MicroRNA-145 is a potential prognostic factor of scirrhous type gastric cancer

Emerging roles of miR-145 in gastrointestinal cancers: A new paradigm

Gastrointestinal (GI) carcinomas are a group of cancers affecting the GI tract and digestive organs, such as the gastric, liver, bile ducts, pancreas, small intestine, esophagus, colon, and rectum. MicroRNAs (miRNAs) are small functional non-coding RNAs (ncRNAs) which are involved in regulating the expression of multiple target genes; mainly at the post-transcriptional level, via complementary binding to their 3'-untranslated region (3'-UTR). Increasing evidence has shown that miRNAs have critical roles in modulating of various physiological and pathological cellular processes and regulating the occurrence and development of human malignancies. Among them, miR-145 is recognized for its anti-oncogenic properties in various cancers, including GI cancers. MiR-145 has been implicated in diverse biological processes of cancers through the regulation of target genes or signaling, including, proliferation, differentiation, tumorigenesis, angiogenesis, apoptosis, metastasis, and therapy resistance. In this review, we have summarized the role of miR-145 in selected GI cancers and also its downstream molecules and cellular processes targets, which could lead to a better understanding of the miR-145 in these cancers. In conclusion, we reveal the potential diagnostic, prognostic, and therapeutic value of miR-145 in GI cancer, and hope to provide new ideas for its application as a biomarker as well as a therapeutic target for the treatment of these cancer.

Noncoding RNAs: Master Regulator of Fibroblast to Myofibroblast Transition in Fibrosis

Myofibroblasts escape apoptosis and proliferate abnormally under pathological conditions, especially fibrosis; they synthesize and secrete a large amount of extracellular matrix (ECM), such as α-SMA and collagen, which leads to the distortion of organ parenchyma structure, an imbalance in collagen deposition and degradation, and the replacement of parenchymal cells by fibrous connective tissues. Fibroblast to myofibroblast transition (FMT) is considered to be the main source of myofibroblasts. Therefore, it is crucial to explore the influencing factors regulating the process of FMT for the prevention, treatment, and diagnosis of FMT-related diseases. In recent years, non-coding RNAs, including microRNA, long non-coding RNAs, and circular RNAs, have attracted extensive attention from scientists due to their powerful regulatory functions, and they have been found to play a vital role in regulating FMT. In this review, we summarized ncRNAs which regulate FMT during fibrosis and found that they mainly regulated signaling pathways, including TGF-β/Smad, MAPK/P38/ERK/JNK, PI3K/AKT, and WNT/β-catenin. Furthermore, the expression of downstream transcription factors can be promoted or inhibited, indicating that ncRNAs have the potential to be a new therapeutic target for FMT-related diseases.

Construction of miRNA-mRNA-TF Regulatory Network for Diagnosis of Gastric Cancer

Gastric cancer (GC), as an epidemic cancer worldwide, has more than 1 million new cases and an estimated 769,000 deaths worldwide in 2020, ranking fifth and fourth in global morbidity and mortality. In mammals, both miRNAs and transcription factors (TFs) play a partial role in gene expression regulation. The mRNA expression profile and miRNA expression profile of GEO database were screened by GEO2R for differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs). Then, DAVID annotated the functions of DEGs to understand the functions played in biological processes. The prediction of potential target genes of miRNA and key TFs of mRNA was performed by mipathDB V2.0 and CHEA3, respectively, and the gene list comparison was performed to look for overlapping genes coregulated by key TFs and DEMs. Finally, the obtained miRNAs, TF, and overlapping genes were used to construct the miRNA-mRNA-TF regulatory network, which was verified by RT-qPCR. 76 upregulated DEGs, 199 downregulated DEGs, and 3 upregulated miRNAs (miR-199a-3p/miR-199b-3p, miR-125b-5p, and miR-199a-5p) were identified from the expression profiles of mRNA (GSE26899, GSE29998, GSE51575, and GSE13911) and miRNA (GSE93415), respectively. Through database prediction and gene list comparison, it was found that among the 199 downregulated DEGs, 61, 71, and 69 genes were the potential targets of miR-199a-3p/miR-199b-3p, miR-125b-5p, and miR-199a-5p, respectively. 199 downregulated DEGs were used as the gene list for the prediction of key TFs, and the results showed that RFX6 ranked the highest. The potential target overlap genes of miR-199a-3p/miR-199b-3p, miR-125b-5p, and miR-199a-5p were 4 genes (SH3GL2, ATP4B, CTSE, and SORBS2), 7 genes (SLC7A8, RNASE4, ESRRG, PGC, MUC6, Fam3B, and FMO5), and 6 genes (CHGA, PDK4, TMPRSS2, CLIC6, GPX3, and PSCA), respectively. Finally, we constructed a miRNA-mRNA-TF regulatory network based on the above 17 mRNAs, 3 miRNAs, and 1 TF and verified by RT-qPCR and western blot results that the expression of RFX6 was downregulated in GC tissues. These identified miRNAs, mRNAs, and TF have a certain reference value for further exploration of the regulatory mechanism of GC.

