Dual strands of pre-miR‑150 (miR‑150‑5p and miR‑150‑3p) act as antitumor miRNAs targeting SPOCK1 in naïve and castration-resistant prostate cancer

Diverse activity of miR-150 in Tumor development: shedding light on the potential mechanisms

There is a growing interest to understand the role and mechanism of action of microRNAs (miRNAs) in cancer. The miRNAs are defined as short non-coding RNAs (18-22nt) that regulate fundamental cellular processes through mRNA targeting in multicellular organisms. The miR-150 is one of the miRNAs that have a crucial role during tumor cell progression and metastasis. Based on accumulated evidence, miR-150 acts as a double-edged sword in malignant cells, leading to either tumor-suppressive or oncogenic function. An overview of miR-150 function and interactions with regulatory and signaling pathways helps to elucidate these inconsistent effects in metastatic cells. Aberrant levels of miR-150 are detectable in metastatic cells that are closely related to cancer cell migration, invasion, and angiogenesis. The ability of miR-150 in regulating of epithelial-mesenchymal transition (EMT) process, a critical stage in tumor cell migration and metastasis, has been highlighted. Depending on the cancer cells type and gene expression profile, levels of miR-150 and potential target genes in the fundamental cellular process can be different. Interaction between miR-150 and other non-coding RNAs, such as long non-coding RNAs and circular RNAs, can have a profound effect on the behavior of metastatic cells. MiR-150 plays a significant role in cancer metastasis and may be a potential therapeutic target for preventing or treating metastatic cancer.

Non-coding RNAs in enzalutamide resistance of castration-resistant prostate cancer

Enzalutamide (Enz) is a next-generation androgen receptor (AR) antagonist used to treat castration-resistant prostate cancer (CRPC). Unfortunately, the relapsing nature of CRPC results in the development of Enz resistance in many patients. Non-coding RNAs (ncRNAs) are RNA molecules that do not encode proteins, which include microRNAs (miRNA), long ncRNAs (lncRNAs), circular RNAs (circRNAs), and other ncRNAs with known and unknown functions. Recently, dysregulation of ncRNAs in CRPC, particularly their regulatory function in drug resistance, has attracted more and more attention. Herein, we introduce the roles of dysregulation of different ncRNAs subclasses in the development of CRPC progression and Enz resistance. Recently determined mechanisms of Enz resistance are discussed, focusing mainly on the role of AR-splice variant-7 (AR-V7), mutations, circRNAs and lncRNAs that act as miRNA sponges. Also, the contributions of epithelial-mesenchymal transition and glucose metabolism to Enz resistance are discussed. We summarize the different mechanisms of miRNAs, lncRNAs, and circRNAs in the progression of CRPC and Enz resistance, and highlight the prospect of future therapeutic strategies against Enz resistance.

Acquired resistance mechanisms to osimertinib: The constant battle

Lung cancer is the leading cause of cancer-related mortality worldwide. Detectable driver mutations have now changed the course of lung cancer treatment with the emergence of targeted therapy as a novel strategy that widely improved lung cancer prognosis, especially in metastatic patients. Osimertinib (AZD9291) is an irreversible third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) used to treat stage IV EGFR-mutated non-small-cell lung cancer. It was initially designed to target both EGFR-activating mutations and the EGFR T790M mutation as well, which is the most common resistance mechanism to first- and second-generation EGFR-TKIs. Following the FLAURA trial, osimertinib is now widely used in the first-line setting. However, resistance to osimertinib inevitably develops, with numerous mechanisms leading to its resistance, classified into two main categories: EGFR-dependent and EGFR-independent mechanisms. While EGFR-dependent mechanisms consist mainly of the C797S EGFR mutation, EGFR-independent mechanisms include bypass pathways, oncogenic fusions, and phenotypic transformation, among others. This review summarizes the molecular resistance mechanisms to osimertinib, with the aim of identifying novel therapeutic approaches to overcome osimertinib resistance and improve patient outcome.

Ginsenoside Rh2 suppresses colon cancer growth by targeting the miR-150-3p/SRCIN1/Wnt axis

Ginsenoside Rh2, which is extracted from ginseng, exerts antitumor activity. Recent studies suggest that Rh2 may suppress the growth of colon cancer (CC) in vitro. However, the underlying mechanism remains unclear. In this study, we identified the relative levels of miR-150-3p in CC tissues and cells by a comprehensive strategy of data mining, computational biology, and real-time reverse transcription PCR (qRT-PCR) experiments. The regulatory effects of miR-150-3p/SRCIN1 on the proliferative and invasive abilities of CC cells are evaluated by CCK-8, EdU, wound healing, and transwell assays. Cell cycle- and apoptosis-related protein levels are assessed by western blot analysis. An in vivo tumor formation assay was conducted to explore the effects of miR-150-3p on tumor growth. Furthermore, bioinformatics and dual luciferase reporter assays are applied to determine the functional binding of miRNA to mRNA of the target gene. Finally, the relationship between Rh2 and miR-150-3p was further verified in SW620 and HCT-116 cells. miR-150-3p is downregulated in CC tissues and cell lines. Functional assays indicate that the upregulation of miR-150-3p inhibits tumor growth both in vivo and in vitro. In addition, SRCIN1 is upregulated in CC and predicts a poor prognosis, and it is the direct target for miR-150-3p. Moreover, the miR-150-3p mimic decreases Topflash/Fopflash-dependent luciferase activity, resulting in the inhibition of Wnt pathway activity. Rh2 can suppress the growth of CC by increasing miR-150-3p expression. Rh2 alleviates the accelerating effect on Wnt pathway activity, cell proliferation/migration, and colony formation caused by miR-150-3p inhibition. Rh2 inhibits the miR-150-3p/SRCIN1/Wnt axis to suppress colon cancer growth.

A Cross-Comparison of High-Throughput Platforms for Circulating MicroRNA Quantification, Agreement in Risk Classification, and Biomarker Discovery in Non-Small Cell Lung Cancer

Background

Circulating microRNAs (ct-miRs) are promising cancer biomarkers. This study focuses on platform comparison to assess performance variability, agreement in the assignment of a miR signature classifier (MSC), and concordance for the identification of cancer-associated miRs in plasma samples from non‐small cell lung cancer (NSCLC) patients.

Methods

A plasma cohort of 10 NSCLC patients and 10 healthy donors matched for clinical features and MSC risk level was profiled for miR expression using two sequencing-based and three quantitative reverse transcription PCR (qPCR)-based platforms. Intra- and inter-platform variations were examined by correlation and concordance analysis. The MSC risk levels were compared with those estimated using a reference method. Differentially expressed ct-miRs were identified among NSCLC patients and donors, and the diagnostic value of those dysregulated in patients was assessed by receiver operating characteristic curve analysis. The downregulation of miR-150-5p was verified by qPCR. The Cancer Genome Atlas (TCGA) lung carcinoma dataset was used for validation at the tissue level.

