Identification of miR-30b-3p and miR-30d-5p as direct regulators of androgen receptor signaling in prostate cancer by complementary functional microRNA library screening

Spatial analysis of microRNA regulation at defined tumor hypoxia levels reveals biological traits of aggressive prostate cancer

Mechanisms regulating the gene expression program at different hypoxia severity levels in patient tumors are not understood. We aimed to determine microRNA (miRNA) regulation of this program at defined hypoxia levels from moderate to severe in prostate cancer. Biopsies from 95 patients were used, where 83 patients received the hypoxia marker pimonidazole before prostatectomy. Forty hypoxia levels were extracted from pimonidazole-stained histological sections and correlated with miRNA and gene expression profiles determined by RNA sequencing and Illumina bead arrays. This identified miRNAs associated with moderate (n = 7) and severe (n = 28) hypoxia and predicted their target genes. The scores of miRNAs or target genes showed prognostic significance, as validated in an external cohort of 417 patients. The target genes showed enrichment of gene sets for cell proliferation and MYC activation at all hypoxia levels and PTEN inactivation at severe hypoxia. This was confirmed by RT-qPCR for MYC and PTEN, by Ki67 immunohistochemistry, and by gene set analysis in an external cohort. To assess whether miRNA regulation occurred within the predicted hypoxic regions, a method to quantify co-localization of multiple histopathology parameters at defined hypoxia levels was applied. A high Ki67 proliferation index co-localized significantly with hypoxia at all levels. The co-localization index was strongly associated with poor prognosis. Absence of PTEN staining co-localized significantly with severe hypoxia. The scores for miRNAs correlated with the co-localization index for Ki67 staining and hypoxia, consistent with miRNA regulation within the overlapping regions. This was confirmed by showing miR-210-3p expression within severe hypoxia by in situ hybridization. Cell line experiments (22Rv1, PC3) were conducted to determine whether miRNAs and target genes were regulated directly by hypoxia. Most of them were hypoxia-unresponsive, and probably regulated by other mechanisms such as MYC activation. In conclusion, in aggressive, hypoxic prostate tumors, cancer cells exhibit different proliferative gene expression programs that is regulated by miRNAs and depend on whether the cells reside in moderate or severe hypoxic regions. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Natural products modulate phthalate-associated miRNAs and targets

Phthalates are widespread and commonly used plasticizers that lead to adverse health effects. Several natural products provide a protective effect against phthalates. Moreover, microRNAs (miRNAs) are regulated by natural products and phthalates. Therefore, miRNAs' impacts and potential targets may underlie the mechanism of phthalates. However, the relationship between phthalate-modulated miRNAs and phthalate protectors derived from natural products is poorly understood and requires further supporting information. In this paper, we review the adverse effects and potential targets of phthalates on reproductive systems as well as cancer and non-cancer responses. Information on natural products that attenuate the adverse effects of phthalates is retrieved through a search of Google Scholar and the miRDB database. Moreover, information on miRNAs that are upregulated or downregulated in response to phthalates is collected, along with their potential targets. The interplay between phthalate-modulated miRNAs and natural products is established. Overall, this review proposes a straightforward pathway showing how phthalates modulate different miRNAs and targets and cause adverse effects, which are partly attenuated by several natural products, thereby providing a direction for investigating the natural product-miRNA-target axis against phthalate-induced effects.

MicroRNA signature of stromal-epithelial interactions in prostate and breast cancers

Stromal-epithelial communication is an absolute necessity when it comes to the morphogenesis and pathogenesis of solid tissues, including the prostate and breast. So far, signalling pathways of several growth factors have been investigated. Besides such chemical factors, non-coding RNAs such as miRNAs have recently gained much interest because of their variety and complexity of action. Prostate and breast tissues being highly responsive to steroid hormones such as androgen and estrogen, respectively, it is not surprising that a huge set of available literature critically investigated the interplay between such hormones and miRNAs, especially in carcinogenesis. This review showcases our effort to highlight hormonally-related miRNAs that also somehow perturb the regular stromal-epithelial interactions during carcinogenesis in the prostate and breast. In future, we look forward to exploring how hormonal changes in the tissue microenvironment bring about miRNA-mediated changes in stromal-epithelial interactome in carcinogenesis and cancer progression.

The RNA secondary structure of androgen receptor-FL and V7 transcripts reveals novel regulatory regions

The androgen receptor (AR) is a ligand-dependent nuclear transcription factor belonging to the steroid hormone nuclear receptor family. Due to its roles in regulating cell proliferation and differentiation, AR is tightly regulated to maintain proper levels of itself and the many genes it controls. AR dysregulation is a driver of many human diseases including prostate cancer. Though this dysregulation often occurs at the RNA level, there are many unknowns surrounding post-transcriptional regulation of AR mRNA, particularly the role that RNA secondary structure plays. Thus, a comprehensive analysis of AR transcript secondary structure is needed. We address this through the computational and experimental analyses of two key isoforms, full length (AR-FL) and truncated (AR-V7). Here, a combination of in-cell RNA secondary structure probing experiments (targeted DMS-MaPseq) and computational predictions were used to characterize the static structural landscape and conformational dynamics of both isoforms. Additionally, in-cell assays were used to identify functionally relevant structures in the 5' and 3' UTRs of AR-FL. A notable example is a conserved stem loop structure in the 5'UTR of AR-FL that can bind to Poly(RC) Binding Protein 2 (PCBP2). Taken together, our results reveal novel features that regulate AR expression.

Epigenetic regulation of androgen dependent and independent prostate cancer

Prostate cancer is one of the most common malignancies among men worldwide. Besides genetic alterations, epigenetic modulations including DNA methylation, histone modifications and miRNA mediated alteration of gene expression are the key driving forces for the prostate tumor development and cancer progression. Aberrant expression and/or the activity of the epigenetic modifiers/enzymes, results in aberrant expression of genes involved in DNA repair, cell cycle regulation, cell adhesion, apoptosis, autophagy, tumor suppression and hormone response and thereby disease progression. Altered epigenome is associated with prostate cancer recurrence, progression, aggressiveness and transition from androgen-dependent to androgen-independent phenotype. These epigenetic modifications are reversible and various compounds/drugs targeting the epigenetic enzymes have been developed that are effective in cancer treatment. This chapter focuses on the epigenetic alterations in prostate cancer initiation and progression, listing different epigenetic biomarkers for diagnosis and prognosis of the disease and their potential as therapeutic targets. This chapter also summarizes different epigenetic drugs approved for prostate cancer therapy and the drugs available for clinical trials.

Deregulated miRNAs in enzalutamide resistant prostate cancer: A comprehensive review of key molecular alterations and clinical outcomes

Prostate cancer (PC) is the second most frequently diagnosed cancer and the fifth leading cause of cancer-related deaths in male population worldwide. Since the growth and progression of PC highly depend on the androgen pathway, androgen deprivation therapy (ADT) is the mainstay of systemic treatment. Enzalutamide is a second-generation antiandrogen, which is widely used for the treatment of advanced and metastatic PC. However, treatment failure and disease progression, caused by the emergence of enzalutamide resistant phenotypes, remains an important clinical challenge. MicroRNAs (miRNAs) are key regulators of gene expression and have recently emerged as potential biomarkers for being stable and easily analysed in several biological fluids. Several miRNAs that exhibit dysregulated expression patterns in enzalutamide-resistant PC have recently been identified, including miRNAs that modulate critical signalling pathways and genes involved in PC growth, survival and in the acquisition of enzalutamide phenotype. The understanding of molecular mechanisms by which miRNAs promote the development of enzalutamide resistance can provide valuable insights into the complex interplay between miRNAs, gene regulation, and treatment response in PC. Moreover, these miRNAs could serve as valuable tools for monitoring treatment response and disease progression during enzalutamide administration. This review summarises the miRNAs associated with enzalutamide resistance in PC already described in the literature, focusing on their biological roles and on their potential as biomarkers.

Clinical Significance of Extracellular Vesicles in Prostate and Renal Cancer

Extracellular vesicles (EVs)-including apoptotic bodies, microvesicles, and exosomes-are released by almost all cell types and contain molecular footprints from their cell of origin, including lipids, proteins, metabolites, RNA, and DNA. They have been successfully isolated from blood, urine, semen, and other body fluids. In this review, we discuss the current understanding of the predictive value of EVs in prostate and renal cancer. We also describe the findings supporting the use of EVs from liquid biopsies in stratifying high-risk prostate/kidney cancer and advanced disease, such as castration-resistant (CRPC) and neuroendocrine prostate cancer (NEPC) as well as metastatic renal cell carcinoma (RCC). Assays based on EVs isolated from urine and blood have the potential to serve as highly sensitive diagnostic studies as well as predictive measures of tumor recurrence in patients with prostate and renal cancers. Overall, we discuss the biogenesis, isolation, liquid-biopsy, and therapeutic applications of EVs in CRPC, NEPC, and RCC.