Therapeutic Targeting of MicroRNAs in the Tumor Microenvironment

The tumor-microenvironment (TME) is an amalgamation of various factors derived from malignant cells and infiltrating host cells, including cells of the immune system. One of the important factors of the TME is microRNAs (miRs) that regulate target gene expression at a post transcriptional level. MiRs have been found to be dysregulated in tumor as well as in stromal cells and they emerged as important regulators of tumorigenesis. In fact, miRs regulate almost all hallmarks of cancer, thus making them attractive tools and targets for novel anti-tumoral treatment strategies. Tumor to stroma cell cross-propagation of miRs to regulate protumoral functions has been a salient feature of the TME. MiRs can either act as tumor suppressors or oncogenes (oncomiRs) and both miR mimics as well as miR inhibitors (antimiRs) have been used in preclinical trials to alter cancer and stromal cell phenotypes. Owing to their cascading ability to regulate upstream target genes and their chemical nature, which allows specific pharmacological targeting, miRs are attractive targets for anti-tumor therapy. In this review, we cover a recent update on our understanding of dysregulated miRs in the TME and provide an overview of how these miRs are involved in current cancer-therapeutic approaches from bench to bedside.

A systematic review of microRNAs as potential biomarkers for diagnosis and prognosis of gastric cancer

Gastric cancer (GC) is the third leading cause of global cancer morbidity and mortality. One of the significant challenges in GC treatment is that most GC patients are diagnosed with advanced-stage disease due to the lack of suitable biomarkers. Recent studies have shown that microRNAs (miRNAs) can acts as a potential biomarker in GC diagnosis and prognosis. I performed a systematic review of published miRNA studies in GC, which includes the miRNA expression profiles between GC tissues and normal tissues and also miRNA studies to evaluate their potential value in the diagnosis and prognosis of GC. Among the studies, upregulation of miR-21, miR-106b, miR-25, miR-214, miR-18a, miR-191, and miR-93 and downregulation of miR-375, miR-148a, miR-92, miR-155, and miR-564 were observed in GC tissues. In evaluating of diagnosis value of miRNAs, the study was performed on a combined miRNA include miR-21, miR-93, miR-106a, and miR-106b indicated the panel of these miRNAs have the highest AUC 0.887 to discriminate GC patients from healthy. Also, miR-940 with a sensitivity of 81.25% and specificity of 98.57% may be used for diagnostic biomarkers for GC. Finally, the pooled prognostic result of miR-21 for hazard ratios (HR) was 1.260 (95% CI 0.370-4.330, P < 0.001), showing that miR-21 could predict poor survival in GC patients. This systematic review can confirm that we need to find a miRNA or a panel of miRNAs with high sensitivity and specificity for further exploration to investigate a better diagnostic or therapeutic tool for personalized management of GC patients.

The promising role of noncoding RNAs in cancer-associated fibroblasts: an overview of current status and future perspectives

As the most important component of the stromal cell population in the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) are crucial players in tumor initiation and progression. The interaction between CAFs and tumor cells, as well as the resulting effect, is much greater than initially expected. Numerous studies have shown that noncoding RNAs (ncRNAs) play an irreplaceable role in this interplay, and related evidence continues to emerge and advance. Under the action of ncRNAs, normal fibroblasts are directly or indirectly activated into CAFs, and their metabolic characteristics are changed; thus, CAFs can more effectively promote tumor progression. Moreover, via ncRNAs, activated CAFs can affect the gene expression and secretory characteristics of cells, alter the TME and enhance malignant biological processes in tumor cells to contribute to tumor promotion. Previously, ncRNA dysregulation was considered the main mechanism by which ncRNAs participate in the crosstalk between CAFs and tumor cells. Recently, however, exosomes containing ncRNAs have been identified as another vital mode of interaction between these two types of cells, with a more direct and clear function. Gaining an in-depth understanding of ncRNAs in CAFs and the complex regulatory network connecting CAFs with tumor cells might help us to establish more effective and safer approaches for cancer therapies targeting ncRNAs and CAFs and offer new hope for cancer patients.

