Sources and Functions of Extracellular Small RNAs in Human Circulation

Various biotypes of endogenous small RNAs (sRNAs) have been detected in human circulation, including microRNAs, transfer RNAs, ribosomal RNA, and yRNA fragments. These extracellular sRNAs (ex-sRNAs) are packaged and secreted by many different cell types. Ex-sRNAs exhibit differences in abundance in several disease states and have, therefore, been proposed for use as effective biomarkers. Furthermore, exosome-borne ex-sRNAs have been reported to elicit physiological responses in acceptor cells. Exogenous ex-sRNAs derived from diet (most prominently from plants) and microorganisms have also been reported in human blood. Essential issues that remain to be conclusively addressed concern the (a) presence and sources of exogenous ex-sRNAs in human bodily fluids, (b) detection and measurement of ex-sRNAs in human circulation, (c) selectivity of ex-sRNA export and import, (d) sensitivity and specificity of ex-sRNA delivery to cellular targets, and (e) cell-, tissue-, organ-, and organism-wide impacts of ex-sRNA-mediated cell-to-cell communication. We survey the present state of knowledge of most of these issues in this review.

Circulating small noncoding RNAs as biomarkers of aging

Small noncoding RNAs (sncRNAs) mediate a variety of cellular functions in animals and plants. Deep sequencing has made it possible to obtain highly detailed information on the types and abundance of sncRNAs in biological specimens, leading to the discovery that sncRNAs circulate in the blood of humans and mammals. The most abundant types of circulating sncRNAs are microRNAs (miRNAs), 5' transfer RNA (tRNA) halves, and YRNA fragments, with minute amounts of other types that may nevertheless be significant. Of the more abundant circulating sncRNAs only miRNAs have well described functions, but characteristics of the others suggest specific processing and secretion as complexes that protect the RNA from degradation. The properties of circulating sncRNAs are consistent with their serving as signaling molecules, and investigations of circulating miRNAs support the view that they can enter cells and regulate cellular functions. The serum levels of specific sncRNAs change markedly with age, and these changes can be mitigated by calorie restriction (CR), indicating that levels are under physiologic control. The ability of circulating sncRNAs to transmit functions between cells and to regulate a broad spectrum of cellular functions, and the changes in their levels with age, implicate them in the manifestations of aging. Our understanding of the functions of circulating sncRNA, particularly in relation to aging, is currently at a very early stage; results to date suggest that more extensive investigation will yield important insights into mechanisms of aging.

Large-scale analysis of small RNAs derived from traditional Chinese herbs in human tissues

Plant-derived microRNAs have recently been reported to function in human blood and tissues. Controversy was immediately raised due to possible contamination and the lack of large sample sizes. Here, we report thousands of unique small RNAs derived from traditional Chinese medicine (TCM) herbs found in human blood cells and mouse lung tissues using a large-scale analysis. We extracted small RNAs from decoctions of 10 TCM plants (Ban Zhi Lian, Chai Hu, Chuan Xin Lian, Di Ding Zi Jin, Huang Qin, Jin Yin Hua, Lian Qiao, Pu Gong Ying, Xia Ku Cao, and Yu Xing Cao) and obtained millions of RNA sequences from each herb. We also obtained RNA-Seq data from the blood cells of humans who consumed herbal decoctions and from the lung tissues of mice administered RNAs from herbal decoctions via oral gavage. We identified thousands of unique small RNA sequences in human blood cells and mouse lung tissues. Some of these identified small RNAs from Chuan Xin Lian and Hong Jing Tian could be mapped to the genomes of the herbs, confirming their TCM plant origin. Small RNAs derived from herbs regulate mammalian gene expression in a sequence-specific manner, and thus are a superior novel class of herbal drug components that hold great potential as oral gene-targeted therapeutics, highlighting the important role of herbgenomics in their development.

Discovery and Validation of Circulating Biomarkers of Colorectal Adenoma by High-Depth Small RNA Sequencing

