MiR 21-5p as a predictor of recurrence in young gastric cancer patients

DSCR9/miR-21-5p axis inhibits pancreatic cancer proliferation and resistance to gemcitabine via BTG2 signaling

The outcome of pancreatic adenocarcinoma (PAAD) patients is poor, given resistance to gemcitabine. Long noncoding RNA (lncRNA) has been implicated in the carcinogenesis of pancreatic cancer; however, its function and mechanism in PAAD resistance to gemcitabine (GEM) are yet unknown. Herein, we demonstrate that lncRNA DSCR9 is significantly reduced in PAAD in vitro and in vivo. CCK-8, BrdU and flow cytometry assays show that overexpression of DSCR9 markedly suppresses pancreatic cancer cell proliferation and invasion, and promotes apoptosis under gemcitabine treatment. BTG2 acts as a tumor suppressor by reducing the proliferation and invasion of pancreatic cancer cells and increasing gemcitabine-induced apoptosis. Immunofluorescence (IF) staining combined with fluorescence in situ hybridization (FISH) of pancreatic cancer tissues shows that DSCR9 and BTG2 are both increased in pancreatic cancer tissues. Luciferase assay shows that miR-21-5p simultaneously binds to DSCR9 and 3'UTR of BTG2; DSCR9 relieves miR-21-5p-induced inhibition of BTG2 by competing with BTG2 for miR-21-5p binding. Overexpression of miR-21-5p enhances the invasiveness of pancreatic cancer cells by promoting cancer cell proliferation and invasion and attenuating gemcitabine-induced apoptosis. Overexpression of miR-21-5p attenuates the effect of DSCR9 overexpression on BTG2 expression and invasiveness of pancreatic cancer cells. Finally, miR-21-5p expression is increased, while BTG2 expression is decreased in pancreatic cancer tissues. miR-21-5p is negatively correlated with DSCR9 and BTG2. In conclusion, the DSCR9/miR-21-5p/BTG2 axis modulates pancreatic cancer proliferation, invasion, and gemcitabine resistance.

Exosomal MicroRNA as Biomarkers for Diagnosing or Monitoring the Progression of Ovarian Clear Cell Carcinoma: A Pilot Study

Ovarian cancer is the most common cause of gynecological malignancy-related mortality since early-stage disease is difficult to diagnose. Advanced clear cell carcinoma of the ovary (CCCO) has dismal prognosis, and its incidence has been increasing in Japan, emphasizing the need for highly sensitive diagnostic and prognostic CCCO biomarkers. Exosomal microRNAs (miRNAs) secreted by tumor cells are known to play a role in carcinogenesis; however, their involvement in ovarian cancer is unclear. In this study, we performed expression profiling of miRNAs from exosomes released by five cell lines representing different histological types of ovarian cancer. Exosomes isolated from culture media of cancer and normal cells were compared for miRNA composition using human miRNA microarray. We detected 143 exosomal miRNAs, whose expression was ≥1.5-fold higher in ovarian cancer cells than in the control. Among them, 28 miRNAs were upregulated in cells of all histological ovarian cancer types compared to control, and three were upregulated in CCCO cells compared to other types. Functional analyses indicated that miR-21 overexpressed in CCCO cells targeted tumor suppressor genes PTEN, TPM1, PDCD4, and MASP1. The identified miRNAs could represent novel candidate biomarkers to diagnose or monitor progression of ovarian cancer, particularly CCCO.

Lidocaine Suppresses Gastric Cancer Development Through Circ_ANO5/miR-21-5p/LIFR Axis

BACKGROUND

Lidocaine has been manifested to exert anti-tumor role in gastric cancer (GC) progression. However, the action mechanism by which Lidocaine functions in GC has not been fully elucidated.

AIM

The study aimed to reveal the molecular mechanism of Lidocaine in GC progression.

METHODS

Cell clonogenicity and viability were assessed by colony formation and methyl thiazolyl tetrazolium assays, respectively. Transwell assay was employed to detect cell migration and invasion. Flow cytometry was implemented to monitor cell apoptosis. Relative expression of circular RNA ANO5 (circ_ANO5), microRNA (miR)-21-5p and Leukemia inhibitory factor receptor (LIFR) was examined by quantitative reverse transcription-polymerase chain reaction. Western blot assay was performed to analyze the levels of LIFR and cell metastasis-related proteins. The target relationship between miR-21-5p and circ_ANO5 or LIFR was confirmed by dual-luciferase reporter assay. In addition, xenograft model was established to explore the role of Lidocaine in vivo.

RESULTS

Lidocaine inhibited cell proliferation, migration and invasion, while promoted apoptosis of GC cells. Lidocaine upregulated circ_ANO5 and LIFR expression, but downregulated miR-21-5p expression in GC cells. Additionally, expression of circ_ANO5 and LIFR was decreased, while miR-21-5p expression was increased in GC cells. Circ_ANO5 depletion or miR-21-5p overexpression attenuated Lidocaine-induced anti-proliferative and anti-metastatic effects on GC cells. Circ_ANO5 could sponge miR-21-5p, and miR-21-5p targeted LIFR. Moreover, Lidocaine suppressed the tumor growth in vivo.