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.

Deregulated microRNAs Involved in Prostate Cancer Aggressiveness and Treatment Resistance Mechanisms

Prostate cancer (PCa) is the most frequently diagnosed cancer and the second leading cause of cancer deaths among American men. Complex genetic and epigenetic mechanisms are involved in the development and progression of PCa. MicroRNAs (miRNAs) are short noncoding RNAs that regulate protein expression at the post-transcriptional level by targeting mRNAs for degradation or inhibiting protein translation. In the past two decades, the field of miRNA research has rapidly expanded, and emerging evidence has revealed miRNA dysfunction to be an important epigenetic mechanism underlying a wide range of diseases, including cancers. This review article focuses on understanding the functional roles and molecular mechanisms of deregulated miRNAs in PCa aggressiveness and drug resistance based on the existing literature. Specifically, the miRNAs differentially expressed (upregulated or downregulated) in PCa vs. normal tissues, advanced vs. low-grade PCa, and treatment-responsive vs. non-responsive PCa are discussed. In particular, the oncogenic and tumor-suppressive miRNAs involved in the regulation of (1) the synthesis of the androgen receptor (AR) and its AR-V7 splice variant, (2) PTEN expression and PTEN-mediated signaling, (3) RNA splicing mechanisms, (4) chemo- and hormone-therapy resistance, and (5) racial disparities in PCa are discussed and summarized. We further provide an overview of the current advances and challenges of miRNA-based biomarkers and therapeutics in clinical practice for PCa diagnosis/prognosis and treatment.

Systematic Analysis of Tissue-Derived and Biofluid Extracellular Vesicle miRNAs Associated with Prostate Cancer

Extracellular vesicles (EVs) are emerging as biomarker candidates for early detection of prostate cancer. Studies compare EV-microRNA (miRNA) expression in individuals with prostate cancer (PCa) with cancer-free samples for diagnostic purposes. The aim of this study is to review miRNA signatures to investigate the overlap between miRNAs enriched in PCa tissue and miRNAs enriched in EVs isolated from subjects with PCa biofluids (i.e., urine, serum, and plasma). Signatures dysregulated in EVs from PCa biofluids and tissue are potentially associated with the primary tumor site and might be more indicative of PCa at an early stage. A systematic review of EV-derived miRNAs and a reanalysis of PCa tissue miRNA sequencing data for comparison is presented. Articles in the literature are screened for validated miRNA dysregulation in PCa and compared with TCGA primary PCa tumor data using DESeq2. This resulted in 190 dysregulated miRNAs being identified. Thirty-one eligible studies are identified, indicating 39 dysregulated EV-derived miRNAs. The top ten markers identified as significantly dysregulated in the PCa tissue dataset TCGA (e.g., miR-30b-3p, miR-210-3p, miR-126-3p, and miR-196a-5p) have a significant expression change in EVs with the same directionality in one or several statistically significant results. This analysis highlights several less frequently studied miRNAs in PCa literature.

LncRNA NEAT1 and MALAT1 are involved in polycystic ovary syndrome pathogenesis by functioning as competing endogenous RNAs to control the expression of PCOS-related target genes

Accumulating evidence has shown an abnormal expression of several non-coding RNAs in ovarian tissues which might be closely linked with the pathogenesis of PCOS. The aim of this study was to identify competing endogenous (ce) RNA network: long non-coding RNA (lncRNA), microRNA (miRNA) and their target genes: androgen receptor (AR), follistatin (FST) and insulin receptor substrate-2 (IRS-2), which are relevant to PCOS, to underline the molecular pathogenesis of PCOS and assist in early diagnosis and treatment. Bioinformatic analysis was performed to retrieve a ceRNA network: [lncRNA (NEAT1 and MALAT1) - miRNA (miR-30a-5p and miR-30d-5p) - mRNA (AR, FST and IRS-2)] linked to PCOS. Expression of the selected RNAs was examined by qPCR in peripheral blood leukocytes obtained from 73 PCOS patients (41 obese and 32 non-obese) and 31 healthy controls. PCOS patients showed significantly higher expression levels of NEAT1, miR-30a-5p, AR, FST and IRS-2, with significantly lower expression levels of MALAT1 and miR-30d-5p relative to controls especially in obese versus non-obese patients. Receiver operating characteristic (ROC) curve analysis indicated that most of the selected RNAs could serve as potential early diagnostic markers for PCOS with the highest efficiency obtained upon combining NEAT1 and miR-30d-5p or MALAT1 and miR-30a-5p with either of PCOS target genes. Moreover, all addressed RNAs had been proved as potential predictors of PCOS. The obtained data of ceRNA network raised the possibility that NEAT1 overexpression may increase the expression levels of AR, FST and IRS-2 by sponging miR-30d-5p, while low expression of MALAT1 may allow higher expression of the above genes via increasing miR-30a-5p, suggesting their involvement in PCOS pathogenesis and promising role for future diagnosis and targeted therapy.

A trio of tumor suppressor miRNA downregulates CREB5 dependent transcription to modulate neoadjuvant hormonal therapy sensitivity

Neoadjuvant hormonal therapy (NHT) prior to radical prostatectomy (RP) is an approach that can potentially maximize survival outcomes in prostate cancer (PCa) patients with high-risk disease. Unfortunately, subsets of patients do not respond well to such hormonal therapy. We previously identified several pathological parameters in predicting differences in response to NHT of PCa. However, little is known about the potential role and mechanism of miRNAs mediated NHT resistance (NHT-R) in PCa. Here we demonstrate that miR-l42-3p, miR-150-5p and miR-342-3p are the top downregulated miRNAs in PCa tissues with NHT-R. Functional analysis reveals that the three miRNAs inhibit cell proliferation in vitro. Transfection of miRNAs mimics strengthens the inhibitory effects of bicalutamide and enzalutamide to PCa cells. Luciferase reporter assay reveals that CREB5 is the common target of these three miRNAs. Clinically, high expression level of CREB5 correlates with high Gleason score, advanced tumor stage and NHT-R in PCa tissues. CREB5 expression promotes antiandrogen therapy resistance in LNCaP cells and IL6 signaling pathway may be involved in this process. In all, our findings highlight an important role of miR-142-3p, miR-150-5p, and miR-342-3p in contributing NHT-R by targeting CREB5 in PCa.

Inhibition of MicroRNA-92a Improved Erectile Dysfunction in Streptozotocin-Induced Diabetic Rats via Suppressing Oxidative Stress and Endothelial Dysfunction

PURPOSE

To determine whether microRNA could be a therapy target of erectile dysfunction (ED) and the underlying mechanisms.

MATERIALS AND METHODS

Eight-week-old fasting male SD rats were intraperitoneally injected with streptozotocin to construct diabetic rat models. Diabetic ED rats were treated with miRNA-92a inhibitor. The cavernous nerves were electrically stimulated to measure the intracavernous pressure and mean arterial pressure of rats in each group. After the detection, the penile cavernous tissues are properly stored for subsequent experiments. Rat aortic endothelial cells were used in in vitro studies.

RESULTS

The expression of miR-92a was significantly increased in the corpus cavernosum of Streptozocin (STZ)-induced diabetic rats and injection of miR-92a antagomir into the corpus cavernosum of diabetic rats significantly increased eNOS/NO/cGMP signaling pathway activities, cavernous endothelial cell proliferation, endothelial cell-cell junction protein expression and decreased the levels of oxidative stress. These changes restored erectile function in STZ-induced diabetic rats. Moreover, in vitro study demonstrated that the miR-92a expression increased significantly in endothelial cells treated with high glucose, inhibiting AMPK/eNOS and AMPK/Nrf2/HO-1 signaling pathways in rat aortic endothelial cells via targeting Prkaa2, causing endothelial dysfunction and overactive oxidative stress, miR-92a inhibitor can improve the above parameters.

CONCLUSIONS

miRNA-92a inhibitor could exert an inhibition role on oxidative stress and endothelial dysfunction to improve diabetic ED effectively.

