tRNA-derived fragment tRF Lys-CTT-010 promotes triple-negative breast cancer progression by regulating glucose metabolism via G6PC

The novel tRNA-derived fragment, tiRNA-Met, inhibits the malignant progression of triple-negative breast cancer by regulating RANBP3L via a targeted interaction with SNRPA

BACKGROUND

tRNA-derived fragments (tRFs) have emerged as significant noncoding RNAs in cancer biology; however, their roles and mechanisms in triple-negative breast cancer (TNBC) remain inadequately characterized.

METHODS

tRF and tiRNA sequencing, real-time quantitative polymerase chain reaction (RT-qPCR), fluorescence in situ hybridization (FISH), and subcellular fractionation were used to explore the expression and characteristic of tiRNA-Met in TNBC. The biological functions of tiRNA-Met were assessed using CCK-8 assays, colony formation assays, and Transwell assays in vitro, alongside mouse xenograft models in vivo. RNA pull-down, mass spectrum, RNA immunoprecipitation (RIP), western blot, ubiquitination assays, RNA sequencing, actinomycin D assays, immunofluorescence, immunohistochemical staining, and rescue experiments were performed to explore the regulatory mechanisms of tiRNA-Met in TNBC.

RESULTS

tiRNA-Met was an uncharacterized tRF that originated from mitochondrial tRNAMet-CAT and was primarily localized in the cytoplasm. Its expression was significantly downregulated in TNBC tumor tissues compared with adjacent normal tissues. Overexpression of tiRNA-Met markedly inhibited the proliferation, migration, and invasion of TNBC cells; whereas, its reduced expression elicited opposite effects. In addition, tiRNA-Met overexpression suppressed TNBC cell growth in vivo. Mechanistically, tiRNA-Met directly interacted with the RNA recognition motif 2 (RRM2) domain of small nuclear ribonucleoprotein A (SNRPA), promoting SNRPA protein degradation via the ubiquitin/proteasome pathway. This interaction enhanced the stability of Ran-binding protein 3-like (RANBP3L) mRNA, resulting in increased RANBP3L expression and subsequent inhibition of the mTORC1/RPS6 signaling pathway.

CONCLUSIONS

Our study identified tiRNA-Met as a novel anti-oncogenic tRF and elucidated its mechanism for inhibiting the malignancy of TNBC. tiRNA-Met directly bound to SNRPA, promoting its degradation and stabilizing RANBP3L mRNA, ultimately leading to the inhibition of the mTORC1 signaling pathway. These findings position tiRNA-Met as a promising candidate for diagnostic and therapeutic applications in TNBC.

Research trends on lactate in cancer: a bibliometric analysis and comprehensive review (2015-2024)

Objective

A bibliometric approach was employed to systematically analyze the trends and potential future developments in lactic acid-related cancer research over the past 10 years.

Method

We conducted a bibliometric analysis of literature on lactic acid in cancer research from 2015 to 2024, using data collected from the Web of Science database. A bibliometric analysis was conducted to identify general research directions and trends in current publications, as well as to determine the most prolific and influential authors, institutions, countries, and keywords in lactate and cancer research. The data were collected and analyzed using VOSviewer (Leiden University, Leiden, Netherlands), Microsoft Excel (Microsoft, Redmond, Washington, USA), CiteSpace, and Biblioshiny, with a focus on analysis and visualization.

Results

A total of 5,999 publications were analyzed, focusing on various aspects of the relevant literature, including year of publication, country, institution, author, journal, category, keywords, and research frontiers. The analysis of these publications reveals a general upward trend in publication volume from 2015 to 2024, with China and University of California System emerging as the most prolific country and institution, respectively. SCIENTIFIC REPORTS is the most frequently published journal, while Oncotarget is the most cited journal in the field. Zhang Y. was the most prolific author, publishing 100 documents over 10 years, with the highest citation count and an H-index of 28.Keyword analysis revealed five key themes in lactate-cancer research (2013-2023): Metabolic-epigenetic crosstalk, Tumor immunosuppressive microenvironment, Innovative therapies/drug delivery, Lactate-mediated signaling, Metabolic-targeted treatment strategies. Current research emphasizes the application of lactic acid metabolism in metabolic intervention, immune microenvironment regulation, combination of new therapeutic techniques and applications in specific cancer types.

