Novel roles of PIWI proteins and PIWI-interacting RNAs in human health and diseases

piRNAs in leukemogenesis: Mechanisms, biomarkers, and therapeutic implications

The small, non-coding RNAs known as piwi-interacting RNAs (piRNAs) serve essential roles in gene regulation by silencing transposable elements and protecting oncogenes and tumour suppressors. The production of piRNA bioactive forms uses precursor mRNAs, which team with Piwi proteins to support genome maintenance. Accurate leukaemia regulation requires piRNAs because abnormalities in these regulatory elements contribute to disease development and drug resistance progression. Their utility in disease detection appears promising through their distinct pattern expression across different leukaemia subtypes. These piRNA markers promise to enhance early detection of diseases and provide treatment effectiveness and outcome information. Lesions examined by microarrays qRT-PCR and high-throughput sequencing provide professionals with essential tools for studying piRNA profiles and tracking their activities in leukaemia treatment. PiRNAs establish interactions with microRNAs and long non-coding RNAs through complex regulatory networks, contributing to leukaemia development. The therapeutic applications of piRNAs in leukaemia treatment have proven promising, yet additional research is necessary to understand their specific functions and improve standardized detection capability. The field requires future investigations dedicated to designing piRNA-based diagnostic instruments, researching piRNA-derived drug resistance prevention strategies, and optimizing individualized treatment plans for leukaemia patients.

piRNA/PIWI pathways and epigenetic crosstalk in human diseases: Molecular insights into HIV-1 infection and drugs of abuse

P-element-induced wimpy (PIWI)-interacting RNAs (piRNAs) and PIWI proteins have long been studied in insects and germline cells for their roles in regulating transposable elements (TEs). However, emerging evidence suggests that piRNAs and PIWI proteins also play crucial roles in human diseases beyond gametocyte protection, and these molecules are implicated in the onset and progression of various human diseases, particularly those arising in somatic cells. Notably, piRNAs and PIWI proteins are increasingly recognized for their involvement in cancers, cardiovascular diseases, neurodegenerative disorders, and viral infections, including HIV. This review first provides an overview of piRNAs/PIWIs and their interactions with TEs and primary targets. We then explore the molecular mechanisms and signaling pathways through which piRNAs and PIWIs modulate human disease processes, focusing on neurodegeneration, cancers, and HIV. Special attention is given to the role of piRNA/PIWI complexes in regulating gene transcription, translation, and post-translational modifications in the context of disease. Additionally, we address emerging research into the role of piRNAs/PIWIs in HIV- and drug abuse or substance abuse-associated neurodegenerative diseases, highlighting existing knowledge gaps. Finally, we discuss future research directions to understand better the functions of piRNAs/PIWI proteins in human health and disease.

Emerging roles of noncoding RNAs in cardiovascular pathophysiology

This review comprehensively examines the diverse roles of noncoding RNAs (ncRNAs) in the pathogenesis and treatment of cardiovascular disease (CVD), focusing on microRNA (miRNA), long noncoding RNA (lncRNA), piwi-interacting RNA (piRNA), small-interfering RNA (siRNA), circular RNA (circRNA), and vesicle-associated RNAs. These ncRNAs are integral regulators of key cellular processes, including gene expression, inflammation, and fibrosis, and they hold great potential as both diagnostic biomarkers and therapeutic targets. The review highlights novel insights into how these RNA species, particularly miRNAs, lncRNAs, and piRNAs, contribute to various CVDs such as hypertension, atherosclerosis, and myocardial infarction. In addition, it explores the emerging role of extracellular vesicles (EVs) in intercellular communication and their therapeutic potential in cardiovascular health. The review underscores the need for continued research into ncRNAs and RNA-based therapies, with a focus on advancing delivery systems and expanding personalized medicine approaches to improve cardiovascular outcomes.