An overview of prostate cancer (PCa) diagnosis: Potential role of miRNAs

Prostate cancer is the second most frequently diagnosed cancer among men worldwide, with the estimated sixth leading cause of cancer death. Despite major advancements in clinical biology and imaging, digital rectal examination (DRE), prostate-specific antigen (PSA), and biopsies indication remain the keystone for screening. Several kits are used to detect genomic changes and non-coding RNAs in the sample. However, its indication remains controversial for screening purposes. There is an urged need for non-invasive biomarkers to implement precision medicine. Recent research shows that miRNAs have an important role in the diagnostic, prognostic, and therapeutic agents as non-invasive biomarkers. Though prostate cancer data remains controversial in other cancer types, such as breast cancer, miR-21 expression is upregulated. Here, we reported a prolonged revision of miRNAs as prostate cancer prognostic, diagnostic, and predictive tools, including data on androgen receptor (AR) signaling, epithelial-mesenchymal transition (EMT) process, and cancer stem cells (CSCs) regulation. The combined utilization of miRNAs with other tests will help patients and clinicians to select the most appropriate personalized treatment and to avoid overdiagnosis and unnecessary biopsies. Future clinical applications of our reported novel miRNAs have a substantial role in the primary diagnosis of prostate cancer to help treatment decisions.

SUBATOMIC: a SUbgraph BAsed mulTi-OMIcs clustering framework to analyze integrated multi-edge networks

BACKGROUND

Representing the complex interplay between different types of biomolecules across different omics layers in multi-omics networks bears great potential to gain a deep mechanistic understanding of gene regulation and disease. However, multi-omics networks easily grow into giant hairball structures that hamper biological interpretation. Module detection methods can decompose these networks into smaller interpretable modules. However, these methods are not adapted to deal with multi-omics data nor consider topological features. When deriving very large modules or ignoring the broader network context, interpretability remains limited. To address these issues, we developed a SUbgraph BAsed mulTi-OMIcs Clustering framework (SUBATOMIC), which infers small and interpretable modules with a specific topology while keeping track of connections to other modules and regulators.

RESULTS

SUBATOMIC groups specific molecular interactions in composite network subgraphs of two and three nodes and clusters them into topological modules. These are functionally annotated, visualized and overlaid with expression profiles to go from static to dynamic modules. To preserve the larger network context, SUBATOMIC investigates statistically the connections in between modules as well as between modules and regulators such as miRNAs and transcription factors. We applied SUBATOMIC to analyze a composite Homo sapiens network containing transcription factor-target gene, miRNA-target gene, protein-protein, homologous and co-functional interactions from different databases. We derived and annotated 5586 modules with diverse topological, functional and regulatory properties. We created novel functional hypotheses for unannotated genes. Furthermore, we integrated modules with condition specific expression data to study the influence of hypoxia in three cancer cell lines. We developed two prioritization strategies to identify the most relevant modules in specific biological contexts: one considering GO term enrichments and one calculating an activity score reflecting the degree of differential expression. Both strategies yielded modules specifically reacting to low oxygen levels.

CONCLUSIONS

We developed the SUBATOMIC framework that generates interpretable modules from integrated multi-omics networks and applied it to hypoxia in cancer. SUBATOMIC can infer and contextualize modules, explore condition or disease specific modules, identify regulators and functionally related modules, and derive novel gene functions for uncharacterized genes. The software is available at https://github.com/CBIGR/SUBATOMIC .

Anti-cancer function of microRNA-30e is mediated by negative regulation of HELLPAR, a noncoding macroRNA, and genes involved in ubiquitination and cell cycle progression in prostate cancer

Prostate cancer (PCa) progression relies on androgen receptor (AR) function, making AR a top candidate for PCa therapy. However, development of drug resistance is common, which eventually leads to development of castration‐resistant PCa. This warrants a better understanding of the pathophysiology of PCa that facilitates the aberrant activation of key signaling pathways including AR. MicroRNAs (miRNAs) function as regulators of cancer progression as they modulate various cellular processes. Here, we demonstrate a multidimensional function of miR‐30e through the regulation of genes involved in various signaling pathways. We noted loss of miR‐30e expression in prostate tumors, which, when restored, led to cell cycle arrest, induction of apoptosis, improved drug sensitivity of PCa cells and reduced tumor progression in xenograft models. We show that experimental upregulation of miR‐30e reduces expression of mRNAs including AR, FBXO45, SRSF7 and MYBL2 and a novel long noncoding RNA (lncRNA) HELLPAR, which are involved in cell cycle, apoptosis and ubiquitination, and the effects could be rescued by inhibition of miR‐30e expression. RNA immunoprecipitation analysis confirmed direct interactions between miR‐30e and its RNA targets. We noted a newly identified reciprocal relationship between miR‐30e and HELLPAR, as inhibition of HELLPAR improved stabilization of miR‐30e. Transcriptome profiling and quantitative real‐time PCR (qRT‐PCR) validation of miR‐30e‐expressing PCa cells showed differential expression of genes involved in cell cycle progression, apoptosis and ubiquitination, which supports our in vitro study. This study demonstrates an integrated function of miR‐30e on dysregulation of miRNA/lncRNA/mRNA axes that may have diagnostic and therapeutic significance in aggressive PCa.

Knockdown of lncRNA LINC00662 suppresses malignant behaviour of osteosarcoma cells via competition with miR-30b-3p to regulate ELK1 expression

Purpose

Osteosarcoma is a type of bone malignancy that mainly occurred in teenagers. This investigation is aimed to clarify the effect of long non-coding RNA (lncRNA) LINC00662 on the proliferation, migration, and invasion in osteosarcoma and explore the underlying action mechanisms.

Methods

The mRNA expression of LINC00662 was determined by real-time quantitative polymerase chain reaction. Cell proliferation, migration, and invasion were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing, and transwell assays, respectively. A dual-luciferase reporter assay was used to validate the target relationships Between microRNA (miR)-30b-3p and LINC00662/ ETS domain-containing protein 1 (ELK1). Western blotting was performed to determine the protein expression of ELK1. Xenograft model was established to evaluate the effects of LINC00662 silencing on tumor growth in vivo.

Results

LncRNA LINC00662 and ELK1 were significantly increased, while miR-30b-3p was reduced in osteosarcoma tissues. The results of functional experiments indicated that transfection of small hairpin (sh)-LINC00662 and miR-30b-3p mimics repressed the migration, invasion, and proliferation of osteosarcoma cells. LncRNA LINC00662 also appeared to sponge miR-30b-3p in order to affect the expression of ELK1. Simultaneously, there were weak negative correlations between the expression of miR-30b-3p and LINC00662/ELK1 in osteosarcoma tissues. Rescue experiments suggested that ELK1 overexpression and downregulation of miR-30b-3p reversed the suppressive effects of sh-LINC00662 on the cell migration, invasion, and proliferation in osteosarcoma.

Conclusions

The current study indicated that knockdown of LINC00662 repressed cell migration, invasion, and proliferation through sponging miR-30b-3p to regulate the expression of ELK1 in osteosarcoma. These results may uncover a promising target for the treatment of osteosarcoma.

A review of the biological role of miRNAs in prostate cancer suppression and progression

Prostate cancer (PC) is the third-leading cause of cancer-related deaths worldwide. Although the current treatment strategies are progressing rapidly, PC is still representing a substantial medical problem for affected patients. Several factors are involved in PC initiation, progression, and treatments failure including microRNAs (miRNAs). The miRNAs are endogenous short non-coding RNA sequence negatively regulating target mRNA expression via degradation or translation repression. miRNAs play a pivotal role in PC pathogenesis through its ability to initiate the induction of cancer stem cells (CSCs) and proliferation, as well as sustained cell cycle, evading apoptosis, invasion, angiogenesis, and metastasis. Furthermore, miRNAs regulate major molecular pathways affecting PC such as the androgen receptor (AR) pathway, p53 pathway, PTEN/PI3K/AKT pathway, and Wnt/β-catenin pathway. Furthermore, miRNAs alter PC therapeutic response towards the androgen deprivation therapy (ADT), chemotherapy and radiation therapy (RT). Thus, the understanding and profiling of the altered miRNAs expression in PC could be utilized as a non-invasive biomarker for the early diagnosis as well as for patient sub-grouping with different prognoses for individualized treatment. Accordingly, in the current review, we summarized in updated form the roles of various oncogenic and tumor suppressor (TS) miRNAs in PC, revealing their underlying molecular mechanisms in PC initiation and progression.

miR-30d-5p: A Non-Coding RNA With Potential Diagnostic, Prognostic and Therapeutic Applications

