Plasma tRNA Fragments Derived from 5' Ends as Novel Diagnostic Biomarkers for Early-Stage Breast Cancer

Research progress on the tsRNA biogenesis, function, and application in lung cancer

In recent years, there has been a mounting occurrence of lung cancer, which stands as one of the most prevalent malignancies globally. This rise in incidence poses a significant hazard to human health, making lung cancer a matter of grave concern. It has been shown that tRNA-derived small non-coding RNA (tsRNA) is involved in the development of tumors, especially lung cancer, through mechanisms such as regulating mRNA stability, influencing protein translation, and acting as epigenetic regulators. Recent studies have shown that tsRNA is abnormally expressed in the plasma and tissues of lung cancer patients, and its expression level is closely related to the malignancy degree and postoperative recurrence of lung cancer. Therefore, for lung cancer patients, tsRNA represents a promising non-invasive biomarker, exhibiting significant potential for facilitating early diagnosis and prognostic evaluation, and for achieving precision treatment of lung cancer by regulating its expression. This article focuses on the biogenesis of tsRNA and its ability to promote lung cancer cell proliferation and invasion. In addition, the specific clinical significance of tsRNA in lung cancer was discussed. Finally, we discuss the need for further improvement of small RNA sequencing technology, and the future research directions and strategies of tsRNA in lung cancer and tumor diseases were summarized.

Small RNA sequencing data of plasma extracellular vesicles in a breast cancer screening population

The pathogenesis of breast cancer is still unclear. Small RNAs associated with extracellular vesicles (EVs) have been found to be involved in tumor development. It is important to explore the role of EVs small RNAs in breast cancer. In this study, we established a plasma EVS-associated small RNA dataset that included 120 women who were positive for breast cancer screening and 60 women who were negative. These small RNA included 2656 miRNAs, 728 piRNAs, and 154 tsRNAs. These data provide a reference for researchers to explore molecular diagnostic biomarkers for early breast lesions.

tRNA-derived small RNAs (tsRNAs): establishing their dominance in the regulation of human cancer

The main function of transfer RNAs (tRNAs) is to carry amino acids into the ribosome and synthesize proteins under the guidance of messenger RNAs (mRNAs). In addition to this, it has been observed that tRNAs undergo precise cleavage at specific loci, giving rise to an extensive array of distinct small RNAs, termed tRNA-derived small RNAs (tsRNAs). Existing studies have shown that tsRNAs are widely present across various organisms and comprehensively regulate gene expression, aberrant expression of tsRNAs is inextricably linked to tumorigenesis and development, thus, a systematic understanding of tsRNAs is necessary. This review aims to comprehensively delineate the genesis and expression patterns of tsRNAs, elucidate their diverse functions and emphasize their prospective clinical application as biomarkers and targets for therapy. It is noteworthy that we innovatively address the roles played by tsRNAs in human cancers at the level of the hallmarks of tumorigenesis proposed by Hanahan in anticipation of a broad understanding of tsRNAs and to guide the treatment of tumors.

Exosomal non-coding RNAs (ncRNAs) as potential biomarkers in tumor early diagnosis

Exosomes, extracellular vesicles carrying a cargo rich in various non-coding RNAs (ncRNAs), have emerged as crucial mediators of intercellular communication. Their stability, abundance, and specificity make exosomal ncRNAs promising candidates for biomarker discovery. The discovery of exosomal ncRNAs has unveiled a novel avenue for the exploration of biomarkers in tumor early diagnosis. This review consolidates current knowledge on the role of exosomal ncRNAs as potential biomarkers in the early detection of various tumors. We provide an overview of recent studies demonstrating the diagnostic potential of exosomal ncRNAs across multiple cancer types, highlighting their sensitivity, specificity, and feasibility for early detection. This review underscores the potential of exosomal ncRNAs as non-invasive biomarkers for early tumor diagnosis, paving the way for improved clinical outcomes through timely intervention and personalized management strategies.

Aberrantly Expressed tRNA-Val Fragments Can Distinguish Canine Hepatocellular Carcinoma from Canine Hepatocellular Adenoma

Hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC) can be difficult to differentiate but must be diagnosed correctly as treatment and prognosis for these tumors differ markedly. Relevant diagnostic biomarkers are thus needed, and those identified in dogs may have utility in human medicine because of the similarities between human and canine HCA and HCC. A tRNA-derived fragment (tRF), tRNA-Val, is a promising potential biomarker for canine mammary gland tumors but has not previously been investigated in hepatic tumors. Accordingly, we aimed to elucidate the potential utility of tRNA-Val as a biomarker for canine HCA and HCC using clinical samples (tumor tissue and plasma extracellular vesicles [EVs]) and tumor cell lines with qRT-PCR assays. We also investigated relevant functions and signaling pathways with bioinformatic analyses (Gene Ontology and Kyoto Encyclopedia of Genes and Genomes). tRNA-Val was markedly downregulated in HCC tumor tissue versus HCA tumor tissue and normal liver tissue, and a similar trend was shown in plasma EVs and HCC cell lines versus healthy controls. Based on areas under the receiver operating characteristic curves (AUCs), tRNA-Val significantly distinguished HCC (AUC = 1.00, p = 0.001) from healthy controls in plasma EVs and HCC from HCA (AUC = 0.950, p = 0.01). Bioinformatics analysis revealed that tRNA-Val may be primarily involved in DNA repair, mRNA processing, and splicing and may be linked to the N-glycan and ubiquitin-mediated proteasome pathways. This is the first report on the expression of tRNA-Val in canine HCC and HCA and its possible functions and signaling pathways. We suggest that tRNA-Val could be a promising novel biomarker to distinguish canine HCC from HCA. This study provides evidence for a greater understanding of the role played by tRNA-Val in the development of canine HCC.

Transfer RNA‑derived small RNAs: A class of potential biomarkers in multiple cancers (Review)

Transfer (t)RNA-derived small RNAs (tsRNAs) are a class of novel non-coding small RNAs that are created via precise cleavage of tRNAs or tRNA precursors by different enzymes. tsRNAs are specific biological molecules that serve essential roles in cell proliferation, apoptosis, transcriptional regulation, post-transcriptional modification and translational regulation. Additionally, tsRNAs participate in the pathogenesis of several diseases, particularly in the development of malignant tumors. At present, the process of discovering and understanding the functions of tsRNAs is still in its early stages. The present review introduces the known biological functions and mechanisms of tsRNAs, and discusses the tsRNAs progression in several types of cancers as well as the possibility of tsRNAs becoming novel tumor biomarkers. Furthermore, tsRNAs may promote and hinder tumor formation according to different mechanisms and act as oncogenic or oncostatic molecules. Therefore, tsRNAs may be future potential tumor biomarkers or therapeutic targets.