Results

The intra-platform reproducibility was consistent, whereas the highest values of inter-platform correlations were among qPCR-based platforms. MSC classification concordance was >80% for four platforms. The dysregulation and discriminatory power of miR-150-5p and miR-210-3p were documented. Both were significantly dysregulated also on TCGA tissue-originated profiles from lung cell carcinoma in comparison with normal samples.

Conclusion

Overall, our studies provide a large performance analysis between five different platforms for miR quantification, indicate the solidity of MSC classifier, and identify two noninvasive biomarkers for NSCLC.

MicroRNAs and Progesterone Receptor Signaling in Endometriosis Pathophysiology

Endometriosis is a significant disease characterized by infertility and pelvic pain in which endometrial stromal and glandular tissue grow in ectopic locations. Altered responsiveness to progesterone is a contributing factor to endometriosis pathophysiology, but the precise mechanisms are poorly understood. Progesterone resistance influences both the eutopic and ectopic (endometriotic lesion) endometrium. An inability of the eutopic endometrium to properly respond to progesterone is believed to contribute to the infertility associated with the disease, while an altered responsiveness of endometriotic lesion tissue may contribute to the survival of the ectopic tissue and associated symptoms. Women with endometriosis express altered levels of several endometrial progesterone target genes which may be due to the abnormal expression and/or function of progesterone receptors and/or chaperone proteins, as well as inflammation, genetics, and epigenetics. MiRNAs are a class of epigenetic modulators proposed to play a role in endometriosis pathophysiology, including the modulation of progesterone signaling. In this paper, we summarize the role of progesterone receptors and progesterone signaling in endometriosis pathophysiology, review miRNAs, which are over-expressed in endometriosis tissues and fluids, and follow this with a discussion on the potential regulation of key progesterone signaling components by these miRNAs, concluding with suggestions for future research endeavors in this area.

SPOCK1 with unexpected function. The start of a new career

SPOCK1, 2 and 3 are considered as matricellular proteoglycans without structural role. Their functions are only partly elucidated. SPOCK1 was detected in the brain as a member of the neural synapses, then in the neuromuscular junctions. It plays a role in the regulation of blood-brain barrier. Its best characterized activity was its oncogenic potential discovered in 2012. Its deleterious effect on tumor progression was detected on 36 different types of tumors by the end of 2020. However, its mode of actions is still not completely understood. Furthermore, even less was discovered about its physiological function. The fact that it was found to localize in the mitochondria and interfered with the lipid metabolism indicated, that the full discovery of SPOCK1 still waiting for us.

LncRNA THEMIS2-211, a tumor-originated circulating exosomal biomarker, promotes the growth and metastasis of hepatocellular carcinoma by functioning as a competing endogenous RNA

Hepatocellular carcinoma (HCC) is a major challenge for human health. Finding reliable diagnostic biomarkers and therapeutic targets for HCC is highly desired in the clinic. Currently, circulating exosomal lncRNA is a promising biomarker for the diagnosis of cancer and lncRNA is also a potential target in cancer therapy. Here, the diagnostic value of a panel based on exosomal lncRNA THEMIS2-211 and PRKACA-202, superior to that of AFP, was identified for diagnosing human HCC. Besides, the performance of exosomal lncRNA THEMIS2-211 alone exceeds that of AFP in diagnosing early-stage HCC patients (stage I). Furthermore, lncRNA THEMIS2-211 is highly expressed in HCC tissues and correlated with the poor prognosis of HCC patients. LncRNA THEMIS2-211 is upregulated and localized in the cytoplasm of HCC cells. LncRNA THEMIS2-211 exerts its biological function as an oncogene that promotes the proliferation, migration, invasion, EMT of HCC cells by physically interacting with miR-940 and therefore promoting SPOCK1 expressions. Rescue assays show the regulation of SPOCK1 by lncRNA THEMIS2-211 dependents on miR-940. The discovery of lncRNA THEMIS2-211 further illuminates the molecular pathogenesis of HCC and the THEMIS2-211/miR-940/SPOCK1 axis may act as a potential therapeutic target for HCC.

Differential expression of miRNAs involved in biological processes responsible for inflammation and immune response in lichen sclerosus urethral stricture disease

Purpose

To better understand the pathophysiology of lichen sclerosus (LS) urethral stricture disease (USD), we aimed to investigate expression profiles of microRNAs (miRNAs) in tissue samples from men undergoing urethroplasty.

Methods

Urethral stricture tissue was collected from 2005–2020. Histologic features diagnostic of LS were the basis of pathologic evaluation. Foci of areas diagnostic for LS or non-LS strictures were chosen for RNA evaluation. In an initial screening analysis, 13 LS urethral strictures and 13 non-LS strictures were profiled via miRNA RT-qPCR arrays for 752 unique miRNA. A validation analysis of 23 additional samples (9 LS and 14 non-LS) was performed for 15 miRNAs. Statistical analyses were performed using SPSS v25. Gene Ontology (GO) analysis was performed using DIANA-mirPath v. 3.0.

Results

In the screening analysis 143 miRNAs were detected for all samples. 27 were differentially expressed between the groups (false discovery p-value <0.01). 15 of these miRNAs individually demonstrated an area under the curve (AUC)>0.90 for distinguishing between between LS and non-LS strictures. 11-fold upregulation of MiR-155-5p specifically was found in LS vs. non-LS strictures (p<0.001, AUC = 1.0). In the validation analysis, 13 of the 15 miRNAs tested were confirmed to have differential expression (false discovery p-value <0.10).

Conclusions

To our knowledge this is the first study evaluating miRNA expression profiles in LS and non-LS USD. We identified several miRNAs that are differentially expressed in USD caused by LS vs other etiologies, which could potentially serve as biomarkers of LS USD. The top eight differentially expressed miRNAs have been linked to immune response processes as well as involvement in wound healing, primarily angiogenesis and fibrosis.

Multiomic analysis of the function of SPOCK1 across cancers: an integrated bioinformatics approach

Objective

To investigate SPARC (osteonectin), cwcv and kazal like domains proteoglycan 1 (SPOCK1) gene expression across The Cancer Genome Atlas (TCGA) cancers, both in cancer versus normal tissues and in different stages across the cancer types.