CONCLUSION

Lidocaine might GC cell malignancy by modulating circ_ANO5/miR-21-5p/LIFR axis, highlighting a novel insight for GC treatment.

The Molecular Roles and Clinical Implications of Non-Coding RNAs in Gastric Cancer

Gastric cancer (GC) is one of the most common malignancies in the world. It is also the fifth most common cancer in China. In recent years, a large number of studies have proved that non-coding RNAs (ncRNAs) can regulate cell proliferation, invasion, metastasis, apoptosis, and angiogenesis. NcRNAs also influence the therapeutic resistance of gastric cancer. NcRNAs mainly consist of miRNAs, lncRNAs and circRNAs. In this paper, we summarized ncRNAs as biomarkers and therapeutic targets for gastric cancer, and also reviewed their role in clinical trials and diagnosis. We sum up different ncRNAs and related moleculars and signaling pathway in gastric cancer, like Bcl-2, PTEN, Wnt signaling. In addition, the potential clinical application of ncRNAs in overcoming chemotherapy and radiotherapy resistance in GC in the future were also focused on.

Assessment of a panel of miRNAs in serum and pleural fluid for the differential diagnosis of malignant and benign pleural effusion

BACKGROUND

Differential diagnosis between malignant pleural effusion (MPE) and benign pleural effusion (BPE) remains a clinical challenge.

OBJECTIVE

The aim of the study is to assess the efficacy of the serum and pleural fluid (PF) miRNA panels in distinguishing MPE from BPE.

METHODS

Fourteen candidate miRNAs which were shown aberrant expression in lung cancer based on previous studies were tested by quantitative real-time PCR (qRT-PCR) in 20 MPE patients and 20 BPE patients. Significantly aberrantly expressed miRNAs were further assessed by qRT-PCR in all patients enrolled in this study. A receiver operating characteristic (ROC) curve was constructed, and the area under the ROC curve (AUC) was calculated to evaluated the diagnostic performance of the miRNAs.

RESULTS

miR-21, miR-29c and miR-182 were found to be significantly aberrantly expressed in the serum and PF of MPE patients. The AUCs for the combination of miR-21, miR-29c and miR-182 in serum and PF were 0.832 and 0.89 respectively in distinguishing MPE from infection-associated PE including tuberculous pleurisy and parapneumonia PE, and 0.866 and 0.919 respectively for differentiating MPE from heart failure-associated PE, which were superior to AUC of each individual miRNAs.

CONCLUSIONS

miR-21, miR-29c and miR-182 in serum and PF could be useful biomarkers for MPE of diagnosis.

Human blood microRNA hsa-miR-21-5p induces vitellogenin in the mosquito Aedes aegypti

Mosquito vectors transmit various diseases through blood feeding, required for their egg development. Hence, blood feeding is a major physiological event in their life cycle, during which hundreds of genes are tightly regulated. Blood is a rich source of proteins for mosquitoes, but also contains many other molecules including microRNAs (miRNAs). Here, we found that human blood miRNAs are transported abundantly into the fat body tissue of Aedes aegypti, a key metabolic center in post-blood feeding reproductive events, where they target and regulate mosquito genes. Using an artificial diet spiked with the mimic of an abundant and stable human blood miRNA, hsa-miR-21-5p, and proteomics analysis, we found over 40 proteins showing differential expression in female Ae. aegypti mosquitoes after feeding. Of interest, we found that the miRNA positively regulates the vitellogenin gene, coding for a yolk protein produced in the mosquito fat body and then transported to the ovaries as a protein source for egg production. Inhibition of hsa-miR-21-5p followed by human blood feeding led to a statistically insignificant reduction in progeny production. The results provide another example of the involvement of small regulatory molecules in the interaction of taxonomically vastly different taxa.

MiR-21 in the Cancers of the Digestive System and Its Potential Role as a Diagnostic, Predictive, and Therapeutic Biomarker

MicroRNAs (miRNAs) are small non-coding RNAs. They can regulate the expression of their target genes, and thus, their dysregulation significantly contributes to the development of cancer. Growing evidence suggests that miRNAs could be used as cancer biomarkers. As an oncogenic miRNA, the roles of miR-21 as a diagnostic and prognostic biomarker, and its therapeutic applications have been extensively studied. In this review, the roles of miR-21 are first demonstrated via its different molecular networks. Then, a comprehensive review on the potential targets and the current applications as a diagnostic and prognostic cancer biomarker and the therapeutic roles of miR-21 in six different cancers in the digestive system is provided. Lastly, a brief discussion on the challenges for the use of miR-21 as a therapeutic tool for these cancers is added.

miR-21-5p promotes lung adenocarcinoma cell proliferation, migration and invasion via targeting WWC2

OBJECTIVE

Studies have suggested that miR-21-5p and WWC2 are key players in most cancer types, yet the underlying mechanisms in lung adenocarcinoma (LUAD) remain elusive. This study made in-depth research on the two factors-dependent mechanisms underlying LUAD occurrence and development.