Conclusion

Research on lactic acid in cancer is growing rapidly, with China at the forefront of this field. Research into lactic acid's role in immune cell regulation, metabolism, and signaling pathways, combined with multi-modal imaging, big data analytics, and innovative drug delivery, is set to become a key trend in future studies, which promises new directions for identifying therapeutic targets, biomarkers, and developing advanced treatments.

The functions and modifications of tRNA-derived small RNAs in cancer biology

Recent progress in noncoding RNA research has highlighted transfer RNA-derived small RNAs (tsRNAs) as key regulators of gene expression, linking them to numerous cellular functions. tsRNAs, which are produced by ribonucleases such as angiogenin and Dicer, are classified based on their size and cleavage positions. They play diverse regulatory roles at the transcriptional, post-transcriptional, and translational levels. Furthermore, tRNAs undergo various modifications that influence their biogenesis, stability, functionality, biochemical characteristics, and protein-binding affinity. tsRNAs, with their aberrant expression patterns and modifications, act as both oncogenes and tumor suppressors. This review explores the biogenetic pathways of tsRNAs and their complex roles in gene regulation. We then focus on the importance of RNA modifications in tsRNAs, evaluating their impact on the biogenesis and biological functions on tsRNAs. Furthermore, we summarize recent data indicating that tsRNAs exhibit varied expression profiles across different cancer types, highlighting their potential as innovative biomarkers and therapeutic targets. This discussion integrates both existing and new knowledge about tsRNAs, emphasizing their importance in cancer biology and clinical advancement.

β-lapachone suppresses carcinogenesis of cervical cancer via interaction with AKT1

Introduction

Cervical cancer is one of the most prevalent malignant tumors affecting women worldwide, and affected patients often face a poor prognosis due to its high drug resistance and recurrence rates. β-lapachone, a quinone compound originally extracted from natural plants, is an antitumor agent that specifically targets NQO1.

Methods

CC cells were treated with varying concentrations of β-lapachone to examine its effects on glucose metabolism, proliferation, metastasis, angiogenesis, and EMT in vitro. The targets and action pathways of β-lapachone were identified using network pharmacology and molecular docking, with KEGG pathway enrichment analysis. Its effects and toxicity were verified in vivo using a nude mouse xenograft model.

Results

β-lapachone significantly inhibited the proliferation and metastasis of cervical cancer cells by regulating glucose metabolism, reducing tumor angiogenesis, and suppressing epithelial-mesenchymal transition (EMT) in cells with high NQO1 expression. Furthermore, we identified the inactivation of the PI3K/AKT/mTOR pathway as the key mechanism underlying these effects. AKT1 was identified as a potential target of β-lapachone in modulating glucose metabolism and EMT in cervical cancer cells.

Conclusion

These findings suggest that β-lapachone inhibits the malignant progression of cervical cancer by targeting AKT1 to regulate glucose metabolism in NQO1-overexpressing cells, providing a theoretical basis for developing novel therapeutic strategies for cervical cancer.

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.

tRNA-derived fragments: Unveiling new roles and molecular mechanisms in cancer progression

tRNA-derived fragments (tRFs) are novel small noncoding RNAs (sncRNAs) that range from approximately 14 to 50 nt. They are generated by the cleavage of mature tRNAs or precursor tRNAs (pre-tRNAs) at specific sites. Based on their origin and length, tRFs can be classified into three categories: (1) tRF-1 s; (2) tRF-3 s, tRF-5 s, and internal tRFs (i-tRFs); and (3) tRNA halves. They play important roles in stress response, signal transduction, and gene expression processes. Recent studies have identified differential expression of tRFs in various tumors. Aberrantly expressed tRFs have critical clinical value and show promise as new biomarkers for tumor diagnosis and prognosis and as therapeutic targets. tRFs regulate the malignant progression of tumors via various mechanisms, primarily including modulation of noncoding RNA biogenesis, global chromatin organization, gene expression regulation, modulation of protein translation, regulation of epigenetic modification, and alternative splicing regulation. In conclusion, tRF-mediated regulatory pathways could present new avenues for tumor treatment, and tRFs could serve as promising therapeutic targets for cancer therapy.