Methods

This integrated bioinformatics study used data from several bioinformatics databases (Cancer Cell Line Encyclopedia, Genotype-Tissue Expression, TCGA, Tumor Immune Estimation Resource [TIMER]) to define the expression pattern of the SPOCK1 gene. A survival analysis was undertaken across the cancers. The search tool for retrieval of interacting genes (STRING) database was used to identify proteins that interacted with SPOCK1. Gene Set Enrichment Analysis was conducted to determine pathway enrichment. The TIMER database was used to explore the correlation between SPOCK1 and immune cell infiltration.

Results

This multiomic analysis showed that the SPOCK1 gene was expressed differently between normal tissues and tumours in several cancers and that it was involved in cancer progression. The overexpression of the SPOCK1 gene was associated with poor clinical outcomes. Analysis of gene expression and tumour-infiltrating immune cells showed that SPOCK1 correlated with several immune cells across cancers.

Conclusions

This research showed that SPOCK1 might serve as a new target for several cancer therapies in the future.

Role of noncoding RNA in drug resistance of prostate cancer

Prostate cancer is one of the most prevalent forms of cancer around the world. Androgen-deprivation treatment and chemotherapy are the curative approaches used to suppress prostate cancer progression. However, drug resistance is extensively and hard to overcome even though remarkable progress has been made in recent decades. Noncoding RNAs, such as miRNAs, lncRNAs, and circRNAs, are a group of cellular RNAs which participate in various cellular processes and diseases. Recently, accumulating evidence has highlighted the vital role of non-coding RNA in the development of drug resistance in prostate cancer. In this review, we summarize the important roles of these three classes of noncoding RNA in drug resistance and the potential therapeutic applications in this disease.

The Identification of Plasma Exosomal miR-423-3p as a Potential Predictive Biomarker for Prostate Cancer Castration-Resistance Development by Plasma Exosomal miRNA Sequencing

Castration-resistant prostate cancer (CRPC) is the major cause of death from prostate cancer. Biomarkers to improve early detection and prediction of CRPC especially using non-invasive liquid biopsies could improve outcomes. Therefore, we investigated the plasma exosomal miRNAs associated with CRPC and their potential for development into non-invasive early detection biomarkers for resistance to treatment. RNA-sequencing, which generated approximately five million reads per patient, was performed to identify differentially expressed plasma exosomal miRNAs in 24 treatment-naive prostate cancer and 24 CRPC patients. RT-qPCR was used to confirm the differential expressions of six exosomal miRNAs, miR-423-3p, miR-320a, miR-99a-5p, miR-320d, miR-320b, and miR-150-5p (p = 7.3 × 10^-8, 0.0020, 0.018, 0.0028, 0.0013, and 0.0058, respectively) firstly in a validation cohort of 108 treatment-naive prostate cancer and 42 CRPC patients. The most significant differentially expressed miRNA, miR-423-3p, was shown to be associated with CRPC with area under the ROC curve (AUC) = 0.784. Combining miR-423-3p with prostate-specific antigen (PSA) enhanced the prediction of CRPC (AUC = 0.908). A separate research center validation with 30 treatment-naive and 30 CRPC patients also confirmed the differential expression of miR-423-3p (p = 0.016). Finally, plasma exosomal miR-423-3p expression in CRPC patients was compared to 36 non-CRPC patients under androgen depletion therapy, which showed significantly higher expression in CRPC than treated non-CRPC patients (p < 0.0001) with AUC = 0.879 to predict CRPC with no difference between treatment-naive and treated non-CRPC patients. Therefore, our findings demonstrate that a number of plasma exosomal miRNAs are associated with CRPC and miR-423-3p may serve as a biomarker for early detection/prediction of castration-resistance.

MicroRNA‑149‑3p inhibits cell proliferation by targeting AKT2 in oral squamous cell carcinoma

MicroRNAs (miRs) exhibit oncogenic or tumor suppressive functions that contribute to the initiation and development of various types of human cancer. miR-149-3p has been reported to serve multiple roles in the regulation of proliferation, apoptosis and metastasis. However, the effects and detailed mechanism of miR-149-3p in oral squamous cell carcinoma (OSCC) remain unclear. In the present study, miR-149-3p mimic, mimic control, miR-149-3p inhibitor and inhibitor control were transiently transfected into Cal27 and SCC-9 cells. The viability, proliferation and apoptosis of OSCC cells were determined using Cell Counting Kit-8, colony formation and Annexin V assays, respectively. The mRNA expression levels of miR-149-3p and AKT2 were determined by reverse transcription-quantitative PCR. The protein expression levels of AKT2, cleaved caspase-3 and cleaved PARP were examined by western blot analysis. The binding of miR-149-3p to the AKT2 3′-untranslated region was evaluated by a dual luciferase reporter assay. In the present study, overexpression of miR-149-3p reduced the viability and proliferation of OSCC cells. By contrast, increased cell viability and proliferation was observed in miR-149-3p-deficient OSCC cells. Dual luciferase reporter assay indicated that miR-149-3p significantly decreased the luciferase activity of the wild-type AKT2 3′-untranslated region. Moreover, overexpression of miR-149-3p downregulated the mRNA and protein expression levels of AKT2, suggesting that miR-149-3p was a negative modulator of AKT2. Restoration of AKT2 efficiently reversed the miR-149-3p-mediated reduction in the proliferative capacity of OSCC cells. In addition, miR-149-3p enhanced the sensitivity of OSCC cells to the chemotherapeutic drug 5-fluorouracil. Taken together, the current findings revealed an inhibitory effect of miR-149-3p on the proliferation of OSCC cells through the post-transcriptional suppression of AKT2, and indicated a potential chemosensitizing function of miR-149-3p for the treatment of patients with OSCC.

Identification of candidate miRNAs in early-onset and late-onset prostate cancer by network analysis

The incidence of patients under 55 years old diagnosed with Prostate Cancer (EO-PCa) has increased during recent years. The molecular biology of PCa cancer in this group of patients remains unclear. Here, we applied weighted gene coexpression network analysis of the expression of miRNAs from 24 EO-PCa patients (38–45 years) and 25 late-onset PCa patients (LO-PCa, 71–74 years) to identify key miRNAs in EO-PCa patients. In total, 69 differentially expressed miRNAs were identified. Specifically, 26 and 14 miRNAs were exclusively deregulated in young and elderly patients, respectively, and 29 miRNAs were shared. We identified 20 hub miRNAs for the network built for EO-PCa. Six of these hub miRNAs exhibited prognostic significance in relapse‐free or overall survival. Additionally, two of the hub miRNAs were coexpressed with mRNAs of genes previously identified as deregulated in EO-PCa and in the most aggressive forms of PCa in African-American patients compared with Caucasian patients. These genes are involved in activation of immune response pathways, increased rates of metastasis and poor prognosis in PCa patients. In conclusion, our analysis identified miRNAs that are potentially important in the molecular pathology of EO-PCa. These genes may serve as biomarkers in EO-PCa and as possible therapeutic targets.