METHODS

Bioinformatics methods were employed to identify the miRNA and its target gene of interest. In all, 20 pairs of LUAD tumor tissue samples and matched adjacent normal samples along with 5 LUAD cell lines were collected for evaluating the aberrant expression of miR-21-5p and WWC2. Dual-luciferase reporter assay was performed to validate the targeted relationship between miR-21-5p and WWC2. A series of in vitro experiments including colony formation assay, EdU, wound healing assay and Transwell were conducted for assessment of the LUAD cell biological behaviors. In addition, Western blot was carried out to determine the protein expression of epithelial-mesenchymal transition (EMT)-related proteins.

RESULTS

miR-21-5p was found to be considerably increased in LUAD tissue and cells relative to that in the adjacent tissue and the human bronchial epithelial cells, whereas WWC2 was significantly decreased. Dual-luciferase reporter assay revealed that miR-21-5p targeted WWC2 and down-regulated its expression. Besides, silencing miR-21-5p or overexpressing WWC2 played an inhibitory role in PC-9 cancer cell proliferation, migration and invasion, but such effect was suppressed when miR-21-5p was overexpressed. Furthermore, Western blot uncovered that WWC2 overexpression impeded the EMT process in LUAD cells.

CONCLUSION

miR-21-5p facilitates LUAD cell proliferation, migration and invasion through targeting WWC2, which provides a novel therapeutic target for LUAD treatment.

Circulating miR-21-5p and miR-126-3p: diagnostic, prognostic value, and multivariate analysis in non-small-cell lung cancer

One of the most recent of tumor molecular characterization approaches is the microRNA (miR) expression profile. No single marker is sufficiently accurate for clinical use. Numerous biomarkers panels were created for three main purposes: tumor subtype, classification and, early detection, and prediction of tumor responses to treatment and prognosis of patients. miR-21-5p and miR-126-3p have received special attention because of their relationship with many cancer sites such as lung cancer, colorectal cancer, and renal cell carcinoma. We aimed to study their diagnostic and prognostic utility in lung cancer patients. Serum carcinoembryonic antigen (CEA) level was measured using an enzyme-linked immunosorbent assay (ELISA) technique. The expression levels of miR-21-5p and miR-126-3p were determined by real-time PCR in 60 non small cell lung cancer (NSCLC) patients and 40 healthy controls to detect diagnostic utility. Moreover, it was correlated with all disease clinicopathological characters and patient survival. Higher miR-21-5p and lower miR-126-3p levels were found in lung cancer patients than in controls. The sensitivity of CEA and miR-21-5p and miR-126-3p were 78.3, 96.7, and 90% at cutoff points 7.5, 2.35, and 2.175, respectively to distinguish NSCLC patients from controls. On combining both miR-21-5p and miR-126-3p, an improvement of sensitivity to 97% was noted. For patients, miR-21-5P increased significantly with metastatic stage and the highest grade (GIII). There was significantly longer overall survival (OS) among patients with early stages, lower grades GI&II, low miR-21-5p, and high miR-126-3p. miR-126-3p and presence of metastasis, the last two factors were the independent factors affecting OS with a hazard ratio of 0.26 (95% CI: 0.06-1.09) and 3.64 (95% CI: 1.22-16.5), respectively. Circulating miR-21-5p and miR-126-3p may play a significant role in diagnosis and prognosis in NSCLC patients.

MicroRNA related prognosis biomarkers from high throughput sequencing data of kidney renal clear cell carcinoma

BACKGROUND

Kidney renal clear cell carcinoma (KIRC) is the most common type of kidney cell carcinoma which has the worst overall survival rate. Almost 30% of patients with localized cancers eventually develop to metastases despite of early surgical treatment carried out. MicroRNAs (miRNAs) play a critical role in human cancer initiation, progression, and prognosis. The aim of our study was to identify potential prognosis biomarkers to predict overall survival of KIRC.

METHODS

All data were downloaded from an open access database The Cancer Genome Atlas. DESeq2 package in R was used to screening the differential expression miRNAs (DEMs) and genes (DEGs). RegParallel and Survival packages in R was used to analysis their relationships with the KIRC patients. David version 6.8 and STRING version 11 were used to take the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis.

RESULTS

We found 2 DEGs (TIMP3 and HMGCS1) and 3 DEMs (hsa-miR-21-5p, hsa-miR-223-3p, and hsa-miR-365a-3p) could be prognosis biomarkers for the prediction of KIRC patients. The constructed prognostic model based on those 2 DEGs could effectively predict the survival status of KIRC. And the constructed prognostic model based on those 3 DEMs could effectively predict the survival status of KIRC in 3-year and 5-year.

CONCLUSION

The current study provided novel insights into the miRNA related mRNA network in KIRC and those 2 DEGs biomarkers and 3 DEMs biomarkers may be independent prognostic signatures in predicting the survival of KIRC patients.