Lycium barbarum polysaccharide protects against Homocysteine-induced Vascular smooth muscle cell proliferation and phenotypic transformation via PI3K/Akt pathway

Lycium barbarum polysaccharide (LBP) is an alkaloid extracted from lycium barbarum. LBP is the active component of lycium barbarum used to treat hypertension, atherosclerosis and other cardiovascular diseases in Chinese traditional medicine. However, the underlying cellular and molecular mechanisms of LBP- mediated activity in vascular disease remain poorly understood. In the present study, we showed the protective effect of LBP in vascular smooth muscle cells. Our results indicate that LBP significantly reduces the proliferation of VSMCs caused by Homocysteine (Hcy) and inhibits the phenotypic transformation of VSMCs caused by Hcy, from contractile to synthetic. LBP inhibited the protein expression of PI3K and Akt caused by Hcy, and increased the expression of miR-145. The results indicate that LBP exhibits substantial therapeutic potential for the treatment of Hcy-induced VSMCs proliferation and phenotypic transformation through inhibition of PI3K/Akt signaling pathway.

Serum miR-101-3p combined with pepsinogen contributes to the early diagnosis of gastric cancer

BACKGROUND

This study aimed to explore the diagnostic value of serum miR-101-3p combined with pepsinogen (PG) on early diagnosis of gastric cancer (GC).

METHODS

A total of 61 atrophic gastritis (AG) and 86 GC patients, and 50 healthy volunteers were enrolled. The serum expression of miR-101-3p was measured by qRT-PCR. The serum content of carcinoembryonic antigen (CEA) was measured by Electrochemiluminescence immunoassay. The serum contents of PGI and PGII were measured by Enzyme linked immunosorbent assay. The diagnostic value of serum markers on AG and GC was analyzed by receiver operating characteristic (ROC) analysis.

RESULTS

The expression of miR-101-3p, the content of PGI and the ratio of PGI/II were significantly decreased, and the content of PGII was significantly increased in AG patients compared with those in normal controls. The changes of the above serum indicators were more obvious in GC patients than those in AG patients. The content of CEA was significantly higher in GC patients than that in AG patients. In addition, the expression of miR-101-3p was negatively associated with the submucosal infiltration in GC patients. MiR-101-3p exhibited high diagnostic value on AG (AUC 0.8493, sensitivity 80.33%, specificity 80%) and GC (AUC 0.8749, sensitivity 72.09%, specificity 86.49%). MiR-101-3p + PGI + PGI/II (AUC 0.856, sensitivity 80.23%, specificity 77.05%) exhibited a high diagnostic value in distinguishing between AG and GC.

CONCLUSIONS

MiR-101-3p was a potential diagnostic marker for AG and GC. MiR-101-3p + PGI + PGI/II was effective in distinguishing between AG and GC.

Genome-wide analysis to identify a novel microRNA signature that predicts survival in patients with stomach adenocarcinoma

Objective: Using genome-wide screening, this study was aimed at identifying prognostic microRNA (miRNA) in those patients suffering from stomach adenocarcinoma (STAD).

Methods: A genome-wide miRNA sequencing dataset and relevant STAD clinical information was obtained via The Cancer Genome Atlas (TCGA). Prognostic miRNA selection was carried out through a whole genome multivariate Cox regression model in order to establish a prognostic STAD signature.

Results: Eleven miRNAs (hsa-mir-509-2, hsa-mir-3917, hsa-mir-495, hsa-mir-653, hsa-mir-3605, hsa-mir-2115, hsa-mir-1292, hsa-mir-137, hsa-mir-6511b-1, hsa-mir-145, and hsa-mir-138-2) were recognized as prognostic and used for the construction of a STAD prognostic signature. This signature exhibited good performance in predicting prognosis (adjusted P<0.0001, adjusted hazard ratio= 3.047, and 95% confidence interval=2.148-4.323). The time-dependent receiver operating characteristic examination exhibited area under curve values of 0.711, 0.697, 0.716, 0.733, 0.805, and 0.805, for 1-, 2-, 3-, 4-, 5-, and 10-year overall survival (OS) estimation, respectively. Comprehensive survival analysis suggests that the 11-miRNA prognostic signature acts as an independent feature of STAD prognosis and exhibits superior performance in OS prediction when compared to traditional clinical parameters. Furthermore, fourteen miRNA target genes were linked to STAD OS. These included SERPINE1, MLEC, ANGPT2, C5orf38, FZD7, MARCKS, PDGFD, DUSP6, IRS1, PSAT1, TENM3, TMEM127, BLMH, and TIRAP. Functional and gene set enrichment analysis suggested that target genes and the 11-miRNA prognostic signature were both participate in various biological processes and pathways, including the growth factor beta, Wnt, and Notch signaling pathways.

Conclusions: By means of a genome-wide analysis, an 11-miRNA expression signature that may serve as an underlying prognostic indicator for those patients suffering from STAD has been identified and described here.

