miRNAs in prostate cancer: Intercellular and extracellular communications

Identification and Characterization of Differentially Expressed MicroRNAs in Benign Prostatic Hyperplasia

OBJECTIVES

The primary aim of this research is to identify and describe the distinct patterns of microRNAs (miRNAs) that are unusually expressed in benign prostatic hyperplasia (BPH) tissues compared to normal prostatic tissues.

MATERIALS AND METHODS

The investigation began with the collection of three samples each from normal prostatic and BPH tissues. These samples underwent miRNA microarray analysis using the Agilent platform. Following the preliminary screening, a larger sample set, comprising five normal prostatic tissues and 36 BPH tissues, was subjected to qRT-PCR to confirm the differential expression of the miRNAs initially identified.

RESULTS

The microarray analysis revealed that only miR-126-3p and miR-4672 exhibited an expression profile marked by both a fold change > 1.5 and p < 0.05, indicating significant downregulation in BPH tissues. MiR-145-3p and miR-143-3p also showed downregulation with fold changes greater than 1.5; however, these changes did not reach statistical significance as their p-values were above 0.05. Further attempts to validate these findings through qRT-PCR did not confirm any notable dysregulation among the four miRNAs studied; the variations in their expression levels between normal and BPH tissues did not achieve statistical significance, with p-values exceeding 0.1. From the data accrued, it can be inferred that the roles of miR-4672, miR-126-3p, miR-145-3p, and miR-143-3p in BPH development continue to be an unresolved mystery, and the need for further investigation.

CONCLUSIONS

This preliminary investigation establishes a foundation for subsequent studies aimed at elucidating the regulatory mechanisms underlying BPH. However, these results highlight the need for further investigation employing a more extensive sample size and comprehensive clinical data to elucidate their potential roles in the pathogenesis of BPH.

MiRNAs and tempol therapeutic potential in prostate cancer: a preclinical approach

This study investigated tempol action on genes and miRNAs related to NFκB pathway in androgen dependent or independent cell lines and in TRAMP model in the early and late-stages of cancer progression. A bioinformatic search was conducted to select the miRNAs to be measured based on the genes of interest from NFκB pathway. The miR-let-7c-5p, miR-26a-5p and miR-155-5p and five target genes (BCL2, BCL2L1, RELA, TNF, PTGS2) were chosen for RT-PCR and gene enrichment analyses. In vitro, PC-3 and LNCaP cells were exposed, respectively, to 1.0 or 2.0 mM of tempol during 48 h. In vivo, five experimental groups were evaluated regarding tempol effects in the early (CT12 and TPL12 groups) and late-stages (CT20, TPL20-I and TLP20-II) of PCa development. TPL groups were treated with 50 mg/kg or 100 mg/kg of tempol. The ventral lobe of the prostate and the plasma was collected. Tempol treatment increased miRs expression in PC-3 and LNCaP. For both cell lines, tempol decreased RELA expression. In TRAMP model, tempol increased miRNA expression in prostate for all treated groups. Tempol upregulated the miRNA expressions related to the NFκB pathway in the prostate tissue and human tumor cell lines. Their increase is mainly linked to increased cell death and delayed CaP aggressivenes. Thus, tempol's capacity for miRNA-mediated gene silencing to decrease tissue proliferation and cell survival processes is part of its tissue mechanics.

Role of non-coding RNA in lineage plasticity of prostate cancer

The treatment of prostate cancer (PCa) has made great progress in recent years, but treatment resistance always develops and can even lead to fatal disease. Exploring the mechanism of drug resistance is of great significance for improving treatment outcomes and developing biomarkers with predictive value. It is increasingly recognized that mechanism of drug resistance in advanced PCa is related to lineage plasticity and tissue differentiation. Specifically, one of the mechanisms by which castration-resistant prostate cancer (CRPC) cells acquire drug resistance and transform into neuroendocrine prostate cancer (NEPC) cells is lineage plasticity. NEPC is a subtype of PCa that is highly aggressive and lethal, with a median survival of only 7 months. With the development of high-throughput RNA sequencing technology, more and more non-coding RNAs have been identified, which play important roles in different diseases through different mechanisms. Several ncRNAs have shown great potential in PCa lineage plasticity and as biomarkers. In the review, the role of ncRNA in PCa lineage plasticity and its use as biomarkers were reviewed.

Extracellular vesicles as novel uro-oncology biomarkers: insights toward clinical applications

PURPOSE OF REVIEW

We discussed the challenges associated with the clinical application of extracellular vesicles and summarized their potential impact on oncological clinical practice in urology.

RECENT FINDINGS

Despite extensive research on extracellular vesicles, their clinical applications remain limited; this is likely to be because of small study cohorts, a lack of large-scale analyses, and the impact of variable extraction and storage methods on analysis outcomes. However, promising results have emerged from clinical trials targeting urinary extracellular vesicles in prostate cancer using ExoDx Prostate Test. The ExoDx Prostate Test has demonstrated its efficacy in diagnosing prostate cancer in previous studies and is the only FDA-approved kit for this purpose. Moreover, recent trials have investigated the use of the ExoDx Prostate Test to determine the optimal timing for biopsies in prostate cancer patients undergoing active surveillance.