Purpose: Colorectal cancer is the third most common cancer worldwide, causing approximately 700,000 deaths each year. The majority of colorectal cancers begin as adenomas. Definitive screening for colorectal adenomas is currently accomplished through colonoscopy but, owing largely to costs and invasiveness, is typically limited to patient groups at higher risk by virtue of age or family history. We sought to determine if blood-based small RNA markers could detect colorectal adenoma.Experimental Design: We applied high-depth small RNA sequencing to plasma from a large (n = 189) cohort of patients, balanced for age, sex, and ancestry. Our analytical methodology allowed for the detection of both microRNAs and other small RNA species. We replicated sequencing results by qPCR on plasma samples from an independent cohort (n = 140).Results: We found several small RNA species with significant associations to colorectal adenoma, including both microRNAs and non-microRNA small RNAs. These associations were robust to correction for patient covariates, including age. Among the adenoma-associated small RNAs, two, a miR-335-5p isoform and an un-annotated small RNA, were validated by qPCR in an independent cohort. A classifier trained on measures of these two RNAs in the discovery cohort yields an AUC of 0.755 (0.775 with age) for adenoma detection in the independent cohort. This classifier accurately detects adenomas in patients under 50 and is robust to sex or ancestry.Conclusions: Circulating small RNAs (including but not limited to miRNAs) discovered by sequencing and validated by qPCR identify patients with colorectal adenomas effectively. Clin Cancer Res; 24(9); 2092-9. ©2018 AACR.

Comparative analysis of small RNAs released by the filarial nematode Litomosoides sigmodontis in vitro and in vivo

Background

The release of small non-coding RNAs (sRNAs) has been reported in parasitic nematodes, trematodes and cestodes of medical and veterinary importance. However, little is known regarding the diversity and composition of sRNAs released by different lifecycle stages and the portion of sRNAs that persist in host tissues during filarial infection. This information is relevant to understanding potential roles of sRNAs in parasite-to-host communication, as well as to inform on the location within the host and time point at which they can be detected.

Methodology and principal findings

We have used small RNA (sRNA) sequencing analysis to identify sRNAs in replicate samples of the excretory-secretory (ES) products of developmental stages of the filarial nematode Litomosoides sigmodontis in vitro and compare this to the parasite-derived sRNA detected in host tissues. We show that all L. sigmodontis developmental stages release RNAs in vitro, including ribosomal RNA fragments, 5’-derived tRNA fragments (5’-tRFs) and, to a lesser extent, microRNAs (miRNAs). The gravid adult females (gAF) produce the largest diversity and abundance of miRNAs in the ES compared to the adult males or microfilariae. Analysis of sRNAs detected in serum and macrophages from infected animals reveals that parasite miRNAs are preferentially detected in vivo, compared to their low levels in the ES products, and identifies miR-92-3p and miR-71-5p as L. sigmodontis miRNAs that are stably detected in host cells in vivo.

Conclusions

Our results suggest that gravid adult female worms secrete the largest diversity of extracellular sRNAs compared to adult males or microfilariae. We further show differences in the parasite sRNA biotype distribution detected in vitro versus in vivo. We identify macrophages as one reservoir for parasite sRNA during infection, and confirm the presence of parasite miRNAs and tRNAs in host serum during patent infection.

Lymphatic and visceral filariasis, as well as loiasis and onchocerciasis, are parasitic infections caused by filarial nematodes that can cause extensive and diverse clinical manifestations, including edemas of the lower limbs and visual impairment. These parasites successfully maintain a crosstalk with the immune system of their host and one potential mediator of this communication is extracellular small non-coding RNAs (sRNAs) released by the parasite. However, little is known of the mechanisms of sRNA export, how the exported sRNAs differ between lifecycle stages, and how the parasite microenvironment (e.g. in vitro vs. in vivo) contributes to the composition of sRNAs that can be detected. In this report, we show that all the developmental stages of the filarial parasite Litomosoides sigmodontis release sRNAs, which include tRNA fragments and miRNAs, in vitro. A subset of the miRNAs are differentially represented in the ES products between adult stages (males and gravid females) and larval stages (microfilariae) in vitro, however all of the miRNAs detected in serum or macrophages in vivo are present in the ES from all life stages. We show that the parasite-derived miRNAs are protected from degradation in vitro and are stable in vivo, as they are readily detectable in the serum of infected jirds. Several parasite miRNAs are also detected within macrophages purified from infected hosts, consistent with parasite RNAs having a yet unidentified functional role in host cells.

Circulating Non-Coding RNAs as a Signature of Autism Spectrum Disorder Symptomatology

Autism spectrum disorder (ASD) is a multifaced neurodevelopmental disorder that becomes apparent during early childhood development. The complexity of ASD makes clinically diagnosing the condition difficult. Consequently, by identifying the biomarkers associated with ASD severity and combining them with clinical diagnosis, one may better factionalize within the spectrum and devise more targeted therapeutic strategies. Currently, there are no reliable biomarkers that can be used for precise ASD diagnosis. Consequently, our pilot experimental cohort was subdivided into three groups: healthy controls, individuals those that express severe symptoms of ASD, and individuals that exhibit mild symptoms of ASD. Using next-generation sequencing, we were able to identify several circulating non-coding RNAs (cir-ncRNAs) in plasma. To the best of our knowledge, this study is the first to show that miRNAs, piRNAs, snoRNAs, Y-RNAs, tRNAs, and lncRNAs are stably expressed in plasma. Our data identify cir-ncRNAs that are specific to ASD. Furthermore, several of the identified cir-ncRNAs were explicitly associated with either the severe or mild groups. Hence, our findings suggest that cir-ncRNAs have the potential to be utilized as objective diagnostic biomarkers and clinical targets.

