miR-133 is a key negative regulator of CDC42-PAK pathway in gastric cancer

Molecular Insight into Gastric Cancer Invasion-Current Status and Future Directions

Gastric cancer (GC) is one of the most common malignancies worldwide. There has been no efficient therapy for stage IV GC patients due to this disease's heterogeneity and dissemination ability. Despite the rapid advancement of molecular targeted therapies, such as HER2 and immune checkpoint inhibitors, survival of GC patients is still unsatisfactory because the understanding of the mechanism of GC progression is still incomplete. Invasion is the most important feature of GC metastasis, which causes poor mortality in patients. Recently, genomic research has critically deepened our knowledge of which gene products are dysregulated in invasive GC. Furthermore, the study of the interaction of GC cells with the tumor microenvironment has emerged as a principal subject in driving invasion and metastasis. These results are expected to provide a profound knowledge of how biological molecules are implicated in GC development. This review summarizes the advances in our current understanding of the molecular mechanism of GC invasion. We also highlight the future directions of the invasion therapeutics of GC. Compared to conventional therapy using protease or molecular inhibitors alone, multi-therapy targeting invasion plasticity may seem to be an assuring direction for the progression of novel strategies.

PAX5-miR-142 feedback loop promotes breast cancer proliferation by regulating DNMT1 and ZEB1

BACKGROUND

Breast cancer is one of the most common malignancies occurred in female around the globe. Recent studies have revealed the crucial characters of miRNA and genes, as well as the essential roles of epigenetic regulation in breast cancer initiation and progression. In our previous study, miR-142-3p was identified as a tumor suppressor and led to G2/M arrest through targeting CDC25C. However, the specific mechanism is still uncertain.

METHODS

We identified PAX5 as the upstream regulator of miR-142-5p/3p through ALGGEN website and verified by series of assays in vitro and in vivo. The expression of PAX5 in breast cancer was detected by qRT-PCR and western blot. Besides, bioinformatics analysis and BSP sequencing were performed to analyze the methylation of PAX5 promoter region. Finally, the binding sites of miR-142 on DNMT1 and ZEB1 were predicted by JASPAR, and proved by luciferase reporter assay, ChIP analysis and co-IP.

RESULTS

PAX5 functioned as a tumor suppressor by positive regulation of miR-142-5p/3p both in vitro and in vivo. The expression of PAX5 was regulated by the methylation of its promoter region induced by DNMT1 and ZEB1. In addition, miR-142-5p/3p could regulate the expression of DNMT1 and ZEB1 through binding with their 3'UTR region, respectively.

CONCLUSION

In summary, PAX5-miR-142-DNMT1/ZEB1 constructed a negative feedback loop to regulate the progression of breast cancer, which provided emerging strategies for breast cancer therapy.

Molecular dynamics simulations reveal the inhibition mechanism of Cdc42 by RhoGDI1

Cell division control protein 42 homolog (Cdc42), which controls a variety of cellular functions including rearrangements of the cell cytoskeleton, cell differentiation and proliferation, is a potential cancer therapeutic target. As an endogenous negative regulator of Cdc42, the Rho GDP dissociation inhibitor 1 (RhoGDI1) can prevent the GDP/GTP exchange of Cdc42 to maintain Cdc42 into an inactive state. To investigate the inhibition mechanism of Cdc42 through RhoGDI1 at the atomic level, we performed molecular dynamics (MD) simulations. Without RhoGDI1, Cdc42 has more flexible conformations, especially in switch regions which are vital for binding GDP/GTP and regulators. In the presence of RhoGDI1, it not only can change the intramolecular interactions of Cdc42 but also can maintain the switch regions into a closed conformation through extensive interactions with Cdc42. These results which are consistent with findings of biochemical and mutational studies provide deep structural insights into the inhibition mechanisms of Cdc42 by RhoGDI1. These findings are beneficial for the development of novel therapies targeting Cdc42-related cancers.

DNA methylation-induced ablation of miR-133a accelerates cancer aggressiveness in glioma through upregulating peroxisome proliferator-activated receptor γ

Emerging evidences suggest that miRNAs can be used as theranostic biomarkers for multiple cancers, including glioma. Thus, identification of novel miRNAs for glioma treatment and prognosis becomes necessary and urgent. Here, by analyzing miRNA expression profiles in the glioma and para-cancer tissues by miRNA microarray and verified by RT-PCR, we found that miR-133a was significantly downregulated in the cancerous tissues, and patients with low-expressed miR-133a levels predicted an unfavorable prognosis. The following functional experiments confirmed that overexpression of miR-133a restrained cell proliferation and colony formation abilities, and induced cell cycle arrest to restrain cancer progression in glioma cells. Then, the underlying mechanisms were uncovered, and the peroxisome proliferator-activated receptor γ (PPARγ, PPARG) was verified as the downstream target of miR-133a. Mechanistically, miR-133a negatively regulated PPARG expressions by binding to its 3' untranslated regions (3'UTR). The following rescuing experiments evidenced that miR-133a overexpression-induced anti-cancer effects in glioma cells were abrogated by upregulating PPARγ. Interestingly, we noticed that the promoter region of miR-133a was hypermethylated, and removal of DNA methylation by 5-Azacytidine (AZA) significantly increased the expression levels of miR-133a in glioma cells. Taken together, we concluded that DNA-methylation-induced miR-133a silence contributed to cancer progression in glioma through upregulating PPARγ, and firstly identified the DNA-methylation-regulated miR-133a/PPARG axis as the novel indicators for glioma treatment and prognosis.

MicroRNAs in Cancer and Cardiovascular Disease

Although cardiac tumor formation is rare, accumulating evidence suggests that the two leading causes of deaths, cancers, and cardiovascular diseases are similar in terms of pathogenesis, including angiogenesis, immune responses, and fibrosis. These similarities have led to the creation of new exciting field of study called cardio-oncology. Here, we review the similarities between cancer and cardiovascular disease from the perspective of microRNAs (miRNAs). As miRNAs are well-known regulators of translation by binding to the 3'-untranslated regions (UTRs) of messenger RNAs (mRNAs), we carefully dissect how a specific set of miRNAs are both oncomiRs (miRNAs in cancer) and myomiRs (muscle-related miRNAs). Furthermore, from the standpoint of similar pathogenesis, miRNAs categories related to the similar pathogenesis are discussed; namely, angiomiRs, Immune-miRs, and fibromiRs.