Exploring the functional role of tRF-39-8HM2OSRNLNKSEKH9 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is associated with high morbidity and mortality globally. tRNA-derived small RNAs (tsRNAs) have emerged as potential targets for cancer treatment. However, the specific impact of tsRNAs on HCC remains undiscovered. In this study, we aimed to investigate the biological significance of tsRNAs in HCC. First, we screened the differentially expressed tsRNAs in HCC tissues and normal tissues adjacent to the tumor (NAT) using high-throughput sequencing and the results showed that tRF-39-8HM2OSRNLNKSEKH9 was more highly expressed in HCC tissues than NATs. Agarose gel electrophoresis (AGE), nuclear-cytoplasmic separation assays and fluorescence in situ hybridization (FISH) were employed to assess the characterization of tRF-39-8HM2OSRNLNKSEKH9. The relationship between the expression of tRF-39-8HM2OSRNLNKSEKH9 and clinicopathological parameters was evaluated and we found that it was positively associated with tumor size. The cell counting kit-8 (CCK8) assay, colony formation assay and EdU staining assay were employed to investigate the role of tRF-39-8HM2OSRNLNKSEKH9 in the proliferation of HCC cells. Additionally, transwell assays demonstrated that overexpression of tRF-39-8HM2OSRNLNKSEKH9 could accelerate cell migration capability. Taken together, tRF-39-8HM2OSRNLNKSEKH9 was highly expressed in HCC cells, serum and tissues, and it may play an oncogenic role in HCC cells through interacting with downstream mRNA targets.

tsRNA: A Promising Biomarker in Breast Cancer

tRNA-derived small RNAs (tsRNAs) are a novel class of non-coding small RNAs, generated from specific cleavage sites of tRNA or pre-tRNA. tsRNAs can directly participate in RNA silencing, transcription, translation, and other processes. Their dysregulation is closely related to the occurrence and development of various cancers. Breast cancer is one of the most common and fastest-growing malignant tumors in humans. tsRNAs have been found to be dysregulated in breast cancer, serving as a new target for exploring the pathogenesis of breast cancer. They are also considered new tumor markers, providing a basis for diagnosis and treatment. This article reviews the generation, classification, mechanism of action, function of tsRNAs, and their biological effects and related mechanisms in breast cancer, in the hope of providing a new direction for the diagnosis and treatment of breast cancer.

The Emerging Function and Promise of tRNA-Derived Small RNAs in Cancer

Fragments derived from tRNA, called tRNA-derived small RNAs (tsRNAs), have attracted widespread attention in the past decade. tsRNAs are widespread in prokaryotic and eukaryotic transcriptome, which contains two main types, tRNA-derived fragments (tRFs) and tRNA-derived stress-inducing RNA (tiRNAs), derived from the precursor tRNAs or mature tRNAs. According to differences in the cleavage position, tRFs can be divided into tRF-1, tRF-2, tRF-3, tRF-5, and i-tRF, whereas tiRNAs can be divided into 5'-tiRNA and 3'-tiRNA. Studies have found that tRFs and tiRNAs are abnormally expressed in a variety of human malignant tumors, promote or inhibit the proliferation and apoptosis of cancer cells by regulating the expression of oncogene, and play an important role in the aggressive metastasis and progression of tumors. This article reviews the biological origins of various tsRNAs, introduces their functions and new concepts of related mechanisms, and focuses on the molecular mechanisms of tsRNAs in cancer, including breast cancer, prostate cancer, colorectal cancer, lung cancer, b-cell lymphoma, and chronic lymphoma cell leukemia. Lastly, this article puts forward some unresolved problems and future research prospects.

Prognostic, diagnostic and clinicopathological roles of tsRNAs: a meta-analysis in breast cancer

Breast cancer (BC) is one of the most common malignancies in women and the leading cause of cancer-related death in women. The newly emerged non-coding RNAs tsRNAs (tRNA-derived small RNAs) play an important role in the occurrence and development of BC. The purpose of this study was to comprehensively evaluate the prognostic, diagnostic and clinicopathological roles of tsRNAs in BC. Through literature screening, a total of 13 BC-related tsRNA studies were included in this meta-analysis, all of which passed quality assessment. Prognostic studies showed upregulated tsRNAs to be associated with poor survival outcomes (HR = 1.64, 95%CI 1.51-1.77) and downregulated tsRNAs to be associated with better outcomes (HR = 0.58, 95%CI 0.50-0.68). Results of diagnostic studies showed a combined sensitivity of 72% (95%CI 68-76%) and combined specificity of 64% (95%CI 61-67%); the AUC was 0.72 (95%CI 0.68-0.75) and the DOR 4.62 (95%CI 3.76-5.68). Finally, correlation analysis of clinicopathological features showed that downregulation of tsRNAs correlated significantly with age, TNM stage and lymphatic metastasis. Sensitivity analysis and publication bias showed no significant difference. In conclusion, BC-associated tsRNAs are closely related to the prognosis and clinicopathological features of patients with this disease and can be used to assist in early diagnosis of BC. Therefore, tsRNAs are potential targets for the diagnosis and treatment of BC.

The Role of tRNA-Centered Translational Regulatory Mechanisms in Cancer

Cancer is a leading cause of morbidity and mortality worldwide. While numerous factors have been identified as contributing to the development of malignancy, our understanding of the mechanisms involved remains limited. Early cancer detection and the development of effective treatments are therefore critical areas of research. One class of molecules that play a crucial role in the transmission of genetic information are transfer RNAs (tRNAs), which are the most abundant RNA molecules in the human transcriptome. Dysregulated synthesis of tRNAs directly results in translation disorders and diseases, including cancer. Moreover, various types of tRNA modifications and the enzymes responsible for these modifications have been implicated in tumor biology. Furthermore, alterations in tRNA modification can impact tRNA stability, and impaired stability can prompt the cleavage of tRNAs into smaller fragments known as tRNA fragments (tRFs). Initially believed to be random byproducts lacking any physiological function, tRFs have now been redefined as non-coding RNA molecules with distinct roles in regulating RNA stability, translation, target gene expression, and other biological processes. In this review, we present recent findings on translational regulatory models centered around tRNAs in tumors, providing a deeper understanding of tumorigenesis and suggesting new directions for cancer treatment.

Pan-cancer tRNA-derived fragment CAT1 coordinates RBPMS to stabilize NOTCH2 mRNA to promote tumorigenesis

Transfer RNA-derived fragments (tRFs) are a class of small non-coding regulatory RNAs that are involved in the pathophysiology of many diseases. However, the role of tRFs in cancer progression remains largely elusive. Here, we demonstrate that a pan-cancer 3'-tRF, CAT1 (cancer associated tRF 1), is ubiquitously upregulated in tumors and associated with poor prognosis of a variety of cancers, including lung cancer. The upregulated CAT1 in cancer cells binds to RNA-binding protein with multiple splicing (RBPMS) and displaces NOTCH2 association from RBPMS, thereby inhibiting the subsequent CCR4-NOT deadenylation-complex-mediated NOTCH2 mRNA decay. The CAT1-enhanced NOTCH2 expression promotes lung cancer cell proliferation and metastasis in vitro and in vivo. In addition, plasma CAT1 levels are substantially increased in patients with lung cancer compared to non-cancer control subjects. Our findings reveal an intrinsic connection between cancer-specific upregulation of CAT1 and cancer progression, show the regulation of NOTCH signaling in cancer by a 3'-tRF, and highlight its great clinical potential.

