Investigation of miR-21, miR-141, and miR-221 expression levels in prostate adenocarcinoma for associated risk of recurrence after radical prostatectomy

The role of microRNA-21 (miR-21) in pathogenesis, diagnosis, and prognosis of gastrointestinal cancers: A review

MicroRNAs (miRNAs) are small non-coding RNAs regulating the expression of several target genes. miRNAs play a significant role in cancer biology, as they can downregulate their corresponding target genes by impeding the translation of mRNA (at the mRNA level) as well as degrading mRNAs by binding to the 3'-untranslated (UTR) regions (at the protein level). miRNAs may be employed as cancer biomarkers. Therefore, miRNAs are widely investigated for early detection of cancers which can lead to improved survival rates and quality of life. This is particularly important in the case of gastrointestinal cancers, where early detection of the disease could substantially impact patients' survival. MicroRNA-21 (miR-21 or miRNA-21) is one of the most frequently researched miRNAs, where it is involved in the pathophysiology of cancer and the downregulation of several tumor suppressor genes. In gastrointestinal cancers, miR-21 regulates phosphatase and tensin homolog (PTEN), programmed cell death 4 (PDCD4), mothers against decapentaplegic homolog 7 (SMAD7), phosphatidylinositol 3-kinase /protein kinase B (PI3K/AKT), matrix metalloproteinases (MMPs), β-catenin, tropomyosin 1, maspin, and ras homolog gene family member B (RHOB). In this review, we investigate the functions of miR-21 in pathogenesis and its applications as a diagnostic and prognostic cancer biomarker in four different gastrointestinal cancers, including colorectal cancer (CRC), pancreatic cancer (PC), gastric cancer (GC), and esophageal cancer (EC).

The Role of miRNA-221 and miRNA-34a in Non-Melanoma Skin Cancer of the Head and Neck Region

Non-melanoma skin cancer (NMSC) is one of the most frequent types of malignancy in the human body with an increasing incidence. Short, non-coding RNA molecules called microRNAs (miRNAs) can control post-transcriptional gene expression and they have a significant role in several physiological cellular processes and pathologies, including cancer. Depending on the functions of the genes, miRNAs may function as oncogenes or tumor suppressors. The aim of this paper was to describe the role of miRNA-34a and miRNA-221 in head and neck NMSC. Thirty-eight NMSC match paired (tumor and adjacent) tissue samples were evaluated by qRT-PCR. Total RNA was extracted and isolated from tissue samples using the phenol-chloroform (Trireagent) method according to the manufacturer's protocol. The concentration of RNA was measured by a NanoDrop-1000 spectrophotometer. The expression level of each miRNA was calculated by threshold cycle. For all statistical tests, the 0.05 significance level was used and two-tailed p values. All analyses were conducted in an R environment for statistical computing and graphics. We found the miRNA-221 being overexpressed in squamous cell carcinoma (SCC) (p < 0.05), basal cell carcinoma (BCC) and basosquamous cell carcinoma (BSC) compared with adjacent normal tissue. Additionally, the levels of miRNA-221 were two times higher (p < 0.05) in cases where the excision of the tumor was done with positive margins (R1), which means that we are the first to highlight the potential role of miRNA-221 in the microscopical local invasion. Mi-RNA-34a expression was altered in the malignant tissue compared with the adjacent normal one both in BCC and SCC but not statistically significantly. In conclusion, NMSC are challenging because of their increasing incidence and rapidly evolving development and discovering their molecular mechanisms of action lead us to understand tumorigenesis and evolution, while also contributing to the implementation of novel therapeutic keys.

The Potential of MicroRNAs as Non-Invasive Prostate Cancer Biomarkers: A Systematic Literature Review Based on a Machine Learning Approach

Simple Summary

Prostate cancer (PCa) is the most common cancer in men worldwide. Screening and diagnosis are based on prostate-specific antigen (PSA) blood testing and digital rectal examination. Nevertheless, these methods are not specific and have a high risk of mistaken results. This has led to overtreatment and unnecessary radical therapy; thus, better prognostic tools are urgently needed. In this view, microRNAs (miRs) appear as potential non-invasive biomarkers for PCa diagnosis, prognosis, and therapy. As the scientific literature available in this field is huge and very often controversial, we identified and discussed three topics that characterize the investigated research area by combining the big data from the literature together with a novel machine learning approach. By analyzing the papers clustered into these topics we have offered a deeper understanding of the current research, which helps to contribute to the advancement of this research field.

Abstract

Background: Prostate cancer (PCa) is the second leading cause of cancer-related deaths in men. Although the prostate-specific antigen (PSA) test is used in clinical practice for screening and/or early detection of PCa, it is not specific, thus resulting in high false-positive rates. MicroRNAs (miRs) provide an opportunity as biomarkers for diagnosis, prognosis, and recurrence of PCa. Because the size of the literature on it is increasing and often controversial, this study aims to consolidate the state-of-art of relevant published research. Methods: A Systematic Literature Review (SLR) approach was applied to analyze a set of 213 scientific publications through a text mining method that makes use of the Latent Dirichlet Allocation (LDA) algorithm. Results and Conclusions: The result of this activity, performed through the MySLR digital platform, allowed us to identify a set of three relevant topics characterizing the investigated research area. We analyzed and discussed all the papers clustered into them. We highlighted that several miRs are associated with PCa progression, and that their detection in patients’ urine seems to be the more reliable and promising non-invasive tool for PCa diagnosis. Finally, we proposed some future research directions to help future scientists advance the field further.

miRNA in Molecular Diagnostics

MicroRNAs are a class of small non-coding RNA molecules that regulate gene expression on post-transcriptional level. Their biogenesis consists of a complex series of sequential processes, and they regulate expression of many genes involved in all cellular processes. Their function is essential for maintaining the homeostasis of a single cell; therefore, their aberrant expression contributes to development and progression of many diseases, especially malignant tumors and viral infections. Moreover, they can be associated with certain states of a specific disease, obtained in the least invasive manner for patients and analyzed with basic molecular methods used in clinical laboratories. Because of this, they have a promising potential to become very useful biomarkers and potential tools in personalized medicine approaches. In this review, miRNAs biogenesis, significance in cancer and infectious diseases, and current available test and methods for their detection are summarized.

Urinary MicroRNA Sensing Using Electrochemical Biosensor to Evaluate Colorectal Cancer Progression

Research in cancer diagnostics has recently established its footing and significance in the biosensor sphere, emphasizing the idea of a unique probe design used as a sensor and actuator, to identify the presence of protein, DNA, RNA, or miRNA. The fluorescein isothiocyanate (FITC) probe and biotinylated probe are designed for a two-pronged approach to the detection of the urinary miR-21 and miR-141, both of which have demonstrated significance in the development and progression of colorectal cancer, a leading cause of mortality and morbidity. The remainder of the apparatus is composed of a modified screen-printed carbon electrode (SPCE), to which the probes adhere, that transduces signals via the redox reaction between H2O2 and HRP, measured with chronoamperometry and cyclic voltammetry. The precise nature of our ultra-non-invasive biosensor makes for a highly sensitive and practical cancer detector, concluded by the significance when establishing disease presence (miR-21 p-value = 0.0176, miR-141 p-value = 0.0032), disease follow-up (miR-21 p-value = 0.00154, miR141 p-value < 0.0005), and even disease severity. This article hopes to emphasize the potential of an additional clinical tool for the management of colorectal cancer.