Identification and Validation a Necroptosis‑related Prognostic Signature and Associated Regulatory Axis in Stomach Adenocarcinoma

BACKGROUND

Gastric cancer (GC) ranks fifth in global cancer incidence and third in cancer-related mortality. The prognosis of GC patients was poor. Necroptosis is a type of regulated cell death mediated by RIP1, RIP3, and MLKL. Necroptosis was found to be involved in antitumor immunity in the cancer immunotherapy.

METHODS

LASSO Cox regression analysis was performed to construct a prognostic signature. Bioinformatics analysis was performed to construct a lncRNA-miRNA-mRNA regulatory axis. qRT-PCR was performed to verify the expression and prognosis of hub gene in STAD.

RESULTS

Most of necroptosis regulators were upregulated, while the mRNA level of TLR3, ALDH2, and NDRG2 was downregulated in STAD versus gastric tissues. The genetic mutation and copy number variation of necroptosis regulator in STAD were also summarized. GO and KEGG pathways analysis revealed that these necroptosis regulators were mainly involved in programmed necrotic cell death and TNF signaling pathway. A necroptosis‑related prognostic signature based on four genes (EZH2, PGAM5, TLR4, and TRAF2) had a good performance in predicting the prognosis of STAD patients. We also identified lncRNA SNHG1/miR-21-5p/TLR4 regulatory axis in the progression in STAD. Verification study suggested that the hub gene TLR4 upregulated in STAD and correlated with a poor overall survival. Moreover, Cox regression analysis revealed that TLR4 expression and clinical stage were independent factors affecting the prognosis of STAD patients.

CONCLUSION

We performed a comprehensive bioinformatics analysis and identified a necroptosis‑related prognostic signature and a lncRNA SNHG1/miR-21-5p/TLR4 regulatory axis in STAD. Further study should be performed to confirm our result.

Revisiting the Relationship Between Alzheimer's Disease and Cancer With a circRNA Perspective

BACKGROUND

Increasing evidence indicates an association between the incidence of Alzheimer's disease (AD) and cancer development. Despite advances being made by comparisons from epidemiological studies, common pathways and molecular mechanisms, little is known about the identities of the circular RNAs (circRNAs) involved in the development and progression of these two pathologies and their possible correlations. The aim of this study was to explore the circRNA relationship between AD and cancer.

MATERIALS AND METHODS

In this investigation, circRNAs that were significantly dysregulated in AD or associated with AD diagnosis, clinical dementia severity, and neuropathological severity, were examined in a large panel of 28 cancer types. On the basis of shared abnormal circRNAs in AD and cancers, we constructed a circRNA-micro RNA (miRNA)-messenger RNA (mRNA) network by leveraging experimentally identified miRNA-circRNA and miRNA-mRNA interactions from crosslinking-immunoprecipitation sequencing data.

RESULTS

An inverse correlation of expression pattern was found in acute myeloid leukemia, juvenile myelomonocytic leukemia, renal cell carcinoma, and myelofibrosis. CircRNAs associated with AD diagnosis and clinical severity demonstrated negative correlation in more cancer types. Notably, differentially expressed candidate circRNAs in temporal lobe epilepsy were not associated with any cancers. Gene Ontology and KEGG pathway analysis suggested the circRNA-regulated genes are significantly associated with interleukin-12-mediated signaling and viral response. CircPICALM, circRTN4 and circMAN2A1 are the hub nodes in the circRNA-miRNA-target network.

CONCLUSION

Our results indicated the relevance of inflammation signaling as a common pathogenesis shared by cancer and AD and provided novel insight for therapeutics targeting circRNAs.

Paeonol Inhibits Cell Proliferation, Migration and Invasion and Induces Apoptosis in Hepatocellular Carcinoma by Regulating miR-21-5p/KLF6 Axis

Background

Hepatocellular carcinoma (HCC) is one of the most common tumors with high mortality. MicroRNAs (miRNAs) were reported as crucial markers for the diagnosis of HCC. Paeonol exerted many pharmacological effects on tumor progression. This study aimed to elucidate the underlying molecular mechanism of paeonol in HCC progression.

Methods

Cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. Cell apoptosis was examined by flow cytometry. The levels of Cyclin D1, cyclin-dependent kinase 4 (CDK4), B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) were detected by Western blot assay. Cell migration and invasion were assessed by transwell assay. The levels of matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) were measured by Western blot. The expression of miR-21-5p and kruppel-like factor 6 (KLF6) was detected by quantitative real-time PCR (qRT-PCR) or Western blot assay, respectively. Dual-luciferase reporter assay was performed to analyze the interaction between miR-21-5p and KLF6. The enrichment of miR-21-5p was determined by RNA pull-down assay. Xenograft assay was conducted to analyze tumor growth in vivo.

Results

The results demonstrated that cell viability of Hep3B and Huh-7 cells was inhibited, while cell apoptosis was promoted after treatment with paeonol. Transwell assay indicated that cell migration and invasion were blocked in paeonol-treated cells. Moreover, miR-21-5p expression was markedly decreased in paeonol-treated cells and its knockdown suppressed cell viability, migration and invasion, but contributed to cell apoptosis. MiR-21-5p targeted KLF6 and its silencing prominently elevated KLF6 level. Furthermore, the restoration experiment determined that miR-21-5p and KLF6 were antagonisms on cell viability, apoptosis, migration and invasion. Also, paeonol abated the decrease in KLF6 level caused by miR-21-5p up-regulation. Besides, paeonol suppressed tumor growth in vivo.