Triple‑negative breast cancer cell‑derived piR‑31115 promotes the proliferation and migration of endothelial cells via METTL3‑mediated m6A modification of YAP1

Triple‑negative breast cancer (TNBC), a highly malignant breast cancer subtype with a pronounced metastatic propensity, forms the focus of the present investigation. MDA‑MB‑231, a prevalently utilized TNBC cell line in cancer research, was employed. In accordance with the tumour angiogenesis theory, cancer cells are capable of instigating angiogenesis and the formation of a novel vascular system within the tumour microenvironment, which subsequently sustains malignant proliferation and metastasis. Consequently, impeding the growth of tumour blood vessels holds substantial significance in suppressing TNBC metastasis. Piwi‑interacting RNAs (piRNAs), a category of endogenous non‑coding RNAs, have been demonstrated to modulate cancer progression. However, studies regarding the role of piRNAs in regulating angiogenesis within cancer cells are relatively scant. In the present study, via cell co‑culture experiments, it was revealed that piR‑31115 (a kind of piRNA) in MDA‑MB‑231 cells notably enhanced the recruitment of a human microvascular endothelial cell line (HMEC‑1). Moreover, the conditioned medium (CM, which was obtained from MDA‑MB‑231 cells via a specific culturing methodology and was employed for the subsequent treatment of HMEC‑1 cells to explore its impacts on the biological behaviors such as the proliferation and migration of HMEC‑1 cells) derived from MDA‑MB‑231 cells with upregulated piR‑31115 expression stimulated the proliferation and migration of HMEC‑1 cells. These findings suggest that piR‑31115 in MDA‑MB‑231 cells may play a pivotal role in modulating tumour angiogenesis. Further studies disclosed that the CM from MDA‑MB‑231 cells augmented the N6‑methyladenosine (m6A) RNA modification level via METTL3 in HMEC‑1 cells. Transcriptome sequencing revealed that METTL3 functions as an m6A writer protein for Yes‑associated protein 1 (YAP1), which exerts a positive influence on promoting the proliferation and migration of HMEC‑1 cells. Concurrently, the IGF2BP plays a crucial role in stabilizing YAP1 protein expression. Collectively, the present findings identified a signalling pathway through which MDA‑MB‑231 cells induce HMEC‑1 cell proliferation and migration by regulating m6A RNA methylation.

Development and validation of a novel artificial intelligence algorithm for precise prediction the postoperative prognosis of esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a highly aggressive malignancy, and current postoperative prognostic assessment methods remain unsatisfactory, underlining the urgent to develop a reliable approach for precision medicine. Given the similarities with gametogenesis, cancer/testis genes (CTGs) are acknowledged for regulation unrestrained multiplication and immune microenvironment during oncogenic processes. These processes are associated with advanced disease and poorer prognosis, indicating that CTGs could serve as ideal prognostic biomarkers in ESCC. The purpose of this study is to develop a novel clinically prognostic prediction system to facilitate the individualized postoperative care.

METHODS

We conducted LASSO regression analysis of protein-coding CTGs and clinical characteristics from 119 pathologically confirmed ESCC patients to recognize powerful predictive variables. We employed nine supervised machine learning classifiers and integrated best predictive machine learning classifiers by weighted voting method to construct an ensemble model called PPMESCC. Additionally, functional assay was conducted to examine the potential effect of top-ranking CTG HENMT1 in ESCC.

RESULTS

LASSO regression identified five CTGs and TNM stage as optimized prognostic features. Six machine learning classifiers were integrated to construct an ensemble model, PPMESCC, which exhibited outstanding performance in ESCC prediction. The AUC for PPMESCC was 0.9828 (95% confidence interval: 0.9608 to 0.9926), with an accuracy of 98.32% (95% CI: 96.64-99.16%) in the discovery cohort and 0.9057 (95% CI: 0.8897 to 0.9583) of AUC with an accuracy of 90% (95% CI: 89.08-93.28%) in validation cohort. In addition, the top-ranking CTG HENMT1 encodes 2'-O-methyltransferase of piRNAs that was confirmed positively correlated with the proliferation capacity of ESCC cells. Then we systematically screen piRNAs associated with esophageal carcinoma based on GWAS, eQTL-piRNA, and i2OM databases, and successfully discovered 8 piRNAs potentially regulated by HENMT1.

CONCLUSION

The study highlights the clinical utility of PPMESCC algorithm in prognostic prediction that may facilitate to establish the personalized screening and management strategies for postoperative ESCC patients.