CMEP: a database for circulating microRNA expression profiling

MOTIVATION

In recent years, several experimental studies have revealed that the microRNAs (miRNAs) in serum, plasma, exosome and whole blood are dysregulated in various types of diseases, indicating that the circulating miRNAs may serve as potential noninvasive biomarkers for disease diagnosis and prognosis. However, no database has been constructed to integrate the large-scale circulating miRNA profiles, explore the functional pathways involved and predict the potential biomarkers using feature selection between the disease conditions. Although there have been several studies attempting to generate a circulating miRNA database, they have not yet integrated the large-scale circulating miRNA profiles or provided the biomarker-selection function using machine learning methods.

RESULTS

To fill this gap, we constructed the Circulating MicroRNA Expression Profiling (CMEP) database for integrating, analyzing and visualizing the large-scale expression profiles of phenotype-specific circulating miRNAs. The CMEP database contains massive datasets that were manually curated from NCBI GEO and the exRNA Atlas, including 66 datasets, 228 subsets and 10 419 samples. The CMEP provides the differential expression circulating miRNAs analysis and the KEGG functional pathway enrichment analysis. Furthermore, to provide the function of noninvasive biomarker discovery, we implemented several feature-selection methods, including ridge regression, lasso regression, support vector machine and random forests. Finally, we implemented a user-friendly web interface to improve the user experience and to visualize the data and results of CMEP.

AVAILABILITY AND IMPLEMENTATION

CMEP is accessible at http://syslab5.nchu.edu.tw/CMEP.

MiR-133a-5p inhibits androgen receptor (AR)-induced proliferation in prostate cancer cells via targeting FUsed in Sarcoma (FUS) and AR

Androgens and androgen receptors are vital factors involved in prostate cancer progression, and androgen ablation therapies are commonly employed to treat advanced prostate cancer. Previously, FUsed in Sarcoma (FUS) was identified as an AR-interacting protein that enhances AR transcriptional activity. In the present study, we attempted to identify miRNAs that might target both FUS and AR to inhibit FUS and AR expression. Based on TCGA data and the online tools UALCAN, Kaplan Meier-plotter (KMplot), LncTar and miRWalk prediction, miR-133a-5p was selected. MiR-133a-5p expression was significantly downregulated in prostate cancer, and low miR-133a-5p expression was correlated with low survival probability. As predicted by LncTar and miRWalk, miR-133a-5p could bind to the 3'UTR of FUS and AR to inhibit their expression. MiR-133a-5p overexpression significantly suppressed the cell viability of the AR-positive prostate cancer cell lines VCaP and LNCaP, inhibited the expression of FUS, AR, as well as AR downstream targets IGF1R and EGFR. More importantly, miR-133a inhibition increased cancer cell proliferation as well as the expression of AR and AR downstream factors, while FUS knockdown exerted an opposite effect; the effect of miR-133a on cancer cell proliferation and AR could be significantly reversed by FUS knockdown. Moreover, IGF1R and EGFR knockdown reversed the effect of the miR-133a-5p inhibition. In summary, miR-133a-5p inhibits AR-positive prostate cancer cell proliferation by targeting FUS/AR, thus improving the resistance of prostate cancer to androgen ablation therapies, which requires further in vivo validation. We provided a novel miRNA regulation mechanism for proliferation regulation in AR-positive prostate cancer cells.

Emerging role of microRNA 628-5p as a novel biomarker for cancer and other diseases

MicroRNAs are a family of small, single-stranded RNAs that have key roles in regulating multiple signaling pathways within a cell. Studies have implicated aberrant expression of microRNAs in the development and progression of several pathologies including cancer. MicroRNAs are relatively stable and readily available in body fluids and tissues, making them desirable biomarkers for prognostic and diagnostic purposes in an array of diseases. MicroRNA 628 (5p/3p variants) is located in the 15q21.3 cancer-related region, and evidence suggests its association with various pathologies. The -5p mature variant, microRNA 628-5p, has been reported to be differentially expressed in various cancers, and its expression has been mostly associated with tumor suppression but there are few reports identifying its role in cancer progression. Several studies have also suggested its utility in diagnosis and prognosis of various cancers. Dysregulation of microRNA 628-5p has also been implicated in embryonal implantation defects, autism, immune modulation, myogenesis, cardiovascular disease, viral infection, and skeletal muscle repair. Here, we have provided a comprehensive review on available literature explaining the role of microRNA 628-5p as a potential cancer biomarker as well as briefly describe its function in other diseases and normal physiological conditions.

Biomarker Potential of Plasma MicroRNA-150-5p in Prostate Cancer

Background and Objectives: Over decades, prostate cancer (PCa) has become one of the leading causes of cancer mortality in men. Extensive evidence exists that microRNAs (miRNAs or miRs) are key players in PCa and a new class of non-invasive cancer biomarkers. Materials and Methods: We performed miRNA profiling in plasma and tissues of PCa patients and attempted the validation of candidate individual miRs as biomarkers. Results: The comparison of tissue and plasma profiling results revealed five commonly dysregulated miRs, namely, miR-130a-3p, miR-145-5p, miR-148a-3p, miR-150-5p, and miR-365a-3p, of which only three show concordant changes—miR-130a-3p and miR-150-5p were downregulated and miR-148a-3p was upregulated in both tissue and plasma samples, respectively. MiR-150-5p was validated as significantly downregulated in both plasma and tissue cancer samples, with a fold change of −2.697 (p < 0.001), and −1.693 (p = 0.035), respectively. ROC analysis showed an area under the curve (AUC) of 0.817 (95% CI: 0.680–0.995) for plasma samples and 0.809 (95% CI: 0.616–1.001) for tissue samples. Conclusions: We provide data indicating that miR-150-5p plasma variations in PCa patients are associated with concordant changes in prostate cancer tissues; however, given the heterogeneous nature of previous findings of miR-150-5p expression in PCa cells, additional future studies of a larger sample size are warranted in order to confirm the biomarker potential and role of miRNA-150-5p in PCa biology.