Conclusion

Paeonol impeded cell viability, migration and invasion and triggered apoptosis by regulating miR-21-5p/KLF6 axis in HCC cells. Xenograft assay confirmed that paeonol inhibited tumor growth through miR-21-5p/KLF6 axis in HCC in vivo.

Circulating plasma microRNA signature for the diagnosis of cervical cancer

OBJECTIVE

To determine the utility of plasma microRNAs (miRNAs) as biomarkers in cervical cancer (CC).

METHODS

Some studies were conducted about the specific expression of plasma miRNAs in the diagnosis of CC. Plasma samples of 97 CC patients and 87 normal controls (NCs) were used to identify dysregulation of miRNAs in the training, testing, and external validation phases. Receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) were used to evaluate the sensitivity and specificity of identified individual miRNAs and miRNA panels for the diagnosis of CC. Expression levels of specific miRNAs were also examined in plasma exosomes and tissue samples of CC patients.

RESULTS

Four plasma miRNAs (miR-146a-5p, miR-151a-3p, miR-2110 and miR-21-5p) which showed up-regulation were identified and validated in CC patients. A panel of the four miRNAs were constructed as potential diagnostic markers for CC. The AUCs of the panel of these four-miRNAs for the training, testing, and external validation phases were 0.911, 0.774, and 0.786, respectively. miR-146a-5p and miR-21-5p levels were all up-regulated in CC tissue specimens, whereas miR-146a-5p, miR-151a-3p, and miR-2110 levels were up-regulated in plasma exosomes.

CONCLUSION

The signature of the four-miRNAs identified in peripheral plasma is a promising novel biomarker for the diagnosis of CC.

Tunneling Nanotubes Mediated microRNA-155 Intercellular Transportation Promotes Bladder Cancer Cells' Invasive and Proliferative Capacity

Objective

To investigate differential microRNAs' expression in heterogeneous bladder cancer cells, as well as to investigate the mechanism of changes in invasive and proliferative capacity induced by tunneling nanotubes (TNTs) mediated transport of microRNA between bladder cancer cells of varying histological grade.

Materials and methods

Differences in microRNA expression between bladder cancer cells of different grade were identified from a literature review. The identified heterogeneous microRNAs were analyzed by qPCR in T24 (high grade) and RT4 (low grade) bladder cancer cells. Scanning electron microscopy (SEM) and laser confocal fluorescence microscopy (LCM) were used to observe tunneling nanotubes (TNTs) between RT4 and T24 cells. Differentially expressed microRNA was labeled and traced by Fluorescent In Situ Hybridization (FISH) following co-culture of T24 and RT4 cells. MicroRNA mimic and inhibition technologies were applied to investigate how TNTs-mediated intercellular transport of microRNA affects the invasive and proliferative behavior of bladder cancer cells.

Results

MicroRNA-155 (miR-155) levels were highly expressed in T24 cells, whereas the same was not true in RT4 cells. MiR-155 was confirmed to be a crucial factor sustaining T24 bladder cancer cell proliferation, migration and cell cycle progression by CCK8, Matrigel test and cell cycle analysis, respectively. After T24 and RT4 co-culture, TNTs were assessed by SEM and LCM between T24 and RT4 cells. In addition, we observed TNTs mediated transport of miR-155 from T24 cells to RT4 cells, which thereby acquired a higher proliferative rate, an increased frequency of cells in the S phase, and increased invasive ability in Matrigel test. At the same time, Deptor, the target protein of miR-155 in RT4 cells, was downregulated, followed by mTOR/4EBP1/p70S6K- eIF4e/S6RP signaling activation.

Conclusion

MiR-155 was differentially expressed between RT4 and T24 bladder cancer cells. Intercellular transport of miR-155 via TNTs can promote bladder cancer cell reprogramming by Deptor-mTOR signal pathway activation.

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miR-21-5p Suppressed the Sensitivity of Hepatocellular Carcinoma Cells to Cisplatin by Targeting FASLG

Accumulating evidence has suggested that microRNAs play important roles in the development of hepatocellular carcinoma (HCC) and are involved in drug resistance. miR-21-5p was overexpressed in a variety of cancers and promoted the tumorigenesis; however, the function of miR-21-5p in HCC still remains unknown. In this study, our results showed that miR-21-5p was highly expressed in HCC tissues and cell lines. Notably, the level of miR-21-5p was relatively higher in cisplatin (DDP)-resistant HCC patients. Overexpression of miR-21-5p attenuated the inhibitory effect of DDP on the proliferation and apoptosis of HCC cells. Mechanistically, the luciferase report assay-identified FAS ligand (FASLG) was a direct target of miR-21-5p. Overexpression of miR-21-5p decreased both the mRNA and protein levels of FASLG in HCC cells. FASLG was downregulated in HCC tissues and was significantly negatively correlated with the expression of miR-21-5p. Restoring the expression of FASLG upregulated the chemosensitivity of HCC cells expressing miR-21-5p. In conclusion, our results demonstrated that miR-21-5p targeted FASLG and suppressed the sensitivity of HCC cells to DDP treatment.