Nickel's Role in Pancreatic Ductal Adenocarcinoma: Potential Involvement of microRNAs

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancer types with a limited overall survival rate due to the asymptomatic progression of symptoms in metastatic stages of the malignancy and the lack of an early reliable diagnostic biomarker. MicroRNAs (miRs/miRNAs) are small (~18–24 nucleotides), endogenous, non-coding RNAs, which are closely linked to the development of numerous malignancies comprising PDAC. Recent studies have described the role of environmental pollutants such as nickel (Ni) in PDAC, but the mechanisms of Ni-mediated toxicity in cancer are still not completely understood. Specifically, Ni has been found to alter the expression and function of miRs in several malignancies, leading to changes in target gene expression. In this study, we found that levels of Ni were significantly higher in cancerous tissue, thus implicating Ni in pancreatic carcinogenesis. Hence, in vitro studies followed by using both normal and pancreatic tumor cell lines and increasing Ni concentration increased lethality. Comparing LC50 values, Ni-acetate groups demonstrated lower values needed than in NiCl₂ groups, suggesting greater Ni-acetate. Panc-10.05 cell line appeared the most sensitive to Ni compounds. Exposure to Ni-acetate resulted in an increased phospho-AKT, and decreased FOXO1 expression in Panc-10.05 cells, while NiCl₂ also increased PTEN expression in Panc-10.05 cells. Specifically, following NiCl₂ exposure to PDAC cells, the expression levels of miR-221 and miR-155 were significantly upregulated, while the expression levels of miR-126 were significantly decreased. Hence, our study has suggested pilot insights to indicate that the environmental pollutant Ni plays an important role in the progression of PDAC by promoting an association between miRs and Ni exposure during PDAC pathogenesis.

Prognostic value of miR-21 for prostate cancer: a systematic review and meta-analysis

Elevated levels of miR-21 expression are associated with many cancers, suggesting it may be a promising clinical biomarker. In prostate cancer (PCa), however, there is still no consensus about the usefulness of miR-21 as an indicator of disease progression. This systematic review and meta-analysis was conducted to investigate the value of miR-21 expression as a prognostic measurement in PCa patients. Medline (Ovid), EMBASE, Web of Science, Scopus and Cochrane Library databases were systematically searched for relevant publications between 2010 to 2021. Studies exploring the relationship between miR-21 expression, PCa prognosis and clinicopathological factors were selected for review. Those reporting hazard ratio (HR) and 95% confidence intervals (CIs) were subject to meta-analyses. Fixed-effect models were employed to calculated pooled HRs and 95% CIs. Risk of bias in each study was assessed using QUIPS tool. Certainty of evidence in each meta-analysis was assessed using GRADE guidelines. A total of 64 studies were included in the systematic review. Of these, 11 were eligible for inclusion in meta-analysis. Meta-analyses revealed that high miR-21 expression was associated with poor prognosis: HR = 1.58 (95% CI = 1.19–2.09) for biochemical recurrence, MODERATE certainty; HR = 1.46 (95% CI = 1.06–2.01) for death, VERY LOW certainty; and HR = 1.26 (95% CI = 0.70–2.27) for disease progression, VERY LOW certainty. Qualitative summary revealed elevated miR-21 expression was significantly positively associated with PCa stage, Gleason score and risk groups. This systematic review and meta-analysis suggests that elevated levels of miR-21 are associated with poor prognosis in PCa patients. miR-21 expression may therefore be a useful prognostic biomarker in this disease.

Role of microRNAs in response to cadmium chloride in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal and aggressive malignancies with a 5-year survival rate less than 9%. Early detection is particularly difficult due to the lack of symptoms even in advanced stages. microRNAs (miRs/miRNAs) are small (~ 18–24 nucleotides), endogenous, non-coding RNAs, which are involved in the pathogenesis of several malignancies including PDAC. Alterations of miR expressions can lead to apoptosis, angiogenesis, and metastasis. The role of environmental pollutants such as cadmium (Cd) in PDAC has been suggested but not fully understood. This study underlines the role of miRs (miR-221, miR-155, miR-126) in response to cadmium chloride (CdCl₂) in vitro. Lethal concentration (LC50) values for CdCl₂ resulted in a toxicity series of AsPC-1 > HPNE > BxPC-3 > Panc-1 = Panc-10.5. Following the treatment with CdCl₂, miR-221 and miR-155 were significantly overexpressed, whereas miR-126 was downregulated. An increase in epithelial–mesenchymal transition (EMT) via the dysregulation of mesenchymal markers such as Wnt-11, E-cadherin, Snail, and Zeb1 was also observed. Hence, this study has provided evidence to suggest that the environmental pollutant Cd can have a significant role in the development of PDAC, suggesting a significant correlation between miRs and Cd exposure during PDAC progression. Further studies are needed to investigate the precise role of miRs in PDAC progression as well as the role of Cd and other environmental pollutants.

Signaling Modulation by miRNA-221-3p During Tooth Morphogenesis in Mice

miRNAs are conserved short non-coding RNAs that play a role in the modulation of various biological pathways during tissue and organ morphogenesis. In this study, the function of miRNA-221-3p in tooth development, through its loss or gain in function was evaluated. A variety of techniques were utilized to evaluate detailed functional roles of miRNA-221-3p during odontogenesis, including in vitro tooth cultivation, renal capsule transplantation, in situ hybridization, real-time PCR, and immunohistochemistry. Two-day in vitro tooth cultivation at E13 identified altered cellular events, including cellular proliferation, apoptosis, adhesion, and cytoskeletal arrangement, with the loss and gain of miRNA-221-3p. qPCR analysis revealed alterations in gene expression of tooth-related signaling molecules, including β-catenin, Bmp2, Bmp4, Fgf4, Ptch1, and Shh, when inhibited with miRNA-221-3p and mimic. Also, the inhibition of miRNA-221-3p demonstrated increased mesenchymal localizations of pSMAD1/5/8, alongside decreased expression patterns of Shh and Fgf4 within inner enamel epithelium (IEE) in E13 + 2 days in vitro cultivated teeth. Moreover, 1-week renal transplantation of in vitro cultivated teeth had smaller tooth size with reduced enamel and dentin matrices, along with increased cellular proliferation and Shh expression along the Hertwig epithelial root sheath (HERS), within the inhibitor group. Similarly, in 3-week renal calcified teeth, the overexpression of miRNA-221-3p did not affect tooth phenotype, while the loss of function resulted in long and slender teeth with short mesiodistal length. This study provides evidence that a suitable level of miRNA-221-3p is required for the modulation of major signaling pathways, including Wnt, Bmp, and Shh, during tooth morphogenesis.

