MicroRNA-195 inhibits human gastric cancer by directly targeting basic fibroblast growth factor

An epigenetic modulator with promising therapeutic impacts against gastrointestinal cancers: A mechanistic review on microRNA-195

Due to their high prevalence, gastrointestinal cancers are one of the key causes of cancer-related death globally. The development of drug-resistant cancer cell populations is a major factor in the high mortality rate, and it affects about half of all cancer patients. Because of advances in our understanding of cancer molecular biology, non-coding RNAs (ncRNAs) have emerged as critical factors in the initiation and development of gastrointestinal cancers. Gene expression can be controlled in several ways by ncRNAs, including through epigenetic changes, interactions between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) and proteins, and the function of lncRNAs as miRNA precursors or pseudogenes. As lncRNAs may be detected in the blood, circulating ncRNAs have emerged as a promising new class of non-invasive cancer biomarkers for use in the detection, staging, and prognosis of gastrointestinal cancers, as well as in the prediction of therapy efficacy. In this review, we assessed the role lncRNAs play in the progression, and maintenance of colorectal cancer, and how they might be used as therapeutic targets in the future.

A systematic method introduced a common lncRNA-miRNA-mRNA network in the different stages of prostate cancer

Introduction

The present study aimed to investigate the interaction of the common lncRNA-miRNA-mRNA network involved in signaling pathways in different stages of prostate cancer (PCa) by using bioinformatics and experimental methods.

Methods

Seventy subjects included sixty PCa patients in Local, Locally Advanced, Biochemical Relapse, Metastatic, and Benign stages, and ten healthy subjects were entered into the current study. The mRNAs with significant expression differences were first found using the GEO database. The candidate hub genes were then identified by analyzing Cytohubba and MCODE software. Cytoscape, GO Term, and KEGG software determined hub genes and critical pathways. The expression of candidate lncRNAs, miRNAs, and mRNAs was then assessed using Real-Time PCR and ELISA techniques.

Results

4 lncRNAs, 5 miRNAs, and 15 common target genes were detected in PCa patients compared with the healthy group. Unlike the tumor suppressors, the expression levels of common onco-lncRNAs, oncomiRNAs, and oncogenes showed a considerable increase in patients with advanced stages; Biochemical Relapse and Metastatic, in comparison to the primary stages; Local and Locally Advanced. Additionally, their expression levels significantly increased with a higher Gleason score than a lower one.

Conclusion

Identifying a common lncRNA-miRNA-mRNA network associated with prostate cancer may be clinically valuable as potential predictive biomarkers. They can also serve as novel therapeutic targets for PCa patients.

Role of Basic Fibroblast Growth Factor in Cancer: Biological Activity, Targeted Therapies, and Prognostic Value

Cancer is the leading cause of death worldwide; thus, it is necessary to find successful strategies. Several growth factors, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF, FGF2), and transforming growth factor beta (TGF-β), are involved in the main processes that fuel tumor growth, i.e., cell proliferation, angiogenesis, and metastasis, by activating important signaling pathways, including PLC-γ/PI3/Ca2+ signaling, leading to PKC activation. Here, we focused on bFGF, which, when secreted by tumor cells, mediates several signal transductions and plays an influential role in tumor cells and in the development of chemoresistance. The biological mechanism of bFGF is shown by its interaction with its four receptor subtypes: fibroblast growth factor receptor (FGFR) 1, FGFR2, FGFR3, and FGFR4. The bFGF–FGFR interaction stimulates tumor cell proliferation and invasion, resulting in an upregulation of pro-inflammatory and anti-apoptotic tumor cell proteins. Considering the involvement of the bFGF/FGFR axis in oncogenesis, preclinical and clinical studies have been conducted to develop new therapeutic strategies, alone and/or in combination, aimed at intervening on the bFGF/FGFR axis. Therefore, this review aimed to comprehensively examine the biological mechanisms underlying bFGF in the tumor microenvironment, the different anticancer therapies currently available that target the FGFRs, and the prognostic value of bFGF.

Waldenström Macroglobulinemia: Mechanisms of Disease Progression and Current Therapies

Waldenström macroglobulinemia is an indolent, B-cell lymphoma without a known cure. The bone marrow microenvironment and cytokines both play key roles in Waldenström macroglobulinemia (WM) tumor progression. Only one FDA-approved drug exists for the treatment of WM, Ibrutinib, but treatment plans involve a variety of drugs and inhibitors. This review explores avenues of tumor progression and targeted drug therapy that have been investigated in WM and related B-cell lymphomas.

Effects of mir-195 Targeted Regulation of JAK2 on Proliferation, Invasion, and Apoptosis of Gastric Cancer Cells