The biomarker features of miR-145-3p determined via meta-analysis validated by qRT-PCR in metastatic cancer cell lines

MicroRNAs (miRNAs) play important roles in the cancer biology such as proliferation, differentiation, and apoptosis. The pivotal roles that miRNA expression plays, make them ideal candidates for detection of cancer progression as well as cancer metastasis. Especially for breast, lung and prostate cancer which are originated from soft tissues and prone to metastasis. Thus, the aim of this study is to evaluate the expression level of miR-145-3p which is a shared potential biomarker identified by meta-analysis of breast, prostate and lung cancer data sets. Six different data sets representative of three different cancer types were analyzed. These data sets are pooled together to have a master metamiRNA list while getting rid of the platform differentiations between them. As a result, 24 common differentially expressed miRNAs are determined in which miR-145-3p has the topmost rank. To mimic in vivo cancer microenvironment, hypoxia and serum deprivation were used to induce metastasis in breast (MCF-7, MDA-MB-231, MDA-MB-453), prostate (PC3, LNCaP, DU145), lung (A549, NCIH82,) cancer cell lines and noncancerous cell lines of the coresponding tissues (MCF10A, RWPE-1, MRC-5). miR-145-3p expression levels were determined by qRT-PCR. It has been shown that it is down regulated by the induction of metastasis in cancer cell lines while it is up regulated in normal cell lines to suppress the tumor formation. As a conclusion, as representing the same results in three different cancer cell types, miR-145-3p will be a promising biomarker to follow up its expression to detect cancer metastasis.

Function of microRNA-145 and mechanisms underlying its role in malignant tumor diagnosis and treatment

miRNAs are single-stranded small RNAs that do not encode proteins. They can combine complementarily with the 3′-UTRs of target gene mRNA molecules to promote targeted mRNA degradation or inhibit mRNA translation, thereby regulating gene expression at the post-transcriptional level. MiRNAs participate in regulation of cell cycling, growth, apoptosis, differentiation, and stress responses. MiRNA-145 (miR-145) is a tumor suppressor that targets various tumor-specific genes and proteins, thereby influencing related signaling pathways. MiR-145 not only regulates tumor growth, invasion, and metastasis, but is also important for tumor angiogenesis and tumor stem cell proliferation. Here, we review the roles and mechanisms of miR-145 in the diagnosis and treatment of malignant tumors. Published data confirm that miR-145 expression in various tumors is significantly lower than that in normal tissues and that overexpression of miR-145 inhibits the growth of different tumor cells, significantly reduces the ability of tumors to spread, and improves sensitivity to chemotherapeutic drugs. We conclude that miR-145 is a potential marker for use in the early diagnosis and prognostic evaluation of patients with cancer, has a role as a tumor suppressor, and is a promising cancer treatment target candidate.

The Prognostic Value and Regulatory Mechanisms of microRNA-145 in Various Tumors: A Systematic Review and Meta-analysis of 50 Studies

Acting as an important tumor-related miRNA, the clinical significance and underlying mechanisms of miR-145 in various malignant tumors have been investigated by numerous studies. This study aimed to comprehensively estimate the prognostic value and systematically illustrate the regulatory mechanisms of miR-145 based on all eligible literature.Relevant studies were acquired from multiple online databases. Overall survival (OS) and progression-free survival (PFS) were used as primary endpoints. Detailed subgroup analyses were performed to decrease the heterogeneity among studies and recognize the prognostic value of miR-145. All statistical analyses were performed with RevMan software version 5.3 and STATA software version 14.1. A total of 48 articles containing 50 studies were included in the meta-analysis. For OS, the pooled results showed that low miR-145 expression in tumor tissues was significantly associated with worse OS in patients with various tumors [HR = 1.70; 95% confidence interval (CI), 1.46-1.99; P < 0.001). Subgroup analysis based on tumor type showed that the downregulation of miR-145 was associated with unfavorable OS in colorectal cancer (HR = 2.17; 95% CI, 1.52-3.08; P < 0.001), ovarian cancer (HR = 2.15; 95% CI, 1.29-3.59; P = 0.003), gastric cancer (HR = 1.78; 95% CI, 1.35-2.36; P < 0.001), glioma (HR = 1.65; 95% CI, 1.30-2.10; P < 0.001), and osteosarcoma (HR = 2.28; 95% CI, 1.50-3.47; P < 0.001). For PFS, the pooled results also showed that the downregulation of miR-145 was significantly associated with poor PFS in patients with multiple tumors (HR = 1.39; 95% CI, 1.16-1.67; P < 0.001), and the subgroup analyses further identified that the low miR-145 expression was associated with worse PFS in patients with lung cancer (HR = 1.97; 95% CI, 1.25-3.09; P = 0.003) and those of Asian descent (HR = 1.50; 95% CI, 1.23-1.82; P < 0.001). For the regulatory mechanisms, we observed that numerous tumor-related transcripts could be targeted by miR-145-5p or miR-145-3p, as well as the expression and function of miR-145-5p could be regulated by multiple molecules.This meta-analysis indicated that downregulated miR-145 in tumor tissues or peripheral blood predicted unfavorable prognostic outcomes for patients suffering from various malignant tumors. In addition, miR-145 was involved in multiple tumor-related pathways and the functioning of significant biological effects. miR-145 is a well-demonstrated tumor suppressor, and its expression level is significantly correlated with the prognosis of patients with multiple malignant tumors.