Detection of mycobacterial small RNA in the bacterial culture supernatant and plasma of patients with active tuberculosis

Bacterial small RNA (sRNA) has been shown to play an important role in control of bacteria virulence, stress response and physiological metabolism by post-transcriptional regulation of gene expression. However, there were few reports about bacterial sRNA as a biomarker of infection. To test the potential role of sRNA in indicating infection of Mycobacterium tuberculosis, total RNA were extracted from the filtrated bacterial cultural supernatant. After synthesis of cDNA by reverse transcription, four Mycobacterial sRNAs including ASdes, ASpks, AS1726, and AS1890, which have been experimentally confirmed by Kristine B in the year of 2009, were detected by real time PCR. The specificity was verified by sequencing of the amplified products. Moreover, we demonstrate that the presence of sRNA Asdes in plasma of 55.56% (15/27) TB patients and 25.00% (6/24) normal controls with BCG vaccination (P < 0.05). Our results suggest that bacterial non-coding sRNA can be detected from either bacterial culture supernatants or patient's plasma. Detecting of Mycobacterial sRNA provides a rapid and relatively noninvasive approach for diagnosing disease and could be developed as a biomarker to identify patients with active tuberculosis to help make informed decisions about proper therapies.¹.

A 10-year prediagnostic follow-up study shows that serum RNA signals are highly dynamic in lung carcinogenesis

The majority of lung cancer (LC) patients are diagnosed at a late stage, and survival is poor. Circulating RNA molecules are known to have a role in cancer; however, their involvement before diagnosis remains an open question. In this study, we investigated circulating RNA dynamics in prediagnostic LC samples, focusing on smokers, to identify if and when disease-related signals can be detected in serum. We sequenced small RNAs in 542 serum LC samples donated up to 10 years before diagnosis and 519 matched cancer-free controls coming from 905 individuals in the Janus Serum Bank. This sample size provided sufficient statistical power to independently analyze time to diagnosis, stage, and histology. The results showed dynamic changes in differentially expressed circulating RNAs specific to LC histology and stage. The greatest number of differentially expressed RNAs was identified around 7 years before diagnosis for early-stage LC and 1-4 years prior to diagnosis for locally advanced and advanced-stage LC, regardless of LC histology. Furthermore, NSCLC and SCLC histologies have distinct prediagnostic signals. The majority of differentially expressed RNAs were associated with cancer-related pathways. The dynamic RNA signals pinpointed different phases of tumor development over time. Stage-specific RNA profiles may be associated with tumor aggressiveness. Our results improve the molecular understanding of carcinogenesis. They indicate substantial opportunity for screening and improved treatment and will guide further research on early detection of LC. However, the dynamic nature of the RNA signals also suggests challenges for prediagnostic biomarker discovery.

Circulating Extracellular RNA Markers of Liver Regeneration

BACKGROUND AND AIMS

Although a key determinant of hepatic recovery after injury is active liver regeneration, the ability to detect ongoing regeneration is lacking. The restoration of liver mass after hepatectomy involves systemic changes with coordinated changes in gene expression guiding regenerative responses, activation of progenitor cells, and proliferation of quiescent hepatocytes. We postulated that these responses involve intercellular communication involving extracellular RNA and that these could represent biomarkers of active regenerative responses.

METHODS

RNA sequencing was performed to identify temporal changes in serum extracellular non-coding RNA after partial hepatectomy in C57BL/6 male mice. Tissue expression of selected RNA was performed by microarray analysis and validated using qRT-PCR. Digital PCR was used to detect and quantify serum expression of selected RNA.

RESULTS

A peak increase in extracellular RNA content occurred six hours after hepatectomy. RNA sequencing identified alterations in several small non-coding RNA including known and novel microRNAs, snoRNAs, tRNA, antisense and repeat elements after partial hepatectomy. Combinatorial effects and network analyses identified signal regulation, protein complex assembly, and signal transduction as the most common biological processes targeted by miRNA that altered. miR-1A and miR-181 were most significantly altered microRNA in both serum and in hepatic tissues, and their presence in serum was quantitated using digital PCR.