Background. Overexpression of miR-195 can make gastric cancer cells stay in G1/G2 phase. miR-195 has been shown to inhibit gastric cancer cell replication and accelerate cell death by targeting JAK2. However, the relationship between miR-195, JAK2, and gastric cancer is not clear. Objective. To observe the effect of mir-195 regulated by JAK2 on the growth, invasion, and death of gastric cancer cells. Methods. MGC803 and NCI gastric N87 cells were introduced into the negative control sequences of miR-195 and RNA, respectively. To detect the expression of miR-195 in cells, to detect the effect of miR-195 on mitosis and proliferation of tumor cells, to analyze the effect of miR-195 on cell invasion and metastasis, and to detect the regulation of miR-195 on JAK2 expression. Results. The level of miR-195 in miR-195-MIMICS group was significantly higher than that in miR-NC group. The cell survival rate of miR-195 mimic group was lower than that of miR-NC group ( $P<0.05$ ). Compared with miR-NC group, the number of cells in G1 phase increased, the cells in G2 phase and S phase decreased, and the proportion of cells in G2 and S phase decreased in miR-195 mimic group. The scratch distance of miR-195 simulator group was larger than that of control group. The number of invasive cells in the miR-195 mimic group was significantly lower than that in the control group. The expression of JAK2 protein in miR-195 mimic group was lower than that in miR-NC group. There was a significant negative correlation between the expression level of miR-195 and JAK2 (rhabdomile 0.326 and record 0.00). There are continuous interaction fragments between JAK2 and miR-195. The luciferase activity of miR-195 mimic and wild type JAK2 sequence expression vector was significantly lower than that of wild type JAK2 sequence expression vector. Conclusion. miR-195 may inhibit the occurrence, metastasis, and invasion of gastric tumor by downregulating the expression of JAK2. miR-195/JAK2 may be a new molecular target for the treatment of gastrointestinal tumors.

Roles and mechanisms of miR-195-5p in human solid cancers

Cancer persists as a worldwide disease that contributes to high morbidity and mortality rates. As a class of non-coding RNA, microRNAs (miRNAs) are one kind of important regulators in cancer and frequently implicated in tumor development and progression. Emerging experiments have suggested that miRNA-195-5p (miR-195-5p) can regulate neoplastic processes in many pathways. For instance, miR-195-5p can not only regulate proliferation, migration and invasion of tumor cells but also promote tumor cell apoptosis. Furthermore, low expression of miR-195-5p could induce drug resistance. Our review focuses on the expression of miR-195-5p in various tumors and elucidates the related mechanisms of which miR-195-5p participates in tumor biology, as well as summarizes the roles of miR-195-5p in tumor progression. We believe that miR-195-5p might have potential utility as a novel diagnostic biomarker and therapeutic target for cancer.

Long intergenic non-protein coding RNA 662 accelerates the progression of gastric cancer through up-regulating centrosomal protein 55 by sponging microRNA-195-5p

Long non-coding RNAs (lncRNAs) are important players in regulating diverse human diseases, including cancers. Nonetheless, the function of long intergenic non-protein coding RNA 662 (LINC00662) in gastric cancer (GC) carcinogenesis and progression remains to be delineated. In the present study, LINC00662, microRNA-195-5p (miR-195-5p) and centrosomal protein 55 (CEP55) mRNA expression levels were quantified by qRT-PCR. GC cell proliferation, migration and invasion were analyzed by CCK-8, BrdU and Transwell assays. Besides, dual-luciferase reporter and RNA pull-down assays were conducted for verifying the targeting relationships of LINC00662, miR-195-5p and CEP55. The regulatory functions of LINC00662 and miR-195-5p on CEP55 were examined utilizing Western blot. In this study, it was revealed that LINC00662 expression level was elevated in GC tissues and cells. LINC00662 overexpression facilitated the malignant biological behaviors of GC cells whereas knockdown of LINC00662 worked oppositely. In terms of mechanism, LINC00662 targeted miR-195-5p to modulate CEP55 expression. In conclusion, LINC00662 facilitates the malignant biological behaviors of GC cells via miR-195-5p/CEP55 axis, and therefore, it may be a promising target for GC treatment.

LINC00511 promotes gastric cancer progression by regulating SOX4 and epigenetically repressing PTEN to activate PI3K/AKT pathway

Gastric cancer (GC) serves as a common malignancy. Long non-coding RNAs (lncRNAs) have been proven to regulate many cancers, including GC. Long intergenic non-protein-coding RNA 511 (LINC00511) has been poorly studied in GC, but its detailed regulatory mechanism has not been identified. Here, LINC00511 was detected to be highly expressed in GC cells. Functional assays were conducted and uncovered that LINC00511 boosted cell proliferation, migration, stemness and EMT process while inhibiting the apoptosis of GC cells. From a series of mechanism experiments, it was found that at the transcriptional level, LINC00511 recruited EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) to the promoter of PTEN (phosphatase and tensin homolog) and facilitated methylation of PTEN promoter. LINC00511 epigenetically repressed PTEN to activate the PI3K/AKT pathway. Moreover, SRY-box transcription factor 4 (SOX4) activated the transcription of LINC00511. At the post-transcriptional level, LINC00511 sponged miR-195-5p to elevate SOX4 expression in GC cells. On the whole, the present study disclosed that SOX4-induced LINC00511 activated SOX4 via competing endogenous RNA (ceRNA) pattern and epigenetically repressed PTEN to activate PI3K/AKT pathway by recruiting EZH2, thus facilitating GC cell proliferation, migration and stemness while inhibiting GC cell apoptosis.

Gastric Cancer: Identification of microRNAs Inhibiting Druggable Targets and Mediating Efficacy in Preclinical In Vivo Models

In addition to chemotherapy, targeted therapies have been approved for treatment of locally advanced and metastatic gastric cancer. The therapeutic benefit is significant but more durable responses and improvement of survival should be achieved. Therefore, the identification of new targets and new approaches for clinical treatment are of paramount importance. In this review, we searched the literature for down-regulated microRNAs which interfere with druggable targets and exhibit efficacy in preclinical in vivo efficacy models. As druggable targets, we selected transmembrane receptors, secreted factors and enzymes. We identified 38 microRNAs corresponding to the criteria as outlined. A total of 13 miRs target transmembrane receptors, nine inhibit secreted proteins and 16 attenuate enzymes. These microRNAs are targets for reconstitution therapy of gastric cancer. Further target validation experiments are mandatory for all of the identified microRNAs.