Downregulation of tRF-Cys-GCA-029 by hyperglycemia promotes tumorigenesis and glycolysis of diabetic breast cancer through upregulating PRKCG translation

BACKGROUND

Diabetes mellitus (DM) affects up to one-third of breast cancer (BC) patients. Patients with co-existing BC and DM (BC-DM) have worsened BC prognosis. Nevertheless, the molecular mechanisms orchestrating BC-DM prognosis remain poorly understood. tRNA-derived fragments (tRFs) have been shown to regulate cancer progression. However, the biological role of tRFs in BC-DM has not been explored.

METHODS

tRF levels in tumor tissues and cells were detected by tRF sequencing and qRT-PCR. The effects of tRF on BC cell malignancy were assessed under euglycemic and hyperglycemic conditions in vitro. Metabolic changes were assessed by lactate, pyruvate, and extracellular acidification rate (ECAR) assays. Diabetic animal model was used to evaluate the impacts of tRF on BC tumor growth. RNA-sequencing (RNA-seq), qRT-PCR, Western blot, polysome profiling, luciferase reporter assay, and rescue experiments were performed to explore the regulatory mechanisms of tRF in BC-DM.

RESULTS

We identified that tRF-Cys-GCA-029 was downregulated in BC-DM tissues and under hyperglycemia conditions in BC cells. Functionally, downregulation of tRF-Cys-GCA-029 promoted BC cell proliferation and migration in a glucose level-dependent manner. tRF-Cys-GCA-029 knockdown also enhanced glycolysis metabolism in BC cells, indicated by increasing lactate/pyruvate production and ECAR levels. Notably, injection of tRF-Cys-GCA-029 mimic significantly suppressed BC tumor growth in diabetic-mice. Mechanistically, tRF-Cys-GCA-029 regulated BC cell malignancy and glycolysis via interacting with PRKCG in two ways: binding to the coding sequence (CDS) of PRKCG mRNA to regulate its transcription and altering polysomal PRKCG mRNA expression to modify its translation.

CONCLUSIONS

Hyperglycemia-downregulated tRF-Cys-GCA-029 enhances the malignancy and glycolysis of BC cells. tRF-Cys-GCA-029-PRKCG-glycolysis axis may be a potential therapeutic target against BC-DM.

tRNA-derived small RNAs in human cancers: roles, mechanisms, and clinical application

Transfer RNA (tRNA)-derived small RNAs (tsRNAs) are a new type of non-coding RNAs (ncRNAs) produced by the specific cleavage of precursor or mature tRNAs. tsRNAs are involved in various basic biological processes such as epigenetic, transcriptional, post-transcriptional, and translation regulation, thereby affecting the occurrence and development of various human diseases, including cancers. Recent studies have shown that tsRNAs play an important role in tumorigenesis by regulating biological behaviors such as malignant proliferation, invasion and metastasis, angiogenesis, immune response, tumor resistance, and tumor metabolism reprogramming. These may be new potential targets for tumor treatment. Furthermore, tsRNAs can exist abundantly and stably in various bodily fluids (e.g., blood, serum, and urine) in the form of free or encapsulated extracellular vesicles, thereby affecting intercellular communication in the tumor microenvironment (TME). Meanwhile, their abnormal expression is closely related to the clinicopathological features of tumor patients, such as tumor staging, lymph node metastasis, and poor prognosis of tumor patients; thus, tsRNAs can be served as a novel type of liquid biopsy biomarker. This review summarizes the discovery, production, and expression of tsRNAs and analyzes their molecular mechanisms in tumor development and potential applications in tumor therapy, which may provide new strategies for early diagnosis and targeted therapy of tumors.