Therapeutic Implications of miRNAs for Muscle-Wasting Conditions

MicroRNAs (miRNAs) are small, non-coding RNA molecules that are mainly involved in translational repression by binding to specific messenger RNAs. Recently, miRNAs have emerged as biomarkers, relevant for a multitude of pathophysiological conditions, and cells can selectively sort miRNAs into extracellular vesicles for paracrine and endocrine effects. In the overall context of muscle-wasting conditions, a multitude of miRNAs has been implied as being responsible for the typical dysregulation of anabolic and catabolic pathways. In general, chronic muscle disorders are associated with the main characteristic of a substantial loss in muscle mass. Muscular dystrophies (MDs) are a group of genetic diseases that cause muscle weakness and degeneration. Typically, MDs are caused by mutations in those genes responsible for upholding the integrity of muscle structure and function. Recently, the dysregulation of miRNA levels in such pathological conditions has been reported. This revelation is imperative for both MDs and other muscle-wasting conditions, such as sarcopenia and cancer cachexia. The expression levels of miRNAs have immense potential for use as potential diagnostic, prognostic and therapeutic biomarkers. Understanding the role of miRNAs in muscle-wasting conditions may lead to the development of novel strategies for the improvement of patient management.

The Identification of Alternative Polyadenylation in Stomach Adenocarcinomas Using the Genotype-Tissue Expression Project and the Cancer Genome Atlas- Stomach Adenocarcinoma Profiles

Objective

Alternative polyadenylation (APA) is a common mechanism that is present in most human genes and determines the length of the messenger ribonucleic acid (mRNA) three prime untranslated region (3ʹ-UTR), which can give rise to changes in mRNA stability and localization. However, little is known about the specific changes related to APA in stomach adenocarcinomas (STADs).

Methods

We integrated RNA sequencing data from The Cancer Genome Atlas and Genotype-Tissue Expression project to comprehensively analyze APA events in 289 cases of STAD.

Results

Our results showed that APA events were widespread in patients with STAD and were rich in genes related to known STAD pathways. The APA events result in the loss of tumor-suppressing micro-ribonucleic acid (miRNA) binding sites and increased heterogeneity in the length of the 3ʹ-UTR altered genes. Survival analysis revealed that specific subsets of 3ʹ-UTR-altered genes independently characterized a poor prognostic cohort among patients with STAD, thereby indicating the potential of APA as a new prognostic biomarker.

Conclusion

Our single-cancer analysis showed that by losing miRNA regulation, APA can become a driving factor for regulating the expression of oncogenic genes in STAD and promote its development. Our research revealed that APA events regulated STAD genes that were functionally related, thereby providing a new approach for gaining a better understanding of the progress of STADs and a means for identifying new drug targets as avenues of treatment.

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

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

MiR-133 Targets YES1 and Inhibits the Growth of Triple-Negative Breast Cancer Cells

Triple-negative breast cancer shows worse outcome compared with other subtypes of breast cancer. The discovery of dysregulated microRNAs and their roles in the progression of triple-negative breast cancer provide novel strategies for the treatment of patients with triple-negative breast cancer. In this study, we identified the significant reduction of miR-133 in triple-negative breast cancer tissues and cell lines. Ectopic overexpression of miR-133 suppressed the proliferation, colony formation, and upregulated the apoptosis of triple-negative breast cancer cells. Mechanism study revealed that the YES Proto-Oncogene 1 was a target of miR-133. miR-133 bound the 3′-untranslated region of YES Proto-Oncogene 1 and decreased the level of YES Proto-Oncogene 1 in triple-negative breast cancer cells. Consistent with miR-133 downregulation, YES1 was significantly increased in triple-negative breast cancer, which was inversely correlated with the level of miR-133. Restoration of YES Proto-Oncogene 1 attenuated the inhibitory effects of miR-133 on the proliferation and colony formation of triple-negative breast cancer cells. Consistent with the decreased expression of YES Proto-Oncogene 1, overexpression of miR-133 suppressed the phosphorylation of YAP1 in triple-negative breast cancer cells. Our results provided novel evidence for the role of miR-133/YES1 axis in the development of triple-negative breast cancer, which indicated miR-133 might be a potential therapeutic strategy for triple-negative breast cancer.

Regulators at Every Step-How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial-mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

Regulators at Every Step—How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial–mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

MicroRNAs in Skeletal Muscle and Hints on Their Potential Role in Muscle Wasting During Cancer Cachexia

Cancer-associated cachexia is a heterogeneous, multifactorial syndrome characterized by systemic inflammation, unintentional weight loss, and profound alteration in body composition. The main feature of cancer cachexia is represented by the loss of skeletal muscle tissue, which may or may not be accompanied by significant adipose tissue wasting. Such phenotypic alteration occurs as the result of concomitant increased myofibril breakdown and reduced muscle protein synthesis, actively contributing to fatigue, worsening of quality of life, and refractoriness to chemotherapy. According to the classical view, this condition is primarily triggered by interactions between specific tumor-induced pro-inflammatory cytokines and their cognate receptors expressed on the myocyte membrane. This causes a shift in gene expression of muscle cells, eventually leading to a pronounced catabolic condition and cell death. More recent studies, however, have shown the involvement of regulatory non-coding RNAs in the outbreak of cancer cachexia. In particular, the role exerted by microRNAs is being widely addressed, and several mechanistic studies are in progress. In this review, we discuss the most recent findings concerning the role of microRNAs in triggering or exacerbating muscle wasting in cancer cachexia, while mentioning about possible roles played by long non-coding RNAs and ADAR-mediated miRNA modifications.

MicroRNAs Regulating Cytoskeleton Dynamics, Endocytosis, and Cell Motility-A Link Between Neurodegeneration and Cancer?

The cytoskeleton is one of the most mobile and complex cell structures. It is involved in cellular transport, cell division, cell shape formation and adaptation in response to extra- and intracellular stimuli, endo- and exocytosis, migration, and invasion. These processes are crucial for normal cellular physiology and are affected in several pathological processes, including neurodegenerative diseases, and cancer. Some proteins, participating in clathrin-mediated endocytosis (CME), play an important role in actin cytoskeleton reorganization, and formation of invadopodia in cancer cells and are also deregulated in neurodegenerative disorders. However, there is still limited information about the factors contributing to the regulation of their expression. MicroRNAs are potent negative regulators of gene expression mediating crosstalk between different cellular pathways in cellular homeostasis and stress responses. These molecules regulate numerous genes involved in neuronal differentiation, plasticity, and degeneration. Growing evidence suggests the role of microRNAs in the regulation of endocytosis, cell motility, and invasiveness. By modulating the levels of such microRNAs, it may be possible to interfere with CME or other processes to normalize their function. In malignancy, the role of microRNAs is undoubtful, and therefore changing their levels can attenuate the carcinogenic process. Here we review the current advances in our understanding of microRNAs regulating actin cytoskeleton dynamics, CME and cell motility with a special focus on neurodegenerative diseases, and cancer. We investigate whether current literature provides an evidence that microRNA-mediated regulation of essential cellular processes, such as CME and cell motility, is conserved in neurons, and cancer cells. We argue that more research effort should be addressed to study the neuron-specific functions on microRNAs. Disease-associated microRNAs affecting essential cellular processes deserve special attention both from the view of fundamental science and as future neurorestorative or anti-cancer therapies.