MicroRNAs in prostate cancer following radiotherapy: Towards predicting response to radiation treatment

Prostate cancer (PCa) is the second most frequently diagnosed male cancer worldwide. Early diagnosis of PCa, response to therapy and prognosis still represent a challenge. Nearly 60% of PCa patients undergo radiation therapy (RT) which might cause side effects. In spite of numerous researches in this field, predictive biomarkers for radiation toxicity are still not elucidated. MicroRNAs as posttranscriptional regulators of gene expression are shown to be changed during and after irradiation. Manipulation with miRNA levels might be used to modulate response to RT-to reverse radioresistance-to induce radiosensitivity, or if needed, to reduce sensitivity to treatment to avoid side effects. In this review we have listed and described miRNAs involved in response to RT in PCa, and highlighted potential candidates for future biological tests predicting radiation response to RT, with the special focus on side effects of RT. Individual radiation response is a result of the interactions between physical characteristics of radiation treatment and biological background of each patient, and miRNA expression changes among others. According to described literature we concluded that let-7, miR-21, miR-34a, miR-146a, miR-155, and members of miR-17/92 cluster might be promising candidates for biological tests predicting radiosensitivity of PCa patients undergoing radiation treatment, and as future agents for modulation of radiation response. Predictive miRNA panels, especially for acute and late side effects of RT can serve as a starting point for decisions for individualized RT planning. We believe that this review might be one step closer to understanding molecular mechanisms underlying individual radiation response of patients with PCa.

Peptidylarginine Deiminase Inhibitor Application, Using Cl-Amidine, PAD2, PAD3 and PAD4 Isozyme-Specific Inhibitors in Pancreatic Cancer Cells, Reveals Roles for PAD2 and PAD3 in Cancer Invasion and Modulation of Extracellular Vesicle Signatures

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies with limited survival rate. Roles for peptidylarginine deiminases (PADs) have been studied in relation to a range of cancers with roles in epigenetic regulation (including histone modification and microRNA regulation), cancer invasion, and extracellular vesicle (EV) release. Hitherto though, knowledge on PADs in PDAC is limited. In the current study, two PDAC cell lines (Panc-1 and MiaPaCa-2) were treated with pan-PAD inhibitor Cl-amidine as well as PAD2, PAD3, and PAD4 isozyme-specific inhibitors. Effects were assessed on changes in EV signatures, including EV microRNA cargo (miR-21, miR-126, and miR-221), on changes in cellular protein expression relevant for pancreatic cancer progression and invasion (moesin), for mitochondrial housekeeping (prohibitin, PHB), and gene regulation (deiminated histone H3, citH3). The two pancreatic cancer cell lines were found to predominantly express PAD2 and PAD3, which were furthermore expressed at higher levels in Panc-1, compared with MiaPaCa-2 cells. PAD2 isozyme-specific inhibitor had the strongest effects on reducing Panc-1 cell invasion capability, which was accompanied by an increase in moesin expression, which in pancreatic cancer is found to be reduced and associated with pancreatic cancer aggressiveness. Some reduction, but not significant, was also found on PHB levels while effects on histone H3 deimination were variable. EV signatures were modulated in response to PAD inhibitor treatment, with the strongest effects observed for PAD2 inhibitor, followed by PAD3 inhibitor, showing significant reduction in pro-oncogenic EV microRNA cargo (miR-21, miR-221) and increase in anti-oncogenic microRNA cargo (miR-126). While PAD2 inhibitor, followed by PAD3 inhibitor, had most effects on reducing cancer cell invasion, elevating moesin expression, and modulating EV signatures, PAD4 inhibitor had negligible effects and pan-PAD inhibitor Cl-amidine was also less effective. Compared with MiaPaCa-2 cells, stronger modulatory effects for the PAD inhibitors were observed in Panc-1 cells, which importantly also showed strong response to PAD3 inhibitor, correlating with previous observations that Panc-1 cells display neuronal/stem-like properties. Our findings report novel PAD isozyme regulatory roles in PDAC, highlighting roles for PAD isozyme-specific treatment, depending on cancer type and cancer subtypes, including in PDAC.

The Influence of Radical Prostatectomy on the Expression of Cell-Free MiRNA

MiRNAs of blood and urine have been shown to represent a convenient source of biomarkers for prostate cancer (PCa) diagnosis and assessment of the therapy effectiveness due to their high stability and representation and the low invasiveness of sample collection. Here, we studied the influence of radical prostatectomy (RP) on the expression of 12 cell-free miRNAs previously shown as potential markers of PCa (i.e., miR-19b, miR-22, miR-92a, miR-378, miR-425, miR-30e, miR-31, miR-125b, miR-200b, miR-205, miR-375 and miR-660). The relative expression of the miRNAs combined into 31 paired ratios was evaluated in the urine extracellular vesicles (EVs), clarified urine (CU) and blood plasma of healthy donors, pre- and post-RP samples of PCa patients. Nineteen miRNA ratios based on combinations of ten of the miRNAs (miR-19b, miR-30e, miR-31, miR-125b, miR-200b, miR-205, miR-375, miR-378, miR-425, and miR-660) were altered by RP. The comparative expression analysis of the cell-free miRNA ratios between healthy donors and PCa patients revealed miR-125b/miR-30e and miR-375/miR-30e as potential markers for evaluating therapeutic efficacy. MiR-378/miR-19b, miR-425/miR-19b, miR-200/miR-30e, miR-660/miR-30e, and miR-205/miR-30e had minor prognostic value but could be used to increase the steadiness of the diagnostic system. The urine EVs had the highest potential as a source of markers.

Long Non-Coding RNA (lncRNA) CRNDE Regulated Lipopolysaccharides (LPS)-Induced MRC-5 Inflammation Injury Through Targeting MiR-141

Background

Pneumonia is a common disease with high morbidity and even death. In our country, pneumonia is the leading cause of child death. Therefore, research on the pathogenesis of pneumonia can help improve the treatment of pneumonia. Long non-coding RNA (lncRNA) is an important regulator of disease development, and its regulatory mechanism is closely related to cellular processes. However, the function and regulatory network of lncRNA is not fully elucidated in pneumonia.

Material/Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the expression of CRNDE and miR-141 in lipopolysaccharides (LPS)-induced MRC-5 cells and pneumonia tissues. MTT (3-(4,5-dimethylthiazol-2-yl)-2 5-diphenyl-2-tetrazolium) assay was used to assess cell proliferation. Flow cytometry assay was performed to detect cell apoptosis in LPS-induced MRC-5 cells. Enzyme-linked immunosorbent assay and western blot were used to measure the levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, respectively. In addition, luciferase reporter assay and RNA immunoprecipitation (RIP) assay were applied to prove the relationship between CRNDE and miR-141.

Results

In this study, we found that CRNDE expression was induced in LPS-induced MRC-5 cells and pneumonia tissues. Moreover, miR-141 expression was low in LPS-induced MRC-5 cells and was verified was a target miRNA of CRNDE by using luciferase reporter assay and RIP assay. The downregulation of CRNDE and upregulation of miR-141 promoted cell viability, inhibited cell apoptosis, as well as decreased the levels of IL-1β, IL-6, and TNF-α. Moreover, we demonstrated that si-CRNDE transfection increased cell viability and suppressed cell apoptosis and the levels of IL-1β, IL-6, and TNF-α, which were alleviated by anti-miR-141 transfection in LPS-induced MRC-5 cells.