The FOXO1/G6PC axis promotes gastric cancer progression and mediates 5-fluorouracil resistance by targeting the PI3K/AKT/mTOR signaling pathway

Gastric cancer (GC) is a prevalent malignancy of the digestive system. Distant metastasis and chemotherapy resistance are the crucial obstacles to prognosis in GC. Recent research has discovered that the glucose-6-phosphatase catalytic subunit (G6PC) plays an important role in tumor malignant development. However, little evidence has highlighted its role in GC. Herein, through a comprehensive analysis including profiling of tissue samples and functional validation in vivo and in vitro, we identify G6PC as a crucial factor in GC tumorigenesis. Importantly, we found that the FOXO1/G6PC axis could accelerate GC cell proliferation, metastasis, and 5-Fluorouracil (5-FU) resistance by targeting the PI3K/AKT/mTOR signaling pathway, implicating that as a prospective therapeutic approach in GC.

tRF-1:30-Gly-CCC-3 inhibits thyroid cancer via binding to PC and modulating metabolic reprogramming

tRFs and tiRNAs (tRNA-derived fragments) are an emerging class of small noncoding RNAs produced by the precise shearing of tRNAs in response to specific stimuli. They have been reported to regulate the pathological processes of numerous human cancers. However, the biofunction of tRFs and tiRNAs in the development and progression of papillary thyroid cancer (PTC) has not been reported yet. In this study, we aimed to explore the biological roles of tRFs and tiRNAs in PTC and discovered that a novel 5'tRNA-derived fragment called tRF-1:30-Gly-CCC-3 (tRF-30) was markedly down-regulated in PTC tissues and cell lines. Functionally, tRF-30 inhibited the proliferation and invasion of PTC cells. Mechanistically, tRF-30 directly bound to the biotin-dependent enzyme pyruvate carboxylase (PC), downregulated its protein level, interfered with the TCA cycle intermediate anaplerosis, and thus affected metabolic reprogramming and PTC progression. These findings revealed a novel regulatory mechanism for tRFs and a potential therapeutic target for PTC.

Multiple regulatory roles of the transfer RNA-derived small RNAs in cancers

With the development of sequencing technology, transfer RNA (tRNA)-derived small RNAs (tsRNAs) have received extensive attention as a new type of small noncoding RNAs. Based on the differences in the cleavage sites of nucleases on tRNAs, tsRNAs can be divided into two categories, tRNA halves (tiRNAs) and tRNA-derived fragments (tRFs), each with specific subcellular localizations. Additionally, the biogenesis of tsRNAs is tissue-specific and can be regulated by tRNA modifications. In this review, we first elaborated on the classification and biogenesis of tsRNAs. After summarizing the latest mechanisms of tsRNAs, including transcriptional gene silencing, post-transcriptional gene silencing, nascent RNA silencing, translation regulation, rRNA regulation, and reverse transcription regulation, we explored the representative biological functions of tsRNAs in tumors. Furthermore, this review summarized the clinical value of tsRNAs in cancers, thus providing theoretical support for their potential as novel biomarkers and therapeutic targets.

Metabolism-regulating non-coding RNAs in breast cancer: roles, mechanisms and clinical applications

Breast cancer is one of the most common malignancies that pose a serious threat to women's health. Reprogramming of energy metabolism is a major feature of the malignant transformation of breast cancer. Compared to normal cells, tumor cells reprogram metabolic processes more efficiently, converting nutrient supplies into glucose, amino acid and lipid required for malignant proliferation and progression. Non-coding RNAs(ncRNAs) are a class of functional RNA molecules that are not translated into proteins but regulate the expression of target genes. NcRNAs have been demonstrated to be involved in various aspects of energy metabolism, including glycolysis, glutaminolysis, and fatty acid synthesis. This review focuses on the metabolic regulatory mechanisms and clinical applications of metabolism-regulating ncRNAs involved in breast cancer. We summarize the vital roles played by metabolism-regulating ncRNAs for endocrine therapy, targeted therapy, chemotherapy, immunotherapy, and radiotherapy resistance in breast cancer, as well as their potential as therapeutic targets and biomarkers. Difficulties and perspectives of current targeted metabolism and non-coding RNA therapeutic strategies are discussed.

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.

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.