Crocin inhibits the migration, invasion, and epithelial-mesenchymal transition of gastric cancer cells via miR-320/KLF5/HIF-1α signaling

The biological activities of crocin, one of the main bioactive compounds of saffron, include anti-inflammatory, antioxidant, antidepressant, and anticancer effects. Crocin has been shown to trigger the apoptosis of gastric cancer cells, but its effect on the metastasis of gastric cancer cells remains unclear. Krüppel-like factor 5 (KLF5) and hypoxia-inducible factor-1α (HIF-1α) are important transcription factors in the development of gastric cancer. KLF5 and HIF-1α expression were analyzed in gastric cancer tissues and cells. Following exposure to crocin, AGS and HGC-27 gastric cancer cells were assessed with regard to migration, invasion, and epithelial-mesenchymal transition (EMT) as well as the expression of KLF5, HIF-1α, and microRNA-320 (miR-320). The miR-320/KLF5/HIF-1α signaling pathway became the focus for further investigation of the mechanism of crocin in gastric cancer cell migration, invasion, and EMT. KLF5 and HIF-1α expression were elevated in gastric cancer tissues and cells, and KLF5 expression was positively correlated with the HIF-1α level in gastric cancer tissues. Crocin was associated with reduced expression of KLF5 and HIF-1α, whereas miR-320 expression was increased. Crocin also inhibited the migration, invasion, and EMT of gastric cancer cells. Upregulation of KLF5 attenuated crocin's function and elevated HIF-1α expression. Dual-luciferase reporter assay demonstrated that KLF5 was a target gene of miR-320. Crocin modulated KLF5 expression via elevation of miR-320 expression. In conclusion, crocin inhibits the EMT, migration, and invasion of gastric cancer cells, and this activity is mediated through miR-320/KLF5/HIF-1α signaling.

The Impact of MicroRNA-133a on Prognosis and Clinicopathological Parameters for Digestive System Cancers: a Comprehensive Study Based on Meta-Analysis and TCGA Database

We conducted a meta-analysis on the impact of microRNA-133a (miR-133a) on digestive system cancers, and verified the results through The Cancer Genome Atlas (TCGA). Relevant studies were searched in English and Chinese database and meta-analysis was performed using Stata 12.0. The corresponding information of miR-133a and digestive system cancers were obtained from TCGA database and analysis was performed using SPSS. Increased miR-133a expression was linked with favorable overall survival (OS) in digestive system cancers (HR = 0.539, 95% CI: 0.416-0.698, P < 0.001), digestive tract cancers (HR =0.558, 95% CI: 0.406-0.767, P < 0.001), esophageal squamous cell carcinoma (ESCC) (HR = 0.427, 95% CI: 0.265-0.690, P = 0.001) and gastric cancer (HR = 0.541, 95% CI: 0.385-0.761, P < 0.001). The expression of miR-133a was significantly lower in cancer tissue compared with adjacent tissue for ESCC (P < 0.001), gastric cancer (P < 0.001), colorectal cancer (P < 0.001) and hepatocellular carcinoma (P = 0.002). Meanwhile, the area under the ROC curve (AUC) value for miR-133a was 0.836, 0.888, and 0.99 in ESCC, gastric cancer and colorectal cancer. MiR-133a is a tumor suppressor with prognostic and diagnostic values for digestive system cancers. High miR-133a expression was associated with better prognosis and less adverse clinicopathological parameters. More research should be performed to test these findings.

MiR-133 inhibits cell proliferation, migration, and invasion in gastric cancer cells by targeting JAK2

AIM

To investigate the role of miR-133 in the proliferation, migration, and invasion of gastric cancer (GC) cells, and to explore the underlying mechanism.

METHODS

The expression of miR-133 and JAK2 mRNA in tissues and cells was detected by qRT-PCR. AGS and MGC-803 cells were transfected with miR-133 mimic (miR-133 group), miR-133 inhibitor (miR-133 inhibitor group), nonspecific inhibitor (inhibitor-NC group), psiCHECK2-JAK2-3 UTR WT vector and miR-133 mimic (JAK2 WT group), psiCHECK2-JAK2-3 UTR MUT vector and miR-133 mimic (JAK2 MUT group), miR-133 mimic and JAK2 (miR-133 + JAK2 group), or miR-133 mimic and pc-DNA 3.1 (miR-133 + vector group) using a liposome-mediated method. Untransfected cells (miR-NC group) were also included as a control. The protein expression of JAK2 was detected by Western blot. Cell proliferation was detected by MTT assay. Cell migration and invasion were detected by Transwell assay. The luciferase activity was detected by double luciferase reporter assay.

RESULTS

Compared with human paracancerous tissues or normal gastric mucosal cells (GES-1), miR-133 was down-regulated in GC tissues and GC cells (AGS and MGC-803), and JAK2 was highly expressed in GC tissues and AGS and MGC-803 cells (P < 0.05). Overexpression of miR-133 or silencing JAK2 could inhibit cell proliferation, migration, and invasion in GC cells. JAK2 is a target of miR-133, and JAK2 could rescue the inhibitory effect of miR-133 on cell proliferation, migration, and invasion in GC cells.

CONCLUSION

MiR-133 could inhibit the proliferation, migration, and invasion of GC cells via mechanisms possibly related to targeting of JAK2, which will provide a new target for the clinical diagnosis and treatment of GC.

APC gene is modulated by hsa-miR-135b-5p in both diffuse and intestinal gastric cancer subtypes

Background

Several genetic and epigenetic alterations are related to the development and progression of Gastric Cancer (GC), one of those being the deregulated microRNA (miRNA) expression profile. miRNAs are small noncoding RNAs that negatively regulate the expression of thousands of genes, including oncogenes and tumor suppressor genes. Our group identified, in previous studies, some miRNAs that are differentially expressed in GC when compared to the gastric mucosa without cancer, including hsa-miR-29c and hsa-miR-135b. The aim of the study was to modulate the expression of the miRNAs hsa-miR-29c-5p and hsa-miR-135b-5p and evaluate the expression of their target genes in 2D and 3D cell cultures.