Investigation of the clinical significance and prognostic value of microRNA-145 in human hepatocellular carcinoma

We aimed to investigate the clinical significance and prognostic value of miR-145 in hepatocellular carcinoma (HCC).HCC tissue samples and adjacent normal liver tissues were obtained from 139 patients diagnosed with HCC. The relationships between the expression level of miR-145 and clinicopathologic factors were evaluated by Chi square test. Kaplan-Meier survival analysis with the log-rank test was used to evaluate the association between miR-145 expression and HCC prognosis.miR-145 was significantly down-regulated in HCC tissues compared with the adjacent noncancerous tissues (P < .001). Its expression level was significantly correlated with tumor size (P = .010), tumor number (P = .033), lymph node metastasis (P < .000), TNM stage (P < .001) and tumor differentiation (P < .001). Kaplan-Meier curves with log rank test showed that the overall survival of the patients with low miR-145 expression was significantly shorter in comparison with the high miR-145 expression patients (P = .043). Furthermore, multivariate analysis using the Cox proportional hazards model for all variables showed that miR-145 expression was an independent prognostic factor for overall survival (P = .033).Our results indicate that low expression of miR-145 is an independent poor prognostic factor for patients with HCC. Further investigations are needed to confirm our findings.

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.

Dysregulation of miRNA Expression in Cancer Associated Fibroblasts (CAFs) and Its Consequences on the Tumor Microenvironment

The tumor microenvironment, including cancer-associated fibroblasts (CAF), has developed as an important target for understanding tumor progression, clinical prognosis and treatment responses of cancer. Cancer cells appear to transform normal fibroblasts (NF) into CAFs involving direct cell-cell communication and epigenetic regulations. This review summarizes the current understanding on miR involvement in cancer cell—tumor environment/stroma communication, transformation of NFs into CAFs, their involved targets and signaling pathways in these interactions; and clinical relevance of CAF-related miR expression profiles. There is evidence that miRs have very similar roles in activating hepatic (HSC) and pancreatic stellate cells (PSC) as part of precancerous fibrotic diseases. In summary, deregulated miRs affect various intracellular functional complexes, such as transcriptional factors, extracellular matrix, cytoskeleton, EMT/MET regulation, soluble factors, tyrosine kinase and G-protein signaling, apoptosis and cell cycle & differentiation, but also formation and composition of the extracellular microenvironment. These processes result in the clinical appearance of desmoplasia involving CAFs and fibrosis characterized by deregulated stellate cells. In addition, modulated release of soluble factors can act as (auto)activating feedback loop for transition of NFs into their pathological counterparts. Furthermore, epigenetic communication between CAFs and cancer cells may confer to cancer specific functional readouts and transition of NF. MiR related epigenetic regulation with many similarities should be considered as key factor in development of cancer and fibrosis specific environment.

Roles of microRNAs in cancer associated fibroblasts of gastric cancer

Cancer associated fibroblasts (CAFs) are a key component of the tumor microenvironment (TME). They play critical roles in the occurrence and development of gastric cancer (GC) through controlling various cytokines secretion and direct cell-to-cell interaction. However, the underlying mechanism of CAFs in tumor progression has not been entirely elucidated. MicroRNAs (miRNAs) as important factors have a central role in the interplay between tumor cell and TME. Recent studies also highlight that the aberrant expression of miRNAs in CAFs is involved in multiple functions in tumorigenesis and malignant process of GC. In this article, we shortly introduce the miRNAs biogenesis and provide an overview of the mechanisms and emerging roles of CAFs-related miRNAs. Focusing on these miRNAs as potential therapeutic targets may bring better treatment effect on GC and other diseases.