Protective role of astragaloside IV in gastric cancer through regulation of microRNA-195-5p-mediated PD-L1

AIM

Astragaloside IV (AS-IV) was reported to exert anti-cancer function in many cancers, but its actions in gastric cancer (GC) remain unclear. In the present study, we tried to elaborate the underlying mechanism by which AS-IV regulated the epithelial-mesenchymal transition (EMT) and angiogenesis of GC cells.

METHODS

The expressions of hsa-miR-15b-5p, hsa-miR-15a-5p, hsa-miR-195-5p, hsa-miR-424-5p and hsa-miR-497-5p in GC tissues and adjacent normal tissues were predicted by TCGA database. SGC7901 or MGC803 cells were treated with AS-IV, or transfected with miR-195-5p inhibitor/mimic or pcDNA3.1-PD-L1 followed by detection of cell proliferation, EMT and angiogenesis. The target relation between miR-195-5p and PD-L1 was confirmed by dual luciferase reporter gene assay.

RESULTS

Elevated hsa-miR-15b-5p, hsa-miR-15a-5p and hsa-miR-424-5p expressions were found in GC tissues, while decreased hsa-miR-195-5p and hsa-miR-497-5p expressions were observed in GC tissues. AS-IV inhibits EMT and angiogenesis in GC. PD-L1 was a potential target of miR-195-5p. Down-regulation of miR-195-5p or elevated PD-L1 expression reverses the inhibitory effect of AS-IV on EMT and angiogenesis of GC cells.

CONCLUSION

The present study demonstrated that AS-IV inhibited EMT and angiogenesis in GC through upregulation of miR-195-5p, highlighting the potential therapeutic effect of AS-IV on GC via miR-195-5p-regulated PD-L1.

Identification of miRNAs associated with dendritic cell dysfunction during acute and chronic hepatitis B virus infection

The uptake or expression of hepatitis B virus (HBV) proteins by dendritic cells (DCs) is considered important for disease outcome. Differential expression of microRNA (miRNA) may have a role in viral persistence and hepatocellular injury. The miRNA expression was investigated by microarray in DCs from different stages of HBV infection and liver disease namely, immune active (IA; n = 20); low replicative (LR; n = 20); HBeAg negative (n = 20); acute viral hepatitis (AVH, n = 20) and healthy controls (n = 20). miRNA levels were analyzed by unsupervised hierarchical clustering and principal component analyses and validated by quantitative polymerase Chain Reaction (qPCR). The miRNA-messenger RNA (mRNA)regulatory networks identified 19 miRNAs and 12 target gene interactions in major histocompatibility complex and other immune pathways. miR-2278, miR-615-3p, and miR-3681-3p were downregulated in the IA group compared to healthy control, miR-152-3p and miR-3613-3p in the LR group compared to IA group and miR-152-3p and miR-503-3p in HBe negative compared to LR group. However, miR-7-1-1-3p, miR-192-5p, miR-195-5p, and miR-32-5p in LR, miR-342-3p, and miR-940 in HBe negative, and miR-34a-5p, miR-130b-3p, miR-221-3p, miR-320a, miR-324-5p, and miR-484 in AVH were upregulated. Further, qPCR confirmed changes in miRNA levels and their target genes associated with antigen processing and presentation. Thus, a deregulated network of miRNAs-mRNAs in DCs seems responsible for an impaired immune response during HBV pathogenesis.

Overexpression of secretory clusterin (sCLU) induces chemotherapy resistance in human gastric cancer cells by targeting miR-195-5p

Recent focus has turned to secretory clusterin (sCLU) as a key contributor to chemoresistance of anticancer agents, but the role of sCLU on chemotherapy drug response to gastric cancer cells is not fully understood. Previous research found that sCLU was overexpressed in the induced multidrug-resistant MGC-803/5-FU cell line, suggesting that sCLU upregulation was closely related to chemoresistance to anticancer agents. In the present study, we aimed to clarify the role and mechanisms of sCLU in regulating the chemoresistance of gastric cancer cells. Cell apoptosis and cell viability were evaluated by annexin V/propidium iodide staining and CCK8. Expression of sCLU and miR-195-5P was detected using quantitative RT-PCR assays. The expression of sCLU in gastric cancer tissues was detected by RT-PCR assays. Upregulating or downregulating sCLU or miR-195-5P in gastric cancer cells was used to evaluate the mechanisms of chemoresistance. We found that sCLU was significantly elevated in the MGC-803/5-FU and SGC-7901 cells, and the downregulating sCLU sensitized MGC-803/5-FU and SGC-7901 cells to cisplatin and Docetaxel by upregulation of miR-195-5P. Upregulating sCLU in MGC-803 and HGC-27 cells was resistant to cisplatin and Docetaxel by downregulating miR-195-5p. Targeting miR-195-5P reduced the sensitivity of MGC-803 cells to 5-FU, and miR-195-5P overexpression enhanced the sensitivity of MGC-803/5-FU cells to 5-FU. The overexpression of sCLU in gastric cancer tissues was associated with chemoresistance. Our findings suggest that overexpression of sCLU induced chemoresistance in gastric cancer cells by downregulating miR-195-5p, thus providing a potential target for the development of agents that targeting sCLU for gastric cancer therapy.