High SPOCK1 Expression is Associated with Advanced Stage, T Value, and Gleason Grade in Prostate Cancer

Background and objectives: Prostate cancer (PCa) is a common malignancy in males and has a relatively slower progression than other cancers. Our goal was to evaluate the clinical role of SPARC (secreted protein acidic and cysteine rich, osteonectin), cwcv, and kazal-like domains’ proteoglycan 1 (SPOCK1) in PCa. Materials and Methods: SPOCK1 expression was studied through the immunohistochemical staining of specimens from 71 patients with PCa. The correlation between SPOCK1 expression and clinicopathological features was quantitatively analyzed. We used Kaplan–Meier analysis and Cox proportional hazard models to analyze the prognostic value. Results: Of 71 PCa patients, high SPOCK1 expression was more likely to be seen in those with an advanced stage (p = 0.018) of the disease and an advanced tumor (T) value (p = 0.014). Patients in Gleason grade groups 3 and 4 had significantly higher SPOCK1 expression (p = 0.044 and 0.003, respectively) compared to those of Gleason grade group 1. However, this trend was not observed in patients in Gleason grade group 5. For the survival analysis, although it was not statistically significant, patients with a high SPOCK1 expression had a shorter median overall survival (6.2 years) compared to those with low expression (7.8 years). Conclusions: High SPOCK1 expression may be related to advanced clinicopathological features and possibly a poor prognosis. Further analysis with a larger patient base would help clarify this issue.

LncRNA MALAT1 promotes osteoarthritis by modulating miR-150-5p/AKT3 axis

BACKGROUND

Many studies have reported that long noncoding RNAs (lncRNAs) could act as sponges for microRNAs (miRNAs) and play important roles in the regulation of osteoarthritis (OA). Yet, the underlying mechanisms of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in OA are still unclear. Therefore, we aimed to explore the regulation mechanisms of MALAT1 in OA procession.

METHODS

IL-1β treatment in chondrocyte was used to mimic OA in vitro. MALAT1, miR-150-5p and AKT3 expression levels were detected via qRT-PCR. The protein levels of AKT3, MMP-13, ADAMTS-5, Bax, Bcl-2, cleaved-PARP, collagen II and aggracan were measured by western blot. MTT assay was performed to detect cell proliferation ability. The apoptosis of chondrocytes was determined using flow cytometry and western blot. Luciferase assay and RNA immunoprecipitation (RIP) assays were used to confirm the relationship among MALAT1, miR-150-5p and AKT3.

RESULTS

In our study, MALAT1 and AKT3 were upregulated while miR-150-5p was downregulated in OA in vitro and vivo. The level of miR-150-5p was negatively correlated with that of MALAT1 or AKT3. More importantly, overexpression of MALAT1 promoted the expression of AKT3 by negatively regulating miR-150-5p. MALAT1 knockdown inhibited cell proliferation, promoted apoptosis, increased MMP-13, ADAMTS-5 expression and decreased collagen II, aggracan expression in IL-1β treated chondrocytes. MALAT1 upregulation or AKT3 overexpression enhanced proliferation, inhibited apoptosis and extracellular matrix (ECM) degradation, which was undermined by overexpression of miR-150-5p. By contrast, miR-150-5p depletion rescued the effect of MALAT1 downregulation or loss of AKT3 on IL-1β-stimulated chondrocytes.

CONCLUSION

MALAT1 was responsible for cell proliferation, apoptosis, and ECM degradation via miR-150-5p/AKT3 axis.

Targeting the SPOCK1-snail/slug axis-mediated epithelial-to-mesenchymal transition by apigenin contributes to repression of prostate cancer metastasis

Background

Prostate cancer (PCa) is considered one of the most prevalent malignancy globally, and metastasis is a major cause of death. Apigenin (API) is a dietary flavonoid which exerts an antimetastatic effect in various cancer types. Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1) is a crucial modulator of tumor growth and metastasis in cancers. However, the role and underlying regulatory mechanisms of SPOCK1 in the API-mediated antimetastatic effects of PCa remain unclear.

Methods

MTS, colony formation, wound-healing, and transwell assays were conducted to evaluate the effects of API on PCa cell proliferative, migratory, and invasive potentials. In vivo orthotopic bioluminescent xenograft model were employed to determine antitumor activity of API. PCa cells were transfected with either Snail-, Slug-, SPOCK1-overexpressing vector, or small hairpin (sh)SPOCK1 to determine the invasive abilities and expression levels of SPOCK1 and epithelial-to-mesenchymal transition (EMT) biomarkers in response to API treatment. Immunohistochemical (IHC) assays were carried out to evaluate the expression level of SPOCK1 in PCa xenografts and a PCa tissue array. Associations of SPOCK1 expression with clinicopathological features and prognoses of patients with PCa were analyzed by GEO or TCGA RNA-sequencing data.

Results

API significantly suppressed in vitro PCa cell proliferation, migration, and invasion and inhibited in vivo PCa tumor growth and metastasis. Moreover, survival times of animals were also prolonged after API treatment. Mechanistic studies revealed that API treatment resulted in downregulation of SPOCK1, which was accompanied by reduced expressions of mesenchymal markers and subsequent attenuation of invasive abilities of PCa cells. Overexpression of SPOCK1 in PCa xenografts resulted in significant promotion of tumor progression and relieved the anticancer activities induced by API, whereas knockdown of SPOCK1 had opposite effects. In clinical, SPOCK1 levels were higher in tumor tissues compared to non-tumor tissues, which was also significantly correlated with shorter disease-free survival in PCa patients.

Conclusions

Levels of SPOCK1 increase with the progression of human PCa which suggests that SPOCK1 may act as a prognostic marker or therapeutic target for patients with PCa. Suppression of SPOCK1-mediated EMT signaling contributes to the antiproliferative and antimetastatic activities of API in vitro and in vivo.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1247-3) contains supplementary material, which is available to authorized users.

Micro-ribonucleic acid expression signature of metastatic castration-resistant prostate cancer: Regulation of NCAPH by antitumor miR-199a/b-3p

OBJECTIVES

To identify oncogenes regulated by micro-ribonucleic acid, miR-199a/b-3p, in metastatic castration-resistant prostate cancer.

METHODS

Advanced ribonucleic acid sequencing technologies were applied to construct a micro-ribonucleic acid expression signature using metastatic castration-resistant prostate cancer autopsy specimens. Ectopic expression of mature micro-ribonucleic acids or small-interfering ribonucleic acids were applied to functional assays for cancer cell lines. Genome-wide gene expression and in silico database analyses were carried out to predict micro-ribonucleic acid targets.

RESULTS

Ectopic expression of miR-199a/b inhibited cancer cell aggressiveness. The gene coding for non-structural maintenance of chromosomes condensin I complex subunit H was directly regulated by miR-199a/b-3p. High expression of condensin I complex subunit H was significantly associated with poor disease-free survival by The Cancer Genome Atlas database analysis (P < 0.0001). Overexpression of condensin I complex subunit H was detected in hormone-sensitive prostate cancer and castration-resistant prostate cancer specimens, and knockdown assays showed that its expression enhanced cancer cell migration and invasive abilities.