Cancer is a great challenge facing global public health. Scholars have made plentiful efforts in the research of cancer therapy, but the results are still not satisfactory. In relevant literature, the role of miRNA in cancer has been widely concerned. MicroRNAs (miRNAs) are a non-coding, endogenous, single-stranded RNAs that regulate a variety of biological functions. The abnormal level of miR-30d-5p, a type of miRNAs, has been associated with various human tumor types, including lung cancer, colorectal cancer, esophageal cancer, prostate cancer, liver cancer, cervical cancer, breast cancer and other types of human tumors. This reflects the vital function of miR-30d-5p in tumor prognosis. miR-30d-5p can be identified either as an inhibitor hindering the development of, or a promoter accelerating the occurrence of tumors. In addition, the role of miR-30d-5p in cell proliferation, motility, apoptosis, autophagy, tumorigenesis, and chemoresistance are also noteworthy. The multiple roles of miR-30d-5p in human cancer suggest that it has broad feasibility as a biomarker and therapeutic target. This review describes the connection between miR-30d-5p and the clinical indications of tumors, and summarizes the mechanisms by which miR-30d-5p mediates cancer progression.

miR-514a-3p: a novel SHP-2 regulatory miRNA that modulates human cytotrophoblast proliferation

Src homology-2 domain-containing protein tyrosine phosphatase 2 (SHP-2), encoded by the PTPN11 gene, forms a central component of multiple signalling pathways and is required for insulin-like growth factor (IGF)-induced placental growth. Altered expression of SHP-2 is associated with aberrant placental and fetal growth indicating that drugs modulating SHP-2 expression may improve adverse pregnancy outcome associated with altered placental growth. We have previously demonstrated that placental PTPN11/SHP-2 expression is controlled by miRNAs. SHP-2 regulatory miRNAs may have therapeutic potential; however, the individual miRNA(s) that regulate SHP-2 expression in the placenta remain to be established. We performed in silico analysis of 3'UTR target prediction databases to identify libraries of Hela cells transfected with individual miRNA mimetics, enriched in potential SHP-2 regulatory miRNAs. Analysis of PTPN11 levels by quantitative (q) PCR revealed that miR-758-3p increased, while miR-514a-3p reduced PTPN11 expression. The expression of miR-514a-3p and miR-758-3p within the human placenta was confirmed by qPCR; miR-514a-3p (but not miR-758-3p) levels inversely correlated with PTPN11 expression. To assess the interaction between these miRNAs and PTPN11/SHP-2, specific mimetics were transfected into first-trimester human placental explants and then cultured for up to 4 days. Overexpression of miR-514a-3p, but not miR-758-3p, significantly reduced PTPN11 and SHP-2 expression. microRNA-ribonucleoprotein complex (miRNP)-associated mRNA assays confirmed that this interaction was direct. miR-514a-3p overexpression attenuated IGF-I-induced trophoblast proliferation (BrdU incorporation). miR-758-3p did not alter trophoblast proliferation. These data demonstrate that by modulating SHP-2 expression, miR-514a-3p is a novel regulator of IGF signalling and proliferation in the human placenta and may have therapeutic potential in pregnancies complicated by altered placental growth.

Regulation of Neuroendocrine-like Differentiation in Prostate Cancer by Non-Coding RNAs

Neuroendocrine prostate cancer (NEPC) represents a variant of prostate cancer that occurs in response to treatment resistance or, to a much lesser extent, de novo. Unravelling the molecular mechanisms behind transdifferentiation of cancer cells to neuroendocrine-like cancer cells is essential for development of new treatment opportunities. This review focuses on summarizing the role of small molecules, predominantly microRNAs, in this phenomenon. A published literature search was performed to identify microRNAs, which are reported and experimentally validated to modulate neuroendocrine markers and/or regulators and to affect the complex neuroendocrine phenotype. Next, available patients’ expression datasets were surveyed to identify deregulated microRNAs, and their effect on NEPC and prostate cancer progression is summarized. Finally, possibilities of miRNA detection and quantification in body fluids of prostate cancer patients and their possible use as liquid biopsy in prostate cancer monitoring are discussed. All the addressed clinical and experimental contexts point to an association of NEPC with upregulation of miR-375 and downregulation of miR-34a and miR-19b-3p. Together, this review provides an overview of different roles of non-coding RNAs in the emergence of neuroendocrine prostate cancer.

Interaction between Non-Coding RNAs and Androgen Receptor with an Especial Focus on Prostate Cancer

The androgen receptor (AR) is a member of the nuclear receptor superfamily and has three functional domains, namely the N-terminal, DNA binding, and C-terminal domain. The N-terminal domain harbors potent transactivation functions, whereas the C-terminal domain binds to androgens and antiandrogens used to treat prostate cancer. AR has genomic activity being DNA binding-dependent or through interaction with other DNA-bound transcription factors, as well as a number of non-genomic, non-canonical functions, such as the activation of the ERK, AKT, and MAPK pathways. A bulk of evidence indicates that non-coding RNAs have functional interactions with AR. This type of interaction is implicated in the pathogenesis of human malignancies, particularly prostate cancer. In the current review, we summarize the available data on the role of microRNAs, long non-coding RNAs, and circular RNAs on the expression of AR and modulation of AR signaling, as well as the effects of AR on their expression. Recognition of the complicated interaction between non-coding RNAs and AR has practical importance in the design of novel treatment options, as well as modulation of response to conventional therapeutics.

miRNAs and androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) is mainly used for the treatment of advanced, metastatic or recurrent prostate cancer (PCa). However, patients progress to ADT resistance and castration-resistant prostate cancer (CRPC) with a poor prognosis. Reliable validated markers of ADT resistance with proven clinical utility are necessary for timely correction of the therapy as well as for improvement of patient quality of life. MiRNAs involved in the ADT response and CRPC development via multiple mechanisms may act as biomarkers for patient outcomes. Available data on miRNAs associated with the ADT response (resistance and sensitivity) are summarized and analyzed in the manuscript, including analyses using bioinformatics resources. Molecular targets of miRNAs, as well as reciprocal relations between miRNAs and their targets, were studied using different databases. Special attention was dedicated to the mechanisms of ADT resistance and CRPC development, including testosterone, PI3K-AKT, VEGF pathways and associated genes. Several different approaches can be used to search for miRNAs associated with the ADT response, each of which focuses on the associated set of miRNAs - potential markers of ADT. The intersection of these approaches and combined analysis allowed us to select the most promising miRNA markers of the ADT response. Meta-analysis of the current data indicated that the selected 5 miRNAs (miRNAs - 125b, miR-21, miR-23b, miR-27b and miR-221) and 14 genes are involved in the regulation of key processes of CRPC development and represent the most promising predictors of the ADT response, further demonstrating their potential in combination therapy for advanced PCa.

MicroRNA-regulated transcriptome analysis identifies four major subtypes with prognostic and therapeutic implications in prostate cancer

MicroRNA (miRNA) deregulation plays a critical role in the heterogeneous development of prostate cancer (PCa) by tuning mRNA levels. Herein, we aimed to characterize the molecular features of PCa by clustering the miRNA-regulated transcriptome with non-negative matrix factorization. Using 478 PCa samples from The Cancer Genome Atlas, four molecular subtypes (S-I, S-II, S-III, and S-IV) were identified and validated in two merged microarray and RNAseq datasets with 656 and 252 samples, respectively. Interestingly, the four subtypes showed distinct clinical and biological features after comprehensive analyses of clinical features, multiomic profiles, immune infiltration, and drug sensitivity. S-I is basal/stem/mesenchymal-like and immune-excluded with marked transforming growth factor β, epithelial-mesenchymal transition and hypoxia signals, increased sensitivity to olaparib, and intermediate prognosis. S-II is luminal/metabolism-active and responsive to androgen deprivation therapy with frequent TMPRSS2-ERG fusion and a good prognosis. S-III is characterized by moderate proliferative and metabolic activity, sensitivity to taxane-based chemotherapy, and intermediate prognosis. S-IV is highly proliferative with moderate EMT and stemness, frequent deletions of TP53, PTEN and RB, and the poorest prognosis; it is also immune-inflamed and sensitive to anti-PD-L1 therapy. Overall, based on miRNA-regulated gene profiles, this study identified four distinct PCa subtypes that could improve risk stratification at diagnosis and provide therapeutic guidance.