CONCLUSIONS

Extracellular RNA selectively enriched during acute regeneration can be detected within serum and represent biomarkers of ongoing liver regeneration in mice. The ability to detect ongoing active regeneration would improve the assessment of hepatic recovery from liver injury.

Circulating microbial small RNAs are altered in patients with rheumatoid arthritis

OBJECTIVES

To determine if plasma microbial small RNAs (sRNAs) are altered in patients with rheumatoid arthritis (RA) compared with control subjects, associated with RA disease-related features, and altered by disease-modifying antirheumatic drugs (DMARDs).

METHODS

sRNA sequencing was performed on plasma from 165 patients with RA and 90 matched controls and a separate cohort of 70 patients with RA before and after starting a DMARD. Genome alignments for RA-associated bacteria, representative bacterial and fungal human microbiome genomes and environmental bacteria were performed. Microbial genome counts and individual sRNAs were compared across groups and correlated with disease features. False discovery rate was set at 0.05.

RESULTS

Genome counts of Lactobacillus salivarius, Anaerobaculum hydrogeniformans, Staphylococcus epidermidis, Staphylococcus aureus, Paenisporosarcina spp, Facklamia hominis, Sphingobacterium spiritivorum, Lentibacillus amyloliquefaciens, Geobacillus spp, and Pseudomonas fluorescens were significantly decreased in the plasma of RA compared with control subjects. Three microbial transfer RNA-derived sRNAs were increased in RA versus controls and inversely associated with disease activity. Higher total microbial sRNA reads were associated with lower disease activity in RA. Baseline total microbial sRNAs were threefold higher among patients who improved with DMARD versus those who did not but did not change significantly after 6 months of treatment.

CONCLUSION

Plasma microbial sRNA composition is altered in RA versus control subjects and associated with some measures of RA disease activity. DMARD treatment does not alter microbial sRNA abundance or composition, but increased abundance of microbial sRNAs at baseline was associated with disease activity improvement at 6 months.

Androgen-responsive non-coding small RNAs extend the potential of HCG stimulation to act as a bioassay of androgen sufficiency

BACKGROUND

It is unclear whether a short-term change in circulating androgens is associated with changes in the transcriptome of the peripheral blood mononuclear cells (PBMC).

AIMS AND METHODS

To explore the effect of hCG stimulation on the PBMC transcriptome, 12 boys with a median age (range) of 0.7 years (0.3, 11.2) who received intramuscular hCG 1500u on 3 consecutive days as part of their investigations underwent transcriptomic array analysis on RNA extracted from peripheral blood mononuclear cells before and after hCG stimulation.

RESULTS

Median pre- and post-hCG testosterone for the overall group was 0.7 nmol/L (<0.5, 6) and 7.9 nmol/L (<0.5, 31.5), respectively. Of the 12 boys, 3 (25%) did not respond to hCG stimulation with a pre and post median serum testosterone of <0.5 nmol/L and <0.5 nmol/L, respectively. When corrected for gene expression changes in the non-responders to exclude hCG effects, all 9 of the hCG responders consistently demonstrated a 20% or greater increase in the expression of piR-37153 and piR-39248, non-coding PIWI-interacting RNAs (piRNAs). In addition, of the 9 responders, 8, 6 and 4 demonstrated a 30, 40 and 50% rise, respectively, in a total of 2 further piRNAs. In addition, 3 of the responders showed a 50% or greater rise in the expression of another small RNA, SNORD5. On comparing fold-change in serum testosterone with fold-change in the above transcripts, a positive correlation was detected for SNORD5 (P = 0.01).

CONCLUSIONS

The identification of a dynamic and androgen-responsive PBMC transcriptome extends the potential value of the hCG test for the assessment of androgen sufficiency.

Circulating small non-coding RNA profiling for identification of older adults with low muscle strength and physical performance: A preliminary study

BACKGROUND

Small non-coding RNAs (ncRNAs) have recently emerged as potential biomarkers of sarcopenia. However, previous studies have rarely explored the association of small ncRNAs with sarcopenic components, especially muscle strength and physical performance. We aimed to examine circulating small ncRNA profiles to detect low muscle strength and physical performance in older adults.

METHODS

Ninety-eight older adults were randomly selected from Korean Frailty and Aging Cohort Study and classified into the "Normal," "Low muscle strength (MS) only," "Low physical performance (PP) only," and "Low MS and PP" groups by Asian Working Group for Sarcopenia 2019 criteria. We used high-throughput sequencing to delineate small ncRNA profiles in plasma. Differentially expressed small ncRNAs were analyzed to reveal distinct patterns based on muscle strength and physical performance status.