Methods

hsa-miR-29c-5p and hsa-miR-135b-5p expression profiles were modulated by transfecting mimics and antimiRs, respectively, in 2D and 3D cell cultures. The expression of the proteins coded by the genes CDC42, DNMT3A (target genes of hsa-miR-29c-5p) and APC (target gene of hsa-miR-135b-5p) were measured by Western Blot.

Results

Results showed that mimics and antimiRs transfection significantly altered the expression of both miRNAs, increasing the expression of hsa-miR-29c-5p and reducing the expression of hsa-miR-135b-5p, especially in the 3D culture of the cell lines. When analyzing the proteins expression, we observed that AGP01 and AGP03 cell lines transfected with mimics had a reduction in the levels of CDC42 and DNMT3A and all three cell lines transfected with antimiRs had an increase in the expression of the protein APC.

Conclusion

We concluded that three-dimensional culture can be a more representative in vitro model that resembles better the in vivo reality. Our results also showed that hsa-miR-29c-5p is an important regulator of CDC42 and DNMT3A genes in the intestinal subtype gastric cancer and hsa-miR-135b-5p regulates the APC gene in both intestinal and diffuse subtypes of GC. Dysregulation in their expression, and consequently in their respectively signaling pathways, shows how these miRNAs can influence the carcinogenesis of different histological subtypes of gastric cancer.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4980-7) contains supplementary material, which is available to authorized users.

miR-133: A Suppressor of Cardiac Remodeling?

Cardiac remodeling, which is characterized by mechanical and electrical remodeling, is a significant pathophysiological process involved in almost all forms of heart diseases. MicroRNAs (miRNAs) are a group of non-coding RNAs of 20–25 nucleotides in length that primarily regulate gene expression by promoting mRNA degradation or post-transcriptional repression in a sequence-specific manner. Three miR-133 genes have been identified in the human genome, miR-133a-1, miR-133a-2, and miR-133b, which are located on chromosomes 18, 20, and 6, respectively. These miRNAs are mainly expressed in muscle tissues and appear to repress the expression of non-muscle genes. Based on accumulating evidence, miR-133 participates in the proliferation, differentiation, survival, hypertrophic growth, and electrical conduction of cardiac cells, which are essential for cardiac fibrosis, cardiac hypertrophy, and arrhythmia. Nevertheless, the roles of miR-133 in cardiac remodeling are ambiguous, and the mechanisms are also sophisticated, involving many target genes and signaling pathways, such as RhoA, MAPK, TGFβ/Smad, and PI3K/Akt. Therefore, in this review, we summarize the critical roles of miR-133 and its potential mechanisms in cardiac remodeling.

miR-141-3p is a key negative regulator of the EGFR pathway in osteosarcoma

Background

Many studies have used miRNA to modulate osteosarcoma development by regulating protein expression, and these studies showed that the expression of EGFR is increased in osteosarcoma.

Methods

Western blot, real-time PCR and immunohistochemical were used to detect the expression of EGFR and miR-141 in osteosarcoma tissues and cells. The correlation between miR-141 and the grading of osteosarcoma and the correlation with the survival time of the patients were analyzed. After predicting the target effect of miR-141 on EGFR by miRDB, correlation analysis was used to analyze the correlation between miR-141 and EGFR. Luciferase reporter gene, western blot and real-time PCR were used to detect the targeting effect of miR-141 on EGFR. Then we detected the effect of miR-141 on proliferation by MTT and PI staining. The effect of miR-141 on cell apoptosis was detected by Hochest33258 and AV-PI staining, and the effect of miR-141 on cell migration was detected by Transwell. The regulatory effects of miR-141 on related proteins were detected by western blot and real-time PCR. Finally, we transfected EGFR and EGFR DEL (mutation with miR-141 binding site) in osteosarcoma cells, and detected the effects of miR-141 on cell proliferation, apoptosis, migration and related proteins.

Results

The expression of miR-141-3p was negatively correlated with the expression of EGFR in osteosarcoma. The overexpression of miR-141-3p was not only closely related to the classification and size of the osteosarcoma but also had a negative effect on the growth and migration of the osteosarcoma through negative regulation of the expression of EGFR. MiR-141 can inhibit the growth and metastasis of osteosarcoma cells by targeting EGFR and affecting its downstream pathway proteins.

Conclusion

Our study provides miR-141-3p may be a new theoretical basis for the treatment of osteosarcoma.

MicroRNA-384 inhibits proliferation migration and invasion of glioma by targeting at CDC42

BACKGROUND

Accumulative evidence indicated that microRNAs (miRNAs) play a critical role in carcinogenesis and biological behaviors of glioma. Further bio-molecular mechanisms of miRNAs in glioma cells remain largely unknown, which can contribute to novel therapeutic strategy.

METHODS

In the present study, we detected the expression level of miR-384 by RT-PCR and Western blot. Meanwhile, Gain and loss function assay of miR-384 by transfection of miR-384 mimics and inhibitor. Moreover, wild and mutant psiCHECK-2-CDC42-3'-UTR luciferase reporter vectors were constructed and transfected into glioma cells with miR-384 mimics or miR-NC.

RESULTS

miR-384 was dramatically down-regulated in human glioma tissues. It was also demonstrated that miR-384 significantly inhibited proliferation, migration and invasion of glioma cells. Cell division cycle 42 (Cdc42) was a direct target of miR-384 according to results of RT-PCR and Western blotting.

CONCLUSION

Our research demonstrated that miR-384 exerted an inhibitory effect on proliferation, migration and invasion of glioma via suppressing the expression of CDC42, meaning that miR-384 may be regarded as a potential target in the treatment of glioma.

miR-133a function in the pathogenesis of dedifferentiated liposarcoma

Background

Sarcomas are malignant heterogeneous tumors of mesenchymal derivation. Dedifferentiated liposarcoma (DDLPS) is aggressive with recurrence in 80% and metastasis in 20% of patients. We previously found that miR-133a was significantly underexpressed in liposarcoma tissues. As this miRNA has recently been shown to be a tumor suppressor in many cancers, the objective of this study was to characterize the biological and molecular consequences of miR-133a underexpression in DDLPS.