Small role with big impact: miRNAs as communicators in the cross-talk between cancer-associated fibroblasts and cancer cells

Cancer microenvironment is composed of numerous components that can support cancer cell proliferation, promote cancer progression and contribute to cancer treatment resistance. The major components of caner microenvironment are fibroblasts, endothelial cells, immune cells as well as cytokines, chemokines, and extracellular matrix (ECM) all of which surround tumor cells as the core and cross talk with each other. Among them, cancer-associated fibroblasts (CAFs) play an important role in promoting cancer progression by secreting various pro-inflammatory factors. MicroRNAs (miRNAs) are small noncoding RNAs that negatively regulate protein expression both in cancer cell and normal stromal cells. Changes of miRNAs expression in cancer-associated fibroblasts can be induced both by cancer cells and other stromal cells. This change can arise through direct interaction or by secreted paracrine factors or even by secreted miRNAs. The desregulated miRNAs in cancer-associated fibroblasts then enhance the CAFs phenotype and assist their cancer promotion ability. Explore the regulatory function of miRNAs in the complex communication between cancer cells and cancer microenvironment is important to understand the process of tumor progression and may help to develop new therapeutic strategies. This review provides an updated content of latest research advances about the relevance of miRNAs in the interaction between cancer cells and the CAFs. We will describe miRNAs which are differential expressed by NFs and CAFs, their function in regulating fibroblasts activation as well as miRNAs expressed in CAFs as prognostic factors in cancer stroma in recent studies. We will also discuss miRNA as an important player in CAFs mediated regulation of cancer progression and metastasis, cancer metabolism, cancer stem cell property and chemoresistance.

Mesenchymal Stem/Stromal Cells under Stress Increase Osteosarcoma Migration and Apoptosis Resistance via Extracellular Vesicle Mediated Communication

Studies have shown that mesenchymal stem/stromal cells (MSCs) from bone marrow are involved in the growth and metastasis of solid tumors but the mechanism remains unclear in osteosarcoma (OS). Previous studies have raised the possibility that OS cells may receive support from associated MSCs in the nutrient deprived core of the tumors through the release of supportive macromolecules and growth factors either in vesicular or non-vesicular forms. In the present study, we used stressed mesenchymal stem cells (SD-MSCs), control MSCs and OS cells to examine the hypothesis that tumor-associated MSCs in nutrient deprived core provide pro-proliferative, anti-apoptotic, and metastatic support to nearby tumor cells. Assays to study of the effects of SD-MSC conditioned media revealed that OS cells maintained proliferation when compared to OS cells grown under serum-starved conditions alone. Furthermore, OS cells in MSCs and SD-MSC conditioned media were significantly resistant to apoptosis and an increased wound healing rate was observed in cells exposed to either conditioned media or EVs from MSCs and SD-MSCs. RT-PCR assays of OS cells incubated with extracellular vesicles (EVs) from SD-MSCs revealed microRNAs that could potentially target metabolism and metastasis associated genes as predicted by in silico algorithms, including monocarboxylate transporters, bone morphogenic receptor type 2, fibroblast growth factor 7, matrix metalloproteinase-1, and focal adhesion kinase-1. Changes in the expression levels of focal adhesion kinase, STK11 were confirmed by quantitative PCR assays. Together, these data indicate a tumor supportive role of MSCs in osteosarcoma growth that is strongly associated with the miRNA content of the EVs released from MSCs under conditions that mimic the nutrient deprived core of solid tumors.

Potential Diagnostic, Prognostic and Therapeutic Targets of MicroRNAs in Human Gastric Cancer

Human gastric cancer (GC) is characterized by a high incidence and mortality rate, largely because it is normally not identified until a relatively advanced stage owing to a lack of early diagnostic biomarkers. Gastroscopy with biopsy is the routine method for screening, and gastrectomy is the major therapeutic strategy for GC. However, in more than 30% of GC surgical patients, cancer has progressed too far for effective medical resection. Thus, useful biomarkers for early screening or detection of GC are essential for improving patients’ survival rate. MicroRNAs (miRNAs) play an important role in tumorigenesis. They contribute to gastric carcinogenesis by altering the expression of oncogenes and tumor suppressors. Because of their stability in tissues, serum/plasma and other body fluids, miRNAs have been suggested as novel tumor biomarkers with suitable clinical potential. Recently, aberrantly expressed miRNAs have been identified and tested for clinical application in the management of GC. Aberrant miRNA expression profiles determined with miRNA microarrays, quantitative reverse transcription-polymerase chain reaction and next-generation sequencing approaches could be used to establish sample specificity and to identify tumor type. Here, we provide an up-to-date summary of tissue-based GC-associated miRNAs, describing their involvement and that of their downstream targets in tumorigenic and biological processes. We examine correlations among significant clinical parameters and prognostic indicators, and discuss recurrence monitoring and therapeutic options in GC. We also review plasma/serum-based, GC-associated, circulating miRNAs and their clinical applications, focusing especially on early diagnosis. By providing insights into the mechanisms of miRNA-related tumor progression, this review will hopefully aid in the identification of novel potential therapeutic targets.