RESULTS

In "Low MS and PP" group, 119 miRNAs, 86 piRNAs, 92 snoRNAs, 106 snRNAs, and 15 tRNAs were differentially expressed compared to "Normal" group (p < 0.05). After Benjamini-Hochberg adjustment, 39 miRNAs, 2 piRNAs, 75 snoRNAs, 48 snRNAs, and 15 tRNAs showed differential expression in "Low MS and PP" group compared to than "Normal" group (adjusted p < 0.05). No significant differences were observed in comparisons between the other groups (adjusted p > 0.05).

CONCLUSION

The expression of circulating small ncRNAs were comprehensively characterized, revealing distinct signatures in older adults with both low muscle strength and physical performance compared to normal individuals. Although preliminary, this characterization can advance small ncRNA research on age-related declines in muscle strength and physical performance by providing foundational data for further investigation.

Novel non-invasive molecular signatures for oral cavity cancer, by whole transcriptome and small non-coding RNA sequencing analyses: Predicted association with PI3K/AKT/mTOR pathway

INTRODUCTION

Identification of molecular biomarkers in the saliva and serum of oral cavity cancer patients represents a first step in the development of essential and efficient clinical tools for early detection and post-treatment monitoring. We hypothesized that molecular analyses of paired saliva and serum samples from an individual would likely yield better results than analyses of either serum or saliva alone.

MATERIALS AND METHODS

We performed whole-transcriptome and small non-coding RNA sequencing analyses on 32 samples of saliva and serum collected from the same patients with oral squamous cell carcinoma (OSCC) and healthy controls (HC).

RESULTS

We identified 12 novel saliva and serum miRNAs and a panel of unique miRNA and mRNA signatures, significantly differentially expressed in OSCC patients relative to HC (log2 fold change: 2.6-26.8; DE: 0.02-0.000001). We utilized a combined panel of the 10 top-deregulated miRNAs and mRNAs and evaluated their putative diagnostic potential (>87% sensitivity; 100% specificity), recommending seven of them for further validation. We also identified unique saliva and serum miRNAs associated with OSCC and smoking history (OSCC smokers vs. never-smokers or HC: log2 fold change: 22-23; DE: 0.00003-0.000000001). Functional and pathway analyses indicated interactions between the discovered OSCC-related non-invasive miRNAs and mRNAs and their targets, through PI3K/AKT/mTOR signaling.

CONCLUSION

Our data support our hypothesis that using paired saliva and serum from the same individuals and deep sequencing analyses can provide unique combined mRNA and miRNA signatures associated with canonical pathways that may have a diagnostic advantage relative to saliva or serum alone and may be useful for clinical testing. We believe this data will contribute to effective preventive care by post-treatment monitoring of patients, as well as suggesting potential targets for therapeutic approaches.

Circulating small non-coding RNAs are associated with the insulin-resistant and obesity-related type 2 diabetes clusters

AIM

To uncover differences in small non-coding RNAs (sncRNAs) in individuals with type 2 diabetes (T2D) categorized into five clusters based on individual characteristics, which may aid in the identification of those prone to rapid progression.

MATERIALS AND METHODS

In the Hoorn Diabetes Care System (DCS) cohort, participants were clustered by age, body mass index (BMI), and glycated haemoglobin, C-peptide and high-density lipoprotein (HDL) cholesterol levels, yielding severe insulin-deficient diabetes, severe insulin-resistant diabetes (SIRD), mild obesity-related diabetes (MOD), mild diabetes, and mild diabetes with high HDL cholesterol clusters (n = 412). Utilizing plasma sncRNA-sequencing, we identified distinct cluster-specific sncRNAs. Validation was performed in a smaller DCS Hoorn dataset (n = 138). To elucidate their potential functions, we examined tissue expression, identified potential targets or (co-)regulated proteins, conducted gene set enrichment analyses on the targets through Reactome, and examined tissue expression of the (co-)regulated proteins.

RESULTS

The insulin-resistant cluster exhibited aberrant expression of 10 sncRNAs, while the high BMI cluster featured eight differentially expressed sncRNAs. Multiple (co-)regulated proteins were identified for sncRNAs associated with both clusters. Proteins associated with both clusters showed enrichment for metabolism. Proteins that specifically and only associated with the SIRD cluster showed enrichment for immune-related signalling. Furthermore, MOD cluster-specific associated proteins showed enrichment for the complement system.

CONCLUSIONS

Our research showed differential sncRNA levels among type 2 diabetes clusters. This may reflect and could deepen our understanding of molecular mechanisms, in development, progression, and risk factors for each cluster.