Methods

Real-time PCR was used to evaluate expression levels of miR-133a in human DDLPS tissue, normal fat tissue, and human DDLPS cell lines. DDLPS cells were stably transduced with miR-133a vector to assess the effects in vitro on proliferation, cell cycle, cell death, migration, and metabolism. A Seahorse Bioanalyzer system was also used to assess metabolism in vivo by measuring glycolysis and oxidative phosphorylation (OXPHOS) in subcutaneous xenograft tumors from immunocompromised mice.

Results

miR-133a expression was significantly decreased in human DDLPS tissue and cell lines. Enforced expression of miR-133a decreased cell proliferation, impacted cell cycle progression kinetics, decreased glycolysis, and increased OXPHOS. There was no significant effect on cell death or migration. Using an in vivo xenograft mouse study, we showed that tumors with increased miR-133a expression had no difference in tumor growth compared to control, but did exhibit an increase in OXPHOS metabolic respiration.

Conclusions

Based on our collective findings, we propose that in DDPLS, loss of miR-133a induces a metabolic shift due to a reduction in oxidative metabolism favoring a Warburg effect in DDLPS tumors, but this regulation on metabolism was not sufficient to affect DDPLS.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0583-2) contains supplementary material, which is available to authorized users.

MicroRNA-28-5p inhibits the migration and invasion of gastric cancer cells by suppressing AKT phosphorylation

Gastric cancer is a polygenic disease with a high mortality rate worldwide. Although a number of dysregulated genes have been confirmed to be involved in development and progression of gastric cancer, the molecular mechanisms by which this occurs remain unclear. The present study identified that microRNA (miR-28-5p) was involved in the migration and invasion of gastric cancer cells, and was able to affect the prognosis of patients with gastric cancer. Reverse transcription-quantitative polymerase chain reaction analysis indicated that the expression of miR-28-5p was significantly downregulated in gastric cancer tissues, and that patients with higher expression had a good prognosis. miR-28-5p expression was significantly associated with depth of invasion, lymph node metastasis and pathological stage. Gastric cancer cells overexpressing miR-28-5p exhibited a marked reduction of migration and invasion by Transwell and wound scratch assay. The phosphorylation of RAC serine/threonine-protein kinase (AKT), which affected cellular invasion and metastasis, was significantly inhibited by overexpression of miR-28-5p. In conclusion, miR-28-5p is a tumor suppressor that inhibits gastric cancer cell migration and invasion through repressing AKT phosphorylation. miR-28-5p may therefore represent a potential biomarker for the prognosis of gastric cancer and a novel therapeutic target in advanced gastric cancer.

Regulating Cdc42 and Its Signaling Pathways in Cancer: Small Molecules and MicroRNA as New Treatment Candidates

Despite great improvements in the diagnosis and treatment of neoplasms, metastatic disease is still the leading cause of death in cancer patients, with mortality rates still rising. Given this background, new ways to treat cancer will be important for development of improved cancer control strategies. Cdc42 is a member of the Rho GTPase family and plays an important role in cell-to-cell adhesion, formation of cytoskeletal structures, and cell cycle regulation. It thus influences cellular proliferation, transformation, and homeostasis, as well as the cellular migration and invasion processes underlying tumor formation. Cdc42 acts as a collection point for signal transduction and regulates multiple signaling pathways. Moreover, recent studies show that in most human cancers Cdc42 is abnormally expressed and promoting neoplastic growth and metastasis. Regarding possible new treatments for cancer, miRNA and small molecules targeting Cdc42 and related pathways have been recently found to be effective on cancer. In this review, we analyze the newly recognized regulation mechanisms for Cdc42 and Cdc42-related signal pathways, and particularly new treatments using small molecules and miRNAs to inhibit the abnormal overexpression of Cdc42 that may slow down the metastasis process, improve cancer therapy and lead to novel strategies for development of antineoplastic drugs.

miR-135a inhibits tumor metastasis and angiogenesis by targeting FAK pathway

Tumor metastasis has been the major cause of recurrence and death in patients with gastric cancer. Here, we find miR-135a has a decreased expression in the metastatic cell lines compared with its parental cell lines by analyzing microRNA array. Further results show that miR-135a is downregulated in the majority of human gastric cancer tissues and cell lines. Decreased expression of miR-135a is associated with TNM stage and poor survival. Besides, regaining miR-135a in gastric cancer cells obviously inhibits tumor growth, migration, invasion and angiogenesis by targeting focal adhesion kinase (FAK) pathway. Bioinformatics analysis and molecular experiments further prove that miR-135a is a novel downstream gene of tumor suppressor p53. Blocking FAK with its inhibitor can also enhance miR-135a expression through inducing p53. In summary, this study reveals the expression and function of miR-135a in gastric cancer and uncovers a novel regulatory mechanism of miR-135a.

A Novel Pak1/ATF2/miR-132 Signaling Axis Is Involved in the Hematogenous Metastasis of Gastric Cancer Cells

We, along with others, have shown previously that P21-activated kinase 1 (Pak1) plays a pivotal role in gastric cancer progression and metastasis. However, whether Pak1 controls gastric cancer metastasis by regulating microRNAs (miRNAs) has never been explored. Here, we report a novel mechanism of Pak1 in tumor metastasis. A detailed examination revealed that Pak1 interacts with and phosphorylates the serine 62 residue of ATF2 and then blocks its translocation into the nucleus. We also confirmed that ATF2 binds to the promoter of miR-132 and tightly regulates its transcription, thus explaining the regulatory mechanism of miR-132 by Pak1. miR-132 also significantly reduced cell adhesion, migration, and invasion of gastric cancer cells in vitro and significantly prevented tumor metastasis in vivo. miR-132 specifically inhibited hematogenous metastasis, but not lymph node or implantation metastases. In order to further delineate the effects of the Pak1/ATF2/miR-132 cascade on gastric cancer progression, we identified several targets of miR-132 using a bioinformatics TargetScan algorithm. Notably, miR-132 reduced the expression of CD44 and fibronectin1 (FN1), and such inhibition enabled lymphocytes to home in on gastric cancer cells and induce tumor apoptosis. Taken together, our studies establish a novel cell-signaling pathway and open new possibilities for therapeutic intervention of gastric cancer.

Prognostic value of microRNAs in gastric cancer: a meta-analysis

BACKGROUND

Previous articles have reported that expression levels of microRNAs (miRNAs) are associated with survival time of patients with gastric cancer (GC). A systematic review and meta-analysis was performed to study the outcome of it.

DESIGN

Meta-analysis.