SUMMARY

We summarized recent studies on the potential of extracellular vesicles in the management of urological cancers. Particularly, the diagnosis of prostate cancer using the ExoDx Prostate Test has yielded positive results in several clinical trials. Additionally, while there are other studies suggesting its efficacy, most of these are based on retrospective analyses. These findings warrant further large-scale studies to optimize extracellular vesicle-based diagnostic and monitoring strategies. Although further research is required, extracellular vesicles would be attractive for early detection and surveillance.

Identification of the Oncogenic Role of the Circ_0001326/miR-577/VDAC1 Cascade in Prostate Cancer

Prostate cancer (PCa) is one of the leading causes of cancer death among men worldwide. Circular RNAs (circRNAs) have been implicated in the pathogenesis of PCa. However, the precise action of circ_0001326 in PCa malignant progression is still unknown. The levels of circ_0001326, miR-577 and voltage dependent anion channel 1 (VDAC1) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell proliferation, colony formation, apoptosis, migration and invasion were evaluated by the Cell Counting Kit-8 (CCK-8), EdU staining, colony formation, flow cytometry, wound-healing and transwell assays, respectively. Targeted relationships among circ_0001326, miR-577 and VDAC1 were confirmed by dual-luciferase reporter assays. Xenograft experiments were performed to detect the role of circ_0001326 in tumor growth. Our data revealed that circ_0001326 was overexpressed in PCa tissues and cells. Circ_0001326 depletion repressed PCa cell proliferation, migration, and invasion and enhanced apoptosis in vitro, as well as hampered tumor growth in vivo. Mechanistically, circ_0001326 directly targeted miR-577, and VDAC1 was directly targeted and suppressed by miR-577. Moreover, the effects of circ_0001326 knockdown on PCa cell functional behaviors were mediated by miR-577. VDAC1 silencing phenocopied miR-577 overexpression in regulating PCa cell functional behaviors in vitro. Furthermore, circ_0001326 regulated VDAC1 expression through sponging miR-577. Our findings showed that circ_0001326 regulated PCa cell functional behaviors at least partly through targeting the miR-577/VDAC1 axis.

Targeting the autophagy-miRNA axis in prostate cancer: toward novel diagnostic and therapeutic strategies

Since prostate cancer is one of the leading causes of cancer-related death, a better understanding of the molecular pathways guiding its development is imperative. A key factor in prostate cancer is autophagy, a cellular mechanism that affects both cell survival and death. Autophagy is essential in maintaining cellular homeostasis. Autophagy is a physiological mechanism wherein redundant or malfunctioning cellular constituents are broken down and recycled. It is essential for preserving cellular homeostasis and is implicated in several physiological and pathological conditions, including cancer. Autophagy has been linked to metastasis, tumor development, and treatment resistance in prostate cancer. The deregulation of miRNAs related to autophagy appears to be a crucial element in the etiology of prostate cancer. These miRNAs influence the destiny of cancer cells by finely regulating autophagic mechanisms. Numerous investigations have emphasized the dual function of specific miRNAs in prostate cancer, which alter autophagy-related pathways to function as either tumor suppressors or oncogenes. Notably, miRNAs have been linked to the control of autophagy and the proliferation, apoptosis, and migration of prostate cancer cells. To create customized therapy approaches, it is imperative to comprehend the dynamic interplay between autophagy and miRNAs in prostate cancer. The identification of key miRNAs provides potential diagnostic and prognostic markers. Unraveling the complex network of lncRNAs, like PCA3, also expands the repertoire of molecular targets for therapeutic interventions. This review explores the intricate interplay between autophagy and miRNAs in prostate cancer, focusing on their regulatory roles in cellular processes ranging from survival to programmed cell death.

Recent progress in microRNA research for prostate cancer

In recent years, prostate cancer (PCa) has seen an increasing prevalence, particularly among middle-aged and older men, positioning it as a significant health concern. Current PCa screening predominantly utilizes prostate-specific antigen (PSA) testing, digital rectal examination (DRE), and the Gleason scoring system. However, these diagnostic methods can sometimes be imprecise. Research has identified that specific microRNAs (miRNAs) exhibit altered expression levels in PCa patients, suggesting their potential as biomarkers for both diagnosis and prognosis. Furthermore, advancements in integrating miRNAs with traditional Chinese medicine (TCM) have shown promising results in PCa treatment, potentially serving as micro-markers for TCM syndrome differentiation and treatment effectiveness. Recent developments in anti-cancer therapies that target miRNAs have also been implemented in clinical settings, laying the groundwork for personalized and precise treatment strategies for PCa. This review aims to summarize the expression patterns of miRNAs in PCa patients and explore their roles in the diagnosis, treatment, and prognosis of the disease.