Sex and tissue-specificity of piRNA regulation in adult mice following perinatal lead (Pb) exposure

Lead (Pb) is a neurotoxicant with early life exposure linked to long-term health effects. Piwi-interacting RNAs (piRNAs) are small non-coding RNAs that associate with PIWIL proteins to induce DNA methylation. It remains unknown whether Pb exposure influences piRNA expression. This study evaluated how perinatal Pb exposure (32 ppm in drinking water) impacts piRNA expression in adult mice and assessed piRNA dysregulation as a potential mechanism for Pb-induced toxicity. Pb exposure effects on piRNA expression and associated gene repression in the germline (testis/ovary) and soma (liver and brain) were evaluated. Small RNA sequencing was used to determine differentially expressed piRNAs, RT-qPCR to examine piRNA target expression, and whole genome bisulfite sequencing to evaluate target DNA methylation status. Three piRNAs (mmpiR-1500602, mmpiR-0201406, and mmpiR-0200026) were significant after multiple testing correction (all downregulated in the male Pb-exposed brain in comparison to control; FDR < 0.05). Within piOxiDB, TAO Kinase 3 was identified as a downstream mRNA target for one of the three Pb-sensitive piRNA. The Pb-exposed male brain exhibited increased Taok3 expression (p < 0.05) and decreased DNA methylation (FDR < 0.01). The results demonstrate that perinatal Pb exposure stably influences longitudinal piRNA expression in a tissue- and sex-specific manner, potentially via DNA methylation-directed mechanisms.

Correlating tissue and plasma‑specific piRNA changes to predict their possible role in pancreatic malignancy and chronic inflammation

The aggressiveness of pancreatic ductal adenocarcinoma is primarily due to lack of effective early detection biomarkers. Circulating non-coding RNAs serve as diagnostic or prognostic biomarkers in multiple types of cancer. Comparison of their expression between diseased tissue and relevant body fluids such as saliva, urine, bile, pancreatic juice, blood etc. may reveal mechanistic involvement of common non-coding RNAs. piwi-interacting RNAs (piRNAs) are a class of non-coding RNAs. The aim of the present study was to investigate plasma and tumour tissue piRNA changes in patients with pancreatic cancer (PC) and explore the possible role in tumorigenesis and pancreatic inflammation. Sequencing of circulating plasma small RNAs from patients with PC and chronic pancreatitis (CP) was performed and differentially expressed piRNAs were compared with those in tissues. Subsequent search for target genes for those piRNAs was performed followed by pathway and cluster analysis. A total of 36 piRNAs were shown to be deregulated in pancreatic tumour tissue and alteration of 11 piRNAs was detected in plasma of patients with PC. piRNAs hsa-piR-23246, hsa-piR-32858 and hsa-piR-9137 may serve a key role in PC development as their expression was correlated in both plasma and tumour tissue. Key piRNA-target interactions interfering with key biological pathways were also characterized. A total of 19 deregulated piRNAs in plasma samples of patients with CP was identified; these targeted genes responsible for chronic inflammation. Therefore, the present study provides a comprehensive description of piRNA alteration in pancreatic malignancy and inflammation; these may be explored for biomarker potential in future.

Small non-coding RNAs as diagnostic, prognostic and predictive biomarkers of gynecological cancers: an update

INTRODUCTION

Non-coding RNAs (ncRNAs) comprise a heterogeneous cluster of RNA molecules. Emerging evidence suggests their involvement in various aspects of tumorigenesis, particularly in gynecological malignancies. Notably, ncRNAs have been implicated as mediators within tumor signaling pathways, exerting their influence through interactions with RNA or proteins. These findings further highlight the hypothesis that ncRNAs constitute therapeutic targets and point out their clinical potential as stratification biomarkers.

AREAS COVERED

The review outlines the use of small ncRNAs, including miRNAs, tRNA-derived small RNAs, PIWI-interacting RNAs and circular RNAs, for diagnostic, prognostic, and predictive purposes in gynecological cancers. It aims to increase our knowledge of their functions in tumor biology and their translation into clinical practice.

EXPERT OPINION

By leveraging interdisciplinary collaborations, scientists can decipher the riddle of small ncRNA biomarkers as diagnostic, prognostic and predictive biomarkers of gynecological tumors. Integrating small ncRNA-based assays into clinical practice will allow clinicians to provide cure plans for each patient, reducing the likelihood of adverse responses. Nevertheless, addressing challenges such as standardizing experimental methodologies and refining diagnostic assays is imperative for advancing small ncRNA research in gynecological cancer.