Digging out the biology properties of tRNA-derived small RNA from black hole

An unique subclass of functional non-coding RNAs generated by transfer RNA (tRNA) under stress circumstances is known as tRNA-derived small RNA (tsRNA). tsRNAs can be divided into tRNA halves and tRNA-derived fragments (tRFs) based on the different cleavage sites. Like microRNAs, tsRNAs can attach to Argonaute (AGO) proteins to target downstream mRNA in a base pairing manner, which plays a role in rRNA processing, gene silencing, protein expression and viral infection. Notably, tsRNAs can also directly bind to protein and exhibit functions in transcription, protein modification, gene expression, protein stabilization, and signaling pathways. tsRNAs can control the expression of tumor suppressor genes and participate in the initiation of cancer. It can also mediate the progression of diseases by regulating cell viability, migration ability, inflammatory factor content and autophagy ability. Precision medicine targeting tsRNAs and drug therapy of plant-derived tsRNAs are expected to be used in clinical practice. In addition, liquid biopsy technology based on tsRNAs indicates a new direction for the non-invasive diagnosis of diseases.

Non-Coding RNA in Salivary Extracellular Vesicles: A New Frontier in Sjögren's Syndrome Diagnostics?

Sjögren's syndrome is an autoimmune rheumatic disease characterized by inflammation of the salivary and lacrimal glands, often manifesting as dry mouth and dry eyes. To simplify diagnostics of primary Sjögren's syndrome (pSS), a non-invasive marker is needed. The aim of the study was to compare the RNA content of salivary extracellular vesicles (EVs) between patients with pSS and healthy controls using microarray technology. Stimulated whole saliva was collected from 11 pSS patients and 11 age-matched controls. EV-RNA was isolated from the saliva samples using a Qiagen exoRNeasy Midi Kit and analyzed using Affymetrix Clariom D™ microarrays. A one-way ANOVA test was used to compare the mean signal values of each transcript between the two groups. A total of 9307 transcripts, coding and non-coding RNA, were detected in all samples. Of these transcripts, 1475 showed statistically significant differential abundance between the pSS and the control groups, generating two distinct EV-RNA patterns. In particular, tRNAs were downregulated in pSS patients, with the transcript tRNA-Ile-AAT-2-1 showing a 2-fold difference, and a promise as a potential biomarker candidate. This study therein demonstrates the potential for using salivary EV-RNA in pSS diagnostics.

Transfer RNA-derived fragments as novel biomarkers of the onset and progression of gastric cancer

Gastric cancer (GC) is a particularly malignant disease; thus, early diagnosis and treatment are especially important. Transfer RNA-derived small RNAs (tsRNAs) have been implicated in the onset and progression of various cancers. Therefore, the aim of this study was to explore the role of tRF-18-79MP9P04 (previously named tRF-5026a) in the onset and progression of GC. Expression levels of tRF-18-79MP9P04 were quantified in gastric mucosa specimens of healthy controls and plasma samples of patients with different stages of GC. The results showed that plasma levels of tRF-18-79MP9P04 were significantly decreased in the early and advanced stages of GC. The results of the nucleocytoplasmic separation assay found that tRF-18-79MP9P04 was localized in the nuclei of GC cells. High-throughput transcriptome sequencing identified genes regulated by tRF-18-79MP9P04 in GC cells, and the function of tRF-18-79MP9P04 was predicted by bioinformatics. Collectively, the findings of this study suggest that tRF-18-79MP9P04 would be useful as non-invasive biomarker for early diagnosis of GC and is related to cornification, the type I interferon signaling pathway, RNA polymerase II activities, and DNA binding.

5’tiRNA-Pro-TGG, a novel tRNA halve, promotes oncogenesis in sessile serrated lesions and serrated pathway of colorectal cancer

BACKGROUND

Transfer RNA (tRNA)-derived small RNAs (tsRNAs) are small fragments that form when tRNAs severe. tRNA halves (tiRNAs), a subcategory of tsRNA, are involved in the oncogenic processes of many tumors. However, their specific role in sessile serrated lesions (SSLs), a precancerous lesion often observed in the colon, has not yet been elucidated.

AIM

To identify SSL-related tiRNAs and their potential role in the development of SSLs and serrated pathway of colorectal cancer (CRC).

METHODS

Small-RNA sequencing was conducted in paired SSLs and their adjacent normal control (NC) tissues. The expression levels of five SSL-related tiRNAs were validated by q-polymerase chain reaction. Cell counting kit-8 and wound healing assays were performed to detect cell proliferation and migration. The target genes and sites of tiRNA-1:33-Pro-TGG-1 (5′tiRNA-Pro-TGG) were predicted by TargetScan and miRanda algorithms. Metabolism-associated and immune-related pathways were analyzed by single-sample gene set enrichment analysis. Functional analyses were performed to establish the roles of 5′tiRNA-Pro-TGG based on the target genes.

RESULTS

In total, we found 52 upregulated tsRNAs and 28 downregulated tsRNAs in SSLs compared to NC. The expression levels of tiRNA-1:33-Gly-CCC-2, tiRNA-1:33-Pro-TGG-1, and tiRNA-1:34-Thr-TGT-4-M2 5′tiRNAs were higher in SSLs than those in NC, while that of 5′tiRNA-Pro-TGG was associated with the size of SSLs. It was demonstrated that 5′tiRNA-Pro-TGG promoted cell proliferation and migration of RKO cell in vitro. Then, heparanase 2 (HPSE2) was identified as a potential target gene of 5′tiRNA-Pro-TGG. Its lower expression was associated with a worse prognosis in CRC. Further, lower expression of HPSE2 was observed in SSLs compared to normal controls or conventional adenomas and in BRAF-mutant CRC compared to BRAF-wild CRC. Bioinformatics analyses revealed that its low expression was associated with a low interferon γ response and also with many metabolic pathways such as riboflavin, retinol, and cytochrome p450 drug metabolism pathways.

CONCLUSION

tiRNAs may profoundly impact the development of SSLs. 5′tiRNA-Pro-TGG potentially promotes the progression of serrated pathway CRC through metabolic and immune pathways by interacting with HPSE2 and regulating its expression in SSLs and BRAF-mutant CRC. In the future, it may be possible to use tiRNAs as novel biomarkers for early diagnosis of SSLs and as potential therapeutic targets in serrated pathway of CRC.

The role and mechanism of action of tRNA-derived fragments in the diagnosis and treatment of malignant tumors

Cancer is a leading cause of morbidity and death worldwide. While various factors are established as causing malignant tumors, the mechanisms underlying cancer development remain poorly understood. Early diagnosis and the development of effective treatments for cancer are important research topics. Transfer RNA (tRNA), the most abundant class of RNA molecules in the human transcriptome, participates in both protein synthesis and cellular metabolic processes. tRNA-derived fragments (tRFs) are produced by specific cleavage of pre-tRNA and mature tRNA molecules, which are highly conserved and occur widely in various organisms. tRFs were initially thought to be random products with no physiological function, but have been redefined as novel functional small non-coding RNA molecules that help to regulate RNA stability, modulate translation, and influence target gene expression, as well as other biological processes. There is increasing evidence supporting roles for tRFs in tumorigenesis and cancer development, including the regulation of tumor cell proliferation, invasion, migration, and drug resistance. Understanding the regulatory mechanisms by which tRFs impact these processes has potential to inform malignant tumor diagnosis and treatment. Further, tRFs are expected to become new biological markers for early diagnosis and prognosis prediction in patients with tumors, as well as a targets for precision cancer therapies. Video abstract.