Conclusions

In this study, we found that downregulation of CRNDE and upregulation of miR-141 inhibited cell apoptosis and inflammation response and promoted cell viability in LPS-induced MRC-5 cells. Low CRNDE expression increased cell growth and suppressed inflammation response, which was impaired by inhibition of miR-141. These results suggested that a novel therapeutic target was found in pneumonia treatment.

miRNA in prostate cancer: challenges toward translation

Prostate cancer (PCa) represents the most commonly diagnosed neoplasm among men. miRNAs, as biomarkers, could further improve reliability in distinguishing malignant versus nonmalignant, and aggressive versus nonaggressive PCa. However, conflicting data was reported for certain miRNAs, and there was a lack of consistency and reproducibility, which has been attributed to diverse (pre)analytical factors. In order to address current challenges in miRNA clinical research on PCa, a PubMed-based literature search was conducted with the last update in May 2019. After identifying critical variations in designs and protocols that undermined clear-cut evidence acquisition, and reliable translation into clinical practice, we propose guidelines for most critical steps that should be considered in future research of miRNA as biomarkers, especially in PCa.

ΜicroRNA-221 participates in cerebral ischemic stroke by modulating endothelial cell function by regulating the PTEN/PI3K/AKT pathway

An effective method to improve the blood supply of brain tissue is by angiogenesis, which is crucial for the prognosis of patients with cerebral ischemic stroke (CIS). Therefore, angiogenesis has been a focus of CIS research in recent years. The present study aimed to investigate the expression of microRNA (miR)-221 in patients with CIS and to explore the effect of miR-221 on endothelial cell function. The level of miR-221 was detected using reverse transcription-quantitative PCR (RT-qPCR). The relationship between miR-221 and phosphatase and tensin homolog (PTEN) was predicted and confirmed by bioinformatics and dual luciferase reporter assay. Cell viability, migration and invasion, and cell apoptosis were determined using MTT assay, Transwell assay and flow cytometry respectively. Tube formation in human umbilical vein endothelial cells (HUVECs) was determined by performing the tube formation assay. In addition, protein levels were measured using western blot analysis. The results of the current study indicated that miR-221 levels were significantly decreased in the peripheral blood of patients with CIS. PTEN was confirmed to be a direct target of miR-221. Downregulation of miR-221 significantly inhibited the function of HUVECs as evidenced by the decreased cell viability, migration and invasion with increased cell apoptosis and tube formation inhibition. miR-221 upregulation produced the reverse effects, whilst all the effects of miR-221 upregulation on HUVECs were reversed by PTEN overexpression. The PI3K/AKT pathway was identified to be involved in the regulation of miR-221 on HUVECs. In conclusion, miR-221 was downregulated in CIS patients, and it promoted the function of HUVECs by regulating the PTEN/PI3K/AKT pathway in vitro, suggesting the ability to promote angiogenesis. Therefore, miR-221 may be a novel and promising therapeutic target for CIS treatment.

A Novel Predictor Tool of Biochemical Recurrence after Radical Prostatectomy Based on a Five-MicroRNA Tissue Signature

Within five to ten years after radical prostatectomy (RP), approximately 15–34% of prostate cancer (PCa) patients experience biochemical recurrence (BCR), which is defined as recurrence of serum levels of prostate-specific antigen >0.2 µg/L, indicating probable cancer recurrence. Models using clinicopathological variables for predicting this risk for patients lack accuracy. There is hope that new molecular biomarkers, like microRNAs (miRNAs), could be potential candidates to improve risk prediction. Therefore, we evaluated the BCR prognostic capability of 20 miRNAs, which were selected by a systematic literature review. MiRNA expressions were measured in formalin-fixed, paraffin-embedded (FFPE) tissue RP samples of 206 PCa patients by RT-qPCR. Univariate and multivariate Cox regression analyses were performed, to assess the independent prognostic potential of miRNAs. Internal validation was performed, using bootstrapping and the split-sample method. Five miRNAs (miR-30c-5p/31-5p/141-3p/148a-3p/miR-221-3p) were finally validated as independent prognostic biomarkers. Their prognostic ability and accuracy were evaluated using C-statistics of the obtained prognostic indices in the Cox regression, time-dependent receiver-operating characteristics, and decision curve analyses. Models of miRNAs, combined with relevant clinicopathological factors, were built. The five-miRNA-panel outperformed clinically established BCR scoring systems, while their combination significantly improved predictive power, based on clinicopathological factors alone. We conclude that this miRNA-based-predictor panel will be worth to be including in future studies.

The association of let-7c, miR-21, miR-145, miR-182, and miR-221 with clinicopathologic parameters of prostate cancer in patients diagnosed with low-risk disease

BACKGROUND

The diagnostic benefit of prostate specific antigen (PSA) is limited, owing to its lack of specificity, particularly in men with PSA levels of 4.0 to 10.0 ng/mL. Therefore, there is a need for more specific and sensitive biomarkers to improve diagnostic accuracy and to predict prostate cancer (PCa) progression. Assessing the expression levels of specific microRNAs (miRNAs) in patients with PCa may be helpful in detecting cancer and predicting the cancer prognosis and its evolution, and may serve as markers to decide the treatment. We examined the expression levels of five miRNAs (let-7c, miR-21, miR-145, miR-185, and miR-221) on patients with low-risk PCa who had been eligible for active surveillance but underwent radical prostatectomy. We investigated the correlation between the relative expression of miRNAs and clinicopathologic parameters to evaluate their clinical significance.

MATERIALS AND METHODS

Total RNA was isolated from the tumor and the corresponding non-neoplastic prostate tissue of 45 patients who underwent radical prostatectomy. Quantitative reverse transcriptase-polymerase chain reaction was used to measure the levels of let-7c, miR-21, miR-145, miR-185, miR-221, and RNU6B expression, using TaqMan MicroRNA Assays. miRNA expression was examined in low-risk PCa, and miRNAs' association with Gleason upgraded (GU) and biochemical recurrent (BR) patients was evaluated.

RESULTS

We observed that miR-21 and miR-182 were overexpressed; conversely, let-7c, miR-145, and miR-221 were underexpressed in patients with low-risk PCa. GU patients (n = 16) and non-upgraded patients (n = 28) were compared. miR-145 was downregulated significantly in the GU group (P = 0.03). Similarly, miR-221 was downregulated significantly in patients with BR (n = 14) compared with non-recurrent patients (n = 30) (P = 0.04). Receiver operator characteristics (ROC) curve analysis revealed that miR-221 levels were significantly associated with BR in patients with a cut-off <-1.666, a value at which sensitivity was 70% and specificity 71% (area under curve [AUC] = 0.705, P = 0.030).

CONCLUSIONS

There is still a need for a tumor marker with higher sensitivity and specificity than that of PSA. Among the five miRNAs examined, miR-221 was most associated with biochemical recurrence in low-risk PCa.

miR-221-5p regulates proliferation and migration in human prostate cancer cells and reduces tumor growth in vivo

Background

Despite latest advances in prostate cancer (PCa) therapy, PCa remains the third-leading cause of cancer-related death in European men. Dysregulation of microRNAs (miRNAs), small non-coding RNA molecules with gene expression regulatory function, has been reported in all types of epithelial and haematological cancers. In particular, miR-221-5p alterations have been reported in PCa.

