Differentially Expressed miRNAs and their Downstream mRNAs in Ovarian Cancer and its Associated Endometriosis

Objective

There is an increased risk of developing ovarian cancer (OC) in patients with endometriosis. Hence, development of new biomarkers may provide a positive clinical outcome for early detection. MicroRNAs (miRNAs) are small non-coding RNAs that play an important role in biological and pathological process and are currently used as diagnostic and prognostic markers in various cancers. In the current study, we assessed the differential expression of miRNAs from 19 paired ovarian cancer and its associated endometriosis tissue samples. In addition we also analyzed the downstream targets of those miRNAs.

Methods

Nineteen paired cases of ovarian cancer and endometriosis foci were identified by a gynecologic pathologist and macro-dissected. The total RNAs were extracted and subjected to comprehensive miRNA profiling from the pooled samples of these two different entities using microarray analysis. Later, the abnormal expressions of few selected miRNAs were validated in individual cases by quantitative real-time PCR (qRT-PCR). Ingenuity pathway analysis revealed target mRNAs which were validated by qRT-PCR.

Results

The miRNA profiling identified deregulation of greater than 1156 miRNAs in OC, of which the top seven were further validated by qRT-PCR. The expression of miR-1, miR-133a, and miR-451 were reduced significantly (p<0.0001) in the OC patients compared to its associated endometriosis. In contrast, the expression of miR-141, miR-200a, miR-200c, and miR-3613 were elevated significantly (p<0.05) in most of the OC patients. Furthermore, among the downstream mRNAs of these miRNAs, the level of PTEN expression was significantly (p<0.05) reduced in OC compared to endometriosis while no significant difference was observed in NF-κB expression.

Conclusion

The expression of miRNAs and mRNAs in OC were significantly different compared to its concurrent endometriosis. These differential expressed miRNAs may serve as potential diagnostic and prognostic biomarkers for OC associated with endometriosis.

MicroRNA-1 in Cardiac Diseases and Cancers

MicroRNAs (miRs) are endogenous ≈22-nt non-coding RNAs that participate in the regulation of gene expression at post-transcriptional level. MiR-1 is one of the muscle-specific miRs, aberrant expression of miR-1 plays important roles in many physiological and pathological processes. In this review, we focus on the recent studies about miR-1 in cardiac diseases and cancers. The findings indicate that miR-1 may be a novel, important biomarker, and a potential therapeutic target in cardiac diseases and cancers.

The impact of microRNA-mediated PI3K/AKT signaling on epithelial-mesenchymal transition and cancer stemness in endometrial cancer

Activation of the PI3K/AKT pathway, a common mechanism in all subtypes of endometrial cancers (endometrioid and non-endometrioid tumors), has important roles in contributing to epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) features. MicroRNAs (miRNAs) are small non-coding RNA molecules that concurrently affect multiple target genes, and regulate a wide range of genes involved in modulating EMT and CSC properties. Here we overview the recent advances revealing the impact of miRNAs on EMT and CSC phenotypes in tumors including endometrial cancer via regulating PI3K/AKT pathway. MiRNAs are crucial mediators of EMT and CSC through targeting PTEN-PI3K-AKT-mTOR axis. In endometrial cancer cells, miRNAs can activate or attenuate EMT and CSC by targeting PTEN and other EMT-associated genes, such as Twist1, ZEB1 and BMI-1. More detailed studies of miRNAs will deepen our understanding of the molecular basis underlying PI3K/AKT-induced endometrial cancer initiation and progression. Targeting key signaling components of PI3K/AKT pathway by restoring or inhibiting miRNA function holds promise as a potential therapeutic approach to suppress EMT and CSC in endometrial cancer.

MiR-195 inhibits the growth and metastasis of NSCLC cells by targeting IGF1R

MicroRNAs (miRNAs) are small, non-coding RNAs which act as oncogenes or tumor suppressors in multiple human cancers. Accumulating evidence reveals that aberrant expression of miRNAs contributes to the development and progression of non-small cell lung cancer (NSCLC). Here, we identified miR-195 as a tumor suppressor in NSCLC cells, whose expression level was dramatically decreased in both NSCLC tissues and cell lines. Ectopic expression of miR-195 suppressed NSCLC cell proliferation and metastasis-related traits in vitro. Insulin-like growth factor 1 receptor (IGF1R) was identified as a direct target of miR-195 in NSCLC cells. Furthermore, restoration of IGF1R remarkably attenuated the tumor suppressive effects of miR-195 on NSCLC cells. Our data suggest that miR-195 may be involved in the carcinogenesis of NSCLC partially by targeting IGF1R.

Role of microRNA-1 in human cancer and its therapeutic potentials

While the mechanisms of human cancer development are not fully understood, evidence of microRNA (miRNA, miR) dysregulation has been reported in many human diseases, including cancer. miRs are small noncoding RNA molecules that regulate posttranscriptional gene expression by binding to complementary sequences in the specific region of gene mRNAs, resulting in downregulation of gene expression. Not only are certain miRs consistently dysregulated across many cancers, but they also play critical roles in many aspects of cell growth, proliferation, metastasis, apoptosis, and drug resistance. Recent studies from our group and others revealed that miR-1 is frequently downregulated in various types of cancer. Through targeting multiple oncogenes and oncogenic pathways, miR-1 has been demonstrated to be a tumor suppressor gene that represses cancer cell proliferation and metastasis and promotes apoptosis by ectopic expression. In this review, we highlight recent findings on the aberrant expression and functional significance of miR-1 in human cancers and emphasize its significant values for therapeutic potentials.