Landscape of Clinically Relevant Exosomal tRNA-Derived Non-coding RNAs

Exosomes are extra-cellular vesicles that are < 150 nm that is formed by invagination of the plasma membrane and are released as vesicles. These contain proteins, RNA, and DNA as their cargo. In recent times, the non-coding RNA (ncRNA) present within exosomes has been studied extensively in the context of sorting, localization, and their potential as biomarkers. For example, miR-1246, miR-1290, miR-21, and miR-23a are exosomal biomarkers of cancer, and YBX1 (Y-Box Binding Protein 1) is attributed to exosomal RNA sorting. Transfer RNA-derived fragments are a class of small ncRNAs that were discovered in 2009. They are classified as tRFs (tRNA-derived fragments) and tsRNAs (tRNA halves). Interestingly, these tRNA-derived ncRNAs are emerging as biomarkers in various diseases, and these are found in exosomes. To date, the literature has covered only the biomarker potential of plasma/serum tRNA-derived ncRNAs. Hence, in the current review, we discuss the exosomal tRNA-derived fragments that are clinically relevant in pathological conditions.

Transfer RNA-derived small RNAs in tumor microenvironment

Transfer RNAs (tRNAs) are a class of non-coding RNAs responsible for amino acid translocation during protein synthesis and are ubiquitously found in organisms. With certain modifications and under specific conditions, tRNAs can be sheared and fragmented into small non-coding RNAs, also known as tRNA-derived small RNAs (tDRs). With the development of high-throughput sequencing technologies and bioinformatic strategies, more and more tDRs have been identified and their functions in organisms have been characterized. tRNA and it derived tDRs, have been shown to be essential not only for transcription and translation, but also for regulating cell proliferation, apoptosis, metastasis, and immunity. Aberrant expression of tDRs is associated with a wide range of human diseases, especially with tumorigenesis and tumor progression. The tumor microenvironment (TME) is a complex ecosystem consisting of various cellular and cell-free components that are mutually compatible with the tumor. It has been shown that tDRs regulate the TME by regulating cancer stem cells, immunity, energy metabolism, epithelial mesenchymal transition, and extracellular matrix remodeling, playing a pro-tumor or tumor suppressor role. In this review, the biogenesis, classification, and function of tDRs, as well as their effects on the TME and the clinical application prospects will be summarized and discussed based on up to date available knowledge.

Emerging roles of tRNA-derived fragments in cancer

tRNA-derived fragments (tRFs) are an emerging category of small non-coding RNAs that are generated from cleavage of mature tRNAs or tRNA precursors. The advance in high-throughput sequencing has contributed to the identification of increasing number of tRFs with critical functions in distinct physiological and pathophysiological processes. tRFs can regulate cell viability, differentiation, and homeostasis through multiple mechanisms and are thus considered as critical regulators of human diseases including cancer. In addition, increasing evidence suggest the extracellular tRFs may be utilized as promising diagnostic and prognostic biomarkers for cancer liquid biopsy. In this review, we focus on the biogenesis, classification and modification of tRFs, and summarize the multifaceted functions of tRFs with an emphasis on the current research status and perspectives of tRFs in cancer.

Urinary exosome tsRNAs as novel markers for diagnosis and prediction of lupus nephritis

Objective

Lupus nephritis (LN) is one of the most severe organ manifestations of systemic lupus erythematosus (SLE). Early identification of renal disease in SLE is important. Renal biopsy is currently recognized as the gold standard for diagnosing LN, however, it is invasive and inconvenient for dynamic monitoring. Urine has been considered more promising and valuable than blood in identifying inflamed kidney tissue. Here, we determine whether the signatures of tRNA-derived small noncoding RNA (tsRNA) in urinary exosomes can serve as novel biomarkers for the diagnosis of LN.

Methods

tsRNA sequencing was performed in exosome extracted from pooled urine of 20 LN patients and 20 SLE without LN, and the top 10 upregulated tsRNAs were screened as candidate markers of LN. The candidate urinary exosomal tsRNAs were primarily elected by TaqMan probe-based quantitative reverse transcription-PCR (RT-PCR) in 40 samples (20 LN and 20 SLE without LN) in the training phase. In the validation phase, selected tsRNAs from the training phase were further confirmed in a larger cohort (54 LN patients and 39 SLE without LN). Receiver operating characteristic curve (ROC) analysis was conducted to evaluate the diagnostic efficacy.

Results

Upregulated levels of tRF3-Ile-AAT-1 and tiRNA5-Lys-CTT-1 in the urinary exosomes were observed in LN compared with SLE without LN (P < 0.0001 and P < 0.001) and healthy controls (P < 0.01 and P < 0.01), with the area under the curve (AUC) of 0.777 (95% CI: 0.681-0.874, sensitivity 79.63%, specificity 66.69%) and 0.715 (95% CI: 0.610-0.820, sensitivity 66.96%, specificity 76.92%) for discriminating LN from SLE without LN patients. SLE patients with mild activity and moderate to severe activity had higher levels of urinary exosome derived tRF3-Ile AAT-1 (P = 0.035 and P < 0.001) and tiRNA5-Lys-CTT-1 (P = 0.021 and P < 0.001) compared with patients with no activity. Moreover, bioinformatics analysis revealed that both of the tsRNAs regulate the immune process by modulating metabolism and signal pathway.

Conclusion

In this study, we demonstrated that urinary exosome tsRNAs can be served as noninvasive biomarkers for the efficient diagnosis and prediction of nephritis in SLE.

Plasma exosomal tRNA-derived fragments as diagnostic biomarkers in non-small cell lung cancer

BACKGROUND

tRNA derived small RNAs (tRFs) have recently received extensive attention; however, the effects of tRFs in exosome as biomarkers has been less studied. The objective of this study was to validate novel diagnostic exosomal tRFs with sensitivity and specificity for non-small cell lung cancer (NSCLC).

METHODS

Exosomes extracted from plasma of NSCLC patients and healthy individuals were identified by transmission electron microscopy (TEM), qNano and western blots. The differentially expressed tRFs were screened by high-throughput sequencing in plasma exosomes of NSCLC patients and healthy individuals, and further verified by Quantitative Real-Time PCR (qRT-PCR). To assess the diagnostic efficacy of exosomal tRFs for NSCLC, receiver operating characteristic (ROC) curves were used next.

RESULTS

The expression levels of exosomal tRF-Leu-TAA-005, tRF-Asn-GTT-010, tRF-Ala-AGC-036, tRF-Lys-CTT-049, and tRF-Trp-CCA-057 were significantly decreased in NSCLC patients and early-stage NSCLC patients compared to healthy individuals. Notably, the exepression of tRF-Leu-TAA-005, tRF-Asn-GTT-010, tRF-Ala-AGC-036, tRF-Lys-CTT-049, and tRF-Trp-CCA-057 in the exosomes were higher than the exosome depleted supernatant (EDS).

CONCLUSIONS

Our results showed that the levels of exosomal tRF-Leu-TAA-005, tRF-Asn-GTT-010, tRF-Ala-AGC-036, tRF-Lys-CTT-049, and tRF-Trp-CCA-057 were significantly downregulated in NSCLC patients. This suggests that these five exosomal tRFs may be promising diagnostic biomarkers for NSCLC.