Methods

miRNA expression data was retrieved from a comprehensive publicly available dataset of 218 PCa patients (GSE21036) and miR-221-5p expression levels were analysed. The functional role of miR-221-5p was characterised in androgen- dependent and androgen- independent PCa cell line models (C4–2 and PC-3M-Pro4 cells) by miR-221-5p overexpression and knock-down experiments. The metastatic potential of highly aggressive PC-3M-Pro4 cells overexpressing miR-221-5p was determined by studying extravasation in a zebrafish model. Finally, the effect of miR-221-5p overexpression on the growth of PC-3M-Pro4luc2 cells in vivo was studied by orthotopic implantation in male Balb/cByJ nude mice and assessment of tumor growth.

Results

Analysis of microRNA expression dataset for human primary and metastatic PCa samples and control normal adjacent benign prostate revealed miR-221-5p to be significantly downregulated in PCa compared to normal prostate tissue and in metastasis compared to primary PCa. Our in vitro data suggest that miR-221-5p overexpression reduced PCa cell proliferation and colony formation. Furthermore, miR-221-5p overexpression dramatically reduced migration of PCa cells, which was associated with differential expression of selected EMT markers. The functional changes of miR-221-5p overexpression were reversible by the loss of miR-221-5p levels, indicating that the tumor suppressive effects were specific to miR-221-5p. Additionally, miR-221-5p overexpression significantly reduced PC-3M-Pro4 cell extravasation and metastasis formation in a zebrafish model and decreased tumor burden in an orthotopic mouse model of PCa.

Conclusions

Together these data strongly support a tumor suppressive role of miR-221-5p in the context of PCa and its potential as therapeutic target.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5819-6) contains supplementary material, which is available to authorized users.

Novel Diagnostic Biomarkers of Prostate Cancer: An Update

OBJECTIVE

In recent years, several biomarkers alternative to standard prostate specific antigen (PSA) for prostate cancer (PCa) diagnosis have become available. The aim of this systematic review is to assess the current knowledge about alternative serum and urinary biomarkers for the diagnosis of PCa.

MATERIAL AND METHODS

A research was conducted in Medline, restricted to English language articles published between December 2014 and June 2018 with the aim to update previously published series on PCa biomarkers. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) criteria were used for selecting studies with the lowest risk of bias.

RESULTS

Emerging role and actual controversies on serum and urine alternative biomarkers to standard PSA for PCa diagnosis, staging and prognosis assessment, such as prostate health index (PHI), PCA3, ConfirmMDx, Aberrant PSA glycosylation, MiPS, miRNAs are critically presented in the current review.

CONCLUSION

Although the use of several biomarkers has been recommended or questioned by different international guidelines, larger prospective randomized studies are still necessary to validate their efficacy in PCa detection, discrimination, prognosis and treatment effectiveness. To date, only PHI and 4Kscore have shown clinical relevance for discriminating more aggressive PCa. Furthermore, a new grading classification based on molecular features relevant for PCa risk-stratification and tailoring treatment is still needed.

Circulating microRNAs in plasma among men with low-grade and high-grade prostate cancer at prostate biopsy

BACKGROUND

MicroRNAs (miRNAs or miR-) have been linked to factors associated with aggressive prostate cancer such as biochemical recurrence and metastasis. We investigated whether circulating miRNAs in plasma could be used as diagnostic biomarkers for more aggressive prostate cancer at prostate biopsy.

METHODS

Men, aged 40 years and above, newly diagnosed with prostate cancer were categorized into two risk groups, low-grade (Gleason score, 6 or 7 [3 + 4] and serum prostate-specific antigen [PSA], <20 ng/mL) and high-grade (Gleason score, ≥7 (4 + 3) and serum PSA, ≥20 ng/mL) prostate cancers. The limma R package was used to compare the expression of miRNAs in plasma between the two risk groups, adjusting for age.

RESULTS

There were 66 men, aged 46-86 years, included: 40 men with low-grade and 26 men with high-grade prostate cancers. There were lower expressions of miR-28, miR-100, miR-942, and miR-28-3p, and higher expressions of miR-708, miR-1298, miR-886-3p, miR-374, miR-376c, miR-202, miR-128a, and miR-185 in high-grade compared to low-grade prostate cancer cases at biopsy, after adjusting for age (P < 0.05). These differences were no longer statistically significant after adjusting the P values for multiple comparisons.

CONCLUSION

There was no circulating miRNA associated with high-grade prostate cancer at biopsy after adjusting for age and multiple comparisons. Nevertheless, relationships between these circulating miRNAs and high-grade prostate cancer were observed, which suggest them as promising prostate cancer biomarkers. Further investigation in a larger cohort may provide insight into their diagnostic potential for aggressive prostate cancer.

miRNA-221 promotes cutaneous squamous cell carcinoma progression by targeting PTEN

Background

Cutaneous squamous cell carcinoma (CSCC) is a common type of skin malignancy. MicroRNA-221 (miRNA-221) is a critical non-coding RNA in tumor initiation and progression. However, the molecular mechanisms of miRNA-221 in the development of CSCC remain unknown. This study investigated the expression of miRNA-221 in CSCC and its potential tumor biological functions.

Methods

MTT assay, colony assay, PCR, and Western blot were adopted.

Results

In this study, miRNA-221 expression was significantly higher in CSCC tissues and cell lines than in normal tissues and cells (P < 0.05). Further functional experiments indicated that miRNA-221 knockdown inhibited the proliferation and cell cycle, while upregulation of miRNA-221 presented the opposite role. The dual reporter gene assays indicated that PTEN is a direct target gene of miRNA-221. PTEN protein or mRNA levels were decreased after the cells were transfected with miR-221 mimics.

Conclusions

Taken together, the obtained results indicated that miR-221 plays an oncogenic function in CSCC by targeting PTEN and further suggest that miR-221 may be a potential target for CSCC diagnosis and treatment.

PDCD4 Is an Androgen-Repressed Tumor Suppressor that Regulates Prostate Cancer Growth and Castration Resistance

Androgen receptor (AR) transcriptional activity contributes to prostate cancer development and castration resistance. The growth and survival pathways driven by AR remain incompletely defined. Here, we found PDCD4 to be a new target of AR signaling and a potent regulator of prostate cancer cell growth, survival, and castration resistance. The 3' untranslated region of PDCD4 is directly targeted by the androgen-induced miRNA, miR-21. Androgen treatment suppressed PDCD4 expression in a dose responsive and miR-21-dependent manner. Correspondingly, AR inhibition dose-responsively induced PDCD4 expression. Using data from prostate cancer tissue samples in The Cancer Genome Atlas (TCGA), we found a significant and inverse correlation between miR-21 and PDCD4 mRNA and protein levels. Higher Gleason grade tumors exhibited significantly higher levels of miR-21 and significantly lower levels of PDCD4 mRNA and protein. PDCD4 knockdown enhanced androgen-dependent cell proliferation and cell-cycle progression, inhibited apoptosis, and was sufficient to drive androgen-independent growth. On the other hand, PDCD4 overexpression inhibited miR-21-mediated growth and androgen independence. The stable knockdown of PDCD4 in androgen-dependent prostate cancer cells enhanced subcutaneous tumor take rate in vivo, accelerated tumor growth, and was sufficient for castration-resistant tumor growth. IMPLICATIONS: This study provides the first evidence that PDCD4 is an androgen-suppressed protein capable of regulating prostate cancer cell proliferation, apoptosis, and castration resistance. These results uncover miR-21 and PDCD4-regulated pathways as potential new targets for castration-resistant prostate cancer.