Gastric cancer-associated microRNA expression signatures: integrated bioinformatics analysis, validation, and clinical significance

Background

Gastric cancer (GC) is one of the common gastrointestinal malignancy worldwide and exhibits a poor prognosis. Increasing studies have indicated that microRNAs play critical roles in the cancer progression and have shown great potential as useful biomarkers. The search for potential diagnostic and prognostic biomarkers of gastric cancer (GC) with integrated bioinformatics analyses has been undertaken in previous studies.

Methods

In this study, the robust rank aggregation (RRA) method was used to perform an integrated analysis of differentially expressed miRNAs (DEMs) from five microarray datasets in the Gene Expression Omnibus (GEO) database to find robust biomarkers for GC. Ultimately, seven miRNAs were filtered from fourteen primary miRNAs using the validation set of The Cancer Genome Atlas (TCGA) database. Based on these results, diagnostic and survival analyses were performed, and logistic regression and Cox regression were used to determine the clinicopathological characteristics of the DEM expression and overall survival.

Results

Nine eligible miRNA datasets related to GC were selected from the GEO database for integrated analysis in this study. Diagnostic analysis implied that these miRNAs could be regarded as promising candidate diagnostic biomarkers in GC tissues, but whether the results of the tissue analysis are consistent with those of peripheral blood analysis requires further validation. The logistic regression indicated that the ectopic expression of these DEMs was relevant to the histological type, anatomical region, and pathological grade of GC. However, the survival and Cox regression analyses suggested that the poor prognosis of GC patients was not strongly dependent on the ectopic expression of the seven miRNAs, but rather, a poor prognosis was associated with age, metastasis, and histological grade.

Conclusions

Based on the results presented in this study it can be concluded that these miRNAs (miR-455-3p, miR-135b-5p, let-7a-3p, miR-195-5p, miR-204-5p, miR-149-5p, and miR-143-3p) might be potential biomarkers for the early diagnosis of GC patients, but this finding should be regarded with caution. A large-scale, prospective, and multicenter cohort study should be performed.

miR-195-5p Suppresses Lung Cancer Cell Proliferation, Migration, and Invasion Via FOXK1

Lung cancer remains one of the leading causes of cancer deaths around the world. Previous studies have shown that microRNAs have pivotal functions in tumorigenesis including lung cancer. It is reported that microRNA-195-5p acts as a tumor suppressor role in human cancers. However, the function and molecular mechanism of microRNA-195-5p in lung cancer progression is still unclear. In the present study, the results showed that the expression of microRNA-195-5p was downregulated both in lung cancer tissues and in lung cancer cell lines. Enhanced expression of microRNA-195-5p inhibited cell proliferation, migration, and invasion in lung cancer cells. Furthermore, Forkhead box k1 was identified as the direct target of microRNA-195-5p. Forkhead box k1 overexpression could restore the repressed cell proliferation and metastasis caused by microRNA-195-5p overexpression. Our results demonstrated that a functional mechanism of microRNA-195-5p in regulating lung cancer. It indicates that microRNA-195-5p may regulate lung cancer growth and metastasis through the regulation of Forkhead box k1, highlighting the potential application for the treatment of lung cancer in the future.

IGF2-AS knockdown inhibits glycolysis and accelerates apoptosis of gastric cancer cells through targeting miR-195/CREB1 axis

Dysregulation of long non-coding RNA (lncRNA) insulin growth factor 2 antisense (IGF2-AS) is being found to have relevance to tumorigenesis, including gastric cancer (GC). The purpose of this study was to further explore the detailed role and molecular mechanism of IGF2-AS in GC progression. The expression levels of IGF2-AS, miR-195 and cAMP responsive element binding protein 1 (CREB1) mRNA were assessed by qRT-PCR. Glucose consumption and lactate production were determined using a corresponding Commercial Assay Kit. Hexokinase 2 (HK2) and CREB1 protein levels were detected using western blot. Cell apoptosis was determined by flow cytometry. The targeted interaction between miR-195 and IGF2-AS or CREB1 was validated using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Our data revealed that IGF2-AS was upregulated in GC tissues and predicted poor prognosis. IGF2-AS knockdown hampered glycolysis and accelerated apoptosis of GC cells. Moreover, IGF2-AS acted as a sponge of miR-195 and CREB1 was a direct target of miR-195. MiR-195 mediated the regulatory effect of IGF2-AS knockdown on GC cell glycolysis and apoptosis. MiR-195 exerted its regulatory effect on GC cell glycolysis and apoptosis by CREB1. Furthermore, IGF2-AS regulated CREB1 expression via sponging miR-195. In conclusion, our study suggested that IGF2-AS knockdown suppressed glycolysis and facilitated apoptosis in GC cells at least partly through sponging miR-195 and modulating CREB1 expression, highlighting a novel therapeutic strategy for GC treatment.