Androgen receptor variants: RNA-based mechanisms and therapeutic targets

Prostate cancer is the second leading cause of male cancer death in the United States. The androgen receptor (AR) transcription factor is a master regulator of normal glandular homeostasis in the prostate, as well as growth and survival of prostate cancer cells. Therefore, AR-targeted therapies are effective for improving overall survival of patients with advanced prostate cancer that is incurable by surgery or radiation. However, prostate cancer will inevitably progress on AR-targeted therapies to a castration-resistant prostate cancer (CRPC) phenotype that accounts for virtually all prostate cancer-specific death. mRNA transcript variants of the AR gene are expressed in CRPC cells and can be translated to produce AR variant (AR-V) proteins that function as ligand-independent, constitutively active transcription factors. AR-Vs are able to support growth of CRPC cells by promoting expression of AR target genes that are normally suppressed by AR-targeted therapies. Knowledge of mechanisms that govern expression of AR-Vs is incomplete. Studies have shown genomic rearrangements of the AR gene underlie expression of diverse AR-Vs in certain CRPC tumors, but post-transcriptional processes represent a broader regulatory mechanism for expression of AR-Vs in CRPC. This review focuses on alternative splicing, 3' end processing, miRNA-mediated mRNA repression, of AR and AR-V expression and the potential these mechanisms hold as therapeutic targets for CRPC.

Bioinformatics identification of hub genes and signaling pathways regulated by intravenous immunoglobulin treatment in acute Kawasaki disease

Kawasaki disease (KD) is an acute, self-limiting form of vasculitis commonly encountered in infants and young children. Intravenous immunoglobulin (IVIG) is the primary drug used for the treatment of KD, which may significantly reduce the occurrence of coronary artery lesions. However, the specific molecular profile changes of KD caused by IVIG treatment have remained elusive and require further research. The present study was designed to identify key genes, pathways and immune cells affected by IVIG treatment using multiple bioinformatics analysis methods. The results suggested that myeloid cells and neutrophils were affected by IVIG treatment. Kyoto Encyclopedia of Genes and Genomes pathway analysis identified that hematopoietic cell lineages and osteoclast differentiation may have an important role in the mechanism of action of IVIG treatment. Immune cell analysis indicated that the levels of monocytes, M1 macrophages, neutrophils and platelets were markedly changed in patients with KD after vs. prior to IVIG treatment. The key upregulated genes, including ZW10 interacting kinetochore protein, GINS complex subunit 1 and microRNA-30b-3p in whole blood cells of patients with KD following treatment with IVIG indicated that these IVIG-targeted molecules may have important roles in KD. In addition, these genes were further examined by literature review and indicated to be involved in cell proliferation, apoptosis and virus-related immune response in patients with KD. Therefore, the present results may provide novel insight into the mechanisms of action of IVIG treatment for KD.

miR-30d-5p represses the proliferation, migration, and invasion of lung squamous cell carcinoma via targeting DBF4

OBJECTIVE

This study aims to explore the mechanism of miR-30d-5p in regulating the development of lung squamous cell carcinoma (LUSC) via targeting DBF4.

METHODS

Bioinformatics methods were employed to analyze the differentially expressed genes in LUSC tissue microarray. qRT-PCR was employed to detect the expression of miR-30d-5p and DBF4 mRNA in normal human bronchial epithelial cells and LUSC cells. CCK-8 was used to detect LUSC cell activity. Wound healing assay was employed to detect the migratory ability of LUSC cells. Transwell was employed to detect invasive ability. Dual-luciferase reporter assay was used to detect the targeting relationship between miR-30d-5p and DBF4. Western blot was used to detect the protein expression of marker molecules associated with epithelial-mesenchymal transition (EMT).

RESULTS

In this study, the expression of miR-30d-5p in LUSC cell lines was found to be obviously low compared with that in normal human bronchial epithelial cell line, which was opposite to the expression of DBF4. Dual-luciferase reporter assay verified that miR-30d-5p could target DBF4 and the overexpression of miR-30d-5p downregulated the expression of DBF4. Overexpression of DBF4 promoted the proliferation, migration, invasion, and EMT of LUSC, whereas over-expression of miR-30d-5p could weaken the promotion of DBF4 on cancer cells.

CONCLUSION

miR-30d-5p downregulates the expression of DBF4 to regulate the development of LUSC.

Recruitment of miR-8080 by luteolin inhibits androgen receptor splice variant 7 expression in castration-resistant prostate cancer

A need exists for seeking effective treatments for castration-resistant prostate cancer (CRPC) in response to its emergence following androgen deprivation therapy as a major clinical problem. In the present study, we investigated the chemopreventive and chemotherapeutic potential of luteolin, a flavonoid with antioxidative properties, on prostate cancer, including CRPC. Luteolin inhibited the progression of rat prostate carcinogenesis by induction of apoptosis in a transgenic rat for adenocarcinoma of prostate (TRAP) model. Luteolin decreased cell proliferation in a dose-dependent manner and induced apoptosis with the activation of caspases 3 and 7 in both rat (PCai1, established from a TRAP prostate tumor) and human (22Rv1) CRPC cells. Dietary luteolin also suppressed tumor growth via an increase in apoptosis and inhibition of angiogenesis in PCai1 and 22Rv1 xenografts implanted in castrated nude mice. We also focused on androgen receptor splice variant 7 (AR-V7), which contributes to cell proliferation and therapeutic resistance in CRPC. Luteolin dramatically suppressed AR-V7 protein expression in 22Rv1 cells in vitro and ex vivo. Microarray analysis identified MiR-8080, which contains a possible target sequence for AR-V7 3′-UTR, as a gene upregulated by luteolin. MiR-8080 transfection decreased the AR-V7 expression level and the induction of apoptosis in 22Rv1 cells. Furthermore, miR-8080 knockdown canceled luteolin decreasing AR-V7 and the cell growth of 22Rv1. MiR-8080 induced by luteolin intake enhanced the therapeutic effect of enzalutamide on 22Rv1 xenografts under castration conditions. These results indicate luteolin inhibits CRPC by AR-V7 suppression through miR-8080, highlighting luteolin and miR-8080 as promising therapeutic agents for this disease.

LncRNA PART1 Promotes Proliferation and Migration, Is Associated with Cancer Stem Cells, and Alters the miRNA Landscape in Triple-Negative Breast Cancer

Triple-negative breast cancers (TNBCs) are aggressive, lack targeted therapies and are enriched in cancer stem cells (CSCs). Novel therapies which target CSCs within these tumors would likely lead to improved outcomes for TNBC patients. Long non-coding RNAs (lncRNAs) are potential therapeutic targets for TNBC and CSCs. We demonstrate that lncRNA prostate androgen regulated transcript 1 (PART1) is enriched in TNBCs and in Aldefluor^high CSCs, and is associated with worse outcomes among basal-like breast cancer patients. Although PART1 is androgen inducible in breast cancer cells, analysis of patient tumors indicates its androgen regulation has minimal clinical impact. Knockdown of PART1 in TNBC cell lines and a patient-derived xenograft decreased cell proliferation, migration, tumor growth, and mammosphere formation potential. Transcriptome analyses revealed that the lncRNA affects expression of hundreds of genes (e.g., myosin-Va, MYO5A; zinc fingers and homeoboxes protein 2, ZHX2). MiRNA 4.0 GeneChip and TaqMan assays identified multiple miRNAs that are regulated by cytoplasmic PART1, including miR-190a-3p, miR-937-5p, miR-22-5p, miR-30b-3p, and miR-6870-5p. We confirmed the novel interaction between PART1 and miR-937-5p. In general, miRNAs altered by PART1 were less abundant than PART1, potentially leading to cell line-specific effects in terms miRNA-PART1 interactions and gene regulation. Together, the altered miRNA landscape induced by PART1 explains most of the protein-coding gene regulation changes (e.g., MYO5A) induced by PART1 in TNBC.

MicroRNAs as Epigenetic Determinants of Treatment Response and Potential Therapeutic Targets in Prostate Cancer

Prostate cancer (PCa) is the second most common tumor in men worldwide, and the fifth leading cause of male cancer-related deaths in western countries. PC is a very heterogeneous disease, meaning that optimal clinical management of individual patients is challenging. Depending on disease grade and stage, patients can be followed in active surveillance protocols or undergo surgery, radiotherapy, hormonal therapy, and chemotherapy. Although therapeutic advancements exist in both radiatiotherapy and chemotherapy, in a considerable proportion of patients, the treatment remains unsuccessful, mainly due to tumor poor responsiveness and/or recurrence and metastasis. microRNAs (miRNAs), small noncoding RNAs that epigenetically regulate gene expression, are essential actors in multiple tumor-related processes, including apoptosis, cell growth and proliferation, autophagy, epithelial-to-mesenchymal transition, invasion, and metastasis. Given that these processes are deeply involved in cell response to anti-cancer treatments, miRNAs have been considered as key determinants of tumor treatment response. In this review, we provide an overview on main PCa-related miRNAs and describe the biological mechanisms by which specific miRNAs concur to determine PCa response to radiation and drug therapy. Additionally, we illustrate whether miRNAs can be considered novel therapeutic targets or tools on the basis of the consequences of their expression modulation in PCa experimental models.