Adding the Team into T1 Translational Research: A Case Study of Multidisciplinary Team Science in the Evaluation of Biomarkers of Prostate Cancer Risk and Prognosis

BACKGROUND

Given translational research challenges, multidisciplinary team science is promoted to increase the likelihood of moving from discovery to health effect. We present a case study documenting the utility of multidisciplinary team science in prostate cancer tissue biomarker validation.

METHODS

We used primary data generated by a team consisting of a pathologist, cancer biologists, a biostatistician, and epidemiologists. We examined their contributions by phase of biomarker evaluation to identify when, through the practice of team science, threats to internal validity were recognized and solved. Next, we quantified the extent of bias avoided in evaluating the association of Ki67 (immunohistochemistry), stromal cell telomere length (fluorescence in situ hybridization), and microRNA (miRNA) (miR-21, miR-141, miR-221; quantitative RT-PCR) with prostate cancer risk or recurrence in nested case-control studies.

RESULTS

Threats to validity were tissue storage time (Ki67, miRNA) and laboratory equipment maintenance (telomeres). Solutions were all in the data analysis phase and involved using tissue storage-time specific cutpoints and/or batch-specific cutpoints. Bias in the regression coefficient for quantiles of each biomarker ranged from 24% to 423%, and the coefficient for the test for trend ranged from 15% to 910%. The interpretation of the associations changed as follows: Ki67, null to positive; stromal cell telomere length, null to positive; miR-21 and miR-141 remained null; miR-221, weak to moderate inverse.

CONCLUSIONS

In this case study, we documented the inferential benefits of multidisciplinary team science when the team's collaboration and coordination led to the identification of threats to validity and the implementation of appropriate solutions.

RNAs as Candidate Diagnostic and Prognostic Markers of Prostate Cancer-From Cell Line Models to Liquid Biopsies

The treatment landscape of prostate cancer has evolved rapidly over the past five years. The explosion in treatment advances has been witnessed in parallel with significant progress in the field of molecular biomarkers. The advent of next-generation sequencing has enabled the molecular profiling of the genomic and transcriptomic architecture of prostate and other cancers. Coupled with this, is a renewed interest in the role of non-coding RNA (ncRNA) in prostate cancer biology. ncRNA consists of several different classes including small non-coding RNA (sncRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). These families are under active investigation, given their essential roles in cancer initiation, development and progression. This review focuses on the evidence for the role of RNAs in prostate cancer, and their use as diagnostic and prognostic markers, and targets for treatment in this disease.

Cell-type specific expression of oncogenic and tumor suppressive microRNAs in the human prostate and prostate cancer

MiR-1 and miR-143 are frequently reduced in human prostate cancer (PCa), while miR-141 and miR-21 are frequently elevated. Consequently, these miRNAs have been studied as cell-autonomous tumor suppressors and oncogenes. However, the cell-type specificity of these miRNAs is not well defined in prostate tissue. Through two different microdissection techniques, and droplet digital RT-PCR, we quantified these miRNAs in the stroma and epithelium of radical prostatectomy specimens. In contrast to their purported roles as cell-autonomous tumor suppressors, we found miR-1 and miR-143 expression to be predominantly stromal. Conversely, miR-141 was predominantly epithelial. miR-21 was detected in both stroma and epithelium. Strikingly, the levels of miR-1 and miR-143 were significantly reduced in tumor-associated stroma, but not tumor epithelium. Gene expression analyses in human cell lines, tissues, and prostate-derived stromal cultures support the cell-type selective expression of miR-1, miR-141, and miR-143. Analyses of the PCa Genome Atlas (TCGA-PRAD) showed a strong positive correlation between stromal markers and miR-1 and miR-143, and a strong negative correlation between stromal markers and miR-141. In these tumors, loss of miR-1 and gain of miR-21 was highly associated with biochemical recurrence. These data shed new light on stromal and epithelial miRNA expression in the PCa tumor microenvironment.

Novel diagnostic and prognostic classifiers for prostate cancer identified by genome-wide microRNA profiling

Purpose

This study investigates the diagnostic and prognostic biomarker potential of miRNAs in prostate cancer (PC).

Results

We identified several new deregulated miRNAs between non-malignant (NM) and PC tissue samples and between more/less aggressive PC subgroups. We also developed and validated a novel 13-miRNA diagnostic classifier with high sensitivity and specificity for PC. Finally, we trained a new 3-miRNA prognostic classifier (miR-185-5p+miR-221-3p+miR-326) that predicted time to biochemical recurrence (BCR) independently of routine clinicopathological variables in a training radical prostatectomy (RP) cohort (n = 126) as well as in two independent validation cohorts (n = 110 and n = 99).

Experimental Design

After RT-qPCR-based profiling of 752 miRNAs in 13 NM and 134 PC tissue samples (cohort 1), we selected 93 top candidate diagnostic/prognostic miRNAs for validation in two independent patient sets (cohort 2: 19 NM and 138 PC; cohort 3: 28 NM and 113 PC samples). Diagnostic potential was assessed by ROC curve analysis and prognostic potential by Kaplan-Meier, uni- and multivariate Cox regression analyses. BCR after RP was used as endpoint.

Conclusions

This is the first report of a miRNA signature with significant independent prognostic value demonstrated in three PC patient cohorts.

Rapid Loss of RNA Detection by In Situ Hybridization in Stored Tissue Blocks and Preservation by Cold Storage of Unstained Slides

OBJECTIVES

Recent commercialization of methods for in situ hybridization using Z-pair probe/branched DNA amplification has led to increasing adoption of this technology for interrogating RNA expression in formalin-fixed, paraffin-embedded (FFPE) tissues. Current practice for FFPE block storage is to maintain them at room temperature, often for many years.

METHODS

To examine the effects of block storage time on FFPE tissues using a number of RNA in situ probes with the Advanced Cellular Diagnostic's RNAscope assay.

RESULTS

We report marked reductions in signals after 5 years and significant reductions often after 1 year. Furthermore, storing unstained slides cut from recent cases (<1 year old) at -20°C can preserve hybridization signals significantly better than storing the blocks at room temperature and cutting the slides fresh when needed.

CONCLUSIONS

We submit that the standard practice of storing FFPE tissue blocks at room temperature should be reevaluated to better preserve RNA for in situ hybridization.

Downregulation of miR-221-3p and upregulation of its target gene PARP1 are prognostic biomarkers for triple negative breast cancer patients and associated with poor prognosis

The purpose of this study was to identify microRNAs (miRNAs) closely associated with the prognosis of triple-negative breast cancer (TNBC) and their possible targets. This study recruited 125 early-stage TNBC patients, including 40 cases in the experimental group (20 cases with poor prognoses vs. 20 cases with good prognoses) and 85 cases in the validation group (27 cases with poor prognoses vs. 58 cases with good prognoses). In the experimental group, miRNA microarray showed 34 differentially expressed miRNAs in patients with different prognoses. We selected 5 miRNAs for validation. The differential expression of miR-221-3p was further verified in the experimental and validation groups using real-time polymerase chain reaction (PCR). High miR-221-3p expression was associated with better 5-year disease-free survival (DFS) (HR = 0.480; 95% CI, 0.263-0.879; p = 0.017) of TNBC patients. High expression of its target gene PARP1 predicted poorer 5-year DFS (HR = 2.236, 95% CI, 1.209-4.136, p = 0.010). MiR-221-3p down-regulated PARP1 by targeting its 3'-untranslated region. In conclusion, low miR-221-3p expression may contribute to the poor outcome of TNBC patients through regulating PARP1. MiR-221-3p likely plays a role as a PARP1 inhibitor by directly regulating PARP1 expression, thereby affecting the prognoses of TNBC patients.