METHODS

English studies estimating expression levels of miRNAs with any of survival curves in GC were identified up till March 19, 2017 through performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two authors independently. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

RESULTS

Sixty-nine relevant articles about 26 miRNAs with 6148 patients were ultimately included. GC patients with high expression of miR-20b (HR=2.38, 95%CI=1.16-4.87), 21 (HR=1.77, 95%CI=1.01-3.08), 106b (HR=1.84, 95%CI=1.15-2.94), 196a (HR=2.66, 95%CI=1.94-3.63), 196b (HR=1.67, 95%CI=1.38-2.02), 214 (HR=1.84, 95%CI=1.27-2.67) or low expression of miR-125a (HR=2.06, 95%CI=1.26-3.37), 137 (HR=3.21, 95%CI=1.68-6.13), 141 (HR=2.47, 95%CI=1.34-4.56), 145 (HR=1.62, 95%CI=1.07-2.46), 146a (HR=2.60, 95%CI=1.63-4.13), 206 (HR=2.85, 95%CI=1.73-4.70), 218 (HR=2.61, 95%CI=1.74-3.92), 451 (HR=1.73, 95%CI=1.19-2.52), 486-5p (HR=2.45, 95%CI=1.65-3.65), 506 (HR=2.07, 95%CI=1.33-3.23) have significantly poor OS (P<0.05).

CONCLUSIONS

In summary, miR-20b, 21, 106b, 125a, 137, 141, 145, 146a, 196a, 196b, 206, 214, 218, 451, 486-5p and 506 demonstrate significantly prognostic value. Among them, miR-20b, 125a, 137, 141, 146a, 196a, 206, 218, 486-5p and 506 are strong biomarkers of prognosis in GC.

Prognostic role of microRNAs in human gastrointestinal cancer: A systematic review and meta-analysis

BACKGROUND

Gastrointestinal cancers (GICs) mainly including esophageal, gastric and colorectal cancer, are the most common cause of cancer-related death and lead into high mortality worldwide. We performed this systematic review and meta-analysis to elucidate relationship between multiple microRNAs (miRs) expression and survival of GIC patients.

METHODS

We searched a wide range of database. Fixed-effects and random-effects models were used to calculate the pooled hazard ratio values of overall survival and disease free survival. In addition, funnel plots were used to qualitatively analyze the publication bias and verified by Begg's test while it seems asymmetry.

RESULTS

60 studies involving a total of 6225 patients (1271 with esophageal cancer, 3467 with gastric cancer and 1517 with colorectal cancer) were included in our meta-analysis. The pooled hazard ratio values of overall survival related to different miRs expression in esophageal, gastric, colorectal and gastrointestinal cancer were 2.10 (1.78-2.49), 2.02 (1.83-2.23), 2.54 (2.14-3.02) and 2.15 (1.99-2.31), respectively. We have identified a total of 59 miRs including 23 significantly up-regulated expression miRs (miR-214, miR-17, miR-20a, miR-200c, miR-107, miR-27a, etc.) and 36 significantly down-regulated expression miRs (miR-433, let-7g, miR-125a-5p, miR-760, miR-206, miR-26a, miR-200b, miR-185, etc.) correlated with poor prognosis in GIC patients. Moreover, 35 of them revealed mechanisms.

CONCLUSION

Overall, specific miRs are significantly associated with the prognosis of GIC patients and potentially eligible for the prediction of patients survival. It also provides a potential value for clinical decision-making development and may serve as a promising miR-based target therapy waiting for further elucidation.

miR-133 involves in lung adenocarcinoma cell metastasis by targeting FLOT2

BACKGROUND

Dysregulated microRNAs (miRNAs) reported to involve into the oncogenesis and progression in various human cancers. However, the roles and mechanism of miR-133 in lung adenocarcinoma remain largely unclear.

METHODS

In this study, qPCR assay and western blot were used to detect the expression levels of miR-133, Akt and FLOT2. Luciferase reporter assay was used to identify the target role of miR-133 on FLOT2. The cell invasion and the migration capability were performed using the transwell invasion assay and wound healing assay.

RESULTS

We found that miR-133 expression levels were downregulated in human lung adenocarcinoma specimens and cell lines compared with the adjacent normal tissues and normal human bronchial epithelial cell. miR-133 significantly suppressed metastasis of lung adenocarcinoma cells in vitro. Furthermore, FLOT2 (flotillin-2) identified as a direct target of miR-133, and FLOT2 expression levels were inversely correlated with miR-133 expression levels in human lung adenocarcinoma specimens. And the restoration studies suggested FGF2 as a downstream effector of miR-133 which acted through Akt signalling pathway.

CONCLUSIONS

Our study revealed the mechanism that miR-133 suppresses lung adenocarcinoma metastasis by targeting FLOT2 via Akt signalling pathway, implicating a potential prognostic biomarker and therapeutic target for lung adenocarcinoma treatment.

Down-regulation of MicroRNA-133 predicts poor overall survival and regulates the growth and invasive abilities in glioma

miRNAs were reported as oncogene or tumour suppressors in various cancers and played important roles in tumour development and progression. Dysregulated miR-133 has been reported in several cancers, however, the expression and biological function of miR-133 in glioma remained unclear. In this study, we found that miR-133 expression level was significantly decreased in glioma tissues and cell lines by RT-qPCR. Then miR-133 mimics were used to evaluate the effects of miR-133 on cell proliferation and invasion in vitro. We found that overexpressed miR-133 could significantly suppress cell growth, and invasion in U87 cells. Additionally, we found that forkhead box C1 (FOXC1) was overexpressed in glioma tissue and it was directly regulated by miR-133. Overall, this study is the first proof to demonstrate that miR-133 function as tumour suppressor in glioma and inhibit cell proliferation and invasioned by directly targeting FOXC1, implying miR-133 as a potential therapeutic target for glioma.

MiR-133b inhibits growth of human gastric cancer cells by silencing pyruvate kinase muscle-splicer polypyrimidine tract-binding protein 1

The metabolism in tumor cells shifts from oxidative phosphorylation to glycolysis even in an aerobic environment. This phenomenon is known as the Warburg effect. This effect is regulated mainly by polypyrimidine tract‐binding protein 1 (PTBP1), which is a splicer of the mRNA for the rate‐limiting enzymes of glycolysis, pyruvate kinase muscle 1 and 2 (PKM1 and PKM2). In the present study, we demonstrated that miR‐133b reduced PTBP1 expression at translational level and that the expression levels of miR‐133b were significantly downregulated in gastric cancer clinical samples and human cell lines, whereas the protein expression level of PTBP1 was upregulated in 80% of the 20 clinical samples of gastric cancer examined. Ectopic expression of miR‐133b and knockdown of PTBP1 in gastric cancer cells inhibited cell proliferation through the induction of autophagy by the switching of PKM isoform expression from PKM2‐dominant to PKM1‐dominant. The growth inhibition was partially canceled by an autophagy inhibitor 3‐MA or a reactive oxygen species scavenger N‐acetylcysteine. These findings indicated that miR‐133b acted as a tumor‐suppressor through negative regulation of the Warburg effect in gastric cancer cells.