MicroRNAs May Serve as Emerging Molecular Biomarkers for Diagnosis and Prognostic Assessment or as Targets for Therapy in Gastric Cancer

Gastric cancer (GC) is one of the most common cancers, with high incidences in East Asia countries. Most GC patients have been reported with low early diagnosis rate and show extremely poor prognosis. Therefore, it is necessary to develop novel and more sensitive biomarkers to improve early diagnosis and therapy in order to provide longer survival and better quality of life for gastric cancer patients. MicroRNAs (miRNAs) play crucial roles in GC development and progression. miRNAs have emerged as a novel molecular biomarker for cancer diagnosis, prognosis and therapy with surprising stability in tissues, serum or other body fluids. This review summarizes major advances in our current knowledge about potential miRNA biomarkers for GC that have been reported in the past two years.

MicroRNA-335 is downregulated in bladder cancer and inhibits cell growth, migration and invasion via targeting ROCK1

The expression of microRNA‑335 (miR‑335) has been demonstrated to be downregulated in numerous types of cancer. Thus far, no previous studies have investigated the miR‑335 expression in bladder cancer. In the present study, the expression and effects of miR‑335 were assessed in bladder cancer. The results of the present study provided, to the best of our knowledge, the first evidence that miR‑335 is downregulated in the tumor tissue of patients with bladder cancer. Following transfection of miR‑335, MTT, cell migration and invasion, luciferase and western blot assays were conducted in bladder cancer cell lines. The results demonstrated that miR‑335 inhibited cell proliferation, migration and invasion in T24 and EJ cells. In addition, the results suggested that miR‑335 directly targets Rho‑associated protein kinase 1 (ROCK1) in bladder cancer. The present study provided a novel therapeutic target, the miR‑335/ROCK1 axis in bladder cancer. The suggested approach will be beneficial in developing an effective treatment against bladder cancer.

Comparison of Prognostic MicroRNA Biomarkers in Blood and Tissues for Gastric Cancer

Gastric cancer (GC) still keeps up high mortality worldwide with poor prognosis. Efficient and non-invasive prognostic biomarkers are urgently needed. MicroRNAs are non-coding RNAs playing roles in post-transcriptional gene regulation, which contribute to various biological processes such as development, differentiation and carcinogenesis. MicroRNA expression profiles have been associated with the prognosis and outcome in GC. MicroRNA prognostic biomarkers have been identified from blood or tissues samples, but with different prognostic features. Understanding the various roles of microRNAs in different sample sources of GC will provide deep insights into GC progression. In this review, we highlight the distinct prognostic roles of microRNAs biomarkers in blood and tissue according to their relationships with prognostic parameters, survival rates and target pathways. This will be useful for non-invasive biomarker development and selection in prognosis of GC.

The transcribed-ultraconserved regions in prostate and gastric cancer: DNA hypermethylation and microRNA-associated regulation

The transcribed-ultraconserved regions (T-UCRs) are a novel class of non-coding RNAs, which are absolutely conserved (100%) between the orthologous regions of the human, rat and mouse genomes. Previous studies have described that several T-UCRs show differential expressions in cancers and might be involved in cancer development. We investigated the transcriptional levels of representative 26 T-UCRs and determined the regions that were differently expressed in prostate cancer (PCa) and gastric cancer (GC). A quantitative reverse transcription-polymerase chain reaction analysis revealed the downregulation of Uc.158+A expression by a DNA methylation-associated mechanism, which was restored by 5-Aza-dC (5-aza-2'-deoxycytidine) treatment. Bisulfite genomic sequencing using cell lines and tissue samples demonstrated cancer-specific CpG hypermethylation in both GC and PCa. However, Uc.416+A was only overexpressed in GC and we identified an miR-153 binding site in the possible regulatory region of Uc.416+A using online databases. Along with a forced expression or knockdown of miR-153 in MKN-74 GC cells, the transcriptional levels of Uc.416+A were significantly disturbed. A luciferase reporter gene assay supported the direct regulation of Uc.416+A expression by miR-153. Furthermore, Uc.416+A was associated with cell growth through the regulation of IGFBP6 (insulin-like growth factor-binding protein 6) in GC. These findings suggest an oncogenic role of Uc.416+A in GC, which suggests that our approach would provide new insights into functional studies of T-UCRs in cancer biology.