Deregulation of selected microRNAs in sinonasal carcinoma: Value of miR-21 as prognostic biomarker in sinonasal squamous cell carcinoma

BACKGROUND

Tumors occurring in the sinonasal area are characterized by unfavorable outcome due to difficult diagnosis, treatment, and prognosis of the disease corresponding with the anatomic complexity of the area.

METHODS

We used quantitative real-time polymerase chain reaction (PCR) to compare relative expression of miR-21, miR-141, and miR-200c in 70 formalin-fixed, paraffin-embedded samples of sinonasal carcinoma tissue (majority of squamous cell carcinoma [SCC] samples) with 17 control samples of sinonasal tissue.

RESULTS

Our data showed significant upregulation of miR-21 in sinonasal cancer tissue. Expression levels of miR-141 and miR-200c were below detectable levels in both sinonasal cancer samples and healthy tissue. Kaplan-Meier analysis with log-rank survival showed that patients with SCC with high expression of miR-21 (highest quartile) had impaired survival close to reaching statistical significance (P = .0630).

CONCLUSION

Our results suggest that miR-21 upregulation is involved in tumorigenesis of sinonasal carcinoma and that it is associated with poor prognosis. Thus, miR-21 could be used as a valuable prognostic biomarker.

Tissue-Based MicroRNAs as Predictors of Biochemical Recurrence after Radical Prostatectomy: What Can We Learn from Past Studies?

With the increasing understanding of the molecular mechanism of the microRNAs (miRNAs) in prostate cancer (PCa), the predictive potential of miRNAs has received more attention by clinicians and laboratory scientists. Compared with the traditional prognostic tools based on clinicopathological variables, including the prostate-specific antigen, miRNAs may be helpful novel molecular biomarkers of biochemical recurrence for a more accurate risk stratification of PCa patients after radical prostatectomy and may contribute to personalized treatment. Tissue samples from prostatectomy specimens are easily available for miRNA isolation. Numerous studies from different countries have investigated the role of tissue-miRNAs as independent predictors of disease recurrence, either alone or in combination with other clinicopathological factors. For this purpose, a PubMed search was performed for articles published between 2008 and 2017. We compiled a profile of dysregulated miRNAs as potential predictors of biochemical recurrence and discussed their current clinical relevance. Because of differences in analytics, insufficient power and the heterogeneity of studies, and different statistical evaluation methods, limited consistency in results was obvious. Prospective multi-institutional studies with larger sample sizes, harmonized analytics, well-structured external validations, and reasonable study designs are necessary to assess the real prognostic information of miRNAs, in combination with conventional clinicopathological factors, as predictors of biochemical recurrence.

Significance of microRNAs in Androgen Signaling and Prostate Cancer Progression

The androgen receptor (AR) plays important roles in prostate cancer development and prostate tumor growth. After binding to androgens, AR functions as a nuclear receptor and translocates to the nucleus to bind to specific AR-binding sites (ARBSs). AR regulates epigenetic factor recruitments to activate its downstream signaling. Although androgen deprivation therapy (ADT) is initially useful for prostate cancer patients, most patients eventually show resistance with hormone-refractory prostate cancers (HRPCs) or castration-resistant prostate cancers (CRPCs). Thus, new therapeutic strategies targeting HRPCs/CRPCs should be very important for clinical medicine as well as prostate cancer biology. Past studies have shown that mechanisms such as AR overexpression, hypersensitivity, variants and reprograming are responsible for developing HRPCs/CRPCs. These findings suggest that AR target genes will be major key factors. In this review article, we focus mainly on the androgen-regulated microRNAs (miRNAs) to summarize the contribution of miRNA-mediated pathways for prostate cancer progression.

Meta-analysis of miRNA expression profiles for prostate cancer recurrence following radical prostatectomy

Background

Prostate cancer (PCa) is a leading reason of death in men and the most diagnosed malignancies in the western countries at the present time. After radical prostatectomy (RP), nearly 30% of men develop clinical recurrence with high serum prostate-specific antigen levels. An important challenge in PCa research is to identify effective predictors of tumor recurrence. The molecular alterations in microRNAs are associated with PCa initiation and progression. Several miRNA microarray studies have been conducted in recurrence PCa, but the results vary among different studies.

Methods

We conducted a meta-analysis of 6 available miRNA expression datasets to identify a panel of co-deregulated miRNA genes and overlapping biological processes. The meta-analysis was performed using the ‘MetaDE’ package, based on combined P-value approaches (adaptive weight and Fisher's methods), in R version 3.3.1.

Results

Meta-analysis of six miRNA datasets revealed miR-125A, miR-199A-3P, miR-28-5P, miR-301B, miR-324-5P, miR-361-5P, miR-363*, miR-449A, miR-484, miR-498, miR-579, miR-637, miR-720, miR-874 and miR-98 are commonly upregulated miRNA genes, while miR-1, miR-133A, miR-133B, miR-137, miR-221, miR-340, miR-370, miR-449B, miR-489, miR-492, miR-496, miR-541, miR-572, miR-583, miR-606, miR-624, miR-636, miR-639, miR-661, miR-760, miR-890, and miR-939 are commonly downregulated miRNA genes in recurrent PCa samples in comparison to non-recurrent PCa samples. The network-based analysis showed that some of these miRNAs have an established prognostic significance in other cancers and can be actively involved in tumor growth. Gene ontology enrichment revealed many target genes of co-deregulated miRNAs are involved in “regulation of epithelial cell proliferation” and “tissue morphogenesis”. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that these miRNAs regulate cancer pathways. The PPI hub proteins analysis identified CTNNB1 as the most highly ranked hub protein. Besides, common pathway analysis showed that TCF3, MAX, MYC, CYP26A1, and SREBF1 significantly interact with those DE miRNA genes. The identified genes have been known as tumor suppressors and biomarkers which are closely related to several cancer types, such as colorectal cancer, breast cancer, PCa, gastric, and hepatocellular carcinomas. Additionally, it was shown that the combination of DE miRNAs can assist in the more specific detection of the PCa and prediction of biochemical recurrence (BCR).