Insights into roles of the miR-1, -133 and -206 family in gastric cancer (Review)

Gastric cancer (GC) remains the third most common cause of cancer deaths worldwide and carries a high rate of metastatic risk contributing to the main cause of treatment failure. An accumulation of data has resulted in a better understanding of the molecular network of GC, however, gaps still exist between the unique bio-resources and clinical application. MicroRNAs are an important part of non-coding RNAs and behave as major regulators of tumour biology, alongside their well-known roles as intrinsic factors of gene expression in cellular processes, via their post-transcriptional regulation of components of signalling pathways in a coordinated manner. Deregulation of the miR-1, -133 and -206 family plays a key role in tumorigenesis, progression, invasion and metastasis. This review aims to provide a summary of recent findings on the miR-1, -133 and -206 family in GC and how this knowledge might be exploited for the development of future miRNA-based therapies for the treatment of GC.

Negative regulation of CDC42 expression and cell cycle progression by miR-29a in breast cancer

Objective

The inhibitory role of microRNA-29a (miR-29a) has been assessed in breast cancer cells. Herein, we analyze the underlying mechanisms of its role in cell cycle progression in breast cancer cells.

Methods

We applied real-time polymerase chain reaction (PCR) to detect the expression of miR-29 in breast cancer cell lines. Then one of the cell lines, MDA-MB-453, was transfected with mimics of miR-29a. The cell cycle was analyzed by fluorescence-activated cell sorting after staining the cells with propidium iodide. Real-time PCR, luciferase assay and western blot were used together to verify the regulation of the predicted target, cell division cycle 42 (CDC42) by miR-29a.

Results

MiR-29s were decreased in our selected mammary cell lines, among which miR-29a was the dominant isoform. Overexpression of miR-29a caused cell cycle arrest at the G0/G1 phase. We further found that miR-29a could target the expression of CDC42, which is a small GTPase associated with cell cycle progression.

Conclusion

We suggest that miR-29a exerts its tumor suppressor role in breast cancer cells partially by arresting the cell cycle through negative regulation of CDC42.

Expression of microRNA-133 inhibits epithelial-mesenchymal transition in lung cancer cells by directly targeting FOXQ1

INTRODUCTION

MicroRNA (miR) was implicated in the tumorigenesis of many types of cancer, but no study was conducted on the exact role of miR-133 in lung cancer.

METHODS

We have identified miR-133 as a putative regulator of FOXQ1 expression, and investigated the potential involvement of miR-133 in the migration and invasion of lung cancer cells, as well as the underlying molecular mechanism.

RESULTS

MiR-133 directly targeted and down-regulated FOXQ1 expression, which in turn reduced TGF-β level. MiR-133 was down-regulated in lung cancer cell lines A549 and HCC827, and its re-expression significantly inhibited the migration and invasion of the lung cancer cells. Further investigation revealed that this inhibition was caused by reversing the epithelial-mesenchymal transition, evidenced by miR-133 induced elevation of epithelial marker E-cadherin, and reduction of mesenchymal marker Vimentin.

CONCLUSIONS

Our study is the first to identify miR-133 as a biomarker for lung cancer. It functions to down-regulate FOXQ1, and inhibit epithelial-mesenchymal transition, which antagonizes lung cancer tumorigenesis. Therefore our data support the role of miR-133 as a potential molecular therapeutic tool in treating lung cancer.

miR-133 regulates Evi1 expression in AML cells as a potential therapeutic target

The Ecotropic viral integration site 1 (Evi1) is a zinc finger transcription factor, which is located on chromosome 3q26, over-expression in some acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Elevated Evi1 expression in AML is associated with unfavorable prognosis. Therefore, Evi1 is one of the strong candidate in molecular target therapy for the leukemia. MicroRNAs (miRNAs) are small non-coding RNAs, vital to many cell functions that negatively regulate gene expression by translation or inducing sequence-specific degradation of target mRNAs. As a novel biologics, miRNAs is a promising therapeutic target due to its low toxicity and low cost. We screened miRNAs which down-regulate Evi1. miR-133 was identified to directly bind to Evi1 to regulate it. miR-133 increases drug sensitivity specifically in Evi1 expressing leukemic cells, but not in Evi1-non-expressing cells The results suggest that miR-133 can be promising therapeutic target for the Evi1 dysregulated poor prognostic leukemia.

CancerNet: a database for decoding multilevel molecular interactions across diverse cancer types

Protein–protein interactions (PPIs) and microRNA (miRNA)–target interactions are important for deciphering the mechanisms of tumorigenesis. However, current PPI databases do not support cancer-specific analysis. Also, no available databases can be used to retrieve cancer-associated miRNA–target interactions. As the pathogenesis of human cancers is affected by several miRNAs rather than a single miRNA, it is needed to uncover miRNA synergism in a systems level. Here for each cancer type, we constructed a miRNA–miRNA functionally synergistic network based on the functions of miRNA targets and their topological features in that cancer PPI network. And for the first time, we report the cancer-specific database CancerNet (http://bis.zju.edu.cn/CancerNet), which contains information about PPIs, miRNA–target interactions and functionally synergistic miRNA–miRNA pairs across 33 human cancer types. In addition, PPI information across 33 main normal tissues and cell types are included. Flexible query methods are allowed to retrieve cancer molecular interactions. Network viewer can be used to visualize interactions that users are interested in. Enrichment analysis tool was designed to detect significantly overrepresented Gene Ontology categories of miRNA targets. Thus, CancerNet serves as a comprehensive platform for assessing the roles of proteins and miRNAs, as well as their interactions across human cancers.