A Functional Variant of the miR-15 Family Is Associated with a Decreased Risk of Esophageal Squamous Cell Carcinoma

MicroRNAs (miRNAs)-related single-nucleotide polymorphisms (SNPs) have been shown to be implicated in the susceptibility to different types of cancer, including esophageal squamous cell carcinoma (ESCC). Identification of miRNA-related SNPs may provide candidate biomarkers for early diagnosis of ESCC. We performed a genome-wide microarray assay to identify differentially expressed miRNAs, which indicated that the miR-15 family may play an important role in ESCC biology. We then investigated the association of miR-15 family-related SNPs with ESCC. Five miR-15 family-related SNPs were genotyped in 300 patients and 418 controls. Unconditional logistic regression was used to evaluate the relationships of these SNPs with ESCC. Generalized multifactor dimensionality reduction was employed to analyze the SNP-SNP and SNP-smoking interactions. The expression quantitative trait loci (eQTL) databases were queried for in silico functional validation. We found that miR-15b SNP rs1451761T>G was associated with a significantly decreased risk of ESCC and there was a significant SNP-SNP interaction between rs1451761 and rs2740545. SNP-smoking interaction analysis also indicated that the association between rs1451761 and ESCC risk could be changed by smoking status. Additionally, the eQTL analysis revealed that rs1451761 was significantly correlated with structural maintenance of chromosomes 4 and karyopherin subunit alpha 4 mRNA expression. Our results suggest that miR-15b SNP rs1451761 may affect an individual's susceptibility to ESCC, alone and in SNP-SNP and SNP-smoking interaction manners.

LncRNA BANCR Promotes Pancreatic Cancer Tumorigenesis via Modulating MiR-195-5p/Wnt/β-Catenin Signaling Pathway

Long noncoding BRAF-activated noncoding RNA has been reported to be tightly associated with tumorigenesis and development in various types of cancers. However, the expression, biological function, and modulatory mechanism of BRAF-activated noncoding RNA in pancreatic cancer remained unclear. In the present work, we explored the carcinogenic activity and underlying mechanism of BRAF-activated noncoding RNA on pancreatic cancer in vitro. We identified that BRAF-activated noncoding RNA was upregulated in pancreatic cancer tissues and cell lines, and BRAF-activated noncoding RNA was related to tumor metastasis and stage. BRAF-activated noncoding RNA reinforces proliferation, invasion, and migration in PANC-1 and SW1990 cells. Moreover, miR-195-5p was downregulated in both PC tissues and cell lines. Our results based on luciferase reporter, RIP-Ago2 and qRT-PCR assays, showed that miR-195-5p was a direct target of BRAF-activated noncoding RNA. Furthermore, miR-195-5p inhibitor abrogated the effects of short-interfering BRAF-activated noncoding RNA on PANC-1 and SW1990 cell growth and invasion in vitro. We further identified that BRAF-activated noncoding RNA played a vital role in activating the Wnt/β-catenin pathway by sponging miR-195-5p. Collectively, our study showed that BRAF-activated noncoding RNA promotes pancreatic cancer tumorigenesis through miR-195-5p/Wnt/β-catenin axis may serve as a potential target for diagnostics and therapeutics in pancreatic cancer.

PELP1 is a novel oncogene in gastric tumorigenesis and negatively regulated by miR-15 family microRNAs

BACKGROUD

Gastric cancer (GC) is one of the leading causes of cancer-related death in East Asia and some South American countries, but its mechanism has not been clarified clearly. Proline-, glutamic acid-, and leucine-rich protein-1 (PELP1), a co-regulatory molecule of estrogen receptor α (ER α), is up-regulated in series of cancers such as endometrial carcinoma, ovarian cancer, colorectal cancer, breast cancer, and non-small cell lung cancer. However, PELP1's role in GC is still obscure, and its aberrant expression in cancers also remains to be explained.

METHODS

Immunohistochemical staining and Real-time PCR were used to compare the expression level of PELP1 in GC tissues and adjacent tissues. Western blot was used to detect the expression of PELP1 in cell lines. Kaplan-meier analysis and chi-square test were applied to evaluate the potential of PELP1 to function as a cancer biomarker. RNA interference was used to inhibit PELP1 expression in GC cells, followed by detecting cell proliferation, apoptosis, migration and invasion. Luciferase assay was conducted to validate whether miR-15 family members can directly target PELP1.

RESULTS

In this study, we validated that PELP1 was significantly up-regulated in GC samples and cell lines. It was also demonstrated that the up-regulation of PELP1 was associated with several clinicopathologic features such as tumor diameter (P< 0.001), serum CEA level (P= 0.034), and lymphatic metastasis (P= 0.0009) of GC patients, and its high expression was correlated with shorter disease-free survival and overall survival of the patients. Knockdown of PELP1 remarkably arrested the proliferationï¼ migration and invasion, while promoted apoptosis. We also confirmed that miR-15 family microRNAs, most of which were down-regulated and tumor suppressor in cancers, were posttranscriptional regulators of PELP1.

CONCLUSION

In conclusion, we demonstrated that PELP1 was an oncogene of GC associated with patients' prognosis and miR-15 family members contributed to its aberrant expression in cancers.