Plasma tRF-1:29-Pro-AGG-1-M6 and tRF-55:76-Tyr-GTA-1-M2 as novel diagnostic biomarkers for lung adenocarcinoma

Objective

TRNA-derived fragments (tRFs) and tRNA-derived stress-induced RNAs (tiRNAs) are recognized as novel and potential types of non-coding RNAs (ncRNAs), and several tRF/tiRNA signatures are closely associated with tumor diagnosis. This study aimed to analyze the expression profiles of plasma tRFs/tiRNAs and to clarify their diagnostic value in lung adenocarcinoma (LUAD).

Methods

The differential expression profiles of plasma tRFs/tiRNAs in patients with four patients with early LUAD, four patients with advanced LUAD, and four healthy controls were analyzed using high-throughput sequencing technology. Then, plasma tRFs/tiRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR), and their diagnostic efficiency was appraised by receiver operating characteristic curve analysis. The correlation of candidate plasma tRFs/tiRNAs with clinicopathological features was also analyzed. Finally, bioinformatics analysis was performed to explore and identify the potential biological pathways induced by tRFs/tiRNAs.

Results

The sequencing results revealed that tRFs/tiRNAs from plasma samples in patients with LUAD were differently expressed, supporting the necessity of exploring their potential as biomarkers. The validation results of qRT-PCR demonstrated that the expression level of tRF-1:29-Pro-AGG-1-M6 was downregulated in LUAD, while that of tRF-55:76-Tyr-GTA-1-M2 was upregulated, which was consistent with the sequencing data. The areas under the receiver operating characteristic curve of tRF-1:29-Pro-AGG-1-M6 and tRF-55:76-Tyr-GTA-1-M2 were 0.882 and 0.896, respectively, which have significant values in the diagnosis of LUAD. The expressions of tRF-1:29-Pro-AGG-1-M6 and tRF-55:76-Tyr-GTA-1-M2 in LUAD were obviously correlated with various clinicopathological features such as tumor–node–metastasis stage, node stage, and the expression levels of carcinoembryonic antigen. In addition, their expression was significantly altered from before to after tumor resection in LUAD patients. The results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses further indicated that tRF-1:29-Pro-AGG-1-M6 and tRF-55:76-Tyr-GTA-1-M2 are widely distributed and apparently enriched in several tumor-related signaling pathways.

Conclusions

Plasma tRF-1:29-Pro-AGG-1-M6 and tRF-55:76-Tyr-GTA-1-M2 may be promising components in the development of highly sensitive and non-invasive biomarkers for LUAD diagnosis.

Plasma-Derived Exosomal SncRNA as a Promising Diagnostic Biomarker for Early Detection of HBV-Related Acute-on-Chronic Liver Failure

Objectives

The small noncoding RNAs (sncRNAs) including microRNAs and the noncanonical sncRNAs [i.e., tRNA-derived small RNAs (tsRNAs) and rRNA-derived small RNAs (rsRNAs)] are a vital class of gene regulators in response to a variety of diseases. We focus on an sncRNA signature enriched in hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) to develop a plasma exosome-based noninvasive biomarker for human ACLF.

Methods

In this work, sncRNAs related to HBV-ACLF were identified by small RNA sequencing (RNA-seq) in plasma exosomes collected from 3 normal subjects, 4 chronic hepatitis B (CHB) patients with flare, and 6 HBV-ACLF patients in the discovery cohort. Thereafter, the differentially expressed sncRNAs were further verified in a validation cohort (n = 313) using the newly developed molecular signature incorporating different mi/ts/rsRNAs (named as MTR-RNAs) through qRT-PCR assays. Subsequently, using the least absolute shrinkage and selection operator (LASSO) logistic regression (LR) model analysis, we developed an MTR-RNA classifier for early detection of ACLF.

Results

The identified sncRNAs (hsa-miR-23b-3p, hsa-miR-223-3p, hsa-miR-339-5p, tsRNA-20, tsRNA-46, and rsRNA-249) were specifically differentially expressed in plasma exosomes of HBV-ACLF. The MTR-RNA signature (AUC = 0.787) containing the above sncRNAs distinguished HBV-ACLF cases among normal subjects with 71.67% specificity and 74.29% sensitivity, CHB patients with flare (AUC = 0.694, 85.71% sensitivity/59.5% specificity), and patients with CHB/cirrhosis (AUC = 0.785, 57.14% sensitivity/94.59% specificity). Notably, it revealed 100% specificity/94.80% sensitivity in detecting patients or normal people.

Conclusions

Our as-constructed plasma-derived exosomal sncRNA signature can serve as a reliable biomarker for ACLF detection and also be adopted to be the pre−triage biomarker for selecting cases that can gain benefits from adjuvant treatment.

Exosomal tRF-Leu-AAG-001 derived from mast cell as a potential non-invasive diagnostic biomarker for endometriosis

BACKGROUND

The diagnosis of endometriosis (EMs) is still based on laparoscopic observation. This study tries to verify whether exosomal tRNA-derived fragments (tRFs) in leucorrhea can be used as non-invasive diagnostic markers.

METHODS

Endometrial tissues and leucorrhea were sampled from women hospitalized in Ningbo University Affiliated Hospital from January 2021 to July 2021 with (n = 26) and without endometriosis (n = 25). Exosomes were isolated from samples by differential centrifugation. The small RNA sequencing was performed to detect the exosomal tRNA halves (tiRNAs)&tRFs. RNA probe and immunofluorescence antibody were used to localize the origin of tRFs. From mast cell lines infected with tRF-Leu-AAG-001 siRNA, we observed the change in vascular capacity and expression of inflammatory factors. The specificity and sensitivity tRF were determined by receiver operating characteristic analyses.

RESULTS

63 up-regulated and 45 down-regulated tRFs&tiRNAs were identified in ectopic exosomes. We selected tRF-Leu-AAG-001 as a candidate marker through KEGG pathway enrichment and PCR verification. We found that mast cells highly expressed tRF-Leu-AAG-001 in ectopic foci by immunofluorescence staining. We used siRNA to silenced tRF-Leu-AAG-001 expression in luva, qPCR analysis showed IL-6, IL-10, IL-1β, and TNF-α were significantly decreased. Meanwhile, tRF-Leu-AAG-001 siRNA dramatically reduced the angiogenic ability of luva. Finally, we examined the expression of exosomal tRF-Leu-AAG-001 in the leucorrhea. It was found exosomal tRF-Leu-AAG-001 had high specificity and sensitivity for predicting the occurrence of ectopic disease.

CONCLUSIONS

Exosomal tRF-Leu-AAG-001 derived from mast cells in ectopic foci might promote inflammation and angiogenesis. Meanwhile, leucorrhea exosomal tRF-Leu-AAG-001 could be a potential diagnostic biomarker for endometriosis.

Transfer RNA-derived small RNA: an emerging small non-coding RNA with key roles in cancer

Transfer RNAs (tRNAs) promote protein translation by binding to the corresponding amino acids and transporting them to the ribosome, which is essential in protein translation. tRNA-derived small RNAs (tsRNAs) are derived fragments of tRNAs that are cleaved explicitly under certain conditions. An increasing amount of research has demonstrated that tsRNAs have biological functions rather than just being degradation products. tsRNAs can exert functions such as regulating gene expression to influence cancer progression. Their dysregulation is closely associated with various cancers and can serve as diagnostic and prognostic biomarkers for cancer. This review summarizes the generation, classification, and biological functions of tsRNAs, and highlights the roles of tsRNAs in different cancers and their applications as tumor markers.