Absolute quantification of a plasma tRNA-derived fragment for the diagnosis and prognosis of gastric cancer

Background

The transition from a healthy gastric mucosa to gastric cancer is a multi-step process. Early screening can significantly improve the survival rate of gastric cancer patients. A reliable liquid biopsy for gastric cancer prediction is urgently needed and since tRNA-derived fragments (tRFs) are abundant in various body fluids, tRFs are possible new biomarkers for gastric cancer.

Methods

A total of 438 plasma samples from patients with different gastric mucosal lesions as well as healthy individuals were collected. A specific reverse transcription primer, a forward primer, a reverse primer, and a TaqMan probe were designed. A standard curve was constructed and an absolute quantitation method was devised for detection of tRF-33-P4R8YP9LON4VDP in plasma samples of individuals with differing gastric mucosa lesions. Receiver operating characteristic curves were constructed to evaluate the diagnostic values of tRF-33-P4R8YP9LON4VDP for individual with differing gastric mucosa. A Kaplan-Meier curve was established to calculate the prognostic value of tRF-33-P4R8YP9LON4VDP for advanced gastric cancer patients. Finally, a multivariate Cox regression analysis was performed to assess the independent prognostic value of tRF-33-P4R8YP9LON4VDP for advanced gastric cancer patients.

Results

A detection method for plasma tRF-33-P4R8YP9LON4VDP was successfully established. Levels of plasma tRF-33-P4R8YP9LON4VDP were shown to reflect a gradient change from healthy individuals to gastritis patients to early and advanced gastric cancer patients. Significant differences were found among individuals with differing gastric mucosa, with reduced levels of tRF-33-P4R8YP9LON4VDP significantly related to a poor prognosis. tRF-33-P4R8YP9LON4VDP was found to be an independent predictor of an unfavorable survival outcome.

Conclusions

In this study, we developed a quantitative detection method for plasma tRF-33-P4R8YP9LON4VDP that exhibited hypersensitivity, convenience, and specificity. Detection of tRF-33-P4R8YP9LON4VDP was found to be a valuable means by which to monitor different gastric mucosa and to predict patient prognosis.

Transcription factor c-Jun modulates GLUT1 in glycolysis and breast cancer metastasis

As the main isoforms of membranous glucose transporters (GLUT), GLUT1 involves tumorigenesis, metastasis and prognosis in a variety of cancers. However, its role in breast cancer metastasis remains to be elucidated. Here we examined its transcriptional and survival data in patients with breast cancer from several independent databases including the Oncomine, Gene Expression Profiling Interactive Analysis, Gene Expression across Normal and Tumor tissue, UALCAN, cBioPortal, Kaplan-Meier Plotter and PROGgeneV2. We found that its mRNA expression was significantly high in cancer tissues, which was associated with metastasis and poor survival. Transcription factor c-Jun might bind to GLUT1 promoter to downregulate its gene expression or mRNA stability, therefore to suppress glycolysis and metastasis. By qRT-PCR, we verified that GLUT1 was significantly increased in 38 paired human breast cancer samples while JUN was decreased. Furthermore, the protein level of GLUT1 was higher in tumor than in normal tissues by IHC assay. To explore underlying pathways, we further performed GO and KEGG analysis of genes related to GLUT1 and JUN and found that GLUT1 was increased by transcription factor c-Jun in breast cancer tissues to influence glycolysis and breast cancer metastasis.

Expression profiles of tRNA‑derived fragments in high glucose‑treated tubular epithelial cells