Propofol Reduces Epithelial to Mesenchymal Transition, Invasion and Migration of Gastric Cancer Cells through the MicroRNA-195-5p/Snail Axis

BACKGROUND Gastric cancer (GC) is a life-threating malignancy worldwide. Accumulating studies suggest propofol has anti-tumor functions in addition to the anesthetic effect. This study aimed to figure out the effects of propofol treatment in GC development. MATERIAL AND METHODS Human GC SGC-7901 and NCI-N87 cells were treated with different doses of propofol. Then the invasion and migration of GC cells was measured. SGC-7901 cells following 10 μM propofol treatment were applied in the following experiments. MicroRNAs (miRNAs) with differential expression in cells with or without propofol treatment were analyzed. Expression of miR-195-5p, Snail, vimentin and E-cadherin in SGC-7901 cells was measured, and then loss-of-function of miR-195-5p and gain-of-function of Snail were performed. Target relation between miR-195-5p and Snail was confirmed using luciferase assay. Xenograft tumor was induced in nude mice to identify the effect of propofol on GC in vivo. RESULTS Propofol reduced epithelial to mesenchymal transition (EMT), invasion and migration of GC cells in a dose-dependent manner. Propofol elevated miR-195-5p expression but reduced Snail expression, and it reduced vimentin but increased E-cadherin expression in SGC-7901 cells. miR-195-5p directly bound to Snail. miR-195-5p inhibition or Snail promotion reversed propofol-inhibited malignant behaviors of SGC-7901 cells. In vitro results were reproduced in in vivo experiments. CONCLUSIONS Our study found that propofol could inhibit EMT, invasion, and migration of GC cells by promoting miR-195-5p expression and suppressing Snail expression. This study may provide novel insights in GC treatment.

Identification of Potentially Functional CircRNA-miRNA-mRNA Regulatory Network in Gastric Carcinoma using Bioinformatics Analysis

Background

As all we know, gastric cancer (GC) is a highly aggressive disease. Recently, circular RNA (circRNA) was found to play a vital role in regulation of GC. Some circRNAs could regulate messenger RNA (mRNA) expression by functioning as a microRNA (miRNA) sponge. Nevertheless, the circRNA-miRNA-mRNA regulatory network involved GC rarely has been explored and researched.

Material/Methods

All the differentially expressed circRNAs, miRNAs, and mRNA were derived from Gene Expression Omnibus (GEO) microarray data (GSE78092, GSE89143, GSE93415, and GSE54129). GC level 3 miRNA-sequencing data and clinical information were downloaded from The Cancer Genome Atlas (TCGA) database. Furthermore, a circRNA-miRNA-mRNA regulatory network was constructed by Cytoscape (version 3.6.1). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway revealed the functions and signaling pathways associated with these target genes. Hub genes of protein-protein interaction (PPI) network were identified by STRING database and cytoHubba.

Results

The regulatory network consists of 3 circRNAs, 22 miRNAs, and 128 mRNAs. Only 3 miRNAs of the network were consistent with the expression of TCGA and were associated with some clinical features. The results of the functional analysis of 128 mRNAs showed that GO analysis and KEGG pathways of inclusion criteria were 49 and 24, respectively. PPI network and Cytoscape showed that the top 10 hub genes were MYC, CTGF, TGFBR2, TGFBR1, SERPINE1, KRAS, ZEB1, THBS1, CDK6, and TNS1; 4 of which were verified by GEPIA based on TCGA. Highly expressed SERPINE1 had a poor OS (over survival) and DFS (disease-free survival), and TGFBR1 expression increased along with the increase of clinical stages.

Conclusions

This study looked at a circRNA-miRNA-mRNA regulatory network associated with GC and explored the potential functions of mRNA in the network, then identified a new molecular marker for prediction, prognosis, and therapeutic targets for clinical patients.

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

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

Identification of HGF as a novel target of miR-15a/16/195 in gastric cancer

Background Gastric malignancy is the third most frequently encountered cancer globally and have been documented to confer extremely poor prognosis, given their limited treatment options. The up-regulation of hepatocyte growth factor (HGF) has been found in various tumor tissues, including GC tissue, and has been linked with tumor development. Nevertheless, the pathways leading to HGF upregulation have yet to be fully explored. Methods Immunohistochemistry (IHC) assay was used to detect HGF expression in human gastric tumor tissues, while western blotting allowed quantification of protein levels. Bioinformatics tools were used to predict potential miRNA that may target HGF mRNA. Relative levels of miR-15a/16/195 as well as the target mRNA levels were analyzed with qRT-PCR. Direct targeting between miRNA and mRNA was then validated by luciferase assay. Finally, a mouse xenograft tumor model was selected to demonstrate the in vivo effects of miR-15a/16/195. Results HGF protein expressions were markedly raised, while miR-15a/16/195 levels were dramatically down-regulated in tumor tissues of GC. miR-15a/16/195 were shown to directly bind with the 3'-UTR of HGF mRNA. This study demonstrated that HGF can be repressed by overexpressed miR-15a/16/195, which resulted in the suppression of GC cell proliferation and migration. Furthermore, in the xenograft mouse model, miR-15a/16/195 were also found to have a tumor growth suppression effect. Conclusions miR-15a/16/195 suppresses tumorigenesis by targeting HGF and may have a potential therapeutic application in the clinical treatment of GC.

lncRNA SNHG1 cooperated with miR-497/miR-195-5p to modify epithelial-mesenchymal transition underlying colorectal cancer exacerbation