Identification of miRNomes in human stomach and gastric carcinoma reveals miR-133b/a-3p as therapeutic target for gastric cancer

Gastric cancer (GC) is the fourth most frequent malignant disease and the second leading cause of cancer mortality worldwide, but the molecular mechanisms underlying this clinically heterogeneous disease are complex and remain far from completely understood. Accumulating evidence suggests that abnormal microRNA (miRNA) expression is involved in tumorigenesis. However, their accurate expression pattern, function, and mechanism in GC remain unclear. Here, a heatmap analysis of the miRNomes was performed across TCGA datasets and the expression of miR-133 family was found to be consistently downregulated in GC. This result was confirmed in two GC cell lines and 20 pairs of primary GC tissues, and further study demonstrated that the downregulation of miR-133 was mainly mediated by histone modification within its promoter region. Importantly, restoration of miR-133b/a-3p expression could suppress GC cell proliferation and promote cell apoptosis by targeting anti-apoptotic molecules Mcl-1 and Bcl-xL. Consistent with in vitro results, reintroducing of miR-133b/a-3p expression significantly delayed tumor formation and reduced tumor size of GC cells in xenograft nude mice. And the inverse relationship between miR-133b/a-3p and its targets was verified in xenograft mice. Taken together, our findings suggest that miR-133b/a-3p acts as a tumor suppressor in GC by directly targeting Mcl-1 and Bcl-xL. Revealing novel mechanism for oncogene inhibition by miRNA-mediated pathways offers new avenues for GC treatment.

Impairment of growth of gastric carcinoma by miR-133-mediated Her-2 inhibition

Gastric carcinoma (GC) is a leading cause of cancer-related death in China. Dysregulation of microRNAs (miRNAs) has been shown to contribute to the development of GC, whereas the role of miR-133 in GC is unknown. Here, we analyzed the levels of miR-133 in GC tissues by reverse and quantitative transcription polymerase chain reaction (RT-qPCR). We overexpressed or inhibited miR-133 in GC cells. Cell growth was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell apoptosis was evaluated by fluorescence-activated cell sorting (FACS) analysis. Targeted genes were predicted by a bioinformatics algorithm and confirmed by a dual-luciferase reporter assay. We detected lower miR-133 levels in GC tissues compared with normal gastric tissue. Moreover, the low miR-133 levels were correlated with low survival rate. Overexpression of miR-133 inhibited cell growth and promoted apoptosis, while depletion of miR-133 increased cell growth and suppressed apoptosis. Moreover, the 3'-untranslated region (3'UTR) of Her-2, the epidermal growth factor receptor (EGFR) that transduces cell growth signals, appeared to be targeted by miR-133. Together, these data suggest that reduced miR-133 levels in GC tissues promote GC growth, which possibly contributes to a low survival rate of GC patients. MiR-133 may target Her-2 to suppress GC cell growth.

A serum microRNA classifier for early detection of hepatocellular carcinoma: a multicentre, retrospective, longitudinal biomarker identification study with a nested case-control study

BACKGROUND

The ability of circulating microRNAs (miRNAs) to detect preclinical hepatocellular carcinoma has not yet been reported. We aimed to identify and assess a serum miRNA combination that could detect the presence of clinical and preclinical hepatocellular carcinoma in at-risk patients.

METHODS

We did a three-stage study that included healthy controls, inactive HBsAg carriers, individuals with chronic hepatitis B, individuals with hepatitis B-induced liver cirrhosis, and patients with diagnosed hepatocellular carcinoma from four hospitals in China. We used array analysis and quantitative PCR to identify 19 candidate serum miRNAs that were increased in six patients with hepatocellular carcinoma compared with eight control patients with chronic hepatitis B. Using a training cohort of patients with hepatocellular carcinoma and controls, we built a serum miRNA classifier to detect hepatocellular carcinoma. We then validated the classifiers' ability in two independent cohorts of patients and controls. We also established the classifiers' ability to predict preclinical hepatocellular carcinoma in a nested case-control study with sera prospectively collected from patients with hepatocellular carcinoma before clinical diagnosis and from matched individuals with hepatitis B who did not develop cancer from the same surveillance programme. We used the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) to evaluate diagnostic performance, and compared the miRNA classifier with α-fetoprotein at a cutoff of 20 ng/mL (AFP20).

FINDINGS

Between Aug 1, 2009, and Aug 31, 2013, we recruited 257 participants to the training cohort, and 352 and 139 participants to the two independent validation cohorts. In the third validation cohort, 27 patients with hepatocellular carcinoma and 135 matched controls were included in the nested case-control study, which ran from Aug 1, 2009, to Aug 31, 2014. We identified a miRNA classifier (Cmi) containing seven differentially expressed miRNAs (miR-29a, miR-29c, miR-133a, miR-143, miR-145, miR-192, and miR-505) that could detect hepatocellular carcinoma. Cmi showed higher accuracy than AFP20 to distinguish individuals with hepatocellular carcinoma from controls in the validation cohorts, but not in the training cohort (AUC 0·826 [95% CI 0·771-0·880] vs 0·814 [0·756-0·872], p=0·72 in the training cohort; 0·817 [0·769-0·865] vs 0·709 [0·653-0·765], p=0·00076 in validation cohort 1; and 0·884 [0·818-0·951] vs 0·796 [0·706-0·886], p=0·042 for validation cohort 2). In all four cohorts, Cmi had higher sensitivity (range 70·4-85·7%) than did AFP20 (40·7-69·4%) to detect hepatocellular carcinoma at the time of diagnosis, whereas its specificity (80·0-91·1%) was similar to that of AFP20 (84·9-100%). In the nested case-control study, sensitivity of Cmi to detect hepatocellular carcinoma was 29·6% (eight of 27 cases) 12 months before clinical diagnosis, 48·1% (n=13) 9 months before clinical diagnosis, 48·1% (n=13) 6 months before clinical diagnosis, and 55·6% (n=15) 3 months before clinical diagnosis, whereas sensitivity of AFP20 was only 7·4% (n=2), 11·1% (n=3), 18·5% (n=5), and 22·2% (n=6) at the corresponding timepoints (p=0·036, p=0·0030, p=0·021, p=0·012, respectively). Cmi had a larger AUC than did AFP20 to identify small-size (AUC 0·833 [0·782-0·883] vs 0·727 [0·664-0·792], p=0·0018) and early-stage (AUC 0·824 [0·781-0·868] vs 0·754 [0·702-0·806], p=0·015) hepatocellular carcinoma and could also detect α-fetoprotein-negative (AUC 0·825 [0·779-0·871]) hepatocellular carcinoma.

INTERPRETATION

Cmi is a potential biomarker for hepatocellular carcinoma, and can identify small-size, early-stage, and α-fetoprotein-negative hepatocellular carcinoma in patients at risk. The miRNA classifier could be valuable to detect preclinical hepatocellular carcinoma, providing patients with a chance of curative resection and longer survival.

FUNDING

National Key Basic Research Program, National Science and Technology Major Project, National Natural Science Foundation of China.