Transfer RNA-Derived Small RNAs: Novel Regulators and Biomarkers of Cancers

Transfer RNA-derived small RNAs (tsRNAs) are conventional non-coding RNAs (ncRNAs) with a length between18 and 40 nucleotides (nt) playing a crucial role in treating various human diseases including tumours. Nowadays, with the use of high-throughput sequencing technologies, it has been proven that certain tsRNAs are dysregulated in multiple tumour tissues as well as in the blood serum of cancer patients. Meanwhile, data retrieved from the literature show that tsRNAs are correlated with the regulation of the hallmarks of cancer, modification of tumour microenvironment, and modulation of drug resistance. On the other side, the emerging role of tsRNAs as biomarkers for cancer diagnosis and prognosis is promising. In this review, we focus on the specific characteristics and biological functions of tsRNAs with a focus on their impact on various tumours and discuss the possibility of tsRNAs as novel potential biomarkers for cancer diagnosis and prognosis.

Serum mitochondrial tsRNA serves as a novel biomarker for hepatocarcinoma diagnosis

Hepatocellular carcinoma (HCC), which makes up the majority of liver cancer, is induced by the infection of hepatitis B/C virus. Biomarkers are needed to facilitate the early detection of HCC, which is often diagnosed too late for effective therapy. The tRNA-derived small RNAs (tsRNAs) play vital roles in tumorigenesis and are stable in circulation. However, the diagnostic values and biological functions of circulating tsRNAs, especially for HCC, are still unknown. In this study, we first utilized RNA sequencing followed by quantitative reverse-transcription PCR to analyze tsRNA signatures in HCC serum. We identified tRF-Gln-TTG-006, which was remarkably upregulated in HCC serum (training cohort: 24 HCC patients vs. 24 healthy controls). In the validation stage, we found that tRF-Gln-TTG-006 signature could distinguish HCC cases from healthy subjects with high sensitivity (80.4%) and specificity (79.4%) even in the early stage (Stage I: sensitivity, 79.0%; specificity, 74.8%; 155 healthy controls vs. 153 HCC patients from two cohorts). Moreover, in vitro studies indicated that circulating tRF-Gln-TTG-006 was released from tumor cells, and its biological function was predicted by bioinformatics assay and validated by colony formation and apoptosis assays. In summary, our study demonstrated that serum tsRNA signature may serve as a novel biomarker of HCC.

The Clinical Significance of Transfer RNAs Present in Extracellular Vesicles

Extracellular vesicles (EVs) are important for intercellular signalling in multi-cellular organisms. However, the role of mature transfer RNAs (tRNAs) and tRNA fragments in EVs has yet to be characterised. This systematic review aimed to identify up-to-date literature on tRNAs present within human EVs and explores their potential clinical significance in health and disease. A comprehensive and systematic literature search was performed, and the study was conducted in accordance with PRISMA guidelines. Electronic databases MEDLINE and EMBASE were searched up until 1 January 2022. From 685 papers, 60 studies were identified for analysis. The majority of papers reviewed focussed on the role of EV tRNAs in cancers (31.7%), with numerous other conditions represented. Blood and cell lines were the most common EV sources, representing 85.9% of protocols used. EV isolation methods included most known methods, precipitation being the most common (49.3%). The proportion of EV tRNAs was highly variable, ranging between 0.04% to >95% depending on tissue source. EV tRNAs are present in a multitude of sources and show promise as disease markers in breast cancer, gastrointestinal cancers, and other diseases. EV tRNA research is an emerging field, with increasing numbers of papers highlighting novel methodologies for tRNA and tRNA fragment discovery.

Plasma tRNA-derived small RNAs signature as a predictive and prognostic biomarker in lung adenocarcinoma

Background

The prevalence of lung adenocarcinoma (LUAD) has increased, thus novel biomarkers for its early diagnosis is becoming more important than ever. tRNA-derived small RNA (tsRNA) is a new class of non-coding RNA which has important regulatory roles in cancer biology. This study was designed to identify novel predictive and prognostic tsRNA biomarkers.

Methods

tsRNAs were identified and performed differential expression analysis from 10 plasma samples (6 LUAD and 4 normal, SRP266333) and 96 tissue samples (48 LUAD and 48 normal, SRP133217). Then a tsRNA-mRNA regulatory network was constructed to find hub tsRNAs. Functional enrichment analysis was performed to infer the potential pathways associated with tsRNAs. Afterwards, a Support Vector Machine (SVM) algorithm was used to explore the potential biomarkers for diagnosing LUAD. Lastly, the function of tRF-21-RK9P4P9L0 was explored in A549 and H1299 cell lines.

Results

A significant difference of read distribution was observed between normal people and LUAD patients whether in plasma or tissue. A tsRNA-mRNA regulatory network consisting of 155 DEtsRNAs (differential expression tsRNAs) and 406 DEmRNAs (differential expression mRNAs) was established. Three tsRNAs (tRF-16-L85J3KE, tRF-21-RK9P4P9L0 and tRF-16-PSQP4PE) were identified as hub genes with degree > 100. We found Co-DEmRNAs (intersection of DEtsRNAs target mRNAs and differentially expressed mRNAs in LUAD) were engaged in a number of cancer pathways. The AUC of the three hub tsRNAs’ expression for diagnosing LUAD reached 0.92. Furthermore, the qPCR validation of the three hub tsRNAs in 37 paired normal and LUAD tissues was consistent with the RNA-Seq results. In addition, tRF-21-RK9P4P9L0 was negatively associated with LUAD prognosis. Inhibition of tRF-21-RK9P4P9L0 expression reduced the proliferation, migration and invasion ability of A549 and H1299 cell lines.

Conclusion

These findings will help us further understand the molecular mechanisms of LUAD and contribute to novel diagnostic biomarkers and therapeutic target discovery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02481-6.

tRF-19-W4PU732S promotes breast cancer cell malignant activity by targeting inhibition of RPL27A (ribosomal protein-L27A)

Breast cancer (BC) is a serious threat to female health. tRNA-derived fragments (tRFs) are popular biomarkers for the diagnosis and treatment of cancer. The purpose of this study was to identify tRFs related to BC and to explore the function and regulatory mechanism of crucial tRFs in BC cells. Small RNA database was used to detect the tRF profiles from BC patients and controls. Differentially expressed tRFs were determined by quantitative reverse transcription PCR (RT-qPCR), and a crucial tRF was evaluated through silence and overexpression experiments, and the target gene was investigated by luciferase reporter gene assay, Western blot and rescue experiment. We screened tRF-19-W4PU732S, which was processed from the mature tRNA-Ser-AGA, and significantly highlyexpressed in BC tissues and cells. Inhibition of tRF-19-W4PU732S weakened MDA-MB-231 cell proliferation, migration and invasion, while enhanced apoptosis. On the contrary, overexpression of tRF-19-W4PU732S promoted MCF-7 cell proliferation, migration and invasion, whereasreduced apoptosis. Furthermore, tRF-19-W4PU732S induced BC cell epithelial-to-mesenchymal transition (EMT) and cancer stem-like cells (CSC) phenotypes, such as up-regulation of OCT-4A, SOX2 and Vimentin and down-regulation of E-cadherin. Ribosomal protein-L27A (RPL27A) was a downstream target of tRF-19-W4PU732S, which was lowly expressed in BC cells. The knockdown of RPL27A expression partially restored the promoting effects of tRF-19-W4PU732S on BC cell viability, invasion, migration, EMT and CSC phenotypes, and the suppression of apoptosis. In conclusion, our results manifested that tRF-19-W4PU732S promotes the malignant activity of BC cells by inhibiting RPL27A, which provides a new scientific basis for the treatment of BC.Abbreviations BC: breast cancer; tRNAs: transfer RNAs; tiRNAs: tRNA-derived stressinduced RNAs; tRFs: tRNA-derived fragments; CCK-8: Cell Counting Kit-8; PI: propidium iodide; EMT: epithelial-to-mesenchymal transition; CSC: cancer stem-like cells; RPL27A: ribosomal protein-L27A; RT-qPCR: quantitative reverse transcription PCR.