MiR-181a, a new regulator of TGF-β signaling, can promote cell migration and proliferation in gastric cancer

Transforming growth factor-beta (TGF-β) signaling pathway plays pivotal roles in various types of cancer. TGF-β receptor 2 (TGFβR2) contains a kinase domain that phosphorylates and activates the downstream of the TGF-β signaling pathway. Our previous microarray analysis revealed marked changes in miR-181a expression in gastric cancers, and the bioinformatics analysis suggested that miR-181a negatively regulated TGFβR2. In order to verify the effect of miR-181a on TGFβR2 and clarify the influence of miR-181a on the migration and proliferation of gastric cancer, studies in gastric cancer cell lines and xenograft mouse models were carried out. We found that a reduced expression of TGFβR2 and an increased expression miR-181a in gastric cancer tissues compared to adjacent noncancerous tissues. A luciferase reporter assay confirmed that TGFβR2 was a target of miR-181a. In addition, we found that miR-181a mimics, which increased the level of miR-181a, downregulated the expression of TGFβR2 in the gastric cancer cell line SGC-7901. Moreover, both the overexpression of miR-181a and the downregulation of TGFβR2 promoted the migration and proliferation of SGC-7901 cells. Conversely, SGC-7901 cell migration and proliferation were inhibited by the downregulation of miR-181a and the overexpression of TGFβR2. Furthermore, the increased expression of miR-181a and the decreased expression of TGFβR2 also enhanced the tumor growth in mice bearing gastric cancer. Our results herein indicated that miR-181a promoted the migration and proliferation of gastric cancer cells by downregulating TGFβR2 at the posttranscriptional level. The present study suggests that miR-181a is a novel negative regulator of TGFβR2 in the TGF-β signaling pathway and thus represents a potential new therapeutic target for gastric cancer.

MiR-21-5p promotes the progression of non-small-cell lung cancer by regulating the expression of SMAD7

Objective

The objective of this study was to detect the expression of MiR-21-5p in non-small-cell lung cancer (NSCLC) tissues, and to investigate the effect of its expression on the progression of NSCLC.

Methods

Real-time fluorescent quantitative PCR was used to detect the relative expression of MiR-21-5p in 118 NSCLC tumor tissues to their adjacent normal tissues. The expressions of SMAD7, MMP-9, E-cadherin, and vimentin proteins were detected by Western blotting or immunohistochemistry. Cell colony formation, scratch, and Transwell assays were used to detect the proliferation, migration, and invasion ability of A549 cells, respectively.

Results

MiR-21-5p was highly expressed in the tumor tissues of NSCLC patients, and its expression was significantly correlated with the clinical classification of NSCLC patients (χ²=7.154, P=0.007), tumor size (χ²=4.372, P=0.037), differentiation (χ²=13.713, P=0.001), lymph node metastasis (χ²=5.101, P=0.024), distant metastasis (χ²=12.599, P=0.000), and TNM stage (χ²=6.344, P=0.012), whereas it was positively correlated with the expression of SMAD7 protein (r=0.669, P<0.05). The results of the luciferase gene reporter system showed that MiR-21-5p targeted and promoted the expression of SMAD7 gene, which enhanced NSCLC cell proliferation. Furthermore, MiR-21-5p promoted the expressions of MMP-9 and vimentin proteins as well as inhibited the expression of E-cadherin protein, which is associated with an elevated SMAD7 protein expression and enhanced the invasion/migration ability of NSCLC cells.

Conclusion

MiR-21-5p was highly expressed in NSCLC tumor tissues, and its high expression could promote NSCLC progression by targeting the expression of SMAD7.

Overview upon miR-21 in lung cancer: focus on NSCLC

Considering the high mortality rate encountered in lung cancer, there is a strong need to explore new biomarkers for early diagnosis and also improved therapeutic targets to overcome this issue. The implementation of microRNAs as important regulators in cancer and other pathologies expanded the possibilities of lung cancer management and not only. MiR-21 represents an intensively studied microRNA in many types of cancer, including non-small cell lung cancer (NSCLC). Its role as an oncogene is underlined in multiple studies reporting the upregulated expression of this sequence in patients diagnosed with this malignancy; moreover, several studies associated this increased expression of miR-21 with a worse outcome within NSCLC patients. The same pattern is supported by the data existent in the Cancer Genome Atlas (TCGA). The carcinogenic advantage generated by miR-21 in NSCLC resides in the target genes involved in multiple pathways such as cell growth and proliferation, angiogenesis, invasion and metastasis, but also chemo- and radioresistance. Therapeutic modulation of miR-21 by use of antisense sequences entrapped in different delivery systems has shown promising results in impairment of NSCLC. Hereby, we review the mechanisms of action of miR-21 in cancer and the associated changes upon tumor cells together a focused perspective on NSCLC signaling, prognosis and therapy.