Our study was intended to provide evidence for whether long noncoding RNA (lncRNA) SNHG1 would accelerate the epithelial-mesenchymal transition (EMT) course intrinsic in colorectal cancer (CRC) by sponging downstream miR-497-5p and miR-195-5p. We altogether collected 338 pairs of CRC and noncancerous tissues, and meanwhile purchased five CRC cell lines (i.e., SW480, HCT116, Lovo, CaCO-2, and HT29) and human embryo intestinal mucosal tissue-sourced cell line (i.e., CCC-HIE-2). The CRC cells as mentioned above were appraised regarding their potencies in proliferation, migration, and invasion, after being transfected with pcDNA3.1-SNHG1, si-SNHG1, miR-195-5p mimic/inhibitor, and miR-497-5p mimic/inhibitor. Eventually, we depended on reverse transcription-polymerase chain reaction to assess SNHG1, miR-497-5p, and miR-195-5p expressions, and the protein levels of EMT-specific molecules were determined on the strength of western blotting. It seemed that there was a high potential for highly expressed SNHG1 and lowly expressed miR-497/miR-195 to symbolize CRC patients' unfavorable prognosis (p < .05). Concurrently, CRC cells were detected with higher SNHG1 expression and lower miR-497/miR-195 expression than CCC-HIE-2 cells (p < .05). In addition, the EMT process of CRC cells was facilitated markedly against the contexts of overexpressed SNHG1 and underexpressed miR-497-5p/miR-195-5p. Intriguingly, the strength of miR-195-5p collaborating with miR-497-5p in affecting the activity of CRC cells seemed to overweigh that of miR-497/miR-195-5p alone. Besides, both miR-195-5p and miR-497-5p were subjected to in vivo and in vitro modification of SNHG1 (p < .05). Conclusively, application of lncRNA SNHG1 for treating CRC might be promising, given its dual modulation of miR-497 and miR-195 underlying CRC pathogenesis.

ELK1-induced upregulation of lncRNA TRPM2-AS promotes tumor progression in gastric cancer by regulating miR-195/ HMGA1 axis

Long noncoding RNAs (lncRNAs) have been confirmed to be aberrantly expressed in various diseases including tumors. Recently, a new tumor-related lncRNA, lncRNA TRPM2 antisense RNA (TRPM2-AS), was shown to be involved in many tumors, such as lung cancer and breast cancer. However, the expression and role of TRPM2-AS in the development of gastric cancer (GC) have not been elucidated. In the current study, we provided evidence that the expression levels of TRPM2-AS were increased in both GC tissues and cell lines. We also showed that overexpression of TRPM2-AS was modulated by ELK1, a transcription factor. The results of clinical assays showed that higher expressions of TRPM2-AS were significantly related with invasion depth, TNM stage, lymphatic metastasis, and shorter overall survival. Further clinical assays using multivariate analysis suggested that TRPM2-AS expression was an independent prognostic factor in patients with GC. Functional experiments illustrated that depression of TRPM2-AS suppressed proliferation, migration, and invasion in GC cells. In terms of mechanism, we found that TRPM2-AS directly inhibited miR-195, which targeted the 3'-untranslated region of high-mobility group AT-hook 1 (HMGA1) messenger RNA. Overall, these findings revealed that ELK1-induced overexpression of TRPM2-AS promoted the development and progression of GC in part through miR-195/HMGA1 signaling axis, and established its candidacy as a new cancer biomarker for GC patients.

MicroRNA-195: a review of its role in cancers

MicroRNAs (miRNAs) are small and highly conserved noncoding RNAs that regulate gene expression at the posttranscriptional level by binding to the 3′-UTR of target mRNAs. Recently, increasing evidence has highlighted their profound roles in various pathological processes, including human cancers. Deregulated miRNAs function as either oncogenes or tumor suppressor genes in multiple cancer types. Among them, miR-195 has been reported to significantly impact oncogenicity in various neoplasms by binding to critical genes and signaling pathways, enhancing or inhibiting the progression of cancers. In this review, we focus on the expression of miR-195 in regulatory mechanisms and tumor biological processes and discuss the future potential therapeutic implications of diverse types of human malignancies.

miRNA‑195 suppresses cell proliferation of ovarian cancer cell by regulating VEGFR2 and AKT signaling pathways

The present study aimed to investigate the functional effects of microRNA‑195 on ovarian cancer cells and the underling mechanism involved. Reverse transcription‑quantitative polymerase chain reaction was used to measure the expression of microRNA‑195 in patients with ovarian cancer. Cell proliferation and apoptosis were measured with MTT assay and flow cytometry, respectively. Caspase‑3/9 activity, vascular endothelial growth factor receptor (VEGFR)2 and phosphorylated protein kinase B (p‑AKT) protein expression were analyzed using caspase‑3/9 activity kits and western blot analysis. The expression of microRNA‑195 was downregulated in ovarian cancer, compared with the normal control group. Furthermore, microRNA‑195 suppresses cell proliferation and induced apoptosis of ovarian cancer cells. In addition, microRNA‑195 suppressed VEGFR2 and p‑AKT protein expression in ovarian cancer cells. The inhibition of VEGFR2 and p‑AKT increased the functional effects of microRNA‑195 on apoptosis of ovarian cancer cells. The results demonstrated that microRNA‑195 suppresses cell proliferation of ovarian cancer cells through regulation of VEGFR2 and AKT signaling pathways.