Conclusion

We found that the identified miRNAs through meta-analysis are candidate predictive markers for recurrent PCa after radical prostatectomy.

miRNA-221 acts as an oncogenic role by directly targeting TIMP2 in non-small-cell lung carcinoma

MicroRNA-221 (miRNA-221) plays an important role in occurrence and development of tumor. However, expression pattern and role of miRNA-221 in the non-small-cell lung carcinoma (NSCLC) remains poorly understood. In the current study, we explored the roles and the underlying mechanism of miR-221 in NSCLC by gain and loss of function analysis. We found that the expression of miRNA-221 is significantly higher in NSCLC tissues and NSCLC cells compared to normal tissues and cells, respectively (P<0.05). NSCLC cell lines SPCA1 and H1299 were transfected with miRNA-221 mimic or inhibitor, respectively, and then performed to analysis. Experiments indicated that upregulation of miRNA-221 promotes cell proliferation, cell cycle, migration, invasion in SPCA1 cells, while downregulation of miRNA-221 exhibited the opposite role. Tissue inhibitor of metallopeptidases-2 (TIMP2) mRNA or protein levels were downregulated after miRNA-221 overexpression in SPCA1 and H1299 cells, respectively. Furthermore, TIMP2 was identified as a direct target of miRNA-221. In summary, our results indicate that miRNA-221 promotes NSCLC growth and invasion through repressing the expression of TIMP2, which suggest that inhibition of miRNA-221 could be a potential target for the treatment of NSCLC.

Differential long-term stability of microRNAs and RNU6B snRNA in 12-20 year old archived formalin-fixed paraffin-embedded specimens

Background

The quantitative analysis of microRNA (miRNA) gene expression in archived formalin-fixed, paraffin embedded (FFPE) tissues has been instrumental to identifying their potential roles in cancer biology, diagnosis, and prognosis. However, it remains unclear whether miRNAs remain stable in FFPE tissues stored for long periods of time.

Methods

Here we report Taqman real-time RT-PCR quantification of miR-21, miR-141, miR-221, and RNU6B small nuclear RNA (snRNA) levels from 92 radical prostatectomy specimens stored for 12–20 years in FFPE blocks. The relative stability of each transcript over time was assessed using general linear models. The correlation between transcript quantities, sample age, and RNA integrity number (RIN) were determined utilizing Spearman rank correlation.

Results

All transcript levels linearly decreased with sample age, demonstrating a clear loss of miRNA stability and RNU6B snRNA stability over time. The most rapid rates of degradation were observed for RNU6B and miR-21, while miR-141 and miR-221 were more stable. RNA quality was not correlated with sample age or with miR-21, miR-221, or RNU6B snRNA levels. Conversely, miR-141 levels increased with RNA quality.

Conclusions

MiRNA and snRNA levels gradually decreased over an eight year period in FFPE tissue blocks. Sample age was the most consistent feature associated with miRNA stability. The reference snRNA, RUN6B, was more rapidly degraded when compared to miR-141 and miR-221 miRNAs. Various miRNAs demonstrated differential rates of degradation. Quantitative miRNA studies from long-term archived FFPE tissues may therefore benefit from epidemiologic study design or statistical analysis methods that take into account differential storage-dependent transcript degradation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-3008-4) contains supplementary material, which is available to authorized users.

Exosomal miR-221 targets DNM3 to induce tumor progression and temozolomide resistance in glioma

MicroRNA is an important regulator of glioblastoma. This study aims at validating microRNA-221 (miR-221) as a biomarker for glioblastoma, and understanding how miR-221 regulates glioblastoma progression. Using clinical samples, miR-221 expression was analyzed by quantitative reverse-transcriptase PCR (qPCR). SHG-44 cells were treated with anti-miR-221 or U87MG-derived exosomes followed by monitoring changes in cell viability, migration and temozolomide (TMZ) resistance. Bioinformatics approach was used to identify targets of miR-221. The interaction between miR-221 and its target, DNM3 gene, was studied with dual-luciferase reporter assay, Spearman's correlation analysis, and western blotting. To verify that RELA regulates miR-221 expression, RELA-expressing vector or shRNA was introduced into SHG-44 cells and its effect on miR-221 expression was monitored. Both tissue-level and exosomal miR-221 expression increased with glioma grades. In SHG-44 cells, downregulating miR-221 expression inhibited cell proliferation, migration, and TMZ resistance, whereas incubation with U87MG-derived exosomes exerted tumor-promoting effects. DNM3 gene is a target of miR-221. RELA induced miR-221 expression. In glioma, elevated miR-221 expression is a biomarker for glioma. DNM3 is a target of miR-221 and RELA regulates miR-221 expression. The RELA/miR-221 axis is a target for glioma diagnosis and therapy.

MiR-148a Functions as a Tumor Suppressor by Targeting CCK-BR via Inactivating STAT3 and Akt in Human Gastric Cancer

MicroRNAs (miRNAs) have been widely accepted as a class of gene expression regulators which post-translationally regulate protein expression. These small noncoding RNAs have been proved closely involved in the modulation of various pathobiological processes in cancer. In this research, we demonstrated that miR-148a expression was significantly down-regulated in gastric cancer tissues in comparison with the matched normal mucosal tissues, and its expression was statistically associated with lymph node metastasis. Ectopic expression of miR-148a inhibited tumor cell proliferation and migration in vitro, and inhibited tumor formation in vivo. Subsequently, we identified cholecystokinin B receptor (CCK-BR) as a direct target of miR-148a using western blot and luciferase activity assay. More importantly, siRNA-induced knockdown of CCK-BR elicited similar anti-oncogenic effects (decreased proliferation and migration) as those induced by enforced miR-148a expression. We also found that miR-148a-mediated anti-cancer effects are dependent on the inhibition of STAT3 and Akt activation, which subsequently regulates the pathways involved in cell proliferation and migration. Taken together, our results suggest that miR-148a serves as a tumor suppressor in human gastric carcinogenesis by targeting CCK-BR via inactivating STAT3 and Akt.

The Potential of MicroRNAs as Prostate Cancer Biomarkers

CONTEXT

Short noncoding RNAs known as microRNAs (miRNAs) control protein expression through the degradation of RNA or the inhibition of protein translation. The miRNAs influence a wide range of biologic processes and are often deregulated in cancer. This family of small RNAs constitutes potentially valuable markers for the diagnosis, prognosis, and therapeutic choices in prostate cancer (PCa) patients, as well as potential drugs (miRNA mimics) or drug targets (anti-miRNAs) in PCa management.

OBJECTIVE

To review the currently available data on miRNAs as biomarkers in PCa and as possible tools for early detection and prognosis.

EVIDENCE ACQUISITION

A systematic review was performed searching the PubMed database for articles in English using a combination of the following terms: microRNA, miRNA, cancer, prostate cancer, miRNA profiling, diagnosis, prognosis, therapy response, and predictive marker.

EVIDENCE SYNTHESIS

We summarize the existing literature regarding the profiling of miRNA in PCa detection, prognosis, and response to therapy. The articles were reviewed with the main goal of finding a common recommendation that could be translated from bench to bedside in future clinical practice.

CONCLUSIONS

The miRNAs are important regulators of biologic processes in PCa progression. A common expression profile characterizing each tumor subtype and stage has still not been identified for PCa, probably due to molecular heterogeneity as well as differences in study design and patient selection. Large-scale studies that should provide additional important information are still missing. Further studies, based on common clinical parameters and guidelines, are necessary to validate the translational potential of miRNAs in PCa clinical management. Such common signatures are promising in the field and emerge as potential biomarkers.

PATIENT SUMMARY

The literature shows that microRNAs hold potential as novel biomarkers that could aid prostate cancer management, but additional studies with larger patient cohorts and common guidelines are necessary before clinical implementation.