Advances in different adult stem cell-derived exosomal non-coding RNAs for the treatment of neurological disorders: a narrative review

Neurological disorders are being increasingly recognized as major causes of death and disability around the world. Neurological disorders refer to a broad range of medical conditions that affect the brain and spinal cord. These disorders can have various causes, including genetic factors, infections, trauma, autoimmune reactions, or neurodegenerative processes. Each disorder has its own unique symptoms, progression, and treatment options. Optimal communication between interneurons and neuron-glia cells within the homeostatic microenvironment is of paramount importance. Within this microenvironment, exosomes play a significant role in promoting intercellular communication by transferring a diverse cargo of contents, including proteins, lipids, and non-coding RNAs (ncRNAs). Partially, nervous system homeostasis is preserved by various stem cell-derived exosomal ncRNAs, which include circular RNAs (circRNAs), long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and PIWI-interacting RNAs (piRNAs). The diversity of these exosomal ncRNAs suggests their potential to influence multiple pathways and cellular processes within the nervous system. Stem cell-derived exosomes and their ncRNA contents have been investigated for potential therapeutic uses in neurological disorders, owing to their demonstrated capabilities in neuroprotection, neuroregeneration, and modulation of disease-related pathways. The ability of stem cell-derived exosomes to cross the blood-brain barrier makes them a promising delivery vehicle for therapeutic ncRNAs. This review aims to summarize the current understanding of different stem cell-derived exosomal ncRNAs and their therapeutic potential and clinical applications.

Saliva, a molecular reflection of the human body? Implications for diagnosis and treatment

For many diseases, and cancer in particular, early diagnosis allows a wider range of therapies and a better disease management. This has led to improvements in diagnostic procedures, most often based on tissue biopsies or blood samples. Other biological fluids have been used to diagnose disease, and among them saliva offers a number of advantages because it can be collected non-invasively from large populations at relatively low cost. To what extent might saliva content reveal the presence of a tumour located at a distance from the oral cavity and the molecular information obtained from saliva be used to establish a diagnosis are current questions. This review focuses primarily on the content of saliva and shows how it potentially offers a source of diagnosis, possibly at an early stage, for pathologies such as cancers or endometriosis.

PIWI-Interacting RNAs: A Pivotal Regulator in Neurological Development and Disease

PIWI-interacting RNAs (piRNAs), a class of small non-coding RNAs (sncRNAs) with 24-32 nucleotides (nt), were initially identified in the reproductive system. Unlike microRNAs (miRNAs) or small interfering RNAs (siRNAs), piRNAs normally guide P-element-induced wimpy testis protein (PIWI) families to slice extensively complementary transposon transcripts without the seed pairing. Numerous studies have shown that piRNAs are abundantly expressed in the brain, and many of them are aberrantly regulated in central neural system (CNS) disorders. However, the role of piRNAs in the related developmental and pathological processes is unclear. The elucidation of piRNAs/PIWI would greatly improve the understanding of CNS development and ultimately lead to novel strategies to treat neural diseases. In this review, we summarized the relevant structure, properties, and databases of piRNAs and their functional roles in neural development and degenerative disorders. We hope that future studies of these piRNAs will facilitate the development of RNA-based therapeutics for CNS disorders.

Untangling the gordian knot: The intertwining interactions between developmental hormone signaling and epigenetic mechanisms in insects

Hormones control developmental and physiological processes, often by regulating the expression of multiple genes simultaneously or sequentially. Crosstalk between hormones and epigenetics is pivotal to dynamically coordinate this process. Hormonal signals can guide the addition and removal of epigenetic marks, steering gene expression. Conversely, DNA methylation, histone modifications and non-coding RNAs can modulate regional chromatin structure and accessibility and regulate the expression of numerous (hormone-related) genes. Here, we provide a review of the interplay between the classical insect hormones, ecdysteroids and juvenile hormones, and epigenetics. We summarize the mode-of-action and roles of these hormones in post-embryonic development, and provide a general overview of epigenetic mechanisms. We then highlight recent advances on the interactions between these hormonal pathways and epigenetics, and their involvement in development. Furthermore, we give an overview of several 'omics techniques employed in the field. Finally, we discuss which questions remain unanswered and possible avenues for future research.