Plasma tsRNA Signatures Serve as a Novel Biomarker for Bladder Cancer

Bladder cancer (BLCA) is one of the most common tumors of the urinary tract. The diagnosis of BLCA is mostly by invasive tests, which are damaging and unsuitable for early screening. Current non-invasive diagnostic modalities are insufficient in sensitivity and specificity. Therefore, novel diagnostic markers are urgently needed to facilitate early detection of bladder cancer. tRNA-derived small RNAs (tsRNAs) are considered to be novel and potentially biologically functional non-coding RNAs (ncRNAs). tsRNAs have been used to help early diagnosis of a variety of tumors. However, whether tsRNAs in BLCA are altered or involved in BLCA progression or regulation remains unclear. Here, we identified a group of up-regulated tsRNAs in BLCA by sequencing tsRNAs in the plasma of BLCA patients and normal controls and further screened two highly correlated tsRNAs with BLCA in the training set and validation set, which were named as tRF-1:28-chrM.Ser-TGA and tiRNA-1:34-Glu-CTC-1-M2. ROC analyses of the expression profiles of these two tsRNAs by the validation set identified a high diagnostic value. We also found that circulating tRF-1:28-chrM.Ser-TGA and tiRNA-1:34-Glu-CTC-1-M2 were specifically expressed and released by BLCA cells and were positively correlated with the degree of disease malignancy. In vitro and in vivo experiments revealed that the two tsRNAs exacerbated BLCA progression and played a role in promoting tumor lipid metabolism. Our study screened two plasma tsRNAs that could serve as valuable early screening and diagnostic biomarkers for BLCA and is also expected to provide potential novel molecular targets for the treatment of BLCA.

Role and clinical value of serum hsa_tsr011468 in lung adenocarcinoma

Transfer RNA‑derived small RNAs (tsRNAs) are novel non‑coding RNAs that are associated with the pathogenesis of various diseases. However, their association with lung adenocarcinoma (LUAD) has not been studied comprehensively. Therefore, the present study aimed to explore the diagnostic value of a tsRNA, hsa_tsr011468, in LUAD. The OncotRF database was used to screen tsRNAs and reverse transcription‑quantitative PCR (RT‑qPCR) was performed to detect the expression levels of hsa_tsr011468 in various samples. Subsequently, the diagnostic and prognostic values of hsa_tsr011468 for LUAD were determined via receiver operating characteristic (ROC) curve and survival curve analyses, and by assessing clinicopathological parameters. In addition, both nuclear and cytoplasmic RNA were extracted to assess the location of hsa_tsr011468. The OncotRF database identified high expression of hsa_tsr011468 in LUAD. In addition, the results of RT‑qPCR showed that the relative expression levels of hsa_tsr011468 in the serum and tissues of patients with LUAD were higher than those in normal controls. Furthermore, its expression was lower in postoperative serum samples than in preoperative serum samples from patients with LUAD. ROC and survival curves indicated that hsa_tsr011468 had good diagnostic and prognostic value. Furthermore, the clinicopathological analysis revealed that hsa_tsr011468 was associated with tumor size. In addition, hsa_tsr011468 was mainly localized in the cytoplasm of LUAD cells. The present study indicated that hsa_tsr011468 has good diagnostic value and, therefore, could be employed as a serum marker for LUAD.

Non-canonical small noncoding RNAs in the plasma extracellular vesicles as novel biomarkers in gastric cancer

Identifying robust diagnostic biomarkers for gastric cancer (GC) remains a significant challenge. Emerging studies highlight extracellular vesicle (EV)-derived RNAs in cancer biology, but the diagnostic potential of circulating EV-derived small non-coding RNAs (sncRNAs) in GC is poorly understood. Using panoramic RNA display by overcoming RNA modification aborted sequencing (PANDORA-seq), we mapped non-canonical sncRNAs-specifically ribosomal RNA-derived small RNAs (rsRNAs) and transfer RNA-derived small RNAs (tsRNAs)-in plasma EVs. We identified a three-rs/tsRNA signature that discriminates GC patients from healthy individuals with high sensitivity (80.42%) and specificity (87.43%) (143 GC vs 167 controls). For early-stage GC (stage I), sensitivity and specificity were 81.97% and 81.44%, respectively. Furthermore, the three-rs/tsRNA signature was evaluated in two independent cohorts, resulting in AUC values of 0.97 and 0.91 for distinguishing GC from healthy controls. Functional analyses revealed that these rs/tsRNAs regulate the ErbB/Hippo pathways, suggesting them in the underlying pathogenesis and therapeutic potential. This study establishes a novel EV-derived sncRNA signature for early GC detection.