Extracellular vesicles in prostate cancer: a narrative review

Over the past decade, there has been remarkable progress in prostate cancer biomarker discovery using urine- and blood-based assays. A liquid biopsy is a minimally invasive procedure to investigate the cancer-related molecules in circulating tumor cells (CTCs), cell-free DNA, and extracellular vesicles (EVs). Liquid biopsies have the advantage of detecting heterogeneity as well as acquired resistance in cancer. EVs are cell-derived vesicles enclosed by a lipid bilayer and contain various molecules, such as nucleic acids, proteins, and lipids. In patients with cancer, EVs derived from tumors can be isolated from urine, plasma, and serum. The advances in isolation techniques provide the opportunity to use EVs as biomarkers in the clinic. Emerging evidence suggests that EVs can be useful biomarkers for the diagnosis of prostate cancer, especially high-grade cancer. EVs can also be potent biomarkers for the prediction of disease progression in patients with castration-resistant prostate cancer (CRPC). EVs shed from cancer and stromal cells are involved in the development of tumor microenvironments, enhancing cancer progression, metastasis, and drug resistance. Here, we provide an overview of the use of EVs for the diagnosis of clinically significant prostate cancer as well as for predicting disease progression. We also discuss the biological function of EVs, which regulate cancer progression.

Androgen Receptor-Related Non-coding RNAs in Prostate Cancer

Prostate cancer (PCa) is the second leading cause of cancer-related death among men in the United States. Androgen receptor (AR) signaling is the dominant oncogenic pathway in PCa and the main strategy of PCa treatment is to control the AR activity. A large number of patients acquire resistance to Androgen deprivation therapy (ADT) due to AR aberrant activation, resulting in castration-resistant prostate cancer (CRPC). Understanding the molecular mechanisms underlying AR signaling in the PCa is critical to identify new therapeutic targets for PCa patients. The recent advances in high-throughput RNA sequencing (RNA-seq) techniques identified an increasing number of non-coding RNAs (ncRNAs) that play critical roles through various mechanisms in different diseases. Some ncRNAs have shown great potentials as biomarkers and therapeutic targets. Many ncRNAs have been investigated to regulate PCa through direct association with AR. In this review, we aim to comprehensively summarize recent findings of the functional roles and molecular mechanisms of AR-related ncRNAs as AR regulators or targets in the progression of PCa.

MiR-30b-3p and miR-126-3p of urinary extracellular vesicles could be new biomarkers for prostate cancer

Background

Extracellular vesicles (EVs) including exosomes are present in blood, urine, and saliva and contain proteins, microRNAs, and messenger RNAs. We investigated microRNAs in urinary EVs to discover new biomarkers of prostate cancer (PCa).

Methods

We isolated EVs from urine obtained following digital rectal examination (DRE) of 14 men with elevated levels of serum prostate-specific antigen (PSA) [negative biopsy (n=4) and PCa with Gleason scores of 6 (n=3), 7 (n=3), and 8-9 (n=4)]. MicroRNAs extracted from EVs were analyzed by microRNA microarray.

Results

MicroRNAs miR-30b-3p and miR-126-3p were identified as being overexpressed in urinary EVs of the PCa patients versus the biopsy-negative men, but no microRNAs were associated with the Gleason score. In the independent cohort as well, these two microRNAs were overexpressed in urinary EVs from the PCa patients versus the negative-biopsy men. Logistic regression analysis adjusted by age and PSA showed that these two microRNAs were significantly associated with the prediction of PCa in biopsy specimens. Sensitivity and specificity of miR-30b-3p and miR-126-3p for the prediction of PCa were 46.4% and 88.0% and 60.7% and 80.0%, respectively, which were better than those of serum PSA (53.5% and 64.0%, respectively).

Conclusions

MiR-30b-3p and miR-126-3p in urinary EVs could be potential biomarkers of PCa.

Targeting androgen receptor signaling with MicroRNAs and Curcumin: a promising therapeutic approach for Prostate Cancer Prevention and intervention

Prostate cancer (PC) is a multifactorial disease characterized by the abrogation of androgen receptor signaling. Advancement in microbiology techniques has highlighted the significant role of microRNAs (miRNAs) in the progression of PC cells from an androgen-dependent to an androgen-independent state. At that stage, prostate tumors also fail to respond to currently practiced hormone therapies. So, studies in recent decades are focused on investigating the anti-tumor effects of natural compounds in PC. Curcumin is widely recognized and now of huge prestige for its anti-proliferative abilities in different types of cancer. However, its limited solubility, compatibility, and instability in the aqueous phase are major hurdles when administering. Nanoformulations have proven to be an excellent drug delivery system for various drugs and can be used as potential delivery platforms for curcumin in PC. In this review, a shed light is given on the miRNAs-mediated regulation of androgen receptor (AR) signaling and miRNA-curcumin interplay in PC, as well as on curcumin-based nanoformulations that can be used as possible therapeutic solutions for PC.

Molecular Origin, Expression Regulation, and Biological Function of Androgen Receptor Splicing Variant 7 in Prostate Cancer

The problem of resistance to therapy in prostate cancer (PCa) is multifaceted. Key determinants of drug resistance include tumor burden and growth kinetics, tumor heterogeneity, physical barriers, immune system and microenvironment, undruggable cancer drivers, and consequences of therapeutic pressures. With regard to the fundamental importance of the androgen receptor (AR) in all stages of PCa from tumorigenesis to progression, AR is postulated to have a continued critical role in castration-resistant prostate cancer (CRPC). Suppression of AR signaling mediated by the full-length AR (AR-FL) is the therapeutic goal of all AR-directed therapies. However, AR-targeting agents ultimately lead to AR aberrations that promote PCa progression and drug resistance. Among these AR aberrations, androgen receptor variant 7 (AR-V7) is gaining attention as a potential predictive marker for as well as one of the resistance mechanisms to the most current anti-AR therapies in CRPC. Meanwhile, development of next-generation drugs that directly or indirectly target AR-V7 signaling is urgently needed. In the present review of the current literature, we have summarized the origin, alternative splicing, expression induction, protein conformation, interaction with coregulators, relationship with AR-FL, transcriptional activity, and biological function of AR-V7 in PCa development and therapeutic resistance. We hope this review will help further understand the molecular origin, expression regulation, and role of AR-V7 in the progression of PCa and provide insight into the design of novel selective inhibitors of AR-V7 in PCa treatment.

Prognostic values of GPNMB identified by mining TCGA database and STAD microenvironment

The survival rate of stomach adenocarcinoma patients with immune and stromal scores and different clinicopathological features obtained from the TCGA datasets was systematically compared. A list of genes that are correlated with stomach adenocarcinoma microenvironment were extracted using the TCGA database to predict the prognosis and survival. In addition, the differentially expressed genes were extracted by comparing the immune and stromal scores of the groups. The protein-protein interaction network, and functional and pathway enrichment analyses of differentially expressed genes were performed. A total of 8 hub genes were selected from the differentially expressed genes to predict the overall survival and disease-free survival rates. GPNMB was selected from the hub genes based on the survival and prognosis analyses. A nomogram was built by including the potential risk factors based on multivariate Cox analysis. Cell function experiments and xenograft tumors were conducted in vivo to further verify the role of GPNMB in tumor progression. The predicted microRNA, miR-30b-3p, might act as upstream negative regulator and binding to 3’ UTR of GPNMB, confirming by fluorescent enzyme reporter gene experiment. In summary, immune-related scores are crucial factors in the malignant progression of stomach adenocarcinoma and GPNMB acts as a potentially useful prognostic factor for stratification and in developing the treatment strategy

Effects of miR-218-1-3p and miR-149 on proliferation and apoptosis of non-small cell lung cancer cells

The aim of the present study was to explore the effects of miR-218-1-3p and miR-149 on the biological function of non-small cell lung cancer (NSCLC) cells A549. Paired NSCLC and adjacent tissues were obtained from 50 NSCLC patients admitted to Shandong Provincial Chest Hospital Affiliated to Shandong University (Jinan, China) from April 2015 to May 2018. The expression levels of miR-218-1-3p and miR-149 were detected by reverse transcription-quantitative PCR (RT-qPCR). The lung adenocarcinoma A549 cells were assigned into the blank group (without transfection), negative control (NC) group (transfected with miRNA NC), and the transfected groups miR-218-1-3p mimic and miR-149 mimic groups. Proliferation and cell growth were determined by CCK-8 assay and cell invasion ability in vitro was assessed by Transwell assay. Flow cytometry was carried out for the detection of cell apoptosis. RT-qPCR results showed that the expression levels of miR-218-1-3p and miR-149 in NSCLC tissues were significantly lower than those in adjacent tissues (P<0.001). At 48 and 72 h, the cell growth of the A549 cells in the miR-218-1-3p mimic and miR-149 mimic groups was significantly lower than that in the NC and blank groups (P<0.05). The number of invasive cells in the miR-218-1-3p mimic and miR-149 mimic groups was significantly lower than that in the NC and blank groups (P<0.05). The apoptotic rate of A549 cells in the miR-218-1-3p mimic and miR-149 mimic groups was significantly higher than that in the NC and blank groups (P<0.05). In conclusion, upregulation of miR-218-1-3p and miR-149 can inhibit the proliferation, invasion and migration of A549 cells in NSCLC, thereby promoting the apoptosis of A549 cells. Thus, miR-218-1-3p and miR-149 can be used as new molecular targets for the diagnosis and treatment of NSCLC.