Prostate cancer and liquid biopsies: Clinical applications and challenges

Liquid biopsy has emerged as a valuable and minimally invasive tool for real-time detection of clinically actionable abnormalities across various cancer types. Its applicability is particularly compelling in the realm of prostate cancer, where novel therapeutic agents, including those targeting DNA repair systems, are under development. Despite these advancements, challenges persist in effectively screening for prostate cancer, enhancing risk stratification, and determining optimal approaches for treating advanced disease. Consequently, there is a pressing need for improved biomarkers to aid clinicians in decision-making within these contexts. Cell-free DNA and extracellular vesicle analysis have demonstrated promise in diagnosis, prognostication, assessment of treatment responses, and identification of emerging mechanisms of resistance. Nevertheless, obstacles must be addressed before liquid biopsies can be integrated into routine clinical practice. These challenges encompass preanalytical considerations such as sample collection and storage, methods of extracellular vesicle isolation and enrichment, and the need for enhanced interpretation of generated sequencing data. This review provides a comprehensive overview of current clinical opportunities in managing prostate cancer through blood-based liquid biopsy, highlighting the progress made, and acknowledging the challenges that remain. Additionally, we discuss the next steps required for the effective implementation of liquid biopsies in guiding personalized treatment strategies for prostate cancer.

Circ_0082878 contributes to prostate cancer progression via the miR-455-3p/WTAP axis

Circ_0082878 has been found to be strongly expressed in prostate cancer (PCa). However, its roles and potential mechanism in PCa have not been investigated. This study aims to clarify it. RNase R digestion method was adopted for verifying the circular structure of circ_0082878. RT-qPCR assay is aimed to detect the expressions of circ_0082878, miR-455-3p and WTAP in PCa tissues and cells. For identifying cell proliferation, migration and invasion abilities, CCK-8 and transwell assay were used. To show the correlation between miR-455-3p and WTAP or circ_0082878, the luciferase reporter gene, RNA RIP and RNA pull-down experiments were employed. We employed western blot to detect protein level of WTAP. In addition, the impact of circ_0082878 on PCa cells in vivo was also studied. It was found that circ_0082878 and WTAP were highly expressed in PCa tissues and cells, whereas miR-455-3p was lowly expressed. Inhibition of circ_0082878 restrained the growth of PCa in vitro and in vivo. Regarding mechanism, miR-455-3p was the target of circ_0082878, and WTAP was the target of miR-455-3p. Circ_0082878 could downregulate the level of miR-455-3p, and inhibiting of miR-455-3p expression could partially eliminate the inhibitory impact of low expression of circ_0082878 on the proliferation and migration of PCa cells. Additionally, over-expression of miR-455-3p resulted in the reduced level of WTAP, and WTAP over-expression counteracted the tumor suppressive impact of miR-455-3p in PCa cells. Moreover, the obtained findings indicated that circ_0082878 may exert tumor-promoting activity in PCa via sponging miR-455-3p and then upregulating WTAP. This indicates that the circ_0082878/miR-455-3p/WTAP axis can probably become the possible therapeutic target for PCa.

METTL3-mediated m6A modification of pri-miR-148a-3p affects prostate cancer progression by regulating TXNIP

OBJECTIVE

Prostate cancer (PCa) severely affects men's health worldwide. The mechanism of methyltransferase-like 3 (METTL3) in affecting PCa development by regulating miR-148a-3p expression via N6-methyladenosine (m6A) modification was investigated.

METHODS

METTL3, miR-148a-3p, and thioredoxin interacting protein (TXNIP) levels were determined using RT-qPCR and Western blotting. The m6A modification level of miR-148a-3p was observed by Me-RIP assay. Bioinformatics website predicted miR-148a-3p and TXNIP levels in PCa and their correlation, and the binding site between them was verified by dual-luciferase assay. The proliferation, migration, invasion, and apoptosis of PCa cells were examined by CCK-8 assay, Transwell assay, and flow cytometry. A transplanted tumor model was established in nude mice to observe the tumor growth ability, followed by determination of TXNIP levels in tumor tissues by immunohistochemistry.

RESULTS

METTL3 interference restrained the proliferation, migration, and invasion and promoted apoptosis of PCa cells. METTL3 up-regulated miR-148a-3p by promoting the m6A modification of pri-miR-148a-3p in PCa cells. miR-148a-3p overexpression nullified the inhibitory actions of silencing METTL3 on PCa cell growth. miR-148a-3p facilitated PCa cell growth by silencing TXNIP. METTL3 interference inhibited tumor growth by down-regulating miR-148a-3p and up-regulating TXNIP.

CONCLUSION

METTL3 promoted miR-148a-3p by mediating the m6A modification of pri-miR-148a-3p, thereby targeting TXNIP, interfering with METTL3 to inhibit the proliferation, migration and invasion of PCa cells, promote apoptosis, and inhibit tumor growth in nude mice.

Epigenetic Modifications in Prostate Cancer Metastasis and Microenvironment

The gradual evolution of prostate tissue from benign tumor to malignant lesion or distant metastasis is driven by intracellular epigenetic changes and the tumor microenvironment remodeling. With the continuous study of epigenetic modifications, these tumor-driving forces are being discovered and are providing new treatments for cancer. Here we introduce the classification of epigenetic modification and highlight the role of epigenetic modification in tumor remodeling and communication of the tumor microenvironment.