Identification of serum small non-coding RNA as biomarkers for endometrial receptivity

BACKGROUND

Current endometrial receptivity analysis is invasive, preventing embryo transfer during the biopsy cycle. This study aims to screen serum sncRNAs as non-invasive biomarkers for ERA tests.

METHODS

The study included 12 infertile patients undergoing IVF-ET and ERA, whose serum samples were collected for high-energy sequencing technology to detect sncRNA expression profiles. We overexpressed and knocked down tsRNA-35:73-Asp-GTC-1 in the decidualized Immortalized Human Eutopic Endometrial Stromal Cells (HESC) model cultured in vitro to further investigate the its effect on decidualization. The predicted tsRNA-35:73-Asp-GTC-1 target gene was verified by PCR analysis.

RESULTS

We screened 286 differentially expressed tsRNAs, 46 miRNAs, and 106 piRNAs. KEGG analysis indicated that differentially expressed tsRNAs were associated with pathways such as 'Calcium signaling pathway,' 'Sphingolipid signaling pathway,' etc. The results of RT-qPCR validation showed that the trends of four significantly differentially expressed tsRNAs in serum and endometrium were consistent with sequencing results. ROC curves demonstrated that these four tsRNAs have good predictive value for endometrial receptivity. Overexpression of tsRNA-35:73-Asp-GTC-1 affected the morphology of decidualized cells, and the decidualization indicators also showed a decreasing trend. While knocking down tsRNA-35:73-Asp-GTC-1 had the opposite effect. The RT-qPCR results showed that tsRNA-35:73-Asp-GTC-1 was associated with the Wnt3 target gene.

CONCLUSION

Serum sncRNA analysis shows potential for studying the molecular mechanisms of endometrial receptivity. Four serum tsRNAs can serve as novel biomarkers for non-invasive endometrial receptivity detection. TsRNA-35:73-Asp-GTC-1 may further regulate endometrial receptivity by targeting Wnt3.

Identification of serum tRNA-derived small RNAs biosignature for diagnosis of tuberculosis

The tRNA-derived small RNAs (tsRNAs) are a new class of non coding RNAs, which are stable in body fluids and can be used as potential biomarkers for disease diagnosis. However, the exact value of tsRNAs in the diagnosis of tuberculosis (TB) is still unclear. The objective of the present study was to evaluate the performance of the serum tsRNAs biosignature to distinguish between active TB, healthy controls, latent TB infection, and other respiratory diseases. The differential expression profiles of tsRNAs in serum from active TB patients and healthy controls were analyzed by high-throughput sequencing. A total of 905 subjects were prospectively recruited for our study from three different cohorts. Levels of tsRNA-Gly-CCC-2, tsRNA-Gly-GCC-1, and tsRNA-Lys-CTT-2-M2 were significantly elevated in the serum of TB patients compared to non-TB individuals, showing a correlation with lung injury severity and acid-fast bacilli grades in TB patients. The accuracy of the three-tsRNA biosignature for TB diagnosis was evaluated in the training (n = 289), test (n = 124), and prediction (n = 292) groups. By utilizing cross-validation with a random forest algorithm approach, the training cohort achieved a sensitivity of 100% and specificity of 100%. The test cohort exhibited a sensitivity of 75.8% and a specificity of 91.2%. Within the prediction group, the sensitivity and specificity were 73.1% and 92.5%, respectively. The three-tsRNA biosignature generally decreased within 3 months of treatment and then remained stable. In conclusion, the three-tsRNA biosignature might serve as biomarker to diagnose TB and to monitor the effectiveness of treatment in a high-burden TB clinical setting.

Circulating extracellular vesicles and small non-coding RNAs cargo in idiopathic inflammatory myopathies reveal differences across myositis subsets

OBJECTIVE

To investigate the epigenetic footprint of idiopathic inflammatory myopathies (IIM) through characterization of circulating extracellular vesicles (EVs) and the expression of EV-derived small non-coding RNAs (sncRNAs).

METHODS

In this cross-sectional study, EVs were isolated by size-exclusion chromatography from plasma of patients with IIM and age- and sex-matched healthy donors (HD). EV-derived sncRNAs were sequenced and quantified using Next-Generation Sequencing (NGS). Following quality control and normalization, filtered count reads were used for differential microRNA (miRNA) and piwi-interacting RNA (piRNA) expression analyses. Putative gene targets enriched for pathways implicated in IIM were analyzed. Patients' clinical and laboratory characteristics at the time of sampling were recorded.