MicroRNAs as Guardians of the Prostate: Those Who Stand before Cancer. What Do We Really Know about the Role of microRNAs in Prostate Biology?

Prostate cancer is the second leading cause of cancer-related deaths of men in the Western world. Despite recent advancement in genomics, transcriptomics and proteomics to understand prostate cancer biology and disease progression, castration resistant metastatic prostate cancer remains a major clinical challenge and often becomes incurable. MicroRNAs (miRNAs), about 22-nucleotide-long non-coding RNAs, are a group of regulatory molecules that mainly work through post-transcriptional gene silencing via translational repression. Expression analysis studies have revealed that miRNAs are aberrantly expressed in cancers and have been recognized as regulators of prostate cancer progression. In this critical review, we provide an analysis of reported miRNA functions and conflicting studies as they relate to expression levels of specific miRNAs and prostate cancer progression; oncogenic and/or tumor suppressor roles; androgen receptor signaling; epithelial plasticity; and the current status of diagnostic and therapeutic applications. This review focuses on select miRNAs, highly expressed in normal and cancer tissue, to emphasize the current obstacles faced in utilizing miRNA data for significant impacts on prostate cancer therapeutics.

Coordinated AR and microRNA regulation in prostate cancer

The androgen receptor (AR) remains a key driver of prostate cancer (PCa) progression, even in the advanced castrate-resistant stage, where testicular androgens are absent. It is therefore of critical importance to understand the molecular mechanisms governing its activity and regulation during prostate tumourigenesis. MicroRNAs (miRs) are small ∼22 nt non-coding RNAs that regulate target gene, often through association with 3′ untranslated regions (3′UTRs) of transcripts. They display dysregulation during cancer progression, can function as oncogenes or tumour suppressors, and are increasingly recognised as targets or regulators of hormonal action. Thus, understanding factors which modulate miRs synthesis is essential. There is increasing evidence for complex and dynamic bi-directional cross-talk between the multi-step miR biogenesis cascade and the AR signalling axis in PCa. This review summarises the wealth of mechanisms by which miRs are regulated by AR, and conversely, how miRs impact AR's transcriptional activity, including that of AR splice variants. In addition, we assess the implications of the convergence of these pathways on the clinical employment of miRs as PCa biomarkers and therapeutic targets.

miR-30a inhibits androgen-independent growth of prostate cancer via targeting MYBL2, FOXD1, and SOX4

BACKGROUND

Castrate-resistant prostate cancer (CRPC) is an aggressive and lethal disease. The pathogenesis of CRPC is not fully understood and novel therapeutic targets need to be identified to improve the patients' prognosis. MicroRNA-30a (miR-30a) has been demonstrated to be a tumor suppressor in many types of solid malignancies. However, its role in androgen-independent (AI) growth of prostate cancer (PCa) received limited attention as yet.

METHODS

The clinical association of miR-30a and its potential targets with AI growth was characterized by bioinformatics analyses. Regulation of cell proliferation and colony formation rates by miR-30a were tested using PCa cell models. Xenograft models were used to measure the regulation of prostate tumor growth by miR-30a. The real-time quantitative polymerase chain reaction was used to validate whether miR-30a and its targets regulate cell cycle control genes and androgen receptor (AR)-dependent transcription. Bioinformatics tools, Western blot, and luciferase reporter assays were utilized to identify miR-30a targets.

RESULTS

Bioinformatic analysis showed that low expression of miR-30a is associated with castration resistance of PCa patients and poor outcomes. Transfection of miR-30a mimics inhibited the AI growth of PCa cells in vitro and in vivo. Upregulation of miR-30a in 22RV1 cells altered the expression of cell cycle control genes and AR-mediated transcription, while downregulation of miR-30a in LNCaP cells had the opposite effects to AR-mediated transcription. MYBL2, FOXD1, and SOX4 were identified as miR-30a targets. Downregulation of MYBL2, FOXD1, and SOX4 affected the expression of cell cycle control genes and AR-mediated transcription and suppressed the AI growth of 22RV1 cells.

CONCLUSIONS

Our results suggest that miR-30a inhibits AI growth of PCa by targeting MYBL2, FOXD1, and SOX4. They provide novel insights into developing new treatment strategies for CRPC.

Long non‑coding RNA FLVCR1‑AS1 promotes glioma cell proliferation and invasion by negatively regulating miR‑30b‑3p

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults that originates from glial cells. The prognosis of patients with high‑grade glioma is poor. It is therefore crucial to develop effective therapeutic strategies. Long non‑coding RNAs (lncRNAs) have been reported as potential inducers or suppressors of tumor progression. Previous studies have indicated that the lncRNA Feline Leukemia Virus Subgroup C Cellular Receptor 1 Antisense RNA 1 (FLVCR1‑AS1) is involved in the development and progression of gastric and lung cancer, as well as hepatocellular carcinoma and cholangiocarcinoma; however, the biological effect of FLVCR1‑AS1 in glioma is not completely understood. The aim of the present study was to investigate how FLVCR1‑AS1 modulates cell proliferation and invasion in glioma. FLVCR1‑AS1 expression was significantly upregulated in GBM tissues compared with adjacent normal brain samples, and was higher in GBM cell lines compared with normal human astrocyte cells. Furthermore, the microRNA (miR)‑30b‑3p was revealed to be a putative target of FLVCR1‑AS1, and the suppressive effects of miR‑30b‑3p on cellular proliferation and invasion were reversed following FLVCR1‑AS1‑knockdown. The results from Cell Counting Kit‑8 and Transwell assays confirmed that FLVCR1‑AS1‑knockdown inhibited GBM cell proliferation and invasion ability. In addition, FLVCR1‑AS1 was found to directly interact with miR‑30b‑3p, and a rescue experiment further established that FLVCR1‑AS1 contributed to glioma progression by inhibiting miR‑30b‑3p. The results from the present study demonstrated that FLVCR1‑AS1 may serve an oncogenic role in GBM and promote disease progression by interacting with miR‑30b‑3p. These findings suggested that FLVCR1‑AS1 may be considered as a novel therapeutic target and diagnostic biomarker for GBM.

Seminal plasma microRNAs improve diagnosis/prognosis of prostate cancer in men with moderately altered prostate-specific antigen

There is an urgent need for accurate non-invasive biomarkers for prostate cancer (PCa) diagnosis and disease risk stratification. Previous data suggests that total seminal plasma (SP) represents a source of miRNAs for screening. We have evaluated a panel of eight PCa-associated miRNAs for their potential use as PCa biomarkers in SP by analyzing their levels using RT-qPCR. Multivariate logistic regression modelling and clinical risk assessment were performed for those SP miRNAs statistically altered between PCa and non-PCa (HCt and/or BPH) groups. Our results provide evidence that altered miRNA expression in PCa tissue can also be detected in total SP. We obtained a clinically useful SP miRNA-based combined model (PSA+miR-142-3p+miR-223-3p+miR-93-5p), which improves PCa specificity of the PSA test, for, firstly, predicting the presence of malignant tumors in a sample from the total population and secondly, and more interestingly for clinicians, for predicting PCa in samples from the positive PSA screening test (PSA>4 ng/ml). Additionally, [PSA+miR-30d-5p+miR-93-5p] and [PSA+miR-30d-5p] models have been shown to be useful for predicting the disease aggressiveness with diagnostic accuracy. In conclusion, our results provide evidence that miRNAs in total SP represent a useful target for evaluation for PCa, which technically simplifies the future use of semen miRNA-based models as non-invasive biomarkers to increase the efficiency of PCa diagnosis and prognosis.