Characterization of selective exosomal microRNA expression profile derived from laryngeal squamous cell carcinoma detected by next generation sequencing

Exosomes are nanometer-scale extracellular vesicles derived from almost all types of cells and key signaling mediators between cancer cells and their microenvironment. Certain microRNAs (miRNAs) are selected for exosome packing and exclusion from parental cells, while other miRNAs are selectively retained by cells, suggesting a biological role for these miRNAs in tumor malignant progression. In the present study, we isolated and characterized the exosomes derived from the laryngeal squamous cell carcinoma (LSCC) cell line AMC-HN-8 for the first time, and identified a subset of miRNAs enriched in the exosomes compared with parental cells, such as miR-1246, miR-1290, miR-335-5p, miR-127-3p and miR-122-5p through small RNA sequencing combined with reverse transcription-quantitative PCR (RT-qPCR) analysis. Potential target prediction, Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed possible functions associated with these selective exosomal miRNAs. In conclusion, the present study demonstrated that the LSCC cell line AMC-HN-8 can release exosomes and cells can selectively pack certain miRNAs into exosomes.

MicroRNAs as potential biomarkers for diagnosis, therapy and prognosis of gastric cancer

Despite the widespread use of endoscopy and conventional tumor biomarkers, gastric cancer (GC) remains one of the most frequent causes of cancer-related deaths worldwide due to its late diagnosis and poor response to treatment. Valuable and practical biomarkers are urgently needed to screen patients with a high risk of GC that can complement endoscopic diagnosis. Such biomarkers will enable the efficient prediction of therapeutic response and prognosis of GC patients and favor the establishment of an effective treatment strategy for each and every patient. MicroRNAs (miRNAs) are a class of small non-coding RNA sequences that play important roles in modulating key biological processes by regulating the expression of target genes. Expectedly, miRNAs are abnormally expressed within the tumor tissue and in associated biological fluids of GC patients including their blood, gastric juice, and urine. Accumulating evidence indicates that miRNAs are potential biomarkers with multiple diagnostic functions for GC. Here, we review recent advances and challenges in using miRNAs, particularly biofluid miRNAs, as GC biomarkers with potential clinical applications including diagnosing, clinically staging, and predicting malignant behaviors, therapy response, recurrence after surgery and survival time.

Global miRNA expression profiling of domestic cat livers following acute Toxoplasma gondii infection

Although microRNAs (miRNAs) play an important role in liver homeostasis, the extent to which they can be altered by Toxoplasma gondii infection is unknown. Here, we utilized small RNA sequencing and bioinformatic analyses to characterize miRNA expression profiles in the liver of domestic cats at 7 days after oral infection with T. gondii (Type II) strain. A total of 384 miRNAs were identified and 82 were differentially expressed, of which 33 were up-regulated and 49 down-regulated. Also, 5690 predicted host gene targets for the differentially expressed miRNAs were identified using the bioinformatic algorithm miRanda. Gene ontology analysis revealed that the predicted gene targets of the dysregulated miRNAs were significantly enriched in apoptosis. Kyoto Encyclopedia of Genes and Genomes analysis showed that the predicted gene targets were involved in several pathways, including acute myeloid leukemia, central carbon metabolism in cancer, choline metabolism in cancer, estrogen signaling pathway, fatty acid degradation, lysosome, nucleotide excision repair, progesterone-mediated oocyte maturation, and VEGF signaling pathway. The expression level of 6 upregulated miRNAs (mmu-miR-21a-5p, mmu-miR-20a-5p, mmu-miR-17-5p, mmu-miR-30e-3p, mmu-miR-142a-3p, and mmu-miR-106b-3p) was confirmed by stem-loop quantitative reverse transcription PCR, which yielded results consistent with the sequencing data. These findings expand our understanding of the regulatory mechanisms of miRNAs underlying T. gondii pathogenesis and contribute new database information on cat miRNAs, opening a new perspective on the prevention and treatment of T. gondii infection.

MicroRNA-21-5p induces the metastatic phenotype of human cervical carcinoma cells in vitro by targeting the von Hippel-Lindau tumor suppressor

Numerous studies have indicated that microRNAs (miRs), a group of small non-coding RNAs, are determining regulatory elements involved in the pathogenesis of various types of cancer, including cervical cancer (CC). Although miR-21-5p upregulation has been demonstrated to associate with tumorigenesis by controlling the expression of oncogenic and tumor suppressor genes, only a small number of studies have investigated the expression of miR-21-5p and its functional role in CC. The objective of the present study was to investigate the effect of miR-21-5p on the proliferation, apoptosis, migration and invasion of CC cells, and the potential underlying molecular mechanism of these effects. The measurement of miR-21-5p levels using quantitative polymerase chain reaction revealed that miR-21-5p was markedly increased in CC cell lines compared with normal cells. Upon silencing of miR-21-5p, a marked suppression of the proliferation, migration and invasion of CaSki cells was observed, with induction of cell apoptosis. These effects were reversed with miR-21-5p overexpression. A database search followed by a luciferase reporter assay ascertained that the 3'-untranslated region of the von Hippel-Lindau tumor suppressor (VHL) mRNA sequence was a direct target of miR-21-5p. Furthermore, silencing of VHL neutralized the effects of miR-21-5p inhibition. These observations suggested that miR-21-5p is an oncogene that is able to promote the metastatic phenotype of CC cells through downregulation of VHL expression, which may present a path to novel therapeutic stratagems for the CC therapy.