MicroRNA‑195 inhibits cell proliferation, migration and invasion by targeting defective in cullin neddylation 1 domain containing 1 in cervical cancer

MicroRNAs (miRs), a class of small non-coding RNAs, have been demonstrated to perform promoting or suppressive roles in various types of human malignancy. Deregulation of miR-195 has been observed in numerous types of human cancer, including cervical cancer; however, the detailed molecular mechanism of miR-195 underlying the malignant progression of cervical cancer remains largely unclear. In the present study, miR-195 was significantly down-regulated in cervical cancer tissue samples compared with adjacent non-tumor tissue samples, and the reduced expression level of miR-195 was associated with node metastasis and an advanced clinical stage in cervical cancer. Furthermore, the patients with low miR-195 expression levels demonstrated shorter survival times when compared with those with high miR-195 expression levels. In vitro experiments indicated that miR-195 exerted suppressive effects on the proliferation, migration and invasion of cervical cancer cells. Luciferase reporter gene assay identified defective in cullin neddylation 1 domain containing 1 (DCUN1D1) as a novel target gene of miR-195 and the expression level of DCUN1D1 was identified to be negatively regulated by miR-195 in cervical cancer cells. DCUN1D1 was significantly upregulated in cervical cancer, with a negative correlation to miR-195 expression. Furthermore, upregulation of DCUN1D1 was associated with the malignant progression and poor prognosis of cervical cancer. DCUN1D1 overexpression attenuated the suppressive effects of miR-195 on the malignant phenotypes of cervical cancer cells. Notably, the expression levels of miR-195 were significantly lower in HeLa [human papilloma virus (HPV)18⁺] and SiHa (HPV16⁺) cells compared with those in C33A (HPV⁻) cells, and knockdown of E6 using small interfering RNA significantly increased the miR-195 expression while the DCUN1D1 expression level was reduced in HeLa and SiHa cells. Thus, these findings indicate that miR-195 exerts a suppressive role in cervical cancer by targeting DCUN1D1. Therefore, miR-195 may present as a potential therapeutic candidate for cervical cancer.

MiR-497-5p, miR-195-5p and miR-455-3p function as tumor suppressors by targeting hTERT in melanoma A375 cells

Background

hTERT gene plays an important role in melanoma, although the specific mechanism involved is unclear. The aim of this study was to screen and identify the relative miRNAs with the regulation of hTERT in melanoma.

Materials and methods

Quantitative real-time polymerase chain reaction (q-PCR) and immunohistochemistry were performed to detect hTERT mRNA and protein expression in 36 formalin-fixed paraffin-embedded melanoma tissues and 36 age- and sex-matched pigmented nevi cases, respectively. Bioinformatics analysis and custom miRNA polymerase chain reaction array were determined for predicting, screening and verifying miRNAs with the regulation of the hTERT gene. To investigate the biological functions, miRNAs mimics or inhibitors were transfected into melanoma A375 cells. The relative expression of miR-497-5p, miR-195-5p, miR-455-3p and hTERT mRNA was determined by q-PCR. The protein expression of hTERT was detected by Western blot. 3-(4,5-Dimethylthiazolyl-2-yl)-2,5-biphenyl tetrazolium bromide and flow cytometry were employed to detect cell proliferation ability, cell apoptosis and cell cycle. Transwell and wound healing assays were used to observe cell invasion and migration abilities. A direct target gene of miRNAs was analyzed by a dual luciferase reporter activity assay.

Results

MiR-497-5p, miR-195-5p, miR-455-3p were significantly downregulated, while hTERT was upregulated in melanoma tissues. hTERT expression level was inversely correlated with miR-497-5p, miR-195-5p and miR-455-3p. Overexpression of miR-497-5p, miR-195-5p and miR-455-3p inhibited A375 cell proliferation, migration and invasion, arrested the cell cycle, induced cell apoptosis and decreased hTERT expression at both mRNA and protein levels. Suppression of miR-497-5p, miR-195-5p and miR-455-3p partially reversed the inhibitory effects. Finally, hTERT was identified as a direct target of miR-497-5p, miR-195-5p and miR-455-3p.

Conclusions

MiR-497-5p, miR-195-5p and miR-455-3p act as tumor suppressors by targeting hTERT in melanoma A375 cells. Therefore, miR-497-5p, miR-195-5p and miR-455-3p could be potential targeted therapeutic choice for melanoma.

MicroRNA-155 promotes gastric cancer growth and invasion by negatively regulating transforming growth factor-β receptor 2

Gastric cancer (GC) is one of the most common malignancies worldwide and has high morbidity and mortality rates. It is essential to elucidate the molecular events of GC proliferation and invasion, which will provide new therapeutic targets for GC. The inactivation of transforming growth factor-β receptor 2 (TGFβR2) correlates with cancer cell growth and metastasis, but the mechanisms underlying the downregulation of TGFβR2 expression remain unknown. MicroRNAs (miRNAs) act as post-transcriptional regulators and play a key role in the development of cancers. Bioinformatics analysis and luciferase reporter assays have shown that miR-155 directly binds to the 3'-UTR of TGFβR2 mRNA. In this study, we found that the TGFβR2 protein levels, but not mRNA levels, were downregulated in GC tissues, and the levels of miR-155 were significantly increased in GC tissues. We deduced that miR-155 was inversely correlated with TGFβR2 in GC cells. In vitro studies showed that overexpression of miR-155 in SGC7901 inhibited the expression of TGFβR2 and then promoted GC cell proliferation and migration, whereas miR-155 inhibitor showed opposite effects. In addition, the tumor-suppressing function of TGFβR2 was verified by using siRNA and TGFβR2 overexpressing plasmids. The results showed that miR-155 promotes cell growth and migration by negatively regulating TGFβR2. Thus, miR-155-regulated TGFβR2 as a potential therapeutic target in GC.