CONCLUSIONS

Small ribonucleic acid sequencing of metastatic castration-resistant prostate cancer specimens showed the presence of several antitumor micro-ribonucleic acids whose targets are involved in hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer pathogenesis. Condensin I complex subunit H seems to be a promising diagnostic marker and therapeutic target for this disease. Our approach, based on the roles of anti-tumor micro-ribonucleic acids and their targets, will contribute to an improved understanding of the molecular pathogenesis of hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer.

Pirin: a potential novel therapeutic target for castration-resistant prostate cancer regulated by miR-455-5p

Androgen deprivation therapy is frequently used to treat prostate cancer (PCa), but resistance can occur, a condition known as castration‐resistant prostate cancer (CRPC). Thus, novel approaches for identification of CRPC are important for designing effective PCa treatments. Analysis of microRNA (miRNA) expression signatures by RNA sequencing showed that both passenger and guide strands of the miR‐455‐duplex (miR‐455‐5p and miR‐455‐3p, respectively) acted as antitumor miRNAs in PCa cells. The involvement of miRNA passenger strands in cancer pathogenesis is a novel concept for miRNA functionality. Based on a large patient cohort in The Cancer Genome Atlas, expression of eight miR‐455‐5p/‐3p target genes (PIR: P = 0.0137, LRP8: P = 0.0495, IGFBP3: P = 0.0172, DMBX1: P = 0.0175, CCDC64: P = 0.0446, TUBB1: P = 0.0149, KIF21B: P = 0.0336, and NFAM1: P = 0.0013) was significantly associated with poor prognosis of PCa patients. Here, we focused on PIR (pirin), a highly conserved member of the cupin superfamily. PIR expression was directly regulated by miR‐455‐5p, and PIR overexpression was detected in hormone‐sensitive prostate cancer (HSPC) surgical specimens and CRPC autopsy specimens. Loss‐of‐function assays using siRNA or an inhibitor (bisamide) showed that downregulation of PIR expression blocked cancer cell migration and invasion. Moreover, the miR‐455‐5p/PIR axis contributed to cancer cell aggressiveness. These results suggest that PIR might be a promising diagnostic marker for HSPC and CRPC. Furthermore, CRPC treatment strategies targeting PIR may be possible in the future. Identification of antitumor miRNAs, including miRNA passenger strands, may contribute to the development of new diagnostic markers and therapeutic strategies for CRPC.

miRNA arm switching identifies novel tumour biomarkers

Background

microRNAs have been reported to play critical roles in cancer and to have potential as diagnostic biomarkers. During miRNA biogenesis, one strand of the miRNA hairpin precursor is preferentially selected as a functionally mature miRNA, while the other strand is typically degraded. Arm switching occurs when the strand preference is changed. This preference can be different and can change dynamically depending upon the species, tissue types, or development stages. Due to recent advances in next-generation sequencing methods, arm switching has been observed in a variety of cancers.

Methods

A tumour miRNA-Seq dataset was collected from The Cancer Genome Atlas (TCGA). The support vector machine (SVM) method combined with 5-fold cross validation was applied to select the best combination of arm-switched miRNA tumour markers. Survival analysis was also applied to identify patient survival associated miRNA markers.

Findings

We observed 51 arm-switched miRNAs and of these, 7 were associated with patient survival. Twenty-three 1-combination arm switching miRNAs with excellent diagnostic value were identified. Interestingly, ovarian cancer showed a significant difference in arm switching pattern compared with 32 other cancers.

Interpretation

These results suggest that arm switching miRNAs could be used as potential biomarkers for various cancers.

Fund

This work was partially supported by the National Natural Science Foundation of China (no. 61472158, 61572227), and University of Macau Faculty of Health Sciences (MYRG2016-00101-FHS).

Dual strands of the miR-145 duplex (miR-145-5p and miR-145-3p) regulate oncogenes in lung adenocarcinoma pathogenesis

Our original microRNA (miRNA) expression signatures (based on RNA sequencing) revealed that both strands of the miR-145 duplex (miR-145-5p, the guide strand, and miR-145-3p, the passenger strand) were downregulated in several types of cancer tissues. Involvement of passenger strands of miRNAs in cancer pathogenesis is a new concept in miRNA biogenesis. In our continuing analysis of lung adenocarcinoma (LUAD) pathogenesis, we aimed here to identify important oncogenes that were controlled by miR-145-5p and miR-145-3p. Downregulation of miR-145-5p and miR-145-3p was confirmed in LUAD clinical specimens. Functional assays showed that miR-145-3p significantly blocked the malignant abilities in LUAD cells, e.g., cancer cell proliferation, migration and invasion. Thus, the data showed that expression of the passenger strand of the miR-145-duplex acted as an anti-tumor miRNA. In LUAD cells, we identified four possible target genes (LMNB2, NLN, SIX4, and DDC) that might be regulated by both strands of miR-145. Among the possible targets, high expression of LMNB2 predicted a significantly poorer prognosis of LUAD patients (disease-free survival, p = 0.0353 and overall survival, p = 0.0017). Overexpression of LMNB2 was detected in LUAD clinical specimens and its aberrant expression promoted malignant transformation of LUAD cells. Genes regulated by anti-tumor miR-145-5p and miR-145-3p are closely involved in the molecular pathogenesis of LUAD. We suggest that they are promising prognostic markers for this disease. Our approach, based on the roles of anti-tumor miRNAs, will contribute to improved understanding of the molecular pathogenesis of LUAD.

Anti-tumor roles of both strands of the miR-455 duplex: their targets SKA1 and SKA3 are involved in the pathogenesis of renal cell carcinoma

Recent studies revealed that some passenger strands of miRNAs acted as anti-tumor or oncogenic miRNAs in cancer cells. In this study, we focused on miR-455-5p (the passenger strand) and miR-455-3p (the guide strand) based on microRNA (miRNA) expression signatures of cancer cells. Both miR-455-5p and miR-455-3p were downregulated in renal cell carcinoma (RCC) tissues and low expression of these miRNAs was significantly associated with poor prognosis. Cancer cell proliferation, migration and invasive abilities were significantly inhibited by ectopic expression of miR-455-5p and miR-455-3p. To identify their oncogenic targets, we applied a combination of genome-wide gene expression and in silico miRNA database analyses. We focused on spindle and kinetochore-associated proteins, SKA1 and SKA3 and demonstrated direct regulation of SKA1 by miR-455-5p and SKA3 by miR-455-3p in RCC cells. Our present data demonstrated overexpression of SKA3 in RCC clinical specimens. Moreover, the study showed that the miR-455-3p/SKA3 axis contributed to cancer cell aggressiveness. Analytic strategies based on anti-tumor miRNAs, including passenger strands of miRNAs, are effective approaches for the elucidation of the molecular pathogenesis of RCC.