Transfer RNA-derived fragments (tRFs), a novel class of small non-coding RNA produced by the cleavage of pre- and mature tRNAs, are involved in various diseases. Renal tubulointerstitial fibrosis is a common final pathway in diabetic nephropathy (DN) in which hyperglycemia-induced tubular extracellular matrix (ECM) accumulation serves a vital role. The present study aimed to detect and investigate the role of tRFs in the accumulation of tubular ECM. Differentially expressed tRFs were analysed with high-throughput sequencing in primary mouse tubular epithelial cells treated with high glucose (HG). The Gene Ontology (GO) was used to analyze the potential molecular functions of these differentially expressed tRFs, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the associated signaling pathways involved in these differentially expressed tRFs. tRF-1:30-Gln-CTG-4 was overexpressed using tRF-1:30-Gln-CTG-4 mimic, followed by HG treatment. A total of 554 distinct tRFs were detected and 64 differentially expressed tRFs (fold change >2; P<0.05) were identified in tubular epithelial cells following high glucose (HG) treatment, among which 27 were upregulated and 37 were downregulated. Ten selected tRFs with the greatest difference (fold change >2; P<0.05) were verified to be consistent with small RNA-sequencing data, of which tRF-1:30-Gln-CTG-4 showed the most pronounced difference in expression and was significantly decreased in response to HG. GO analysis indicated that the differentially expressed tRFs were associated with 'cellular process', 'biological regulation' and 'metabolic process'. An analysis of the KEGG database suggested that these differentially expressed tRFs were involved in 'autophagy' and signaling pathways for 'forkhead box O', 'the mammalian target of rapamycin' and 'mitogen-activated protein kinase'. Finally, the overexpression of tRF-1:30-Gln-CTG-4 ameliorated HG-induced ECM accumulation in tubular epithelial cells. Therefore, the present study demonstrated that there may be a significant association between tRFs and HG-induced ECM accumulation in tubular epithelial cells; these differentially expressed tRFs warrant further study to explore the pathogenesis of DN.

Transfer RNA-derived small RNAs (tsRNAs): Versatile regulators in cancer

tRNA-derived small RNAs (tsRNAs) represent a novel class of regulatory small non-coding RNAs (sncRNAs), produced by the specific cleavage of transfer RNAs (tRNAs). In recent years, pilot studies one after the other have uncovered the critical roles of tsRNAs in various fundamental biological processes as well as in the development of human diseases including cancer. Based on the newly updated hallmarks of cancer, we provide a comprehensive review regarding the dysregulation, functional implications and complicated molecular mechanisms of tsRNAs in cancer. In addition, the potential technical challenges and future prospects in the fields of tsRNA research are discussed in this review.

Advances in Hybrid Vesicular-based Drug Delivery Systems: Improved Biocompatibility, Targeting, Therapeutic Efficacy and Pharmacokinetics of Anticancer Drugs

Anticancer drugs and diagnostics can be transported in nanoscale vesicles that provide a flexible platform. A hybrid nanoparticle, a nano assembly made up of many types of nanostructures, has the greatest potential to perform these two activities simultaneously. Nanomedicine has shown the promise of vesicular carriers based on lipopolymersomes, lipid peptides, and metallic hybrid nano-vesicle systems. However, there are significant limitations that hinder the clinical implementation of these systems at the commercial scale, such as low productivity, high energy consumption, expensive setup, long process durations, and the current cancer therapies described in this article. Combinatorial hybrid systems can be used to reduce the above limitations. A greater therapeutic index and improved clinical results are possible with hybrid nanovesicular systems, which integrate the benefits of many carriers into a single structure. Due to their unique properties, cell-based drug delivery systems have shown tremendous benefits in the treatment of cancer. Nanoparticles (NPs) can benefit significantly from the properties of erythrocytes and platelets, which are part of the circulatory cells and circulate for a long time. Due to their unique physicochemical properties, nanomaterials play an essential role in cell-based drug delivery. Combining the advantages of different nanomaterials and cell types gives the resulting delivery systems a wide range of desirable properties. NPs are nextgeneration core-shell nanostructures that combine a lipid shell with a polymer core. The fabrication of lipid-polymer hybrid NPs has recently undergone a fundamental shift, moving from a two-step to a one-step technique based on the joint self-assembly of polymers and lipids. Oncologists are particularly interested in this method as a combinatorial drug delivery platform because of its two-in-one structure. This article addresses various preparative methods for the preparation of hybrid nano-vesicular systems. It also discusses the cellular mechanism of hybrid nano-vesicular systems and describes the thorough knowledge of various hybrid vesicular systems.