A signature of saliva-derived exosomal small RNAs as predicting biomarker for esophageal carcinoma: a multicenter prospective study

BACKGROUND

The tRNA-derived small RNAs (tsRNAs) are produced in a nuclease-dependent manner in responses to variety of stresses that are common in cancers. We focus on a cancer-enriched tsRNA signature to develop a salivary exosome-based non-invasive biomarker for human esophageal squamous cell carcinoma (ESCC).

METHODS

Cancer-enriched small RNAs were identified by RNA sequencing of salivary exosomes obtained from ESCC patients (n = 3) and healthy controls (n = 3) in a pilot study and further validated in discovery cohort (n = 66). A multicenter prospective observational study was conducted in two ESCC high-incidence regions (n = 320 and 200, respectively) using the newly developed biomarker signature.

RESULTS

The tsRNA (tRNA-GlyGCC-5) and a previously undocumented small RNA were specifically enriched in salivary exosomes of ESCC patients, ESCC tissues and ESCC cells. The bi-signature composed of these small RNAs was able to discriminate ESCC patients from the controls with high sensitivity (90.50%) and specificity (94.20%). Based on the bi-signature Risk Score for Prognosis (RSP), patients with high-RSP have both shorter overall survival (OS) (HR 4.95, 95%CI 2.90-8.46) and progression-free survival (PFS) (HR 3.69, 95%CI 2.24-6.10) than those with low-RSP. In addition, adjuvant therapy improved OS (HR 0.47, 95%CI 0.29-0.77) and PFS (HR 0.36, 95%CI 0.21-0.62) only for patients with high but not low RSP. These findings are consistent in both training and validation cohort.

CONCLUSIONS

The tsRNA-based signature not only has the potential for diagnosis and prognosis but also may serve as a pre-operative biomarker to select patients who would benefit from adjuvant therapy.

TRIAL REGISTRATION

A prospective study of diagnosis biomarkers of esophageal squamous cell carcinoma, ChiCTR2000031507 . Registered 3 April 2016 - Retrospectively registered.

Deciphering the tRNA-derived small RNAs: origin, development, and future

Transfer RNA (tRNA)-derived small RNAs (tsRNAs), a novel category of small noncoding RNAs, are enzymatically cleaved from tRNAs. Previous reports have shed some light on the roles of tsRNAs in the development of human diseases. However, our knowledge about tsRNAs is still relatively lacking. In this paper, we review the biogenesis, classification, subcellular localization as well as action mechanism of tsRNAs, and discuss the association between chemical modifications of tRNAs and the production and functions of tsRNAs. Furthermore, using immunity, metabolism, and malignancy as examples, we summarize the molecular mechanisms of tsRNAs in diseases and evaluate the potential of tsRNAs as new biomarkers and therapeutic targets. At the same time, we compile and introduce several resource databases that are currently publicly available for analyzing tsRNAs. Finally, we discuss the challenges associated with research in this field and future directions.

Regulatory roles of tRNA-derived RNA fragments in human pathophysiology

Hundreds of tRNA genes and pseudogenes are encoded by the human genome. tRNAs are the second most abundant type of RNA in the cell. Advancement in deep-sequencing technologies have revealed the presence of abundant expression of functional tRNA-derived RNA fragments (tRFs). They are either generated from precursor (pre-)tRNA or mature tRNA. They have been found to play crucial regulatory roles during different pathological conditions. Herein, we briefly summarize the discovery and recent advances in deciphering the regulatory role played by tRFs in the pathophysiology of different human diseases.

tRNA-derived small RNAs: novel regulators of cancer hallmarks and targets of clinical application

tRNAs are a group of conventional noncoding RNAs (ncRNAs) with critical roles in the biological synthesis of proteins. Recently, tRNA-derived small RNAs (tsRNAs) were found to have important biological functions in the development of human diseases including carcinomas, rather than just being considered pure degradation material. tsRNAs not only are abnormally expressed in the cancer tissues and serum of cancer patients, but also have been suggested to regulate various vital cancer hallmarks. On the other hand, the application of tsRNAs as biomarkers and therapeutic targets is promising. In this review, we focused on the basic characteristics of tsRNAs, and their biological functions known thus far, and explored the regulatory roles of tsRNAs in cancer hallmarks including proliferation, apoptosis, metastasis, tumor microenvironment, drug resistance, cancer stem cell phenotype, and cancer cell metabolism. In addition, we also discussed the research progress on the application of tsRNAs as tumor biomarkers and therapeutic targets.

tRNA-derived fragments: tRF-Gly-CCC-046, tRF-Tyr-GTA-010 and tRF-Pro-TGG-001 as novel diagnostic biomarkers for breast cancer

BACKGROUND

tRNA-derived fragments (tRFs) have been found to play a regulatory role in the occurrence and development of many tumors. The aim of this study was to identify the expression of tRFs in breast cancer and their ability to serve as diagnostic markers for breast cancer.

METHODS

Total RNA was extracted from breast cancer and paracancerous tissues (n = 83), as well as from the sera of breast cancer patients (n = 214) and healthy donors (n = 113) using trizol reagents. Expression of tRFs was then detected by q-PCR, and analyzed using t-test and ROC to illuminate their potential as biomarkers for breast cancer.

RESULTS

Our results demonstrated that tRFs: tRF-Gly-CCC-046, tRF-Tyr-GTA-010 and tRF-Pro-TGG-001 were downregulated in both tissues and sera from breast cancer patients as well as early-stage patients compared with those in the healthy donors. More importantly, the three tRFs were capable of serving as circulating biomarkers of diagnostics and early diagnosis of breast cancer, possessing areas under the curve (AUC) of 0.7871 and 0.7987, respectively.

CONCLUSIONS

tRFs: tRF-Gly-CCC-046, tRF-Tyr-GTA-010 and tRF-Pro-TGG-001 are downregulated in breast cancer and early breast cancer and act as new potential biomarkers for the diagnosis and early diagnosis of breast cancer.

Expression and Diagnostic Value of tRNA-Derived Fragments Secreted by Extracellular Vesicles in Hypopharyngeal Carcinoma

OBJECTIVE

To detect the expression level of tRNA-derived fragments secreted by extracellular vesicles in hypopharyngeal cancer and explore the influence of tRNA-derived fragments on the occurrence of hypopharyngeal cancer and lung metastasis.