miR‑21‑5p confers doxorubicin resistance in gastric cancer cells by targeting PTEN and TIMP3

Drug resistance and disease recurrence are major obstacles to the effective treatment of cancer, including gastric cancer (GC). However, the mechanisms of drug resistance remain to be fully elucidated. The present study investigated the roles of microRNA (miR)-21-5p in the doxorubicin (DOX) resistance of GC cells and the underlying mechanisms. miR-21-5p expression levels were identified to be inversely correlated with two well-known tumor suppressor genes, phosphatase and tensin homologue and tissue inhibitor of matrix metalloproteinases 3, and were upregulated in GC cell lines in proportion to their degree of resistance. Suppressing miR-21-5p expression partially sensitized SGC7901/DOX cells to DOX, suggesting that knockdown of miR-21-5p expression may be used as a therapeutic strategy to improve GC cell resistance. Importantly, increased miR-21-5p expression levels at diagnosis were correlated with clinicopathological characteristics including advanced stage and poor prognosis, further implying that a relapse of GC may be a consequence of miR-21-5p upregulation, thus providing evidence for the potential utility of miR-21-5p antagonism to sensitize GC cells to DOX chemotherapy.

MicroRNA-223 and microRNA-21 in peripheral blood B cells associated with progression of primary biliary cholangitis patients

Recently, there is ample evidence suggesting the important role of microRNAs (miRNAs) in autoimmune diseases via modulating B cells function. Primary biliary cholangitis (PBC) is a progressive immune-mediated liver disease with unclear pathogenic mechanism. Whether the miRNA in peripheral B cells of PBC involve the mechanisms of pathology and progression is not known. The present study explores miRNA deregulation in peripheral B-cell of PBC from stage I to IV and healthy controls. Peripheral B cells were obtained from 72 PBC patients (stage I, n = 17; stage II, n = 23; stage III, n = 16; stage IV, n = 16) and 15 healthy controls. Initially, in a discovery study, miRNA array analysis was performed, subsequently, in a validation study, quantitative PCR was used to investigate miRNA expression profile in B cells of PBS patients compared to healthy controls. Based on bioinformatics analysis, we identified the potential biological processes and significant signaling pathways affected by these microRNAs, and generated the microRNA–gene network. The discovery study identified 558 miRNAs differentially expressed in B cells of PBC patients compared to controls. Interestingly, among all differentially expressed miRNAs, hsa-miR-223-3p and hsa-miR-21-5p were the only miRNAs that showed consistent and significant down-regulation from stage I to stage III of PBC. Bioinformatics showed that potential target genes of both miRNAs involved in migration, cell differentiation, apoptosis, and signal transduction pathways. In conclusion, our results suggest that the expression profiles of miRNA in peripheral B cells of PBC patients are closely associated with the disease progression, especially the down-regulation of hsa-miR-223-3p and hsa-miR-21-5p. Taken together, our study offers novel perspectives on the role of miRNAs in PBC pathogenesis.

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.

MicroRNA-145 exerts tumor-suppressive and chemo-resistance lowering effects by targeting CD44 in gastric cancer

AIM

To determine the potential roles of CD4 and microRNA (miR)-145 in gastric cancer.

METHODS

The levels of CD44 and miR-145 were determined in gastric cancer cells. Quantitative real-time polymerase chain reaction was used to measure to the level of CD44 mRNA. A luciferase reporter assay and western blotting were performed to examine the effect of miR-145 on CD44 expression. Tumor sphere and MTT assays were carried out to evaluate the self-renewal and chemo-resistance properties of gastric cancer cells.

RESULTS

The expression of CD44 was greatly increased and miR-145 was decreased in gastric cancer cells that were highly enriched in cancer stem cells (CSCs). The results demonstrated that miR-145 regulated CD44 by targeting directly the CD44 3’-untranslated region (3’-UTR). In gastric cancer cells, overexpression of miR-145 repressed the activity of the CD44 3’-UTR, and disruption of miR-145/CD44 3’-UTR interactions abrogated the silencing effects. In addition, miR-145 inhibition stimulated CD44 3’-UTR activity and disruption of miR-145/CD44 3’-UTR interactions abrogated this stimulatory effect. Enforced CD44 expression greatly increased tumor sphere formation and chemo-resistance in gastric cancer cells. Furthermore, the inhibition of CSCs and the chemo-sensitivity of gastric cancer cells treated with miR-145 were significantly abrogated by overexpression of CD44.

CONCLUSION

miR-145 targeting of CD44 plays critical roles in the regulation of tumor growth and chemo-resistance in gastric cancer.