Regulation of NCAPG by miR-99a-3p (passenger strand) inhibits cancer cell aggressiveness and is involved in CRPC

Effective treatments for patients with castration-resistant prostate cancer (CRPC) have not yet been established. Novel approaches for identification of putative therapeutic targets for CRPC are needed. Analyses of RNA sequencing of microRNA (miRNA) expression revealed that miR-99a-3p (passenger strand) is significantly downregulated in several types of cancers. Here, we aimed to identify novel miR-99a-3p regulatory networks and therapeutic targets for CRPC. Ectopic expression of miR-99a-3p significantly inhibited cancer cell proliferation, migration, and invasion in PCa cells. Non-SMC condensin I complex subunit G (NCAPG) was a direct target of miR-99a-3p in PCa cells. Overexpression of NCAPG was detected in CRPC clinical specimens and was significantly associated with shorter disease-free survival and advanced clinical stage. Knockdown of NCAPG inhibited cancer cell aggressiveness. The passenger strand miR-99a-3p acted as an antitumor miRNA in naïve PCa and CRPC. NCAPG was regulated by miR-99a-3p, and its overexpression was involved in CRPC pathogenesis. Involvement of passenger strand of miRNA in cancer pathogenesis is novel concept, and identification of antitumor miRNA regulatory networks in CRPC might be provided novel prognostic markers and therapeutic targets for this disease.

Impact of novel oncogenic pathways regulated by antitumor miR-451a in renal cell carcinoma

Recent analyses of our microRNA (miRNA) expression signatures obtained from several types of cancer have provided novel information on their molecular pathology. In renal cell carcinoma (RCC), expression of microRNA‐451a (miR‐451a) was significantly downregulated in patient specimens and low expression of miR‐451a was significantly associated with poor prognosis of RCC patients (P = .00305) based on data in The Cancer Genome Atlas. The aims of the present study were to investigate the antitumor roles of miR‐451a and to identify novel oncogenic networks it regulated in RCC cells. Ectopic expression of miR‐451a significantly inhibited cancer cell migration and invasion by RCC cell lines, suggesting that miR‐451a had antitumor roles. To identify oncogenes regulated by miR‐451a in RCC cells, we analyzed genome‐wide gene expression data and examined information in in silico databases. A total of 16 oncogenes and were found to be possible targets of miR‐451a regulation. Interestingly, high expression of 9 genes (PMM2,CRELD2,CLEC2D,SPC25,BST2,EVL,TBX15,DPYSL3, and NAMPT) was significantly associated with poor prognosis. In this study, we focused on phosphomannomutase 2 (PMM2), which was the most strongly associated with prognosis. Overexpression of PMM2 was detected in clinical specimens and Spearman's rank test indicated a negative correlation between the expression levels of miR‐451a and PMM2 (P = .0409). Knockdown of PMM2 in RCC cells inhibited cancer cell migration and invasion, indicating overexpression of PMM2 could promote malignancy. Analytic strategies based on antitumor miRNAs is an effective tool for identification of novel pathways of cancer.

Downregulation of matrix metalloproteinase 14 by the antitumor miRNA, miR-150-5p, inhibits the aggressiveness of lung squamous cell carcinoma cells

In the present study, in order to elucidate the aggressive nature of lung squamous cell carcinoma (LUSQ), we investigated the oncogenic RNA networks regulated by antitumor microRNAs (miRNAs or miRs) in LUSQ cells. The analysis of our original miRNA expression signatures of human cancers revealed that microRNA‑150‑5p (miR‑150‑5p) was downregulated in various types of cancer, indicating that miR‑150‑5p acts as an antitumor miRNA by targeting several oncogenic genes. Thus, the aims of this study were to investigate the antitumor roles of miR‑150‑5p in LUSQ cells and to identify oncogenes regulated by miR‑150‑5p that are involved in the aggressive behavior of LUSQ. The downregulation of miR‑150‑5p was validated in clinical samples of LUSQ and cell lines (SK-MES‑1 and EBC‑1). The ectopic overexpression of miR‑150‑5p significantly suppressed cancer cell aggressiveness. Comprehensive gene expression analyses revealed that miR‑150‑5p regulated 9 genes in the LUSQ cells. Among these, matrix metalloproteinase 14 (MMP14) was found to be a direct target of miR‑150‑5p, as shown by luciferase reporter assay. The knockdown of MMP14 using siRNA against MMP14 (si-MMP14) significantly inhibited cancer cell migration and invasion. The overexpression of MMP14 was detected in clinical specimens of LUSQ by immunohistochemistry. On the whole, these findings suggest that the downregulation of miR‑150‑5p and the overexpression of MMP14 may be deeply involved in the pathogenesis of LUSQ.

KISS1 tumor suppressor restricts angiogenesis of breast cancer brain metastases and sensitizes them to oncolytic virotherapy in vitro

KISS1 tumor suppressor protein regulates cancer cell invasion via MMP9 metalloproteinase. Downregulation of KISS1 gene expression promotes progression of breast cancer and melanoma, resulting in the development of distant metastases. In the current study, we investigated whether restoration of KISS1 expression in KISS1-deficient human metastatic breast cancer cells holds potential as an advanced anticancer strategy. To this end we engineered an infectivity-enhanced conditionally-replicative human adenovirus type 5 encoding KISS1 as an "arming" transgene in the Ad5 E3 region for an ectopic KISS1 expression in transduced cancer cells. The oncolytic potential of the vector was examined using brain-invading metastatic clones of CN34 and MDA-MB-231 breast cancer cells, which supported high levels of AdKISS1 replication, correlating with a robust CRAd-mediated cytotoxicity. Secretion of cellular factors responsible for tumor angiogenesis, cell-to-cell communication and anti-tumoral immune responses upon KISS1 expression in breast cancer cells was analyzed by a RayBiotech Kiloplex Quantibody array. Overall, our results indicate that KISS1 transgene expression provides an important benefit for CRAd-mediated cytotoxicity in breast cancer cells and holds potential as an anticancer treatment in conjunction with oncolytic virotherapy of breast and other metastatic cancers.