METHODS

After high-speed centrifugation, tRNA, which was extracted from the extracellular vesicles of patients with hypopharyngeal cancer and healthy subjects, was sequenced using microarrays. The expression of three differentially expressed tRNAs in hypopharyngeal cancer, healthy subjects, human normal laryngeal epithelial cells and hypopharyngeal cancer line was detected by qRT-PCR. The correlation between the upregulated tRNA, as identified by qRT-PCR, and the clinicopathological features of the non-lung metastatic patients was further analyzed. Finally, the expressions of upregulated tRNA were compared between the non-lung metastatic and lung metastatic patients. The risk factors of hypopharyngeal cancer with lung metastatic were identified by the Cox regression analysis.

RESULTS

By high-speed centrifugation, extracellular vesicles were extracted successfully. It was found that a variety of tRNAs in the extracellular vesicles from patients with hypopharyngeal cancer by sequencing. qRT-PCR validation indicated that tRF-1:30-Lys-CTT-1-M2 was significantly overexpressed in hypopharyngeal cancer patients and tumor cells, especially in lung metastatic patients. It was indicated that tRF-1:30-Lys-CTT-1-M2 overexpression was closely related to such pathological features as tumor staging, differentiation grade, smoking history and drinking history. According to the Cox regression analysis, stage III-IV, smoking history, drinking history and tRF-1:30-Lys-CTT-1-M2 overexpression were independent risk factors for metastasis of hypopharyngeal cancer.

CONCLUSION

tRF-1:30-Lys-CTT-1-M2 was overexpressed in patients with hypopharyngeal cancer and was identified as an independent risk factor for lung metastasis. It can be used as a novel biomarker for the diagnosis and lung metastasis monitoring of hypopharyngeal cancer.

Current Search through Liquid Biopsy of Effective Biomarkers for Early Cancer Diagnosis into the Rich Cargoes of Extracellular Vesicles

There exist many different human cancers, but regardless of the cancer type, an early diagnosis is a necessary condition for further optimal outcomes from the disease. Therefore, efficient specific and sensitive cancer biomarkers are urgently needed. This is especially true for the cancers depicting a silent progression, and those only diagnosed in an already metastatic state with a poor survival prognostic. After a rapid overview of the previous methods for cancer diagnosis, the outstanding characteristics of extracellular vesicles (EVs) will be presented, as new interesting candidates for early cancer diagnosis in human biofluid non-invasive liquid biopsy. The present review aims to give the state-of-the-art of the numerous searches of efficient EV-mediated cancer diagnosis. The corresponding literature quest was performed by means of an original approach, using a powerful Expernova Questel big data platform, which was specifically adapted for a literature search on EVs. The chosen collected scientific papers are presented in two parts, the first one drawing up a picture of the current general status of EV-mediated cancer diagnosis and the second one showing recent applications of such EV-mediated diagnosis for six important human-specific cancers, i.e., lung, breast, prostate, colorectal, ovary and pancreatic cancers. However, the promising perspective of finally succeeding in the worldwide quest for the much-needed early cancer diagnosis has to be moderated by the many remaining challenges left to solve before achieving the efficient clinical translation of the constantly increasing scientific knowledge.

Toward an Understanding of Extracellular tRNA Biology

Extracellular RNAs (exRNAs) including abundant full length tRNAs and tRNA fragments (tRFs) have recently garnered attention as a promising source of biomarkers and a novel mediator in cell-to-cell communication in eukaryotes. Depending on the physiological state of cells, tRNAs/tRFs are released to the extracellular space either contained in extracellular vesicles (EVs) or free, through a mechanism that is largely unknown. In this perspective article, we propose that extracellular tRNAs (ex-tRNAs) and/or extracellular tRFs (ex-tRFs) are relevant paracrine signaling molecules whose activity depends on the mechanisms of release by source cells and capture by recipient cells. We speculate on how ex-tRNA/ex-tRFs orchestrate the effects in target cells, depending on the type of sequence and the mechanisms of uptake. We further propose that tRNA modifications may be playing important roles in ex-tRNA biology.

Non-coding RNAs: Emerging from the discovery to therapeutic applications

The knowledge about non-coding RNAs (ncRNAs) is rapidly increasing with new data continuously emerging, regarding their diverse types, applications, and roles. Particular attention has been given to ncRNA with regulatory functions, which may have a critical role both in biological and pathological conditions. As a result of the diversity of ncRNAs and their ubiquitous involvement in several biologic processes, ncRNA started to be considered in the biomedical field, with immense potential to be exploited either as biomarkers or as therapeutic agents in certain pathologies. Indeed, ncRNA-based therapeutics have been proposed in many disorders and some even reached clinical trials. However, to prepare an RNA product suitable for pharmacological applications, certain criteria must be fulfilled, and it has to be guaranteed RNA purity, stability, and bioactivity. So, in this review, the different types of ncRNAs are identified and characterized, by describing their biogenesis, functions, and applications. A perspective on the main challenges and innovative approaches for the future and broad therapeutic application of RNA is also presented.

tRNA-Derived Fragments (tRFs) in Bladder Cancer: Increased 5'-tRF-LysCTT Results in Disease Early Progression and Patients' Poor Treatment Outcome

Simple Summary

Bladder cancer (BlCa) management relies on lifelong surveillance strategies with invasive interventions that adversely affect patients’ quality-of-life and lead to a high economic burden for healthcare systems. Exploitation of bladder tumors’ molecular background could lead to modern precision medicine. tRNA-derived fragments (tRFs), rather than degradation debris, are novel functional small ncRNAs that have emerged as key regulators of cellular homeostasis. This is the first study of the clinical utility of tRFs in BlCa. Using in silico analysis of the TCGA-BLCA project, we identified 5′-tRF-LysCTT (5′-tRF of tRNA^LysCTT) to be significantly deregulated in BlCa, and we have studied its clinical value in our cohort of 230 BlCa patients. Elevated 5′-tRF-LysCTT levels were significantly associated with aggressive tumor phenotype as well as early disease progression and poor treatment outcome. Integration of 5′-tRF-LysCTT with established disease markers resulted in superior prediction of patients’ prognosis, supporting personalized treatment and monitoring decisions.

Abstract

The heterogeneity of bladder cancer (BlCa) prognosis and treatment outcome requires the elucidation of tumors’ molecular background towards personalized patients’ management. tRNA-derived fragments (tRFs), although originally considered as degradation debris, represent a novel class of powerful regulatory non-coding RNAs. In silico analysis of the TCGA-BLCA project highlighted 5′-tRF-LysCTT to be significantly deregulated in bladder tumors, and 5′-tRF-LysCTT levels were further quantified in our screening cohort of 230 BlCa patients. Recurrence and progression for non-muscle invasive (NMIBC) patients, as well as progression and patient’s death for muscle-invasive (MIBC) patients, were used as clinical endpoint events. TCGA-BLCA were used as validation cohort. Bootstrap analysis was performed for internal validation and the clinical net benefit of 5′-tRF-LysCTT on disease prognosis was assessed by decision curve analysis. Elevated 5′-tRF-LysCTT was associated with unfavorable disease features, and significant higher risk for early progression (multivariate Cox: HR = 2.368; p = 0.033) and poor survival (multivariate Cox: HR = 2.151; p = 0.032) of NMIBC and MIBC patients, respectively. Multivariate models integrating 5′-tRF-LysCTT with disease established markers resulted in superior risk-stratification specificity and positive prediction of patients’ progression. In conclusion, increased 5′-tRF-LysCTT levels were strongly associated with adverse disease outcome and improved BlCa patients’ prognostication.