Implications of miR cluster 143/145 as universal anti-oncomiRs and their dysregulation during tumorigenesis

Tumorigenesis is a multistep process, de-regulated due to the imbalance of oncogenes as well as anti-oncogenes, resulting in disruption of tissue homeostasis. In many cases the effect of oncogenes and anti-oncogenes are mediated by various other molecules such as microRNAs. microRNAs are small non-coding RNAs established to post-transcriptionally regulate more than half of the protein coding genes. miR cluster 143/145 is one such cancer-related microRNA cluster which is down-regulated in most of the cancers and is able to hinder tumorigenesis by targeting tumor-associated genes. The fact that they could sensitize drug-resistant cancer cells by targeting multidrug resistant genes makes them potent tools to target cancer cells. Their low levels precede events which lead to cancer progression and therefore could be considered also as biomarkers to stage the disease. Interestingly, evidence suggests the existence of several in vivo mechanisms by which this cluster is differentially regulated at the molecular level to keep their levels low in cancer. In this review, we summarize the roles of miR cluster 143/145 in cancer, their potential prognostic applications and also their regulation during tumorigenesis.

Role of cancer-associated fibroblasts in invasion and metastasis of gastric cancer

Cancer-associated fibroblasts (CAFs) are important components of various types of tumors, including gastric cancer (GC). During tumorigenesis and progression, CAFs play critical roles in tumor invasion and metastasis via a series of functions including extracellular matrix deposition, angiogenesis, metabolism reprogramming and chemoresistance. However, the mechanism of the interaction between gastric cancer cells and CAFs remains largely unknown. MicroRNAs (miRNAs) are a class of non-coding small RNA molecules, and their expression in CAFs not only regulates the expression of a number of target genes but also plays an essential role in the communication between tumor cells and CAFs. In this review, we provide an overview of recent studies on CAF miRNAs in GC and the relevant signaling pathways in gastrointestinal tumors. Focusing the attention on these signaling pathways may help us better understand their role in tumor invasion and metastasis and identify new molecular targets for therapeutic strategies.

RNA-Sequencing Analysis of Messenger RNA/MicroRNA in a Rabbit Aneurysm Model Identifies Pathways and Genes of Interest

BACKGROUND AND PURPOSE

Rabbit aneurysm models are used for the testing of embolization devices and elucidating the mechanisms of human intracranial aneurysm growth and healing. We used RNA-sequencing technology to identify genes relevant to induced rabbit aneurysm biology and to identify genes and pathways of potential clinical interest. This process included sequencing microRNAs, which are important regulatory noncoding RNAs.

MATERIALS AND METHODS

Elastase-induced saccular aneurysms were created at the origin of the right common carotid artery in 6 rabbits. Messenger RNA and microRNA were isolated from the aneurysm and from the control left common carotid artery at 12 weeks and processed by using RNA-sequencing technology. The results from RNA sequencing were analyzed by using the Ingenuity Pathway Analysis tool.

RESULTS

A total of 9396 genes were analyzed by using RNA sequencing, 648 (6.9%) of which were found to be significantly differentially expressed between the aneurysms and control tissues (P < .05; false-discovery rate, <0.01; fold change, >2 or <.5). Of these genes, 614 were mapped successfully, 143 were down-regulated, and 471 were up-regulated in the aneurysms as compared with controls. Using the same criteria for significance, 3 microRNAs were identified as down-regulated and 5 were identified as up-regulated. Pathway analysis associated these genes with inflammatory response, cellular migration, and coagulation, among other functions and pathologies.

CONCLUSIONS

RNA-sequencing analysis of rabbit aneurysms revealed differential regulation of some key pathways, including inflammation and antigen presentation. ANKRD1 and TACR1 were identified as genes of interest in the regulation of matrix metalloproteinases.

MiR-144 Inhibits Uveal Melanoma Cell Proliferation and Invasion by Regulating c-Met Expression

MicroRNAs (miRNAs) are a group endogenous small non-coding RNAs that inhibit protein translation through binding to specific target mRNAs. Recent studies have demonstrated that miRNAs are implicated in the development of cancer. However, the role of miR-144 in uveal melanoma metastasis remains largely unknown. MiR-144 was downregulated in both uveal melanoma cells and tissues. Transfection of miR-144 mimic into uveal melanoma cells led to a decrease in cell growth and invasion. After identification of two putative miR-144 binding sites within the 3' UTR of the human c-Met mRNA, miR-144 was proved to inhibit the luciferase activity inMUM-2B cells with a luciferase reporter construct containing the binding sites. In addition, the expression of c-Met protein was inhibited by miR-144. Furthermore, c-Met-mediated cell proliferation and invasion were inhibited by restoration of miR-144 in uveal melanoma cells. In conclusion, miR-144 acts as a tumor suppressor in uveal melanoma, through inhibiting cell proliferation and migration. miR-144 might serve as a potential therapeutic target in uveal melanoma patients.