Antitumor miR-150-5p and miR-150-3p inhibit cancer cell aggressiveness by targeting SPOCK1 in head and neck squamous cell carcinoma

OBJECTIVE

Our recent studies have revealed that both strands of pre-miRNAs, the guide strand and the passenger strand, are involved in cancer pathogenesis. Analyses of miRNA expression signatures by RNA sequencing in head and neck squamous cell carcinoma (HNSCC) showed that both of the strands of pre-miR-150 (miR-150-5p and miR-150-3p) were significantly downregulated, and that these miRNAs acted as antitumor miRNAs in HNSCC cells. The aim of this study was to identify oncogenic genes in HNSCC cells that were regulated by miR-150-5p and miR-150-3p.

METHODS

Genome-wide gene expression studies, in silico analyses and dual-luciferase reporter assays were carried out to predict miR-150-5p and miR-150-3p regulation in HNSCC cells. Knockdown assay was applied to investigate the functional significance of the target gene. Overall patient survival as a function of target gene expression was estimated by The Cancer Genome Atlas (TCGA) database.

RESULTS

A total of 19 genes were putative targets of both miR-150-5p and miR-150-3p regulation. Among them, SPOCK1 (SPARC/osteonectin, cwcv and kazal-like domains proteoglycan 1) was directly regulated by both miRNAs in HNSCC cells. Knockdown studies using si-SPOCK1 showed that expression of SPOCK1 enhanced HNSCC cell aggressiveness. Overexpression of SPOCK1/SPOCK1 was confirmed in HNSCC clinical specimens. Interestingly, analysis of a large number of patients in the TCGA database (n=248) demonstrated that patients with high SPOCK1 expression had significantly shorter survival than did those with low SPOCK1 expression (P=0.0003). Moreover, 15 pathways were identified as SPOCK1-mediated downstream pathways.

CONCLUSION

Downregulation of both strands of pre-miR-150 (miR-150-5p and miR-150-3p) and overexpression of SPOCK1 contribute to the aggressive nature of HNSCC. The involvement of passenger strand miRNA in the regulation of HNSCC pathogenesis is a novel concept in RNA research.

Regulation of HMGB3 by antitumor miR-205-5p inhibits cancer cell aggressiveness and is involved in prostate cancer pathogenesis

Our recent determination of a microRNA (miRNA) expression signature in prostate cancer (PCa) revealed that miR-205-5p was significantly reduced in PCa tissues and that it acted as an antitumor miRNA. The aim of this study was to identify oncogenic genes and pathways in PCa cells that were regulated by antitumor miR-205-5p. Genome-wide gene expression analyses and in silico miRNA database searches showed that 37 genes were putative targets of miR-205-5p regulation. Among those genes, elevated expression levels of seven in particular (HMGB3, SPARC, MKI67, CENPF, CDK1, RHOU, and POLR2D) were associated with a shorter disease-free survival in a large number of patients in the The Cancer Genome Atlas (TCGA) database. We focused on high-mobility group box 3 (HMGB3) because it was the most downregulated by ectopic expression of miR-205-5p in PC3 cells and its expression was involved in PCa pathogenesis. Luciferase reporter assays showed that HMGB3 was directly regulated by miR-205-5p in PCa cells. Knockdown studies using si-HMGB3 showed that expression of HMGB3 enhanced PCa cell aggressiveness. Overexpression of HMGB3/HMGB3 was confirmed in naive PCa and castration-resistant PCa (CRPC) clinical specimens. Novel approaches to analysis of antitumor miRNA-regulated RNA networks in PCa cells may provide new insights into the pathogenic mechanisms of the disease.

Passenger strand of miR-145-3p acts as a tumor-suppressor by targeting MYO1B in head and neck squamous cell carcinoma

Analysis of the microRNA (miRNA) expression signature of head and neck squamous cell carcinoma (HNSCC) based on RNA sequencing showed that dual strands of pre-miR-145 (miR-145-5p, guide strand; and miR-145-3p, passenger strand) were significantly reduced in cancer tissues. In miRNA biogenesis, passenger strands of miRNAs are degraded and have no biological activities in cells. The aims of this study were to investigate the functional significance of the passenger strand of miR-145 and to identify miR-145-3p-regulated oncogenic genes in HNSCC cells. Expression levels of miR-145-5p and miR-145-3p were significantly downregulated in HNSCC tissues and cell lines (SAS and HSC3 cells). Ectopic expression of miR-145-3p inhibited cancer cell proliferation, migration and invasion, similar to miR-145-5p, in HNSCC cells. Myosin 1B (MYO1B) was directly regulated by miR-145-3p, and knockdown of MYO1B by siRNA inhibited cancer cell aggressiveness. Overexpression of MYO1B was confirmed in HNSCC clinical specimens by analysis of protein and mRNA levels. Interestingly, high expression of MYO1B was associated with poor prognosis in patients with HNSCC by analysis of The Cancer Genome Atlas database (p=0.00452). Our data demonstrated that the passenger strand of miR-145 acted as an antitumor miRNA through targeting MYO1B in HNSCC cells. The involvement of dual strands of pre-miR-145 (miR-145-5p and miR-145-3p) in the regulation of HNSCC pathogenesis is a novel concept in present RNA research.

Dual Strands of Pre-miR-149 Inhibit Cancer Cell Migration and Invasion through Targeting FOXM1 in Renal Cell Carcinoma

Our recent studies revealed that dual strands of certain pre-microRNAs, e.g., pre-miR-144, pre-miR-145, and pre-miR-150, act as antitumor microRNAs (miRNAs) in several cancers. The involvement of passenger strands of miRNAs in cancer pathogenesis is a novel concept in miRNA research. The analysis of a miRNA expression signature in clear cell renal cell carcinoma (ccRCC) has revealed that the guide strand of pre-miR-149 is significantly downregulated in cancer tissues. The aims of this study were to investigate the functional significance of miR-149’s guide strand (miR-149-5p) and passenger strand (miR-149-3p), and to identify the oncogenic genes regulated by these miRNAs in ccRCC cells. The ectopic expression of these miRNAs significantly inhibited cancer cell migration and invasion in ccRCC cells. Forkhead box protein M1 (FOXM1) was directly regulated by miR-149-5p and miR-149-3p in ccRCC cells. Knockdown studies using si-FOXM1 showed that the expression of FOXM1 enhanced RCC cell aggressiveness. Interestingly, the analysis of a large number of patients in the The Cancer Genome Atlas (TCGA) database (n = 260) demonstrated that patients with high FOXM1 expression had significantly shorter survival than did those with low FOXM1 expression (p = 1.5 × 10⁻⁶). Taken together, dual strands of pre-miR-149 (miR-149-5p and miR-149-3p) acted as antitumor miRNAs through the targeting of FOXM1 in ccRCC cells.