Role of the Ribonuclease ONCONASE in miRNA Biogenesis and tRNA Processing: Focus on Cancer and Viral Infections

The majority of transcribed RNAs do not codify for proteins, nevertheless they display crucial regulatory functions by affecting the cellular protein expression profile. MicroRNAs (miRNAs) and transfer RNA-derived small RNAs (tsRNAs) are effectors of interfering mechanisms, so that their biogenesis is a tightly regulated process. Onconase (ONC) is an amphibian ribonuclease known for cytotoxicity against tumors and antiviral activity. Additionally, ONC administration in patients resulted in clinical effectiveness and in a well-tolerated feature, at least for lung carcinoma and malignant mesothelioma. Moreover, the ONC therapeutic effects are actually potentiated by cotreatment with many conventional antitumor drugs. This review not only aims to describe the ONC activity occurring either in different tumors or in viral infections but also to analyze the molecular mechanisms underlying ONC pleiotropic and cellular-specific effects. In cancer, data suggest that ONC affects malignant phenotypes by generating tRNA fragments and miRNAs able to downregulate oncogenes expression and upregulate tumor-suppressor proteins. In cells infected by viruses, ONC hampers viral spread by digesting the primer tRNAs necessary for viral DNA replication. In this scenario, new therapeutic tools might be developed by exploiting the action of ONC-elicited RNA derivatives.

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.

The tRNA-Derived Fragment tRF-24-V29K9UV3IU Functions as a miRNA-like RNA to Prevent Gastric Cancer Progression by Inhibiting GPR78 Expression

Emerging studies have proved that tRNA-derived fragments (tRFs) play vital roles in tumor metastasis; however, the function of tRFs in gastric cancer (GC) remains largely unclear. We investigated the role of tRF-24-V29K9UV3IU in growth and metastasis of GC using a xenograft mouse model. Differential gene expression downstream of tRF-24-V29K9UV3IU was identified by transcriptome sequencing, and interaction was then verified by a dual luciferase reporter and RNA immunoprecipitation. MKN-45 cells were also used to explore the biological functions of tRF-24-V29K9UV3IU in vitro. Here, knockdown of tRF-24-V29K9UV3IU promoted tumor growth and metastasis of GC in vivo. The expression of tRF-24-V29K9UV3IU and E-cadherin (epithelial cell marker) was down-regulated in tumors of mice following tRF-24-V29K9UV3IU knockdown, whereas the mesenchymal cell markers N-cadherin and vimentin displayed an opposite trend. Transcriptome sequencing identified 87 differentially expressed genes (DEGs) down-regulated in the tRF-24-V29K9UV3IU-overexpressed groups compared with the control group. Among them, G-protein–coupled receptor 78 (GPR78), the most significantly down-regulated DEG, was also predicted to be a target of tRF-24-V29K9UV3IU. Moreover, tRF-24-V29K9UV3IU could function as a miRNA-like fragment and bind to AGO2 and directly silence GPR78 expression by complementing with the 3′-untranslated region of the GPR78 mRNA. Functionally, overexpression of tRF-24-V29K9UV3IU significantly suppressed proliferation, migration, and invasion and promoted apoptosis of MKN-45 cells, whereas GPR78 attenuated these effects. Therefore, our data suggest that tRF-24-V29K9UV3IU functions as a miRNA-like fragment to suppress GPR78 expression and thus inhibit GC progression. These observations suggest that the tRF-24-V29K9UV3IU/GPR78 axis serves as a potential therapeutic target in GC.

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.

An emerging role of the 5' termini of mature tRNAs in human diseases: Current situation and prospects

The fundamental biological roles of a class of small noncoding RNAs (sncRNAs), derived from mature tRNAs or pre-tRNAs, in human diseases have received increasing attention in recent years. These ncRNAs are called tRNA-derived fragments (tRFs) or tRNA-derived small RNAs (tsRNAs). tRFs mainly include tRF-1, tRF-5, tRF-3 and tRNA halves (tiRNAs or tRHs), which are produced by enzyme-specific cleavage of tRNAs. Here, we classify tRF-5 and 5' tiRNAs into the same category: 5'-tRFs and review the biological functions and regulatory mechanisms of 5'-tRFs in cancer and other diseases (metabolic diseases, neurodegenerative diseases, pathological stress injury and virus infection) to provide a new theoretical basis for the diagnosis and treatment of diseases.

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.