Transcriptomic and Functional Screens Reveal MicroRNAs That Modulate Prostate Cancer Metastasis

Identifying new mechanisms that underlie the complex process of metastasis is vital to combat this fatal step in prostate cancer (PCa) progression. Small non-coding RNAs are emerging as important regulators of tumor cell biology. Here we take an integrative approach to elucidate the contribution of microRNAs to metastatic progression, combining transcriptomic analysis with functional screens for migration and morphology. We developed high-content microscopy, high-throughput functional screens for migration and morphology in PCa cells using a microRNA library. RNA-Seq analysis of paired epithelial and mesenchymal PCa cells identified differential expression of 200 microRNAs. Data integration identified two microRNAs that inhibited migration, induced an epithelial-like morphology and were increased in epithelial PCa cells. An overrepresentation of the AAGUGC seed sequence was detected in all three datasets. Analysis of published datasets of patients with PCa identified microRNAs of clinical relevance. The integration of high-throughput functional and expression analyses identifies microRNAs with clinical significance that modulate metastatic behavior in PCa.

Identification of Specific Long Non-Coding Ribonucleic Acid Signatures and Regulatory Networks in Prostate Cancer in Fine-Needle Aspiration Biopsies

Prostate cancer (PCa) is one of the most common tumors in men and can be lethal, especially if left untreated. A substantial majority of PCa patients not only are diagnosed based on fine needle aspiration (FNA) biopsies, but their treatment choices are also largely driven by the pathological findings obtained with these FNA specimens. It is widely believed that lncRNAs have strong biological significance, but their specific functions and regulatory networks have not been elucidated. LncRNAs may serve as key players and regulators of PCa carcinogenesis and could be novel biomarkers of this cancer. To identify potential markers for early detection of PCa, in this study, we employed a competing endogenous RNA (ceRNA) microarray to identify differentially expressed lncRNAs (DelncRNAs) in PCa tissue and quantitative real-time PCR (qRT-PCR) analysis to validate these DelncRNAs in FNA biopsies. We demonstrated that a total of 451 lncRNAs were differentially expressed in four pairs of PCa/adjacent tissues, and upregulation of the lncRNAs RP11-33A14.1, RP11-423H2.3, and LAMTOR5-AS1 was confirmed in FNA biopsies of PCa by qRT-PCR and was consistent with the ceRNA array data. The association between the expression of the lncRNA LAMTOR5-AS1 and aggressive cancer was also investigated. Regulatory network analysis of DelncRNAs showed that the lncRNAs RP11-33A14.1 and RP11-423H2.3 targeted miR-7, miR-24-3p, and miR-30 and interacted with the RNA binding protein FUS. Knockdown of these DelncRNAs in PCa cells also demonstrated the effects of RP11-423H2.3 on miR-7/miR-24/miR-30 or LAMTOR5-AS1 on miR-942-5p/miR-542-3p via direct interaction. The results of these studies indicate that these three specific lncRNA signatures and regulatory networks might serve as risk prediction and diagnostic biomarkers for prostate cancer, even in biopsies obtained by FNA.

miR-30b-3p Inhibits Proliferation and Invasion of Hepatocellular Carcinoma Cells via Suppressing PI3K/Akt Pathway

Background: The micro-RNA miR-30b-3p has been reported to play a crucial role in several cancers. However, the biological function of miR-30b-3p in hepatocellular carcinoma (HCC) is still unknown.

Methods: RT-qPCR was employed to determine the expression of miR-30b-3p in HCC tissues and cells. The MTT assay, colony formation assay, and cell migration and invasion assay were employed to evaluate the role of miR-30b-3p in HCC cells. A dual-luciferase reporter assay was employed to verify the target of miR-30b-3p. Western blotting was employed to determine the expression of key molecular signal transducers along TRIM27-PI3K/Akt axis.

Results: Expression of miR-30b-3p was markedly decreased in HCC tissues and cells and positively correlated with higher overall survival. Moreover, miR-30b-3p overexpression significantly repressed cell viability, proliferation, migration, and invasion of HCC cells in vitro. Notably, we demonstrated that miR-30b-3p directly bound to the 3′-untranslated region of tripartite motif containing 27 (TRIM27) mRNA by downregulating the expression of TRIM27, which was demonstrated to be negatively correlated with miR-30b-3p expression. TRIM27 was demonstrated to have an oncogenic role in HCC cells by enhancing cell viability, proliferation, migration, and invasion. Finally, the miR-30-3p-TRIM27-PI3K/Akt axis was shown to play a crucial role in HCC cells in vitro.

Conclusion: Our results indicated that miR-30-3p might act as a new biomarker for the future diagnosis and treatment HCC.

Systematic discovery of the functional impact of somatic genome alterations in individual tumors through tumor-specific causal inference

Cancer is mainly caused by somatic genome alterations (SGAs). Precision oncology involves identifying and targeting tumor-specific aberrations resulting from causative SGAs. We developed a novel tumor-specific computational framework that finds the likely causative SGAs in an individual tumor and estimates their impact on oncogenic processes, which suggests the disease mechanisms that are acting in that tumor. This information can be used to guide precision oncology. We report a tumor-specific causal inference (TCI) framework, which estimates causative SGAs by modeling causal relationships between SGAs and molecular phenotypes (e.g., transcriptomic, proteomic, or metabolomic changes) within an individual tumor. We applied the TCI algorithm to tumors from The Cancer Genome Atlas (TCGA) and estimated for each tumor the SGAs that causally regulate the differentially expressed genes (DEGs) in that tumor. Overall, TCI identified 634 SGAs that are predicted to cause cancer-related DEGs in a significant number of tumors, including most of the previously known drivers and many novel candidate cancer drivers. The inferred causal relationships are statistically robust and biologically sensible, and multiple lines of experimental evidence support the predicted functional impact of both the well-known and the novel candidate drivers that are predicted by TCI. TCI provides a unified framework that integrates multiple types of SGAs and molecular phenotypes to estimate which genome perturbations are causally influencing one or more molecular/cellular phenotypes in an individual tumor. By identifying major candidate drivers and revealing their functional impact in an individual tumor, TCI sheds light on the disease mechanisms of that tumor, which can serve to advance our basic knowledge of cancer biology and to support precision oncology that provides tailored treatment of individual tumors.

Androgen receptor-modulatory microRNAs provide insight into therapy resistance and therapeutic targets in advanced prostate cancer

Androgen receptor (AR) signalling is a key prostate cancer (PC) driver, even in advanced 'castrate-resistant' disease (CRPC). To systematically identify microRNAs (miRs) modulating AR activity in lethal disease, hormone-responsive and -resistant PC cells expressing a luciferase-based AR reporter were transfected with a miR inhibitor library; 78 inhibitors significantly altered AR activity. Upon validation, miR-346, miR-361-3p and miR-197 inhibitors markedly reduced AR transcriptional activity, mRNA and protein levels, increased apoptosis, reduced proliferation, repressed EMT, and inhibited PC migration and invasion, demonstrating additive effects with AR inhibition. Corresponding miRs increased AR activity through a novel and anti-dogmatic mechanism of direct association with AR 6.9 kb 3'UTR and transcript stabilisation. In addition, miR-346 and miR-361-3p modulation altered levels of constitutively active AR variants, and inhibited variant-driven PC cell proliferation, so may contribute to persistent AR signalling in CRPC in the absence of circulating androgens. Pathway analysis of AGO-PAR-CLIP-identified miR targets revealed roles in DNA replication and repair, cell cycle, signal transduction and immune function. Silencing these targets, including tumour suppressors ARHGDIA and TAGLN2, phenocopied miR effects, demonstrating physiological relevance. MiR-346 additionally upregulated the oncogene, YWHAZ, which correlated with grade, biochemical relapse and metastasis in patients. These AR-modulatory miRs and targets correlated with AR activity in patient biopsies, and were elevated in response to long-term enzalutamide treatment of patient-derived CRPC xenografts. In summary, we identified miRs that modulate AR activity in PC and CRPC, via novel mechanisms, and may represent novel PC therapeutic targets.

MiR-30a-5p frequently downregulated in prostate cancer inhibits cell proliferation via targeting PCLAF

MicroRNAs (miRNAs) have vastly expanded our view of RNA world in intracellular signal regulating networks. Here, we functionally characterized a normally highly expressed miRNA, miR-30a-5p (MIMAT0000087), which exhibits downregulated expression profiles in prostate cancer samples. MiR-30a-5p knockdown and overexpression in PC-3 cell line alters cell proliferation supporting a tumour suppressor role. We also discovered that PCLAF is the direct target of miR-30a-5p. Notably, PC-3 cell proliferation is inhibited by miR-30a-5p/PCLAF axis. miR-30a-5p represents a novel molecule of functionally important miRNAs which may shed light on the novel therapeutic targets for prostate cancer.