RESULTS

Forty-seven IIM patients and 45 HD were enrolled. MiR-486-5p (p < 0.01), miR-122-5p, miR-192-5p, and miR-32-5p were significantly upregulated (p < 0.05 for all), while miR-142-3p (p < 0.001), miR-141-3p (p < 0.01), let-7a-5p (p < 0.05) and miR-3613-5p (p < 0.05) downregulated in EVs from IIM patients versus HD. MiR-486-5p was associated with raised muscle enzymes levels. Several target genes of up/downregulated miRNAs in IIM participate in inflammation, necroptosis, interferon and immune signaling. Six piRNAs were significantly dysregulated in IIM EVs versus HD (p < 0.05). Within IIM, miR-335-5p was selectively upregulated and miR-27a-5p downregulated in dermatomyositis (n = 21, p < 0.01). Finally, plasma EV levels were significantly increased in cancer-associated myositis (CAM, n = 12) versus non-CAM IIM (n = 35, p = 0.02) and HD (p < 0.01). EVs cargo in CAM was significantly enriched of let-7f-5p and depleted of miR-143-3p.

CONCLUSION

Through an unbiased screening of EV-derived sncRNAs, we characterize miRNAs and piRNAs in the EVs cargo as potential biomarkers and modifiers of diverse IIM phenotypes.

Dysregulated transfer RNA-derived small RNAs as potential gastric cancer biomarkers

Gastric cancer (GC) is the kind of carcinoma that has the highest rates of morbidity and death worldwide. In the early stages of GC, there is currently an absence of sensitive and specific biomarkers. The newly-discovered class of non-coding RNAs (ncRNAs) known as transfer RNA-derived small RNAs (tsRNAs) is highly expressed in bodily fluids and neoplastic cells. High-throughput sequencing was initially employed to identify differentially expressed tsRNAs in early GC patients, followed by validation in patient serum, GC tissues, and cell lines by quantitative real-time polymerase chain reaction (qRT-PCR). We identified dysregulated tsRNAs (the up-regulated tsRNAs included tRF-31-PNR8YP9LON4VD, tRF-30-MIF91SS2P4FI, and tRF-30-IK9NJ4S2I7L7, whereas the down-regulated tsRNAs included tRF-38-W6RM7KYUPRENRHD2, tRF-37-LBRY73W0K5KKOV2, tRF-36-JB59V3WD8YQ84VD, tRF-25-MBQ4NKKQBR, and tRF-36-0KFMNKYUHRF867D) in GC, and we verified that the serum of patients, GC cells and tissues both consistently expressed these tsRNAs. Additionally, GC patients' serum had considerably greater expression levels of the three up-regulated tsRNAs than did healthy controls. Receiver operating characteristic (ROC) curve analysis demonstrated that the sensitivity and specificity of the three up-regulated tsRNAs were superior to those of CEA, CA199, and CA724 in the process of diagnosing GC, particularly in its early stages. This suggests that tsRNAs have great diagnostic efficacy and potential as new "liquid biopsy" biomarkers for the diagnosis of GC. Using bioinformatics software, we predicted that dysregulation of tsRNAs may be a potential regulatory mechanism for the development of GC.

Identification of serum tsRNA-Thr-5-0015 and combined with AFP and PIVKA-II as novel biomarkers for hepatocellular carcinoma

Accumulating evidence has shown that tRNA-derived small RNAs (tsRNAs) play crucial roles in malignant tumor development. However, whether serum tsRNAs can act as potential biological markers for hepatocellular carcinoma (HCC) are still largely unknown. In the current study, a novel tsRNA, namely tsRNA-Thr-5-0015, was prominently elevated in the sera of HCC patients than that of hepatitis cases and healthy check-ups, and it was related with TNM stage and lymphatic metastasis of HCC patients. Moreover, methodological evaluation confirmed that tsRNA-Thr-5-0015 had excellent stability, precision, accuracy and linear range. Additionally, the combined detection of serum tsRNA-Thr-5-0015 with AFP as well as PIVKA-II improved the diagnostic sensitivity for HCC. Furthermore, dynamic monitoring found that the serum tsRNA-Thr-5-0015 was drastically decreased in the postoperative HCC patients. Besides, Kaplan-Meier analysis displayed that patients with high level of serum tsRNA-Thr-5-0015 had shorter overall survival than that of the low level ones. In addition, bioinformatic prediction unveiled that the downstream targets of tsRNA-Thr-5-0015 were enriched in several signaling pathways, such as MAPK, PI3K-Akt, etc. In summary, tsRNA-Thr-5-0015 may be a promising biomarker for HCC diagnosis, therapeutic effect assessment and prognosis judgement. Especially, the combination with serum tsRNA-Thr-5-0015, AFP and PIVKA-II can enhance the diagnostic efficiency for HCC.